Fast Sorting on a Distributed-Memory Architecture

We consider the often-studied problem of sorting, for a parallel computer. Given an input array distributed evenly over p processors, the task is to compute the sorted output array, also distributed over the p processors. Many existing algorithms take the approach of approximately load-balancing the output, leaving each processor with Θ(n/p) elements. However, in many cases, approximate load-balancing leads to inefficiencies in both the sorting itself and in further uses of the data after sorting. We provide a deterministic parallel sorting algorithm that uses parallel selection to produce any output distribution exactly, particularly one that is perfectly load-balanced. Furthermore, when using a comparison sort, this algorithm is 1-optimal in both computation and communication. We provide an empirical study that illustrates the efficiency of exact data splitting, and shows an improvement over two sample sort algorithms.

Pelican shared writing : non-fiction teacher's book 2.

Ofrece al profesor notas detalladas sobre la enseñanza de las veinte unidades de trabajo que componen el libro de gran formato con textos de no ficción y de diferentes géneros utilizados para la escritura compartida. Tambien, ofrece ejemplos de actividades de escritura compartida y fotocopias de aquellos textos.

Pelican shared writing : year two non-fiction resource book.

Este recurso del profesor proporciona varios textos de no ficción de diferentes géneros para ser utilizados en sesiones de escritura compartida, que, además, se ajustan al NLS. Se compone de veinte unidades de trabajo, cada una de las cuales cumple un objetivo de composición escrita del NLS y que se describen detalladamente en las notas del Libro del Profesor que le acompaña.

The internet, information architecture and community memory

This article reviews current technological developments, particularly Peer-to-Peer technologies and Distributed Data Systems, and their value to community memory projects, particularly those concerned with the preservation of the cultural, literary and administrative data of cultures which have suffered genocide or are at risk of genocide. It draws attention to the comparatively good representation online of genocide denial groups and changes in the technological strategies of holocaust denial and other far-right groups. It draws on the author's work in providing IT support for a UK-based Non-Governmental Organization providing support for survivors of genocide in Rwanda.

Global exponential periodicity of a class of bidirectional associative memory networks with finite distributed delays

In this paper, we study the periodic oscillatory behavior of a class of bidirectional associative memory (BAM) networks with finite distributed delays. A set of criteria are proposed for determining global exponential periodicity of the proposed BAM networks, which assume neither differentiability nor monotonicity of the activation function of each neuron. In addition, our criteria are easily checkable. (c) 2005 Elsevier Inc. All rights reserved.

Experimental separation of the coherent component of X-ray scattering prior to RDF analysis of non-crystalline polymers

An experimental method is described which enables the inelastically scattered X-ray component to be removed from diffractometer data prior to radial density function analysis. At each scattering angle an energy spectrum is generated from a Si(Li) detector combined with a multi-channel analyser from which the coherently scattered component is separated. The data obtained from organic polymers has an improved signal/noise ratio at high values of scattering angle, and a commensurate enhancement of resolution of the RDF at low r is demonstrated for the case of PMMA (ICI `Perspex'). The method obviates the need for the complicated correction for multiple scattering.

Conceptual representation in bilinguals: the role of language specificity and conceptual change

Most prominent models of bilingual representation assume a degree of interconnection or shared representation at the conceptual level. However, in the context of linguistic and cultural specificity of human concepts, and given recent findings that reveal a considerable amount of bidirectional conceptual transfer and conceptual change in bilinguals, a particular challenge that bilingual models face is to account for non-equivalence or partial equivalence of L1 and L2 specific concepts in bilingual conceptual store. The aim of the current paper is to provide a state-of-the-art review of the available empirical evidence from the fields of psycholinguistics, cognitive, experimental, and cross-cultural psychology, and discuss how these may inform and develop further traditional and more recent accounts of bilingual conceptual representation. Based on a synthesis of the available evidence against theoretical postulates of existing models, I argue that the most coherent account of bilingual conceptual representation combines three fundamental assumptions. The first one is the distributed, multi-modal nature of representation. The second one concerns cross-linguistic and cross-cultural variation of concepts. The third one makes assumptions about the development of concepts, and the emergent links between those concepts and their linguistic instantiations.

Scattered power from non-thermal, F-region plasma observed by EISCAT—evidence for coherent echoes?

Three rapid, poleward bursts of plasma flow, observed by the U.K.-POLAR EISCAT experiment, are studied in detail. In all three cases the large ion velocities (> 1 kms−1) are shown to drive the ion velocity distribution into a non-Maxwellian form, identified by the characteristic shape of the observed spectra and the fact that analysis of the spectra with the assumption of a Maxwellian distribution leads to excessive rises in apparent ion temperature, and an anticorrelation of apparent electron and ion temperatures. For all three periods the total scattered power is shown to rise with apparent ion temperature by up to 6 dB more than is expected for an isotropic Maxwellian plasma of constant density and by an even larger factor than that expected for non-thermal plasma. The anomalous increases in power are only observed at the lower altitudes (< 300 km). At greater altitudes the rise in power is roughly consistent with that simulated numerically for homogeneous, anisotropic, non-Maxwellian plasma of constant density, viewed using the U.K.-POLAR aspect angle. The spectra at times of anomalously high power are found to be asymmetric, showing an enhancement near the downward Doppler-shifted ion-acoustic frequency. Although it is not possible to eliminate completely rapid plasma density fluctuations as a cause of these power increases, such effects cannot explain the observed spectra and the correlation of power and apparent ion temperature without an unlikely set of coincidences. The observations are made along a beam direction which is as much as 16.5° from orthogonality with the geomagnetic field. Nevertheless, some form of coherent-like echo contamination of the incoherent scatter spectrum is the most satisfactory explanation of these data.

Coherent states of non-relativistic electron in the magnetic-solenoid field

In the present work we construct coherent states in the magnetic-solenoid field, which is a superposition of the Aharonov-Bohm field and a collinear uniform magnetic field. In the problem under consideration there are two kinds of coherent states, those which correspond to classical trajectories which embrace the solenoid and those which do not. The constructed coherent states reproduce exactly classical trajectories, maintain their form under the time evolution and form a complete set of functions, which can be useful in semiclassical calculations. In the absence of the solenoid field these states are reduced to the well known in the case of uniform magnetic field Malkin-Man`ko coherent states.

Strategic alliances between companies and non-governmental organizations pursuing the creation of shared value: an exploratory study at the base of the pyramid in Brazil

Na última década, uma crescente atenção tem sido dedicada ao desenvolvimento de estratégias que permitem uma empresa de atender os mercados de baixa renda de uma forma rentável e ao mesmo tempo enfrentar os desafios sociais. Uma das ferramentas estratégicas identificados para operar com sucesso na base da pirâmide ( BoP ), consiste no estabelecimento de alianças com organizações não governamentais (ONGs). Isso, no entanto, é um desafio, especialmente porque os atores do setor empresarial e da sociedade civil são movidos por um propósito diferente e adotam uma abordagem diferente na condução das suas atividades. O objetivo desta pesquisa é, portanto, investigar precisamente como ONGs e empresas podem alavancar os seus respectivos recursos e capacidades para criar valor econômico e social , servindo este segmento. Um estudo de casos múltiplos, com foco na base da pirâmide brasileira é utilizado, a fim de entender as dificuldades e fatores de sucesso para a criação e gestão de tais alianças e identificar os recursos e capacidades que são mobilizados por cada parceiro. Os resultados sugerem que as principais dificuldades estão em encontrar um parceiro adequado; superar percepções estereotipadas negativos e falta de confiança e, finalmente, na diferente estrutura, cultura e processos. Por sua vez, os fatores mais importantes que levam ao sucesso incluem a escolha do parceiro certo; compatibilidade em termos de missão, estratégia e valores; estabelecimento de confiança e comprometimento; comunicação eficaz e, finalmente, a capacidade da aliança de gerar valor para ambos os parceiros. Além disso, os resultados demostram que o papel das ONGs é na maior parte limitado a agir como uma ponte entre a empresa e as comunidades de baixa renda, enquanto as capacidades operacionais e os recursos financeiros são fornecidos pelas empresas.

Understanding the critical distance in sparse distributed memory

Modelos de tomada de decisão necessitam refletir os aspectos da psi- cologia humana. Com este objetivo, este trabalho é baseado na Sparse Distributed Memory (SDM), um modelo psicologicamente e neuro- cientificamente plausível da memória humana, publicado por Pentti Kanerva, em 1988. O modelo de Kanerva possui um ponto crítico: um item de memória aquém deste ponto é rapidamente encontrado, e items além do ponto crítico não o são. Kanerva calculou este ponto para um caso especial com um seleto conjunto de parâmetros (fixos). Neste trabalho estendemos o conhecimento deste ponto crítico, através de simulações computacionais, e analisamos o comportamento desta “Critical Distance” sob diferentes cenários: em diferentes dimensões; em diferentes números de items armazenados na memória; e em diferentes números de armazenamento do item. Também é derivada uma função que, quando minimizada, determina o valor da “Critical Distance” de acordo com o estado da memória. Um objetivo secundário do trabalho é apresentar a SDM de forma simples e intuitiva para que pesquisadores de outras áreas possam imaginar como ela pode ajudá-los a entender e a resolver seus problemas.

On a nonlinear and chaotic non-ideal vibrating system with shape memory alloy (SMA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

THEORY OF NON-STEADY-STATE ELECTRICAL CHARACTERISTICS OF METAL-INSULATOR-METAL STRUCTURES WITH SCHOTTKY BARRIERS AND UNIFORMLY DISTRIBUTED INTERFACE IMPURITY STATES

The metal-insulator (or amorphous semiconductor) blocking contact is still not well understood. In the present paper, we discuss the non steady state characteristics of Metal-lnsulator-Metal Structure with non-intimate blocking contacts (i.e. Metal-Oxide-Insulator-Metal Structure). We consider a uniform distribution (in energy) of impurity states in addition to impurity states at a single energy level within the depletion region. We discuss thermal as well as isothermal characteristics and present expressions for the temperature of maximum current (T-m) and a method to calculate the density of uniformly distributed impurity states. The variation of mobility with electrical field has also been considered. Finally we plot the theoretical curves under different conditions. The present results are closing into available experimental results.

Simulation of free surface flows in a distributed memory environment

A parallel technique, for a distributed memory machine, based on domain decomposition for solving the Navier-Stokes equations in cartesian and cylindrical coordinates in two dimensions with free surfaces is described. It is based on the code by Tome and McKee (J. Comp. Phys. 110 (1994) 171-186) and Tome (Ph.D. Thesis, University of Strathclyde, Glasgow, 1993) which in turn is based on the SMAC method by Amsden and Harlow (Report LA-4370, Los Alamos Scientific Laboratory, 1971), which solves the Navier-Stokes equations in three steps: the momentum and Poisson equations and particle movement, These equations are discretized by explicit and 5-point finite differences. The parallelization is performed by splitting the computation domain into vertical panels and assigning each of these panels to a processor. All the computation can then be performed using nearest neighbour communication. Test runs comparing the performance of the parallel with the serial code, and a discussion of the load balancing question are presented. PVM is used for communication between processes. (C) 1999 Elsevier B.V. B.V. All rights reserved.