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Grammond, Line. "Analyse de la fiabilité des chargeuses-navettes LHD." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq25314.pdf.
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Danielsson, Markus. "Borehole Dimension Impact on LHD Operation in Malmberget Mine." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-59679.
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Sublevel caving is a highly mechanizable mass mining method normally utilized in large, steeply dipping orebodies. The fragmented ore flows freely, aided by gravity, down to the drawpoint while the surrounding waste rock caves in due to induced stresses and gravity. Fragmentation of the blasted ore is a vital component in any mining operation and directly affects productivity and efficiency of the following production steps (Nielsen et. al, 1996). In an attempt to reduce mining induced seismicity in Malmberget, LKAB is initiating various trials. One of these trials involves a reduction in blasthole dimension and an increase in the number of blastholes utilized in each ring. A reduction in blasthole dimension is undertaken to achieve a less impactful mining operation in terms of disturbances to surface populated areas, particularly addressed to ground vibrations. Therefore, it is of utmost importance to analyse if fragmentation and production is affected as a consequence of this change. This thesis sets out to evaluate how fragmentation and the LHD operation is affected by variations in blasthole dimension. The evaluation is carried out through analysis of logged production data, on-site filming of the loading sequence and interviews with the LHD operators. The discoveries will be presented chronologically to illustrate the complexities related to compiling a viable dataset to rely on for a credible analysis. The initial theory did not hold up properly and therefore the project was reshaped along the course of progression to provide further information and clarify uncertainties. Unfortunate, major production delays inhibited a quantitative comparison of two parallel drifts with different blasthole dimensions. Hence, no final answer can be provided in this thesis whether a change in blasthole dimension causes any differences in loadability and/or fragmentation or not. However, an analysis of how cycle times vary depending on causes such as operator induced differences, machine induced differences and road conditions will be provided. The field test also provides information on various loading scenarios and the difficulties connected to these. The result obtained in this project mainly addresses the significant operator difference in terms of cycle times which can extend to, on average, 60% depending on experience, road conditions and, most likely, preferences amongst operators. Time differences amongst seemingly experienced operators can reach more than, on average, 30% in hauling time alone. Roughly 96% of the operators state that road conditions in the production area is the controlling factor for hauling speed. Many of the operators further states that the risk of injuries is directly related to road conditions and this is a likely cause to why cycle times vary in this magnitude. Fragmentation was found to affect loadability but not to the same extent as shape and looseness of the muck pile. Compaction of the muck pile and flow disturbances where normally found to be connected to one another. Hence, good loadability would indicate a low occurrence of flow disturbances and a continuous flow of material into the drawpoint. This thesis is written as a part of the final stage of the civil engineering program at Luleå University of Technology (LTU) and represents 30 credits in the field of Soil and Rock Construction. The thesis is a part of a larger project, Face to surface, which sets out to analyse the impact of fragmentation on different stages in the production chain.
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García, Olaya Jerónimo. "Study of electron heat transport in LHD and TJ-II." Doctoral thesis, Universitat Politècnica de Catalunya, 2006. http://hdl.handle.net/10803/6609.
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The magnetically confined plasmas study is one of the most promising research fields in the present days due to the high perspectives of unlimited and clean energy that fusion has generated. In this framework, the stellarator devices play a significant role because of, unlike in the tokamak case, their continuum working regime, which will be an essential feature of the future fusion commercial reactor.<br/>Heat transport studies in stellarator devices are completely necessary since the main plasma properties (and therefore, the total fusion power generated) are absolutely dependent. Nowadays, the largest stellarator in the world is the Large Helical Device (LHD). There is also a stellarator device is Spain, TJ-II, which is located in the installations of CIEMAT in Madrid. In this thesis, turbulent and conductive heat transport is studied in both devices with the aim of comparing its formation and suppression. <br/>First of all, collisional transport, i.e. neoclassical transport, which is caused by the particle collisions, is studied by means of a new transport model implemented in the transport code PRETOR-Stellarator. This model is able to calculate heat diffusivities as well as the neoclassical electric field with reasonable accuracy without spending as much computational time as in the Monte Carlo techniques. It is deduced from the results that, for both TJ-II and LHD, neoclassical transport may be quite important in plasmas with low density and high temperatures, although higher levels of neoclassical transport are obtained in TJ-II. Both devices share the feature that in low collisional plasmas, a high positive neoclassical electric field with a high shear appears in the plasma core. This electric field can be responsible of the suppression of the turbulence heat transport.<br/>Some new turbulent heat transport models have been added to PRETOR-Stellarator in order to study this kind of transport. Both, LHD and TJ-II, share a common heat transport in the confinement region (plasma core), called drift wave electromagnetic transport, and which is due to the fluctuations of the magnetic field. Outside this region, turbulent heat transport in LHD has similar characteristic to that in tokamaks, whereas in TJ-II, turbulent transport is maintained.<br/>Turbulent heat transport reduction is a major issue in fusion research, since the capability of producing commercial fusion energy depends strongly on the low levels of turbulence of the plasma. The appearance of a neoclassical electric field in the plasma core and its interaction with turbulent transport has been studied. It is shown that this electric field is able to generate a rotation in the plasma which is able to suppress turbulent transport to neoclassical levels when density is low enough. These plasmas are called to have an internal transport barrier and have stepped electron temperature profiles with hollow electron density profiles. <br/>Another important phenomenon related with electron heat transport is non-local transport, which can not be studied within the general diffusive framework that is used to study turbulent transport in plasmas. The non-local transport is caused by the interaction of long distant parts of the plasma. In this thesis, a new model for this type of transport, which is based on the convolution over a kernel of the neoclassical transport, has been proposed to explain this phenomenon. It has been shown that this model is able to simulate the main characteristics of this transport, e.g. fast pulses propagation, ballistic transport or the growing of the turbulence levels close to the axis of the device. All these phenomena have been observed in LHD and TJ-II. <br/>Finally, once electron heat transport in stellarators has been clarified, a comparison of the designs of the future commercial reactor based on both, stellarators and tokamaks, has been carried out. A stellarator commercial reactor, based on the design of the LHD, would have a 15.5 m major radius, 2.5 m minor radius, with a continuum working regime based on low temperatures and high densities. Main energy sinks are due to conductive-convective heat losses and radiation losses (in a 95% from Bremmstrahlung radiation). The fact that it has such a large major radius makes this design expensive and difficult to build. A tokamak fusion reactor would be smaller, however, the high temperatures achieved make cyclotron radiation losses to be very high, and a wall with a high reflection coefficient seems to be necessary.<br>L'estudi de les propietats dels plasmes confinats magnèticament esta esdevenint un dels temes primordials de recerca degut a les prometedores perspectives (de netedat i ampli abast) que l'energia produïda per fusió nuclear està fomentant. Es dins d'aquest context on l'estudi dels dispositius de confinament magnètic de tipus stellarator juguen un paper molt important, ja que un reactor de fusió basat en aquest concepte podria tenir (al contrari dels tokamaks) un mode de funcionament continu i no polsat.<br/>L'estudi del transport de calor en el dispositius de fusió per confinament magnètic de tipus stellarator és totalment necessari, ja que les propietats del plasma (i per tant de l'energia produïda per fusió) en depenen completament. Actualment, el stellarator més gran del món es troba al Japó i es diu Large Helical Device (LHD), mentre que a Espanya, el stellarator TJ-II es troba a les instal·lacions del CIEMAT a Madrid. En aquesta tesi, s'estudien ambdós dispositius per tal de determinar de que depèn que aparegui o que desaparegui el transport de calor turbulent en aquests dispositius, i si hi ha algun tipus de punt en comú.<br/>En primer lloc, s'analitza el transport de calor colisional (degut a la col·lisió de les partícules que formen el plasma) mitjançant la introducció d'un model de transport colisional (anomenat neoclàssic) al codi de transport PRETOR-Stellarator. Aquest model es capaç de calcular magnituds físiques tal com difusivitats i camps elèctrics neoclàssics però sense consumir tant de temps com a d'altres tècniques que utilitzen mètodes de Monte Carlo. Dels resultats es desprèn que el transport neoclàssic, tant al TJ-II com al LHD, pot ser important, en plasmes amb baixa densitat i temperatures grans. Ambdós dispositius comparteixen la característica de que apareix, en aquests casos, un gran camp elèctric al centre del plasma que pot ser fa que el transport turbulent disminueixi. <br/>Mitjançant la introducció de diferents models pel transport turbulent a PRETOR-Stellarator, s'estudia el transport turbulent als dos dispositius. De l'anàlisi es dedueix que ambdós dispositius poden compartir el mateix tipus de transport (anomenat electromagnètic) i que es degut a les variacions locals del camp magnètic. Tanmateix, fora de la zona central, el LHD té un tipus de transport semblant al que existeix al tokamak JET (Joint European Torus), mentre que el TJ-II continua amb el transport electromagnètic.<br/>La reducció del transport turbulent prèviament estudiat és un tema capdal ja que permetria un millor confinament del plasma. S'ha estudiat com el camp elèctric format al centre del plasma pot generar un rotació que disminueix el transport turbulent tant al LHD com al TJ-II. Aquests plasmes es diuen que tenen una barrera interna del transport que redueix el transport turbulent a valors neoclàssics sempre que la densitat sigui prou baixa.<br/>Un altre fenomen lligat al transport molt important és el transport no local, que es degut a les correlacions entre parts llunyanes del plasma i que no es pot entendre dintre del context del transport difusió que se sol emprar per a estudiar el plasmes confinats. En el marc d'aquesta tesi s'ha dissenyat un model de transport no local per mitjà d'una convolució sobre el transport neoclàssic. Amb aquest model s'ha aconseguit reproduir molts del efectes no locals que apareixen als plasmes (com ara la ràpida propagació de fenòmens turbulents o la propagació de fronts turbulents que mantenen una forma d'ona ), i que s'han descrit tant al LHD com al TJ-II.<br/>Finalment es realitza una comparació entre els dissenys dels reactors de fusió basats en stellarators i tokamaks. Un reactor de fusió stellarator tindria un radi major de 15.5 m i treballaria en mode continu amb alta densitat i baixa temperatura. Les pèrdues d'energia més importants serien, en aquest cas, degudes a la convenció i conducció dins del plasma. El fet que tingui una grandària tan gran el faria molt car de construir. En el cas dels tokamaks, la seva grandària seria més petita, però les pèrdues per radiació ciclotró serien molt grans (degut al règim d'alta temperatura i baixa densitat) i el disseny d'una paret del reactor amb un coeficient de reflexió molt gran fora totalment necessari.
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Lindmark, Daniel. "Simulation based exploration of a loading strategy for a LHD-vehicle." Thesis, Umeå universitet, Institutionen för fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-126419.
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Optimizing the loading process of a front loader vehicle is a challenging task. The design space is large and depends on the design of the vehicle, the strategy of the loading process, the nature of the material to load etcetera. Finding an optimal loading strategy, with respect to production and damage on equipment would greatly improve the production and environmental impacts in mining and construction. In this thesis, a method for exploring the design space of a loading strategy is presented. The loading strategy depends on four design variables that controls the shape of the trajectory relative to the shape of the pile. The responses investigated is the production, vehicle damage and work interruptions due to rock spill. Using multi-body dynamic simulations many different strategies can be tested with little cost. The result of these simulations are then used to build surrogate models of the original unknown function. The surrogate models are used to visualize and explore the design space and construct Pareto fronts for the competing responses. The surrogate models were able to predict the production function from the simulations well. The damage and rock spill surrogate models was moderately good in predicting the simulations but still good enough to explore how the design variables affect the response. The produced Pareto fronts makes it easy for the decision maker to compare sets of design variables and choose an optimal design for the loading strategy.
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Carrasco, Jerez Francisco Alfredo. "Asignación dinámica de operadores de LHD para operación a distancia en minería subterránea." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/144483.
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Magíster en Gestión y Dirección de Empresas<br>El desarrollo de los proyectos estructurales subterráneos de Codelco permitirá incorporar una nueva visión del negocio de minería subterránea masiva, basada en las tendencias observadas en cuanto a tecnología, gestión operacional, recurso humano y sustentabilidad. En este contexto es que la tesis propuesta participa, apoyando la implantación de una operación y gestión desde superficie de un proceso productivo importante como el que realiza el equipo LHD Semi Autónomo (LHD SA).
Para ello, se desarrollan en esta tesis los aspectos formales que permitan implementar un sistema de asignación dinámica de tareas telecomandadas asociadas al carguío de puntos de extracción en la operación de minas subterráneas explotadas por hundimiento de bloques. Se estudia en particular la aplicación de este tipo de sistema para mejorar la productividad del sistema de extracción de mineral de las operaciones de la futura Mina Chuquicamata Subterránea (PMChS). Finalmente, se profundiza en algunos aspectos tecnológicos, de gestión, culturales y otros elementos que puedan representar factores de riesgo para la captura total o parcial del valor asociado a la propuesta.
Como conclusión, se obtiene que el proceso conducido por los equipos LHD SA con Operadores en superficie sigue la forma de un proceso de cola y, por lo mismo, es posible aplicar gestión de tiempos de espera (o teoría de colas), de forma similar a como se realiza en otras industrias. En particular, desde el punto de vista teórico, el proceso del LHD SA se podría estudiar en base a un modelo markoviano del tipo M/M/c/FIFO/K. En efecto, la simulación detallada realizada en la Ingeniería Básica del PMChS y los resultados basados en un enfoque analítico son consistentes entre sí, lo que muestra la validez de los resultados obtenidos.
Finalmente, el sistema de asignación dinámica propuesto para el proceso de operación de equipos LHD´s SA conlleva oportunidades de eficiencia y productividad que permiten optimizar el sistema por sobre los resultados que puedan lograrse utilizando sistemas de asignación estática.
Los riesgos de una implantación exitosa están asociados principalmente a los aspectos culturales que conlleva su materialización. Además, es también importante el desarrollo de aspectos técnicos dentro de los próximos años, tales como la interoperabilidad de sistemas, la consolidación de una filosofía de operación adecuada y la implementación del centro integrado de operación y gestión del PMChS.<br>Este trabajo ha sido apoyado por la Vicepresidencia de Proyectos de Codelco
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Prudencio, Gerald, Diego Pino, Luis Arauzo, and Carlos Raymundo. "Productivity analysis of LHD equipment using the multiple linear regression method in an underground mine in Peru." International Institute of Informatics and Systemics, IIIS, 2019. http://hdl.handle.net/10757/656294.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.<br>The current study is based on a multiple linear regression analysis with an objective to formulate an equation related to the productivity analysis of LHD equipment using independent variables such as the effective utilization of the equipment. To identify the independent variables, main productive factors, such as the actual capacity of the buckets, the transport cycles in the cleaning process, and the performance by means of curves, were analyzed. Comparisons of a Peruvian underground mine case study exhibited that the battery-powered equipment denoted similar production efficiencies to that exhibited by its diesel counterparts; however, the three-tier approach observed that the battery-powered equipment could achieve production efficiencies that are up to 13.8% more as compared to that achieved using its diesel counterparts because of increased effective utilization that can be attributed to long MTBF. The results of this study exhibit that LHDs under battery-powered storage are feasible for underground mining not only because of the fact that they do not emit any polluting gases, which helps to mitigate pollution, but also because of their good production performance that can be considered to be an important pillar in deep mining. Copyright 2019.
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Bouveron, Martin E. "An analysis of the ordance offload/onload costs of Pacific Fleet large deck amphibious assault ships (LHA and LHD) homeported in San Diego." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA305854.
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Tampier, Cotoras Carlos Andrés. "Carga autónoma y su inserción en un modelo integral de operación subterránea para máquinas LHD." Tesis, Universidad de Chile, 2018. http://repositorio.uchile.cl/handle/2250/168702.
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Rojas, Lafuente Gonzalo Esteban. "Introducción de un LHD híbrido a la industria minera y sus posibilidades en el mercado chileno." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/146623.
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Ingeniero Civil de Minas<br>El presente estudio busca determinar las posibilidades de mercado del nuevo LHD híbrido diésel eléctrico, 18HD, en la industria minera en Chile. Para establecer las posibilidades primero se compara la tecnología híbrida con las tecnologías presentes hasta ahora en la industria y posteriormente se hace un análisis de mercado de los equipos subterráneos en Chile. La industria minera en general, y particularmente en Chile, ha estado dominada por los equipos con accionamiento mediante Diésel, mientras que la participación de los equipos eléctricos ha estado bastante restringida debido a sus limitaciones operacionales. La principal desventaja de los equipos diésel es la alta emisión de material particulado y contaminante. Esta desventaja sumada a los nuevos desafíos de la minería que buscan aumentar la productividad, confiabilidad y mantenibilidad han impulsado a las empresas proveedoras de equipos a desarrollar de nuevas tecnologías que permitan entregar soluciones acordes a los desafíos de la actualidad. Un ejemplo de esto es el equipo híbrido desarrollado por Joy Global, el cual tiene un sistema de accionamiento diésel eléctrico. Entre los principales beneficios de este equipo destacan: recuperación de energía de frenado, mayor aceleración, menores costos de mantenimiento, menor uso de combustible y requerimientos de mantención, aumento de la disponibilidad mecánica, entre otros. Este equipo ha completado su etapa de prototipo y se someterá a una prueba industrial en una operación en Chile para cuantificar todos los posibles beneficios que entrega. El mercado de los equipos en Chile está principalmente dominado por grandes proveedores mundiales de la minería subterránea como los son Atlas Copco, Sandvik y Caterpillar. Los clientes se dividen en dos grandes grupos; la gran minería, principalmente aquellas minas explotadas por block caving, las cuales tienen un gran poder de negociación al momento de comprar equipos; y la mediana minería, la cual se ha visto afectada en mayor parte por la situación del mercado. Para que el equipo pueda ser comercializado con éxito debe aprovechar las oportunidades que ofrece el mercado, las cuales son; el envejecimiento de la flota de equipos en Chile, la construcción de grandes proyectos y la recuperación del precio. Además, debe destacar por sobre la competencia en cuanto a los servicios entregados.
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Madrid, Carrasco Aníbal Alejandro. "Determinación de granulometría y estrategia de extracción de material minero para LHD minero por medio de mediciones laser." Tesis, Universidad de Chile, 2015. http://repositorio.uchile.cl/handle/2250/133398.
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Ingeniero Civil Eléctrico<br>La robótica y automatización han tenido un gran impacto en la industria en el país, aumentando sustancialmente la productividad de ésta a lo largo de los años. Uno de los procesos que se ha buscado automatizar en minería, es la extracción de mineral en minas subterráneas, el que se realiza por un Load Haul Dump. Este proceso ha sido parcialmente automatizado, quedando pendiente desarrollar de manera efectiva proceso de carguío para que sea autónomo. Este es difícil de automatizar debido a la variabilidad de la granulometría del material a cargar que se encuentra en el punto te extracción.
Esta memoria se enmarcó en el proyecto de automatización del proceso de carga de un LHD en el Advanced Mining Technology Center (AMTC) de la Universidad de Chile. El trabajo consistió en el diseño y desarrollo de un sistema de medición granulometría del mineral en un punto de extracción y la entrega de un punto en donde se recomiende iniciar la carga de este. En este trabajo se diseña y desarrolla una maqueta a escala del punto de extracción real, en la que utilizando un láser actuado por medio de un servo motor y el framework ROS, se obtiene una nube de puntos la que es procesada por un algoritmo que ocupa segmentación en tres dimensiones. De esta manera se obtiene una serie de clústeres representando cada una de las rocas. Además se implementa un filtro de manera que rocas detectadas con un volumen menor al impuesto por el usuario, no serán consideradas, y finalmente utilizando esta información se entrega una línea en la que se recomienda comenzar el carguío. Este sistema fue sujeto a una serie de pruebas con distintas rocas en diferentes configuraciones obteniendo un error promedio de 14,17 %. También fue sujeto a prueba en un ambiente húmedo, en el que el rendimiento se mantuvo constante y a pruebas en un ambiente con polvo, en donde el láser no fue capaz de atravesarlo por lo que no se obtuvieron resultados. Finalmente se encontró que el tiempo en el que se entrega una nube de puntos por el sistema es 12 segundos y se realizó un análisis teórico para concluir que estos resultados son representativos en un ambiente real.
Concluyendo, se desarrolló un sistema capaz de diferenciar las rocas relevantes del fino, obteniendo su granulometría utilizando el framework ROS y el hardware requerido. El trabajo realizado abre las puertas para el desarrollo y prueba de nuevas estrategias de carguío autónomo en el AMTC. Como trabajo futuro se propone caracterizar rigurosamente el desempeño del láser en ambientes con polvo y realizar pruebas con un LHD a escala para determinar la efectividad de la estrategia de carguío entregada en este trabajo, además de una serie de sugerencias para mejorar el desempeño del algoritmo desarrollado.
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Lerider, Malcolm. "Autonomous Calibration and Control of Mine Vehicles." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-91034.
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The mining industry desires to cut costs and to operate in more dangerous mines, which is why companies such as Atlas Copco are developing autonomous vehicles. The problem to navigate autonomously is however complex, so the vehicles have in the recent years become more intelligent; the number of computers, actuators and sensors are increasing. For example, an autonomous LHD (Loading – Hauling – Dump) vehicle has sensors including: inertial measurement unit (IMU), odometer, hinge angle sensor, laser range finders and cameras. The parameters for the sensors needs to be calibrated before the vehicle can be used in a mine. There are also a number of electrical currents which needs to be calibrated for the actuators.The calibration of parameters has traditionally been made manually, but Atlas Copco realizes that manual calibration is not feasible once the sales of intelligent mine vehicles increases. Effort is therefore put into automation of the calibration procedures.Interviews with employees were carried out at Atlas Copco to identify the most time consuming procedures during calibration and installation of autonomous mine vehicles. The calibration of steering currents was not only identified as the most time consuming procedure, but also as one of the most complex procedures.The goal of this thesis is to enable easier and quicker installation of mine vehicles. This is done through investigation of methods for automatic calibration of steering currents. The problem is approached from two angles: a grey box model using system identification and a black box model using neural network with resilient backpropagation. The models are compared to a search algorithm, used for simulation of the manual calibration method. In the end, the models are evaluated with regard to performance and ease of implementation.The hypothesis was that the more complex grey box or black box model would have higher accuracy than a simple search algorithm. However, the search algorithm proves to outperform the other models both with regard to accuracy and calibration time, and is also easier to implement. The search algorithm is thus suggested to be implemented instead of a complex model. Moreover, it is suggested that a straightforward mapping of 20 currents may outperform even the search calibration. It is also concluded that calibration of steering currents can be done when the vehicle is standing still.
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Prudencio, Ríos Gerald Roy, and Carhuancho Diego Jesus Pino. "Propuesta de uso de equipo LHD a batería como alternativa competitiva frente al equipo diésel en el proceso de limpieza de labores subterráneas horizontales en una operación minera mecanizada." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/654906.
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La presente investigación se titula “Propuesta de uso de equipo LHD a batería como alternativa competitiva frente al equipo diésel en el proceso de limpieza de labores subterráneas horizontales en una operación minera mecanizada”. Este estudio tiene como objetivo evaluar una propuesta de uso del equipo LHD a batería como alternativa competitiva frente al equipo diésel en el proceso de limpieza de labores subterráneas horizontales determinando los factores productivos, analizando la sostenibilidad ambiental y evaluando los costos operacionales relacionada a los equipos LHD diésel y batería. Asimismo, para la evaluación comparativa de estos equipos se realizó un análisis a través de un caso de estudio en una unidad minera de operación mecanizada, con similares características a la Unidad Minera Atacocha. Los equipos que serán utilizados para la evaluación, bajo las mismas condiciones de trabajo, son el LHD a batería (ST7), de la empresa Epiroc, y el LHD diésel (R 1300G), de la empresa Caterpillar; ambos con una capacidad de carga útil nominal de 6,800 kg (4.2 yd3).
Los resultados obtenidos a través del caso de estudio se dieron en tres niveles: productivo, sostenible ambiental y económico. En el aspecto productivo, se determinó que el equipo LHD a batería en comparación con el equipo LHD a diésel, para una distancia de acarreo de 150 m, tiene un menor tiempo de ciclo de 8.23%, y un mayor rendimiento productivo de 8.98%. En relación a los indicadores de gestión, se determinó que los equipos LHD a batería posee una ventaja frente a los equipos diésel como en los indicadores de disponibilidad mecánica, utilización efectiva, MTBF y MTTR, obteniendo que en los tres primeros es mayor en 0.51%, 10.45%, 4.8%, respectivamente; por el lado del indicador de MTTR, con un resultado de 12.52% menor que el equipo diésel.
En el aspecto de sostenibilidad ambiental, cuando se tiene al equipo diésel en funcionamiento se incrementan los niveles de gases en comparación a los equipos a batería en 76.63% en CO, 72.45% en CO2, 50% en NO2; asimismo, en la zona de trabajo del equipo diésel, se genera un incremento de temperatura de 19°C mientras que con el equipo a batería se tiene un incremento de 3.5°C. Finalmente, en el aspecto económico, se determinó que los equipos a diésel poseen un menor costo de posesión de 35.28 $/hr, un mayor costo operacional de 31.24 $/hr y un mayor costo total, incluyendo costo ventilación, de 1.63 $/hr a diferencia del equipo a batería.<br>This research is titled "Proposal for the use of battery-powered LHD equipment as a competitive alternative to diesel equipment in the cleaning process of horizontal underground workings in a mechanized mining operation." This study aims to evaluate a proposal for the use of battery-powered LHD equipment as a competitive alternative to diesel equipment in the cleaning process of horizontal underground workings, determining the productive factors, analyzing environmental sustainability and evaluating the operational costs related to LHD equipment. diesel and battery. Likewise, for the comparative evaluation of these equipment, an analysis was carried out through a case study in a mechanized mining unit, with similar characteristics to the Atacocha Mining Unit. The equipment that will be used for the evaluation, under the same working conditions, are the battery-powered LHD (ST7), from Epiroc, and the diesel LHD (R 1300G), from Caterpillar; both with a rated payload capacity of 6,800 kg (4.2 yd3).
The results obtained through the case study occurred at three levels: productive, environmentally sustainable and economic. In the productive aspect, it was determined that the battery-powered LHD equipment compared to the diesel-powered LHD equipment, for a hauling distance of 150 m, has a shorter cycle time of 8.23%, and a higher productive performance of 8.98%. In relation to the management indicators, it was determined that battery-powered LHD equipment has an advantage over diesel equipment as in the indicators of mechanical availability, effective use, MTBF and MTTR, obtaining that in the first three it is greater by 0.51% , 10.45%, 4.8%, respectively; on the side of the MTTR indicator, with a result of 12.52% lower than the diesel equipment.
In the aspect of environmental sustainability, when the diesel equipment is in operation, the levels of gases are increased compared to battery-powered equipment by 76.63% in CO, 72.45% in CO2, 50% in NO2; Likewise, in the work area of the diesel equipment, a temperature increase of 19 °C is generated, while with the battery-powered equipment there is an increase of 3.5 °C. Finally, in the economic aspect, it was determined that diesel equipment has a lower cost of ownership of 35.28 $/hr, a higher operating cost of 31.24 $ /hr and a higher total cost, including ventilation cost, of 1.63 $/hr unlike battery powered equipment.<br>Tesis
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Manyike, Amukelani Portia. "A descriptive study to determine the prevalence of obstructive airways disease amongst Load Haul Drivers (LHD) in trackless mines." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46137.
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Background: During day to day mining activities, miners are exposed to different airborne pollutants, which may result in occupational lung diseases (OLDs). In South Africa mining is a primary industrial activity that contributes significantly to the gross domestic product (GDP). Mine related lung diseases depend on the type of commodity that is mined, aerodynamic size of airborne pollutants, exposure time, environmental conditions and the employee’s lifestyle.
Aim and Objectives: To determine the prevalence of obstructive airway disease amongst load haul drivers (LHD) occupationally exposed to mineral dusts and diesel particulate matter (DPM) in trackless mines. The study was also aimed at determining the relationship of selected epidemiological determinants on the status of obstructive airway disease in LHD and to determine whether a difference existed between employees that worked only day or night shift.
Methodology: The study area was a platinum mine in Mpumalanga. The study population comprised of underground LHD drivers who were frequently exposed to mineral dust and DPM during loading and off-loading of raw minerals. The study population was divided into two groups: day shift and night shift, a questionnaire was used to obtain information on demographics; self-reported social and health history, including respiratory symptoms. Spirometry was performed to determine the Forced Vital Lung Capacity (FVC) and Forced Expiratory Volume 1 sec (FEV1). Employees who presented an FEV1/FVC of <70% underwent a second spirometry after using a bronchodilator (Combivent, 0.5mg ipratropium bromide anhydrous, 2.5mg salbutamol base, & 0.52mg ipratroniumbromide).This was done to rule out reversible obstructive lung cases.
Results: Employees on night shift had a significantly higher prevalence of obstructive airway disease patterns (32.6%) compared to the day shift prevalence (12.5%). There was a significantly higher (p = 0.009) prevalence of acute coughing in night shift LHD (41.3%) compared to day shift LHD drivers (15.0%)). Over 3 months, night shift workers (73.68%) also presented with significantly more (p = 0.036) symptoms of chronic coughing than day shift workers (0.00%) night shift workers (47.83%) presented sputum production while day shift workers presented only 14.29%. Furthermore, night shift LHD showed a significance change (p = 0.729) in measured lung function of FEV1/FVC, in comparison with day shift LHD. Multivariate regression analysis also showed that night shift LHD had a 3 times higher odds of developing obstructive airway disease than day shift workers (OR 3.30, 95% Cl 1.08, 10.04, p = 0.036).
Conclusion: The night shift LHD drivers presented a marked reduction in lung function as well as acute and chronic respiratory symptoms. It is therefore concluded that night shift LHD are at higher risk of developing obstructive airway disease when exposed to diesel particulate matter as compared to day shift workers.<br>Dissertation (MPH)--University of Pretoria, 2014.<br>tm2015<br>School of Health Systems and Public Health (SHSPH)<br>MPH<br>Unrestricted
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Guerrero, González Armando Fabián. "Simulación de sistema LHD automatizado mediante eventos discretos - aplicación a minería de Caving Proyecto Nuevo Nivel Mina División El Teniente." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/147419.
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Magíster en Minería<br>Dentro de los hitos relevantes que deben ser estudiados en el contexto de la Ingeniería del Proyecto Nuevo Nivel Mina, se encuentra el análisis del sistema de extracción de mineral para calcular los indicadores de productividad y utilización de los equipos principales, tal que permitan determinar la flota de equipos y cumplir metas productivas, identificando las vulnerabilidades del proceso para el término del primer quinquenio de operación del proyecto.
Como límite de batería del estudio se consideran los procesos mineros desde la etapa de extracción de mineral en zanjas hasta la descarga de mineral a los piques de traspaso, incluyendo las operaciones asociadas a la reducción secundaria en zanjas y parrillas. Se excluyen las operaciones aguas abajo de los piques.
El análisis del sistema de extracción permitirá optimizar los rendimientos asociados con productividad e incrementar la eficiencia en los ciclos productivos que permitan asegurar el cumplimiento de las metas de producción, paralelamente permitirá definir la flota de equipos LHD para la toma de decisiones, factor importante en el momento de proceder con las adquisiciones.
La primera etapa de este trabajo, consta de una definición de los objetivos y motivación que origina el estudio, para posteriormente realizar un análisis bibliográfico con temas relacionados principalmente con simulación dinámica y automatización. Luego se procede con la recopilación de información y estadística de los datos relacionados con el proceso de extracción de mineral, que entregarán la confiabilidad para la configuración y programación del modelo computacional.
En el caso del Proyecto Nuevo Nivel Mina no existe una configuración similar para el manejo de mineral en el Nivel de Producción con piques de traspaso ubicados cada 120 m y equipos que cuenten con el mismo grado de automatización, tal que permita extrapolar datos de utilización y rendimientos, dada esta incertidumbre, considerando además que las herramientas analíticas se encuentran limitadas frente a la interacción de variables, se implementa un modelo computacional del sistema de extracción de mineral, utilizando simulación dinámica de eventos discretos.
La segunda y última etapa, considera realizar la logística de operación, construcción, verificación y validación del modelo computacional, para luego proceder con la captura y análisis de datos estadísticos que permita responder los objetivos e interrogantes planteadas en este estudio. Junto con esto, se procede con los respaldos en la configuración y programación con software Promodel para profesionales de la industria.
Respecto a los resultados, la flota estimada corresponde a 11 unidades de equipos LHD cumpliendo la capacidad productiva de 56.000 t/d específicamente para el término del primer quinquenio de operación.
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藤井, 恵介. "大型プラズマ閉じ込め装置LHDにおける水素リサイクリングの分光研究". 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/157526.
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Seaver, George A. "An electromagnetic compatibility analysis of the AN/URC-109 HF Wideband Communication System as installed on the LHD-1 Amphibious Assault Ship." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23025.
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The purpose of this study was to evaluate the performance of the AN/URC-109 HF Wideband Communication System as it is to be installed on the LHD-1 Amphibious Assault Ship. The system is configured so that as many as twenty-two HF transmitters can be operated simultaneously. The COSAM II(DECAL/PECAL)Wideband and Narrowband RF Architecture Analysis Program was used in conducting the evaluation. The program was first run in the necessary desired power mode to determine if any of the 506 possible RF coupling paths would have unsatisfactory interference levels and to determine the mean necessary desired power for each receiver. Then the program was run in the system performance score mode to evaluate the performance of each of the twenty-three receivers. Although two of the receivers had marginally unsatisfactory scores, the overall system performance was determined to be satisfactory, with an average performance score of 84%. (Theses) (rh)
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Uribe, Neira Pablo Alberto. "Análisis de la funcionalidad y desempeño de la operación semiautónoma en equipos de carga; acarreo y descarga en minería subterránea Load Haul-Dump Vehicle (LHD)." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/130844.
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Tesis para optar al grado de Magíster en Gestión y Dirección de Empresas<br>Actualmente existen importantes desafíos en minería, no solo por las cifras de inversión estimadas, sino también por necesidad de incorporar nuevas tecnologías, generadas en base a los desafíos planteados por el aumento de costos. Los principales nuevos desafíos son derivados de las características de la roca primaria, la baja en la ley de mineral, los requerimientos de sustentabilidad y la mayor preocupación por mejorar los estándares de seguridad y salud ocupacional de los operadores.
Para el futuro se requieren procesos altamente automatizados, equipamientos autónomos y operaciones telecomandadas, gestionadas fuera de las minas en busca de la continuidad operacional. Tratar de mantener los costos bajos y mejorar la productividad es el gran desafío que presenta la Minería Subterránea. En esta tesis se analizará el estado del arte de la tecnología de equipos LHD semiautónomos, sus limitaciones, las lecciones aprendidas, así como los sistemas y metodologías de navegación existentes asociados con el automatizado subterráneo en la carga, transporte y descarga, además de los resultados obtenidos en la División el Teniente.
La implementación de esta tecnología en División el Teniente nació como solución a los problemas de seguridad y calidad de vida de los trabajadores, así como también para contar con un equipo robusto capaz de enfrentar las exigencias que demanda el mineral primario a ser extraído, una de las ventajas que se espera obtener como resultado, es un mayor tiempo de operación en comparación con los equipos manuales.
El análisis se basará en la utilización de equipos LHD (cargadores de bajo perfil para la tarea de extracción de mineral, que consiste en cargar, transportar y descargar la roca mineralizada), los cuales cuentan con la tecnología que les permite operar en una condición semi-automática, es decir sin operador a bordo, controlados a distancia por operadores ubicados al exterior de la mina en una la sala de control distante kilómetros del área productiva.
La tecnología ha demostrado ser factible de aplicar, sin embargo, se han detectado brechas en el desempeño y funcionalidades respecto de los requerimientos planteados para la División El Teniente en su Proyecto Estructural Nuevo Nivel Mina, por lo cual se requiere incorporar nuevos desarrollos tecnológicos a través de un programa de innovaciones incrementales de la tecnología de automatización de LHD, bajo un Modelo de Negocio ad-hoc y efectuar un cambio significativo de las estrategias y tácticas operacionales, mantenimiento, planificación, control centralizado, diseños mineros, entre las más relevantes, para así optimizar y capturar el mayor valor del uso de los equipos LHD semi-autónomos.
El gran desafío que hoy nos impone la minería, de expandir la capacidad de producción para satisfacer las futuras demandas de los minerales, está requiriendo con urgencia de un mayor desarrollo y apoyo de las tecnologías de automatización en la minería. La dimensión de los proyectos permite generar cambios tecnológicos en pos de encontrar herramientas y sistemas que garanticen en mayor medida la calidad, eficiencia y control de las operaciones mineras. Es ahí donde está el desafío: identificar, adaptar, prepararse e implementar estas tecnologías.
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Svatoš, Hynek. "Design nízkoprofilového nakladače." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230112.
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Master thesis concerns with a design of a low profile loader. This work deals with concept design of a loader, while keeping with ergonomic, economical and psychological aspect dictated by modern society and technological know-how of today’s world with possible overview in to a near future. By extrapolating of a today’s technological development, this thesis is looking in to a design of a loader which is a solution for a lot of contemporary problems and improves utility value. The design improves working environment of operators as well as economical gain of the owners.
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Jäderblom, Niklas. "From Diesel to Battery Power in Underground Mines : A Pilot Study of Diesel Free LHDs." Thesis, Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67154.
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Load, haul and dump machines (LHDs) are commonly used in underground mines around the world. The machines are used to transport fragmented ore after blasting in the ore body. The main propellant used is diesel which accounts for a large part of the diesel consumed in mines today. This master thesis is a pilot study for further work to be done by LTU and Atlas Copco in a project called SIMS or Sustainable Intelligent Mining Systems, where the aim is to physically demonstrate diesel free LHDs doing productive work in mines. The objective of the thesis was to assess if the integration of battery-powered LHD machines is plausible in today’s underground mines. The aims were to map the current state of the production and to perform risk and job analysis of the new technology in the current systems. A theoretical framework was constructed with focus on safety, risk, hazards and change in work content. Social acceptance was then researched to be able to analyze how the new technology is received. Data gathering was done through interviews, observations, a focus group and reviewing documents while visiting Atlas Copco and two underground mines in Sweden. Diesel and electric-powered LHDs were studied in the mines and battery-powered LHDs were studied at Atlas Copco. The results present the current state of diesel, electric and battery-powered LHDs. How the machines are used in the visited mines and the identified risks with the work is presented along with the mapping of the battery system being developed by Atlas Copco. New risks that the battery system will bring to the work environment were identified using energy and deviation analyzes. The change in work content was discussed using the information from the visits and identifying what tasks will change, disappear and be added with the new technology. A large part of the thesis was analyzing the results with support from the theoretical framework. The analysis showed that a switch from diesel to battery-power would improve the overall health and safety inside the mines. A switch does not change the skill needed to operate the machines but can increase the qualifications for the service personnel. The main obstacles, in terms of social acceptance, with implementing the battery systems in the current state are that the need for constant battery exchange would cause problems in the production, the prejudice that the batteries would increase the consequences of a fire and the initial cost of making the switch. Recommendations for Atlas Copco going forward in the SIMS project were made. They need to emphasizing the safety of the technology to the users, developing the battery exchange so it can be done closer to the stopes and involve the operators in the projects of SIMS to help them understand the benefits it will have on them directly.<br>Gruvlastmaskiner (LHD) används ofta i gruvor runt om i världen. Maskinerna används för transportera fragmenterade malm efter malmen sprängts. Det huvudsakliga drivmedlet som används är diesel, som står för en stor del av den diesel som förbrukas i gruvor idag. Detta examensarbete är en pilotstudie för ytterligare arbete som ska utföras av LTU och Atlas Copco i ett projekt som heter SIMS eller Sustainable Intelligent Mining Systems. Syftet är att fysiskt demonstrera dieselfria LHD-maskiner göra produktivt arbete i gruvor. Syftet med examensarbetet var att bedöma om integrationen av batteridrivna LHD-maskiner är möjligt i dagens underjordiska gruvor. Målet var att kartlägga den aktuella produktionssituationen och att utföra risk- och arbetsanalyser av den nya tekniken i nuvarande system. En teoretisk referensram konstruerades med fokus på säkerhet, risk och förändring i arbetsinnehåll. Social acceptans undersöktes sedan för att kunna analysera hur den nya tekniken tas emot. Datainsamlingen gjordes genom intervjuer, observationer, en fokusgrupp och granskning av dokument givna vid besök på Atlas Copco och två underjordiska gruvor i Sverige. Diesel- och el-drivna maskiner studerades i gruvorna och batteridrivna studerades hos Atlas Copco. Resultaten presenterar det nuvarande läget för diesel, elektriska och batteridrivna LHDmaskiner. Hur maskinerna används i de besökta gruvorna och de identifierade riskerna med arbetet presenteras tillsammans med kartläggningen av batterisystemet som utvecklas av Atlas Copco. Nya risker med batterisystemet identifierades med hjälp av energi- och avvikelsesanalyser. Ändringarna i arbetsinnehåll diskuterades med hjälp av informationen från besöken och klargör vilka uppgifter som ska förändras, försvinnas och läggas till med den nya tekniken. En stor del av arbetet var att analysera resultaten med stöd från den teoretiska referensramen. Analysen visade att bytet från diesel till batterier skulle förbättra hälsan och säkerheten i gruvorna. Teknologibytet förändrar inte den färdighet som krävs för att kunna manövrera maskinerna men kan öka kvalifikationerna för servicepersonalen. De viktigaste hindren när det gäller social acceptans med att implementera batterisystemen i det nuvarande tillståndet är att behovet av konstant batteribyte skulle orsaka problem i produktionen, fördomarna om att batterierna skulle öka konsekvenserna av en brand och de initiala kostnaderna att göra ett byte. Rekommendationer för Atlas Copco för fortsatt arbete i SIMS-projektet gjordes. De behöver klargöra säkerheten hos den nya teknik för användarna, utveckla batteribytet så att det kan göras närmare produktionen och involvera operatörerna i SIMS-projekten för att hjälpa dem att förstå de fördelar som det kommer att ha på dem direkt.
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Dragt, Bruce James. "Modelling and control of an autonomous underground mine vehicle." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08282007-101213.
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McCormack, Oisin. "Advanced Thomson scattering techniques as diagnostics for fusion plasmas." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3427160.
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The content of this thesis was carried out within the framework of the global magnetic confinement fusion (MCF) effort. The flagship project for MCF is the International Thermonuclear Experimental Reactor (ITER), currently under construction and due for commissioning in 2025. ITER is an unprecedented device that pushes the limits of technology and physics across all sectors, and the field of plasma diagnostics is no exception.
Thomson scattering (TS) is one of the most powerful diagnostics available to fusion devices, providing high resolution spatial and temporal profiles of the plasma electron temperature and electron density, which are measurements vital to the understanding of the plasma. Although conventional TS is a well proven method and used in almost all MCF devices in current operation, it too must advance and adapt to the demanding environment of ITER. In this thesis we explore two advanced Thomson scattering techniques which aim to address some of the challenges of ITER TS, through three independent experiments performed on three separate devices.
Chapter 1 provides a brief introduction to MCF as part of the solution to the current global energy crisis.
Chapter 2 introduces the general theory of Thomson scattering and a description of the advanced techniques under investigation.
Chapter 3 describes the dual-laser TS experiment performed in RFX-mod, Padova, during the first year of the PhD. To the author’s knowledge, this was the first successful practical testing of this advanced technique.
Chapter 4 describes the polarimetric TS experiment performed in JET, Oxford, during the second year of the PhD. To the author’s knowledge, this was the first successful practical testing of this advanced technique.
Chapter 5 describes the dual-laser TS experiment performed in LHD, Japan, during the second year of the PhD. To the author’s knowledge, this was the second successful practical testing of this technique.
The experiments performed and described in this thesis demostrate the feasibility of these two previously untested advanced TS techniques, which are both of great interest for application in the next generation of fusion devices.<br>I contenuti di questa tesi sono stati svolti nella cornice della ricerca globale sulla Fusione nucleare a Confinamento Magnetico (FCM). Il progetto guida per la FCM è ITER (International Thermonuclear Experimental Reactor), in costruzione a Cadarache, nel sud della Francia, e con messa in esercizio prevista per il 2025. ITER è una macchina senza precedenti, che spinge all’estremo i limiti della tecnologia e della scienza in tutti i settori, e il campo della diagnostica di plasma non fa eccezione.
Lo scattering Thomson (ST) è una delle diagnostiche più potenti tra quelle disponibili su una macchina a fusione, ed è in grado di misurare con elevata risoluzione spaziale e temporale la temperatura e la densità degli elettroni, misure chiave per lo studio dei plasmi. Sebbene lo ST sia una diagnostica già collaudata e in uso su quasi tutte le macchine a fusione esistenti, anch’esso deve essere migliorato e reso adatto agli esigenti requisiti di ITER. In questo lavoro di tesi sono state esplorate due tecniche di scattering Thomson avanzato che hanno lo scopo di risolvere alcune delle sfide dello ST di ITER attraverso tre esperimenti indipendenti svolti su tre macchine separate.
Capitolo 1 fornisce una breve introduzione alla FCM vista come parte della soluzione all’attuale crisi globale dell’energia.
Capitolo 2 introduce la teoria generale dello scattering di Thomson e una descrizione delle tecniche avanzate trattate in questo lavoro di tesi.
Capitolo 3 descrive l’esperimento di ST con laser duale svolto su RFX-mod, Padova, durante il primo anno di dottorato. Questo è stato per l’autore il primo esperimento svolto con successo su questa tecnica avanzata.
Capitolo 4 descrive l’esperimento di ST polarimetrico svolto su JET, Oxford, durante il secondo anno di dottorato. Questo è stato per l’autore il primo esperimento svolto con successo su questa tecnica avanzata.
Capitolo 5 descrive l’esperimento di ST con laser duale svolto su LHD, Giappone, durante il secondo anno di dottorato. Questo è stato per l’autore il secondo esperimento svolto con successo su questa tecnica avanzata.
Gli esperimenti svolti, descritti in questo lavoro di tesi, dimostrano la fattibilità di queste due tecniche di ST avanzato, mai testate prima, e che sono entrambe di grande interesse per l’applicazione sulla prossima generazione di macchine a fusione.
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Marklund, Simon. "The comparison of automatic and manual loading in an underground mining environment." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-64900.
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Mine automation has been in development since the 1980s and began to be implemented in the 1990s with the biggest drivers being safety, reduced maintenance and increased productivity. Automation is used in many different mining methods performing a variety of tasks. However, very few studies have been conducted regarding the performance of automatic vehicles in real world mines, neither has much research been done when comparing automated and manual loading. The purpose of this thesis is twofold. First it is to identify and produce metrics that can be used to compare automatic and manual loading in an underground mining environment. A literary study is presented as a basis for these metrics where the development history is chronicled and the mechanics by which an automated system controls an automatic vehicle is explained. Also included is a description of different mining methods and the part that automation plays in them. Secondly, the goal is to use these metrics in a real world case study of automated loading in an actual operational mine. The Garpenberg mine, owned by Boliden Minerals, is an underground metal mine located in Dalarna, Sweden, and mining has been done there since the 1200s. Load-Haul-Dump (LHD) machines are used to load and haul ore ether using automation or tele operation. For this study information is extracted from Bolidens internal databases to calculate the metrics which are then used to analyze the performance and reliability of automated loaders, and also to compare manual and automatic loading. There are mainly three types of metrics that are relevant to automatic and manual loading, these being time related metrics, production related metrics and reliability related metrics. Since the LHDs dealt with in this thesis are operated both manually and automatically the main use of the time related metrics is to find the relationship between modes of operation in regards to engine hours spent in action, the amount and character of downtime that occurred during the analyzed time span, and the utilization of automatic LHDs during the workday. The most straightforward comparison between manual and automatic loading is the production, i.e. the tonnage of loaded material per unit time. In this thesis production will be analyzed per hour and per loading activity (which run between 3 and 4 hours). Lastly automated and manual loading will be compared on the basis of availability and maintenance, the reason being that LHDs are driven in different ways depending on the mode of operation. The results show that automatic loading consists of between 14 and 29% of production time while contributing to between 17 and 28% of downtime. No clear connection can be seen between downtime and the relationship of automatic to manual loading, as the difference is not bigger than 10% either way. Manual loading constitutes between 2500 and 3250 engine hours, while time spent during automatic loading constitutes between 420 and 1095 engine hours. The majority of all downtime is not specific to either mode of operation, although automatic specific stops constitutes up to 50% of total downtime for two of the LHDs studied. The distribution of loading activities is similar for both manual and automatic loading, with the number of concurrent activities dipping during lunch breaks and stopping entirely during shift changes. Manual loading peaks around 1000 concurrent jobs while automatic peaks at just fewer than 200. Regarding production the results show that manual loading is more effective in the short term, as three out of four LHDs has had a higher tonnage loaded per hour. However, when locking at the tonnage loaded per activity, automatic loading catches up to manual loading and produces more tonnage in the long term, with three out of four LHDs getting this higher production. One interesting result can be found in regards to fuel economy, as one of the LHDs show a reduced consumption of fuel while at the same time having had the largest percentage of time spent in automatic mode. No clear connection can be seen with the rest of the LHDs however, as they show no clear connection between time spent in ether mode of operation and the amount of fuel consumed. Automatic loading proved to have slightly higher availability than manual loading. In all cases however, the difference in no more than 10% and both modes of operation is above 90% availability. The higher availability of automatic loading is attributed to the fact that manual loading constitutes much more time than automatic loading, and thus there has been more time for breakdowns and production stops to occur for manual loading. The relationship of preventive and corrective maintenance is the same for all four LHDs irrespective of amount of time spent in ether operating mode. Preventive maintenance jobs accounts for more than 90% of the number maintenance actions for all LHDs. When analyzing what kinds of production stops are the most prevalent, there are differences between manual and automatic loading. For manual loading the most common stops are those that have to do with external circumstances in the mine such as blocked access and fallen boulders, and those to do with minor breakdowns of the LHD. For automatic loading the most common stops are those to do with the automatic system and the equipment used to operate the automated LHD, followed by those caused by external circumstances, similarly to manual loading. Automatic loading has proportionally fewer stops than manual loading in all categories except those unique to automation, which is in turn the biggest category of all production stops. The conclusions that can be drawn from these results are that automatic loading can outperform manual loading in the long term, but that continuous uninterrupted loading activates are important to achieve this. Automatic and manual loading show comparable reliability when it comes to maintenance and repairs (serious breakdowns are very rare). Availability and the relationship of preventive and corrective maintenance are similar between both modes of operation. The analysis of production stops show that the biggest problem with automatic loading is the automatic systems and the specialized equipments inability to handle the underground environment. Problems with recorded routes and falsely tripped safety systems are the most common stops. Recommendations to Boliden Minerals regarding the automatic system consist of improving remote troubleshooting and streamlining of problem solving dealing with automation software and hardware. Steps should also be takes towards tailoring the underground environment to better suit automation. Suggestions to further research consist of deeper studies of all the metrics presented in this thesis to better analyze the role of automation in the global mining industry. Another avenue of study is the combination of the findings in this thesis with the actual environment and layout in the Garpenberg mine to better understand the connection between operating environment and the reliability and productivity of the automatic system.
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Drewelow, Peter [Verfasser], Marcin W. [Akademischer Betreuer] Jakubowski, Suguru [Akademischer Betreuer] Masuzaki, Mario [Akademischer Betreuer] Dähne, Dieter [Akademischer Betreuer] Breitschwerdt, and Robert [Akademischer Betreuer] Wolf. "Investigation of divertor heat flux pattern and their correlation to the edge magnetic field of the plasma confinement experiment LHD / Peter Drewelow. Gutachter: Mario Dähne ; Dieter Breitschwerdt ; Robert Wolf ; Suguru Masuzaki. Betreuer: Marcin W. Jakubowski ; Suguru Masuzaki." Berlin : Technische Universität Berlin, 2013. http://d-nb.info/1067385290/34.
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Holinka, David. "Prototyp adaptivní zadní svítilny." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-399452.
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The thesis focuses on the design of hardware and software prototype of adaptive automotive rear-lighting. Hardware includes a control module and LED module with 150 high brightneess light emitting diodes. These diodes are serve as an adaptive backlight for color LCD display. The device Raspberry Pi 3 was selected as the control element. This device insludes the support of all communications buses which are used in this thesis.
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Prokš, Jiří. "Zákaznicky upravitelný modul zadní skupinové svítilny s HD rozlišením." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318409.
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This thesis deals with the design of LED matrix array contains 150 LEDs. In the first part, the thesis identifies source of light like OLED and LED and provide an overview of their lifetime, reliability and basic principle of design systems with LEDs. The thesis then describe design of LED matrix array, deals with power supply of this LED array and with cooling of LED. Finally the thesis describes a software for contol of LED matrix array.
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Gunnarsson, Simon, and Robert Lucchesi. "Utbytesplan för kvicksilverlampor åt fastighetsbolag." Thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19024.
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Underlaget till den här studien är ett ekodesignkrav fastställt på EU-nivå om att alla kvicksilverlampor ska förbjudas år 2015. Tanken är att studien skall ge läsaren vägledning och visa på exempel hur en konkret utbytesplan skulle kunna se ut. Studien innehåller ekonomiska kalkyler som visar att utbyte av kvicksilverlampor bör ses som en investering som på sikt kan ge stora besparingar, snarare än som en kostnad.
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Vincenzi, Pietro. "Interaction between neutral beam fast particles and plasma in fusion experiments." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424363.
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Neutral beam injection (NBI) is one of the most used and reliable methods to heat plasmas in magnetically confined fusion devices. NBI is used in most of the present experiments, it will be used as dominant auxiliary power system in ITER experiment and studies are ongoing for DEMO reactor preconceptual designs with neutral beam (NB) systems. NBI is an essential actuator for plasma scenarios in terms of heating and driven current. This thesis presents the work performed during the 3 years of my Ph.D.. It focuses on numerical studies of the interaction between energetic particles coming from NBI and magnetically confined hot plasmas. The main aspects discussed in this thesis are the neutral beam ionization, fast ion confinement, fast ion losses, power deposition and driven current. A brief discussion of NBI as fuelling source is also presented. NBI modelling tools have been applied to study different devices with dominant NB power: the largest tokamak in operation (JET), the largest helical device in operation (LHD) and DEMO tokamak reactor concept. Detailed modelling of NBI by means of a Monte Carlo orbit following code has been provided for JET discharge analyses. A predictive simulation aimed at reconstructing the ion temperature profile with strong ion heating from NBI has been performed, resulting in a reliable prediction when the experimental measurement was not available due to a diagnostic fault. JET NBI-plasma interaction has been studied by predictive simulations for H discharges starting from reference D discharges in support of JET isotope studies. The isotopic change and the consequent effect on NBI-plasma interaction has been discussed also for LHD helical device, where studies in preparation of future D experiments (instead of H) are ongoing. NBI is one of the options as additional power system for a demonstrative fusion power plant (DEMO), and a pre-conceptual design of the reactor is ongoing within EUROfusion activities. DEMO scenario simulations have been carried out both for pulsed and steady-state concepts. The role of NBI as dominant heating and current drive system has been investigated by sensitivity studies, comparisons with other heating systems and transport investigations of transient phases (plasma ramp-up and ramp-down).<br>L’iniezione di fasci di particelle neutre (neutral beam injection NBI) é uno dei metodi piú utilizzati e affidabili per scaldare il plasma in esperimenti sulla fusione termonucleare confinata magneticamente. L’NBI é utilizzato nella maggior parte degli attuali esperimenti, verrá applicato come riscaldamento dominante in ITER e studi sono in corso per implementare l’NBI nel progetto europeo del futuro reattore dimostrativo DEMO. L’NBI gioca un ruolo fondamentale per i plasmi fusionistici in termini di riscaldamento e capacitá di indurre corrente nel plasma. Questa tesi presenta il lavoro svolto durante i tre anni del mio dottorato e si focalizza su studi numerici dell’interazione tra particelle energetiche provenienti dall’NBI e plasmi confinati magneticamente. Gli aspetti principali discussi sono la ionizzazione del fascio di neutri nel plasma, il confinamento e le perdite degli ioni veloci, la deposizione di potenza e la corrente di plasma indotta dal fascio. Viene inoltre presentata una breve discussione sull’NBI come sorgente di particelle. Diversi codici numerici sono stati applicati per lo studio di esperimenti caratterizzati da un riscaldamento dominante tramite NBI: sono stati studiati il piú grande tokamak attivo al mondo (JET), il piú grande stellarator attivo al mondo (LHD) e il progetto del reattore dimostrativo europeo DEMO.
Accurate simulazioni dell’iniezione del fascio neutro sono state elaborate grazie ad un codice Monte Carlo per l’analisi di esperimenti di JET. Una simulazione predittiva é stata condotta con l’intento di ricostruire il profilo di temperature ionica del plasma nel caso di rilevante riscaldamento ionico da parte dell’NBI. Ció ha prodotto un’attendibile ricostruzione in un caso in cui le misure sperimentali non erano disponibili a causa di un problema con lo strumento di misura. L’interazione tra NBI e plasma al JET é stata studiata tramite simulazioni predittive anche per scariche in idrogeno, partendo da scariche di riferimento in deuterio, con l’obbiettivo di studiare gli effetti che il cambiamento isotopico provoca sul plasma di JET. Studi sugli effetti isotopici sono stati effettuati anche per LHD, esperimento a configurazione elicoidale, dove si stanno preparando i futuri esperimenti in deuterio al posto degli usuali esperimenti in idrogeno.
L’iniezione di particelle neutre é una delle opzioni come riscaldamento addizionale del plasma per il futuro reattore dimostrativo DEMO. Attualmente uno studio pre-concettuale di questo reattore é in corso a livello europeo. Simulazioni degli scenari di DEMO sono state effettuate sia per il progetto di un DEMO pulsato, sia per un DEMO a funzionamento stazionario. Il ruolo dell’NBI come riscaldamento principale e sistema per indurre la corrente di plasma é stato investigato tramite studi di sensibilitá, confronti con altri sistemi di riscaldamento e simulazioni delle fasi transitorie del plasma (accensione - ramp-up - e spegnimento - ramp-down - della scarica).
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Martin, Samuel James Louis. "The 'Lad Lit' dilemma : institutional influences on creative writing practice." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/17032/1/Sam_Martin_-_eighteenth.pdf.
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This thesis consists of a novel, eighteenth, and an exegesis, The ‘Lad Lit’ Dilemma: Institutional influences on creative writing practice. It will address my research question; how did institutional factors surrounding the publishing category of Lad Lit influence my creative practice in drafting and re-drafting the novel eighteenth?
eighteenth is the story of Will Swift, a seventeen year-old Brisbane university student. Will is part of a close group of friends from high school. When he falls for Kate, family friend of his mate Simon, his first semester of study becomes more complicated than he might have expected. Will’s movement through these issues and character development is represented symbolically through four eighteenth birthday parties. The project’s exegesis then analyses the changing nature of the publishing industry in the last twenty years, and the implications of these changes for creative writers.
Together, the two elements of this practice-led research will articulate the shift in the balance between the cultural and commercial imperatives of publishers, explain the impact of this shift for the publishing category of Lad Lit, and explore the ramifications of this for creative writing practitioners.
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Martin, Samuel James Louis. "The 'Lad Lit' dilemma : institutional influences on creative writing practice." Queensland University of Technology, 2008. http://eprints.qut.edu.au/17032/.
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This thesis consists of a novel, eighteenth, and an exegesis, The ‘Lad Lit’ Dilemma: Institutional influences on creative writing practice. It will address my research question; how did institutional factors surrounding the publishing category of Lad Lit influence my creative practice in drafting and re-drafting the novel eighteenth?
eighteenth is the story of Will Swift, a seventeen year-old Brisbane university student. Will is part of a close group of friends from high school. When he falls for Kate, family friend of his mate Simon, his first semester of study becomes more complicated than he might have expected. Will’s movement through these issues and character development is represented symbolically through four eighteenth birthday parties. The project’s exegesis then analyses the changing nature of the publishing industry in the last twenty years, and the implications of these changes for creative writers.
Together, the two elements of this practice-led research will articulate the shift in the balance between the cultural and commercial imperatives of publishers, explain the impact of this shift for the publishing category of Lad Lit, and explore the ramifications of this for creative writing practitioners.
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Alekic, Anis, and Andreas Carmvall. "Displayintegrering." Thesis, Linnaeus University, School of Computer Science, Physics and Mathematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-2412.
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<p>Arbetet är ett examensarbete i högskoleingenjörsutbildningen, inriktning datateknik, på Linnéuniversitet. Arcoma AB är ett företag i Växjö som utvecklar och tillverkar kompletta röntgensystem. Företaget har som mål att förbättra användarvänligheten av systemet med hjälp av en LED-display. De kan förbättra systemet genom att byta ut en enhet som styr röntgengeneratorn mot LED-displayen. Detta leder till att användaren får bättre kontroll och styrning av systemet, samtidigt som patienten behandlas.</p><p>I rapporten beskrivs implementering av både hårdvara och mjukvara till displayen, samt den tekniska bakgrunden som till exempel HDMI och LED-tekniken. Mjukvaran har testats direkt mot displayen vilket har gjort testningen intressant. För att lösa uppgiften har vi fått använda Arcomas system och utvecklingsverktyg. Programspråket som användes var framförallt C++.</p><p>Resultatet blev ett system som byggs upp av Arcomas hårdvaruplattform, vår kringelektronik och displayen där de sistnämnda byggdes in i en låda. Utöver displayen utvecklades en demoapplikation för generatorstyrning som styrs av en USB-mus. Arcoma är nöjda över resultatet då vi löst huvuduppgiften med displayen, men även löst de extrauppgifter som fanns. Idag försöker Arcoma skapa en efterfrågan för lösningen i deras nya produkter.</p><br><p>This abstract describes the Bachelor of Science in engineering thesis for computer science at Linnaeus University. Arcoma AB in Växjö is a company that constructs and develops complete x-ray systems. The goal of the company is to improve the usability of the system with the help of a LED display. Arcoma can improve the system by exchange the unit that controls the x-ray generator with the LED display instead. This will give the user the ability to have better overview and control of the system, while treating the patient.</p><p>This report describes the implementation of both the software and the hardware for the display, but also the technical background for some standards like HDMI and the LED technologic. The software has been tested directly to the display, and therefore made the testing interesting. We have used the Arcoma system and the development tools to solve the problem. The programming language that was used to solve the problem was mainly C++.</p><p>The result was a system that is build up by the Arcoma hardware platform, our surrounding electronics and the display where the last ones were built in a box. Aside the display a demo application was developed for controlling the generator. This applications is controlled by a USB mouse. Arcoma is pleased with the result of the main problem with the display, and they are also pleased with us solving the additional problems that existed. Arcoma wants to create a demand of this solution in their new products.</p>
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Bohutínský, Jaroslav. "Řídicí a signalizační jednotka pro sportovní utkání." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218393.
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The aim of this study is a design of a control and signalling unit for sport meetings controlled by a microcontroller. The unit should display the time, the state of the match, eventually another data important for a course of the match. It should be fitted by an audible alarm of the end of the match. A touch control panel with a liquid crystal display serves as input of control data. The unit operates in a countdown mode, it is possible anytime to start or to stop the time by pressing the button. The equipment is mains-operated and backed up by an external battery. In the case of a power failure, it is switched over to the battery. A representation of the time, the state of the match and other data is done by LED displays. The unit allows a connection to PC.
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Somora, Rastislav. "Konstrukce polovodičového optického zesilovače." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220345.
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Diploma thesis deals with the construction of a moder semiconductor optical amplifier SOA. In the first chapter optical comunication and the use of optical amplifiers is described. In the next chapter some types of optical fibers, their chemical composition and properties are described in detail. The third chapter overviews optical amplifiers, their use today, describes their advantages and disadvantages and their proper use in optical comunications. The fourth chapter describes the solution of the objective, the right layout of separate blocks and connections used in measurements. Fifth chapter describes used components, describes their basic parameters and proper use in circuit. The last chapter evaluates outputs of measurements and their impact on the objective.
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Tian, Feng. "Etude et optimisation des systèmes d'éclairage pour la croissance des plantes en milieu contrôlé." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30248/document.
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Les systèmes d'éclairage artificiels sont couramment utilisés pour la croissance des plantes en serre ou environnement contrôlé (culture hydroponique, hors sol, etc...). Leur principale fonction est d'améliorer la qualité et la quantité de la production agricole indépendamment des saisons et de l'ensoleillement. L'utilisation d'une source de rayonnement artificielle pour plantes (PARS pour "Plant Artificial Radiation Sources") signifie que la lumière du soleil n'a pas été l'unique source de lumière pour la production agricole, mais qu'elle a été remplacé ou complété par une source artificielle (PARS). Les serres ou les complexes de culture hydroponique avec éclairage artificiel (Plant Factory with Artificial Lighting, "PFAL"), notamment à LED, sont une technologie innovante pour l'agriculture moderne susceptible de changer fondamentalement certains concepts. Cependant, certaines difficultés persistent avec ces nouvelles techniques. Tout d'abord, par manque de formation ou d'information, certaines personnes ne comprennent pas les caractéristiques techniques des sources de lumière artificielle moderne. Deuxièmement, les mécanismes de photobiologie sous différents spectres sont encore mal définis en fonction des espèces de plantes. Troisièmement, le secteur agricole est une grande entité qui présente également une grande complexité de part la variabilité des cultures. En conséquence, les "PARS" ont généralement une faible efficacité et présentent une consommation énergétique élevée, ce qui devient le principal obstacle pour leur application. Les PARS et leurs systèmes sont la technique de base pour développer l'horticulture contrôlée, en particulier dans la culture hydroponique qui n'utilisent que les sources d'éclairage artificielle. Toutefois, la consommation d'énergie et les défauts de conception deviennent des difficultés rédhibitoires à leur mise en oeuvre. Par conséquent, la sélection d'une source de lumière efficace et l'optimisation des systèmes d'éclairage sont d'une grande importance. Connaître le type de spectre optimal pour une variété de plante ou d'algue nécessite donc des études plus approfondies. Les diodes électroluminescentes (LED) pour l'éclairage constituent une source de lumière de dernière génération compatible avec les puissances lumineuses nécessaires à la croissance de plantes. Par rapport aux sources traditionnelles, elles présentent des avantages incomparables tels qu'un rendement élevé, une longue durée de vie, un rayonnement relativement simple à contrôler par rapport aux sources de lumières classiques, une lumière dite "froide" (pas d'émission infra-rouge), de petite taille, robuste, etc. En outre, les systèmes d'éclairage à LED ("LED Lighting Systems", LLS) utilisent une alimentation en courant continu, ce qui est plus fiable et plus facile à contrôler. Par conséquent, les "LLS" deviennent de plus en plus populaire pour les chercheurs, ingénieurs, fabricants, biologistes et industriels du secteur agronomique. En particulier, les applications des LEDs pour la production agricole suscitent une vive attention dans le monde ces dernières années. Les sources de lumière à LED sont connues comme étant le choix idéal en horticulture sous conditions contrôlées (notamment vis-à-vis de leur faible consommation énergétique)<br>Artificial lighting systems can be used for plant growth in protected horticulture. Their main function is to improve the quality and quantity of agricultural products. Plant factory and greenhouse with supplemental lighting are the concrete manifestation of protected horticulture. The applications of Plant Artificial Radiation Sources (PARS) mean that the sunlight has not been the unique light source for agricultural production but can be replaced by PARS. Especially, Plant Factory with Artificial Lighting (PFAL) is an innovative technology for modern agriculture that fundamentally change the concept of farming. However, there are some problems for this new technique. First, some people do not understand well the characteristics of artificial light source. Second, photobiology mechanism under different spectra is not clear enough for all the species. Third, agricultural field is a large system of great complexity. As a result, the PARS usually have low efficiency and high energy consumption, which become the main obstacles for plant applications. PARS and their systems are the core technique to develop protected horticulture, especially for plant factory that can only use PARS for photosynthesis and agricultural production. However, the high energy consumption and design flaws become the bottleneck problems. Therefore, how to select the light sources and optimize the lighting systems are of great importance. Which kind of spectrum is optimal for plants or algae needs further study. Light emitting diode (LED) is the fourth (the latest) generation light source. Compared with traditional light sources, it has unparalleled advantages such as high efficiency, long lifetime, flexible spectrum, cool light, small size, robust, etc. Besides, LED lighting systems (LLS) use DC power supply, which is more reliable and easier to control. Therefore, LLS become more and more popular to the researchers, engineers, manufacturers and biologists. Particularly, LED applications for agricultural production also attract broad attention in the world in recent years. LED is known as the ideal choice to spread in the protected horticulture
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Legentil, Paul. "Développement de poudres hybrides "Hydroxydes Doubles Lamellaires-luminosphores" sans terres rares. Intégration dans des revêtements composites compatibles avec des sources d'excitation LED." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC013.
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Ces travaux de thèse ont pour ambition de proposer des solutions alternatives, aux luminophores avec terres rares, offrant des performances convenables pour des applications dans des dispositifs à LED comme l’éclairage mais également la visualisation ou encore le marquage ou la signalétique. Nous nous sommes intéressés à des luminophores organiques mais également inorganiques tels que les quantum dots (QD). Le problème majeur de ces familles de luminophores est leur instabilité sous contrainte thermique et/ou photonique. Aussi, afin de pallier ce problème nous avons choisi d’utiliser des matériaux inorganiques plaquettaires de type « hydroxyde doubles lamellaires » (HDL) comme matrice hôte du luminophore. Les luminophores étudiés sont la fluorescéine, la sulforhodamine B et des quantum dots InP/ZnS. Plusieurs techniques expérimentales ont été utilisées afin de caractériser leurs propriétés structurales et morphologiques (DRX, SAXS, IR, MEB, MET…). Les propriétés optiques ont également été enregistrées (émission, excitation, rendement quantique de photoluminescence, déclins…). Ces travaux ont mis en évidence la plus-value de la matrice HDL qui permet de reproduire un effet de solvatation pour le luminophore organique ou QD dans une matrice solide et de retrouver des propriétés d’émission semblables à celles de ces luminophores en solution diluée. La dispersion dans une matrice silicone est également favorisée et la stabilité de ces revêtements composites (HDL-Luminophore/silicone) sous différentes contraintes est nettement améliorée<br>These works have the ambition to offer alternative solutions to phosphors with rare-earth elements, displaying suitable performance for LED devices applications as well as signage or display applications. We have been interested in organic as well as inorganic phosphors such as quantum dots (QD). The main problem encountered with these compounds is their relative instability under thermal and/or photonic stresses. Thus, in order to overcome this issue, we decided to use inorganic materials called layered double hydroxide (LDH) as host matrix to protect these phosphors. Several experimental techniques (XRD, SAXS, IR, SEM, TEM…) have been used to characterize structural and morphological properties. Optical properties have also been recorded (emission and excitation spectra, photoluminescence quantum yields, fluorescence decay…). Using extremely small amounts of phosphors, it is demonstrated here that Zn2Al cation-based LDH tethering acts as a «solid solvent» for the dye, enabling its luminescence even in powder form. Additionally, LDH platelets are found to help the dispersion of the dye or QD in silicone to obtain homogeneous composite films, which exhibit luminescent properties. Finally, the stability of composite coatings (LDH-phosphor/silicone) under different stresses (thermal and photonic) is most often improved
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Kwon, Ojin. "Monolithic integration of III-V optoelectronics on SI." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1124192126.
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Nascimento, Valtemir Emerencio do. "Aplicação da técnica LOD em métodos no domínio do tempo e freqüência para modelagem de meios convencionais e metamateriais." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-18122007-105116/.
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Este trabalho tem por objetivo o desenvolvimento de métodos numéricos eficientes, tanto no domínio do tempo quanto na freqüência, para a modelagem da propagação de ondas em estruturas que apresentem combinações de meios convencionais e/ou metamateriais, particularmente os metamateriais onde tanto a permissividade quanto a permeabilidade são simultaneamente negativos. Em alguns casos à simulação de tais estruturas representa um grande desafio em virtude da grande demanda computacional requerida. Uma forma eficiente de se contornar este problema é a utilização de técnicas de divisão de operador, com destaque para a técnica implícita das direções alternadas (ADI), já amplamente explorada nos domínios do tempo e da freqüência, e mais recentemente a técnica localmente unidimensional (LOD). A técnica LOD é utilizada com destaque neste trabalho, onde pela primeira vez esta foi empregada em um método de propagação de feixe de ângulo largo em diferenças finitas no domínio da freqüência, o qual foi denominado por LOD FD-BPM. O passo seguinte foi estender sua aplicação para o domínio do tempo, sendo a primeira abordagem empregada em um método de propagação de onda em diferenças finitas no domínio do tempo, denominado por LOD TD-WPM. Em seguida, a técnica LOD foi aplicada ao método FDTD resultando em um formalismo implícito, denominado LOD-FDTD, o qual apresenta uma maior eficiência computacional do que o tradicional ADI-FDTD. Estas abordagens apresentaram uma excelente eficiência computacional em virtude da possibilidade de utilização de passos de tempos maiores do que o permitido pela condição de estabilidade de Courant-Friedrich-Levy (CFL), além de serem incondicionalmente estáveis como conseqüência da aplicação do esquema de Crank-Nicolson (CN). A restrição do método LOD-FDTD, referente à sua precisão de apenas primeira ordem no tempo, foi contornada com o uso do esquema de divisão de operadores conhecido como Strang splitting (SS), resultando no método de segunda ordem no tempo LOD-FDTD-SS. Os métodos FDTD, ADI-FDTD, LOD-FDTD e LOD-FDTD-SS foram também implementados com base no modelo de Drude com perdas, possibilitando, assim, uma modelagem adequada de meios metamateriais. Outra contribuição importante deste trabalho foi à implementação da condição de contorno split PML no formalismo LOD-FDTD para a simulação de problemas eletromagnéticos abertos.<br>This work focuses on developing efficient numerical methods, both in time and frequency domains, for modeling wave propagation in structures that present conventional media and/or metamaterial media combinations, particularly the metamaterials where both permeability and permittivity are simultaneously negative. In some cases, the simulation of such structures represent a great challenge, due to the great computational requirements. An efficient way of solving this problem is the usage of operator splitting techniques, specifically the alternate direction implicit (ADI) technique, already explored both in time and frequency domains, and recently the locally one-dimensional (LOD) . This work dedicates special attention to the LOD technique, where, for the first time, this one was applied in a finite difference frequency domain wide-angle propagation method, which was denominated LOD FD-BPM. The next step was to extend its application to the time domain, the first approach was used in a finite difference time domain wave propagation method, denominated LOD TD-WPM. Next, the LOD technique was applied to the FDTD method, resulting in an implicit formalism, denominated LOD-FDTD, which presents a better computational efficiency than the traditional ADI-FDTD. These approaches present an excellent computational efficiency, due to the possibility of using greater time steps than those permitted by the Courant-Friedrich-Levy (CFL) stability condition, being unconditionally stable as a consequence of applying the Crank-Nicolson (CN) scheme as well. The LOD-FDTD method restriction, referring to its first order accuracy in time, was circumvented by using the operator division scheme known as Strang splitting (SS), resulting in a second order time method LOD-FDTD-SS. The FDTD, ADI-FDTD, LOD-FDTD and LOD-FDTD-SS methods were also implemented with a lossy Drude model, making, this way, possible an adequate metamaterial media modeling. Another important contribution of this work was the implementation of the split PML contour condition in the LOD-FDTD formalism for the simulation of open electromagnetic problems.
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Пронозов, І. С. "LED діод". Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/38856.
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Світлодіод складається з чіпа напівпровідникового матеріалу, легованого домішками для створення р-n переходу. В діодах легко протікає струм від p-сторони (анода), до n-сторони (катода), але не в
зворотньому напрямку. Принцип роботи полягає у наступному, коли електрон зустрічає отвір, він потрапляє в більш низький енергетичний рівень і вивільняє енергію у вигляді фотона.
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Kančo, Jan. "LCD monitory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217462.
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LCD monitors brought new problems to plotting of quality of monitors (and visual equipment). Important parameter is response time of LCD monitor. The consequences of nonzero response time are motion artifacts, which are undesirable part of final scene. Response time depends on technology of production and dimension is typical for single technology. Measuring of response time may bring idea of using measured LCD monitor. Rightly response time decides, if monitor is enough “fast” for action video, games, etc, or other parameters are decisive. Producers of LCD panels assign response time which are measured in certain conditions and measured in different ways. The target of this project is designing digital meter response of LCD monitors, but also verification of response times of choice panels.
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Pokorný, Jiří. "Modernizace hlavních hodin pro řízení systémů podružných hodin." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242182.
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This diploma thesis describes modernization of the master clock HN 50 created by company ELEKON, s.r.o. Master clock can be used for controlling of analog or digital slave clock or for switching school bells. Exact differences between old and new version of the clock are described and ways of synchronization and controlling of slave clock are explained. Main goal of modernization is applying the SMT technology for automation of production. Another problems and shortcomings of previous version are developed, such as new power supply structure, selection of a new microcontroller and usage of several different displays. Every problem is developed and new solutions are chosen. Last part of the document describes the software which is clarified on several flowcharts. Outputs of the thesis are complete schematics, printed circuit boards and 3D models of the modernized device.
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Kavouras, Alex M. Sr. "AN ELECTROLYTIC CAPACITOR-LESS APPROACH TO ELIMINATING FLICKER IN LED LIGHTING." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1452360658.
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Sivertsson, Erik. "LED Projekt ombord ms Cinderella : LED Projekt ombord ms Cinderella." Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-25830.
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Nyström, Anton. "Optimering av grid LED-armatur : Optimization of grid LED-armature." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69726.
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Nordic Light are one off the leading companies in manufacturing and development of lamparmatures and have been doing that since 1980. Since LED lamps are getting more and more common, the demands on optimizing thearmatures are rising. Because of the competition in the lamp industry the customers put highdemands on the efficiency and price. The purpose of this paper is to optimize an existingarmature and the focus will be on efficiency and manufacturing costs. An analysis of the existing armature was made to establish the function and cost of everycomponent. This was the foundation for the ideation of the new armature. To ensure that thenew armature would manage the requirements, a calculations of manufacturing costs and ananalysis in OpticStudio was made. The result shows a solution more cost efficiant than the original with high efficiency where itis possible to attach the armature in the roof or to profiles. It is recommended to make aprototype and to perceive with additional calculations before the manufacturing starts.
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Fernandez, Garcia Javier David, Wouter Beek, Miguel A. Martínez-Prieto, and Mario Arias. "LOD-a-lot: A Queryable Dump of the LOD Cloud." Springer International Publishing, 2017. http://epub.wu.ac.at/6484/1/LODALot%2DISWC17.pdf.
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LOD-a-lot democratizes access to the Linked Open Data (LOD) Cloud by serving more than 28 billion unique triples from 650 K datasets over a single self-indexed file. This corpus can be queried online with a sustainable Linked Data Fragments interface, or downloaded and consumed locally: LOD-a-lot is easy to deploy and demands affordable resources (524 GB of disk space and 15.7 GB of RAM), enabling Web-scale repeatable experimentation and research even by standard laptops.
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Janík, Daniel. "Provozní parametry LED světelných zdrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316394.
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The aim of the thesis is to introduce the basic photometric quantities and operating parameters of LED light sources, according to which the light sources are evaluated and compared. The thesis examines effects of high temperature and elevated stress on LED retrofits and a design of measurement methods to measure these influences. According to the proposed methods, nine samples of light sources were measured and compared to each other on a basis of the measurements. Comparison was made from the point of view of the energy as well as the quality of the produced light. The results were also compared to the parameters specified by the producers.
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"Study of electron heat transport in LHD and TJ-II." Universitat Politècnica de Catalunya, 2006. http://www.tesisenxarxa.net/TDX-1009106-120316/.
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"The Right Side of the Public Health Ledger: How Revenue Dynamics Influence LHD Finances and Operations." Tulane University, 2019.
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archives@tulane.edu<br>Public health finance is still a relatively young field and, as such, many questions have yet to be asked—and answered. To date, few have examine how specific revenue streams—alone or in combination—shape local health departments’ (LHD) resources and capacity to accomplish their public health missions. Given ongoing policy conversations about financing for public health, it’s important for researchers to rigorously examine the and the potential costs and benefits associated with different revenue sources.
Introduction Chapter: The central thesis for the body of work encapsulated by this dissertation is simple: where money comes from matters. This chapter critically examines published evidence and theory linking public health financing mechanisms and their interactions to LHD operations, outputs, and even outcomes. The chapter also introduces situates the specific research questions addressed in this dissertation within a broader conceptual framework.
Paper 1: The first paper examines the relationship between revenue diversification and revenue volatility among Washington State LHDs. Using fixed effects linear regression models and revenue data reported during 1998-2014 by all LHDs operating in Washington State, the paper finds little evidence to suggest revenue diversification is significantly associated with revenue volatility.
Paper 2: The second paper evaluates whether available revenue sources differentially effected the scope of programs provided by Washington State LHDs between 2000 and 2011. Using two measures of program scope and both linear and non-linear fixed effects panel regression models, the paper finds that only funding received from federal Medicaid was consistently and significantly associated with both measures of program scope.
Paper 3: The third paper examines changes in total LHD expenditures in Washington State between 2006 and 2013 following introduction of a new state funding program to support core public health services and infrastructure. Using a pre-post design regression model to evaluate changes in LHD expenditures, the paper finds overall spending among LHDs significantly increased with receipt of the new state funds in the first years of the program. However, those increases were not sustained over the longer term
Conclusion Chapter: The final chapter reviews findings from the three papers and discusses their implications for public health policy, practice, finance, and research.<br>1<br>Abigail Hope Viall
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Chung, Shih-Hsun, and 鐘世勳. "Luminance management of LED backlighting for LCD TV." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/19842327000902550311.
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碩士<br>國立中央大學<br>光電科學研究所<br>94<br>In the thesis, we study the luminance management of LCD backlights based on LED lighting. First, we study the characteristics of the LCD and the backlight module. Then we study LEDs in different colors. The third step is to calculate the required total flux of the backlight module based on photometry theory, and thus we calculate the numbers of the light source. Finally, we simulate the uniformity of the backlight module with precise LED model.
Based on the luminance management of the LCD backlight, we fabricate two LED backlight module. One is 28’’ LCD TV with white-light LEDs, and the other is 42’’ LCD TV with RGB LEDs. The performance of both panels are presented and analyzed.
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Wu, Chang-Yu, and 吳昌諭. "Sequential Color LED Backlight Driving System for LCD Panels." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/81829646664628406053.
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碩士<br>國立中正大學<br>電機工程所<br>94<br>In this thesis, a sequential color light emitting diode (LED) backlight driving system for liquid crystal display (LCD) panels is proposed. Due to improvement on luminous efficacy, long life and wide color gamut, LED has gradually substituted for cold cathode fluorescent lamp as backlight. The proposed driving system adopts sequential color scanning scheme to improve light utilization efficiency by removing color filter. This thesis also proposes a family of output current ripple free topologies to improve chromaticity accuracy and reliability of LED. In addition, an LED bypass circuit is proposed to prevent LED arrays from open-circuit, and a driving voltage reseter is introduced to resolve current-spike problem, improving backlight reliability and availability significantly. A forward-type current ripple free converter has been built, from which experimental measurements have verified the discussed performance and feasibility of the proposed system.
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Liao, Te-Chih, and 廖得志. "New LCD-TV LED Backlight Driver Circuit Module Design." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12403200046454449179.
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碩士<br>元智大學<br>電機工程學系<br>99<br>ABSTRACT
In the carbon reduction of environmental consensus, unlike the traditional backlighting elements (such as CCFL), the lower power consumption of the LED has become a new generation of LCD TV backlight trend. Compared to the application of monitor, TV as a larger size, they need more strings of the LED backlight modules to achieve the required brightness of the LED control and on it’s multi-serial LED strings. The first problem is the current imbalances will be encountered among LED strings. The imbalance will cause the serial current uneven brightness, and thus the image quality. How to reach a balance under the given cost and getting the current balance among the LED strings, will be a challenge to for LED driver designers.
Conventional AC load multiple drivers [ such as CCFL, EEFL ( External Electrode Fluorescent Lamp ), etc. ] often connected passive components in each group sharing the loads among AC power input, so one can achieve multiple AC load flow with current balance.
This thesis proposes a lower power loss and cheaper method LED driver module for a typical 60” LED TV. For balancing the multiple LED strings, the LCD-TV LED driver circuit prototype design with passive components used in the DC load current connection. In addition, the circuit outputs data and waveforms were also measured. The AC power connecting with a rectifier can provide the DC power for the DC loads. By the connection of passive components, it will get the current balance among the DC loads.
This thesis uses a LLC resonant converter design integrated with "A power supply with a H- balance LED driver for the multiple DC loads." The main purpose of the new power module for LED driver is to provide a cheaper and also efficient power supply circuit for current balance. Different from the traditional with linear structure, the new design can have current balance in each group of DC loads and the same brightness, the lower power consumption and high efficiency. The new design has relatively few components and low complexity, and substantial cost savings. With the actual measurements, we will measure and evaluate the performance of the new LED driver design with current balance circuits.
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Wu, Chih-hung, and 吳志宏. "DESIGN OF LED BACKLIGHT CIRCUIT MODULE FOR LCD-MONITOR." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/85132301767942524568.
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碩士<br>大同大學<br>電機工程學系(所)<br>98<br>A LED arrays driver circuit of module is proposed, and is used in the backlight of LCD-monitor and illumination system. As constant-power dissipation curve, calculate the optimal voltage and current and determine the appropriate LED arrays. With Fly-back converter to be a AC to DC power supply and get the fixed voltage (12V) by pulse width modulation (PWM) of current feedback mode, then adopt the Boost converter to arise the voltage. Depend on feedback of LED arrays and generate the driver voltage. In order to reduce the luminance difference between each LED, this makes stable current of LED arrays by current mirror. And using the dynamic select function let LED arrays light at the same. The feature of this circuit is module design that applies various LED backlight models and generates the applicable voltage and stable current then achieve the common-design purpose.