A thermoelastic system of memory type in noncylindrical domains

In this paper, we consider a hyperbolic thermoelastic system of memory type in domains with moving boundary. The problem models vibrations of an elastic bar under thermal effects according to the heat conduction law of Gurtin and Pipkin. Global existence is proved by using the penalty method of Lions. (c) 2007 Elsevier Inc. All rights reserved.

Mice and larvae tracking using a particle filter with an auto-adjustable observation model

This paper proposes a novel way to combine different observation models in a particle filter framework. This, so called, auto-adjustable observation model, enhance the particle filter accuracy when the tracked objects overlap without infringing a great runtime penalty to the whole tracking system. The approach has been tested under two important real world situations related to animal behavior: mice and larvae tracking. The proposal was compared to some state-of-art approaches and the results show, under the datasets tested, that a good trade-off between accuracy and runtime can be achieved using an auto-adjustable observation model. (C) 2009 Elsevier B.V. All rights reserved.

Exact penalties for variational inequalities with applications to nonlinear complementarity problems

In this paper, we present a new reformulation of the KKT system associated to a variational inequality as a semismooth equation. The reformulation is derived from the concept of differentiable exact penalties for nonlinear programming. The best theoretical results are presented for nonlinear complementarity problems, where simple, verifiable, conditions ensure that the penalty is exact. We close the paper with some preliminary computational tests on the use of a semismooth Newton method to solve the equation derived from the new reformulation. We also compare its performance with the Newton method applied to classical reformulations based on the Fischer-Burmeister function and on the minimum. The new reformulation combines the best features of the classical ones, being as easy to solve as the reformulation that uses the Fischer-Burmeister function while requiring as few Newton steps as the one that is based on the minimum.

Structured minimal-memory inexact quasi-Newton method and secant preconditioners for augmented Lagrangian optimization

Augmented Lagrangian methods for large-scale optimization usually require efficient algorithms for minimization with box constraints. On the other hand, active-set box-constraint methods employ unconstrained optimization algorithms for minimization inside the faces of the box. Several approaches may be employed for computing internal search directions in the large-scale case. In this paper a minimal-memory quasi-Newton approach with secant preconditioners is proposed, taking into account the structure of Augmented Lagrangians that come from the popular Powell-Hestenes-Rockafellar scheme. A combined algorithm, that uses the quasi-Newton formula or a truncated-Newton procedure, depending on the presence of active constraints in the penalty-Lagrangian function, is also suggested. Numerical experiments using the Cute collection are presented.

Augmented Lagrangian methods under the constant positive linear dependence constraint qualification

Two Augmented Lagrangian algorithms for solving KKT systems are introduced. The algorithms differ in the way in which penalty parameters are updated. Possibly infeasible accumulation points are characterized. It is proved that feasible limit points that satisfy the Constant Positive Linear Dependence constraint qualification are KKT solutions. Boundedness of the penalty parameters is proved under suitable assumptions. Numerical experiments are presented.

Los asilados de las embajadas de Europa Occidental en Chile tras el golpe militar y sus consecuencias diplomáticas : El caso de Suecia

Given the expectations that western governments had in the reforms being implemented by the Unidad Popular, the September 1973 coup d’état in Chile caused a great international outcry. The violence and repression that accompanied the military coup produced a worldwide repudiation of the military junta. Sweden stood out most consistently among the countries that declared their opposition to Chile during the period of the dictatorship by continuously denouncing the violations to human rights. In this context, Sweden’s Ambassador to Chile, Harald Edelstam, played a very important role in saving the lives of hundreds of Chilean citizens and foreign nationals who sought refuge from the regime’s bloody repression. Making use of the privileges he enjoyed as a diplomat, Edelstam confronted the military authorities to release people wrongfully sentenced to the death penalty. As a result, he was declared persona non grata and forced to leave Chile. This was the beginning of a long and controversial diplomatic relationship that lasted until the return of democracy in Chile in 1990. This article is a first attempt at understanding how human rights violations affected bilateral relations between Chile and Sweden with respect to the diplomatic efforts of Ambassador Harald Edelstam.

Determining the Trustworthiness of New Electronic Contracts

Expressing contractual agreements electronically potentially allows agents to automatically perform functions surrounding contract use: establishment, fulfilment, renegotiation etc. For such automation to be used for real business concerns, there needs to be a high level of trust in the agent-based system. While there has been much research on simulating trust between agents, there are areas where such trust is harder to establish. In particular, contract proposals may come from parties that an agent has had no prior interaction with and, in competitive business-to-business environments, little reputation information may be available. In human practice, trust in a proposed contract is determined in part from the content of the proposal itself, and the similarity of the content to that of prior contracts, executed to varying degrees of success. In this paper, we argue that such analysis is also appropriate in automated systems, and to provide it we need systems to record salient details of prior contract use and algorithms for assessing proposals on their content. We use provenance technology to provide the former and detail algorithms for measuring contract success and similarity for the latter, applying them to an aerospace case study.

The LaGuardia - Red Hook Caregiver

Vol. II, No. 2; This document was produced as a result of a training and development project for staff in the social services system through a contractual agreement between the New York State Department of Social Services and the Research Foundation of the City University of New York on behalf of La Guardia Community College. No date, library receipt, 1979.

The LaGuardia - Red Hook Caregiver

Vol. I, No. 5; This document was produced as a result of a training and development project for staff in the social services system through a contractual agreement between the New York State Department of Social Services and the Research Foundation of the City University of New York on behalf of La Guardia Community College. No date, library receipt, 30 January 1979.

The LaGuardia - Red Hook Caregiver

Vol. II, No. 3; This document was produced as a result of a training and development project for staff in the social services system through a contractual agreement between the New York State Department of Social Services and the Research Foundation of the City University of New York on behalf of La Guardia Community College. No date, library receipt, 13 September 1979.

Impactos da votalidade cambial na atividade de turismo receptivo: novos desenhos de contratos

De 2002 a 2006 a moeda nacional brasileira, o real, vem sofrendo crescente valorização, tendência que afeta negativamente o setor exportativo no Brasil. Este trabalho refere-se o impacto desta valorização numa indústria específica do setor de exportação, a de turismo receptivo. São destacados os modelos de contratos atuais e analisada a proposição de um novo modelo de contrato, fechado em moeda nacional para as vendas internacionais, visando minimizar o risco cambial inerente à atividade. Os resultados indicam que a adoção deste novo modelo contratual eliminaria o risco cambial da parte da cadeia de distribuição situada no território nacional, trocando este por risco de demanda em função da flutuação do preço para o cliente final.

Signalling and arbitrage

Given a competitive signalling game, we study a transformed game which includes the natural enrichment of contractual opportunities in a market. We show that subgame perfect equilibrium outcomes in the new game which satisfy certa in competitive hypotheses induce sequential equilibrium outcomes in the original game which satisfy the Cho-Kreps extended intuitive criterion. Arbitrage opportunities in the transformed game achieve results similar to refinements of sequential equilibria in the original game.

Desenho de um sistema de metas sociais

Este trabalho discute a racionalidade econômica para o desenvolvimento de um sistema de metas sociais como forma do governo federal aumentar a eficiência na utilização dos recursos sociais transferidos para os municípios. O trabalho desenvolve algumas extensões do modelo de agente-principal incluindo abordagens estáticas com e sem informação imperfeita. Os resultados dos modelos estáticos indicam que o uso de critérios usuais de focalização onde localidades mais pobres recebem mais recursos podem levar a incentivos adversos para a erradicação da pobreza. Demonstramos que transferências incondicionais do governo federal deslocam gastos sociais locais. O trabalho argumenta em favor do uso de contratos onde quanto maior for a melhora no indicador social escolhido, mais recursos o município receberia. A introdução de informação imperfeita neste modelo basicamente gera uma penalidade aos segmentos pobres de áreas onde os governos demonstram ser menos avessos a pobreza. O trabalho também aborda o problema de favoritismo político onde determinados grupos sociais têm maior, ou menor, atenção por parte de governos locais. O resultado é que as políticas sociais acabam privilegiando determinados setores em detrimento de outros. Com o estabelecimento de metas sociais é possível, se não eliminar o problema, ao menos criar incentivos corretos para que os gastos sociais sejam distribuídos de forma mais equânime.

Desenho de um sistema de metas sociais

Este trabalho discute a racionalidade econômica para o desenvolvimento de um sistema de metas sociais como forma do governo federal aumentar a eficiência na utilização dos recursos sociais transferidos para os municípios. O trabalho desenvolve algumas extensões do modelo de agente-principal incluindo abordagens estáticas com e sem informação imperfeita. Os resultados dos modelos estáticos indicam que o uso de critérios usuais de focalização onde localidades mais pobres recebem mais recursos podem levar a incentivos adversos para a erradicação da pobreza. Demonstramos que transferências incondicionais do governo federal deslocam gastos sociais locais. O trabalho argumenta em favor do uso de contratos onde quanto maior for a melhora no indicador social escolhido, mais recursos o município receberia. A introdução de informação imperfeita neste modelo basicamente gera uma penalidade aos segmentos pobres de áreas onde os governos demonstram ser menos avessos a pobreza. O trabalho também aborda o problema de favoritismo político onde determinados grupos sociais têm maior, ou menor, atenção por parte de governos locais. O resultado é que as políticas sociais acabam privilegiando determinados setores em detrimento de outros. Com o estabelecimento de metas sociais é possível, se não eliminar o problema, ao menos criar incentivos corretos para que os gastos sociais sejam distribuídos de forma mais equânime.

The insurance function of contracts

One of the central problems in contract law is to define the frontier between legal and illegal breaches of promises. The distinction between good and bad faith is perhaps the conceptual tool most commonly used to tell one from the other. Lawyers spend a lot of energy trying to frame better definitions of the concepts of good and bad faith based on principles of ethics or justice, but often pay much less attention to theories dealing with the incentives that can engender good faith behavior in contractual relationships. By describing the economics of what Stiglitz defined as “explicit” and “implicit” insurance, I highlight the “insurance function” hidden in any promise with basically no mathematical notation. My aim is to render the subject intelligible and useful to lawyers with little familiarity with economics.