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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
361

Nonlinear Least-Square Curve Fitting of Power-Exponential Functions: Description and comparison of different fitting methods

Altoumaimi, Rasha Talal January 2017 (has links)
This thesis examines how to find the best fit to a series of data points when curve fitting using power-exponential models. We describe the different numerical methods such as the Gauss-Newton and Levenberg-Marquardt methods to compare them for solving non-linear least squares of curve fitting using different power-exponential functions. In addition, we show the results of numerical experiments that illustrate the effectiveness of this approach.Furthermore, we show its application to the practical problems by using different sets of data such as death rates and rocket-triggered lightning return strokes based on the transmission line model.
362

Modélisation de la tenue diélectrique dans les grands intervalles d'air : application aux intervalles complexes

Konate, Lamine Boubacar 12 December 2016 (has links)
Cette thèse est consacrée à l’étude de la décharge positive dans les grands intervalles d’air. L’objectif initial est de se doter d’un modèle capable de déterminer la tension U50 ainsi que le facteur d’intervalle k, deux facteurs importants entrant dans le dimensionnement des ouvrages hautes tensions, dans des géométries complexes. Pour ce faire un bilan des modèles de la décharge disponibles dans la littérature a été fait. Notre choix s’est porté sur le modèle de type circuit développé par le groupe du professeur Beroual et appliqué aussi bien à la décharge positive qu’à la décharge négative. Ce modèle est basé sur un schéma électrique équivalent, ses paramètres variant avec le temps en fonction des caractéristiques du canal et de la géométrie de la décharge. La propagation du leader est basée sur un critère lié au calcul du champ à sa tête et où le caractère aléatoire du trajet de la décharge est pris en compte. Comme la plupart des modèles présents dans la littérature, ce modèle ne s’intéresse qu’à l’intervalle de type pointe-plan. Une partie de ce travail a consisté à étendre le domaine d’applicabilité de ce modèle aux intervalles de géométrie complexes. Une étude détaillée de la géométrie pointe-pointe nous a permis de valider notre modèle dans sa capacité à simuler un exemple d’intervalle complexe. De plus, des essais expérimentaux nous ont permis de comparer la valeur de la U50 déterminée à l’aide de notre modèle et celle issue des expériences pour cette géométrie pointe-pointe. Les résultats obtenus sont en bon accord avec une marge d’erreur inférieure à 5%. Au vu du bon accord résultant de la confrontation modèle - expérience de laboratoire et de la grande similarité, grande étincelle - décharge atmosphérique, un modèle de foudre positif a été élaboré. Ce modèle nous a permis d’utiliser pour la première fois le modèle circuit pour modéliser le processus d’attachement de la foudre. Les résultats obtenues permettent de valider la faisabilité de trouver, aux méthodes standards de protection contre la foudre, une alternative numérique basé sur une simulation de la foudre. Une estimation du champ rayonné par le canal du leader a été effectuée. Ce qui ouvre une voie à l’étude de l’interaction de ces champs rayonnés avec les systèmes d’ingénierie. / This thesis is devoted to the study of the positive discharge in large air gaps. The initial goal is to develop a model able to determine the voltage U50 and the k-factor, two important factors involved in the design of high voltage structures in complex geometries. To do this, a review of the discharge models available in the literature was done. We chose the circuit model developed by Professor Beroual’s group and applied to the positive discharge and also to the negative discharge. This model is based on an equivalent circuit diagram, his parameters varying with time according to the leader channel characteristics and the geometry of the discharge. The spread of the leader is based on a criterion related to the calculation of the field at its head and where the randomness of the discharge path is taken into account. As most of models found in the literature, this model applies only to the point-plane type interval. Part of this work was to extend the domain of applicability of this model to complex geometries. A detailed study of the rod-rod gap allowed us to validate our model in its ability to simulate an example of complex geometry. Moreover, experimental tests allowed us to compare the value of the U50 voltage determined using our model and the one from experiments for to this rod-rod geometry. The results are in good agreement with a margin of error of less than 5%. Given the good agreement resulting from the confrontation model - laboratory experience and the great similarity, large spark - atmospheric discharge, a positive lightning model was developed. This model allowed us to use for the first time the circuit model to model the lightning attachment process. The results obtained allow to validate the feasibility to find, to the standard methods of protection against lightning, digital alternative based on a simulation of lightning. An estimate of the field radiated by the leader channel was performed. This opens a way for the study of the interaction of these fields radiated with engineering systems.
363

The relative impact of an argumentation-based instructional intervention programme on grade 10 learners’ conceptions of lightning and thunder

Moyo, Partson Virira January 2012 (has links)
Philosophiae Doctor - PhD / The basic premise of this study was that when a learner is confronted with two contradictory explanations of the same phenomenon, there is cognitive dissonance in the learner as the learner tries to determine which of the two explanations is correct. An argumentation-based instructional intervention programme (ABIIP) was created for and used on and by the Grade 10 learners in order to attempt to ameliorate this cognitive conflict. The purpose of this study was to determine the relative impact of that intervention programme on Grade 10 learners’ conceptions of lightning and thunder. The programme was designed to help learners to develop argumentative skills and use the acquired skills to negotiate and harmonise divergent and conflicting explanations of the nature of lightning and thunder that are propounded by different worldviews (Science and indigenous knowledge).
364

Effects of a dialogical argumentation instructional model on grade 10 learners’ conceptions of lightning

Hlazo, Noluthando January 2014 (has links)
Magister Educationis - MEd / The study employed a quasi-experimental design to determine the effect of DAIM on learners’ conceptions of lightning. The experimental group was taught using DAIM while the control group was taught the same content using TLM. Data was collected using the Science Attitude Questionnaire (SAQ), Beliefs about Lightning Questionnaire (BALQ), Conceptions of Lightning Questionnaire (COLQ) and Science Achievement Test on Lightning (SATOL) which was used to determine learners’ overall performance on the topic of electrostatics. The data was analysed using both qualitative and quantitative methods. The findings of the study revealed that prior to the intervention (DAIM); the two groups of learners had both the scientific and the indigenous knowledge about lightning. A majority of the learners believed that lightning is caused by witches and traditional doctors. After being exposed to the DAIM most of the learners in the experimental group were found to have changed to the more scientific explanation of cause of lightning and protective measures against lightning. Few learners in the control were classified as possessing an equipollent worldview in terms of the CAT after the post tests. Some learners’ conceptions about lightning wavered between the scientific and traditional worldviews. The Science Attitude Questionnaire showed that both groups of learners had a positive attitude towards science. The findings also suggested that the inclusion of indigenous knowledge in science lessons promoted active participation from the learners, reinforced the learning of science because it promoted conceptual development and scientific literacy. The learners in the study also supported the integration of the scientific and the traditional worldviews about lightning. After the instruction, the learners in both groups seemed to still hold indigenous beliefs in relation to lightning. The post-test results showed that the DAIM group seemed to have been able to link the concept of lightning with electrostatics when they related lightning storms to electric discharge. The experimental group was found to be more elaborate in their explanations of the scientific nature of lightning than the control group which was not exposed to DAIM
365

Energeticky úsporný administrativní objekt s posilovnou a wellness Kostka / Energy efficient office building with gym and wellness Kostka

Kotas, Marek Unknown Date (has links)
The master thesis describes a complete design of an office building, including its technical equipment. The building's technical equipment contains HVAC, lighting, DHW and photovoltaics design, water demand. The building has two floors. It contains offices, a bistro with a lounge, a wellness area and two gyms, a children's playground and facilities. This master thesis is divided into three parts. Firstly, the thesis presents building documentation with an engineering and an accompanying report. Secondly, the thesis introduces the design of the building's technical equipment and engineering reports. Lastly, the results of a conducted experiment are presented. In this experiment, a system for the optimization of blind tilt angle is proposed.
366

Návrh ochrany proti úderu blesku a jištění datových rozvodů u FVE / Design of protection against lightning and data distributions photovoltaic plant

Manduch, Viliam January 2012 (has links)
This thesis deals with the problems associated with the lightning. It deals with the stablishment, descriptions and analyzes of risk the living organisms and objects are facing. The work focuses on the description and implementation of protection against these adverse effects. Its objective is to devise a system for lightning protection for chosen PV power plant to meet the requirements of standard of EN 62305. The work is also the analysis of shadow effects in the collecting system for PV power systems.
367

Cirkulär ekonomiför plastavfall : Hantering av akrylplast som ett steg mot ett merhållbart samhälle / Circular economy of plasticwaste : A step towards a more sustainable society by handling acrylic plastic

Bondemark, Emma, Heinevik, Josefin January 2022 (has links)
Purpose – The aim of the study is to investigate the possibilities for circular economy in acrylicplastic in the lighting industry. To answer the purpose, it was broken down into two researchquestions: [1] What characterizes the handling of acrylic plastic waste by lighting manufacturers? [2] How can lighting manufacturers achieve a more circular handling of acrylic plastic waste? Method – To be able to answer the research questions, a case study was conducted at acompany active in the lighting industry. The data collection consisted of observations,interviews, and document studies. The observations were unmasked and of a direct nature. Theinterviews that were held were both unstructured and semi-structured. The documents wereinvoices and quotations mostly collected from the case company. Furthermore, four differentsolutions were developed with help of the theoretical framework and collected data. The empiricand the theoretical chapters were compared to be able to analyse and answer the researchquestions. Findings – The study shows that a company in the lighting industry throw away plastic lensesas they believe that they have no use for them. The lenses are made of acrylic plastic and arethrown in combustible waste. The waste goes to energy recovery that provides electricity,district heating and district cooling. During the combustion process, carbon dioxide is releasedwhich affects the environment. It is better to let the waste go to energy recovery than landfilling.To achieve a more circular handling of acrylic plastic waste, it is recommended to first andforemost reduce the waste. It is the result of one of the solution proposals "Minimize worksteps" which involves a point effort to take advantage of acrylic plastic instead of throwing itaway. In situations where there is no possibility of reducing, companies should instead try toreuse the acrylic lenses, which is a result of the solution proposal "reuse". In 2024, there willopen a new chemical recycling centre in Sweden that companies should keep track of. Implications – The study has implications for companies in the lighting industry that useacrylic plastic. It is also suitable for companies outside the lighting industry that handle acrylicplastic waste, as the study contributes to increased knowledge about circular economy and howacrylic plastic waste should be handled to benefit the circular economy. The study helps tohighlight potential approaches for environmentally friendly handling of acrylic plastic. A newrecycling centre opens 2024 in Stenungsund, which is the first in Sweden that can chemicallyrecycle acrylic plastic. It is recommended to talk to them early to review costs and opportunitiesthat arise in connection with the opening of the recycling centre. Limitations – The environmental impact of the study is measured in carbon dioxideemissions. No other environmental aspects are considered as carbon dioxide includes the areasthat are relevant, based on the size of the study. Due to the time constraint, the study wasconducted on only one case company, which may lower credibility. More companies should bestudied in order to further generalize and strengthen credibility even more.
368

Trygga torg : En studie av torg ur ett trygghetsperspektiv / Perceived safety in squares : A study of squares with a perceived safety perspective

Jarlegård, Hanna, Lacombe, Bastien January 2019 (has links)
Trygghetsarbete ärnågot som både statliga myndigheter och kommuner intresserar sig för. Kommunernämner gärna i sina översiktsplaner att trygghetsfrämjande åtgärder ska vidtasoch att områden ska utvecklas med hänsyn till tryggheten. Hur dettatrygghetsarbete tar sig form i den fysiska miljön är mindre tydligt och syftetmed denna studie har således varit att ta fram aspekter som går att arbeta medför att främja trygghet. Dessa aspekter har sedan använts för att analyseratorg i Stockholm stad, Nacka kommun och Vaxholm stad för att se hur väl torgensvarar mot dessa aspekter. Aspekterna som tagits fram med hjälp av enlitteraturstudie och den fallstudie som har utförts har sedan legat till grundför att ta fram tips för hur trygga torg kan utformas.Litteraturstudien ledde till att fem aspekter av stor betydelse för trygghetentogs fram: närhet till andra människor, synlighet och överblickbarhet,belysning, grönska och skötsel av allmän plats. Inget av de torg som omfattadesav fallstudien uppnådde samtliga trygghetsaspekter, men vissa uppfyllde fler änandra. Utöver de slutsatser som har dragits kring vilka aspekter som är trygghetsfrämjandeså ledde studien till slutsatser kring vilka torg som uppfyller vilka aspekter.Slutligen ledde studien fram till konkreta förbättringsförslag för trygghetenpå de torg som fallstudien omfattade och handfasta tips för hur torg kanutformas med hänsyn till trygghet / Working with perceived safety is something that both government agencies and municipalities are interested in. Municipalities gladly mention in their general plans that perceived safety actions is something that should be prioritised and that new areas should be developed with regard to the perceived safety. Exactly how these perceived safety actions takes shape in the physical environment is less clear and the purpose has thus been to identify aspects that are possible to work with and that promotes the perceived safety. The identified aspects have then been used to analyse squares in Stockholm stad, Nacka kommun and Vaxholm stad to see how well these places correspond to the these aspects. Tips on how squares that are perceived as safe was then formulated based on the case study and the aspects that was identified in the literature study.The literature study led to the identification of five aspects with great significance to the perceived safety: closeness to other people, visibility and overview, lightning, greenery and maintenance of public space. None of the observed squares fulfill all the aspects, but some fulfill more than others. Other than the conclusions that were drawn concerning which aspects that are promoting for the perceived safety, the study also led to conclusions regarding which squares that fulfill which aspects. Finally the study led to improvement-proposals for perceived safety on the squares of the case study and concrete tips on how squares can be designed with regard to perceived safety.
369

Generating lightning bolt videos perceived as real in images using machine learning

Johansson, Henrik January 2022 (has links)
Background. Weather and weather effects are important features when trying to immerse the viewer into a virtual world. Lightning and thunder is one of those effects when attempting to create rough weather, realistic lightning however requires heavy computations, using physics, weather systems, and knowledge of the 3d world. Objectives. This thesis investigates the possibility of leveraging the predictive power of machine learning to generate animated lightning bolts inside of images, and then investigates the possibility to generate the animated lightning bolts in real time.   Methods. A new data-set for training will be created consisting of videos of lightning bolts. Four image to video machine learning architectures will be investigated and two will be tested in an attempt to find a suitable model for generating the animated lightning bolts. The selected model will be used to generate videos for a questionnaire to collect qualititive data regarding the perceived realism of the animated lightning bolts. To figure out if it is possible to generate the animated lightning bolts in real time the final model will be performance measured and compared to real time requirements of video games and video editing software. Results. For the training data-set 106 curated and pre-processed videos were collected. By gathering four and testing two different machine learning architectures it was found that the architecture based on stochastic Image-to-Video Synthesis using conditional invertible neural networks were the most suited for generating animated lightning bolts. The questionnaire received a 77% positive rating for the generated lightning bolts, with a 1% statistical significance a p-value of 0.00005 was obtained. The performance of the selected machine learning model were measured to be inadequate for real time applications like video games but more than enough for video editing software. Conclusions. The goal of generating animated lightning bolts percieved as real were achieved by creating a new data-set and investigating multiple machine learning architectures. Real time generation is achievable for video editing applications, but real time generation for video games is not yet possible unless the background is static. / Bakgrund. Väder och vädereffekter är viktiga verktyg för att skapa en virtuell värld som fördjupar användaren. Åska och blixtar kan användas för att skapa en upplevelse av dåligt väder men verklighetstrogna representationer kräver tunga matematiska beräkningar och kunskap om den virtuella världen. \newline\textbf{ Syfte. Den här uppsatsen undersöker möjligheten att utnyttja kraften bakom maskininlärning för att generera blixtar som ser verklighetstrogna ut. Uppsatsen undersöker också om det är möjligt att generera blixtar i realtid. Metod. Ett nytt data-set som består av videos av blixtar skapas med syftet att träna modellerna. Fyra bild till video maskininlärnings arkitekturer kommer undersökas och två kommer testas i ett försök att finna en lämplig modell för att generera de animerade blixtarna. Videos från den utvalda modellen kommer användas i ett frågeformulär. Detta formulär kommer användas för att samla in kvalitativ data gällande den upplevda realismen av de genererade blixtarna. För att ta reda på om det är möjligt att generera blixtarna i realtid prestandamäts den slutgiltiga modellen och jämförs med kraven för spel och videoredigeringsverktyg i realtid. Resultat. Modellens träningsdata består av 106 insamlade videoklipp som blivit förbearbetade. Genom att testa två olika maskininlärnings arkitekturer visade det sig att stokastiska bild-till-video arkitekturen baserad på cINN konceptet var den mest lämpade för att generera videos av blixtar. Frågeformuläret mottog ett positivt betyg på 77\% gällande de genererade blixtarna, med en 1\% statistisk signifikans framkom ett p-värde på 0.00005. Prestandan av den utvalda maskin inlärningsmodellen uppmättes vara undermålig för en realtidsapplikation som digitala spel men tillräcklig för videoredigering. Slutsatser. Målet att generera animerade blixtar som uppfattas som realistiska uppnåddes genom att skapa ny träningsdata och undersöka flera olika bild till video maskininlärnings arkitekturer. Realtidsgenerering går att uppnås av applikationer för video redigering, men för applikationer som spel nås inte realtidskraven i dagsläget om kameran i spelet inte står stilla.
370

Contribuciones a los sistemas de protección contra el rayo

Ruiz Muñoz, David 07 January 2016 (has links)
Tesis por compendio / [EN] This thesis addresses to the current status of lightning protection, focusing on the external protection with emphasis on the process of interception. Under this approach, three pillars are studied due to their obvious interest in the evaluation and practical application of lightning protection during the first phase, the lightning interception. Those pillars are: Laboratory Tests Field Tests Lightning Protection Models. These three points can be treated individually; nevertheless, they are interrelated, not only for the technical field they belong to, all together pose an evolution in the magnitude of the electric discharge, starting by the study of the electric discharge in laboratory in order to understand the processes that involves its behavior. It is no possible reproduce the whole event of lightning in laboratory, so field tests are essential to characterize empirically the most important parameters of lightning in natural conditions. The measurements made in natural conditions, are employed to fundament some protection models, furthermore with the statistics, it is possible the definition of the lightning protection levels which determines the practical application of the lightning protection. The fact of encompassing different points in a technical field is imposed because this thesis has been made in a company specialized in lightning protection, which implies a need of knowledge applied to all the points concerning its scope. The main contributions of the thesis are collected in each of the chapters and in the proposals made in them, opening new lines of work on which to base a set of techniques and practices that could complement the ones currently applied. After an introductory chapter, it is treated the main core of the Thesis, composed by the chapters 3, 4 and 5 where the contributions, published by the author are exposed. In the chapter 3 it is made a revision of the laboratory tests studying the physical processes associated to the electric discharge. At this point and after the review, the author focuses on the U50 parameter (amplitude of a pulse voltage in a determined configuration whose application involves a 50% of probability to get a disruptive discharge) using a tool based on neural networks with a configuration of multilayer perceptron (MLP) with which the level of predictability of an individual pulse is evaluated with different configurations, data input and time windows, as indicative of the influence of a variable in the process of generation and interception of the electric arc. Regarding the field tests, its application typically involves monitoring high-rise structures, the use of rockets for artificial lightning triggering or lightning detection networks. At this point the different measurement strategies are evaluated and a new point of view that could be used to obtain reliable statistics in a short period of time is introduced, which resulted in a paper. The dissertation also introduces a methodology for continuous evaluation of lightning protection systems, comparing the performance of the installed systems and considering also the protection model used for the design of the installation. About protection models, in a brief introduction the author discusses the different models of protection by extending information about those standardized which, despite their lacks, remain widely used today. After evaluating the current context under standardized lightning protection, it is indicated that one way to complement physically the protection models is the inclusion of methods whose application is consistent with standardized lightning protection models. In this line the author presents a contribution embodied in an article. / [ES] En esta Tesis se aborda el estado actual de la protección contra el rayo centrándose en la protección externa y concretamente en el proceso de intercepción. Bajo este planteamiento, se estudian tres pilares fundamentales que presentan un evidente interés para la evaluación y aplicación de la protección contra el rayo en la fase de intercepción: Los ensayos de laboratorio Los estudios en campo Los modelos de protección Estos tres puntos pueden tratarse de forma individual, no obstante están relacionados entre sí, no sólo por el campo de la técnica al que pertenecen, sino también porque juntos plantean una evolución en la magnitud de la descarga eléctrica, comenzando con la descarga eléctrica en laboratorio para comprender los procesos que gobiernan su comportamiento. Al no ser posible la completa reproducción del fenómeno del rayo en laboratorio, los estudios de campo resultan necesarios para poder caracterizar empíricamente los parámetros característicos de los rayos en la naturaleza. Con las medidas en la naturaleza, además de fundamentar algunos modelos de protección, también se realizan estadísticas que son empleadas en la definición de los niveles de protección que determinan la aplicación práctica de la protección contra el rayo. El hecho de abarcar diferentes puntos de un campo de la técnica viene impuesto porque esta Tesis se ha realizado dentro del marco de una empresa especializada en la protección contra el rayo, lo que implica una necesidad de conocimiento aplicado a todos los puntos que conciernen a su campo de aplicación. Las principales contribuciones de la Tesis quedan recogidas en cada uno de los capítulos y las propuestas que se hacen en ellos, abriendo nuevas líneas de trabajo sobre las que fundamentar un conjunto de técnicas y prácticas que podrían complementar a las aplicadas actualmente. Tras un capítulo introductorio, se trata el núcleo principal de la Tesis, formado por los capítulos 3, 4 y 5 donde se presentan las contribuciones del autor en forma de publicación. En el capítulo 3 se revisan los ensayos en laboratorio, donde se pueden estudiar los procesos físicos asociados a los arcos eléctricos. En este punto y, tras una revisión, el autor se centra en el parámetro U50 (amplitud de un pulso de tensión en una configuración determinada cuya aplicación implica un 50% de probabilidad de obtener una descarga disruptiva) empleando una herramienta basada en redes neuronales en la configuración de perceptrón multicapa (MLP) con la que se analiza el nivel de predicción del resultado de un impulso individual con diferentes configuraciones, datos de entrada y ventanas temporales, como indicativo de la influencia de una variable en el proceso de generación e intercepción del arco eléctrico. Sobre los ensayos en campo, su aplicación implica normalmente la monitorización de estructuras de gran altura, el empleo de cohetes para el cebado artificial de rayos, o las redes de detección de rayos. En este punto se evalúan las diferentes estrategias de medida y se introduce un nuevo punto de vista que podría utilizarse para la obtención de estadísticas fiables en un tiempo reducido y que ha dado lugar a un artículo. También se menciona una metodología para la evaluación continua de los sistemas de protección contra el rayo con la que se podría comparar el rendimiento de los sistemas instalados, con el modelo de protección empleado para realizar el diseño de la instalación. Sobre los modelos de protección, tras una revisión de varios modelos de protección, la Tesis se centra en los modelos normalizados los cuales, pese a sus carencias son los más utilizados. Tras evaluar el contexto actual bajo las normativas de protección contra el rayo se indica que una vía para complementar físicamente los modelos de protección es la inclusión de métodos con fundamentación física cuya aplicación sea compatible con los modelos de protección normalizad / [CA] A aquesta Tesi s'aborda l'estudi del estat actual de la protecció contra el llamp centrant l'objectiu en la protecció externa i amb èmfasi en el procés de intercepció. Baix aquest plantejament, s'estudien tres pilars fonamentals que presenten un evident interès par la avaluació y aplicació pràctica de la protecció contra el raig a la seua primera fase, la intercepció del llamp: Els assajos de laboratori Els estudis de camp Els models de protecció Aquests tres punts poden tractar-se de forma individual, però estan relacionats entre si, no només pel camp de la tècnica al que pertanyen, sino també perquè junts plantegen una evolució en la magnitud de la descàrrega elèctrica, començant amb l'estudi de la descàrrega elèctrica al laboratori per a comprendre el processos que governen el seu comportament. Al no ser possible la completa reproducció del fenomen del raig al laboratori, els estudis de camp resulten imprescindibles per a poder caracteritzar empíricament els paràmetres característics dels rajos a la naturalesa. Amb les mesures realitzades a la naturalesa, amés de fonamentar alguns models de protecció, també es realitzen estadístiques que son emprades a la definició dels nivells de protecció que determinen la aplicació pràctica de la protecció contra el raig. El fet de comprendre diferents punts d'un camp de la tècnica ve impost per el fet de que aquesta Tesi ha sigut realitzada dins del marc d'una empresa especialitzada en la protecció contra el llamp, i açò implica la necessitat de coneixement aplicat a tots els punts que concerneixen al seu camp d'aplicació. Les principals contribucions de la Tesi queden arreplegades en cada un dels capítols i les propostes que se fan en ells, obrint noves línies de treball sobre les que fonamentar un conjunt de tècniques i practiques que podrien complementar a les aplicades actualment. Després d'un capítol introductori, es tracta el nucli principal de la Tesi, format per els capítols 3, 4 y 5 on es presenten les contribucions de l'autor en forma de publicació. Al capítol 3, es revisen els assajos en laboratori, a on es poden estudiar els processos físics associats als arcs elèctrics. En aquest punt i, desprès de una revisió, l'autor es centra en el paràmetre U50 (amplitut d'un impuls de tensió a una configuració determinada que implica un 50% de probabilitat de obtenir una descarrega disruptiva) emprant una ferramenta basada en xarxes neuronals amb configuració de perceptró multicapa (MLP) en la que s'analitza el nivell de predicció del resultat d'un impuls individual amb diferents configuracions, senyals d'entrada i finestres temporals, com indicatiu de l'influencia d'un variable en el procés de generació i intercepció de l'arc elèctric. Referent als assajos en camp, la seua aplicació implica normalment la monitorització d'estructures de gran alçada, la utilització de coets per al encebat artificial de rajos, o les xarxes de detecció de llamps. En aquest punt s'avaluen les diferents estratègies de mesura i s'introdueix un nou punt de vista que es podria utilitzar per a l'obtenció d'estadístiques fiables en un temps reduït, del que també ha sorgit un article. També es menciona una metodologia per a l'avaluació continua dels sistemes de protecció contra el raig en la que se podria comparar el rendiment dels sistemes instal¿lats, amb el model de protecció empleat per a realitzar el disseny de la instal.lació. Sobre els models de protecció, tres una revisió dels diferents models de protecció existents, la Tesi es centra en els models normalitzats, el quals, a pesar de les seues carències segueix sent els mes utilitzats en l'actualitat. Desprès de avaluar el context actual baix les normatives de protecció contra el raig s'indica que una via per a complementar físicament els models de protecció es la inclusió de mètodes amb fonamentació física que continuen sent compatibles amb els models de protecció / Ruiz Muñoz, D. (2015). Contribuciones a los sistemas de protección contra el rayo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59440 / Compendio

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