Catálogo de publicaciones - libros

The paper discuss reasons why service-oriented architecture is a new software paradigm and the consequences of this fact for the design of enterprise information systems. It is shown that such systems called confederations need not use web services in the sense of W3C. It is, however, more or less a necessity in e-commerce. Confederations (service-oriented systems with known set of services) are typical for manufacturing systems. As business processes supported by enterprise systems must be supervised by businessmen, the same must hold for communication inside service-oriented systems. It implies that the interfaces of the services must be user-oriented (user-friendly). It can be easier achieved in confederations than in e-commerce systems. User oriented interface has positive consequences for the software engineering properties of the confederation. Confederations should sometimes include parts based on different implementation philosophies (e.g. data orientation). Pros and cons of it are discussed. Open issues of service orientation are presented.

Presently, digital continuous media (CM) are well established as an integral part of many applications. In recent years, a considerable amount of research has focused on the efficient retrieval of such media. Scant attention has been paid to servers that can record such streams in real time. However, more and more devices produce direct digital output streams. Hence, the need arises to capture and store these streams with an efficient data stream recorder that can handle both recording and playback of many streams simultaneously and provide a central repository for all data.

In this report we investigate memory management in the context of large scale data stream recorders. We are especially interested in finding the minimal buffer space needed that still provides adequate resources with varying workloads. We show that computing the minimal memory is an -complete problem and will require further study to discover efficient heuristics.

One of the key decision activities in financial institutions is to assess the credit-worthiness of an applicant for a loan, and thereupon decide whether or not to grant the loan. Many classification methods have been suggested in the credit-scoring literature to distinguish good payers from bad payers. Especially neural networks have received a lot of attention. However, a major drawback is their lack of transparency. While they can achieve a high predictive accuracy rate, the reasoning behind how they reach their decisions is not readily available, which hinders their acceptance by practitioners. Therefore, we have, in earlier work, proposed a two-step process to open the neural network black box which involves: (1) extracting rules from the network; (2) visualizing this rule set using an intuitive graphical representation. In this paper, we will focus on the second step and further investigate the use of two types of representations: decision tables and diagrams. The former are a well-known representation originally used as a programming technique. The latter are a generalization of decision trees taking on the form of a rooted, acyclic digraph instead of a tree, and have mainly been studied and applied by the hardware design community. We will compare both representations in terms of their ability to compactly represent the decision knowledge extracted from two real-life credit-scoring data sets.

Large product variety in mass customization involves a high internal complexity level inside a company’s operations, as well as a high external complexity level from a customer’s perspective. To cope with both complexity problems, an information system based on agent technology is able to be identified as a suitable solution approach. The mass customized products are assumed to be based on a modular architecture and each module variant is associated with an autonomous rational agent. Agents have to compete with each other in order to join coalitions representing salable product variants which suit real customers’ requirements. The negotiation process is based on a market mechanism supported by the target costing concept and a Dutch auction. Furthermore, in order to integrate the multi-agent system in the existing information system landscape of the mass customizer, a technical architecture is proposed and a scenario depicting the main communication steps is specified.

In the past years, the arena has suffered a remarkable development, where tools, such as , have been successfully applied in the design of medical systems. In this work, are applied to the prediction of organ dysfunction in . The novelty of this approach comes from the use of , which are triggered from four bedside alarms, being achieved an overall predictive accuracy of 70%.

Temporal mining is a natural extension of data mining with added capabilities of discovering interesting patterns, inferring relationships of contextual and temporal proximity and may also lead to possible cause-effect associations. Temporal mining covers a wide range of paradigms for knowledge modeling and discovery. A common practice is to discover frequent sequences and patterns of a single variable. In this paper we present a new algorithm which is the combination of many existing ideas consists of the reference event as proposed in (Bettini, Wang et al. 1998), the event detection technique proposed in (Guralnik and Srivastava 1999), the large fraction proposed in (Mannila, Toivonen et al. 1997), the causal inference proposed in (Blum 1982) We use all of these ideas to build up our new algorithm for the discovery of multivariable sequences in the form of the predisposing factor and co-incident factor of the reference event of interest. We define the event as positive direction of data change or negative direction of data change above a threshold value. From these patterns we infer predisposing and co-incident factors with respect to a reference variable. For this purpose we study the Open Source Software data collected from SourceForge website. Out of 240+ attributes we only consider thirteen time dependent attributes such as Page-views, Download, Bugs0, Bugs1, Support0, Support1, Patches0, Patches1, Tracker0, Tracker1, Tasks0, Tasks1 and CVS. These attributes indicate the degree and patterns of activities of projects through the course of their progress. The number of the Download is a good indication of the progress of the projects. So we use the Download as the reference attribute. We also test our algorithm with four synthetic data sets including noise up to 50 %. The results show that our algorithm can work well and tolerate the noise data.

With the development and the availability of large textual corpora, there is a need for enriching and organizing these corpora so as to make easier the research and navigation among the documents. The Semantic Web research focuses on augmenting ordinary Web pages with semantics. Indeed, wealth of information exists today in electronic form, they cannot be easily processed by computers due to lack of external semantics. Furthermore, the semantic addition is an help for user to locate, process information and compare documents contents. For now, Semantic Web research has been focused on the standardization, internal structuring of pages, and sharing of ontologies in a variety of domains. Concerning external structuring, hypertext and information retrieval communities propose to indicate relations between documents via hyperlinks or by organizing documents into concepts hierarchies, both being manually developed. We consider here the problem of automatically structuring and organizing corpora in a way that reflects semantic relations between documents. We propose an algorithm for automatically inferring concepts hierarchies from a corpus. We then show how this method may be used to create specialization/generalization links between documents leading to document hierarchies. As a byproduct, documents are annotated with keywords giving the main concepts present in the documents. We also introduce numerical criteria for measuring the relevance of the automatically generated hierarchies and describe some experiments performed on data from the LookSmart and New Scientist web sites.

The Differential Evolution algorithm goes back to the class of Evolutionary Algorithms and inherits its philosophy and concept. Possessing only three control parameters (size of population, differentiation and recombination constants) Differential Evolution has promising characteristics of robustness and convergence. In this paper we introduce a new principle of Energetic Selection. It consists in both decreasing the population size and the computation efforts according to an energetic barrier function which depends on the number of generation. The value of this function acts as an energetic filter, through which can pass only individuals with lower fitness. Furthermore, this approach allows us to initialize the population of a sufficient (large) size. This method leads us to an improvement of algorithm convergence.

In this work, we start from a database built with soil information from heterogeneous scientific sources (Local Soil Databases, LSDB). We call this an Aggregated Soil Database (ASDB). We are interested in determining if knowledge obtained by means of fuzzy association rules or fuzzy approximate dependencies can represent adequately expert knowledge for a soil scientific, familiarized with the study zone. A master relation between two soil attributes was selected and studied by the expert, in both ASDB and LSDB. Obtained results reveal that knowledge extracted by means of fuzzy data mining tools is significatively better than crisp one. Moreover, it is highly satisfactory from the soil scientific expert’s point of view, since it manages with more flexibility imprecision factors (IFASDB) commonly related to this type of information.

To an increasing extend software systems are integrated across the borders of individual enterprises. The Web service approach provides group of technologies to describe components and their composition, based on well established protocols. Focused on business processes, one Web service implements a local subprocess. A distributed business processes is implemented by the composition a set of communicating Web services.

At the moment, there are various modeling languages under development to describe the internal structure of one Web service and the choreography of a set of Web services. Nevertheless, there is a need for methods for stepwise construction and verification of such components.

This paper abstracts from concrete syntax of any proposed language definition. Instead, we apply Petri nets to model Web services. Thus, we are able to reason about essential properties, e. g. of a Web service — our notion of a quality criterion. Based on this framework, we present an algorithm to analyze a given Web service and to transfer a complex process model into a appropriate model of a Web service.