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-...
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.
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...
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....
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...
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,...
A systematic review of algorithms with linear-time behaviour to generate Delaunay and Voronoi tessellations
- Sanderson L. Gonzaga de Oliveira; Jéssica Renata Nogueira; João Manuel R. S. Tavares
Triangulations and tetrahedrizations are important geometrical discretization procedures applied to several areas, such as the reconstruction of surfaces and data visualization. Delaunay and Voronoi tessellations are discretization structures of domains with desirable geometrical properties. In this work, a systematic review of algorithms with linear-time behaviour to generate 2D/3D Delaunay and/or Voronoi tessellations is presented.
ESM2014 - The 2014 European Simulation and Modelling Conference, Modelling and Simulation 2014
- Carlos Bragança de Oliveira
ESM2014 - The 2014 European Simulation and Modelling Conference, Modelling and Simulation 2014(Proceedings of the ESM2014 - 28th European Simulation and Modelling Conference, Porto, Portugal, October 22-24, 2014)Editors: António Carvalho Brito, João Manuel R.S. Tavares, Carlos Bragança de OliveiraISBN: 978-90-77381-86-1, EAN: 9789077381861, EUROSIS-ETI, Publication Date: October, 2014
Operation Planning of Hydro Stations Using Genetic Algorithms Considering their Impact on the Electricity Market Prices
- Carlos Guerreiro; João Tomé Saraiva; José Carlos Sousa; Virgílio T. Mendes
With the advent of restructuring, generation companies have to plan the operation of their stations in order to maximize their profits. This is very relevant for companies having a large share of hydro stations, and even more if these stations have pumping capacity. This paper describes a model to plan the operation of a set of hydro stations eventually installed in cascade and admitting that some of them are pumping stations. Once a first set of operation orders is obtained using a Genetic Algorithm, their generation/load values are included in the expected market selling/buying curves and the hourly prices are...
Strategies to parallelize ILP systems
- Nuno A Fonseca; Fernado Silva; Rui Camacho
It is well known by Inductive Logic Programming (ILP) practionersthat ILP systems usually take a long time to nd valuable models(theories). The problem is specially critical for large datasets, preventingILP systems to scale up to larger applications. One approach to reducethe execution time has been the parallelization of ILP systems. In thispaper we overview the state-of-the-art on parallel ILP implementationsand present work on the evaluation of some major parallelization strategiesfor ILP. Conclusions about the applicability of each strategy arepresented.
Minimizing Airport Peaks Problem by Improving Airline Operations Performance through an Agent Based System
- António J. M. Castro; António Mota; Luís Paulo Reis; Eugénio Oliveira
Da transferência de suporte ao sistema de informação organizacional: um posicionamento urgente e estratégico
- Maria Manuela Gomes de Azevedo Pinto
Since the late 90s that digitization has assumed a growing importance considering of traditional techniques such as microfilming and photography, and increasingly conquering users e professional that also benefiting from attractive financing options, either within the Digital Cultural Heritage, or in the dematerialisation process at organizations or public and private institutions. However, digitization, and is no longer just a means to create digital reproductions of physical objects, facilitating access and support when preserving the quot;analogquot; original or solving problems of lack of storage space. It means in fact the production of digital information and as any kind of digital information...
Efficient Data Structures for Inductive Logic Programming
- Nuno A Fonseca; Ricardo Rocha; Rui Camacho; Fernado Silva
This work aims at improving the scalability of memory usagein Inductive Logic Programming systems. In this context, we propose twoecient data structures: the Trie, used to represent lists and clauses;and the RL-Tree, a novel data structure used to represent the clausescoverage. We evaluate their performance in the April system using wellknown datasets. Initial results show a substantial reduction in memoryusage without incurring extra execution time overheads. Our proposal isapplicable in any ILP system.
Evaluation of ductile fracture in sheet metal forming using a damage model
- J. M. A. César de Sá; Abel D. Santos; Francisco M. A. Pires; Pedro Teixeira
Continuous Damage Mechanics (CDM) may constitute an alternative to the traditional use of Forming Limit Diagrams (FLDs) to predict the onset of formability in sheet metal forming . In CDM, at the constitutive level, a damage variable is introduced to model, at the macro scale, the internal material degradation due to micro-defects that occur during plastic loading. This approach is used in this work and the implementation of a continuum damage model in a commercial code is described, in order to identify ductile fracture in sheet metal forming. The model includes Lemaitres ductile damage evolution law coupled with an orthotropic...
Analysis of Medical Images by Computational Methods: Algorithms and Applications
- João Manuel R. S. Tavares
Impact of Feed-in Generation in Market Prices and Calibration of a Capacity Term to Pay to Traditional Generation Application to the Iberian Market
- Adelino Pereira; João Tomé Saraiva
In this paper we describe the models and the simulations that were conducted in order to access the impact of feed-in subsidized generation in the market price in Portugal in the context of the Iberian Electricity Market. In Portugal and Spain feed-in generation (namely wind power) has a large share both in terms of installed capacity and generated energy and the presence of this energy in the hourly balance originates the reduction of the market price and of the number of hours during which traditional generation (namely coal and CCGT stations) are scheduled. This paper aims at evaluating this impact...
Sistemas de Informação na Construção: Casos de Aplicação
- Alfredo Soeiro
O processo da construção é composto por operações que visam o manuseamento da informação. A informação necessária ao projecto construtivo é traduzida em desenhos, memórias descritivas e justificativas, cadernos de encargos, contratos, concursos, legislação normativa e descritiva, autos de medição, guias de transporte e outras, planos de segurança e saúde, normas técnicas, propostas, etc.. A construção é provavelmente a engenharia que mais documentos utiliza como suporte da actividade. Actualmente os documentos de suporte da construção têm sido produzidos e utilizados em formato digital. O recurso a documentos digitais tem facilitado a gestão documental da informação. Por outro lado a possibilidade...
STUDY OF EXTRAORAL FORCE DELIVERY SYSTEMS USING HOLOGRAPHIC TECHNIQUES
- Jaime Monteiro; Nuno Ramos; Joaquim Silva Gomes; Laiz Cavalcanti; Maria João Ponces; Mário Vaz
RobTech - Task 1.1 - Survey in Computational Design
- 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 computational design technologies.
THE LEAST-SQUARES METHOD APPLIED TO A FRACTURE-MECHANICS PROBLEM
- guedes, rm; dalmeida, fd