19 resultados para shared conceptual space
em Repositório Científico do Instituto Politécnico de Lisboa - Portugal
Resumo:
Workflows have been successfully applied to express the decomposition of complex scientific applications. This has motivated many initiatives that have been developing scientific workflow tools. However the existing tools still lack adequate support to important aspects namely, decoupling the enactment engine from workflow tasks specification, decentralizing the control of workflow activities, and allowing their tasks to run autonomous in distributed infrastructures, for instance on Clouds. Furthermore many workflow tools only support the execution of Direct Acyclic Graphs (DAG) without the concept of iterations, where activities are executed millions of iterations during long periods of time and supporting dynamic workflow reconfigurations after certain iteration. We present the AWARD (Autonomic Workflow Activities Reconfigurable and Dynamic) model of computation, based on the Process Networks model, where the workflow activities (AWA) are autonomic processes with independent control that can run in parallel on distributed infrastructures, e. g. on Clouds. Each AWA executes a Task developed as a Java class that implements a generic interface allowing end-users to code their applications without concerns for low-level details. The data-driven coordination of AWA interactions is based on a shared tuple space that also enables support to dynamic workflow reconfiguration and monitoring of the execution of workflows. We describe how AWARD supports dynamic reconfiguration and discuss typical workflow reconfiguration scenarios. For evaluation we describe experimental results of AWARD workflow executions in several application scenarios, mapped to a small dedicated cluster and the Amazon (Elastic Computing EC2) Cloud.
Resumo:
Workflows have been successfully applied to express the decomposition of complex scientific applications. However the existing tools still lack adequate support to important aspects namely, decoupling the enactment engine from tasks specification, decentralizing the control of workflow activities allowing their tasks to run in distributed infrastructures, and supporting dynamic workflow reconfigurations. We present the AWARD (Autonomic Workflow Activities Reconfigurable and Dynamic) model of computation, based on Process Networks, where the workflow activities (AWA) are autonomic processes with independent control that can run in parallel on distributed infrastructures. Each AWA executes a task developed as a Java class with a generic interface allowing end-users to code their applications without low-level details. The data-driven coordination of AWA interactions is based on a shared tuple space that also enables dynamic workflow reconfiguration. For evaluation we describe experimental results of AWARD workflow executions in several application scenarios, mapped to the Amazon (Elastic Computing EC2) Cloud.
Resumo:
Methodological issues in research with children have sparked a growing interest by the Sociology of Childhood since the last decades. In Portugal, this interest is more recent, but it has had a significant increase. Considering several researches, namely master thesis, supervised by the authors on the framework of Sociology of Childhood, this proposal intends to characterize some methodological complexities in research with children in Portugal, when we consider their voice and agency in the knowledge producing about them. The goal of this paper is to contribute to the methodological discussion on research with children through the identification of a set of challenges related to: (i) the diversity of methodologies uses in children’s research, (ii) ethical concerns and (iii) the role of the researcher.
Resumo:
We present new populational growth models, generalized logistic models which are proportional to beta densities with shape parameters p and 2, where p > 1, with Malthusian parameter r. The complex dynamical behaviour of these models is investigated in the parameter space (r, p), in terms of topological entropy, using explicit methods, when the Malthusian parameter r increases. This parameter space is split into different regions, according to the chaotic behaviour of the models.
Resumo:
A Auditoria (Inspecção) Tributária tem sido encarada como um corpo estranho à Auditoria Financeira, apesar das características peculiares que lhe são reconhecidas não constituírem justificação para o afastametno conceptual face aos restantes tipos de auditoria. O desenvolvimento de um quadro conceptual para a Auditoria Tributária, aproximando-a, definitivamente, da Auditoria Financeira, criando assim sinergias ao nível dos procedimentos, constitui um passo fundamental para missão que lhe subjaz, sendo que o mote foi dado pela própria Comissão para o Desenvolvimento da Reforma Fiscal ao referir que "(...) os métodos de inspecção devem seguir os procedimentos normalmente usados em auditoria." (CDFR, 1996: §2.5.2). A identificação das suas características peculiares por contraste com os restantes ramos da auditoria, contextualizada por um sistema contabilístico claramente fiscalista, deverá constituir o ponto de partida para a análise de alguns conceitos nucleares, como a caracterização, neste âmbito, da matriz risco ou dos critérios de selecção.
Resumo:
This paper presents an algorithm to efficiently generate the state-space of systems specified using the IOPT Petri-net modeling formalism. IOPT nets are a non-autonomous Petri-net class, based on Place-Transition nets with an extended set of features designed to allow the rapid prototyping and synthesis of system controllers through an existing hardware-software co-design framework. To obtain coherent and deterministic operation, IOPT nets use a maximal-step execution semantics where, in a single execution step, all enabled transitions will fire simultaneously. This fact increases the resulting state-space complexity and can cause an arc "explosion" effect. Real-world applications, with several million states, will reach a higher order of magnitude number of arcs, leading to the need for high performance state-space generator algorithms. The proposed algorithm applies a compilation approach to read a PNML file containing one IOPT model and automatically generate an optimized C program to calculate the corresponding state-space.
Resumo:
In music genre classification, most approaches rely on statistical characteristics of low-level features computed on short audio frames. In these methods, it is implicitly considered that frames carry equally relevant information loads and that either individual frames, or distributions thereof, somehow capture the specificities of each genre. In this paper we study the representation space defined by short-term audio features with respect to class boundaries, and compare different processing techniques to partition this space. These partitions are evaluated in terms of accuracy on two genre classification tasks, with several types of classifiers. Experiments show that a randomized and unsupervised partition of the space, used in conjunction with a Markov Model classifier lead to accuracies comparable to the state of the art. We also show that unsupervised partitions of the space tend to create less hubs.
Resumo:
Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ciências da Educação - Especialidade Educação Especial
Resumo:
This paper presents the foundations of an Academic Social Network (ASN) focusing the Bologna Declaration and the Bologna Process (BP) mobility issues using ontological support. An ASN will permit students to share commons academic interests, preferences and mobility paths in the European Higher Education Space (EHES). The description of the conceptual support is ontology based allowing knowledge sharing and reuse. An approach is presented by merging Academic Ontology to Support the Bologna Mobility Process with Friend of a Friend ontology. The resulting ontology supports the student mobility profile in the ASN. The strategies to make available, in the network, knowledge about mobility issues, are presented including knowledge discovery and simulation approaches to cover student's mobility scenarios for BP.
Resumo:
In this work, we present a neural network (NN) based method designed for 3D rigid-body registration of FMRI time series, which relies on a limited number of Fourier coefficients of the images to be aligned. These coefficients, which are comprised in a small cubic neighborhood located at the first octant of a 3D Fourier space (including the DC component), are then fed into six NN during the learning stage. Each NN yields the estimates of a registration parameter. The proposed method was assessed for 3D rigid-body transformations, using DC neighborhoods of different sizes. The mean absolute registration errors are of approximately 0.030 mm in translations and 0.030 deg in rotations, for the typical motion amplitudes encountered in FMRI studies. The construction of the training set and the learning stage are fast requiring, respectively, 90 s and 1 to 12 s, depending on the number of input and hidden units of the NN. We believe that NN-based approaches to the problem of FMRI registration can be of great interest in the future. For instance, NN relying on limited K-space data (possibly in navigation echoes) can be a valid solution to the problem of prospective (in frame) FMRI registration.
Resumo:
Mestrado em Contabilidade e Gestão das Instituições Financeiras
Resumo:
Drawing on postcolonial studies and the theorization on imperial gothic, this paper centres on three texts: The Hosts of the Lord (1900) by Flora Annie Steel; East of Suez (1901) by Alice Perrin, and The Way of an Eagle (1912)by Ethel Dell. These three texts highlight in different ways the discursive mediation of the Other and its destabilizing effects on the identity of the European-minded colonizer, thus foregrounding the multifarious nature of the British imaginative engagement with India. In this context, it is particularly relevant to examine the political and ideological implications of representing anywhere East of Suez as a locus of primitivism and chaos vis-à-vis the colonizer’s ambivalent reactions. Thus we seek to demonstrate the power of two distinct practices or modes of representation – namely, the power of a metaphorical discourse versus metonymic discourse- within the proces of constructing the East for a vast Western readership.
Resumo:
Cet article se propose réfléchir à la présence créatrice du performer depuis la notion d’ambiance du choréographe japonais Y. Amagatzu. La notion d’ambiance est décrite par Yoshio Amagatzu comme une spatialité émergente de la rencontre des sujets – performers et public – dans l’espace performatif ; une spatialité sensible exprimant le potentiel de cette rencontre avec une « force orientatrice » spécifique. Mon approche s’intéresse en particulier aux conditions d’accordage (attunement) du performer au potentiel de cette spatialité émergente et aux effets de cette « adhérence perceptive» sur sa présence créatrice. Une approche qui m’a mené à étendre la notion de mouvement à l’espace de la relation performative, au delà des contours visibles du corps physique.
Resumo:
Relatório da Prática Profissional Supervisionada Mestrado em Educação Pré-Escolar
Resumo:
Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1º e 2º Ciclo do Ensino Básico