1,721,010 research outputs found

    Synchronization Can Improve Reactive Systems Control and Modularity

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    We concentrate on two major aspects of reactive system design: behavior control and modularity. These are studied from a formal point of view, within the framework of action systems. The traditional interleaving paradigm is completed with a barrier synchronization mechanism. This is achieved by introducing a new parallel composition operator, applicable to bot h discrete and hybrid models. While offering improvements with respect to control and modularity, the approach uses the correctness preserving mechanisms provided by the underlying reasoning environment 1. 1) A shorter version of this study appeared as "Modular Design of Reactive Systems", in Proceedings of the 28th Annual International Computer Software and Applications Conference (COMPSAC 2004), IEEE Computer Society Press, September 2004, Hong Kong. Pages 265-271

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    A Tool Integration Framework for Sustainable Embedded Systems Development

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    Tool integration in the context of embedded systems development and maintenance is challenging due to such systems' lengthy life cycles and adaptability to process specifications. The iFEST frameworkprovides flexibility in development processes and extends support for long product life cycles.</p

    FPGA-Based Encryption for Peer-to-Peer Industrial Network Links

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    Securing company networks has become a critical aspect of modern industrial environments. With the recent rise of Industry 4.0 concepts, it became essential to extend IT security across increasingly connected factories. However, in the highly specialised field of operations technology and embedded systems, not every device can run additional security measures, as they are old or designed with sparse resources. We introduce here the concept of a “universal” encryption device that enables the securing of communication links in a direct peer-to-peer industrial setting by using the AES-128 encryption standard. We propose a design of such an encryption device by developing a modular system architecture with decoupled communication and cryptography. The resulting architecture is implemented as a proof of concept for Ethernet communication and tested through simulation as well as on an FPGA device. The impact of the encryption device is briefly investigated in a lab setup, followed by conclusions on system stability and performance.</p

    Modeling Communication with Synchronized Environments

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    A deterministic behavior of systems composed of several modules is a desirable design goal. Assembling a complex system from components requires also a high degree of re-usability. The compatibility of the selected components may become a problem even at abstract design levels, due to possible different degrees of model determinacy, possible different execution models, etc. In this cases, an overall deterministic system behavior is difficult to achieve. The development of communication mechanisms between such components will have then to accommodate the differences, so that both correct processing and information exchange (data and control, appropriate choices and relative timing or sequencing) are achieved. For instance, human-machine interaction offers a good example of cooperation between deterministic models (machines) communicating with highly non-deterministic counterparts (the human models, if not restricted). We analyze here such communication mechanisms by "confronting" synchronized and un-synchronized models of execution, in the framework of action systems, a state based formalism. We "force" the two models to coexist within the same context and explore the possibilities of building trustworthy communication channels between them. We base our approach on a combined polling - interrupt scheme, which allows us to mitigate communication issues that may otherwise compromise the correct input-output system behavior. More robust system models are obtained by applying specific correctness rules of refinement. We illustrate our methods on an audio system example, implementable as either a software or a hardware device.</p

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Complex Systems: Simply, Improve Life

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    Cyber-Physical Systems, building on embedded systems and ICT are large complex systems that pose challenges at multiple stages, out of which we mention here design, ownership and utilization. These systems are more and more penetrating our every-day life, impacting on multiple aspects of our activities. In spite of their complexity, or due to that, these systems are offering new opportunities for improving the quality of our lives, simplify our work while helping us to improve the results, and provide support for longer life-spans. </p

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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