Fuzzy logic to predict thermal damages of ground parts

One of the critical problems in implementing an intelligent grinding process is the automatic detection of workpiece surface burn. This work uses fuzzy logic as a tool to classify and predict burn levels in the grinding process. Based on acoustic emission signals, cutting power, and the mean-value deviance (MVD), linguistic rules were established for the various burn situations (slight, intermediate, severe) by applying fuzzy logic using the Matlab Toolbox. Three practical fuzzy system models were developed. The first model with two inputs resulted only in a simple analysis process. The second and third models have an additional MVD statistic input, associating information and precision. These two models differ from each other in terms of the rule base developed. The three developed models presented valid responses, proving effective, accurate, reliable and easy to use for the determination of ground workpiece burn. In this analysis, fuzzy logic translates the operator's human experience associated with powerful computational methods.

Uma contribuição da aplicação de modelos fuzzy empregados na detecção da queima de peças na retificação plana

Pós-graduação em Engenharia Mecânica - FEB

Reconstruction of the Environmental Quality Fuzzy Index

In the world stage, the environmental condition has been a big public policies issue. A clear understanding of the parameters that determine the state of the environment is essential for estimation of the quality of life of the population, not least since ecosystems are highly complex. Consequently, definition of public policies demands the use of evaluation tools that can combine and quantify information in a clear way. The use of indicators and indices that are able to translate the complexity of environmental conditions in cities into simpler terms has been increasingly effective in decision-making, since they assist in general evaluation of the situation in question, identification of priority actions and anticipation of future trends. In an attempt to evaluate the environmental conditions of the Brazilian city, Sorocaba, an Environmental Quality Fuzzy Index (IFQAmb) was proposed. In this work this methodology is improved. After reviewing the IFQAmb methodology, a number of changes in the index are proposed. Additional variables are suggested, derived from a State Environment Department program whose objective is to grant municipalities the title of Municipio Verde e Azul (Green and Blue City). In addition, a new rule base is being drafted to enable consideration of all possibilities, since in the existing version the use of specific criteria eliminates a significant number of rules. The changes seek to define with clarity and precision the conceptual aspects and structure of the IFQAmb, so that it can provide an even more effective evaluation of environmental performance, guiding future actions in order to improve the living conditions of the population of Sorocaba.

Metodologia de determinação de funções de pertinência de controla-dores fuzzy para a avaliação energética de empresas de avicultura de postura

The objective of this work is to determine the membership functions for the construction of a fuzzy controller to evaluate the energy situation of the company with respect to load and power factors. The energy assessment of a company is performed by technicians and experts based on the indices of load and power factors, and analysis of the machines used in production processes. This assessment is conducted periodically to detect whether the procedures performed by employees in relation to how of use electricity energy are correct. With a fuzzy controller, this performed can be done by machines. The construction of a fuzzy controller is initially characterized by the definition of input and output variables, and their associated membership functions. We also need to define a method of inference and a processor output. Finally, you need the help of technicians and experts to build a rule base, consisting of answers that provide these professionals in function of characteristics of the input variables. The controller proposed in this paper has as input variables load and power factors, and output the company situation. Their membership functions representing fuzzy sets called by linguistic qualities, as “VERY BAD” and “GOOD”. With the method of inference Mandani and the processor to exit from the Center of Area chosen, the structure of a fuzzy controller is established, simply by the choice by technicians and experts of the field energy to determine a set of rules appropriate for the chosen company. Thus, the interpretation of load and power factors by software comes to meeting the need of creating a single index that indicates an overall basis (rational and efficient) as the energy is being used.

Desequilíbrio de ligação e associação entre polimorfismos de base única com maciez da carne e espessura de gordura em bovinos Nelore utilizando painéis de alta densidade

Pós-graduação em Genética e Melhoramento Animal - FCAV

Análise do crescimento das empresas de base tecnológica no Brasil

Technology-Based Firms (TBFs) are companies with intensive innovation dynamics based on technical competences, and for which high growth rates are expected. Nevertheless, even in developed countries, the evidence suggests that significantly high growth rates are more the exception than the rule. In Brazil, most studies on TBFs focus on factors that limit their success, such as managerial experience and capital availability. Based on extensive field research and on a reliable enterprise growth rate indicator, this article aims to evaluate the expansion of those firms, analyzing its relation to key elements such as degree of consolidation, market insertion, and public policy support. We found a growth rate which, although widely varied amongst firms, was significant and was not directly related to the amount of public policy support.

Fuzzy rule-based system for evaluation of uncertainty transaction in cassava chain

A fuzzy ruled-based system was developed in this study and resulted in an index indicating the level of uncertainty related to commercial transactions between cassava growers and their dealers. The fuzzy system was developed based on Transaction Cost Economics approach. The fuzzy system was developed from input variables regarding information sharing between grower and dealer on “Demand/purchase Forecasting”, “Production Forecasting” and “Production Innovation”. The output variable is the level of uncertainty regarding the transaction between seller and buyer agent, which may serve as a system for detecting inefficiencies. Evidences from 27 cassava growers registered in the Regional Development Offices of Tupa and Assis, São Paulo, Brazil, and 48 of their dealers supported the development of the system. The mathematical model indicated that 55% of the growers present a Very High level of uncertainty, 33% present Medium or High. The others present Low or Very Low level of uncertainty. From the model, simulations of external interferences can be implemented in order to improve the degree of uncertainty and, thus, lower transaction costs.