ISEP - Departamento de Engenharia Informática
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- Abordagens ao Problema de Escalonamento em Ambientes Reais de ProduçãoPublication . Madureira, Ana Maria; Almeida, Ana[Resumo] Num sistema de fabrico do tipo Job-Shop podem ser identificados alguns factores que contribuem para a dificuldade do processo de escalonamento, nomeadamente, a complexidade, as restrições e a incerteza. Os ambientes industriais reais são sujeitos a várias fontes de mudança, as quais são tratadas como ocorrências aleatórias, tais como, lançamento de novas ordens de fabrico, avarias, alterações de prioridades, atrasos nas operações, etc. Por escalonamento dinâmico consideramos a situação na qual um plano flexível é executado, isto é, o plano inicial é dinamicamente ajustado (re-escalonado) sempre que eventos inesperados ocorrem no sistema. Esta comunicação tem por objectivo principal efectuar uma sistematização de conceitos e classificações de problemas e tipos de escalonamento, bem como das abordagens usadas na sua resolução. Inicialmente, é apresentado o problema de escalonamento, através da caracterização dos seus elementos e da referência a algumas definições encontradas na literatura, A seguir descrevem-se algumas classificações para os problemas de escalonamento e os tipos de abordagens de resolução a adoptar. Finalmente, são propostas duas arquitecturas para a resolução do problema de escalonamento em ambientes reais de produção caracterizados por um elevado grau de dinamismo. À primeira baseada em Sistemas de Apoio à Decisão e a segunda em Algoritmos Genéticos.
- C Tutor usage in relation to student achievement and progress: A study of introductory programming courses in Portugal and SerbiaPublication . Alves, Luís; Gajić, Dušan; Henriques, Pedro Rangel; Ivančević, Vladimir; Ivković, Vladimir; Lalić, Maksim; Luković, Ivan; Pereira, Maria João Varanda; Popov, Srđan; Tavares, Paula CorreiaPrevious research studies on introductory programming courses in engineering education in Portugal and Serbia have indicated that although high motivation and high expectations seem to be reported by students, many students may fail the course. This prompted a further inquiry into student attitudes, behavior, and achievement, and it also led to the introduction of C Tutor, a widely known program visualization tool, into courses in both countries. As a result, in the present study, self-reported student achievement (grades), self-reported student progress (knowledge improvement and confidence), and self-reported usage and helpfulness of C Tutor were investigated. Anonymous data about students and their experience in the course, which also included the usage of C Tutor, were collected in a survey in Portugal and Serbia. Quantitative methods, including descriptive statistics, clustering, statistical testing of independence, and partial correlation analysis, were applied in analyses of survey data. The distribution of grades differed between the two countries, but overall attitudes were similar. Various uncovered patterns involving student attitudes and usage of C Tutor may serve as a starting point for new research studies.
- CEPP: Conversion and execution of process plansPublication . Ramos, Carlos; Figueiredo, LinoThis paper deals with a method to produce a program in numerical control (NC) language from a part drawing in a CAD system. This method is applied to any piece with revolution axis that can be machined in a CNC lathe. The method was developed with the goal of being integrated in the control software of the flexible manufacturing system existent in the CIM center of ISEP. The proposed method involves three phases, which are presented and explained.
- CHARACTERIZATION OF MV CONSUMERS USING HIERARCHICAL CLUSTERINGPublication . Figueiredo, V.; Pinheiro, R.; Carvalho Ramos, Sérgio Filipe; Rodrigues, Maria de Fátima Coutinho; Vale, Zita; Ramos, Carlos; Vale, ZitaWith the electricity market liberalization, distribution and retail companies are looking for better market strategies based on adequate information upon the consumption patterns of its electricity customers. A fair insight on the customers’ behaviour will permit the definition of specific contract aspects based on the different, consumption patterns. In this paper, we propose a Knowledge Discovery in Databases project applied to electricity consumption data from a utility client’s database. To form the different customers’ classes, and find a set of representative consumption patterns, we have used the Two-Step algorithm which is a hierarchical clustering algorithm. Each consumer class will be represented by its load profile resulting from the clustering operation. Next, to characterize each consumer class a classification model will be constructed with the C5.0 classification algorithm.
- Computational Intelligence and Decision Making: Trends and ApplicationsPublication . Madureira, Ana Maria; Reis, Cecília; Marques, ViriatoAdvances in Computational Intelligence and Decision Making: Trends and Applications provides an overview and original analysis of new developments and applications in several areas of Computational Intelligence and Information Systems, in general. Computational Intelligence became the roadmap for engineers to develop and analyze novel techniques to solve problems in basic sciences such as physics, chemistry, biology, engineering, environment and social sciences. The material contained in this book addresses the foundations and applications of Artificial Intelligence and Decision Support Systems, Complex and Biological Inspired Systems, Simulation and Evolution of real and artificial life forms, Intelligent Models and Control Systems, Knowledge and Learning Technologies, Web Semantics and Ontologies, Intelligent Tutoring Systems, Intelligent Power Systems, Self-Organized and Distributed Systems, Intelligent Manufacturing Systems and Affective Computing. The contributions are written by international experts, who provide up-to-date aspects of the topics discussed and present recent, original insights of their own experience in these fields. Its aim is the presentation of state-of-the-art technologies in the field of Computational Intelligence as well as the discussion of new research findings in this field. The book is suitable for scientists, engineers, educators and students, as it addresses a large diversity of subjects presented in a broad band of complexity, ranging from simple natural language, found in some state-of-the-art articles, to some more complex mathematical issues, found in control applications, robotics and power systems, such as fractional calculus, fuzzy systems and rough-sets theory. Data Mining techniques, such as Support-Vector Machines and Neural Networks, are presented in application of the Biomedical and Bioinformatics fields, among others. Briefly, we believe that this book provides a good window on most of the subjects that directly or indirectly make use of Computational Intelligence, also showing the contributions that it is already giving, or can be given in a near future, for solving some of the more pressing problems of today’s world, such as energy and environment, society and economy.
- Conceitos básicos para o desenvolvimento de cursos multimédiaPublication . Vaz de Carvalho, Carlos[Excerto] Este módulo pretende descrever, de forma necessariamente sintética, as etapas associadas à criação de cursos de e-learning multimédia. No final, o leitor deverá compreender os conceitos básicos da concepção e desenvolvimento de cursos multimédia e ajustá-los de acordo com as matérias a ensinar e com o perfil dos formandos (utilizadores). Deverá ainda dominar as principais fases do desenvolvimento de cursos multimédia - análise e especificação, concepção, desenvolvimento e integração, avaliação e manutenção - incluindo a compreensão da importância de cada etapa, as ferramentas a utilizar e as competências necessárias.
- Constraint programming approach to solve facility layout design problemsPublication . Tavares, José António; Neves, José; Ramos, CarlosWe propose a methodology to solve the facility layout design problem by using constraint logic programming (CLP), which has proved to be a technology that gives good results when applied to a combinatorial problem optimisation. Methods to solve facility layout problems have to deal with a large set of factors, namely sales and production estimations, manufacturing process compatibilities, delivery dates, quality, spatial requirements, economics, management, human resources and environment. These factors make the facility layout design an extremely complex problem to solve. This complexity motivated the development of a methodology to solve the facility layout design problem using CLP.
- Cooperation in Learning Power Systems Restoration TechniquesPublication . Silva, António; Ramos, Carlos; Vale, Zita; Ramos, Carlos; Vale, ZitaAdequate training programs for power systems restoration tasks must take into account that this is a cooperative activity involving several entities. The proposed architecture of the Intelligent Tutoring System presented in this paper is based on a multi-agent system offering a simulated training environment.
- Decision support system for dynamic production schedulingPublication . Marinho, José; Ramos, Carlos; Bragança, AlexandreThis paper presents a system to support decision-making of the production manager when scheduling the manufacturing orders. This system is mainly appropriate for small and medium size enterprises with productive systems like batch or job-shop. The manufacturing orders are dynamically scheduled considering namely deadlines and resource allocation. The system combines three modules: pre-scheduling, dynamic scheduling and re-scheduling. Each module applies heuristics to select the best solutions depending on the scheduling policies defined by the production manager.
- DEFINING A MODEL FOR AGENT-BASED PARTICIPANT SUPPORT IN GROUP DECISION MEETINGPublication . Marreiros, Goreti; Ramos, Carlos; Neves, José; Ramos, Carlos; Vale, ZitaThis paper aim to present a multi-agent model for a simulation system, whose goal is to help one specific participant of multi-criteria group decision making process. This model has five main intervenients types: the human participant, who is using the simulation and argumentation support system; the participant agents, one associated to the human participant and the others simulating the others members of the decision meeting group; the directory agent; the proposal agents, representing the different alternatives for a decision (the alternatives are evaluated based on criteria); and the voting agent responsible for all the voting mechanisms. At this stage it is proposed a two phase algorithm. In the first phase each participant agent makes his own evaluation of the proposals under discussion, and the voting agent proposes a simulation of a voting. In second phase, after the dissemination of the voting results, each one of the participant agents will argue to convince the others to choose one of the possible alternatives. The arguments used to convince a specific participant are dependent on agent knowledge about that participant. The two-phase algorithm is applied iteratively.