Geometric documentation of the flour factory "El Puente Colgante" in Aranjuez (Madrid).

The goal of this communication is to offer, through computer-aided design tools, a methodology to recover and virtually reconstruct disappeared buildings of our industrial historical heritage. It will be applied to the case of the flour factory "El Puente Colgante" (The Suspended Bridge) in Aranjuez, which was demolished in 2001. The process is as follows: After a historical analysis of the evolution in time of the flour factory, a field work provides data allowing an info graphic reconstruction of the factory. Once this information has been processed, a lifting of the current state is made with AutoCAD, and a three-dimensional model is built with the Rhinoceros application. Then images of the ensemble are obtained with the applications Rhinoceros and V-Ray, ending with a postproduction with Photoshop. The proposed methodology has permitted to obtain a three-dimensional model of the flour factory ?El Puente Colgante? in Aranjuez, with an accurate virtual reconstruction of its original state prior to demolition. The procedure exposed is susceptible to be generalized for any other example of industrial architecture.

The p-Adaptive Biem Approach for Two-Dimensional Elasticity Analysis

This paper presents the development and application of the p-adaptive BIEM version in elastostatics. The basic concepts underlying the p-adaptive technique are summarized and discussed. Some Pascal pseudocodes which show the way how such a technique can be implemented easily in microcomputers are also provided. Both the applicability and the accuracy of the method proposed here are illustrated through a numerical example.

Toward mass production of microtextured microdevices: linking rapid prototyping with microinjection molding

The possibility of manufacturing textured materials and devices, with surface properties controlled from the design stage, instead of being the result of machining processes or chemical attacks, is a key factor for the incorporation of advanced functionalities to a wide set of micro and nanosystems. Recently developed high-precision additive manufacturing technologies, together with the use of fractal models linked to computer-aided design tools, allow for a precise definition and control of final surface properties for a wide set of applications, although the production of larger series based on these resources is still an unsolved challenge. However, rapid prototypes, with controlled surface topography, can be used as original masters for obtaining micromold inserts for final large-scale series manufacture of replicas using microinjection molding. In this study, an original procedure is presented, aimed at connecting rapid prototyping with microinjection molding, for the mass production of two different microtextured microsystems, linked to tissue engineering tasks, using different thermoplastics as ultimate materials.

Artificial Neural Nets with Interaction of Afferents

The aim is to obtain computationally more powerful, neuro physiologically founded, artificial neurons and neural nets. Artificial Neural Nets (ANN) of the Perceptron type evolved from the original proposal by McCulloch an Pitts classical paper [1]. Essentially, they keep the computing structure of a linear machine followed by a non linear operation. The McCulloch-Pitts formal neuron (which was never considered by the author’s to be models of real neurons) consists of the simplest case of a linear computation of the inputs followed by a threshold. Networks of one layer cannot compute anylogical function of the inputs, but only those which are linearly separable. Thus, the simple exclusive OR (contrast detector) function of two inputs requires two layers of formal neurons

Dendritic-Like Reliable Computation in Artificial Neurons

Dendritic computation is a term that has been in neuro physiological research for a long time [1]. It is still controversial and far for been clarified within the concepts of both computation and neurophysiology [2], [3]. In any case, it hasnot been integrated neither in a formal computational scheme or structure, nor into formulations of artificial neural nets. Our objective here is to formulate a type of distributed computation that resembles dendritic trees, in such a way that it shows the advantages of neural network distributed computation, mostly the reliability that is shown under the existence of holes (scotomas) in the computing net, without ?blind spots?.

Contribución a las nuevas tendencias en el diseño de tuberías en construcción naval

En la situación actual, tanto las posibilidades de contratar como los resultados económicos de un astillero, dependen de su capacidad para construir un buque en el plazo mas corto posible. Dentro de los trabajos de diseño y construcción de de un buque el trabajo de tuberías ha sido el que tradicionalmente ha condicionado los plazos de construcción. En este estudio se considerara que se han tenido en cuenta los criterios necesarios para que las instalaciones del buque funcionen correctamente y se verá como los sistemas de diseño influyen en el coste y plazo del buque y, por tanto, en la productividad del astillero. Se estudian los distintos procesos de diseño, fabricación y montaje de tuberías, la evolución de estos procesos a lo largo del tiempo, los módulos de armamento que se realizan en los astilleros, los modelos de cámara de máquinas, y los sistemas de ayuda al diseño por ordenador. El autor, en su puesto de Jefe de la Oficina Tecnológica de la Factoría de Sevilla de Astilleros Españoles en los últimos 12 años, ha tomado parte activa en esta evolución, formando parte de un equipo que ha situado a este astillero entre los mas avanzarlos de Europa. Todo lo anterior sirve de base para la segunda parte de este estudio, donde se abordan las que, en opinión del autor, son las nuevas tendencias en el diseño de tuberías en la construcción naval. V Integración del CAD/CAM o CIM : CAD = computer aided design o diseño asistido por ordenador, CAM = computer aided manufacturing o fabricación asistida por ordenador, CIM = computer integrated manufacturing o fabricación integrada por ordenador. Se estudia la integración de los procesos de diseño con el resto de los procesos de gestión y de producción de un astillero, proponiéndose un modelo de cómo el autor ve esta integración. Se comenta la actual tendencia a pasar de las automatizaciones duras con maquinas especializadas para cada proceso, a las automatizaciones blandas en las que un robot puede realizar distintos procesos modificando su programación. Se estudian las nuevas posibilidades de la normal i zacio'n, de los planos parametrizados y de la tecnología de grupos aportando algunos ejemplos. Se estudia también como los procesos anteriores conducirán a una optimización del producto en sí, es decir a conseguir mejores buques. En las conclusiones destacamos como el camino que tienen los países desarrollados, como el nuestro, para mantener una industria competitiva de construcción naval va por la mecanización de los procesos constructivos siguiendo las tendencias anteriores y obteniendo buques optimizados. vi SUMMARY Under the present situation the possibilities to contract and the economical results of a Shipyard depend on its capacity to build a ship within the shortest time. i Within the works of design and construction of a ship, piping work has traditionally conditioned the construction time. In this study it shall be considered that the necessary criteria for the ship installations to operate correctly have been taken into account and it shall be noticed how the design systems influence on the cost and time of a ship and therefore on the Shipyard's productivity. Studies are made of different design processes, manufacturing and installation of piping, evolution of these processes along the time, outfitting modules made in the Shipyard, engine room models and computerized design aid systems. The author, in his post of Chief of the Technological Office of Sevilla Shipyard of Astilleros Españoles for the last 12 years, has taken an active part in this evolution, making part of a team which has placed this Shipyard among the most advanced in Europe. All of the above is used for the second part of this study, whereby an approach is made to those who, in the author's opinion, are the new trends in the piping design of shipbuilding. vii Integration of CAD/CAM or CIM: CAD = computer aided design, CAM = computer aided manufacturing, CIM = computer integrated manufacturing. i A study is made of the integration of design processes with the remaining step and production Shipyard processes, proposing a model of how the author views this integration. Comments are made on the present trend to go from hard automations with specialized machines for each process to soft automations, in which a robot can carry out different processes modifying its programmes. Studies are made of: New possibility of standardization, parametrized drawings and group technology, bringing some examples. It is also studied how the above processes shall lead to optimize the product itself, that is, to obtain better ships. In the conclusions we stand out how the way of developed countries (as ours) to maintain a competitive shipbuilding industry is by computerizing constructive processes, following the above trends and obtaining better ships.

Seed image analysis and taxonomy of Diplotaxis DC. (Brassicaceae, Brassiceae)

The genus Diplotaxis, comprising 32 or 34 species, plus several additional infraspecific taxa, displays a considerable degree of heterogeneity in the morphology, molecular markers, chromosome numbers and geographical amplitude of the species. The taxonomic relationships within the genus Diplotaxis were investigated by phenetic characterisation of germplasm belonging to 27 taxa of the genus, because there is an increasing interest in Diplotaxis, since some of its species (D. tenuifolia, D. muralis) are gathered or cultivated for human consumption, whereas others are frequent arable weeds (D. erucoides) in many European vineyards. Using a computer-aided vision system, 33 morpho-colorimetric features of seeds were electronically measured. The data were used to implement a statistical classifier, which is able to discriminate the taxa within the genus Diplotaxis, in order to compare the resulting species grouping with the current infrageneric systematics of this genus. Despite the high heterogeneity of the samples, due to the great intra-population variability, the stepwise Linear Discriminant Analysis method, applied to distinguish the groups, was able to reach over 80% correct identification. The results obtained allowed us to confirm the current taxonomic position of most taxa and suggested the taxonomic position of others for reconsideration.

Dispersive optical bistability in quantum wells with logarithmic gain

We present an analytical model for studying optical bistability in semiconductor lasers that exhibit a logarithmic dependence of the optical gain on carrier concentration. Model results are shown for a Fabry–Pérot quantum-well laser and compared with the predictions of a commercial computer-aided design (CAD) software tool.

Implementación de algoritmos para la manipulación de curvas concoides en diseño geométrico

Este proyecto se enmarca dentro de la Computación Simbólica y de los fundamentos matemáticos del Diseño Geométrico Asistido por ordenador (CAGD). Se abordara uno de los problemas principales en el ámbito del CAGD y que es la manipulación de las Curvas Concoide. La importancia del avance en la manipulación de las curvas concoide radica en el papel fundamental que desempeñan en múltiples aplicaciones en la actualidad dentro de campos de diversa índole tales como la medicina, la óptica, el electromagnetismo, la construcción, etc. El objetivo principal de este proyecto es el diseño e implementación de algoritmos para el estudio, cálculo y manipulación de curvas concoides, utilizando técnicas propias del Calculo Simbólico. Esta implementación se ha programado utilizando el sistema de computación simbólica Maple. El proyecto consiste en dos partes bien diferenciadas, una parte teórica y otra más practica. La primera incluye la descripción geométrica y definición formal de curvas concoide, así como las ideas y propiedades básicas. De forma más precisa, se presenta un estudio matemático sobre el análisis de racionalidad de estas curvas, explicando los algoritmos que serán implementados en las segunda parte, y que constituye el objetivo principal de este proyecto. Para cerrar esta parte, se presenta una pequeña introducción al sistema y a la programación en Maple. Por otro lado, la segunda parte de este proyecto es totalmente original, y en ella el autor desarrolla las implementaciones en Maple de los algoritmos presentados en la parte anterior, así como la creación de un paquete Maple que las recoge. Por último, se crean las paginas de ayudas en el sistema Maple para la correcta utilización del paquete matemático anteriormente mencionado. Una vez terminada la parte de implementación, se aplican los algoritmos implementados a una colección de curvas clásicas conocidas, recogiendo los datos y resultados obtenidos en un atlas de curvas. Finalmente, se presenta una recopilación de las aplicaciones más destacadas en las que las concoides desempeñan un papel importante así como una breve reseña sobre las concoides de superficies, objeto de varios estudios en la actualidad y a los que se considera que el presente proyecto les puede resultar de gran utilidad. Abstract This project is set up in the framework of Symbolic Computation as well as in the implementation of algebraic-geometric problems that arise from Computer Aided Geometric Design (C.A.G.D.) applications. We address problems related to conchoid curves. The importance of these curves is the fundamental role that they play in current applications as medicine, optics, electromagnetism, construction, etc. The main goal of this project is to design and implement some algorithms to solve problems in studying, calculating and generating conchoid curves with symbolic computation techniques. For this purpose, we program our implementations in the symbolic system “Maple". The project consists of two differentiated parts, one more theoretical part and another part more practical. The first one includes the description of conchoid curves as well as the basic ideas about the concept and its basic properties. More precisely, we introduce in this part the mathematical analysis of the rationality of the conchoids, and we present the algorithms that will be implemented. Furthermore, the reader will be brie y introduced in Maple programming. On the other hand, the second part of this project is totally original. In this more practical part, the author presents the implemented algorithms and a Maple package that includes them, as well as their help pages. These implemented procedures will be check and illustrated with some classical and well known curves, collecting the main properties of the conchoid curves obtained in a brief atlas. Finally, a compilation of the most important applications where conchoids play a fundamental role, and a brief introduction to the conchoids of surfaces, subject of several studies today and where this project could be very useful, are presented.

Contribución al desarrollo de técnicas CAD para el diseño de antenas impresas y dispositivos pasivos de microondas basadas en el método de elementos finitos

El objetivo principal de esta tesis es el desarrollo de herramientas numéricas basadas en técnicas de onda completa para el diseño asistido por ordenador (Computer-Aided Design,‘CAD’) de dispositivos de microondas. En este contexto, se desarrolla una herramienta numérica basada en el método de los elementos finitos para el diseño y análisis de antenas impresas mediante algoritmos de optimización. Esta técnica consiste en dividir el análisis de una antena en dos partes. Una parte de análisis 3D que se realiza sólo una vez en cada punto de frecuencia de la banda de funcionamiento donde se sustituye una superficie que contiene la metalización del parche por puertas artificiales. En una segunda parte se inserta entre las puertas artificiales en la estructura 3D la superficie soportando una metalización y se procede un análisis 2D para caracterizar el comportamiento de la antena. La técnica propuesta en esta tesis se puede implementar en un algoritmo de optimización para definir el perfil de la antena que permite conseguir los objetivos del diseño. Se valida experimentalmente dicha técnica empleándola en el diseño de antenas impresas de banda ancha para diferentes aplicaciones mediante la optimización del perfil de los parches. También, se desarrolla en esta tesis un procedimiento basado en el método de descomposición de dominio y el método de los elementos finitos para el diseño de dispositivos pasivos de microonda. Se utiliza este procedimiento en particular para el diseño y sintonía de filtros de microondas. En la primera etapa de su aplicación se divide la estructura que se quiere analizar en subdominios aplicando el método de descomposición de dominio, este proceso permite analizar cada segmento por separado utilizando el método de análisis adecuado dado que suele haber subdominios que se pueden analizar mediante métodos analíticos por lo que el tiempo de análisis es más reducido. Se utilizan métodos numéricos para analizar los subdominios que no se pueden analizar mediante métodos analíticos. En esta tesis, se utiliza el método de los elementos finitos para llevar a cabo el análisis. Además de la descomposición de dominio, se aplica un proceso de barrido en frecuencia para reducir los tiempos del análisis. Como método de orden reducido se utiliza la técnica de bases reducidas. Se ha utilizado este procedimiento para diseñar y sintonizar varios ejemplos de filtros con el fin de comprobar la validez de dicho procedimiento. Los resultados obtenidos demuestran la utilidad de este procedimiento y confirman su rigurosidad, precisión y eficiencia en el diseño de filtros de microondas. ABSTRACT The main objective of this thesis is the development of numerical tools based on full-wave techniques for computer-aided design ‘CAD’ of microwave devices. In this context, a numerical technique based on the finite element method ‘FEM’ for the design and analysis of printed antennas using optimization algorithms has been developed. The proposed technique consists in dividing the analysis of the antenna in two stages. In the first stage, the regions of the antenna which do not need to be modified during the CAD process are initially characterized only once from their corresponding matrix transfer function (Generalized Admittance matrix, ‘GAM’). The regions which will be modified are defined as artificial ports, precisely the regions which will contain the conducting surfaces of the printed antenna. In a second stage, the contour shape of the conducting surfaces of the printed antenna is iteratively modified in order to achieve a desired electromagnetic performance of the antenna. In this way, a new GAM of the radiating device which takes into account each printed antenna shape is computed after each iteration. The proposed technique can be implemented with a genetic algorithm to achieve the design objectives. This technique is validated experimentally and applied to the design of wideband printed antennas for different applications by optimizing the shape of the radiating device. In addition, a procedure based on the domain decomposition method and the finite element method has been developed for the design of microwave passive devices. In particular, this procedure can be applied to the design and tune of microwave filters. In the first stage of its implementation, the structure to be analyzed is divided into subdomains using the domain decomposition method; this process allows each subdomains can be analyzed separately using suitable analysis method, since there is usually subdomains that can be analyzed by analytical methods so that the time of analysis is reduced. For analyzing the subdomains that cannot be analyzed by analytical methods, we use the numerical methods. In this thesis, the FEM is used to carry out the analysis. Furthermore the decomposition of the domain, a frequency sweep process is applied to reduce analysis times. The reduced order model as the reduced basis technique is used in this procedure. This procedure is applied to the design and tune of several examples of microwave filters in order to check its validity. The obtained results allow concluding the usefulness of this procedure and confirming their thoroughness, accuracy and efficiency for the design of microwave filters.

Simulation of impulse response for indoor visible light communications using 3D CAD models

n this article, a tool for simulating the channel impulse response for indoor visible light communications using 3D computer-aided design (CAD) models is presented. The simulation tool is based on a previous Monte Carlo ray-tracing algorithm for indoor infrared channel estimation, but including wavelength response evaluation. The 3D scene, or the simulation environment, can be defined using any CAD software in which the user specifies, in addition to the setting geometry, the reflection characteristics of the surface materials as well as the structures of the emitters and receivers involved in the simulation. Also, in an effort to improve the computational efficiency, two optimizations are proposed. The first one consists of dividing the setting into cubic regions of equal size, which offers a calculation improvement of approximately 50% compared to not dividing the 3D scene into sub-regions. The second one involves the parallelization of the simulation algorithm, which provides a computational speed-up proportional to the number of processors used.

Control and command systems concepts from early work on a Mars Rover

We recover and develop some robotic systems concepts (on the light of present systems tools) that were originated for an intended Mars Rover in the sixties of the last century at the Instrumentation Laboratory of MIT, where one of the authors was involved. The basic concepts came from the specifications for a type of generalized robot inspired in the structure of the vertebrate nervous systems, where the decision system was based in the structure and function of the Reticular Formation (RF). The vertebrate RF is supposed to commit the whole organism to one among various modes of behavior, so taking the decisions about the present overall task. That is, it is a kind of control and command system. In this concepts updating, the basic idea is that the RF comprises a set of computing units such that each computing module receives information only from a reduced part of the overall, little processed sensory inputs. Each computing unit is capable of both general diagnostics about overall input situations and of specialized diagnostics according to the values of a concrete subset of the input lines. Slave systems to this command and control computer, there are the sensors, the representations of external environment, structures for modeling and planning and finally, the effectors acting in the external world.

Conchoid surfaces of spheres

The conchoid of a surface F with respect to given xed point O is roughly speaking the surface obtained by increasing the radius function with respect to O by a constant. This paper studies conchoid surfaces of spheres and shows that these surfaces admit rational parameterizations. Explicit parameterizations of these surfaces are constructed using the relations to pencils of quadrics in R3 and R4. Moreover we point to remarkable geometric properties of these surfaces and their construction.

Modelos predictivos para el estudio del abandono en centros universitarios

El abandono universitario es un problema que siempre ha afectado a las distintas universidades públicas. La Universidad Politécnica de Madrid, en concreto la Escuela Técnica Superior de Ingenieros Informáticos, pretende reducir dicho abandono aplicando técnicas de Data Mining para detectar aquellos alumnos que abandonan antes de que lo hagan. Este proyecto, a través de la metodología CRISP-DM (CRoss Industry Standard Process for Data Mining) y con los datos obtenidos del SIIU (Sistema Integrado de Información Universitaria), tiene como fin identificar a los alumnos que abandonan el primer añoo para poder aplicar distintas políticas en ellos y así evitarlo. ---ABSTRACT---Early university abandonment is a problem which has affected different public universities. The Universidad Polit´ecnica de Madrid (Polytechnic University of Madrid), inparticular the Escuela Técnica Superior de Ingenieros Informáticos (Computer Science Engineering School), wants to reduce this abandonment rate using Data Mining techniques to find students who are likely to leave before they do. The purpose of this project, through CRISP-DM (CRoss Industry Standard Process for Data Mining) methodology and using the data from SIIU (Sistema Integrado de Informaci´on Universitaria), is to identify those students who leave the first year in order to apply different policies and avoid it.

Interfaz gráfica de usuario para la detección de microcalcificaciones mediante análisis de mamografía digitalizada

The graphical user interface (GUI) are all graphic elements that help to communicate with a system. The design of a GUI allow to land the central idea of a draft information technology. Today technology has become one of the largest and most useful tools to automate and facilitate processes for that reason fit into any kind of productive sectors, for example, in the health sector. The CAD systems (Systems Computer Aided Diagnosis) are the type of technology used in the health sector, in order to automate online modular learning environment with a fast placed in service. In the present paper the use of a Learning Management Systems (LMS) as continuous education tool is proposed.