7 research outputs found

    Distributed mobile platforms and applications for intelligent transportation systems

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 70-75).Smartphones are pervasive, and possess powerful processors, multi-faceted sensing, and multiple radios. However, networked mobile apps still typically use a client-server programming model, sending all shared data queries and uploads through the cellular network, incurring bandwidth consumption and unpredictable latencies. Leveraging the local compute power and device-to-device communications of modern smartphones can mitigate demand on cellular networks and improve response times. This thesis presents two systems towards this vision. First, we present DIPLOMA, which aids developers in achieving this vision by providing a programming layer to easily program a collection of smartphones connected over adhoc wireless. It presents a familiar shared data model to developers, while underneath, it implements a distributed shared memory system that provides coherent relaxed-consistency access to data across different smartphones and addresses the issues that device mobility and unreliable networking pose against consistency and coherence. We evaluated our prototype on 10 Android phones on both 3G (HSPA) and 4G (LTE) networks with a representative location-based photo-sharing service and a synthetic benchmark. We also simulated large scale scenarios up to 160 nodes on the ns-2 network simulator. Compared to a client-server baseline, our system shows response time improvements of 10x over 3G and 2x over 4G. We also observe cellular bandwidth reductions of 96%, comparable energy consumption, and a 95.3% request completion rate with coherent caching. With RoadRunner, we apply our vision to Intelligent Transportation Systems (ITS). RoadRunner implements vehicular congestion control as an in-vehicle smartphone app that judiciously harnesses onboard sensing, local computation, and short-range communications, enabling large-scale traffic congestion control without the need for physical infrastructure, at higher penetration across road networks, and at finer granularity. RoadRunner enforces a quota on the number of cars on a road by requiring vehicles to possess a token for entry. Tokens are circulated and reused among multiple vehicles as they move between regions. We implemented RoadRunner as an Android application, deployed it on 10 vehicles using 4G (LTE), 802.11p DSRC and 802.11n adhoc WiFi, and measured cellular access reductions up to 84%, response time improvements up to 80%, and effectiveness of the system in enforcing congestion control policies. We also simulated large-scale scenarios using actual traffic loop-detector counts from Singapore.by Jason Hao Gao.S.M

    DESIGN METHODOLOGIES FOR RELIABLE AND ENERGY-EFFICIENT MULTIPROCESSOR SYSTEM

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    Ph.DDOCTOR OF PHILOSOPH

    Human factors aspects of control room design: Guidelines and annotated bibliography

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    A human factors analysis of the workstation design for the Earth Radiation Budget Satellite mission operation room is discussed. The relevance of anthropometry, design rules, environmental design goals, and the social-psychological environment are discussed

    Semantic discovery and reuse of business process patterns

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    Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

    A Reusability Model That Creates Design Frameworks Using a Formal Specification Clustering Approach.

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    Software reuse has been advocated as a technique with great potential to increase software development productivity, reduce development cycle time, and improve product quality. Challenges for successful reuse include populating the repository with the right type of components, representing and organizing the components in a way that the components are easy to be retrieved, and providing mechanisms to compare the candidate components with the requirement of the new component and to assist adaptation. While many existing researches are emphasizing one or two challenges, this research proposes a reusability model that targets all challenges in reuse. The inspiration for the model is group technology which identifies and exploits the similarities in the parts to be manufactured and the sequence of machines that are necessary for the processing of those products. The Requirement Reusability Model (RRM) is proposed in this research to capture the aspect of reuse that a component can be constructed by modifying another component. There are two major phases in RRM. At the Reusability Analysis (RA) phase, a measurement space is defined to represent the functional semantics of the components based on the formal specifications of the components. Clustering analysis is employed to group the components that are similar in function into the same clusters. At the Reusability Realization (RR) phase, the generic requirements for clusters are automatically extracted to create reusable frameworks for the clusters. The frameworks created are useful for constructing the implementation of individual transactions in the same cluster. Guidelines for adaptation from the frameworks to actual implementation are also provided. An automated system, called REST (a Reusers\u27 assistant) implements RRM. The input to REST is the formal specification of a relational database system. Based on the input, REST produces a repository of reusable frameworks. The products of REST also include a data dictionary and a transaction dictionary. Each entry of the transaction dictionary indicates the name of a transaction, the description of the functional semantics of the transaction, the cluster to which the transaction belongs, and a suggested framework to be reused for the implementation of the transaction

    Actas do 10º Encontro Português de Computação Gráfica

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    Actas do 10º Encontro Portugês de Computação Gráfica, Lisboa, 1-3 de Outubro de 2001A investigação, o desenvolvimento e o ensino na área da Computação Gráfica constituem, em Portugal, uma realidade positiva e de largas tradições. O Encontro Português de Computação Gráfica (EPCG), realizado no âmbito das actividades do Grupo Português de Computação Gráfica (GPCG), tem permitido reunir regularmente, desde o 1º EPCG realizado também em Lisboa, mas no já longínquo mês de Julho de 1988, todos os que trabalham nesta área abrangente e com inúmeras aplicações. Pela primeira vez no historial destes Encontros, o 10º EPCG foi organizado em ligação estreita com as comunidades do Processamento de Imagem e da Visão por Computador, através da Associação Portuguesa de Reconhecimento de Padrões (APRP), salientando-se, assim, a acrescida colaboração, e a convergência, entre essas duas áreas e a Computação Gráfica. Este é o livro de actas deste 10º EPCG.INSATUniWebIcep PortugalMicrografAutodes

    First CLIPS Conference Proceedings, volume 2

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    The topics of volume 2 of First CLIPS Conference are associated with following applications: quality control; intelligent data bases and networks; Space Station Freedom; Space Shuttle and satellite; user interface; artificial neural systems and fuzzy logic; parallel and distributed processing; enchancements to CLIPS; aerospace; simulation and defense; advisory systems and tutors; and intelligent control
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