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Error control coded data transmision over FM supplementary signal transmission radio channels13 October 2015 (has links)
M.Ing. (Electrical and Electronic Engineering) / With all the talk about the Information Highway and its construction, there is also a channel which is highly underestimated and thus almost ignored. On normal FM radio transmissions extra bandwidth exists, suitable for the transmission of audio and data. In this thesis the effects of interference on data transmission over the Supplementary Signal Transmission (SST) channel are analysed. The channel is characterized in terms of the Bit Error Rate (BER) versus field strength and distance from a transmitter ...
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Plane-Wave Scattering of a Periodic Corrugated CylinderUnknown Date (has links)
In this dissertation, a novel approach to modeling the scattered field of a periodic
corrugated cylinder, from an oblique incident planewave, is presented. The approach
utilizes radial waveguide approximations for fields within the corrugations, which are
point matched to approximated scattered fields outside of the corrugation to solve for the
expansion coefficients. The point matching is done with TMz and TEz modes
simultaneously, allowing for hybrid modes to exist.
The derivation of the fields and boundary conditions used are discussed in detail.
Axial and radial propagating modes for the scattered fields are derived and discussed.
Close treatment is given to field equations summation truncation and conversion to
matrix form, for numerical computing. A detailed account of the modeling approach
using Mathematica® and NCAlgebra for the noncommutative algebra, involved in
solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the
scattered field of a periodic corrugated cylinder. The model is configured to approximate
a smooth cylinder, which is then compared against that of a textbook standard smooth
cylinder. The methodology and analysis applied in this research provide a solution for
computational electromagnetics, RF communications, Radar systems and the like, for the
design, development, and analysis of such systems. Through the rapid modeling
techniques developed in this research, early knowledge discovery can be made allowing
for better more effective decision making to be made early in the design and investigation
process of an RF project. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
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Plane-Wave Scattering of a Periodic Corrugated CylinderUnknown Date (has links)
In this dissertation, a novel approach to modeling the scattered field of a periodic
corrugated cylinder, from an oblique incident planewave, is presented. The approach
utilizes radial waveguide approximations for fields within the corrugations, which are
point matched to approximated scattered fields outside of the corrugation to solve for the
expansion coefficients. The point matching is done with TMz and TEz modes
simultaneously, allowing for hybrid modes to exist.
The derivation of the fields and boundary conditions used are discussed in detail.
Axial and radial propagating modes for the scattered fields are derived and discussed.
Close treatment is given to field equations summation truncation and conversion to
matrix form, for numerical computing. A detailed account of the modeling approach
using Mathematica® and NCAlgebra for the noncommutative algebra, involved in
solving for the expansion coefficients, are also given. The modeling techniques offered provide a full description and prediction of the
scattered field of a periodic corrugated cylinder. The model is configured to approximate
a smooth cylinder, which is then compared against that of a textbook standard smooth
cylinder. The methodology and analysis applied in this research provide a solution for
computational electromagnetics, RF communications, Radar systems and the like, for the
design, development, and analysis of such systems. Through the rapid modeling
techniques developed in this research, early knowledge discovery can be made allowing
for better more effective decision making to be made early in the design and investigation
process of an RF project. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
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The value of item-level RFID in the supply chainGoebel, Christoph Michael 12 February 2010 (has links)
Diese Dissertation beschäftigt sich mit den Auswirkungen der Radiofrequenzidentifikation (RFID) auf das Lieferkettenmanagement. Wir entwickeln mehrere ökonomische Modelle zur quantitativen Evaluation der RFID-Technologie und den strategischen Implikationen ihres unternehmensübergreifenden Einsatzes. Dabei wenden wir uns insbesondere folgenden Forschungsfragen zu: (i) Welcher ökonomische Wert kann durch den Einsatz von RFID entlang der Lieferkette realisiert werden? (ii) Welche ökonomische Anreize haben die Teilnehmer von Lieferketten, RFID gemeinsam zu nutzen? (iii) Welche innovativen Praktiken im Bereich des Lieferkettenmanagements wird RFID ermöglichen und was ist der jeweilige Nutzen? Im Gegensatz zu früheren Untersuchungen konzentrieren wir uns auf die Bestimmung des Informations- bzw. Transformationsnutzens von RFID auf der Einzelteilebene in der Lieferkette bestimmter Konsumgüter. Das erste Kapitel der Dissertation enthält die notwendigen Hintergründe über die Möglichkeiten der RFID Technologie und ihr erwarteter Einfluss auf das Lieferkettenmanagement. Das zweite Kapitel untersucht die strategischen Konsequenzen der Möglichkeit, den Güterfluss in Lieferketten auf der Einzelteilebene zu überwachen. Im dritten Kapitel veranschaulichen wir den Wert der durch RFID ermöglichten Sichtbarkeit von Produkten in Einzelhandelsfilialen wenn die logistischen Prozesse durch verschiedene Fehlerarten, speziell Fehlplatzierungen, Schwund und Transaktionsfehler, beeinflusst werden. Im vierten Kapitel quantifizieren wir den Wert von Bestandsreallokationen zwischen Einzelhandelsfilialen – eine Praktik, die durch den Einsatz von RFID auf der Einzelteilebene ermöglicht werden könnte. Das fünfte Kapitel beschäftigt sich mit der Rolle des Austauschs von Logistikinformationen im Kontext der Vorwärtsintegration. Kapitel sechs beschließt die Dissertation und bietet Hinweise für weitere Forschungsvorhaben im Bereich des Wertes von RFID und entsprechender Einführungsstrategien an. / This dissertation investigates the impact of Radio Frequency Identification (RFID) on supply chain management. We develop several economic models that allow for a quantitative evaluation of RFID’s value and the strategic implications resulting from its inter-organizational use. Although the ongoing hype about RFID has lead to a high availability of general literature on RFID technology as well as numerous value propositions, the amount of quantitative research about RFID’s business value is still small. We address this research gap by investigating three research questions: (i) What economic value can be realized by deploying RFID along the supply chain? (ii) What economic incentives have supply chain participants to use RFID cooperatively? (iii) What innovative supply chain practices will RFID enable and what is their economic value? In contrast to earlier research, we constrain our research focus to the determination of the information and transformation value of item-level RFID in the supply chain of certain "high-impact" consumer products. The first chapter of this dissertation provides the necessary background about RFID’s capabilities and expected impact on supply chain management. The second chapter analyses the strategic consequences of being able to monitor the flow of goods in a supply chain on the item-level. The third chapter demonstrates the value of RFID-enabled visibility in retail stores if logistical operations are subject to certain kinds of error, in particular misplacements, shrinkage, and transaction errors. The fourth chapter investigates the value of item-level transshipments between retail stores – a practice that could be enabled by the use of item-level RFID. The fifth chapter deals with the role of logistical information sharing practices in the context of vertical integration strategies. Chapter six concludes the dissertation and provides hints for further research on RFID value and strategy.
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Performance analyses of Slotted ALOHA protocol in a Weibull fading environmentUnknown Date (has links)
In past and recent literature, random access protocols have been investigated with growing interest. In particular, the Slotted ALOHA protocol has been extensively used in satellite communications, and has also attracted considerable attention in many areas of wireless communication systems, especially in the cellular mobile environment. In this thesis, we investigate the performance of Slotted ALOHA, an effective random access protocol, in a Weibull fading environment. We study the performance metrics based on the signal-to-interference-and-noise ratio (SINR) model, in a cellular network system, assuming two captures models. The capture effect, also called co-channel interference tolerance, is the ability to correctly receive a strong signal from one transmitter despite significant interference from other transmitters. We derive closed-formed expressions and numerical evaluations for both the capture probability and the system throughput. he analytical results will be validated with computer simulations. Finally, to mitigate the effects of Weibull fading channel we also consider the effect of dual selection diversity that will increase the capture probability and the system throughput. / by Jean N. Rene. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
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Outdoor localization system for mobile robots based on radio-frequency signal strengthMaidana, Renan Guedes 02 March 2018 (has links)
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Previous issue date: 2018-03-02 / Na ?rea da Rob?tica M?vel, o problema da localiza??o ? definido como a determina??o da posi??o e orienta??o de um rob? em um espa?o tri-dimensional atrav?s de informa??es de seus sensores. A solu??o mais comum para esse problema ? utilizar um receptor de GPS (doingl?s, Global Positioning System), que reporta posi??o absoluta com rela??o a um sistema de coordenadas fixo e centralizado na Terra. Por?m, o sinal de GPS ? muito afetado por condi??es ambientais e oclus?o de linha de vis?o, por vezes fornecendo estimativas de posi??o de baixa qualidade, se houverem .Com inspira??o nestes problemas, este projeto prop?e um sistema de localiza??o para ser usado por um rob? terrestre em um ambiente externo n?o-controlado, onde h? indisponibilidade de GPS ou que suas medidas s?o de baixa qualidade. Tendo em vista que sensores de baixo custo apresentam medi??es imprecisas devido a fatores ambientais (e.g. terreno acidentado), ? proposta a
utiliza??o de pares receptor-transmissor de R?dio-Frequ?ncia, onde a medida do Indicador
de Pot?ncia de Sinal Recebido ? usada para estimar as dist?ncias entre receptor e trans-
missor, que s?o por sua vez usadas para posicionamento. Essa medida possuia vantagem
de ser independente da ilumina??o do ambiente e do estado do terreno, que afetam outros
m?todos de localiza??o como Odometria Visual ou por rodas. Um erro m?dio de posiciona-
mento de 0.41m foi alcan?ado atrav?s da fus?o de odometria por rodas, velocidade angular
de um girosc?pio e pot?ncia de sinal recebido, em um algoritmo de Filtro de Kalman Esten-
dido Aumentado, comum a melhoria de 82.66% referente ao erro m?dio de 2.38 m obtido
com um sensor GPS comum. / In the field of Mobile Robotics, the localization problem consists on determining a robot?s position and orientation in a three-dimensional space through sensor information. The most common solution to this problem is to employ a Global Positioning System receiver, also known as GPS, which reports absolute position in relation to an Earth-centered fixed coordinate system. However, GPS signals are greatly affected by atmospheric conditions and line-of-sight occlusion, sometimes providing very poor position estimates, if any at all. Inspired by these problems, this project proposes a localization system to be used by a robot in an uncontrolled outdoor environment, where GPS measurements are poor or unavailable. As common sensors provide inaccurate position estimates due to environmental factors (e.g. rough terrain), we propose the use of Radio-Frequency receiver-transmitter pairs, in which the Received Signal Strength Indicator is used for estimating the distances between receiver and transmitter, which in turn are used for positioning. This measurement has the advantage of being independent from lighting conditions or the state of the terrain, factors which affect other localization methods such as visual or wheel odometry. A mean positioning error of 0.41 m was achieved by fusing wheel odometry, angular velocity from a gyroscope and the received signal strength, in an Augmented Extended Kalman Filter algorithm, with an improvement of 82.66% relative to the mean error of 2.38 m obtained with a common GPS sensor.
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Avalia??o de transmiss?o de fluxo cont?nuo de v?deo em redes IP sem fio Padr?o IEEE 802.11b e 802.11gFerreira, Gildevane Aparecido 25 February 2008 (has links)
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Previous issue date: 2008-02-25 / This MSc. thesis presents new results of activities with the development and characterization on RF devices operating on the 2,4 GHz channel, which has been done using a flat fast fading emulator. This RF emulator has been developed with the use of electronic circuits between them, and the presence of an attenuator which can be controlled by software and another one controlled by a power supply. The performance and characterization of the emulator has been done with some tests of video streaming links. The essential purpose is to present a simple and efficient approach to implement a testbed emulation of flat fast fading that can allow the RF signal to be confined inside a coaxial cable, where there is a controlled ambient whose permits to investigate the performance over all wireless networks. We perform also in this work some comparison to evaluate the behavior of both the 802.11b and 802.11g standards in flat fast fading channel through a video transmission and a further analysis of the jitter in many different power levels of the signal by assuming that the emulator has a perfect control of the system. / An?lise comparativa do desempenho das redes locais sem fio (WLANs), padr?o IEEE 802.11b e 802.11g, na transmiss?o de fluxo cont?nuo de v?deo, tamb?m conhecido como streaming de v?deo, simulando caracter?sticas de uma transmiss?o de v?deo em formato IPTV, com o intuito de identificar qual dos dois padr?es tem melhor desempenho na transmiss?o desse tipo de tr?fego. Esse trabalho foi motivado pela necessidade de implanta??o da segunda fase do projeto Exibe da TV PUC Campinas, que prev? a distribui??o da programa??o do canal universit?rio, em formato IPTV, atrav?s de redes IP sem fio. Para simula??o desse sistema de distribui??o de v?deo, foram feitas an?lises das caracter?sticas de distribui??o, transmiss?o e formatos do v?deo transmitido. As transmiss?es foram realizadas com o uso de um emulador de R?dio Freq??ncia que disp?e de dois atenuadores, um controlado por software e outro por uma fonte de tens?o. O emulador pode proporcionar um ambiente controlado, onde todas as transmiss?es puderam ser realizadas utilizando os dois padr?es de rede, garantindo uma correta identifica??o do canal, controle das atenua??es e acompanhamento dos fen?menos de propaga??o.
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Desenvolvimento de um modelo de referência para a aplicação da tecnologia RFID na logística de ambulatórios de ensino / Development of a reference model for RFID application in the teaching ambulatory logisticsBarbosa, Danilo Hisano 19 November 2012 (has links)
As aplicações da tecnologia de identificação por radiofrequência (RFID) em hospitais movimenta uma importante área de estudo no setor de saúde. Acompanhando o crescente número de trabalhos na área, encontra-se a necessidade de sistematização e categorização destas aplicações e de estudos que apresente soluções para o processo logístico hospitalar, particularmente, sob a perspectiva do fluxo de pacientes em ambulatórios de ensino. Diante deste cenário, a presente tese propõe um modelo de referência para a identificação e análise de aplicações RFID, considerando o objeto de estudo em questão. A revisão da literatura inicia-se abordando a Logística Hospitalar, apresentando os principais autores e correntes dessa área de pesquisa, apontando para a importância do fluxo de pacientes como elemento direcionador dos demais fluxos logísticos. Em seguida, é realizado um levantamento e categorização das aplicações da RFID em organizações hospitalares, permitindo a análise e o entendimento de suas principais características. Dessa forma, três bases apoiam o método de pesquisa. O primeiro é a revisão bibliográfica. O segundo é a metodologia para o desenvolvimento de modelos de referência na área de TI e por final, a avaliação do modelo por profissionais de saúde e TI, futuros usuários do modelo. Como contribuição da pesquisa, destaca-se o desenvolvimento e prescrição de um conjunto de atividades voltadas à identificação e análise de aplicações RFID dentro da visão de Logística Hospitalar, objetivando uma maior aproximação entre profissionais de saúde e TI na etapa de planejamento do processo de implantação da tecnologia em um ambiente ambulatorial de ensino. / The applications of radio frequency identification technology (RFID) in hospitals move an important area of study in the healthcare. Accompanying the growing body of research on this topic, there is a need for systematization of such applications and proposals for solutions to the hospital logistics processes, particularly from the perspective of patient flow logistics in teaching ambulatory care setting. In this way, this thesis proposes a reference model for the identification and analysis of RFID applications, considering this object of research. The literature review begins by addressing the hospital logistics management, presenting the main authors of this emerging area of research, pointing to the importance of patient flow. Next, we conducted a review and categorization of RFID applications in hospital organizations, theme of this research, allowing the analysis and understanding of its main characteristics. Thus, three bases support the research method. The first is the literature review. The second is the methods for reference model development in IT field and the third, the evaluation by health and IT professionals, potential users of model. As a research contribution, a set of activities designed to identifying and analyzing RFID applications in hospital logistics was developed, aimed to approach health and IT professionals in the planning stage of RFID implementation process.
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Study of spectral regrowth and harmonic tuning in microwave power amplifier.January 2000 (has links)
Kwok Pui-ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves [79]-85). / Abstracts in English and Chinese. / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- NONLINEAR BEHAVIOR OF RF POWER AMPLIFIERS --- p.5 / Chapter 2.1 --- Single Tone Excitation --- p.6 / Chapter 2.1.1 --- AM-AM Conversion --- p.7 / Chapter 2.1.2 --- AM-PM Conversion --- p.9 / Chapter 2.2 --- Two-Tone Excitation --- p.11 / Chapter 2.2.1 --- Intermodulation Distortion --- p.12 / Chapter 2.3 --- Digitally Modulated Signal Excitation --- p.13 / Chapter 2.3.1 --- Spectral Regeneration --- p.14 / Chapter 2.3.2 --- Adjacent Channel Power Ratio (ACPR) --- p.16 / Chapter CHAPTER 3 --- LINEARIZATION TECHNIQUES --- p.18 / Chapter 3.1 --- pre-distortion --- p.20 / Chapter 3.2 --- Feed-forward Techniques --- p.23 / Chapter 3.3 --- Harmonics Control Techniques --- p.24 / Chapter CHAPTER 4 --- SPECTRAL REGROWTH ANALYSIS USING VOLTERRA SERIES METHOD --- p.26 / Chapter 4.1 --- Introduction To Volterra Series Analysis --- p.27 / Chapter 4.1.1 --- Linear and Nonlinear Systems --- p.27 / Chapter 4.1.2 --- Evaluation of Volterra transfer function --- p.29 / Chapter 4.1.3 --- Volterra Series Analysis of Spectral Regrowth --- p.31 / Chapter 4.2 --- Nonlinear Model of GaAs MESFET Device --- p.33 / Chapter 4.3 --- Evaluation Of Nonlinear Responses --- p.35 / Chapter 4.3.1 --- First-Order Response --- p.36 / Chapter 4.3.2 --- Second-Order Response --- p.38 / Chapter 4.3.3 --- Third-Order Response --- p.39 / Chapter CHAPTER 5 --- EFFECT OF HARMONIC TUNING ON SPECTRAL REGROWTH --- p.42 / Chapter 5.1 --- Simulation of Digitally Modulated Signal --- p.43 / Chapter 5.2 --- Effect of Source Second Harmonic Termination --- p.44 / Chapter CHAPTER 6 --- EXPERIMENTAL VERIFICATION --- p.48 / Chapter 6.1 --- Circuit Design and Construction --- p.49 / Chapter 6.2 --- Setup and Measurement --- p.55 / Chapter 6.3 --- Experimental Results --- p.56 / Chapter 6.3.1 --- Small Signal Measurement --- p.56 / Chapter 6.3.2 --- Single Tone Characterization --- p.57 / Chapter 6.3.3 --- Two-Tone Characterization --- p.59 / Chapter 6.3.4 --- ACPR Characterization --- p.60 / Chapter 6.4 --- Comparison of Measurement and Simulation --- p.66 / Chapter CHAPTER 7 --- NONLINEAR TRANSCONDUCTANCE COEFFICIENTS EXTRACTION --- p.68 / Chapter 7.1 --- Large Signal Model --- p.69 / Chapter 7.2 --- Extraction of Nonlinear Transconductance --- p.71 / Chapter 7.2.1 --- Extraction of g1 --- p.71 / Chapter 7.2.2 --- Extraction of g2 and g3 --- p.72 / Chapter CHAPTER 8 --- CONCLUSION --- p.76 / FUTURE WORK RECOMMENDATION --- p.78 / REFERENCE
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Utilising radio-frequency identification technologies as knowledge management enablers in academic libraries: a case study of the University of South AfricaMogiba, Ntombizandile Cynthia 27 July 2018 (has links)
The quest to generate, preserve and utilise knowledge is driving firms and organisations towards a knowledge-based approach to managing organisational knowledge assets. Therefore, knowledge management (KM) is becoming increasingly important for organisations such as academic libraries to enhance their competitive edge in performance, to become more effective and to keep the organisation’s knowledge for future use. The importance of KM cannot be overemphasised in terms of how academic libraries can find meaningful and effective ways to manage knowledge resources to improve the services rendered to information users. Pressure is mounting for academic libraries to attain, retain and share knowledge for strategic planning, decision-making and remaining competitive. The adoption of radio-frequency identification (RFID) technologies is one of the preferred approaches to managing organisational knowledge assets; therefore, this was the motivation for undertaking this study in order to understand how these new technologies can change the knowledge management landscape in academic libraries.
A qualitative research methodology, informed by the interpretivist research philosophy, was adopted in this study. Data were collected from a sample of 12 participants using non-probability purposive and convenience sampling techniques. The use of purposive and convenience techniques was ideal for this study because the participants were readily available and possessed the relevant data required to address the research questions and research problem of the study. Open-ended questions were designed to form an interview guide, which was the main data collection instrument. Annual reports, system manuals and user manuals were consulted to augment the primary data collected to address the problem at hand. The findings from the study showed that RFID technologies improved efficiency, tracking and tracing, inventory management and assisted with planning. It was revealed that users of RFID technologies required further training and development to fully utilise these systems for the benefit of the organisation.
The study was conducted using a small sample of 12 participants; therefore, it was recommended that further studies could be conducted with large sample sizes using different research strategies. It was suggested that further research should be conducted to establish how change programmes have been managed before in other departments or sections and how the staff exodus was managed. An organisation-wide research would be recommended to ascertain the views and opinions of a larger population so that findings can be generalisable. / Information Science / M. Inf. (Information Science)
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