--- _id: '51208' abstract: - lang: eng text: AbstractApproximation of subdifferentials is one of the main tasks when computing descent directions for nonsmooth optimization problems. In this article, we propose a bisection method for weakly lower semismooth functions which is able to compute new subgradients that improve a given approximation in case a direction with insufficient descent was computed. Combined with a recently proposed deterministic gradient sampling approach, this yields a deterministic and provably convergent way to approximate subdifferentials for computing descent directions. author: - first_name: Bennet full_name: Gebken, Bennet id: '32643' last_name: Gebken citation: ama: Gebken B. A note on the convergence of deterministic gradient sampling in nonsmooth optimization. Computational Optimization and Applications. Published online 2024. doi:10.1007/s10589-024-00552-0 apa: Gebken, B. (2024). A note on the convergence of deterministic gradient sampling in nonsmooth optimization. Computational Optimization and Applications. https://doi.org/10.1007/s10589-024-00552-0 bibtex: '@article{Gebken_2024, title={A note on the convergence of deterministic gradient sampling in nonsmooth optimization}, DOI={10.1007/s10589-024-00552-0}, journal={Computational Optimization and Applications}, publisher={Springer Science and Business Media LLC}, author={Gebken, Bennet}, year={2024} }' chicago: Gebken, Bennet. “A Note on the Convergence of Deterministic Gradient Sampling in Nonsmooth Optimization.” Computational Optimization and Applications, 2024. https://doi.org/10.1007/s10589-024-00552-0. ieee: 'B. Gebken, “A note on the convergence of deterministic gradient sampling in nonsmooth optimization,” Computational Optimization and Applications, 2024, doi: 10.1007/s10589-024-00552-0.' mla: Gebken, Bennet. “A Note on the Convergence of Deterministic Gradient Sampling in Nonsmooth Optimization.” Computational Optimization and Applications, Springer Science and Business Media LLC, 2024, doi:10.1007/s10589-024-00552-0. short: B. Gebken, Computational Optimization and Applications (2024). date_created: 2024-02-07T07:23:23Z date_updated: 2024-02-08T08:05:54Z department: - _id: '101' doi: 10.1007/s10589-024-00552-0 keyword: - Applied Mathematics - Computational Mathematics - Control and Optimization language: - iso: eng publication: Computational Optimization and Applications publication_identifier: issn: - 0926-6003 - 1573-2894 publication_status: published publisher: Springer Science and Business Media LLC status: public title: A note on the convergence of deterministic gradient sampling in nonsmooth optimization type: journal_article user_id: '32643' year: '2024' ... --- _id: '51518' abstract: - lang: eng text: In applications of piezoelectric actuators and sensors, the dependability and particularly the reliability throughout their lifetime are vital to manufacturers and end-users and are enabled through condition-monitoring approaches. Existing approaches often utilize impedance measurements over a range of frequencies or velocity measurements and require additional equipment or sensors, such as a laser Doppler vibrometer. Furthermore, the non-negligible effects of varying operating conditions are often unconsidered. To minimize the need for additional sensors while maintaining the dependability of piezoelectric bending actuators irrespective of varying operating conditions, an online diagnostics approach is proposed. To this end, time- and frequency-domain features are extracted from monitored current signals to reflect hairline crack development in bending actuators. For validation of applicability, the presented analysis method was evaluated on piezoelectric bending actuators subjected to accelerated lifetime tests at varying voltage amplitudes and under external damping conditions. In the presence of a crack and due to a diminished stiffness, the resonance frequency decreases and the root-mean-square amplitude of the current signal simultaneously abruptly drops during the lifetime tests. Furthermore, the piezoelectric crack surfaces clapping is reflected in higher harmonics of the current signal. Thus, time-domain features and harmonics of the current signals are sufficient to diagnose hairline cracks in the actuators. article_number: '521' article_type: original author: - first_name: Osarenren Kennedy full_name: Aimiyekagbon, Osarenren Kennedy id: '9557' last_name: Aimiyekagbon - first_name: Amelie full_name: Bender, Amelie id: '54290' last_name: Bender - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel - first_name: Walter full_name: Sextro, Walter id: '21220' last_name: Sextro citation: ama: Aimiyekagbon OK, Bender A, Hemsel T, Sextro W. Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions. Electronics. 2024;13(3). doi:10.3390/electronics13030521 apa: Aimiyekagbon, O. K., Bender, A., Hemsel, T., & Sextro, W. (2024). Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions. Electronics, 13(3), Article 521. https://doi.org/10.3390/electronics13030521 bibtex: '@article{Aimiyekagbon_Bender_Hemsel_Sextro_2024, title={Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions}, volume={13}, DOI={10.3390/electronics13030521}, number={3521}, journal={Electronics}, publisher={MDPI AG}, author={Aimiyekagbon, Osarenren Kennedy and Bender, Amelie and Hemsel, Tobias and Sextro, Walter}, year={2024} }' chicago: Aimiyekagbon, Osarenren Kennedy, Amelie Bender, Tobias Hemsel, and Walter Sextro. “Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions.” Electronics 13, no. 3 (2024). https://doi.org/10.3390/electronics13030521. ieee: 'O. K. Aimiyekagbon, A. Bender, T. Hemsel, and W. Sextro, “Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions,” Electronics, vol. 13, no. 3, Art. no. 521, 2024, doi: 10.3390/electronics13030521.' mla: Aimiyekagbon, Osarenren Kennedy, et al. “Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions.” Electronics, vol. 13, no. 3, 521, MDPI AG, 2024, doi:10.3390/electronics13030521. short: O.K. Aimiyekagbon, A. Bender, T. Hemsel, W. Sextro, Electronics 13 (2024). date_created: 2024-02-20T06:46:43Z date_updated: 2024-03-15T16:15:56Z department: - _id: '151' doi: 10.3390/electronics13030521 funded_apc: '1' intvolume: ' 13' issue: '3' keyword: - piezoelectric transducer - self-sensing - fault detection - diagnostics - hairline crack - condition monitoring language: - iso: eng publication: Electronics publication_identifier: issn: - 2079-9292 publication_status: published publisher: MDPI AG quality_controlled: '1' status: public title: Diagnostics of Piezoelectric Bending Actuators Subjected to Varying Operating Conditions type: journal_article user_id: '9557' volume: 13 year: '2024' ... --- _id: '52726' abstract: - lang: eng text: Heteroclinic structures organize global features of dynamical systems. We analyse whether heteroclinic structures can arise in network dynamics with higher-order interactions which describe the nonlinear interactions between three or more units. We find that while commonly analysed model equations such as network dynamics on undirected hypergraphs may be useful to describe local dynamics such as cluster synchronization, they give rise to obstructions that allow to design of heteroclinic structures in phase space. By contrast, directed hypergraphs break the homogeneity and lead to vector fields that support heteroclinic structures. article_type: original author: - first_name: Christian full_name: Bick, Christian last_name: Bick - first_name: Sören full_name: von der Gracht, Sören id: '97359' last_name: von der Gracht orcid: 0000-0002-8054-2058 citation: ama: Bick C, von der Gracht S. Heteroclinic dynamics in network dynamical systems with higher-order interactions. Journal of Complex Networks. 2024;12(2). doi:10.1093/comnet/cnae009 apa: Bick, C., & von der Gracht, S. (2024). Heteroclinic dynamics in network dynamical systems with higher-order interactions. Journal of Complex Networks, 12(2). https://doi.org/10.1093/comnet/cnae009 bibtex: '@article{Bick_von der Gracht_2024, title={Heteroclinic dynamics in network dynamical systems with higher-order interactions}, volume={12}, DOI={10.1093/comnet/cnae009}, number={2}, journal={Journal of Complex Networks}, publisher={Oxford University Press (OUP)}, author={Bick, Christian and von der Gracht, Sören}, year={2024} }' chicago: Bick, Christian, and Sören von der Gracht. “Heteroclinic Dynamics in Network Dynamical Systems with Higher-Order Interactions.” Journal of Complex Networks 12, no. 2 (2024). https://doi.org/10.1093/comnet/cnae009. ieee: 'C. Bick and S. von der Gracht, “Heteroclinic dynamics in network dynamical systems with higher-order interactions,” Journal of Complex Networks, vol. 12, no. 2, 2024, doi: 10.1093/comnet/cnae009.' mla: Bick, Christian, and Sören von der Gracht. “Heteroclinic Dynamics in Network Dynamical Systems with Higher-Order Interactions.” Journal of Complex Networks, vol. 12, no. 2, Oxford University Press (OUP), 2024, doi:10.1093/comnet/cnae009. short: C. Bick, S. von der Gracht, Journal of Complex Networks 12 (2024). date_created: 2024-03-22T09:04:57Z date_updated: 2024-03-22T09:11:53Z ddc: - '510' department: - _id: '101' doi: 10.1093/comnet/cnae009 external_id: arxiv: - '2309.02006' file: - access_level: closed content_type: application/pdf creator: svdg date_created: 2024-03-22T09:06:07Z date_updated: 2024-03-22T09:06:07Z file_id: '52728' file_name: heteroclinic-dynamics-in-network-dynamical-systems-with-higher-order-interactions.pdf file_size: 649155 relation: main_file success: 1 file_date_updated: 2024-03-22T09:06:07Z has_accepted_license: '1' intvolume: ' 12' issue: '2' keyword: - Applied Mathematics - Computational Mathematics - Control and Optimization - Management Science and Operations Research - Computer Networks and Communications language: - iso: eng main_file_link: - open_access: '1' url: https://academic.oup.com/comnet/article-pdf/12/2/cnae009/56832119/cnae009.pdf oa: '1' publication: Journal of Complex Networks publication_identifier: issn: - 2051-1329 publication_status: published publisher: Oxford University Press (OUP) status: public title: Heteroclinic dynamics in network dynamical systems with higher-order interactions type: journal_article user_id: '97359' volume: 12 year: '2024' ... --- _id: '47522' abstract: - lang: eng text: Artificial benchmark functions are commonly used in optimization research because of their ability to rapidly evaluate potential solutions, making them a preferred substitute for real-world problems. However, these benchmark functions have faced criticism for their limited resemblance to real-world problems. In response, recent research has focused on automatically generating new benchmark functions for areas where established test suites are inadequate. These approaches have limitations, such as the difficulty of generating new benchmark functions that exhibit exploratory landscape analysis (ELA) features beyond those of existing benchmarks.The objective of this work is to develop a method for generating benchmark functions for single-objective continuous optimization with user-specified structural properties. Specifically, we aim to demonstrate a proof of concept for a method that uses an ELA feature vector to specify these properties in advance. To achieve this, we begin by generating a random sample of decision space variables and objective values. We then adjust the objective values using CMA-ES until the corresponding features of our new problem match the predefined ELA features within a specified threshold. By iteratively transforming the landscape in this way, we ensure that the resulting function exhibits the desired properties. To create the final function, we use the resulting point cloud as training data for a simple neural network that produces a function exhibiting the target ELA features. We demonstrate the effectiveness of this approach by replicating the existing functions of the well-known BBOB suite and creating new functions with ELA feature values that are not present in BBOB. author: - first_name: Raphael Patrick full_name: Prager, Raphael Patrick last_name: Prager - first_name: Konstantin full_name: Dietrich, Konstantin last_name: Dietrich - first_name: Lennart full_name: Schneider, Lennart last_name: Schneider - first_name: Lennart full_name: Schäpermeier, Lennart last_name: Schäpermeier - first_name: Bernd full_name: Bischl, Bernd last_name: Bischl - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Heike full_name: Trautmann, Heike id: '100740' last_name: Trautmann orcid: 0000-0002-9788-8282 - first_name: Olaf full_name: Mersmann, Olaf last_name: Mersmann citation: ama: 'Prager RP, Dietrich K, Schneider L, et al. Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features. In: Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms. FOGA ’23. Association for Computing Machinery; 2023:129–139. doi:10.1145/3594805.3607136' apa: Prager, R. P., Dietrich, K., Schneider, L., Schäpermeier, L., Bischl, B., Kerschke, P., Trautmann, H., & Mersmann, O. (2023). Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features. Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, 129–139. https://doi.org/10.1145/3594805.3607136 bibtex: '@inproceedings{Prager_Dietrich_Schneider_Schäpermeier_Bischl_Kerschke_Trautmann_Mersmann_2023, place={New York, NY, USA}, series={FOGA ’23}, title={Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features}, DOI={10.1145/3594805.3607136}, booktitle={Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms}, publisher={Association for Computing Machinery}, author={Prager, Raphael Patrick and Dietrich, Konstantin and Schneider, Lennart and Schäpermeier, Lennart and Bischl, Bernd and Kerschke, Pascal and Trautmann, Heike and Mersmann, Olaf}, year={2023}, pages={129–139}, collection={FOGA ’23} }' chicago: 'Prager, Raphael Patrick, Konstantin Dietrich, Lennart Schneider, Lennart Schäpermeier, Bernd Bischl, Pascal Kerschke, Heike Trautmann, and Olaf Mersmann. “Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features.” In Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, 129–139. FOGA ’23. New York, NY, USA: Association for Computing Machinery, 2023. https://doi.org/10.1145/3594805.3607136.' ieee: 'R. P. Prager et al., “Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features,” in Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, 2023, pp. 129–139, doi: 10.1145/3594805.3607136.' mla: Prager, Raphael Patrick, et al. “Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features.” Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, Association for Computing Machinery, 2023, pp. 129–139, doi:10.1145/3594805.3607136. short: 'R.P. Prager, K. Dietrich, L. Schneider, L. Schäpermeier, B. Bischl, P. Kerschke, H. Trautmann, O. Mersmann, in: Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, Association for Computing Machinery, New York, NY, USA, 2023, pp. 129–139.' date_created: 2023-09-27T15:43:17Z date_updated: 2023-10-16T12:33:02Z department: - _id: '34' - _id: '819' doi: 10.1145/3594805.3607136 keyword: - Benchmarking - Instance Generator - Black-Box Continuous Optimization - Exploratory Landscape Analysis - Neural Networks language: - iso: eng page: 129–139 place: New York, NY, USA publication: Proceedings of the 17th ACM/SIGEVO Conference on Foundations of Genetic Algorithms publication_identifier: isbn: - '9798400702020' publisher: Association for Computing Machinery series_title: FOGA ’23 status: public title: Neural Networks as Black-Box Benchmark Functions Optimized for Exploratory Landscape Features type: conference user_id: '15504' year: '2023' ... --- _id: '48869' abstract: - lang: eng text: Evolutionary algorithms have been shown to obtain good solutions for complex optimization problems in static and dynamic environments. It is important to understand the behaviour of evolutionary algorithms for complex optimization problems that also involve dynamic and/or stochastic components in a systematic way in order to further increase their applicability to real-world problems. We investigate the node weighted traveling salesperson problem (W-TSP), which provides an abstraction of a wide range of weighted TSP problems, in dynamic settings. In the dynamic setting of the problem, items that have to be collected as part of a TSP tour change over time. We first present a dynamic setup for the dynamic W-TSP parameterized by different types of changes that are applied to the set of items to be collected when traversing the tour. Our first experimental investigations study the impact of such changes on resulting optimized tours in order to provide structural insights of optimization solutions. Afterwards, we investigate simple mutation-based evolutionary algorithms and study the impact of the mutation operators and the use of populations with dealing with the dynamic changes to the node weights of the problem. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Aneta full_name: Neumann, Aneta last_name: Neumann - first_name: Frank full_name: Neumann, Frank last_name: Neumann citation: ama: 'Bossek J, Neumann A, Neumann F. On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO’23. Association for Computing Machinery; 2023:248–256. doi:10.1145/3583131.3590384' apa: Bossek, J., Neumann, A., & Neumann, F. (2023). On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem. Proceedings of the Genetic and Evolutionary Computation Conference, 248–256. https://doi.org/10.1145/3583131.3590384 bibtex: '@inproceedings{Bossek_Neumann_Neumann_2023, place={New York, NY, USA}, series={GECCO’23}, title={On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem}, DOI={10.1145/3583131.3590384}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Neumann, Aneta and Neumann, Frank}, year={2023}, pages={248–256}, collection={GECCO’23} }' chicago: 'Bossek, Jakob, Aneta Neumann, and Frank Neumann. “On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem.” In Proceedings of the Genetic and Evolutionary Computation Conference, 248–256. GECCO’23. New York, NY, USA: Association for Computing Machinery, 2023. https://doi.org/10.1145/3583131.3590384.' ieee: 'J. Bossek, A. Neumann, and F. Neumann, “On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2023, pp. 248–256, doi: 10.1145/3583131.3590384.' mla: Bossek, Jakob, et al. “On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2023, pp. 248–256, doi:10.1145/3583131.3590384. short: 'J. Bossek, A. Neumann, F. Neumann, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2023, pp. 248–256.' date_created: 2023-11-14T15:58:56Z date_updated: 2023-12-13T10:46:27Z department: - _id: '819' doi: 10.1145/3583131.3590384 extern: '1' keyword: - dynamic optimization - evolutionary algorithms - re-optimization - weighted traveling salesperson problem language: - iso: eng page: 248–256 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - '9798400701191' publisher: Association for Computing Machinery series_title: GECCO’23 status: public title: On the Impact of Basic Mutation Operators and Populations within Evolutionary Algorithms for the Dynamic Weighted Traveling Salesperson Problem type: conference user_id: '102979' year: '2023' ... --- _id: '30289' abstract: - lang: eng text: This chapter presents a discussion of the concept of agency. Agency is understood as a multifaceted construct describing the idea that human beings make choices, act on these choices, and thereby exercise influence on their own lives as well as their environment. We argue that the concept is discussed from three different perspectives in the literature—transformational, dispositional, and relational—that are each related to learning and development in work contexts. These perspectives do not reflect incompatible positions but rather different aspects of the same phenomena. The chapter also offers an avenue of insight into empirical studies that employ agency as a central concept as well as discussions about concepts that closely overlap with ideas of human beings as agents of power and influence. author: - first_name: Michael full_name: Goller, Michael id: '30984' last_name: Goller orcid: 0000-0002-2820-9178 - first_name: Susanna full_name: Paloniemi, Susanna last_name: Paloniemi citation: ama: 'Goller M, Paloniemi S. Agency: Taking Stock of Workplace Learning Research. In: Research Approaches on Workplace Learning. Springer International Publishing; 2022. doi:10.1007/978-3-030-89582-2_1' apa: 'Goller, M., & Paloniemi, S. (2022). Agency: Taking Stock of Workplace Learning Research. In Research Approaches on Workplace Learning. Springer International Publishing. https://doi.org/10.1007/978-3-030-89582-2_1' bibtex: '@inbook{Goller_Paloniemi_2022, place={Cham}, title={Agency: Taking Stock of Workplace Learning Research}, DOI={10.1007/978-3-030-89582-2_1}, booktitle={Research Approaches on Workplace Learning}, publisher={Springer International Publishing}, author={Goller, Michael and Paloniemi, Susanna}, year={2022} }' chicago: 'Goller, Michael, and Susanna Paloniemi. “Agency: Taking Stock of Workplace Learning Research.” In Research Approaches on Workplace Learning. Cham: Springer International Publishing, 2022. https://doi.org/10.1007/978-3-030-89582-2_1.' ieee: 'M. Goller and S. Paloniemi, “Agency: Taking Stock of Workplace Learning Research,” in Research Approaches on Workplace Learning, Cham: Springer International Publishing, 2022.' mla: 'Goller, Michael, and Susanna Paloniemi. “Agency: Taking Stock of Workplace Learning Research.” Research Approaches on Workplace Learning, Springer International Publishing, 2022, doi:10.1007/978-3-030-89582-2_1.' short: 'M. Goller, S. Paloniemi, in: Research Approaches on Workplace Learning, Springer International Publishing, Cham, 2022.' date_created: 2022-03-13T19:09:20Z date_updated: 2022-03-13T19:14:43Z department: - _id: '452' doi: 10.1007/978-3-030-89582-2_1 keyword: - Agency Workplace learning Professional development Proactivity Self-direction language: - iso: eng place: Cham publication: Research Approaches on Workplace Learning publication_identifier: isbn: - '9783030895815' - '9783030895822' issn: - 2210-5549 - 2210-5557 publication_status: published publisher: Springer International Publishing related_material: link: - relation: other url: https://link.springer.com/chapter/10.1007/978-3-030-89582-2_1#Abs1 status: public title: 'Agency: Taking Stock of Workplace Learning Research' type: book_chapter user_id: '50788' year: '2022' ... --- _id: '30290' abstract: - lang: eng text: The article explores the particular quality of changes introduced through the latest wave of digital transformation of workplaces. It has effects on workflow processes, on distribution of work and tasks, and the mode of distributing working tasks, e.g. through cyber-physical systems. Hence, the changes in work are manifold and require changes in vocational education and training as well as in workplace learning. These changes reveal new challenges for research on workplace learning. Finally, conclusions for future workplace learning research will be developed. author: - first_name: Christian full_name: Harteis, Christian id: '27503' last_name: Harteis orcid: https://orcid.org/0000-0002-3570-7626 citation: ama: 'Harteis C. Research on Workplace Learning in Times of Digitalisation. In: Research Approaches on Workplace Learning. Springer International Publishing; 2022. doi:10.1007/978-3-030-89582-2_19' apa: Harteis, C. (2022). Research on Workplace Learning in Times of Digitalisation. In Research Approaches on Workplace Learning. Springer International Publishing. https://doi.org/10.1007/978-3-030-89582-2_19 bibtex: '@inbook{Harteis_2022, place={Cham}, title={Research on Workplace Learning in Times of Digitalisation}, DOI={10.1007/978-3-030-89582-2_19}, booktitle={Research Approaches on Workplace Learning}, publisher={Springer International Publishing}, author={Harteis, Christian}, year={2022} }' chicago: 'Harteis, Christian. “Research on Workplace Learning in Times of Digitalisation.” In Research Approaches on Workplace Learning. Cham: Springer International Publishing, 2022. https://doi.org/10.1007/978-3-030-89582-2_19.' ieee: 'C. Harteis, “Research on Workplace Learning in Times of Digitalisation,” in Research Approaches on Workplace Learning, Cham: Springer International Publishing, 2022.' mla: Harteis, Christian. “Research on Workplace Learning in Times of Digitalisation.” Research Approaches on Workplace Learning, Springer International Publishing, 2022, doi:10.1007/978-3-030-89582-2_19. short: 'C. Harteis, in: Research Approaches on Workplace Learning, Springer International Publishing, Cham, 2022.' date_created: 2022-03-13T19:11:33Z date_updated: 2022-03-13T19:14:38Z department: - _id: '452' doi: 10.1007/978-3-030-89582-2_19 keyword: - Digitalisation Self organisation Distribution of labour Automation language: - iso: eng place: Cham publication: Research Approaches on Workplace Learning publication_identifier: isbn: - '9783030895815' - '9783030895822' issn: - 2210-5549 - 2210-5557 publication_status: published publisher: Springer International Publishing related_material: link: - relation: other url: https://link.springer.com/chapter/10.1007/978-3-030-89582-2_19#citeas status: public title: Research on Workplace Learning in Times of Digitalisation type: book_chapter user_id: '50788' year: '2022' ... --- _id: '30861' abstract: - lang: eng text: AbstractWe consider the problem of maximization of metabolite production in bacterial cells formulated as a dynamical optimal control problem (DOCP). According to Pontryagin’s maximum principle, optimal solutions are concatenations of singular and bang arcs and exhibit the chattering or Fuller phenomenon, which is problematic for applications. To avoid chattering, we introduce a reduced model which is still biologically relevant and retains the important structural features of the original problem. Using a combination of analytical and numerical methods, we show that the singular arc is dominant in the studied DOCPs and exhibits the turnpike property. This property is further used in order to design simple and realistic suboptimal control strategies. author: - first_name: Jean-Baptiste full_name: Caillau, Jean-Baptiste last_name: Caillau - first_name: Walid full_name: Djema, Walid last_name: Djema - first_name: Jean-Luc full_name: Gouzé, Jean-Luc last_name: Gouzé - first_name: Sofya full_name: Maslovskaya, Sofya id: '87909' last_name: Maslovskaya - first_name: Jean-Baptiste full_name: Pomet, Jean-Baptiste last_name: Pomet citation: ama: Caillau J-B, Djema W, Gouzé J-L, Maslovskaya S, Pomet J-B. Turnpike Property in Optimal Microbial Metabolite Production. Journal of Optimization Theory and Applications. Published online 2022. doi:10.1007/s10957-022-02023-0 apa: Caillau, J.-B., Djema, W., Gouzé, J.-L., Maslovskaya, S., & Pomet, J.-B. (2022). Turnpike Property in Optimal Microbial Metabolite Production. Journal of Optimization Theory and Applications. https://doi.org/10.1007/s10957-022-02023-0 bibtex: '@article{Caillau_Djema_Gouzé_Maslovskaya_Pomet_2022, title={Turnpike Property in Optimal Microbial Metabolite Production}, DOI={10.1007/s10957-022-02023-0}, journal={Journal of Optimization Theory and Applications}, publisher={Springer Science and Business Media LLC}, author={Caillau, Jean-Baptiste and Djema, Walid and Gouzé, Jean-Luc and Maslovskaya, Sofya and Pomet, Jean-Baptiste}, year={2022} }' chicago: Caillau, Jean-Baptiste, Walid Djema, Jean-Luc Gouzé, Sofya Maslovskaya, and Jean-Baptiste Pomet. “Turnpike Property in Optimal Microbial Metabolite Production.” Journal of Optimization Theory and Applications, 2022. https://doi.org/10.1007/s10957-022-02023-0. ieee: 'J.-B. Caillau, W. Djema, J.-L. Gouzé, S. Maslovskaya, and J.-B. Pomet, “Turnpike Property in Optimal Microbial Metabolite Production,” Journal of Optimization Theory and Applications, 2022, doi: 10.1007/s10957-022-02023-0.' mla: Caillau, Jean-Baptiste, et al. “Turnpike Property in Optimal Microbial Metabolite Production.” Journal of Optimization Theory and Applications, Springer Science and Business Media LLC, 2022, doi:10.1007/s10957-022-02023-0. short: J.-B. Caillau, W. Djema, J.-L. Gouzé, S. Maslovskaya, J.-B. Pomet, Journal of Optimization Theory and Applications (2022). date_created: 2022-04-08T17:23:13Z date_updated: 2022-04-08T18:23:02Z department: - _id: '636' doi: 10.1007/s10957-022-02023-0 keyword: - Applied Mathematics - Management Science and Operations Research - Control and Optimization language: - iso: eng publication: Journal of Optimization Theory and Applications publication_identifier: issn: - 0022-3239 - 1573-2878 publication_status: published publisher: Springer Science and Business Media LLC status: public title: Turnpike Property in Optimal Microbial Metabolite Production type: journal_article user_id: '87909' year: '2022' ... --- _id: '29842' abstract: - lang: eng text: To build successful software products, developers continuously have to discover what features the users really need. This discovery can be achieved with continuous experimentation, testing different software variants with distinct user groups, and deploying the superior variant for all users. However, existing approaches do not focus on explicit modeling of variants and experiments, which offers advantages such as traceability of decisions and combinability of experiments. Therefore, our vision is the provision of model-driven continuous experimentation, which provides the developer with a framework for structuring the experimentation process. For that, we introduce the overall concept, apply it to the experimentation on component-based software architectures and point out future research questions. In particular, we show the applicability by combining feature models for modeling the software variants, users, and experiments (i.e., model-driven) with MAPE-K for the adaptation (i.e., continuous experimentation) and implementing the concept based on the component-based Angular framework. author: - first_name: Sebastian full_name: Gottschalk, Sebastian id: '47208' last_name: Gottschalk - first_name: Enes full_name: Yigitbas, Enes id: '8447' last_name: Yigitbas orcid: 0000-0002-5967-833X - first_name: Gregor full_name: Engels, Gregor id: '107' last_name: Engels citation: ama: 'Gottschalk S, Yigitbas E, Engels G. Model-driven Continuous Experimentation on Component-based Software Architectures . In: Proceedings of the 18th International Conference on Software Architecture Companion . IEEE; 2022. doi:10.1109/ICSA-C54293.2022.00011' apa: Gottschalk, S., Yigitbas, E., & Engels, G. (2022). Model-driven Continuous Experimentation on Component-based Software Architectures . Proceedings of the 18th International Conference on Software Architecture Companion . 18th International Conference on Software Architecture , Hawaii. https://doi.org/10.1109/ICSA-C54293.2022.00011 bibtex: '@inproceedings{Gottschalk_Yigitbas_Engels_2022, title={Model-driven Continuous Experimentation on Component-based Software Architectures }, DOI={10.1109/ICSA-C54293.2022.00011}, booktitle={Proceedings of the 18th International Conference on Software Architecture Companion }, publisher={IEEE}, author={Gottschalk, Sebastian and Yigitbas, Enes and Engels, Gregor}, year={2022} }' chicago: Gottschalk, Sebastian, Enes Yigitbas, and Gregor Engels. “Model-Driven Continuous Experimentation on Component-Based Software Architectures .” In Proceedings of the 18th International Conference on Software Architecture Companion . IEEE, 2022. https://doi.org/10.1109/ICSA-C54293.2022.00011. ieee: 'S. Gottschalk, E. Yigitbas, and G. Engels, “Model-driven Continuous Experimentation on Component-based Software Architectures ,” presented at the 18th International Conference on Software Architecture , Hawaii, 2022, doi: 10.1109/ICSA-C54293.2022.00011.' mla: Gottschalk, Sebastian, et al. “Model-Driven Continuous Experimentation on Component-Based Software Architectures .” Proceedings of the 18th International Conference on Software Architecture Companion , IEEE, 2022, doi:10.1109/ICSA-C54293.2022.00011. short: 'S. Gottschalk, E. Yigitbas, G. Engels, in: Proceedings of the 18th International Conference on Software Architecture Companion , IEEE, 2022.' conference: end_date: 2022-03-15 location: Hawaii name: '18th International Conference on Software Architecture ' start_date: 2022-03-12 date_created: 2022-02-15T07:32:10Z date_updated: 2022-07-04T12:34:53Z ddc: - '000' department: - _id: '66' - _id: '534' doi: 10.1109/ICSA-C54293.2022.00011 file: - access_level: open_access content_type: application/pdf creator: sego date_created: 2022-07-04T12:33:18Z date_updated: 2022-07-04T12:34:52Z file_id: '32322' file_name: ICSA_CR.pdf file_size: 183185 relation: main_file file_date_updated: 2022-07-04T12:34:52Z has_accepted_license: '1' keyword: - continuous experimentation - model-driven - component-based software architectures - self-adaptation language: - iso: eng oa: '1' project: - _id: '1' name: 'SFB 901: SFB 901' - _id: '4' name: 'SFB 901 - C: SFB 901 - Project Area C' - _id: '17' name: 'SFB 901 - C5: SFB 901 - Subproject C5' publication: 'Proceedings of the 18th International Conference on Software Architecture Companion ' publisher: IEEE status: public title: 'Model-driven Continuous Experimentation on Component-based Software Architectures ' type: conference user_id: '47208' year: '2022' ... --- _id: '34614' abstract: - lang: ger text: "Mit steigenden Optimierungsanforderungen an das Individuum wächst auch das indivi-\r\nduelle Bedürfnis nach Kontrolle. Dieses kann u. a. durch self tracking-Technologien erfüllt werden.\r\nAnhand von drei Fallbeispielen – der Personenwaage, dem Wearable und dem habit tracker – zeigt\r\ndieser Aufsatz, wie sich medienbasierte Selbsttechnologien im historischen Verlauf intensiviert und\r\nstärker in den Alltag integriert haben. Ein besonderer Fokus liegt dabei auf der Ambivalenz dieser\r\nMedien: Ermöglichen sie auf der einen Seite zwar eine Selbstkontrolle und stellen so potenziell sta-\r\nbilisierende Ressourcen für das Individuum dar, schaffen sie auf der anderen Seite auch neue\r\nAnforderungen, die es zu erfüllen gilt." article_type: original author: - first_name: Franziska Margarete full_name: Schloots, Franziska Margarete id: '33185' last_name: Schloots citation: ama: Schloots FM. ‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker. ffk Journal. 2022;6(7):74-91. doi:10.25969/MEDIAREP/18238 apa: Schloots, F. M. (2022). ‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker. ffk Journal, 6(7), 74–91. https://doi.org/10.25969/MEDIAREP/18238 bibtex: '@article{Schloots_2022, title={‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker}, volume={6}, DOI={10.25969/MEDIAREP/18238}, number={7}, journal={ffk Journal}, author={Schloots, Franziska Margarete}, year={2022}, pages={74–91} }' chicago: 'Schloots, Franziska Margarete. “‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker.” ffk Journal 6, no. 7 (2022): 74–91. https://doi.org/10.25969/MEDIAREP/18238.' ieee: 'F. M. Schloots, “‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker,” ffk Journal, vol. 6, no. 7, pp. 74–91, 2022, doi: 10.25969/MEDIAREP/18238.' mla: Schloots, Franziska Margarete. “‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker.” ffk Journal, vol. 6, no. 7, 2022, pp. 74–91, doi:10.25969/MEDIAREP/18238. short: F.M. Schloots, ffk Journal 6 (2022) 74–91. date_created: 2022-12-20T14:20:56Z date_updated: 2022-12-20T14:30:15Z ddc: - '040' doi: 10.25969/MEDIAREP/18238 file: - access_level: closed content_type: application/pdf creator: fms date_created: 2022-12-20T14:23:57Z date_updated: 2022-12-20T14:23:57Z file_id: '34616' file_name: ffk_journal_07_74-91_Schloots_Selbstkontrolle_.pdf file_size: 530069 relation: main_file success: 1 file_date_updated: 2022-12-20T14:23:57Z has_accepted_license: '1' intvolume: ' 6' issue: '7' keyword: - self-tracking - Selbsttechnologien - Wearable - Bullet Journal - Personenwaage - Selbstvermessung language: - iso: ger page: 74-91 publication: ffk Journal publication_status: published status: public title: ‚Understand what’s happening within‘. Selbstkontrolle mit Personenwaage, Wearable und habit tracker type: journal_article user_id: '33185' volume: 6 year: '2022' ... --- _id: '35136' abstract: - lang: ger text: "Im Zentrum dieses Beitrags stehen Ergebnisse der Messung pädagogischer Kompetenzen Studierender der Theologie, die das Praxissemester in Deutschland absolviert haben. Das bildungswissenschaftliche Wissen, Kompetenzselbsteinschätzungen und ihre Entwicklung sowie die Einschätzung der im Praxissemester erreichten Ziele Studierender werden dabei unter Berücksichtigung der Ausrichtung des Lehramtsstudiums auf eine Schulform betrachtet. Um die Ergebnisse der Messung bildungswissenschaftlichen Wissens und die der Messung von Kompetenzselbsteinschätzungen zu kontextualisieren (N = 304), wird zuerst die Relevanz des (bildungswissenschaftlichen) Wissens als Ausgangspunkt des Könnens herausgearbeitet. Daran anschließend werden Befunde zur schulformspezifischen Professionalisierung resümiert. Anschließend werden Hypothesen hergeleitet, die Anlage der Studie sowie die Testinstrumente vorge- stellt, die Ergebnisse präsentiert und diskutiert. Die Ergebnisse zeigen wider Erwarten, dass sich weder das bildungswissenschaftliche Wissen, die Kompetenzselbsteinschätzungen und ihre Entwicklung noch die Einschätzung der im Praxissemester erreichten Ziele angehender Lehrkräfte in Abhängigkeit der Schulformen unterscheiden. Die Diskussion bezieht sich u.a. auf die Struktur der Lehramtsstudiengänge, die Denkfiguren zur Entwicklung von Können und die Konzeption der Messinstrumente.\r\n" - lang: eng text: "The focus of this article are the results of the measurement of pedagogical competencies of students of theology who have completed an internship in Germany. The educational knowledge, competence self-assessments and their development as well as the assessment of the goals achieved by students in the internship are considered, taking into account the orientation of the teacher education course towards a school type. In order to contextualize the results of the measurement of educational knowledge and those of the survey of competence self-assessments (N = 304), ideas are shown how the relationship between knowledge and ability is constituted and findings on the type of school-specific professionalization are summarized. Subsequently, hypotheses are derived, the design of the study, the method and the test instruments are described, the results are presented and discussed. Contrary to expectations, the results show that neither the educational science knowledge, the competence self-assessments and their development nor the assessment of the goals achieved in the internship by pros- pective teachers differ depending on the type of school. The discussion relates to on the structure of the teacher training courses, the mental figures for the development of skills and the conception of the measuring instruments.\r\n" alternative_title: - Ergebnisse der Messung pädagogischer Kompetenzen Studierender in Deutschland author: - first_name: Carina full_name: Caruso, Carina id: '23123' last_name: Caruso - first_name: Andreas full_name: Seifert, Andreas last_name: Seifert citation: ama: Caruso C, Seifert A. Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch? Österreichische Religionspädagogische Forum. 2022;30(1):239-260. doi:10.30:2022.1.14 apa: Caruso, C., & Seifert, A. (2022). Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch? Österreichische Religionspädagogische Forum, 30(1), 239–260. https://doi.org/10.30:2022.1.14 bibtex: '@article{Caruso_Seifert_2022, title={ Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch?}, volume={30}, DOI={10.30:2022.1.14}, number={1}, journal={Österreichische Religionspädagogische Forum}, publisher={Universitätsbibliothek Graz}, author={Caruso, Carina and Seifert, Andreas}, year={2022}, pages={239–260} }' chicago: 'Caruso, Carina, and Andreas Seifert. “ Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch?” Österreichische Religionspädagogische Forum 30, no. 1 (2022): 239–60. https://doi.org/10.30:2022.1.14.' ieee: 'C. Caruso and A. Seifert, “ Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch?,” Österreichische Religionspädagogische Forum, vol. 30, no. 1, pp. 239–260, 2022, doi: 10.30:2022.1.14.' mla: Caruso, Carina, and Andreas Seifert. “ Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch?” Österreichische Religionspädagogische Forum, vol. 30, no. 1, Universitätsbibliothek Graz, 2022, pp. 239–60, doi:10.30:2022.1.14. short: C. Caruso, A. Seifert, Österreichische Religionspädagogische Forum 30 (2022) 239–260. date_created: 2023-01-03T12:41:20Z date_updated: 2023-01-06T12:08:14Z doi: 10.30:2022.1.14 intvolume: ' 30' issue: '1' keyword: - Bildungswissenschaftliches Wissen - Kompetenzmessung - Kompetenzselbsteinschätzung - Praxissemester - Professionalisierung / competence measurement - competence self-assessment - educational knowledge - internship - professionalization language: - iso: ger page: 239-260 publication: Österreichische Religionspädagogische Forum publication_identifier: issn: - 1018-1539 publication_status: published publisher: Universitätsbibliothek Graz status: public title: ' Inwiefern ist die Professionalisierung in Praxisphasen schulformspezifisch?' type: journal_article user_id: '86519' volume: 30 year: '2022' ... --- _id: '35137' abstract: - lang: ger text: Im Zentrum dieses Beitrags stehen Ergebnisse der Messung pädagogischer Kompetenzen Studierender. Dabei werden sowohl das bildungswissenschaftliche Wissen als auch die Entwicklung der Kompe­tenzselbsteinschätzungen in den Bereichen Unterrichten, Erziehen, Beurteilen und Innovieren unter Berücksichtigung individueller Voraussetzungen (Alter, Geschlecht, Abiturnote, Bachelornote, Konfession) betrachtet. Um die Ergeb­nisse hinsichtlich ihrer Bedeutung für die Professionalisierung angehender Lehrkräfte diskutieren zu können, wird, den empirischen Erkenntnissen voranstehend, die Bedeutung von Wissen für berufliches Können herausgearbeitet. Daran anschließend werden Hypothesen hergeleitet, die Anlage der Studie sowie die Testinstrumente vorgestellt, die Ergebnisse präsentiert und diskutiert. Die Ergebnisse zeigen, dass die Abitur- und Bachelornote die Varianz hinsichtlich des pädagogischen Wissens aufklären, sich eine signifikante Entwicklung der Kompetenzselbsteinschätzungen angehender Lehrkräfte feststellen lässt, aber sich angehende Religionslehrkräfte kaum von anderen Studierenden unterscheiden. Die Diskussion nimmt u. a. Rückbezug auf die Denkfiguren zur Entwicklung berufli­chen Könnens und benennt Limitationen, die mit der Studie und Kompetenzmessungen verbunden sind. Daran schließt die Formulierung eines Ausblicks an. Der Beitrag zielt insbesondere darauf, repräsentative Ergebnisse der Kompetenzmessung zu präsentieren und dabei potenzielle Einflussfaktoren auf die studentische Kompetenzent­wicklung zu beleuchten. Ein dadurch angereichertes Konglomerat belastbarer Erkenntnisse zielt darauf, langfristig zur Ableitung lehrerbildungsdidaktischer Überlegungen herangezogen werden zu können, die die studentische Professionalisierung unterstützen. - lang: eng text: 'This paper focuses on the results of the measurement of pedagogical competences of students. In doing so, both the knowledge of the educational sciences and the development of competence self-assessments in the fields of teaching, education, assessment andinnovating are taken into account. The study makes use of the following individual requirements: age, sex, Abitur grade, Bachelor grade, Confession. In order to be able to discuss the re-sults regarding their importance for the professionalization of prospective teachers, the importance of knowledge for professional skills is highlighted, preceded by empirical findings. Subsequently, hypotheses are derived, the plan of the study as well as the test instruments are presented, the results presented and discussed. The results show that the Abitur and Bachelor grades clarify the variance in pedagogical knowledge, that there is a significant development in the competence self-assessments of prospective teachers, and that prospective religious teachers are not different from other students. The discussion takes into account, among other things, the ideas for the devel-opment of professional skills and identifies limitations associated with the study. This is followed by the formula-tion of an outlook. The main aim of the paper is to present representative results of the competence measurement and to examine potential influencing factors on student competence development. A conglomerate of resilient knowledge enriched by this aims to be used in the long term to derive teacher training didactic considerations that support student professionalization.' author: - first_name: Carina full_name: Caruso, Carina id: '23123' last_name: Caruso - first_name: Andreas full_name: Seifert, Andreas last_name: Seifert citation: ama: Caruso C, Seifert A. Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen. Religionspädagogische Beiträge Journal for Religion in Education . 2022;45(1):3-15. doi:10.20377/rpb-101 apa: Caruso, C., & Seifert, A. (2022). Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen. Religionspädagogische Beiträge. Journal for Religion in Education , 45(1), 3–15. https://doi.org/10.20377/rpb-101 bibtex: '@article{Caruso_Seifert_2022, title={Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen}, volume={45}, DOI={10.20377/rpb-101}, number={1}, journal={Religionspädagogische Beiträge. Journal for Religion in Education }, publisher={University of Bamberg Press}, author={Caruso, Carina and Seifert, Andreas}, year={2022}, pages={3–15} }' chicago: 'Caruso, Carina, and Andreas Seifert. “Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen.” Religionspädagogische Beiträge. Journal for Religion in Education 45, no. 1 (2022): 3–15. https://doi.org/10.20377/rpb-101.' ieee: 'C. Caruso and A. Seifert, “Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen,” Religionspädagogische Beiträge. Journal for Religion in Education , vol. 45, no. 1, pp. 3–15, 2022, doi: 10.20377/rpb-101.' mla: Caruso, Carina, and Andreas Seifert. “Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen.” Religionspädagogische Beiträge. Journal for Religion in Education , vol. 45, no. 1, University of Bamberg Press, 2022, pp. 3–15, doi:10.20377/rpb-101. short: C. Caruso, A. Seifert, Religionspädagogische Beiträge. Journal for Religion in Education 45 (2022) 3–15. date_created: 2023-01-03T12:45:09Z date_updated: 2023-01-06T12:21:07Z doi: 10.20377/rpb-101 intvolume: ' 45' issue: '1' keyword: - Bildungswissenschaftliches Wissen - Kompetenzmessung - Kompetenzselbsteinschätzung - Praxissemester - Professionalisierung / competence measurement - competence self-assessment - educational knowledge - internship - professionalization language: - iso: ger page: 3-15 publication: 'Religionspädagogische Beiträge. Journal for Religion in Education ' publication_identifier: issn: - 2750 - 3941 publication_status: published publisher: University of Bamberg Press status: public title: Pädagogische Kompetenz als Ausgangspunkt beruflichen Könnens!? Ergebnisse der Kompetenzmessung angehender Lehrkräfte unter Berücksichtigung individueller Voraussetzungen type: journal_article user_id: '86519' volume: 45 year: '2022' ... --- _id: '35206' author: - first_name: Bernard full_name: Bonnard, Bernard last_name: Bonnard - first_name: Jérémy full_name: Rouot, Jérémy last_name: Rouot - first_name: Boris Edgar full_name: Wembe Moafo, Boris Edgar id: '95394' last_name: Wembe Moafo citation: ama: Bonnard B, Rouot J, Wembe Moafo BE. Accessibility properties of abnormal geodesics in optimal control illustrated by two case studies. Mathematical Control and Related Fields. 2022;0(0):0-0. doi:10.3934/mcrf.2022052 apa: Bonnard, B., Rouot, J., & Wembe Moafo, B. E. (2022). Accessibility properties of abnormal geodesics in optimal control illustrated by two case studies. Mathematical Control and Related Fields, 0(0), 0–0. https://doi.org/10.3934/mcrf.2022052 bibtex: '@article{Bonnard_Rouot_Wembe Moafo_2022, title={Accessibility properties of abnormal geodesics in optimal control illustrated by two case studies}, volume={0}, DOI={10.3934/mcrf.2022052}, number={0}, journal={Mathematical Control and Related Fields}, publisher={American Institute of Mathematical Sciences (AIMS)}, author={Bonnard, Bernard and Rouot, Jérémy and Wembe Moafo, Boris Edgar}, year={2022}, pages={0–0} }' chicago: 'Bonnard, Bernard, Jérémy Rouot, and Boris Edgar Wembe Moafo. “Accessibility Properties of Abnormal Geodesics in Optimal Control Illustrated by Two Case Studies.” Mathematical Control and Related Fields 0, no. 0 (2022): 0–0. https://doi.org/10.3934/mcrf.2022052.' ieee: 'B. Bonnard, J. Rouot, and B. E. Wembe Moafo, “Accessibility properties of abnormal geodesics in optimal control illustrated by two case studies,” Mathematical Control and Related Fields, vol. 0, no. 0, pp. 0–0, 2022, doi: 10.3934/mcrf.2022052.' mla: Bonnard, Bernard, et al. “Accessibility Properties of Abnormal Geodesics in Optimal Control Illustrated by Two Case Studies.” Mathematical Control and Related Fields, vol. 0, no. 0, American Institute of Mathematical Sciences (AIMS), 2022, pp. 0–0, doi:10.3934/mcrf.2022052. short: B. Bonnard, J. Rouot, B.E. Wembe Moafo, Mathematical Control and Related Fields 0 (2022) 0–0. date_created: 2023-01-04T10:26:56Z date_updated: 2023-01-16T12:07:51Z doi: 10.3934/mcrf.2022052 issue: '0' keyword: - Applied Mathematics - Control and Optimization - General Medicine language: - iso: eng page: 0-0 publication: Mathematical Control and Related Fields publication_identifier: issn: - 2156-8472 - 2156-8499 publication_status: published publisher: American Institute of Mathematical Sciences (AIMS) status: public title: Accessibility properties of abnormal geodesics in optimal control illustrated by two case studies type: journal_article user_id: '95394' volume: '0' year: '2022' ... --- _id: '40046' abstract: - lang: eng text: Theoretical approaches to the transformation towards an inclusive educational system in Germany mostly agree on the involvement of developmental tasks in subject related research (Hinz, 2011). The common understanding of inclusion as a process geared towards equal participation of all children (Booth, 2012) requires a reflexive questioning of established values, attitudes and practices in order to develop inclusive subject related research, teacher training and teaching and learning (Pech & Schomaker, 2013). Among other things, this results in consequences for the design of pre- service teacher training. To a large extent, teacher education is driven by the promotion of central competencies, interests and self-efficacy (Baumert & Kunter, 2011). It aims towards the development and realisation of inclusive interdisciplinary science and social studies (‘Sachunterricht’) in primary education (Moser, 2018). In conjunction with largely acknowledged constructivist approaches to teaching and learning (Möller, 2001), the development of personality, the consideration of basic needs (Deci & Ryan, 1993) and promotion of individual potentials are repeatedly fundamentally represented in subject related and pedagogical considerations (Feuser, 1989; GDSU, 2013). Therefore, the aforementioned constructivist approach is connected to several certain key paradigms for teaching and learning processes (e.g., Vygotskij, 1978; Posner et al., 1982; van de Pol et al., 2010). In this regard, the nature of primary school students’ basic needs have empirically not been sufficiently studied yet. Theoretical frameworks from motivational psychology (Deci & Ryan, 1993) do not explicitly address how individual needs differ and how the diversity of needs can be included in joint-learning, multi-perspective technology education classes. The research project the present paper is part of aims to develop a research-based concept for the professionalisation of pre-service teachers in a seminar course. Therefore, the promotion of the pre- service teachers’ interests and self-efficacy expectations have been assessed in a pre-post research design with a control group visiting another course not related to technology education and inclusion. The present paper describes and discusses first results of the project and will give an outlook on subsequent developmental tasks. author: - first_name: Franz full_name: Schröer, Franz id: '71764' last_name: Schröer - first_name: Claudia full_name: Tenberge, Claudia id: '67302' last_name: Tenberge citation: ama: 'Schröer F, Tenberge C. How to enable pre-service teachers to design technological teaching and learning inclusively? – On the nature and consideration of basic needs in teacher training. In: Gill D, Tuff J, Kennedy T, Pendergast S, Jamil S, eds. PATT39 - PATT on the Edge Technology, Innovation and Education. PATT Proceedings. ; 2022:49-57.' apa: Schröer, F., & Tenberge, C. (2022). How to enable pre-service teachers to design technological teaching and learning inclusively? – On the nature and consideration of basic needs in teacher training. In D. Gill, J. Tuff, T. Kennedy, S. Pendergast, & S. Jamil (Eds.), PATT39 - PATT on the Edge Technology, Innovation and Education (pp. 49–57). bibtex: '@inproceedings{Schröer_Tenberge_2022, place={St. John’s, Newfoundland and Labrador, Canada}, series={PATT Proceedings}, title={How to enable pre-service teachers to design technological teaching and learning inclusively? – On the nature and consideration of basic needs in teacher training}, booktitle={PATT39 - PATT on the Edge Technology, Innovation and Education}, author={Schröer, Franz and Tenberge, Claudia}, editor={Gill, David and Tuff, Jim and Kennedy, Thomas and Pendergast, Shawn and Jamil, Sana}, year={2022}, pages={49–57}, collection={PATT Proceedings} }' chicago: Schröer, Franz, and Claudia Tenberge. “How to Enable Pre-Service Teachers to Design Technological Teaching and Learning Inclusively? – On the Nature and Consideration of Basic Needs in Teacher Training.” In PATT39 - PATT on the Edge Technology, Innovation and Education, edited by David Gill, Jim Tuff, Thomas Kennedy, Shawn Pendergast, and Sana Jamil, 49–57. PATT Proceedings. St. John’s, Newfoundland and Labrador, Canada, 2022. ieee: F. Schröer and C. Tenberge, “How to enable pre-service teachers to design technological teaching and learning inclusively? – On the nature and consideration of basic needs in teacher training,” in PATT39 - PATT on the Edge Technology, Innovation and Education, St. John’s, Newfoundland and Labrador, Canada, 2022, pp. 49–57. mla: Schröer, Franz, and Claudia Tenberge. “How to Enable Pre-Service Teachers to Design Technological Teaching and Learning Inclusively? – On the Nature and Consideration of Basic Needs in Teacher Training.” PATT39 - PATT on the Edge Technology, Innovation and Education, edited by David Gill et al., 2022, pp. 49–57. short: 'F. Schröer, C. Tenberge, in: D. Gill, J. Tuff, T. Kennedy, S. Pendergast, S. Jamil (Eds.), PATT39 - PATT on the Edge Technology, Innovation and Education, St. John’s, Newfoundland and Labrador, Canada, 2022, pp. 49–57.' conference: end_date: 2022-06-24 location: St. John’s, Newfoundland and Labrador, Canada name: PATT39 - PATT on the Edge Technology, Innovation and Education start_date: 2022-06-21 date_created: 2023-01-25T15:13:45Z date_updated: 2023-01-25T15:13:57Z department: - _id: '588' editor: - first_name: David full_name: Gill, David last_name: Gill - first_name: Jim full_name: Tuff, Jim last_name: Tuff - first_name: Thomas full_name: Kennedy, Thomas last_name: Kennedy - first_name: Shawn full_name: Pendergast, Shawn last_name: Pendergast - first_name: Sana full_name: Jamil, Sana last_name: Jamil keyword: - Inclusion - basic needs - pre-service teacher training - interest - self-efficacy language: - iso: eng main_file_link: - url: https://research.edgehill.ac.uk/ws/portalfiles/portal/50821651/patt39_proceedings_june_17_2022.pdf page: 49-57 place: St. John’s, Newfoundland and Labrador, Canada publication: PATT39 - PATT on the Edge Technology, Innovation and Education publication_identifier: unknown: - https://research.edgehill.ac.uk/ws/portalfiles/portal/50821651/patt39_proceedings_june_17_2022.pdf publication_status: published quality_controlled: '1' series_title: PATT Proceedings status: public title: How to enable pre-service teachers to design technological teaching and learning inclusively? – On the nature and consideration of basic needs in teacher training type: conference user_id: '71764' year: '2022' ... --- _id: '36083' author: - first_name: Ioanna full_name: Constantiou, Ioanna last_name: Constantiou - first_name: Alivelu full_name: Mukkamala, Alivelu last_name: Mukkamala - first_name: Mimmi full_name: Sjöklint, Mimmi last_name: Sjöklint - first_name: Matthias full_name: Trier, Matthias id: '72744' last_name: Trier citation: ama: 'Constantiou I, Mukkamala A, Sjöklint M, Trier M. Engaging with self-tracking applications: how do users respond to their performance data? European Journal of Information Systems. Published online 2022:1-21. doi:10.1080/0960085x.2022.2081096' apa: 'Constantiou, I., Mukkamala, A., Sjöklint, M., & Trier, M. (2022). Engaging with self-tracking applications: how do users respond to their performance data? European Journal of Information Systems, 1–21. https://doi.org/10.1080/0960085x.2022.2081096' bibtex: '@article{Constantiou_Mukkamala_Sjöklint_Trier_2022, title={Engaging with self-tracking applications: how do users respond to their performance data?}, DOI={10.1080/0960085x.2022.2081096}, journal={European Journal of Information Systems}, publisher={Informa UK Limited}, author={Constantiou, Ioanna and Mukkamala, Alivelu and Sjöklint, Mimmi and Trier, Matthias}, year={2022}, pages={1–21} }' chicago: 'Constantiou, Ioanna, Alivelu Mukkamala, Mimmi Sjöklint, and Matthias Trier. “Engaging with Self-Tracking Applications: How Do Users Respond to Their Performance Data?” European Journal of Information Systems, 2022, 1–21. https://doi.org/10.1080/0960085x.2022.2081096.' ieee: 'I. Constantiou, A. Mukkamala, M. Sjöklint, and M. Trier, “Engaging with self-tracking applications: how do users respond to their performance data?,” European Journal of Information Systems, pp. 1–21, 2022, doi: 10.1080/0960085x.2022.2081096.' mla: 'Constantiou, Ioanna, et al. “Engaging with Self-Tracking Applications: How Do Users Respond to Their Performance Data?” European Journal of Information Systems, Informa UK Limited, 2022, pp. 1–21, doi:10.1080/0960085x.2022.2081096.' short: I. Constantiou, A. Mukkamala, M. Sjöklint, M. Trier, European Journal of Information Systems (2022) 1–21. date_created: 2023-01-11T12:13:54Z date_updated: 2023-01-29T23:05:59Z department: - _id: '195' doi: 10.1080/0960085x.2022.2081096 keyword: - Library and Information Sciences - Information Systems - Self-Tracking - User Behaviour - Discontinuance language: - iso: eng page: 1-21 publication: European Journal of Information Systems publication_identifier: issn: - 0960-085X - 1476-9344 publication_status: published publisher: Informa UK Limited status: public title: 'Engaging with self-tracking applications: how do users respond to their performance data?' type: journal_article user_id: '14931' year: '2022' ... --- _id: '31066' abstract: - lang: eng text: 'While trade-offs between modeling effort and model accuracy remain a major concern with system identification, resorting to data-driven methods often leads to a complete disregard for physical plausibility. To address this issue, we propose a physics-guided hybrid approach for modeling non-autonomous systems under control. Starting from a traditional physics-based model, this is extended by a recurrent neural network and trained using a sophisticated multi-objective strategy yielding physically plausible models. While purely data-driven methods fail to produce satisfying results, experiments conducted on real data reveal substantial accuracy improvements by our approach compared to a physics-based model. ' author: - first_name: Oliver full_name: Schön, Oliver last_name: Schön - first_name: Ricarda-Samantha full_name: Götte, Ricarda-Samantha id: '43992' last_name: Götte - first_name: Julia full_name: Timmermann, Julia id: '15402' last_name: Timmermann citation: ama: 'Schön O, Götte R-S, Timmermann J. Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems. In: 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022). Vol 55. ; 2022:19-24. doi:https://doi.org/10.1016/j.ifacol.2022.07.282' apa: Schön, O., Götte, R.-S., & Timmermann, J. (2022). Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems. 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022), 55(12), 19–24. https://doi.org/10.1016/j.ifacol.2022.07.282 bibtex: '@inproceedings{Schön_Götte_Timmermann_2022, title={Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems}, volume={55}, DOI={https://doi.org/10.1016/j.ifacol.2022.07.282}, number={12}, booktitle={14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022)}, author={Schön, Oliver and Götte, Ricarda-Samantha and Timmermann, Julia}, year={2022}, pages={19–24} }' chicago: Schön, Oliver, Ricarda-Samantha Götte, and Julia Timmermann. “Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems.” In 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022), 55:19–24, 2022. https://doi.org/10.1016/j.ifacol.2022.07.282. ieee: 'O. Schön, R.-S. Götte, and J. Timmermann, “Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems,” in 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022), Casablanca, Morocco, 2022, vol. 55, no. 12, pp. 19–24, doi: https://doi.org/10.1016/j.ifacol.2022.07.282.' mla: Schön, Oliver, et al. “Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems.” 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022), vol. 55, no. 12, 2022, pp. 19–24, doi:https://doi.org/10.1016/j.ifacol.2022.07.282. short: 'O. Schön, R.-S. Götte, J. Timmermann, in: 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022), 2022, pp. 19–24.' conference: end_date: 2022-07-01 location: Casablanca, Morocco name: 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022) start_date: 2022-06-29 date_created: 2022-05-05T06:22:55Z date_updated: 2023-05-02T15:11:20Z department: - _id: '153' doi: https://doi.org/10.1016/j.ifacol.2022.07.282 intvolume: ' 55' issue: '12' keyword: - neural networks - physics-guided - data-driven - multi-objective optimization - system identification - machine learning - dynamical systems language: - iso: eng page: 19-24 publication: 14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022) quality_controlled: '1' status: public title: Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems type: conference user_id: '43992' volume: 55 year: '2022' ... --- _id: '32403' abstract: - lang: eng text: Due to failures or even the absence of an electricity grid, microgrid systems are becoming popular solutions for electrifying African rural communities. However, they are heavily stressed and complex to control due to their intermittency and demand growth. Demand side management (DSM) serves as an option to increase the level of flexibility on the demand side by scheduling users’ consumption patterns profiles in response to supply. This paper proposes a demand-side management strategy based on load shifting and peak clipping. The proposed approach was modelled in a MATLAB/Simulink R2021a environment and was optimized using the artificial neural network (ANN) algorithm. Simulations were carried out to test the model’s efficacy in a stand-alone PV-battery microgrid in East Africa. The proposed algorithm reduces the peak demand, smoothing the load profile to the desired level, and improves the system’s peak to average ratio (PAR). The presence of deferrable loads has been considered to bring more flexible demand-side management. Results promise decreases in peak demand and peak to average ratio of about 31.2% and 7.5% through peak clipping. In addition, load shifting promises more flexibility to customers. article_number: '5215' author: - first_name: Godiana Hagile full_name: Philipo, Godiana Hagile last_name: Philipo - first_name: Josephine Nakato full_name: Kakande, Josephine Nakato id: '88649' last_name: Kakande - first_name: Stefan full_name: Krauter, Stefan id: '28836' last_name: Krauter orcid: 0000-0002-3594-260X citation: ama: Philipo GH, Kakande JN, Krauter S. Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping. Energies. 2022;15(14). doi:10.3390/en15145215 apa: Philipo, G. H., Kakande, J. N., & Krauter, S. (2022). Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping. Energies, 15(14), Article 5215. https://doi.org/10.3390/en15145215 bibtex: '@article{Philipo_Kakande_Krauter_2022, title={Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping}, volume={15}, DOI={10.3390/en15145215}, number={145215}, journal={Energies}, publisher={MDPI AG}, author={Philipo, Godiana Hagile and Kakande, Josephine Nakato and Krauter, Stefan}, year={2022} }' chicago: Philipo, Godiana Hagile, Josephine Nakato Kakande, and Stefan Krauter. “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping.” Energies 15, no. 14 (2022). https://doi.org/10.3390/en15145215. ieee: 'G. H. Philipo, J. N. Kakande, and S. Krauter, “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping,” Energies, vol. 15, no. 14, Art. no. 5215, 2022, doi: 10.3390/en15145215.' mla: Philipo, Godiana Hagile, et al. “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping.” Energies, vol. 15, no. 14, 5215, MDPI AG, 2022, doi:10.3390/en15145215. short: G.H. Philipo, J.N. Kakande, S. Krauter, Energies 15 (2022). date_created: 2022-07-20T11:46:09Z date_updated: 2023-10-11T08:26:43Z department: - _id: '53' doi: 10.3390/en15145215 intvolume: ' 15' issue: '14' keyword: - Energy (miscellaneous) - Energy Engineering and Power Technology - Renewable Energy - Sustainability and the Environment - Electrical and Electronic Engineering - Control and Optimization - Engineering (miscellaneous) - Building and Construction language: - iso: eng publication: Energies publication_identifier: issn: - 1996-1073 publication_status: published publisher: MDPI AG status: public title: Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping type: journal_article user_id: '16148' volume: 15 year: '2022' ... --- _id: '47961' abstract: - lang: eng text: Due to failures or even the absence of an electricity grid, microgrid systems are becoming popular solutions for electrifying African rural communities. However, they are heavily stressed and complex to control due to their intermittency and demand growth. Demand side management (DSM) serves as an option to increase the level of flexibility on the demand side by scheduling users’ consumption patterns profiles in response to supply. This paper proposes a demand-side management strategy based on load shifting and peak clipping. The proposed approach was modelled in a MATLAB/Simulink R2021a environment and was optimized using the artificial neural network (ANN) algorithm. Simulations were carried out to test the model’s efficacy in a stand-alone PV-battery microgrid in East Africa. The proposed algorithm reduces the peak demand, smoothing the load profile to the desired level, and improves the system’s peak to average ratio (PAR). The presence of deferrable loads has been considered to bring more flexible demand-side management. Results promise decreases in peak demand and peak to average ratio of about 31.2% and 7.5% through peak clipping. In addition, load shifting promises more flexibility to customers. article_number: '5215' author: - first_name: Godiana Hagile full_name: Philipo, Godiana Hagile last_name: Philipo - first_name: Josephine Nakato full_name: Kakande, Josephine Nakato id: '88649' last_name: Kakande - first_name: Stefan full_name: Krauter, Stefan id: '28836' last_name: Krauter orcid: 0000-0002-3594-260X citation: ama: Philipo GH, Kakande JN, Krauter S. Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping. Energies. 2022;15(14). doi:10.3390/en15145215 apa: Philipo, G. H., Kakande, J. N., & Krauter, S. (2022). Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping. Energies, 15(14), Article 5215. https://doi.org/10.3390/en15145215 bibtex: '@article{Philipo_Kakande_Krauter_2022, title={Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping}, volume={15}, DOI={10.3390/en15145215}, number={145215}, journal={Energies}, publisher={MDPI AG}, author={Philipo, Godiana Hagile and Kakande, Josephine Nakato and Krauter, Stefan}, year={2022} }' chicago: Philipo, Godiana Hagile, Josephine Nakato Kakande, and Stefan Krauter. “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping.” Energies 15, no. 14 (2022). https://doi.org/10.3390/en15145215. ieee: 'G. H. Philipo, J. N. Kakande, and S. Krauter, “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping,” Energies, vol. 15, no. 14, Art. no. 5215, 2022, doi: 10.3390/en15145215.' mla: Philipo, Godiana Hagile, et al. “Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping.” Energies, vol. 15, no. 14, 5215, MDPI AG, 2022, doi:10.3390/en15145215. short: G.H. Philipo, J.N. Kakande, S. Krauter, Energies 15 (2022). date_created: 2023-10-11T08:13:13Z date_updated: 2023-10-11T08:14:06Z department: - _id: '53' doi: 10.3390/en15145215 intvolume: ' 15' issue: '14' keyword: - Energy (miscellaneous) - Energy Engineering and Power Technology - Renewable Energy - Sustainability and the Environment - Electrical and Electronic Engineering - Control and Optimization - Engineering (miscellaneous) - Building and Construction language: - iso: eng publication: Energies publication_identifier: issn: - 1996-1073 publication_status: published publisher: MDPI AG status: public title: Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping type: journal_article user_id: '16148' volume: 15 year: '2022' ... --- _id: '29803' abstract: - lang: eng text: "Ultrasonic wire bonding is a solid-state joining process used to form electrical interconnections in micro and\r\npower electronics and batteries. A high frequency oscillation causes a metallurgical bond deformation in\r\nthe contact area. Due to the numerous physical influencing factors, it is very difficult to accurately capture\r\nthis process in a model. Therefore, our goal is to determine a suitable feed-forward control strategy for the\r\nbonding process even without detailed model knowledge. We propose the use of batch constrained Bayesian\r\noptimization for the control design. Hence, Bayesian optimization is precisely adapted to the application of\r\nbonding: the constraint is used to check one quality feature of the process and the use of batches leads to\r\nmore efficient experiments. Our approach is suitable to determine a feed-forward control for the bonding\r\nprocess that provides very high quality bonds without using a physical model. We also show that the quality\r\nof the Bayesian optimization based control outperforms random search as well as manual search by a user.\r\nUsing a simple prior knowledge model derived from data further improves the quality of the connection.\r\nThe Bayesian optimization approach offers the possibility to perform a sensitivity analysis of the control\r\nparameters, which allows to evaluate the influence of each control parameter on the bond quality. In summary,\r\nBayesian optimization applied to the bonding process provides an excellent opportunity to develop a feedforward\r\ncontrol without full modeling of the underlying physical processes." author: - first_name: Michael full_name: Hesse, Michael id: '29222' last_name: Hesse - first_name: Matthias full_name: Hunstig, Matthias last_name: Hunstig - first_name: Julia full_name: Timmermann, Julia id: '15402' last_name: Timmermann - first_name: Ansgar full_name: Trächtler, Ansgar id: '552' last_name: Trächtler citation: ama: 'Hesse M, Hunstig M, Timmermann J, Trächtler A. Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design. In: Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM). ; 2022:383-394.' apa: Hesse, M., Hunstig, M., Timmermann, J., & Trächtler, A. (2022). Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design. Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM), 383–394. bibtex: '@inproceedings{Hesse_Hunstig_Timmermann_Trächtler_2022, title={Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design}, booktitle={Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM)}, author={Hesse, Michael and Hunstig, Matthias and Timmermann, Julia and Trächtler, Ansgar}, year={2022}, pages={383–394} }' chicago: Hesse, Michael, Matthias Hunstig, Julia Timmermann, and Ansgar Trächtler. “Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-Forward Control Design.” In Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM), 383–94, 2022. ieee: M. Hesse, M. Hunstig, J. Timmermann, and A. Trächtler, “Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design,” in Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM), Online, 2022, pp. 383–394. mla: Hesse, Michael, et al. “Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-Forward Control Design.” Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM), 2022, pp. 383–94. short: 'M. Hesse, M. Hunstig, J. Timmermann, A. Trächtler, in: Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM), 2022, pp. 383–394.' conference: end_date: 2022-02-05 location: Online name: 11th International Conference on Pattern Recognition Applications and Methods start_date: 2022-02-03 date_created: 2022-02-09T12:50:25Z date_updated: 2023-11-06T15:17:12Z department: - _id: '153' keyword: - Bayesian optimization - Wire bonding - Feed-forward control - model-free design language: - iso: eng page: 383-394 publication: Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM) publication_identifier: isbn: - 978-989-758-549-4 quality_controlled: '1' status: public title: Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design type: conference user_id: '29222' year: '2022' ... --- _id: '48882' abstract: - lang: eng text: In multimodal multi-objective optimization (MMMOO), the focus is not solely on convergence in objective space, but rather also on explicitly ensuring diversity in decision space. We illustrate why commonly used diversity measures are not entirely appropriate for this task and propose a sophisticated basin-based evaluation (BBE) method. Also, BBE variants are developed, capturing the anytime behavior of algorithms. The set of BBE measures is tested by means of an algorithm configuration study. We show that these new measures also transfer properties of the well-established hypervolume (HV) indicator to the domain of MMMOO, thus also accounting for objective space convergence. Moreover, we advance MMMOO research by providing insights into the multimodal performance of the considered algorithms. Specifically, algorithms exploiting local structures are shown to outperform classical evolutionary multi-objective optimizers regarding the BBE variants and respective trade-off with HV. author: - first_name: Jonathan full_name: Heins, Jonathan last_name: Heins - first_name: Jeroen full_name: Rook, Jeroen last_name: Rook - first_name: Lennart full_name: Schäpermeier, Lennart last_name: Schäpermeier - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Heike full_name: Trautmann, Heike last_name: Trautmann citation: ama: 'Heins J, Rook J, Schäpermeier L, Kerschke P, Bossek J, Trautmann H. BBE: Basin-Based Evaluation of Multimodal Multi-objective Optimization Problems. In: Rudolph G, Kononova AV, Aguirre H, Kerschke P, Ochoa G, Tusar T, eds. Parallel Problem Solving from Nature (PPSN XVII). Lecture Notes in Computer Science. Springer International Publishing; 2022:192–206. doi:10.1007/978-3-031-14714-2_14' apa: 'Heins, J., Rook, J., Schäpermeier, L., Kerschke, P., Bossek, J., & Trautmann, H. (2022). BBE: Basin-Based Evaluation of Multimodal Multi-objective Optimization Problems. In G. Rudolph, A. V. Kononova, H. Aguirre, P. Kerschke, G. Ochoa, & T. Tusar (Eds.), Parallel Problem Solving from Nature (PPSN XVII) (pp. 192–206). Springer International Publishing. https://doi.org/10.1007/978-3-031-14714-2_14' bibtex: '@inproceedings{Heins_Rook_Schäpermeier_Kerschke_Bossek_Trautmann_2022, place={Cham}, series={Lecture Notes in Computer Science}, title={BBE: Basin-Based Evaluation of Multimodal Multi-objective Optimization Problems}, DOI={10.1007/978-3-031-14714-2_14}, booktitle={Parallel Problem Solving from Nature (PPSN XVII)}, publisher={Springer International Publishing}, author={Heins, Jonathan and Rook, Jeroen and Schäpermeier, Lennart and Kerschke, Pascal and Bossek, Jakob and Trautmann, Heike}, editor={Rudolph, Günter and Kononova, Anna V. and Aguirre, Hernán and Kerschke, Pascal and Ochoa, Gabriela and Tusar, Tea}, year={2022}, pages={192–206}, collection={Lecture Notes in Computer Science} }' chicago: 'Heins, Jonathan, Jeroen Rook, Lennart Schäpermeier, Pascal Kerschke, Jakob Bossek, and Heike Trautmann. “BBE: Basin-Based Evaluation of Multimodal Multi-Objective Optimization Problems.” In Parallel Problem Solving from Nature (PPSN XVII), edited by Günter Rudolph, Anna V. Kononova, Hernán Aguirre, Pascal Kerschke, Gabriela Ochoa, and Tea Tusar, 192–206. Lecture Notes in Computer Science. Cham: Springer International Publishing, 2022. https://doi.org/10.1007/978-3-031-14714-2_14.' ieee: 'J. Heins, J. Rook, L. Schäpermeier, P. Kerschke, J. Bossek, and H. Trautmann, “BBE: Basin-Based Evaluation of Multimodal Multi-objective Optimization Problems,” in Parallel Problem Solving from Nature (PPSN XVII), 2022, pp. 192–206, doi: 10.1007/978-3-031-14714-2_14.' mla: 'Heins, Jonathan, et al. “BBE: Basin-Based Evaluation of Multimodal Multi-Objective Optimization Problems.” Parallel Problem Solving from Nature (PPSN XVII), edited by Günter Rudolph et al., Springer International Publishing, 2022, pp. 192–206, doi:10.1007/978-3-031-14714-2_14.' short: 'J. Heins, J. Rook, L. Schäpermeier, P. Kerschke, J. Bossek, H. Trautmann, in: G. Rudolph, A.V. Kononova, H. Aguirre, P. Kerschke, G. Ochoa, T. Tusar (Eds.), Parallel Problem Solving from Nature (PPSN XVII), Springer International Publishing, Cham, 2022, pp. 192–206.' date_created: 2023-11-14T15:58:58Z date_updated: 2023-12-13T10:47:50Z department: - _id: '819' doi: 10.1007/978-3-031-14714-2_14 editor: - first_name: Günter full_name: Rudolph, Günter last_name: Rudolph - first_name: Anna V. full_name: Kononova, Anna V. last_name: Kononova - first_name: Hernán full_name: Aguirre, Hernán last_name: Aguirre - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Gabriela full_name: Ochoa, Gabriela last_name: Ochoa - first_name: Tea full_name: Tusar, Tea last_name: Tusar extern: '1' keyword: - Anytime behavior - Benchmarking - Continuous optimization - Multi-objective optimization - Multimodality - Performance metric language: - iso: eng page: 192–206 place: Cham publication: Parallel Problem Solving from Nature (PPSN XVII) publication_identifier: isbn: - 978-3-031-14714-2 publisher: Springer International Publishing series_title: Lecture Notes in Computer Science status: public title: 'BBE: Basin-Based Evaluation of Multimodal Multi-objective Optimization Problems' type: conference user_id: '102979' year: '2022' ... --- _id: '48896' abstract: - lang: eng text: Hardness of Multi-Objective (MO) continuous optimization problems results from an interplay of various problem characteristics, e. g. the degree of multi-modality. We present a benchmark study of classical and diversity focused optimizers on multi-modal MO problems based on automated algorithm configuration. We show the large effect of the latter and investigate the trade-off between convergence in objective space and diversity in decision space. author: - first_name: Jeroen full_name: Rook, Jeroen last_name: Rook - first_name: Heike full_name: Trautmann, Heike last_name: Trautmann - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Christian full_name: Grimme, Christian last_name: Grimme citation: ama: 'Rook J, Trautmann H, Bossek J, Grimme C. On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems. In: Proceedings of the Genetic and Evolutionary Computation Conference Companion. GECCO’22. Association for Computing Machinery; 2022:356–359. doi:10.1145/3520304.3528998' apa: Rook, J., Trautmann, H., Bossek, J., & Grimme, C. (2022). On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems. Proceedings of the Genetic and Evolutionary Computation Conference Companion, 356–359. https://doi.org/10.1145/3520304.3528998 bibtex: '@inproceedings{Rook_Trautmann_Bossek_Grimme_2022, place={New York, NY, USA}, series={GECCO’22}, title={On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems}, DOI={10.1145/3520304.3528998}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference Companion}, publisher={Association for Computing Machinery}, author={Rook, Jeroen and Trautmann, Heike and Bossek, Jakob and Grimme, Christian}, year={2022}, pages={356–359}, collection={GECCO’22} }' chicago: 'Rook, Jeroen, Heike Trautmann, Jakob Bossek, and Christian Grimme. “On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems.” In Proceedings of the Genetic and Evolutionary Computation Conference Companion, 356–359. GECCO’22. New York, NY, USA: Association for Computing Machinery, 2022. https://doi.org/10.1145/3520304.3528998.' ieee: 'J. Rook, H. Trautmann, J. Bossek, and C. Grimme, “On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems,” in Proceedings of the Genetic and Evolutionary Computation Conference Companion, 2022, pp. 356–359, doi: 10.1145/3520304.3528998.' mla: Rook, Jeroen, et al. “On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems.” Proceedings of the Genetic and Evolutionary Computation Conference Companion, Association for Computing Machinery, 2022, pp. 356–359, doi:10.1145/3520304.3528998. short: 'J. Rook, H. Trautmann, J. Bossek, C. Grimme, in: Proceedings of the Genetic and Evolutionary Computation Conference Companion, Association for Computing Machinery, New York, NY, USA, 2022, pp. 356–359.' date_created: 2023-11-14T15:59:00Z date_updated: 2023-12-13T10:50:24Z department: - _id: '819' doi: 10.1145/3520304.3528998 extern: '1' keyword: - configuration - multi-modality - multi-objective optimization language: - iso: eng page: 356–359 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference Companion publication_identifier: isbn: - 978-1-4503-9268-6 publisher: Association for Computing Machinery series_title: GECCO’22 status: public title: On the Potential of Automated Algorithm Configuration on Multi-Modal Multi-Objective Optimization Problems type: conference user_id: '102979' year: '2022' ... --- _id: '21004' abstract: - lang: eng text: 'Automated machine learning (AutoML) supports the algorithmic construction and data-specific customization of machine learning pipelines, including the selection, combination, and parametrization of machine learning algorithms as main constituents. Generally speaking, AutoML approaches comprise two major components: a search space model and an optimizer for traversing the space. Recent approaches have shown impressive results in the realm of supervised learning, most notably (single-label) classification (SLC). Moreover, first attempts at extending these approaches towards multi-label classification (MLC) have been made. While the space of candidate pipelines is already huge in SLC, the complexity of the search space is raised to an even higher power in MLC. One may wonder, therefore, whether and to what extent optimizers established for SLC can scale to this increased complexity, and how they compare to each other. This paper makes the following contributions: First, we survey existing approaches to AutoML for MLC. Second, we augment these approaches with optimizers not previously tried for MLC. Third, we propose a benchmarking framework that supports a fair and systematic comparison. Fourth, we conduct an extensive experimental study, evaluating the methods on a suite of MLC problems. We find a grammar-based best-first search to compare favorably to other optimizers.' author: - first_name: Marcel Dominik full_name: Wever, Marcel Dominik id: '33176' last_name: Wever orcid: ' https://orcid.org/0000-0001-9782-6818' - first_name: Alexander full_name: Tornede, Alexander id: '38209' last_name: Tornede - first_name: Felix full_name: Mohr, Felix last_name: Mohr - first_name: Eyke full_name: Hüllermeier, Eyke id: '48129' last_name: Hüllermeier citation: ama: 'Wever MD, Tornede A, Mohr F, Hüllermeier E. AutoML for Multi-Label Classification: Overview and Empirical Evaluation. IEEE Transactions on Pattern Analysis and Machine Intelligence. Published online 2021:1-1. doi:10.1109/tpami.2021.3051276' apa: 'Wever, M. D., Tornede, A., Mohr, F., & Hüllermeier, E. (2021). AutoML for Multi-Label Classification: Overview and Empirical Evaluation. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1–1. https://doi.org/10.1109/tpami.2021.3051276' bibtex: '@article{Wever_Tornede_Mohr_Hüllermeier_2021, title={AutoML for Multi-Label Classification: Overview and Empirical Evaluation}, DOI={10.1109/tpami.2021.3051276}, journal={IEEE Transactions on Pattern Analysis and Machine Intelligence}, author={Wever, Marcel Dominik and Tornede, Alexander and Mohr, Felix and Hüllermeier, Eyke}, year={2021}, pages={1–1} }' chicago: 'Wever, Marcel Dominik, Alexander Tornede, Felix Mohr, and Eyke Hüllermeier. “AutoML for Multi-Label Classification: Overview and Empirical Evaluation.” IEEE Transactions on Pattern Analysis and Machine Intelligence, 2021, 1–1. https://doi.org/10.1109/tpami.2021.3051276.' ieee: 'M. D. Wever, A. Tornede, F. Mohr, and E. Hüllermeier, “AutoML for Multi-Label Classification: Overview and Empirical Evaluation,” IEEE Transactions on Pattern Analysis and Machine Intelligence, pp. 1–1, 2021, doi: 10.1109/tpami.2021.3051276.' mla: 'Wever, Marcel Dominik, et al. “AutoML for Multi-Label Classification: Overview and Empirical Evaluation.” IEEE Transactions on Pattern Analysis and Machine Intelligence, 2021, pp. 1–1, doi:10.1109/tpami.2021.3051276.' short: M.D. Wever, A. Tornede, F. Mohr, E. Hüllermeier, IEEE Transactions on Pattern Analysis and Machine Intelligence (2021) 1–1. date_created: 2021-01-16T14:48:13Z date_updated: 2022-01-06T06:54:42Z department: - _id: '34' - _id: '355' - _id: '26' doi: 10.1109/tpami.2021.3051276 keyword: - Automated Machine Learning - Multi Label Classification - Hierarchical Planning - Bayesian Optimization language: - iso: eng page: 1-1 project: - _id: '1' name: SFB 901 - _id: '3' name: SFB 901 - Project Area B - _id: '10' name: SFB 901 - Subproject B2 - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: IEEE Transactions on Pattern Analysis and Machine Intelligence publication_identifier: issn: - 0162-8828 - 2160-9292 - 1939-3539 publication_status: published status: public title: 'AutoML for Multi-Label Classification: Overview and Empirical Evaluation' type: journal_article user_id: '5786' year: '2021' ... --- _id: '21808' abstract: - lang: eng text: "Modern services consist of interconnected components,e.g., microservices in a service mesh or machine learning functions in a pipeline. These services can scale and run across multiple network nodes on demand. To process incoming traffic, service components have to be instantiated and traffic assigned to these instances, taking capacities, changing demands, and Quality of Service (QoS) requirements into account. This challenge is usually solved with custom approaches designed by experts. While this typically works well for the considered scenario, the models often rely on unrealistic assumptions or on knowledge that is not available in practice (e.g., a priori knowledge).\r\n\r\nWe propose DeepCoord, a novel deep reinforcement learning approach that learns how to best coordinate services and is geared towards realistic assumptions. It interacts with the network and relies on available, possibly delayed monitoring information. Rather than defining a complex model or an algorithm on how to achieve an objective, our model-free approach adapts to various objectives and traffic patterns. An agent is trained offline without expert knowledge and then applied online with minimal overhead. Compared to a state-of-the-art heuristic, DeepCoord significantly improves flow throughput (up to 76%) and overall network utility (more than 2x) on realworld network topologies and traffic traces. It also supports optimizing multiple, possibly competing objectives, learns to respect QoS requirements, generalizes to scenarios with unseen, stochastic traffic, and scales to large real-world networks. For reproducibility and reuse, our code is publicly available." article_type: original author: - first_name: Stefan Balthasar full_name: Schneider, Stefan Balthasar id: '35343' last_name: Schneider orcid: 0000-0001-8210-4011 - first_name: Ramin full_name: Khalili, Ramin last_name: Khalili - first_name: Adnan full_name: Manzoor, Adnan last_name: Manzoor - first_name: Haydar full_name: Qarawlus, Haydar last_name: Qarawlus - first_name: Rafael full_name: Schellenberg, Rafael last_name: Schellenberg - first_name: Holger full_name: Karl, Holger id: '126' last_name: Karl - first_name: Artur full_name: Hecker, Artur last_name: Hecker citation: ama: Schneider SB, Khalili R, Manzoor A, et al. Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning. Transactions on Network and Service Management. 2021. doi:10.1109/TNSM.2021.3076503 apa: Schneider, S. B., Khalili, R., Manzoor, A., Qarawlus, H., Schellenberg, R., Karl, H., & Hecker, A. (2021). Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning. Transactions on Network and Service Management. https://doi.org/10.1109/TNSM.2021.3076503 bibtex: '@article{Schneider_Khalili_Manzoor_Qarawlus_Schellenberg_Karl_Hecker_2021, title={Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning}, DOI={10.1109/TNSM.2021.3076503}, journal={Transactions on Network and Service Management}, publisher={IEEE}, author={Schneider, Stefan Balthasar and Khalili, Ramin and Manzoor, Adnan and Qarawlus, Haydar and Schellenberg, Rafael and Karl, Holger and Hecker, Artur}, year={2021} }' chicago: Schneider, Stefan Balthasar, Ramin Khalili, Adnan Manzoor, Haydar Qarawlus, Rafael Schellenberg, Holger Karl, and Artur Hecker. “Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning.” Transactions on Network and Service Management, 2021. https://doi.org/10.1109/TNSM.2021.3076503. ieee: S. B. Schneider et al., “Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning,” Transactions on Network and Service Management, 2021. mla: Schneider, Stefan Balthasar, et al. “Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning.” Transactions on Network and Service Management, IEEE, 2021, doi:10.1109/TNSM.2021.3076503. short: S.B. Schneider, R. Khalili, A. Manzoor, H. Qarawlus, R. Schellenberg, H. Karl, A. Hecker, Transactions on Network and Service Management (2021). date_created: 2021-04-27T08:04:16Z date_updated: 2022-01-06T06:55:15Z ddc: - '000' department: - _id: '75' doi: 10.1109/TNSM.2021.3076503 file: - access_level: open_access content_type: application/pdf creator: stschn date_created: 2021-04-27T08:01:26Z date_updated: 2021-04-27T08:01:26Z description: Author version of the accepted paper file_id: '21809' file_name: ris-accepted-version.pdf file_size: 4172270 relation: main_file file_date_updated: 2021-04-27T08:01:26Z has_accepted_license: '1' keyword: - network management - service management - coordination - reinforcement learning - self-learning - self-adaptation - multi-objective language: - iso: eng oa: '1' project: - _id: '1' name: SFB 901 - _id: '4' name: SFB 901 - Project Area C - _id: '16' name: SFB 901 - Subproject C4 publication: Transactions on Network and Service Management publisher: IEEE status: public title: Self-Learning Multi-Objective Service Coordination Using Deep Reinforcement Learning type: journal_article user_id: '35343' year: '2021' ... --- _id: '33854' abstract: - lang: eng text: "Macrodiversity is a key technique to increase the capacity of mobile networks. It can be realized using coordinated multipoint (CoMP), simultaneously connecting users to multiple overlapping cells. Selecting which users to serve by how many and which cells is NP-hard but needs to happen continuously in real time as users move and channel state changes. Existing approaches often require strict assumptions about or perfect knowledge of the underlying radio system, its resource allocation scheme, or user movements, none of which is readily available in practice.\r\n\r\nInstead, we propose three novel self-learning and self-adapting approaches using model-free deep reinforcement learning (DRL): DeepCoMP, DD-CoMP, and D3-CoMP. DeepCoMP leverages central observations and control of all users to select cells almost optimally. DD-CoMP and D3-CoMP use multi-agent DRL, which allows distributed, robust, and highly scalable coordination. All three approaches learn from experience and self-adapt to varying scenarios, reaching 2x higher Quality of Experience than other approaches. They have very few built-in assumptions and do not need prior system knowledge, making them more robust to change and better applicable in practice than existing approaches." author: - first_name: Stefan Balthasar full_name: Schneider, Stefan Balthasar id: '35343' last_name: Schneider orcid: 0000-0001-8210-4011 - first_name: Holger full_name: Karl, Holger id: '126' last_name: Karl - first_name: Ramin full_name: Khalili, Ramin last_name: Khalili - first_name: Artur full_name: Hecker, Artur last_name: Hecker citation: ama: 'Schneider SB, Karl H, Khalili R, Hecker A. DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning.; 2021.' apa: 'Schneider, S. B., Karl, H., Khalili, R., & Hecker, A. (2021). DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning.' bibtex: '@book{Schneider_Karl_Khalili_Hecker_2021, title={DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning}, author={Schneider, Stefan Balthasar and Karl, Holger and Khalili, Ramin and Hecker, Artur}, year={2021} }' chicago: 'Schneider, Stefan Balthasar, Holger Karl, Ramin Khalili, and Artur Hecker. DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning, 2021.' ieee: 'S. B. Schneider, H. Karl, R. Khalili, and A. Hecker, DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning. 2021.' mla: 'Schneider, Stefan Balthasar, et al. DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning. 2021.' short: 'S.B. Schneider, H. Karl, R. Khalili, A. Hecker, DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning, 2021.' date_created: 2022-10-20T16:44:19Z date_updated: 2022-11-18T09:59:27Z ddc: - '004' department: - _id: '75' file: - access_level: open_access content_type: application/pdf creator: stschn date_created: 2022-10-20T16:41:10Z date_updated: 2022-10-20T16:41:10Z file_id: '33855' file_name: preprint.pdf file_size: 2521656 relation: main_file file_date_updated: 2022-10-20T16:41:10Z has_accepted_license: '1' keyword: - mobility management - coordinated multipoint - CoMP - cell selection - resource management - reinforcement learning - multi agent - MARL - self-learning - self-adaptation - QoE language: - iso: eng oa: '1' project: - _id: '4' name: 'SFB 901 - C: SFB 901 - Project Area C' - _id: '16' name: 'SFB 901 - C4: SFB 901 - Subproject C4' - _id: '1' name: 'SFB 901: SFB 901' status: public title: 'DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning' type: working_paper user_id: '477' year: '2021' ... --- _id: '32558' abstract: - lang: eng text: With the rapid progress of technological development, self-efficacy in reference to digital devices (i.e., information and computer technology [ICT] self-efficacy) is an important driver that helps students to deal with technological problems and support their lifelong learning processes. Schools, peers, and home learning environments are important sources for the development of positive self-efficacy. Expanding on previous research, we investigated the associations between different aspects of the digital home learning environment and students’ ICT self-efficacy. The moderation effects of gender were also tested. A total of 651 children answered a questionnaire about different digital home learning environment dimensions and estimated their ICT self-efficacy using an adapted scale—Schwarzer and Jerusalem’s (1999) general self-efficacy scale. Using the structural equation modeling technique, a digital home learning environment containing six different qualities of parental support was investigated. Families’ cultural capital, parents’ attitudes toward the Internet, and shared Internet activities at home contributed positively to ICT self-efficacy. We observed small gender differences, with the moderation effect being nonsignificant. The results help researchers and practitioners to understand how different dimensions of the digital home learning environment support ICT self-efficacy. We will discuss how parents can enhance the home learning environment and how teachers can integrate this knowledge into formal education. author: - first_name: Sabrina full_name: Bonanati, Sabrina last_name: Bonanati - first_name: Heike M. full_name: Buhl, Heike M. id: '27152' last_name: Buhl citation: ama: Bonanati S, Buhl HM. The digital home learning environment and its relation to children’s ICT self-efficacy. Learning Environments Research. 2021;25(2):485-505. doi:10.1007/s10984-021-09377-8 apa: Bonanati, S., & Buhl, H. M. (2021). The digital home learning environment and its relation to children’s ICT self-efficacy. Learning Environments Research, 25(2), 485–505. https://doi.org/10.1007/s10984-021-09377-8 bibtex: '@article{Bonanati_Buhl_2021, title={The digital home learning environment and its relation to children’s ICT self-efficacy}, volume={25}, DOI={10.1007/s10984-021-09377-8}, number={2}, journal={Learning Environments Research}, publisher={Springer Science and Business Media LLC}, author={Bonanati, Sabrina and Buhl, Heike M.}, year={2021}, pages={485–505} }' chicago: 'Bonanati, Sabrina, and Heike M. Buhl. “The Digital Home Learning Environment and Its Relation to Children’s ICT Self-Efficacy.” Learning Environments Research 25, no. 2 (2021): 485–505. https://doi.org/10.1007/s10984-021-09377-8.' ieee: 'S. Bonanati and H. M. Buhl, “The digital home learning environment and its relation to children’s ICT self-efficacy,” Learning Environments Research, vol. 25, no. 2, pp. 485–505, 2021, doi: 10.1007/s10984-021-09377-8.' mla: Bonanati, Sabrina, and Heike M. Buhl. “The Digital Home Learning Environment and Its Relation to Children’s ICT Self-Efficacy.” Learning Environments Research, vol. 25, no. 2, Springer Science and Business Media LLC, 2021, pp. 485–505, doi:10.1007/s10984-021-09377-8. short: S. Bonanati, H.M. Buhl, Learning Environments Research 25 (2021) 485–505. date_created: 2022-08-03T05:53:48Z date_updated: 2022-08-29T06:36:37Z department: - _id: '427' doi: 10.1007/s10984-021-09377-8 intvolume: ' 25' issue: '2' keyword: - Digital media use - Gender - Home learning environment - ICT self-efcacy - Motivation - Parental involvement language: - iso: eng main_file_link: - open_access: '1' url: https://link.springer.com/content/pdf/10.1007/s10984-021-09377-8.pdf oa: '1' page: 485-505 publication: Learning Environments Research publication_identifier: issn: - 1387-1579 - 1573-1855 publication_status: published publisher: Springer Science and Business Media LLC status: public title: The digital home learning environment and its relation to children’s ICT self-efficacy type: journal_article user_id: '42165' volume: 25 year: '2021' ... --- _id: '37136' abstract: - lang: eng text: This study examines the relation between voluntary audit and the cost of debt in private firms. We use a sample of 4,058 small private firms operating in the period 2006‐2017 that are not subject to mandatory audits. Firms decide for a voluntary audit of financial statements either because the economic setting in which they operate effectively forces them to do so (e.g., ownership complexity, export‐oriented supply chain, subsidiary status) or because firm fundamentals and/or financial reporting practices limit their access to financial debt, both reflected in earnings quality. We use these factors to model the decision for voluntary audit. In the outcome analyses, we find robust evidence that voluntary audits are associated with higher, rather than lower, interest rate by up to 3.0 percentage points. This effect is present regardless of the perceived audit quality (Big‐4 vs. non‐Big‐4), but is stronger for non‐Big‐4 audits where auditees have a stronger position relative to auditors. Audited firms’ earnings are less informative about future operating performance relative to unaudited counterparts. We conclude that voluntary audits facilitate access to financial debt for firms with higher risk that may otherwise have no access to this form of financing. The price paid is reflected in higher interest rates charged to firms with voluntary audits – firms with higher information and/or fundamental risk. author: - first_name: Riste full_name: Ichev, Riste last_name: Ichev - first_name: Jernej full_name: Koren, Jernej last_name: Koren - first_name: Urska full_name: Kosi, Urska id: '54068' last_name: Kosi - first_name: Katarina full_name: Sitar Sustar, Katarina last_name: Sitar Sustar - first_name: Aljosa full_name: Valentincic, Aljosa last_name: Valentincic citation: ama: 'Ichev R, Koren J, Kosi U, Sitar Sustar K, Valentincic A. Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk.; 2021.' apa: 'Ichev, R., Koren, J., Kosi, U., Sitar Sustar, K., & Valentincic, A. (2021). Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk.' bibtex: '@book{Ichev_Koren_Kosi_Sitar Sustar_Valentincic_2021, title={Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk}, author={Ichev, Riste and Koren, Jernej and Kosi, Urska and Sitar Sustar, Katarina and Valentincic, Aljosa}, year={2021} }' chicago: 'Ichev, Riste, Jernej Koren, Urska Kosi, Katarina Sitar Sustar, and Aljosa Valentincic. Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk, 2021.' ieee: 'R. Ichev, J. Koren, U. Kosi, K. Sitar Sustar, and A. Valentincic, Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk. 2021.' mla: 'Ichev, Riste, et al. Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk. 2021.' short: 'R. Ichev, J. Koren, U. Kosi, K. Sitar Sustar, A. Valentincic, Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk, 2021.' date_created: 2023-01-17T15:03:08Z date_updated: 2023-01-18T13:40:40Z department: - _id: '635' - _id: '186' - _id: '551' keyword: - private firms - voluntary audit - cost of debt - self‐selection bias - risk language: - iso: eng main_file_link: - url: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3853927 status: public title: 'Cost of Debt for Private Firms Revisited: Voluntary Audits as a Reflection of Risk' type: working_paper user_id: '88603' year: '2021' ... --- _id: '22930' abstract: - lang: eng text: Self-piercing riveting is an established technique for joining multi-material structures in car body manufacturing. Rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and their surface condition. To shorten the manufacturing process by omitting the heat treatment and the coating process, the authors have elaborated a concept for the use of stainless steel with high strain hardening as a rivet material. The focus of the present investigation is on the evaluation of the influences of the rivet’s geometry and material on its deformation behaviour. Conventional rivets of types P and HD2, a rivet with an improved geometry made of treatable steel 38B2, and rivets made of the stainless steels 1.3815 and 1.4541 are examined. The analysis is conducted by means of multi-step joining tests for two material combinations comprising high-strength steel HCT70X and aluminium EN AW-5083. The joints are cut to provide a cross-section and the deformation behaviour of the different rivets is analysed on the basis of the measured changes in geometry and hardness. In parallel, an examination of the force-stroke curves provides further insights. It can be demonstrated that, besides the geometry, the material strength, in particular, has a significant influence on the deformation behaviour of the rivet. The strength of steel 1.4541 is seen to be too low for the joining task, while the strength of steel 1.3815 is sufficient, and hence the investigation confirms the capability of rivets made of 1.3815 for joining even challenging material combinations. author: - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Marion full_name: Merklein, Marion last_name: Merklein - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: 'Uhe B, Kuball C-M, Merklein M, Meschut G. Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening. In: Daehn G, Cao J, Kinsey B, Tekkaya E, Vivek A, Yoshida Y, eds. Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. Springer; 2021:1495-1506. doi:10.1007/978-3-030-75381-8_124' apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2021). Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening. In G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, & Y. Yoshida (Eds.), Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. (pp. 1495–1506). Springer. https://doi.org/10.1007/978-3-030-75381-8_124 bibtex: '@inbook{Uhe_Kuball_Merklein_Meschut_2021, place={Cham}, title={Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening}, DOI={10.1007/978-3-030-75381-8_124}, booktitle={Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series.}, publisher={Springer}, author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}, editor={Daehn, Glenn and Cao, Jian and Kinsey, Brad and Tekkaya, Erman and Vivek, Anupam and Yoshida, Yoshinori}, year={2021}, pages={1495–1506} }' chicago: 'Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut. “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening.” In Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., edited by Glenn Daehn, Jian Cao, Brad Kinsey, Erman Tekkaya, Anupam Vivek, and Yoshinori Yoshida, 1495–1506. Cham: Springer, 2021. https://doi.org/10.1007/978-3-030-75381-8_124.' ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening,” in Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, and Y. Yoshida, Eds. Cham: Springer, 2021, pp. 1495–1506.' mla: Uhe, Benedikt, et al. “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening.” Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., edited by Glenn Daehn et al., Springer, 2021, pp. 1495–506, doi:10.1007/978-3-030-75381-8_124. short: 'B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, in: G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, Y. Yoshida (Eds.), Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., Springer, Cham, 2021, pp. 1495–1506.' date_created: 2021-08-04T14:02:32Z date_updated: 2023-04-28T09:20:35Z department: - _id: '157' doi: 10.1007/978-3-030-75381-8_124 editor: - first_name: Glenn full_name: Daehn, Glenn last_name: Daehn - first_name: Jian full_name: Cao, Jian last_name: Cao - first_name: Brad full_name: Kinsey, Brad last_name: Kinsey - first_name: Erman full_name: Tekkaya, Erman last_name: Tekkaya - first_name: Anupam full_name: Vivek, Anupam last_name: Vivek - first_name: Yoshinori full_name: Yoshida, Yoshinori last_name: Yoshida keyword: - Self-piercing riveting - Lightweight design - Deformation behaviour - Stainless steel - High nitrogen steel language: - iso: eng page: 1495-1506 place: Cham publication: Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. publication_status: published publisher: Springer quality_controlled: '1' status: public title: Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening type: book_chapter user_id: '38131' year: '2021' ... --- _id: '22274' abstract: - lang: eng text: 'The use of high-strength steel and aluminium is rising due to the intensified efforts being made in lightweight design, and self-piercing riveting is becoming increasingly important. Conventional rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and the coating. To shorten the manufacturing process, the use of stainless steel with high strain hardening as the rivet material represents a promising approach. This allows the coating of the rivets to be omitted due to the corrosion resistance of the material and, since the strength of the stainless steel is achieved by cold forming, heat treatment is no longer required. In addition, it is possible to adjust the local strength within the rivet. Because of that, the authors have elaborated a concept for using high nitrogen steel 1.3815 as the rivet material. The present investigation focusses on the joint strength in order to evaluate the capability of rivets in high nitrogen steel by comparison to conventional rivets made of treatable steel. Due to certain challenges in the forming process of the high nitrogen steel rivets, deviations result from the targeted rivet geometry. Mainly these deviations cause a lower joint strength with these rivets, which is, however, adequate. All in all, the capability of the new rivet is proven by the results of this investigation. ' author: - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Marion full_name: Merklein, Marion last_name: Merklein - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: 'Uhe B, Kuball C-M, Merklein M, Meschut G. Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel. In: ; 2021. doi:10.25518/esaform21.1911' apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2021). Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel. 24th International Conference on Material Forming (ESAFORM), Liège, Belgien. https://doi.org/10.25518/esaform21.1911 bibtex: '@inproceedings{Uhe_Kuball_Merklein_Meschut_2021, title={Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel}, DOI={10.25518/esaform21.1911}, author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}, year={2021} }' chicago: Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut. “Strength of Self-Piercing Riveted Joints with Conventional Rivets and Rivets Made of High Nitrogen Steel,” 2021. https://doi.org/10.25518/esaform21.1911. ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel,” presented at the 24th International Conference on Material Forming (ESAFORM), Liège, Belgien, 2021, doi: 10.25518/esaform21.1911.' mla: Uhe, Benedikt, et al. Strength of Self-Piercing Riveted Joints with Conventional Rivets and Rivets Made of High Nitrogen Steel. 2021, doi:10.25518/esaform21.1911. short: 'B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, in: 2021.' conference: end_date: 2021-04-16 location: Liège, Belgien name: 24th International Conference on Material Forming (ESAFORM) start_date: 2021-04-14 date_created: 2021-05-31T10:17:37Z date_updated: 2023-04-28T09:20:05Z department: - _id: '157' doi: 10.25518/esaform21.1911 keyword: - Self-piercing Riveting - Joining Technology - Rivet Geometry - Rivet Material - High Nitrogen Steel - Joint Strength language: - iso: eng quality_controlled: '1' status: public title: Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel type: conference user_id: '38131' year: '2021' ... --- _id: '21436' abstract: - lang: eng text: Ultrasonic wire bonding is a solid-state joining process, used in the electronics industry to form electrical connections, e.g. to connect electrical terminals within semiconductor modules. Many process parameters affect the bond strength, such like the bond normal force, ultrasonic power, wire material and bonding frequency. Today, process design, development, and optimization is most likely based on the knowledge of process engineers and is mainly performed by experimental testing. In this contribution, a newly developed simulation tool is presented, to reduce time and costs and efficiently determine optimized process parameter. Based on a co-simulation of MATLAB and ANSYS, the different physical phenomena of the wire bonding process are considered using finite element simulation for the complex plastic deformation of the wire and reduced order models for the transient dynamics of the transducer, wire, substrate and bond formation. The model parameters such as the coefficients of friction between bond tool and wire and between wire and substrate were determined for aluminium and copper wire in experiments with a test rig specially developed for the requirements of heavy wire bonding. To reduce simulation time, for the finite element simulation a restart analysis and high performance computing is utilized. Detailed analysis of the bond formation showed, that the normal pressure distribution in the contact between wire and substrate has high impact on bond formation and distribution of welded areas in the contact area. author: - first_name: Reinhard full_name: Schemmel, Reinhard id: '28647' last_name: Schemmel - first_name: Viktor full_name: Krieger, Viktor last_name: Krieger - first_name: Tobias full_name: Hemsel, Tobias id: '210' last_name: Hemsel - first_name: Walter full_name: Sextro, Walter id: '21220' last_name: Sextro citation: ama: Schemmel R, Krieger V, Hemsel T, Sextro W. Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization. Microelectronics Reliability. 2021;119:114077. doi:https://doi.org/10.1016/j.microrel.2021.114077 apa: Schemmel, R., Krieger, V., Hemsel, T., & Sextro, W. (2021). Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization. Microelectronics Reliability, 119, 114077. https://doi.org/10.1016/j.microrel.2021.114077 bibtex: '@article{Schemmel_Krieger_Hemsel_Sextro_2021, title={Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization}, volume={119}, DOI={https://doi.org/10.1016/j.microrel.2021.114077}, journal={Microelectronics Reliability}, author={Schemmel, Reinhard and Krieger, Viktor and Hemsel, Tobias and Sextro, Walter}, year={2021}, pages={114077} }' chicago: 'Schemmel, Reinhard, Viktor Krieger, Tobias Hemsel, and Walter Sextro. “Co-Simulation of MATLAB and ANSYS for Ultrasonic Wire Bonding Process Optimization.” Microelectronics Reliability 119 (2021): 114077. https://doi.org/10.1016/j.microrel.2021.114077.' ieee: 'R. Schemmel, V. Krieger, T. Hemsel, and W. Sextro, “Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization,” Microelectronics Reliability, vol. 119, p. 114077, 2021, doi: https://doi.org/10.1016/j.microrel.2021.114077.' mla: Schemmel, Reinhard, et al. “Co-Simulation of MATLAB and ANSYS for Ultrasonic Wire Bonding Process Optimization.” Microelectronics Reliability, vol. 119, 2021, p. 114077, doi:https://doi.org/10.1016/j.microrel.2021.114077. short: R. Schemmel, V. Krieger, T. Hemsel, W. Sextro, Microelectronics Reliability 119 (2021) 114077. date_created: 2021-03-10T09:37:02Z date_updated: 2023-09-21T14:15:33Z department: - _id: '151' doi: https://doi.org/10.1016/j.microrel.2021.114077 intvolume: ' 119' keyword: - Ultrasonic heavy wire bonding - Co-simulation - ANSYS - MATLAB - Process optimization - Friction coefficient - Copper-copper - Aluminium-copper language: - iso: eng page: '114077' publication: Microelectronics Reliability publication_identifier: issn: - 0026-2714 publication_status: published quality_controlled: '1' status: public title: Co-simulation of MATLAB and ANSYS for ultrasonic wire bonding process optimization type: journal_article user_id: '210' volume: 119 year: '2021' ... --- _id: '46318' abstract: - lang: eng text: 'Multi-objective (MO) optimization, i.e., the simultaneous optimization of multiple conflicting objectives, is gaining more and more attention in various research areas, such as evolutionary computation, machine learning (e.g., (hyper-)parameter optimization), or logistics (e.g., vehicle routing). Many works in this domain mention the structural problem property of multimodality as a challenge from two classical perspectives: (1) finding all globally optimal solution sets, and (2) avoiding to get trapped in local optima. Interestingly, these streams seem to transfer many traditional concepts of single-objective (SO) optimization into claims, assumptions, or even terminology regarding the MO domain, but mostly neglect the understanding of the structural properties as well as the algorithmic search behavior on a problem’s landscape. However, some recent works counteract this trend, by investigating the fundamentals and characteristics of MO problems using new visualization techniques and gaining surprising insights. Using these visual insights, this work proposes a step towards a unified terminology to capture multimodality and locality in a broader way than it is usually done. This enables us to investigate current research activities in multimodal continuous MO optimization and to highlight new implications and promising research directions for the design of benchmark suites, the discovery of MO landscape features, the development of new MO (or even SO) optimization algorithms, and performance indicators. For all these topics, we provide a review of ideas and methods but also an outlook on future challenges, research potential and perspectives that result from recent developments.' author: - first_name: Christian full_name: Grimme, Christian last_name: Grimme - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Pelin full_name: Aspar, Pelin last_name: Aspar - first_name: Heike full_name: Trautmann, Heike id: '100740' last_name: Trautmann orcid: 0000-0002-9788-8282 - first_name: Mike full_name: Preuss, Mike last_name: Preuss - first_name: André H. full_name: Deutz, André H. last_name: Deutz - first_name: Hao full_name: Wang, Hao last_name: Wang - first_name: Michael full_name: Emmerich, Michael last_name: Emmerich citation: ama: 'Grimme C, Kerschke P, Aspar P, et al. Peeking beyond peaks: Challenges and research potentials of continuous multimodal multi-objective optimization. Computers & Operations Research. 2021;136:105489. doi:https://doi.org/10.1016/j.cor.2021.105489' apa: 'Grimme, C., Kerschke, P., Aspar, P., Trautmann, H., Preuss, M., Deutz, A. H., Wang, H., & Emmerich, M. (2021). Peeking beyond peaks: Challenges and research potentials of continuous multimodal multi-objective optimization. Computers & Operations Research, 136, 105489. https://doi.org/10.1016/j.cor.2021.105489' bibtex: '@article{Grimme_Kerschke_Aspar_Trautmann_Preuss_Deutz_Wang_Emmerich_2021, title={Peeking beyond peaks: Challenges and research potentials of continuous multimodal multi-objective optimization}, volume={136}, DOI={https://doi.org/10.1016/j.cor.2021.105489}, journal={Computers & Operations Research}, author={Grimme, Christian and Kerschke, Pascal and Aspar, Pelin and Trautmann, Heike and Preuss, Mike and Deutz, André H. and Wang, Hao and Emmerich, Michael}, year={2021}, pages={105489} }' chicago: 'Grimme, Christian, Pascal Kerschke, Pelin Aspar, Heike Trautmann, Mike Preuss, André H. Deutz, Hao Wang, and Michael Emmerich. “Peeking beyond Peaks: Challenges and Research Potentials of Continuous Multimodal Multi-Objective Optimization.” Computers & Operations Research 136 (2021): 105489. https://doi.org/10.1016/j.cor.2021.105489.' ieee: 'C. Grimme et al., “Peeking beyond peaks: Challenges and research potentials of continuous multimodal multi-objective optimization,” Computers & Operations Research, vol. 136, p. 105489, 2021, doi: https://doi.org/10.1016/j.cor.2021.105489.' mla: 'Grimme, Christian, et al. “Peeking beyond Peaks: Challenges and Research Potentials of Continuous Multimodal Multi-Objective Optimization.” Computers & Operations Research, vol. 136, 2021, p. 105489, doi:https://doi.org/10.1016/j.cor.2021.105489.' short: C. Grimme, P. Kerschke, P. Aspar, H. Trautmann, M. Preuss, A.H. Deutz, H. Wang, M. Emmerich, Computers & Operations Research 136 (2021) 105489. date_created: 2023-08-04T07:28:34Z date_updated: 2023-10-16T12:58:42Z department: - _id: '34' - _id: '819' doi: https://doi.org/10.1016/j.cor.2021.105489 intvolume: ' 136' keyword: - Multimodal optimization - Multi-objective continuous optimization - Landscape analysis - Visualization - Benchmarking - Theory - Algorithms language: - iso: eng page: '105489' publication: Computers & Operations Research publication_identifier: issn: - 0305-0548 status: public title: 'Peeking beyond peaks: Challenges and research potentials of continuous multimodal multi-objective optimization' type: journal_article user_id: '15504' volume: 136 year: '2021' ... --- _id: '48853' abstract: - lang: eng text: In practise, it is often desirable to provide the decision-maker with a rich set of diverse solutions of decent quality instead of just a single solution. In this paper we study evolutionary diversity optimization for the knapsack problem (KP). Our goal is to evolve a population of solutions that all have a profit of at least (1 - {$ϵ$}) {$\cdot$} OPT, where OPT is the value of an optimal solution. Furthermore, they should differ in structure with respect to an entropy-based diversity measure. To this end we propose a simple ({$\mu$} + 1)-EA with initial approximate solutions calculated by a well-known FPTAS for the KP. We investigate the effect of different standard mutation operators and introduce biased mutation and crossover which puts strong probability on flipping bits of low and/or high frequency within the population. An experimental study on different instances and settings shows that the proposed mutation operators in most cases perform slightly inferior in the long term, but show strong benefits if the number of function evaluations is severely limited. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Aneta full_name: Neumann, Aneta last_name: Neumann - first_name: Frank full_name: Neumann, Frank last_name: Neumann citation: ama: 'Bossek J, Neumann A, Neumann F. Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’21. Association for Computing Machinery; 2021:556–564. doi:10.1145/3449639.3459364' apa: Bossek, J., Neumann, A., & Neumann, F. (2021). Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms. Proceedings of the Genetic and Evolutionary Computation Conference, 556–564. https://doi.org/10.1145/3449639.3459364 bibtex: '@inproceedings{Bossek_Neumann_Neumann_2021, place={New York, NY, USA}, series={GECCO ’21}, title={Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms}, DOI={10.1145/3449639.3459364}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Neumann, Aneta and Neumann, Frank}, year={2021}, pages={556–564}, collection={GECCO ’21} }' chicago: 'Bossek, Jakob, Aneta Neumann, and Frank Neumann. “Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms.” In Proceedings of the Genetic and Evolutionary Computation Conference, 556–564. GECCO ’21. New York, NY, USA: Association for Computing Machinery, 2021. https://doi.org/10.1145/3449639.3459364.' ieee: 'J. Bossek, A. Neumann, and F. Neumann, “Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2021, pp. 556–564, doi: 10.1145/3449639.3459364.' mla: Bossek, Jakob, et al. “Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2021, pp. 556–564, doi:10.1145/3449639.3459364. short: 'J. Bossek, A. Neumann, F. Neumann, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2021, pp. 556–564.' date_created: 2023-11-14T15:58:54Z date_updated: 2023-12-13T10:45:22Z department: - _id: '819' doi: 10.1145/3449639.3459364 extern: '1' keyword: - evolutionary algorithms - evolutionary diversity optimization - knapsack problem - tailored operators language: - iso: eng page: 556–564 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-8350-9 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’21 status: public title: Breeding Diverse Packings for the Knapsack Problem by Means of Diversity-Tailored Evolutionary Algorithms type: conference user_id: '102979' year: '2021' ... --- _id: '48860' abstract: - lang: eng text: In the area of evolutionary computation the calculation of diverse sets of high-quality solutions to a given optimization problem has gained momentum in recent years under the term evolutionary diversity optimization. Theoretical insights into the working principles of baseline evolutionary algorithms for diversity optimization are still rare. In this paper we study the well-known Minimum Spanning Tree problem (MST) in the context of diversity optimization where population diversity is measured by the sum of pairwise edge overlaps. Theoretical results provide insights into the fitness landscape of the MST diversity optimization problem pointing out that even for a population of {$\mu$} = 2 fitness plateaus (of constant length) can be reached, but nevertheless diverse sets can be calculated in polynomial time. We supplement our theoretical results with a series of experiments for the unconstrained and constraint case where all solutions need to fulfill a minimal quality threshold. Our results show that a simple ({$\mu$} + 1)-EA can effectively compute a diversified population of spanning trees of high quality. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Frank full_name: Neumann, Frank last_name: Neumann citation: ama: 'Bossek J, Neumann F. Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’21. Association for Computing Machinery; 2021:198–206. doi:10.1145/3449639.3459363' apa: Bossek, J., & Neumann, F. (2021). Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem. Proceedings of the Genetic and Evolutionary Computation Conference, 198–206. https://doi.org/10.1145/3449639.3459363 bibtex: '@inproceedings{Bossek_Neumann_2021, place={New York, NY, USA}, series={GECCO ’21}, title={Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem}, DOI={10.1145/3449639.3459363}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Neumann, Frank}, year={2021}, pages={198–206}, collection={GECCO ’21} }' chicago: 'Bossek, Jakob, and Frank Neumann. “Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem.” In Proceedings of the Genetic and Evolutionary Computation Conference, 198–206. GECCO ’21. New York, NY, USA: Association for Computing Machinery, 2021. https://doi.org/10.1145/3449639.3459363.' ieee: 'J. Bossek and F. Neumann, “Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2021, pp. 198–206, doi: 10.1145/3449639.3459363.' mla: Bossek, Jakob, and Frank Neumann. “Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2021, pp. 198–206, doi:10.1145/3449639.3459363. short: 'J. Bossek, F. Neumann, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2021, pp. 198–206.' date_created: 2023-11-14T15:58:55Z date_updated: 2023-12-13T10:45:37Z department: - _id: '819' doi: 10.1145/3449639.3459363 extern: '1' keyword: - evolutionary algorithms - evolutionary diversity optimization - minimum spanning tree - runtime analysis language: - iso: eng page: 198–206 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-8350-9 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’21 status: public title: Evolutionary Diversity Optimization and the Minimum Spanning Tree Problem type: conference user_id: '102979' year: '2021' ... --- _id: '48854' abstract: - lang: eng text: We contribute to the theoretical understanding of randomized search heuristics for dynamic problems. We consider the classical vertex coloring problem on graphs and investigate the dynamic setting where edges are added to the current graph. We then analyze the expected time for randomized search heuristics to recompute high quality solutions. The (1+1) Evolutionary Algorithm and RLS operate in a setting where the number of colors is bounded and we are minimizing the number of conflicts. Iterated local search algorithms use an unbounded color palette and aim to use the smallest colors and, consequently, the smallest number of colors. We identify classes of bipartite graphs where reoptimization is as hard as or even harder than optimization from scratch, i.e., starting with a random initialization. Even adding a single edge can lead to hard symmetry problems. However, graph classes that are hard for one algorithm turn out to be easy for others. In most cases our bounds show that reoptimization is faster than optimizing from scratch. We further show that tailoring mutation operators to parts of the graph where changes have occurred can significantly reduce the expected reoptimization time. In most settings the expected reoptimization time for such tailored algorithms is linear in the number of added edges. However, tailored algorithms cannot prevent exponential times in settings where the original algorithm is inefficient. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Frank full_name: Neumann, Frank last_name: Neumann - first_name: Pan full_name: Peng, Pan last_name: Peng - first_name: Dirk full_name: Sudholt, Dirk last_name: Sudholt citation: ama: Bossek J, Neumann F, Peng P, Sudholt D. Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem. Algorithmica. 2021;83(10):3148–3179. doi:10.1007/s00453-021-00838-3 apa: Bossek, J., Neumann, F., Peng, P., & Sudholt, D. (2021). Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem. Algorithmica, 83(10), 3148–3179. https://doi.org/10.1007/s00453-021-00838-3 bibtex: '@article{Bossek_Neumann_Peng_Sudholt_2021, title={Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem}, volume={83}, DOI={10.1007/s00453-021-00838-3}, number={10}, journal={Algorithmica}, author={Bossek, Jakob and Neumann, Frank and Peng, Pan and Sudholt, Dirk}, year={2021}, pages={3148–3179} }' chicago: 'Bossek, Jakob, Frank Neumann, Pan Peng, and Dirk Sudholt. “Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem.” Algorithmica 83, no. 10 (2021): 3148–3179. https://doi.org/10.1007/s00453-021-00838-3.' ieee: 'J. Bossek, F. Neumann, P. Peng, and D. Sudholt, “Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem,” Algorithmica, vol. 83, no. 10, pp. 3148–3179, 2021, doi: 10.1007/s00453-021-00838-3.' mla: Bossek, Jakob, et al. “Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem.” Algorithmica, vol. 83, no. 10, 2021, pp. 3148–3179, doi:10.1007/s00453-021-00838-3. short: J. Bossek, F. Neumann, P. Peng, D. Sudholt, Algorithmica 83 (2021) 3148–3179. date_created: 2023-11-14T15:58:54Z date_updated: 2023-12-13T10:51:34Z department: - _id: '819' doi: 10.1007/s00453-021-00838-3 intvolume: ' 83' issue: '10' keyword: - Dynamic optimization - Evolutionary algorithms - Running time analysis language: - iso: eng page: 3148–3179 publication: Algorithmica publication_identifier: issn: - 0178-4617 status: public title: Time Complexity Analysis of Randomized Search Heuristics for the Dynamic Graph Coloring Problem type: journal_article user_id: '102979' volume: 83 year: '2021' ... --- _id: '19609' abstract: - lang: eng text: "Modern services comprise interconnected components,\r\ne.g., microservices in a service mesh, that can scale and\r\nrun on multiple nodes across the network on demand. To process\r\nincoming traffic, service components have to be instantiated and\r\ntraffic assigned to these instances, taking capacities and changing\r\ndemands into account. This challenge is usually solved with\r\ncustom approaches designed by experts. While this typically\r\nworks well for the considered scenario, the models often rely\r\non unrealistic assumptions or on knowledge that is not available\r\nin practice (e.g., a priori knowledge).\r\n\r\nWe propose a novel deep reinforcement learning approach that\r\nlearns how to best coordinate services and is geared towards\r\nrealistic assumptions. It interacts with the network and relies on\r\navailable, possibly delayed monitoring information. Rather than\r\ndefining a complex model or an algorithm how to achieve an\r\nobjective, our model-free approach adapts to various objectives\r\nand traffic patterns. An agent is trained offline without expert\r\nknowledge and then applied online with minimal overhead. Compared\r\nto a state-of-the-art heuristic, it significantly improves flow\r\nthroughput and overall network utility on real-world network\r\ntopologies and traffic traces. It also learns to optimize different\r\nobjectives, generalizes to scenarios with unseen, stochastic traffic\r\npatterns, and scales to large real-world networks." author: - first_name: Stefan Balthasar full_name: Schneider, Stefan Balthasar id: '35343' last_name: Schneider orcid: 0000-0001-8210-4011 - first_name: Adnan full_name: Manzoor, Adnan last_name: Manzoor - first_name: Haydar full_name: Qarawlus, Haydar last_name: Qarawlus - first_name: Rafael full_name: Schellenberg, Rafael last_name: Schellenberg - first_name: Holger full_name: Karl, Holger id: '126' last_name: Karl - first_name: Ramin full_name: Khalili, Ramin last_name: Khalili - first_name: Artur full_name: Hecker, Artur last_name: Hecker citation: ama: 'Schneider SB, Manzoor A, Qarawlus H, et al. Self-Driving Network and Service Coordination Using Deep Reinforcement Learning. In: IEEE International Conference on Network and Service Management (CNSM). IEEE; 2020.' apa: Schneider, S. B., Manzoor, A., Qarawlus, H., Schellenberg, R., Karl, H., Khalili, R., & Hecker, A. (2020). Self-Driving Network and Service Coordination Using Deep Reinforcement Learning. In IEEE International Conference on Network and Service Management (CNSM). IEEE. bibtex: '@inproceedings{Schneider_Manzoor_Qarawlus_Schellenberg_Karl_Khalili_Hecker_2020, title={Self-Driving Network and Service Coordination Using Deep Reinforcement Learning}, booktitle={IEEE International Conference on Network and Service Management (CNSM)}, publisher={IEEE}, author={Schneider, Stefan Balthasar and Manzoor, Adnan and Qarawlus, Haydar and Schellenberg, Rafael and Karl, Holger and Khalili, Ramin and Hecker, Artur}, year={2020} }' chicago: Schneider, Stefan Balthasar, Adnan Manzoor, Haydar Qarawlus, Rafael Schellenberg, Holger Karl, Ramin Khalili, and Artur Hecker. “Self-Driving Network and Service Coordination Using Deep Reinforcement Learning.” In IEEE International Conference on Network and Service Management (CNSM). IEEE, 2020. ieee: S. B. Schneider et al., “Self-Driving Network and Service Coordination Using Deep Reinforcement Learning,” in IEEE International Conference on Network and Service Management (CNSM), 2020. mla: Schneider, Stefan Balthasar, et al. “Self-Driving Network and Service Coordination Using Deep Reinforcement Learning.” IEEE International Conference on Network and Service Management (CNSM), IEEE, 2020. short: 'S.B. Schneider, A. Manzoor, H. Qarawlus, R. Schellenberg, H. Karl, R. Khalili, A. Hecker, in: IEEE International Conference on Network and Service Management (CNSM), IEEE, 2020.' date_created: 2020-09-22T06:28:22Z date_updated: 2022-01-06T06:54:08Z ddc: - '006' department: - _id: '75' file: - access_level: open_access content_type: application/pdf creator: stschn date_created: 2020-09-22T06:29:16Z date_updated: 2020-09-22T06:36:00Z file_id: '19610' file_name: ris_with_copyright.pdf file_size: 642999 relation: main_file file_date_updated: 2020-09-22T06:36:00Z has_accepted_license: '1' keyword: - self-driving networks - self-learning - network coordination - service coordination - reinforcement learning - deep learning - nfv language: - iso: eng oa: '1' project: - _id: '1' name: SFB 901 - _id: '4' name: SFB 901 - Project Area C - _id: '16' name: SFB 901 - Subproject C4 publication: IEEE International Conference on Network and Service Management (CNSM) publisher: IEEE status: public title: Self-Driving Network and Service Coordination Using Deep Reinforcement Learning type: conference user_id: '35343' year: '2020' ... --- _id: '19976' abstract: - lang: eng text: The aim to reduce pollutant emission has led to a trend towards lightweight construction in car body development during the last years. As a consequence of the resulting need for multi-material design, mechanical joining technologies become increasingly important. Mechanical joining allows for the combination of dissimilar materials, while thermic joining techniques reach their limits. Self-piercing riveting enables the joining of dissimilar materials by using semi-tubular rivets as mechanical fasteners. The rivet production, however, is costly and time-consuming, as the rivets generally have to be hardened, tempered and coated after forming, in order to achieve an adequate strength and corrosion resistance. A promising approach to improve the efficiency of the rivet manufacturing is the use of high-strength high nitrogen steel as rivet material because these additional process steps would not be necessary anymore. As a result of the comparatively high nitrogen content, such steels have various beneficial properties like higher strength, good ductility and improved corrosion resistance. By cold bulk forming of high nitrogen steels high-strength parts can be manufactured due to the strengthening which is caused by the high strain hardening. However, high tool loads thereby have to be expected and are a major challenge during the production process. Consequently, there is a need for appropriate forming strategies. This paper presents key aspects concerning the process design for the manufacturing of semi-tubular self-piercing rivets made of high-strength steel. The aim is to produce the rivets in several forming stages without intermediate heat treatment between the single stages. Due to the high strain hardening of the material, a two stage forming concept will be investigated. Cup-backward extrusion is chosen as the first process step in order to form the rivet shank without forming the rivet foot. Thus, the strain hardening effects in the area of the rivet foot are minimized and the tool loads during the following process step can be reduced. During the second and final forming stage the detailed geometry of the rivet foot and the rivet head is formed. In this context, the effect of different variations, for example concerning the final geometry of the rivet foot, on the tool load is investigated using multistage numerical analysis. Furthermore, the influence of the process temperature on occurring stresses is analysed. Based on the results of the investigations, an adequate forming strategy and a tool concept for the manufacturing of semi-tubular self-piercing rivets made of high-strength steel are presented. citation: ama: Kuball C-M, Uhe B, Meschut G, Merklein M, eds. Process Design for the Forming of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel. Vol 50.; 2020:280-285. doi:10.1016/j.promfg.2020.08.052 apa: Kuball, C.-M., Uhe, B., Meschut, G., & Merklein, M. (Eds.). (2020). Process design for the forming of semi-tubular self-piercing rivets made of high nitrogen steel (Vol. 50, pp. 280–285). https://doi.org/10.1016/j.promfg.2020.08.052 bibtex: '@book{Kuball_Uhe_Meschut_Merklein_2020, series={Procedia Manufacturing}, title={Process design for the forming of semi-tubular self-piercing rivets made of high nitrogen steel}, volume={50}, DOI={10.1016/j.promfg.2020.08.052}, year={2020}, pages={280–285}, collection={Procedia Manufacturing} }' chicago: Kuball, Clara-Maria, Benedikt Uhe, Gerson Meschut, and Marion Merklein, eds. Process Design for the Forming of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel. Vol. 50. Procedia Manufacturing, 2020. https://doi.org/10.1016/j.promfg.2020.08.052. ieee: C.-M. Kuball, B. Uhe, G. Meschut, and M. Merklein, Eds., Process design for the forming of semi-tubular self-piercing rivets made of high nitrogen steel, vol. 50. 2020, pp. 280–285. mla: Kuball, Clara-Maria, et al., editors. Process Design for the Forming of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel. Vol. 50, 2020, pp. 280–85, doi:10.1016/j.promfg.2020.08.052. short: C.-M. Kuball, B. Uhe, G. Meschut, M. Merklein, eds., Process Design for the Forming of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel, 2020. date_created: 2020-10-12T08:30:08Z date_updated: 2022-01-06T06:54:17Z department: - _id: '157' doi: 10.1016/j.promfg.2020.08.052 editor: - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 - first_name: Marion full_name: Merklein, Marion last_name: Merklein intvolume: ' 50' keyword: - high nitrogen steel - self-piercing riveting - joining by forming - bulk forming - tool design language: - iso: eng page: 280-285 publication_status: published quality_controlled: '1' series_title: Procedia Manufacturing status: public title: Process design for the forming of semi-tubular self-piercing rivets made of high nitrogen steel type: conference_editor user_id: '38131' volume: 50 year: '2020' ... --- _id: '17370' abstract: - lang: eng text: " We consider a natural extension to the metric uncapacitated Facility Location Problem (FLP) in which requests ask for different commodities out of a finite set \\( S \\) of commodities.\r\n Ravi and Sinha (SODA 2004) introduced the model as the \\emph{Multi-Commodity Facility Location Problem} (MFLP) and considered it an offline optimization problem.\r\n The model itself is similar to the FLP: i.e., requests are located at points of a finite metric space and the task of an algorithm is to construct facilities and assign requests to facilities while minimizing the construction cost and the sum over all assignment distances.\r\n \ In addition, requests and facilities are heterogeneous; they request or offer multiple commodities out of $S$.\r\n A request has to be connected to a set of facilities jointly offering the commodities demanded by it.\r\n In comparison to the FLP, an algorithm has to decide not only if and where to place facilities, but also which commodities to offer at each.\r\n\r\n To the best of our knowledge we are the first to study the problem in its online variant in which requests, their positions and their commodities are not known beforehand but revealed over time.\r\n We present results regarding the competitive ratio.\r\n On the one hand, we show that heterogeneity influences the competitive ratio by developing a lower bound on the competitive ratio for any randomized online algorithm of \\( \\Omega ( \\sqrt{|S|} + \\frac{\\log n}{\\log \\log n} ) \\) that already holds for simple line metrics.\r\n Here, \\( n \\) is the number of requests.\r\n \ On the other side, we establish a deterministic \\( \\mathcal{O}(\\sqrt{|S|} \\cdot \\log n) \\)-competitive algorithm and a randomized \\( \\mathcal{O}(\\sqrt{|S|} \\cdot \\frac{\\log n}{\\log \\log n} ) \\)-competitive algorithm.\r\n Further, we show that when considering a more special class of cost functions for the construction cost of a facility, the competitive ratio decreases given by our deterministic algorithm depending on the function." author: - first_name: Jannik full_name: Castenow, Jannik id: '38705' last_name: Castenow - first_name: Björn full_name: Feldkord, Björn id: '22704' last_name: Feldkord - first_name: Till full_name: Knollmann, Till id: '39241' last_name: Knollmann orcid: 0000-0003-2014-4696 - first_name: Manuel full_name: Malatyali, Manuel last_name: Malatyali - first_name: Friedhelm full_name: Meyer auf der Heide, Friedhelm id: '15523' last_name: Meyer auf der Heide citation: ama: 'Castenow J, Feldkord B, Knollmann T, Malatyali M, Meyer auf der Heide F. The Online Multi-Commodity Facility Location Problem. In: Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures. ; 2020. doi:10.1145/3350755.3400281' apa: Castenow, J., Feldkord, B., Knollmann, T., Malatyali, M., & Meyer auf der Heide, F. (2020). The Online Multi-Commodity Facility Location Problem. In Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures. https://doi.org/10.1145/3350755.3400281 bibtex: '@inproceedings{Castenow_Feldkord_Knollmann_Malatyali_Meyer auf der Heide_2020, title={The Online Multi-Commodity Facility Location Problem}, DOI={10.1145/3350755.3400281}, booktitle={Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures}, author={Castenow, Jannik and Feldkord, Björn and Knollmann, Till and Malatyali, Manuel and Meyer auf der Heide, Friedhelm}, year={2020} }' chicago: Castenow, Jannik, Björn Feldkord, Till Knollmann, Manuel Malatyali, and Friedhelm Meyer auf der Heide. “The Online Multi-Commodity Facility Location Problem.” In Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures, 2020. https://doi.org/10.1145/3350755.3400281. ieee: J. Castenow, B. Feldkord, T. Knollmann, M. Malatyali, and F. Meyer auf der Heide, “The Online Multi-Commodity Facility Location Problem,” in Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures, 2020. mla: Castenow, Jannik, et al. “The Online Multi-Commodity Facility Location Problem.” Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures, 2020, doi:10.1145/3350755.3400281. short: 'J. Castenow, B. Feldkord, T. Knollmann, M. Malatyali, F. Meyer auf der Heide, in: Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures, 2020.' date_created: 2020-07-14T07:53:20Z date_updated: 2022-01-06T06:53:10Z ddc: - '000' department: - _id: '63' doi: 10.1145/3350755.3400281 external_id: arxiv: - '2005.08391' file: - access_level: closed content_type: application/pdf creator: tillk date_created: 2020-07-14T07:56:52Z date_updated: 2020-07-14T07:56:52Z file_id: '17373' file_name: 3350755.3400281.pdf file_size: 1271416 relation: main_file success: 1 file_date_updated: 2020-07-14T07:56:52Z has_accepted_license: '1' keyword: - Online Multi-Commodity Facility Location - Competitive Ratio - Online Optimization - Facility Location Problem language: - iso: eng project: - _id: '1' name: SFB 901 - _id: '2' name: SFB 901 - Project Area A - _id: '5' name: SFB 901 - Subproject A1 publication: Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures publication_identifier: isbn: - '9781450369350' publication_status: published status: public title: The Online Multi-Commodity Facility Location Problem type: conference user_id: '39241' year: '2020' ... --- _id: '20143' author: - first_name: Mortaza full_name: Otroshi, Mortaza id: '71269' last_name: Otroshi orcid: 0000-0002-8652-9209 - first_name: Moritz full_name: Rossel, Moritz last_name: Rossel - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: Otroshi M, Rossel M, Meschut G. Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model. Journal of Advanced Joining Processes. 2020;1. doi:10.1016/j.jajp.2020.100015 apa: Otroshi, M., Rossel, M., & Meschut, G. (2020). Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model. Journal of Advanced Joining Processes, 1. https://doi.org/10.1016/j.jajp.2020.100015 bibtex: '@article{Otroshi_Rossel_Meschut_2020, title={Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model}, volume={1}, DOI={10.1016/j.jajp.2020.100015}, journal={Journal of Advanced Joining Processes}, publisher={Elsevier}, author={Otroshi, Mortaza and Rossel, Moritz and Meschut, Gerson}, year={2020} }' chicago: Otroshi, Mortaza, Moritz Rossel, and Gerson Meschut. “Stress State Dependent Damage Modeling of Self-Pierce Riveting Process Simulation Using GISSMO Damage Model.” Journal of Advanced Joining Processes 1 (2020). https://doi.org/10.1016/j.jajp.2020.100015. ieee: 'M. Otroshi, M. Rossel, and G. Meschut, “Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model,” Journal of Advanced Joining Processes, vol. 1, 2020, doi: 10.1016/j.jajp.2020.100015.' mla: Otroshi, Mortaza, et al. “Stress State Dependent Damage Modeling of Self-Pierce Riveting Process Simulation Using GISSMO Damage Model.” Journal of Advanced Joining Processes, vol. 1, Elsevier, 2020, doi:10.1016/j.jajp.2020.100015. short: M. Otroshi, M. Rossel, G. Meschut, Journal of Advanced Joining Processes 1 (2020). date_created: 2020-10-20T14:49:15Z date_updated: 2022-04-25T07:49:50Z department: - _id: '157' doi: 10.1016/j.jajp.2020.100015 intvolume: ' 1' keyword: - Self-pierce riveting - Ductile fracture - Damage modeling - GISSMO damage model language: - iso: eng main_file_link: - open_access: '1' oa: '1' publication: Journal of Advanced Joining Processes publisher: Elsevier quality_controlled: '1' status: public title: Stress state dependent damage modeling of self-pierce riveting process simulation using GISSMO damage model type: journal_article user_id: '71269' volume: 1 year: '2020' ... --- _id: '35298' abstract: - lang: ger text: Im Artikel werden drei verschiedene Lernzugänge (kom-petenzorientiertes, ästhetisches und biographisches Lernen) vorgestellt und aus theoretischer Perspektive deren motivierender Gehalt für selbstreguliertes Lernen in Praxisphasen des Lehramtsstudiumsherausgearbeitet. Als theoretische Grund-lage dient die Selbstbestimmungstheorie als zentrale motivationale Theorie zur Erklärung selbstbestimmten Handelns. - lang: eng text: The article addresses how motivational learning approaches (competency-oriented, aesthetic and biographical) can contribute to the professionalization of preservice teachers during a long-term internship. As a theoretical basis, the self-determination theory serves as a central motivational theory for explaining self-determined action. alternative_title: - Ein Blick auf kompetenzorientiertes, ästhetisches und biographisches Lernen im Lehramtsstudium author: - first_name: Carina full_name: Caruso, Carina id: '23123' last_name: Caruso - first_name: Christine full_name: Adammek, Christine last_name: Adammek - first_name: Sabrina full_name: Bonanati, Sabrina last_name: Bonanati - first_name: Sybille full_name: Wiescholek, Sybille last_name: Wiescholek citation: ama: Caruso C, Adammek C, Bonanati S, Wiescholek S. Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen. Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion. 2020;3(1):18-33. doi:10.4119/hlz-2540 apa: Caruso, C., Adammek, C., Bonanati, S., & Wiescholek, S. (2020). Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen. Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion, 3(1), 18–33. https://doi.org/10.4119/hlz-2540 bibtex: '@article{Caruso_Adammek_Bonanati_Wiescholek_2020, title={Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen}, volume={3}, DOI={10.4119/hlz-2540}, number={1}, journal={Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion}, author={Caruso, Carina and Adammek, Christine and Bonanati, Sabrina and Wiescholek, Sybille}, year={2020}, pages={18–33} }' chicago: 'Caruso, Carina, Christine Adammek, Sabrina Bonanati, and Sybille Wiescholek. “Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen.” Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion 3, no. 1 (2020): 18–33. https://doi.org/10.4119/hlz-2540.' ieee: 'C. Caruso, C. Adammek, S. Bonanati, and S. Wiescholek, “Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen,” Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion, vol. 3, no. 1, pp. 18–33, 2020, doi: 10.4119/hlz-2540.' mla: Caruso, Carina, et al. “Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen.” Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion, vol. 3, no. 1, 2020, pp. 18–33, doi:10.4119/hlz-2540. short: C. Caruso, C. Adammek, S. Bonanati, S. Wiescholek, Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion 3 (2020) 18–33. date_created: 2023-01-05T13:58:28Z date_updated: 2023-01-06T12:18:16Z doi: 10.4119/hlz-2540 intvolume: ' 3' issue: '1' keyword: - ästhetische Forschung - Biographiearbeit - Praxissemester - Professionalisierung - selbstreguliertes Lernen - Motivation / aesthetic research - biographical work - long-term internship - profes-sionalization - self-regulated learning - motivation language: - iso: other page: 18-33 publication: Herausforderung Lehrer*innenbildung - Zeitschrift Zur Konzeption, Gestaltung Und Diskussion publication_identifier: issn: - 2625-0675 publication_status: published status: public title: Motivierende Lernzugänge als Ausgangspunkt der Professionalisierung angehender Lehrer_innen type: journal_article user_id: '86519' volume: 3 year: '2020' ... --- _id: '33866' abstract: - lang: eng text: Helhmoltz–Kirchhoff equations of motions of vortices of an incompressible fluid in the plane define a dynamics with singularities and this leads to a Zermelo navigation problem describing the ship travel in such a field where the control is the heading angle. Considering one vortex, we define a time minimization problem which can be analyzed with the technics of geometric optimal control combined with numerical simulations, the geometric frame being the extension of Randers metrics in the punctured plane, with rotational symmetry. Candidates as minimizers are parameterized thanks to the Pontryagin Maximum Principle as extremal solutions of a Hamiltonian vector field. We analyze the time minimal solution to transfer the ship between two points where during the transfer the ship can be either in a strong current region in the vicinity of the vortex or in a weak current region. The analysis is based on a micro-local classification of the extremals using mainly the integrability properties of the dynamics due to the rotational symmetry. The discussion is complex and related to the existence of an isolated extremal (Reeb) circle due to the vortex singularity. The explicit computation of cut points where the extremal curves cease to be optimal is given and the spheres are described in the case where at the initial point the current is weak. article_number: S10 author: - first_name: Bernard full_name: Bonnard, Bernard last_name: Bonnard - first_name: Olivier full_name: Cots, Olivier last_name: Cots - first_name: Boris Edgar full_name: Wembe Moafo, Boris Edgar id: '95394' last_name: Wembe Moafo citation: ama: 'Bonnard B, Cots O, Wembe Moafo BE. A Zermelo navigation problem with a vortex singularity. ESAIM: Control, Optimisation and Calculus of Variations. 2020;27. doi:10.1051/cocv/2020058' apa: 'Bonnard, B., Cots, O., & Wembe Moafo, B. E. (2020). A Zermelo navigation problem with a vortex singularity. ESAIM: Control, Optimisation and Calculus of Variations, 27, Article S10. https://doi.org/10.1051/cocv/2020058' bibtex: '@article{Bonnard_Cots_Wembe Moafo_2020, title={A Zermelo navigation problem with a vortex singularity}, volume={27}, DOI={10.1051/cocv/2020058}, number={S10}, journal={ESAIM: Control, Optimisation and Calculus of Variations}, publisher={EDP Sciences}, author={Bonnard, Bernard and Cots, Olivier and Wembe Moafo, Boris Edgar}, year={2020} }' chicago: 'Bonnard, Bernard, Olivier Cots, and Boris Edgar Wembe Moafo. “A Zermelo Navigation Problem with a Vortex Singularity.” ESAIM: Control, Optimisation and Calculus of Variations 27 (2020). https://doi.org/10.1051/cocv/2020058.' ieee: 'B. Bonnard, O. Cots, and B. E. Wembe Moafo, “A Zermelo navigation problem with a vortex singularity,” ESAIM: Control, Optimisation and Calculus of Variations, vol. 27, Art. no. S10, 2020, doi: 10.1051/cocv/2020058.' mla: 'Bonnard, Bernard, et al. “A Zermelo Navigation Problem with a Vortex Singularity.” ESAIM: Control, Optimisation and Calculus of Variations, vol. 27, S10, EDP Sciences, 2020, doi:10.1051/cocv/2020058.' short: 'B. Bonnard, O. Cots, B.E. Wembe Moafo, ESAIM: Control, Optimisation and Calculus of Variations 27 (2020).' date_created: 2022-10-24T12:51:05Z date_updated: 2023-01-16T12:09:22Z doi: 10.1051/cocv/2020058 intvolume: ' 27' keyword: - Computational Mathematics - Control and Optimization - Control and Systems Engineering language: - iso: eng publication: 'ESAIM: Control, Optimisation and Calculus of Variations' publication_identifier: issn: - 1292-8119 - 1262-3377 publication_status: published publisher: EDP Sciences status: public title: A Zermelo navigation problem with a vortex singularity type: journal_article user_id: '95394' volume: 27 year: '2020' ... --- _id: '19974' abstract: - lang: eng text: Due to the trend towards lightweight design in car body development mechanical joining technologies become increasingly important. These techniques allow for the joining of dissimilar materials and thus enable multi-material design, while thermic joining methods reach their limits. Semi-tubular self-piercing riveting is an important mechanical joining technology. The rivet production, however, is costly and time-consuming, as the process consists of several process steps including the heat treatment and coating of the rivets in order to achieve an adequate strength and corrosion resistance. The use of high nitrogen steel as rivet material leads to the possibility of reducing process steps and hence increasing the efficiency of the process. However, the high tool loads being expected due to the high strain hardening of the material are a major challenge during the rivet production. Thus, there is a need for appropriate forming strategies, such as the manufacturing of the rivets at elevated temperatures. Prior investigations led to the conclusion that forming already at 200 °C results in a distinct reduction of the yield strength. To create a deeper understanding of the forming behaviour of high nitrogen steel at elevated temperatures, compression tests were conducted in a temperature range between room temperature and 200 °C. The determined true stress – true strain curves are the basis for the further process and tool design of the rivet production. Another key factor for the rivet manufacturing at elevated temperatures is the influence of the process temperature on the tribological conditions. For this reason, ring compression tests at room temperature and 200 °C are carried out. The friction factors are determined on the basis of calibration curves resulting from the numerical analysis of the ring compression process. The investigations indicate that the friction factor at 200 °C is significantly higher compared to room temperature. This essential fact has to be taken into account for the process and tool design for the rivet production using high nitrogen steel. article_number: '100023' citation: ama: Kuball C-M, Jung R, Uhe B, Meschut G, Merklein M, eds. Influence of the Process Temperature on the Forming Behaviour and the Friction during Bulk Forming of High Nitrogen Steel. Vol 1.; 2020. doi:10.1016/j.jajp.2020.100023 apa: Kuball, C.-M., Jung, R., Uhe, B., Meschut, G., & Merklein, M. (Eds.). (2020). Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel (No. 100023; Vol. 1). https://doi.org/10.1016/j.jajp.2020.100023 bibtex: '@book{Kuball_Jung_Uhe_Meschut_Merklein_2020, series={Journal of Advanced Joining Processes}, title={Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel}, volume={1}, DOI={10.1016/j.jajp.2020.100023}, number={100023}, year={2020}, collection={Journal of Advanced Joining Processes} }' chicago: Kuball, Clara-Maria, R Jung, Benedikt Uhe, Gerson Meschut, and Marion Merklein, eds. Influence of the Process Temperature on the Forming Behaviour and the Friction during Bulk Forming of High Nitrogen Steel. Vol. 1. Journal of Advanced Joining Processes, 2020. https://doi.org/10.1016/j.jajp.2020.100023. ieee: C.-M. Kuball, R. Jung, B. Uhe, G. Meschut, and M. Merklein, Eds., Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel, vol. 1. 2020. mla: Kuball, Clara-Maria, et al., editors. Influence of the Process Temperature on the Forming Behaviour and the Friction during Bulk Forming of High Nitrogen Steel. 100023, 2020, doi:10.1016/j.jajp.2020.100023. short: C.-M. Kuball, R. Jung, B. Uhe, G. Meschut, M. Merklein, eds., Influence of the Process Temperature on the Forming Behaviour and the Friction during Bulk Forming of High Nitrogen Steel, 2020. date_created: 2020-10-12T08:23:27Z date_updated: 2023-04-28T09:19:41Z department: - _id: '157' doi: 10.1016/j.jajp.2020.100023 editor: - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: R full_name: Jung, R last_name: Jung - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 - first_name: Marion full_name: Merklein, Marion last_name: Merklein intvolume: ' 1' keyword: - High nitrogen steel - Self-piercing riveting - Joining by forming - Bulk forming - Strain hardening language: - iso: eng publication_status: published quality_controlled: '1' series_title: Journal of Advanced Joining Processes status: public title: Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel type: conference_editor user_id: '38131' volume: 1 year: '2020' ... --- _id: '19973' abstract: - lang: eng text: As a result of lightweight design, increased use is being made of high-strength steel and aluminium in car bodies. Self-piercing riveting is an established technique for joining these materials. The dissimilar properties of the two materials have led to a number of different rivet geometries in the past. Each rivet geometry fulfils the requirements of the materials within a limited range. In the present investigation, an improved rivet geometry is developed, which permits the reliable joining of two material combinations that could only be joined by two different rivet geometries up until now. Material combination 1 consists of high-strength steel on both sides, while material combination 2 comprises aluminium on the punch side and high-strength steel on the die side. The material flow and the stress and strain conditions prevailing during the joining process are analysed by means of numerical simulation. The rivet geometry is then improved step-by-step on the basis of this analysis. Finally, the improved rivet geometry is manufactured and the findings of the investigation are verified in experimental joining tests. article_type: original author: - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Marion full_name: Merklein, Marion last_name: Merklein - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: Uhe B, Kuball C-M, Merklein M, Meschut G. Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints. Production Engineering. 2020;14:417-423. doi:10.1007/s11740-020-00973-w apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2020). Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints. Production Engineering, 14, 417–423. https://doi.org/10.1007/s11740-020-00973-w bibtex: '@article{Uhe_Kuball_Merklein_Meschut_2020, title={Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints}, volume={14}, DOI={10.1007/s11740-020-00973-w}, journal={Production Engineering}, author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}, year={2020}, pages={417–423} }' chicago: 'Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut. “Improvement of a Rivet Geometry for the Self-Piercing Riveting of High-Strength Steel and Multi-Material Joints.” Production Engineering 14 (2020): 417–23. https://doi.org/10.1007/s11740-020-00973-w.' ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints,” Production Engineering, vol. 14, pp. 417–423, 2020, doi: 10.1007/s11740-020-00973-w.' mla: Uhe, Benedikt, et al. “Improvement of a Rivet Geometry for the Self-Piercing Riveting of High-Strength Steel and Multi-Material Joints.” Production Engineering, vol. 14, 2020, pp. 417–23, doi:10.1007/s11740-020-00973-w. short: B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, Production Engineering 14 (2020) 417–423. date_created: 2020-10-12T08:14:13Z date_updated: 2023-04-28T09:20:41Z department: - _id: '157' doi: 10.1007/s11740-020-00973-w intvolume: ' 14' keyword: - Self-piercing riveting - Joining technology - Rivet geometry - Multi-material design - High-strength steel - Aluminium language: - iso: eng page: 417-423 publication: Production Engineering publication_status: published quality_controlled: '1' status: public title: Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints type: journal_article user_id: '38131' volume: 14 year: '2020' ... --- _id: '46334' abstract: - lang: eng text: We build upon a recently proposed multi-objective view onto performance measurement of single-objective stochastic solvers. The trade-off between the fraction of failed runs and the mean runtime of successful runs – both to be minimized – is directly analyzed based on a study on algorithm selection of inexact state-of-the-art solvers for the famous Traveling Salesperson Problem (TSP). Moreover, we adopt the hypervolume indicator (HV) commonly used in multi-objective optimization for simultaneously assessing both conflicting objectives and investigate relations to commonly used performance indicators, both theoretically and empirically. Next to Penalized Average Runtime (PAR) and Penalized Quantile Runtime (PQR), the HV measure is used as a core concept within the construction of per-instance algorithm selection models offering interesting insights into complementary behavior of inexact TSP solvers. author: - first_name: Jakob full_name: Bossek, Jakob last_name: Bossek - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Heike full_name: Trautmann, Heike id: '100740' last_name: Trautmann orcid: 0000-0002-9788-8282 citation: ama: Bossek J, Kerschke P, Trautmann H. A multi-objective perspective on performance assessment and automated selection of single-objective optimization algorithms. Applied Soft Computing. 2020;88:105901. doi:https://doi.org/10.1016/j.asoc.2019.105901 apa: Bossek, J., Kerschke, P., & Trautmann, H. (2020). A multi-objective perspective on performance assessment and automated selection of single-objective optimization algorithms. Applied Soft Computing, 88, 105901. https://doi.org/10.1016/j.asoc.2019.105901 bibtex: '@article{Bossek_Kerschke_Trautmann_2020, title={A multi-objective perspective on performance assessment and automated selection of single-objective optimization algorithms}, volume={88}, DOI={https://doi.org/10.1016/j.asoc.2019.105901}, journal={Applied Soft Computing}, author={Bossek, Jakob and Kerschke, Pascal and Trautmann, Heike}, year={2020}, pages={105901} }' chicago: 'Bossek, Jakob, Pascal Kerschke, and Heike Trautmann. “A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms.” Applied Soft Computing 88 (2020): 105901. https://doi.org/10.1016/j.asoc.2019.105901.' ieee: 'J. Bossek, P. Kerschke, and H. Trautmann, “A multi-objective perspective on performance assessment and automated selection of single-objective optimization algorithms,” Applied Soft Computing, vol. 88, p. 105901, 2020, doi: https://doi.org/10.1016/j.asoc.2019.105901.' mla: Bossek, Jakob, et al. “A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms.” Applied Soft Computing, vol. 88, 2020, p. 105901, doi:https://doi.org/10.1016/j.asoc.2019.105901. short: J. Bossek, P. Kerschke, H. Trautmann, Applied Soft Computing 88 (2020) 105901. date_created: 2023-08-04T07:42:26Z date_updated: 2023-10-16T13:07:59Z department: - _id: '34' - _id: '819' doi: https://doi.org/10.1016/j.asoc.2019.105901 intvolume: ' 88' keyword: - Algorithm selection - Multi-objective optimization - Performance measurement - Combinatorial optimization - Traveling Salesperson Problem language: - iso: eng page: '105901' publication: Applied Soft Computing publication_identifier: issn: - 1568-4946 status: public title: A multi-objective perspective on performance assessment and automated selection of single-objective optimization algorithms type: journal_article user_id: '15504' volume: 88 year: '2020' ... --- _id: '48847' abstract: - lang: eng text: Dynamic optimization problems have gained significant attention in evolutionary computation as evolutionary algorithms (EAs) can easily adapt to changing environments. We show that EAs can solve the graph coloring problem for bipartite graphs more efficiently by using dynamic optimization. In our approach the graph instance is given incrementally such that the EA can reoptimize its coloring when a new edge introduces a conflict. We show that, when edges are inserted in a way that preserves graph connectivity, Randomized Local Search (RLS) efficiently finds a proper 2-coloring for all bipartite graphs. This includes graphs for which RLS and other EAs need exponential expected time in a static optimization scenario. We investigate different ways of building up the graph by popular graph traversals such as breadth-first-search and depth-first-search and analyse the resulting runtime behavior. We further show that offspring populations (e. g. a (1 + {$\lambda$}) RLS) lead to an exponential speedup in {$\lambda$}. Finally, an island model using 3 islands succeeds in an optimal time of {$\Theta$}(m) on every m-edge bipartite graph, outperforming offspring populations. This is the first example where an island model guarantees a speedup that is not bounded in the number of islands. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Frank full_name: Neumann, Frank last_name: Neumann - first_name: Pan full_name: Peng, Pan last_name: Peng - first_name: Dirk full_name: Sudholt, Dirk last_name: Sudholt citation: ama: 'Bossek J, Neumann F, Peng P, Sudholt D. More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’20. Association for Computing Machinery; 2020:1277–1285. doi:10.1145/3377930.3390174' apa: Bossek, J., Neumann, F., Peng, P., & Sudholt, D. (2020). More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization. Proceedings of the Genetic and Evolutionary Computation Conference, 1277–1285. https://doi.org/10.1145/3377930.3390174 bibtex: '@inproceedings{Bossek_Neumann_Peng_Sudholt_2020, place={New York, NY, USA}, series={GECCO ’20}, title={More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization}, DOI={10.1145/3377930.3390174}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Neumann, Frank and Peng, Pan and Sudholt, Dirk}, year={2020}, pages={1277–1285}, collection={GECCO ’20} }' chicago: 'Bossek, Jakob, Frank Neumann, Pan Peng, and Dirk Sudholt. “More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization.” In Proceedings of the Genetic and Evolutionary Computation Conference, 1277–1285. GECCO ’20. New York, NY, USA: Association for Computing Machinery, 2020. https://doi.org/10.1145/3377930.3390174.' ieee: 'J. Bossek, F. Neumann, P. Peng, and D. Sudholt, “More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2020, pp. 1277–1285, doi: 10.1145/3377930.3390174.' mla: Bossek, Jakob, et al. “More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2020, pp. 1277–1285, doi:10.1145/3377930.3390174. short: 'J. Bossek, F. Neumann, P. Peng, D. Sudholt, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2020, pp. 1277–1285.' date_created: 2023-11-14T15:58:53Z date_updated: 2023-12-13T10:43:41Z department: - _id: '819' doi: 10.1145/3377930.3390174 extern: '1' keyword: - dynamic optimization - evolutionary algorithms - running time analysis - theory language: - iso: eng page: 1277–1285 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-7128-5 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’20 status: public title: More Effective Randomized Search Heuristics for Graph Coloring through Dynamic Optimization type: conference user_id: '102979' year: '2020' ... --- _id: '48849' abstract: - lang: eng text: One-shot optimization tasks require to determine the set of solution candidates prior to their evaluation, i.e., without possibility for adaptive sampling. We consider two variants, classic one-shot optimization (where our aim is to find at least one solution of high quality) and one-shot regression (where the goal is to fit a model that resembles the true problem as well as possible). For both tasks it seems intuitive that well-distributed samples should perform better than uniform or grid-based samples, since they show a better coverage of the decision space. In practice, quasi-random designs such as Latin Hypercube Samples and low-discrepancy point sets are indeed very commonly used designs for one-shot optimization tasks. We study in this work how well low star discrepancy correlates with performance in one-shot optimization. Our results confirm an advantage of low-discrepancy designs, but also indicate the correlation between discrepancy values and overall performance is rather weak. We then demonstrate that commonly used designs may be far from optimal. More precisely, we evolve 24 very specific designs that each achieve good performance on one of our benchmark problems. Interestingly, we find that these specifically designed samples yield surprisingly good performance across the whole benchmark set. Our results therefore give strong indication that significant performance gains over state-of-the-art one-shot sampling techniques are possible, and that evolutionary algorithms can be an efficient means to evolve these. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Carola full_name: Doerr, Carola last_name: Doerr - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Aneta full_name: Neumann, Aneta last_name: Neumann - first_name: Frank full_name: Neumann, Frank last_name: Neumann citation: ama: 'Bossek J, Doerr C, Kerschke P, Neumann A, Neumann F. Evolving Sampling Strategies for One-Shot Optimization Tasks. In: Parallel Problem Solving from Nature (PPSN XVI). Springer-Verlag; 2020:111–124. doi:10.1007/978-3-030-58112-1_8' apa: Bossek, J., Doerr, C., Kerschke, P., Neumann, A., & Neumann, F. (2020). Evolving Sampling Strategies for One-Shot Optimization Tasks. Parallel Problem Solving from Nature (PPSN XVI), 111–124. https://doi.org/10.1007/978-3-030-58112-1_8 bibtex: '@inproceedings{Bossek_Doerr_Kerschke_Neumann_Neumann_2020, place={Berlin, Heidelberg}, title={Evolving Sampling Strategies for One-Shot Optimization Tasks}, DOI={10.1007/978-3-030-58112-1_8}, booktitle={Parallel Problem Solving from Nature (PPSN XVI)}, publisher={Springer-Verlag}, author={Bossek, Jakob and Doerr, Carola and Kerschke, Pascal and Neumann, Aneta and Neumann, Frank}, year={2020}, pages={111–124} }' chicago: 'Bossek, Jakob, Carola Doerr, Pascal Kerschke, Aneta Neumann, and Frank Neumann. “Evolving Sampling Strategies for One-Shot Optimization Tasks.” In Parallel Problem Solving from Nature (PPSN XVI), 111–124. Berlin, Heidelberg: Springer-Verlag, 2020. https://doi.org/10.1007/978-3-030-58112-1_8.' ieee: 'J. Bossek, C. Doerr, P. Kerschke, A. Neumann, and F. Neumann, “Evolving Sampling Strategies for One-Shot Optimization Tasks,” in Parallel Problem Solving from Nature (PPSN XVI), 2020, pp. 111–124, doi: 10.1007/978-3-030-58112-1_8.' mla: Bossek, Jakob, et al. “Evolving Sampling Strategies for One-Shot Optimization Tasks.” Parallel Problem Solving from Nature (PPSN XVI), Springer-Verlag, 2020, pp. 111–124, doi:10.1007/978-3-030-58112-1_8. short: 'J. Bossek, C. Doerr, P. Kerschke, A. Neumann, F. Neumann, in: Parallel Problem Solving from Nature (PPSN XVI), Springer-Verlag, Berlin, Heidelberg, 2020, pp. 111–124.' date_created: 2023-11-14T15:58:53Z date_updated: 2023-12-13T10:43:53Z department: - _id: '819' doi: 10.1007/978-3-030-58112-1_8 extern: '1' keyword: - Continuous optimization - Fully parallel search - One-shot optimization - Regression - Surrogate-assisted optimization language: - iso: eng page: 111–124 place: Berlin, Heidelberg publication: Parallel Problem Solving from Nature (PPSN XVI) publication_identifier: isbn: - 978-3-030-58111-4 publication_status: published publisher: Springer-Verlag status: public title: Evolving Sampling Strategies for One-Shot Optimization Tasks type: conference user_id: '102979' year: '2020' ... --- _id: '48851' abstract: - lang: eng text: Several important optimization problems in the area of vehicle routing can be seen as variants of the classical Traveling Salesperson Problem (TSP). In the area of evolutionary computation, the Traveling Thief Problem (TTP) has gained increasing interest over the last 5 years. In this paper, we investigate the effect of weights on such problems, in the sense that the cost of traveling increases with respect to the weights of nodes already visited during a tour. This provides abstractions of important TSP variants such as the Traveling Thief Problem and time dependent TSP variants, and allows to study precisely the increase in difficulty caused by weight dependence. We provide a 3.59-approximation for this weight dependent version of TSP with metric distances and bounded positive weights. Furthermore, we conduct experimental investigations for simple randomized local search with classical mutation operators and two variants of the state-of-the-art evolutionary algorithm EAX adapted to the weighted TSP. Our results show the impact of the node weights on the position of the nodes in the resulting tour. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Katrin full_name: Casel, Katrin last_name: Casel - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Frank full_name: Neumann, Frank last_name: Neumann citation: ama: 'Bossek J, Casel K, Kerschke P, Neumann F. The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’20. Association for Computing Machinery; 2020:1286–1294. doi:10.1145/3377930.3390243' apa: 'Bossek, J., Casel, K., Kerschke, P., & Neumann, F. (2020). The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics. Proceedings of the Genetic and Evolutionary Computation Conference, 1286–1294. https://doi.org/10.1145/3377930.3390243' bibtex: '@inproceedings{Bossek_Casel_Kerschke_Neumann_2020, place={New York, NY, USA}, series={GECCO ’20}, title={The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics}, DOI={10.1145/3377930.3390243}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Casel, Katrin and Kerschke, Pascal and Neumann, Frank}, year={2020}, pages={1286–1294}, collection={GECCO ’20} }' chicago: 'Bossek, Jakob, Katrin Casel, Pascal Kerschke, and Frank Neumann. “The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics.” In Proceedings of the Genetic and Evolutionary Computation Conference, 1286–1294. GECCO ’20. New York, NY, USA: Association for Computing Machinery, 2020. https://doi.org/10.1145/3377930.3390243.' ieee: 'J. Bossek, K. Casel, P. Kerschke, and F. Neumann, “The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2020, pp. 1286–1294, doi: 10.1145/3377930.3390243.' mla: 'Bossek, Jakob, et al. “The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2020, pp. 1286–1294, doi:10.1145/3377930.3390243.' short: 'J. Bossek, K. Casel, P. Kerschke, F. Neumann, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2020, pp. 1286–1294.' date_created: 2023-11-14T15:58:53Z date_updated: 2023-12-13T10:43:33Z department: - _id: '819' doi: 10.1145/3377930.3390243 extern: '1' keyword: - dynamic optimization - evolutionary algorithms - running time analysis - theory language: - iso: eng page: 1286–1294 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-7128-5 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’20 status: public title: 'The Node Weight Dependent Traveling Salesperson Problem: Approximation Algorithms and Randomized Search Heuristics' type: conference user_id: '102979' year: '2020' ... --- _id: '48845' abstract: - lang: eng text: In practice, e.g. in delivery and service scenarios, Vehicle-Routing-Problems (VRPs) often imply repeated decision making on dynamic customer requests. As in classical VRPs, tours have to be planned short while the number of serviced customers has to be maximized at the same time resulting in a multi-objective problem. Beyond that, however, dynamic requests lead to the need for re-planning of not yet realized tour parts, while already realized tour parts are irreversible. In this paper we study this type of bi-objective dynamic VRP including sequential decision making and concurrent realization of decisions. We adopt a recently proposed Dynamic Evolutionary Multi-Objective Algorithm (DEMOA) for a related VRP problem and extend it to the more realistic (here considered) scenario of multiple vehicles. We empirically show that our DEMOA is competitive with a multi-vehicle offline and clairvoyant variant of the proposed DEMOA as well as with the dynamic single-vehicle approach proposed earlier. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Christian full_name: Grimme, Christian last_name: Grimme - first_name: Heike full_name: Trautmann, Heike last_name: Trautmann citation: ama: 'Bossek J, Grimme C, Trautmann H. Dynamic Bi-Objective Routing of Multiple Vehicles. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’20. Association for Computing Machinery; 2020:166–174. doi:10.1145/3377930.3390146' apa: Bossek, J., Grimme, C., & Trautmann, H. (2020). Dynamic Bi-Objective Routing of Multiple Vehicles. Proceedings of the Genetic and Evolutionary Computation Conference, 166–174. https://doi.org/10.1145/3377930.3390146 bibtex: '@inproceedings{Bossek_Grimme_Trautmann_2020, place={New York, NY, USA}, series={GECCO ’20}, title={Dynamic Bi-Objective Routing of Multiple Vehicles}, DOI={10.1145/3377930.3390146}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Grimme, Christian and Trautmann, Heike}, year={2020}, pages={166–174}, collection={GECCO ’20} }' chicago: 'Bossek, Jakob, Christian Grimme, and Heike Trautmann. “Dynamic Bi-Objective Routing of Multiple Vehicles.” In Proceedings of the Genetic and Evolutionary Computation Conference, 166–174. GECCO ’20. New York, NY, USA: Association for Computing Machinery, 2020. https://doi.org/10.1145/3377930.3390146.' ieee: 'J. Bossek, C. Grimme, and H. Trautmann, “Dynamic Bi-Objective Routing of Multiple Vehicles,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2020, pp. 166–174, doi: 10.1145/3377930.3390146.' mla: Bossek, Jakob, et al. “Dynamic Bi-Objective Routing of Multiple Vehicles.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2020, pp. 166–174, doi:10.1145/3377930.3390146. short: 'J. Bossek, C. Grimme, H. Trautmann, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2020, pp. 166–174.' date_created: 2023-11-14T15:58:52Z date_updated: 2023-12-13T10:43:24Z department: - _id: '819' doi: 10.1145/3377930.3390146 extern: '1' keyword: - decision making - dynamic optimization - evolutionary algorithms - multi-objective optimization - vehicle routing language: - iso: eng page: 166–174 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-7128-5 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’20 status: public title: Dynamic Bi-Objective Routing of Multiple Vehicles type: conference user_id: '102979' year: '2020' ... --- _id: '48850' abstract: - lang: eng text: Sequential model-based optimization (SMBO) approaches are algorithms for solving problems that require computationally or otherwise expensive function evaluations. The key design principle of SMBO is a substitution of the true objective function by a surrogate, which is used to propose the point(s) to be evaluated next. SMBO algorithms are intrinsically modular, leaving the user with many important design choices. Significant research efforts go into understanding which settings perform best for which type of problems. Most works, however, focus on the choice of the model, the acquisition function, and the strategy used to optimize the latter. The choice of the initial sampling strategy, however, receives much less attention. Not surprisingly, quite diverging recommendations can be found in the literature. We analyze in this work how the size and the distribution of the initial sample influences the overall quality of the efficient global optimization (EGO) algorithm, a well-known SMBO approach. While, overall, small initial budgets using Halton sampling seem preferable, we also observe that the performance landscape is rather unstructured. We furthermore identify several situations in which EGO performs unfavorably against random sampling. Both observations indicate that an adaptive SMBO design could be beneficial, making SMBO an interesting test-bed for automated algorithm design. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Carola full_name: Doerr, Carola last_name: Doerr - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke citation: ama: 'Bossek J, Doerr C, Kerschke P. Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB. In: Proceedings of the Genetic and Evolutionary Computation Conference. GECCO ’20. Association for Computing Machinery; 2020:778–786. doi:10.1145/3377930.3390155' apa: 'Bossek, J., Doerr, C., & Kerschke, P. (2020). Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB. Proceedings of the Genetic and Evolutionary Computation Conference, 778–786. https://doi.org/10.1145/3377930.3390155' bibtex: '@inproceedings{Bossek_Doerr_Kerschke_2020, place={New York, NY, USA}, series={GECCO ’20}, title={Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB}, DOI={10.1145/3377930.3390155}, booktitle={Proceedings of the Genetic and Evolutionary Computation Conference}, publisher={Association for Computing Machinery}, author={Bossek, Jakob and Doerr, Carola and Kerschke, Pascal}, year={2020}, pages={778–786}, collection={GECCO ’20} }' chicago: 'Bossek, Jakob, Carola Doerr, and Pascal Kerschke. “Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB.” In Proceedings of the Genetic and Evolutionary Computation Conference, 778–786. GECCO ’20. New York, NY, USA: Association for Computing Machinery, 2020. https://doi.org/10.1145/3377930.3390155.' ieee: 'J. Bossek, C. Doerr, and P. Kerschke, “Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB,” in Proceedings of the Genetic and Evolutionary Computation Conference, 2020, pp. 778–786, doi: 10.1145/3377930.3390155.' mla: 'Bossek, Jakob, et al. “Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB.” Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, 2020, pp. 778–786, doi:10.1145/3377930.3390155.' short: 'J. Bossek, C. Doerr, P. Kerschke, in: Proceedings of the Genetic and Evolutionary Computation Conference, Association for Computing Machinery, New York, NY, USA, 2020, pp. 778–786.' date_created: 2023-11-14T15:58:53Z date_updated: 2023-12-13T10:44:01Z department: - _id: '819' doi: 10.1145/3377930.3390155 extern: '1' keyword: - continuous black-box optimization - design of experiments - initial design - sequential model-based optimization language: - iso: eng page: 778–786 place: New York, NY, USA publication: Proceedings of the Genetic and Evolutionary Computation Conference publication_identifier: isbn: - 978-1-4503-7128-5 publication_status: published publisher: Association for Computing Machinery series_title: GECCO ’20 status: public title: 'Initial Design Strategies and Their Effects on Sequential Model-Based Optimization: An Exploratory Case Study Based on BBOB' type: conference user_id: '102979' year: '2020' ... --- _id: '48848' abstract: - lang: eng text: We build upon a recently proposed multi-objective view onto performance measurement of single-objective stochastic solvers. The trade-off between the fraction of failed runs and the mean runtime of successful runs \textendash both to be minimized \textendash is directly analyzed based on a study on algorithm selection of inexact state-of-the-art solvers for the famous Traveling Salesperson Problem (TSP). Moreover, we adopt the hypervolume indicator (HV) commonly used in multi-objective optimization for simultaneously assessing both conflicting objectives and investigate relations to commonly used performance indicators, both theoretically and empirically. Next to Penalized Average Runtime (PAR) and Penalized Quantile Runtime (PQR), the HV measure is used as a core concept within the construction of per-instance algorithm selection models offering interesting insights into complementary behavior of inexact TSP solvers. \textbullet The multi-objective perspective is naturally generalizable to multiple objectives. \textbullet Proof of relationship between HV and the PAR in the considered bi-objective space. \textbullet New insights into complementary behavior of stochastic optimization algorithms. author: - first_name: Jakob full_name: Bossek, Jakob id: '102979' last_name: Bossek orcid: 0000-0002-4121-4668 - first_name: Pascal full_name: Kerschke, Pascal last_name: Kerschke - first_name: Heike full_name: Trautmann, Heike last_name: Trautmann citation: ama: Bossek J, Kerschke P, Trautmann H. A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms. Applied Soft Computing. 2020;88(C). doi:10.1016/j.asoc.2019.105901 apa: Bossek, J., Kerschke, P., & Trautmann, H. (2020). A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms. Applied Soft Computing, 88(C). https://doi.org/10.1016/j.asoc.2019.105901 bibtex: '@article{Bossek_Kerschke_Trautmann_2020, title={A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms}, volume={88}, DOI={10.1016/j.asoc.2019.105901}, number={C}, journal={Applied Soft Computing}, author={Bossek, Jakob and Kerschke, Pascal and Trautmann, Heike}, year={2020} }' chicago: Bossek, Jakob, Pascal Kerschke, and Heike Trautmann. “A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms.” Applied Soft Computing 88, no. C (2020). https://doi.org/10.1016/j.asoc.2019.105901. ieee: 'J. Bossek, P. Kerschke, and H. Trautmann, “A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms,” Applied Soft Computing, vol. 88, no. C, 2020, doi: 10.1016/j.asoc.2019.105901.' mla: Bossek, Jakob, et al. “A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms.” Applied Soft Computing, vol. 88, no. C, 2020, doi:10.1016/j.asoc.2019.105901. short: J. Bossek, P. Kerschke, H. Trautmann, Applied Soft Computing 88 (2020). date_created: 2023-11-14T15:58:53Z date_updated: 2023-12-13T10:52:17Z department: - _id: '819' doi: 10.1016/j.asoc.2019.105901 intvolume: ' 88' issue: C keyword: - Algorithm selection - Combinatorial optimization - Multi-objective optimization - Performance measurement - Traveling Salesperson Problem language: - iso: eng publication: Applied Soft Computing publication_identifier: issn: - 1568-4946 status: public title: A Multi-Objective Perspective on Performance Assessment and Automated Selection of Single-Objective Optimization Algorithms type: journal_article user_id: '102979' volume: 88 year: '2020' ... --- _id: '4562' abstract: - lang: eng text: Employing main and sector-specific investment-grade CDS indices from the North American and European CDS market and performing mean-variance out-of-sample analyses for conservative and aggressive investors over the period from 2006 to 2014, this paper analyzes portfolio benefits of adding corporate CDS indices to a traditional financial portfolio consisting of stock and sovereign bond indices. As a baseline result, we initially find an increase in portfolio (downside) risk-diversification when adding CDS indices, which is observed irrespective of both CDS markets, investor-types and different sub-periods, including the global financial crisis and European sovereign debt crisis. In addition, the analysis reveals higher portfolio excess returns and performance in CDS index portfolios, however, these effects clearly differ between markets, investor-types and sub-periods. Overall, portfolio benefits of adding CDS indices mainly result from the fact that institutional investors replace sovereign bond indices rather than stock indices by CDS indices due to better risk-return characteristics. Our baseline findings remain robust under a variety of robustness checks. Results from sensitivity analyses provide further important implications for institutional investors with a strategic focus on a long-term conservative portfolio management. article_type: original author: - first_name: Benjamin full_name: Hippert, Benjamin id: '48476' last_name: Hippert - first_name: André full_name: Uhde, André id: '36049' last_name: Uhde orcid: https://orcid.org/0000-0002-8058-8857 - first_name: Sascha Tobias full_name: Wengerek, Sascha Tobias id: '48837' last_name: Wengerek orcid: 0000-0002-7820-3903 citation: ama: 'Hippert B, Uhde A, Wengerek ST. Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe. Review of Derivatives Research . 2019;22(2):203-259. doi:https://doi.org/10.1007/s11147-018-9148-8' apa: 'Hippert, B., Uhde, A., & Wengerek, S. T. (2019). Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe. Review of Derivatives Research , 22(2), 203–259. https://doi.org/10.1007/s11147-018-9148-8' bibtex: '@article{Hippert_Uhde_Wengerek_2019, title={Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe}, volume={22}, DOI={https://doi.org/10.1007/s11147-018-9148-8}, number={2}, journal={Review of Derivatives Research }, author={Hippert, Benjamin and Uhde, André and Wengerek, Sascha Tobias}, year={2019}, pages={203–259} }' chicago: 'Hippert, Benjamin, André Uhde, and Sascha Tobias Wengerek. “Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe.” Review of Derivatives Research 22, no. 2 (2019): 203–59. https://doi.org/10.1007/s11147-018-9148-8.' ieee: 'B. Hippert, A. Uhde, and S. T. Wengerek, “Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe,” Review of Derivatives Research , vol. 22, no. 2, pp. 203–259, 2019, doi: https://doi.org/10.1007/s11147-018-9148-8.' mla: 'Hippert, Benjamin, et al. “Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe.” Review of Derivatives Research , vol. 22, no. 2, 2019, pp. 203–59, doi:https://doi.org/10.1007/s11147-018-9148-8.' short: B. Hippert, A. Uhde, S.T. Wengerek, Review of Derivatives Research 22 (2019) 203–259. date_created: 2018-10-01T12:17:35Z date_updated: 2022-05-04T06:15:02Z department: - _id: '188' - _id: '186' doi: https://doi.org/10.1007/s11147-018-9148-8 intvolume: ' 22' issue: '2' jel: - C61 - G01 - G11 - G15 - G23 keyword: - Corporate credit default swap indices - Mean-variance asset allocation - Out-of-sample portfolio optimization - Portfolio risk-diversification - Portfolio performance evaluation language: - iso: eng page: 203-259 publication: 'Review of Derivatives Research ' publication_status: published status: public title: 'Portfolio Benefits of Adding Corporate Credit Default Swap Indices: Evidence from North America and Europe' type: journal_article user_id: '36049' volume: 22 year: '2019' ... --- _id: '10000' abstract: - lang: eng text: Ultraschall wird zur Effizienzsteigerung in verfahrenstechnischen Prozessen eingesetzt. Die Betriebsparamter der Ultraschallsysteme werden empirisch ermittelt, da derzeit keine systematische Analyse der Wechselwirkung zwischen Ultraschallwandler und Schallfeld sowie kein Verfahren zur Messung der Kavitationsaktivität ohne zusätzlichen Sensor existieren. Auf Basis einer experimentellen Analyse des betrachteten sonochemischen Reaktors wird ein Finite-Elemente-Modell aufgebaut, das die Wechselwirkung zwischen Schallfeld und Ultraschallwandler berücksichtigt. Die modellbasierte Analyse zeigt, dass wegen der akustischen Eigenschaften des Autoklavs nur direkt an der Sonotrode Kavitation entsteht. Die Wechselwirkung zwischen Ultraschallwandler und Schallfeld ermöglicht Aussagen über das Schallfeld und die Kavitationsaktivität auf Basis der Rückwirkung auf den Ultraschallwandler. Die lineare Schalldruckverteilung ermöglicht eine Prognose über die Verteilung von Kavitationszonen. Das beschriebene Modell liefert wertvolle Erkenntnisse für die Auslegung, Analyse und Skalierung sonochemischer Reaktoren. Auf Grund der rauen Prozessrandbedingungen ist die Applikation von Sensoren zur Überwachung der Kavitationsaktivität in vielen sonochemischen Prozessen nicht möglich. Zur prozessbegleitenden Messung der Kavitationsaktivität wird ein Verfahren entwickelt, das die Bewertung der Kavitationsaktivität durch Auswertung der Rückwirkung auf den Ultraschallwandler erlaubt. Das Messverfahren ermöglicht eine vorhersagbare und reproduzierbare Durchführung kavitationsbasierter Prozesse und stellt eine wichtige Erweiterung für bestehende und neue Ultraschallsysteme dar. author: - first_name: Peter full_name: Bornmann, Peter last_name: Bornmann citation: ama: Bornmann P. Modellierung Und Experimentelle Charakterisierung Der Wechselwirkung Zwischen Ultraschallwandler Und Flüssigkeit in Kavitationsbasierten Prozessen. Shaker; 2019. apa: Bornmann, P. (2019). Modellierung und experimentelle Charakterisierung der Wechselwirkung zwischen Ultraschallwandler und Flüssigkeit in kavitationsbasierten Prozessen. Shaker. bibtex: '@book{Bornmann_2019, title={Modellierung und experimentelle Charakterisierung der Wechselwirkung zwischen Ultraschallwandler und Flüssigkeit in kavitationsbasierten Prozessen}, publisher={Shaker}, author={Bornmann, Peter}, year={2019} }' chicago: Bornmann, Peter. Modellierung Und Experimentelle Charakterisierung Der Wechselwirkung Zwischen Ultraschallwandler Und Flüssigkeit in Kavitationsbasierten Prozessen. Shaker, 2019. ieee: P. Bornmann, Modellierung und experimentelle Charakterisierung der Wechselwirkung zwischen Ultraschallwandler und Flüssigkeit in kavitationsbasierten Prozessen. Shaker, 2019. mla: Bornmann, Peter. Modellierung Und Experimentelle Charakterisierung Der Wechselwirkung Zwischen Ultraschallwandler Und Flüssigkeit in Kavitationsbasierten Prozessen. Shaker, 2019. short: P. Bornmann, Modellierung Und Experimentelle Charakterisierung Der Wechselwirkung Zwischen Ultraschallwandler Und Flüssigkeit in Kavitationsbasierten Prozessen, Shaker, 2019. date_created: 2019-05-27T10:29:53Z date_updated: 2023-09-15T12:23:55Z department: - _id: '151' keyword: - Sonochemie - Akustische Kavitation - Kavitationsmessung - Kavitationsdetektion - FEM-Simulation Ultraschallwandler - Prozessüberwachung - FEM-Simulation Schallfeld - Self-Sensing - Piezoelektrische Ultraschallwandler - Ultraschallreinigung language: - iso: eng publisher: Shaker status: public title: Modellierung und experimentelle Charakterisierung der Wechselwirkung zwischen Ultraschallwandler und Flüssigkeit in kavitationsbasierten Prozessen type: dissertation user_id: '210' year: '2019' ...