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.

CPITN: time and cost estimates for periodontal prevention and treatment procedures.

The aim of this study was to estimate the necessary time and cost for periodontal prevention and treatment in a working population from sugar and alcohol refineries in Araraquara, SP, Brazil. A stratified sample of 528 employees aged 18-64 from administrative, industrial and agricultural staffs was examined by one examiner, previously trained, according to the community periodontal index of treatment needs (CPITN). The time required for procedures and the cost was extrapolated to the total worker population. The results showed that the estimated time required for periodontal prevention/treatment was 4527 hours. Of this time, 1783 hours were required for oral hygiene instruction, 2531 for scaling, 151 for surgery and 62 for maintenance. The cost would be US $17,655 for hiring a dentist for 8 hours/day to provide oral hygiene instruction, scaling, surgery and maintenance. However, the cost would be US $9,028 for hiring a dentist for 4 hours/day to provide surgery and maintenance and a dental hygienist for 8 hours/day to provide scaling and oral hygiene instruction. Taking into account epidemiologic, technical and economic aspects, the decision relating to manpower should be this second option.

Spinning reserve opportunity cost in hydroelectric plants

Starting from the deregulated process of the Electric Sector, there was the need to attribute responsibilities to several agents and to elaborate appropriate forms of remuneration of the services rendered by the same. One of the services of great importance within this new electric sector is the Ancillary Services. Among the various types of Ancillary Services, Spinning Reserve is a service necessary for maintaining the integrity of the transmission system from either generation interruptions or load variations. This paper uses the application of the Economic Dispatch theory with the objective of quantifies the availability of Spinning Reserve supply in hydroelectric plants. The proposed methodology utilizes the generating units as well as their efficiencies so as to attend the total demand with the minimum water discharge. The proposed methodology was tested through the data provided by the Água Vermelha Hydroelectric Power Plant. These tests permitted the opportunity cost valuation to the Spinning Reserve supply in hydroelectric plants. © 2005 IEEE.

A comercialização de uvas finas na região de Jales – SP

A produção de uvas finas para mesa destaca-se entre as principais atividades econômicas da região noroeste do Estado de São Paulo, Brasil. Entretanto, os produtores comumente apontam os problemas relativos à comercialização da fruta como um dos mais importantes obstáculos interpostos ao desenvolvimento da fruticultura regional. Este trabalho analisa as transações entre produtores e agentes de comercialização da fruta, discutindo as estruturas de governança presentes e as razões que explicam a exposição dos produtores a comportamentos oportunísticos associados aos distribuidores. Conclui-se que produtores que desenvolvem sistemas produtivos mais especializados, ofertadores de frutas de melhor qualidade, são atendidos por agentes de intermediação também especializados e, portanto, estão menos expostos a comportamentos oportunísticos. Nestes casos, a relação entre os agentes torna-se mais efetiva e sistemática, e a estrutura de governança transita de coordenação via mercado para formas híbridas.