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1
Reinertsen, Ingerid R. „Vessel driven correction of brain-shift“. Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111865.
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The displacement and deformation of brain tissue is a major source of error in image-guided neurosurgery systems. This thesis presents the design, implementation and validation of an image registration algortithm to detect and correct brain-shift using pre-operative MR images and intraoperative Doppler ultrasound data. The registration algorithm uses segmented vessels from both modalities, and estimates the displacement using a modified version of the iterative closest point (ICP) algorithm. The least trimmed squares (LTS) was used to reduce the number of outliers in the point matching procedure. The selected points were first used to estimate a linear transformation between the two data-sets, and then used to drive a thin-plate spline transform to achieve non-linear registration.A deformable brain phantom was designed, constructed and characterized in order to serve as a gold standard in the validation of the registration algorithm. The reproducibility of the elastic deformation of the phantom was evaluated using MR imaging and surface measurements. The experiments showed that the phantom was well suited for MR and ultrasound imaging (B-mode and Doppler) with sub-millimeter reproducibility for the deformations.
Validation of the registration technique was then completed in three parts. First, the technique was tested and validated using realistic simulations where the results were compared to the known deformation. The registration technique recovered 75% of the deformation in the region of interest accounting for deformations as large as 20 mm.
Second, a phantom study was performed where both MR and ultrasound images of the phantom were obtained for three different deformations. The registration results based on MR data were used as a gold standard to evaluate the performance of the ultrasound based registration. On average, deformations of 7.5 mm magnitude were corrected to within 1.6 mm for the ultrasound based registration and 1.07 mm for the MR based registration. Finally, the registration algorithm was validated using five retrospective clinical data-sets. Because the true displacement remained unknown, the method was validated using homologous landmarks identified in the original data, the exclusion of selected vessels, and finally manual segmentation of non-vascular structures in anatomical data. The tracking of homologous landmarks show that the registration algorithm was able to correct the deformation to within 1.24 mm, and the validation using excluded vessels and anatomical structures show an accuracy close to 1 mm. Pre-processing of the data can be completed in 30 seconds per dataset, and registrations can be performed in less than 30 seconds. This makes the technique well suited for intra-operative use.
2
Liu, Wenjie. „Estimation and bias correction of the magnitude of an abrupt level shift“. Thesis, Linköpings universitet, Statistik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-84618.
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Consider a time series model which is stationary apart from a single shift in mean. If the time of a level shift is known, the least squares estimator of the magnitude of this level shift is a minimum variance unbiased estimator. If the time is unknown, however, this estimator is biased. Here, we first carry out extensive simulation studies to determine the relationship between the bias and three parameters of our time series model: the true magnitude of the level shift, the true time point and the autocorrelation of adjacent observations. Thereafter, we use two generalized additive models to generalize the simulation results. Finally, we examine to what extent the bias can be reduced by multiplying the least squares estimator with a shrinkage factor. Our results showed that the bias of the estimated magnitude of the level shift can be reduced when the level shift does not occur close to the beginning or end of the time series. However, it was not possible to simultaneously reduce the bias for all possible time points and magnitudes of the level shift.
3
Hopkins, Kevin S. „Error detection and correction for a multiple frequency quaternary phase shift keyed signal“. Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27027.
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4
Wong, Dominic P. C. „Nonredundant error correction of π/4-shift DQPSK systems for mobile and cellular system applications“. Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30120.
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The application of the nonredundant error correction (NEC) technique to the new North American and Japanese Digital Cellular modulation standard, the π/4-shift DQPSK modulation format, is proposed, analyzed and evaluated. Due to the nature of the mobile cellular communication
channel, it is assumed that the π/4-shift DQPSK system is operated in a combined additive white Gaussian noise (AWGN) and cochannel interference (CCI) environment as well as in a frequency-nonselective fading environment.
The NEC techniques can be accommodated to the π/4-shift DQPSK by a modification of the NEC receivers for the DQPSK following which the performance of the NEC receivers with single-, double- and triple-error correction capability are theoretically analyzed and evaluated. The most elaborate system analyzed is the triple-error NEC receiver which employs four differential detectors with delay elements of one up to four symbol duration long and which requires the computation of 12 syndromes for the correction of error symbols.
For the CCI, the general model which includes M statistical independent interferers also employing the π/4-shift DQPSK modulation format is adopted. The theoretical symbol error rate (SER) versus carrier-to-noise (C/N) ratio have been obtained having M and the carrier-to-interference (C/I) ratio as parameters. These performance evaluation results indicate significant performance improvements over conventional differentially detected π/4-shift DQPSK systems without requiring any bandwidth expansion. For example, at a SER = 10ˉ⁴ and for C/I = 14 dB and M = 6, gains of more than 7 dB have been obtained. Compared with a coherent π/4-shift QPSK system operated in the same environment, this triple error correcting NEC is inferior by only 1.5 dB. Some of these theoretical results have also been verified by computer simulation. The gains offered by the NEC receivers have been found to increase as C/I decreases and/or M increases. In addition to the performance improvements, significant error floor reductions (of at least one order of magnitude) have been observed.
For the fading channel, the theoretical error rate equation for the single-error correcting NEC receiver is newly derived. Since numerical evaluation of the derived equation is extremely time consuming, computer simulations were used to obtain the performance evaluation result of π/4-shift DQPSK system employing single- and double-error correcting NEC receivers. In general, the improvement are not as high as that in the CCI environment. For example, at a BER = IOˉ² and for a Rician fading channel with the K-factor of 1 dB with BDT = 6.29, a performance gain of 6 dB is achieved. The gains offered by the NEC receivers increases as the K-factor decreases and/or when the BDT is large.
Since the NEC technique does not require any bandwidth or signal constellation expansion as do other coding schemes, it is a powerful and attractive technique to increase the capacity of digital communication systems operated in CCI controlled (frequency reuse) environment, such as the new all digital North American and Japanese mobile/cellular network. The significant improvement of the NEC receivers in a very fast fading environment suggests the NEC receivers can also be applied to communication applications in which the speed of the mobile unit is very high, for example, in aeronautical communication systems. Finally, it is noteworthy that the results obtained in this thesis for the π/4-shift DQPSK systems are directly applicable to the DQPSK systems in a linear channel.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
5
Meißner, Mirko [Verfasser], und Jürgen [Akademischer Betreuer] Hennig. „Chemical Shift Artefact Correction in 19F Magnetic Resonance Imaging = Korrektur des Artefakts der Chemischen Verschiebung in der 19F Magnetresonanzbildgebung“. Freiburg : Universität, 2014. http://d-nb.info/1123478813/34.
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6
Chen, Xi. „Automatic 13C Chemical Shift Reference Correction of Protein NMR Spectral Data Using Data Mining and Bayesian Statistical Modeling“. UKnowledge, 2019. https://uknowledge.uky.edu/biochem_etds/40.
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Nuclear magnetic resonance (NMR) is a highly versatile analytical technique for studying molecular configuration, conformation, and dynamics, especially of biomacromolecules such as proteins. However, due to the intrinsic properties of NMR experiments, results from the NMR instruments require a refencing step before the down-the-line analysis. Poor chemical shift referencing, especially for 13C in protein Nuclear Magnetic Resonance (NMR) experiments, fundamentally limits and even prevents effective study of biomacromolecules via NMR. There is no available method that can rereference carbon chemical shifts from protein NMR without secondary experimental information such as structure or resonance assignment.
To solve this problem, we constructed a Bayesian probabilistic framework that circumvents the limitations of previous reference correction methods that required protein resonance assignment and/or three-dimensional protein structure. Our algorithm named Bayesian Model Optimized Reference Correction (BaMORC) can detect and correct 13C chemical shift referencing errors before the protein resonance assignment step of analysis and without a three-dimensional structure. By combining the BaMORC methodology with a new intra-peaklist grouping algorithm, we created a combined method called Unassigned BaMORC that utilizes only unassigned experimental peak lists and the amino acid sequence.
Unassigned BaMORC kept all experimental three-dimensional HN(CO)CACB-type peak lists tested within ± 0.4 ppm of the correct 13C reference value. On a much larger unassigned chemical shift test set, the base method kept 13C chemical shift referencing errors to within ± 0.45 ppm at a 90% confidence interval. With chemical shift assignments, Assigned BaMORC can detect and correct 13C chemical shift referencing errors to within ± 0.22 at a 90% confidence interval. Therefore, Unassigned BaMORC can correct 13C chemical shift referencing errors when it will have the most impact, right before protein resonance assignment and other downstream analyses are started. After assignment, chemical shift reference correction can be further refined with Assigned BaMORC.
To further support a broader usage of these new methods, we also created a software package with web-based interface for the NMR community. This software will allow non-NMR experts to detect and correct 13C referencing errors at critical early data analysis steps, lowering the bar of NMR expertise required for effective protein NMR analysis.
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Lin, Jinsong, und Kamilo Feher. „BANDWIDTH EFFICIENCY AND BER PERFORMANCE OF ENHANCED AND FEC CODED FQPSK“. International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/607727.
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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaBit error rate (BER) and bandwidth efficiency of several variations of enhanced Feher patented quadrature phase shift keying (FQPSK) [1] are described. An enhanced FQPSK increases the channel packing density of that of the IRIG 106-00 standardized FQPSK-B by approximately 50% in adjacent channel interference (ACI) environment. As the bandwidth efficiency of FQPSK-B DOUBLES (2×) that of pulse code modulation/Frequency modulation (PCM/FM) [5], the enhanced FQPSK, with a simpler transceiver than FQPSK-B, has a channel packing density of TRIPLE (3×) that of PCM/FM. One of the other enhanced FQPSK prototypes has an end to end system loss of only 0.4 dB at BER=1x10^(-3) and 0.5 dB at BER=1x10^(-4) from ideal linearly amplified QPSK theory. The enhanced FQPSK has a simple architecture, thus is inexpensive and has small size, for ultra high bit rate implementation. With low redundancy forward error correction (FEC) coding which expands the spectrum by approximately 10%, further improvement of about 3-4.5dB E N b o is attained with NLA FQPSK-B and enhanced FQPSK at BER=1x10^(-5) .
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Endstrasser, Zdeněk. „Kalibrace a interpretace obrazových dat měřených zařízením LEEM“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443243.
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This thesis deals with the software development to calibration and interpretation of image data measured by a LEEM device. As the imaging technique is uniquely suited for in-situ studies of surface dynamical processes, the attention is mainly paid to methods enabling the evaluation of measurement time series. The phase correlation method based on Fourier transform of images is proposed to temperature shift correction between consecutive frames. The thesis describes the methods of additive and impulse noise filtering, image visualization, the filtration of secondary electrons and the determination of I-V curves from measured image data. Implemented methods are described not only in terms of their mathematical origin, but also with emphasis on the revealing of critical aspects associated with their use. The thesis also focuses on the application of the created algorithm to image data capturing the spatial and temporal evolution of 4,4’-biphenyl-dicarboxylic acid surface phases induced by sample annealing. Based on these evaluations, a suitable procedure is then determined to perform accurate detection and compensation of temperature shift said.
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Grimnell, Mikael, und Mats Tjäder. „Efficient Message Passing Decoding Using Vector-based Messages“. Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5205.
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The family of Low Density Parity Check (LDPC) codes is a strong candidate to be used as Forward Error Correction (FEC) in future communication systems due to its strong error correction capability. Most LDPC decoders use the Message Passing algorithm for decoding, which is an iterative algorithm that passes messages between its variable nodes and check nodes. It is not until recently that computation power has become strong enough to make Message Passing on LDPC codes feasible. Although locally simple, the LDPC codes are usually large, which increases the required computation power. Earlier work on LDPC codes has been concentrated on the binary Galois Field, GF(2), but it has been shown that codes from higher order fields have better error correction capability. However, the most efficient LDPC decoder, the Belief Propagation Decoder, has a squared complexity increase when moving to higher order Galois Fields. Transmission over a channel with M-PSK signalling is a common technique to increase spectral efficiency. The information is transmitted as the phase angle of the signal.
The focus in this Master’s Thesis is on simplifying the Message Passing decoding when having inputs from M-PSK signals transmitted over an AWGN channel. Symbols from higher order Galois Fields were mapped to M-PSK signals, since M-PSK is very bandwidth efficient and the information can be found in the angle of the signal. Several simplifications of the Belief Propagation has been developed and tested. The most promising is the Table Vector Decoder, which is a Message Passing Decoder that uses a table lookup technique for check node operations and vector summation as variable node operations. The table lookup is used to approximate the check node operation in a Belief Propagation decoder. Vector summation is used as an equivalent operation to the variable node operation. Monte Carlo simulations have shown that the Table Vector Decoder can achieve a performance close to the Belief Propagation. The capability of the Table Vector Decoder depends on the number of reconstruction points and the placement of them. The main advantage of the Table Vector Decoder is that its complexity is unaffected by the Galois Field used. Instead, there will be a memory space requirement which depends on the desired number of reconstruction points.
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Reymond, Cédric. „Conception d'une structure innovante de convertisseur AC-DC de type Totem-pole avec correction du facteur de puissance : application aux chargeurs de batteries des véhicules électriques“. Thesis, Tours, 2019. http://www.theses.fr/2019TOUR4015.
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Les gouvernements responsabilisent les états sur l’environnement avec la mise en œuvre de solution pour décarboner la production de l’électricité. En 2020, 20 % de l’énergie produite sera générée par les énergies renouvelables. Cependant ces énergies vertes sont intermittentes et nécessitent une capacité de stockage importante pour la gestion locale des « smart grids ». Cette solution pose deux nouvelles problématiques : la nécessité d’un convertisseur bidirectionnel et la gestion des courants d’appel. Pour faciliter l’étude de ces problématiques, la thèse propose de lier au travers d’un bilan de puissance, les performances des différents limiteurs de courant sur une topologie de convertisseur innovante. Cette analyse permet de mettre en exergue une solution alternative de limitation des courants d’appel dans la conversion de l’énergie. Enfin, un circuit novateur sur le contrôle des composants de puissance de type thyristors/Triacs sera proposé et caractérisé pour palier une des contraintes liées à la réversibilité du convertisseurGovernments empower states over the environment with implementation of solution to clean up the electricity production sources. In 2020, 20% of the produced energy will be generated by renewable energies. However, theses green energies are occasional and require a huge storage capacitance for the local smart grids management. This solution puts two new issues: the necessity of having a bidirectional converter and the inrush currents management. To facilitate the study of these problems, the thesis suggests binding through a power balance, the performances of the current limiter on an innovative topology converter. This analysis highlight an alternative solution of inrush current strategy in energy conversion. Finally, a novel control circuit for SCRs/Triacs components will be proposed and characterized for landing one of the constraints linked to the converter reversibility
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Poerschke, Rafael Pentiado. „Análise da importação brasileira de arroz“. Universidade do Vale do Rio dos Sinos, 2011. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3056.
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O presente trabalho procurou avaliar o comportamento da função de demanda brasileira por arroz pós-Mercosul e sua relação com a variação na renda, nos preços internos e externos, na indústria e política comercial brasileira. Para a análise, foi desenvolvido um modelo teórico, o qual fundamentou a especificação dos modelos econométricos para o arroz em casca e beneficiado. Considerou-se na investigação estatística dados históricos de janeiro de 1995 a junho de 2010, tendo como objetivo geral testar a adequação de modelos lineares e não-lineares que representem as relações de curto e longo prazo das variáveis de comércio exterior brasileiro do setor. Além disso, pretende-se datar a cronologia dos ciclos das importações de arroz e verificar a relação desses com as idiossincrasias da condução das políticas econômicas, bem como com eventos climáticos. As elasticidades encontradas apresentaram sinais coerentes com o modelo econômico definido em sua maioria. Os resultados obtidos permitiram interpretar a dinâmica do mercado importador de arroz no Brasil. Em geral, os impactos de longo prazo da renda e preço doméstico foram os principais determinantes das importações e ressalta-se o comportamento de bem inferior de ambos os tipos de arroz nas equações trimestrais. Já o preço de importação contribui menos que proporcionalmente, ao passo que o importador parece ajustar a quantidade importada do período com certo grau de defasagem. Já a indústria, tendo como base dados trimestrais, manteve uma relação contra-cíclica com as importações de ambos os tipos de arroz, embora não tenha se mostrado significativa para a maioria dos modelos. A dinâmica de correção do modelo a choques no longo prazo foi atenuada nas estimativas não-lineares mensais, enquanto permaneceu praticamente estável nas estimativas trimestrais. Ainda, conforme os resultados é possível afirmar que os ciclos de expansão das importações de arroz beneficiado durante o período foram, em média, mais longos que as retrações. Finalmente, pode-se entender que os ciclos de importação se mostraram fortemente relacionados a eventos climáticos adversos e à alterações da política comercial.
This study tried to investigate the behavior of Brazilian demand for post-Mercosur rice and its relation with variation in income, in domestic and foreign prices, in industry and in Brazil?s trade policy. For the analysis, a theoretical model was developed, which based the specification of econometric models for rough and milled rice. The statistical investigation considered historical data from January 1995 through June 2010, aiming mainly to test the adequacy of linear and nonlinear relations that represent short and long-term variables of the Brazilian foreign trade in the sector. Furthermore, there is the goal of setting the chronology of the cycles of rice imports and verifying their relationship with idiosyncrasies of the conduct of economic policies, as well as of weather events. The elasticities estimated showed signs consistent with the economic model set in their majority. The results achieved allowed the interpretation of the rice import market dynamics in Brazil. In general, long-term impacts from income and domestic prices were the main determinants of imports; it should be pointed out the much lower behavior of both types of rice in quarterly equations. The price of imports contributes less than proportionately, while the importer seems to adjust the quantity imported in the period with some lag. The industry, based on quarterly data, sustained its counter-cyclical relation with the imports of both types of rice, although it has been not proved significant for most models. The correction dynamic of the model to long-term shocks was eased in monthly non-linear equations, while it remained nearly stable in quarterly estimates. Besides, still according to results, it is possible to say that expansion cycles of imports of milled rice are on average longer than the contractions. Finally, one can understand that import cycles were strongly related to adverse climatic events, as well as to alterations in trade policy.
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Grymel, Martin-Thomas. „Error control with binary cyclic codes“. Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/error-control-with-binary-cyclic-codes(a5750b4a-e4d6-49a8-915b-3e015387ad36).html.
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Error-control codes provide a mechanism to increase the reliability of digital data being processed, transmitted, or stored under noisy conditions. Cyclic codes constitute an important class of error-control code, offering powerful error detection and correction capabilities. They can easily be generated and verified in hardware, which makes them particularly well suited to the practical use as error detecting codes.A cyclic code is based on a generator polynomial which determines its properties including the specific error detection strength. The optimal choice of polynomial depends on many factors that may be influenced by the underlying application. It is therefore advantageous to employ programmable cyclic code hardware that allows a flexible choice of polynomial to be applied to different requirements. A novel method is presented in this thesis to realise programmable cyclic code circuits that are fast, energy-efficient and minimise implementation resources.It can be shown that the correction of a single-bit error on the basis of a cyclic code is equivalent to the solution of an instance of the discrete logarithm problem. A new approach is proposed for computing discrete logarithms; this leads to a generic deterministic algorithm for analysed group orders that equal Mersenne numbers with an exponent of a power of two. The algorithm exhibits a worst-case runtime in the order of the square root of the group order and constant space requirements.This thesis establishes new relationships for finite fields that are represented as the polynomial ring over the binary field modulo a primitive polynomial. With a subset of these properties, a novel approach is developed for the solution of the discrete logarithm in the multiplicative groups of these fields. This leads to a deterministic algorithm for small group orders that has linear space and linearithmic time requirements in the degree of defining polynomial, enabling an efficient correction of single-bit errors based on the corresponding cyclic codes.
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Ingram, Phyllis. „Shift Rotation Among Correctional Officers as a Source of Perceived Job Related Stress“. UNF Digital Commons, 1986. http://digitalcommons.unf.edu/etd/678.
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My formal hypothesis for this study is that shift rotation among correctional officers has an effect on correctional officer stress. Although there are many definitions of stress, for the purpose of this study stress is defined as conscious nervous tension. Many authors believe that stress develops from a person's reactions to certain situations that are threatening or exert pressure on them. It is felt that whatever the cause, stress depends not on the outside event but on how one reacts to it. For the purpose of this study, stress was not formally defined to the correctional officers because I was looking for perceptions of stress, or how an officer reacts to certain situations.
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Naab-Levy, Adam O. „Enhanced Distance Measuring Equipment Data Broadcast Design, Analysis, Implementation, and Flight-Test Validation“. Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1449158180.
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Koglin, Ingo. „Estimation of residual static time shifts by means of the CRS-based residual static correction approach“. Berlin Logos-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2672486&prov=M&dok_var=1&dok_ext=htm.
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16
Huang, Ming Chuan. „Comparison of shaft position estimation and correction techniques for sensorless control of surface mounted PM synchrononous motors“. Thesis, Cardiff University, 2009. http://orca.cf.ac.uk/54888/.
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This thesis is a detailed study of how two error correction schemes affect the precision of shaft position estimation in state-observer techniques for sensorless control surface-mounted Permanent Magnet Synchronous Motors (PMSM), variance correction and variable PI regulation. A novel sensorless estimation technique based on Linear Kalman Filter (LKF) through constant variance correction is proposed and compared with the conventional Flux Linkage Observer (FLO) method and other state-estimation sensorless control techniques namely, Extended Kalman Filter (EKF), variable variance correction, Single Dimension Luenberger (SDL) observer and Full-Order Luenberger (FOLU) observer both through variable PI regulation. These five sensorless control techniques for PMSM are successfully implemented in the same lab-based hardware platform, i.e. full digital float-point-type DSP control inverter-fed PMSM system. Experiments are reported on each sensorless method covering position estimation, speed response, self-startup and load behaviour. Intensive analysis has also been carried out on the impact of error correction of estimated position on the steady/dynamic PMSM characteristics with different sensorless approaches. The experiment demonstrates that the novel Linear Kalman Filter can achieve the minimum average position estimation error throughout the electrical cycle of the five sensorless estimation techniques during no load operation at rated speed and also makes PMSM capable of self-startup for any initial rotor position except the dead area. A speed response experiment for LKF shows that individual speed estimation can be extracted directly from LKF state estimation for sensorless control PMSM. Experiments on the five sensorless methods proves that position error correction scheme is the dominating factor for state estimation sensorless control PMSM and better dynamic/steady control performance can be achieved using a variance correction scheme applied in EKF/LKF than with variable PI regulation applied in SDL/FOLU. The thesis also concludes that the novel Linear Kalman Filter is an optimised cost-effective sensorless estimation method for the PMSM drive industry compared with classic and Flux Linkage observers/Extended Kalman Filters.
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Smit, Maria Elizabeth Catharina (Marietjie). „The positive and negative impact of permanent night duty on officials in the Department of Correctional Services“. Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/43246.
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The Department of Correctional Services is the South African Government Department that is responsible for the smooth running of the South African correctional system. Correctional facilities have to be staffed twenty four hours a day and therefore correctional officials have to work fixed or rotating shifts to ensure that the needs of offenders are taken care of. The number of staff members in many South African correctional centres is not sufficient to ensure proper care and management of offenders, but staff shortages during the night is even more chronic compared to staff shortages experienced during the day. It is vital that correctional officials be alert and vigilant at all times and therefore these staff shortages contribute to high levels of stress, lack of motivation and feelings of being overwhelmed by the work load.
Shift work is a phenomenon that is increasing worldwide. It is important to understand the impact of work schedules as more people seem to be working shifts that do not conform to the standard work week. Shift workers seem very healthy when their illnesses are compared to that of the general public. Many health problems have been detected in shift workers, including stress related conditions, as any work schedule can act as a stressor if the needs of the individual worker are not taken into consideration.
Sleeping patterns during the day differ from sleeping patterns at night. Shift work disrupts a person’s circadian rhythms and therefore contributes to poorer physical and psychological health. It further causes poorer productivity and increases the possibility of becoming involved in accidents. Working night duty is very stressful to the night shift worker who has to cope with challenges at work and at home. There is a variety of common stressors at work that affect shift workers physiologically (cardiovascular, stroke, digestive problems, back pain and arthritis, headaches, increased blood pressure and hormonal), psychologically (burnout, depression, anxiety, family problems, sleep problems and job dissatisfaction) and behaviouraly (absence, tardiness, substance abuse, accidents, sabotage / violence, poor decision making, poor job performance and a high personnel turnover).
This study focused on understanding the positive and negative impact of working permanent night duty on correctional officials. The findings of this study will be helpful to correctional officials who work permanent night duty in addressing employee workplace support.Dissertation (MSW (Health Care))--University of Pretoria, 2014.
lk2014
Social Work and Criminology
MSW (Health Care)
Unrestricted
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Johnson, Kevin Russell. „Advancements in Thermal Integrity Profiling Data Analysis“. Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6520.
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Thermal Integrity Profiling (TIP) is a relatively new non-destructive test method for evaluating the post-construction quality of drilled shafts. Therein anomalies in a shaft are indicated by variations in its thermal profile when measured during the curing stages of the concrete. A considerable benefit with this method is in the ability to detect anomalies both inside and outside the reinforcement cage, as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a straightforward interpretation of data. As with any test method, however, the quality of the results depends largely on the level of analysis and the way in which test data is interpreted, which was the focus of this study. This dissertation presents the findings from both field data and computer models to address and improve TIP analysis methods, specifically focusing on: (1) the analysis of non-uniform temperature distributions caused by external boundary conditions, (2) proper selection of temperature-radius relationships, and (3) understanding the effects of time on analysis.
Numerical modeling was performed to identify trends in the temperature distributions in drilled shafts during concrete hydration. Specifically, computer generated model data was used to identify the patterns of the non-linear temperature distributions that occur at the ends of a shaft caused by the added heat loss boundary in the longitudinal direction. Similar patterns are observed at locations in a shaft where drastic changes in external boundary conditions exist (e.g. shafts that transition from soil to water or air). Numerical modeling data was also generated to examine the relationship between measured temperatures and shaft size/shape which is a fundamental concept of traditional TIP analysis.
A case study involving a shaft from which 24hrs of internal temperature data was investigated and compared to results from a computer generated model made to mimic the field conditions of the shaft. Analysis of field collected and model predicted data was performed to examine the treatment of non-linear temperature distributions at the ends of the shaft and where a mid-shaft change in boundary was encountered. Additionally, the analysis was repeated for data over a wide range of concrete ages to examine the effects of time on the results of analysis.
Finally, data from over 200 field tested shafts was collected and analyzed to perform a statistical evaluation of the parameters used for interpretation of the non-linear distributions at the top and bottom of each shaft. This investigation incorporated an iterative algorithm which determined the parameters required to provide a best-fit solution for the top and bottom of each shaft. A collective statistical evaluation of the resulting parameters was then used to better define the proper methods for analyzing end effects.
Findings revealed that the effects of non-uniform temperature distributions in drilled shaft thermal profiles can be offset with a curve-fitting algorithm defined by a hyperbolic tangent function that closely matches the observed thermal distribution. Numerical models and statistical evaluations provided a rationale for proper selection of the function defining parameters. Additionally, numerical modeling showed that the true temperature-to-radius relationship in drilled shafts is non-linear, but in most cases a linear approximation is well suited. Finally, analysis of both model and field data showed that concrete age has virtually no effect on the final results of thermal profile analysis, as long as temperature measurements are taken within the dominate stages of concrete hydration.
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Dragonu, Iulius. „Imagerie rapide par IRM pour le monitorage des thermothérapies“. Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13964/document.
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L’hyperthermie guidée par IRM permet l’ablation thermique des tumeurs, l’activation de l’expression d’un transgène sous contrôle d’un promoteur thermo-sensible ainsi que le dépôt local de médicaments à l’aide de nanovéhicules sensibles à la température ou à la pression locale. L’imagerie de température par IRM, basée sur la technique du décalage de la fréquence de résonance du proton permet le monitorage des interventions d’hyperthermie. Les procèdes interventionnels guides par IRM sur cible mobile requièrent des séquences d’imagerie rapides afin d’obtenir des images de phases ayant une résolution spatio-temporelle élevée. Nous avons démontré l’efficacité de l’association des méthodes adaptatives d’imagerie parallèle telles que TSENSE et TGRAPPA et de la méthode multi-référence de l’atlas de mouvement afin de compenser les variations du champ magnétique induites par les organes en mouvement. Les procédés interventionnels guides par IRM sont basés sur des séquences d’imagerie rapides capables de fournir des images en temps-réel ayant une relation précise entre la position de la cible représentée dans l’image et sa vraie position spatiale. Les séquences écho-planar sont très rapides mais possèdent des distorsions géométriques. Nous avons proposé une méthode de correction des distorsions des images EPI. Cette technique est basée sur des approches existantes utilisant l’acquisition de deux images EPI ayant deux temps d’écho différents. L’efficacité de la méthode proposée a été démontrée pour une expérience de thermométrie par IRM. La rapidité du traitement des données, associée à une faible diminution de la rapidité d’acquisition, rend cette méthode particulièrement adaptée pour les procédés interventionnels guides par IRM. La perfusion sanguine, la diffusion thermique ainsi que le coefficient d’absorption des ondes acoustiques ou électromagnétiques déterminent la distribution de la température durant les procédés interventionnels. Certaines tumeurs ont des taux de perfusion élevés conduisant à une évacuation importante de la chaleur et par conséquent, un refroidissement rapide de la cible. Cet effet réduit la température maximale atteinte pour une puissance donne et peut conduire à des zones d’ablation plus petites réduisant ainsi l’efficacité de l’intervention. La connaissance précise des paramètres thermiques du tissu peut aider à la planification des procédés interventionnels. Dans ce but, nous avons proposé une méthode permettant la détermination précise des paramètres cités précédemmentMR-guided HIFU-induced hyperthermia allows for thermal ablation of tumors, for gene therapy by thermal induction of transgenic expression (based on a thermo-sensitive promoter) and for local drug delivery using thermo-sensitive liposomes. These applications require accurate temperature measurement during the therapeutic intervention. Dynamic MR-temperature imaging based on the proton resonance frequency shift technique allows monitoring the local temperature evolution during hyperthermia. MR-guided thermotherapy on moving organs requires imaging sequences providing phase images with high temporal and spatial resolution. We demonstrated the feasibility of combining adaptive parallel imaging techniques such as TSENSE or TGRAPPA with the atlas-based multi-baseline method for compensating the magnetic field variations produced by moving organs during the respiratory cycle. Many MR-guided interventional procedures rely on real-time imaging sequences for providing precise relations between the target position in the image and the true position in the scanner. Although echo-planar imaging (EPI) sequences are very fast, they are prone to geometric distortions. For correcting these distortions, we proposed a real-time correction method by applying existing approaches based on a dual EPI acquisition with varying echo times. It is demonstrated that this method works well in combination with MR-thermometry for guiding thermal therapies. Short data-processing times as well as a small penalty in acquisition speed make this method well-adapted for MR-guided interventions. Local blood perfusion, thermal conductivity and the absorption coefficient of acoustic or electro-magnetic waves determine the temperature distribution in living tissue. Some tumors have high perfusion rates resulting in considerable heat evacuation. This effect reduces the maximal temperature increase achievable for a given deposited energy and produces smaller ablation zones, which can impair the efficiency of the therapeutic procedure. A method for accurately estimating the above mentioned tissue parameters, was presented. This method could thus be useful in quantifying the influence of perfusion during thermal interventions
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Chan, Chia-Wei, und 詹佳瑋. „Bias Correction for Positive to Negative Mood Shift: Hedonic and Utilitarian Evaluation Orientation“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/57578991614225835333.
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碩士國立臺灣大學
商學研究所
104
This research proposes three main issues. For one thing, when consumers are not aware of mood bias, the mood state shift from positive to negative leads to a lower product evaluation compared to the situation of constant negative mood state. The above conditions occur only when judging hedonic evaluative orientation product rather than utilitarian evaluative orientation product. Second, when consumers are aware that mood shift will affect the objectivity of product judgment, the direction of correction would be opposite to the direction of the mood state shift, and the amount of correction will be bigger due to the shift of mood state which only existing in assessing hedonic evaluative orientation product. Third, regardless of the use of correction instruction or priming article to remind consumers to perceive mood as a bias factor, even the latter is a subtle cue, both of them can achieve the same effect. Two main studies were performed to verify the hypothesis, and the results successfully validated that when consumers are under positive to negative mood state shift and they are not aware of the mood bias, they will have a lower product attitude on hedonic evaluative orientation product. Besides, if providing clear correction instruction, consumers will correct the bias by giving the product a better judgment because of the opposite direction of bias correction. In addition, there is no significant difference of product attitude between the steady mood state and mood shift and whether the correction instruction exists or not when assessing utilitarian evaluative orientation product. However, the effect of priming article is too subtle to convince the related hypothesis.
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Tseng, Kai-Hung, und 曾凱宏. „The Design and Implementation of Active Power Factor Correction onFull Bridge Phase Shift Converter“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/j9e6e4.
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碩士中原大學
電機工程研究所
92
This paper presents the design, experimental results and analysis of an active power factor correction on full bride phase shift inverter, it gives a steady power, low harmonics and high power factor system. And the inverter achieves the Zero-Voltage Switching (ZVS) for reducing power lost. Finally, we could get the power system (include power factor correction) is better than one (include variable transformer) from experimental results, validate the feasibility of the implemented system in high power application.
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Teng, Jui-Ting, und 鄧睿婷. „Product Judgment and Bias Correction in Positive Mood Shift: Hedonic and Utilitarian Based Evaluation“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/47207865271921508100.
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碩士國立臺灣大學
商學研究所
104
The purpose of this research was designed to demonstrate three main issues. To begin with, when consumers are under mood state shift from positive to neutral and notice that mood is bias for target product judgment, they will correct their previous product judgments. Moreover, the amount of correction from consumers primed with utilitarian processing are likely to be more than from those primed with hedonic processing. Second, when consumers are aware of the mood state shift and perceive the shift as a potential bias factor which affects product judgment, the direction of correction would be opposite to the direction of mood state shift. Last but not the least, when consumers are under neutral mood condition without mood shift, no matter they are aware of mood as a potential factor, they will not correct their product judgment toward the bias. Furthermore, there’s no difference between the amount of correction from consumers primed with utilitarian processing and the amount of correction from those primed with hedonic processing. The study was performed to investigate the hypothesis based on the three issues above. And the results demonstrated that when consumers are under mood state shift from positive to neutral and perceive mood shift as a bias, they are likely to correct their bias of product judgment and the amount of correction is larger in consumers primed with utilitarian processing than those primed with hedonic processing. However, the hypotheses in direction of correction and in product judgment under neutral mood are not convincing.
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Shih, I.-Ching, und 史義清. „Correction and Simulation of Post-Weld-Shift by Laser Hammering for Laser Module Packaging“. Thesis, 2006. http://ndltd.ncl.edu.tw/handle/62399363858851614658.
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碩士長庚大學
機械工程研究所
94
The objective of this study is to use laser hammering technique to correct the post-weld-shift (PWS) in laser module packaging joined by laser welding. Laser welding is known for its rapid and readily automatic process, as well as product reliability. However, the lost of coupling efficiency of laser packaging modules due to PWS after laser welding results in poor product yield. Therefore, in this study laser hammering technique was used to correct the PWS in order to improve the coupling efficiency of butterfly modules. This study was to correct the PWS of fiber by laser hammering and simulate the laser hammering process by finite element method (FEM). In the laser hammering process, laser beam was directed and heated the specific areas of weldclips. Consequently, different degrees of thermal displacements of fiber and weldclips took place in the X and Y directions according to the locations of laser hammering. The materials of weldclips included type 304 stainless steel and low expansion alloy Invar, and the types of weldclips were type L and type T. According to the experimental results, the primary factors influencing laser hammering included material and type of weldclip, and energy, sequence, and numbers of laser hammering. It was found that the laser hammering could successfully and effectively correct the PWS in both X and Y directions. In case of over-correction, reversal hammering was able to be carried out successfully by proper selection of subsequent hammering locations and energy/sequence. In summary, a laser hammering procedure is proposed in this study which can significantly reduce the PWS to be less than 1 μm, and recover the coupling efficiency to be more than 95%. Simultaneously, the results of finite element analysis correspond well with the experimental results, and therefore the FEM models can be used in the future study and commercial applications.
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„Error Detection and Error Correction for PMU Data as Applied to Power System State Estimators“. Master's thesis, 2013. http://hdl.handle.net/2286/R.I.20951.
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abstract: In modern electric power systems, energy management systems (EMSs) are responsi-ble for monitoring and controlling the generation system and transmission networks. State estimation (SE) is a critical `must run successful' component within the EMS software. This is dictated by the high reliability requirements and need to represent the closest real time model for market operations and other critical analysis functions in the EMS. Tradi-tionally, SE is run with data obtained only from supervisory control and data acquisition (SCADA) devices and systems. However, more emphasis on improving the performance of SE drives the inclusion of phasor measurement units (PMUs) into SE input data. PMU measurements are claimed to be more accurate than conventional measurements and PMUs `time stamp' measurements accurately. These widely distributed devices meas-ure the voltage phasors directly. That is, phase information for measured voltages and currents are available. PMUs provide data time stamps to synchronize measurements. Con-sidering the relatively small number of PMUs installed in contemporary power systems in North America, performing SE with only phasor measurements is not feasible. Thus a hy-brid SE, including both SCADA and PMU measurements, is the reality for contemporary power system SE. The hybrid approach is the focus of a number of research papers. There are many practical challenges in incorporating PMUs into SE input data. The higher reporting rates of PMUs as compared with SCADA measurements is one of the salient problems. The disparity of reporting rates raises a question whether buffering the phasor measurements helps to give better estimates of the states. The research presented in this thesis addresses the design of data buffers for PMU data as used in SE applications in electric power systems. The system theoretic analysis is illustrated using an operating electric power system in the southwest part of the USA. Var-ious instances of state estimation data have been used for analysis purposes. The details of the research, results obtained and conclusions drawn are presented in this document.Dissertation/Thesis
M.S. Electrical Engineering 2013
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Fang, Jia-Feng, und 方嘉鋒. „Application of Phase Shift and Optic Proximity Correction Technology for Single Mask Dual Damascene Process“. Thesis, 2007. http://ndltd.ncl.edu.tw/handle/87036721446850303863.
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碩士國立成功大學
微電子工程研究所碩博士班
95
Dual damascene process has been used for copper interconnect. There are many schemes to fabricate dual damascene structure. The most common integration approaches for the dual damascene architecture are via first, trench first and buried hard mask. Which mask first, using etch stop and hard masks or not and the use of ultra low k materials in advanced interconnect make dual damascene process very complicated. No matter which dual damascene scheme used all of them need two masks and two lithography processes. One advanced mask cost about two million NT$ and one metal layer needs two masks. With the increasing trend of metal layers of modern IC, the mask cost will add additional burden on already high manufacture cost. With rapidly decreasing chip feature size, the misalignment tolerance is not that far from critical dimension (CD). The existence of misalignment between via and trench mask will cause more rework on lithography steps. The increases of metal layers and higher rework rate on high cost lithography steps can only make things worse. Misalignment will also degrade the process and product yield. It is also a reliability killer. This thesis is to develop novel lithography process to fabricate dual damascene structure just one mask. The unique mask combines via and trench pattern layout. To achieve one exposure having dual damascene shape on photoresist, we need different exposure energy settings or conditions at via and trench areas at the same time. This thesis used phase shift and optic interference technique to weaken the exposure energy on trench to obtain partial exposure. Zebra pattern phase shifted gratings on trench area were used to achieve destructive interference. Via area is clear (no Cr for positive resist) to obtain full exposure. The thesis used KLA-Tencor’s Prolith v.9.2 to simulate the lithographic processes using the combined mask structure. The combined mask has DOF of 0.51μm and 6% exposure latitude for via and trench overlap process window. The light intensity pass through trench area can be adjusted by changing the grating phase. Degree of shifted phase will affects the transmission energy which influences image contrast. The contrast between via and trench can be modified by adjusting grating width. For grating width less than the optical resolution, smaller grating width has better contrast on relative intensity between via and trench. In order to fulfill the design rule, trench pattern with turning corner was also simulated. Trench turning area needs aggressive optical proximity correction. To obtain preferred workable process like depth of focus, target CD, numerical aperture and sigma, optical proximity correction technique was used. By using this unique single mask instead of two traditional masks, we can fabricate dual damascene structure. This cut the high mask cost in half. With one mask, we need only one lithography step, one etch, one ash and one clean instead of two each. It saves process cost significantly, simplifies the complicated dual damascene process and completely removed two masks’ misalignment problems. It will also boost yield and improves product reliability.
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Pålsson, Matilda Guthartz, und 馬迪. „Positive to Neutral Mood Shift and Bias Correction Effect on Product Judgement: Utilitarian vs Hedonic Evaluative Orientation“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/87z5yh.
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碩士國立臺灣大學
商學研究所
105
This paper examines consumer mood bias correction following a happy-to-neutral mood shift and steady neutral mood state when people are reminded of mood bias either directly through correction instruction or indirectly through a bias-priming article. This paper proposes that consumers in a happy-to-neutral mood shift, exposed to the correction instruction and who are viewing either utilitarian or hedonic target products will correct in the opposite direction of the perceived mood shift. It is also proposed that participants exposed to the bias-priming article but under the same conditions will only correct when viewing utilitarian target product but not hedonic. Participants in steady neutral mood states are not expected to correct for either target product. The results of the two main studies in this paper supported that participants in steady neutral mood conditions did not correct for perceived mood bias for either utilitarian or hedonic target product following either type of reminder. It was also found that participants in happy-to-neutral mood states viewing utilitarian target products corrected their product judgments when they were exposed to the bias-priming article. However, no significant amount of correction or main effect by mood shift was found for participants exposed to correction instruction.
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Lee, Meng-Hsuan, und 李孟軒. „Effect of Negative to Positive Mood Shift and Bias Correction on Product Judgment: Utilitarian and Hedonic Evaluative Orientation“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/pmr844.
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碩士國立臺灣大學
商學研究所
104
The study intends to analyze the effect of mood bias on product attitude. To be exact, how mood biases influence the dirction and magnitude of correction under different mood shifts. This research predicts that in the circumstance that consumers are aware of mood bias and target product is utilitarian evaluative oriented, bias correction will not occure. However, when the target product is replaced with a hedonic evaluative oriented one, correction occures in an opposite direction of mood shift; when in a condition without mood shift (steady mood), the correction direction will be opposite to the current mood state. Moreover, mood effect and amount of correction are larger in mood shift compared with steady mood. There are two studies. Study 1 uses correction instruction as hint to draw attention to mood bias but in study 2, bias priming is used. In study 1, the result showed that consumers did not correct for uitilitarian evaluative oriented product but they corrected for hedonic evaluative oriented product under mood shift. Also, as predicted, when consumers’ mood shifted, amount of correction was larger than in steady mood. However, the hypothesis about mood effect was not confirmed. In study 2, the hypothesis concerning uitilitarian evaluative oriented product were confirmed. As for hedonic evaluative oriented product, contrary to the prediction, correction was not presented. Moreover, the prediction regarding mood effect and amount of correction were not confirmed either.
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Chen, Pan-Ju, und 陳盼如. „Effect of Negative to Neutral Mood Shift and Bias Correction on Product Judgment: Utilitarian and Hedonic Evaluative Orientation“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/4rzcj5.
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碩士國立臺灣大學
商學研究所
104
The research intends to investigate that when consumers experience mood shift from negative to neutral and are aware of mood as a source of bias for target product judgment, they will correct bias in different ways depending on the evaluative orientation of the target product. Reminded of mood as a possible bias factor, consumers evaluating the hedonic evaluative orientation product will correct their evaluation in the direction opposite to the perceived mood change, leading to a correction toward the negative direction, because they do take mood into consideration when making judgments. However, consumers evaluating the utilitarian evaluative orientation product do not think themselves affected by mood, resulting in no correction. Besides, when consumers keep in neutral mood (i.e., steady neutral mood state), in neither hedonic nor utilitarian evaluative orientation will consumers correct their judgments. In this research, two methods are used to remind participants of potential mood bias. An explicit correction instruction is given in Study 1, whereas an implicit bias-priming article is given in Study 2. The result showed that in negative to neutral shift, participants judging the hedonic evaluative orientation product do correct their evaluation. Nevertheless, the direction of the correction is opposite to what we had expected. It may be that participants correct the strong negative mood rather than the mood shift, leading to a correction toward the positive direction.
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Van, Wyk Daniel Jacobus. „Four-dimensional Q2PSK modulation and coding for mobile digital communication“. Diss., 1996. http://hdl.handle.net/2263/29078.
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Please read the abstract in the section 00front of this document.Dissertation (MEng (Electronic Engineering))--University of Pretoria, 2006.
Electrical, Electronic and Computer Engineering
unrestricted
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Agamy, Mohammed S. „SINGLE STAGE POWER FACTOR CORRECTED THREE-LEVEL RESONANT CONVERTERS“. Thesis, 2008. http://hdl.handle.net/1974/1011.
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In this thesis, a new approach for single-stage power factor correction converters is proposed to increase their power ratings to be in the multiple kilowatts levels. The proposed techniques are based on the utilization of modified three-level resonant converter topologies. These topologies provide low component stresses, high frequency operation, zero voltage switching, applicability under a wide range of input and output conditions as well as added control flexibility. The proposed control algorithms are based on a combination of variable frequency and asymmetrical pulse width modulation control or variable frequency and phase shift modulation control. In either case, the variable frequency control is used to tightly regulate the output voltage, whereas, pulse width or phase shift modulation is used to regulate the dc-bus voltage as well as the input power factor. New converter topologies, their operation and steady state and dynamic analyses are presented in details.
A modelling approach based on average multiple frequency methods is also proposed. This approach leads to the development of a full order state space model with the two control variables explicitly separated allowing a better controller design. The model can be used either at high level of detail expressing the non-linearities of the system or it can readily be simplified to a linear decoupled model for approximate solutions.
Finally, a discrete time controller for the proposed converters, which is suitable for FPGA implementation, is presented. Analytical, simulation and experimental results are provided to verify the proposed concepts.Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2008-01-30 14:28:15.725
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Tsai, Pei-Jan, und 蔡沛然. „Health Promoting Lifestyle Profile among Night Shift Administrators of Correctional Facilities in Taitung County“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/41986438957248581058.
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碩士國立臺東大學
身心整合與運動休閒產業學系
103
The night shift administrators of correctional facilities must guard inmates closely all day and night. But working in day and night shifts will affect their lifestyle seriously, and even their health. The aim of this study was to investigate the health promoting lifestyle profile among night shift administrators of correctional facilities. We applied a cross-sectional design that targeted all night shift administrators of six correctional facilities in Taitung county used structured questionnaires distributed by researcher in person to collect data. Data were collected from 274 administrators with 155 valid responses. Most of the night shift administrators are male. Average age of the subjects is 40. Half of them the education level is college graduate, married and no children. The average of their job experience is 10 years. The night shift administrators are under great pressure of work. The biggest stress is fatigue; then, unsatisfication, depression, anxiety and low self-esteem according to the subscale scored. Their lifestyle is very unhealthy. The worst facet is physical activity; then, stress management, health responsibility, nutrition, interpersonal relations and spiritual growth according to the subscale scored. Major factors of influence on health promoting lifestyle in night shift administrators included the level of education and job stress. By driving workplace health promotion program and encouraging active participation in leisure activities after work, to effectively improve the overall health promoting lifestyle for night shift administrators of correctional facilities.
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Yang, Chun-Yu, und 楊淳宇. „Design and Implementation ofDSP-controlled Power Factor Corrector and Phase-shift Full-bridge Converter“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/86503862796546776047.
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碩士國立臺北科技大學
電力電子產業研發碩士專班
99
The objective of this thesis is to design and implement digital-controlled power factor corrector and phase-shift full-bridge converter. Average current mode control method is used for the front-end control to achieve in-phase control between the current and its sinusoidal reference to improve the power factor. And phase-shift control is applied to the full-bridge converter to achieve ZVS feature and thereby increasing the efficiency. Since the output is with low output voltage and high output current, current doubler rectifier is used on the secondary side of full converter. The digital signal processor, TMS320F2812, TI, is used as the controller for the realization. The specifications of the converter are as follows: Input voltage = AC 110V Output voltage = DC 12V Output power = 360W Switching frequency = 100kHz Experimental results show that the efficiency can go up to 83 % and power factor is 0.997 under full load condition.
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Lin, Hung-Ming, und 林宏明. „A Method of Correcting the Shift Error of Multilevel Flash Memory by the Skill of Gray Code“. Thesis, 2007. http://ndltd.ncl.edu.tw/handle/02734713967112399244.
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碩士中興大學
資訊科學系所
95
In new-generation Flash memories, in order to economize the use of density of a cell that certainly will decrease the reliability of device. Thus, it is very important that how to maintain and improve the reliability of device in multilevel flash. In this work, we propose a new scheme of gray coding to reduce error bits caused by shift level in multilevel flash. Furthermore, the proposed scheme also can effectively enhance the reliability of multilevel flash. In our experiment results, gray coding method can limit the error bits caused by shift level in a scope, and validly reduce check bit number for error correction code. Moreover, it diminishes memory of error check code, area penalty and peak power dissipation.
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Li, Chi-Long, und 李奇龍. „Design and Implementation for a Series and Parallel System of Power Factor Corrector and Phase-Shift Full-Bridge Converter“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4jd9ku.
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碩士國立臺北科技大學
電機工程系所
102
The objective of this thesis is to design and implement a series and parallel system of power factor corrector and phase-shift full-bridge converter. The inputs of power factor correctors are connected in series and the PFC is controlled using average current mode control. The outputs of phase-shift full bridge converters are connected in parallel and phase-shift control is applied to the full-bridge converter control to achieve ZVS and thereby reducing the switching loss of power devices A digital signal processor, TMS320F28035, TI, is used as the controller for the realization. The specifications of the system are as follows: Input voltage = AC 220V Output voltage = DC 12V Output power = 600W Switching frequency of power factor corrector = 80 kHz Switching frequency of phase-shift full-bridge converter = 80 kHz Experimental results show the design specifications can be met and thereby confirming the effectiveness of the topology.
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Lin, Shenghui-hui, und 林昇輝. „The Study on the Relationship among Quality of Work Life, burnout and Shift- Work in the Crime correctional organization basic level officers“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/00839037095173028297.
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36
Plaatjies, Minette Feona. „The application of restorative justice in the South African correctional system“. Diss., 2005. http://hdl.handle.net/10500/2527.
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This dissertation is the culmination of extensive literature study on the application of Restorative Justice in the South African Correctional System. International and national resources on the application of Restorative Justice both in Corrections and as pre-sentence option had been studied.
The background of the penal system and the development of Restorative Justice as part of the Criminal Justice System are investigated by looking at ancient practices, indigenous and modern practices. The study intends to draw on experience from other countries, while at the same time advocate for the development of a uniquely South African model or practice.
The role of the most important stakeholders, namely victim, offender and community is emphasized with reference to the challenges that offenders face in terms of reintegration and the lack of resources in communities to enable them to honour Restorative Justice agreements.Criminology
M. A. (Criminology)