Sharing Non-Processor Resources in Multiprocessor Real-Time Systems

Computing devices are increasingly being leveraged in cyber-physical systems, in which computing devices sense, control, and interact with the physical world. Associated with many such real-world interactions are strict timing constraints, which if unsatisfied, can lead to catastrophic consequences. Modern examples of such timing constraints are prevalent in automotive systems, such as airbag controllers, anti-lock brakes, and new autonomous features. In all of these examples, a failure to correctly respond to an event in a timely fashion could lead to a crash, damage, injury and even loss of life. Systems with imperative timing constraints are called real-time systems, and are broadly the subject of this dissertation. Much previous work on real-time systems and scheduling theory assumes that computing tasks are independent, i.e., the only resource they share is the platform upon which they are executed. In practice, however, tasks share many resources, ranging from more overt resources such as shared memory objects, to less overt ones, including data buses and other hardware and I/O devices. Accesses to some such resources must be synchronized to ensure safety, i.e., logical correctness, while other resources may exhibit better run-time performance if accesses are explicitly synchronized. The goal of this dissertation was to develop new synchronization algorithms and associated analysis techniques that can be used to synchronize access to many classes of resources, while improving the overall resource utilization, specifically as measured by real-time schedulability. Towards that goal, the Real-Time Nested Locking Protocol (RNLP), the first multiprocessor real-time locking protocol that supports lock nesting or fine-grained locking is proposed and analyzed. Furthermore, the RNLP is extended to support reader/writer locking, as well as k-exclusion locking. All presented RNLP variants are proven optimal. Furthermore, experimental results demonstrate the schedulability-related benefits of the RNLP. Additionally, three new synchronization algorithms are presented, which are specifically motivated by the need to manage shared hardware resources to improve real-time predictability. Furthermore, two new classes of shared resources are defined, and the first synchronization algorithms for them are proposed. To analyze these new algorithms, a novel analysis technique called idleness analysis is presented, which can be used to incorporate the effects of blocking into schedulability analysis.Doctor of Philosoph

Distributed systems : architecture-driven specification using extended LOTOS

The thesis uses the LOTOS language (ISO International Standard ISO 8807) as a basis for the formal specification of distributed systems. Contributions are made to two key research areas: architecture-driven specification and LOTOS language extensions. The notion of architecture-driven specification is to guide the specification process by providing a reference-base of pre-defined domain-specific components. The thesis builds an infra-structure of architectural elements, and provides Extended LOTOS (XL) definitions of these elements. The thesis develops Extended LOTOS (XI.) for the specification of distributed systems. XL- is LOTOS enhanced with features for the formal specification of quantitative timing. probabilistic and priority requirements. For distributed systems, the specification of these ‘performance’ requirements, ran be as important as the specification of the associated functional requirements. To support quantitative timing features, the XL semantics define a global, discrete clock which can be used both to force events to occur at specific times, and to measure Intervals between event occurrences. XL introduces time policy operators ASAP (as soon as possible’ corresponding to “maximal progress semantics") and ALAP (late as possible'). Special internal transitions are introduced in XL semantics for the specification of probability, Conformance relations based on a notion of probabilization, together with a testing framework, are defined to support reasoning about probabilistic XL specifications. Priority within the XL semantics ensures that permitted events with the highest priority weighting of their class are allowed first. Both functional and performance specification play important roles in CIM (Computer Integrated Manufacturing) systems. The thesis uses a CIM system known as the CIM- OSA lntegrating Infrastructure as a case study of architecture-driven specification using XL. The thesis thus constitutes a step in the evolution of distributed system specification methods that have both an architectural basis and a formal basis

Anpassen verteilter eingebetteter Anwendungen im laufenden Betrieb

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

Parallel Natural Language Parsing: From Analysis to Speedup

Electrical Engineering, Mathematics and Computer Scienc

The Politicized Indian Woman: India’s Agendas on Women’s Education

As development and humanitarian agencies frame the education and empowerment of women and girls as the cornerstone of sustainable development; the rise of a new generation of transnational feminist scholarship and advocacy, is consolidating attention and policy commitments toward critical perspectives on education and democracy. In India this movement is crystalizing through youth activism, social medias, rapid urbanization, and multinational economic partnerships: prompting raucous debates about gender roles, communal positions, and the function of political leadership and global identity. Multinational collaboration and global market shifts continually influence national policy structures as they are practiced today; while public intellectuals and academics dissect how the frameworks of key strategic policy documents respond to the dialogue and resource interface of international aid, and center to state transfer mechanisms. This economic context – an eddy of inter- and intra-relationships formed under the long shadow of colonialism – requires the exploration of educational governance through a critical examination of policy leadership, language, ideas, and knowledge formation, to ensure that unequal gender relations do not alienate and propagate violence, silence, and discrimination. This study concentrates on national policy articulations of women’s educational opportunity and the historical development of women as political objects and subjects. Tracing the meta-narratives of masculinity and femininity that fed into educational initiatives, this historical narrative charts the exercise of post-colonial nationhood and the institution of education aiding this cause. The questions guiding this endeavor do not take for granted terms or analytic categories, but seek the orchestrations of political commitments and their consequent creation of the Indian Woman as a political agent. I study primary policy articulations like the Report on the Commission on Women’s Education (1959), Report on the Differentiation of Curricula for Boys and Girls (1964), the Education Commission Report (1966), Towards Equality: Report of the Committee on the Status of Women in India (1974), the National Policy on Education (1968; 1986), and Right to Education (2005); as well as other key primary accounts by policy actors. Since my study takes a gendered perspective on the performance of political leadership, the historical narrative is organized based on the Government of India’s incumbent Prime Minister and Union Council of Ministers. Through rich narrative, the catachrestic tensions that distance policy constructions from sociopolitical realities are critically analyzed through feminist theory’s gendered analysis and public policy frameworks. Since the goal was to identify the socio-political construction of women’s positions in educational policy, the historical narrative of Indian policymaking is followed by a deconstructive analysis of the structures, symbols, and mechanisms for systemic gendered heteronormativity. The test of legitimacy for any given practice should be embedded in the capacity to respond to the needs for whom the practice exists. Unless policy design mimics the diversity within its target populations and is punctured by the inclusion of more data points, policy making for education will remain an exercise in abstraction, a solipsism bound by socio-political singularities

Gender in Agriculture Sourcebook

The purpose of the Sourcebook is to act as a guide for practitioners and technical staff in addressing gender issues and integrating gender-responsive actions in the design and implementation of agricultural projects and programs. It speaks not with gender specialists on how to improve their skills but rather reaches out to technical experts to guide them in thinking through how to integrate gender dimensions into their operations. The Sourcebook aims to deliver practical advice, guidelines, principles, and descriptions and illustrations of approaches that have worked so far to achieve the goal of effective gender mainstreaming in the agricultural operations of development agencies. It captures and expands the main messages of the World Development Report 2008: Agriculture for Development and is considered an important tool to facilitate the operationalization and implementation of the report's key principles on gender equality and women's empowerment

Exploiting similarity patterns in web applications for enhanced genericity and maintainability

Ph.DDOCTOR OF PHILOSOPH

Implementation of a social Networks aggregation platform

This project is part of an innovation project developed by Telefonica R&D. The project's goal is to develop the SociaLuna platform, which will be an aggregator of different social networks that exist in the Internet. Due to the popularity of social networks on the Internet, users commonly need to sign in into multiple sites to retrieve all their social activity. This fact leads to think of a platform to aggregate social networks, in which a user who is registered in different social networks may get unified information of all movements his/her accounts. In these months I have been working on developing a web application for such platform that allows the access to different social networks such as Flickr, Twitter, Youtube and Facebook. The project has great prospects

2005 Labour Overview: Latin America and the Caribbean

[Excerpt] In summary, although regional economic growth has led to an improvement in some key labour market indicators, there remains a substantial decent work deficit which requires the continuous application of integrated economic and social policies whose focus should be the generation of decent work, balancing the need for competitiveness and efficiency with that of social protection, employment security and respect for labour and human rights. This edition includes two feature articles. The first analyzes voluntary migration trends both within and outside the region, as well as the internal and external conditions that drive migration. The article concludes that labour migration has both positive and negative effects for the countries of origin and destination, as well as for immigrants and their families. A box article provides a proposal for a regional plan of action regarding migrant workers. The second feature article analyzes economic and labour progress in Latin America and the Caribbean since the application of economic stabilization policies in the early 1990s. The conclusion is that while important progress has been made, particularly in improving macroeconomic imbalances, these positive changes have been accompanied by an increase in unemployment and precarious employment as well as a deterioration in income distribution. To address these issues, the article presents policy proposals designed to achieve economic growth compatible with decent work. The Labour Overview Advance Report for 2005 also includes a statistical annex that accompanies the labour situation report as well as an explanatory note with concepts, definitions and information sources. Latin American and Caribbean countries face a paradox from a labour market perspective: the regional economy is in a better situation than ever to improve the quality of life for the region’s inhabitants; nevertheless, current labour and social challenges are more daunting than ever before. In the task of achieving decent work for all, governments, workers and entrepreneurs of the region have at their disposal the instruments, experience and technical support of the International Labour Office