1,720,976 research outputs found
Parallel Component Descriptor Language: XML based deployment descriptors for Grid application components
No full textGrid computing represents one of the most
interesting recent developments of distributed computing,
nevertheless its low level of usability is hampering any
form of widespread adoption. The concept of Service
Oriented Computing may mark a turning point, however,
most of the advancements in this field are related to the
management of huge structures composed of full
applications requiring a supercomputer each. In this paper
we present Parallel Component Description Language, a
language designed to allow the description of
applications’ components both in terms of their
computational requirements and their relationships in the
structure of the complete application. The information
provided by a PCDL deployment descriptor allow mapping
the components onto the node of a computational Grid
Evaluation of Java Web Services Toolkit for Grid Computing
No full textDistributed Computing is rapidly gaining importance with the advent of Web Services [1] and grid computing paradigms [2]. Java-based frameworks in particular, are receiving special attention due to their portability and interoperability.
The growing synergy between the two types of technology can make possible a new generation of distributed computing frameworks based on independently written software components. Actual grid systems are typically tied to message passing interface such as MPI [3] and PVM [4] or to proprietary methods that impose strong limitations to the level of interoperability with other systems and other technologies. Web Services are based on a widely spread and standardized set of communication technology like XML and SOAP-HTTP. Therefore, Web Services technology seems to be a good way to overcome the interoperability problems typical of actual grid systems.
However, the adoption of the standards fostered by Web Services for distributed scientific computing is limited to ancillary services and has not penetrated the core computational model of grid and meta computing. The motivation stays in the different community where the technologies have been developed: the scientific community for grid systems and the business community for Web Services.
Web Services are oriented to transactions involving little amount of data where SOAP [5] is the standard communication protocol used. This protocol allows a platform independent and XML-based information encoding. However, such an encoding is extremely inefficient. In a scientific scenario big amounts of data are involved in the computation, typically in the form of numeric arrays. The use of SOAP introduces a huge overhead due to its XML information encoding.
It is our opinion that this issue is very important. In fact, we think that the adoption of Web Services inside the computational core of grid computing applications is totally unfeasible as long as this problem has not been solved.
In order to make Web Services standards well-suited to the requirements of high performance computing some modifications are needed, and it is necessary to exploit the extensibility of Web Services technologies. In this paper we provide a technological overview and an investigation on the performance result of different Java based Web Services implementation. We consider the actual de-facto Web Services standard framework, namely AXIS [6] that is provided by Apache Software Foundation and two frameworks that aim at providing Web Services-like communication methods oriented to high performance computing: the XSOAP [7] toolkit provided by the University of Indiana and the WSDL Grid Binding [8], a WSIF [9] extension provided by the University of Genoa. This paper is structured as follows: in section 2 we provide a general overview of the Web Services standard technologies, in section 3 we describe how the three infrastructures implement those standards, in section 4 we show our performances analysis and in section 5 we provide some concluding remarks
Performance improvement in Web services invocation framework
Get PDFSummary form only given. Two of the the two main threads in distributed computing that recently show noticeable progress are grid computing and the development of Web-based services. It is our opinion that the adoption of the standards fostered by the Web-service community could improve the level of usability and interoperability of grid systems and lead to the development of metacomputing systems based on reusable, interoperable components. Up to now the adoption of Web services in grid projects has never penetrated the core computational model. This is mainly due to the fact that Web services use by default the SOAP protocol which is extremely ill suited to computational science applications. We show how we leveraged the Web service invocation framework (WSIF) to develop a new high performance binding based on XDR coding and how we improved the general WSIF performance by developing an extension based on a fully static service invocation
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
A server-side software engine providing context-aware services
No full textIn this work we describe an architecture supporting the exposition of Context-Aware services. First, we discussed the meaning of context in computing. Second, the data sources composing the context are listed and defined. Finally, a definition of the meaning of Context Awareness service is also provided. Our design is based on these definitions, and targeted to provide Context Awareness services to mobile users. The key-feature of the architecture is the explicit orientation toward working in a condition where direct knowledge of the user state is minimal. Its power resides in the capability to infer the user context from indirect information. Its minimal configuration, called Context-based Content Engine (CCE), is designed to ease its integration with existing systems such as a typical telecom operators portal. Our service oriented design could be implemented by several programming framework. However we choose to adopt Java technology because of its wide diffusion among the telecom operators and we show the main details of our reference implementation
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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