ABSTRACT This study analyses the importance of Brazilian ports, based on the flow of non-containerized cargo in 2014, considering both national and foreign trades. For that, we study a non-traditional centrality, called layer centrality, which evaluates the importance of ports, based on how well they are connected to influential ports. This measurement was preliminarily proposed in 2011 and applied to a simple nonweighted network, though herein we extend it to weighted graphs. For comparison purposes, we also apply three traditional measures, namely degree, eigenvector, and flow betweenness centralities. Our findings show that the most impactful ports are private terminals Ponta da Madeira and Tubarão, although public ports, particularly Santos, are usually impactful for national trades. Moreover, we analysed the map for public ports and suggest a suitable location for a new public port.

Resumen A pesar de que los modelos estándar del Análisis Envolvente de Datos (DEA) han sido ampliamente utilizados en la evaluación de la eficiencia en educación, existen pocos estudios que utilizan modelos DEA en red (Network DEA - NDEA) en la evaluación educativa. En el presente trabajo, se ha propuesto una alternativa a la evaluación oficial realizada a cada tres años por la CAPES (agencia brasileña para la regulación de los programas de post-graduación) mediante un modelo DEA en red. El uso de NDEA se justifica ya que dependiendo del punto de vista algunas variables pueden ser consideradas como entradas o como salidas. El uso de NDEA evita la necesidad de decidir si una variable es una entrada o una salida de todo el proceso. Esto ocurre porque una variable puede ser tanto una salida para una etapa y una entrada para otro. Nuestro modelo relacional NDEA evalúa tanto la productividad como la calidad junto con la eficiencia global, a partir de datos bibliométricos.

Abstract Despite standard Data Envelopment Analysis (DEA) models having been widely used in assessing efficiency in education, a few studies use Network DEA (NDEA) models in educational evaluation. In this paper, we proposed an alternative to the official evaluation performed every three years by CAPES (Brazilian agency for post-graduation programs regulation) using an NDEA model. The use of NDEA is justified because depending on the point of view, some variables can be considered either inputs or outputs. The use of NDEA avoids the need to decide whether a variable is an input or output of the entire process. This happens because a variable can be both an output for one stage and an input for another. Our relational NDEA model computes both productivity and quality assessments together with global efficiency using bibliometric data.

ResumoNeste artigo, realiza-se uma análise comparativa dos resultados de eficiência obtidos usando duas abordagens preexistentes de Análise Envoltória de Dados em relação à metodologia aqui proposta, que representa uma alternativa para lidar com diferenças de escala. Para tanto, é conduzido um estudo sobre o desempenho operacional das empresas brasileiras de transporte aéreo de passageiros, quanto ao uso da frota. A proposta combina clusterização estática ao modelo para retornos constantes de escala, e compensação das diferenças de escala entre os clusters. A inovação está na adaptação de técnica, a princípio, idealizada para lidar com a não-homogeneidade, ao tratamento de diferenças de escala. Os resultados revelam que a metodologia proposta aumenta a discriminação entre as empresas, havendo unidades 100% eficientes nas abordagens preexistentes testadas, cuja eficiência foi reduzida, ocasionando menos empates. Outro aspecto relevante é que a metodologia proposta apresenta vantagens comparativas em relação as alternativas existentes na literatura.

AbstractIn this article, we carried out a comparative analysis of the efficiency results obtained using two existing approaches of DEA in relation to the methodology proposed here, which is an alternative to deal with differences of scale. For this, a study on the operational performance of the Brazilian air passenger transportation business is conducted. The proposal combines static clustering to the constant returns-to-scale model, and compensation scale differences among the clusters. The innovation relies on the adaption of a technique, originally designed to handle non-homogeneity to treat differences of scale. The results show that the proposed methodology increases the discrimination among companies, that is, some units that resulted 100% efficient in the existing approaches, had their efficiency reduced, resulting in less draws. Another relevant aspect is that the proposed methodology has comparative advantages over existing alternatives in the literature.

Ao longo do tempo, o número e o campo de aplicações em DEA aumentaram sobremaneira. A complexidade decorrente das relações entre os múltiplos inputs e outputs das Unidades Tomadoras de Decisão (DMUs) em estudo dificulta o uso de outras metodologias, tornando a ferramenta DEA bastante atrativa na busca da identificação da eficiência dessas DMUs. O objetivo deste estudo é definir um método de resolução da ambiguidade na determinação dos pesos das DMUs extremo-eficientes, de forma que cada DMU tenha um conjunto único de pesos, permitindo conhecer a importância relativa de cada inputou output. A proposta é substituir a fronteira DEA CCR original, que é linear por partes, por uma fronteira suavizada, o mais próximo possível da primeira, mas continuamente diferenciável em todos os seus pontos. A suavização possibilita a realização de aplicações como o cálculo dos trade-offs nas DMUs extremo-eficientes e a Avaliação Cruzada.

Over time, the number and range of applications in the DEA have increased greatly. The resulting complexity of the relationships between the multiple inputs and outputs of decision making units (DMUs) in a study hinders the use of other methodologies. This makes DEA quite attractive for identifying the performance of these DMU's. The aim of this study is to define a method of solving the ambiguity in determining the weights of extremely efficient DMUs so that each DMU has a single set of weights, allowing for determination of the relative importance of each input or output. The proposal is to replace the original CCR DEA frontier, which is piece-wise linear, with a smoothed one, which is as close as possible to the first but continuously differentiable at all points. Smoothing allows for the calculation of trade-offs in the extreme-efficient DMUs and in Cross-Evaluation, among other applications.

This study evaluated the performance of 21 beef cattle modal production systems that conduct only the raising phase. These production systems were developed in 21 municipalities in seven Brazilian states. We used two different DEA BCC models, corresponding to different points of view. Firstly we used an economic model that measured the ability of a production system to generate revenue with the preservation of native forest, using labor, capital, and current spending as inputs. The socio-environmental approach, corresponding to the second BCC model, uses the production factor labor as an output. In that model our interest was to assess whether the capital costs generate economic, environmental, and social benefits. Weight restrictions were imposed on the output variables of each model to explain the proposed viewpoints and to avoid inconsistent results. The results pointed out sources of inefficiency in terms of labor with low qualification, and use of bulls of questionable quality, factors that are common in extensive systems. These are some of the major bottlenecks in animal production systems as a whole.

Neste artigo propõe-se analisar comparativamente o desempenho de sistemas de produção modais de pecuária extensiva de corte na fase de cria em 21 municípios brasileiros. A cria é a fase da atividade que sustenta toda a cadeia de produção da pecuária de corte. É usado o modelo de análise envoltória de dados (DEA) com retornos variáveis de escala. O objetivo é medir o desempenho da decisão do produtor em relação à composição do sistema produtivo. As variáveis usadas são número de reprodutores, quantidade de bezerros e vacas de descarte. Dos 21 sistemas avaliados, quatro foram DEA BCC eficientes e a maioria dos sistemas avaliados opera na região de retornos crescentes de escala.

In this article, the performance of extensive livestock modal production systems was analyzed comparatively during its rearing phase in 21 Brazilian municipalities. This phase constitutes the activity that sustains the entire livestock production chain. Data envelopment analysis (DEA) models were used with variable returns to scale. The objective was to measure the performance of the producer's decision regarding the composition of the production system. The number of bull breeders, number of calves and number of cull cows were the variables used. Four of the 21 systems evaluated were DEA efficient and most of them were operating under increasing returns to scale.

O sistema portuário é elemento-chave para o desenvolvimento macroeconômico da sua área de influência. A avaliação de desempenho do setor portuário torna-se fundamental para o monitoramento e o aprimoramento das atividades deste setor para buscar atingir a eficiência. Para que se possa procurar a eficiência é preciso medi-la e conhecer as ineficiências. Estas medidas podem ser feitas com a Análise Envoltória de Dados (Data Envelopment Analysis - DEA) que é um método baseado em programação matemática, que analisa, com base nos recursos (inputs) e produtos (outputs) utilizados em dado processo, a eficiência de um conjunto de unidades tomadoras de decisão (Decision Making Units - DMU). O presente trabalho teve como objetivo elaborar e analisar modelo para a medição da eficiência dos portos da Região Nordeste do Brasil, no ano de 2006, adotando o método DEA. A seleção de variáveis foi feita com auxílio do método Compensatório de Normalização Única, o qual determina as variáveis a serem utilizadas através do índice S que depende da eficiência média (relação causal) e da quantidade de DMU na fronteira (poder de discriminação). Foram analisadas as instalações e operações de contêineres e granéis sólidos dos principais portos da Região Nordeste. A obtenção da eficiência portuária, efetuada por tipo de carga, auxilia no planejamento de médio e longo prazo, de forma a organizar os portos para aumentar a movimentação horária e a movimentação de cargas, contribuindo, assim, para a eficiência dos terminais.

The port system is a key element for the macroeconomic development of its area of influence. The performance evaluation of the port sector becomes fundamental to the monitoring and improvement of the activities of this sector aiming at accomplishing efficiency. The Data Envelopment Analysis - DEA is a method based on mathematic programming which analyzes, based on the inputs and outputs utilized in a certain process, the efficiency of a set of Decision Making Units - DMU. This paper aims to elaborate and analyze models for the efficiency measuring of the ports in Brazil's northwest in 2006, adopting the DEA method. The variables selection was done with the aid of the Compensatory method of Normalization (Single Parameter), which determines the variables to be utilized through index S that depends on the average efficiency (causal relation) and the quantity of DMU in the frontier (discrimination power). The facilities of containers and solid bulks of the main ports in northwest were analyzed. The obtaining of the port efficiency executed by the type of load helps in the medium and long-term planning, so that it organizes the ports to increase the timetable turnover and the loads turnover, contributing to the efficiency of the terminals.

O objetivo deste artigo é a realização de uma avaliação da eficiência das autoridades portuárias brasileiras no desempenho de suas funções, no período de 2007 a 2009, com a utilização da Análise Envoltória de Dados (DEA). Consideraram-se como inputs: Número de funcionários, Custo operacional, Investimento e como Outputs: Faturamento e Carga Movimentada. Destaca-se ainda a orientação a Output e a utilização na análise do estudo proposto da eficiência de escala e da avaliação cruzada. Foram consideradas oito autoridades portuárias em três anos totalizando 24 DMUs. O estudo proposto permitiu avaliar se as operações das Companhias Docas estão sendo eficientes do ponto de vista operacional e permitiu comparar o desempenho entre as autoridades portuárias para identificar quais elementos de gestão devem ser modificados para o alcance de um desempenho satisfatório. De forma consolidada, pôde-se perceber que a CODESP (São Paulo) foi a companhia Docas mais eficiente no período, seguida pela CODOMAR (Maranhão) e pela CDRJ (Rio de Janeiro).

This article aims to make an efficiency evaluation of Brazilian port authorities in performing their functions, from 2007 to 2009, using Data Envelopment Analysis (DEA). It is considered as inputs: quantity of employees, operational costs, investments; and as outputs: billing and handled cargo. The used DEA model is output-oriented and uses for its analysis scale efficiency and cross efficiency evaluation. Eight port authorities are considered in three years, resulting in 24 DMUs. This study allows us to evaluate if the Docks Companies operations are being efficient from the operational point of view, as well as to compare the performance between the port authorities, in order to identify which management elements should be turned to the achievement of a satisfactory performance. On a consolidated basis, we could notice that Docks Company CODESP (São Paulo) was the more efficient company in the period, followed by CODOMAR (Maranhão) and CDRJ (Rio de Janeiro).

Este trabalho busca auxiliar na solução de um problema de seleção de uma aeronave enfrentado por uma empresa aérea que estuda o investimento na atividade de voo charter regional. A empresa em análise, pertencente a um grupo econômico cujo negócio principal é a logística, dispõe de oito alternativas a serem avaliadas sob onze diferentes critérios. A metodologia utilizada para a solução do problema é um novo método de apoio à decisão multicritério derivado do método de Borda, denominado Método de Borda com Utilização das Medianas. A utilização do método se justifica por sua característica de ser menos influenciado que o método original pelas alternativas irrelevantes e por sua facilidade de entendimento e baixa complexidade computacional. O método forneceu resultados consistentes, dando suporte confiável à decisão.

This article tries to solve a problem of selecting an airship for an airline company whose core business is regional charter flights. The company belongs to an economic group whose main activity is logistics. The decision problem that the company faces has eight alternatives to be accessed according to eleven criteria. For approaching the problem a novel multicriteria decision aiding method is used. This new method is one variant of the classical Borda method denoted by Modified or Median-based Borda Method. Using this new method is justified by the fact that it is less influenced by the irrelevant alternatives as well as by its easy of understanding and its low computational complexity. The thus Modified Borda Method provided for consistent results and thus led to a reliable decision support.

DEA models assume the homogeneity of the units under evaluation (DMUs). However,in some cases, the DMUs use different production technologies. In such cases, they should be evaluated separately. In this paper we evaluate the efficiency of family farmers from the Brazilian Eastern Amazon, who use different agricultural production systems. We propose an alternative algorithm to assess the global efficiency, taking into account the non-homogeneity. The results show that the farmers that use the classical technology are more efficient than those considered "environmental friendly", as we took into account only the economic point of view.

O crescente aumento da competitividade do setor de transporte aéreo nos últimos anos tem provocado uma mudança na dinâmica de mercado, levando as companhias aéreas a buscar novas estratégias para garantir a sua posição. Este artigo tem o objetivo de analisar o desempenho das companhias aéreas brasileiras no que tange à sua gestão operacional, após a crise do setor, ocorrida em 2006. A eficiência das empresas aéreas em 2007 foi avaliada através da comparação dos resultados obtidos no modelo de Análise Envoltória de Dados (Data Envelopment Analysis - DEA) clássico com os calculados pelo método da fronteira invertida. Este artigo inclui ainda a identificação das companhias com as melhores e piores práticas gerenciais.

The increase of the air transportation sector competition in recent years has changed this market dynamics, leading airlines to seek new strategies to ensure their position. This article aims to analyze the performance of Brazilian air carriers regarding their operational management after the crisis of the sector in 2006. The analysis of the companies' efficiency in 2007 is done by comparing the results obtained with a classic DEA model to those obtained with the Inverted Frontier method. This paper includes the identification of the airlines with the best and the worst managerial practices.

The final ranking of a championship is determined by quality attributes combined with other factors which should be filtered out of any decision on relegation or draft for upper level tournaments. Factors like referees' mistakes and difficulty of certain matches due to its accidental importance to the opponents should have their influence reduced. This work tests approaches to combine classification rules considering the imprecision of the number of points as a measure of quality and of the variables that provide reliable explanation for it. Two home-advantage variables are tested and shown to be apt to enter as explanatory variables. Independence between the criteria is checked against the hypothesis of maximal correlation. The importance of factors and of composition rules is evaluated on the basis of correlation between rank vectors, number of classes and number of clubs in tail classes. Data from five years of the Brazilian Soccer Championship are analyzed.

The cow-calf beef production sector in Brazil has a wide variety of operating systems. This suggests the identification and the characterization of homogeneous regions of production, with consequent implementation of actions to achieve its sustainability. In this paper we attempted to measure the performance of 21 livestock modal production systems, in their cow-calf phase. We measured the performance of these systems, considering husbandry and production variables. The proposed approach is based on data envelopment analysis (DEA). We used unitary input DEA model, with apparent input orientation, together with the efficiency measurements generated by the inverted DEA frontier. We identified five modal production systems typologies, using the isoefficiency layers approach. The results showed that the knowledge and the processes management are the most important factors for improving the efficiency of beef cattle production systems.

The objective of this study was to propose Data Envelopment Analysis (DEA) models and non-parametric Malmquist indexes to evaluate the efficiency of 11 livestock farms in the Pantanal region. These farms took out a loan from 'Fundo Constitucional de Financiamento do Centro-Oeste' - FCO (Constitutional Financial Fund for the Midwest), a line of credit for financing heifer retention. The beneficiaries were the farmers whose properties met the following conditions: farms located in the plain of Pantanal, with at least 50% of native pasture; farms that were part of managerial capacity building projects intended to ensure better management and animal performance indexes; and farms with pasture areas where the activity could potentially evolve. The management of the loan on 11 farms were studied in relation to the technology introduced in the period from 2004 to 2008. Five properties presented technical efficiency below 1, that is, the technical management efficiency with the objective to increase the cattle through heifer retention and the purchase of higher genetic quality heifers was not achieved. However, the index of technological progress was above 1 on all tested farms, which means that technology was in fact incorporated in all properties, which resulted in total factor productivity growth on all farms. The main objective was fully met, even on the technically inefficient farms.

O presente trabalho faz uso de Análise Envoltória de Dados para avaliar a eficiência temporal de rodovias federais que fazem parte do Programa de Concessão de Rodovias com base nos relatórios anuais publicados pela Agência Nacional de Transportes Terrestres (ANTT) nos anos 2005 até 2008. Dois modelos DEA são considerados: o primeiro visa medir a eficiência da concessionária que administra a rodovia com relação ao uso de bens de capital e a gestão de pessoal na operacionalização da rodovia enquanto o segundo avalia a eficiência da rodovia com relação ao uso das receitas e investimentos em segurança. É proposto ainda um índice de eficiência global que é produto dos índices de eficiência dos dois modelos utilizados.

The present study uses Data Envelopment Analysis (DEA) to evaluate the temporal efficiency of Brazilian federal highways that take part on the Highways Grant Program. The study is based on the annual reports published by Brazilian National Land Transport from 2005 to 2008. We apply two DEA models: the first one aims to evaluate the concessionaire of the highway efficiency regarding the use of capital goods and human resources while the second one measures the efficiency regarding the use of incomes and investments for the highway security. We also propose a efficiency global index which is the product of efficiency indices of the two models applied.