No description available.

The following abstract is for a thesis submitted to the University of Manchester for the degree of Doctor in Philosophy by Omar AbdelRehim AbdelKerim in 2015.Anti-personnel (AP) mines remain a global problem that affects communities around the world, with 110 million active landmines still present. Landmines are a particularly callous and indiscriminate type of weapon detonating irrespective of presence of an enemy soldier or a child. Their devastating effect on communities has led to their ban through the 1997 Mine Ban Treaty. Current detectors used for mine clearance operations have an impeding weakness that has prompted this research; metal detectors used in humanitarian demining suffer from a high False Alarm Rate (FAR) prompting regular excavation of metallic clutter. The research presented aims to develop a detector capable of discriminating between metallic clutter and mines through the use of the magnetic polarizability dyadic tensor to reduce FARs, increase demining efficiency and improve deminer’s safety. A measurement apparatus was designed and constructed to perform spectroscopic magnetic measurements of small symmetrical metallic objects and produce for the first time unscaled accurate tensor values. The tensors deduced from the measurements were validated against analytical and simulated results and were found to be within 5% of measured tensors. The tensors of minimum metal AP mine surrogates and metallic clutter of symmetrical shape were measured and formed part of a tensor library to be used later by future research. This is in addition to a set of un-circulated US coinage which could be used as a calibration metric and a comparison piece for future work in this area. A detailed description of the coil design and manufacturing process is presented to develop a coil array capable of inverting buried metallic object tensors. The selection criterion was poised to identify an array that was best suited to perform the correct measurements in order to invert to an accurate tensor. The manufactured coil exhibited strong mutual coupling between the receive coils deeming it unfit for the portable detector; however, the findings of the work presented and the selection criterion developed has aided the future design of a suitable coil array. Expected signal levels from minimum metal mine detection were calculated and helped aide in the design of future detectors to ensure suitable SNR performance is achieved. A portable detector has been developed using the sensor head presented within this thesis. Work still lies ahead to achieve the complete detector capable of performing target characterisation and clutter elimination; however, significant advances have been made and are presented throughout this thesis.

This portfolio thesis describes work undertaken by the author under the Engineering Doctorate program of the Institute for System Level Integration. It was carried out in conjunction with the sponsor company Teledyne Defence Limited. A radar warning receiver is a device used to detect and identify the emissions of radars. They were originally developed during the Second World War and are found today on a variety of military platforms as part of the platform’s defensive systems. Teledyne Defence has designed and built components and electronic subsystems for the defence industry since the 1970s. This thesis documents part of the work carried out to create Phobos, Teledyne Defence’s first complete radar warning receiver. Phobos was designed to be the first low cost radar warning receiver. This was made possible by the reuse of existing Teledyne Defence products, commercial off the shelf hardware and advanced UK government algorithms. The challenges of this integration are described and discussed, with detail given of the software architecture and the development of the embedded application. Performance of the embedded system as a whole is described and qualified within the context of a low cost system.

No description available.

En los albores del siglo XV se dio inicio en el continente europeo a una transformación tecnológica que habría de afectar las más diversas disciplinas humanas: en 1494 una nueva y poderosa arma batió rápidamente -de manos de las tropas francesas- las hasta ahora muy sólidas murallas italianas: se trataba del cañón accionado con pólvora. Con él, un novedoso conjunto de conocimientos especializados comenzó a estructurarse; la investigación y la experiencia obtenida en las acciones bélicas permitió conocer los efectos de las nuevas armas, la valoración de los ángulos de tiro, el efecto de las minas, e incluso procedimientos clínicos para la atención de los heridos en el campo de batalla ...; pero fue sin duda en el arte de construcción de fortificaciones en donde se produjo un cambio realmente significativo que tiró por los suelos -junto a los muchos recintos amurallados de las ciudades medievales-, todo un conjunto de saberes que hasta ahora se había servido del cuerpo doctrinal de dos remotos autores romanos: Vitruvio y Vegecio.No fueron pocos los hombres del siglo XVI que dieron inicio al esfuerzo por lograr un mejor entendimiento de la aplicación de los materiales en la construcción de cortinas y baluartes, del asiento y espesor de cimentaciones y muros, de la profundidad y ancho de los fosos, de la inclinación de taludes, de la resistencia de las bóvedas y forjados, del suministro y evacuación de las aguas, e incluso de la aparentemente mágica relación que se establecía entre el trazado hecho sobre polígonos regulares y el perímetro perfecto capaz de resistir el peor de los asedios ... Portadores de ese extenso conjunto de conocimientos, se llevaron a las imprentas europeas un número indeterminado de libros dedicados al tema de la arquitectura y la ingeniería militar: los llamados tratados de arquitectura militar o tratados de fortificación, los mismos en donde todavía es posible apreciar el encomiable esfuerzo de sus autores por construir y reglar una técnica: la del ingeniero militar, la del arquitecto.Tal proceso no fue fácil: él demandó una transformación en los métodos de elaboración de ideas y conceptos, tal y como lo expresan los muchos autores en las formas de sus discursos, en el uso de las palabras, en el orden en que se exponen las ideas, en la manera de relacionarse con las ciencias ... Y es que tuvieron que apropiarse de saberes ajenos inscritos dentro del marco común de las acciones propias del arte de construir y guiarse por la explícita necesidad de definir unos límites propios de su actividad con el fin de conformar un corpus doctrinal autónomo.Esta Tesis da cuenta de ese proceso a través de un estudio detallado de los tratados de fortificación impresos en Europa (siglos XVI - XVIII) y de sus contenidos de construcción. / The dawn of the 15th century, saw the beginning of a technological transformation in the European continent; one which would affect the most diverse human disciplines: in 1494, a new and powerful weapon, at the hands of French troops, quickly defeated the, till then, very solid Italian defense walls - it was the gunpowder-activated canon. With it, a novel set of specialized knowledge began its structuring; investigation and experience gathered in war actions allowed for knowledge in the effects of the new weapons, the assessment of the launching angles, the effect of land mines, and even clinical procedures to aid the wounded on the battle field .; but it was without a doubt in the art of fortress construction where a truly significant change came about, toppling - along with many walled installations in medieval cities - a whole set of previous knowledge, which till hence had availed itself of the doctrinal corpus of two remote Roman authors: Vitruvious and Vegecious. Many men since then have given start to the effort of reaching a better understanding of the application of materials in the construction of rampart curtains and bastions, the settlement and thickness of foundations and walls, the depth and width of moats, the inclination of taluses, the resistance of vaults and mortared cements, the supply and evacuation of water, and even to the apparently magical relationship established between the tracing from regular polygons and the perfect perimeter capable of withstanding the worst of attacks .Bearers of that vast set of knowledge, an indeterminate number of books dedicated to the issue of military architecture and engineering were brought to European printers between the painfully long years between 1500 and 1800: the so-called treatises on military architecture or fortification treatises, the very same that can today still be appreciated in their authors' praiseworthy effort to build and regulate a technique: that of a military engineer, that of an architect.Such a process was not easy: it called for a transformation in the methods of elaborating ideas and concepts, just as it is expressed by many authors in many ways through their discourse, in the use of words, in the order ideas are presented, in the manner of relating to science. And it is that they had to appropriate themselves of the knowledge of others inscribed within the common scope of the very actions in the art of building and guiding themselves by the explicit necessity of defining the limits appertaining to their activity, in order to conform an autonomous doctrinal corpus. This thesis reviews that process through detailed study of the fortification treatises and their construction contents printed in Europe from the 16th to the 18th centuries.

La tesis doctoral se refiere al proceso fundacional escasamente conocido por encontrarse sus fuentes primarias en los archivos de Londres y París de la población menorquina anteriormente denominada Georgetown, hoy Es Castell, planificada por el ingeniero militar escocés Patrick Mackellar en el puerto de Mahón durante la segunda dominación británica de la isla (1763-1782).Se trata de una labor de investigación que está estructurada en tres partes. En la primera, se realiza una aproximación al urbanismo de origen militar desarrollado por Gran Bretaña a lo largo de los siglos XVII y XVIII, coincidiendo con el auge de la artillería bélica. En este sentido es demostrable la influencia, en el plano teórico, de la supremacía militar de Francia y sobre todo, de la polifacética labor de Vauban reflejada, entre otras cuestiones, en los Manuales de Fortificación de obligatorio estudio durante la formación de los ingenieros militares británicos.Hasta el siglo XVIII, los ingenieros agrupados en torno a la Board Ordnance tuvieron escasas ocasiones de crear nuevas ciudades, fundamentalmente por dos razones. La primera, que Inglaterra no inició su expansión colonial hasta la resolución de sus problemas internos que finalizaron con la anexión de Irlanda y Escocia. La segunda, que su condición insular la obligó a basar la defensa de sus territorios en el desarrollo de una poderosa flota armada.Sin embargo, el modelo colonial inglés, basado en el protagonismo de las compañías comerciales, propicia la intervención de los ingenieros militares en las labores de planificación y verificación de los nuevos asentamientos del norte de Irlanda, la costa de Coromandel, el este norteamericano y las Antillas.La segunda línea de investigación incursiona en la vida del planificador de Georgetown, destacando su experiencia bélica en los frentes americanos durante la Guerra de los Siete Años (1756-1763). Gracias a su participación en las campañas militares, Patrick Mackellar conoce en primera persona las características del urbanismo practicado por Inglaterra y Francia en los territorios de ultramar, y se dota de un importante bagaje cultural que demostrará cuando, en su definitivo destino como Ingeniero-Jefe en Menorca, acomete la empresa de planificar y diseñar una nueva ciudad.La tercera línea de investigación se centra en el proceso fundacional de Georgetown. La operación basada en razones defensivas consistió en demoler un asentamiento surgido a los pies de la principal fortaleza de la Isla, y trasladar la morada de sus casi cuatro mil pobladores a una enclave prudentemente alejado de la fortificación.Llamada Vila Jordi por sus primeros moradores, Georgetown resultó un excelente ejemplo de pragmatismo urbanístico. La plaza central o génesis del asentamiento, se ubicó sobre una pequeña meseta portuaria que ya había sido elegida por un ingeniero militar galo durante la dominación francesa de la isla y se aprovechó el trazado de una antigua vía de comunicación territorial como eje longitudinal del nuevo conjunto urbano. Igualmente, el reparto de suelo se realizó en función del tamaño de las parcelas existentes en el pueblo anterior. Sin embargo, la atención a las gentes y a una geografía del lugar marcada por la costa portuaria, no impidió a Mackellar el desarrollo de un conjunto urbano de calles rectas, paralelas y jerarquizadas trazadas a partir de un espacio central conformado por las edificaciones propias de una ciudadela militar barroca.Tras una comparación formal con otras poblaciones estudiadas, el desarrollo de la tesis analiza, finalmente, los elementos principales de la población, tales como la anchura y distancia de las calles, los edificios cuarteleros y otras construcciones notables, la tipología residencial y la historia de la población en los dos últimos siglos.Como conclusión, el autor considera que el proyecto de Mackellar para Georgetown combina acertadamente las bases empíricas que lo sustentan con una variante del prototipo urbanístico aplicado en la colonización de Nueva Escocia como garantía de la satisfacción de las exigencias de orden y regularidad propias de la planificación militar y del urbanismo dieciochesco.Nacida entre la agonía del Antiguo Régimen y el estallido de las revoluciones americana y francesa, hija del Barroco y madre del urbanismo decimonónico, esta operación urbanística financiada por la corona inglesa fue el fruto de un compromiso, un proyecto de transición. / The doctoral thesis refers to the foundation process quite unknown, as the first sources are in the archives of London and Paris of the Minorca's town before named Georgetown, nowadays known as Es Castell, planned by the Scottish military Engineer Patrick Mackellar in Mahon's harbour during the second british domination on the island (1763-1782).It is a research work and is structured in 3 parts. First part, it's an approximation to a source of military urbanism developed by Great Britain during the XVII and XVIII centuries, coinciding with the increase of war artillery. This is shown by the influence in the theoretical survey, of France's military supremacy and above all, the versatile labour of Vauban revealed, apart from other issues, by the Guides of Fortifications which were of compulsory study, for the british military engineers during their training.Until the XVIII century, the engineers round about the Board Ordnance had few occasions to create new towns, basically for two reasons. The first, is that England didn't begin its colonial expansion until it had solved its own internal problems, which came to an end with the annexation of Ireland and Scotland. The second, that it's insular status obliged it to base its defence of its territories in the development of a powerful navy.Nevertheless, the english colonial model, based on the commercial companies playing the main part, helped the intervention of the military engineers in the work of verifying and planning the new settlement in North Ireland, the Coromandel Coast, the east part of North America and the Antilles.The second line of research attacked the life of the planner of Georgetown, emphasising his war experience on the american front during the Seven-Year War (1756-1763). Thanks to his partaking in the military campaigns, Patrick Mackellar found out himself the characteristics of English and French development overseas, and he endowed himself with an important cultural knowledge which he revealed when, in his last post as Chief Engineer in Minorca, he undertook the designing and planning of a new town.The third research is centred in the foundational process of Georgetown. The transaction based on defensive reasons consisted in demolishing a settlement at the foot of the main fort of the island, and moves the homes of its almost 4.000 inhabitants to a more prudential area, away from the fort.Named Villa Jordi by its first inhabitants, Georgetown was an excellent example of city planning pragmatism. The central square or genesis of the settlement, was built on a small portside plateau which had already been chosen by a french military engineer during the France's domination of the island and, an old communicating land route, was made use of as an essential longitudinal part of the new urban unit. In the same manner the distribution of the ground was made according to the size of the existing plots in the old village. Nevertheless, the attention to the people and the geographical situation, marked by the port coastland, didn't stop Mackellar developing an urban unit with straight roads, parallel hierarchical layout from a central space, almost exactly like the buildings of a baroque military fortress.After a formal comparison with other populations under study, finally the thesis development analyses the principal elements of the population, like the length and the distance of the streets, the barrack buildings and other notable constructions, the residential types and the history of the population over the last two centuries.Concluding, the author considers that Mackellar's project for Georgetown, succeeds in combining the empirical bases that maintains it with a variation of the urban prototype applied in the colonization of New Scotland as a guarantee of satisfaction for the demand and regularity of a military planning as well as eighteenth century urbanism. Born between the agony of the Old Regime and the outburst of the american and French revolutions, daughter of the Baroque and mother of nineteenth century development, this town planning exploitation financed by the English Crown, was the result of a commitment, a design of the transitional period.

The main objective of this thesis is to present a new image processing technique to improve the detectability of buried objects such as landmines using Ground Penetrating Radar (GPR). The main challenge of GPR based landmine detection is to have an accurate image analysis method that is capable of reducing false alarms. However an accurate image relies on having sufficient spatial resolution in the received signal. An Antipersonnel mine (APM) can have a diameter as little as 2cm, whereas many soils have very high attenuation at frequencies above 450 MHz. In order to solve the detection problem, a system level analysis of the issues involved with the recognition of landmines using image reconstruction is required. The thesis illustrates the development of a novel technique called the SIMCA (“SIMulated Correlation Algorithm”) based on area or volume correlation between the trace that would be returned by an ideal point reflector in the soil conditions at the site (obtained using the realistic simulation of Maxwell’s equations) and the actual trace. During an initialization phase, SIMCA carries out radar simulation using the system parameters of the radar and the soil properties. Then SIMCA takes the raw data as the radar is scanned over the ground and uses a clutter removal technique to remove various unwanted signals of clutter such as cross talk, initial ground reflection and antenna ringing. The trace which would be returned by a target under these conditions is then used to form a correlation kernel using a GPR simulator. The 2D GPR scan (B scan), formed by abutting successive time-amplitude plots taken from different spatial positions as column vectors,is then correlated with the kernel using the Pearson correlation coefficient resulting in a correlated image which is brightest at points most similar to the canonical target. This image is then raised to an odd power >2 to enhance the target/background separation. The first part of the thesis presents a 2-dimensional technique using the B scans which have been produced as a result of correlating the clutter removed radargram (’B scan’) with the kernel produced from the simulation. In order to validate the SIMCA 2D algorithm, qualitative evidence was used where comparison was made between the B scans produced by the SIMCA algorithm with B scans from some other techniques which are the best alternative systems reported in the open literature. It was found from this that the SIMCA algorithm clearly produces clearer B scans in comparison to the other techniques. Next quantitative evidence was used to validate the SIMCA algorithm and demonstrate that it produced clear images. Two methods are used to obtain this quantitative evidence. In the first method an expert GPR user and 4 other general users are used to predict the location of landmines from the correlated B scans and validate the SIMCA 2D algorithm. Here human users are asked to indicate the location of targets from a printed sheet of paper which shows the correlated B scans produced by the SIMCA algorithm after some training, bearing in mind that it is a blind test. For the second quantitative evidence method, the AMIRA software is used to obtain values of the burial depth and position of the target in the x direction and hence validate the SIMCA 2D algorithm. Then the absolute error values for the burial depth along with the absolute error values for the position in the x direction obtained from the SIMCA algorithm and the Scheers et al’s algorithm when compared to the corresponding ground truth values were calculated. Two-dimensional techniques that use B scans do not give accurate information on the shape and dimensions of the buried target, in comparison to 3D techniques that use 3D data (’C scans’). As a result the next part of the thesis presents a 3-dimensional technique. The equivalent 3D kernel is formed by rotating the 2D kernel produced by the simulation along the polar co-ordinates, whilst the 3D data is the clutter removed C scan. Then volume correlation is performed between the intersecting parts of the kernel and the data. This data is used to create iso-surfaces of the slices raised to an odd power > 2. To validate the algorithm an objective validation process which compares the actual target volume to that produced by the re-construction process is used. The SIMCA 3D technique and the Scheers et al’s (the best alternative system reported in the open literature) technique are used to image a variety of landmines using GPR scans. The types of mines included plastic, wooden and glass ones. In all cases clear images were obtained with SIMCA. In contrast Scheers’ algorithm, the present state-of-the-art, failed to provide clear images of non metallic landmines. For this thesis, the above algorithms have been tested for landmine data and for locating foundations in demolished buildings and to validate and demonstrate that the SIMCA algorithms are better than existing technologies such as the Scheers et al’s method and the REFLEXW commercial software.

No description available.

No description available.

Gas problems have created severe difficulties for the mining industry around the world, leading to high expenditures and intensity research efforts, and determined attempts to enhance the various ventilation optimization and gas drainage techniques. Meanwhile, gas research is thriving in recent years, and gas drainage technology will continue to be a growing industry over the coming decades in many mining countries. Safety mining technologies including field investigation, numerical simulation and laboratorial experiments have been improved to develop a better understanding of the causes of mine gas-related disasters over the last two decades. In addition, new and multiple gas control strategies and technologies have been developed, including optimizing the ventilation system constantly, preventing goaf spontaneous combustion timely, enhancing gas risk management effectively, determining the gas emission zone exactly, and implementing a reasonable gas drainage plan correctly. The first part of the dissertation introduces a multiple gas disaster prevention, control and reduction strategy. Firstly, the basic theories of gas emission, distribution and migration are discussed. Then a numerical prediction model based on a specific coal mine is established to predict its gas emission. The second part of the dissertation offers the establishment of the numerical simulation model (CFD) and laboratorial experimental model for the purpose of discussing the gas distribution and migration rule and determining the most effective gas drainage zones in the working face and goaf. Both of the numerical simulation results and the laboratorial experimental results also demonstrate that the most effective gas drainage spot constantly varies with the area where mining activities are performed. In the case of numerical simulation experimental results, it is mainly located in the area of 40m-250m (between working face and deep goaf), 30m-40m from the working face floor (between the working face floor to the roof), and approximately 60m-170m (between air inlet and air outlet). In the case of laboratorial simulation experimental results, it mainly locates in coal seam and rock stratum separation area of 27cm-243cm (between working face and deep goaf), 28cm-42cm (between the working face floor to the roof) and 78cm-182cm (between air inlet and air outlet). The last part of this dissertation provides a field study in order to obtain the gas distribution and migration rule in the working face and goaf. The field measured results show the average gas drainage rate increased from 39.6 m3·min-1 (U-type ventilation system) to approximately 48.9 m3·min-1 (U+L-type ventilation system) while the gas concentration of the special drainage tunnel, upper corner and air outlet decreased from 1.88%, 0.85% and 0.61% (U-type ventilation system) to 1.69%, 0.75% and 0.55% (U+L-type ventilation system), respectively. These results indicate the layout of the gas drainage boreholes is rational and effective; the gas drainage volume is reliable. Therefore, it is feasible and reliable to arrange the layout of gas drainage tunnels based on the experimental results of numerical simulation and laboratorial test. / Los problemas ocasionados por gas han creado graves dificultades para la industria minera en todo el mundo, por lo que ha implicado altos gastos y esfuerzos de investigación y intentos de mejorar en diversas técnicas de optimización de la ventilación y drenaje de gas. Mientras tanto, la investigación sobre gas ha aumentado considerable en los últimos años y la tecnología de drenaje de gas seguirá siendo una industria en crecimiento en las próximas décadas en muchos países mineros. Las tecnologías mineras de seguridad, incluyendo la investigación de campo, la simulación numérica y experimentos en laboratorio han mejorado para una mejor comprensión de las causas de los desastres relacionados con el gas de las minas en las últimas dos décadas. Además, se han desarrollado nuevos y múltiples estrategias y tecnologías de control de gas, incluyendo la optimización del sistema de ventilación, impidiendo excavaciones de combustión espontánea oportuna, mejorando así la gestión eficaz de riesgos causados por gases, determinando la zona de emisión de gases con exactitud, y la implementación de un plan de drenaje de gas correctamente. La primera parte de la tesis se presenta una estrategia múltiple de la prevención de desastres de gas, control y reducción. En primer lugar, se analizarán las teorías básicas de la emisión de gases, la distribución y la migración. Luego se establecerá un modelo de predicción numérica basada en una mina de carbón específica para predecir su emisión de gases. La segunda parte de la tesis ofrece el establecimiento del modelo numérico de simulación (CFD) y el modelo experimental de laboratorio con el fin de discutir la distribución de gas y norma de migración y la determinación de las zonas de drenaje de gas más eficaces en el frente de trabajo y terraplén. Tanto los resultados del simulación numéricos como los resultados experimentales de laboratorio demuestran que el punto de drenaje más eficaz de gas varía constantemente según el área donde se realizan las actividades mineras. En el caso de los resultados experimentales de simulación numérica, que se encuentra principalmente en el área de 40m-250m (entre la superficie del tierra y el zona excavada), 30m-40m desde la superficie de trabajo (desde la superficie del trabajo hasta el techo), y aproximadamente 60m-170m (entre el entrada y salida de aire). En el caso de los resultados experimentales de simulación en el laboratorio, se localiza principalmente en la veta de carbón y la zona de separación del estrato rocoso de 27cm-243cm (entre la superficie de la tierra y la zona excavada), 28cm-42cm (desde la superficie del trabajo hasta el techo) y 78cm-182cm (entre la entrada y salida de aire). La última parte de esta tesis concluye un estudio de campo con el fin de obtener la distribución de gas y el estado migratorio entre la superficie y la zona escavada. Los resultados de campo medidos muestran que la tasa de drenaje de gas en promedio aumentó 39,6 m3·min-1 (sistema de ventilación de tipo T) a aproximadamente 48,9 m3 · min-1 (sistema de ventilación de T + L-tipo), mientras que la concentración de gas del drenaje especial en túnel, esquina superior y salida de aire se redujo de 1,88%, 0,85% y 0,61% (sistema de ventilación de tipo U) a 1,69%, 0,75% y 0,55% (U + de tipo L sistema de ventilación), respectivamente. Estos resultados indican que la disposición de las perforaciones de drenaje de gas es racional y eficaz; el volumen de drenaje de gas es fiable. Por lo tanto, es factible y fiable para organizar la disposición de túneles de drenaje de gas sobre la base de los resultados experimentales de simulación numérica y la prueba de laboratorio.