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Tools assisted analog design, from reconfigurable design to analog design automation. / CUHK electronic theses & dissertations collectionJanuary 2011 (has links)
To solve these issues, in this thesis the consistent effort in developing a quick tools assisted IC design platform is presented. First, a reconfigurable solution is proposed for some analog/mixed-signal (AMS) system which requires flexibility to a certain extent, such as a reconfigurable RFID solution for different communicating distances. Second, for further demand of increasing the flexibility, a novel approach for ADA is presented, which provides a highly automatic design flow for analog circuits to realize the "SPEC (Specification) in, GDS out" goal. Considering all kinds of higher order effects and uncertainties under deep submicron or even more advanced technologies, reliable design and fastness in processing are the two major concerns instead of the traditional pure optimization for best performance. To get a good balance among performance, reliability and turnaround time, an Application-Specific design flow with in-built knowledge-based algorithms is applied to deal with ADA issues under advanced technologies, which can quickly provide a reliable design with performance good enough to meet the SPECs for common use. / Unlike the highly automatic flow for digital circuits design, analog design automation (ADA) is still far from mature. For mixed-signal applications, analog circuit occupies only a small part on the layout, but the design requires a considerable amount of time and effort, making ADA extremely attractive. However, there are a lot more considerations to cover in analog design flow than its digital counterparts. In addition, the ever downscaling IC means analog circuits have to face more and more small-size effects, insufficient modelings, and the inaccuracy of classic formulas, which are quite difficult to handle. To solve the problem, various tools and methods have been proposed, but all in a digital-like flow, which are trying to develop general algorithms to realize circuit and layout synthesis. Up to now there is still a lot of problems. / Hong, Yang. / Adviser: C.S. Choy. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 140-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Avaliação de projetos logísticos de RFID aplicados na indústria aeronáutica brasileira /Castro, Jefferson Inácio de. January 2014 (has links)
Orientador: Jorge Muniz Junior / Coorientador: José Arnaldo Barra Montevechi / Banca: Valério Pamplona Salomon / Banca: Luis Alberto Ducan Rangel / Resumo: A tecnologia de Radio Frequency Identification (RFID) tornou-se um tema importante desde 2006, quando vários autores começaram a avaliá-la. A aplicação de RFID para processos industriais tem uma abordagem estratégica, objetivando a melhoria da satisfação dos clientes e criar novas oportunidades de negócios, bem como uma abordagem operacional com foco na eficiência operacional e na flexibilidade dos processos. A tecnologia é aplicada na logística e nos demais processos da cadeia de suprimentos com o objetivo do rastreamento dos materiais, aumento de visibilidade, aumento da eficiência operacional, redução dos desvios do processo e aumento da acessibilidade do inventário. Neste cenário, a presente dissertação tem como objetivo a avaliação de projetos logísticos aplicados à indústria aeronáutica brasileira com o uso do AHP - Analytic Hierarchy Process com ratings - passando pela identificação e avaliação das características que motivam e restringem a utilização da tecnologia através de uma revisão da literatura e pesquisa de campo / Abstract: Research on Radio Frequency Identification technology (RFID) has become an important issue since 2006 and several authors have begun to assess this technology. The application of RFID to industrial processes has a strategic approach, seeking to improve customer satisfaction and new business opportunities, and has an operational approach focusing on operational efficiency and flexibility of the processes. There is a great application of RFID in logistics, warehouse and supply chain processes seeking tracking materials, increase supply chain visibility, labor savings, shrinkage reduction and inventory visibility. In this scenario, this paper aims to evaluate logistics projects applied to the brazilian aircraft industry using the AHP - Analytic Hierarchy Process with ratings, in addition to the identification and evaluation of the characteristics that motivate and restrict the use of technology through a literature review and a survey / Mestre
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Fast RFID counting under unreliable radio channels.January 2009 (has links)
Sze, Wai Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 77-83). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background and Related Work --- p.8 / Chapter 3 --- RFID Tag-set Cardinality estimation based on a Two-parameter implicit Channel Model --- p.13 / Chapter 3.1 --- System Model --- p.14 / Chapter 3.2 --- Number of Empty Slots Observed by the Reader --- p.16 / Chapter 3.3 --- Estimator Accuracy and Performance Analysis --- p.25 / Chapter 3.4 --- Results and Discussions --- p.32 / Chapter 3.5 --- Chapter Summary --- p.41 / Chapter 4 --- RFID Tag-set Cardinality estimation over Unknown Channel --- p.42 / Chapter 4.1 --- System Model --- p.43 / Chapter 4.2 --- Baseline: The Union-based approach --- p.45 / Chapter 4.2.1 --- Motivation --- p.46 / Chapter 4.2.2 --- Union Algorithm --- p.46 / Chapter 4.2.3 --- Analysis of the Union algorithm --- p.47 / Chapter 4.3 --- "Probabilistic Tag-counting over Lossy, Unknown channels via the Mh model" --- p.52 / Chapter 4.3.1 --- "Novel Interpretation of Mh for RFID Counting over Lossy, Unknown Channels" --- p.52 / Chapter 4.3.2 --- The Moment Estimator --- p.55 / Chapter 4.3.3 --- Sample Coverage Estimator --- p.57 / Chapter 4.3.4 --- Estimating the overall Tag population t --- p.59 / Chapter 4.4 --- Performance Validation and Comparison --- p.62 / Chapter 4.5 --- Chapter Summary --- p.65 / Chapter 5 --- Conclusions and Future Work --- p.73 / Chapter A --- Proof of Equation (3.6) in Chapter 3 --- p.75 / Bibliography --- p.77
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Text-Independent Speaker Recognition Using Source Based FeaturesWildermoth, Brett Richard, n/a January 2001 (has links)
Speech signal is basically meant to carry the information about the linguistic message. But, it also contains the speaker-specific information. It is generated by acoustically exciting the cavities of the mouth and nose, and can be used to recognize (identify/verify) a person. This thesis deals with the speaker identification task; i.e., to find the identity of a person using his/her speech from a group of persons already enrolled during the training phase. Listeners use many audible cues in identifying speakers. These cues range from high level cues such as semantics and linguistics of the speech, to low level cues relating to the speaker's vocal tract and voice source characteristics. Generally, the vocal tract characteristics are modeled in modern day speaker identification systems by cepstral coefficients. Although, these coeficients are good at representing vocal tract information, they can be supplemented by using both pitch and voicing information. Pitch provides very important and useful information for identifying speakers. In the current speaker recognition systems, it is very rarely used as it cannot be reliably extracted, and is not always present in the speech signal. In this thesis, an attempt is made to utilize this pitch and voicing information for speaker identification. This thesis illustrates, through the use of a text-independent speaker identification system, the reasonable performance of the cepstral coefficients, achieving an identification error of 6%. Using pitch as a feature in a straight forward manner results in identification errors in the range of 86% to 94%, and this is not very helpful. The two main reasons why the direct use of pitch as a feature does not work for speaker recognition are listed below. First, the speech is not always periodic; only about half of the frames are voiced. Thus, pitch can not be estimated for half of the frames (i.e. for unvoiced frames). The problem is how to account for pitch information for the unvoiced frames during recognition phase. Second, the pitch estimation methods are not very reliable. They classify some of the frames unvoiced when they are really voiced. Also, they make pitch estimation errors (such as doubling or halving of pitch value depending on the method). In order to use pitch information for speaker recognition, we have to overcome these problems. We need a method which does not use the pitch value directly as feature and which should work for voiced as well as unvoiced frames in a reliable manner. We propose here a method which uses the autocorrelation function of the given frame to derive pitch-related features. We call these features the maximum autocorrelation value (MACV) features. These features can be extracted for voiced as well as unvoiced frames and do not suffer from the pitch doubling or halving type of pitch estimation errors. Using these MACV features along with the cepstral features, the speaker identification performance is improved by 45%.
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New directions in advanced RFID systems.Ranasinghe, Damith Chinthana January 2007 (has links)
Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / A combination of Radio Frequency Identification technology and ubiquitous computing are revolutionising the manner in which we look at simple objects. Radio Frequency Identification (RFID) allows RFID labeled objects to be identified at a distance without physical contact, and ubiquitous computing provides a virtually connected environment for the objects. RFID labels are frequently referred to as the next generation barcodes. RFID Systems provide increased productivity, efficiency, convenience and many advantages over bar codes for numerous applications, especially global supply chain management. RFID labeling has a number of advantages over conventional bar code systems. The optics based bar code systems could be rendered useless by common everyday environments containing dirt, dust, smoke, grease, condensation and by misorientation and misalignment. Furthermore bar codes are subject to fraudulent duplication and counterfeiting with minimal effort. However, there are limitations and constraints inherent to RFID technology: semiconductor thresholds, limits on transmitted power, costs, antenna and coupling inefficiencies. Thus it is important for RFID designers to understand these limitations and constraints in order to optimise system designs and overcome inefficiencies where possible. Therefore the work presented in this dissertation seeks to improve the performance of advanced RFID systems by overcoming a number of these limitations. Prior to a discussion of improving performance, the author's interpretation of a modem RFID system along its evolutionary path as a ubiquitous RFID network and its application to supply chain management is described. Performance improvements are achieved by: the development of electromagnetic theory for RFID system analysis and optimisation; design and development of interrogator antennas; analysis of electrically small and tiny antennas for RFID labels; and development and utilisation of a design methodology for creating high performance label antennas and antennas for tagging metallic objects. Implementations of RFID systems have raised concerns regarding information security and possible violations of end-user privacy. The most profound concerns are raised against low cost RFID technology because of its potential for mass scale deployment, its pervasive nature, and the resource limitations preventing the provision of strong cryptographic solutions. There is a growing need in the RFID community to discover and develop techniques and methods to overcome various hurdles posed by the above-mentioned concerns. Thus, the thesis also considers the vulnerabilities of low cost RFID systems and associated insecurities and privacy concerns resulting from the latter. Prior to addressing such concerns impeding the deployment of low cost RFID technology, a framework within which to provide security services is also detailed. It has become important to both defme and identity a framework based around low cost RFID systems since RFID has become a "catch all" phrase for various other forms of technology. Addressing security and privacy of low cost RFID systems requires novel thinking. The later parts of the thesis outline design considerations for security mechanisms and a number of practicable solutions for providing the features of: mutual authentication; confidentiality; message content security; product authentication; anonymity and untraceability, that are necessary for low cost RFID systems to overcome the weaknesses identified in this dissertation. Implementing these security mechanisms requires the generation of true random tag parameters and true random numbers. Achieving these objectives using a hardware based true random number generator is also described and analysed. A final part of the thesis focuses on active RFID labels and improving their performance. The primary concern with active labels is the life of the onboard battery. Turn-on circuits provide a method of turning "on" and "off" an active label remotely to conserve valuable battery power. Analysis, development and testing of a turn-on circuit concept, based on interrogator field sensing, have provided a means of remotely activating and deactivating active RFID labels and conserving battery power. The final chapter of this thesis provides a detailed analysis, based on coupling relations between electromechanical systems, for evaluating the feasibility of a theft detection sensor, based on a turn-on circuit for an active RFID label, for preventing the theft of high value items. While low cost RFID needs to overcome certain security and privacy related barriers, RFID technology does provide novel and valid approaches to such security related applications as product authentication, anti-counterfeiting and theft detection. It is believed that the contributions from this thesis will extend and elaborate on the existing knowledge base, paving the way forward to allow further significant deployment of advanced RFID techno logy. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1368084 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2007
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Ubiquitous monitoring of distributed infrastructures /Jiang, Bing, January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 134-141).
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Crack detection using a passive wireless strain sensorLantz, Gabriel Antoine 29 August 2011 (has links)
Nearly one third of the 604,426 bridges in the United-States are either structurally deficient or functionally obsolete. Monitoring these bridges is essential to avoid catastrophic accidents. In steel bridges fatigue induced crack/rupture, which is one of the most common modes of failure, can be avoided if the crack is detected at the early stages of its formation. Cracks usually originate at stress concentration areas but their precise origin is random. Such strain concentration can be monitored with traditional strain gages, but their installation requires lengthy wires and equipment, which are expensive and labor intensive. Therefore wireless sensors are being developed to cope with these problems. In this work, a passive wireless strain sensor based on RFID technology is described. The sensor is a patch antenna that resonates at a certain frequency, which shifts in presence of strain. The relation between the resonance frequency and the strain is approximately linear. The slope of the relation is called sensitivity. The behavior of the sensor's sensitivity is studied using experimental work and simulations that couple electromagnetism and mechanics. The sensitivity measured in experiments and in simulations in presence of uniform strain is different. This difference is lower for the sensitivity in presence of a crack, probably due to a parameter variation that is currently not accurately modeled in the simulations.
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Improved Performance of a Radio Frequency Identification Tag Antenna on a Metal Ground PlaneProthro, Joel Thomas 18 May 2007 (has links)
Simulation and experiments quantify the effect of moving a horizontal dipole antenna close to a metal ground plane. Solutions to the radiation problems are offered.
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Design and development of novel radio frequency identification (RFID) tag structuresYang, Li 13 November 2009 (has links)
The objective of the proposed research is to design and develop a series of radio frequency identification (RFID) tag structures that exhibit good performance characteristics with cost optimization and can be realized on flexible substrates such as liquid crystal polymer (LCP), paper-based substrate and magnetic composite material for conformal applications.
The demand for flexible RFID tags has recently increased tremendously due to the requirements of automatic identification in various areas. Several major challenges existing in today's RFID technologies need to be addressed before RFID can eventually march into everyone's daily life, such as how to design high performance tag antennas with effective impedance matching for passive RFID IC chips to optimize the power performance, how to fabricate ultra-low-cost RFID tags in order to facilitate mass production, how to integrate sensors with passive RFID tags for pervasive sensing applications, and how to realize battery-free active RFID tags in which changing battery is not longer needed. In this research, different RFID tag designs are realized on flexible substrates. The design techniques presented set the framework for answering these technical challenges for which, the focus will be on RFID tag structure design, characterization and optimization from the perspectives of both costs involved and technical constraints.
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Efficient bit encoding in backscatter wireless systemsGraf, Patrick Anthony 08 April 2010 (has links)
As the size and power consumption of microelectronic circuits continues to decrease, passively-powered sensors promise to come to the forefront of commercial electronics. One of the most promising technologies that could realize this goal is backscatter sensing. Backscatter sensors could harvest power from and modulate data onto an impinging carrier waveform. Currently radio frequency identification (RFID) technology passively powers itself and transmits statically stored data. However, this technology has two major weaknesses: lack of resiliency against narrowband interference and slow data rates. Both of these issues could be detrimental in sensing applications. This thesis will lay out a method for addressing both of these weaknesses through a unique application of spread spectrum encoding. Instead of spread spectrum being viewed as the multiplication of an already encoded data sequence with a periodic pseudorandom sequence, each sequence could be viewed in an aperiodic manner, where a single period of a pseudorandom sequence represents a data symbol. In this manner, backscatter sensors not only benefit from the increased resiliency that spread spectrum provides, but also can have higher data rates, since multiple bits can be encoded on a single symbol and multiple nodes can be read simultaneously, using spread spectrum multiple access techniques. In this thesis, 63-chip and 255-chip Kasami sequences, as well as 127-chip Gold sequences, will be analyzed for their use in various aperiodic direct sequence spread spectrum/multiple access system configurations (systems that have up to three nodes and use up to four different aperiodic sequences per node to represent different symbols). For each different configuration, near-"ideal" code configurations/rotations will be determined for use in the system.
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