In this paper using the information obtained from the daily working of a Web directory, we attempt to expand the knowledge about the behavior of the users in order to improve and adapt the Internet search engines to their users. We have analysed more than 320,000 requests of the transaction log of a Spanish Web directory, focusing our attention, firstly, in the searches in order to confirm the main differences between Internet and traditional Information Retrieval systems. Furthermore, we have developed an exhaustive statistical analysis of searches, categories visited and documents viewed to achieve a mathematical pattern of behaviour for each one, and what it is more important, to establish a relationship between the variations in the behaviour of each one.

Development of distributed applications is a difficult task. Object Requests Brokers (ORBs) facilitate the development of large and complex distributed applications. However, the programmer still has to deal with a complex framework, which increases the learning curve. In this paper, we present a middleware that tries to facilitate the transition from the design to the implementation. The middleware is made up of a C++ framework and an Agent Definition Language (ADL). The framework is implemented on top of a CORBA ORB and provides the programmer with high-level abstractions, such as "agent" and "FUN" (a special class of agent that delegate part of its functionality into a number of cooperating agents). ADL is a template-like language, which hides the underlying C++ framework from the programmer (including the CORBA ORB). The paper makes special emphasis in describing such a language.

This paper addresses the problem of integrating legacy PDH equipments into a TMN-based management system. A real case study, the equipments of a power utility telecommunications network, is presented. The focus is on the information model: how general information models can be applied to PDH equipments and how real constraints derived from legacy equipments can affect the model and its implementation. Because of their special interest, two main features of this model are studied in detail: how to express connectivity, including an extension of general models to cover cross-connection, tables, and issues about fault management, emphasizing the model support for maintaining equipments state in the presence of alarms.

No abstract available.

Unlike other real-time systems, data acquisition applications spend most of their time performing synchronous and asynchronous I/O operations. This fact, that affects the tasks' abilities to meet deadlines, can be modelled with some extensions to the classic rate monotonic schedulability test. In this paper, we address this issue by investigating a case study for the application of rate monotonic analysis (RMA) to data acquisition systems. We describe a technique for modelling tasks that perform asynchronous I/O at the end of their executing period; and we also show the logistic and technical problems that can arise when applying RMA at different stages during the development process of an application. We illustrate our ideas with a real-time data acquisition system that we have developed, characterized by a very heterogeneous architecture whose technological components have been pushed to the limits of their performance and capacity.>

Effective monitoring of device-supported patients in the intensive care unit (ICU) is complex, involving interpretation of many variables, comparative evaluation of many therapy options, and control of many patient-management parameters. Even skilled clinicians make errors that limit the quality of care, harm patients, or cause life-threatening situations. A growing body of research aims to improve ICU monitoring with computer technology. Most of this research falls in two areas: (a) short-term engineering of practical solutions to narrowly defined immediate problems (e.g. smart alarm systems); or (b) basic research on fundamental issues potentially relevant to ICU monitoring (e.g. temporal reasoning). By contrast, our project aims to develop a more comprehensive ‘intelligent agent’, having a broad range of capabilities, to cooperate on the ICU team. We do not aim to produce a practical system suitable for near-term deployment in the ICU, but rather a ‘proof of concept’, an experimental system that: (a) demonstrably performs and coordinates a range of intelligent reasoning tasks of use in ICU monitoring; (b) does so reliably in a significant range of medical situations; and (c) arguably will scale up to meet the comprehensive set of practical requirements with an appropriate development effort. We have developed an experimental system called Guardian, which exhibits several of the required capabilities and utilizes an underlying architecture hypothesized to support the full range of required capabilities. In this paper, we describe the Guardian system, its architecture, and its current knowledge base. We describe its performance and summarize the results of preliminary evaluations. Finally, we discuss ongoing and planned research on Guardian.