Recent developments in data packets based high speed digital communications have opened the door for new types of applications in power system protection and control. Intelligent Electronic Devices (IEDs) are equipped with various communication capabilities that make their functional integration a natural next step. Existing integration of substation equipment is not capable of clustering with the purpose of pooling hardware resources. <p> Presently, every electric device requiring protection has its dedicated hardware performing the predetermined set of protective functions. A new function-based protection and control philosophy is proposed, based on an open-system solution. In the proposed system, the resources of the protective and control hardware are pooled, and as a clustered system provide each protected unit (line, transformer, breaker, etc) with functions required for complete direct and backup protection. <p> The work presented in this thesis identifies the performance requirements of a digital relaying algorithm for processing samples that are sent across Ethernet-based communication channels. The work shows the shortcomings and unstable performance of widely used protective algorithms in accommodating data samples that are out of step from their proper position due to variable time delays of the communications media. A new digital relaying algorithm was developed that is able to extract the amplitude and phase angle of signals from data samples received across Ethernet networks with variable jitter. <p> The performance of the algorithm was tested by using the recovered phasor amplitude and phase angle information in protective solutions. The results show that there is significant flexibility in the algorithm that can be used to facilitate less performant communication channels, or, to take advantage of faster communications channels by reducing the response time of the protective function. <p> The results show that the algorithm works well with variable length data windows, and variable sampling frequencies. Higher sampling rates make communications problems more visible, but the presented algorithm is able to compensate for wide variations in network performance, effectively maintaining sampled signal phase and amplitude information during network performance fluctuations.

The essay is about the unnamed husband in Jean Rhys's Wide Sargasso Sea. About how he is depicted as the European "Other" and made into a feminized and zombified weak character from a Caribbean/feminist perspective...

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This thesis has described a wide tuning range transconductor combining source degeneration, cross-coupled, translinear loop to achieve high linearity. The transconductance tuning range from 220£gs to 1050£gs with 1V input range and the total harmonic distortion is -50dB with 0.6Vpp input voltage. And its application to a fifth-order elliptic low-pass Gm-C filter for the front-end RF circuit is presented. In order to transform the passive element circuit into a Gm-C based filter, a GIC flow method has been used. The proposal Gm-C based filter achieve a with performance a low frequency filtering range from 5Mhz to 10Mhz by transconductance tuning.

PDMS has not only the characteristics of good chemical and physical properties,flexible, low surface free energy, and good optically transparent, also has the advantages of low cost, low toxicity and environmental protection. In this study we use PDMS to fabricate liquid crystal device with different micro-confined structures. We had a discussion about liquid crystal in the micro-confined structure through optical textures and measured electro-optical characteristics on our device. Through the experiment we found the liquid crystal device with micro-confined structure had not only the characteristics of wide viewing angle and contrast ratio has been up to standard in normal display. And it also demonstrated the capability in flexible liquid crystal display.

To increase genetic diversity with elite upland cotton, introgression populations with wild species of cotton, Gossypium mustelinum and G. tomentosum, were created. To accomplish this objective, F1, F2, BC1F1, and BC1F2 generations were developed along with random mating populations (BC1rm1 and BC1rm2) and grown in a randomized complete block design with four replications in College Station, Texas during 2003 and 2004, and in Mexico during 2005 for G. mustelinum introgression populations. These generations were tested with microsatellite markers from chromosome 11 in order to measure the effects of selection and recombination. Later generations (BC2F1, BC2rm1, BC2F2, BC3F1, BC3rm1 and BC3F2) and composite generations were evaluated in a randomized complete block design with four replications during 2004 and 2005 for agronomic properties. Introgression barriers for G. mustelinum were found to include daylength sensitivity and hybrid breakdown, which was only apparent in Mexico. Backcross generations had improved fiber quality. Random mating populations did not have increased variance and means differed little from BC1F1 levels. Microsatellite markers showed decreased frequency of G. mustelinum alleles and decreasing heterozygosity, but no increase in map distances in random mating populations. Upper-half mean length and upper quartile length by weight were highly heritable, as measured with parent-offspring regression. Most other agronomic traits had moderate heritabilities. Composite generations were found to be favorable for selection and breeding. For G. tomentosum populations, hybrid breakdown was also a problem with low yields for F2 and BC1F2 generations, but day length sensitivity was not. Little or no increase in variance was found in random mating populations when compared to BC1F1 levels. G. tomentosum populations did not show improvements in fiber length as seen in G. mustelinum populations, but did have increased strength in BC1F1 and F1 generations over TM-1. Mapping distances increased in the random mating populations for G. tomentosum, and the frequency of alien alleles did not decrease in random mating populations. Generation means approached recurrent parental values for most traits within three backcrosses. Composite generations were found to be the most useful for breeding and selection.

Frequency reuse scheme is used to enhance the spectral efficiency in a cellular system, but inevitably the system suffers from co-channel interference of other users. Signal-to-interference ratio (SIR) is often used as a quality index of communication links. Several wireless communication algorithms, such as channel assignment, handover and power control, need real-time SIR information. All of these algorithms are under the assumptions that real-time SIR is available, but the methods of obtaining real-time SIR are seldom mentioned with these algorithms. In this thesis, we investigate three simple SIR estimation methods including statistics of spreading chips method, decorrelation detection method, and orthogonal stochastic approximation method. The performance of these SIR estimation methods are evaluated by computer simulations in a WCDMA system.

The main purpose of this thesis is to estimate the direct path in dense multipath Ultra Wide-Band (UWB) environment. The time-of-arrival (ToA) estimation algorithm used is based on Generalized Maximum-Likelihood (GML) algorithm. Nevertheless, GML algorithm is so time-consuming that the results usually take a very long period of time, and sometimes fail to converge. Hence, the schemes that would improve the algorithm are investigated. In the schemes, the search was executed in sequential form. Two threshold parameters are to be determined¡Xone is about the arrival time of the estimation path while the other is the fading amplitude of the estimation path. The thresholds are determined in order to terminate the sequential algorithm. The determination of thresholds is based on error analysis, including the probability of error and root-mean-square error. The analysis of the probability of error is subject to the probability of false alarm and the probability of miss. However, a trade-off problem on the probability of false alarm and the probability of miss exists in the process of determining thresholds. The thresholds are determined according to the requirement of the probability of error. We propose an improvement scheme for determining the two thresholds. In the proposed scheme, candidate pairs are evaluated within an appropriate range. The root-mean-square error value for each pair of thresholds is calculated. The smallest error, corresponding to the desired thresholds, is chosen for use in ToA estimation. From the simulation results, it is seen that, when SNR falls between -4dB and 16dB, the improvement proposed scheme results has the smaller estimation error.

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Novel designs of three-dimensional patch antennas for beamdwidth enhancement and broadband peration have been proposed in this dissertation. For the beamwidth enhancement, the patch antenna with an inverted V-shaped patch has been proposed, and the antenna¡¦s radiation beamwidths have been broadened. Another beamwidth enhancement design using a three-dimensional square ground structure has also been demonstrated, and the 3-dB beamwidth of the CP radiation can reach more than 110¢X. In addition to the designs of beamwidth enhancement, the broadband patch antennas with a V-shaped patch, a W-shaped ground plane and a short probe-pin have been proposed. These novel structures can have significantly reduced probe-pin length and obtain a good impedance matching over a wide frequency range. Finally, a 1 ¡Ñ 2 broadband patch antenna array, suitable for base-station antenna applications for mobile communications systems, has also been studied.