40ar/39ar Dating of alunite from the Pueblo Viejo Gold-Silver District, Dominican Republic

New 40Ar/39Ar ages for alunite from the Moore and Monte Negro deposits in the Pueblo Viejo district, as well as from a newly discovered alunite-bearing zone on Loma la Cuaba west of the known deposits, are reported here. The ages range from about 80 to 40 Ma, with closely adjacent samples exhibiting very different ages. Interpretation of these results in the context of estimated closure temperatures for alunite and the geologic and tectonic evolution of Hispaniola does not lead to a simple conclusion about the age of mineralization. The simplest interpretation, that mineralization was caused by a buried Late Cretaceous (~80 Ma) intrusion, is complicated by lack of intrusions of this age in the area and absence of alteration in overlying limestone. The alternative interpretation, that mineralization was formed during Early Cretaceous (~110 Ma) magmatism and that the 40Ar/39Ar ages were completely reset by Late Cretaceous thrusting, is complicated by a lack of information on the timing and thermal effects of thrusting in central Hispaniola. Alunite studies have yielded similar unclear results in other pre-Cenozoic ore systems, notably those of the Lachlan fold belt in Australia

Omnidirectional bearing-only see-and-avoid for small aerial robots:

Motivated by the growing interest in unmanned aerial system's applications in indoor and outdoor settings and the standardisation of visual sensors as vehicle payload. This work presents a collision avoidance approach based on omnidirectional cameras that does not require the estimation of range between two platforms to resolve a collision encounter. It will achieve a minimum separation between the two vehicles involved by maximising the view-angle given by the omnidirectional sensor. Only visual information is used to achieve avoidance under a bearing-only visual servoing approach. We provide theoretical problem formulation, as well as results from real flight using small quadrotors

Ferromanganese nodules and micro-hardgrounds associated with the Cadiz Contourite Channel (NE Atlantic): Palaeoenvironmental records of fluid venting and bottom currents

Ferromanganese nodule fields and hardgrounds have recently been discovered in the Cadiz Contourite Channel in the Gulf of Cadiz (850–1000 m). This channel is part of a large contourite depositional system generated by the Mediterranean Outflow Water. Ferromanganese deposits linked to contourites are interesting tools for palaeoenviromental studies and show an increasing economic interest as potential mineral resources for base and strategic metals. We present a complete characterisation of these deposits based on submarine photographs and geophysical, petrographic, mineralogical and geochemical data. The genesis and growth of ferromanganese deposits, strongly enriched in Fe vs. Mn (av. 39% vs. 6%) in this contourite depositional system result from the combination of hydrogenetic and diagenetic processes. The interaction of the Mediterranean Outflow Water with the continental margin has led to the formation of Late Pleistocene–Holocene ferromanganese mineral deposits, in parallel to the evolution of the contourite depositional system triggered by climatic and tectonic events. The diagenetic growth was fuelled by the anaerobic oxidation of thermogenic hydrocarbons (δ13CPDB=−20 to −37‰) and organic matter within the channel floor sediments, promoting the formation of Fe–Mn carbonate nodules. High 87Sr/86Sr isotopic values (up to 0.70993±0.00025) observed in the inner parts of nodules are related to the influence of radiogenic fluids fuelled by deep-seated fluid venting across the fault systems in the diapirs below the Cadiz Contourite Channel. Erosive action of the Mediterranean Outflow Water undercurrent could have exhumed the Fe–Mn carbonate nodules, especially in the glacial periods, when the lower core of the undercurrent was more active in the study area. The growth rate determined by 230Thexcess/232Th was 113±11 mm/Ma, supporting the hypothesis that the growth of the nodules records palaeoenvironmental changes during the last 70 ka. Ca-rich layers in the nodules could point to the interaction between the Mediterranean Outflow Water and the North Atlantic Deep Water during the Heinrich events. Siderite–rhodochrosite nodules exposed to the oxidising seabottom waters were replaced by Fe–Mn oxyhydroxides. Slow hydrogenetic growth of goethite from the seawaters is observed in the outermost parts of the exhumed nodules and hardgrounds, which show imprints of the Mediterranean Outflow Water with low 87Sr/86Sr isotopic values (down to 0.70693±0.00081). We propose a new genetic and evolutionary model for ferromanganese oxide nodules derived from ferromanganese carbonate nodules formed on continental margins above the carbonate compensation depth and dominated by hydrocarbon seepage structures and strong erosive action of bottom currents. We also compare and discuss the generation of ferromanganese deposits in the Cadiz Contourite Channel with that in other locations and suggest that our model can be applied to ferromanganiferous deposits in other contouritic systems affected by fluid venting.

Camera localization using trajectories and maps

We propose a new Bayesian framework for automatically determining the position (location and orientation) of an uncalibrated camera using the observations of moving objects and a schematic map of the passable areas of the environment. Our approach takes advantage of static and dynamic information on the scene structures through prior probability distributions for object dynamics. The proposed approach restricts plausible positions where the sensor can be located while taking into account the inherent ambiguity of the given setting. The proposed framework samples from the posterior probability distribution for the camera position via data driven MCMC, guided by an initial geometric analysis that restricts the search space. A Kullback-Leibler divergence analysis is then used that yields the final camera position estimate, while explicitly isolating ambiguous settings. The proposed approach is evaluated in synthetic and real environments, showing its satisfactory performance in both ambiguous and unambiguous settings.

Radio-holografía de microondas para la optimización de la superficie de grandes antenas reflectoras

En el presente trabajo de tesis se afronta el problema de la optimización de la superficie de grandes antenas reflectoras. Es sabido que los grandes reflectores, formados por una superficie panelada, sufren deformaciones debidas al impacto del viento, a los cambios de temperatura y a los efectos gravitacionales derivados del gran peso de la estructura. Estos efectos hacen que los reflectores pierdan su forma ideal, generalmente de paraboloide, y se reduzca su eficiencia de apertura y, por tanto, se limite la máxima frecuencia de uso de los mismos. Es necesario, por tanto, disponer de técnicas que permitan medir el estado de la superficie de grandes reflectores, y derivar los ajustes necesarios a aplicar sobre los tornillos de soporte de cada uno de los paneles que conforman dicha superficie. De esta manera, se devolvería al reflector su forma óptima y aumentaría la eficiencia de apertura y el rango de frecuencias de uso. Hay que resaltar que el aumento de la eficiencia de un radiotelescopio supone una reducción en el tiempo de integración necesario para la detección de las debilísimas señales generadas por las radiofuentes naturales, ahorrando así valioso tiempo de observación. Además, el incremento en el rango de frecuencias permite la detección de nuevas líneas o especies moleculares en dichas radiofuentes. Tras un primer capítulo introductorio, se presenta, en el capítulo segundo, la geometría de estos grandes reflectores y la influencia de los distintos factores que afectan a la calidad de la superficie de los mismos, como la gravedad, el viento y la temperatura, particularizando para el caso del radiotelescopio de 40 metros del Centro Astronómico de Yebes. En el tercer capítulo, se presentan las diferentes técnicas metrológicas empleadas actualmente para abordar la determinación de estos ajustes, mostrándose las ventajas e inconvenientes de cada una de ellas. Actualmente, la técnica metrológica más precisa y rápida para llevar a cabo esta tarea de caracterización de la superficie de un gran reflector, es la radio-holografía de microondas presentada en el capítulo cuarto. A partir de las medidas proporcionadas por esta técnica, realizadas con la ayuda de un transmisor, y mediante transformaciones de campo, se calculan los errores de la superficie del reflector, respecto al paraboloide ideal, y se derivan los ajustes necesarios. En los capítulos quinto y sexto se presentan los resultados de la aplicación de esta técnica a dos radiotelescopios: el de 30 metros de IRAM en Pico de Veleta (Granada) y los prototipos de 12 metros de las antenas del proyecto ALMA. Por su parte, el capítulo séptimo contiene el núcleo fundamental de esta tesis y presenta el desarrollo de la técnica de radio-holografía de microondas para optimizar la superficie del radiotelescopio de 40 metros del Centro Astronómico de Yebes. Para ello, ha sido necesario diseñar, construir e instalar un receptor de doble canal en banda Ku en foco primario, y la instrumentación asociada para hacer las medidas de amplitud y fase del diagrama de radiación. Además, ha sido necesario desarrollar el software para llevar a cabo las transformaciones de campo y derivar los ajustes de los paneles. De las medidas holográficas iniciales resultó un error de la superficie del radiotelescopio de 485 μm WRMS, respecto al paraboloide ideal en dirección normal. Tras varias iteraciones del proceso de medida y ajuste, se consiguió reducir dicho error a 194 μm WRMS. Esta notable mejora de la calidad de la superficie ha supuesto aumentar la eficiencia de apertura desde 2,6% al 38,2% a 86 GHz, para un receptor a esta frecuencia situado en el foco primario que produjese la misma iluminación que el receptor de holografía. In this thesis the problem of large reflector antenna surface optimization is faced. It is well known that large reflectors, which are made of a panelled surface, suffer from deformations due to the impact of wind, temperature gradients and gravity loads coming from the high weigth of the structure. These effects distort the ideal reflector shape, which is a paraboloid in most cases, hence reducing the aperture efficiency of the reflector and limiting the maximum frequency of operation. Therefore, it is necessary to have some techniques to measure the status of large reflector surfaces and to derive the adjustment values to be applied to the screws that connect the surface panels to the reflector back-up structure. In this way, the reflector would recover its optimum shape and the aperture efficiency and frequency range would increase. It has to be stated that an increment in the radiotelescope aperture efficiency would imply a reduction in the integration time needed to detect such weak signals coming from natural radiosources in space and, hence, an important saving in observation time. In addition, the increase in the frequency range of operation would allow the detection of new molecular lines in those radiosources. After the introduction, the second chapter shows the geometry of large reflector antennas and the impact on its surface quality of different factors like gravity, wind and temperature, particularly for the case of the Centro Astronómico de Yebes 40 meter radiotelescope. The third chapter deals with the different metrology techniques used to determine the panel adjustments, including the advantages and drawbacks of each one Currently, the most accurate and fast metrologic technique to carry out the characterization of large reflector surfaces is microwave radio-holography2, which is shown in chapter four. From the measurements provided by microwave radio-holography, performed with the help of a transmitter, and with the use of field transformations, the reflector surface errors are computed and the panel adjustments are derived. Chapters five and six show the results of holographic measurements applied to two first class radiotelescopes: the IRAM 30 meter radiotelescope and the 12 meter prototype antennas for the ALMA project. Chapter seven contains the main work of this thesis. It presents the development of the microwave radio-holography technique for the optimization of the Centro Astronómico de Yebes 40m radiotelescope. The work implied the design, construction and instalation of a prime focus Ku-band dual channel receiver, together with the associated instrumentation to measure the amplitude and phase of the radiotelescope radiation pattern. In addition, the software to carry out field transformations and screw settings computations was developed too. Initial holography measurements came up with an surface error of 485 μmWRMS in normal direction with respect to the best-fit paraboloid. After a few iterations of the measurementadjustment cycle, the surface error was reduced to 194 μm WRMS. This remarkable improvement in surface quality means an increment in aperture efficiency from 2,6% to 38,2% at 86 GHz, assuming a receiver at this frequency in prime focus position which produces the same illumination as the holography receiver.

Cine en 3D

Este proyecto pretende documentar el proceso completo de una producción audiovisual en 3D. Para ello, se hace un recorrido por cada una de sus etapas, desde los primeros pasos de la escritura hasta que la película llega a los espectadores. Como el flujo de trabajo para realizar una película es enorme, el estudio se centra exclusivamente en las peculiaridades estereoscópicas, dejando al margen los procesos habituales de una producción convencional. El proyecto está dividido en cinco grandes bloques, centrados en cada etapa de producción. El primer capítulo es una introducción al mundo tridimensional, que sienta las bases de la percepción humana para entender cómo funcionan todas las demás etapas. Además, se hace un repaso por los distintos avances producidos en el campo estereoscópico a lo largo de la historia. El segundo capítulo se centra en la pre-producción, el primer paso para llevar a cabo cualquier proyecto audiovisual, consistente en la planificación del trabajo a realizar y la organización de los distintos elementos que serán necesarios durante el rodaje, teniendo en cuenta desde el primer momento la tercera dimensión. El tercer capítulo está dedicado a la grabación de las imágenes, centrándose principalmente en las características y configuraciones de las cámaras o rigs con los que se obtienen las dos secuencias. El cuarto capítulo aborda la percepción de la película 3D, explicando las características de los variados sistemas de visualización de las imágenes grabadas, que dan a su vez diferentes sistemas de proyección estereoscópica. El quinto y último capítulo se centra en el procesado digital de las imágenes estéreo, que permite juntar el material grabado, corregirlo o perfeccionarlo, y darle la forma adecuada de película que llega al público final. La documentación escrita en español sobre todas estas fases es algo escasa, centrándose normalmente en alguna parte concreta de la cadena, por lo que el proyecto trata también de llenar ese vacío, explicándolo de manera sencilla para hacerlo accesible y factible para toda persona interesada. ABSTRACT. This project has the intention of document the complete process of 3D audiovisual production. For that reason, we make a journey through each of its stages, from the first steps of writing until the film reaches the final viewers. Since the workflow for a film is huge, the study focuses exclusively on the stereoscopic peculiarities, leaving aside the usual processes of conventional production. The Project is divided into five major sections focused on each stage of production. The first chapter is an introduction to three-dimensional world, which lays the foundation of human perception to understand how the other stages work. In addition, we review the various advances in the stereoscopic field throughout history. The second chapter focuses on the pre-production, the first step in carrying out any audiovisual project, including the design of all the works to do and the organization of the different elements that will be needed during filming, taking into account the third dimension from the first moment. The third chapter is devoted to the image recording, focusing mainly on the features and the settings of the cameras or rigs used to obtain the two sequences. The fourth chapter deals with the 3D film perception, explaining the characteristics of the various systems used for displaying the recorded images, which, in turn, give different stereoscopic projection systems. The fifth and final chapter focuses on the digital processing of stereo images, which allows collecting all the recorded material, correcting or improving it, and giving it the proper style for a film that reaches the end consumer. The documents written in Spanish about all these phases are somewhat sparse, usually focusing on a particular part of the chain, so the project also aims to fill that gap, with simple explanations in order to make it accessible and doable for anyone interested.

Max Bill: variaciones sobre la búsqueda de la belleza

Max Bill es un artista lógico. Quince variaciones sobre el mismo tema 1938, podría ser el epítome de la lógica de Bill: la obra como resultado de la aplicación de leyes distintas sobre una estructura de orden. La gran diversidad formal de la obra de Max Bill –entre sus diseños de objetos, su tipografía, su pintura, su escultura o su arquitectura no parece haber líneas formales evidentes- se debe a que, para él, cada tarea es diferente y depende de medios y leyes propios. Una diversidad que podría ser erróneamente interpretada como un tipo de eclecticismo. Su conferencia en el Werkbund suizo de 1948 “belleza de la función, belleza como función”, se aleja del discurso funcionalista al proponer la belleza como una igual al resto de funciones. Cada obra ha de satisfacer la finalidad para la que ha sido construida y cumplir todas las funciones que en ella intervienen pero, además, ha de ser bella. La particularidad de Bill estriba en que, reconociéndose a sí mismo como un artista lógico, incluye la belleza como una más de las funciones a cumplir por cualquier objeto. Su famoso aforismo en relación a la configuración del entorno, desde la cuchara a la ciudad, incluiría la arquitectura en el ámbito de los objetos que han de cumplir esta nueva función. La búsqueda de la belleza será una constante en su obra. No una belleza generalizable y determinada a priori, sino una belleza entendida como predicado singular, individualizada para cada tarea. De este modo, podemos analizar, alternativamente, la belleza lógica de sus construcciones geométricas y la belleza simbólica de sus monumentos; la belleza del espacio sin fin en las superficies de una sola cara y la belleza prefabricada en sus más austeras realizaciones; la belleza elemental de sus esculturas y la belleza corriente con que sus arquitecturas se integran en la ciudad. Podemos plantearnos la posibilidad de una belleza de la estructura y entender simultáneamente la belleza cruda de su obra maestra, los edificios de la Escuela de Ulm. La búsqueda de la belleza nos ayudará a entender que, en la obra de Bill, la razón intuitiva -como modo de conocimiento- toma mayor importancia de la que parece. La forma como suma de todas las funciones en unidad armónica, será el resultado de un adecuado equilibrio entre razón lógica y razón intuitiva. ABSTRACT Max Bill is a logical artist. We could consider “Fitfteen variations on the same theme”, 1938, as the Bill’s logic epitome: the work as a result of the application of different tectonic laws on the order structure. The variety of the form in Bill’s work –his designed objects, his typography, his painting, his sculpture, or his architecture do not seem to have, between them, a direct line connecting the form- is due to the fact that, for him, each task is different and it depends on the own means and tectonic laws. A kind of diversity that could be misinterpreted like certain type of eclecticism. His lecture at the Suisse Werkbund (1948) “beauty from function and as function” is far from the functionalist speech, when proposing beauty as an equal to the rest of functions. In his own words, each work has to satisfy the purpose it was built for and fulfill all functions, and furthermore it has to be beautiful. Seeing himself as a logical artist, Bill however introduces beauty as one more of the functions that any object has to fulfill. His famous aphorism related to the environment management, from the spoon to the city, would include architecture as one more of the objects that have to satisfy this new function. The pursuit of beauty is a constant in his work. It won’t be a general beauty determined in advance, but a singular predicate, individualized for each task. That way, we can analyze, alternatively, the logical beauty of his geometric constructions and the symbolical beauty of his monuments; the beauty of the endless space in the single-sided surfaces and the prefabricated beauty in his most stricts constructions; the elemental beauty of his sculptures and the ordinary beauty with which some of his architectures are integrated in the city. We can also try the possibility of a beauty from the structure and understand, at the same time, the raw beauty of his architectural masterpiece, the buildings of the Ulm School of Design. The pursuit of beauty in Bill’s work will help us to understand that intuitive reason, as a way of knowledge, takes more importance than it seems. Form, as the harmonious expression of the sum of all functions, will be the result of an appropriate balance between logical and intuitive reason.

El lugar de la mente. Sobre la capilla Sogn Benedetg de Peter Zumthor en Sumvitg/ The place of the mind. On Peter Zumthor’s Sogn Benedetg Chapel in Sumvitg

La Capilla de Sogn Benedetg en Sumvitg, parte de la obra temprana de Peter Zumthor, condensa aspectos de sus ideas, de su forma de proyectar y construir, que aún hoy siguen vigentes en él. Los recuerdos de infancia cimientan su enfoque de la arquitectura, en el que trata de reunir trazas de la vida cotidiana, sensible al lugar y utilizando materiales tratados de un modo preciso que bajo la luz adquieren su presencia. Con un lenguaje táctil y tectónico, desde una aproximación fenomenológica, persigue compartir una experiencia multisensorial, englobando percepciones complementarias que trascienden la geometría visual. Como Kahn, se apoya en el pensamiento de Heidegger, y se inspira en la pequeña cabaña que el filósofo habitaba en la Selva Negra, así como en la arquitectura religiosa de Rudolf Schwarz, cuya huella puede apreciarse tanto en el edificio como en los objetos que se encuentran en él. La tensión que genera entre interior y exterior mantiene despiertos los sentidos del visitante, a la vez que las características de la capilla enlazan con un regionalismo integrador que no se aparta de las formas abstractas contemporáneas. : Sogn Benedetg Chapel in Sumvitg, part of the early work of Peter Zumthor, condenses aspects of his ideas and his way of designing and building, which still remain valid today. Remembrances of childhood lay the foundation for his focus to architecture, which involves the collection of daily life traces, sensitive to the place and using materials treated in a precise manner, acquiring their presence under the light. With a tactile and tectonic language, from a phenomenological approach, he seeks to share a multi-sensory experience, encompassing complementary perceptions that transcend the visual geometry. As Kahn does, he relies on Heidegger?s thinking and is inspired by the little hut that the philosopher inhabited in the Black Forest, as well as by Rudolf Schwarz?s religious architecture, whose imprint can be appreciated in both the building and the objects encountered within it. The tension generated between interior and exterior keeps awake the senses of the visitor, while the characteristics of the chapel connect with an integrative regionalism that does not exclude contemporary abstract forms.

A flexible open source web platform to facilitate Learning Object evaluation

Systematic evaluation of Learning Objects is essential to make high quality Web-based education possible. For this reason, several educational repositories and e-Learning systems have developed their own evaluation models and tools. However, the differences of the context in which Learning Objects are produced and consumed suggest that no single evaluation model is sufficient for all scenarios. Besides, no much effort has been put in developing open tools to facilitate Learning Object evaluation and use the quality information for the benefit of end users. This paper presents LOEP, an open source web platform that aims to facilitate Learning Object evaluation in different scenarios and educational settings by supporting and integrating several evaluation models and quality metrics. The work exposed in this paper shows that LOEP is capable of providing Learning Object evaluation to e-Learning systems in an open, low cost, reliable and effective way. Possible scenarios where LOEP could be used to implement quality control policies and to enhance search engines are also described. Finally, we report the results of a survey conducted among reviewers that used LOEP, showing that they perceived LOEP as a powerful and easy to use tool for evaluating Learning Objects.

Monitorización de sistemas en alta disponibilidad

El objetivo del proyecto es implantar un sistema de monitorización, con la peculiaridad de encontrarse en alta disponibilidad, esto es, que el servicio (la monitorización de una infraestructura) se preste forma continua y no se vea interrumpido. Dado que el propósito del sistema es monitorizar activamente una infraestructura, ha sido necesario desplegar una infraestructura, además del sistema de monitorización. La infraestructura en cuestión está compuesta por un servidor de documentación, un servidor de base de datos, un servidor de aplicaciones y un servidor web. El sistema de monitorización se ha desplegado en la misma red de área local de esta infraestructura y monitoriza que los servicios prestados por los componentes de esta infraestructura se encuentren operativos y funcionando adecuadamente. Así pues, se tendría un sistema de monitorización local funcional. No obstante, el proyecto plantea un sistema escalable, que esté preparado para el crecimiento de la infraestructura y continúe siendo eficiente. Para ello, sistema de monitorización se encuentre dividido por dos componentes:  Sonda delegada: monitoriza localmente los activos de la infraestructura a monitorizar, es el escenario anteriormente descrito.  Sonda maestra: recibe los resultados de la monitorización realizada, este sistema puede estar desplegado en otra red distinta a la sonda delegada. Este enfoque no solo es escalable, sino también es fiel a la realidad, pues puede darse el caso de que las sondas pertenezcan a distintas infraestructuras e inclusive, distintas organizaciones, y se comuniquen a través de internet, mediante un mecanismo confiable a ser posible. El proyecto plantea que ambas sondas se encuentren en alta disponibilidad (en adelante HA, referente a high availability), y que cada sonda está compuesta por dos equipos (nodos, en adelante). Como se analizará en posteriores capítulos, existen diversas configuraciones que permiten implantar un sistema en HA, la configuración escogida para el proyecto es Activo – Pasivo(los detalles de esta configuración también se explican en posteriores capítulos). Para finalizar, se estudiara la posibilidad de ofrecer respuestas activas en ciertas situaciones y configuraciones adicionales sobre el sistema de monitorización base. Por otro lado, para la implantación del proyecto se ha usado software de código abierto para la virtualización de la infraestructura (Virtual Box y GNS3), los sistemas operativos base (Linux), el sistema de monitorización(Nagios Core) así como el software que implementa la HA (corosync y pacemaker).---ABSTRACT---The aim of the Project is to implement a monitoring system, with the peculiarity of being deployed in high availability, what it is that the service (monitoring infrastructure) is provided continuously and not interrupted. As the purpose of the system is monitoring infrastructure actively, an infrastructure has been deployed, and also the monitoring system. The infrastructure monitored is composed of a documentation server, a server database, an application server and a Web server. The monitoring system has been also deployed on the same LAN of this infrastructure and monitors the services provided by the components of this infrastructure are operational and working as expected. This is a local monitoring system functional. However, the project also proposes a scalable system that is ready for growth of infrastructure and efficient. This is the reason of divide the system in two components:  Slave Component: monitors locally the infrastructure assets to be monitored, this is the scenario described above.  Master Component: get the results from the monitoring, provided by the Slave Component. This system can be deployed in a different network than the slave component. This approach is not only scalable but also a real scenario, as may be the case that the Components belongs to different infrastructures and even, different organizations, also this components can communicate over the Internet, through a reliable mechanism if possible. The project proposes that both Components are deployed in high availability (HA onwards concerning high availability), each Component is composed of two servers (nodes, hereafter). As will be discussed in later chapters, there are several settings available to deploy a system in HA, the configuration chosen for the project is Active - Passive (details of this configuration are also explained in later chapters). Finally the possibility of offering active responses in certain situations and additional settings on the monitoring system will be discussed. On the other hand, for the implementation of the project, open source software has been used, for virtualization infrastructure (Virtual Box and GNS3), code-based operating systems (Linux), the monitoring system (Nagios core), as well as the software that implements the HA (corosync and pacemaker).

Microinformática en entornos profesionales : instalación, configuración, mantenimiento y reparación

Los sistemas microinformáticos se componen principalmente de hardware y software, con el paso del tiempo el hardware se degrada, se deteriora y en ocasiones se avería. El software evoluciona, requiere un mantenimiento, de actualización y en ocasiones falla teniendo que ser reparado o reinstalado. A nivel hardware se analizan los principales componentes que integran y que son comunes en gran parte estos sistemas, tanto en equipos de sobre mesa como portátiles, independientes del sistema operativo, además de los principales periféricos, también se analizan y recomiendan algunas herramientas necesarias para realizar el montaje, mantenimiento y reparación de estos equipos. Los principales componentes hardware internos son la placa base, memoria RAM, procesador, disco duro, carcasa, fuente de alimentación y tarjeta gráfica. Los periféricos más destacados son el monitor, teclado, ratón, impresora y escáner. Se ha incluido un apartado donde se detallan los distintos tipos de BIOS y los principales parámetros de configuración. Para todos estos componentes, tanto internos como periféricos, se ha realizado un análisis de las características que ofrecen y los detalles en los que se debe prestar especial atención en el momento de seleccionar uno frente a otro. En los casos que existen diferentes tecnologías se ha hecho una comparativa entre ambas, destacando las ventajas y los inconvenientes de unas frente a otras para que sea el usuario final quien decida cual se ajusta mejor a sus necesidades en función de las prestaciones y el coste. Un ejemplo son las impresoras de inyección de tinta frente a las laser o los discos duros mecánicos en comparación con y los discos de estado sólido (SSD). Todos estos componentes están relacionados, interconectados y dependen unos de otros, se ha dedicado un capítulo exclusivamente para estudiar cómo se ensamblan estos componentes, resaltando los principales fallos que se suelen cometer o producir y se han indicado unas serie tareas de mantenimiento preventivo que se pueden realizar para prolongar la vida útil del equipo y evitar averías por mal uso. Los mantenimientos se pueden clasificar como predictivo, perfectivo, adaptativo, preventivo y correctivo. Se ha puesto el foco principalmente en dos tipos de mantenimiento, el preventivo descrito anteriormente y en el correctivo, tanto software como hardware. El mantenimiento correctivo está enfocado al análisis, localización, diagnóstico y reparación de fallos y averías hardware y software. Se describen los principales fallos que se producen en cada componente, cómo se manifiestan o qué síntomas presentan para poder realizar pruebas específicas que diagnostiquen y acoten el fallo. En los casos que es posible la reparación se detallan las instrucciones a seguir, en otro caso se recomienda la sustitución de la pieza o componente. Se ha incluido un apartado dedicado a la virtualización, una tecnología en auge que resulta muy útil para realizar pruebas de software, reduciendo tiempos y costes en las pruebas. Otro aspecto interesante de la virtualización es que se utiliza para montar diferentes servidores virtuales sobre un único servidor físico, lo cual representa un importante ahorro en hardware y costes de mantenimiento, como por ejemplo el consumo eléctrico. A nivel software se realiza un estudio detallado de los principales problemas de seguridad y vulnerabilidades a los que está expuesto un sistema microinformático enumerando y describiendo el comportamiento de los distintos tipos de elementos maliciosos que pueden infectar un equipo, las precauciones que se deben tomar para minimizar los riesgos y las utilidades que se pueden ejecutar para prevenir o limpiar un equipo en caso de infección. Los mantenimientos y asistencias técnicas, en especial las de tipo software, no siempre precisan de la atención presencial de un técnico cualificado, por ello se ha dedicado un capítulo a las herramientas de asistencia remota que se pueden utilizar en este ámbito. Se describen algunas de las más populares y utilizadas en el mercado, su funcionamiento, características y requerimientos. De esta forma el usuario puede ser atendido de una forma rápida, minimizando los tiempos de respuesta y reduciendo los costes. ABSTRACT Microcomputer systems are basically made up of pieces of hardware and software, as time pass, there’s a degradation of the hardware pieces and sometimes failures of them. The software evolves, new versions appears and requires maintenance, upgrades and sometimes also fails having to be repaired or reinstalled. The most important hardware components in a microcomputer system are analyzed in this document for a laptop or a desktop, with independency of the operating system they run. In addition to this, the main peripherals and devices are also analyzed and a recommendation about the most proper tools necessary for maintenance and repair this kind of equipment is given as well. The main internal hardware components are: motherboard, RAM memory, microprocessor, hard drive, housing box, power supply and graphics card. The most important peripherals are: monitor, keyboard, mouse, printer and scanner. A section has been also included where different types of BIOS and main settings are listed with the basic setup parameters in each case. For all these internal components and peripherals, an analysis of their features has been done. Also an indication of the details in which special attention must be payed when choosing more than one at the same time is given. In those cases where different technologies are available, a comparison among them has been done, highlighting the advantages and disadvantages of selecting one or another to guide the end user to decide which one best fits his needs in terms of performance and costs. As an example, the inkjet vs the laser printers technologies has been faced, or also the mechanical hard disks vs the new solid state drives (SSD). All these components are interconnected and are dependent one to each other, a special chapter has been included in order to study how they must be assembled, emphasizing the most often mistakes and faults that can appear during that process, indicating different tasks that can be done as preventive maintenance to enlarge the life of the equipment and to prevent damage because of a wrong use. The different maintenances can be classified as: predictive, perfective, adaptive, preventive and corrective. The main focus is on the preventive maintains, described above, and in the corrective one, in software and hardware. Corrective maintenance is focused on the analysis, localization, diagnosis and repair of hardware and software failures and breakdowns. The most typical failures that can occur are described, also how they can be detected or the specific symptoms of each one in order to apply different technics or specific tests to diagnose and delimit the failure. In those cases where the reparation is possible, instructions to do so are given, otherwise, the replacement of the component is recommended. A complete section about virtualization has also been included. Virtualization is a state of the art technology that is very useful especially for testing software purposes, reducing time and costs during the tests. Another interesting aspect of virtualization is the possibility to have different virtual servers on a single physical server, which represents a significant savings in hardware inversion and maintenance costs, such as electricity consumption. In the software area, a detailed study has been done about security problems and vulnerabilities a microcomputer system is exposed, listing and describing the behavior of different types of malicious elements that can infect a computer, the precautions to be taken to minimize the risks and the tools that can be used to prevent or clean a computer system in case of infection. The software maintenance and technical assistance not always requires the physical presence of a qualified technician to solve the possible problems, that’s why a complete chapter about the remote support tools that can be used to do so has been also included. Some of the most popular ones used in the market are described with their characteristics and requirements. Using this kind of technology, final users can be served quickly, minimizing response times and reducing costs.