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Projeto e construção de um restaurador dinâmico de tensão. / Project and construction of a dynamic voltage restorer.Galassi, Maurício 27 March 2006 (has links)
A crescente utilização de cargas sensíveis em aplicações industriais, atualmente tem levado a uma preocupação real devido aos custos provocados por interrupções e danos causados a linhas de produção automatizadas. Este trabalho apresenta uma solução baseada em sistemas de eletrônica de potência capaz de compensar Voltage Sags, Voltage Swells e distorções harmônicas de tensão, restaurando a tensão da carga a valores aceitáveis através de um transformador de injeção conectado em série entre a rede e a carga. As características de projeto para um protótipo de Restaurador Dinâmico de Tensão (DVR) são detalhadas, estratégias de controle são comparadas e uma das alternativas é implementada em um DSP (Digital Signal Processor). Finalmente, resultados experimentais de um protótipo de 5kVA são apresentados. / The increasing use of voltage sensitive loads on industrial applications has led to a real concern about interruption costs and damages on automatic production lines. This work presents a power-electronic-based device which compensates Voltage Sags, Voltage Swells and Voltage Harmonic Distortion, restoring the load voltage to acceptable values through a series connected injection transformer. The ratings and power requirements of a Dynamic Voltage Restorer (DVR) are derived, as well as its control algorithm implemented in a Digital Signal Processor (DSP). Finally, simulation and experimental results of a 5kVA prototype are presented.
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Projeto e construção de um restaurador dinâmico de tensão. / Project and construction of a dynamic voltage restorer.Maurício Galassi 27 March 2006 (has links)
A crescente utilização de cargas sensíveis em aplicações industriais, atualmente tem levado a uma preocupação real devido aos custos provocados por interrupções e danos causados a linhas de produção automatizadas. Este trabalho apresenta uma solução baseada em sistemas de eletrônica de potência capaz de compensar Voltage Sags, Voltage Swells e distorções harmônicas de tensão, restaurando a tensão da carga a valores aceitáveis através de um transformador de injeção conectado em série entre a rede e a carga. As características de projeto para um protótipo de Restaurador Dinâmico de Tensão (DVR) são detalhadas, estratégias de controle são comparadas e uma das alternativas é implementada em um DSP (Digital Signal Processor). Finalmente, resultados experimentais de um protótipo de 5kVA são apresentados. / The increasing use of voltage sensitive loads on industrial applications has led to a real concern about interruption costs and damages on automatic production lines. This work presents a power-electronic-based device which compensates Voltage Sags, Voltage Swells and Voltage Harmonic Distortion, restoring the load voltage to acceptable values through a series connected injection transformer. The ratings and power requirements of a Dynamic Voltage Restorer (DVR) are derived, as well as its control algorithm implemented in a Digital Signal Processor (DSP). Finally, simulation and experimental results of a 5kVA prototype are presented.
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A Household Level Model of Television Viewing with Implications for Advertising TargetingDeng, Yiting January 2015 (has links)
<p>Television (TV) is the predominant advertising medium, and recent technological advances such as digital video recorders (DVRs) and set-top boxes (STBs) have the potential to transform this industry by enabling household-specific advertising. Since exposure to TV represents a substantial share of consumer time and attention, this potential to micro-target communications represents an enormous opportunity for the TV advertising market. </p><p>This paper outlines an approach to facilitate the micro-targeting of TV advertising. We employ a unique dataset, integrating TV program and advertisement viewing at the household level with purchase data, to address the question of how advertisers can achieve better advertising targeting in the digital context. Based on this dataset, we first develop a model of household TV viewing behavior. The viewing model comprises three integrated components: TV show sampling and watching, TV show recording, and advertising viewing. All three components are motivated by the theoretical concept of flow utility, that is, the moment-by-moment enjoyment a household derives from different activities: watching a TV show, watching a TV advertisement, and other non-TV activities. This model has decent out-of-sample prediction power on show choices and time spent on each selected show. We then link household advertising exposure with purchase. Finally, the viewing model and identified advertising-sales relationship are utilized to conduct counterfactual policy experiments on advertising targeting. We consider several household-level targeting scenarios by manipulating: 1) whether the advertising purchase is made in advance; and 2) whether the objective function is to minimize costs for a given set of exposures or to maximize revenues from advertising. Results indicate micro-targeting can lower advertising costs and raise incremental revenue.</p><p>The key contributions of this paper are as follows. Theoretically, we develop an integrated model on TV show viewing, TV advertising viewing, purchasing and advertising targeting. Methodologically, we propose a new modeling framework on media consumption by explicitly accounting for the role of uncertainty, and propose targeting strategies leveraging household-level data. Substantively, we offer policy recommendations to advertisers on micro-targeting which can be of great potential.</p> / Dissertation
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The reshaping of the traditional television advertising model: An analysis of media agency perceptions and decision-making processes regarding the effects of digital video recorders on television commercial effectiveness.Way, Heather C. 08 1900 (has links)
This research analyzes media agency executives' perceptions and strategic decision-making processes when accessing the impact of digital video recorders (DVRs) on the traditional television commercial spot. Strategic decision-making models, as well as major industry research, forms the theoretical framework used to guide the study. The research takes a quantitative approach using a survey in order to obtain the perceptions and decision-making processes of the media agency executives'. The findings are presented while a discussion of the findings is detailed. The thesis concludes with a summary of the overall thesis research as applied to the field of study.
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Desenvolupament de mètodes estàtics i dinàmics per a la caracterització de la funció d'ona nuclear. Aplicació a l'estudi de l'estructura, constants d'equilibri i la dinàmica de sistemes químicsTorres Casas, Laia 29 January 2003 (has links)
La protagonista d'aquesta tesi doctoral és la funció d'ona nuclear. Tot i que la majoria d'estudis de química teòrica basen els seus raonaments només en càlculs electrònics, la funció d'ona nuclear és essencial per a compendre gran quantitat de fenòmens químics i per això és necessari avançar en el seu càlcul. Els objectius de la tesi es poden dividir en dos grans blocs: (I) el desenvolupament de mètodes que ens permetin caracteritzar la funció d'ona nuclear i (II) l'aplicació d'aquests mètodes en la comprensió de fenòmens químics en els cuals es manifesta la seva deslocalització. En l'apartat de resultats s'inclouen cinc treballs diferents que combinen aplicació i desenvolupament. El primer treball se centra en un estudi de les vibracions de la molècula de CO adsorbida sobre una superfície de Pt, en el cual es resol el problema que planteja la manca d'ortogonalitat entre els dos moviments estudiats (Pt-CO i C-O). S'implementa l'anomenada transformació afí que permet passar d'un sistema de coordenades no ortogonals a un sistema de coordenades ortogonals, fent així possible l'aplicació del mètode estàtic DVR (Discrete Variable Representation).En el segon treball [1] s'estudia la desviació de la linealitat de la Llei d'Arrhenius en la doble transferència protònica intramolecular que es produeix en les dues oxalamidines bicícliques 2,2'-bis(3,4,5,6-tetraahidro-1,3-diazina) (OA6) i 2,2'-bis(4,5,6,7-tetrahidro-1,3-diacepina) (OA7). El disseny i l'ús d'un potencial analític bidimensional que inclou els punts estacionaris implicats en els dos mecanismes que fan possible la transferència permet obtenir els valors propis característics del sistema. La menor densitat de l'espectre vibracional de l'OA6 permet explicar que experimentalment (1H RMN en el rang de temperatures 280-910 K) només es detecti doble transferència protònica intramolecular en l'OA7.En el tercer treball [2] es desenvolupa un mètode que permet incloure l'anharmonicitat de les interaccions nuclears en el càlcul de magnituds termodinàmiques i s'aplica a l'estudi de l'Efecte Isotòpic d'Equilibri (EIE) del procés d'addició de H2 en tres complexes organometàlics: W(CO)3(PCy3)2(h2-H2), [Ru(HLH)(C5Me5)(dppm)]+ i trans-[Os(HLH)Cl(dppe)2]+. Els resultats mostren que l'EIE harmònic (calculat en el marc de l'aproximació harmònica) és invers (<1) en els tres complexos, mentre que l'EIE anharmònic (calculat incorporant anharmonicitat) segueix essent invers en el complex de W però esdevé normal (>1) en els complexos de Ru i Os.En el quart treball [3] s'aplica el mètode desenvolupat en el treball anterior a l'estudi de l'Efecte Isotòpic d'Equilibri del tautomerisme dihidrur/dihidrogen (EIET) del complex de Kubas W(CO)3(PCy3)2(h2-H2). Els resultats mostren que tant l'EIET harmònic com l'EIET anharmònic són inversos (<1).En el cinquè i darrer treball [4] s'estudia l'estructura del complex de dihidrogen allargat [Ru(HLH)(C5Me5)(dppm)]+ per tal de validar l'ús de l'estratègia semiclàssica en aquest tipus de problemes químics. Es posa a punt un mètode que combina l'SC-HK-IVR (Semiclassical Herrman Kluk Initial Value Representation) amb el mètode espectral i es comparen els resultats SC-HK-IVR amb els resultats que s'obtenen a partir d'un càlcul DVR realitzat sobre la mateixa superfície d'energia potencial. El bon acord entre els dos grups de resultats mostra la validesa de l'estratègia semiclàssica en la descripció de l'estructura molecular i la presenta com una bona solució al problema dinàmic de la reducció dimensional. / The main character of this doctoral thesis is the nuclear wave function. Although most of theoretical studies are based only on electronic calculations, nuclear wave function is essential for the comprehension of an important amount of chemical fenomena and that is the reason why going forward on dynamical methods is necessary. The purposes of this thesis are: (I) the development of methods for the calculation of the nuclear wave function and (II) application of the former methods on the comprehension of chemical fenomena where delocalisation shows up. Results appear in five different works which combine application and development.The first work is based on a study of the stretching vibrations of a CO molecule adsorbed on a Pt surface, where the problem derived from the lack of ortogonality between the studied movements (Pt-CO and C-O) is solved. The so called Affine Transformation is implemented, which transforms a non ortogonal coordinate system into an ortogonal coordinate system and so it allows the application of the static method DVR (Discrete Variable Representation) to the CO-Pt system.In the second work [1] the deviation of the Arrhenius Law lineality is studied in the intramolecular double proton transfer occurred in the bicyclic oxalamidines 2,2'-bis(3,4,5,6-tetraahidro-1,3-diazine) (OA6) and 2,2'-bis(4,5,6,7-tetrahidro-1,3-diacepine) (OA7). Design and use of a bidimensional analitic potential which includes all stationary points involved in the two possible mechanisms allows the obtention of the system eigenvalues. The smaller vibrational spectrum density in OA6 explains the experimental results (1H RMN in the temperature range of 280-910 K) which indicates that only OA7 shows intramolecular double proton transfer.In the third work [2] a method which accounts for anharmonicity in the calculation of termodynamic magnitudes is developed and applied to the study of the Equilibrium Isotope Effect (EIE) of the H2 binding in three organometallic complexes: W(CO)3(PCy3)2(h2-H2), [Ru(HLH)(C5Me5)(dppm)]+ and trans-[Os(HLH)Cl(dppe)2]+. Results show that harmonic EIE (calculated within the harmonic approximation) is inverse (<1) for the three complexes, while anharmonic EIE (which includes anharmonicity) is also invers for the W complex but becomes normal (>1) for the Ru and Os complexes.In the fourth work [3] the method developed in the former job [2] is applied on the study of the Equilibrium Isotope Effect of the dihydrogen/dihidride tautomerism (EIET) of the Kubas complex W(CO)3(PCy3)2(h2-H2). Results show that harmonic EIET and anharmonic EIET are both inverse (<1).In the fifth and last work [4] the structure of the elongated dihydrogen complex [Ru(HLH)(C5Me5)(dppm)]+ is studied with the purpose of validate the use of the semiclassical strategy in this kind of chemical problems. A method which combines SC-HK-IVR (Semiclassical Herrman Kluk Initial Value Representation) and a spectral method is prepared and SC-HK-IVR results are compared with those obtained from DVR calculations over the same PES. Good agreement between both groups of results shows the validity of the semiclassic strategy in the description of molecular structures and presents it as a reliable solution to the dynamic problem of the dimensional reduction.
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以4C策略行銷理論分析安全監控產業-以H公司為例鄭子釗 Unknown Date (has links)
安全監控產業在美國遭受911恐怖攻擊世事件後,加上隨後英國、西班牙、印尼峇里島等陸續遭到爆炸恐怖攻擊,造成嚴重的生命財產損失,因而喚起各國政府對安全防護的重視,所以該產業隨之發展迅速,但也相對的吸引了其它相對低毛利的產業競相跨足進入此一新興產業,而使得原本一個不顯眼的產業一下子熱絡了起來,當然競爭的情況也日益加劇。
安全監控未來的發展將會朝向數位化、網路化以及系統整合方向發展,此乃世界潮流之趨勢,其中又以網路攝影機及NVR網路數位式錄影軟體、DVR數位式錄影機等所扮演之角色日趨重要。
如何在這個具有高度競爭的產業脫穎而出,筆者以波特的五力分析模型及邱志聖的4C策略行銷架構剖析H公司所從事之安控產業的競爭現況後,得到的結論認為:
若單以成本優勢為主要策略而不搭配其產品功能效益是不易成功的,廠商應該以長期投入研發、配合降低成本,以市場需求為導向,而突顯出產品價值才有可能勝出。從長期培養客戶關係著手,隨時提供最新產品資訊或者公司未來將要開發的產品,以降低客戶對現在及未來產品的資訊蒐集成本。與上游供應商保持密切合作關係,如IC設計開發公司智原以及與SONY、 PANASONIC等CCD元件供應商持續合作,並提供良好的售後服務,以降低客戶的道德危機成本等。透過軟體的高度整合以及提供良好的客製化服務及產品,使客戶消除專屬陷入成本的疑慮,以上將是H公司對未來發展重要參考策略,或者可為有意加入此行業的新進者做為參考方向。
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Avaliação do desempenho do restaurador dinâmico de tensão frente aos afundamentos e elevações de tensãoJesus, Daniel Maia Fonseca de 03 August 2006 (has links)
Nowadays, national and international electric utilities and end users are
becoming more and more concerned about the quality of the electrical power.
Such concerns are related with the occurrence of electric disturbances capable
to effect the operation and the life expectance of equipments and devices, as well
as affecting and interrupting varied industrial processes. Of the above
mentioned phenomena, short-duration voltage variations deserve special
attention once they are the disturbances that cause the largest damages to the
consumers. As a consequence of that, there are several devices available that
minimize the effects of such disturbances on the equipments. Among those
devices, the Dynamic Voltage Restorer (DVR) represents a modern proposal for
the solution of the problems caused by voltage sags and swells. In this work,
three different system topologies for DVRs are analysed throughout computer
implementations. Comparisons are made between these topologies, with focus
on both the general performance and on the electrical power quality of the
entire system. / As preocupações com os diversos assuntos relacionados à Qualidade da Energia
Elétrica têm sido cada vez mais comuns às empresas de energia e aos
consumidores em geral, e vêm assumindo importância destacada nos cenários
nacional e internacional. Tais preocupações são voltadas para a ocorrência de
distúrbios elétricos capazes de comprometer o desempenho e a vida útil de
equipamentos e dispositivos, além de afetar ou interromper variados processos
industriais. Desses distúrbios, as VTCDs (Variações de Tensão de Curta
Duração) são consideradas as que mais causam prejuízos aos consumidores.
Com isso, já existe na literatura técnica uma série de metodologias de prevenção
e variados dispositivos de atenuação dos efeitos das VTCDs. Destes
dispositivos, destaca-se o Restaurador Dinâmico de Tensão (DVR Dynamic
Voltage Restorer) que é um compensador estático série avançado aplicado à
distribuição de energia elétrica e que representa hoje o que há de mais moderno
em termos de mitigação de afundamentos e elevações de tensão. O presente
trabalho visa contribuir para o estudo do desempenho de algumas topologias de
DVR, comparando a atuação de três opções de configuração através de
simulações computacionais em plataforma SABER. A análise comparativa do
desempenho das topologias não considera apenas a eficiência na compensação
dos distúrbios elétricos, mas também os efeitos que causam na qualidade da
tensão do sistema elétrico, sejam por injeção de harmônicos ou por oscilações
transitórias. / Mestre em Ciências
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Design and implementation of recording functionality for an IP-based set-top box / Design och implementation av inspelningsfunktionalitet för en IP-baserad set-top-boxGusic, Aner January 2004 (has links)
<p>This theses covers the design and implementation of recording functionality for a set-top box in a home network. An initial investigation is done and possibilities for extending the system to support specific features are presented. </p><p>Digital TV is becoming more common each day, and soon it will be more widely used than todays analogue standard. At the same time the need for recording TV shows remains the same or is increasing, which is shown by the number of PVR solutions popping up on the market. </p><p>The goal of this thesis work was to investigate the possibilities for extending an existing set-top box to support common PVR features and, if possible, to implement a prototype. This was supposed to be done in a home network environment with the set-top box as the digital media center. </p><p>A satisfying solution, covering basic recording functionality is defined and implemented. The solution includes recording to a USB hard drive and to a PC on the local network. On top of this, a graphical user interface is built and some simple benchmarks show the performance of the set-top box with the new functionality.</p>
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Design and implementation of recording functionality for an IP-based set-top box / Design och implementation av inspelningsfunktionalitet för en IP-baserad set-top-boxGusic, Aner January 2004 (has links)
This theses covers the design and implementation of recording functionality for a set-top box in a home network. An initial investigation is done and possibilities for extending the system to support specific features are presented. Digital TV is becoming more common each day, and soon it will be more widely used than todays analogue standard. At the same time the need for recording TV shows remains the same or is increasing, which is shown by the number of PVR solutions popping up on the market. The goal of this thesis work was to investigate the possibilities for extending an existing set-top box to support common PVR features and, if possible, to implement a prototype. This was supposed to be done in a home network environment with the set-top box as the digital media center. A satisfying solution, covering basic recording functionality is defined and implemented. The solution includes recording to a USB hard drive and to a PC on the local network. On top of this, a graphical user interface is built and some simple benchmarks show the performance of the set-top box with the new functionality.
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Commercial Media Viewing Habits: Digital Natives vs. Digital ImmigrantsKing, Brian J. 20 November 2009 (has links)
No description available.
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