In the study, two methods for recommending application software were implemented and evaluated based on their ability to recommend alternative applications with related functionality to the one that a user is currently browsing. One method was based on Term Frequency–Inverse Document Frequency (TF-IDF) and the other was based on Latent Semantic Indexing (LSI). The dataset used was a set of 2501 articles from Wikipedia, each describing a distinct application. Two experiments were performed to evaluate the methods. The first experiment consisted of measuring to what extent the recommendations for an application belong to the same software category, and the second was a set of structured interviews in which recommendations for a subset of the applications in the dataset were evaluated more in-depth. The results from the two experiments showed only a small difference between the methods, with a slight advantage to LSI for smaller sets of recommendations retrieved, and an advantage for TF-IDF for larger sets of recommendations retrieved. The interviews indicated that the recommendations from when LSI was used to a higher extent had a similar functionality as the evaluated applications. The recommendations from when TF-IDF was used had a higher fraction of applications with functionality that complemented or enhanced the functionality of the evaluated applications. / I studien implementerades och utvärderades två alternativa implementationer av ett rekommendationssystem för applikationsprogramvara. Implementationerna utvärderades baserat på deras förmåga att föreslå alternativa applikationer med relaterad funktionalitet till den applikation som användaren av ett system besöker eller visar. Den ena implementationen baserades på Term Frequency-Inverse Document Frequency (TF-IDF) och den andra på Latent Semantic Indexing (LSI). Det data som användes i studien bestod av 2501 artiklar från engelska Wikipedia, där varje artikel bestod av en beskrivning av en applikation. Två experiment utfördes för att utvärdera de båda metoderna. Det första experimentet bestod av att mäta till vilken grad de rekommenderade applikationerna tillhörde samma mjukvarukategori som den applikation de rekommenderats som alternativ till. Det andra experimentet bestod av ett antal strukturerade intervjuer, där rekommendationerna för en delmängd av applikationerna utvärderades mer djupgående. Resultaten från experimenten visade endast en liten skillnad mellan de båda metoderna, med en liten fördel till LSI när färre rekommendationer hämtades, och en liten fördel för TF-IDF när fler rekommendationer hämtades. Intervjuerna visade att rekommendationerna från den LSI-baserade implementationen till en högre grad hade liknande funktionalitet som de utvärderade applikationerna, och att rekommendationerna från när TF-IDF användes till en högre grad hade funktionalitet som kompletterade eller förbättrade de utvärderade applikationerna.

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This work deals with the issue of poviding recommendations for individual users of e-shop based on the obtained user preferences. The work includes an overview of existing recommender systems, their methods of getting user preferences, the methods of using objects' content and recommender algorithms. An integral part of this work is design and implementated for independent software component for Content-based recommendation. Component is able to receive various user preferences and various forms of object's input data. The component also contains various processing methods for implicit feedback and various methods for making recommendations. Component is written in the Java programming language and uses a PostgreSQL database. The thesis also includes experiments that was carried out with usage of component designed on datasets slantour.cz and antikvariat-ichtys.cz e-shops.

The dissemination of various types of data faces ongoing challenges with the growing need of accessing manifold information. Since the interest in content is what drives data networks, some new technologies and thoughts attempt to cope with these challenges by developing content-based rather than address-based architectures. The Publish/ Subscribe paradigm can be a promising approach toward content-based data dissemination, especially that it provides total decoupling between publishers and subscribers. However, in content-based publish/subscribe systems, subscriptions are expressive and the information is often delivered based on the matched expressive content - which may not deeply alleviate considerable performance challenges. This dissertation explores a hardware solution for disseminating data in content-based publish/subscribe systems. This solution consists of an efficient hardware architecture of an XML/XPath broker that can route information based on content to either other XML/XPath brokers or to ultimate users. A network of such brokers represent an overlay structure for XML content-based publish/subscribe data dissemination systems. Each broker can simultaneously process many XPath subscriptions, efficiently parse XML publications, and subsequently forward notifications that result from high-performance matching processes. In the core of the broker architecture, locates an XML parser that utilizes a novel Skeleton CAM-Based XML Parsing (SCBXP) technique in addition to an XPath processor and a high-performance matching engine. Moreover, the broker employs effective mechanisms for content-based routing, so as subscriptions, publications, and notifications are routed through the network based on content. The inherent reconfigurability feature of the broker’s hardware provides the system architecture with the capability of residing in any FPGA device of moderate logic density. Furthermore, such a system-on-chip architecture is upgradable, if any future hardware add-ons are needed. However, the current architecture is mature and can effectively be implemented on an ASIC device. Finally, this thesis presents and analyzes the experiments conducted on an FPGA prototype implementation of the proposed broker/router. The experiments tackle tests for the SCBXP alone and for two phases of development of the whole broker. The corresponding results indicate the high performance that the involved parsing, storing, matching, and routing processes can achieve.

Made available in DSpace on 2016-06-02T20:24:58Z (GMT). No. of bitstreams: 1 DissLFPSD.pdf: 801179 bytes, checksum: 757f280a7d8d89975af5d340fb81e2f2 (MD5) Previous issue date: 2007-03-16 / Financiadora de Estudos e Projetos / There are many foreign language teacher Education courses in Brazil which try to teach the pre-service teachers some language apart from theory studies and the practice needed to the professional development of these future teachers. We have seen that the theory and the classroom practice are almost always placed at the end of the courses in just some semesters. The language and literature course analyzed in this research tries to break with this tradition by using a different methodology which integrates aspects concerning theory studies and classroom practice through language studies (more specifically English). When adopting an innovative methodology to the Brazilian teacher education context, the course we propose to analyze brings many possibilities for research attempting to clarify the results in the usage of this methodology. Among other possibilities, this work focuses the students assessment. Through our personal experience in dealing with this course - since the researcher is a former English teacher of the course in study - we could notice a lot of questioning relating to the students assessment process. During the development of many competences in the course, we found some dilemmas in order to find assessment instruments and procedures which could serve to the integration proposed by the course. As a result, we invited three former teachers from the course to take part in this work in order to investigate how these teachers understood the methodology used in the course and how they performed the assessment process with their students. We have come to the conclusion that the assessment process is done intuitively and there is the need of developing a more appropriate assessment process for this context. We also try to define and characterize the methodology used in the course based on what has been developed in terms of learning-teaching theory. / Encontramos muitos cursos de licenciatura em Letras que buscam ensinar uma língua estrangeira aos alunos-futuros-professores separadamente dos estudos teóricos relacionados à formação profissional desses alunos, o que fica relegado a alguns semestres no final do curso. O curso de Letras analisado neste estudo tenta romper com essa tradição ao integrar os estudos e práticas necessários à formação profissional dos alunos-futurosprofessores com e por meio dos estudos em língua estrangeira (mais especificamente em língua inglesa). Ao buscar adotar uma metodologia de ensino inovadora ao contexto brasileiro para a formação de professores, o curso em questão proporciona várias possibilidades de estudo na tentativa de iluminar os resultados da utilização dessa metodologia. O estudo que este trabalho apresenta volta-se para o processo de avaliação desses alunos. Com a experiência pessoal do pesquisador, então professor de língua inglesa do curso analisado, houve a percepção dos questionamentos relacionados ao processo de avaliação dos alunos. Uma vez que várias competências são desenvolvidas durante o curso, alguns dilemas foram encontrados na busca por procedimentos e instrumentos que contemplassem a integração de competências no processo de avaliação. Então, convidamos três professoras que trabalharam no curso de Letras em questão para participarem desta pesquisa a fim de investigar como essas professoras entendiam a metodologia de ensino adotada no curso e como conceberam o processo de avaliação dos alunos. Constatamos que a avaliação é feita de forma intuitiva e existe a necessidade de desenvolvimento de um direcionamento mais adequado no processo de avaliação para o contexto estudado. Tentamos também caracterizar e definir a metodologia de ensino utilizada no curso com base no que já foi desenvolvido teoricamente para o processo de ensino-aprendizagem de línguas.

The dissemination of various types of data faces ongoing challenges with the growing need of accessing manifold information. Since the interest in content is what drives data networks, some new technologies and thoughts attempt to cope with these challenges by developing content-based rather than address-based architectures. The Publish/ Subscribe paradigm can be a promising approach toward content-based data dissemination, especially that it provides total decoupling between publishers and subscribers. However, in content-based publish/subscribe systems, subscriptions are expressive and the information is often delivered based on the matched expressive content - which may not deeply alleviate considerable performance challenges. This dissertation explores a hardware solution for disseminating data in content-based publish/subscribe systems. This solution consists of an efficient hardware architecture of an XML/XPath broker that can route information based on content to either other XML/XPath brokers or to ultimate users. A network of such brokers represent an overlay structure for XML content-based publish/subscribe data dissemination systems. Each broker can simultaneously process many XPath subscriptions, efficiently parse XML publications, and subsequently forward notifications that result from high-performance matching processes. In the core of the broker architecture, locates an XML parser that utilizes a novel Skeleton CAM-Based XML Parsing (SCBXP) technique in addition to an XPath processor and a high-performance matching engine. Moreover, the broker employs effective mechanisms for content-based routing, so as subscriptions, publications, and notifications are routed through the network based on content. The inherent reconfigurability feature of the broker’s hardware provides the system architecture with the capability of residing in any FPGA device of moderate logic density. Furthermore, such a system-on-chip architecture is upgradable, if any future hardware add-ons are needed. However, the current architecture is mature and can effectively be implemented on an ASIC device. Finally, this thesis presents and analyzes the experiments conducted on an FPGA prototype implementation of the proposed broker/router. The experiments tackle tests for the SCBXP alone and for two phases of development of the whole broker. The corresponding results indicate the high performance that the involved parsing, storing, matching, and routing processes can achieve.

This work addresses the need for an alternative to keyword-based search for sifting through large PDF medical journal article document collections for literature review purposes. Despite users' best efforts to form precise and accurate queries, it is often difficult to guess the right keywords to find all the related articles while finding a minimum number of unrelated ones. Failure during literature review to find relevant, related research results in wasted research time and effort in addition to missing significant work in the related area which could affect the quality of the research work being conducted. The purpose of this work is to explore the benefits of a retrieval system for professional journal articles in PDF format that supports hybrid queries composed of both text and images. PDF medical journal articles contain formatting and layout information that imply the structure and organization of the document. They also contain figures and tables rich with content and meaning. Stripping a PDF into “full-text” for indexing purposes disregards these important features. Specifically, this work investigated the following: (1) what effect the incorporation of a document's embedded figures into the query (in addition to its text) has on retrieval performance (precision) compared to plain keyword-based search; (2) how current text-based document-query similarity methods can be enhanced by using formatting and font-size information as a structure and organization model for a PDF document; (3) whether to use the standard Euclidean distance function or the matrix distance function for content-based image retrieval; (4) how to convert a PDF into a structured, formatted, reflowable XML representation given a pure-layout PDF document; (5) what document views (such as a term frequency cloud, a document outline, or a document's figures) would help users wade through search results to quickly select those that are worth a closer look. While the results of the experiments were unexpectedly worse than their baselines of comparison (see the conclusion for a summary), the experimental methods are very valuable in showing others what directions have already been pursued and why they did not work and what remaining problems need to be solved in order to achieve the goal of improving literature review through use of a hybrid text and image retrieval system.

Master of Science / Department of Computing and Information Sciences / William H. Hsu / A recommender system is a computational mechanism for information filtering, where users provide recommendations (in the form of ratings or selecting items) as inputs, which the system then aggregates and directs to appropriate recipients. With the advent of web based media and publicity methods, the age where standardized methods of publicity, sales, production and marketing strategies do not. As such, in many markets the users are given a wide range of products and information to choose which product they like, to find a way out of this recommender systems are used in a way similar to the live social scenario, that is a user tries to get reviews from friends before opting for a product in a similar way recommender system tries to be a friend who recommends the options. Most of the recommender systems currently developed solely accuracy driven, i.e., reducing the Mean Absolute Error (MAE) between the predictions of the recommender system and actual ratings of the user. This leads to various problems for recommender systems such as lack of diversity and freshness. Lack of diversity arises when the recommender system is overly focused on accuracy by recommending a set of items, in which all of the items are too similar to each other, because they are predicted to be liked by the user. Lack of freshness also arises with overly focusing on accuracy but as a limitation on the set of items recommended making it overly predictable. This thesis work is directed at addressing the issues of diversity, by developing an approach, where a threshold of accuracy (in terms of Mean Absolute Error in prediction) is maintained while trying to diversify the set of item recommendations. Here for the problem of diversity a combination of Attribute-based diversification and user preference based diversification is done. This approach is then evaluated using non-classical methods along with evaluating the base recommender algorithm to prove that diversification is indeed is possible with a mixture of collaborative and content based approach.

A flexible, scalable, and asynchronous middleware abstract is needed for business process management, which involves thousands of tasks and a large number of running instances of large business processes. The content-based publish/subscribe system is an ideal candidate to serve as enterprise service bus for these applications. In the publish/subscribe paradigm, information providers called publishers disseminate publications to all subscribers who have expressed interests by registering subscriptions through a loosely coupled interface. However, the traditional publish/subscribe paradigm only supports stateless subscriptions, that is, event correlation is ignored. Moreover, subscribers can only receive publications issued after their subscriptions. There are many application contexts, however, where access to publications from the past is necessary,such as for replaying a business process execution to debug it. Even more interesting uses arise when data from the past can be correlated with those in the future. Therefore, new languages and new functionalities are needed in the standard publish/subscribe model in order to support business process management. A new subscription language PADRES SQL(PSQL) which can express event patterns and unify both historic and future views for subscribers. PADRES allows a subscriber to access data published both in the past and in the future. Furthermore, complex event detection happens in the broker network. The main difficulties of distributed event detection are routing a composite subscription, including where and how to decompose the composite subscription, and routing the individual parts of the subscription. Our composite subscription routing decisions are based on a cost model which minimizes the routing and detection delay. An adaptive subscription routing protocol is proposed to determine efficient location with dynamic changing workloads. PADRES also provides robust message delivery by exploring alternative paths in a cyclic overlay. Routing optimizations and efficient matching algorithms are studied to improve the performance of the extended publish/subscribe model. With the above features, we propose the Ninos system, the distributed business process execution architecture as a case study,which uses light-weight activity agents to carry out business process execution in a distributed environment. Ninos proves that decentralized business process execution is the trend for next generation products, and the publish/subscribe model is ideal to serve as an enterpriser service bus (ESB) for distributed applications.