05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

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Institute: search.filters.UBSInstitut.Fakultätsübergreifend / Sonstige EinrichtungPublication Type: search.filters.UBSTyp.Konferenzbeitrag

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Now showing 1 - 10 of 27
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    Empirical research plan: effects of sketching on program comprehension
    (2016) Baltes, Sebastian; Wagner, Stefan
    Sketching 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.
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    VisRecall++: analysing and predicting visualisation recallability from gaze behaviour
    (2024) Wang, Yao; Jiang, Yue; Hu, Zhiming; Ruhdorfer, Constantin; Bâce, Mihai; Bulling, Andreas
    Question 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.
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    A comprehensive safety engineering approach for software-intensive systems based on STPA
    (2015) Abdulkhaleq, Asim; Wagner, Stefan; Leveson, Nancy
    Formal 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.
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    Modelling the quality economics of defect-detection techniques
    (2006) Wagner, Stefan
    There 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.
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    Synchronisierung von digitalen Modellen mit realen Fertigungszellen auf Basis einer Ankerpunktmethode am Beispiel der Automobilindustrie
    (2017) Ashtari Talkhestani, Behrang; Schlögl, Wolfgang; Weyrich, Michael
    Die zunehmende Produktvielfalt und die Verkürzung der Produktlebenszyklen erfordern eine schnelle und kostengünstige Rekonfiguration bestehender Produktionssysteme [1]. Um diesen Herausforderungen zu begegnen, ist ein aktuelles digitales Modell der bestehenden Fertigungszelle, im Folgenden Digitaler Zwilling genannt, eine geeignete Lösung. Der Digitale Zwilling führt zu einer Kostenreduktion durch Verkürzung der Umrüstzeiten durch virtuelle Planung und Simulation basierend auf dem aktuellen Zustand der realen Produktionsanlage als auch durch eine frühzeitige Erkennung von Konstruktions- oder Prozessablauffehlern in der Produktionsanlage. Voraussetzung für die Verwendbarkeit des Digitalen Zwillings vom Produktionssystem ist allerdings, dass ein aktuelles (virtuelles) Anlagenmodell von den mechatronischen Bestandteilen der realen Anlage während der verschiedenen Phasen ihres Lebenszyklus existiert. In diesem Beitrag wird die domänenübergreifende, mechatronische Datenstruktur der virtuellen Fertigungszellen in der Automobilindustrie diskutiert. Es wird eine systematische Ankerpunktmethode vorgestellt, mithilfe derer die Abweichungen zwischen den virtuellen Modellen und der Realität detektiert und ermittelt werden können. Basierend darauf wird eine sogenannte regelbasierte Konsistenzprüfung zur durchgängigen, domänenübergreifenden Synchronisierung der aktuellen mechatronischen Ressourcenkomponenten der Produktionssysteme mit deren virtuellem Anlagemodell vorgestellt.
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    SalChartQA: question-driven saliency on information visualisations
    (2024) Wang, Yao; Wang, Weitian; Abdelhafez, Abdullah; Elfares, Mayar; Hu, Zhiming; Bâce, Mihai; Bulling, Andreas
    Understanding the link between visual attention and user’s needs when visually exploring information visualisations is under-explored due to a lack of large and diverse datasets to facilitate these analyses. To fill this gap, we introduce SalChartQA - a novel crowd-sourced dataset that uses the BubbleView interface as a proxy for human gaze and a question-answering (QA) paradigm to induce different information needs in users. SalChartQA contains 74,340 answers to 6,000 questions on 3,000 visualisations. Informed by our analyses demonstrating the tight correlation between the question and visual saliency, we propose the first computational method to predict question-driven saliency on information visualisations. Our method outperforms state-of-the-art saliency models, improving several metrics, such as the correlation coefficient and the Kullback-Leibler divergence. These results show the importance of information needs for shaping attention behaviour and paving the way for new applications, such as task-driven optimisation of visualisations or explainable AI in chart question-answering.
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    Software quality models : purposes, usage scenarios and requirements
    (2009) Deißenböck, Florian; Juergens, Elmar; Lochmann, Klaus; Wagner, Stefan
    Software quality models are a well-accepted means to support quality management of software systems. Over the last 30 years, a multitude of quality models have been proposed and applied with varying degrees of success. Despite successes and standardisation efforts, quality models are still being criticised, as their application in practice exhibits various problems. To some extent, this criticism is caused by an unclear definition of what quality models are and which purposes they serve. Beyond this, there is a lack of explicitly stated requirements for quality models with respect to their intended mode of application. To remedy this, this paper describes purposes and usage scenarios of quality models and, based on the literature and experiences from the authors, collects critique of existing models. From this, general requirements for quality models are derived. The requirements can be used to support the evaluation of existing quality models for a given context or to guide further quality model development.
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    Informationsmodelle mit intelligenter Auswertung für den Digitalen Zwilling
    (2020) Müller, Manuel; Ashtari Talkhestani, Behrang; Jazdi, Nasser; Rosen, Roland; Wehrstedt, Jan Christoph; Weyrich, Michael
    Die zunehmende Komplexität hochautomatisierter Systeme bringt neue Herausforderungen bei der Verwaltung ihrer Modelle entlang des gesamten Lebenszyklus des Systems mit sich - von der Kundenakquise über Engineering und Rekonfiguration bis hin zum Systemrecycling. Der Digitale Zwilling ist ein Konzept, welches über den gesamten Lebenszyklus eines Assets hinweg das Management dieser Modelle sicherstellen kann. Es unterstützt jedoch nicht die automatisierte Modellerweiterung. Hier setzt diese Arbeit an. Die Anreicherung des Digitalen Zwillings um Modellverständnis und KI-Algorithmen zur eigenständigen Modellerweiterung bildet die Grundlager des vorgestellten Konzepts. Über die intelligente Auswertung der Informationsmodelle -angereichert mit aktuellen Prozessdaten- erkennt der Digitale Zwilling, wenn Modelle an ihre Grenzen stoßen. Zwei mögliche Ursachen für diesen Sachverhalt werden genauer betrachtet: (1) es fehlt eine Fähigkeit oder Information (2) der Gültigkeitsbereich des Modells wurde verlassen. Für beide Zustände wird ein Verfahren vorgeschlagen, welches auf Basis kooperativer Information aus dem Wertschöpfungsnetzwerk automatisiert eine Lösung findet. Die Evaluierung des Konzepts anhand eines Szenarios aus der Logistik und aus der Produktion liefert vielversprechende Ergebnisse.
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    The Quamoco product quality modelling and assessment approach
    (2012) Wagner, Stefan; Lochmann, Klaus; Heinemann, Lars; Kläs, Michael; Trendowicz, Adam; Plösch, Reinhold; Seidl, Andreas; Goeb, Andreas; Streit, Jonathan
    Published software quality models either provide abstract quality attributes or concrete quality assessments. There are no models that seamlessly integrate both aspects. In the project Quamoco, we built a comprehensive approach with the aim to close this gap. For this, we developed in several iterations a meta quality model specifying general concepts, a quality base model covering the most important quality factors and a quality assessment approach. The meta model introduces the new concept of a product factor, which bridges the gap between concrete measurements and abstract quality aspects. Product factors have measures and instruments to operationalise quality by measurements from manual inspection and tool analysis. The base model uses the ISO 25010 quality attributes, which we refine by 200 factors and 600 measures for Java and C# systems. We found in several empirical validations that the assessment results fit to the expectations of experts for the corresponding systems. The empirical analyses also showed that several of the correlations are statistically significant and that the maintainability part of the base model has the highest correlation, which fits to the fact that this part is the most comprehensive. Although we still see room for extending and improving the base model, it shows a high correspondence with expert opinions and hence is able to form the basis for repeatable and understandable quality assessments in practice.
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    Mining valence, arousal, and dominance - possibilities for detecting burnout and productivity?
    (2016) Mäntylä, Mika; Adams, Bram; Destefanis, Giuseppe; Graziotin, Daniel; Ortu, Marco
    Similar to other industries, the software engineering domain is plagued by psychological diseases such as burnout, which lead developers to lose interest, exhibit lower activity and/or feel powerless. Prevention is essential for such diseases, which in turn requires early identification of symptoms. The emotional dimensions of Valence, Arousal and Dominance (VAD) are able to derive a person's interest (attraction), level of activation and perceived level of control for a particular situation from textual communication, such as emails. As an initial step towards identifying symptoms of productivity loss in software engineering, this paper explores the VAD metrics and their properties on 700,000 Jira issue reports containing over 2,000,000 comments, since issue reports keep track of a developer's progress on addressing bugs or new features. Using a general-purpose lexicon of 14,000 English words with known VAD scores, our results show that issue reports of different type (e.g., Feature Request vs. Bug) have a fair variation of Valence, while increase in issue priority (e.g., from Minor to Critical) typically increases Arousal. Furthermore, we show that as an issue's resolution time increases, so does the arousal of the individual the issue is assigned to. Finally, the resolution of an issue increases valence, especially for the issue Reporter and for quickly addressed issues. The existence of such relations between VAD and issue report activities shows promise that text mining in the future could offer an alternative way for work health assessment surveys.