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Nomenclatura Unesco > (33) Ciencias Tecnológicas

Mostrando recursos 181 - 200 de 2,342

181. Utilização de XML numa plataforma de Data Mining distribuído - Ruy Ramos; Carlos Gonçalves; Rui Camacho
O processo de Extracção de Conhecimento em Bases de Dados(Knowledge Discovery in Databases - KDD) envolve a análise deextensas bases de dados e recurso a complexos algoritmos de análise dedados (Data Mining). Este processo requer, geralmente, recursos computacionaisdedicados e de elevado custo o que reduz signicativamenteo número de utilizadores capazes de efectuar tais análises. Neste artigoapresentamos uma arquitectura baseada em computadores pessoais distribuídos numa rede de computadores de uma organização e que permitea realização de tarefas de KDD sem recursos computacionais dedicadose sem perturbar o funcionamento da organização. A arquitectura é denominadaHarvard - HARVesting Architecture of idle machines foRData mining....

182. Proceedings CLME 2008 - 5º Congresso Luso-Moçambicano de Engenharia, IICEM - 2º Congresso de Engenharia de Moçambique.

183. An Evolutionary Particle Swarm Optimization, EPSO, Approach to Optimize the Operation of Hydro Stations in Market Environment - André Pacheco; João Tomé Saraiva
This paper describes the application of Evolutionary Particle Swarm Optimization, EPSO, to the optimization of the short term operation of hydro stations in market environment. The maximization of the revenues of hydro stations, namely pumping stations, is gaining increasing attention by generation companies. However, this is typically a complex problem given the non linear relation between the power, the flow and the head, the temporal coupling between stations in cascade and the increasing number of pumping stations. The EPSO based algorithm displayed a very good performance in terms of the quality of the final operation plan as well as regarding...

184. RobTech - Task 1.3 - Survey in Architectural Design and Construction - José Pedro Sousa; João Pedro Xavier; Rui Póvoas
This report is part of the research project quot;Robotic Technologies for a Non-Standard Design and Construction in Architecturequot;, supported by the FCT - Fundação para a Ciência e a Tecnologia. In the scope of the introductory activities of the project (T1.1, T.1.2 and T1.3), the present task surveys architectural projects showing pertinent issues regarding material, formal (geometry) or construction. These projects has the potential to inspire interesting challenges to be tackled by means of robotic fabrication technologies.

185. Hybrid simulation-optimization methods: A taxonomy and discussion - figueira, g; almada-lobo, b
The possibilities of combining simulation and optimization are vast and the appropriate design highly depends on the problem characteristics. Therefore, it is very important to have a good overview of the different approaches. The taxonomies and classifications proposed in the literature do not cover the complete range of methods and overlook some important criteria. We provide a taxonomy that aims at giving an overview of the full spectrum of current simulation-optimization approaches. Our study may guide researchers who want to use one of the existing methods, give insights into the cross-fertilization of the ideas applied in those methods and create...

186. Improving the efficiency of ILP systems using an Incremental Language Level Search - Rui Camacho
We propose and evaluate a technique to improve the eciency of an ILP system. The technique avoids the generation of useless hypotheses.It denes a language bias coupled with a search strategy and is called Incremental Language Level Search (ILLS). The techniques havebeen encoded in the ILP system IndLog. The proposal leads to substantial eciency improvements in a set of ILP datasets referenced on theliterature.

187. Models for capacitated lot-sizing problem with backlogging, setup carryover and crossover - Marcio Belo Filho; Bernardo Almada Lobo; Franklina Toledo
Setup operations are significant in some production environments. It is mandatory that their production plans consider some features, as setup state conservation across periods through setup carryover and crossover. The modelling of setup crossover allows more flexible decisions and is essential for problems with long setup times. This paper proposes two models for the capacitated lot-sizing problem with backlogging and setup carryover and crossover.The first is in line with other models from the literature, whereas the second considers a disaggregated setup variable, which tracks the starting and completion times of the setupoperation. This innovative approach permits a more compact formulation....

188. A multi-agent system for intelligent monitoring of airline operations - Eugénio da CostaOliveira; António Jesus Monteiro de Castro
There are quite a few solutions for crew scheduling, including some commercial applications. The same happens for aircraft scheduling and for flight scheduling including revenue management. However, the airline operations problem did not receive the same attention has the other airline scheduling problems. In this paper we introduce this problem and report thework we are doing in the development of a Distributed Multi-agent System that will be capable of dealing with the crew and aircraft recovery problem, during the airline operations phase. The MAS deals with different operational bases and all bases cooperate to find the solutions to the local...

189. Plano de Emergência Municipal e Proteção Civil de Alfândega da Fé - Caraterização do Território e Riscos Naturais - António Gomes; Laura Soares; Inês Marafuz; Carlos Delgado; Municípia SA

190. Automated segmentation of the incus and malleus ossicles in conventional tri-dimensional computed tomography images - Francisco P. M. Oliveira; Diogo Borges Faria; João Manuel R. S. Tavares
This paper proposes a fully automated computational solution to segment the incus and malleus ear ossicles in conventional tri-dimensional (3D) X-ray computed tomography (CT) images. The solution uses a registration-based segmentation paradigm, followed by image segmentation refinement. It was tested against a dataset comprising 21 CT volumetric images of the ear acquired using standard protocols and with resolutions varying from 0.162×0.162×0.6 to 0.166×0.166×1.0 mm3. The images used were randomly selected from subjects that had had a CT exam of the ear due to ear related pathologies. Dices coefficient and the Hausdorff distance were used to compare the results of the...

191. Recovering from airline operational problems with a multi-agent system: a case study - António Mota; António J. M. Castro; Luis Paulo Reis
The Airline Operations Control Centre (AOCC) tries to solve unexpected problems during the airline operation. Problems with aircraft, crewmembers and passengers are common and very hard to solve due to the several variables involved. This paper presents the implementation of a real-world multi-agent system for operations recovery in an airline company. The analysis and design of the system was done following a GAIA based methodology. We present the system specification as well as the implementation using JADE. A case study is included, where we present how the system solved a real problem.

A methodology is proposed to address the recognition of competences acquired online. It is derived from the project VIRQUAL ( outputs. It addresses current issues of the working world like Virtual Mobility, Learning Outcomes, e-Assessment, Qualification Frameworks and Recognition of Prior Learning. The approach is based on the application of proper methods of assessment for each type of learning outcomes. A matrix is proposed to align the different types of competences (based on revised Bloom#180;s taxonomy) with the different types of assessment online. The involvement of professional stakeholders derives from the inclusion of the professional qualification frameworks in the choice...

193. Institutional services for dynamic virtual organizations - cardoso, hl; malucelli, a; rocha, ap; oliveira, e
Electronic Institutions are comprehensive frameworks that may effectively help in the collaborative work of virtual organization activities. This paper focuses on an effort to create e-contracting and ontology-based services in the context of Electronic Institutions. The e-contracting services provide automatic specification of business agreements by formalizing them through e-contracts, plus the procedures for enforcing them. Moreover. ontology-based services enable the interoperability between agents representing organizations using different ontologies. Ontology services provide useful advices on how to negotiate specific items, leading to appropriate conversations and making agreements possible. We believe that the rendering of these services will provide a level of...

194. Delamination in carbon/epoxy plates drilling: tool and feed rate effect - Luís Miguel Pereira Durão; Daniel Gonçalves; João Manuel R.S. Tavares; António Aguiar Vieira; António Paulo Monteiro Baptista
The attractive characteristics of carbon fibre reinforced plastics had widespread their use. In order to join different components, drilling is often necessary. It is known that a drilling process that reduces the drill thrust force can decrease the risk of delamination. In this work, three combinations of the drilling process are compared: tool diameter, tool geometry and feed rate. The parameters studied were: thrust force, delamination extension and mechanical strength of the drilled region bearing test. This work demonstrates that a proper combination of the drilling variables can contribute to reduce the delamination damage and, consequently, enhance mechanical resistance of...

195. Análise de Imagens Biomédicas por Métodos Computacionais - João Manuel R. S. Tavares

196. Morfometria do trato vocal por ressonância magnética: simulação de padrões patológicos articulatórios - Sandra M. Rua Ventura; Diamantino Rui S. Freitas; Isabel Maria A. P. Ramos; João Manuel R. S. Tavares
Introduction The shape or morphologic analysis of anatomical structures, such as the vocal tract can be performed from two-dimensional (2D) or volumetric acquisitions (3D) of magnetic resonance imaging (MRI). This imaging technique has had an increasing use in the study of speech production. Objectives To determine a method to perform the morphometric analysis of the vocal tract from magnetic resonance imaging; to present anatomical patterns during the normal speech production of some vowels and two pathological articulatory disorders in simulated context. Methods The image data was collected from 2D (Turbo Spin Echo) and 3D (Flash Gradient Echo) acquisitions of MRI...

197. Improving the efficiency of ILP systems - Rui Camacho
Inductive Logic Programming (ILP) is a promising technol-ogy for knowledge extraction applications. ILP has produced intelligiblesolutions for a wide variety of domains where it has been applied. TheILP lack of eciency is, however, a major impediment for its scalabilityto applications requiring large amounts of data. In this paper we pro-pose a set of techniques that improve ILP systems eciency and makethen more likely to scale up to applications of knowledge extraction fromlarge datasets. We propose and evaluate the lazy evaluation of examples,to improve the eciency of ILP systems. Lazy evaluation is essentiallya way to avoid or postpone the evaluation of...

198. Voltage Stability Assessment Using a New FSQV Method and Artificial Neural Networks - António Andrade

199. A parallel ILP algorithm that incorporates incremental batch learning - Nuno A Fonseca; Rui Camacho; Fernado Silva
In this paper we tackle the problems of eciency and scala-bility faced by Inductive Logic Programming (ILP) systems. We proposethe use of parallelism to improve eciency and the use of an incrementalbatch learning to address the scalability problem. We describe a novelparallel algorithm that incorporates into ILP the method of incremen-tal batch learning. The theoretical complexity of the algorithm indicatesthat a linear speedup can be achieved.

200. The ATLANTIC news studio: reference model and field trial - Maria Teresa Andrade; Artur Pimenta Alves; José Ruela; Luís Teixeira; Richard Storey


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