Latin American Web Congress 

About: Latin American Web Congress is an academic conference. The conference publishes majorly in the area(s): The Internet & Web modeling. Over the lifetime, 276 publications have been published by the conference receiving 4708 citations.

MAAN: a multi-attribute addressable network for grid information services

Abstract: Recent structured peer-to-peer (P2P) systems such as distributed hash tables (DHTs) offer scalable key-based lookup for distributed resources. However, they cannot be simply applied to grid information services because grid resources need to be registered and searched using multiple attributes. We propose a multiattribute addressable network (MAAN) which extends chord to support multiattribute and range queries. MAAN addresses range queries by mapping attribute values to the chord identifier space via uniform locality preserving hashing. It uses an iterative or single attribute dominated query routing algorithm to resolve multiattribute based queries. Each node in MAAN only has O(logN) neighbors for N nodes. The number of routing hops to resolve a multiattribute range query is O(logN+N/spl times/s/sub min/), where s/sub min/ is the minimum range selectivity on all attributes. When s/sub min/=/spl epsiv/, it is logarithmic to the number of nodes, which is scalable to a large number of nodes and attributes. We also measured the performance of our MAAN implementation and the experimental results are consistent with our theoretical analysis.

Optimized index structures for querying RDF from the Web

Abstract: Storing and querying resource description framework (RDF) data is one of the basic tasks within any semantic Web application. A number of storage systems provide assistance for this task. However, current RDF database systems do not use optimized indexes, which results in a poor performance behavior for querying RDF. In this paper we describe optimized index structures for RDF, show how to process and evaluate queries based on the index structure, describe a lightweight adaptable implementation in Java, and provide a performance comparison with existing RDF databases.

De lo sólido a lo líquido: Las nuevas alfabetizaciones ante los cambios culturales de la Web 2.0

Abstract: En este articulo se propone un modelo de nuevas alfabetizaciones para la formacion de la ciudadania de la sociedad digital. Usando la metafora de Baumman se hace referencia a la oposicion entre la cultura «solida» predominante en los siglos XIX y XX con la cultura de la informacion «liquida» en la que la Web 2.0 tiene efectos muy relevantes sobre multiples planos de nuestra cultura actual. En un primer momento, se examinan las principales caracteristicas de la Web 2.0 definiendola en relacion a seis grandes dimensiones o planos que se entrecruzan y son simultaneos: la Web 2.0 como la biblioteca universal, como mercado global, como un puzzle gigante de hipertextos, como una plaza publica de comunicacion e interaccion social, como un territorio de expresion multimedia y audiovisual, y como multiples entornos virtuales interactivos. En una segunda parte, se propone un modelo teorico de la alfabetizacion del ciudadano ante esta cultura digital que consta de dos ejes o planos basicos: el primero referido a los ambitos o dimensiones de la alfabetizacion, y el segundo a las competencias de aprendizaje (instrumentales, cognitivo-intelectuales, sociocomunicacionales, emocionales y axiologicas) a desarrollar en los sujetos. Por ultimo, se defiende que las nuevas alfabetizaciones son un derecho de los individuos y una condicion necesaria para un desarrollo social y democratico de la sociedad en el siglo XXI.

The Benefit of Using Tag-Based Profiles

Abstract: Collaborative tagging, i.e. the process of assigning metadata in the form of keywords to shared content by many users, has emerged as an important way to provide information about resources on the Web and elsewhere. Such keywords (tags) are used to enable the organization of information within personal information spaces, such as photo collections, but can also be shared, allowing browsing and searching with the help of tags attached by other users to information resources from the Web. Recent research has shown that such tag distributions stabilize over time and can be used to improve search on the Web. In this paper we are interested in another aspect, namely how they characterize the user and enable personalized recommendations. Using data from a frequently used music search portal, Last.fm, we analyze tag usage and statistics and investigate the use of tag-based user profiles in contrast to conventional user profiles based on song and track usage. We specify recommendation algorithms based on tag user profiles, and explore how collaborative filtering recommendations based on these tag profiles are different from recommendations based on song/track profiles. Finally, we describe a new search-based method, which uses tags to recommend songs interesting to a user, yielding substantially improved results. The paper finishes with a discussion of some future work to further improve tag-based search and recommendation in community Web sites.

Evaluating scheduling and replica optimisation strategies in OptorSim

Abstract: Grid computing is fast emerging as the solution to the problems posed by the massive computational and data handling requirements of many current international scientific projects. Simulation of the grid environment is important to evaluate the impact of potential data handling strategies before being deployed on the grid. We look at the effects of various job scheduling and data replication strategies and compare them in a variety of grid scenarios, evaluating several performance metrics. We use the grid simulator OptorSim, and base our simulations on a world-wide grid testbed for data intensive high energy physics experiments. Our results show that the choice of scheduling and data replication strategies can have a large effect on both job throughput and the overall consumption of grid resources.