2,572 research outputs found

    Differential spectrum modeling and sensitivity for keV sterile neutrino search at KATRIN

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    Starting in 2026, the KATRIN experiment will conduct a high-statistics measurement of the differential tritium Ξ²\beta-spectrum to energies deep below the kinematic endpoint. This enables the search for keV sterile neutrinos with masses less than the kinematic endpoint energy m4≀E0=18.6 keVm_\mathrm{4} \leq E_0 = 18.6\,\mathrm{keV}, aiming for a statistical sensitivity of ∣Ue4∣2=sin⁑2θ∼10βˆ’6|U_\mathrm{e4}|^2=\sin^2\theta\sim 10^{-6} for the mixing amplitude. The differential spectrum is obtained by decreasing the retarding potential of KATRIN\u27s main spectrometer, and by determining the Ξ²\beta-electron energies by their energy deposition in the new TRISTAN SDD array. In this mode of operation, the existing integral model of the tritium spectrum is insufficient, and a novel differential model is developed in this work. The new model (TRModel) convolves the differential tritium spectrum using responese matrices to predict the energy spectrum of registered events after data acquisition. Each response matrix encodes the spectral spectral distrortion from individual experimental effects, which depend on adjustable systematic parameters. This approach allows to efficiently assess the sensitivity impact of each systematics individually or in combination with others. The response matrices are obtained from monte carlo simulations, numerical convolution, and analytical computation. In this work, the sensitivity impact of 20 systematic parameters is assessed for the TRISTAN Phase-1 measurement for which nine TRISTAN SDD modules are integrated into the KATRIN beamline. Furthermore, it is demonstrated that the sensitivity impact is significantly mitigated with several beamline field adjustments and minimal hardware modifications

    On the real world practice of Behaviour Driven Development

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    Surveys of industry practice over the last decade suggest that Behaviour Driven Development is a popular Agile practice. For example, 19% of respondents to the 14th State of Agile annual survey reported using BDD, placing it in the top 13 practices reported. As well as potential benefits, the adoption of BDD necessarily involves an additional cost of writing and maintaining Gherkin features and scenarios, and (if used for acceptance testing,) the associated step functions. Yet there is a lack of published literature exploring how BDD is used in practice and the challenges experienced by real world software development efforts. This gap is significant because without understanding current real world practice, it is hard to identify opportunities to address and mitigate challenges. In order to address this research gap concerning the challenges of using BDD, this thesis reports on a research project which explored: (a) the challenges of applying agile and undertaking requirements engineering in a real world context; (b) the challenges of applying BDD specifically and (c) the application of BDD in open-source projects to understand challenges in this different context. For this purpose, we progressively conducted two case studies, two series of interviews, four iterations of action research, and an empirical study. The first case study was conducted in an avionics company to discover the challenges of using an agile process in a large scale safety critical project environment. Since requirements management was found to be one of the biggest challenges during the case study, we decided to investigate BDD because of its reputation for requirements management. The second case study was conducted in the company with an aim to discover the challenges of using BDD in real life. The case study was complemented with an empirical study of the practice of BDD in open source projects, taking a study sample from the GitHub open source collaboration site. As a result of this Ph.D research, we were able to discover: (i) challenges of using an agile process in a large scale safety-critical organisation, (ii) current state of BDD in practice, (iii) technical limitations of Gherkin (i.e., the language for writing requirements in BDD), (iv) challenges of using BDD in a real project, (v) bad smells in the Gherkin specifications of open source projects on GitHub. We also presented a brief comparison between the theoretical description of BDD and BDD in practice. This research, therefore, presents the results of lessons learned from BDD in practice, and serves as a guide for software practitioners planning on using BDD in their projects

    Language Design for Reactive Systems: On Modal Models, Time, and Object Orientation in Lingua Franca and SCCharts

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    Reactive systems play a crucial role in the embedded domain. They continuously interact with their environment, handle concurrent operations, and are commonly expected to provide deterministic behavior to enable application in safety-critical systems. In this context, language design is a key aspect, since carefully tailored language constructs can aid in addressing the challenges faced in this domain, as illustrated by the various concurrency models that prevent the known pitfalls of regular threads. Today, many languages exist in this domain and often provide unique characteristics that make them specifically fit for certain use cases. This thesis evolves around two distinctive languages: the actor-oriented polyglot coordination language Lingua Franca and the synchronous statecharts dialect SCCharts. While they take different approaches in providing reactive modeling capabilities, they share clear similarities in their semantics and complement each other in design principles. This thesis analyzes and compares key design aspects in the context of these two languages. For three particularly relevant concepts, it provides and evaluates lean and seamless language extensions that are carefully aligned with the fundamental principles of the underlying language. Specifically, Lingua Franca is extended toward coordinating modal behavior, while SCCharts receives a timed automaton notation with an efficient execution model using dynamic ticks and an extension toward the object-oriented modeling paradigm

    Pristup specifikaciji i generisanju proizvodnih procesa zasnovan na inΕΎenjerstvu voΔ‘enom modelima

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    In this thesis, we present an approach to the production process specification and generation based on the model-driven paradigm, with the goal to increase the flexibility of factories and respond to the challenges that emerged in the era of Industry 4.0 more efficiently. To formally specify production processes and their variations in the Industry 4.0 environment, we created a novel domain-specific modeling language, whose models are machine-readable. The created language can be used to model production processes that can be independent of any production system, enabling process models to be used in different production systems, and process models used for the specific production system. To automatically transform production process models dependent on the specific production system into instructions that are to be executed by production system resources, we created an instruction generator. Also, we created generators for different manufacturing documentation, which automatically transform production process models into manufacturing documents of different types. The proposed approach, domain-specific modeling language, and software solution contribute to introducing factories into the digital transformation process. As factories must rapidly adapt to new products and their variations in the era of Industry 4.0, production must be dynamically led and instructions must be automatically sent to factory resources, depending on products that are to be created on the shop floor. The proposed approach contributes to the creation of such a dynamic environment in contemporary factories, as it allows to automatically generate instructions from process models and send them to resources for execution. Additionally, as there are numerous different products and their variations, keeping the required manufacturing documentation up to date becomes challenging, which can be done automatically by using the proposed approach and thus significantly lower process designers' time.Π£ овој Π΄ΠΈΡΠ΅Ρ€Ρ‚Π°Ρ†ΠΈΡ˜ΠΈ прСдстављСн јС приступ ΡΠΏΠ΅Ρ†ΠΈΡ„ΠΈΠΊΠ°Ρ†ΠΈΡ˜ΠΈ ΠΈ Π³Π΅Π½Π΅Ρ€ΠΈΡΠ°ΡšΡƒ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса заснован Π½Π° ΠΈΠ½ΠΆΠ΅ΡšΠ΅Ρ€ΡΡ‚Π²Ρƒ Π²ΠΎΡ’Π΅Π½ΠΎΠΌ ΠΌΠΎΠ΄Π΅Π»ΠΈΠΌΠ°, Ρƒ Ρ†ΠΈΡ™Ρƒ ΠΏΠΎΠ²Π΅Ρ›Π°ΡšΠ° флСксибилности ΠΏΠΎΡΡ‚Ρ€ΠΎΡ˜Π΅ΡšΠ° Ρƒ Ρ„Π°Π±Ρ€ΠΈΠΊΠ°ΠΌΠ° ΠΈ Π΅Ρ„ΠΈΠΊΠ°ΡΠ½ΠΈΡ˜Π΅Π³ Ρ€Π°Π·Ρ€Π΅ΡˆΠ°Π²Π°ΡšΠ° ΠΈΠ·Π°Π·ΠΎΠ²Π° који сС ΠΏΠΎΡ˜Π°Π²Ρ™ΡƒΡ˜Ρƒ Ρƒ Π΅Ρ€ΠΈ Π˜Π½Π΄ΡƒΡΡ‚Ρ€ΠΈΡ˜Π΅ 4.0. Π—Π° ΠΏΠΎΡ‚Ρ€Π΅Π±Π΅ Ρ„ΠΎΡ€ΠΌΠ°Π»Π½Π΅ ΡΠΏΠ΅Ρ†ΠΈΡ„ΠΈΠΊΠ°Ρ†ΠΈΡ˜Π΅ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса ΠΈ ΡšΠΈΡ…ΠΎΠ²ΠΈΡ… Π²Π°Ρ€ΠΈΡ˜Π°Ρ†ΠΈΡ˜Π° Ρƒ Π°ΠΌΠ±ΠΈΡ˜Π΅Π½Ρ‚Ρƒ Π˜Π½Π΄ΡƒΡΡ‚Ρ€ΠΈΡ˜Π΅ 4.0, ΠΊΡ€Π΅ΠΈΡ€Π°Π½ јС Π½ΠΎΠ²ΠΈ намСнски јСзик, Ρ‡ΠΈΡ˜Π΅ ΠΌΠΎΠ΄Π΅Π»Π΅ Ρ€Π°Ρ‡ΡƒΠ½Π°Ρ€ ΠΌΠΎΠΆΠ΅ Π΄Π° ΠΎΠ±Ρ€Π°Π΄ΠΈ Π½Π° Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°Ρ‡ΠΈΠ½. ΠšΡ€Π΅ΠΈΡ€Π°Π½ΠΈ јСзик ΠΈΠΌΠ° могућност модСловања ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса који ΠΌΠΎΠ³Ρƒ Π±ΠΈΡ‚ΠΈ нСзависни ΠΎΠ΄ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… систСма ΠΈ Ρ‚ΠΈΠΌΠ΅ ΡƒΠΏΠΎΡ‚Ρ€Π΅Π±Ρ™Π΅Π½ΠΈ Ρƒ Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΡ‚ΠΈΠΌ ΠΏΠΎΡΡ‚Ρ€ΠΎΡ˜Π΅ΡšΠΈΠΌΠ° ΠΈΠ»ΠΈ Ρ„Π°Π±Ρ€ΠΈΠΊΠ°ΠΌΠ°, Π°Π»ΠΈ ΠΈ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса који су спСцифични Π·Π° ΠΎΠ΄Ρ€Π΅Ρ’Π΅Π½ΠΈ систСм. Како Π±ΠΈ ΠΌΠΎΠ΄Π΅Π»Π΅ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса зависних ΠΎΠ΄ ΠΊΠΎΠ½ΠΊΡ€Π΅Ρ‚Π½ΠΎΠ³ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΎΠ³ систСма Π±ΠΈΠ»ΠΎ ΠΌΠΎΠ³ΡƒΡ›Π΅ Π½Π° Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°Ρ‡ΠΈΠ½ трансформисати Ρƒ ΠΈΠ½ΡΡ‚Ρ€ΡƒΠΊΡ†ΠΈΡ˜Π΅ којС рСсурси ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΎΠ³ систСма ΠΈΠ·Π²Ρ€ΡˆΠ°Π²Π°Ρ˜Ρƒ, ΠΊΡ€Π΅ΠΈΡ€Π°Π½ јС Π³Π΅Π½Π΅Ρ€Π°Ρ‚ΠΎΡ€ ΠΈΠ½ΡΡ‚Ρ€ΡƒΠΊΡ†ΠΈΡ˜Π°. Π’Π°ΠΊΠΎΡ’Π΅ су ΠΊΡ€Π΅ΠΈΡ€Π°Π½ΠΈ ΠΈ Π³Π΅Π½Π΅Ρ€Π°Ρ‚ΠΎΡ€ΠΈ Ρ‚Π΅Ρ…Π½ΠΈΡ‡ΠΊΠ΅ Π΄ΠΎΠΊΡƒΠΌΠ΅Π½Ρ‚Π°Ρ†ΠΈΡ˜Π΅, који Π½Π° Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°Ρ‡ΠΈΠ½ Ρ‚Ρ€Π°Π½ΡΡ„ΠΎΡ€ΠΌΠΈΡˆΡƒ ΠΌΠΎΠ΄Π΅Π»Π΅ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ… процСса Ρƒ Π΄ΠΎΠΊΡƒΠΌΠ΅Π½Ρ‚Π΅ Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΡ‚ΠΈΡ… Ρ‚ΠΈΠΏΠΎΠ²Π°. Π£ΠΏΠΎΡ‚Ρ€Π΅Π±ΠΎΠΌ ΠΏΡ€Π΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠ³ приступа, намСнског јСзика ΠΈ софтвСрског Ρ€Π΅ΡˆΠ΅ΡšΠ° доприноси сС ΡƒΠ²ΠΎΡ’Π΅ΡšΡƒ Ρ„Π°Π±Ρ€ΠΈΠΊΠ° Ρƒ процСс Π΄ΠΈΠ³ΠΈΡ‚Π°Π»Π½Π΅ Ρ‚Ρ€Π°Π½ΡΡ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΡ˜Π΅. Како Ρ„Π°Π±Ρ€ΠΈΠΊΠ΅ Ρƒ Π΅Ρ€ΠΈ Π˜Π½Π΄ΡƒΡΡ‚Ρ€ΠΈΡ˜Π΅ 4.0 ΠΌΠΎΡ€Π°Ρ˜Ρƒ Π±Ρ€Π·ΠΎ Π΄Π° сС ΠΏΡ€ΠΈΠ»Π°Π³ΠΎΠ΄Π΅ Π½ΠΎΠ²ΠΈΠΌ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΠΌΠ° ΠΈ ΡšΠΈΡ…ΠΎΠ²ΠΈΠΌ Π²Π°Ρ€ΠΈΡ˜Π°Ρ†ΠΈΡ˜Π°ΠΌΠ°, Π½Π΅ΠΎΠΏΡ…ΠΎΠ΄Π½ΠΎ јС Π΄ΠΈΠ½Π°ΠΌΠΈΡ‡ΠΊΠΈ Π²ΠΎΠ΄ΠΈΡ‚ΠΈ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΡšΡƒ ΠΈ Π½Π° Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°Ρ‡ΠΈΠ½ слати ΠΈΠ½ΡΡ‚Ρ€ΡƒΠΊΡ†ΠΈΡ˜Π΅ рСсурсима Ρƒ Ρ„Π°Π±Ρ€ΠΈΡ†ΠΈ, Ρƒ зависности ΠΎΠ΄ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π° који сС ΠΊΡ€Π΅ΠΈΡ€Π°Ρ˜Ρƒ Ρƒ ΠΊΠΎΠ½ΠΊΡ€Π΅Ρ‚Π½ΠΎΠΌ ΠΏΠΎΡΡ‚Ρ€ΠΎΡ˜Π΅ΡšΡƒ. Π’ΠΈΠΌΠ΅ ΡˆΡ‚ΠΎ јС Ρƒ ΠΏΡ€Π΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠΌ приступу ΠΌΠΎΠ³ΡƒΡ›Π΅ ΠΈΠ· ΠΌΠΎΠ΄Π΅Π»Π° процСса Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ΠΎ гСнСрисати ΠΈΠ½ΡΡ‚Ρ€ΡƒΠΊΡ†ΠΈΡ˜Π΅ ΠΈ послати ΠΈΡ… рСсурсима, доприноси сС ΠΊΡ€Π΅ΠΈΡ€Π°ΡšΡƒ јСдног Π΄ΠΈΠ½Π°ΠΌΠΈΡ‡ΠΊΠΎΠ³ ΠΎΠΊΡ€ΡƒΠΆΠ΅ΡšΠ° Ρƒ саврСмСним Ρ„Π°Π±Ρ€ΠΈΠΊΠ°ΠΌΠ°. Π”ΠΎΠ΄Π°Ρ‚Π½ΠΎ, услСд Π²Π΅Π»ΠΈΠΊΠΎΠ³ Π±Ρ€ΠΎΡ˜Π° Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΡ‚ΠΈΡ… ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄Π° ΠΈ ΡšΠΈΡ…ΠΎΠ²ΠΈΡ… Π²Π°Ρ€ΠΈΡ˜Π°Ρ†ΠΈΡ˜Π°, ΠΏΠΎΡΡ‚Π°Ρ˜Π΅ ΠΈΠ·Π°Π·ΠΎΠ²Π½ΠΎ ΠΎΠ΄Ρ€ΠΆΠ°Π²Π°Ρ‚ΠΈ Π½Π΅ΠΎΠΏΡ…ΠΎΠ΄Π½Ρƒ Ρ‚Π΅Ρ…Π½ΠΈΡ‡ΠΊΡƒ Π΄ΠΎΠΊΡƒΠΌΠ΅Π½Ρ‚Π°Ρ†ΠΈΡ˜Ρƒ, ΡˆΡ‚ΠΎ јС Ρƒ ΠΏΡ€Π΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠΌ приступу ΠΌΠΎΠ³ΡƒΡ›Π΅ ΡƒΡ€Π°Π΄ΠΈΡ‚ΠΈ Π½Π° Π°ΡƒΡ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°Ρ‡ΠΈΠ½ ΠΈ Ρ‚ΠΈΠΌΠ΅ Π·Π½Π°Ρ‡Π°Ρ˜Π½ΠΎ ΡƒΡˆΡ‚Π΅Π΄Π΅Ρ‚ΠΈ Π²Ρ€Π΅ΠΌΠ΅ ΠΏΡ€ΠΎΡ˜Π΅ΠΊΡ‚Π°Π½Π°Ρ‚Π° процСса.U ovoj disertaciji predstavljen je pristup specifikaciji i generisanju proizvodnih procesa zasnovan na inΕΎenjerstvu voΔ‘enom modelima, u cilju poveΔ‡anja fleksibilnosti postrojenja u fabrikama i efikasnijeg razreΕ‘avanja izazova koji se pojavljuju u eri Industrije 4.0. Za potrebe formalne specifikacije proizvodnih procesa i njihovih varijacija u ambijentu Industrije 4.0, kreiran je novi namenski jezik, čije modele računar moΕΎe da obradi na automatizovan način. Kreirani jezik ima moguΔ‡nost modelovanja proizvodnih procesa koji mogu biti nezavisni od proizvodnih sistema i time upotrebljeni u različitim postrojenjima ili fabrikama, ali i proizvodnih procesa koji su specifični za odreΔ‘eni sistem. Kako bi modele proizvodnih procesa zavisnih od konkretnog proizvodnog sistema bilo moguΔ‡e na automatizovan način transformisati u instrukcije koje resursi proizvodnog sistema izvrΕ‘avaju, kreiran je generator instrukcija. TakoΔ‘e su kreirani i generatori tehničke dokumentacije, koji na automatizovan način transformiΕ‘u modele proizvodnih procesa u dokumente različitih tipova. Upotrebom predloΕΎenog pristupa, namenskog jezika i softverskog reΕ‘enja doprinosi se uvoΔ‘enju fabrika u proces digitalne transformacije. Kako fabrike u eri Industrije 4.0 moraju brzo da se prilagode novim proizvodima i njihovim varijacijama, neophodno je dinamički voditi proizvodnju i na automatizovan način slati instrukcije resursima u fabrici, u zavisnosti od proizvoda koji se kreiraju u konkretnom postrojenju. Time Ε‘to je u predloΕΎenom pristupu moguΔ‡e iz modela procesa automatizovano generisati instrukcije i poslati ih resursima, doprinosi se kreiranju jednog dinamičkog okruΕΎenja u savremenim fabrikama. Dodatno, usled velikog broja različitih proizvoda i njihovih varijacija, postaje izazovno odrΕΎavati neophodnu tehničku dokumentaciju, Ε‘to je u predloΕΎenom pristupu moguΔ‡e uraditi na automatizovan način i time značajno uΕ‘tedeti vreme projektanata procesa

    Mapping the Focal Points of WordPress: A Software and Critical Code Analysis

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    Programming languages or code can be examined through numerous analytical lenses. This project is a critical analysis of WordPress, a prevalent web content management system, applying four modes of inquiry. The project draws on theoretical perspectives and areas of study in media, software, platforms, code, language, and power structures. The applied research is based on Critical Code Studies, an interdisciplinary field of study that holds the potential as a theoretical lens and methodological toolkit to understand computational code beyond its function. The project begins with a critical code analysis of WordPress, examining its origins and source code and mapping selected vulnerabilities. An examination of the influence of digital and computational thinking follows this. The work also explores the intersection of code patching and vulnerability management and how code shapes our sense of control, trust, and empathy, ultimately arguing that a rhetorical-cultural lens can be used to better understand code\u27s controlling influence. Recurring themes throughout these analyses and observations are the connections to power and vulnerability in WordPress\u27 code and how cultural, processual, rhetorical, and ethical implications can be expressed through its code, creating a particular worldview. Code\u27s emergent properties help illustrate how human values and practices (e.g., empathy, aesthetics, language, and trust) become encoded in software design and how people perceive the software through its worldview. These connected analyses reveal cultural, processual, and vulnerability focal points and the influence these entanglements have concerning WordPress as code, software, and platform. WordPress is a complex sociotechnical platform worthy of further study, as is the interdisciplinary merging of theoretical perspectives and disciplines to critically examine code. Ultimately, this project helps further enrich the field by introducing focal points in code, examining sociocultural phenomena within the code, and offering techniques to apply critical code methods

    Cybersecurity knowledge graphs

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    Cybersecurity knowledge graphs, which represent cyber-knowledge with a graph-based data model, provide holistic approaches for processing massive volumes of complex cybersecurity data derived from diverse sources. They can assist security analysts to obtain cyberthreat intelligence, achieve a high level of cyber-situational awareness, discover new cyber-knowledge, visualize networks, data flow, and attack paths, and understand data correlations by aggregating and fusing data. This paper reviews the most prominent graph-based data models used in this domain, along with knowledge organization systems that define concepts and properties utilized in formal cyber-knowledge representation for both background knowledge and specific expert knowledge about an actual system or attack. It is also discussed how cybersecurity knowledge graphs enable machine learning and facilitate automated reasoning over cyber-knowledge

    On the Utility of Representation Learning Algorithms for Myoelectric Interfacing

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    Electrical activity produced by muscles during voluntary movement is a reflection of the firing patterns of relevant motor neurons and, by extension, the latent motor intent driving the movement. Once transduced via electromyography (EMG) and converted into digital form, this activity can be processed to provide an estimate of the original motor intent and is as such a feasible basis for non-invasive efferent neural interfacing. EMG-based motor intent decoding has so far received the most attention in the field of upper-limb prosthetics, where alternative means of interfacing are scarce and the utility of better control apparent. Whereas myoelectric prostheses have been available since the 1960s, available EMG control interfaces still lag behind the mechanical capabilities of the artificial limbs they are intended to steerβ€”a gap at least partially due to limitations in current methods for translating EMG into appropriate motion commands. As the relationship between EMG signals and concurrent effector kinematics is highly non-linear and apparently stochastic, finding ways to accurately extract and combine relevant information from across electrode sites is still an active area of inquiry.This dissertation comprises an introduction and eight papers that explore issues afflicting the status quo of myoelectric decoding and possible solutions, all related through their use of learning algorithms and deep Artificial Neural Network (ANN) models. Paper I presents a Convolutional Neural Network (CNN) for multi-label movement decoding of high-density surface EMG (HD-sEMG) signals. Inspired by the successful use of CNNs in Paper I and the work of others, Paper II presents a method for automatic design of CNN architectures for use in myocontrol. Paper III introduces an ANN architecture with an appertaining training framework from which simultaneous and proportional control emerges. Paper Iv introduce a dataset of HD-sEMG signals for use with learning algorithms. Paper v applies a Recurrent Neural Network (RNN) model to decode finger forces from intramuscular EMG. Paper vI introduces a Transformer model for myoelectric interfacing that do not need additional training data to function with previously unseen users. Paper vII compares the performance of a Long Short-Term Memory (LSTM) network to that of classical pattern recognition algorithms. Lastly, paper vIII describes a framework for synthesizing EMG from multi-articulate gestures intended to reduce training burden

    Beam scanning by liquid-crystal biasing in a modified SIW structure

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    A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

    Measuring the impact of COVID-19 on hospital care pathways

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    Care pathways in hospitals around the world reported significant disruption during the recent COVID-19 pandemic but measuring the actual impact is more problematic. Process mining can be useful for hospital management to measure the conformance of real-life care to what might be considered normal operations. In this study, we aim to demonstrate that process mining can be used to investigate process changes associated with complex disruptive events. We studied perturbations to accident and emergency (A &E) and maternity pathways in a UK public hospital during the COVID-19 pandemic. Co-incidentally the hospital had implemented a Command Centre approach for patient-flow management affording an opportunity to study both the planned improvement and the disruption due to the pandemic. Our study proposes and demonstrates a method for measuring and investigating the impact of such planned and unplanned disruptions affecting hospital care pathways. We found that during the pandemic, both A &E and maternity pathways had measurable reductions in the mean length of stay and a measurable drop in the percentage of pathways conforming to normative models. There were no distinctive patterns of monthly mean values of length of stay nor conformance throughout the phases of the installation of the hospital’s new Command Centre approach. Due to a deficit in the available A &E data, the findings for A &E pathways could not be interpreted

    Intelligent interface agents for biometric applications

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    This thesis investigates the benefits of applying the intelligent agent paradigm to biometric identity verification systems. Multimodal biometric systems, despite their additional complexity, hold the promise of providing a higher degree of accuracy and robustness. Multimodal biometric systems are examined in this work leading to the design and implementation of a novel distributed multi-modal identity verification system based on an intelligent agent framework. User interface design issues are also important in the domain of biometric systems and present an exceptional opportunity for employing adaptive interface agents. Through the use of such interface agents, system performance may be improved, leading to an increase in recognition rates over a non-adaptive system while producing a more robust and agreeable user experience. The investigation of such adaptive systems has been a focus of the work reported in this thesis. The research presented in this thesis is divided into two main parts. Firstly, the design, development and testing of a novel distributed multi-modal authentication system employing intelligent agents is presented. The second part details design and implementation of an adaptive interface layer based on interface agent technology and demonstrates its integration with a commercial fingerprint recognition system. The performance of these systems is then evaluated using databases of biometric samples gathered during the research. The results obtained from the experimental evaluation of the multi-modal system demonstrated a clear improvement in the accuracy of the system compared to a unimodal biometric approach. The adoption of the intelligent agent architecture at the interface level resulted in a system where false reject rates were reduced when compared to a system that did not employ an intelligent interface. The results obtained from both systems clearly express the benefits of combining an intelligent agent framework with a biometric system to provide a more robust and flexible application
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