José Valdeni de Lima

A framework for awareness support in groupware systems

This paper introduces a framework for awareness support in groupware systems. Awareness gathers the group knowledge, its activities and its overall status. Awareness support is an important feature for groupware systems. It provides a context for individual contributions, improving these contributions and avoiding contradictory interactions among group members. Despite its importance, awareness support is not systematic and developers must build it from scratch for each new application. The framework presented here addresses this issue. This framework, called Big Watch (BW), intends to support groupware implementers to easily build past event awareness mechanisms. It has been designed to develop new groupware applications and to improve existing ones. This paper presents the features and the structure of BW, and describes two applications that use it.

Design and evaluation of a hypervideo environment to support veterinary surgery learning

In the search of alternative ways to learning veterinary surgery with live animals, hypervideo was considered a promising candidate as a learning tool. Video can enhance the realism and authenticity of a learning environment. By adding structure and interactivity to video, hypervideo allows to navigate video and to explore other related media to complement it. Hypervideo might then support the creation of a rich and realistic learning environment, through the interactive access, construction and communication of knowledge on veterinary surgery. In this paper, we present the design and evaluation of Hvet, a hypervideo environment to support learning of veterinary surgery. Design was based on cognitive and media theories, and evaluation was based on the use of Hvet by veterinary students, in order to test its efficacy in substitution of learning and training with live animals. Results support the hypothesis, showing the potential of hypervideo as a valuable and effective tool to support learning of surgery techniques and revealing the most appreciated design options.

Adaptivity Conditions Evaluation for the User of Hypermedia Presentations Built with AHA

The importance of adaptive hypermedia propelled the development of several authoring tools. Even though most tools are efficient for their designed task, they do not guarantee that the adaptivity is used in a high degree, in order to satisfy users with distinct goals, preferences, background and/or needs, as usual on the Web. In this paper we will present a system in development built to evaluate the adaptivity degree of presentations built into the AHA! authoring tool. The author, after build his presentation in AHA!, submits it to our system for evaluation. The results obtained from the evaluation can aid the author to know if the built presentation it is according to the proposed goals or the adaptivity degree should be increased.

Hardware integrated quantization solution for improvement of computational H.264 encoder module

The computational module of several MPEG-based video encoders, which includes the known algorithms of Discrete Cosine Transform, Hadamard Transform and Quantization, is widely used to identify and compress spatial redundancy in intra (raw input) or inter (computed residue) data pixel matrices. For some modern multimedia applications, like high definition (HD H.264/AVC) or scalable (H.264/SVC) encoder solutions, the demand for fast module implementations becomes critical. Practical experiments indicate that, inside a H.264 computational module, the quantization module normally represents a real bottleneck for fast hardware implementations. Considering that we propose a complete integrated solution of H.264 computational module, which incorporates the direct and inverse algorithms of Discrete Cosine Transform, Hadamard and Quantization with minimal communication delays. Also in this paper it is presented a practical study, considering distinct levels of parallelism for the quantization to demonstrate its influence in order to optimize global encoder complexity and performance. All proposed alternatives were designed using hardware description language VHDL and implemented into commercial FPGA boards to obtain experimental results.

Binary lexical relations for text representation in information retrieval

Text representation is crucial for many natural language processing applications. This paper presents an approach to extraction of binary lexical relations (BLR) from Portuguese texts for representing phrasal cohesion mechanisms. We demonstrate how this automatic strategy may be incorporated to information retrieval systems. Our approach is compared to those using bigrams and noun phrases for text retrieval. BLR strategy is shown to improve on the best performance in an experimental information retrieval system.

Adaptweb: um ambiente para ensino-aprendizagem adaptativo na Web

Este artigo, com enfase nos aspectos tecnicos, apresenta os resultados obtidos no âmbito dos projetos Electra e Adaptweb, voltados para a autoria e apresentacao adaptativa de disciplinas integrantes de cursos EAD na Web. O objetivo e permitir a adequacao de taticas e formas de apresentacao de conteudos para alunos de diferentes cursos de graduacao e com diferentes estilos de aprendizagem, possibilitando diferentes formas de apresentacao de cada conteudo, de forma adequada a cada curso e as preferencias individuais dos alunos participantes. Esta proposta foi validada atraves de um estudo de caso real, envolvendo a disciplina de Metodos Numericos da Universidade Estadual de Londrina (UEL). Esta disciplina e oferecida para tres cursos universitarios: Matematica, Engenharia e Ciencia da Computacao. Em cada curso, o professor-autor configura uma sequencia de conceitos, com seus respectivos niveis de profundidade, bem como exemplos, exercicios e materiais complementares apropriados. Os alunos podem utilizar diferentes estilos de aprendizagem atraves da selecao do modo de navegacao e dos estilos de apresentacao. Os aspectos de adaptabilidade navegacional incluem navegacao em modo tutorial ou livre, oferecendo diferentes alternativas de taticas de ensino. O ambiente completo para autoria e apresentacao de cursos encontra- se atualmente disponivel na fase de prototipo operacional. Este prototipo esta sendo incorporado na plataforma de EAD em software livre da Universidade Federal do Rio Grande do Sul (UFRGS). O ambiente esta baseado em um conjunto de componentes que suportam as fases de pre-autoria, adaptacao de conteudo e navegacao. A implementacao utiliza primordialmente a linguagem de programacao PHP, o gerenciador de banco de dados MySQL e a linguagem XML. Adaptweb: a teaching-learning environment adaptable in Web Abstract This article, which emphasizes the technical aspects, presents the results obtained within the ambit of Electra and Adaptweb projects, applied to the authorship and the adaptable presentation of the disciplines that compound the courses EAD in the Web. The aim is to allow the adequacy of tactics and ways to present the contents to the students from different graduation courses and with different learning styles, enabling different ways of presenting each one of the contents, adjusting it to each course and to the individual preferences of the participating students. This proposal was validated through a real case study, involving the Numeric Methods discipline at the State University of Londrina (UEL). This discipline is offered to three university courses: Mathematics, Engineering and Computer Science. In each course, the author-professor sets a sequence of concepts, with their respective levels of complexity, as well as with their respective examples, exercises and suitable complementary materials. The students may use different learning styles through the selection of the navigation way and of the presentation styles. The navigational adjustment aspects include navigation in a tutorial or in a free way, offering different alternatives of teaching tactics. The complete environment for the authorship and presentation of courses is available at the present moment at the phase of operational prototype. This prototype is being incorporated to the platform of EAD into some free software from the Federal University of Rio Grande do Sul (UFRGS). The environment is based on a set of components that back up the pre-authorship, adaptation of content and navigation phases. The implementation primordially uses the language of PHP programming, the database carrier MySOL and the XML language.

Subjective video quality assessment applied to scalable video coding and transmission instability

This paper presents a study of subjective quality of scalable video sequences, coded using the scalable extension of the H.264 standard (SVC). A group of experiments was performed to measure, primarily, the effects that the transmission instability has in the video quality and the relationship between the three scalability methods (spatial, temporal and quality) in terms of subjective quality. The decisions taken to model the tests were based on layered transmission systems that use protocols for adaptability and congestion control. To run the subjective assessments we used the ACRHRR methodology and recommendations given by ITU-R Rec. BT.500 and ITU-T Rec. P.910. The results show that the instability modeled does not cause signifficant alterations on the overall video quality when compared to a stable video and that temporal scalability usually produces videos with worse quality than spatial and quality scalabilities, the latter being the one with the better quality.

Tools for nominalization: an alternative for lexical normalization

The recognition of morphological variation and conceptual proximity of the words is crucial for tasks where the lexical normalization is used, such as term generation and matching in an information retrieval environment. We present tools that automatically perform nominalization for lexical normalization in Portuguese. Comparing the effects of three alternative strategies (stemming, lemmatizing, and our proposal: nominalization), we demonstrate through an experimental evaluation that nominalization, as lexical normalization, contributes to the performance improvement in a probabilistic information retrieval approach for Portuguese.

The SPIDERobot: A Cable-Robot System for On-site Construction in Architecture

The use of robots in architectural construction has been a research field since the 1980s. Driven by both productive and creative concerns, different systems have been devised based on large-scale robotic structures, mobile robotic units or flying robotic vehicles. By analyzing these approaches and discussing their advantages and limitations, this paper presents an alternative strategy to automate the building construction processes in on-site scenarios. The SPIDERobot is a cable-robot system developed to perform assembly operations, which is driven by a specific Feedback Dynamic Control System (FDCS) based on a vision system. By describing and illustrating this research work, the authors argue about the advantages of this cable robot system to deal with the complexity and the scale of building construction in architecture.

Robust Robot Localization Based on the Perfect Match Algorithm

Self-localization of a robot in an indoor plant is one of the most important requirement in mobile robotics. This paper addresses the application and improvement of a well known localization algorithm used in Robocup Midsize league competition in real service and industrial robots. This new robust approach is based on modeling the quality of several measures and minimizing the maching error. The presented innovative work applies the robotic football knowledge to other fields with high accuracy. Real and simulated results allow to validate the proposed methodology.