Towards an intelligent graphical interface for linear programming modelling

The increase of computing power of the microcomputers has stimulated the building of direct manipulation interfaces that allow graphical representation of Linear Programming (LP) models. This work discusses the components of such a graphical interface as the basis for a system to assist users in the process of formulating LP problems. In essence, this work proposes a methodology which considers the modelling task as divided into three stages which are specification of the Data Model, the Conceptual Model and the LP Model. The necessity for using Artificial Intelligence techniques in the problem conceptualisation and to help the model formulation task is illustrated.

Negative dimensional integration: Lab testing at two loops

Negative dimensional integration method (NDIM) is a technique to deal with D-dimensional Feynman loop integrals. Since most of the physical quantities in perturbative Quantum Field Theory (pQFT) require the ability of solving them, the quicker and easier the method to evaluate them the better. The NDIM is a novel and promising technique, ipso facto requiring that we put it to test in different contexts and situations and compare the results it yields with those that we already know by other well-established methods. It is in this perspective that we consider here the calculation of an on-shell two-loop three point function in a massless theory. Surprisingly this approach provides twelve non-trivial results in terms of double power series. More astonishing than this is the fact that we can show these twelve solutions to be different representations for the same well-known single result obtained via other methods. It really comes to us as a surprise that the solution for the particular integral we are dealing with is twelvefold degenerate.

Optimized delta expansion for relativistic nuclear models: Renormalization of vacuum fluctuations

We use the optimized linear δ expansion and functional methods to study vacuum contributions in nuclear matter up to the lowest non-trivial order which includes exchange terms. We show that well known results (MFT, RHA and HF) can be easily reproduced when appropriate limits are taken. Neglecting vacuum contributions we explicitly show that the δ expansion goes beyond the traditional loop approximation previously used to study two loop vacuum contributions in nuclear matter. We then evaluate and renormalize vacuum exchange contributions showing that they are numerically very large, as predicted by the ordinary loop approximation.

Integrability and conformal symmetry in higher dimensions: A model with exact hopfion solutions

We use ideas on integrability in higher dimensions to define Lorentz invariant field theories with an infinite number of local conserved currents. The models considered have a two-dimensional target space. Requiring the existence of lagrangean and the stability of static solutions singles out a class of models which have an additional conformal symmetry. That is used to explain the existence of an ansatz leading to solutions with non-trivial Hopf charges. © SISSA/ISAS 2002.

Exact time dependent Hopf solitons in 3+1 dimensions

We construct an infinite number of exact time dependent soliton solutions, carrying non-trivial Hopf topological charges, in a 3+1 dimensional Lorentz invariant theory with target space S2. The construction is based on an ansatz which explores the invariance of the model under the conformal group SO(4,2) and the infinite dimensional group of area preserving diffeomorphisms of S2. The model is a rare example of an integrable theory in four dimensions, and the solitons may play a role in the low energy limit of gauge theories. © SISSA 2006.

Spinning Hopf solitons on S3 × ℝ

We consider a field theory with target space being the two dimensional sphere S2 and defined on the space-time S3 × . The Lagrangean is the square of the pull-back of the area form on S2. It is invariant under the conformal group SO(4,2) and the infinite dimensional group of area preserving diffeomorphisms of S2. We construct an infinite number of exact soliton solutions with non-trivial Hopf topological charges. The solutions spin with a frequency which is bounded above by a quantity proportional to the inverse of the radius of S3. The construction of the solutions is made possible by an ansatz which explores the conformal symmetry and a U(1) subgroup of the area preserving diffeomorphism group. © SISSA 2006.

MERCOSUR in transition: macroeconomic perspectives

Includes bibliography

Design and implementation of a dc-dc converter based on variable structure control of switched systems

This paper presents a control method for a class of continuous-time switched systems, using state feedback variable structure controllers. The method is applied to the control of a non-trivial dc-dc power converter and a simple and inexpensive control circuit design, that was simulated using the software PSpice, is proposed. The design is based on Lyapunov-Metzler-SPR systems and the performance of the resulting control system is superior to that afforded by a recently proposed alternative sliding-mode control technique. © 2011 IFAC.

Sobre a analgesia pós-operatória da morfina, cetamina ou da associação em cadelas submetidas à ovariossalpingohisterectomia eletiva

This study aimed to evaluate the post operative analgesic effects of morphine or ketamine alone or their combination in 24 healthy bitches, weighing 11.01±8.69kg and aging 27±17 months, submitted to elective ovariohysterectomy. The animals were distributed to one of the three treatments after the anaesthetic induction: morphine (GM, n=8, 0.5mg kg-1 IM), ketamine (GK, n=8, 2.5mg kg-1 IM) or ketamine combined to morphine (GKM) using the same doses previously described. Sedation score and pain assessment were performed blindly two hours before surgery and at 1, 2, 4, 8, 12, and 24 hours after extubation, using the Dobbins scale (sedation) and visual analogue scale (pain) and Glasgow modified pain scale (GMPS). Rescue analgesia was performed with 1.0mg kg-1 of morphine and if not sufficient, followed by 0.2mg kg-1 of meloxicam, both IM, when the GMPS reached above 33% of the total score. Non parametric data were analyzed using Friedmańs test followed by Dunńs test for differences in time. Kruskal-Walliś test followed by Dunńs test were used to investigate differences in the number of analgesic rescues and among groups at each time. Parametric data were evaluated by ANOVA followed by Tukey's test (P<0.05). Except for GMPS, where the values of GM were greater than for GKM at 1h post-extubation, there were no other differences among groups. The number of rescue analgesia was greater in GM (11 in total; twice in 3 animals,) when compared to GKM (3; twice in 1 animal) and GK (2; twice in 1 animal). Analgesia provided by pre-incisional ketamine was more effective when compared to morphine. According to that, ketamine alone may be used as a preemptive analgesic in bitches undergoing ovariohysterectomy; however, rescue analgesia may be necessary.

Avaliações cardiovasculares e comportamentais em gatos após a injeção intravenosa de amitraz ou xilazina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da anestesia por isofluorano em eqüinos submetidos à infusão contínua de medetomidina ou xilazina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização fenotípica e genética e do comportamento de reintegração social de perdizes (Rhynchotus rufescens) criadas em cativeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Analgesia pós-operatória em gatas submetidas à ovariohisterectomia tratadas com buprenorfina por diferentes vias de administração

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da degradação do meio físico por áreas de empréstimo usando geoindicadores e sistema de informações geográficas - área urbana de Ilha Solteira (SP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uma abordagem lógica para o gerenciamento de identificadores de objetos em sistemas gerenciadores de banco de dados não convencionais

Pós-graduação em Ciência da Computação - IBILCE