Aspects of linear programming and accounting in a manufacturing company

Imperial Users onl

An Analytical Approach to Programs as Data Objects

This essay accompanies a selection of 32 articles (referred to in bold face in the text and marginally marked in the bibliographic references) submitted to Aarhus University towards a Doctor Scientiarum degree in Computer Science.The author's previous academic degree, beyond a doctoral degree in June 1986, is an "Habilitation à diriger les recherches" from the Université Pierre et Marie Curie (Paris VI) in France; the corresponding material was submitted in September 1992 and the degree was obtained in January 1993.The present 32 articles have all been written since 1993 and while at DAIMI.Except for one other PhD student, all co-authors are or have been the author's students here in Aarhus

La noción de principalidad en especialización de tipos

Cuando se consideran las maneras de producir programas, la técnica principal queviene a la mente de cada uno de nosotros es la de escribir el programa a mano. Aunqueexisten técnicas de derivación y herramientas para producir programas automáticamente,su aplicación está usualmente restringida a cierta clase de problemas, o ciertos dominios (como los generadores de parsers, o las interfaces visuales). En los casos donde talestécnicas se pueden aplicar, la productividad y la confiabilidad se ven ampliamente incrementadas. Por esa razón, nos interesamos en la producción automática de programasen un marco general. La especialización de programas es una manera particular de producir programasautomáticamente. En ella se utiliza un programa fuente general dado para generardiversas versiones particulares, especializadas, del mismo, cada una resolviendo una instanciaparticular del problema original. La técnica más conocida y más ampliamenteestudiada de especialización de programas es llamada evaluación parcial; se la ha utilizadocon éxito en varias áreas de aplicación diferentes. Sin embargo, la evaluaciónparcial tiene problemas cuando se considera la producción automática de programas contipos. La especialización de tipos es una forma de especialización de programas que puedeproducir automáticamente programas con tipos a partir de uno fuente. Comprendediversas técnicas muy poderosas, tales como especialización polivariante, especializaciónde constructores, conversión de clausuras; es la primera de las variantes de especializaciónde programas que puede generar tipos arbitrarios a partir de un único programa fuente. Creemos que la especialización de tipos puede ser la base sobre la que desarrollar unmarco de producción automática de programas. En esta tesis consideramos la especialización de programas, extendiéndola para producirprogramas polimórficos. Ilustramos eso considerando un intérprete para un lambdacálculo con tipos a la Hindley-Milner, y especializándolo con cualquier programa objetopara producir un programa residual que sea esencialmente igual que el original. En labúsqueda de la generación de polimorfismo, extendemos la especialización de tipos paraque pueda expresar la especialización de programas con información estática incompleta,y probamos que para cada término podemos inferir una especialización particular quepuede ser usada para reconstruir cada uno de las otras especializaciones de tal término. Llamamos especialización de tipos principal a tal técnica, debido a la analogía de estapropiedad con la noción de tipos principales. Nuestra presentación clarifica muchos delos problemas existentes en la especialización de tipos, lo cual puede ser usado como unaguía en la búsqueda de soluciones para ellos. La presentación se divide en cuatro partes. En la primera Parte, presentamos la Especialización de Tipos en su forma original, junto con material complementario. Enla Parte II desarrollamos la presentación de la Especialización de Tipos Principal, explicandotodos los detalles técnicos, dando varios ejemplos, y presentando nuestra implementación del prototipo. En la Parte III describimos las posibilidades de la formulaciónnueva, proveyendo una extensión de la Especialización de Tipos para generar programaspolimórficos. Finalmente, la última parte describe trabajos relacionados, trabajosfuturos, y concluye. Este trabajo es el resultado de siete a˜nos de investigación, realizados durante misestudios de doctorado.When considering the ways in which programs are produced, the main techniquethat comes to everybody’s mind is writing by hand. Although derivation techniquesand tools for producing programs exist, their application is usually restricted to certainkind of problems, or certain domains (such as parsing generators, or visual interfaces). In those cases where such techniques can be applied, productivity and reliability arehighly boosted. For that reason, we are concerned with the automatic production ofprograms in a general setting. Program specialisation is a particular way to produce programs automatically. Agiven, general source program is used to generate several particular, specialised versionsof it, each one solving a particular instance of the original problem. The best-known andthoroughly studied technique for program specialisation is called partial evaluation; ithas been successfully used in several different application areas. But partial evaluationfalls short when automatic production of typed programs is considered. Type specialisation is a form of program specialisation that can automatically producetyped programs from some general source one. It comprises several powerful techniques,such as polyvariant specialisation, constructor specialisation, and closure conversion,and it is the first variant of program specialisation that can generate arbitrarytypes from a single source program. We believe that type specialisation can be the basisin which to develop a framework for automatic program production. In this thesis we consider type specialisation, extending it to produce polymorphicprograms. We illustrate that by considering an interpreter for Hindley-Milner typedlambda-calculus, and specialising it to any given object program, producing a residualprogram that is essentially the same as the original one. In achieving the generationof polymorphism, we extend type specialisation to be able to express specialisation ofprograms with incomplete static information, and prove that for each term we can infera particular specialisation that can be used to reconstruct every other for that term. Wecall that principal type specialisation because of the analogy this property has with thenotion of principal types. Our presentation clarifies some of the problems existing intype specialisation, clarification that can be used as a guide in the search for solutionsto them. The presentation is divided in four parts. In the first Part we present Type Specialisationin its original form, together with some background material. In Part II wedevelop the presentation of Principal Type Specialisation, explaining all the technicaldetails, offering several examples, and presenting our prototype implementation. In Part III we describe the posibilities of the new formulation, by providing an extensionof Type Specialisation to generate polymorphic programs. And finally, in the last Partwe describe related and future work and conclude. This work is the result of seven years of research, performed during my PhD studies.Fil: Martínez López, Pablo E.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Operational Research: Methods and Applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

Operational research:methods and applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

Operational Research: methods and applications

This is the final version. Available on open access from Taylor & Francis via the DOI in this recordThroughout its history, Operational Research has evolved to include methods, models and algorithms that have been applied to a wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first summarises the up-to-date knowledge and provides an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion and used as a point of reference by a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes

Aeronautical Engineering: A continuing bibliography with indexes

This bibliography lists 725 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1985