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Publications

Publications by António Carvalho Brito

2007

Know-how retention and divulgation with a fuzzy CBR system

Authors
Marques, VM; Farinha, JT; Brito, AC; Pincho, NL;

Publication
PROCEEDINGS OF THE 7TH INTERNATIONAL CONFERENCE ON INTELLIGENT SYSTEMS DESIGN AND APPLICATIONS

Abstract
This paper describes how Fuzzy Logic helped the representation and handling of equipment fault descriptions and diagnosis in a Case-Based Reasoning (CBR) system, in a way close to common spoken language, frequently vague, used by maintenance teams in daily maintenance tasks. These descriptions may be of two types as sometimes they contain a judgment based on the technician own know-how and sometimes they don't. For case similarity computation the "meaning" of these observations must be understood and all must be reduced to the same format before any further calculus may take place. In this context another important issue is relevance: the weight of each observation for each possible diagnosis is automatically captured by the CBR system according to the experiences it stores along its life-cycle. A prototype has been tested in the health-equipment maintenance field. The system acts as a know-how repository and a divulgation support, part Of an intelligent e-learning plafform for staff training,

2009

Holistic Metrics, a Trial on Interpreting Complex Systems

Authors
Feliz Teixeira, JM; Carvalho Brito, AESC;

Publication
COMPLEX SYSTEMS AND SELF-ORGANIZATION MODELLING

Abstract
In this text is proposed a simple method for estimating or characterize the behaviour of complex systems, in particular when these are being studied throughout simulation. Usual ways of treating the complex output data obtained from the activity (real or simulated) of such a kind of systems, which in many cases people classify and analyse along the time domain, usually the most, complex perspective, is herein substituted by the idea of representing such data in the frequency domain, somehow like what is commonly done in Fourier Analysis and in Quantum Mechanics. This is expected to give the analyst a more holistic perspective oil the system's behaviour, as well as letting him/her choose almost freely the complex states in which such behaviour is to be projected. We hope this will lead to simpler processes in characterizing complex systems.

2009

Case-based reasoning and fuzzy logic in fault diagnosis

Authors
Marques, V; Farinha, JT; Brito, A;

Publication
WSEAS Transactions on Computers

Abstract
This paper is divided into four parts: the first one introduces SADEX, a fuzzy Case Based Reasoning (CBR) System for fault diagnosis. The second focus on its observation relevance factors and shows how the results are in complete agreement with the relevance concept introduced by Robertson and Spark-Jones in their well known and proved technique for document retrieval. The third describes how equipment composition information can be used to generalize and adapt case solutions to new and unknown occurrences; this generalization is based on a taxonomic similarity between functionally autonomous modules (FAMs). Finally the MKM-Maintenance Knowledge Manager system is introduced.

2008

Holistic metrics applied to a practical supply chain study

Authors
Carvalho Brito, AESC; Feliz Teixeira, JM;

Publication
15TH EUROPEAN CONCURRENT ENGINEERING CONFERENCE/5TH FUTURE BUSINESS TECHNOLOGY CONFERENCE

Abstract
In this article we present a practical example where the concept of Holistic Metrics (Feliz-Teixeira & Brito, 2006) is used as a way for sensing the results obtained in a simulation study related to the Portuguese enterprise GalpEnergia. Previously described in Feliz-Teixeira & Brito (2005), that case is used again in this article in order to demonstrate the practical value of the Holistic Metrics concept. This is basically a simple method for estimating or characterizing the behaviour of complex systems, in particular when these are studied throughout simulation. Instead of treating the complex output data obtained from this kind of system along the time domain, this perspective encourages analysts to represent such data in the frequency domain, somewhat as is adopted in Fourier Analysis and in Quantum Mechanics.

2009

CBR for Diagnosis: Evidence Relevance and Case Adaptation

Authors
Marques, V; Farinha, JT; Brito, A;

Publication
PROCEEDINGS OF THE 13TH WSEAS INTERNATIONAL CONFERENCE ON COMPUTERS

Abstract
This paper is divided into three parts: the first one introduces SADEX, a fuzzy Case Based Reasoning (CBR) Expert System (ES) for fault diagnosis. The second focus on its observation relevance factors and shows how the results are in entire agreement with the relevance concept introduced by Robertson and Spark-Jones in their well known and proved technique of document retrieval. Finally we describe how the equipment composition information can be used to generalize and adapt case solutions to unknown occurrences. This generalization is based on a taxonomic similarity between functionally autonomous modules (FAM) or components. Some formulae for evaluating this similarity are derived.

2007

A simulation study of an automated system for a shoe factory using arena

Authors
Brito, AC; Marques, PS;

Publication
EUROPEAN SIMULATION AND MODELLING CONFERENCE 2007

Abstract
One of the issues in the shoe industry is that market seeks the fulfilment of product orders for smaller production lots with shorter deadlines. A need therefore arises to respond to these market changes. Such a response includes amongst other things improving the internal organization of the enterprise, by for example rationalizing the production floor layout. A portuguese shoe factory decided to cut costs related to the transportation of all work in progress within the factory plant by implementing a fully automated storage and retrieval system. This Paper presents the development of a Simulation model, using the Arena simulation software tool, to analyse the performance of the automated storage and retrieval system based oil a number of scenarios. The simulation model uses VBA (Visual Basic for Applications) to implement the control logic and graphics to Visualize the sequences of movements and storage / retrieval operations.

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