Dissertations / Theses on the topic 'Utility lines'

Thesis (M.S.) University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 28, 2007) Vita. Includes bibliographical references.

This paper is focusing on the data mining solutions for the WWW, specifically how it can be used for the hyperlinks evaluation. We are focusing on the hyperlinks used in the web sites systems and on the problem which consider evaluation of its utility. Since hyperlinks reflect relation to other webpage one can expect that there exist way to verify if users follow desired navigation paths. The Challenge is to use available techniques to discover usage behavior patterns and interpret them. We have evaluated hyperlinks of the selected pages from www.bth.se web site. By using web expert’s help the usefulness of the data mining as the assessment basis was validated. The outcome of the research shows that data mining gives decision support for the changes in the web site navigational structure.
akasha.kate@gmail.com

Conventionally, the focus during supplier evaluation has been to assess cost, quality and delivery effectiveness due to their impact on profitability. In recent years, there has been increased emphasis on promoting more sustainable business practices that focus on reducing environmental impact and improve societal well-being, in addition to economic benefits. However, most of the existing supplier evaluation methods in literature as well as those used by leading companies fall short of comprehensively assessing suppliers from a Triple Bottom Line (TBL) perspective. TBL defined as holistically looking at the economic, environmental, and societal aspects of an entity. This paper presents a review and selection of metrics for economic, environmental and societal sustainability evaluation. In addition, this work proposes a methodology for combining the scores into a comprehensive score that can be used to compare two entities performance relative to the TBL.

This master’s thesis deals with analysis of documents for the realization of the new buildings the wider area of Brno. It is divided into the theoretical part and the empirical part. The theoretical part describes defines and characterize different stages of implementation of building plots in the framework of utility lines and roads on agricultural land (greenfields), designated for residential housing. In the empirical part goals and methodology of the research project are mentioned and it is divided into two parts. The first part is devoted to case studies comparing and analyzing the costs and revenues of the developer selected localities of satellite towns. The second part is focused on the actual development of land prices. It points to items affecting profit or loss of the developer. In the last chapter the author of this thesis describes creating a preliminary calculation, which the developer can determine whether a satellite town of the selected project will be successful or not. In conclusion, the thesis points out important factors affecting the project success of the satellite town.

This thesis presents the results of the development of a user-friendly computer code (in MATLAB) that can be used to calculate co-channel interferences, both in the downlink and in the uplink of a single satellite/space-based mobile communications system, due to the reuse of frequencies in spot beams or coverage cells. The analysis and computer code can be applied to any type of satellite or platform elevated at any height above earth. The cells or beams are defined in the angular domain, as measured from the satellite or the elevated platform, and cell centers are arranged in a hexagonal lattice. The calculation is only for a given instant of time for which the system parameters are input into the program. The results obtained in one program run are for the overall carrier to interference ratio (CIR) along with CIR for both the uplink and downlink paths. An overall carrier to noise plus interference ratio (CNIR) is also calculated, which exemplifies the degradation in the carrier to noise ratio (CNR) of the system. Comparisons for systems with differing system scenarios are also made. For example, overall CIRs are compared for different reuse numbers (3, 4, 7, and 13) in LEO and GEO satellite systems. In conclusion, as expected, it is observed that the co-channel interference generally increases as we decrease the reuse number employed for the frequency reuse in the cells. It is also observed that co-channel interference can cause substantial degradation to the overall CNR of a system.
Master of Science

Les réservoirs composites de type IV utilisés pour le stockage de l’hydrogène gazeux rencontrent du succès dans les applications mobiles de la pile à combustible. Au cours de leur utilisation, ces supports de stockage sont soumis à des cycles successifs de remplissage/maintien/vidange en hydrogène. Sous des conditions spécifiques de vidange, l’apparition d’un décollement entre l’enveloppe en polyamide 6 qui assure l’étanchéité (liner) et la paroi composite, peut être observée. Ce décollement, encore appelé collapse, peut poser des problèmes de limitation à un débit de vidange lent ou à un seuil minimal de pression résiduelle du gaz sur le liner.Air Liquide a cherché à élucider expérimentalement l’influence des cycles de pression en hydrogène sur le comportement mécanique des liners en situation de collapse. Mais compte tenu des coûts très élevés des essais, l’utilisation d’un outil numérique prédictif s’avérait nécessaire. L’enjeu principal dans le développement d’un tel outil était la modélisation du comportement d’un liner collapsé sous des chargements de cyclage – fluage.L’objectif de cette thèse est de proposer une loi de comportement capable de prédire l’évolution cyclique de la déformée d’un liner en situation collapsée.Le liner est exposé à plusieurs variations de son environnement : présence d’un résidu d’humidité dans le liner après épreuve hydraulique, variations de températures générées par la compression/détente de l’hydrogène, diffusion de l’hydrogène dans le liner. Un travail préliminaire a donc consisté à évaluer l’influence de ces différents facteurs environnementaux sur la réponse mécanique du polyamide 6. Cette première étape a permis de définir un cadre de sollicitation à l’échelle du laboratoire, mais qui préserve les principales caractéristiques du collapse. Les essais de caractérisation sur éprouvette ont montré que le liner pouvait être modélisé par une loi viscoélastique multiaxiale formulée dans le cadre thermodynamique des processus irréversibles en petites déformations, faiblement couplée avec la thermique. Des modifications mineures ont été introduites pour permettre à cette loi de capter les effets du comportement en fatigue-fluage d’un liner en situation collapsé. Ces modifications ont malheureusement pénalisé l’identification manuelle et par conséquent, ont conduit à développer une stratégie d’identification spécifique. La qualité de d’identification a été évaluée dans le cadre isotherme en regardant les effets de la vitesse de la sollicitation, du niveau de contrainte et de la température. Puis, le modèle a été validé en présence de transitoires thermiques, d’abord sur éprouvette, ensuite dans un réservoir en présence d’un collapse
Hyperbaric hydrogen storage vessels of type IV are encountering success for portable applications of fuel cell. During their use, these cylindric containers undergo repeated fill in/fill out cycles of H2-gaz. Under specific fillout conditions, an emerging detachment between the sealing inner layer (liner) and the composite wall, can be observed. This layer debonding also called collapse may limit the pressure release rate of H2-vessels or increase the residual gas pressure prescribed to avoid collapse.Experimental studies have been conducted by Air Liquide at vessel scale to identify some parameters responsible for the collapse onset. But the high cost of these studies and the complexity of the operating conditions makes the use of numerical tools necessary. That led to a numerical modeling approach. The main goal in the numerical approach is to model the cyclic mechanical response of a collapsed liner under fatigue – creep loadings.In this thesis, the purpose was to develop a mechanical constitutive law able to predict the cyclic deformation of a collapsed liner subjected to hydrogen pressure cycles.The liner was subjected to several environment variations due to: (i) the presence of residual water into the liner after initial hydraulic vessel tests, (ii) the temperature changes caused by the hydrogen compression/expansion, and (iii) the hydrogen diffusion/saturation. So, a preliminary work consisted in investigating the influence of each environmental factor on the polyamide 6 mechanical response. This first step allowed to outline a loading frame at laboratory scale that preserved main characteristics of the collapse phenomenon. Characterization tests on tensile specimens revealed that the liner could be modelled by a non linear viscoelastic law written within the thermodynamic framework of the irreversible processes in small deformations, and coupled with the temperature. Minor changes were introduced to extend the model capacity to capture liner behavior effects during fatigue – creep. These changes had negative impact on the manual method of model calibration, and consequently required to develop a specific identification strategy. The identification performance was assessed in different isothermal frames through stress rate, stress level and temperature effects. Then, the calibrated model was validated by taking temperature gradients into account, firstly on a tensile specimen, secondly within a H2-vessel

El món de les comunicacions per la xarxa elèctrica (CXE) pot ser dividit en tres grans tipus: CXE en baix voltatge (CXE-BV), en mig voltatge (CXE-MV) i en alt voltatge (CXE-AV). En aquests últims anys, les CXE-BV han atret una gran expectació, ja que les seves capacitats han fet d'aquesta tecnologia una bona opció com alternativa pel bucle local d'accés i pel desplegament de xarxes d'àrea local, focalitzades aquestes últimes en l'entorn domèstic. A més, les CXE-BV inclouen un conjunt d'aplicacions de baixa velocitat orientades a l'operador, com la lectura automàtica de comptadors (LAC), distribució de càrrega, facturació dinàmica, etc. Per altra banda, les CXE-MV i CXE-AV, històricament lligades a tasques de telecontrol i teleprotecció, s'estan començant a considerar com un canal de comunicacions eficient i fiable. El desenvolupament de sistemes digitals i els esforços d'estandardització estan fent d'aquests canals un medi atractiu per a que els operadors elèctrics ofereixin serveis de comunicacions, ja que no necessiten invertir en infraestructura perquè la xarxa elèctrica ja està desplegada.
En aquesta Tesi s'introduiran i es comentaran les particularitats de les tres xarxes elèctriques, després, es mostraran al lector les solucions tecnològiques existents pels canals de BV basats en la norma Europea CENELEC així com pels canals d'AV, mostrant que els sistemes actuals de LAC ofereixen una diversitat freqüencial molt baixa i que els mòdems CXE-AV estan ancorats en estendards antiquats.
Aquest treball es mou per les tres topologies de la xarxa, particularment, en aplicacions orientades a la banda CENELEC, en mesura i modelat de canal, i en mesura i disseny del nivell físic per sistemes CXE-BV, CXE-MV i CXE-AV respectivament. Els sistemes actuals que exploten la banda CENELEC ofereixen mecanismes d'explotació de la diversitat freqüencial del canal molt limitats o nuls, donant lloc a una baixa robustesa en front a interferències i soroll de fons acolorit. Aquest treball proposa un esquema de modulació multiportadora que, mantenint una complexitat baixa, ofereix unes altes prestacions permetent un bon nivell d'explotació de la selectivitat freqüencial. Per al que a CXE-MV respecta, aquesta Tesi desenvolupa un model de canal determinístic-estadístic pels anells urbans de distribució de potència i, finalment, en sistemes CXE-AV, aquest treball proposa, basat en mesures de canal i proves de camp, un nivell físic de banda ampla capaç de incrementar la velocitat de comunicació mentre manté una baixa densitat espectral de potència limitant així la interferència a altres sistemes.
PARAULES CLAU: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
El mundo de las comunicaciones por la red eléctrica (CRE) puede ser dividido en tres grandes tipos: CRE en bajo voltaje (CRE-BV), en medio voltaje (CRE-MV) y en alto voltaje (CRE-AV). En estos últimos años, las CRE-BV han atraído una gran expectación, ya que sus capacidades han hecho de esta tecnología una buena opción como alternativa para el bucle local de acceso y para el despliegue de redes de área local, focalizadas estas últimas en el entorno doméstico. Además, las CRE-BV incluyen un conjunto de aplicaciones de baja velocidad orientadas al operador como la lectura automática de contadores (LAC), distribución de carga, facturación dinámica, etc. Por otro lado, las CRE-MV y CRE-AV, históricamente ligadas a tareas de telecontrol y teleprotección, se están empezando a considerar como un canal de comunicaciones eficiente y fiable. El desarrollo de sistemas digitales y los esfuerzos de estandarización están haciendo de estos canales un medio atractivo para que los operadores eléctricos ofrezcan servicios de comunicaciones, ya que no necesitan invertir en infraestructura porque la red eléctrica ya está desplegada.
En esta Tesis se introducirán y se comentarán las particularidades de las tres redes eléctricas, luego, se mostrarán al lector las soluciones tecnológicas existentes para los canales de BV basados en la norma Europea CENELEC así como para los canales de AV, mostrando que los sistemas actuales de LAC ofrecen una diversidad frecuencial muy baja y que los módems CRE-AV están anclados en estándares anticuados.
Este trabajo se mueve por las tres topologías de red, particularmente, en aplicaciones orientadas a la banda CENELEC, en medida y modelado de canal, y en medida y diseño del nivel físico para sistemas CRE-BV, CRE-MV y CRE-AV respectivamente. Los sistemas actuales que explotan la banda CENELEC ofrecen mecanismos de explotación de la diversidad frecuencial del canal muy limitados o nulos, dando lugar a una escasa robustez frente a interferencias y ruido de fondo coloreado. Este trabajo propone un esquema de modulación multiportadora que, manteniendo una complejidad baja, ofrece unas altas prestaciones permitiendo un buen nivel de explotación de la selectividad frecuencial. Por lo que a CRE-MV respecta, esta Tesis desarrolla un modelo de canal determinístico-estadístico para los anillos urbanos de distribución de potencia y, finalmente, en sistemas de CRE-AV, este trabajo propone, basado en medidas de canal y pruebas de campo, un nivel físico de banda ancha capaz de incrementar la velocidad de comunicación mientras mantiene una baja densidad espectral de potencia limitando así la interferencia a otros sistemas.
PALABRAS CLAVE: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
The world of Power line communications (PLC) can be divided into three main types: low voltage PLC (LV-PLC), medium voltage PLC (MV-PLC) and high voltage PLC (HV-PLC). These last years, LV-PLC has attracted a great expectation since its wideband capabilities has made this technology a suitable choice for last-mile access and in-home communications. Moreover, LV-PLC also includes a utility oriented low frequency and low speed applications, such as automatic meter reading (AMR), load distribution, dynamic billing and so on. On the other hand, MV-PLC and HV-PLC, historically oriented to teleprotection and telecontrol tasks, are being considered as a reliable communication channel. The development of digital equipment and the standardization efforts are making those channels an attractive medium for electrical utilities telecommunications services, since the network, as well as in LV-PLC, is already deployed.
In this PhD dissertation, the three different PLC topologies are reviewed and the different communications techniques in such channels exposed. Then, a deep technological review of existing AMR solutions for the European CENELEC band, as well as HV-PLC systems is given, showing that existing AMR systems deliver low frequency diversity and HV-PLC systems are anchored in old fashioned standards.
This work walks around the three topologies, specifically, CENELEC band utility oriented applications, channel measurement and modeling and channel measurement and physical layer design, regarding LV-PLC, MV-PLC and HV-PLC respectively. Existing CENELEC compliant systems deliver low or none frequency diversity mechanisms, yielding in a low robustness against colored noise and interference. This work propose a multicarrier based physical layer approach that, while keeping the complexity low, delivers high performance allowing a great level of frequency diversity. Focusing on MV-PLC, a hybrid deterministic-statistical channel model for urban underground rings is developed and, finally, in HV-PLC systems, this work proposes, based on measurements and field tests, a wideband physical layer in order to increase data rate while keeping low both the power spectral density and possible interference to other systems.
KEYWORDS: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.

The subject of this diploma thesis is the elaboration of a construction technological project for the construction of a residential complex Nový Žižkov in Poděbrady, where I will focus on the technological stage of the gross building of the main building SO-01 apartment building – section BI+BII (56 dwelling units). The supporting system of the building is composed of a combination of monolithic reinforced concrete structures and ceramic blocks. The foundation of a residential building is designed as a reinforced concrete basin with reinforcing ribs. The diploma thesis contains a text and attachment part.

Detta examensarbete jämför olika rättighetsupplåtelser som kan användas för att säkra allmänna VA-ledningar som ligger i mark som inte ägs av ledningshavaren. När fastighetsägaren och ledningshavaren har en överenskommelse bör de välja att säkra ledningen med ett avtalsservitut eller en ledningsrätt. Avtalsservitutets främsta egenskaper är en låg upprättandekostnad, går att upprätta snabbt samt att den underlättar vid en framtida flytt av ledningen medan ledningsrättens främsta fördel är att den gäller med bästa rätt i fastigheten. Jämförelsen mellan de olika rättigheterna visade att ledningshavaren borde använda sig av ledningsrätten men i de fall avtalsservitutets fördelar passar bättre för situationen kan även den användas. När det inte finns en överenskommelse har ledningshavaren möjlighet att expropriera marken genom ledningsrätt eller mark- och miljödomstolen.   Arbetet behandlar de negativa konsekvenserna med en oskyddad VA-ledning, ledningshavaren kan t.ex. bli ersättningsskyldig pga en oskyddad  ledning. Om ledningen är oskyddad finns det även möjlighet för fastighetsägaren att ta bort ledningen genom att ansöka om handräckning hos kronofogden.     Examensarbetet innehåller även en inventering av alla Nacka kommuns VA-ledningar som inte ligger inom Nacka kommuns fastigheter. Inventeringen av Nacka kommuns VA-ledningar visade att drygt hälften av alla ledningar som inte ligger på kommunens mark är oskyddade. De övriga ledningarna skyddades till största delen av avtalsservitut och ledningsrätt, det fanns även några officialservitut. Inventeringen visade att kommunen inte har upprättat en enda rättighet sedan 2008, vilket tydligt bekräftar Nacka kommuns misstankar om att det finns en brist i tillvägagångssätt med att upprätta ett skydd för ledningarna. För att lösa detta problem måste Nackas organisation få klara riktlinjer för hur ledningarna ska skyddas. Det bästa vore om enhetschefen för VA & Avfallsenheten fick befogenheten att skriva på servitut och nyttjanderättsavtal samt befogenheten att skriva under en ledningsrättsansökan.
This thesis compares different rights that could be used to secure public water and sewage lines that lies in other people's property. In cases where the property owner and the pipeline owner have an agreement they should choose to secure the pipeline with an agreement easement or a utility easement. An agreement easement main characteristic is that it´s not expensive, can be established quickly and that it is easy to relocate the pipelines in the future. The utility easements main advantage is that it applies with the best right in the property. The comparison between the various rights showed that the pipeline owner should use utility easement but can also use an agreement easement in cases where its advantages are best suitable for the situation.   In situations when pipelines are unprotected and when the pipeline owner are in a dispute with the property owner he could apply for a utility easement or turn to a court of justice to secure the pipelines. If the pipelines owner doesn’t get a right, the property owner could apply for assistance to remove the pipelines at the enforcement office.   The thesis also includes an inventory of all public water and sewage lines located in land not owned by themunicipalityofNacka. The inventory ofNacka’s water and sewage lines showed that about half of all pipelines lying on someone else's land were unprotected. The rest of the pipelines were largely protected by agreement easements and utility easement. The inventory showed that the municipality haven´t created a right since 2008, which means that there have to be some weakness in the municipality's organization. To solve this problem the organization must have clear directives about what rules that are applicable for each right and who it is that are responsible for establish the right.

Introduction Movies are considered entertainment goods. Entertainment is one of the experience industries. Intangibility, perishability and heterogeneity are the most significant characteristics of the movie industry. An emotional reaction of consumers cannot be calculated in the same sense that most other physical goods can. If the movie succeeded in meeting the expectations, ticket price decreases will not necessarily indicate further purchases in the future. There are high risks and uncertainty in the movie industry. Purpose The purpose of this paper is to define through a hedonic price theory establishing whether the recognition is a significant factor to the global success of movies. The global success of the movies is determined by the global box office revenue. There are eight independent variables tested in this paper: global movie popularity, global popularity of the directors, global popularity of the authors, fame (determined by wining Academy Award), major studios, sequel, family genre and animation genre. Only one control variable, which is year of release, is included. Method The paper uses empirical model and the data set along with the results of the empirical analysis to achieve the purpose. Only secondary data were collected for the paper. Conclusion To reduce uncertainty in movie industry box office revenue, according to the data collected, recognition is significant to the consumers’ willingness to pay. The willingness to pay is determined by the global box office revenue. Only four independent variables, namely: sequels, Academy Award, the global popularity of the directors and the global popularity of the authors of the original script, are significant recognition factors to the global box office revenue. Movie producers shall be aware that consumers have to make sure utility gained from the consumption exceeds the costs in order to make purchases. Based on the sample collected, it can be summarized that consumers of the movie industry in general rely on previous consumption and recognition to reduce risks and uncertainty in terms of making purchases.

Målet med denna studie var att studera olika aspekter av den prioritetsordning som används för att prioritera elanvändare i svenska elnät i händelse av nationell-, regional eller lokal elbrist. Studien redogör för hur prioriteringar av olika elanvändare går till och hur nyttan av olika elnät förändras utifrån en beslutsfattares egna preferenser, vidare redovisas hur samverkan mellan olika elnät påverkar den totala nyttan som varje invånare i ett samhäller erbjuds. Objekten i ett samhälle som förekommer på ett elnät delas in i åtta prioriteringsklasser beroende av objektets funktion. Området för denna studie har varit beslutsanalys. Studien har genomförts med hjälp av resultat från tidigare studier och teorier kring beslutsanalys, med detta som grund har en simulering genomförts för att påvisa hur nyttan av ett elnät ändras då förutsättningarna ändras. Förutsättningarna har varit; total kapacitet av elektricitet till samhället, avstånd mellan samhällen och de olika objektens efterfrågan av elektricitet. Studiens resultat har påvisat att ellinjer med objekt av hög prioriteringsklass ska prioriteras före ellinjer med objekt av låg prioriteringsklass. Vidare har studien visat att det kan finnas elnät i ett samhälle vars nytta skulle kunna vara större än de elnät som förespråkas av prioritetsordningen, och att dessa kan vara disjunkta. Detta för att prioriteringsordningen ska prioritera det elnät med högprioriterade objekt, inte nödvändigtvis det elnät med störst nytta. Studie har därmed resulterat i att elnät bör prioriteras efter dess nytta och att en beslutsfattare bör vara medveten om elbristens storlek, avstånd mellan samhällen och varje objekts efterfrågan av kapacitet för att kunna fatta ett bra beslut. Gällande samverkan mellan elnät visade studien på att detta kan genomföras om avståndet mellan samhällena inte var för stort.
The aim of this study was to study the Styrel concept as an approach to identify electricity users and prioritize them in the event of a power shortage on a power grid. The study has examined and investigated how the priorities of different electricity users go to, how the benefits of manual disconnection change according to the decision makers' different priorities and how interaction between different local networks affects total utility. The features of a community on a local area, also called objects, are divided into eight priority classes depending on the function of the objects. The area for this study has been decision management. The study has been conducted using results from previous studies and theories on decision analysis as the basis for constructing a simulator that simulates how the power of a power failure changes for a local area dependent on the extent of the electricity supply (capacity). The study's findings have shown that prioritization of electricity supply line with higher priority classes should be prioritized than an electricity supply line with lower priority classes. This is also the result of previous studies. On the other hand, the study has shown that the fixed asset for an electricity supply line with lower priority objects is higher than an electricity supply line with higher priority objects, but with less benefit, priority should be given to the electricity supply line of higher priority objects. This study has thus resulted in the fact that electricity supply lines should be prioritized after the benefit if a decision maker is aware of the extent of the deficiency. Current collaboration between local networks showed that this could be dependent on the factors: distance, risk profile of decision makers and change of benefit through collaboration.

Made available in DSpace on 2014-12-17T14:55:12Z (GMT). No. of bitstreams: 1 HumbertoDA_TESE.pdf: 4762435 bytes, checksum: 20aae983d6895db90a85b0e2b107200f (MD5) Previous issue date: 2013-09-02
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In the globalized world modern telecommunications have assumed key role within the company, causing a large increase in demand for the wireless technology of communication, which has been happening in recent years have greatly increased the number of applications using this technology. Due to this demand, new materials are developed to enable new control mechanisms and propagation of electromagnetic waves. The research to develop new technologies for wireless communication presents a multidisciplinary study that covers from the new geometries for passive antennas, active up to the development of materials for devices that improve the performance at the frequency range of operation. Recently, planar antennas have attracted interest due to their characteristics and advantages when compared with other types of antennas. In the area of mobile communications the need for antennas of this type has become increasingly used, due to intensive development, which needs to operate in multifrequency antennas and broadband. The microstrip antennas have narrow bandwidth due to the dielectric losses generated by irradiation. Another limitation is the degradation of the radiation pattern due to the generation of surface waves in the substrate. Some techniques have been developed to minimize this limitation of bandwidth, such as the study of type materials PBG - Photonic Band Gap, to form the dielectric material. This work has as main objective the development project of a slot resonator with multiple layers and use the type PBG substrate, which carried out the optimization from the numerical analysis and then designed the device initially proposed for the band electromagnetic spectrum between 3-9 GHz, which basically includes the band S to X. Was used as the dielectric material RT/Duroid 5870 and RT/Duroid 6010.LM where both are laminated ceramic-filled PTFE dielectric constants 2.33 and 10.2, respectively. Through an experimental investigation was conducted an analysis of the simulated versus measured by observing the behavior of the radiation characteristics from the height variation of the dielectric multilayer substrates. We also used the LTT method resonators structures rectangular slot with multiple layers of material photonic PBG in order to obtain the resonance frequency and the entire theory involving the electromagnetic parameters of the structure under consideration. xviii The analysis developed in this work was performed using the method LTT - Transverse Transmission Line, in the field of Fourier transform that uses a component propagating in the y direction (transverse to the real direction of propagation z), thus treating the general equations of the fields electric and magnetic and function. The PBG theory is applied to obtain the relative permittivity of the polarizations for the sep photonic composite substrates material. The results are obtained with the commercial software Ansoft HFSS, used for accurate analysis of the electromagnetic behavior of the planar device under study through the Finite Element Method (FEM). Numerical computational results are presented in graphical form in two and three dimensions, playing in the parameters of return loss, frequency of radiation and radiation diagram, radiation efficiency and surface current for the device under study, and have as substrates, photonic materials and had been simulated in an appropriate computational tool. With respect to the planar device design study are presented in the simulated and measured results that show good agreement with measurements made. These results are mainly in the identification of resonance modes and determining the characteristics of the designed device, such as resonant frequency, return loss and radiation pattern
No mundo globalizado moderno, as telecomunica??es assumiram um papel fundamental dentro das sociedades, provocando um grande aumento da demanda por tecnologia de comunica??o sem fio, isto vem acontecendo nos ?ltimos anos e tem aumentado bastante o n?mero de aplica??es que utilizam esta tecnologia. Em decorr?ncia dessa demanda, novos materiais s?o desenvolvidos no sentido de possibilitar novos mecanismos de controle e propaga??o de ondas eletromagn?ticas. A pesquisa para o desenvolvimento de novas tecnologias para comunica??o sem fios apresenta um car?ter multidisciplinar que abrange desde o estudo de novas geometrias para antenas passivas e ativas at? o de desenvolvimento de materiais para dispositivos que melhorem o desempenho naquela faixa de frequ?ncia de opera??o. Recentemente as antenas planares tem despertado interesses devido as suas caracter?sticas e vantagens que oferecem quando comparadas com os demais tipos de antenas. Na ?rea de comunica??es m?veis a necessidade de antenas desse tipo tem se tornado cada vez maior, devido ao seu intenso desenvolvimento, que necessita de antenas que operem em multifrequ?ncia e em banda larga. As antenas de microfita apresentam largura de banda estreita devido ?s perdas no diel?trico geradas pela irradia??o. Outra limita??o ? a degrada??o do diagrama de irradia??o devido ? gera??o de ondas de superf?cie no substrato. Algumas t?cnicas est?o sendo desenvolvidas para minimizar esta limita??o de banda, como ? o caso do estudo de materiais do tipo PBG Photonic Band Gap, para compor o material diel?trico. Este trabalho tem como objetivo principal o desenvolvimento do projeto de um ressoador de fenda com m?ltiplas camadas e com a utiliza??o de substrato do tipo PBG, onde foi realizada a otimiza??o a partir da analise num?rica e em seguida, projetado o dispositivo proposto inicialmente para a faixa do espectro eletromagn?tico compreendida entre 3-9 GHz, que inclui basicamente a banda S at? X. Foi utilizado como material diel?trico o RT/Duroid 5870 e RT/Duroid 6010.2LM onde ambos s?o laminados cer?micos PTFE com constantes diel?tricas de 2.33 e 10.2, respectivamente. Atrav?s de uma investiga??o experimental foi realizada uma an?lise dos resultados simulados versus medidos observando o comportamento das xvi caracter?sticas de radia??o a partir da varia??o da altura das multicamadas de subtrato diel?trico. Foi utilizado tamb?m o m?todo LTT ?s estruturas ressoadoras retangulares de fenda com m?ltiplas camadas, para a obten??o da freq??ncia de resson?ncia bem como toda a teoria que envolva os par?metros eletromagn?ticos da estrutura em estudo. As an?lises desenvolvidas neste trabalho foram realizadas com utiliza??o do m?todo LTT Linha de Transmiss?o Transversa, no dom?nio da Transformada de Fourier que utiliza uma componente de propaga??o na dire??o y (transversa ? dire??o real de propaga??o z), tratando assim as equa??es gerais dos campos el?tricos e magn?ticos em fun??o de yE e yH . A teoria PBG ser? aplicada para a obten??o da permissividade relativa para as polariza??es s e p dos substratos compostos de material fot?nico. Os resultados s?o obtidos com o software comercial Ansoft HFSS, usado para a an?lise precisa do comportamento eletromagn?tico do dispositivo planar em estudo, por meio do M?todo dos Elementos Finitos (FEM). Resultados num?rico-computacionais s?o apresentados em forma de gr?fico em duas e tr?s dimens?es, para aos par?metros de perda de retorno, frequ?ncia de radia??o, e diagrama de radia??o, efici?ncia de radia??o e densidade superficial de corrente para o dispositivo em estudo, e que tem como substratos, materiais fot?nicos e que fora simulado em uma ferramenta computacional apropriada. . No que diz respeito ao projeto do dispositivo planar em estudo s?o apresentados os resultados medidos e os simulados que apresentam boa concord?ncia com as medi??es efetuadas. Estes resultados consistem principalmente na identifica??o dos modos de resson?ncia e na determina??o das caracter?sticas do dispositivo projetado, como freq??ncia de resson?ncia, perda de retorno e diagrama de radia??o

yes
This work presents the development of a new approach of modelling the source excitation and the penetration of structures by continuous propagating electromagnetic (EM) plane waves. The technique incorporates the solution of time-dependent Maxwell¿s equations and the initial value problem as the structures are illuminated by the plane waves. The propagation of waves from source excitation is simulated by solving a finite-difference Maxwell's equation in the time domain. Subgridding method is used to condense the lattice at the point of interest locally for observing field distribution in high resolution. The computational burden due to huge number of time steps has been eased by employing quasi-static approach. An example of induced EM fields near an underground pipeline runs parallel to a 132 kV overhead power transmission line (OHTL) has been presented which paves the way in the development of new approach of EM fields interaction modelling.
MSCRC

RSAT (Reticulation Sag And Tension) software is a tool available for use as part of the medium voltage Eskom Distribution standard. This software is scrutinised for its usability and for errors such that it can be revised to improve the usability of the tool. The type of software being studied is used to ensure optimum design performance and reduce the probability of a conductor failure on distribution lines. The algorithms for calculating tension, sag and clearance values take into account research into optimum design tensions. This ensures low bending forces due to conductor vibration. An algorithm for creep is designed based on common life expectancy of line conductors. The design methodology and algorithms were then put into software form as RSAT. Review and alterations include the changing of compiler, user interface, data storage mechanisms and the inclusion of options allowing the addition of new data.

The main objective of the thesis was to evaluate the reproductive utility and the achieved parameters of its own utility of the nucleus herd reared on the farm in Mladotice. The detected results have been compared with the average of the Prestice black-pied breed population. The attention has been paid to the lines of the boar representation. The number of all born piglets, the alive born ones and the weaned ones has been regarded during reproductive qualities assessment. The average daily growth, the muscle proportion and the back fat height have been evaluated while assessing the own utility. The origin of the Prestice black-pied breed with the following regeneration process with the assistance of Mirgorod, Liven, Cornwall, Berkshire, Wessex and German saddleback breeds, which contributed to the resistance of the Prestice black-pied breed, has been described in the literature review. The improvement process followed after the regeneration, especially by using Pietrain, Hampshire and Landrase breeds. The characteristics of the Prestice breed with reference to its tilted ear and typical black-pied coloring without body parts defining have been elaborated. Furthermore, the utility, the population development in the last five years and the preservation of the breed as a genetic resource have been described there. In the thesis the own utility of the Prestice black-pied breed of the nucleus herd reared on the Mladotice farm has been evaluated that does not reach breeding goal. The Akoga line is the best line considering its own utility. The reproductive utility has been evaluated as excellent. The Wiskont line has the best results. Statistically significant differences have been found among the lines considering both its own utility and reproduction.

In this thesis, we study the tradeoff of average delay with average service cost and average utility for both continuous time and discrete time single server queueing models without and with admission control. The continuous time and discrete time queueing models that we consider are motivated by cross-layer models for point-to-point links with random packet arrivals and fading at slow and fast time scales. Our studies are motivated by the need to optimally tradeoff the average delay of the packets (a network layer performance measure) with the average service cost of transmitting the packets, e.g. the average power required for transmission (a physical layer performance measure) under a lower bound constraint on the average throughput, in various point-to-point communication scenarios. The tradeoff problems are studied for a class of monotone and stationary scheduling policies and under the assumption that the service cost rate and utility rate are respectively convex and concave functions of the service rate and arrival rate. We also consider the problem of optimally trading off the average delay and average error rate of randomly arriving message symbols which are transmitted over a noisy point-to-point link, in which case the service cost function is non-convex. The solutions to the tradeoff problems that we address in the thesis are asymptotic in nature, and are similar in spirit to the Berry-Gallager asymptotic bounds. It is intuitive that to keep a queue stable under a lower bound constraint on the average utility a minimum number of customers have to be served per unit time. This in turn implies that queue stability requires a minimum average service cost expenditure. In the thesis we obtain an asymptotic characterization of the minimum average delay for monotone stationary policies subject to an upper bound constraint on the average service cost and a lower bound constraint on the average utility, in the asymptotic regime where the average service cost constraint is made arbitrarily close to the above minimum average service cost. In the thesis, we obtain asymptotic lower bounds on the minimum average delay for the cases for which lower bounds were previously not known. The asymptotic characterization of the minimum average delay for monotone stationary policies, for both continuous time and discrete time models, is obtained via geometric bounds on the stationary probability of the queue length, in the above asymptotic regime. The restriction to monotone stationary policies enables us to obtain an intuitive explanation for the behaviour of the asymptotic lower bounds using the above geometric bounds on the stationary probability distribution of the queue length. The geometric bounds on the stationary probability of the queue length also lead to a partial asymptotic characterization of the structure of any optimal monotone stationary policy, in the above asymptotic regime, which was not available in previous work. Furthermore, the geometric bounds on the stationary probability can be extended to analyse the tradeoff problem in other scenarios, such as for other continuous time queueing models, multiple user communication models, queueing models with service time control, and queueing models with general holding costs. Usually, queueing models with integer valued queue evolution, are approximated by queueing models with real valued queue evolution and strictly convex service cost functions for analytical tractability. Using the asymptotic bounds, we show that for some cases the average delay does not grow to infinity in the asymptotic regime, although the approximate model suggests that the average delay does grow to infinity. In other cases where the average delay does grow to infinity in the asymptotic regime, our results illustrate that the tradeoff behaviour of the approximate model is different from that of the original integer valued queueing model unless the service cost function is modelled as the piecewise linear lower convex envelope of the service cost function for the original model.

There is an increasing demand for multimedia services in heterogeneous wireless networks. Considering the highly dynamic wireless channels and the relatively large size of the multimedia data, how to support efficient and reliable multimedia delivery is a pressing issue. In this dissertation, we investigate the multimedia delivery algorithms in heterogeneous wireless networks from three different aspects. First, we study the single-flow rate adaptation of video streaming algorithm over multiple wireless interfaces. In order to maintain high video streaming quality while reducing the wireless service cost, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of service (QoS) requirements for video traffic, such as the startup latency, playback fluency, average playback quality, playback smoothness and wireless service cost. To solve the MDP in real time, we propose an adaptive, best-action search algorithm to obtain a sub-optimal solution. To evaluate the performance of the proposed adaptation algorithm, we implemented a testbed using the Android mobile phone and the Scalable Video Coding (SVC) codec and conducted experiments with real video flow. Then, with the multiple multimedia flows competing for limited wireless resources, we propose a utility-based scheduling algorithm for multimedia transmission in Drive-thru Internet. A utility model is devised to map the throughput to user's satisfaction level in terms of multimedia data quality, such as Peak Signal-to-Noise Ratio (PSNR) of video. The objective of the scheduling problem is to maximize the total utility. Then the optimization problem is formulated as a finite-state decision problem with the assumption that future arrival information is known, and it is solved by a searching algorithm as the benchmark. To obtain a real-time solution, a practical heuristic algorithm based on the concept of utility potential is devised. We further implemented the solution and conducted extensive simulations using NS-3. Finally, the multimedia dissemination problem in large-scale VANETs is investigated. We first utilize a hybrid-network framework to address the mobility and scalability issues in large-scale VANETs content distribution. Then, we formulate a utility-based maximization problem to find the best delivery strategy and select an optimal path for the multimedia data dissemination, where the utility function has taken the delivery delay, the Quality of Services (QoS) and the storage cost into consideration. We obtain the closed-form of the utility function, and then obtain the optimal solution of the problem with the convex optimization theory. Finally, we conducted extensive trace-driven simulations to evaluate the performance of the proposed algorithm with real traces collected by taxis in Shanghai. In summary, the research outcomes of the dissertation can contribute to three different aspects of multimedia delivery in heterogeneous wireless networks. First, we have proposed a real-time rate adaptation algorithm for video streaming with multiple wireless interfaces, to maintain the high quality while reducing the wireless services cost. Second, we have presented an optimal scheduling algorithm which can maximize the total satisfaction for multimedia transmission in Drive-thru Internet. Third, we have derived the theoretical analysis of the utility functions including delivery delay, QoS and the storage cost, and have obtained an optimal solution for multimedia data dissemination in large-scale VANETs to achieve the highest utility.
Graduate
0984
0544