Route planning in a four-dimensional environment

Robots must be able to function in the real world. The real world involves processes and agents that move independently of the actions of the robot, sometimes in an unpredictable manner. A real-time integrated route planning and spatial representation system for planning routes through dynamic domains is presented. The system will find the safest most efficient route through space-time as described by a set of user defined evaluation functions. Because the route planning algorthims is highly parallel and can run on an SIMD machine in O(p) time (p is the length of a path), the system will find real-time paths through unpredictable domains when used in an incremental mode. Spatial representation, an SIMD algorithm for route planning in a dynamic domain, and results from an implementation on a traditional computer architecture are discussed

Community building and virtual teamwork in an online learning environment

In the world of OTIS, an online Internet School for occupational therapists, students from four European countries were encouraged to work collaboratively through problem based learning by interacting with each other in a virtual semi-immersive environment. This paper aims to explore the issues that there was little interaction between students from different tutorial groups and virtual teamwork developed in each of the cross cultural tutorial groups. Synchronous data from European students was captured during tutorial sessions and peer booked meetings and evidence suggests that communities of interest were established. It is possible to conclude that collaborative systems can be designed, which encourage students to build trust and teamwork in a cross cultural online learning environment. </p

Uma sonda de calor transiente controlada por computador para medir fluxo de fluido em meios porosos.

Uma sonda de calor transiente controlada por computador foi desenvolvida para medir fluxo em meios porosos. O sistema e operado automaticamente com o auxilio de uma placa de computador e basicamente composto de um sensor do tipo sonda-termistor, uma fonte de corrente eletrica constante de dois niveis, um conversor de sinal analogicos para digital, um transistor de efeito de campo e um conjunto de amplificadores operacionais. A sonda e alternadamente comutada entre dois modulos de operacao, alta e baixa potencia. Um programa foi desenvolvido para solicitar ao usuario os tempos para controlar o termistor e permitir os registros de identificacao do local, data, horario e dados para posicoes especificas da memoria. Os principios, a concepcao, a montagem e o funcionamento de toda a instrumentacao sao descritos. O sistema foi testado e avaliado em dois diferentes meios porosos. Resultados indicaram que o termistor aquecido e capaz de detectar o fluxo de fluido uma vez que sua resposta termica transiente foi afetada pela taxa de fluxo local

Thermoelectric transport of perfectly conducting channels in two- and three-dimensional topological insulators

Topological insulators have gapless edge/surface states with novel transport properties. Among these, there are two classes of perfectly conducting channels which are free from backscattering: the edge states of two-dimensional topological insulators and the one-dimensional states localized on dislocations of certain three-dimensional topological insulators. We show how these novel states affect thermoelectric properties of the systems and discuss possibilities to improve the thermoelectric figure of merit using these materials with perfectly conducting channels.Comment: 10 pages, 6 figures, proceedings for The 19th International Conference on the Application of High Magnetic Fields in Semiconductor Physics and Nanotechnology (HMF-19

Sigmoid Neural Transfer Function Realised by Percolation

An experiment using the phenomenon of percolation has been conducted to demonstrate the implementation of neural functionality (summing and sigmoid transfer). A simple analog approximation to digital percolation is implemented. The device consists of a piece of amorphous silicon with stochastic bit-stream optical inputs, in which a current percolating from one end to the other defines the neuron output, also in the form of a stochastic bit stream. Preliminary experimental results are presented

Learning from the experts: enabling and studying DIY development of location-based visitor experiences

In this paper we show how -- with the aid of enabling technology -- creative Location Based Experiences can be developed for visitors by non-technical professionals from the cultural heritage sector. We look at how these "Place Experts" approach and adopt web technologies to create and publish experiences including the roles they take on, the processes they adopt, and the way they appropriate the technology. We describe our short and long-term research engagements with the cultural heritage sector over the last three years and introduce Wander Anywhere, the website developed to enable this research. We find that place experts typically follow a four stage process in their engagement with location-based experiences, moving from comprehension to translation, development and finally approval. We suggest implications for the processes and technologies that might be employed by others seeking to support a similar type of engagement

Paedophiles in the community: inter-agency conflict, news leaks and the local press

This article explores the leaking of confidential information about secret Home Office plans to house convicted paedophiles within a local community (albeit inside a prison). It argues that a politics of paedophilia has emerged in which inter-agency consensus on the issue of ‘what to do’ with high-profile sex offenders has broken down. Accordingly, the article situates newspaper ‘outing’ of paedophiles in the community in relation to vigilante journalism and leaked information from official agencies. The article then presents research findings from a case study of news events set in train following a whistle-blowing reaction by Prison Officers’ Association officials to Home Office plans. Drawing from a corpus of 10 interviews with journalists and key protagonists in the story, the article discusses both the dynamics of whistle blowing about paedophiles and also what happens after the whistle has blown

Lattice dynamics and reduced thermal conductivity of filled skutterudites

The great reduction in thermal conductivity of skutterudites upon filling the ``void'' sites with Rare Earth (RE) ions is key to their favorable thermoelectric properties but remains to be understood. Using lattice dynamic models based on first principles calculations, we address the most popular microscopic mechanism, reduction via rattling ions. The model withstands inelastic neutron scattering and specific heat measurements, and refutes hypotheses of an anharmonic RE potential and of two distinct localized RE vibrations of disparate frequencies. It does indicate a strong hybridization between bare La vibrations and certain Sb-like phonon branches, suggesting anharmonic scattering by harmonic RE motions as an important mechanism for suppression of heat conductivity.Comment: modified version resubmitted to PRB. Results unchanged, text changed substantiall