Incremento de prestaciones en el acceso en Grid de datos

Ponencias de las Decimosextas Jornadas de Paralelismo celebradas del 13 al 16 de septiembre de 2005 en GranadaEl modelo de computación Grid ha evolucionado en los últimos años para proporcionar un entorno de computación de altas prestaciones en redes de área amplia. Sin embargo, uno de los mayores problemas se encuentra en las aplicaciones que hacen uso intensivo y masivo de datos. Como solución a los problemas de estas aplicaciones se ha utilizado la replicación. Sin embargo, la replicación clásica adolece de ciertos problemas como la adaptabilidad y la alta latencia del nuevo entorno. Por ello se propone un nuevo algoritmo de replicación y organización de datos que proporciona un acceso de altas prestaciones en un Data Grid.Publicad

Bloom's Filters : Their Types and Analysis

Bloom filtrelerini ve çeşitlerini inceleyen bir çalışmanın özetidir. Bloom filtresi sorgulama üyeliklerini desteklemek amacıyla setleri temsil eden rasgele bir veri yapısıdır. 1970’lerde daha çok veri tabanı optimizasyonlarında kullanılmıştır. Bu yakınlarda bilgisayar ağları ile ilgili çalışma yapanlar daha sık kullanmaya başlamıştır. Bu çalışmada filtrelerin çeşitleri analiz edilecektir.In this paper we discuss Bloom filter in its original form and the varieties of its extensions. A Bloom filter is a randomized data-structure for concisely representing a set in order to support approximate membership queries. Although it was devised in 1970 for the purpose of spell checking, it was seldom used except in database optimization. In recent years, it has been rediscovered by the networking community, and has become a key component in many networking systems applications. In this paper, we will examine and analyse the different types of this filter

Bloom's Filters : Their Types and Analysis

Bloom filtrelerini ve çeşitlerini inceleyen bir çalışmanın özetidir. Bloom filtresi sorgulama üyeliklerini desteklemek amacıyla setleri temsil eden rasgele bir veri yapısıdır. 1970’lerde daha çok veri tabanı optimizasyonlarında kullanılmıştır. Bu yakınlarda bilgisayar ağları ile ilgili çalışma yapanlar daha sık kullanmaya başlamıştır. Bu çalışmada filtrelerin çeşitleri analiz edilecektir.In this paper we discuss Bloom filter in its original form and the varieties of its extensions. A Bloom filter is a randomized data-structure for concisely representing a set in order to support approximate membership queries. Although it was devised in 1970 for the purpose of spell checking, it was seldom used except in database optimization. In recent years, it has been rediscovered by the networking community, and has become a key component in many networking systems applications. In this paper, we will examine and analyse the different types of this filter

P2P architecture for scientific collaboration.

P2P networks are often associated with file exchange applications among private users. However, their features make them suitable for other uses. In this paper we present a P2P architecture for scientific collaboration networks, which takes advantage of the properties inherent in these social networks - small-world, clustering, community structure, assortative mixing, preferential attachment and small and stable groups - in order to obtain better performance, efficient use of resources and system resilience.Peer Reviewe

A DHT-Based Grid Resource Indexing and Discovery Scheme

This paper presents a DHT-based grid resource indexing and discovery (DGRID) approach. With DGRID, resource-information data is stored on its own administrative domain and each domain, represented by an index server, is virtualized to several nodes (virtual servers) subjected to the number of resource types it has. Then, all nodes are arranged as a structured overlay network or distributed hash table (DHT). Comparing to existing grid resource indexing and discovery schemes, the benefits of DGRID include improving the security of domains, increasing the availability of data, and eliminating stale data.Singapore-MIT Alliance (SMA

Managing Linguistic Data Summaries in Advanced P2P Applications

chapitre... à corrigerAs the amount of stored data increases, data localization techniques become no longer sufficient in P2P systems. A practical approach is to rely on compact database summaries rather than raw database records, whose access is costly in large P2P systems. In this chapter, we describe a solution for managing linguistic data summaries in advanced P2P applications which are dealing with semantically rich data. The produced summaries are synthetic, multidimensional views over relational tables. The novelty of this proposal relies on the double summary exploitation in distributed P2P systems. First, as semantic indexes, they support locating relevant nodes based on their data descriptions. Second, due to their intelligibility, these summaries can be directly queried and thus approximately answer a query without the need for exploring original data. The proposed solution consists first in defining a summary model for hierarchical P2P systems. Second, appropriate algorithms for summary creation and maintenance are presented. A query processing mechanism, which relies on summary querying, is then proposed to demonstrate the benefits that might be obtained from summary exploitation

Redes de Colaboração Científica: Uma Análise das Publicações do Encontro Nacional de Pesquisadores em Gestão Social.

O objetivo deste artigo é aprofundar o conhecimento sobre o grupo de pesquisadores e cientistas sociais que, ao longo dos anos, contribuiu com produção científica para cinco edições do Encontro Nacional de Pesquisadores em Gestão Social. Considerando o campo científico como uma rede, o marco teórico que dá suporte a essa pesquisa reúne autores que valorizam as fronteiras da rede por fazerem convergir uma multiplicidade de competências e experiências complexas na consecução de seus objetivos – é também instrumental e transdisciplinar, na medida em que a produção, reprodução e difusão de conhecimentos são heterogêneas, mas amplamente acessível aos seus integrantes. Em relação ao método, os dados primários foram coletados a partir dos arquivos das diversas edições do Encontro disponíveis no site da RGS (http://www.rgs.wiki.br/). A análise de redes sociotécnicas foi utilizada como metodologia para realização desta pesquisa. Os softwares Excel e ORA foram utilizados como ferramentas para elaboração dos gráficos de análise e cálculo das métricas de redes. Observou-se crescimento no número de instituições participantes e do volume de obras de 2007 a 2010. Quase 40% das obras foram elaboradas a partir da colaboração entre autores advindos de diferentes instituições de ensino superior, o que indica constituição de uma rede efetiva de colaboração entre elas. Da mesma forma, encontrou-se um grupo de quinze autores que exercem papel central na alavancagem das comunidades de autoria, mas que, poucas vezes, aparecem como autores principais, sugerindo que o ENAPEGS é um espaço aberto para que novos pesquisadores sejam primeiros autores de uma diversidade de relatórios de pesquisas

Internal Accession Date Only Approved for External Publication 1 People and Computers XVII

peer-to-peer, knowledge workers, information lifecycle, information sharing, web use, information gathering The success of peer-to-peer (p2p) music-sharing has no doubt contributed to assumptions that individuals' PCs are a vast untapped resource of assets just waiting to be unlocked. This includes the push for opening up our file spaces at work to allow peers access to previously inaccessible information. We explore the potential of these ideas and test some of the assumptions underlying them by looking at 16 knowledge workers' file spaces in the context of Web information-gathering tasks. Knowledge workers' file spaces are more like "workbenches" than "archives" and the information held within them is fundamentally different to that which is placed in shared information spaces. Work is carried out on information to make it shareable, yet this information is found side-by-side on the "workbench" with unshareable information. This leads us to question the potential value of enabling people to open up their file spaces without considering the reusability of this information for others. The success of peer-to-peer (p2p) music sharing has no doubt contributed to assumptions that individuals' PCs are a vast untapped resource of assets just waiting to be unlocked by such systems. This includes the push for opening up our file spaces at work to allow peers access to previously inaccessible information with minimum effort. We wished to explore the potential value of these ideas and to test some of the assumptions underlying them, the motivation being that we believed the issues raised by this investigation would be important to those developing p2p information sharing tools. We do this by looking at the flow of information in and out of 16 knowledge workers' file spaces in the context of carrying out Web information gathering tasks at work. In doing this we find that the file spaces used for knowledge work are more like "workbenches" than "archives" and that the information held within them is fundamentally different in content and organisation to that which knowledge workers place in shared information spaces such as the Web. Knowledge workers work on their information to make it shareable to specific audiences yet this information is found side by side on the "workbench" with unshareable information. This leads us to question the potential value of enabling people to open up their file spaces without having regard to the reusability of this information for others