Development of a Farm Management Tool for the Brazilian Conditions

This paper presents results of a managerial information system prototype developed for modern agriculturalists in the Brazilian Cerrado´s Region. It follows a case study approach. One medium scale (422 hectares) of operation was envisioned, archetypical accounting framework was established, aiming to provide better data and information to support farm management decisions. The system has proved to be useful in examining decision making at farm level and in ex ante evaluations of changes in farm-level input use, output and profitability in response to price, policy, and/or technology changes. Data entry was done in ACCESS for user friendliness and global availability; presentational materials were prepared in ACCESS and in EXCEL.Family farm system, Microsoft ACCESS application, managerial information, cost accounting, Farm Management,

On Aharonov-Casher bound states

In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the $\boldsymbol{\nabla}\cdot\mathbf{E}$ term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem.Comment: 11 pages, matches published versio

A grid broker pricing mechanism for temporal and budget guarantees

We introduce a pricing mechanism for Grid computing, with the aim of showing how a broker can accept the most appropriate jobs to be computed on time and on budget. We analyse the mechanism’s performance via discrete event simulation, and illustrate its viability, the benefits of a new admission policy and to how slack relates to machine heterogeneity