Orientador: Ricardo da Silva Torres / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-11T00:55:04Z (GMT). No. of bitstreams: 1 Pedronette_DanielCarlosGuimaraes_M.pdf: 7416929 bytes, checksum: be0fe860604d3545272fbe4bd4aaa8df (MD5) Previous issue date: 2008 / Resumo: Em virtude do crescimento acelerado de conteúdo nas mais diversas aplicações de bibliotecas digitais, a tarefa de localizar objetos digitais de interesse é cada vez mais desafiadora. Sob essa perspectiva, técnicas de recomendação procuram prover, de acordo com as preferências do usuário final, alternativas de escolha de objetos mantidos em uma biblioteca digital. Essa dissertação concentra-se em aspectos relacionados às técnicas de recomendação e suas interações com aplicações de bibliotecas digitais. Uma plataforma de serviços de recomendação, chamada RecS-DL, é proposta, visando ampliar as possibilidades de utilização das ferramentas de recomendação. A Plataforma RecS-DL apresentada é independente de domínio de aplicação, de tecnologias e técnicas de recomendação. O serviço de recomendação oferecido pode ser facilmente agregado a bibliotecas digitais clientes, assim como novos mecanismos de recomendação podem ser acoplados à plataforma de maneira dinâmica. Este trabalho também apresenta uma especificação formal da plataforma de serviços de recomendação proposta a partir do Arcabouço 5S. Para isso foram propostas novas definições e extensões de conceitos deste arcabouço. Por fim, são apresentados os resultados obtidos a partir de testes realizados com a plataforma. Experimentos foram conduzidos considerando bibliotecas digitais reais e avaliações por potenciais usuários. Resultados experimentais ratificam a hipótese de que a plataforma facilita a interoperabilidade de ferramentas de recomendação em bibliotecas digitais / Abstract: The increasing amount of data in the most diverse digital libraries applications makes the process of finding relevant digital objects a challenging task. From this perspective, recommendation techniques can provide, according to user preferences, relevant digital objects stored in a digital library.This dissertation focuses on recommendation techniques and their interactions with digital libraries applications. A platform for recommendation services, called RecS-DL, has been proposed to support the use of recommendation tools. The proposed RecS-DL Platform is independent of application domain, technology, and recommendation techniques. The recommendation services offered by the platform can be easily incorporated into digital libraries systems. Furthermore, new recommendation engines can also be plugged into the platform in a dynamic way. This work also presents a formal specification of the proposed platform, using the 5S Framework. To do this, new definitions and extensions of this framework are proposed. Finally, we present the results obtained from tests performed with the platform. Experiments were conducted considering real digital libraries and evaluations made by potential users. Experimental results confirm that the platform facilitates the interoperability of recommendation tools in digital libraries systems / Mestrado / Sistemas de Informação / Mestre em Ciência da Computação

The objective of this thesis is to propose fundamental concepts, analytical and numerical tools, and approaches to characterize, understand, and better observe complex systems. The scientific contribution of this thesis can be separated in tree topics. In the first one, we show how to theoretically estimate the Mutual Information Rate (MIR), the amount of mutual information transmitted per unit of time between two time-series. We then show how a quantity derived from it can be successfully used to infer the network structure of a complex system. The proposed inference methodology shows to be robust in the presence of additive noise, different time-series lengths, and heterogeneous node dynamics and coupling strengths. It also shows to be superior in performance for networks formed by nodes possessing different time-scales, as compared to inference methods based on mutual information (MI). In the second topic, a deep analysis of causality from the space-time properties of the observed probabilistic space is performed. We show the existence of special regions in the state space which indicate variable ranges responsible for most of the information exchanged between two variables. We define a new causality measure named CaMI that explores a property we have understood: in order to detect if there is a flow of information from X to Y, one only needs to check the positiveness of the MI between trajectories in X and Y, however assuming that the observational resolution in Y is larger than in X. Moreover, we show how the assessment of causality can be done when we consider partitions with arbitrary, but equal rectangular cells in the probabilist space, what naturally facilitates the calculation of CaMI. In the third topic, we develop a symbolic coefficient of observability that allows us to understand what is the reduced set of accessible variables to observe a complex system, such that it can be fully reconstructed from the set of observed variables, regardless of its dimension. Using this symbolic coefficient, we explain how it is possible to compare different complex systems from the point of view of observability and how to construct systems of any dimensionality that can be fully observed by only one variable.

The implementation of information technology and its impact on organisational change has been an important phenomenon, discussed in the IS literature over the last 30 years. Treating information system (IS) implementation as organisational change is a complex phenomenon. This complexity is mainly due to its multidisciplinary, socio-technical, dynamic and non-linear nature. This challenging nature of IS implementation complexities has a direct relationship to the IS implementation project outcomes - its success or failure. In view of this complexity, this research aims to understand how process studies can improve the understanding of enterprise system implementation. We argue that the socio-technical nature of IS development is inevitable thus the only way to go forward is to explore and understand the phenomenon. Following this, we adopt the stakeholder's perspective solely for the purpose of identification of stakeholders and their embedded interests and expectations. While prior research concentrated on a limited number of stakeholders of IS, we attempt to adopt Pouloudi et al. (2004) in mobilizing a stakeholder perspective to incorporate non-human stakeholders within the analysis. Within the actor-network perspective, complexity is resolved through simplification (black-boxing) - unpacking or collapsing the complexity. However, during this simplification process, the risk of removing useful description of the phenomenon through labelling was avoided. To support this research, the punctuated socio-technical information systems change (PSIC) model was applied. In this model, interactions and relationships between its components (antecedent condition, process, outcomes and organisational context) play a vital role. This research focuses on the implementation of an integrated financial system in three Malaysian universities through three interpretive case studies. Our findings show that each of our case studies provides a unique IS development trajectory. Following stakeholder analysis, the different cases provide interesting combinations of conflicts and coalitions among human and non-human stakeholders which further dictates the project outcomes or the process of IS black-boxing. The relationship between the three case studies on the other hand provides an interesting illustration of IS technology transfer.

This diploma thesis examines the impact of information and communication technologies on the current form of air transport process. The technology is now a key factor of progress in this sphere. This diploma thesis aims to prove this claim and describes the examples of technology impact in the activities of participants in air transport (airlines, airports and passengers) as well as related changes in their behavior.

Die stark wachsende Bedeutung der Analyse von Data Warehouse-Inhalten und bequemere Anfrageschnittstellen für Endbenutzer erhöhen das Aufkommen an OLAP-Queries signifikant. Bei der Reduktion des Arbeitsumfanges und dem Erreichen kurzer Antwortzeiten für diese komplexen Anfragen ist neben der Nutzung von Verarbeitungs- und I/O-Parallelität eine adäquate Datenallokation der Schlüssel zu guter Leistungsfähigkeit. Allerdings ist die Bestimmung einer geeigneten Fragmentierung und Allokation für große Datenmengen, wie sie z.B. in Form von Faktentabellen oder Indexstrukturen in relationalen Sternschemas vorliegen, ein schwieriges Problem. Hierfür existiert heutzutage praktisch keine Werkzeugunterstützung. Wir präsentieren daher einen Ansatz zur analytischen Bestimmung einer passenden multi-dimensionalen, hierarchischen Datenallokation. Unser Ansatz dürfte recht einfach in ein Werkzeug zur automatischen Unterstützung des Allokationsproblems integriert werden können.

Thèse doctorat : Informatique : Villeurbanne, INSA : 2006. / Thèse rédigée en anglais. Titre provenant de l'écran-titre. Bibliogr. p. 215-236. Publications de l'auteur, 1 p. Glossaire.

Thèse doctorat : Informatique : Villeurbanne, INSA : 2005. / Thèse rédigée en anglais. Résumé étendu en anglais. Titre provenant de l'écran-titre. Bibliogr. p. 214-226.

Thesis (M.Info.Tech.)--University of Wollongong, 2005. / Includes appendices. Typescript. Includes bibliographical references: leaf 100-105.

Thesis (Ph.D.)--University of Waikato, 2007. / Title from PDF cover (viewed April 1, 2008) Includes bibliographical references (p. [339]-343)

Thesis (M.S.) -- Mississippi State University. Department of Computer Science and Engineering. / Title from title screen. Includes bibliographical references.