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Nomenclatura Unesco > (33) Ciencias Tecnológicas

Mostrando recursos 181 - 200 de 2,335

181. 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...

182. 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...

184. 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...

185. 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...

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

187. 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...

188. 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...

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

190. 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.

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


193. Glass Science and its Applications - II - José Domingos Santos; Nandyala Sooraj Hussein

194. RobTech - Task 1.2 - Survey in Robotic Technologies - António Paulo Moreira; Germano Veiga; José Pedro Sousa
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 the current state-of-the art in the application of robotic technologies in the field of architecture.

195. Automatic Systems Diagnosis Without Behavioral Models - Shekhar Gupta; Rui Abreu; Johan de Kleer; Arjan J.C. van Gemund
Recent feedback obtainedbased diagnosis (MBD) in industry suggests that the costs in- volved in behavioral modeling (both expertise and labor) can outweigh the benefits of MBD as a high-performance diagnosis approach. In this paper, we propose an automatic approach, called ANTARES, that completely avoids behavioral modeling. Decreasing modeling sacrifices diagnostic accuracy, as the size of the ambiguity group (i.e., components which cannot be dis- criminated because of the lack of information) increases, which in turn increases misdiagnosis penalty. ANTARES further breaks the ambiguity group size by considering the component#8217;s false negative rate (FNR), which is estimated using an analytical ex-...

196. Não tem, de facto, existido uma monitorização adequada do litoral. É uma falha muito grave do País. - Fernando Veloso Gomes
Não tem, de facto, existido uma monitorização adequada do litoral. É uma falha muito grave do País. Erros cometidos a nível do ordenamento do território, com construções em zonas de risco e perda de valores ambientais e o não terem sido assumidos e mitigados os impactes negativos associáveis a importantes infraestruturas portuárias e energéticas, bem como questões institucionais, constituem um desafio permanente na investigação e gestão de zonas muito atrativas, mas naturalmente energéticas e dinâmicas.

197. Flexibilidade do Design como resposta à variação de condicionantes tecnológicasdurante o projecto - Carlos Aguiar; Fernando Gomes Almeida; Carla Rocha; Nuno Couto
Pretende-se realçar a importância da capacidade de adaptação dos conceitosformais propostos pelo Design, potenciando a competitividade das soluçõesimpostas pelos condicionalismos técnicos (características dos materiais eprocessos de fabrico), no contexto de projectos de desenvolvimento deproduto. Esta característica, implícita nos projectos onde o Design intervém,permite obter soluções mais adequadas às necessidades dos utilizadores,quer do ponto de vista do produto acabado quer do ponto de vista doprocesso produtivo (melhor relação custo-utilidade). No presente artigo sãoapresentados diferentes conceitos de design para uma carroçaria emmaterial compósito, do tipo sanduíche, de um autocarro que circulará emserviço de shuttle, no Polo Universitário da Asprela (Porto), no âmbito...

198. Risk Management in Production Planning of Perishable Goods - Pedro Amorim; Douglas Junior; Bernardo Almada Lobo
In food supply chain planning, the trade-off between expected prot and risk is emphasized by the perishable nature of the goods that it has to handle. In particular, the risk of spoilage and the risk of revenue loss are substantial when stochastic parameters related to the demand, the consumer behavior and the spoilage effect are considered. This paper aims to expose and handle this trade-off by developing risk-averse production planning models that incorporate financial risk-measures. In particular, the performance of a risk-neutral attitude is compared to the performance of models takinginto account the upper partial mean and the conditional value-at-risk....

199. Towards high-available and energy-efficient virtual computing environments in the cloud - Altino Sampaio; Jorge Manuel Gomes Barbosa
Empowered by virtualisation technology, cloud infrastructures enable the construction of flexible and elastic computing environments, providing an opportunity for energy and resource cost optimisation while enhancing system availability and achieving high performance. A crucial requirement for effective consolidation is the ability to efficiently utilise system resources for high-availability computing and energy-efficiency optimisation to reduce operational costs and carbon footprints in the environment. Additionally, failures in highly networked computing systems can negatively impact system performance substantially, prohibiting the system from achieving its initial objectives. In this paper, we propose algorithms to dynamically construct and readjust virtual clusters to enable the execution...

200. Segmentation of Skin Lesions Using Level Set Method - Zhen Ma; João Manuel R. S. Tavares
Diagnosis of skin cancers with dermoscopy has been widely accepted as a clinical routine. However, the diagnostic accuracy using dermoscopy relies on the subjective judgment of the dermatologist. To solve this problem, a computer-aided diagnosis system is demanded. Here, we propose a level set method to fulfill the segmentation of skin lesions presented in dermoscopic images. The differences between normal skin and skin lesions in the color channels are combined to define the speed function, with which the evolving curve can be guided to reach the boundary of skin lesions. The proposed algorithm is robust against the influences of noise,...


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