@unpublished{56944, abstract = {{Quantum Max Cut (QMC), also known as the quantum anti-ferromagnetic Heisenberg model, is a QMA-complete problem relevant to quantum many-body physics and computer science. Semidefinite programming relaxations have been fruitful in designing theoretical approximation algorithms for QMC, but are computationally expensive for systems beyond tens of qubits. We give a second order cone relaxation for QMC, which optimizes over the set of mutually consistent three-qubit reduced density matrices. In combination with Pauli level-$1$ of the quantum Lasserre hierarchy, the relaxation achieves an approximation ratio of $0.526$ to the ground state energy. Our relaxation is solvable on systems with hundreds of qubits and paves the way to computationally efficient lower and upper bounds on the ground state energy of large-scale quantum spin systems.}}, author = {{Huber, Felix and Thompson, Kevin and Parekh, Ojas and Gharibian, Sevag}}, booktitle = {{arXiv:2411.04120}}, title = {{{Second order cone relaxations for quantum Max Cut}}}, year = {{2024}}, } @article{48544, abstract = {{When it comes to NP, its natural definition, its wide applicability across scientific disciplines, and its timeless relevance, the writing is on the wall: There can be only one. Quantum NP, on the other hand, is clearly the apple that fell far from the tree of NP. Two decades since the first definitions of quantum NP started rolling in, quantum complexity theorists face a stark reality: There's QMA, QCMA, QMA1, QMA(2), StoqMA, and NQP. In this article aimed at a general theoretical computer science audience, I survey these various definitions of quantum NP, their strengths and weaknesses, and why most of them, for better or worse, actually appear to fit naturally into the complexity zoo.}}, author = {{Gharibian, Sevag}}, journal = {{ACM SIGACT News}}, number = {{4}}, pages = {{54--91}}, title = {{{Guest Column: The 7 faces of quantum NP}}}, volume = {{54}}, year = {{2024}}, } @inbook{62702, abstract = {{Clifford algebras are a natural extension of division algebras, including real numbers, complex numbers, quaternions, and octonions. Previous research in knowledge graph embeddings has focused exclusively on Clifford algebras of a specific type, which do not include nilpotent base vectors—elements that square to zero. In this work, we introduce a novel approach by incorporating nilpotent base vectors with a nilpotency index of two, leading to a more general form of Clifford algebras named degenerate Clifford algebras. This generalization to degenerate Clifford algebras does allow for covering dual numbers and as such include translations and rotations models under the same generalization paradigm for the first time. We develop two models to determine the parameters that define the algebra: one using a greedy search and another predicting the parameters based on neural network embeddings of the input knowledge graph. Our evaluation on seven benchmark datasets demonstrates that this incorporation of nilpotent vectors enhances the quality of embeddings. Additionally, our method outperforms state-of-the-art approaches in terms of generalization, particularly regarding the mean reciprocal rank achieved on validation data. Finally, we show that even a simple greedy search can effectively discover optimal or near-optimal parameters for the algebra.}}, author = {{Kamdem Teyou, Louis Mozart and Demir, Caglar and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{Frontiers in Artificial Intelligence and Applications}}, isbn = {{9781643685489}}, issn = {{0922-6389}}, location = {{Santiago de Compostela}}, publisher = {{IOS Press}}, title = {{{Embedding Knowledge Graphs in Degenerate Clifford Algebras}}}, doi = {{10.3233/faia240627}}, year = {{2024}}, } @inproceedings{62703, abstract = {{We introduce a novel embedding method diverging from conventional approaches by operating within function spaces of finite dimension rather than finite vector space, thus departing significantly from standard knowledge graph embedding techniques. Initially employing polynomial functions to compute embeddings, we progress to more intricate representations using neural networks with varying layer complexities. We argue that employing functions for embedding computation enhances expressiveness and allows for more degrees of freedom, enabling operations such as composition, derivatives and primitive of entities representation. Additionally, we meticulously outline the step-by-step construction of our approach and provide code for reproducibility, thereby facilitating further exploration and application in the field.}}, author = {{Kamdem Teyou, Louis Mozart and Demir, Caglar and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{Proceedings of the 33rd ACM International Conference on Information and Knowledge Management}}, location = {{Boise}}, publisher = {{ACM}}, title = {{{Embedding Knowledge Graphs in Function Spaces}}}, doi = {{10.1145/3627673.3679819}}, year = {{2024}}, } @inproceedings{45778, abstract = {{RISC-V has received worldwide acceptance in the industry and by the academic community. As of today, multiple RISC-V applications and variants are under investigation for embedded IoT systems, from resource-limited single-core processors up to multi-core systems for High-Performance Computing (HPC). Recently, the Grid of Processing Cells (GPC) platform has been proposed as a scalable parallel grid-oriented network of processor cores with local memories. This paper describes a prototype design of the GPC platform for hardware implementation at Register-Transfer Level (RTL) based on modified RISC-V Rocket processors with scratchpad memories. It introduces a scalable Chisel-based implementation of the modified Rocket cores with RTL generation and a functional test using Verilator simulation. This work also includes the adaptation of the Chipyard software toolchain to extend the compiler to multi-core grids with different local address spaces.}}, author = {{Luchterhandt, Lars and Nellius, Tom and Beck, Robert and Dömer, Rainer and Kneuper, Pascal and Müller, Wolfgang and Sadiye, Babak}}, booktitle = {{MBMV 2024 - 27. Workshop Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen“}}, location = {{Germany, Freiburg}}, publisher = {{VDE Verlag}}, title = {{{Implementation of Different Communication Structures for a Rocket Chip Based RISC-V Grid of Processing Cells}}}, year = {{2024}}, } @inproceedings{66834, author = {{Schott, Stefan and Fischer, Wolfram and Ponta, Serena Elisa and Klauke, Jonas and Bodden, Eric}}, booktitle = {{2024 IEEE International Conference on Software Maintenance and Evolution (ICSME)}}, publisher = {{IEEE}}, title = {{{Compilation of Commit Changes Within Java Source Code Repositories}}}, doi = {{10.1109/icsme58944.2024.00038}}, year = {{2024}}, } @article{53542, abstract = {{AbstractThis work deals with the extension problem for the fractional Laplacian on Riemannian symmetric spaces G/K of noncompact type and of general rank, which gives rise to a family of convolution operators, including the Poisson operator. More precisely, motivated by Euclidean results for the Poisson semigroup, we study the long-time asymptotic behavior of solutions to the extension problem for $$L^1$$ L 1 initial data. In the case of the Laplace–Beltrami operator, we show that if the initial data are bi-K-invariant, then the solution to the extension problem behaves asymptotically as the mass times the fundamental solution, but this convergence may break down in the non-bi-K-invariant case. In the second part, we investigate the long-time asymptotic behavior of the extension problem associated with the so-called distinguished Laplacian on G/K. In this case, we observe phenomena which are similar to the Euclidean setting for the Poisson semigroup, such as $$L^1$$ L 1 asymptotic convergence without the assumption of bi-K-invariance.}}, author = {{Papageorgiou, Efthymia}}, issn = {{1424-3199}}, journal = {{Journal of Evolution Equations}}, keywords = {{Mathematics (miscellaneous)}}, number = {{2}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Asymptotic behavior of solutions to the extension problem for the fractional Laplacian on noncompact symmetric spaces}}}, doi = {{10.1007/s00028-024-00959-6}}, volume = {{24}}, year = {{2024}}, } @inproceedings{57816, abstract = {{TLS-Attacker is an open-source framework for analyzing Transport Layer Security (TLS) implementations. The framework allows users to specify custom protocol flows and provides modification hooks to manipulate message contents. Since its initial publication in 2016 by Juraj Somorovsky, TLS-Attacker has been used in numerous studies published at well-established conferences and helped to identify vulnerabilities in well-known open-source TLS libraries. To enable automated analyses, TLS-Attacker has grown into a suite of projects, each designed as a building block that can be applied to facilitate various analysis methodologies. The framework still undergoes continuous improvements with feature extensions, such as DTLS 1.3 or the addition of new dialects such as QUIC, to continue its effectiveness and relevancy as a security analysis framework.}}, author = {{Bäumer, Fabian and Brinkmann, Marcus and Erinola, Nurullah and Hebrok, Sven Niclas and Heitmann, Nico and Lange, Felix and Maehren, Marcel and Merget, Robert and Niere, Niklas and Radoy, Maximilian Manfred and Schmidt, Conrad and Schwenk, Jörg and Somorovsky, Juraj}}, booktitle = {{Proceedings of Cybersecurity Artifacts Competition and Impact Award (ACSAC ’24)}}, keywords = {{SSL, TLS, DTLS, Protocol State Fuzzing, Planning Based}}, location = {{Hawaii}}, title = {{{TLS-Attacker: A Dynamic Framework for Analyzing TLS Implementations}}}, year = {{2024}}, } @inproceedings{55137, abstract = {{Many countries limit their residents' access to various websites. As a substantial number of these websites do not support TLS encryption, censorship of unencrypted HTTP requests remains prevalent. Accordingly, circumvention techniques can and have been found for the HTTP protocol. In this paper, we infer novel circumvention techniques on the HTTP layer from a web security vulnerability by utilizing HTTP request smuggling (HRS). To demonstrate the viability of our techniques, we collected various test vectors from previous work about HRS and evaluated them on popular web servers and censors in China, Russia, and Iran. Our findings show that HRS can be successfully employed as a censorship circumvention technique against multiple censors and web servers. We also discover a standard-compliant circumvention technique in Russia, unusually inconsistent censorship in China, and an implementation bug in Iran. The results of this work imply that censorship circumvention techniques can successfully be constructed from existing vulnerabilities. We conjecture that this implication provides insights to the censorship circumvention community beyond the viability of specific techniques presented in this work.}}, author = {{Müller, Philipp and Niere, Niklas and Lange, Felix and Somorovsky, Juraj}}, booktitle = {{Proceedings on Privacy Enhancing Technologies}}, keywords = {{censorship, censorship circumvention, http, http request smuggling}}, location = {{Bristol}}, title = {{{Turning Attacks into Advantages: Evading HTTP Censorship with HTTP Request Smuggling}}}, year = {{2024}}, } @article{21199, abstract = {{As in almost every other branch of science, the major advances in data science and machine learning have also resulted in significant improvements regarding the modeling and simulation of nonlinear dynamical systems. It is nowadays possible to make accurate medium to long-term predictions of highly complex systems such as the weather, the dynamics within a nuclear fusion reactor, of disease models or the stock market in a very efficient manner. In many cases, predictive methods are advertised to ultimately be useful for control, as the control of high-dimensional nonlinear systems is an engineering grand challenge with huge potential in areas such as clean and efficient energy production, or the development of advanced medical devices. However, the question of how to use a predictive model for control is often left unanswered due to the associated challenges, namely a significantly higher system complexity, the requirement of much larger data sets and an increased and often problem-specific modeling effort. To solve these issues, we present a universal framework (which we call QuaSiModO: Quantization-Simulation-Modeling-Optimization) to transform arbitrary predictive models into control systems and use them for feedback control. The advantages of our approach are a linear increase in data requirements with respect to the control dimension, performance guarantees that rely exclusively on the accuracy of the predictive model, and only little prior knowledge requirements in control theory to solve complex control problems. In particular the latter point is of key importance to enable a large number of researchers and practitioners to exploit the ever increasing capabilities of predictive models for control in a straight-forward and systematic fashion.}}, author = {{Peitz, Sebastian and Bieker, Katharina}}, journal = {{Automatica}}, publisher = {{Elsevier}}, title = {{{On the Universal Transformation of Data-Driven Models to Control Systems}}}, doi = {{10.1016/j.automatica.2022.110840}}, volume = {{149}}, year = {{2023}}, } @article{35428, abstract = {{This paper presents a model of an energy system for a private household extended by a lifetime prognosis. The energy system was designed for fully covering the year-round energy demand of a private household on the basis of electricity generated by a photovoltaic (PV) system, using a hybrid energy storage system consisting of a hydrogen unit and a lithium-ion battery. Hydrogen is produced with a Proton Exchange Membrane (PEM) electrolyser by PV surplus during the summer months and then stored in a hydrogen tank. Mainly during winter, in terms of lack of PV energy, the hydrogen is converted back into electricity and heat by a fuel cell. The model was created in Matlab/Simulink and is based on real input data. Heat demand was also taken into account and is covered by a heat pump. The simulation period is a full year to account for the seasonality of energy production and demand. Due to high initial costs, the longevity of such an energy system is of vital interest. Therefore, this model was extended by a lifetime prediction in order to optimize the dimensioning with the aim of lifetime extension of a hydrogen-based energy system. Lifetime influencing factors were identified on the basis of a literature review and were integrated in the model. An extensive parameter study was performed to evaluate different dimensionings regarding the energy balance and the lifetime of the three components, electrolyser, fuel cell and lithium-ion battery. The results demonstrate the benefits of a holistic modelling approach and enable a design optimization regarding the use of resources, lifetime and self-sufficiency of the system}}, author = {{Möller, Marius Claus and Krauter, Stefan}}, issn = {{2673-9941}}, journal = {{Solar}}, number = {{1}}, pages = {{25--48}}, publisher = {{MDPI AG}}, title = {{{Dimensioning and Lifetime Prediction Model for a Hybrid, Hydrogen-Based Household PV Energy System Using Matlab/Simulink}}}, doi = {{10.3390/solar3010003}}, volume = {{3}}, year = {{2023}}, } @book{47547, editor = {{Kalenborn, Axel and Fazal-Baqaie, Masud and Linssen, Oliver and Volland, Alexander and Yigitbas, Enes and Engstler, Martin and Bertram, Martin}}, publisher = {{Gesellschaft für Informatik e.V}}, title = {{{Projektmanagement Und Vorgehensmodelle 2023 - Nachhaltige IT-Projekte}}}, volume = {{Vol. P340}}, year = {{2023}}, } @inproceedings{47590, author = {{Jonas-Ahrend, Gabriela and Fraser-Abder, Pamela and Kapanadze, Marika and Joubran, Fadeel and Mazzolini, Alexander}}, location = {{Panama City/Panama}}, title = {{{Lessons learned from a global review study of physics textbook evaluation and its implications for teaching and learning in the classroom}}}, year = {{2023}}, } @inproceedings{47591, author = {{Jonas-Ahrend, Gabriela and Kapanadze, Marika and Mazzolini, Alexander and Joubran, Fadeel}}, location = {{Hannover}}, title = {{{Physiklehrbücher im Fokus der fachdidaktischen Forschung - ein internationaler Literatur-Review}}}, year = {{2023}}, } @inproceedings{47602, author = {{Jonas-Ahrend, Gabriela and Kapanadze, Marika and Mazzolini, Alexander and Joubran, Fadeel}}, location = {{Hamburg}}, title = {{{Ergebnisse einer Reviewstudie zur Evaluation von Physiklehrbüchern}}}, year = {{2023}}, } @article{45866, author = {{Knorr, Lukas and Schlosser, Florian and Meschede, Henning}}, issn = {{1848-9257}}, journal = {{Journal of Sustainable Development of Energy, Water and Environment Systems}}, keywords = {{Energy Engineering and Power Technology, Water Science and Technology, Environmental Science (miscellaneous), Renewable Energy, Sustainability and the Environment}}, number = {{3}}, pages = {{0--0}}, publisher = {{SDEWES Centre}}, title = {{{Assessment of Energy Efficiency and Flexibility Measures in Electrified Process Heat Generation Based on Simulations in the Animal Feed Industry}}}, doi = {{10.13044/j.sdewes.d11.0444}}, volume = {{ 11}}, year = {{2023}}, } @article{47800, abstract = {{The introduction of Systems Engineering is an approach for dealing with the increasing complexity of products and their associated product development. Several introduction strategies are available in the literature; nevertheless, the introduction of Systems Engineering into practice still poses a great challenge to companies. Many companies have already gained experience in the introduction of Systems Engineering. Therefore, as part of the SE4OWL research project, the need to conduct a study including expert interviews and to collect the experiences of experts was identified. A total of 78 hypotheses were identified from 13 expert interviews concerning the lessons learned. Using exclusion criteria, 52 hypotheses were validated in a subsequent quantitative survey with 112 participants. Of these 52 hypotheses, 40 could be confirmed based on the survey results. Only four hypotheses were rejected, and eight could neither be confirmed nor rejected. Through this research, guidance is provided to companies to leverage best practices for the introduction of their own Systems Engineering and to avoid the poor practices of other companies.}}, author = {{Wilke, Daria and Grothe, Robin and Bretz, Lukas and Anacker, Harald and Dumitrescu, Roman}}, issn = {{2079-8954}}, journal = {{Systems}}, keywords = {{Information Systems and Management, Computer Networks and Communications, Modeling and Simulation, Control and Systems Engineering, Software}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Lessons Learned from the Introduction of Systems Engineering}}}, doi = {{10.3390/systems11030119}}, volume = {{11}}, year = {{2023}}, } @article{47798, abstract = {{Abstract In diesem Beitrag wird die soziotechnische Gestaltung einer Intelligenten Personaleinsatzplanung beim Unternehmen Miele & Cie. KG im Rahmen des Leuchtturmprojekts „InTime“ im Kompetenzzentrum Arbeitswelt.Plus beschrieben. Hierzu werden die Durchführung und Auswertung einer Interviewreihe sowie das daraus erarbeitete Soll-Konzept vorgestellt.}}, author = {{Gabriel, Stefan and Bentler, Dominik and Bansmann, Michael and Andrew Latos, Benedikt and Kühn, Arno and Dumitrescu, Roman}}, issn = {{2511-0896}}, journal = {{Zeitschrift für wirtschaftlichen Fabrikbetrieb}}, keywords = {{Management Science and Operations Research, Strategy and Management, General Engineering}}, number = {{1-2}}, pages = {{64--68}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Soziotechnische Gestaltung einer intelligenten Personaleinsatzplanung}}}, doi = {{10.1515/zwf-2023-1009}}, volume = {{118}}, year = {{2023}}, } @inbook{47797, author = {{Menzefricke, Jörn Steffen and Gabriel, Stefan and Gundlach, Thomas and Hobscheidt, Daniela and Kürpick, Christian and Schnasse, Felix and Scholtysik, Michel and Seif, Heiko and Koldewey, Christian and Dumitrescu, Roman}}, booktitle = {{Schwerpunkt Business Model Innovation}}, isbn = {{9783658366339}}, issn = {{2569-2348}}, publisher = {{Springer Fachmedien Wiesbaden}}, title = {{{Soziotechnisches Risikomanagement als Erfolgsfaktor für die Digitale Transformation}}}, doi = {{10.1007/978-3-658-36634-6_14}}, year = {{2023}}, } @inproceedings{47799, author = {{Bentler, Dominik and Gabriel, Stefan and Latos, Benedikt A. and Dietrich, Oliver and Dumitrescu, Roman and Maier, Günter W.}}, booktitle = {{GfA-Frühjahrskongress 2023}}, publisher = {{GfA, Sankt Augustin}}, title = {{{Partizipatives Gestaltungsvorgehen bei der Einführung künstlicher Intelligenz in produzierenden Unternehmen}}}, year = {{2023}}, }