Derivación deductiva de programas funcionales con patrones

Una de las dificultades principales en el desarrollo de software es la ausencia de un marco conceptual adecuado para su estudio. Una propuesta la constituye el modelo transformativo, que entiende el desarrollo de software como un proceso iterativo de transformación de especificaciones: se parte de una especificación inicial que va transformándose sucesivamente hasta obtener una especificación final que se toma como programa. Este modelo básico puede llevarse a la práctica de varias maneras. En concreto, la aproximación deductiva toma una sentencia lógica como especificación inicial y su proceso transformador consiste en la demostración de la sentencia; como producto secundario de la demostración se deriva un programa que satisface la especificación inicial. La tesis desarrolla un método deductivo para la derivación de programas funcionales con patrones, escritos en un lenguaje similar a Hope. El método utiliza una lógica multigénero, cuya relación con el lenguaje de programación es estudiada. También se identifican los esquemas de demostración necesarios para la derivación de funciones con patrones, basados en la demostración independiente de varias subsentencias. Cada subsentencia proporciona una subespecificación de una ecuación del futuro programa a derivar. Nuestro método deductivo está inspirado en uno previo de Zohar Manna y Richard Waldinger, conocido como el cuadro deductivo, que deriva programas en un lenguaje similar a Lisp. El nuevo método es una modificación del cuadro de estos autores, que incorpora géneros y permite demostrar una especificación mediante varios cuadros. Cada cuadro demuestra una subespecificación y por tanto deriva una ecuación del programa. Se prevén mecanismos para que los programas derivados puedan contener definiciones locales con patrones y variables anónimas y sinónimas y para que las funciones auxiliares derivadas no usen variables de las funciones principales. La tesis se completa con varios ejemplos de aplicación, un mecanismo que independentiza el método del lenguaje de programación y un prototipo de entorno interactivo de derivación deductiva. Categorías y descriptores de materia CR D.l.l [Técnicas de programación]: Programación funcional; D.2.10 [Ingeniería de software]: Diseño - métodos; F.3.1 [Lógica y significado de los programas]: Especificación, verificación y razonamiento sobre programas - lógica de programas; F.3.3 [Lógica y significado de los programas]: Estudios de construcciones de programas - construcciones funcionales; esquemas de programa y de recursion; 1.2.2 [Inteligencia artificial]: Programación automática - síntesis de programas; 1.2.3 [Inteligencia artificial]: Deducción y demostración de teoremas]: extracción de respuesta/razón; inducción matemática. Términos generales Programación funcional, síntesis de programas, demostración de teoremas. Otras palabras claves y expresiones Funciones con patrones, cuadro deductivo, especificación parcial, inducción estructural, teorema de descomposición.---ABSTRACT---One of the main difficulties in software development is the lack of an adequate conceptual framework of study. The transformational model is one such proposal that conceives software development as an iterative process of specifications transformation: an initial specification is developed and successively transformed until a final specification is obtained and taken as a program. This basic model can be implemented in several ways. The deductive approach takes a logical sentence as the initial specification and its proof constitutes the transformational process; as a byproduct of the proof, a program which satisfies the initial specification is derived. In the thesis, a deductive method for the derivation of Hope-like functional programs with patterns is developed. The method uses a many-sorted logic, whose relation to the programming language is studied. Also the proof schemes necessary for the derivation of functional programs with patterns, based on the independent proof of several subsentences, are identified. Each subsentence provides a subspecification of one equation of the future program to be derived. Our deductive method is inspired on a previous one by Zohar Manna and Richard Waldinger, known as the deductive tableau, which derives Lisp-like programs. The new method incorporates sorts in the tableau and allows to prove a sentence with several tableaux. Each tableau proves a subspecification and therefore derives an equation of the program. Mechanisms are included to allow the derived programs to contain local definitions with patterns and anonymous and synonymous variables; also, the derived auxiliary functions cannot reference parameters of their main functions. The thesis is completed with several application examples, i mechanism to make the method independent from the programming language and an interactive environment prototype for deductive derivation. CR categories and subject descriptors D.l.l [Programming techniques]: Functional programming; D.2.10 [Software engineering]: Design - methodologies; F.3.1 [Logics and meanings of programa]: Specifying and verifying and reasoning about programs - logics of programs; F.3.3 [Logics and meanings of programs]: Studies of program constructs - functional constructs; program and recursion schemes; 1.2.2 [Artificial intelligence]: Automatic programming - program synthesis; 1.2.3 [Artificial intelligence]: Deduction and theorem proving - answer/reason extraction; mathematical induction. General tenas Functional programming, program synthesis, theorem proving. Additional key words and phrases Functions with patterns, deductive tableau, structural induction, partial specification, descomposition theorem.

Perfil de playas sustentadas : estudio hidrodinámico y experimental : directrices de diseño

Las playas sustentadas por medio de un pie sumergido son una atractiva alternativa de diseño de regeneración de playas especialmente cuando las condiciones física del emplazamiento o las características de la arena nativa y de préstamo producen perfiles de alimentación que no se intersectan. La observación y propuesta de este tipo de solución data de los años 1960’s, así como la experiencia internacional en la construcción de este tipo de playas. Sin embargo, a pesar de su utilización y los estudios en campo y laboratorio, no se dispone de criterios ingenieriles que apoyen el diseño de las mismas. Esta tesis consiste en un análisis experimental del perfil de playas sustentadas en un pie sumergido (o colgadas) que se concreta en una propuesta de directrices de diseño general que permiten estimar la ubicación y características geométricas del pie sumergido frente a un oleaje y material que constituye la playa determinados. En la tesis se describe el experimento bidimensional realizado en el modelo físico de fondo móvil, donde se combinan cinco tipos de oleaje con tres configuraciones del pie sumergido (“Sin estructura”, configuración baja o “Estructura 1” y configuración alta o “Estructura 2”), se presentan los resultados obtenidos y se realiza una discusión detallada de las implicaciones de los resultados desde el punto de vista hidrodinámico utilizando monomios adimensionales. Se ha realizado un análisis detallado del estado del arte sobre playas colgadas, presentando el concepto y las experiencias de realizaciones en distintos países. Se ha realizado una cuidadosa revisión de la literatura publicada sobre estudios experimentales de playas colgadas, modelos teóricos y otras cuestiones auxiliares, necesarias para la formulación de la metodología de la tesis. El estudio realizado se ha estructurado en dos fases. En la primera fase se ha realizado una experimentación en un modelo físico de fondo móvil construido en las instalaciones del Centro de Estudios de Puertos y Costas (CEPYC) del Centro de Estudios y Experimentación de Obras Públicas (CEDEX), consistente en un canal de 36 m de longitud, 3 m de anchura y 1.5 m de altura, provisto de un generador de oleaje de tipo pistón. Se ha diseñado una campaña de 15 ensayos, que se obtienen sometiendo a cinco tipos de oleaje tres configuraciones distintas de playa colgada. En los ensayos se ha medido el perfil de playa en distintos instantes hasta llegar al equilibrio, determinando a partir de esos datos el retroceso de la línea de costa y el volumen de sedimentos perdido. El tiempo total efectivo de ensayo asciende a casi 650 horas, y el número de perfiles de evolución de playa obtenidos totaliza 229. En la segunda fase se ha abordado el análisis de los resultados obtenidos con la finalidad de comprender el fenómeno, identificar las variables de las que depende y proponer unas directrices ingenieriles de diseño. Se ha estudiado el efecto de la altura de ola, del periodo del oleaje, del francobordo adimensional y del parámetro de Dean, constatándose la dificultad de comprensión del funcionamiento de estas obras ya que pueden ser beneficiosas, perjudiciales o inocuas según los casos. También se ha estudiado la respuesta del perfil de playa en función de otros monomios adimensionales, tales como el número de Reynolds o el de Froude. En el análisis se ha elegido el monomio “plunger” como el más significativo, encontrando relaciones de éste con el peralte de oleaje, la anchura de coronación adimensional, la altura del pie de playa adimensional y el parámetro de Dean. Finalmente, se propone un método de diseño de cuatro pasos que permite realizar un primer encaje del diseño funcional de la playa sustentada frente a un oleaje de características determinadas. Las contribuciones más significativas desde el punto de vista científico son: - La obtención del juego de resultados experimentales. - La caracterización del comportamiento de las playas sustentadas. - Las relaciones propuestas entre el monomio plunger y las distintas variables explicativas seleccionadas, que permiten predecir el comportamiento de la obra. - El método de diseño propuesto, en cuatro pasos, para este tipo de esquemas de defensa de costas. Perched beaches are an attractive beach nourishment design alternative especially when either the site conditions or the characteristics of both the native and the borrow sand lead to a non-intersecting profile The observation and suggestion of the use of this type of coastal defence scheme dates back to the 1960’s, as well as the international experience in the construction of this type of beaches. However, in spite of its use and the field and laboratory studies performed to-date, no design engineering guidance is available to support its design. This dissertation is based on the experimental work performed on a movable bed physical model and the use of dimensionless parameters in analyzing the results to provide general functional design guidance that allow the designer, at a particular stretch of coast - to estimate the location and geometric characteristics of the submerged sill as well as to estimate the suitable sand size to be used in the nourishment. This dissertation consists on an experimental analysis of perched beaches by means of a submerged sill, leading to the proposal of general design guidance that allows to estimate the location and geometric characteristics of the submerged sill when facing a wave condition and for a given beach material. The experimental work performed on a bi-dimensional movable bed physical model, where five types of wave conditions are combined with three configurations of the submerged sill (“No structure”, low structure or “Structure 1”, and high structure or “Structure 2”) is described, results are presented, and a detailed discussion of the results - from the hydrodynamic point of view – of the implications of the results by using dimensionless parameters is carried out. A detailed state of the art analysis about perched beaches has been performed, presenting the “perched beach concept” and the case studies of different countries. Besides, a careful revision of the literature about experimental studies on perched beaches, theoretical models, and other topics deemed necessary to formulate the methodology of this work has been completed. The study has been divided into two phases. Within the first phase, experiments on a movable-bed physical model have been developed. The physical model has been built in the Centro de Estudios de Puertos y Costas (CEPYC) facilities, Centro de Estudios y Experimentación de Obras Públicas (CEDEX). The wave flume is 36 m long, 3 m wide and 1.5 m high, and has a piston-type regular wave generator available. The test plan consisted of 15 tests resulting from five wave conditions attacking three different configurations of the perched beach. During the development of the tests, the beach profile has been surveyed at different intervals until equilibrium has been reached according to these measurements. Retreat of the shoreline and relative loss of sediment in volume have been obtained from the measurements. The total effective test time reaches nearly 650 hours, whereas the total number of beach evolution profiles measured amounts to 229. On the second phase, attention is focused on the analysis of results with the aim of understanding the phenomenon, identifying the governing variables and proposing engineering design guidelines. The effect of the wave height, the wave period, the dimensionless freeboard and of the Dean parameter have been analyzed. It has been pointed out the difficulty in understanding the way perched beaches work since they turned out to be beneficial, neutral or harmful according to wave conditions and structure configuration. Besides, the beach profile response as a function of other dimensionless parameters, such as Reynolds number or Froude number, has been studied. In this analysis, the “plunger” parameter has been selected as the most representative, and relationships between the plunger parameter and the wave steepness, the dimensionless crest width, the dimensionless crest height, and the Dean parameter have been identified. Finally, an engineering 4-step design method has been proposed, that allows for the preliminary functional design of the perched beach for a given wave condition. The most relevant contributions from the scientific point of view have been: - The acquisition of a consistent set of experimental results. - The characterization of the behavior of perched beaches. - The proposed relationships between the plunger parameter and the different explanatory variables selected, that allow for the prediction of the beach behavior. - The proposed design method, four-step method, for this type of coastal defense schemes.

A contribution on modeling methodologies for multibody systems.

Multibody System Dynamics has been responsible for revolutionizing Mechanical Engineering Design by using mathematical models to simulate and optimize the dynamic behavior of a wide range of mechanical systems. These mathematical models not only can provide valuable informations about a system that could otherwise be obtained only by experiments with prototypes, but also have been responsible for the development of many model-based control systems. This work represents a contribution for dynamic modeling of multibody mechanical systems by developing a novel recursive modular methodology that unifies the main contributions of several Classical Mechanics formalisms. The reason for proposing such a methodology is to motivate the implementation of computational routines for modeling complex multibody mechanical systems without being dependent on closed source software and, consequently, to contribute for the teaching of Multibody System Dynamics in undergraduate and graduate levels. All the theoretical developments are based on and motivated by a critical literature review, leading to a general matrix form of the dynamic equations of motion of a multibody mechanical system (that can be expressed in terms of any set of variables adopted for the description of motions performed by the system, even if such a set includes redundant variables) and to a general recursive methodology for obtaining mathematical models of complex systems given a set of equations describing the dynamics of each of its uncoupled subsystems and another set describing the constraints among these subsystems in the assembled system. This work also includes some discussions on the description of motion (using any possible set of motion variables and admitting any kind of constraint that can be expressed by an invariant), and on the conditions for solving forward and inverse dynamics problems given a mathematical model of a multibody system. Finally, some examples of computational packages based on the novel methodology, along with some case studies, are presented, highlighting the contributions that can be achieved by using the proposed methodology.

Roadway lighting handbook, addendum to chapter six: designing the lighting system using pavement luminance. Final report.

Federal Highway Administration, Implementation Division, Washington, D.C.

Boiling water reactor technology status of the art report / [edited by C. Victor Pearson].

"Reactor technology."

Side impact padding integration study. Final report.

Mode of access: Internet.

Systems studies of automated highway systems: appendix I - conceptual automated highway system designs. Final report.

Federal Highway Administration, Traffic Systems Division, Washington, D.C.

Noise insulation of residences near freeways. Final report.

Mode of access: Internet.

Potential means of cost reduction in grade crossing automatic gate systems. Volume I: overview and low cost railroad/highway grade crossing gate systems. Final report.

Transportation Systems Center, Cambridge, Mass.

Potential means of cost reduction in grade crossing automatic gate systems. Volume II: improved gate arm concepts for railroad/highway grade crossings. Final report.

Transportation Systems Center, Cambridge, Mass.

Systems studies of automated highway systems: appendix II - analysis of automated highway systems. Final report.

Federal Highway Administration, Traffic Systems Division, Washington, D.C.

Potential means of cost reduction in grade crossings motorist-warning control equipment. Volume II: comparison of solid state and relay devices and techniques. Final report.

Transportation Systems Center, Cambridge, Mass.

Honda Motor Company's CVCC engine. Final report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Concrete median barrier research. Volume 1 - executive summary. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

Concrete median barrier research. Volume 2 - research report. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.