Wurtzite (W)-type ZnO condensates showed preferred orientation {10 1} when deposited on glass substrate by pulsed laser ablation on Zn target in the presence of oxygen. Such an artificial epitaxy depends on the well developed {10 1} surfaces of the condensates, which enabled {10 1}-specific coalescence to form twin and single crystal regardless of the co-deposited Zn. The W-ZnO condensates have decreasing particle size with increasing oxygen flow rate and a considerable residual stress due to the combined effects of rapid heating/cooling and thermal/lattice mismatch with Zn following parallel epitaxy or (01 )W-ZnO//(01 0)Zn; [ 2 3]W-ZnO//[0001]Zn involving {10 1} slip (Part I). In addition, wurtzite (W)-type ZnO/Zn composite deposit with preferred orientation {10 1}W-ZnO and (0001)Zn respectively on glass substrate in chapter I under Isothermal (600oC) atmospheric annealing caused self-catalyzed vapor-liquid-solid growth of rod-like W-ZnO whiskers with unusual habit. Analytical electron microscopic observations indicated that the W-ZnO whiskers extend along the zone axis of the well-developed polar surfaces {10 1} for a beneficial lower electrostatic energy and surface energy. Alternatively, the whiskers extend via {11 1}-specific growth twinning and/or coalescence twinning for a beneficial fair coincidence-site lattice at the twin boundary (Part II). Furthermore, Zn particulates overlain with wurtzite (W)-type ZnO condensates having nearly orthogonal {10 1} and {11 1} facets were found to self-catalyze unusual tapered W-ZnO whiskers upon isothermal atmospheric annealing, i.e. thermal oxidation, at 600oC. Analytical electron microscopic observations indicated that such whiskers formed tapered slabs having mosaic {10 1} and {2 1} twinned domains. The tapered whiskers can be rationalized by unconventional vapor-liquid-solid growth, i.e. {hkil}-specific coalescence twinning growth from the ZnO condensates taking advantage of a partially molten bottom source of Zn and the adsorption of atoms at the whisker tips and steps under the influence of capillarity effect (Part III). Finally, Electron irradiation of nano-size wurtzite (W)-type ZnO condensates with intimate mixture of parallel epitaxial Zn caused {10 1}W slip to form a single domain of rock salt (R)-type core and W-type shell. The two polymorphs follow (1 1)R//(0 11)W; [011]R//[ 2 3]W, i.e. chair type Peierls distortion with additional 38 degree tilting (001)R along the ( 2 0)W plane for a fair match of (10 1)W/(1 1)R, the same as one of the two paths for the back-transformation of R-ZnO into a lower crystal symmetry. The martensitic nucleation of R-type ZnO can be attributed to dynamic migration of interstitials/vacancies, lattice mismatch stress, and capillarity effect.

The self-organizing map (SOM) is an unsupervised learning algorithm which has been successfully applied to various applications. One of advantages of SOM is it maintains an incremental property to handle data on the fly. In the last several decades, there have been variants of SOM used in many application domains. In this dissertation, two new SOM algorithms are developed for image quantization and compression. The first algorithm is a sample-size adaptive SOM algorithm that can be used for color quantization of images to adapt to the variations of network parameters and training sample size. The sweep size of neighborhood function is modulated by the size of the training data. In addition, the minimax distortion principle which is modulated by training sample size is used to search the winning neuron. Based on the sample-size adaptive self-organizing map, we use the sampling ratio of training data, rather than the conventional weight change between adjacent sweeps, as a stop criterion. As a result, it can significantly speed up the learning process. Experimental results show that the proposed sample-size adaptive SOM achieves much better PSNR quality, and smaller PSNR variation under various combinations of network parameters and image size. The second algorithm is a novel classified SOM method for edge preserving quantization of images using an adaptive subcodebook and weighted learning rate. The subcodebook sizes of two classes are automatically adjusted in training iterations based on modified partial distortions that can be estimated incrementally. The proposed weighted learning rate updates the neuron efficiently no matter of how large the weighting factor is. Experimental results show that the proposed classified SOM method achieves better quality of reconstructed edge blocks and more spread out codebook and incurs a significantly less computational cost as compared to the competing methods.

No description available.

<p>In order to achieve results that are reliable when using the finite element method one has to use an acceptable element mesh with respect to the shape and size of the elements. As a help to produce an acceptable mesh there are quality criteria that must be fulfilled in most pre-processors.</p><p>One objective with this thesis is to perform a sensitivity study that can be used as a basis for a Mesh guideline for chassis parts which is requested from engineers at Volvo 3P. The software used in the sensitivity study is ANSA as pre-processor, Nastran as solver and Metapost as post-processor.</p><p>In the first part of the sensitivity study three different models are used for studying quality criteria such as aspect ratio, skewness, mid point alignment, mid point deviation and element size. Solid elements of second order, which are used in the three models, can be generated in two ways, which constitutes another part of the sensitivity study. They may either be generated from the beginning or can be converted from first order elements. This means geometrically that if second order elements where generated from the beginning the element mesh would follow the shape of the component in a better way compared to the other method.</p><p>Recently a pre- and post-processing program called SimLab was introduced on the market. Since SimLab supports geometry import from several CAD-systems without loss of feature information, the automatic element mesh generation is supposed to be better as the mesh generator has access to more information concerning the geometry. An evaluation of SimLab is the second major objective of the thesis. More specifically, the evaluation concerns the possibility of using the software at Volvo 3P.</p><p>Results show a surprising insensitivity regarding the criteria and that the method of generating second order elements from the beginning is to be preferred. SimLab is a new program with big potential and the conclusion is that it is possible to use it at Volvo 3P.</p>

<p>A laser-triangulating range camera uses a laser plane to light an object. If the position of the laser relative to the camera as well as certrain properties of the camera is known, it is possible to calculate the coordinates for all points along the profile of the object. If either the object or the camera and laser has a known motion, it is possible to combine several measurements to get a three-dimensional view of the object.</p><p>Camera calibration is the process of finding the properties of the camera and enough information about the setup so that the desired coordinates can be calculated. Several methods for camera calibration exist, but this thesis proposes a new method that has the advantages that the objects needed are relatively inexpensive and that only objects in the laser plane need to be observed. Each part of the method is given a thorough description. Several mathematical derivations have also been added as appendices for completeness.</p><p>The proposed method is tested using both synthetic and real data. The results show that the method is suitable even when high accuracy is needed. A few suggestions are also made about how the method can be improved further.</p>

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 138-149). Also available in print.

The purpose of this study was to evaluate whether the personality trait elevation between honest and applicant contexts that has been widely seen throughout the personality and selection research is merely universal, blatant trait elevation, or whether something else is underlying this faking behavior. By obtaining both honest and applicant context personality responses in which respondents were provided with focal job knowledge, this study determined that while there is near-universal trait elevation across seven personality traits, there is, in fact, some trait differentiation between jobs. As such, this study provided some evidence of knowledgeable faking, defined as distortion of personality test responses based on knowledge of the job being applied to, within applicant contexts.

The Speedy Delivery (SD) waveform was introduced in patent US 6,441,695 B1 issued August 27, 2002 to the inventor Dr. Robert Flake. In the most basic form, the SD boundary condition is an exponential, D⋅e [superscript α⋅t] . The propagating waveform is described by an analytic, closed form solution of the wave equation in lossy media and has several very special properties. The most surprising property is that the leading edge of the waveform propagates with attenuation but without distortion. The lack of distortion occurs even in lossy transmission media with frequency dependent parameters. This is unlike any other known pulse shape. Additionally, varying the waveforms parameter, α, can vary the propagation velocity and the attenuation of the waveform. Because the exponential waveform is unbounded it cannot continue indefinitely and must be truncated and closed by a non-SD closing edge. This dissertation discusses the transmission behavior and two applications of truncated SD waveforms. A brief analysis of SD propagation in lossy transmission lines is presented and some practical considerations associated with truncating the SD waveforms are addressed. The parameters needed to describe the propagation of the SD waveform are defined and techniques for determining their values are presented. Finally, examples applying these truncated SD waveforms to time domain reflectometry and Communication Technology are presented. / text

This study built upon the theoretical feedback process of Ilgen, Fisher and Taylor (1979), as refined by Kinicki, Prussia, Wu, & Mckee-Ryan (2004), to contribute to a more comprehensive understanding of the mechanism underlying an individual's response to performance feedback. The feedback model implicates source credibility and the feedback-rich environment as critical elements in the process explaining recipient accuracy perceptions and responses. Thus the sign and perceived accuracy of performance feedback were investigated in a 3 x 3 (plus control) experimental design. One hundred fifty-six undergraduate students were randomly assigned to feedback conditions, in which they performed on a three-trial Lego model reproduction task. After trial one, participants received false feedback from a confederate supervisor. The feedback was based on fictional norm tables, which framed the participant's performance as falling into the 70th percentile (positive), 50th percenti le (average), or 30th percentile (negative) according to condition. The supervisor then supplemented the norm tables with conclusive comments designed to be perceived as positive distortion of the norm table feedback, reinforcement of norm tables (accurate feedback), or negative distortion of the norm tables. Performance time, errors, task-specific self-efficacy, self-assessment of performance, and self-report effort-expended data were collected on trials one through three. The results indicated a significant interaction between feedback sign and perceived feedback accuracy on participant performance (F(4,132) = 3.72, p < 0.01), whereby the performance in the positively distorted-positive sign feedback condition was significantly higher than performance in the positively distorted-negative sign feedback condition. When the feedback was perceived to be accurate, negative sign feedback resulted in significantly better performance compared to the positive feedback condition (contrar y to previous research). Task-specific self-efficacy was not found to mediate the relationship between type of feedback and performance, and no significant effect of feedback sign or perceived feedback accuracy on task-specific self-efficacy was found. These findings provide possible explanation as to why supervisors tend to positively distort both sign and accuracy in performance appraisals (e.g., Benedict & Levine, 1988). Implications for theoretical expansion of the feedback process model, and application to workplace performance management are discussed.

In this thesis, we examine quasiconformal mappings in Rn. We begin by proving basic properties of the modulus of curve families. We then give the geometric, analytic,and metric space definitions of quasiconformal maps and show their equivalence. We conclude with several computational examples.