@misc{Kraemer, author = {Kr{\"a}mer, Stefan}, title = {Effects of Arbitrary Hardware Faults on Multicore Scheduling in Safety-critical Applications - Evaluation by enhanced Markov models and discrete event simulation}, series = {2014 PESW - The 2nd Prague Embedded Systems Workshop, June 2014}, journal = {2014 PESW - The 2nd Prague Embedded Systems Workshop, June 2014}, language = {en} } @article{JoblinApelMauerer, author = {Joblin, Mitchell and Apel, Sven and Mauerer, Wolfgang}, title = {Evolutionary trends of developer coordination: a network approach}, series = {Empirical Software Engineering}, volume = {22}, journal = {Empirical Software Engineering}, number = {4}, publisher = {Springer}, doi = {10.1007/s10664-016-9478-9}, pages = {2050 -- 2094}, abstract = {Software evolution is a fundamental process that transcends the realm of technical artifacts and permeates the entire organizational structure of a software project. By means of a longitudinal empirical study of 18 large open-source projects, we examine and discuss the evolutionary principles that govern the coordination of developers. By applying a network-analytic approach, we found that the implicit and self-organizing structure of developer coordination is ubiquitously described by non-random organizational principles that defy conventional software-engineering wisdom. In particular, we found that: (a) developers form scale-free networks, in which the majority of coordination requirements arise among an extremely small number of developers, (b) developers tend to accumulate coordination requirements with more and more developers over time, presumably limited by an upper bound, and (c) initially developers are hierarchically arranged, but over time, form a hybrid structure, in which core developers are hierarchically arranged and peripheral developers are not. Our results suggest that the organizational structure of large projects is constrained to evolve towards a state that balances the costs and benefits of developer coordination, and the mechanisms used to achieve this state depend on the project's scale.}, language = {en} } @inproceedings{BauerGrossmannSchlegletal., author = {Bauer, Gregor and Grossmann, Benjamin and Schlegl, Thomas and Kobayashi, Hiroshi}, title = {Modeling, identification and control of an antagonistically actuated joint for telerobotic systems}, series = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, booktitle = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, publisher = {IEEE}, doi = {10.1109/IECON.2015.7392676}, pages = {3696 -- 3701}, abstract = {Within this paper a modeling, identification and control technique for an antagonistically actuated joint consisting of two pneumatically actuated muscles is presented. The antagonistically actuated joint acts as a test bench for control architectures which are going to be used to control an exoskeleton within a telerobotic system. A static and dynamic model of the muscle and the joint is derived and the parameters of the models are identified using a least-squares algorithm. The control architecture, consisting of a inner pressure and an outer position controller is presented. The pressure controller is evaluated using switching valves compared against proportional valves.}, language = {en} } @inproceedings{RamsauerKiszkaLohmannetal., author = {Ramsauer, Ralf and Kiszka, Jan and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Look Mum, no VM Exits! (Almost)}, series = {Proceedings of the 13th Annual Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT '17)}, booktitle = {Proceedings of the 13th Annual Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT '17)}, doi = {10.48550/arXiv.1705.06932}, abstract = {Multi-core CPUs are a standard component in many modern embedded systems. Their virtualisation extensions enable the isolation of services, and gain popularity to implement mixed-criticality or otherwise split systems. We present Jailhouse, a Linux-based, OS-agnostic partitioning hypervisor that uses novel architectural approaches to combine Linux, a powerful general-purpose system, with strictly isolated special-purpose components. Our design goals favour simplicity over features, establish a minimal code base, and minimise hypervisor activity. Direct assignment of hardware to guests, together with a deferred initialisation scheme, offloads any complex hardware handling and bootstrapping issues from the hypervisor to the general purpose OS. The hypervisor establishes isolated domains that directly access physical resources without the need for emulation or paravirtualisation. This retains, with negligible system overhead, Linux's feature-richness in uncritical parts, while frugal safety and real-time critical workloads execute in isolated, safe domains.}, language = {en} } @inproceedings{PichaBradaRamsaueretal., author = {Picha, Petr and Brada, Premek and Ramsauer, Ralf and Mauerer, Wolfgang}, title = {Towards Architect's Activity Detection through a Common Model for Project Pattern Analysis}, series = {First International Workshop on the Social and Organization Dimensions of Software, 5-7 April 2017, Gothenburg, Sweden}, booktitle = {First International Workshop on the Social and Organization Dimensions of Software, 5-7 April 2017, Gothenburg, Sweden}, publisher = {IEEE}, doi = {10.1109/ICSAW.2017.46}, pages = {175 -- 178}, abstract = {Software development projects leave a large amount of data in repositories of Application Lifecycle Management (ALM) tools. These data contain detailed histories of their respective projects, their results and decisions made along the way. Analysis of such data helps uncover various interesting facts about projects, e.g. their socio-technical structures and the actual (vs. purported) roles of team members. Based on experiences with tools supporting our research we are convinced that it is feasible to consolidate data from different ALM tools, tapping into the situation common in real-life projects. In this paper we report on our work towards a shared common data model and tool integration aimed at improved project analysis. We discuss how this can help in the identification of architects in the project organizational structures, their activity patterns and collaboration with other team roles.}, language = {en} } @inproceedings{RamsauerLohmannMauerer, author = {Ramsauer, Ralf and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Observing Custom Software Modifications: A Quantitative Approach of Tracking the Evolution of Patch Stacks}, series = {Proceedings of the 12th International Symposium on Open Collaboration (OpenSym '16)}, booktitle = {Proceedings of the 12th International Symposium on Open Collaboration (OpenSym '16)}, editor = {Wassermann, Tony}, publisher = {ACM}, address = {New York}, doi = {10.1145/2957792.2957810}, pages = {1 -- 4}, abstract = {Modifications to open-source software (OSS) are often provided in the form of "patch stacks" -- sets of changes (patches) that modify a given body of source code. Maintaining patch stacks over extended periods of time is problematic when the underlying base project changes frequently. This necessitates a continuous and engineering-intensive adaptation of the stack. Nonetheless, long-term maintenance is an important problem for changes that are not integrated into projects, for instance when they are controversial or only of value to a limited group of users. We present and implement a methodology to systematically examine the temporal evolution of patch stacks, track non-functional properties like integrability and maintainability, and estimate the eventual economic and engineering effort required to successfully develop and maintain patch stacks. Our results provide a basis for quantitative research on patch stacks, including statistical analyses and other methods that lead to actionable advice on the construction and long-term maintenance of custom extensions to OSS.}, language = {en} } @inproceedings{JoblinMauererApeletal., author = {Joblin, Mitchell and Mauerer, Wolfgang and Apel, Sven and Siegmund, Janet and Riehle, Dirk}, title = {From Developer Networks to Verified Communities: A Fine-Grained Approach}, series = {2015 IEEE/ACM 37th IEEE International Conference on Software Engineering, 16-24 May 2015, Florence, Italy}, booktitle = {2015 IEEE/ACM 37th IEEE International Conference on Software Engineering, 16-24 May 2015, Florence, Italy}, publisher = {IEEE}, isbn = {978-1-4799-1934-5}, doi = {10.1109/icse.2015.73}, pages = {563 -- 573}, abstract = {Effective software engineering demands a coordinated effort. Unfortunately, a comprehensive view on developer coordination is rarely available to support software-engineering decisions, despite the significant implications on software quality, software architecture, and developer productivity. We present a fine-grained, verifiable, and fully automated approach to capture a view on developer coordination, based on commit information and source-code structure, mined from version-control systems. We apply methodology from network analysis and machine learning to identify developer communities automatically. Compared to previous work, our approach is fine-grained, and identifies statistically significant communities using order-statistics and a community-verification technique based on graph conductance. To demonstrate the scalability and generality of our approach, we analyze ten open-source projects with complex and active histories, written in various programming languages. By surveying 53 open-source developers from the ten projects, we validate the authenticity of inferred community structure with respect to reality. Our results indicate that developers of open-source projects form statistically significant community structures and this particular view on collaboration largely coincides with developers' perceptions of real-world collaboration.}, language = {en} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {Open Source in Research and Reality}, series = {Open Source Summit North America and Embedded Linux Conference North America 2020}, journal = {Open Source Summit North America and Embedded Linux Conference North America 2020}, language = {en} } @misc{MauererWagner, author = {Mauerer, Wolfgang and Wagner, Daniel}, title = {Cyclic Tests Unleashed: Large-Scale RT Analysis with Jitterdebugger}, series = {Open Source Summit, North America, 17.07.2019}, journal = {Open Source Summit, North America, 17.07.2019}, language = {en} } @misc{RamsauerDudaMauereretal., author = {Ramsauer, Ralf and Duda, Sebastian and Mauerer, Wolfgang and Bulwahn, Lukas}, title = {The list is our process: An analysis of the kernel's email-based development process}, series = {Linux Plumbers Conference, Lisbon September 9, 2019}, journal = {Linux Plumbers Conference, Lisbon September 9, 2019}, language = {en} } @misc{MauererRamsauer, author = {Mauerer, Wolfgang and Ramsauer, Ralf}, title = {Torturing Git for Fun and Profit}, series = {Microsoft Developer Meetup Regensburg 02.04.2019}, journal = {Microsoft Developer Meetup Regensburg 02.04.2019}, abstract = {In diesem Talk blicken Prof. Dr. Wolfgang Mauerer und Ralf Ramsauer unter die Haube des verteilten Versionskontrollsystems Git. Neben einer genauen Beschreibung der Strukturen und Plumbing APIs, mit denen Git intern Commits erzeugt und verkn{\"u}pft, gehen die Vortragenden auch auf n{\"u}tzliche Features und Standards ein, welche die Kollaborition in großen Open-Source Projekten erleichtern.}, language = {en} } @inproceedings{Mauerer, author = {Mauerer, Wolfgang}, title = {Are any big brothers watching you, and if yes, what can they tell about Debian}, series = {DebConf18 Hsinchu, Taiwan}, booktitle = {DebConf18 Hsinchu, Taiwan}, abstract = {Debian, as a collection of software packages and components, is known to be one of the largest software projects in the history of mankind. Combined with a traceable history over many years, the artefacts created by Debian developers and users make it one of science's favourite targets to quantitatively or qualitatively understand how real-world software development works (or does not), how people collaborate, and many other other related questions. Unfortunately, while scientists make ample use of the resources and artefacts created by FLOSS and friends, the exchange of insights and ideas does not seem to extend in both directions: Developers, users and integrators are often unaware of results obtained in science. This talk will introduce the Debian community to a selection the most important results obtained by scientific (software engineering) research, with a special focus on large-scale socio-technical analysis of projects like Debian, and the possible implications and improvements these may bring to Debian development itself.}, language = {en} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {Embedded Linux Quality Assurance: How to Not Lie with Statistics}, series = {Embedded Linux Conference North America ; OpenIoTSummit North America}, journal = {Embedded Linux Conference North America ; OpenIoTSummit North America}, abstract = {Embedded Linux drives an every-increasing number of appliances in many domains and applications, some even real-time and/or safety critical. Traditional quality assurance of such systems is based on testing and formal verification, but the huge amount of code and the rapid dynamics of the Linux ecosystem, as well as fundamental limitations of formal methods make these approaches unsatisfactory. Statistical quality assurance for reliability, error rates, maximal latencies etc. is needed. We will discuss current best practises, how to design and run automated statistical tests that capture relevant information, and how to properly evaluate the resulting data. Practical real-world examples and recipes are played through using the open source R language. Most importantly, we identify common mistakes in (over-)interpreting statistical results and predictions that may eventually harm people.}, language = {en} } @misc{RamsauerKiszkaMauerer, author = {Ramsauer, Ralf and Kiszka, Jan and Mauerer, Wolfgang}, title = {Spectre and Meltdown vs. Real-Time: How Much do Mitigations Cost?}, series = {Embedded Linux Conference Europe 2018, October 22 - 24, 2018, Edinburgh, UK}, journal = {Embedded Linux Conference Europe 2018, October 22 - 24, 2018, Edinburgh, UK}, language = {en} } @misc{RamsauerKiszkaMauerer, author = {Ramsauer, Ralf and Kiszka, Jan and Mauerer, Wolfgang}, title = {Building Mixed Criticality Linux Systems with the Jailhouse Hypervisor}, series = {Embedded Lunux Conference + OpenIoTSummit, Portland, OR, 21.-23.02.2017}, journal = {Embedded Lunux Conference + OpenIoTSummit, Portland, OR, 21.-23.02.2017}, abstract = {The partitioning hypervisor Jaihouse allows us to run safety critical and uncritical applications in parallel on a single SoC. We present our experiences when porting a safety and real-time critical existing application as a Jailhouse guest. It shows a novel and promising approach for implementing mixed-criticality applications with real-time requirement while not loosing the benefits of Linux. This is done by static partitioning of hardware resources; guests do not interfere. We will present a multicopter platform running the real-time critical flight stack in an isolated Jailhouse guest. This proves the practicability of Jailhouse as well as the suitability for real-time safety critical systems by porting an existing application to a Jailhouse cell. We stress its concept and show up current hardware limitations, like undesired behaviour and present possible workarounds and solutions.}, language = {en} } @inproceedings{MurrMauerer, author = {Murr, Florian and Mauerer, Wolfgang}, title = {McFSM: Globally Taming Complex Systems}, series = {2017 IEEE/ACM 3rd International Workshop on Software Engineering for Smart Cyber-Physical Systems (SEsCPS), 21-21 May 2017, Buenos Aires, Argentina}, booktitle = {2017 IEEE/ACM 3rd International Workshop on Software Engineering for Smart Cyber-Physical Systems (SEsCPS), 21-21 May 2017, Buenos Aires, Argentina}, publisher = {IEEE}, doi = {10.1109/SEsCPS.2017.7}, pages = {26 -- 29}, abstract = {Industrial computing devices, in particular cyber-physical, real-time and safety-critical systems, focus on reacting to external events and the need to cooperate with other devices to create a functional system. They are often implemented with languages that focus on a simple, local description of how a component reacts to external input data and stimuli. Despite the trend in modern software architectures to structure systems into largely independent components, the remaining interdependencies still create rich behavioural dynamics even for small systems. Standard and industrial programming approaches do usually not model or extensively describe the global properties of an entire system. Although a large number of approaches to solve this dilemma have been suggested, it remains a hard and error-prone task to implement systems with complex interdependencies correctly. We introduce multiple coupled finite state machines (McFSMs), a novel mechanism that allows us to model and manage such interdependencies. It is based on a consistent, well-structured and simple global description. A sound theoretical foundation is provided, and associated tools allow us to generate efficient low-level code in various programming languages using model-driven techniques. We also present a domain specific language to express McFSMs and their connections to other systems, to model their dynamic behaviour, and to investigate their efficiency and correctness at compile-time.}, language = {en} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {Safety, Security, Quality: Artificial Intelligence versus Common Sense}, series = {Open Source Summit North America and Embedded Linux Conference North America 2020}, journal = {Open Source Summit North America and Embedded Linux Conference North America 2020}, language = {en} } @misc{MauererWagner, author = {Mauerer, Wolfgang and Wagner, Daniel}, title = {Cyclic Tests Unleashed: Large-Scale RT Analysis with Jitterdebugger}, series = {Open Source Summit Japan (Tokio) and OSSNA 17.07.2019}, journal = {Open Source Summit Japan (Tokio) and OSSNA 17.07.2019}, language = {en} } @misc{RamsauerDudaBulwahnetal., author = {Ramsauer, Ralf and Duda, Sebastian and Bulwahn, Lukas and Mauerer, Wolfgang}, title = {The list is our process! An analysis of the kernel's email-based development process}, series = {Embedded Linux Conference Europe, Lyon 28.10.2019}, journal = {Embedded Linux Conference Europe, Lyon 28.10.2019}, language = {en} } @misc{RamsauerKiszkaLohmannetal., author = {Ramsauer, Ralf and Kiszka, Jan and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Implementierung gemischt kritischer Systeme durch statische Hardwarepartitionierung}, series = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hannover, 2. M{\"a}rz 2018}, journal = {Fr{\"u}hjahrstreffen der Fachgruppen Betriebssysteme, Hannover, 2. M{\"a}rz 2018}, language = {de} } @misc{RamsauerLohmannMauerer, author = {Ramsauer, Ralf and Lohmann, Daniel and Mauerer, Wolfgang}, title = {Quantifying Upstream Integration with PaStA}, series = {LTSI Workshop @ ELC17}, journal = {LTSI Workshop @ ELC17}, language = {en} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {Socio-Technical Aspects of Long Term Embedded Systems Maintenance}, series = {Embedded Linux Conference, April 4-6, 2016, San Diego}, journal = {Embedded Linux Conference, April 4-6, 2016, San Diego}, language = {en} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {Approaches to Ultra Long-Term System Maintenance}, series = {Embedded Linux Conference Europe (Berlin), 2016}, journal = {Embedded Linux Conference Europe (Berlin), 2016}, language = {en} } @inproceedings{Mauerer, author = {Mauerer, Wolfgang}, title = {A Virtual Computing Platform for the Internet of Things}, series = {Embedded Linux Conference (San Diego), 2016}, booktitle = {Embedded Linux Conference (San Diego), 2016}, language = {de} } @misc{Mauerer, author = {Mauerer, Wolfgang}, title = {OSS Community, Health and Ecosystem Research: Theory and, or Theory versus Practice?}, series = {2nd International Workshop on Software Health (SoHEAL@ICSE, Montr{\´e}al), 2019}, journal = {2nd International Workshop on Software Health (SoHEAL@ICSE, Montr{\´e}al), 2019}, language = {en} } @incollection{LangSchlegl, author = {Lang, Jonas and Schlegl, Thomas}, title = {Camera-Projector Calibration - Methods, Influencing Factors and Evaluation Using a Robot and Structured-Light 3D Reconstruction}, series = {Intelligent Robotics and Applications}, volume = {9835}, booktitle = {Intelligent Robotics and Applications}, editor = {Kubota, Naoyuki and Kiguchi, Kazuo and Liu, Honghai and Obo, Takenori}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-43517-6}, doi = {10.1007/978-3-319-43518-3_40}, pages = {413 -- 427}, abstract = {As camera and projector hardware gets more and more affordable and software algorithms more sophisticated, the area of application for camera-projector configurations widens its scope. Unlike for sole camera calibration, only few comparative surveys for projector calibration methods exist. Therefore, in this paper, two readily available algorithms for the calibration of those arrays are studied and methods for the evaluation of the results are proposed. Additionally, statistical evaluations under consideration of different influencing factors like the hardware arrangement, the number of input images or the calibration target characteristics on the accuracy of the calibration results are performed. Ground truth comparison data is realized through a robotic system and structured light 3D scanning.}, language = {en} } @inproceedings{Roesel, author = {R{\"o}sel, Birgit}, title = {Erfahrungen mit einem Konzept f{\"u}r eine Kombination aus Vorlesung, {\"U}bung und Praktikum unter Verwendung aktivierender Lehrmethoden}, series = {Forum der Lehre : Digitale Akzente setzen}, booktitle = {Forum der Lehre : Digitale Akzente setzen}, pages = {33 -- 41}, abstract = {Im Beitrag wird das Konzept mit JiTT-Einheiten, klassischen Vorlesungen, {\"U}bungen und dem Praktikum vorgestellt. Insbesondere erfolgt eine Beschreibung der Struktur der Lehrtexte und der zugeh{\"o}renden Fragen. Nachfolgend werden Herausforderungen bei der Umsetzung des Konzeptes dargestellt. Betrachtet wird hier die Entscheidung {\"u}ber Anzahl der Lehrtexte sowie die Erstellung derselben durch die Autorin sowie die Umsetzung des gesamten Konzeptes auf einer Online-Plattform. Abschließend werden die Reaktionen und R{\"u}ckmeldungen der Studierenden zu dem neuen Lehrkonzept dargestellt. Basis sind hierbei die Auswertung der Beantwortung der Fragen in den JiTT-Einheiten sowie Befragungen der Studierenden mit verschiedenen Frageb{\"o}gen.}, language = {de} } @misc{Schildgen, author = {Schildgen, Johannes}, title = {Sprachkurs Java}, edition = {1. Aufl.}, publisher = {oomoxx media e.K.}, address = {Cuxhafen}, isbn = {9783944787404}, pages = {609 Minuten}, abstract = {Java ist eine der popul{\"a}rsten Programmiersprachen {\"u}berhaupt. Lerne in diesem H{\"o}rbuch die Sprache Java und die Konzepte der objektorientierten Programmierung kennen, egal ob bei der Autofahrt, beim Putzen oder Kochen. Wir beginnen mit den Grundlagen {\"u}bers Programmieren im Allgemeinen. Ein Vorwissen in einer Programmiersprache ist zwar hilfreich, aber absolut nicht notwendig. Du lernst, was Variablen, Schleifen, Klassen und Methoden sind und wie du sie verwendest. Eines der wichtigsten Konzepte der objektorientierten Programmierung nennt sich Vererbung. Daher wirst du alles dazu lernen, was du wissen musst. Auch den Umgang mit Exceptions und mit Dateien will ich dir ans Herz legen. Du lernst zudem die verschiedenen Collection-Types, Generics und Lambda-Ausdr{\"u}cke kennen. Außerdem gibt's am Ende noch einen Ausblick, der zeigt, was du mit Java alles programmieren kannst: Android-Apps, GUI-Anwendungen, Web-Apps und vieles mehr. Programmieren lernen mit einem H{\"o}rbuch ist ein innovatives Format und bietet interaktive M{\"o}glichkeiten der Lernkontrolle in Form von Quiz-Fragen, bei denen du als H{\"o}rer aktiv mitmachen kannst.}, language = {de} } @inproceedings{WeissSchroetterHackenberg, author = {Weiss, Nils and Schr{\"o}tter, Markus and Hackenberg, Rudolf}, title = {On Threat Analysis and Risk Estimation of Automotive Ransomware}, series = {ACM Computer Science in Cars Symposium : [CSCS '19) 08.10.2019, Kaiserslautern, Germany}, booktitle = {ACM Computer Science in Cars Symposium : [CSCS '19) 08.10.2019, Kaiserslautern, Germany}, editor = {Hof, Hans-Joachim and Fritz, Mario and Krauß, Christoph and Wasenm{\"u}ller, Oliver}, publisher = {ACM}, address = {New York, NY, USA}, isbn = {9781450370042}, doi = {10.1145/3359999.3360492}, pages = {1 -- 9}, language = {en} } @article{BorgFrikelJorgensenetal., author = {Borg, Leise and Frikel, J{\"u}rgen and Jorgensen, Jakob Sauer and Quinto, Eric Todd}, title = {Analyzing Reconstruction Artifacts from Arbitrary Incomplete X-ray CT Data}, series = {SIAM Journal on Imaging Sciences}, volume = {11}, journal = {SIAM Journal on Imaging Sciences}, number = {4}, publisher = {SIAM PUBLICATIONS}, doi = {10.1137/18M1166833}, pages = {2786 -- 2814}, abstract = {This article provides a mathematical analysis of singular (nonsmooth) artifacts added to reconstructions by filtered backprojection (FBP) type algorithms for X-ray computed tomography (CT) with arbitrary incomplete data. We prove that these singular artifacts arise from points at the boundary of the data set. Our results show that, depending on the geometry of this boundary, two types of artifacts can arise: object-dependent and object-independent artifacts. Object-dependent artifacts are generated by singularities of the object being scanned, and these artifacts can extend along lines. They generalize the streak artifacts observed in limited-angle tomography. Object-independent artifacts, on the other hand, are essentially independent of the object and take one of two forms: streaks on lines if the boundary of the data set is not smooth at a point and curved artifacts if the boundary is smooth locally. We prove that these streak and curve artifacts are the only singular artifacts that can occur for FBP in the continuous case. In addition to the geometric description of artifacts, the article provides characterizations of their strength in Sobolev scale in certain cases. The results of this article apply to the well-known incomplete data problems, including limited-angle and regionof-interest tomography, as well as to unconventional X-ray CT imaging setups that arise in new practical applications. Reconstructions from simulated and real data are analyzed to illustrate our theorems, including the reconstruction that motivated this work a synchrotron data set in which artifacts appear on lines that have no relation to the object.}, language = {en} } @article{KuypersUcke, author = {Kuypers, Friedhelm and Ucke, Christian}, title = {Bierdeckelsalto}, series = {Physik in unserer Zeit}, volume = {46}, journal = {Physik in unserer Zeit}, number = {4}, publisher = {Wiley}, doi = {10.1002/piuz.201401395}, pages = {194 -- 198}, abstract = {Ein beliebtes Spiel besteht darin, einen auf einer Tischkante liegenden Bierdeckel von unten mit den ausgestreckten Fingern hochzuschnellen und dann nach einem oder mehreren Saltos zwischen Finger und Daumen wieder aufzufangen. Physikalisch gesehen, {\"u}bt man einen Stoß auf den Bierdeckel aus. Die Anwendung von Impuls- und Drehimpulssatz f{\"u}hrt zu einfachen Absch{\"a}tzungen zur Mechanik des Bierdeckelsaltos. Mit Physik-Simulationsprogrammen l{\"a}sst sich dieses Experiment nachvollziehen. Highspeed-Videos erg{\"a}nzen Theorie und Simulation.}, language = {de} } @article{RaulfStein, author = {Raulf, Nicole and Stein, Oliver}, title = {A TRACE FORMULA FOR HECKE OPERATORS ON VECTOR-VALUED MODULAR FORMS}, series = {GLASGOW MATHEMATICAL JOURNAL}, volume = {59}, journal = {GLASGOW MATHEMATICAL JOURNAL}, number = {1}, publisher = {Cambridge University Press}, doi = {10.1017/S0017089516000094}, pages = {143 -- 165}, abstract = {We present a ready to compute trace formula for Hecke operators on vector-valued modular forms of integral weight for SL2(Z) transforming under the Weil representation. As a corollary, we obtain a ready to compute dimension formula for the corresponding space of vector-valued cusp forms, which is more general than the dimension formulae previously published in the vector-valued setting.}, language = {en} } @article{NiedersteinerLangPohltetal., author = {Niedersteiner, Sascha and Lang, Jonas and Pohlt, Clemens and Schlegl, Thomas}, title = {Klassifikation des Arbeitsfortschritts}, series = {atp magazin}, volume = {59}, journal = {atp magazin}, number = {11}, publisher = {Vulkan-Verlag}, doi = {10.17560/atp.v59i11.1911}, pages = {58 -- 66}, abstract = {Steigende Anforderungen an die Qualit{\"a}t von zum Teil manuell gefertigten Produkten f{\"u}hren dazu, dass Handarbeitspl{\"a}tze mit Assistenzsystemen f{\"u}r die Unterst{\"u}tzung der am Arbeitsplatz arbeitenden Mitarbeiterinnen und Mitarbeiter ausgestattet werden. Der Beitrag beschreibt einen neuen Ansatz, um mittels Verfahren des maschinellen Lernens die Objekterkennung sowie die Transitionen eines, den Arbeitsprozess repr{\"a}sentierenden Zustandsautomaten eines solchen Systems einzulernen. Hierf{\"u}r werden nach einer Vorverarbeitung Daten aus einer Tiefenkamera in drei Stufen durch Support Vector Machines (SVM) klassifiziert und das Ergebnis mit dem Zustandsautomaten verkn{\"u}pft. Das Konzept wird an einem industriellen Montageprozess {\"u}berschaubarer Komplexit{\"a}t evaluiert; es zeigt gute Ergebnisse hinsichtlich der Robustheit gegen{\"u}ber Fehlern bei der Objektklassifikation.}, language = {de} } @article{NiedersteinerLangPohltetal., author = {Niedersteiner, Sascha and Lang, Jonas and Pohlt, Clemens and Schlegl, Thomas}, title = {Tracking work task completion - A support vector machine approach for assisting workbenches}, series = {atp edition}, journal = {atp edition}, number = {11}, publisher = {DIV Deutscher Industrieverl.}, doi = {10.17560/atp.v59i11.1911}, pages = {58 -- 66}, abstract = {Tightening quality requirements of industrial products involving manual assembly lead to the development of assisting workbenches with integrated functions to support workers performing these manual tasks. This contribution discusses a new approach to learning transitions of a finite state automaton representing the sequence of work tasks based on the video stream of a 3D depth camera. Preprocessed video data is fed into a three-stage classification scheme based on support vector machines. The results of the classification are then related to the state automation to trigger state transitions indicating the completion of a specific work task and the start of the next one. The proposed approach has been evaluated at an industrial assembly process of moderate complexity and shows very robust results with respect to disturbances caused by inaccurate object classification.}, language = {en} } @inproceedings{GaborZielinskiFeldetal., author = {Gabor, Thomas and Zielinski, Sebastian and Feld, Sebastian and Roch, Christoph and Seidel, Christian and Neukart, Florian and Galter, Isabella and Mauerer, Wolfgang and Linnhoff-Popien, Claudia}, title = {Assessing Solution Quality of 3SAT on a Quantum Annealing Platform}, series = {Quantum Technology and Optimization Problems : First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings}, volume = {11413}, booktitle = {Quantum Technology and Optimization Problems : First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings}, editor = {Feld, Sebastian and Linnhoff-Popien, Claudia}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-14081-6}, doi = {10.1007/978-3-030-14082-3_3}, pages = {23 -- 35}, language = {en} } @article{SonarWeber, author = {Sonar, Arne and Weber, Karsten}, title = {KI gestern und heute : Einsichten aus der Fr{\"u}hgeschichte der KI f{\"u}r aktuelle ethische {\"U}berlegungen zum Einsatz von KI in der Medizin}, series = {Arbeit}, volume = {29}, journal = {Arbeit}, number = {2}, doi = {10.1515/arbeit-2020-0009}, pages = {105 -- 122}, abstract = {Der Einzug K{\"u}nstlicher Intelligenz (KI) in die Medizin scheint angesichts der Nutzenpotenziale unvermeidlich. Durch den Agentencharakter KI-basierter Systeme ergeben sich teils neuartige normative An- und Herausforderungen. F{\"u}r den hochgradig sensiblen Anwendungsbereich der Medizin erscheint es daher notwendig, den KI-Einsatz mit ethischen Leitlinien einzuhegen. Dies wirft die Frage auf, auf welche Erfahrungsbasis eine ethische Fundierung des Einsatzes KI-basierter Technik gestellt werden k{\"o}nnte. Damit ist kein Schluss vom Sein auf das Sollen gemeint, sondern die Ber{\"u}cksichtigung bereits gef{\"u}hrter normativer Debatten. Eine M{\"o}glichkeit, sich der normativen Landschaft der KI anzun{\"a}hern, liegt in der Auseinandersetzung mit der Entwicklungsgeschichte der KI und den damit verbundenen Debatten um ethische und soziale Aspekte. Mit diesem explorativen Ansatz k{\"o}nnen relevante Problemfelder identifiziert, vorl{\"a}ufige Gestaltungs- und Einsatzempfehlungen f{\"u}r KI-Systeme in der Praxis formuliert und Vorschl{\"a}ge zu deren Einbettung in existierende Organisationsstrukturen generiert werden.}, language = {de} } @techreport{BresinskySchroederViscardi, author = {Bresinsky, Markus and Schroeder, Johanna and Viscardi, Valerio}, title = {Strategic Forecasting with Machine Learning for Regional Geopolitical Analysis}, language = {en} } @inproceedings{NeubauerFischerHackenberg, author = {Neubauer, Katrin and Fischer, Sebastian and Hackenberg, Rudolf}, title = {Risk Analysis of the Cloud Infrastructure of Smart Grid and Internet of Things}, series = {The Tenth International Conference on Cloud Computing, GRIDs, and Virtualization, (CLOUD COMPUTING 2019), 10th Mai 2019, Venice, Italy}, booktitle = {The Tenth International Conference on Cloud Computing, GRIDs, and Virtualization, (CLOUD COMPUTING 2019), 10th Mai 2019, Venice, Italy}, publisher = {IARIA}, isbn = {978-1-61208-703-0}, issn = {2308-4294}, pages = {82 -- 87}, abstract = {Cloud Computing (CC), Internet of Thing (IoT) and Smart Grid (SG) are separate technologies. The digital transformation of the energy industry and the increasing digitalization in the private sector connect these technologies. At the moment, CC is used as a service provider for IoT. Currently in Germany, the SG is under construction and a cloud connection to the infrastructure has not been implemented yet. To build the SG cloud, the new laws for privacy must be implemented and therefore it's important to know which data can be stored and distributed over a cloud. In order to be able to use future innovative services, SG and IoT must be combined. For this, in the next step we connect the SG infrastructure with the IoT. A potential insecure device and network (IoT) should be able to transfer data to and from a critical infrastructure (SG). In detail, we focus on two different connections: the communication between the smart meter switching box and the IoT device and the data transferred between the IoT and SG cloud. In our example, a connected charging station with cloud services is connected with a SG infrastructure. To create a really smart service, the charging station needs a connection to the SG to get the current amount of renewable energy in the grid. Private data, such as name, address and payment details, should not be transferred to the IoT cloud. With these two connections, new threads emerge. In this case, availability, confidentiality and integrity must be ensured. A risk analysis over all the cloud connections, including the vulnerability and the ability of an attacker and the resulting risk are developed in this paper.}, language = {en} } @inproceedings{NeubauerFischerHackenberg, author = {Neubauer, Katrin and Fischer, Sebastian and Hackenberg, Rudolf}, title = {Work in Progress: Security Analysis for Safety-critical Systems}, series = {ARCS Workshop 2019; 32nd International Conference on Architecture of Computing Systems, May 2019, Copenhagen, Denmark, Workshop FORMUS³IC}, booktitle = {ARCS Workshop 2019; 32nd International Conference on Architecture of Computing Systems, May 2019, Copenhagen, Denmark, Workshop FORMUS³IC}, editor = {Trinitis, Carsten and Pionteck, Thilo}, publisher = {VDE Verlag GmbH}, address = {Berlin}, isbn = {978-3-8007-4957-7}, pages = {101 -- 106}, abstract = {Internet of Thing (IoT) and Smart Grid (SG) are separate technologies. The digital transformation of the energy industry and the increasing digitalization in the private sector connect these technologies. Currently in Germany, the SG is under construction. In order to use future innovative services, SG and IoT must be combined. For this, we connect the SG Infrastructure with the IoT. A potential insecure device and network (IoT) should be able to transfer data to and from a critical infrastructure (SG). Open research question in this context are the security requirements architecture SG and IoT and the mechanism for authentication and authorisation in future application (SG and IoT). Due to the increasing networking of the systems (SG and IoT) new threats and attack vectors arise. The attacks to the architecture influence the target of authenticity, security and privacy. For the security analysis we focus on two communication points: the communication between the smart meter gateway, and the IoT device. In our example, a connected charging station with cloud services is connected with a SG infrastructure. To create a really smart service, the charging station needs a connection to the SG to get the current amount of renewable energy in the grid. With this two connections, new threats emerge. A security analysis over all the connections, including the vulnerability and the ability of an attacker, is developed in this paper. The analysis shows us challenges of the communication between IoT and SG. For this, we defined technical and organizational requirements for authentication and authorization. Current authentication and authorization mechanisms are no longer sufficient for the defined requirements. We present the Role-based trust model for Safety-critical Systems for these defined requirements. The new trust model is integrated into a role-based access control model. It defines data classes, which separate the sensitive and non-sensitive information.}, language = {en} } @inproceedings{PozzobonWeissRenneretal., author = {Pozzobon, Enrico and Weiss, Nils and Renner, Sebastian and Hackenberg, Rudolf}, title = {A Survey on Media Access Solutions for CAN Penetration Testing}, series = {ACM Computer Science in Cars Symposium (CSCS), 2nd, 2018, Munich, Germany}, booktitle = {ACM Computer Science in Cars Symposium (CSCS), 2nd, 2018, Munich, Germany}, abstract = {Controller Area Network (CAN) is still the most used network technology in today's connected cars. Now and in the near future, penetration tests in the area of automotive security will still require tools for CAN media access. More and more open source automotive penetration tools and frameworks are presented by researchers on various conferences, all with different properties in terms of usability, features and supported use-cases. Choosing a proper tool for security investigations in automotive network poses a challenge, since lots of different solutions are available. This paper compares currently available CAN media access solutions and gives advice on competitive hard-and software tools for automotive penetration testing.}, language = {en} } @misc{WeissPozzobon, author = {Weiss, Nils and Pozzobon, Enrico}, title = {IOT Backdoors in Cars}, series = {IT Security Conference Troopers19, 2019, Heidelberg, Germany}, journal = {IT Security Conference Troopers19, 2019, Heidelberg, Germany}, abstract = {Connecting cheap IoT devices to the safety-critical network of a car can be an extremely bad idea, but at least it allows us to hack together our own automotive gadget. This talk explains the complete procedure involved in transforming a cheap OBD GSM dongle designed for fleet management into a open source automotive hacking tool. First, the hardware reverse engineering is demonstrated, showing how each component is interconnected and working together. With this knowledge, it was possible to capture the communication of the GSM module and understand the OTA protocol used by this dongle, which can be used to extract the firmware. A quick reverse engineering of the software will show that no cryptographic authentication is used for the OTA updates, and therefore a pirate GSM BTS can be used to obtain remote code execution. After that, a new open source firmware is written for the device, which can easily be extended and controlled remotely with the LUA scripting language. Examples on how hacking this dongle remotely can affect the safety of the driver will be also given.}, language = {en} } @unpublished{BorgFrikelJorgensenetal., author = {Borg, Leise and Frikel, J{\"u}rgen and J{\o}rgensen, Jakob and Quinto, Eric Todd}, title = {Theorems that Characterize Artifacts for Arbitrary Limited X-ray CT Data}, edition = {version 6}, abstract = {This article provides a mathematical classification of artifacts from arbitrary incom-plete X-ray tomography data when using the classical filtered backprojection algorithm. Usingmicrolocal analysis, we prove that all artifacts arise from points at the boundary of the data set.Our results show that, depending on the geometry of the data set boundary, two types of artifactscan arise: object-dependent and object-independent artifacts. The object-dependent artifacts aregenerated by singularities of the object being scanned and these artifacts can extend all along lines.This is a generalization of the streak artifacts observed in limited angle CT. The article also char-acterizes two new phenomena: the object-independent artifacts are caused only by the geometryof the data set boundary; they occur along lines if the boundary of the data set is not smooth andalong curves if the boundary of the data set is smooth. In addition to the geometric descriptionof artifacts, the article also provides characterizations of their strength in Sobolev scale in certaincases. Moreover, numerical reconstructions from simulated and real data are presented illustratingour theorems.This work is motivated by a reconstruction we present from a synchrotron data set in whichartifacts along lines appeared that were independent of the object.The results of this article apply to a wide range of well-known incomplete data problems, in-cluding limited angle CT and region of interest tomography, as well as to unconventional x-ray CTimaging setups. Some of those problems are explicitly addressed in this article, theoretically and numerically.}, language = {en} } @article{JostKudrussKoerkeletal., author = {Jost, Felix and Kudruss, Manuel and Koerkel, Stefan and Walter, Sebastian F.}, title = {A computational method for key-performance-indicator-based parameter identification of industrial manipulators}, series = {Journal of mathematics in Industry}, volume = {7}, journal = {Journal of mathematics in Industry}, number = {9}, publisher = {Springer Nature}, doi = {10.1186/s13362-017-0039-7}, abstract = {We present a novel derivative-based parameter identification method to improve the precision at the tool center point of an industrial manipulator. The tool center point is directly considered in the optimization as part of the problem formulation as a key performance indicator. Additionally, our proposed method takes collision avoidance as special nonlinear constraints into account and is therefore suitable for industrial use. The performed numerical experiments show that the optimum experimental designs considering key performance indicators during optimization achieve a significant improvement in comparison to other methods. An improvement in terms of precision at the tool center point of 40\% to 44\% was achieved in experiments with three KUKA robots and 90 notional manipulator models compared to the heuristic experimental designs chosen by an experimenter as well as 10\% to 19\% compared to an existing state-of-the-art method.}, language = {en} } @article{PereiraPereiraSilvaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and Silva, Francisco A. and Masieiro, Joao P. and Weber, Silke A. T. and Hook, Christian and Papa, Jo{\~a}o Paulo}, title = {A new computer vision-based approach to aid the diagnosis of Parkinson's disease}, series = {Computer Methods and Programs in Biomedicine}, volume = {136}, journal = {Computer Methods and Programs in Biomedicine}, publisher = {Elsevier}, doi = {10.1016/j.cmpb.2016.08.005}, pages = {79 -- 88}, abstract = {Background and Objective: Even today, pointing out an exam that can diagnose a patient with Parkinson's disease (PD) accurately enough is not an easy task. Although a number of techniques have been used in search for a more precise method, detecting such illness and measuring its level of severity early enough to postpone its side effects are not straightforward. In this work, after reviewing a considerable number of works, we conclude that only a few techniques address the problem of PD recognition by means of micrography using computer vision techniques. Therefore, we consider the problem of aiding automatic PD diagnosis by means of spirals and meanders filled out in forms, which are then compared with the template for feature extraction. Methods: In our work, both the template and the drawings are identified and separated automatically using image processing techniques, thus needing no user intervention. Since we have no registered images, the idea is to obtain a suitable representation of both template and drawings using the very same approach for all images in a fast and accurate approach. Results: The results have shown that we can obtain very reasonable recognition rates (around approximate to 67\%), with the most accurate class being the one represented by the patients, which outnumbered the control individuals in the proposed dataset. Conclusions: The proposed approach seemed to be suitable for aiding in automatic PD diagnosis by means of computer vision and machine learning techniques. Also, meander images play an important role, leading to higher accuracies than spiral images. We also observed that the main problem in detecting PD is the patients in the early stages, who can draw near-perfect objects, which are very similar to the ones made by control patients. (C) 2016 Elsevier Ireland Ltd. All rights reserved.}, language = {en} } @incollection{PereiraPassosLopesetal., author = {Pereira, Clayton R. and Passos, Leandro A. and Lopes, Ricardo R. and Weber, Silke A. T. and Hook, Christian and Papa, Joao Paulo}, title = {Parkinson's Disease Identification Using Restricted Boltzmann Machines}, series = {Computer Analysis of Images and Patterns, 17th International Conference, CAIP 2017, Ystad, Sweden, August 22-24, 2017, Proceedings, Part II}, volume = {10425}, booktitle = {Computer Analysis of Images and Patterns, 17th International Conference, CAIP 2017, Ystad, Sweden, August 22-24, 2017, Proceedings, Part II}, publisher = {Springer}, isbn = {978-3-319-64697-8}, doi = {10.1007/978-3-319-64698-5_7}, pages = {70 -- 80}, abstract = {Currently, Parkinson's Disease (PD) has no cure or accurate diagnosis, reaching approximately 60, 000 new cases yearly and worldwide, being more often in the elderly population. Its main symptoms can not be easily uncorrelated with other illness, being way more difficult to be identified at the early stages. As such, computer-aided tools have been recently used to assist in this task, but the challenge in the automatic identification of Parkinson's Disease still persists. In order to cope with this problem, we propose to employ Restricted Boltzmann Machines (RBMs) to learn features in an unsupervised fashion by analyzing images from handwriting exams, which aim at assessing the writing skills of potential individuals. These are one of the main symptoms of PD-prone people, since such kind of ability ends up being severely affected. We show that RBMs can learn proper features that help supervised classifiers in the task of automatic identification of PD patients, as well as one can obtain a more compact representation of the exam for the sake of storage and computational load purposes.}, language = {en} } @article{WeinTomeGoldhackeretal., author = {Wein, Simon and Tom{\´e}, Ana Maria and Goldhacker, Markus and Greenlee, Mark W. and Lang, Elmar Wolfgang}, title = {A Constrained ICA-EMD Model for Group Level fMRI Analysis}, series = {Frontiers in Neuroscience}, volume = {14}, journal = {Frontiers in Neuroscience}, publisher = {frontiers}, issn = {1662-453X}, doi = {10.3389/fnins.2020.00221}, pages = {1 -- 10}, abstract = {Independent component analysis (ICA), being a data-driven method, has been shown to be a powerful tool for functional magnetic resonance imaging (fMRI) data analysis. One drawback of this multivariate approach is that it is not, in general, compatible with the analysis of group data. Various techniques have been proposed to overcome this limitation of ICA. In this paper, a novel ICA-based workflow for extracting resting-state networks from fMRI group studies is proposed. An empirical mode decomposition (EMD) is used, in a data-driven manner, to generate reference signals that can be incorporated into a constrained version of ICA (cICA), thereby eliminating the inherent ambiguities of ICA. The results of the proposed workflow are then compared to those obtained by a widely used group ICA approach for fMRI analysis. In this study, we demonstrate that intrinsic modes, extracted by EMD, are suitable to serve as references for cICA. This approach yields typical resting-state patterns that are consistent over subjects. By introducing these reference signals into the ICA, our processing pipeline yields comparable activity patterns across subjects in a mathematically transparent manner. Our approach provides a user-friendly tool to adjust the trade-off between a high similarity across subjects and preserving individual subject features of the independent components.}, language = {en} } @article{SenFalterMayer, author = {Sen, Abhijit and Falter, Sandro and Mayer, Nicolas}, title = {Using DevOps paradigm to deploy web applications}, series = {Issues of Information Systems}, volume = {23}, journal = {Issues of Information Systems}, number = {4}, publisher = {IACIS}, doi = {10.48009/4_iis_2022_113}, pages = {142 -- 156}, abstract = {DevOps paradigm is widely used in industry to develop software faster, deploy high quality frequent releases of features by integrating and harmonizing the Development and IT Operations activities. Industries are taking strategic decisions to remove the barriers that existed between Development and Operational teams by encouraging collaborations among these teams throughout System Development Life Cycle (SDLC). These strategic decisions to implement DevOps paradigm resulted in the development and emergence of large arrays of tool chains to support, monitor, and automate activities of various SDLC stages. In this paper authors attempt to give practical insights on how the using of DevOps can speed up the management, development and deployment process of a simple web application. Widely used DevOps model consisting of eight stages is used to implement the example application. A toolchain consisting of state of arts tools is used at various DevOps stages. A detailed explanation of each tool, including details to their implementation and a short evaluation concludes the study. The results revealed that the usage of DevOps enables to accelerate the development process of web applications, as most steps during the build and testing process can be automated. Especially the outsourcing of operational overhead to an external cloud provider can lead to economic advantages, which will impact the future of software development.}, language = {en} } @article{FeldRochGaboretal., author = {Feld, Sebastian and Roch, Christoph and Gabor, Thomas and Seidel, Christian and Neukart, Florian and Galter, Isabella and Mauerer, Wolfgang and Linnhoff-Popien, Claudia}, title = {A Hybrid Solution Method for the Capacitated Vehicle Routing Problem Using a Quantum Annealer}, series = {Frontiers in ICT}, volume = {6}, journal = {Frontiers in ICT}, publisher = {Frontiers}, doi = {10.3389/fict.2019.00013}, pages = {1 -- 13}, abstract = {he Capacitated Vehicle Routing Problem (CVRP) is an NP-optimization problem (NPO) that has been of great interest for decades for both, science and industry. The CVRP is a variant of the vehicle routing problem characterized by capacity constrained vehicles. The aim is to plan tours for vehicles to supply a given number of customers as efficiently as possible. The problem is the combinatorial explosion of possible solutions, which increases superexponentially with the number of customers. Classical solutions provide good approximations to the globally optimal solution. D-Wave's quantum annealer is a machine designed to solve optimization problems. This machine uses quantum effects to speed up computation time compared to classic computers. The problem on solving the CVRP on the quantum annealer is the particular formulation of the optimization problem. For this, it has to be mapped onto a quadratic unconstrained binary optimization (QUBO) problem. Complex optimization problems such as the CVRP can be translated to smaller subproblems and thus enable a sequential solution of the partitioned problem. This work presents a quantum-classic hybrid solution method for the CVRP. It clarifies whether the implementation of such a method pays off in comparison to existing classical solution methods regarding computation time and solution quality. Several approaches to solving the CVRP are elaborated, the arising problems are discussed, and the results are evaluated in terms of solution quality and computation time.}, language = {en} } @article{PereiraPereiraRosaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and Rosa, Gustavo H. and Albuquerque, Victor Hugo C. and Weber, Silke A. T. and Hook, Christian and Papa, Jo{\~a}o Paulo}, title = {Handwritten dynamics assessment through convolutional neural networks}, series = {Artificial Intelligence in Medicine}, volume = {37}, journal = {Artificial Intelligence in Medicine}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.artmed.2018.04.001}, pages = {67 -- 77}, abstract = {Background and objective Parkinson's disease (PD) is considered a degenerative disorder that affects the motor system, which may cause tremors, micrography, and the freezing of gait. Although PD is related to the lack of dopamine, the triggering process of its development is not fully understood yet. Methods In this work, we introduce convolutional neural networks to learn features from images produced by handwritten dynamics, which capture different information during the individual's assessment. Additionally, we make available a dataset composed of images and signal-based data to foster the research related to computer-aided PD diagnosis. Results The proposed approach was compared against raw data and texture-based descriptors, showing suitable results, mainly in the context of early stage detection, with results nearly to 95\%. Conclusions The analysis of handwritten dynamics using deep learning techniques showed to be useful for automatic Parkinson's disease identification, as well as it can outperform handcrafted features.}, language = {en} } @article{GalkaFollathBross, author = {Galka, Stefan and Follath, Alexander and Bross, Florian}, title = {Vorgehensmodell zur Erstellung Digitaler Zwillinge f{\"u}r Produktion und Logistik}, series = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb}, volume = {117}, journal = {Zeitschrift f{\"u}r wirtschaftlichen Fabrikbetrieb}, number = {11}, editor = {Bauer, Wilhelm and Volk, Wolfram and Z{\"a}h, Michael}, publisher = {De Gruyter}, address = {Berlin}, doi = {10.1515/zwf-2022-1127}, pages = {691 -- 696}, abstract = {Der Digitale Zwilling (DZ) ist ein wichtiger Bestandteil der Industrie 4.0 und erm{\"o}glicht Anwendungen wie Predictive Maintenance, virtuelles Prototyping oder die Steuerung von Produktions- und Logistikprozessen. Herausforderungen bei der Entwicklung des Digitalen Zwillings entstehen durch fehlende Struktur und Standards. Mit diesem Beitrag soll ein Vorgehensmodell f{\"u}r die Erstellung eines Digitalen Zwillings im Bereich der Produktion und Logistik aufgezeigt werden. Das Vorgehensmodell hilft bei der Einordnung, f{\"u}r welche Anwendungsf{\"a}lle ein Digitaler Zwilling entwickelt werden kann, welche Schritte bei einer Umsetzung erfolgen m{\"u}ssen, und gibt einen {\"U}berblick {\"u}ber die Voraussetzungen und Komplexit{\"a}t bei der Entwicklung. Das zentrale Element bildet dabei die zielgerichtete Aufbereitung und Analyse der zugrunde liegenden Daten mittels des in der Industrie etablierten Vorgehensmodell CRISP-DM.}, language = {de} } @inproceedings{KotzStapfBecke, author = {Kotz, Oliver and Stapf, Matthias and Becke, Mark}, title = {GPU-Based Task Specific Evaluation of the Dynamic Performance of a 6DOF Manipulator}, series = {Intelligent Robotics and Applications. 8th International Conference, ICIRA 2015, Portsmouth, UK, August 24-27, 2015, Proceedings, Part II}, booktitle = {Intelligent Robotics and Applications. 8th International Conference, ICIRA 2015, Portsmouth, UK, August 24-27, 2015, Proceedings, Part II}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-319-22876-1_30}, pages = {345 -- 357}, abstract = {This paper addresses the problem of properly placing a given task in the manipulator workspace by a heuristic and numeric approach. Thus, the task is placed relatively to the manipulator for each element of the discretized workspace and the required joint torques are determined. The results are are by a torque-based optimization criterion. The modularity of this approach ensures general applicability on various systems and tasks while the high computational effort is treated by GPU parallelization. The method is presented for a given 6DOF manipulator and a highly dynamic trajectory. The resulting interactive map of the manipulator workspace gives an overview of the task dependent dynamic performance, detailed evaluation of certain solutions will show the dexterity of the proposed approach.}, language = {en} } @article{Schoenberger, author = {Sch{\"o}nberger, Manuel}, title = {Applicability of Quantum Computing on Database Query Optimization}, series = {SIGMOD '22: proceedings of the 2022 International Conference on Management of Data : June 12-17, 2022, Philadelphia, PA, USA}, journal = {SIGMOD '22: proceedings of the 2022 International Conference on Management of Data : June 12-17, 2022, Philadelphia, PA, USA}, publisher = {ACM}, address = {New York, NY}, doi = {10.1145/3514221.3520257}, pages = {2512 -- 2514}, abstract = {We evaluate the applicability of quantum computing on two fundamental query optimization problems, join order optimization and multi query optimization (MQO). We analyze the problem dimensions that can be solved on current gate-based quantum systems and quantum annealers, the two currently commercially available architectures. First, we evaluate the use of gate-based systems on MQO, previously solved with quantum annealing. We show that, contrary to classical computing, a different architecture requires involved adaptations. We moreover propose a multi-step reformulation for join ordering problems to make them solvable on current quantum systems. Finally, we systematically evaluate our contributions for gate-based quantum systems and quantum annealers. Doing so, we identify the scope of current limitations, as well as the future potential of quantum computing technologies for database systems.}, language = {en} } @article{HerrmannHorkovicsKovatsSultanow, author = {Herrmann, Frank and Horkovics-Kovats, Robert and Sultanow, Eldar}, title = {Ein paralleler Algorithmus f{\"u}r API Mining von C\# Code}, series = {Anwendungen und Konzepte der Wirtschaftsinformatik}, volume = {16}, journal = {Anwendungen und Konzepte der Wirtschaftsinformatik}, publisher = {Technische Hochschule Wildau}, issn = {2296-4592}, doi = {10.26034/lu.akwi.2022.3454}, pages = {48 -- 56}, abstract = {Die Konformit{\"a}tsanalyse ist eine Technik der statischen Code-Analyse (SCA) zur Software-Qualit{\"a}tssicherung. Ihr Kernproblem ist, dass Werkzeuge nicht aus bereits eingetretenen Fehlern automatisiert dazulernen. Zur L{\"o}sung wurde in dieser Arbeit das maschinelle Lernen (ML) evaluiert, indem ein wissenschaftlich fundierter und praktisch erprobter Ansatz zur un{\"u}berwachten Lerntechnik angewandt und das Ergebnis analysiert wurde. Es wurde festgestellt, dass zur Anwendung auf verschiedene Programmiersprachen nur ein sprachspezifisches API Mining-Tool notwendig ist. Ein derartiges Tool durchsucht in parallelisierter Form Codezeilen und normalisiert sie f{\"u}r maschinelle Lernprozesse. Dieses System wurde f{\"u}r die Programmiersprache C\# implementiert, da viele Industrieprojekte in dieser Sprache entwickelt werden. Zur funktionalen Validierung wurde in einer Fallstudie gezeigt, dass Regeln mit einem positiven Effekt auf Software-Qualit{\"a}t gelernt wurden. Konkret wurde der Wartungsaufwand eines Code-Smells in einem Beispielprojekt durch das Auslagern einer gelernten Assoziation in eine gemeinsame Methode um den Faktor 30 reduziert. Die Laufzeit des Algorithmus wurde empirisch in acht open-source Repositorys evaluiert. Durch Parallelisierung kann eine durchschnittliche Laufzeitverbesserung von 45,16\% erwartet werden. Allerdings wurden bei der Anwendung auch Grenzen deutlich: Viele Assoziationen sind nutzlos, die Regelbewertung ist von einem subjektiven Faktor abh{\"a}ngig und die Wirtschaftlichkeit des Tools ist deshalb nicht transparent. Dennoch belegt diese Arbeit, dass ein ML-basiertes SCA-Tool als erg{\"a}nzende Qualit{\"a}tssicherungsmaßnahme im Software-Engineering m{\"o}glich ist.}, language = {de} } @article{HerrmannNangmoWankoZeller, author = {Herrmann, Frank and Nangmo Wanko, Merveille and Zeller, Bernhard}, title = {Digitale Transformation in Echtzeit: Die Ziele von morgen basierend auf dem Datenmodell von gestern}, series = {Anwendungen und Konzepte der Wirtschaftsinformatik}, volume = {16}, journal = {Anwendungen und Konzepte der Wirtschaftsinformatik}, publisher = {Technische Hochschule Wildau}, issn = {2296-4592}, doi = {10.26034/lu.akwi.2022.3453}, pages = {37 -- 47}, abstract = {Die Digitale Transformation fordert Unternehmen aller Couleur. Ironischer Weise sind es gerade die bisher verwendeten IT-Systeme mit ihren starren Strukturen, die Unternehmen in Ihrer digitalen Trans-formation oft ausbremsen. Auch wenn die Soft-warehersteller l{\"a}ngst reagiert haben und neue, flexib-lere Versionen ihrer Produkte anbieten, so ist ein gr{\"o}ßerer Softwarewechsel immer noch eine Heraus-forderung f{\"u}r Unternehmen und ein Schritt der wohl-{\"u}berlegt und geplant sein will. In dieser Arbeit wird deshalb ein Vorgehen vorge-stellt, um mittels In-Memory Technologie und Vir-tualisierung zumindest die wichtigsten Ergebnisse der Transformation bereits auf den bestehenden Da-tenmodellen in Echtzeit zu generieren. Dadurch wird genug Zeit gewonnen, um die eigentliche Transfor-mation der IT-Landschaft geplant und mit der not-wendigen Sorgfalt durchzuf{\"u}hren.}, language = {de} } @inproceedings{RamsauerLohmannMauerer, author = {Ramsauer, Ralf and Lohmann, Daniel and Mauerer, Wolfgang}, title = {System Software for Manufacturing Systems}, series = {Proc. First European Advances in Digital Transformation Conference, (2018)}, booktitle = {Proc. First European Advances in Digital Transformation Conference, (2018)}, language = {en} } @phdthesis{Ramsauer, author = {Ramsauer, Ralf Stefan}, title = {OSS Architecture for Mixed-Criticality Systems}, publisher = {Leibniz Universit{\"a}t Hannover}, pages = {188}, abstract = {Computer-based automation in industrial appliances led to a growing number of logically dependent, but physically separated embedded control units per appliance. Many of those components are safety-critical systems, and require adherence to safety standards, which is inconsonant with the relentless demand for features in those appliances. Features lead to a growing amount of control units per appliance, and to a increasing complexity of the overall software stack, being unfavourable for safety certifications. Modern CPUs provide means to revise traditional separation of concerns design primitives: the consolidation of systems, which yields new engineering challenges that concern the entire software and system stack. Multi-core CPUs favour economic consolidation of formerly separated systems with one efficient single hardware unit. Nonetheless, the system architecture must provide means to guarantee the freedom from interference between domains of different criticality. System consolidation demands for architectural and engineering strategies to fulfil requirements (e.g., real-time or certifiability criteria) in safety-critical environments. In parallel, there is an ongoing trend to substitute ordinary proprietary base platform software components by mature OSS variants for economic and engineering reasons. There are fundamental differences of processual properties in development processes of OSS and proprietary software. OSS in safety-critical systems requires development process assessment techniques to build an evidence-based fundament for certification efforts that is based upon empirical software engineering methods. In this thesis, I will approach from both sides: the software and system engineering perspective. In the first part of this thesis, I focus on the assessment of OSS components: I develop software engineering techniques that allow to quantify characteristics of distributed OSS development processes. I show that ex-post analyses of software development processes can be used to serve as a foundation for certification efforts, as it is required for safety-critical systems. In the second part of this thesis, I present a system architecture based on OSS components that allows for consolidation of mixed-criticality systems on a single platform. Therefore, I exploit virtualisation extensions of modern CPUs to strictly isolate domains of different criticality. The proposed architecture shall eradicate any remaining hypervisor activity in order to preserve realtime capabilities of the hardware by design, while guaranteeing strict isolation across domains.}, language = {en} } @misc{MauererRamsauerKoelbl, author = {Mauerer, Wolfgang and Ramsauer, Ralf and K{\"o}lbl, Andreas}, title = {The Many Approaches to Real-Time and Safety-Critical Linux}, series = {Open Source Summit Japan 2017}, journal = {Open Source Summit Japan 2017}, language = {en} } @inproceedings{ReinhardtKucera, author = {Reinhardt, Dominik and Kucera, Markus}, title = {Domain controlled architecture: A new approach for large scale software integrated automotive systems}, series = {PECCS 2013 - Proceedings of the 3rd International Conference on Pervasive Embedded Computing and Communication Systems, 19 - 21 February 2013, Barcelona, Spain}, booktitle = {PECCS 2013 - Proceedings of the 3rd International Conference on Pervasive Embedded Computing and Communication Systems, 19 - 21 February 2013, Barcelona, Spain}, publisher = {IEEE}, pages = {221 -- 226}, abstract = {Electric and electronic functionalities increase exponentially in every mobility domain. The automotive in-dustry is confronted with a rising system complexity and several restricting requirements and standards (likeAUTOSAR), in particular to design embedded software for electronic control units. To stand against rampantfunctionalities software units could be restructured according to their affiliation and should not be attached toa certain place. This can be effected by integration on single controllers. On the one hand the system wideamount of hardware controllers could such be limited. On the other hand the workload for integration CPUswill rise. To support this paradigm, multi-core systems can provide enough processing power in an efficientway. This paper shows a first approach to combine automotive functionality on such a single controller.}, language = {en} } @inproceedings{SchaeferSchildgenDessloch, author = {Sch{\"a}fer, Marc and Schildgen, J{\"u}rgen and Deßloch, Stefan}, title = {Sampling with Incremental MapReduce}, series = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW 2015) : Workshopband ; 02. - 03. M{\"a}rz 2015 in Hamburg}, volume = {242}, booktitle = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW 2015) : Workshopband ; 02. - 03. M{\"a}rz 2015 in Hamburg}, publisher = {Gesellschaft f{\"u}r Informatik e.V.}, pages = {121 -- 130}, abstract = {The goal of this paper is to increase the computation speed of MapReduce jobs by reducing the accuracy of the result. Often, the timely processing is more important than the precision of the result. Hadoop has no built-in functionality for such an approximation technique, so the user has to implement sampling techniques manually. We introduce an automatic system for computing arithmetic approximations. The sampling is based on techniques from statistics and the extrapolation is done generically. This system is also extended by an incremental component which enables the reuse of already computed results to enlarge the sampling size. This can be used iteratively to further increase the sampling size and also the precision of the approximation. We present a transparent incremental sampling approach, so the developed components can be integrated in the Hadoop framework in a non-invasive manner.}, language = {en} } @article{SaidEngelhartKirchesetal., author = {Said, Nadia and Engelhart, Michael and Kirches, Christian and K{\"o}rkel, Stefan and Holt, Daniel V.}, title = {Applying mathematical optimization methods to an ACT-R instance-based learning model}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {7}, publisher = {PLOS}, doi = {10.1371/journal.pone.0158832}, abstract = {Computational models of cognition provide an interface to connect advanced mathematical tools and methods to empirically supported theories of behavior in psychology, cognitive science, and neuroscience. In this article, we consider a computational model of instance-based learning, implemented in the ACT-R cognitive architecture. We propose an approach for obtaining mathematical reformulations of such cognitive models that improve their computational tractability. For the well-established Sugar Factory dynamic decision making task, we conduct a simulation study to analyze central model parameters. We show how mathematical optimization techniques can be applied to efficiently identify optimal parameter values with respect to different optimization goals. Beyond these methodological contributions, our analysis reveals the sensitivity of this particular task with respect to initial settings and yields new insights into how average human performance deviates from potential optimal performance. We conclude by discussing possible extensions of our approach as well as future steps towards applying more powerful derivative-based optimization methods.}, language = {en} } @article{SchreierKohlert, author = {Schreier, Franz and Kohlert, Dieter}, title = {Optimized implementations of rational approximations-a case study on the Voigt and complex error function}, series = {Computer Physics Communications : an international journal for computational physics and physical chemistry}, volume = {179}, journal = {Computer Physics Communications : an international journal for computational physics and physical chemistry}, number = {7}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0010-4655}, doi = {10.1016/j.cpc.2008.04.012}, pages = {457 -- 465}, abstract = {Rational functions are frequently used as efficient yet accurate numerical approximations for real and complex valued special functions. For the complex error function , whose real part is the Voigt function , the rational approximation developed by Hui, Armstrong, and Wray [Rapid computation of the Voigt and complex error functions, J. Quant. Spectrosc. Radiat. Transfer 19 (1978) 509-516] is investigated. Various optimizations for the algorithm are discussed. In many applications, where these functions have to be calculated for a large x grid with constant y, an implementation using real arithmetic and factorization of invariant terms is especially efficient.}, language = {en} } @article{KohlertSchreier, author = {Kohlert, Dieter and Schreier, Franz}, title = {Line-by-Line Computation of Atmospheric Infrared Spectra With Field Programmable Gate Arrays}, series = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing}, volume = {4}, journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing}, number = {3}, doi = {10.1109/JSTARS.2010.2098395}, pages = {701 -- 709}, abstract = {Radiative transfer modelling of high resolution infrared (or microwave) spectra still represents a major challenge for the processing of atmospheric remote sensing data despite significant advances in the numerical techniques utilized in line-by-line modelling by, e.g., optimized Voigt function algorithms or multigrid approaches. Special purpose computing hardware such as Field Programmable Gate Arrays (FPGAs) can be used to cope with the dramatic increase of data quality and quantity. Utilizing a highly optimized implementation of an uniform rational function approximation of the Voigt function, the molecular absorption cross section computation-representing the most compute intensive part of radiative transfer codes-has been realized on FPGA. Design and implementation of the FPGA coprocessor is presented along with first performance tests and an outlook for the ongoing further development.}, language = {de} } @article{Kohlert, author = {Kohlert, Dieter}, title = {The sub-threshold behaviour of the MOS field-effect transistor}, series = {European Journal of Physics}, volume = {19}, journal = {European Journal of Physics}, number = {2}, publisher = {IOP Science}, pages = {125 -- 131}, language = {en} } @inproceedings{PereiraPereiradaSilvaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and da Silva, Francisco A. and Hook, Christian and Weber, Silke A. T. and Pereira, Luis A. M. and Papa, Jo{\~a}o Paulo}, title = {A Step Towards the Automated Diagnosis of Parkinson's Disease: Analyzing Handwriting Movements}, series = {2015 IEEE 28th International Symposium on Computer-Based Medical Systems, 22.-25.06.2015, Sao Carlos, Brazil}, booktitle = {2015 IEEE 28th International Symposium on Computer-Based Medical Systems, 22.-25.06.2015, Sao Carlos, Brazil}, publisher = {IEEE}, isbn = {978-1-4673-6775-2}, issn = {2372-9198}, doi = {10.1109/cbms.2015.34}, pages = {171 -- 176}, abstract = {Parkinson's disease (PD) has affected millions of people world-wide, being its major problem the loss of movements and, consequently, the ability of working and locomotion. Although we can find several works that attempt at dealing with this problem out there, most of them make use of datasets composed by a few subjects only. In this work, we present some results toward the automated diagnosis of PD by means of computer vision-based techniques in a dataset composed by dozens of patients, which is one of the main contributions of this work. The dataset is part of a joint research project that aims at extracting both visual and signal-based information from healthy and PD patients in order to go forward the early diagnosis of PD patients. The dataset is composed by handwriting clinical exams that are analyzed by means of image processing and machine learning techniques, being the preliminary results encouraging and promising. Additionally, a new quantitative feature to measure the amount of tremor of an individual's handwritten trace called Mean Relative Tremor is also presented.}, language = {en} } @article{Kucera, author = {Kucera, Markus}, title = {On end-to-end safety for mobile COTS devices}, series = {Advances in Computer Science : an International Journal}, volume = {4}, journal = {Advances in Computer Science : an International Journal}, number = {5}, publisher = {ACSIJ}, issn = {2322-5157}, pages = {107 -- 109}, abstract = {Today, ubiquitous mobile devices have not only arrived but entered the safety critical domain. There, systems are about to be controlled where human health or even human life is put at risk. For example, in automation systems first ideas surface to control parts of the system via a COTS smartphone. Another example is the idea to control the autonomous parking function of a car via a COTS smartphone too. As beneficial and convenient these ideas are on the first thought, on the second thought, dangers of these approaches become obvious. Especially in case of failures the system's safety has to be maintained. The open question is how to achieve this mandatory requirement with COTS components, e.g. smartphones that are not developed following the development process necessary for safetycritical systems. This paper presents a concept to reliably detect human interaction while activating safety critical functions via COTS mobile devices. Thus a means is provided to detect erroneous activation requests for the safetycritical function.}, language = {en} } @inproceedings{StroblKuceraFoeldietal., author = {Strobl, Marius and Kucera, Markus and Foeldi, Andrei and Balbierer, Norbert and Hilbert, Carolin and Waas, Thomas}, title = {Towards automotive virtualization}, series = {2013 International Conference on Applied Electronics (AE) : 10 - 12 Sept. 2013, Pilsen, Czech Republic}, booktitle = {2013 International Conference on Applied Electronics (AE) : 10 - 12 Sept. 2013, Pilsen, Czech Republic}, publisher = {IEEE}, address = {Piscataway, NJ}, pages = {291 -- 296}, abstract = {Virtualization has come a long way since its beginnings in the 1960s. Nowadays, Virtual Machine Monitor (VMM) - or hypervisor-based virtualization of servers is the de facto standard in data centers and a building block of the cloud hype. In recent years, virtualization has also been adopted to embedded devices such as avionics systems and mobile phones. The first mass deployment of embedded virtualization can probably be seen in video game consoles, though. However, it is still not employed by automotive electronics. This is despite the fact that with the upcoming domain controller architecture, virtualization can yield benefits beyond a mere consolidation of a multitude of Electronic Control Units (ECUs) into a few Domain Controller Units (DCUs). This paper presents merits of automotive virtualization, especially as a foundation for DCUs.}, language = {en} } @unpublished{EbnerFrikelLorenzetal., author = {Ebner, Andrea and Frikel, J{\"u}rgen and Lorenz, Dirk and Schwab, Johannes and Haltmeier, Markus}, title = {Regularization of inverse problems by filtered diagonal frame decomposition}, abstract = {The characteristic feature of inverse problems is their instability with respect to data perturbations. In order to stabilize the inversion process, regularization methods have to be developed and applied. In this work we introduce and analyze the concept of filtered diagonal frame decomposition which extends the standard filtered singular value decomposition to the frame case. Frames as generalized singular system allows to better adapt to a given class of potential solutions. In this paper, we show that filtered diagonal frame decomposition yield a convergent regularization method. Moreover, we derive convergence rates under source type conditions and prove order optimality under the assumption that the considered frame is a Riesz-basis.}, language = {en} } @article{WeberRinkeAlwardt, author = {Weber, Karsten and Rinke, Bernhard and Alwardt, Christian}, title = {Dr. Seltsam, oder wie ich lernte, die Drohne zu lieben}, series = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, volume = {27}, journal = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, number = {3}, publisher = {Institute for Technology Assessment and Systems Analysis / KIT}, doi = {10.14512/tatup.27.3.11}, pages = {11 -- 13}, abstract = {Drohnen werden inzwischen in vielen und sehr unterschiedlichen Kon-texten verwendet. Aus dem Blickwinkel der Technikfolgenabsch{\"a}tzung (TA) scheint es daher sinnvoll, den Umfang der momentanen und zu-k{\"u}nftigen Nutzung von Drohnen und daraus resultierende Implikatio-nen n{\"a}her zu beleuchten und eine Bestandsaufnahme durchzuf{\"u}hren. Dar{\"u}ber hinaus sollen die voraussichtlichen Pfade der weiteren Tech-nikentwicklung, relevante Akteure und deren Interessenslage sowie zu-k{\"u}nftige Anwendungspotenziale und Einsatzfelder analysiert werden}, language = {de} } @article{JoblinMauerer, author = {Joblin, Mitchell and Mauerer, Wolfgang}, title = {An Interactive Survey Framework for Validation of Social Network Analysis}, series = {The R Journal}, volume = {8}, journal = {The R Journal}, number = {1}, pages = {149 -- 158}, abstract = {Abstract Social network analysis is extremely well supported by the R community and is routinely used for studying the relationships between people engaged in collaborative activities. While there has been rapid development of new approaches and metrics in this field, the challenging question of validity (how well insights derived from social networks agree with reality) is often difficult to address. We propose the use of several R packages to generate interactive surveys that are specifically well suited for validating social network analyses. Using our web-based survey application, we were able to validate the results of applying community-detection algorithms to infer the organizational structure of software developers contributing to open-source projects.}, language = {en} } @article{SaxFeldZielinskietal., author = {Sax, Irmi and Feld, Sebastian and Zielinski, Sebastian and Gabor, Thomas and Linnhoff-Popien, Claudia and Mauerer, Wolfgang}, title = {Towards Understanding Approximation Complexity on a Quantum Annealer}, series = {Digitale Welt}, volume = {4}, journal = {Digitale Welt}, number = {1}, publisher = {DIGITALE WELT Academy c/o Ludwig-Maximilians-Universit{\"a}t M{\"u}nchen}, address = {M{\"u}nchen}, doi = {10.1007/s42354-019-0244-1}, pages = {104}, abstract = {Many industrially relevant problems can be deterministically solved by computers in principle, but are intractable in practice, as the seminal P/NP dichotomy of complexity theory and Cobham's thesis testify. For the many NP-complete problems, industry needs to resort to using heuristics or approximation algorithms. For approximation algorithms, there is a more refined classification in complexity classes that goes beyond the simple P/NP dichotomy. As it is well known, approximation classes form a hierarchy, that is, FPTAS \subseteq PTAS \subseteq APX \subseteq NPO. This classification gives a more realistic notion of complexity but—unless unexpected breakthroughs happen for fundamental problems like P = NP or related questions— there is no known efficient algorithm that can solve such problems exactly on a realistic computer. Therefore, new ways of computations are sought. Recently, considerable hope was placed on the possible computational powers of quantum computers and quantum annealing (QA) in particular. However, the precise benefits of such a drastic shift in hardware are still unchartered territory to a good extent. Firstly, the exact relations between classical and quantum complexity classes pose many open questions, and secondly, technical details of formulating and implementing quantum algorithms play a crucial role in real-world applications. Guided by the hierarchy of classical optimisation complexity classes, we discuss how to map problems of each class to a quantum annealer. Those problems are the Minimum Multiprocessor Scheduling (MMS) problem, the Minimum Vertex Cover (MVC) problem and the Maximum Independent Set (MIS) problem. We experimentally investigate if and how the degree of approximability influences implementation and run-time performance. Our experiments indicate a discrepancy between classical approximation complexity and QA behaviour: Problems MIS and MVC, members of APX respectively PTAS, exhibit better solution quality on a QA than MMS, which is in FPTAS, even despite the use of preprocessing the for latter. This leads to the hypothesis that traditional classifications do not immediately extend to the quantum annealing domain, at least when the properties of real-world devices are taken into account. A structural reason, why FPTAS problems do not show good solution quality, might be the use of an inequlity in the problem description of the FPTAS problems. Formulating those inequalities on a quantum hardware (mostly done by formulating a Quadratic Unconstrained Binary optimisation (QUBO) problem in form of a matrix) requires a lot of hardware space which makes finding an optimal solution more difficult. Reducing the density of a QUBO is possible by appropriately pruning QUBO matrices. For the problems considered in our evaluation, we find that the achievable solution quality on a real-world machine is unexpectedly robust against pruning, often up to ratios as high as 50\% or more. Since quantum annealers are probabilistic machines by design, the loss in solution quality is only of subordinate relevance, especially considering that the pruning of QUBO matrices allows for solving larger problem instances on hardware of a given capacity. We quantitatively discuss the interplay between these factors.}, language = {en} } @incollection{Skornia, author = {Skornia, Christoph}, title = {Sicherheit in der Cloud}, series = {IT-Sicherheit}, booktitle = {IT-Sicherheit}, editor = {Lang, Michael and L{\"o}hr, Hans and Angermeier, Daniel}, publisher = {Hanser}, address = {M{\"u}nchen}, isbn = {978-3-446-47223-5}, doi = {10.3139/9783446473478.015}, pages = {263 -- 278}, language = {de} } @inproceedings{HinterbergerWeberFischeretal., author = {Hinterberger, Lukas and Weber, Bernhard and Fischer, Sebastian and Neubauer, Katrin and Hackenberg, Rudolf}, title = {IoT Device IdentificAtion and RecoGnition (IoTAG)}, series = {CLOUD COMPUTING 2020, The Eleventh International Conference on Cloud Computing, GRIDs and Virtualization}, booktitle = {CLOUD COMPUTING 2020, The Eleventh International Conference on Cloud Computing, GRIDs and Virtualization}, publisher = {IARIA}, isbn = {978-1-61208-778-8}, pages = {17 -- 23}, abstract = {To ensure the secure operation of IoT devices in the future, they must be continuously monitored. This starts with an inventory of the devices, checking for a current software version and extends to the encryption algorithms and active services used. Based on this information, a security analysis and rating of the whole network is possible. To solve this challenge in the growing network environments, we present a proposal for a standard. With the IoT Device IdentificAtion and RecoGnition (IoTAG), each IoT device reports its current status to a central location as required and provides information on security. This information includes a unique ID, the exact device name, the current software version, active services, cryptographic methods used, etc. The information is signed to make misuse more difficult and to ensure that the device can always be uniquely identified. In this paper, we introduce IoTAG in detail and describe the necessary requirements.}, language = {en} } @inproceedings{VoglWeberGrafetal., author = {Vogl, Peter and Weber, Sergei and Graf, Julian and Neubauer, Katrin and Hackenberg, Rudolf}, title = {Design and Implementation of an Intelligent and Model-based Intrusion Detection System for Iot Networks}, series = {Cloud Computing 2022: The Thirteenth International Conference on Cloud Computing, GRIDs, and Virtualization, Special Track FAST-CSP, Barcelona, Spain, 24.-28.04.2022}, booktitle = {Cloud Computing 2022: The Thirteenth International Conference on Cloud Computing, GRIDs, and Virtualization, Special Track FAST-CSP, Barcelona, Spain, 24.-28.04.2022}, publisher = {IARIA}, address = {[Wilmington, DE, USA]}, isbn = {978-1-61208-948-5}, pages = {7 -- 12}, abstract = {The ongoing digitization and digitalization entails the increasing risk of privacy breaches through cyber attacks. Internet of Things (IoT) environments often contain devices monitoring sensitive data such as vital signs, movement or surveil-lance data. Unfortunately, many of these devices provide limited security features. The purpose of this paper is to investigate how artificial intelligence and static analysis can be implemented in practice-oriented intelligent Intrusion Detection Systems to monitor IoT networks. In addition, the question of how static and dynamic methods can be developed and combined to improve net-work attack detection is discussed. The implementation concept is based on a layer-based architecture with a modular deployment of classical security analysis and modern artificial intelligent methods. To extract important features from the IoT network data a time-based approach has been developed. Combined with network metadata these features enhance the performance of the artificial intelligence driven anomaly detection and attack classification. The paper demonstrates that artificial intelligence and static analysis methods can be combined in an intelligent Intrusion Detection System to improve the security of IoT environments.}, language = {en} } @inproceedings{SchildgenRosin, author = {Schildgen, Johannes and Rosin, Jessica}, title = {Game-based Learning of SQL Injections}, series = {Proceedings of the 1st ACM SIGMOD International Workshop on Data Systems Education: Bridging Education Practice with Education Research (DataEd 2022): 17 June 2022, Philadelphia, PA, USA}, booktitle = {Proceedings of the 1st ACM SIGMOD International Workshop on Data Systems Education: Bridging Education Practice with Education Research (DataEd 2022): 17 June 2022, Philadelphia, PA, USA}, publisher = {ACM}, doi = {10.1145/3531072.3535321}, pages = {22 -- 25}, abstract = {SQL injections are one of the most widely used techniques to attack data-driven applications. Thus, the potential for cyber-attacks increases consistently. To create awareness of hacker attacks, we demonstrate a web-based educational game. The game shows how SQL injections work and which kind of attacks they enable, e.g., logging in without knowing a user's password, deleting data or retrieving secret or sensitive data. At each level, the players have to fill out login or search forms or use URL parameters to attack an example retail website. While solving these tasks, players can look at the SQL query and the application code. The players learn how SQL injections work, how dangerous they are, and how to make their own applications more robust against SQL injections, for example by using prepared statements.}, language = {en} } @inproceedings{HerboldReindlMeieretal., author = {Herbold, Florian and Reindl, Andrea and Meier, Hans and Niemetz, Michael and Kr{\"a}mer, Stefan}, title = {Secure Software Updates: Challenges and Solutions for Embedded IoT Systems}, series = {Proceedings of the 9th Embedded Systems Workshop: July 1-3, 2021 Horomerice, Czech Republic}, booktitle = {Proceedings of the 9th Embedded Systems Workshop: July 1-3, 2021 Horomerice, Czech Republic}, editor = {Kub{\´a}tov{\´a}, Hana and Fišer, Petr and Boreck{\´y}, Jaroslav}, isbn = {978-80-01-06858-8}, pages = {5 -- 13}, abstract = {The invention of the internet made the development of intelligent networking of millions of embedded systems possible. This enabled smart buildings, power grids and cities as well as applications in the fields of health, agriculture and industry. These systems frequently perform safety-critical applications and operations. This makes it urgent to protect these sensible systems as effectively as possible. Especially firmware updates are often the weak point in the systems. If unauthorised persons gain access to the system during the update, malware can be injected or sensitive data can be read and stolen. This paper describes the challenges of secure firmware updates. To protect an embedded system from potential attackers, the concepts integrity, authenticity and confidentiality have to be adhered during the update process. Otherwise, there is an increased risk of modifying or reverse engineering the firmware image. Likewise, inadequately protected software can enable the installation of third-party firmware as well as the installation of firmware on a third-party system. Threat prevention is presented with solutions derived from functional safety and IT security. Aspects of protection against errors in the transmission of updates and against attacks aiming to compromise the system are explained. Finally, a possible sequence of a secure update process is examined in detail for a real embedded system implementation. For this purpose, the preparation, transmission and installation of a firmware update in the bootloader are discussed}, language = {en} } @inproceedings{WeberHinterbergerFischeretal., author = {Weber, Bernhard and Hinterberger, Lukas and Fischer, Sebastian and Hackenberg, Rudolf}, title = {How to Prevent Misuse of IoTAG?}, series = {Cloud Computing 2021: the Twelfth International Conference on Cloud Computing, GRIDs, and Virtualization: April 18-22, 2021, Porto, Portugal}, booktitle = {Cloud Computing 2021: the Twelfth International Conference on Cloud Computing, GRIDs, and Virtualization: April 18-22, 2021, Porto, Portugal}, editor = {Duncan, Bob and Lee, Yong Woo and Popescu, Manuela}, publisher = {IARIA}, address = {Wilmington, DE, USA}, isbn = {978-1-61208-845-7}, issn = {2308-4294}, abstract = {Since IoT devices are potentially insecure and offer great attack potential, in our past research we presented IoTAG, a solution where devices communicate security-related information about themselves. However, since this information can also be exploited by attackers, we present in this paper a solution against the misuse of IoTAG. In doing so, we address the two biggest problems: authentication and pairing with a trusted device. This is solved by introducing a pairing process, which uses the simultaneous authentication of equals algorithm to securely exchange and verify each others signature, and by using the server and client authentication provided by HTTP over TLS. We provide the minimum requirements and evaluate the methods used. The emphasis is on known and already proven methods. Additionally, we analyze the potential consequences of an attacker tapping the IoTAG information. Finally, we conclude that the solution successfully prevents access to IoTAG by unauthorized clients on the same network.}, language = {en} } @inproceedings{RamsauerKiszkaMauerer, author = {Ramsauer, Ralf and Kiszka, Jan and Mauerer, Wolfgang}, title = {A Novel Software Architecture for Mixed Criticality Systems}, series = {Digital Transformation in Semiconductor Manufacturing: Proceedings of the 1st and 2nd European Advances in Digital Transformation Conference, EADTC 2018, Zittau, Germany and EADTC 2019, Milan, Italy}, booktitle = {Digital Transformation in Semiconductor Manufacturing: Proceedings of the 1st and 2nd European Advances in Digital Transformation Conference, EADTC 2018, Zittau, Germany and EADTC 2019, Milan, Italy}, editor = {Keil, Sophia and Lasch, Rainer and Lindner, Fabian and Lohmer, Jacob}, publisher = {Springer International Publishing}, address = {Cham}, doi = {10.1007/978-3-030-48602-0_11}, pages = {121 -- 128}, abstract = {The advent of multi-core CPUs in nearly all embedded markets has prompted an architectural trend towards combining safety critical and uncritical software on single hardware units. We present a novel architecture for mixed criticality systems based on Linux that allows us to consolidate critical and uncritical parts onto a single hardware unit. CPU virtualisation extensions enable strict and static partitioning of hardware by direct assignment of resources, which allows us to boot additional operating systems or bare metal applications running aside Linux. The hypervisor Jailhouse is at the core of the architecture and ensures that the resulting domains may serve workloads of different criticality and can not interfere in an unintended way. This retains Linux's feature-richness in uncritical parts, while frugal safety and real-time critical applications execute in isolated domains. Architectural simplicity is a central aspect of our approach and a precondition for reliable implementability and successful certification. While standard virtualisation extensions provided by current hardware seem to suffice for a straight forward implementation of our approach, there are a number of further limitations that need to be worked around. This paper discusses the arising issues, and evaluates the suitability of our approach for real-world safety and real-time critical scenarios.}, language = {en} } @inproceedings{SaxFeldZielinskietal., author = {Sax, Irmi and Feld, Sebastian and Zielinski, Sebastian and Gabor, Thomas and Linnhoff-Popien, Claudia and Mauerer, Wolfgang}, title = {Approximate approximation on a quantum annealer}, series = {Proceedings of the 17th ACM International Conference on Computing Frontiers (CF '20): Catania Sicily Italy 11.05.2020 -13.05.2020}, booktitle = {Proceedings of the 17th ACM International Conference on Computing Frontiers (CF '20): Catania Sicily Italy 11.05.2020 -13.05.2020}, editor = {Palesi, Maurizio}, publisher = {Association for Computing Machinery}, address = {New York, NY, United States}, isbn = {9781450379564}, doi = {10.1145/3387902.3392635}, pages = {108 -- 117}, abstract = {Many problems of industrial interest are NP-complete, and quickly exhaust resources of computational devices with increasing input sizes. Quantum annealers (QA) are physical devices that aim at this class of problems by exploiting quantum mechanical properties of nature. However, they compete with efficient heuristics and probabilistic or randomised algorithms on classical machines that allow for finding approximate solutions to large NP-complete problems. While first implementations of QA have become commercially available, their practical benefits are far from fully explored. To the best of our knowledge, approximation techniques have not yet received substantial attention. In this paper, we explore how problems' approximate versions of varying degree can be systematically constructed for quantum annealer programs, and how this influences result quality or the handling of larger problem instances on given set of qubits. We illustrate various approximation techniques on both, simulations and real QA hardware, on different seminal problems, and interpret the results to contribute towards a better understanding of the real-world power and limitations of current-state and future quantum computing.}, language = {en} } @inproceedings{KruegerMauerer, author = {Kr{\"u}ger, Tom and Mauerer, Wolfgang}, title = {Quantum Annealing-Based Software Components}, series = {Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops (ICSE'20): Seoul Republic of Korea 27.06.2020 - 19.07.2020}, booktitle = {Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops (ICSE'20): Seoul Republic of Korea 27.06.2020 - 19.07.2020}, publisher = {Association for Computing Machinery}, address = {New York, NY}, isbn = {9781450379632}, doi = {10.1145/3387940.3391472}, pages = {445 -- 450}, abstract = {Quantum computers have the potential of solving problems more efficiently than classical computers. While first commercial prototypes have become available, the performance of such machines in practical application is still subject to exploration. Quantum computers will not entirely replace classical machines, but serve as accelerators for specific problems. This necessitates integrating quantum computational primitives into existing applications. In this paper, we perform a case study on how to augment existing software with quantum computational primitives for the Boolean satisfiability problem (SAT) implemented using a quantum annealer (QA). We discuss relevant quality measures for quantum components, and show that mathematically equivalent, but structurally different ways of transforming SAT to a QA can lead to substantial differences regarding these qualities. We argue that engineers need to be aware that (and which) details, although they may be less relevant in traditional software engineering, require considerable attention in quantum computing.}, language = {en} } @inproceedings{RamsauerBulwahnLohmannetal., author = {Ramsauer, Ralf and Bulwahn, Lukas and Lohmann, Daniel and Mauerer, Wolfgang}, title = {The Sound of Silence : Mining Security Vulnerabilities from Secret Integration Channels in Open-Source Projects}, series = {Proceedings of the 2020 ACM SIGSAC Conference on Cloud Computing Security Workshop: 09.11.2020, virtual event}, booktitle = {Proceedings of the 2020 ACM SIGSAC Conference on Cloud Computing Security Workshop: 09.11.2020, virtual event}, editor = {Zhang, Yinqian and Sion, Radu}, publisher = {ACM}, address = {New York, NY, USA}, isbn = {9781450380843}, doi = {10.1145/3411495.3421360}, pages = {147 -- 157}, abstract = {Public development processes are a key characteristic of open source projects. However, fixes for vulnerabilities are usually discussed privately among a small group of trusted maintainers, and integrated without prior public involvement. This is supposed to prevent early disclosure, and cope with embargo and non-disclosure agreement (NDA) rules. While regular development activities leave publicly available traces, fixes for vulnerabilities that bypass the standard process do not. We present a data-mining based approach to detect code fragments that arise from such infringements of the standard process. By systematically mapping public development artefacts to source code repositories, we can exclude regular process activities, and infer irregularities that stem from non-public integration channels. For the Linux kernel, the most crucial component of many systems, we apply our method to a period of seven months before the release of Linux 5.4. We find 29 commits that address 12 vulnerabilities. For these vulnerabilities, our approach provides a temporal advantage of 2 to 179 days to design exploits before public disclosure takes place, and fixes are rolled out. Established responsible disclosure approaches in open development processes are supposed to limit premature visibility of security vulnerabilities. However, our approach shows that, instead, they open additional possibilities to uncover such changes that thwart the very premise. We conclude by discussing implications and partial countermeasures.}, language = {en} } @inproceedings{HayakawaAlFaloujiSchickhuberetal., author = {Hayakawa, Shuhei and Al-Falouji, Ghassan and Schickhuber, Gerald and Mandl, Roland and Yoshida, Takahiro and Hangai, Seiichiro}, title = {A Method of Toothbrush Position Measurement using AR Markers}, series = {2020 IEEE 2nd Global Conference on Life Sciences and Technologies (LifeTech): 10-12 March 2020, Kyoto, Japan}, booktitle = {2020 IEEE 2nd Global Conference on Life Sciences and Technologies (LifeTech): 10-12 March 2020, Kyoto, Japan}, publisher = {IEEE}, doi = {10.1109/LifeTech48969.2020.1570619103}, pages = {91 -- 93}, abstract = {Appropriate daily brushing of the teeth is important for preventing oral diseases. Therefore, a personal assistant for assessing and coaching appropriate toothbrushing is needed. Herein, a three-dimensional toothbrush position measurement method using augmented reality (AR) markers is proposed. The AR markers are detected via a brushing video captured using a smartphone camera. The AR markers are installed on each surface of a dodecahedron attached at the rear end of the toothbrush. This report describes the proposed method, the resulting toothbrush position measurement accuracy, and the optimal number of markers needed for an accurate measurement of the position.}, language = {en} } @inproceedings{FischerNeubauerHackenberg, author = {Fischer, Sebastian and Neubauer, Katrin and Hackenberg, Rudolf}, title = {A Study about the Different Categories of IoT in Scientific Publications}, series = {CLOUD COMPUTING 2020: the Eleventh International Conference on Cloud Computing, GRIDs and Virtualization, October 25-29, 2020, Nizza}, booktitle = {CLOUD COMPUTING 2020: the Eleventh International Conference on Cloud Computing, GRIDs and Virtualization, October 25-29, 2020, Nizza}, publisher = {IARIA}, isbn = {978-1-61208-778-8}, pages = {24 -- 30}, abstract = {The Internet of Things (IoT) is widely used as a synonym for nearly every connected device. This makes it really difficult to find the right kind of scientific publication for the intended category of IoT. Conferences and other events for IoT are confusing about the target group (consumer, enterprise, industrial, etc.) and standardisation organisations suffer from the same problem. To demonstrate these problems, this paper shows the results of an analyses over IoT publications in different research libraries. The number of results for IoT, consumer, enterprise and industrial search queries were evaluated and a manual study about 100 publications was done. According to the research library or search engine, different results about the distribution of consumer-, enterprise- and industrial- IoT are visible. The comparison with the results of the manual evaluation shows that some search queries do not show all desired publications or that considerably more, unwanted results are returned. Most researchers do not use the keywords right and the exact category of IoT can only be accessed via the abstract. This shows major problems with the use of the term IoT and its minor limitations.}, language = {en} } @unpublished{GoeppelFrikelHaltmeier, author = {G{\"o}ppel, Simon and Frikel, J{\"u}rgen and Haltmeier, Markus}, title = {A complementary ℓ1 -TV reconstruction algorithm for limited data CT}, abstract = {In a variety of tomographic applications, data cannot be fully acquired, leading to severely underdetermined image reconstruction. Conventional methods result in reconstructions with significant artifacts. In order to remove these artifacts, regularization methods have to be applied that incorporate additional information. An important example is TV reconstruction which is well known to efficiently compensate for missing data and well reduces reconstruction artifacts. At the same time, however, tomographic data is also contaminated by noise, which poses an additional challenge. The use of a single regularizer within a variational regularization framework must therefore account for both the missing data and the noise. However, a single regularizer may not be ideal for both tasks. For example, the TV regularizer is a poor choice for noise reduction over different scales, in which case ℓ1 curvelet regularization methods work well. To address this issue, in this paper we introduce a novel variational regularization framework that combines the advantages of two different regularizers. The basic idea of our framework is to perform reconstruction in two stages, where the first stage mainly aims at accurate reconstruction in the presence of noise, and the second stage aims at artifact reduction. Both reconstruction stages are connected by a data proximity condition. The proposed method is implemented and tested for limited-view CT using a combined curvelet-TV approach. We define and implement a curvelet transform adapted to the limited view problem and demonstrate the advantages of our approach in a series of numerical experiments in this context.}, language = {en} } @inproceedings{BorgSauerJorgensenFrikeletal., author = {Borg, Leise and Sauer J{\o}rgensen, Jakob and Frikel, J{\"u}rgen and Todd Quinto, Eric and Sporring, Jon}, title = {Reducing artifacts from varying projection truncations}, series = {3rd International Conference on Tomography of Materials and Structures Lund, Sweden, 26-30 June 2017, ICTMS2017-65-1}, booktitle = {3rd International Conference on Tomography of Materials and Structures Lund, Sweden, 26-30 June 2017, ICTMS2017-65-1}, abstract = {We study samples with full and partial occlusion causing streak artifacts, and propose two mod-ifications of filtered backprojection for artifact removal. Data is obtained by the SPring-8 synchrotron using a monochromatic parallel-beam scan [1]. Thresholding in the sinogram segments the metal, resulting in edges on which we apply 1) a smooth transition, or 2) a Dirichlet boundary condition.}, language = {en} } @misc{FrikelGoeppelHaltmeier, author = {Frikel, J{\"u}rgen and G{\"o}ppel, Simon and Haltmeier, Markus}, title = {Combining reconstruction and edge detection in CT}, series = {BVM Workshop 2023, 02.-04. Juli 2023, Braunschweig}, journal = {BVM Workshop 2023, 02.-04. Juli 2023, Braunschweig}, abstract = {We present two methods that combine image reconstruction and edge detection in computed tomography (CT) scans. Our first method is as an extension of the prominent filtered backprojection algorithm. In our second method we employ ℓ1-regularization for stable calculation of the gradient. As opposed to the first method, we show that this approach is able to compensate for undersampled CT data.}, language = {en} } @inproceedings{FrikelQuinto, author = {Frikel, J{\"u}rgen and Quinto, E.T.}, title = {Artifacts in limited view tomography}, series = {Oberwolfach Reports}, volume = {11}, booktitle = {Oberwolfach Reports}, number = {3}, editor = {Burger, Martin and Todd Quinto, Eric and Louis, Alfred K.}, doi = {10.4171/OWR/2014/37}, pages = {2047 -- 2114}, language = {en} } @inproceedings{GalkaSchuhegger, author = {Galka, Stefan and Schuhegger, Lukas}, title = {Integration of Discrete-event Simulation in the Planning of a Hydrogen Electrolyzer Production Facility}, series = {Proceedings of the 2022 Winter Simulation Conference (WSC), 11-14 Dec. 2022, Singapore}, booktitle = {Proceedings of the 2022 Winter Simulation Conference (WSC), 11-14 Dec. 2022, Singapore}, editor = {Feng, B. and Pedrielli, G. and Peng, Y. and Shashaani, S. and Song, E. and Corlu, C.G. and Lee, L.H. and Chew, E.P. and Roeder, T. and Lendermann, P.}, publisher = {IEEE}, address = {Singapore}, pages = {2}, abstract = {In the context of production and factory planning, the expansion of the factory must already be taken into account during initial planning. This results in an increase in planning complexity, as the involved planners have to know the expansion stages of the factory in the different time periods and have to evaluate concept modifications across all time periods. This paper presents an idea for a planning tool, which takes expansion stages into consideration. The data model contains all relevant information to generate a simulation model of the factory in an almost automated way. The aim is to enable factory planners to quickly investigate concept changes with the help of simulation, for example, to identify bottlenecks.}, language = {en} } @misc{WildGalkaWappleretal., author = {Wild, Tobias and Galka, Stefan and Wappler, Mona and Xing, Lu}, title = {Integrating supply chain aspects into factory planning, a simulation approach}, series = {The journey to sustainable supply chains: proceedings of the 26th International Symposium on Logistics (ISL 2022), 10-13th July 2022, Cork, Ireland}, journal = {The journey to sustainable supply chains: proceedings of the 26th International Symposium on Logistics (ISL 2022), 10-13th July 2022, Cork, Ireland}, editor = {Potter, A. and Pawar, K. S. and O'Reilly, S. and Jimo, A.}, publisher = {Nottingham University Business School, UK}, address = {Nottingham, UK}, isbn = {978-0-85358-350-9}, pages = {6}, abstract = {One major goal of green-field factory planning is to decide on space requirements in the plant. In this phase, detailed information about the supply chain network (e.g. which suppliers deliver which parts) is often unavailable. Nevertheless, typical decisions in supply chain management, like the definition of replenishment processes and quantities or make-or-buy decisions, impact space requirements in the factory and should therefore be considered in the factory planning. This research article proposes a simulation approach for a factory simulation in which raw material replenishment is integrated to evaluate the space requirements for raw materials.}, language = {de} } @inproceedings{SchmidWildSchneidewindetal., author = {Schmid, Florian and Wild, Tobias and Schneidewind, Jan and Vogl, Tobias and Schuhegger, Lukas and Galka, Stefan}, title = {Simulation Based Approach for Reconfiguration and Ramp up Scenario Analysis in Factory Planning}, series = {Proceedings of the 2022 Winter Simulation Conference (WSG), 11-14 Dec. 2022, Singapore}, booktitle = {Proceedings of the 2022 Winter Simulation Conference (WSG), 11-14 Dec. 2022, Singapore}, publisher = {IEEE}, isbn = {978-1-6654-7661-4}, doi = {10.1109/WSC57314.2022.10015310}, pages = {2842 -- 2852}, abstract = {Structural changes in production entail a potential economic risk for manufacturing companies. It is necessary to identify a suitable strategy for the reconfiguration process and to continue to meet the demand during the change in the factory structure and ramp-up phase. A simulation offers the possibility to analyze different ramp-up scenarios for the factory structure and to select a suitable concept for the reconfiguration process. A discrete event simulation approach is presented that can be used to evaluate variants of structural changes and serves as a basis for deciding on a reconfiguration strategy. This approach is demonstrated using a specific production step of a plant producing hydrogen electrolyzers, the results and generalized conclusions are discussed.}, language = {en} } @incollection{Weber, author = {Weber, Karsten}, title = {Robotik in der Pflege- und Gesundheitsversorgung}, series = {Genese und Folgen der Pflegerobotik}, booktitle = {Genese und Folgen der Pflegerobotik}, number = {196}, editor = {Hergesell, J. and Meister, M. and Maibaum, A.}, publisher = {Beltz/Juventa}, address = {Weinheim}, isbn = {978-3-7799-5243-5}, abstract = {Drei Ver{\"a}nderungen charakterisieren den demografischen Wandel in Deutschland: steigende durchschnittliche Lebenserwartung, der Anteil der Alten und Hochbetagten w{\"a}chst und der Anteil der j{\"u}ngeren Generationen schrumpft. Konsequenzen sind ein Zuwachs chronisch-degenerativer und pflegeintensiver Erkrankungen, ein schrumpfendes Arbeitskr{\"a}ftepotenzial und vor der {\"U}berlastung stehende soziale Sicherungssysteme. Abhilfe soll durch verst{\"a}rkten Technikeinsatz in der Pflege, insbesondere durch Roboter, geleistet werden: Roboter sollen Pflegekr{\"a}fte erg{\"a}nzen oder ersetzen, um dem Pflegenotstand zu begegnen und die Kosten der Pflege zu senken. Damit gehen aber zahlreiche Herausforderungen einher, die nicht zuletzt ethische Fragen ber{\"u}hren: Eine durch Technik bzw. Roboter gest{\"u}tzte Pflege wird diese in ihrem Kern ver{\"a}ndern, Professions- und Menschenbilder werden infrage gestellt und moralische Anspr{\"u}che tangiert. Der Beitrag zeichnet diese Gemengelage nach und skizziert ein diskursethisch ausgerichtetes Verfahren (MEESTAR) zur Aushandlung der Bedingungen f{\"u}r den Robotereinsatz in der Pflege- und Gesundheitsversorgung.}, language = {de} } @article{Weber, author = {Weber, Karsten}, title = {Computers as omnipotent instruments of power}, series = {The ORBIT Journal - An Online Journal for Responsible Research and Innovation in ICT}, volume = {2}, journal = {The ORBIT Journal - An Online Journal for Responsible Research and Innovation in ICT}, number = {1}, publisher = {Elsevier}, doi = {10.29297/orbit.v2i1.97}, pages = {1 -- 19}, abstract = {With examples concerning the development and dissemination of computer technology in the Soviet Union, the U.S., and other Western countries it shall be demonstrated that computer development on the one hand and social change as well as changes in policy making and administration on the other hand are mingled with each other without a clear direction of causation being discernible.It also shall be shown that perceived social and political threats imposed by early computer technology sometimes actually helped to stop or at least slow down social change. One conclusion that can be drawn from the case studies described for RRI is that the conscious steering of innovations fails because of diffuse and uncoordinated resistance from very different stakeholders. The case studies also suggest that the effectiveness of RRI might be rather limited.}, language = {en} } @incollection{KleineUlbrichtWeberetal., author = {Kleine, Nadine and Ulbricht, Max-R. and Weber, Karsten and Pallas, Frank}, title = {Participatory Sensing und Wearable Technologies als partizipative Formen der Datengenerierung im Internet of Things}, series = {'Grand Challenges' meistern - der Beitrag der Technikfolgenabsch{\"a}tzung}, booktitle = {'Grand Challenges' meistern - der Beitrag der Technikfolgenabsch{\"a}tzung}, editor = {Decker, Michael and Lindner, Ralf and Lingner, Stephan and Scherz, Constanze and Sotoudeh, Mahshid}, publisher = {Nomos}, address = {Baden-Baden}, doi = {10.5771/9783845283562-245}, pages = {245 -- 257}, subject = {Wearable Computer}, language = {de} } @article{Weber, author = {Weber, Karsten}, title = {Vorausschau und Regulierung von Innovationsprozessen im Bereich der ubiquit{\"a}ren Informations- und Kommunikationstechnologie}, series = {Modern Management Review / Dawna Nazwa - Zardądzanie i Marketing}, volume = {20}, journal = {Modern Management Review / Dawna Nazwa - Zardądzanie i Marketing}, number = {3}, doi = {10.7862/rz.2013.mmr.39}, abstract = {On the one hand technological innovations can create new markets and can provide for solutions of current social problems; on the other hand the can raise questions concerning environmental and/or social adequacy on short-, middle-, and long-range time scales. In or-der to strengthen the positive outcomes of innovations and to reduce or even prevent nega-tive effects, the task of technology assessment is to predict the positive as well as the nega-tive effects and repercussions of innovations as early as possible. However, it must be pre-supposed that first, it must be possible to make to a certain extent reliable predications about the future development and second, that regulatory measurements in order to strengthen the positive outcomes of innovations and to reduce or even prevent negative effects will find their respective addressees. But if one takes, for instance, ubiquitous information and com-munication technology into account it can be demonstrated that those conditions rarely can be met. This is the result of the types of innovation which take place in case of ICT as well as of the so-called Collingridge dilemma. Both factors reduce the reliability of predictions. Furthermore, regulatory measurements often do not find their addressees since the borders of the societal subsystems in which innovation take place are blurring and therefore, these subsystems often cannot be reached with mainstream regulatory approaches like laws.}, language = {de} } @article{WeberKleinePallasetal., author = {Weber, Karsten and Kleine, Nadine and Pallas, Frank and Ulbricht, Max-R.}, title = {Technik zur Unterst{\"u}tzung von Citizen Science und Open Science}, series = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, volume = {26}, journal = {TATuP - Zeitschrift f{\"u}r Technikfolgenabsch{\"a}tzung in Theorie und Praxis}, number = {1/2}, doi = {10.14512/tatup.26.1-2.25}, pages = {25 -- 30}, abstract = {If citizens actively participate in the process of collecting empirical data, as a key element of empirically oriented scientific projects, this can be seen as a contribution to an open and citizen-oriented science. Such participation can be supported by providing technical tools. The paper therefore presents examples of participatory sensing as the provision of affordable sensors for measuring environmental parameters as well as wearable technologies for recording quantified vital data and physiological states. Conceptually, the provision of data collected with these tools can be understood as a commons - with all opportunities and risks associated with such goods. After describing examples of participatory sensing and wearable technologies, the authors identify potential challenges and outline technical and organizational approaches to solve them.}, language = {de} } @article{Weber, author = {Weber, Karsten}, title = {What is it like to encounter an autonomous artificial agent?}, series = {AI \& Society}, volume = {28}, journal = {AI \& Society}, number = {4}, doi = {10.1007/s00146-013-0453-3}, pages = {483 -- 489}, abstract = {Following up on Thomas Nagel's paper "What is it like to be a bat?" and Alan Turing's essay "Computing machinery and intelligence," it shall be claimed that a successful interaction of human beings and autonomous artificial agents depends more on which characteristics human beings ascribe to the agent than on whether the agent really has those characteristics. It will be argued that Masahiro Mori's concept of the "uncanny valley" as well as evidence from several empirical studies supports that assertion. Finally, some tentative conclusions concerning moral implications of the arguments presented here shall be drawn}, language = {en} } @article{Weber, author = {Weber, Karsten}, title = {Technik in der Pflege}, series = {Evangelium und Wissenschaft}, volume = {39}, journal = {Evangelium und Wissenschaft}, number = {1}, language = {de} } @incollection{WeberKleine, author = {Weber, Karsten and Kleine, Nadine}, title = {Cybersecurity in Health Care}, series = {The Ethics of Cybersecurity}, volume = {21}, booktitle = {The Ethics of Cybersecurity}, editor = {Christen, Markus and Gordijn, Bert and Loi, Michele}, publisher = {Springer Nature}, address = {Cham, Switzerland}, isbn = {978-3-030-29053-5}, doi = {10.1007/978-3-030-29053-5_7}, pages = {139 -- 156}, abstract = {Ethical questions have always been crucial in health care; the rapid dissemination of ICT makes some of those questions even more pressing and also raises new ones. One of these new questions is cybersecurity in relation to ethics in health care. In order to more closely examine this issue, this chapter introduces Beauchamp and Childress' four principles of biomedical ethics as well as additional ethical values and technical aims of relevance for health care. Based on this, two case studies—implantable medical devices and electronic Health Card—are presented, which illustrate potential conflicts between ethical values and technical aims as well as between ethical values themselves. It becomes apparent that these conflicts cannot be eliminated in general but must be reconsidered on a case-by-case basis. An ethical debate on cybersecurity regarding the design and implementation of new (digital) technologies in health care is essential.}, language = {en} } @incollection{Weber, author = {Weber, Karsten}, title = {Technik in der Pflege: Bestandsaufnahme, Entwicklungsm{\"o}glichkeiten und normative Bewertung}, series = {Neue Technologien f{\"u}r die Pflege ; grundlegende Reflexionen und pragmatische Befunde}, booktitle = {Neue Technologien f{\"u}r die Pflege ; grundlegende Reflexionen und pragmatische Befunde}, number = {174}, editor = {H{\"u}lsken-Gießler, M. and Kreutzer, Susanne and D{\"u}tthorn, Nadin}, publisher = {Vandenhoeck \& Ruprecht}, address = {G{\"o}ttingen}, isbn = {978-3-7370-1202-7}, doi = {10.14220/9783737012027.153}, language = {de} } @inproceedings{DuennweberStadlerWeikletal., author = {D{\"u}nnweber, Jan and Stadler, Timo and Weikl, Sandra and Sch{\"a}fer, Andreas and Georg, Peter and Wein, Simon}, title = {Bus Route Classification for Rural Areas using Graph Convolutional Networks}, series = {Proceedings of the 22th International Conference on Artificial Intelligence and Soft Computing, Zakopane, Poland}, booktitle = {Proceedings of the 22th International Conference on Artificial Intelligence and Soft Computing, Zakopane, Poland}, pages = {15}, abstract = {In this paper, we present a new approach to determine the estimated time of arrival (ETA) for bus routes using (Deep) Graph Convolutional Networks (DGCNs). In addition we use the same DGCN to detect detours within a route. In our application, a classification of routes and their underlying graph structure is performed using Graph Learning. Our model leads to a fast prediction and avoids solving the vehicle routing problem (VRP) through expensive computations. Moreover, we describe how to predict travel time for all routes using the same DGCN Model. This method makes it possible not to use a more computationally intensive approximation algorithm when determining long travel times with many intermediate stops, but to use our network for an early estimate of the quality of a route. Long travel times, in our case result from the use of a call-bus system, which must distribute many passengers among several vehicles and can take them to places without a regular stop. For a case study, the rural town of Roding in Bavaria is used. Our training data for this area results from an approximation algorithm that we implemented to optimize routes, and to generate an archive of routes of varying quality simultaneously.}, language = {en} } @inproceedings{MuellerAltDuennweberetal., author = {M{\"u}ller, Jens and Alt, Martin and D{\"u}nnweber, Jan and Gorlatch, Sergei}, title = {Clayworks}, series = {IEEE International Conference on e-Science and Grid Computing (e-Science'06), 2nd, 4-6 Dec 2006, Amsterdam, Netherlands}, booktitle = {IEEE International Conference on e-Science and Grid Computing (e-Science'06), 2nd, 4-6 Dec 2006, Amsterdam, Netherlands}, isbn = {0-7695-2734-5}, doi = {10.1109/E-SCIENCE.2006.261188}, abstract = {Clayworks is a software system which integrates collaborative real-time modeling and distributed computing. It addresses the challenge of developing a collaborative workspace with a seamless access to high-performance servers. Clayworks allows modeling of virtual clay objects and running computation-intensive deformation simulations for objects crashing into each other. To integrate heterogeneous computational resources, we adopted modern Grid middleware and provided the users with an intuitive graphical interface. We parallelized the computation of simulations using a Higher-Order Component (HOC) which abstracts over the Globus Web service resource framework (WSRF) used to interconnect our worksuite to the computation server. Clayworks is a representative of a large class of demanding systems which combine collaborative modeling with performance-critical computations, e.g., crash-tests or simulations for biological population evolution.}, language = {en} }