1,160 research outputs found

    Exploiting Process Algebras and BPM Techniques for Guaranteeing Success of Distributed Activities

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    The communications and collaborations among activities, pro- cesses, or systems, in general, are the base of complex sys- tems defined as distributed systems. Given the increasing complexity of their structure, interactions, and functionali- ties, many research areas are interested in providing mod- elling techniques and verification capabilities to guarantee their correctness and satisfaction of properties. In particular, the formal methods community provides robust verification techniques to prove system properties. However, most ap- proaches rely on manually designed formal models, making the analysis process challenging because it requires an expert in the field. On the other hand, the BPM community pro- vides a widely used graphical notation (i.e., BPMN) to design internal behaviour and interactions of complex distributed systems that can be enhanced with additional features (e.g., privacy technologies). Furthermore, BPM uses process min- ing techniques to automatically discover these models from events observation. However, verifying properties and ex- pected behaviour, especially in collaborations, still needs a solid methodology. This thesis aims at exploiting the features of the formal meth- ods and BPM communities to provide approaches that en- able formal verification over distributed systems. In this con- text, we propose two approaches. The modelling-based ap- proach starts from BPMN models and produces process al- gebra specifications to enable formal verification of system properties, including privacy-related ones. The process mining- based approach starts from logs observations to automati- xv cally generate process algebra specifications to enable veri- fication capabilities

    Anpassen verteilter eingebetteter Anwendungen im laufenden Betrieb

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    The availability of third-party apps is among the key success factors for software ecosystems: The users benefit from more features and innovation speed, while third-party solution vendors can leverage the platform to create successful offerings. However, this requires a certain decoupling of engineering activities of the different parties not achieved for distributed control systems, yet. While late and dynamic integration of third-party components would be required, resulting control systems must provide high reliability regarding real-time requirements, which leads to integration complexity. Closing this gap would particularly contribute to the vision of software-defined manufacturing, where an ecosystem of modern IT-based control system components could lead to faster innovations due to their higher abstraction and availability of various frameworks. Therefore, this thesis addresses the research question: How we can use modern IT technologies and enable independent evolution and easy third-party integration of software components in distributed control systems, where deterministic end-to-end reactivity is required, and especially, how can we apply distributed changes to such systems consistently and reactively during operation? This thesis describes the challenges and related approaches in detail and points out that existing approaches do not fully address our research question. To tackle this gap, a formal specification of a runtime platform concept is presented in conjunction with a model-based engineering approach. The engineering approach decouples the engineering steps of component definition, integration, and deployment. The runtime platform supports this approach by isolating the components, while still offering predictable end-to-end real-time behavior. Independent evolution of software components is supported through a concept for synchronous reconfiguration during full operation, i.e., dynamic orchestration of components. Time-critical state transfer is supported, too, and can lead to bounded quality degradation, at most. The reconfiguration planning is supported by analysis concepts, including simulation of a formally specified system and reconfiguration, and analyzing potential quality degradation with the evolving dataflow graph (EDFG) method. A platform-specific realization of the concepts, the real-time container architecture, is described as a reference implementation. The model and the prototype are evaluated regarding their feasibility and applicability of the concepts by two case studies. The first case study is a minimalistic distributed control system used in different setups with different component variants and reconfiguration plans to compare the model and the prototype and to gather runtime statistics. The second case study is a smart factory showcase system with more challenging application components and interface technologies. The conclusion is that the concepts are feasible and applicable, even though the concepts and the prototype still need to be worked on in future -- for example, to reach shorter cycle times.Eine große Auswahl von Drittanbieter-Lösungen ist einer der Schlüsselfaktoren für Software Ecosystems: Nutzer profitieren vom breiten Angebot und schnellen Innovationen, während Drittanbieter über die Plattform erfolgreiche Lösungen anbieten können. Das jedoch setzt eine gewisse Entkopplung von Entwicklungsschritten der Beteiligten voraus, welche für verteilte Steuerungssysteme noch nicht erreicht wurde. Während Drittanbieter-Komponenten möglichst spät -- sogar Laufzeit -- integriert werden müssten, müssen Steuerungssysteme jedoch eine hohe Zuverlässigkeit gegenüber Echtzeitanforderungen aufweisen, was zu Integrationskomplexität führt. Dies zu lösen würde insbesondere zur Vision von Software-definierter Produktion beitragen, da ein Ecosystem für moderne IT-basierte Steuerungskomponenten wegen deren höherem Abstraktionsgrad und der Vielzahl verfügbarer Frameworks zu schnellerer Innovation führen würde. Daher behandelt diese Dissertation folgende Forschungsfrage: Wie können wir moderne IT-Technologien verwenden und unabhängige Entwicklung und einfache Integration von Software-Komponenten in verteilten Steuerungssystemen ermöglichen, wo Ende-zu-Ende-Echtzeitverhalten gefordert ist, und wie können wir insbesondere verteilte Änderungen an solchen Systemen konsistent und im Vollbetrieb vornehmen? Diese Dissertation beschreibt Herausforderungen und verwandte Ansätze im Detail und zeigt auf, dass existierende Ansätze diese Frage nicht vollständig behandeln. Um diese Lücke zu schließen, beschreiben wir eine formale Spezifikation einer Laufzeit-Plattform und einen zugehörigen Modell-basierten Engineering-Ansatz. Dieser Ansatz entkoppelt die Design-Schritte der Entwicklung, Integration und des Deployments von Komponenten. Die Laufzeit-Plattform unterstützt den Ansatz durch Isolation von Komponenten und zugleich Zeit-deterministischem Ende-zu-Ende-Verhalten. Unabhängige Entwicklung und Integration werden durch Konzepte für synchrone Rekonfiguration im Vollbetrieb unterstützt, also durch dynamische Orchestrierung. Dies beinhaltet auch Zeit-kritische Zustands-Transfers mit höchstens begrenzter Qualitätsminderung, wenn überhaupt. Rekonfigurationsplanung wird durch Analysekonzepte unterstützt, einschließlich der Simulation formal spezifizierter Systeme und Rekonfigurationen und der Analyse der etwaigen Qualitätsminderung mit dem Evolving Dataflow Graph (EDFG). Die Real-Time Container Architecture wird als Referenzimplementierung und Evaluationsplattform beschrieben. Zwei Fallstudien untersuchen Machbarkeit und Nützlichkeit der Konzepte. Die erste verwendet verschiedene Varianten und Rekonfigurationen eines minimalistischen verteilten Steuerungssystems, um Modell und Prototyp zu vergleichen sowie Laufzeitstatistiken zu erheben. Die zweite Fallstudie ist ein Smart-Factory-Demonstrator, welcher herausforderndere Applikationskomponenten und Schnittstellentechnologien verwendet. Die Konzepte sind den Studien nach machbar und nützlich, auch wenn sowohl die Konzepte als auch der Prototyp noch weitere Arbeit benötigen -- zum Beispiel, um kürzere Zyklen zu erreichen

    The In/visible Stockade: Sex Offender Management, Governmentality, and the Search for Normal Life

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    Over the past thirty-five years, the United States has seen a dramatic expansion of regulatory policy around individuals convicted of sexual offenses. Sex offender management policies include national and state registries, notification laws, treatment mandates, residency restrictions, and numerous exclusions from institutions. A growing body of research from sociologists and criminologists has tracked the effects of this sex offender regime by measuring recidivism and collateral consequences among released offenders. Less attention has been paid to how sex offenders adapt to their regulator context—especially the selective public visibility that the registry generates. Furthermore, sociological scholarship has not yet developed strong theoretical tools with which to make sense of sex offense management. Drawing on in-depth interviews with 106 registered citizens in the state of Nevada, I examine how registered citizens experience their contacts with direct state actors, various types of social relationships, and navigating institutions.I find that registered citizens face ever-present tensions across most social domains that are mitigated by how, when, and what information is released about their criminal history. I argue that a constellation of “information triggers” result in their offense history being revealed at critical junctures that systematically exclude them from a variety of interpersonal relations, group membership, and access to essential institutions like work and community. Direct state actors influence registered citizens by actively triggering the release of information to others in the community or to other sex offenders, isolating them from their communities and each other. In order to form or retain social ties, registered citizens worked to establish counternarratives facilitate disclosure and differentiate themselves from cultural perceptions of sex offenders; however, not all ties were as responsive. Registered citizens struggled to form weak social ties in their community, among their neighbors, and with friends, resulting in a much smaller social network and decreased social capital. Registered citizens faced extensive collateral consequences, including employment rejection, termination, housing rejection, harassment, and an unpredictable legal environment that caused registrants to lose a sense of progress toward normal life. I argue that the components of sex offender experience are best understood through the lens of neoliberal governmentality, a theoretical framework that examines government practice and logics as moving through the state and into the public to generate technologies of the self. The registry depends upon the public to expand the range of enforcement beyond what a democratic state would normally allow, enabling the rejection of the registered from most social domains with minimal action by the state. Approaching sex offense management from this perspective enables scholars to reframe sex offense management as a collaborative process between state actors, legislative processes, and the free actions of the public. Furthermore, it reveals how a contemporary state apparatus can employ the selective disclosure of information as a tool of social control, both for offenders and for the public

    “Go Ahead and Erect the Buildings Themselves:” An Archaeological Study of Three Black Schools in Gloucester County, Virginia

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    The focus of this research is on how daily life at and community use of Black schools in Gloucester County, Virginia changed as both the symbol and physical structure of the schoolhouse underwent shifts in perception and discourse from the 1880s through the 1950s. The historical record suggests there were major shifts in how Black schoolhouses were viewed by Black communities in those seventy years. In the 1870s and 1880s, even public schools in poor conditions were celebrated as an achievement after centuries of education being legally prohibited and the Black fight for public education after emancipation. By the 1910s, as Black schools were left out of a national movement for school improvement, there were increasing petitions for more monetary aid and public discussion of unequal conditions. In the 1920s, Gloucester got its first Rosenwald schools, new modern high-quality schoolhouses that were points of pride. Twenty years later, after two decades of neglect by school authorities, these same schools became the focus of the growing Civil Rights movement and a symbol of the discrimination faced by Black communities across the Jim Crow South. I use archaeological evidence from three Black schools in Gloucester, Woodville (44GL523), Bethel (44GL273), and Glenns/Dragon (44GL550) along with historical documents and oral histories to address what, if any, changes in daily life and community use occurred over this seventy-year period. The evidence is used to examine shifts in schoolhouse structures, education, daily life, and community events in Gloucester’s Black schools.Doctor of Philosoph

    When Complex is as Simple as it Gets: Guide for Recasting Policy and Management in the Anthropocene

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    Many readers recognise and understand that complex is about as simple as it gets for major policy and management. This guide is for those unwilling in the Anthropocene to shrink back into the older platitudes about ‘keep it simple’ and ‘not to worry, we’ll scale up the analysis later on’. This guide offers key concepts, methods, counternarratives, and analogies that recast major policy and management issues in ways that do not deny their complexity but help render them more tractable for action.European Research Council, Grant No. 74032US National Science Foundation Grant No. 212152

    Jornadas Nacionales de Investigación en Ciberseguridad: actas de las VIII Jornadas Nacionales de Investigación en ciberseguridad: Vigo, 21 a 23 de junio de 2023

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    Jornadas Nacionales de Investigación en Ciberseguridad (8ª. 2023. Vigo)atlanTTicAMTEGA: Axencia para a modernización tecnolóxica de GaliciaINCIBE: Instituto Nacional de Cibersegurida
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