Variations in physiological responses of participants during different stages of an immersive virtual environment experiment

This paper presents a study of the fine grain physiological responses of participants to an immersive virtual simulation of an urban environment. The analysis of differences in participant responses at various stages of the experiment (baseline recordings, training, first half and second half of the urban simulation) are examined in detail. It was found that participants typically show a stress response during the training phase and a stress response towards the end of the simulation of the urban experience.There is also some evidence that variations in the level of visual realism based the texture strategy used was associated with changes in mental stress. Copyright 2006 ACM

Inventário de Dicksonia sellowiana Hook. em Santa Catarina.

(Inventário de Dicksonia sellowiana Hook. em Santa Catarina). A intensa exploração comercial de Dicksonia sellowiana a deixaram na categoria de ameaçada de extinção, sendo incluída na lista brasileira de espécies da flora ameaçada de extinção. Por isso, o presente trabalho visa apresentar o estudo da distribuição das populações de D. sellowiana para apontar os locais de maior ocorrência da espécie em Santa Catarina, e avaliar a relação da densidade populacional com fatores ambientais, como altitude e clima. Foram instaladas 225 unidades amostrais, com 4.000 m2 nas regiões do planalto e oeste catarinense, baseadas na grade de 10 km x 10 km conforme procedimento do Inventário Florístico Florestal de Santa Catarina. Nestas 225 unidades amostrais, D. sellowiana foi encontrada em 94, com variação de um a 391 indivíduos. A grande densidade da espécie em áreas mais elevadas (superiores a 1.000 m) está relacionada com os dados climáticos que influenciam a população diretamente, apontados pelo Critério de Informação de Akaike corrigido, ou seja, a altitude e a variação de temperatura que ela provoca. Observou-se também, que a espécie apresenta maior concentração da população nos menores intervalos de altura e diâmetro, chegando a elevadas densidades com até 977 indivíduos/ha em algumas áreas. As informações obtidas pelo inventário sobre esta espécie possibilitam indicar medidas de conservação para a espécie, como área a serem conservadas e apoio a produtores rurais

Structure of mixed ombrophyllous forests with Araucaria angustifolia (Araucariaceae) under external stress in Southern Brazil.

This study is part of the Floristic and Forest Inventory of Santa Catarina, conceived to evaluate forest resources, species composition and structure of forest remnants, providing information to update forest conservation and land use policy in Southern Brazilian State of Santa Catarina (95 000km²). In accordance to the Brazilian National Forest Inventory (IFN-BR), the inventory applies systematic sampling, with 440 clusters containing four crosswise 1 000m² plots (20x50m) each, located on a 10x10km grid overlaid to land use map based on classification of SPOT-4 images from 2005. Within the sample units, all woody individuals of the main stratum (DBH?10cm) are measured and collected (fertile and sterile), if not undoubtedly identified in field. Regeneration stratum (height>1.50m; DBH<10cm) is registered in 100m² in each sample unit. Floristic sampling includes collection of all fertile trees, shrubs and herbs within the sample unit and in its surroundings. This study performs analysis based on 92 clusters measured in 2008 within an area of 32 320km² of mixed ombrophyllous forests with Araucaria angustifolia located at the state’s high plateau (500m to 1 560m above sea level at 26º00’-28º30’ S and 49º13’-51º23’ W). Mean density (DBH?10cm) is 578 individuals/ha (ranging from 85/ha to 1 310/ha), mean species richness in measured remnants is 35 (8 to 62), Shannon and Wiener diversity index (H’) varies between 1.05 and 3.48. Despite high total species diversity (364 Magnoliophyta, five Coniferophyta and one tree fern) and relatively high mean basal area (25.75m²/ha, varying from 3.87 to 68.85m²/ ha), the overwhelming majority of forest fragments are considered highly impacted and impoverished, mostly by logging, burning and extensive cattle farming, turning necessary more efficient protection measures. Basal area was considered an appropriate indicator for stand quality and conservation status

Virtual social multimedia streaming with a novel haptic device

none4In the last decade, the technology of multitouch displays has reached a level of maturity that has given new life to virtual reality environments and has introduced in the mass market Graphical User Interfaces previously depicted in SCIFI literature. Three dimensional and stereoscopic displays are moving into mass market and users are getting accustomed to such concepts. This has sparked a new wave of interest in the public and we are now surrounded by several devices that allow the user to experience visuals that were not even thinkable a few years ago. On the other side, devices that allow users to actively interact with the environment are still cumbersome and expensive and not on a par with the evolution of display technologies. In this paper, we introduce a virtual reality application allowing users to stream and share multimedia contents like TV channels, web radio an others. Furthermore we introduce a wireless, light and small vibrotactile haptic device that allows users to interact with the various objects in the virtual scene, increasing the interaction feeling resulting in a more involving experience.noneMarco Gaudina; Andrea Brogni; Mauro Migliardi; Darwin CaldwellMarco, Gaudina; Andrea, Brogni; Migliardi, Mauro; Darwin, Caldwel

Application of Filtering Strategies to Multiple Sclerosis Tremor

Intention tremor severely compromises everyday life tasks in patients suffering from Multiple Sclerosis or Parkinson's disease. We report the result of our investigation on the properties of Multiple Sclerosis tremor. We analysed the case of handwriting and the effects of filtering tremor with proper numerical systems. An index for the evaluation of movements has been proposed, its properties have been verified with healthy users and used for evaluating efficiency of filtering on Multiple Sclerosis patients. The achieved results have been applied in the development of some technological aids for assisting therapist and patients in their work/lif