Particle competition and cooperation to prevent error propagation from mislabeled data in semi-supervised learning

Semi-supervised learning is applied to classification problems where only a small portion of the data items is labeled. In these cases, the reliability of the labels is a crucial factor, because mislabeled items may propagate wrong labels to a large portion or even the entire data set. This paper aims to address this problem by presenting a graph-based (network-based) semi-supervised learning method, specifically designed to handle data sets with mislabeled samples. The method uses teams of walking particles, with competitive and cooperative behavior, for label propagation in the network constructed from the input data set. The proposed model is nature-inspired and it incorporates some features to make it robust to a considerable amount of mislabeled data items. Computer simulations show the performance of the method in the presence of different percentage of mislabeled data, in networks of different sizes and average node degree. Importantly, these simulations reveals the existence of the critical points of the mislabeled subset size, below which the network is free of wrong label contamination, but above which the mislabeled samples start to propagate their labels to the rest of the network. Moreover, numerical comparisons have been made among the proposed method and other representative graph-based semi-supervised learning methods using both artificial and real-world data sets. Interestingly, the proposed method has increasing better performance than the others as the percentage of mislabeled samples is getting larger. © 2012 IEEE.

Fuzzy community structure detection by particle competition and cooperation

Identification and classification of overlapping nodes in networks are important topics in data mining. In this paper, a network-based (graph-based) semi-supervised learning method is proposed. It is based on competition and cooperation among walking particles in a network to uncover overlapping nodes by generating continuous-valued outputs (soft labels), corresponding to the levels of membership from the nodes to each of the communities. Moreover, the proposed method can be applied to detect overlapping data items in a data set of general form, such as a vector-based data set, once it is transformed to a network. Usually, label propagation involves risks of error amplification. In order to avoid this problem, the proposed method offers a mechanism to identify outliers among the labeled data items, and consequently prevents error propagation from such outliers. Computer simulations carried out for synthetic and real-world data sets provide a numeric quantification of the performance of the method. © 2012 Springer-Verlag.

AR | RA: a arte na realidade aumentada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reconstrução e geração de malhas em estruturas biomecânicas tridimensionais para análise por elemento finitos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Design de produtos virtuais e transdisciplinaridade: cibercepção e construção de objetos em Second Life : um estudo acerca do design de relações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da mobilidade, força, fadiga muscular e medo de quedas em idosas não caidoras e caidoras submetidas a um programa de exercício de fortalecimento muscular e equilíbrio

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Effects of strength and balance training on the mobility, fear of falling and grip strength of elderly female fallers

The aim of this study was to evaluate the effects of virtual reality and strength training on the balance, fear of falling and handgrip strength of older women with a history of falls. The fear of falling, mobility and grip strength were evaluated in 11 elderly fallers (72.4 ± 5.2 years). The faller group was submitted to 12 weeks of virtual reality and muscle strength training. The results showed improvement in mobility (p = 0.0004) and in the fear of falling (p = 0.002). No significant difference was observed for hand grip strength. It can be concluded that virtual reality and muscle strength interventions are beneficial for mobility and fear of falling in older women with a history of falls.

Desenvolvimento de aplicações Web com base em modelagem 3D: módulo portal Web

This paper presents the development of a Web application called CityFreedom based on 3D modeling. The developed system demonstrates the use of most revolutionary and innovative techniques to create Web portals with the integrated 3D navigation scenarios to their own pages, without requiring any kind of plug-ins or external software. Everything works on the basis of compatible browsers. The CtyFreedom aims to give the user the feeling of immersion in virtual reality so get to interact with a three-dimensional city in order to see new places, traveling in an area of town that has always thought of knowing or even analyze establishments long before attend-them. It's the freedom to know and traveling around the city in a simple and trivial way. It is a new trend, the future of Web systems development

Museu e suas tipologias: o webmuseu em destaque

The rapid development of Information and Communication Technologies - TIC, coupled with the advancement of the global Internet computer network have framed new concepts and definitions such as virtual reality, immersive environments, webmuseums, digital museums, electronic art, cyber art, among other terminologies that are becoming more and more common and are present in everyday Web users. To better understand the terminologies used to describe museum in the virtual environment, we present a summarized table of terms such as webmuseum, virtual museum, digital museum and their derivatives in order to define the elements that differentiate or resemble them. We used the bibliographic descriptive method for identifying the concepts presented by some expert authors in the field. In conclusion, we recommend the use of the term webmuseum for museums in cyberspace as the most appropriate and we define the concept, comprehending its meaning and characteristics.

Uma metodologia para a geração de conteúdos digitais baseado na utilização de estudios virtuais com realidade aumentada

Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

Física no futebol: objeto de aprendizagem gamificado para o ensino de física em mídias digitais por meio do esporte a partir do edutretenimento

Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

Realidade misturada: conceitos, ferramentas e aplicações

The Mixed Reality proposes scenes combining between virtual and real worlds offering to the user an intuitive way of interaction according to a specific application. This tutorial paper aims at presenting the fundamentals concepts of this emergent kind of human-computer interface.

Teacher-learning process based on an immersive and interactive environment

This paper explores the benefits of using immersive and interactive multiprojection environments (CAVE) to visualize molecules, and how it improves users’ understanding. We have proposed and implemented a tool for teachers to manipulate molecules and another to edit molecules and assist students at home. The contribution of the present research project are these tool that allows investigating structures, properties and dynamics of a molecular system which are extremely complex and comprises millions of atoms. The experience is enriched through multimedia information associated with parts of the model; for example, videos and text can be linked to specific molecule, demonstrating some detail. This solution is based on a teaching-learning process.

O uso das redes sociais online nas interações de produtores e receptores de televisão

This paper discusses the possibility of receiver’s participation in the production of television content mediated by online social networks. Buoyed by media convergence, this research demonstrates how the receiver has been working in online digital media such as TV can take advantage of the specific interaction between the medias to promote the creation of collaborative content, in which the user of social network may interfere the result of the product developed, becoming a new mediatic protagonist. Tool not so used for the production of television that slowly begins to enter the virtual reality, the forging of this new compose process would not only entertain the receiver, but also enrich the language and content television constantly criticized. This study shows the influence of the television medium in which is discussed online, the attitude still shy of the user in content production, and discusses the potential of social networks as a channel of communication between producers and receivers. This work is structured from the definition of social network, in addition to conducting the study what kind of interaction between TV and online social networks is practiced today. Finally, debate whether the potential interaction between TV and social networks is used to its fullest.

Inovações tecnológicas e contexto escolar: reflexões necessárias

In modern society technologies have played an important space exerting influences in different spheres. Today's young people are born immersed in the digital and virtual reality, which has changed the ways of learning, as well as to relate to the world. All this context has intensified the debate on the potential of ICT in education and training means. In this study, we sought to investigate the teachers' vision of ICT in the school environment, how they are being incorporated into the school and the limits and possibilities of the use of ICT in the learning process. Questionnaires were administered to 150 teachers who teach in high school in the state network of São Paulo teaching, but specifically in Piracicaba. Continuing, semi-structured interviews with a group of 8 directors were carried out so that there was a deepening on the issues raised by teachers in the questionnaire. The research brought to light important issues for discussion and referral measures striving to support public policies of integration of ICT in schools. Teachers spoke about the advantages and disadvantages of their use and the process of integration. It was observed that, despite efforts to implementation, there are still problems with infrastructure of schools, teacher training and working conditions