Transputer control of a Puma 560 robot via the virtual bus

The robot control problem is discussed with regard to controller implementation on a multitransputer array. Some high-performance aspects required of such controllers are described, with particular reference to robot force control. The implications for the architecture required for controllers based on computed torque are discussed and an example is described. The idea of treating a transputer array as a virtual bus is put forward for the implementation of fast real-time controllers. An example is given of controlling a Puma 560 industrial robot. Some of the practical considerations for using transputers for such control are described.

Distortion in Distributed Virtual Environments

This paper proposes a solution to the problems associated with network latency within distributed virtual environments. It begins by discussing the advantages and disadvantages of synchronous and asynchronous distributed models, in the areas of user and object representation and user-to-user interaction. By introducing a hybrid solution, which utilises the concept of a causal surface, the advantages of both synchronous and asynchronous models are combined. Object distortion is a characteristic feature of the hybrid system, and this is proposed as a solution which facilitates dynamic real-time user collaboration. The final section covers implementation details, with reference to a prototype system available from the Internet.

A Web Map Service implementation for the visualization of multidimensional gridded environmental data

We describe ncWMS, an implementation of the Open Geospatial Consortium’s Web Map Service (WMS) specification for multidimensional gridded environmental data. ncWMS can read data in a large number of common scientific data formats – notably the NetCDF format with the Climate and Forecast conventions – then efficiently generate map imagery in thousands of different coordinate reference systems. It is designed to require minimal configuration from the system administrator and, when used in conjunction with a suitable client tool, provides end users with an interactive means for visualizing data without the need to download large files or interpret complex metadata. It is also used as a “bridging” tool providing interoperability between the environmental science community and users of geographic information systems. ncWMS implements a number of extensions to the WMS standard in order to fulfil some common scientific requirements, including the ability to generate plots representing timeseries and vertical sections. We discuss these extensions and their impact upon present and future interoperability. We discuss the conceptual mapping between the WMS data model and the data models used by gridded data formats, highlighting areas in which the mapping is incomplete or ambiguous. We discuss the architecture of the system and particular technical innovations of note, including the algorithms used for fast data reading and image generation. ncWMS has been widely adopted within the environmental data community and we discuss some of the ways in which the software is integrated within data infrastructures and portals.

Cognitive and environmental factors influencing the process of spatial knowledge acquisition within virtual reality environments

As the fidelity of virtual environments (VE) continues to increase, the possibility of using them as training platforms is becoming increasingly realistic for a variety of application domains, including military and emergency personnel training. In the past, there was much debate on whether the acquisition and subsequent transfer of spatial knowledge from VEs to the real world is possible, or whether the differences in medium during training would essentially be an obstacle to truly learning geometric space. In this paper, the authors present various cognitive and environmental factors that not only contribute to this process, but also interact with each other to a certain degree, leading to a variable exposure time requirement in order for the process of spatial knowledge acquisition (SKA) to occur. The cognitive factors that the authors discuss include a variety of individual user differences such as: knowledge and experience; cognitive gender differences; aptitude and spatial orientation skill; and finally, cognitive styles. Environmental factors discussed include: Size, Spatial layout complexity and landmark distribution. It may seem obvious that since every individual's brain is unique - not only through experience, but also through genetic predisposition that a one size fits all approach to training would be illogical. Furthermore, considering that various cognitive differences may further emerge when a certain stimulus is present (e.g. complex environmental space), it would make even more sense to understand how these factors can impact spatial memory, and to try to adapt the training session by providing visual/auditory cues as well as by changing the exposure time requirements for each individual. The impact of this research domain is important to VE training in general, however within service and military domains, guaranteeing appropriate spatial training is critical in order to ensure that disorientation does not occur in a life or death scenario.

Using virtual environments for trigger identification in addiction treatment

This paper presents a novel application of virtual environments to assist in encouraging behavior change in individuals who misuse drugs or alcohol. We describe the user-centered design of a series of scenes to engage users in the identification of triggers and to encourage discussions about relevant coping skills. Results from the initial testing of this application with six service users showed variation in user responses. Results also suggested that the system should encourage group discussion and that it was linked to a small improvement in users’ confidence in understanding and identifying triggers.

O mercado fonográfico no Brasil: alterações nas relações de poder a partir do desenvolvimento tecnológico e da pirataria virtual

The phonographic market has experienced a period of significant change caused by technological evolution. This phenomenon of global proportions has been the subject of considerable debate in the media and in academia. The entry of new actors, as well as piracy and new forms of commercialization of musical products, has significantly altered the relationships of power existing in this field. Therefore, the scope of this article is to analyze the phonographic industry in Brazil as an arena of forces and power struggles, based on notions of the field of cultural production, from the perspective of Bourdieu. This study constitutes a qualitative research and data was analyzed using a descriptiveinterpretative approach. In the case of the sector under scrutiny, and on the basis of the theoretical reference material, it would appear to be correct to affirm that economic capital is what is being sought on the part of the actors who comprise the field. Nevertheless, it is important to stress that the critical incidents that brought about the changes in the structure of the field over the course of time were predominantly of a technological nature. The field of the Brazilian phonographic market is currently experiencing a period of structural alteration that was especially affected by the development of MP3 technology and the emergence of virtual piracy. The fact is that formerly the major recording companies dominated the market and had the necessary resources of power to exercise their role as dominant actors and maintain this position. However, the aforementioned factors favored the entry of new actors in the field and the empowerment of those that prior to this time did not have the resources to compete against this domination.

Implantação de tecnologia de monitoramento remoto para e-service: um estudo exploratório

The purpose of this study is to define measures to increase customer satisfaction and company competitiveness using a remote monitoring technology, in an exploratory study of Alpha Elevator Company (nick name chosen to the company by the actor of the dissertation). Regarding the competitive market, the service industry is striving to achieve productivity, following the example of the manufacturing industry. Nevertheless, these efforts are limited by the amount of hours worked per week, month or year, since the sector charges its services based on the hours spent working on the equipment of the client or based on the numbers of visits. This study is based in the overcoming of the traditional paradigm of selling number of hours by a system of selling results and performance. Employing a remote monitoring system, the elevators under the company service are monitored continually and defects are detected and transmitted to the customer care center, via phone line. The customers can access this data through the Internet and obtain information like availability rate of their elevators and call back response time rate, besides being able to buy products on the company¿s home page and to send feedback. The results were obtained by participating in conferences among experts of the company, in Japan and the United States. Through the analysis of the business environment and based on the bibliographic reference, a strategy was developed to implement e-service as a competitive differentiation.

Aceitação e uso de ambiente virtual de aprendizagem no contexto de um curso de capacitação para servidores públicos

This study aimed to examine how students perceives the factors that may influence them to attend a training course offered in the distance virtual learning environment (VLE) of the National School of Public Administration (ENAP). Thus, as theoretical basis it was used the Unified Theory of Acceptance and Use of Technology (UTAUT), the result of an integration of eight previous models which aimed to explain the same phenomenon (acceptance/use of information technology). The research approach was a quantitative and qualitative. To achieve the study objectives were made five semi-structured interviews and an online questionnaire (websurvey) in a valid sample of 101 public employees scattered throughout the country. The technique used to the analysis of quantitative data was the structural equation modeling (SEM), by the method of Partial Least Square Path Modeling (PLS-PM). To qualitative data was the thematic content analysis. Among the results, it was found that, in the context of public service, the degree whose the individual believes that the use of an AVA will help its performance at work (performance expectancy) is a factor to its intended use and also influence its use. Among the results, it was found that the belief which the public employee has in the use of a VLE as a way to improve the performance of his work (performance expectation) was determinant for its intended use that, in turn, influenced their use. It was confirmed that, under the voluntary use of technology, the general opinion of the student s social circle (social influence) has no effect on their intention to use the VLE. The effort expectancy and facilitating conditions were not directly related to the intended use and use, respectively. However, emerged from the students speeches that the opinions of their coworkers, the ease of manipulate the VLE, the flexibility of time and place of the distance learning program and the presence of a tutor are important to their intentions to do a distance learning program. With the results, it is expected that the managers of the distance learning program of ENAP turn their efforts to reduce the impact of the causes of non-use by those unwilling to adopt voluntarily the e-learning, and enhance the potentialities of distance learning for those who are already users

Proposta de uma ferramenta de visualização e realidade virtual para o monitoramento de tráfego de redes de computadores

Pós-graduação em Ciência da Computação - IBILCE

A cultura e o ensino de língua estrangeira: perspectivas para a formação continuada no projeto Teletandem Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A formação inicial do professor de línguas no e para o contexto virtual e a construção de comunidades de prática

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A load-balancing spare capacity reallocation approach in service-rich SONET metro mesh networks

The next-generation SONET metro network is evolving into a service-rich infrastructure. At the edge of such a network, multi-service provisioning platforms (MSPPs) provide efficient data mapping enabled by Generic Framing Procedure (GFP) and Virtual Concatenation (VC). The core of the network tends to be a meshed architecture equipped with Multi-Service Switches (MSSs). In the context of these emerging technologies, we propose a load-balancing spare capacity reallocation approach to improve network utilization in the next-generation SONET metro networks. Using our approach, carriers can postpone network upgrades, resulting in increased revenue with reduced capital expenditures (CAPEX). For the first time, we consider the spare capacity reallocation problem from a capacity upgrade and network planning perspective. Our approach can operate in the context of shared-path protection (with backup multiplexing) because it reallocates spare capacity without disrupting working services. Unlike previous spare capacity reallocation approaches which aim at minimizing total spare capacity, our load-balancing approach minimizes the network load vector (NLV), which is a novel metric that reflects the network load distribution. Because NLV takes into consideration both uniform and non-uniform link capacity distribution, our approach can benefit both uniform and non-uniform networks. We develop a greedy loadbalancing spare capacity reallocation (GLB-SCR) heuristic algorithm to implement this approach. Our experimental results show that GLB-SCR outperforms a previously proposed algorithm (SSR) in terms of established connection capacity and total network capacity in both uniform and non-uniform networks.

Studies on the Helminth Fauna of Alaska. XIII. Disease in the Sea Otter, with Special Reference to Helminth Parasites

During the spring of 1951, the U. S. Fish and Wildlife Service undertook the removal of sea otter, Enhydra lutris (L)., from the Aleutian Island of Amchitka, for the purpose of restocking range from which the animals have long been exterminated. The decision to undertake this activity was influenced by the nature of military operations planned for the island later the same year. The capture and removal of the otter were under the supervision of Mr. Robert D. Jones, Biologist, U. S. Fish and Wildlife Service. Heavy losses among the animals shortly after capture made the venture unsuccessful. Many deaths were concurrent among animals in the wild state. The writer was asked to investigate the causes of disease in the sea otter, and it is the purpose of this paper to report the results of these investigation, with special reference to helminth parasites.

Diseño e instalación de un servicio web de tienda virtual en alta disponibilidad

[ES]Diseño e instalación de un servicio web de tienda virtual en un entorno de computación en clúster para proporcionar alta disponibilidad y balanceo de carga del mencionado servicio. La infraestructura requerida para este despliegue será virtual, utilizándose como plataforma de virtualización KVM. Las tareas se organizan en : 1.Tareas para la creación de un clúster de balanceo de carga donde una máquina será la encargada de recibir las peticiones de los clientes y de redirigirlas a los servidores web según la carga de éstos. 2. Tareas para la creación de un clúster de alta disponibilidad para que en caso de fallo siempre haya un servidor de base de datos que pueda atender a las peticiones de los servidores web.

Evolutionary tendencies in flowers of Marantaceae with special reference to the style movement mechanism

One of the quickest plant movements ever known is made by the ´explosive´ style in Marantaceae in the service of secondary pollen presentation – herewith showing a striking apomorphy to the sister Cannaceae that might be of high evolutionary consequence. Though known already since the beginning of the 19th century the underlying mechanism of the movement has hitherto not been clarified. The present study reports about the biomechanics of the style-staminode complex and the hydraulic principles of the movement. For the first time it is shown by experiment that in Maranta noctiflora through longitudinal growth of the maturing style in the ´straitjacket´ of the hooded staminode both the hold of the style prior to its release and its tensioning for the movement are brought about. The longer the style grows in relation to the enclosing hooded staminode the more does its capacity for curling up for pollen transfer increase. Hereby I distinguish between the ´basic tension´ that a growing style builds up anyway, even when the hooded staminode is removed beforehand, and the ´induced tension´ which comes about only under the pressure of a ´too short´ hooded staminode and which enables the movement. The results of these investigations are discussed in view of previous interpretations ranging from possible biomechanical to electrophysiological mechanisms. To understand furthermore by which means the style gives way to the strong bending movement without suffering outwardly visible damage I examined its anatomical structure in several genera for its mechanical and hydraulic properties and for the determination of the entire curvature after release. The actual bending part contains tubulate cells whose walls are extraordinarily porous and large longitudinal intercellular spaces. SEM indicates the starting points of cell-wall loosening in primary walls and lysis of middle lamellae - probably through an intense pectinase activity in the maturing style. Fluorescence pictures of macerated and living style-tissue confirm cell-wall perforations that do apparently connect neighbouring cells, which leads to an extremely permeable parenchyma. The ´water-body´ can be shifted from central to dorsal cell layers to support the bending. The geometrical form of the curvature is determined by the vascular bundles. I conclude that the style in Marantaceae contains no ´antagonistic´ motile tissues as in Mimosa or Dionaea. Instead, through self-maceration it develops to a ´hydraulic tissue´ which carries out an irreversible movement through a sudden reshaping. To ascertain the evolutionary consequence of this apomorphic pollination mechanism the diversity and systematic value of hooded staminodes are examined. For this hooded staminodes of 24 genera are sorted according to a minimalistic selection of shape characters and eight morphological types are abstracted from the resulting groups. These types are mapped onto an already available maximally parsimonious tree comprising five major clades. An amazing correspondence is found between the morphological types and the clades; several sister-relationships are confirmed and in cases of uncertain position possible evolutionary pathways, such as convergence, dispersal or re-migration, are discussed, as well as the great evolutionary tendencies for the entire family in which – at least as regards the shape of hooded staminodes – there is obviously a tendency from complicated to strongly simplified forms. It suggests itself that such simplifying derivations may very likely have taken place as adaptations to pollinating animals about which at present too little is known. The value of morphological characters in relation to modern phylogenetic analysis is discussed and conditions for the selection of morphological characters valuable for a systematic grouping are proposed. Altogether, in view of the evolutionary success of Marantaceae compared with Cannaceae the movement mechanism of the style-staminode complex can safely be considered a key innovation within the order Zingiberales.