2,572 research outputs found
Differential spectrum modeling and sensitivity for keV sterile neutrino search at KATRIN
Starting in 2026, the KATRIN experiment will conduct a high-statistics measurement of the differential tritium -spectrum to energies deep below the kinematic endpoint. This enables the search for keV sterile neutrinos with masses less than the kinematic endpoint energy , aiming for a statistical sensitivity of for the mixing amplitude. The differential spectrum is obtained by decreasing the retarding potential of KATRIN\u27s main spectrometer, and by determining the -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
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
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 voΔenom modelima
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£ ΠΎΠ²ΠΎΡ Π΄ΠΈΡΠ΅ΡΡΠ°ΡΠΈΡΠΈ ΠΏΡΠ΅Π΄ΡΡΠ°Π²ΡΠ΅Π½ ΡΠ΅ ΠΏΡΠΈΡΡΡΠΏ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠ°ΡΠΈΡΠΈ ΠΈ Π³Π΅Π½Π΅ΡΠΈΡΠ°ΡΡ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° Π·Π°ΡΠ½ΠΎΠ²Π°Π½ Π½Π° ΠΈΠ½ΠΆΠ΅ΡΠ΅ΡΡΡΠ²Ρ Π²ΠΎΡΠ΅Π½ΠΎΠΌ ΠΌΠΎΠ΄Π΅Π»ΠΈΠΌΠ°, Ρ ΡΠΈΡΡ ΠΏΠΎΠ²Π΅ΡΠ°ΡΠ° ΡΠ»Π΅ΠΊΡΠΈΠ±ΠΈΠ»Π½ΠΎΡΡΠΈ ΠΏΠΎΡΡΡΠΎΡΠ΅ΡΠ° Ρ ΡΠ°Π±ΡΠΈΠΊΠ°ΠΌΠ° ΠΈ Π΅ΡΠΈΠΊΠ°ΡΠ½ΠΈΡΠ΅Π³ ΡΠ°Π·ΡΠ΅ΡΠ°Π²Π°ΡΠ° ΠΈΠ·Π°Π·ΠΎΠ²Π° ΠΊΠΎΡΠΈ ΡΠ΅ ΠΏΠΎΡΠ°Π²ΡΡΡΡ Ρ Π΅ΡΠΈ ΠΠ½Π΄ΡΡΡΡΠΈΡΠ΅ 4.0. ΠΠ° ΠΏΠΎΡΡΠ΅Π±Π΅ ΡΠΎΡΠΌΠ°Π»Π½Π΅ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠ°ΡΠΈΡΠ΅ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° ΠΈ ΡΠΈΡ
ΠΎΠ²ΠΈΡ
Π²Π°ΡΠΈΡΠ°ΡΠΈΡΠ° Ρ Π°ΠΌΠ±ΠΈΡΠ΅Π½ΡΡ ΠΠ½Π΄ΡΡΡΡΠΈΡΠ΅ 4.0, ΠΊΡΠ΅ΠΈΡΠ°Π½ ΡΠ΅ Π½ΠΎΠ²ΠΈ Π½Π°ΠΌΠ΅Π½ΡΠΊΠΈ ΡΠ΅Π·ΠΈΠΊ, ΡΠΈΡΠ΅ ΠΌΠΎΠ΄Π΅Π»Π΅ ΡΠ°ΡΡΠ½Π°Ρ ΠΌΠΎΠΆΠ΅ Π΄Π° ΠΎΠ±ΡΠ°Π΄ΠΈ Π½Π° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°ΡΠΈΠ½. ΠΡΠ΅ΠΈΡΠ°Π½ΠΈ ΡΠ΅Π·ΠΈΠΊ ΠΈΠΌΠ° ΠΌΠΎΠ³ΡΡΠ½ΠΎΡΡ ΠΌΠΎΠ΄Π΅Π»ΠΎΠ²Π°ΡΠ° ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° ΠΊΠΎΡΠΈ ΠΌΠΎΠ³Ρ Π±ΠΈΡΠΈ Π½Π΅Π·Π°Π²ΠΈΡΠ½ΠΈ ΠΎΠ΄ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΡΠΈΡΡΠ΅ΠΌΠ° ΠΈ ΡΠΈΠΌΠ΅ ΡΠΏΠΎΡΡΠ΅Π±ΡΠ΅Π½ΠΈ Ρ ΡΠ°Π·Π»ΠΈΡΠΈΡΠΈΠΌ ΠΏΠΎΡΡΡΠΎΡΠ΅ΡΠΈΠΌΠ° ΠΈΠ»ΠΈ ΡΠ°Π±ΡΠΈΠΊΠ°ΠΌΠ°, Π°Π»ΠΈ ΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° ΠΊΠΎΡΠΈ ΡΡ ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ½ΠΈ Π·Π° ΠΎΠ΄ΡΠ΅ΡΠ΅Π½ΠΈ ΡΠΈΡΡΠ΅ΠΌ. ΠΠ°ΠΊΠΎ Π±ΠΈ ΠΌΠΎΠ΄Π΅Π»Π΅ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° Π·Π°Π²ΠΈΡΠ½ΠΈΡ
ΠΎΠ΄ ΠΊΠΎΠ½ΠΊΡΠ΅ΡΠ½ΠΎΠ³ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΎΠ³ ΡΠΈΡΡΠ΅ΠΌΠ° Π±ΠΈΠ»ΠΎ ΠΌΠΎΠ³ΡΡΠ΅ Π½Π° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°ΡΠΈΠ½ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠΈΡΠ°ΡΠΈ Ρ ΠΈΠ½ΡΡΡΡΠΊΡΠΈΡΠ΅ ΠΊΠΎΡΠ΅ ΡΠ΅ΡΡΡΡΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΎΠ³ ΡΠΈΡΡΠ΅ΠΌΠ° ΠΈΠ·Π²ΡΡΠ°Π²Π°ΡΡ, ΠΊΡΠ΅ΠΈΡΠ°Π½ ΡΠ΅ Π³Π΅Π½Π΅ΡΠ°ΡΠΎΡ ΠΈΠ½ΡΡΡΡΠΊΡΠΈΡΠ°. Π’Π°ΠΊΠΎΡΠ΅ ΡΡ ΠΊΡΠ΅ΠΈΡΠ°Π½ΠΈ ΠΈ Π³Π΅Π½Π΅ΡΠ°ΡΠΎΡΠΈ ΡΠ΅Ρ
Π½ΠΈΡΠΊΠ΅ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠ°ΡΠΈΡΠ΅, ΠΊΠΎΡΠΈ Π½Π° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°ΡΠΈΠ½ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠΈΡΡ ΠΌΠΎΠ΄Π΅Π»Π΅ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΠ° Ρ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠ΅ ΡΠ°Π·Π»ΠΈΡΠΈΡΠΈΡ
ΡΠΈΠΏΠΎΠ²Π°. Π£ΠΏΠΎΡΡΠ΅Π±ΠΎΠΌ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠ³ ΠΏΡΠΈΡΡΡΠΏΠ°, Π½Π°ΠΌΠ΅Π½ΡΠΊΠΎΠ³ ΡΠ΅Π·ΠΈΠΊΠ° ΠΈ ΡΠΎΡΡΠ²Π΅ΡΡΠΊΠΎΠ³ ΡΠ΅ΡΠ΅ΡΠ° Π΄ΠΎΠΏΡΠΈΠ½ΠΎΡΠΈ ΡΠ΅ ΡΠ²ΠΎΡΠ΅ΡΡ ΡΠ°Π±ΡΠΈΠΊΠ° Ρ ΠΏΡΠΎΡΠ΅Ρ Π΄ΠΈΠ³ΠΈΡΠ°Π»Π½Π΅ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΡΠ΅. ΠΠ°ΠΊΠΎ ΡΠ°Π±ΡΠΈΠΊΠ΅ Ρ Π΅ΡΠΈ ΠΠ½Π΄ΡΡΡΡΠΈΡΠ΅ 4.0 ΠΌΠΎΡΠ°ΡΡ Π±ΡΠ·ΠΎ Π΄Π° ΡΠ΅ ΠΏΡΠΈΠ»Π°Π³ΠΎΠ΄Π΅ Π½ΠΎΠ²ΠΈΠΌ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΠΌΠ° ΠΈ ΡΠΈΡ
ΠΎΠ²ΠΈΠΌ Π²Π°ΡΠΈΡΠ°ΡΠΈΡΠ°ΠΌΠ°, Π½Π΅ΠΎΠΏΡ
ΠΎΠ΄Π½ΠΎ ΡΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠΊΠΈ Π²ΠΎΠ΄ΠΈΡΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡ ΠΈ Π½Π° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°ΡΠΈΠ½ ΡΠ»Π°ΡΠΈ ΠΈΠ½ΡΡΡΡΠΊΡΠΈΡΠ΅ ΡΠ΅ΡΡΡΡΠΈΠΌΠ° Ρ ΡΠ°Π±ΡΠΈΡΠΈ, Ρ Π·Π°Π²ΠΈΡΠ½ΠΎΡΡΠΈ ΠΎΠ΄ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π° ΠΊΠΎΡΠΈ ΡΠ΅ ΠΊΡΠ΅ΠΈΡΠ°ΡΡ Ρ ΠΊΠΎΠ½ΠΊΡΠ΅ΡΠ½ΠΎΠΌ ΠΏΠΎΡΡΡΠΎΡΠ΅ΡΡ. Π’ΠΈΠΌΠ΅ ΡΡΠΎ ΡΠ΅ Ρ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠΌ ΠΏΡΠΈΡΡΡΠΏΡ ΠΌΠΎΠ³ΡΡΠ΅ ΠΈΠ· ΠΌΠΎΠ΄Π΅Π»Π° ΠΏΡΠΎΡΠ΅ΡΠ° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ΠΎ Π³Π΅Π½Π΅ΡΠΈΡΠ°ΡΠΈ ΠΈΠ½ΡΡΡΡΠΊΡΠΈΡΠ΅ ΠΈ ΠΏΠΎΡΠ»Π°ΡΠΈ ΠΈΡ
ΡΠ΅ΡΡΡΡΠΈΠΌΠ°, Π΄ΠΎΠΏΡΠΈΠ½ΠΎΡΠΈ ΡΠ΅ ΠΊΡΠ΅ΠΈΡΠ°ΡΡ ΡΠ΅Π΄Π½ΠΎΠ³ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠΊΠΎΠ³ ΠΎΠΊΡΡΠΆΠ΅ΡΠ° Ρ ΡΠ°Π²ΡΠ΅ΠΌΠ΅Π½ΠΈΠΌ ΡΠ°Π±ΡΠΈΠΊΠ°ΠΌΠ°. ΠΠΎΠ΄Π°ΡΠ½ΠΎ, ΡΡΠ»Π΅Π΄ Π²Π΅Π»ΠΈΠΊΠΎΠ³ Π±ΡΠΎΡΠ° ΡΠ°Π·Π»ΠΈΡΠΈΡΠΈΡ
ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π° ΠΈ ΡΠΈΡ
ΠΎΠ²ΠΈΡ
Π²Π°ΡΠΈΡΠ°ΡΠΈΡΠ°, ΠΏΠΎΡΡΠ°ΡΠ΅ ΠΈΠ·Π°Π·ΠΎΠ²Π½ΠΎ ΠΎΠ΄ΡΠΆΠ°Π²Π°ΡΠΈ Π½Π΅ΠΎΠΏΡ
ΠΎΠ΄Π½Ρ ΡΠ΅Ρ
Π½ΠΈΡΠΊΡ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠ°ΡΠΈΡΡ, ΡΡΠΎ ΡΠ΅ Ρ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎΠΌ ΠΏΡΠΈΡΡΡΠΏΡ ΠΌΠΎΠ³ΡΡΠ΅ ΡΡΠ°Π΄ΠΈΡΠΈ Π½Π° Π°ΡΡΠΎΠΌΠ°ΡΠΈΠ·ΠΎΠ²Π°Π½ Π½Π°ΡΠΈΠ½ ΠΈ ΡΠΈΠΌΠ΅ Π·Π½Π°ΡΠ°ΡΠ½ΠΎ ΡΡΡΠ΅Π΄Π΅ΡΠΈ Π²ΡΠ΅ΠΌΠ΅ ΠΏΡΠΎΡΠ΅ΠΊΡΠ°Π½Π°ΡΠ° ΠΏΡΠΎΡΠ΅ΡΠ°.U ovoj disertaciji predstavljen je pristup specifikaciji i generisanju proizvodnih procesa zasnovan na inΕΎenjerstvu voΔenom modelima, u cilju poveΔanja 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, Δije modele raΔunar moΕΎe da obradi na automatizovan naΔin. Kreirani jezik ima moguΔnost modelovanja proizvodnih procesa koji mogu biti nezavisni od proizvodnih sistema i time upotrebljeni u razliΔitim postrojenjima ili fabrikama, ali i proizvodnih procesa koji su specifiΔni za odreΔeni sistem. Kako bi modele proizvodnih procesa zavisnih od konkretnog proizvodnog sistema bilo moguΔe na automatizovan naΔin transformisati u instrukcije koje resursi proizvodnog sistema izvrΕ‘avaju, kreiran je generator instrukcija. TakoΔe su kreirani i generatori tehniΔke dokumentacije, koji na automatizovan naΔin transformiΕ‘u modele proizvodnih procesa u dokumente razliΔitih tipova. Upotrebom predloΕΎenog pristupa, namenskog jezika i softverskog reΕ‘enja doprinosi se uvoΔenju fabrika u proces digitalne transformacije. Kako fabrike u eri Industrije 4.0 moraju brzo da se prilagode novim proizvodima i njihovim varijacijama, neophodno je dinamiΔki voditi proizvodnju i na automatizovan naΔin slati instrukcije resursima u fabrici, u zavisnosti od proizvoda koji se kreiraju u konkretnom postrojenju. Time Ε‘to je u predloΕΎenom pristupu moguΔe iz modela procesa automatizovano generisati instrukcije i poslati ih resursima, doprinosi se kreiranju jednog dinamiΔkog okruΕΎenja u savremenim fabrikama. Dodatno, usled velikog broja razliΔitih proizvoda i njihovih varijacija, postaje izazovno odrΕΎavati neophodnu tehniΔku dokumentaciju, Ε‘to je u predloΕΎenom pristupu moguΔe uraditi na automatizovan naΔin i time znaΔajno uΕ‘tedeti vreme projektanata procesa
Mapping the Focal Points of WordPress: A Software and Critical Code Analysis
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
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
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 steerβa 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
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
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 hospitalβs 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
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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