Search results

The purpose of this paper is to improve the transient response and the inter‐sample behavior of a model reference adaptive control system by an appropriate selection of the fractional order hold (FROH) gain β and the multirate gains used in the control reconstruction signal through a fully freely chosen reference model even when the continuous plant possesses unstable zeros.

A multiestimation adaptive control scheme for linear time‐invariant continuous‐time plant with unknown parameters is presented. The set of discrete adaptive models is calculated from a different combination of the correcting gain β in a FROH and the set of gains to reconstruct the plant input under multirate sampling with fast input sampling. Then the scheme selects online the model with the best continuous‐time tracking performance which includes a measure of the inter‐sample ripple, which is improved. The estimated discrete unstable zeros are avoided through an appropriate design of the multirate gains so that the reference model might be freely chosen with no constraints on potential unstable zeros.

The scheme is able to select online the discretization model with the best continuous‐time tracking performance without an appropriate initialization.

The switching mechanism among the different models should maintain in operation the active discretization model at least for a minimum residence time in order to guarantee closed‐loop stability. The inter‐sample behavior is improved, but it is not always completely removed.

The transient response and the inter‐sample behavior are improved by using this multiestimation‐based discrete controller compared with a single estimation‐based one. The implementation of discrete controllers makes it easier and cheaper to implement and also more reliable than continuous‐time controllers.

The main innovation of the paper compared with previous background work is that the reference output is supplied by a stable continuous transfer function. Then the scheme is able to partly regulate the continuous‐time tracking error while the controller is essentially discrete‐time and operated by a FROH in general.

The purpose of this paper is to discuss the properties of transparency and excitability of positive linear time‐invariant systems under internal point delays.

The problem is solved by combining the algebraic conditions for positivity, excitability, and transparency for the case of linear and time‐invariant dynamic systems in the presence of discrete lags.

It is shown that the excitability independent of delay is guaranteed if an auxiliary delay‐free system is excitable. Necessary and sufficient conditions for excitability and transparency are formulated in terms of the parameterization of the dynamics and control matrices, and equivalently, in terms of strict positivity of a matrix of an associate system obtained from the influence graph of the original system. Such conditions are testable through simple algebraic tests involving moderate computational effort.

The practical implications mainly rely on some biological and medical problems where delays are present by nature, excitability means the activation of all the state components under positive controls after a short time in the sense that it cannot remain identically zero. In the same way, it relays on the activation of all the output components under zero controls and non‐negative initial conditions.

The paper extends the concepts of excitability and transparency to dynamic systems with point time‐lags which are very common in nature and some practical problems.

Presents a special issue, enlisting the help of the author’s students and colleagues, focusing on age, sex, colour and disability discrimination in America. Breaks the evidence down into manageable chunks, covering: age discrimination in the workplace; discrimination against African‐Americans; sex discrimination in the workplace; same sex sexual harassment; how to investigate and prove disability discrimination; sexual harassment in the military; when the main US job‐discrimination law applies to small companies; how to investigate and prove racial discrimination; developments concerning race discrimination in the workplace; developments concerning the Equal Pay Act; developments concerning discrimination against workers with HIV or AIDS; developments concerning discrimination based on refusal of family care leave; developments concerning discrimination against gay or lesbian employees; developments concerning discrimination based on colour; how to investigate and prove discrimination concerning based on colour; developments concerning the Equal Pay Act; using statistics in employment discrimination cases; race discrimination in the workplace; developments concerning gender discrimination in the workplace; discrimination in Japanese organizations in America; discrimination in the entertainment industry; discrimination in the utility industry; understanding and effectively managing national origin discrimination; how to investigate and prove hiring discrimination based on colour; and, finally, how to investigate sexual harassment in the workplace.

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.

This study verifies the influence of the dimensions of corporate social responsibility (CSR) practices and consumer involvement on the identification of the individual with the company and the corporate reputation, moderated by the product category.

A covariance-based structural equation modelling is used to test the model, using a sample of 568 Argentine consumers. A multigroup analysis is employed to assess the moderating effect of the product category.

CSR practices have heterogeneous influence based on their dimension, and this influence is moderated by the product category. Accordingly, environmental practices promote consumer identification with the company, whereas those economically oriented have a direct influence on reputation. In contrast, social practices contribute to reputation if they are connected to the business model.

The study is focussed on Argentina, analysing two product categories (laptops and financial services for final consumers) and using a large, but not strictly random, sample. In order to mainstream the results, it would be relevant to replicate the proposed model in other countries and with other product categories.

It provides information about the perception of consumers regarding the CSR practices from a multi-dimensional perspective, since they have an uneven effect on identification of consumer with the company and corporate reputation due to the moderating effect of the product category. The findings of this study may be relevant for managers of technology and banking service companies.

El presente estudio comprueba la influencia de las dimensiones de las prácticas de responsabilidad social empresarial y de la implicación del consumidor sobre la identificación del individuo con la empresa y sobre la reputación empresarial, moderadas por la categoría de producto.

Se aplican ecuaciones estructurales basadas en covarianzas para contrastar el modelo, empleando una muestra de 568 consumidores argentinos. Se efectúa un análisis multigrupo para analizar el efecto moderador de la categoría de producto.

Las prácticas de RSE tienen influencia heterogénea según su dimensión, moderada la influencia por la categoría de producto. Así, las prácticas ambientales promueven la identificación del consumidor con la empresa mientras que aquéllas con orientación económica influyen directamente sobre la reputación. Por el contrario, las prácticas sociales contribuyen a la reputación si están vinculadas al modelo de negocio.

El estudio se ha focalizado en Argentina, analizando dos categorías de producto (computadoras portátiles y servicios financieros para consumidor final) y usando una muestra elevada pero no estrictamente aleatoria. Para generalizar los resultados sería relevante replicar el modelo planteado en otros países y otras categorías de producto.

Proporciona información sobre la percepción de los consumidores respecto de las prácticas de RSE desde una perspectiva multidimensional, pues éstas tienen efecto dispar sobre la identificación del consumidor con la empresa y la reputación empresarial dado el efecto moderador de la categoría de producto. Los hallazgos de este estudio pueden ser relevantes para gerentes de empresas de tecnología y de servicios bancarios.

Globalisation is generally defined as the “denationalisation of clusters of political, economic, and social activities” that destabilize the ability of the sovereign State to control activities on its territory, due to the rising need to find solutions for universal problems, like the pollution of the environment, on an international level. Globalisation is a complex, forceful legal and social process that take place within an integrated whole with out regard to geographical boundaries. Globalisation thus differs from international activities, which arise between and among States, and it differs from multinational activities that occur in more than one nation‐State. This does not mean that countries are not involved in the sociolegal dynamics that those transboundary process trigger. In a sense, the movements triggered by global processes promote greater economic interdependence among countries. Globalisation can be traced back to the depression preceding World War II and globalisation at that time included spreading of the capitalist economic system as a means of getting access to extended markets. The first step was to create sufficient export surplus to maintain full employment in the capitalist world and secondly establishing a globalized economy where the planet would be united in peace and wealth. The idea of interdependence among quite separate and distinct countries is a very important part of talks on globalisation and a significant side of today’s global political economy.

L'Ecole internationale des sciences touristique de Rome est un organisme privé ayant pour but de promouvoir la connaissance culturelle à caractère multidisciplinaire du phénomène touristique par I'enseignement théorique des disciplines correspondantes. Ces disciplines seront intégrées par des travaux pratiques et par des éventuels stages professionnels.

The improvement in the efficiency of public management leads to an increase in the quality of services, boosting confidence in institutions and thus generating a multiplier effect. This paper aims to update the literature on the data envelopment analysis (DEA), which uses a frontier methodology, for measuring the efficiency applied to the defence sector.

Two main research areas are related through this study: Defence Economics and Efficiency and Productivity Analysis. The frontier methods for measuring technical efficiency are grouped into parametric, non-parametric and semi-parametric. The DEA literature review in the selected sector allows to identify three main fields of work that are discussed in detail.

Existing empirical research has hardly applied bootstrapping methods to remove bias from the estimates. No empirical work has applied an analysis of efficiency determinants by the inclusion of exogenous variables.

The managerial implications of efficiency are numerous. A line of research is proposed to examine the extent to which efficiency improvements have an impact on reputation and, therefore, on the image of and confidence in institutions. The link between Defence Economics and Corruption Economics is also considered.

La mejora de la eficiencia de la gestión pública conduce a un aumento de la calidad de los servicios, impulsando la confianza en las instituciones y generando así un efecto multiplicador. El presente trabajo tiene por objeto actualizar la literatura sobre la metodología frontera de medición de la eficiencia DEA, aplicada al sector de la Defensa.

A través de este estudio, se relacionan dos áreas principales de investigación: Economía de la Defensa y Análisis de Eficiencia y Productividad. Los métodos frontera para medir la eficiencia técnica se agrupan en paramétricos, no paramétricos y semiparamétricos. La revisión de la literatura DEA en el sector seleccionado permite identificar tres campos de trabajo principales que se discuten en detalle.

La investigación empírica existente apenas ha aplicado métodos bootstrap para eliminar el sesgo de las estimaciones. Ningún trabajo empírico ha aplicado un análisis de determinantes de la eficiencia mediante la inclusión de variables exógenas.

Las repercusiones de la eficiencia en la gestión son numerosas. Se propone una línea de investigación para examinar en qué medida las mejoras de la eficiencia repercuten en la reputación y, por consiguiente, en la imagen y la confianza en las instituciones. También se considera el vínculo entre la Economía de la Defensa y la Economía de la Corrupción.

Avant‐propos sous les auspices de l'Institut international de Coopération intellectuelle, paraissait en 1934 le t. I, consacré à l'Europe, du Guide international des Archives. Le questionnaire envoyé à tous les États européens comportait sous les points 4 et 6 les questions suivantes: ‘Existe‐t‐il un guide général pour les diverses catégories d'Archives ou des guides particuliers pour l'une ou l'autre d'entre elles?’ et ‘Existe‐t‐il des catalogues imprimés, des publications tant officielles que privées, susceptibles de constituer un instrument complet de référence pour tout ou partie importante des fonds d'archives?’ Les réponses des divers pays à ces questions, malgré leur caractère très inégal, ont fait du Guide international un bon instrument d'information générale sur les Archives. Malheureusement les circonstances ont empêché la publication du volume consacré aux États non européens, tandis que le temps qui s'écoulait tendait à rendre périmés les renseignements fournis sur les Archives européennes.

This article will attempt to answer the following question: what has been done to prevent corruption and promote a “good government” in Latin America, what are the results and what explains the current situation? After analyzing very different experiences, the following could be stated: (1) there is at least a formal concern for promoting integrity in several countries, but there are problems of diagnosis and formulation; (2) the examples of implementation failures are far too many in Latin America. In any case, the most important factor explaining failures of design and implementation is the presence of a social trap and a political trap. The social trap is expressed by the incoherence of society itself, which demands honesty from Government, but in practice incentivizes corruption by paying bribes, breaching rules, and demanding privileges within the framework of clientelist networks. The political trap emerges from the strong path dependency effect resulting from the consolidation of patronage or clientelist networks.