@misc{25846, author = {{Dolzhenko, Irina and Rumlich, Dominik}}, publisher = {{sib.fm}}, title = {{{Понять, как они тикают [Verstehen, wie sie ticken]. Interview on CLIL conducted by Ирина Долженко [Irina Dolzhenko] on behalf of sib.fm}}}, year = {{2017}}, } @article{3523, abstract = {{We numerically simulate the circular polarization ratio of the radar signal backscattered from a large-grain cometary coma and compare the simulation results with the radar measurements for seven comets. We apply the discrete dipole approximation method and a model of random irregular particles. Our results confirm water ice composition of the cm-sized chunks detected by the NASA Deep Impact space probe in the vicinity of the nucleus of Comet 103P/Hartley 2. The index of the power-law size distribution in this case can be constrained to the range n ≈ 3.3–4.3. For the other considered comets the circular polarization ratio can be reproduced with variations of the power index between 2 and 5.}}, author = {{Dogra, Shraddha and Grynko, Yevgen and Zubko, Evgenij and Förstner, Jens}}, issn = {{0004-6361}}, journal = {{Astronomy & Astrophysics}}, keywords = {{tet_topic_scattering}}, pages = {{A20}}, publisher = {{EDP Sciences}}, title = {{{Radar backscattering from a large-grain cometary coma: numerical simulation}}}, doi = {{10.1051/0004-6361/201730801}}, volume = {{608}}, year = {{2017}}, } @article{3828, abstract = {{The 3D implementation of a hybrid analytical/numerical variant of the coupled-mode theory is discussed. Eigenmodes of the constituting dielectric channels are computed numerically. The frequency-domain coupled-mode models then combine these into fully vectorial approximations for the optical electromagnetic fields of the composite structure. Following a discretization of amplitude functions by 1D finite elements, pro- cedures from the realm of finite-element numerics are applied to establish systems of linear equations for the then- discrete modal amplitudes. Examples substantiate the functioning of the technique and allow for some numerical assessment. The full 3D simulations are highly efficient in memory consumption, moderately demanding in com- putational time, and, in regimes of low radiative losses, sufficiently accurate for practical design. Our results include the perturbation of guided modes by changes of the refractive indices, the interaction of waves in parallel, horizontally or vertically coupled straight waveguides, and a series of crossings of potentially overlapping channels with fairly arbitrary relative positions and orientations.}}, author = {{Hammer, Manfred and Alhaddad, Samer and Förstner, Jens}}, issn = {{0740-3224}}, journal = {{Journal of the Optical Society of America B}}, keywords = {{tet_topic_waveguide, tet_topic_numerics}}, number = {{3}}, pages = {{613--624}}, publisher = {{The Optical Society}}, title = {{{Hybrid coupled-mode modeling in 3D: perturbed and coupled channels, and waveguide crossings}}}, doi = {{10.1364/josab.34.000613}}, volume = {{34}}, year = {{2017}}, } @article{3832, abstract = {{Controlling light emission out of subwavelength nanoslit/aperture structures is of great important for highly integrated photonic circuits. Here we propose a new method to achieve direction-tunable emission based on a compact metallic microcavity with double nanoslit. Our method combines the principles of Young’s interference and surface plasmon polaritons interference. We show that the direction of the far-field beam can be controlled over a wide range of angles by manipulating the frequency and relative phase of light arriving at the two slits, which holds promise for applications in the ultracompact optoelectronic devices.}}, author = {{Song, Xiaohong and Wang, Nini and Yan, Ming and Lin, Cheng and Förstner, Jens and Yang, Weifeng}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{tet_topic_plasmonics}}, number = {{12}}, pages = {{13207--13214}}, publisher = {{The Optical Society}}, title = {{{Direction-tunable enhanced emission from a subwavelength metallic double-nanoslit structure}}}, doi = {{10.1364/oe.25.013207}}, volume = {{25}}, year = {{2017}}, } @inproceedings{2967, author = {{Blömer, Johannes and Liske, Gennadij}}, booktitle = {{Proceedings of the International Conference of Mathematical Aspects of Computer and Information Sciences (MACIS)}}, isbn = {{9783319724522}}, issn = {{0302-9743}}, pages = {{438--453}}, publisher = {{Springer International Publishing}}, title = {{{Subtleties in Security Definitions for Predicate Encryption with Public Index}}}, doi = {{10.1007/978-3-319-72453-9_35}}, volume = {{10693}}, year = {{2017}}, } @inproceedings{2343, author = {{Löken, Nils}}, booktitle = {{Proceedings of the 12th International Conference on Availability, Reliability and Security - ARES '17}}, isbn = {{9781450352574}}, publisher = {{ACM Press}}, title = {{{Searchable Encryption with Access Control}}}, doi = {{10.1145/3098954.3098987}}, year = {{2017}}, } @inproceedings{2344, author = {{Blömer, Johannes and Günther, Peter and Krummel, Volker and Löken, Nils}}, booktitle = {{Foundations and Practice of Security}}, isbn = {{9783319756493}}, issn = {{0302-9743}}, pages = {{3--17}}, publisher = {{Springer International Publishing}}, title = {{{Attribute-Based Encryption as a Service for Access Control in Large-Scale Organizations}}}, doi = {{10.1007/978-3-319-75650-9_1}}, year = {{2017}}, } @techreport{2247, author = {{Hoppe, Thomas and Schanz, Deborah and Sturm, Susann and Sureth-Sloane, Caren}}, pages = {{27}}, title = {{{2016 Global MNC Tax Complexity Survey - Executive Summary}}}, doi = {{10.13140/RG.2.2.23707.46881}}, year = {{2017}}, } @techreport{2250, abstract = {{All over the world, firms and governments are increasingly concerned about the rise in tax complexity. To manage it and develop effective simplification measures, detailed information on the current drivers of complexity is required. However, research on this topic is scarce. This is surprising as the latest developments—for example, triggered by the BEPS project—give rise to the conjecture that complexity drivers may have changed, thus questioning the findings of prior studies. In this paper, we shed light on this issue and provide a global picture of the current drivers of tax complexity that multinational corporations face based on a survey of 221 highly experienced tax practitioners from 108 countries. Our results show that prior complexity drivers of the tax code are still relevant, with details and changes of tax regulations being the two most influential complexity drivers. We also find evidence for new relevant complexity drivers emerging from different areas of the tax framework, such as inconsistent decisions among tax officers (tax audits) or retroactively applied tax law amendments (tax enactment). Based on the responses of the practitioners, we develop a concept of tax complexity that distinguishes two pillars, tax code and tax framework complexity, and illustrates the various aspects that should be considered when assessing the complexity of a country’s tax system.}}, author = {{Hoppe, Thomas and Schanz, Deborah and Sturm, Susann and Sureth-Sloane, Caren}}, issn = {{1556-5068}}, keywords = {{Complexity Drivers, International Comparison, Survey, Tax Complexity, Tax Practitioners}}, pages = {{28}}, title = {{{What are the Drivers of Tax Complexity for Multinational Corporations? Evidence from 108 Countries}}}, doi = {{10.2139/ssrn.3046546}}, year = {{2017}}, } @inproceedings{7767, author = {{Schumacher, Jan}}, booktitle = {{Beiträge zum Mathematikunterricht 2017}}, editor = {{Kortenkamp, Ulrich and Kuzle, Ana}}, publisher = {{WTM-Verlag}}, title = {{{Sinnkonstruktion beim Erkunden von Mustern und Strukturen}}}, year = {{2017}}, } @inproceedings{5692, abstract = {{We consider Max-min Share (MmS) fair allocations of indivisible chores (items with negative utilities). We show that allocation of chores and classical allocation of goods (items with positive utilities) have some fundamental connections but also differences which prevent a straightforward application of algorithms for goods in the chores setting and viceversa. We prove that an MmS allocation does not need to exist for chores and computing an MmS allocation - if it exists - is strongly NP-hard. In view of these non-existence and complexity results, we present a polynomial-time 2-approximation algorithm for MmS fairness for chores. We then introduce a new fairness concept called optimal MmS that represents the best possible allocation in terms of MmS that is guaranteed to exist. We use connections to parallel machine scheduling to give (1) a polynomial-time approximation scheme for computing an optimal MmS allocation when the number of agents is fixed and (2) an effective and efficient heuristic with an ex-post worst-case analysis.}}, author = {{Aziz, Haris and Rauchecker, Gerhard and Schryen, Guido and Walsh, Toby}}, booktitle = {{Thirty-First AAAI Conference on Artificial Intelligence (AAAI-17)}}, location = {{San Francisco, CA, USA}}, number = {{1}}, pages = {{1--7}}, title = {{{Algorithms for Max-Min Share Fair Allocation of Indivisible Chores}}}, volume = {{31}}, year = {{2017}}, } @article{58, abstract = {{Network function virtualization and software-defined networking allow services consisting of virtual network functions to be designed and implemented with great flexibility by facilitating automatic deployments, migrations, and reconfigurations for services and their components. For extended flexibility, we go beyond seeing services as a fixed chain of functions. We define the service structure in a flexible way that enables changing the order of functions in case the functionality of the service is not influenced by this, and propose a YANG data model for expressing this flexibility. Flexible structures allow the network orchestration system to choose the optimal composition of service components that for example gives the best results for placement of services in the network. When number of flexible services and number of components in each service increase, combinatorial explosion limits the practical use of this flexibility. In this paper, we describe a selection heuristic that gives a Pareto set of the possible compositions of a service as well as possible combinations of different services, with respect to different optimization objectives. Moreover, we present a heuristic algorithm for placement of a combination of services, which aims at placing service components along shortest paths that have enough capacity for accommodating the services. By applying these solutions, we show that allowing flexibility in the service structure is feasible.}}, author = {{Dräxler, Sevil and Karl, Holger}}, journal = {{International Journal of Network Management}}, number = {{2}}, pages = {{1----16}}, publisher = {{Wiley Online Library}}, title = {{{Specification, Composition, and Placement of Network Services with Flexible Structures}}}, doi = {{10.1002/nem.1963}}, year = {{2017}}, } @inproceedings{4780, abstract = {{Quantifying and designing the cost pool generated by Business Intelligence and Analytics (BI&A) would improve cost transparency and invoicing processes, allowing a fairer, more exact allocation of costs to service consumers. Yet there is still no method for determining BI&A costs to provide a base for allocation purposes. While literature describes several methods for BI&A cost estimation on an ROI or resource-consumption level, none of these methods considers an overall approach for BI&A. To tackle this problem, we propose a service-oriented cost allocation model which calculates BI&A applications based on defined services, enabling a cost transfer to service consumers. This new approach specifies steps towards deriving a usable pricing scheme for an entire BI&A service portfolio – both for allocation purposes as well as improving cost evaluation of BI&A projects. Moreover, it prevents BI&A departments from being considered as the sole cost driver, increasing customer understanding and cost awareness.}}, author = {{Grytz, Raphael and Krohn-Grimberghe, Artus}}, booktitle = {{Proceedings of the 50th Hawaii International Conference on System Sciences (2017)}}, isbn = {{9780998133102}}, publisher = {{Hawaii International Conference on System Sciences}}, title = {{{Service-oriented Cost Allocation for Business Intelligence and Analytics: Who pays for BI&A?}}}, doi = {{10.24251/hicss.2017.123}}, year = {{2017}}, } @inproceedings{717, abstract = {{In conventional large-scale networks, creation and management of network services are costly and complex tasks that often consume a lot of resources, including time and manpower. Network softwarization and network function virtualization have been introduced to tackle these problems, aiming at decreasing costs and complexity of implementing new services, maintaining the implemented services, and managing available resources in service provisioning platforms and underlying infrastructures. To experience the full potential of these approaches, innovative development support tools and service provisioning environments are needed. To answer these needs, we introduce the architecture of the open-source SONATA system, a service programming, orchestration, and management framework. We present a development toolchain for virtualized network services, fully integrated with a service platform and orchestration system. We introduce the modular and flexible architecture of our system and discuss its main components and features, such as function- and service-specific managers that allow fine-grained service management, slicing support to facilitate multi-tenancy, recursiveness for improved scalability, and full-featured DevOps support.}}, author = {{Dräxler, Sevil and Karl, Holger and Peuster, Manuel and Razzaghi Kouchaksaraei, Hadi and Bredel, Michael and Lessmann, Johannes and Soenen, Thomas and Tavernier, Wouter and Mendel-Brin, Sharon and Xilouris, George}}, booktitle = {{2017 IEEE International Conference on Communications Workshops (ICC Workshops)}}, isbn = {{9781509015252}}, location = {{Paris, France}}, publisher = {{IEEE}}, title = {{{SONATA: Service programming and orchestration for virtualized software networks}}}, doi = {{10.1109/iccw.2017.7962785}}, year = {{2017}}, } @inproceedings{723, abstract = {{Developing a virtualized network service does not only involve the implementation and configuration of the network functions it is composed of but also its integration and test with management solutions that will control the service in its production environment. These integration tasks require testbeds that offer the needed network function virtualization infrastructure~(NFVI), like OpenStack, introducing a lot of management and maintenance overheads. Such testbed setups become even more complicated when the multi point-of-presence~(PoP) case, with multiple infrastructure installations, is considered. In this demo, we showcase an emulation platform that executes containerized network services in user-defined multi-PoP topologies. The platform does not only allow network service developers to locally test their services but also to connect real-world management and orchestration solutions to the emulated PoPs. During our interactive demonstration we focus on the integration between the emulated infrastructure and state-of-the-art orchestration solutions like SONATA or OSM.}}, author = {{Peuster, Manuel and Dräxler, Sevil and Razzaghi Kouchaksaraei, Hadi and van Rossem, Steven and Tavernier, Wouter and Karl, Holger}}, booktitle = {{IEEE Conference on Network Softwarization, NetSoft 2017, Bologna, Italy, July 3-7, 2017}}, location = {{Bologna}}, pages = {{1----3}}, title = {{{A flexible multi-pop infrastructure emulator for carrier-grade MANO systems}}}, doi = {{10.1109/NETSOFT.2017.8004250}}, year = {{2017}}, } @inproceedings{87, abstract = {{Management of complex network services requires flexible and efficient service provisioning as well as optimized handling of continuous changes in the workload of the service.To adapt to changes in the demand, service components need to be replicated (scaling) and allocated to physical resources (placement) dynamically. In this paper, we propose a fullyautomated approach to the joint optimization problem of scaling and placement, enabling quick reaction to changes. We formalize the problem, analyze its complexity, and develop two algorithms to solve it. Extensive empirical results show the applicability andeffectiveness of the proposed approach.}}, author = {{Dräxler, Sevil and Karl, Holger and Mann, Zoltan Adam}}, booktitle = {{Proceedings of the 17th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid 2017)}}, title = {{{Joint Optimization of Scaling and Placement of Virtual Network Services}}}, doi = {{10.1109/CCGRID.2017.25}}, year = {{2017}}, } @inproceedings{981, abstract = {{Benchmarking and profiling virtual network functions (VNFs) generates input knowledge for resource management decisions taken by management and orchestration systems. Such VNFs are usually not executed in isolation but are often deployed as part of a service function chain (SFC) that connects single functions into complex structures. To manage such chains, isolated performance profiles of single functions have to be combined to get insights into the overall behavior of an SFC. This becomes particularly challenging in highly agile DevOps environments in which profiling processes need to be fully automated and detailed insights about a chain's internal structures are not always available. In this paper, we introduce a fully automatable, flexible, and platform-agnostic profiling system that allows to profile entire SFCs at once. This obviates manual modeling procedures to combine profiling results from single VNFs to reflect SFC performance. We use a case study with different SFC configurations to show that it is hard to model the resulting SFC performance based on single-VNF measurements and that performance interactions between real, non-trivial functions that are deployed in a chain exist. }}, author = {{Peuster, Manuel and Karl, Holger}}, booktitle = {{IEEE Conference on Network Function Virtualisation and Software Defined Networks (NFV-SDN)}}, location = {{Berlin}}, title = {{{Profile Your Chains, Not Functions. Automated Network Service Profiling in DevOps Environments}}}, doi = {{10.1109/NFV-SDN.2017.8169826}}, year = {{2017}}, } @article{9862, abstract = {{In order to improve the credibility of modern simulation tools, uncertainties of different kinds have to be considered. This work is focused on epistemic uncertainties in the framework of continuum mechanics, which are taken into account by fuzzy analysis. The underlying min-max optimization problem of the extension principle is approximated by α-discretization, resulting in a separation of minimum and maximum problems. To become more universal, so-called quantities of interest are employed, which allow a general formulation for the target problem of interest. In this way, the relation to parameter identification problems based on least-squares functions is highlighted. The solutions of the related optimization problems with simple constraints are obtained with a gradient-based scheme, which is derived from a sensitvity analysis for the target problem by means of a variational formulation. Two numerical examples for the fuzzy analysis of material parameters are concerned with a necking problem at large strain elastoplasticity and a perforated strip at large strain hyperelasticity to demonstrate the versatility of the proposed variational formulation. }}, author = {{Mahnken, Rolf}}, issn = {{ 2325-3444}}, journal = {{Mathematics and Mechanics of complex systems}}, keywords = {{fuzzy analysis, α-level optimization, quantities of interest, optimization with simple constraints, large strain elasticity, large strain elastoplasticity}}, number = {{3-4}}, title = {{{"A variational formulation for fuzzy analysis in continuum mechanics"}}}, volume = {{5}}, year = {{2017}}, } @inproceedings{5594, abstract = {{Design science is a fundamental research stream that contends its position in the information systems discipline. While ongoing debates address the relative importance of design science contributions in the information systems community, insights into the scientific impact of design science research (DSR) are missing and this lack of understanding arguably poses challenges to an informed discourse. To identify the most influential papers and those factors that explain their scientific impact, this paper presents an exploratory study of the scientific impact of DSR papers published in the AIS Senior Scholars' Basket of Journals. We uncover the current DSR landscape by taking stock of influential papers and theories and develop a model to explain the scientific impact of DSR papers. Our findings show that scientific impact is significantly explained by theorization and novelty. We discuss how the implications of our work can be projected on the overarching discourse on DSR.}}, author = {{Wagner, Gerit and Prester, Julian and Schryen, Guido}}, booktitle = {{38th International Conference on Information Systems}}, location = {{Seoul, South Korea}}, title = {{{Exploring the Scientific Impact of Information Systems Design Science Research: A Scientometric Study}}}, year = {{2017}}, } @article{5633, abstract = {{Literature reviews (LRs) are recognized for their increasing impact in the information systems literature. Methodologists have drawn attention to the question of how we can leverage the value of LRs to preserve and generate knowledge. The panelists who participated in the discussion of ?Standalone Literature Reviews in IS Research: What Can Be Learnt from the Past and Other Fields?? at ICIS 2016 in Dublin acknowledged this significant issue and debated a) what the IS field can learn from other fields and where IS-specific challenges occur, b) how the IS field should move forward to foster the genre of LRs, and c) what best practices are to train doctoral IS students in publishing LRs. This article reports the key takeaways of this panel discussion. Guidance for IS scholars is provided on how to conduct LRs that contribute to the cumulative knowledge development within and across the IS field to best prepare the next generation of IS scholars.}}, author = {{Schryen, Guido and Benlian, Alexander and Rowe, Frantz and Shirley, Gregor and Larsen, Kai and Petter, Stacie and Par{\'e}, Guy and Wagner, Gerit and Haag, Steffi and Yasasin, Emrah}}, issn = {{1529-3181}}, journal = {{Communications of the AIS}}, keywords = {{Literature Review, Review Methodology, Research Methodology, Doctoral Training}}, pages = {{557 -- 569}}, publisher = {{Association for Information Systems (AIS)}}, title = {{{Literature Reviews in IS Research: What Can Be Learnt from the Past and Other Fields?}}}, volume = {{40}}, year = {{2017}}, }