Ernesto Ferreira Nobre Júnior

Distribution of Materials in Road Earthmoving and Paving: Mathematical Programming Approach

This paper summarizes a mathematical model that relates the geometric and geotechnical features of a road construction site with the allocation of materials, searching for a minimum construction cost. This paper proposes a linear programming model to optimize excavation and paving services. With this model, it is possible to evaluate site alternatives with different soil strata and different degrees of compaction. The borrow pit materials are allocated in the most economical way, and it is possible to incorporate more inputs like materials mix. Software was used to solve the model, and a spreadsheet application was used as an interface for data input. The proposed model demonstrated possible cost savings in earthwork planning. It is expected that earthwork and paving optimization with linear programming will reduce road construction costs considerably.

Avaliação da eficiência dos portos utilizando análise envoltória de dados: estudo de caso dos portos da região nordeste do Brasil

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.