DATABASES

Author: MARTIN ESCOFET CARME.
Year: 2004.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: EDIFICI C6 Campus NORD.
Place of preparation: EDIFICI C6 Campus NORD.

Summary: This Ph.D. thesis mainly deals with temporal and deductive databases areas and the aim is to obtain a method for integrity constraint checking in bitemporal deductive databases, analyzing the temporal integrity constraint behavior. The existence of a transaction time dimension is especially useful to reduce the number of transition rules. In the valid time dimension, the temporal dependence of database predicate terms has been explored. Moreover, this Ph.D. thesis provides some research advances bringing together the areas of temporal databases and data warehouses. Chapter 1 is an introduction to the problem and the related work of this Ph.D. thesis main area. Chapter 2 presents temporal databases, and chapter 3 deductive databases. Chapter 4 introduces the study of temporal deductive database transaction behavior, explaining the concept of coherent transaction. This concept is used to reject transactions without more information requirements. Chapter 5 defines a new taxonomy of temporal integrity constraints to achieve a better understanding of why constraints are required and a best way to define them using first-order logic. In order to meet these goals, we have studied temporal integrity constraint taxonomies existing on the temporal database area and other deeply related areas such as multiversion databases. These works have been adapted and further developed to cover the scope of bitemporal deductive databases. Chapter 6 proposes an integrity constraint checking method for bitemporal deductive databases that derives a set of transition rules for each temporal integrity constraint. Then, Standard Linear Deduction with Negation as Failure Resolution is used to verify that a transaction does not violate any constraint before the transaction is allowed to commit. The set of transition rules obtained is very large; therefore, a carefully analysis of the integrity constraints using the taxonomy introduced above drastically reduces the number of rules. This chapter includes some examples of this new reduced set of transition rules and application examples of our integrity constraint checking method in bitemporal deductive databases. In chapters 7 and 8, we present our current and further work. In chapter 7, we identify a new type of predicate term dependent of time. This new type of term, named temporally dependent term, is formally defined and deeply studied in order to find its properties and its applicability to queries and integrity constraints. In chapter 8, we explain how to combine temporal database and data warehouse areas. Finally, chapter 9 provides conclusions and further work.

Author: VAQUERIZO GARCÍA MARÍA BELÉN.
Year: 2005.
University: LEÓN [www.unileon.es].
Place of defense: FACULTAD DE CIENCIAS ECONOMICAS Y EMPRESARIALES.
Place of preparation: FACULTAD DE CIENCIAS ECONÓMICAS Y EMPRESARIALES.

Summary: It has tried to make intelligent systems based management metaheurísticos to assist the planning and optimization of a system of Urban Public Transport Collective in a city median. Para ello se ha diseñado un sistema de generación y optimización de rutas y frecuencias de los autobuses de pasajeros utilizados en el transporte, que ayude a conseguir un uso racional de los recursos presentes bajo los criterios más adecuados de tiempos y costes. The system developed is seen as a tool to support decision-making that provides various solutions or options to the user and allows expert or decisor election deemed most suitable based on the level of service desired and the cost optimization. So have addressed two main objectives: to maximize the quality of service and maximize the benefit of the carrier. Moreover, among the variables that higher incidence presented in addressing the development of a system for resolving this problem, stressed the estimate of demand. Indeed, as has been said, one of the objectives being pursued with the development of the model is to maximize the quality of service, defined as minimizing travel times and waiting times, and both factors logically dependent closely in demand between the various stops and / or lines in which it has divided the network topography of the city or territory in question. Therefore, among the major difficulties in dealing with the establishment of a measure of quality of service expressed in the terms outlined above is the need to meet the demand of passengers, in order to determine the number of people using each line in each period. The problem is given by the fact that this is not a variable known with certainty, but nevertheless, it may be possible to make approximations to the values that can make this claim, in which case we should then use mathematical techniques or tools to work with estimated data, so that its development has used the Theory of Subconjuntos Borrosos.

Author: ILARRI ARTIGAS SERGIO.
Year: 2005.
University: ZARAGOZA [www.unizar.es].
Place of defense: CENTRO POLITÉCNICO SUPERIO.
Place of preparation: CENTRO POLITÉCNICO SUPERIOR.

Summary: The work presented in the argument is framed in the context of continuing questions processing dependent on location in mobile environments. It is proposed LOQOMOTION, an architecture based on mobile agents for the processing of continuous consultations in a distributed environment. One of the main features of the work presented is that, unlike others, is a comprehensive solution that works efficiently in a distributed network of computers, which allows for the construction of scalable systems. LOQOMOTION makes no assumption about the accuracy of location data, how they manage those data, the patterns of movement of moving objects, or the number and distribution of computers used. As part of the proposed approach for the processing of queries, it is also proposed a general mechanism for synchronizing Multiagent systems that is fault-tolerant and adapts to changes in existing conditions. In addition, it develops a simulator for mobile environments, which is used to evaluate the proper functioning of LOQOMOTION with minimal cost at any desired situation; this simulator, based on the use of mobile agents, enables distributed simulations comprising both real and simulated elements in a transparent manner to the data service, in addition to allowing simulate moving objects that execute applications Multiagent. Finally, in the absence of platforms for mobile agents who behave in a reliable and efficient manner in contexts with a large number of mobile operators, it is proposed a new platform, called SPRINGS, whose contributions must be emphasized that provides full transparency of location and scalability in contexts where others do not respond adequately.

Author: CÁCERES GARCÍA DE MARINA PALOMA.
Year: 2005.
University: REY JUAN CARLOS [www.urjc.es].
Place of defense: ESCUELA SUPERIOR DE CIENCIAS EXPERIMENTALES Y TECNOLOGÍA.
Place of preparation: ESCUELA SUPERIOR DE CINECIAS EXPERIMENTALES Y TECNOLOGÍA.

Summary: The Web technology has evolved rapidly since its appearance until today. In fact, at present, much of the organizations, both public and private, want to disseminate their information through the web, and extend their capabilities with business and broaden the distribution of its services through this medium. The development of web information systems (SIW) supports these needs. The peculiarities that have these systems, makes it necessary to define specific methods for its development, in fact, it has coined a new term, engineering Web (Web engineering), which refers to the techniques, methodologies, tools, etc., emerging directly with the objective of facilitating the development and systematic (SEMI) automatic SIW, in many cases, adapting the web development practices from software engineering. This doctoral thesis falls within the area of engineering sites. The goal is you work is: on the one hand, the specification of a methodological framework that facilitates development models directed by a SIW, and incorporate techniques agile processes on the other hand, we have specified a method for development of hypertext based on the services that the user requires the system. The main contribution of this method over other existing, is that it allows the definition and signaling pathways by providing navigation, users, navigability through SIW.

Author: Hidalgo Sanz Justo.
Year: 2006.
University: A CORUÑA [www.udc.es].
Place of defense: Facultad de Informática.
Place of preparation: Facultad de Informática.

Summary: The integration of distributed information is one of the most important areas of information management because of the large quantity and variety of data repositories with different access interfaces, communication protocols and standards of representation, but whose combined data rich and information knowledge in enterprises, institutions and research centers. Sources semi-structured and especially data embedded in HTML pages from web applications, set up the public information more populated at present, which also enjoys popularity and steady growth. The most widely used approach for the construction of this type of solution is that of mediator, which is responsible for accessing each of the data sources and combine its output so that it provides a unified view of information, and standardized way homogenea . However, the optimization of queries about these mediators has a significant set of challenges and problems that the source is to integrate Web-type, such as slow access through the network, the lack of statistics on costs, or how little appropriate some classical optimization techniques in these cases. The main objective of this dissertation is to develop a set of techniques and algorithms for optimizing queries mediators integration of web sources. The four main contributions of this study are as follows: (1) the use of a model based on costs to resolve the inadequacy of some strategic classical optimization that do not take into account restrictions on the search capabilities of the web sources, there will be no information about the quality of service of communication and processing costs sources web (2) the election of a set of cost parameters suitable to take into account information stored on web applications it is accessible after a series of navigation through Web pages, which can be distributed over different pages, and that stretches temporary influence on the cost of access; (3) the creation of an algorithm to update costs with a minimum computational complexity that allows their use in real environments with multiple concurrent queries and that adapts quickly to sudden changes in efficiency that can occur when accessing web sources, finally, (4) use of an architecture for access to web-based sources in the the concept of the "pool" of browsers, which allows parallelize access to sources involved in various consultations, and whose browsers are reused when the navigation sequences are in states compatible. These features, along with preloading of browsers in different states specific sequences of navigation from the use of historical information stored in the repository cost, minimizes access time each source.

Author: LOZANO ALBALATE MARIA TERESA.
Year: 2006.
University: JAUME I DE CASTELLON [www.uji.es].
Place of defense: E.S. DE TECNO. Y CIENCIAS EXPERIMENTALES.
Place of preparation: ESCUELA SUPERIOR DE TECNOLOGIA Y CIENCIAS EXPERIMENTALES.

Summary: The work presented in this thesis can be summarized in four contributions. First, two selective algorithms based on the concept of neighborhood housing, which outperform other algorithms presented in the thesis, and also better than other traditional patterns. Secondly, a technique based on adaptive mixtures (mixtures) Gaussianas, which provides better results in accurate classification and size reduction than other traditional adaptive algorithms, and similar to the method LVQ. Thirdly shows how you can use other classification rules, other than the classifier 1-NN, getting even better results. Finally, as is apparent from the experiments carried out, in the case of certain databases (as used here) algorithms presented here get an execution of the processes qualifying time in a less than efficient search techniques .

Author: Basagoiti Astigarraga Rosario María.
Year: 2006.
University: MONDRAGÓN UNIBERTSITATEA [www.mondragon.edu].
Place of defense: Escuela Politécnica Superior.
Place of preparation: Facultad deCiencias Empresariales de Mondragon Unibertsitatea.

Summary: Analyzing large cantitades data quickly is one of the greatest challenges facing companies today. The computer systems provide the ability to store large amounts of data, but we must find a way to analyze them in a reasonable time. The databases are temporary exceptionally large database whose analysis is particularly arduous if not impossible. To reduce the dimensionality of the data so that the time required for such analysis is admissible is a priority. The definition of a good measure of the similarity that allows comparison of the time series will be the second between them. If we move to a domain specifically for economic time series, we see that the time series stock are studied in order to detect possible changes in trends that are told of the opportunities for the purchase or sale of securities. Technical analysis notes the formation of certain patterns and track them using as a reference for making appropriate decisions. It is possible to use the fundamentals of technical analysis as a basis for the representation of time series to study, then using different measures of distance, performance algorimos clustering. The results will be analyzed both from the standpoint of efficiency and effectiveness from the