05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Precise voltage measurement for power electronics with high switching frequencies(2018) Nitzsche, Maximilian; Zehelein, Matthias; Tröster, Nathan; Roth-Stielow, JörgIn this paper different approaches in precise measurement of gate voltages as well as drain-source voltages of modern SiC and GaN transistors are compared. An approach to calculate the necessary bandwidth of a voltage probe to reproduce the voltage slope is presented. Furthermore, state-of-the-art voltage probes are compared in means of bandwidth, common mode reduction and response on EMI.Item Open Access Mining Java packages for developer profiles : an exploratory study(2017) Ramadani, Jasmin; Wagner, StefanItem Open Access Empirical research plan: effects of sketching on program comprehension(2016) Baltes, Sebastian; Wagner, StefanSketching is an important means of communication in software engineering practice. Yet, there is little research investigating the use of sketches. We want to contribute a better understanding of sketching, in particular its use during program comprehension. We propose a controlled experiment to investigate the effectiveness and efficiency of program comprehension with the support of sketches as well as what sketches are used in what way.Item Open Access VisRecall++: analysing and predicting visualisation recallability from gaze behaviour(2024) Wang, Yao; Jiang, Yue; Hu, Zhiming; Ruhdorfer, Constantin; Bâce, Mihai; Bulling, AndreasQuestion answering has recently been proposed as a promising means to assess the recallability of information visualisations. However, prior works are yet to study the link between visually encoding a visualisation in memory and recall performance. To fill this gap, we propose VisRecall++ - a novel 40-participant recallability dataset that contains gaze data on 200 visualisations and five question types, such as identifying the title, and finding extreme values.We measured recallability by asking participants questions after they observed the visualisation for 10 seconds.Our analyses reveal several insights, such as saccade amplitude, number of fixations, and fixation duration significantly differ between high and low recallability groups.Finally, we propose GazeRecallNet - a novel computational method to predict recallability from gaze behaviour that outperforms several baselines on this task.Taken together, our results shed light on assessing recallability from gaze behaviour and inform future work on recallability-based visualisation optimisation.Item Open Access A comprehensive safety engineering approach for software-intensive systems based on STPA(2015) Abdulkhaleq, Asim; Wagner, Stefan; Leveson, NancyFormal verification and testing are complementary approaches which are used in the development process to verify the functional correctness of software. However, the correctness of software cannot ensure the safe operation of safety-critical software systems. The software must be verified against its safety requirements which are identified by safety analysis, to ensure that potential hazardous causes cannot occur. The complexity of software makes defining appropriate software safety requirements with traditional safety analysis techniques difficult. STPA (Systems-Theoretic Processes Analysis) is a unique safety analysis approach that has been developed to identify system hazards, including the software-related hazards. This paper presents a comprehensive safety engineering approach based on STPA, including software testing and model checking approaches for the purpose of developing safe software. The proposed approach can be embedded within a defined software engineering process or applied to existing software systems, allow software and safety engineers integrate the analysis of software risks with their verification. The application of the proposed approach is illustrated with an automotive software controller.Item Open Access CorefAnnotator : a new annotation tool for entity references(2018) Reiter, NilsItem Open Access Languages, methods, and tools for software specification(1989) Ludewig, JochenSpecification systems consist of methods, languages, and tools; the languages may be more or less formal. In this paper, the general ideas of semi-formal specification systems are presented, and some examples are shown.Item Open Access Computer-aided safety analysis of computer-controlled systems : a case example(2000) Biegert, UweComputer controlled systems consist of a complex interaction between technical process, human task and software. For the development of safety critical systems new method are required, which not only consider one of these parts of a computer-controlled system. In this paper a qualitative modeling method is presented. The method is called SQMA, Situationbased Qualitative Modeling and Analysis and it origin goes back to Qualitative Reasoning. First, all parts of a system are modeled separated and then combined to a unique model of a computer-controlled system. With this qualitative model a computer supported hazard analysis can be realised.Item Open Access Modelling the quality economics of defect-detection techniques(2006) Wagner, StefanThere are various ways to evaluate defect-detection techniques. However, for a comprehensive evaluation the only possibility is to reduce all influencing factors to costs. There are already some models and metrics for the cost of quality that can be used in that context. These models allow the structuring of the costs but do not show all influencing factors and their relationships. This paper proposes an analytical model for the economics of defect-detection techniques that can be used for analysis and optimisation of the usage of such techniques. In particular we analyse the sensitivity of the model and how the model can be applied in practice.Item Open Access Process model for the development of system requirements specifications for railway systems(2002) Bitsch, FriedemannIn this paper a process model for the development of system requirements specifications for railway systems is introduced. Demands of the approval of system requirements specifications, which arise from recent European railway standards, are taken into account. The aim is to obtain a system specification, which is unambiguous and easy to understand for all parties involved and in which safety aspects are considered in detail. Correlations between the development of a precise system specification, the performance of safety relevant correctness checks and the performance of risk analysis are presented. Especially the identification, specification and formalisation of safety requirements are treated with regard to correctness checks referred to safety aspects by using model checking. It is also demonstrated how different techniques of risk analysis can be supported by a system model in diagrams of the Unified Modelling Language (UML). This work has been developed in close co-operation with the Institute of Railway Systems Engineering and Traffic Safety (IfEV), Technical University of Braunschweig, Germany within the scope of the project SafeRail (see http://www.ias.uni-stuttgart.de/projekte/saferail/).