1,720,960 research outputs found
Resource-oriented middleware abstractions for pervasive computing
No full textThe pervasive computing vision of the future communication and computational infrastructure is that we will be everywhere virtually connected with invisible computers, embedded in the environment. In this context, the challenge is to provide a middleware support that allows applications to have minimal assumptions about the environment while being able to dynamically adapt to the surrounding context. Specifically, the middleware should (i) deal with the run-time growth of the application in terms of involved resources (flexibility), (ii) accommodate heterogeneous and unforeseen functionalities into the running application (genericity), and (iii) discover new functionality at run time and rearrange the application accordingly (dynamism). To this extent, we devised the P-REST (Pervasive REST) architectural style and built the P RIME (P-rest Runtime) middleware to support it. PRIME allows a quick and effective development and execution P-REST applications by leveraging functional programming and code mobility.</p
PACE: A data-flow coordination language for asynchronous network-based applications
No full textNetwork-based applications usually rely on the explicit distribution of components, which interact by means of message passing. Assembling components into a workflow is challenging due to the asynchronism inherent to the underlying message-passing communication model. This paper presents the PaCE language, which aims at coordinating asynchronous network-based components by exploiting the data-flow execution model. Specifically, PaCE has been designed for dealing with components compliant with the P-REST architectural style for pervasive adaptive systems. Moreover PaCE provides reflective features enabling run-time adaptation and evolution of workflows.</p
RESTful service architectures for pervasive networking environments
No full textComputing facilities are an essential part of the fabric of our society, and an ever-increasing number of computing devices is deployed within the environment in which we live. The vision of pervasive computing is becoming real. To exploit the opportunities offered by pervasiveness, we need to revisit the classic software development methods to meet new requirements: (1) pervasive applications should be able to dynamically configure themselves, also benefiting from third-party functionalities discovered at run time and (2) pervasive applications should be aware of, and resilient to, environmental changes. In this chapter we focus on the software architecture, with the goal of facilitating both the development and the run-time adaptation of pervasive applications. More specifically we investigate the adoption of the REST architectural style to deal with pervasive environment issues. Indeed, we believe that, although REST has been introduced by observing and analyzing the structure of the Internet, its field of applicability is not restricted to it. The chapter also illustrates a proof-of-concept example, and then discusses the advantages of choosing REST over other styles in pervasive environments.</p
Architectural Issues of Adaptive Pervasive Systems
No full textPervasive systems are often made out of distributed software components that run on different computational units (appliances, sensing and actuating devices, computers). Such components are often developed, maintained, and even operated by different parties. Applications are increasingly built by dynamically discovering and composing such components in a situation-aware manner. By this we mean that applications follow some strategies to self-organize themselves to adapt their behavior depending on the changing situation in which they operate, for example the physical environment. They may also evolve autonomously in response to changing requirements. Software architectures are considered a well-suited abstraction to achieve situational adaptation. In this paper, we review some existing architectural approaches to self-adaptation and propose a high-level meta-model for architectures that supports dynamic adaptation. The meta-model is then instantiated in a specific ambient computing case study, which is used to illustrate its applicability.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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