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The work deals with the relationship of the relational model and XML schema document and its technological and pragmatic aspects. It defines the theoretical field of data modeling at conceptual level and the two mentioned possible implementation models at the physical level. The aim is to answer the question when in the design and development of application or system it is appropriate to proceed with one of these models. Furthermore, this work also provides a general procedure for mapping conceptual schema into XML schema structures and solutions to problems that can come across during the mapping process. The problem is solved by analyzing two real issues - timetables of public transportation and the information system of a swimming school, formalized through a mechanism of predicate logic. Unlike most works on a similar topic this one varies in a pragmatic view on the problem - the concept of data, their origin, their target user and structuring.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Semi-Structured Information Retrieval is an intermediate way to retrieve information between Textual Retrieval and Structured Retrieval (typical in relational database systems). In structured retrieval systems, users generally know the available data structure and query languages, so they can formulate queries that produce more accurate results. In textual retrieval users dont known the data structure and formulate queries with keywords only, which produces not so accurate results. In Semi-Structured Retrieval, users generally dont known the data structure and formulate queries that mix textual search and structured retrieval mechanisms. In this context, the problem of how to improve the results accuracy using the structure inside semi-structured documents appears. Semi-structured data is usually stored as XML documents and can be seen as trees. Internal nodes of these trees have the structure of documents, while leaf nodes contain text. The design of interfaces for users in this context is one of the biggest challenges in semi-structured information retrieval. This occurs especially because the users dont known the document structure and have problems in formulating structured queries. This dissertation presents a proposal and a prototype interface developed to help users in the process of formulation of structured queries. The aim is to increase the precision in the results of the queries. The proposal is validated by experiments involving volunteers users and by comparing the results of textual queries and structured queries made with the help of the interface. The improvement reaches 440% for well structured queries, with a user who knows the interface, and 179.75% for reasonably structured queries, by users without experience to use the interface. / A Recuperação Semi-Estruturada é uma forma de recuperação de informação intermediária entre a Recuperação Textual e a Recuperação Estruturada (típica em sistemas de banco de dados relacionais). Em sistemas de recuperação estruturada, o usuário geralmente conhece a estrutura dos dados e as linguagens de consulta disponíveis, conseguindo assim formular consultas que produzem resultados mais precisos. Na Recuperação Textual o usuário não conhece a estrutura dos dados e formula as consultas apenas com palavraschaves, as quais geram resultados não tão precisos. Na Recuperação Semi-Estruturada, o usuário geralmente desconhece a estrutura dos dados e formula consultas que mesclam buscas textuais e mecanismos de recuperação estruturada. Neste contexto, surge o problema de como melhorar a precisão dos resultados aproveitando a estrutura contida nos documentos semi-estruturados. Dados semi-estruturados são comummente armazenados como documentos XML, os quais podem ser vistos como árvores. Nós internos dessas árvores contem a estrutura do documento enquanto os nós folhas contêm os dados. O projeto de interfaces para usuários neste contexto é um dos grandes desafios na recuperação semi-estruturada. Isso ocorre especialmente porque os usuários não conhecem a estrutura do documento e têm dificuldade na formulação de consultas estruturadas. Este trabalho apresenta uma proposta e um protótipo de interface desenvolvido para auxiliar os usuários no processo de formulação de consultas estruturadas. Pretende-se com isso aumentar a precisão nos resultados das consultas. A proposta é validada por meio de experimentos envolvendo usuários voluntários e pela comparação de resultados obtidos com consultas textuais e consultas estruturadas formuladas com o auxílio da ferramenta. A melhoria atinge 440% para consultas bem estruturadas, realizadas por usuário que conhece bem a interface, e 179,75% para consultas razoavelmente estruturadas, realizadas por usuários sem experiência no uso da interface. / Mestre em Ciência da Computação

The aim of this Master thesis has been to summarize the current theoretical knowledge about the possibilities of using stories in management, especially their use as a tool for better and easier decision-making in a nowadays turbulent period, and to summarize the aspects explaining their positive contribution in this issue. In the practical part, the thesis focuses on exploring the use of stories by students of the University of Economics in Prague to decide on subjects and teachers. More specifically, the aim has been to find out how students are influenced by stories told by their colleagues in selection of subjects and teachers, how actively students use stories for obtaining and transmitting knowledge and information, in what form stories spread among students, which communication channel students prefer and why, what the quality of stories is and what the differences between Bachelor's and Master's students in those aspects are. The purpose of this research has been to demonstrate the power of stories in influencing individuals decision-making, applicable also to classical management in the corporate environment. As a research method, a combination of a quantitative and simple qualitative analysis in the form of the semi-structured questionnaire has been used. Based on the research, it has been found out that students do decide about subjects and teachers on the basis of others'stories, they do actively seek those stories and they do prefer personal narrative from friends, as this form has turned out to be considered as the most reliable for students, and also the one which will find the most consistent validation in what they will experience next. Students of Bachelor's and Master's studies differ in the selected communication channel and the activity with which they search for and use the stories.

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