TY - BOOK AU - Schillinger, Rolf AU - Schryen, Guido ID - 6164 SN - 978-3-88246-374-3 TI - Security in Highly Connected IT Systems – Results of the Bavarian Research Alliance FORSEC ER - TY - CONF AB - As data driven decision-making using business intelligence and analytics (BI&A) becomes standard in companies, the importance of mitigating the accompanying growth in costs increases. Research shows that increasing transparency to the granularity of individual BI&A artefacts such as reports or analytic applications is a necessary means, but in practice the introduction of said systems is cumbersome and adoption is slow. We address the status quo of BI&A cost accounting for three types of stakeholders: users, developers and managers. The results show in which areas of application a strong need for action exists and we identify major challenges for further research are ahead. Our findings indicate for example that managers at the same time regard cost accounting for BI&A with a higher potential benefit while they also believe they have already established a higher degree of implementation in their enterprises compared to the other stakeholder types. We conclude that BI&A professionals have to consider these different perceptions to run a successful department and gain traction for BI&A cost accounting. AU - Grytz, Raphael AU - Krohn-Grimberghe, Artus ID - 4778 SN - 9780998133119 T2 - Proceedings of the 51st Hawaii International Conference on System Sciences TI - Business Intelligence & Analytics Cost Accounting: A Survey on the Perceptions of Stakeholders ER - TY - JOUR AU - Hoyer, Britta AU - Rosenkranz, Stephanie ID - 4982 IS - 4 JF - Games TI - Determinants of Equilibrium Selection in Network Formation - An Experiment VL - 9 ER - TY - JOUR AB - Multiobjective optimization plays an increasingly important role in modern applications, where several criteria are often of equal importance. The task in multiobjective optimization and multiobjective optimal control is therefore to compute the set of optimal compromises (the Pareto set) between the conflicting objectives. The advances in algorithms and the increasing interest in Pareto-optimal solutions have led to a wide range of new applications related to optimal and feedback control, which results in new challenges such as expensive models or real-time applicability. Since the Pareto set generally consists of an infinite number of solutions, the computational effort can quickly become challenging, which is particularly problematic when the objectives are costly to evaluate or when a solution has to be presented very quickly. This article gives an overview of recent developments in accelerating multiobjective optimal control for complex problems where either PDE constraints are present or where a feedback behavior has to be achieved. In the first case, surrogate models yield significant speed-ups. Besides classical meta-modeling techniques for multiobjective optimization, a promising alternative for control problems is to introduce a surrogate model for the system dynamics. In the case of real-time requirements, various promising model predictive control approaches have been proposed, using either fast online solvers or offline-online decomposition. We also briefly comment on dimension reduction in many-objective optimization problems as another technique for reducing the numerical effort. AU - Peitz, Sebastian AU - Dellnitz, Michael ID - 8751 IS - 2 JF - Mathematical and Computational Applications SN - 2297-8747 TI - A Survey of Recent Trends in Multiobjective Optimal Control—Surrogate Models, Feedback Control and Objective Reduction VL - 23 ER - TY - JOUR AB - Metal nanoparticles host localized plasmon excitations that allow the manipulation of optical fields at the nanoscale. Despite the availability of several techniques for imaging plasmons, direct access into the symmetries of these excitations remains elusive, thus hindering progress in the development of applications. Here, we present a combination of angle-, polarization-, and space-resolved cathodoluminescence spectroscopy methods to selectively access the symmetry and degeneracy of plasmonic states in lithographically fabricated gold nanoprisms. We experimentally reveal and spatially map degenerate states of multipole plasmon modes with nanometer spatial resolution and further provide recipes for resolving optically dark and out-of-plane modes. Full-wave simulations in conjunction with a simple tight-binding model explain the complex plasmon structure in these particles and reveal intriguing mode-symmetry phenomena. Our approach introduces systematics for a comprehensive symmetry characterization of plasmonic states in high-symmetry nanostructures. AU - Myroshnychenko, Viktor AU - Nishio, Natsuki AU - García de Abajo, F. Javier AU - Förstner, Jens AU - Yamamoto, Naoki ID - 4165 IS - 8 JF - ACS Nano KW - tet_topic_plasmonics SN - 1936-0851 TI - Unveiling and Imaging Degenerate States in Plasmonic Nanoparticles with Nanometer Resolution VL - 12 ER - TY - JOUR AB - We study the dependence of the intensity and linear polarization of light scattered by isolated particles with the compact irregular shape on their size using the discontinuous Galerkin time domain numerical method. The size parameter of particles varies in the range of X = 10 to 150, and the complex refractive index is m = 1.5 + 0i. Our results show that the backscattering negative polarization branch weakens monotonously, but does not disappear at large sizes, up to the geometrical optics regime, and can be simulated without accounting for wave effects. The intensity backscattering surge becomes narrower with increasing particle size. For X = 150, the surge width is several degrees. AU - Grynko, Yevgen AU - Shkuratov, Yuriy AU - Förstner, Jens ID - 4324 IS - 15 JF - Optics Letters KW - tet_topic_scattering SN - 0146-9592 TI - Intensity surge and negative polarization of light from compact irregular particles VL - 43 ER - TY - CONF AB - Physician Review Websites allow users to evaluate their experiences with health services. As these evaluations are regularly contextualized with facts from users’ private lives, they often accidentally disclose personal information on the Web. This poses a serious threat to users’ privacy. In this paper, we report on early work in progress on “Text Broom”, a tool to detect privacy breaches in user-generated texts. For this purpose, we conceptualize a pipeline which combines methods of Natural Language Processing such as Named Entity Recognition, linguistic patterns and domain-specific Machine Learning approaches which have the potential to recognize privacy violations with wide coverage. A prototypical web application is openly accesible. AU - Bäumer, Frederik Simon AU - Kersting, Joschka AU - Orlikowski, Matthias AU - Geierhos, Michaela ED - Khalili, Ali ED - Koutraki, Maria ID - 4349 KW - Detection of Privacy Violations KW - Physician Reviews SN - 1613-0073 T2 - Proceedings of the Posters and Demos Track of the 14th International Conference on Semantic Systems co-located with the 14th International Conference on Semantic Systems (SEMANTiCS 2018) TI - Towards a Multi-Stage Approach to Detect Privacy Breaches in Physician Reviews VL - 2198 ER - TY - CONF AB - Natural language software requirements descriptions enable end users to formulate their wishes and expectations for a future software product without much prior knowledge in requirements engineering. However, these descriptions are susceptible to linguistic inaccuracies such as ambiguities and incompleteness that can harm the development process. There is a number of software solutions that can detect deficits in requirements descriptions and partially solve them, but they are often hard to use and not suitable for end users. For this reason, we develop a software system that helps end-users to create unambiguous and complete requirements descriptions by combining existing expert tools and controlling them using automatic compensation strategies. In order to recognize the necessity of individual compensation methods in the descriptions, we have developed linguistic indicators, which we present in this paper. Based on these indicators, the whole text analysis pipeline is ad-hoc configured and thus adapted to the individual circumstances of a requirements description. AU - Bäumer, Frederik Simon AU - Geierhos, Michaela ID - 44 KW - Software Product Lines: Engineering KW - Services KW - and Management KW - Ambiguities KW - Incompleteness KW - Natural Language Processing KW - Software Requirements SN - 978-0-9981331-1-9 T2 - Proceedings of the 51st Hawaii International Conference on System Sciences TI - Flexible Ambiguity Resolution and Incompleteness Detection in Requirements Descriptions via an Indicator-based Configuration of Text Analysis Pipelines ER - TY - GEN AB - This study analyzes the relation between accounting conservatism, future tax rate cuts and countries’ level of book-tax conformity. Firms have an incentive to increase conservatism in financial reporting when a tax rate cut is imminent to shift taxable income into the lower taxed future. Using a panel of firms across 18 countries from 1995 to 2010 I find that conditional conservatism is positively and significantly associated with future tax rate cuts when book-tax conformity is high. This effect is particularly pronounced for firms that concentrate the majority of their operations in the country in which the tax rate is cut. In contrast, there is no significant relation between future tax rate cuts and unconditional conservatism. AU - Bornemann, Tobias ID - 5007 TI - Tax Avoidance and Accounting Conservatism VL - No. 2018-04 ER - TY - JOUR AB - When analyzing the influence of taxation on agency conflicts between firm owners and managers, one can draw on theoretical principal–agent literature from various research fields. In recent years, this interdisciplinary research has grown significantly covering research with regards to optimal compensation, investment decisions, tax avoidance and transfer pricing while analyzing the effects of corporate income taxes, wage taxes, bonus taxes and shareholder taxes. Our paper provides a comprehensive review of analytical literature that studies the influence of taxation on agency conflicts between firm owners and managers. Above and beyond summarizing research findings, we discuss how taxes are commonly implemented in agency models, derive empirical predictions, and identify research gaps for future tax research. AU - Bauer, Thomas AU - Kourouxous, Thomas AU - Krenn, Peter ID - 5009 IS - 1 JF - Business Research TI - Taxation and Agency Conflicts between Firm Owners and Managers: A Review VL - 11 ER - TY - JOUR AU - Li, C AU - Dau, L A AU - Kabst, Rüdiger ID - 5434 JF - Entrepreneurship Theory and Practice. TI - The more the merrier? Immigrant share and entrepreneurial activities. ER - TY - JOUR AU - Li, C AU - Brodbeck, F C AU - Shenkar, O AU - Ponzi, L J AU - Fischer, J ID - 5435 JF - Strategic Management Journal. TI - Embracing the foreign: Cultural attractiveness and international strategy. ER - TY - JOUR AB - The need to protect resources against attackers is reflected by huge information security investments of firms worldwide. In the presence of budget constraints and a diverse set of assets to protect, organizations have to decide in which IT security measures to invest, how to evaluate those investment decisions, and how to learn from past decisions to optimize future security investment actions. While the academic literature has provided valuable insights into these issues, there is a lack of empirical contributions. To address this lack, we conduct a theory-based exploratory multiple case study. Our case study reveals that (1) firms? investments in information security are largely driven by external environmental and industry-related factors, (2) firms do not implement standardized decision processes, (3) the security process is perceived to impact the business process in a disturbing way, (4) both the implementation of evaluation processes and the application of metrics are hardly existent and (5) learning activities mainly occur at an ad-hoc basis. AU - Weishäupl, Eva AU - Yasasin, Emrah AU - Schryen, Guido ID - 5586 JF - Computers & Security KW - Information Security Investments KW - Multiple Case Study KW - Organizations KW - Single Loop Learning KW - Double Loop Learning TI - Information Security Investments: An Exploratory Multiple Case Study on Decision-Making, Evaluation and Learning VL - 77 ER - TY - CONF AU - Schuster, Richard AU - Wagner, Gerit AU - Schryen, Guido ID - 5600 T2 - Proceedings of the 2018 International Conference on Information Systems (ICIS 2018) TI - Information Systems Design Science Research and Cumulative Knowledge Development: An Exploratory Study ER - TY - CONF AU - Peuster, Manuel AU - Schneider, Stefan Balthasar AU - Christ, Frederic AU - Karl, Holger ID - 6483 T2 - IEEE Conference on Network Function Virtualisation and Software Defined Networks (NFV-SDN) 5GNetApp TI - A Prototyping Platform to Validate and Verify Network Service Header-based Service Chains ER - TY - GEN AU - Rosa, Raphael Vicente AU - Rothenberg, Christian Esteve AU - Peuster, Manuel AU - Karl, Holger ID - 6485 TI - Methodology for VNF Benchmarking Automation ER - TY - CONF AB - Dynamic allocation of resources is a key feature in network function virtualization (NFV), enabling flexible adjustment of slices and contained network services to ever-changing service demands. Considering resource allocation across the entire network, many authors have proposed approaches to optimize the placement and chaining of virtual network function (VNF) instances and the allocation of resources to these VNF instances. In doing so, various optimization objectives are conceivable, e.g., minimizing certain required resources or the end-to-end delay of the placed services. In this paper, we investigate the relationship between four typical optimization objectives when coordinating the placement and resource allocation of chained VNF instances. We observe an interesting trade-off between minimizing the overhead of starting/stopping VNF instances and all other objectives when adapting to changed service demands. AU - Schneider, Stefan Balthasar AU - Dräxler, Sevil AU - Karl, Holger ID - 6970 T2 - IEEE Global Communications Conference (GLOBECOM 2018) TI - Trade-offs in Dynamic Resource Allocation in Network Function Virtualization ER - TY - CONF AB - In recent years, a variety of different approaches have been proposed to tackle the problem of scaling and placing network services, consisting of interconnected virtual network functions (VNFs). This paper presents a placement abstraction layer (PAL) that provides a clear and simple northbound interface for using such algorithms while hiding their internal functionality and implementation. Through its southbound interface, PAL can connect to different back ends that evaluate the calculated placements, e.g., using simulations, emulations, or testbed approaches. As an example for such evaluation back ends, we introduce a novel placement emulation framework (PEF) that allows executing calculated placements using real, containerbased VNFs on real-world network topologies. In a case study, we show how PAL and PEF facilitate reusing and evaluating placement algorithms as well as validating their underlying models and performance claims. AU - Schneider, Stefan Balthasar AU - Peuster, Manuel AU - Karl, Holger ID - 6972 T2 - IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN 2018) TI - A Generic Emulation Framework for Reusing and Evaluating VNF Placement Algorithms ER - TY - CONF AB - A key challenge of network function virtualization (NFV) is the complexity of developing and deploying new network services. Currently, development requires many manual steps that are time-consuming and error-prone (e.g., for creating service descriptors). Furthermore, existing management and orchestration (MANO) platforms only offer limited support of standardized descriptor models or package formats, limiting the re-usability of network services. To this end, we introduce a fully integrated, open-source NFV service development kit (SDK) with multi-MANO platform support. Our SDK simplifies many NFV service development steps by offering initial generation of descriptors, advanced project management, as well as fully automated packaging and submission for on-boarding. To achieve multi-platform support, we present a package format that extends ETSI’s VNF package format. In this demonstration, we present the end-to-end workflow to develop an NFV service that is then packaged for multiple platforms, i.e., 5GTANGO and OSM. AU - Schneider, Stefan Balthasar AU - Peuster, Manuel AU - Tavernier, Wouter AU - Karl, Holger ID - 6974 T2 - IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN 2018) TI - A Fully Integrated Multi-Platform NFV SDK ER - TY - CONF AB - Acoustic event detection, i.e., the task of assigning a human interpretable label to a segment of audio, has only recently attracted increased interest in the research community. Driven by the DCASE challenges and the availability of large-scale audio datasets, the state-of-the-art has progressed rapidly with deep-learning-based classi- fiers dominating the field. Because several potential use cases favor a realization on distributed sensor nodes, e.g. ambient assisted living applications, habitat monitoring or surveillance, we are concerned with two issues here. Firstly the classification performance of such systems and secondly the computing resources required to achieve a certain performance considering node level feature extraction. In this contribution we look at the balance between the two criteria by employing traditional techniques and different deep learning architectures, including convolutional and recurrent models in the context of real life everyday audio recordings in realistic, however challenging, multisource conditions. AU - Ebbers, Janek AU - Nelus, Alexandru AU - Martin, Rainer AU - Haeb-Umbach, Reinhold ID - 11760 T2 - DAGA 2018, München TI - Evaluation of Modulation-MFCC Features and DNN Classification for Acoustic Event Detection ER -