Catálogo de publicaciones - libros

In this paper, we present a document metaphor called for accessing and searching for digital documents in modern distributed information systems. Our approach is based upon a finegrained document concept which glues computational services, data and meta data together. Viewing documents as micro servers is particularly well suited in environments where the document’s content is changing continuously and frequently. Based on a case study of an existing state-of-the-art Web application, we show how to transform database-centric information systems into a hypertext of inter-linked . We also discuss how to effectively use traditional as well as Web information retrieval techniques, namely topic distillation, in such hypertext environment. In particular, an extended version of Kleinberg’s [] algorithm is presented.

This paper describes a corpus linguistic analysis of large text corpora based on collocations with the aim of extracting semantic relations from unstructured text. We regard this approach as a viable method for generating and structuring information about WEB communities. Starting from a short description of our corpora as well as our language analysis tools, we discuss in depth the automatic generation of collocation sets. We further give examples of different types of relations that may be found in collocation sets for arbitrary terms. We conclude with a brief discussion of applying our approach to the analysis of a sample community.

Data mining offers tools for the discovery of relationship, patterns and knowledge from a massive database in order to guide decisions about future activities. Applications from various domains have adopted this technique to perform data analysis efficiently. Several issues need to be addressed when such techniques apply on data these are bulk at size and geographically distributed at various sites. In this paper we describe system architecture for a scalable and a portable distributed data mining application. The system contains modules for secure distributed communication, database connectivity, organized data management and efficient data analysis for generating a global mining model. Performance evaluation of the system is also carried out and presented.

Highlighting text is a common feature in most single-user editors. It provides users with a mechanism of communication and collaboration between the author and readers by emphasizing some important text. This feature is also necessary and even more valuable for multi-user group editors in the Internet environment. However, it is non-trivial to extend this feature from single-user editors to multi-user group editors because of the following challenges: 1) the need to differentiate highlights by different users, 2) the need to tackle inconsistency problems caused by concurrent operations and nondeterministic communication latency in the Internet environment, and 3) the need to provide a flexible undo facility with the capability of undoing any highlighting operation at any time. We will systematically address these issues and offer our solutions accordingly in this paper. These solutions have been implemented in the (REal-time Distributed Unconstrained Collaborative Editing) system.

The design of complex distributed embedded systems often presents great challenges because of the large number and dimensions of their components. This research paper discusses some of the problems of designing such systems. The use of Colored Dynamic Activity Diagrams for modeling complex real-time systems is suggested as a possible solution. The Colored Activity Diagrams bridge a gap between modeling technique and description power of High Level Petri nets. By coloring Activity Diagrams the behavior of several objects or processes can be modeled in a single diagram. They also have additional mechanisms for mapping dependences and relationships between individual objects. The color is a property which supports the intended transformation into the High Level Petri Nets allowing further the formal verification of the whole system. The usability of the method is shown in a modeled reference example.

Production Scheduling is an important function strongly contributing to the competitiveness of industrial and service companies. In this communication we make a contribution for XML based specification of scheduling concepts in order to allow for a standard representation of scheduling problems and related tasks. This information modeling is used in the development of a web based decision support system for the resolution of scheduling problems. An XML-based Knowledge Base System may be useful not only to facilitate the specification of scheduling problems but also in the search for the most suitable available algorithms and methods, which can then be used for finding good solutions to the problems. The existing algorithms, as well as their corresponding implementations, may either be local or remotely available, through the Internet.

A networked information space is a collection of information entities connected by links. In this paper, we propose a method to determine if a given subset of a networked information space is randomly chosen or thematically unified, based solely on the link structure of the subset. The proposed method uses compressibility as a measure of the link structure. The method is illustrated with an example.

In this paper we study properties of the Internet topology on the autonomous system (AS) level. We find that the normalized Laplacian spectrum () of a graph provides a concise fingerprint of the corresponding network topology. The of AS graphs remains stable over time in spite of the explosive growth of the Internet, but the of synthetic graphs obtained using the state-of-the-art topology generator Inet-2.1 is significantly different, in particular concerning the multiplicity of eigenvalue 1. We relate this multiplicity to the sizes of certain subgraphs and thus obtain a new structural classification of the nodes in the AS graphs, which is also plausible in networking terms. These findings as well as new power-law relationships discovered in the interconnection structure of the subgraphs may lead to a new generator that creates more realistic topologies by combining structural and power-law properties.

Bodies of information available through the Internet, such as digital librarises and distributed file-sharing systems, often form a self-organizing networked information space, i.e. a collection of interconnected information entities generated incrementally over time by a large number of agents. The collection of electronically available research papers in Computer Science, linked by their citations, form a good example of such a space. In this work we present a study of the structure of the citation graph of computer science literature. Using a web robot we build several citation graphs from parts of the digital library . After verifying that the degree distributions follow a power law, we apply a series of graph theoretical algorithms to elicit an aggregate picture of the citation graph in terms of its connectivity. The results expand our insight into the structure of self-organizing networked information spaces, and may inform the design of focused crawlers searching such a space for topic-specific information.

A mobile agent system network is, in our definition, a dynamical system where so called agent servers are loosely coupled. In such an environment (mobile) agents may offer and consume services and act on behalf of a (human) user. This paper characterizes the dynamical behavior of such a network. Aspects of dynamical behavior are discussed, dynamical components are characterized, and a ”cartography” method to handle dynamics is introduced. The resulting ”maps” can be used to support the autonomy of agents by calculating itineraries and suggest migration strategies. The application of the map described in this paper is based on one of our current research projects in the context of the mobile agent system Tracy.