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Web Congress, 2003. Proceedings. First Latin American

Date 10-12 Nov. 2003

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Displaying Results 1 - 25 of 38
  • Extracting knowledge from association relationships to build navigational models

    Page(s): 2 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (421 KB) |  | HTML iconHTML  

    We analyze how the semantics of association relationships in OO conceptual modeling can help to build navigational models for Web applications. The work has been developed in the context of OOWS (a model-driven development method for building Web applications). We study some structural and behavioral properties of those conceptual abstractions in order to extract knowledge to be applied in the construction of navigational models. From this study, a set of design rules has been obtained. These rules help the modeler to build navigational models in a systematic way. The results of this work have improved the modeling and code generation processes introduced by OOWS. View full abstract»

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  • Evolution of the Chilean Web structure composition

    Page(s): 11 - 13
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (371 KB) |  | HTML iconHTML  

    We present the evolution of the structure of the Chilean Web between 2000 and 2002. Our results show that although the Web grows as expected, also a significant part of it disappears. In addition, some components are much more stable than others. We also compare the expected life cycle of a Web site in the structure with the actual real data. View full abstract»

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  • Policy and state based secure wrapper and its application to mobile agents

    Page(s): 14 - 26
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (367 KB)  

    Execution process in modern Web applications is usually represented as a partially ordered sequence of basic actions issued by a client (login, buy, exit, etc.; the login action usually precedes purchasing). Based on these actions, a finite automaton of fine-grained authorization checks, may be specified in a separate layer that is easily configurable for security needs of a particular application. In the Mobile case there may be two such state machines - one performing state-based authorization checks of the application execution process and the other performing such checks for the mobile agent execution process. Authorization checks of these machines may be both state-based and policy based, and the policies should distinguish between human clients and mobile agents cases. We develop the framework to specify and enforce finegrained state-based authorization checks of Web application execution, consisting of a Web browser (client) and a server. We adopt this framework to the mobile case so that state machines representing finegrained authorization checks of application and mobile agent execution are synchronized. View full abstract»

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  • Web accessibility, mobility and findability

    Page(s): 239 - 240
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (176 KB) |  | HTML iconHTML  

    This paper addresses the issues of accessibility, mobility and findability as appropriate to a discussion of Web site or Web page interface usability. The goal of this paper is to emphasize the importance of these factors while providing attendees with sufficient vocabulary and conceptual knowledge to make appropriate design decisions. View full abstract»

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  • A semantic matching method for clustering traders in B2B systems

    Page(s): 144 - 153
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (319 KB) |  | HTML iconHTML  

    This is a part of the ICS (intelligent commerce system) project whose aim is to design and implement an effective intelligent B2B commerce system. We present a practical application on semantic Web and Web services concepts where a matching procedure to associate potential buyers and suppliers in a B2B system is shown and the use of patterns and tools in the development of semantic Web's structure is proposed as an alternative for its implementation. View full abstract»

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  • Finding buying guides with a Web carnivore

    Page(s): 84 - 92
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    Research on buying behavior indicates that buying guides perform an important role in the overall buying process. However, while the Web contains many buying guides, finding those guides is difficult to impossible for the average consumer. Web search engines typically index many buying guides on many topics, but simple queries do not often return these results. Given this, we built a Web carnivore that finds buying guides on behalf of consumers. Web carnivores leverage the crawling, scrubbing, indexing and ranking activities of Web search engines (the "herbivores") to provide more specific services. Ours finds buying guides by issuing machine-generated queries to google and filtering the results. We describe our system and quantitatively compares it to a basic search engine. Our system almost always returns more buying guides, often twice as many. Our user study also suggests that we return better buying guides. Finding buying guides is an instance of the more general problem of "genre search;" we point out novel aspects of our system that are applicable to a variety of genre-search problems. View full abstract»

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  • Cooperative crawling

    Page(s): 209 - 211
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (193 KB) |  | HTML iconHTML  

    Web crawler design presents many different challenges: architecture, strategies, performance and more. One of the most important research topics concerns improving the selection of "interesting" Web pages (for the user), according to importance metrics. Another relevant point is content freshness, i.e. maintaining freshness and consistency of temporary stored copies. For this, the crawler periodically repeats its activity going over stored contents (recrawling process). We propose a scheme to permit a crawler to acquire information about the global state of a Website before the crawling process takes place. This scheme requires Web server cooperation in order to collect and publish information on its content, useful for enabling a crawler to tune its visit strategy. If this information is unavailable or not updated the crawler still acts in the usual manner. In this sense the proposed scheme is not invasive and is independent from any crawling strategy and architecture. View full abstract»

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  • The best trail algorithm for assisted navigation of Web sites

    Page(s): 166 - 178
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB) |  | HTML iconHTML  

    We present an algorithm called the best trail algorithm, which helps solve the hypertext navigation problem by automating the construction of memex-like trails through the corpus. The algorithm performs a probabilistic best-first expansion of a set of navigation trees to find relevant and compact trails. We describe the implementation of the algorithm, scoring methods for trails, filtering algorithms and a new metric called potential gain which measures the potential of a page for future navigation opportunities. View full abstract»

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  • Clustering the Chilean Web

    Page(s): 229 - 231
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (267 KB) |  | HTML iconHTML  

    We perform a clustering of the Chilean Web graph using a local fitness measure, optimized by simulated annealing, and compare the obtained cluster distribution to that of two models of the Web graph. Information on Web clusters can be employed both to validate generation models and to study the properties of the graph. Clusters can also be used in semantics-based grouping of Websites or pages e.g. for indexing and browsing. View full abstract»

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  • Estimating the development effort of Web projects in Chile

    Page(s): 114 - 122
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB) |  | HTML iconHTML  

    We present a method to fast estimate the development effort of Web-based information systems in Chile. The method, called Chilean Web application development effort estimation (CWADEE), addresses a necessity to get effort estimations in a short period of 24 to 72 hours using limited information. In contrast with other existing methods, CWADEE uses raw historical information about development capability and high granularity information about the system to be developed, in order to carry out such estimations. This method is simple and specially suited for small or medium-size Web-based information systems. CWADEE has been applied to twenty-two projects with very accurate results. View full abstract»

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  • Multi-tier architecture for Web search engines

    Page(s): 132 - 143
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (954 KB)  

    We describe a novel multitier architecture far a search engine. Based on observations from query log analysis as well as properties of a ranking formula, we derive a method to tier documents in a search engine. This allows for increased performance while keeping the order of the results returned, and hence relevance, almost "untouched". The architecture and method have been tested large scale on a carrier-class search engine with 1 billion documents. The architecture gives a huge increase in capacity, and is today in use for a major search engine. View full abstract»

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  • Quantitative analysis of strategies for streaming media distribution

    Page(s): 154 - 165
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (403 KB) |  | HTML iconHTML  

    Distribution of streaming media content, including live news, music and videos, is becoming increasingly popular in today's Internet. Traditional client/server architectures are inefficient for distributing streaming media objects because of the high demands for system resources, especially server and network bandwidth, which severely limit the total number of simultaneous users the system can support. One proposal for improving the scalability of media distribution systems is the use of P2P overlay networks. Although a number of previous works has evaluated different aspects of P2P systems, mainly through simulation, there is a lack of a thorough quantitative analysis of the requirements for server and network resources (i.e., CPU, server and network bandwidth) in actual P2P systems, compared to traditional client/server systems. We aim at filling this gap by providing experimental results that quantify the savings in server and network resources if a P2P approach is used for distributing live streaming media instead of the traditional client/server approach. Towards this goal, we build an experimental testbed, in a controlled environment, to evaluate actual systems with varying number of clients during periods when the distribution tree is static. A key component of this experimental testbed is a new efficient and scalable application called streaming servant, which can act both as a client and a server, forwarding packets to other clients. We also use simple analytical formulas to evaluate the scalability of our servant application. The experimental results quantify the intuitive better scalability of the P2P architecture. As an example, the total server bandwidth decreases from 15 Mbits/s to 9 Mbits/s (a 40% reduction) if a P2P architecture is used instead of a client/server architecture for live delivery of a given file to 24 clients. View full abstract»

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  • Syntactic similarity of Web documents

    Page(s): 194 - 200
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (302 KB) |  | HTML iconHTML  

    We present and compare two methods for evaluating the syntactic similarity between documents. The first method uses the Patricia tree, constructed from the original document, and the similarity is computed searching the text of each candidate document in the tree. The second method uses shingles concept to obtain the similarity measure for every document pairs, and each shingle from the original document is inserted in a hash table, where shingles of each candidate document are searched. Given an original document and some candidates, two methods find documents that have some similarity relationship with the original document. Experimental results were obtained by using a plagiarized documents generator system, from 900 documents collected from the Web. Considering the arithmetic average of the absolute differences between the expected and obtained similarity, the algorithm that uses shingles obtained a performance of 4.13% and the algorithm that uses Patricia tree a performance of 7.50%. View full abstract»

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  • Application modeling for the semantic Web

    Page(s): 93 - 102
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB) |  | HTML iconHTML  

    We present a method for the design and implementation of Web Applications for the semantic Web. Based on the "object oriented hypermedia design method" approach, we used ontology concepts to define an application conceptual model, extending the expressive power of the original method. The navigational model definitions use a query language capable of querying both schema and instances, enabling the specification of flexible access structures. Additionally, we propose the use of faceted access structures to improve the selection of navigational objects organized by multiple criteria. Finally, we present an implementation architecture that allows the direct use of the application specifications when deriving a final application implementation. View full abstract»

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  • Cooperation schemes between a Web server and a Web search engine

    Page(s): 212 - 213
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    Search engines provide search results based on a large repository of pages downloaded by a Web crawler from several servers. To provide best results, this repository must be kept as fresh as possible, but this can be difficult due to the large volume of pages involved and to the fact that polling is the only method for detecting changes. We explore and compare several alternatives for keeping fresh repositories of cooperation from servers. View full abstract»

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  • Designing collaborative virtual environments based on real spaces to promote community interaction

    Page(s): 58 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (375 KB) |  | HTML iconHTML  

    A collaborative virtual environment (CVE) is a metaphor of a real environment, but it is not a copy of it. Members of a community may not know each other in real life. The design of CVE in which members are known and there is interaction in a real space is different to the traditional design of CVE. It should consider the real location of each resource, appropriated awareness and communication strategies, and the human-human and human-resource relations. Our university department was selected as an example organizational unit for experimentation. We start with the real physical environment and we design a CVE to provide new collaboration features to people working in the unit and those who will visit it. The advantages of the approach are many. First, people are familiar with the basic physical environment. Second, some activities requiring physical presence can be done with virtual presence, enabling more convenient ways to work for employees. Third, new opportunities for collaborative work appear as it is easy to do them with the proposed CVE. Finally, the approach is extensible, since new features can be added. We present the approach and the design of the proposed CVE. View full abstract»

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  • On the image content of the Chilean Web

    Page(s): 72 - 83
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (604 KB) |  | HTML iconHTML  

    We perform a study of the image contents of the Chilean Web (.cl domain) using automatic feature extraction, content-based analysis and face detection algorithms. In an automated process we examine all .cl Websites and download a large number of the images available (approx. 83,000). Then we extract several visual features (color, texture, shape, etc.) and we perform face detection using novel algorithms. Using this process we semiautomatically characterize the image content of the Web in Chile in terms of the detected faces and the visual features obtained automatically. We present statistics of use to anyone concerned with the image content of the Web in Chile. Our study is the first one to use content-based tools to determine the image contents of the Web. View full abstract»

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  • Collaborative learning and creative writing

    Page(s): 180 - 186
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    CSCL software tools must provide support for group work and should be based on a collaborative learning technique. The PBL based CCCuento tool is introduced here. It is intended to support apprentices groups in the collaborative creation of stories in order to improve language use and development of writing skills. The tool follows a model, which includes several positive interdependencies and is implemented as a sequence of individual activities followed by break periods. The break periods are used for reviewing and discussion. An experiment is reported in which several groups of high school students used the tool. View full abstract»

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  • XML retrieval

    Page(s): 234
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (161 KB) |  | HTML iconHTML  

    First Page of the Article
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  • WISDNA: an information visualization paradigm for XML

    Page(s): 205 - 208
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (367 KB) |  | HTML iconHTML  

    We present WISDNA (Web information services DNA) as an information visualization paradigm for XML data from Web information services. We propose a visualization and navigational tool based on Context Lenses and MovieDNA to address the need to support exploratory navigation that seamlessly integrates querying with browsing. We present linear and hierarchical versions of WIDSNA. It is a dynamic visualization that provides concise representation of search results (XML data) for Web information services. It is particularly suited to provide feedback on associated metadata and relationships with previous user searches. We illustrate our work in the context of online retail applications. View full abstract»

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  • SharpSpider: spidering the Web through Web services

    Page(s): 219 - 221
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (207 KB) |  | HTML iconHTML  

    Web search engines have become an indispensable utility for Internet users. In the near future, however, Web search engines will not only be expected to provide quality search results, but also to enable applications to search and exploit their index repositories directly. We present here SharpSpider, a distributed, C# spider designed to address the issues of scalability, decentralisation and continuity of a Web crawl. Fundamental to the design of SharpSpider is the publication of an API for use by other services on the network. Such an API grants access to a constantly refreshed index buiU after successive crawls of the Web. View full abstract»

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  • Structuring information on the Web from below: the case of educational organizations in Chile

    Page(s): 216 - 218
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (202 KB) |  | HTML iconHTML  

    We present an ongoing work to help populate the Web with metadata by structuring and integrating information of organizations at a small scale. This is a natural complement to big scale projects to build the semantic Web infrastructure. We show an implementation for Computer Science departments in Chile, and present current work on educational organizations generalizing previous experience. View full abstract»

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  • Methodological aspects in designing Web-based collaborative systems

    Page(s): 226 - 228
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (198 KB) |  | HTML iconHTML  

    We present methodological aspects related with the development of Web-based collaboration systems in design and education. Collaboration is highlighted as the fundamental aspect in the development of this kind of systems; it consists in a constructive and social process that is modeled in terms of protocols, which capture key acts of conversations involved in team working. View full abstract»

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  • Storing RDF as a graph

    Page(s): 27 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (290 KB) |  | HTML iconHTML  

    RDF is the first W3C standard for enriching information resources of the Web with detailed meta data. The semantics of RDF data is defined using a RDF schema. The most expressive language for querying RDF is RQL, which enables querying of semantics. In order to support RQL, a RDF storage system has to map the RDF graph model onto its storage structure. Several storage systems for RDF data have been developed, which store the RDF data as triples in a relational database. To evaluate an RQL query on those triple structures, the graph model has to be rebuilt from the triples. We present a new approach to store RDF data as a graph in a object-oriented database. Our approach avoids the costly rebuilding of the graph and efficiently queries the storage structure directly. The advantages of our approach have been shown by performance test on our prototype implementation OO-Store. View full abstract»

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