Catálogo de publicaciones - libros

Search engines are the most common gateway for information searching in the WWW. Since Information Retrieval systems do not take web accessibility into account, results displayed are not useful for users with disabilities. We present a framework that includes the requirements to overcome this situation. It is composed of three modules: Content Analysis Module, Accessibility Analysis Module and Results Collector Module. This framework facilitates the implementation of search engines which return results ranked according to accessibility level as well as content relevance. Since criteria to sort results by their accessibility are necessary, we define accurate quantitative accessibility metrics which can be automatically calculated exploiting results yielded by any automatic evaluation tool. A prototype based on these requirements has been implemented to show the validity of the proposal.

In this paper, we present a fast and scalable Bayesian model for improving – which is typically generated by a (semi) automated information extraction (IE) system from Web documents. Weakly annotated data suffers from two major problems: they (i) might contain incorrect ontological role assignments, and (ii) might have many missing attributes. Our experimental evaluations with the TAP and RoadRunner data sets, and a collection of 20,000 home pages from university, shopping and sports Web sites, indicate that the model described here can improve the accuracy of role assignments from 40% to 85% for template driven sites, from 68% to 87% for non-template driven sites. The Bayesian model is also shown to be useful for improving the performance of IE systems by informing them with additional domain information.

We have developed a system for gathering information from the Web, using it to create a personal history, and presenting it as a chronological table. It simplifies the task of sorting out the information for various namesakes and dealing with information in widely scattered sources. The system comprises five components: namesake disambiguation, date expression extraction, date expression normalization and completion, relevant information extraction, and chronological table generation.

In this paper, we analyze some widely employed clustering algorithms to identify duplicated or cloned pages in web applications. Indeed, we consider an agglomerative hierarchical clustering algorithm, a divisive clustering algorithm, k-means partitional clustering algorithm, and a partitional competitive clustering algorithm, namely Winner Takes All (WTA). All the clustering algorithms take as input a matrix of the distances between the structures of the web pages. The distance of two pages is computed applying the Levenshtein edit distance to the strings that encode the sequences of HTML tags of the web pages.

Combining expressiveness and plainness in the design of web documents is a difficult task. Validation languages are very powerful and designers are tempted to over-design specifications. This paper discusses an offbeat approach: describing structured content of document by only using a very small set of patterns, regardless of the format and layout of that document. The paper sketches out a formal analysis of some patterns, based on grammars and language theory. The study has been performed on XML languages and DTDs and has a twofold goal: coding empirical patterns in a formal representation, and discussing their completeness.

The content of many innovative Web sites today often originates from beyond the application. This paper is concerned with building Web applications that heavily integrate and link content from external sources, like e.g. Web services or RSS feeds. Unlike conventional applications, they are characterized by a very dynamic and distributed information space. In this context, traditional Web Engineering approaches suffer from the fact that they rely too much on a-priori knowledge of existing content structures. We present a support system and a method for building such applications in a very flexible way. Flexibility is achieved by managing links separately from the content in a dedicated Web service and by composing the application from fine-grained, reusable components that realize navigation, presentation, and interaction for the linked content.

Several works [20,22] have tried to enforce strict isolation between the model and the view in template based web applications by restricting the computing possibilities of the used templates. From the point of view of graphic designers this is a limitation that may make their work difficult. Besides, in this paper we state that this claimed strict isolation is impossible to achieve in practice for HTML template systems. We propose another approach to study and to attain an effective separation between model and view that does not necessarily restrict the expressive power of the template: the double-model approach. Finally we present an implementation of this approach in a renewed template system called JST2.

This paper presents a model-driven approach to the development of web applications based on the Ubiquitous Web Application (UWA) design framework, the Model-View-Controller (MVC) architectural pattern and the JavaServer Faces technology. The approach combines a complete and robust methodology for the user-centered conceptual design of web applications with the MVC metaphor, which improves separation of business logic and data presentation. The proposed approach, by carrying the advantages of Model-Driven Development (MDD) and user-centered design, produces Web applications which are of high quality from the user’s point of view and easier to maintain and evolve.

Step-wise refinement is a powerful paradigm for developing a complex program from a simple program by adding features incrementally where each feature is an increment in program functionality. Existing works focus on object-oriented representations such as Java or C++ artifacts. For this paradigm to be brought to the Web, refinement should be realised for XML representations. This paper elaborates on the notion of XML refinement by addressing what and how XML can be refined. These ideas are realised in the XAK language. A Struts application serves to illustrate the approach.

In this paper we present a development and runtime environment for creating composite applications by reusing existing components. The granularity of components is that of stand-alone modules encapsulating reusable functionalities. The goal is to allow developers to easily create composite applications by combining the components’ individual user interfaces.