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Sequential Composition of BDD Transition Systems for Model-Based Testing
No full textThis paper presents a compositional approach to model-based test derivation in Behavior-Driven Development (BDD). In BDD, system behavior is specified through scenarios written in natural language. For each scenario, a test case can be derived. However, such test cases do not cover the integration of multiple behaviors, while that is where potential faults may very well occur. To counter this, we introduce a formal composition operator for sequential composition, which integrates the individual BDDs while preserving their test coverage. We also report on a prototype tool that integrates model-based features into an existing testing framework that supports BDD-based test derivation. We show the feasibility and advantages of our approach by applying the prototype to a real-world case study.</p
Large language models for conceptual modeling:Assessment and application potential
Get PDFLarge Language Models (LLMs) are being rapidly adopted for many activities in organizations, business, and education. Included in their applications are capabilities to generate text, code, and models. This leads to questions about their potential role in the conceptual modeling part of information systems development. This paper reports on a panel presented at the 43rd International Conference on Conceptual Modeling where researchers discussed the current and potential role of LLMs in conceptual modeling. The panelists discussed applications and interest levels and expressed both optimism and caution in the adoption of LLMs. Suggested is a need for much continued research by the conceptual modeling community on LLM development and their role in research and teaching.</p
Building Flood Resilience: Lessons from Japan for the EU
Get PDFRecent events in Europe, such as the devastating 2024 floods in Valencia (Spain) and Emilia Romagna (Italy), highlight the growing challenges posed by climate change and emphasize the urgent need for enhanced flood resilience within the EU. Developing effective flood-resilience strategies requires tailored approaches, deeply rooted in the local context. While Japan offers an inspiring example of managing seasonal flooding, its methods cannot be directly applied to the European context without adaptation.In this presentation, I will introduce an ongoing Marie Curie Skłodowska Postdoctoral project, which focuses on the exchange of knowledge and best practices in community disaster preparedness and hazard mapping, with a particular emphasis on integrating lessons from Japan into the EU context while respecting local cultures.The project begins with a focus on the value of local narratives and stories of past disasters, which provide crucial insight into how communities perceive current risks and motivate residents to take proactive steps in disaster preparedness. This research explores the role of local culture, including myths and legends, in shaping these perceptions. Using qualitative methods such as interviews, literature reviews, and surveys, the project aims to propose an educational framework centred on localised resilience and sustainability. Additionally, the project seeks to incorporate qualitative aspects into interactive hazard mapping, with an emphasis on identifying vulnerable social groups and improving evacuation strategies during flood-related emergencies
Effects of chronic volume deprivation on the ventricle
Get PDFOBJECTIVES Little is known of the haemodynamic changes following chronic ventricular volume deprivation, which impact understanding the disease course and treatment results. An animal model was created to study the effects of chronic ventricular volume deprivation and acute reloading. METHODS In 13 lambs, a polytetrafluoroethylene strip was placed around the inferior and superior caval vein through thoracotomy resulting in progressive ventricular volume deprivation during growth. After 10 months, the polytetrafluoroethylene bands were relieved. Magnetic resonance imaging and haemodynamic measurements including pressure-volume loops were performed before and after debanding and compared to age and weight-matched controls (n = 6). RESULTS The end-diastolic pressure was elevated compared to healthy animals (median [interquartile range] 8.1 [7.2-9.1] vs 1.0 [1.0-2.7] mmHg, P 0.030). The end-diastolic pressure after debanding increased to 11.1 (10.4-17.2) mmHg, P 0.038. The end-diastolic volume and end-systolic volume of the intervention group were also significantly less than the healthy controls (71.5 [66.7-74.7] vs 81.5 [74.3-86.3] ml, P 0.004 and 34.5 [27.5-37.6] vs 42.7 [35.0-50.5] ml P 0.001). The end-diastolic pressure-volume relationship was significantly shifted upwards and to the left compared to controls, indicative of a decreased compliance of the chronically deprived left ventricle. Histologic assessment revealed no significant differences in fibrosis between the ventricles of the intervention group and healthy animals. CONCLUSIONS When a healthy ventricle is chronically deprived of an adequate preload, it becomes less compliant with elevated filling pressures. Acute reloading does not lead to ventricular systolic dysfunction, but in the early phase, diastolic pressure may rise. A better understanding of this phenomenon might help to recognition and treatment of impaired ventricular compliance.</p
Energy–speed relationship of quantum particles challenges Bohmian mechanics
Get PDFClassical mechanics characterizes the kinetic energy of a particle, the energy it holds due to its motion, as consistently positive. By contrast, quantum mechanics describes the motion of particles using wave functions, in which regions of negative local kinetic energy can emerge 1. This phenomenon occurs when the amplitude of the wave function experiences notable decay, typically associated with quantum tunnelling. Here, we investigate the quantum mechanical motion of particles in a system of two coupled waveguides, in which the population transfer between the waveguides acts as a clock, allowing particle speeds along the waveguide axis to be determined. By applying this scheme to exponentially decaying quantum states at a reflective potential step, we determine an energy–speed relationship for particles with negative local kinetic energy. We find that the smaller the energy of the particles—in other words, the more negative the local kinetic energy—the higher the measured speed inside the potential step. Our findings contribute to the ongoing tunnelling time debate 2, 3, 4, 5–6 and can be viewed as a test of Bohmian trajectories in quantum mechanics 7, 8–9. Regarding the latter, we find that the measured energy–speed relationship does not align with the particle dynamics postulated by the guiding equation in Bohmian mechanics.</p
High-power and narrow-linewidth laser on thin-film lithium niobate enabled by photonic wire bonding
Get PDFThin-film lithium niobate (TFLN) has emerged as a promising platform for the realization of high-performance chip-scale optical systems, spanning a range of applications from optical communications to microwave photonics. Such applications rely on the integration of multiple components onto a single platform. However, while many of these components have already been demonstrated on the TFLN platform, to date, a major bottleneck of the platform is the existence of a tunable, high-power, and narrow-linewidth on-chip laser. Here, we address this problem using photonic wire bonding to integrate optical amplifiers with a TFLN feedback circuit. We demonstrate an extended cavity diode laser with an excellent side mode suppression ratio exceeding 60 dB and a wide wavelength tunability over 43 nm. At higher currents, the laser produces a high maximum on-chip power of 76.2 mW while maintaining 51 dB side mode suppression. The laser frequency stability over short timescales shows an ultra-narrow intrinsic linewidth of 550 Hz. Long-term recordings indicate a high passive stability of the photonic wire bonded laser with 58 hours of mode-hop-free operation, with a trend in the frequency drift of only 4.4 MHz/h. This work verifies photonic wire bonding as a viable integration solution for high performance on-chip lasers, opening the path to system level upscaling and Watt-level output powers.</p
Prey species richness and secondary forest among the key factors shaping Javan leopard distribution
Get PDFApex predators serve as ecological indicators of a landscape’s capacity to maintain ecological structure, function, and resilience. The Javan leopard (Panthera pardus melas G. Cuvier, 1809), an endangered subspecies endemic to Java, faces escalating threats from habitat loss and anthropogenic pressures. Identifying robust ecological drivers of its distribution is essential for informing effective conservation strategies. In this study, we employed ensemble species distribution modeling using presence-only occurrence data and a suite of abiotic, biotic, and anthropogenic variables to predict the potential distribution of the Javan leopard. The models demonstrated high predictive performance (True Skill Statistic: 0.863–0.878; Area Under the Curve: 0.973–0.979), revealing two main clusters of high habitat suitability in western and eastern Java, with fragmented patches in central Java. Prey species richness and proximity to secondary forests—those recovering from past disturbances—emerged as the strongest predictors of leopard presence. While primary forests (i.e., relatively undisturbed natural ecosystems) and broader landscape features also contributed to habitat suitability, our findings emphasize the importance of trophic interactions and habitat heterogeneity in sustaining leopard populations within human-modified landscapes. The results indicate that habitat protection alone is insufficient; conservation strategies must also prioritize the maintenance of prey populations and the preservation of diverse forest mosaics. Such integrated approaches are essential for ensuring the long-term persistence of this apex predator and the broader ecosystems it supports
Mapping the hydrogen transition in the Netherlands:A sociotechnical multi-system event sequence analysis
Get PDFHydrogen is considered a promising energy carrier that can potentially contribute to low-carbon energy systems and achieving climate goals. Its introduction, however, is complex, involving multiple emerging niches and developments across various sociotechnical systems. Despite its significance, the multi-system nature of hydrogen has received limited attention in sustainability transition scholarship. This paper addresses this knowledge gap by examining the emerging hydrogen transition in the Netherlands from a multi-system sociotechnical perspective. To achieve this, we adopted a framework that considers multiple niches and sociotechnical systems in parallel, using Event Sequence Analysis (ESA). The analysis provides a systematic reconstruction of (niche-)processes as networks of events for analysing hydrogen niche formation from 2001 to 2020 across four sociotechnical systems: industry, electricity, transport, and the built environment. The results reveal that, despite positive discourse and ambitious plans, investments and implementation remained limited. We provide possible explanations for this progress through a multi-system lens.</p
Psychological mechanisms of revenge and revenge ideations in family homicide:results from qualitative research of forensic assessment reports
Get PDFOur aim was to find out which social and psychological factors characterize forensic psychiatric patients who have committed family homicide with revenge as a reason as compared to subjects who committed family homicide with other motives. Qualitative research was carried out on the basis of pre-trial forensic assessment reports of existing cases (N=20), divided between Revenge and No-Revenge cases. In case of revenge, violence was almost always a sort of settling of an interpersonal score. Psychotic symptomatology was absent in the Revenge cases, personality problems (particularly borderline and narcissistic traits) were common. Demoralization because of a decline of well-being seems to be an important factor pushing some persons with such vulnerabilities over the edge. Our expectation is that, at least in a certain proportion of (non-psychotic) patients, there will be more brooding on revenge than the psychotherapist suspects.</p
Component-Based Analytical Modeling of GPU Runtime Performance:a Case-Study in Scientific Computing
Get PDFAnalytical performance models are excellent tools for fast performance prediction and can be used effectively for designing and tuning parallel algorithms. However, such models are non-trivial to build, especially when both the application and the system are very complex. In this context, we study the applicability and limitations of a component-based analytical approach to model (and predict) the performance of GPU operations. Using microbenchmarks, we incorporate dynamic runtime behavior and architecture-dependent factors in the predictions. Our model validation and evaluation focus on a specific case-study: ROOT histogramming - a high-energy physics (HEP) application whose performance is critical in most experiments' data analysis pipeline (i.e., histogramming is run millions of times per analysis). We show our approach in action by constructing the model and showing how it can be useful for scenario analysis, where it can accurately predict trends and performance rankings. In addition, the design process of the model itself can lead to insights into the source of performance bottlenecks. We conclude that component-based modeling is feasible and practical for GPU applications. It is a modeling approach with a reasonable trade-off between accuracy, prediction speed, and interoperability.</p