Francisco de Sousa Ramos

Bilateral Negotiation for Agent-Mediated Electronic Commerce

One of the main issues in electronic commerce is the inclusion of the negotiation facilities commonly available in human client-vendor interaction in real world commerce. E-commerce negotiation processes have usually been modeled as self-interested multi-agent systems. In these systems buyers and sellers are represented by agents that have opposite demands and decide what to do on the flight, based on the available information. However, currently ecommerce systems, such as Kasbah and Magma [21], provide a small number of bilateral negotiation facilities. Fortunately, some general negotiation models could be at first applied to e-commerce domain. This is typically the case of Faratins model, which can be seen as an extension of Kasbahs. In this paper, we propose an original bilateral agent negotiation model, which extends Faratins one. We introduce various facilities, such as alternative product suggestion, ultimatum generation, local contract agreements, etc. These facilities intend to grant users with a more flexible e-commerce environment. We present our model formalization, including the knowledge base that determines agent behavior. Some empirical validation is also presented to the case of computer purchase.

Measuring Public Spending Efficiency in Brazilian Municipalities: A Nonparametric Approach

The importance of public expenditure in such social services as education and public health represent a decisive contribution to a nation’s progress. A major problem is how to allocate government spending in such a way as to provide public services efficiently. In a political federation as the Brazil, the critical issue becomes the choice of the degree of decentralization in the provision of public services. Decentralization is advantageous in the production and distribution of public services due to: i) the proximity of users facilitates the ranking of the priorities; ii) it is easier to control the use of resources; Hi) the requirements of managerial capacity are lower.

STATIC VERSUS DYNAMIC DEA IN FEDERAL HIGHER EDUCATION INSTITUTIONS - IFES

The present study aims to analyze intertemporal changes in productivity at Federal Higher Education Institutions (IFES) from 2004 to 2008. It examines efficient frontiers from each year using slacks-based (SBM-DEA) and dynamic slacks-based measures (DSBM) for data envelopment analysis (DEA). The total set of IFES was divided into two subsets (group A and group B) in order to minimize heterogeneity in the sector. Estimation results show that static frontiers for both groups underestimate the institution efficiency during the study period, indicating that intertemporal frontiers are more accurate when calculating efficiency since they consider a variable link between the inputs and outputs intertemporally.

Evidências de subsídio cruzado no setor de saneamento básico nacional e suas consequências

Este trabalho analisou os diversos tipos de ocorrencia de subsidio cruzado no setor de saneamento. Verificou-se, entao, que existe a sua pratica entre grupos de consumo, residencial, comercial, industrial, publico e derivacoes desses: - por nivel de consumo, ja que os consumidores que consomem mais pagam por um custo unitario de agua superior aos demais; - entre produtos, visto que os servicos de agua, em alguns casos, sao subsidiados pelos servicos de esgoto; - entre localidades, porque, apesar de o custo de captacao, tratamento e distribuicao da agua nao ser uniforme entre os municipios em um estado, a tarifa praticada em determinados casos e unica. Como resultado, identificou-se que tais mecanismos induzem ao consumo superfluo, fazem pessoas aquinhoadas serem patrocinadas por pessoas menos favorecidas e geram conflitos intermunicipais.

Mecanismo de incentivo à renovação da mão-de-obra no mercado de trabalho face ao sistema previdenciário

In this work we tried to model the interaction between workers and firms. The pension system is placed as mediator between interests social in the work market. With the use of both retirement contracts based on the Principal-agent model, we tried to conduct the choice of workers to promote pareto-gains to society trough eficient renewal of labor force. For this purpose, it was necesary to adapt retirement rules to the preferences of worker´s work-leisure choice and to the structure of the market they are inserted in. Contracts defined in a way that disconsider the incentives on the worker have showed the possibility of promoting damage in the formof social costs, competitiveness loss and inificient use of labor.

Custos de Oportunidade para Alocação de Efluentes nas Áreas Plantadas de Cana na Bacia do Rio Pirapama

This paper identifies the opportunity costs in effluent allocation over sugarcane crop acres located more than 2Km away from the agroindustry plant JB, during the harvest season. The optimization problem described herein explains why these opportunity costs are usually missed. Actually, these costs derive from the marginal values associated to the decision-making variables concerning an economic benefit maximization problem resolved using the General Algebraic Modeling System (GAMS) and from the dual analysis of the linearized problem therein. Besides, different effluent transportation and effluent treatment cost coefficients were considered in simulating possible impacts and benefits regarding effluent allocation. This approach supports the optimal definition of charging and/or subsidizing schemes best suited to allocate effluents over sugarcane crops located farther away from hub agroindustry plants, not just for more disseminated productivity gains, but also for best compliance with river water quality constraints.

Há desigualdade de poder entre os estados e regiões do Brasil? Uma abordagem utilizando o índice de poder de Banzhaf e a Penrose Square Root Law

In Brazil there are always discussions about the number of representatives in the Federal Camera, with indications of sub or super representativeness. This discussion has political and economic value because an amount of the public resources is defined in this body and it can be linked to the effective power of the states, which can be measured by the Banzhaf index. A proposal, suggested by Penrose, is analyzed for Brazilian States and Regions. Application shows that, for the current as for the Penrose system, the most favored region is the Southeast. From the viewpoint of States, it is noticed that are those more developed and populous that possess larger voting power in both situations.

Investments in Industrial Automation - A Decision Aid Methodology

Abstract The investments in industrial automation, CIM, or other technologies does not always allow a company to increase its levels of competitiveness. It has been observed that those companies which invest more in new technologies without more detailed analysis, tends to reduce its competitiveness. This article tries to avoid this distortion by proposing a decision aid methodology. This methodology starts with a strategic analysis. Then, a processes reengineering is done in order to verify the investments necessities. Thus, a investment analysis takes place. Finally, is possible to do a investment analysis comparison against the companys strategy, by means of game theory.