CIVINS / The understanding of large and rare waves in the ocean is becoming more important as these rare events are turning into more common observances. In order to design a marine structure or vehicle to withstand such a potentially devastating phenomenon, the designer must have knowledge of extreme waves with return periods of 50 and 100 years. Based on satellite radar altimeter data, researchers have successfully predicted extreme significant wave heights with the return periods of 50 and 100 years. This thesis extends their research further by estimating the most probable extreme wave heights and other wave statistics based on spectral analysis. The same technique used for extreme significant wave height prediction is applied to extrapolation of corresponding mean wave periods, and they are used to construct two parameter spectra representing storm sea conditions. The prediction of the most probable extreme wave heights as well as other statistical data is based on linear theory and short term order statistics. There exists sufficient knowledge of second order effects on wave generation, and it could be applied to a logical progression of the simulation approach in this thesis. However, because this greatly increases computation time, and the kinematics of deep sea spilling breakers are not yet fully understood for which substantial new research is required, the nonlinear effects are not included in this thesis. Spectral analysis can provide valuable statistical information in addition to extreme wave height data, and preliminary results show good agreement with other prediction methods including wave simulation based on the Pierson-Moskowitz spectrum. / Contract number: N662271-97-G-0025 / CIVINS / US Navy (USN) author

With three different proposals for the bonding in metal carbonyls, it was decided to look into the situation more thoroughly in order to see what other evidence was available to support or refute any of these ideas. It became obvious that a definite contradiction existed between the kinetic evidence of various metal carbonyls, and the concept of MC bond strengths as predicted by Cotton's theory.

by Kwong-hon Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves [112-115]). / Chapter CHAPTER 1. --- INTRODUCTION / Chapter CHAPTER 2. --- PRINCIPLE OF ELLIPSOMETER / Chapter CHAPTER 3. --- MATHEMATICAL REPRESENTATION OF ELLIPSOMETRY / Chapter Section 3.1 --- Ambient Substrate / Chapter Section 3.2 --- Single Layer (Ambient-film substrate) / Chapter Section 3.3 --- Multilayer system (Isotropic Stratified planar structure) / Chapter CHAPTER 4. --- CLASSIFICATION OF ELLIPSOMETER / Chapter Section 4.1 --- Null-type Ellipsometer / Chapter Section 4.2 --- Photometric Ellipsometer / Chapter Section 4.3 --- Spectroscopic Ellipsometer / Chapter CHAPTER 5. --- CONSTRUCTION AND CALIBRATION OF THE SPECTROSCOPIC ELLIPSOMETER / Chapter Section 5.1 --- Design and construction / Chapter 5.1.1 --- Optical Assembly / Chapter 5.1.2 --- Electronic Circuit / Chapter 5.1.3 --- Micro-computer (Software) / Chapter 5.1.4 --- Modification of configuration / Chapter Section 5.2 --- Alignment and Calibration / Chapter 5.2.1 --- Alignment of Optical units / Chapter 5.2.2 --- Calibration of the system / Chapter 5.2.3 --- Measurements on standard samples / Chapter CHAPTER 6. --- ANALYSIS OF ELLIPSOMETRIC PARAMETERS / Chapter Section 6.1 --- Ambient-substrate model / Chapter Section 6.2 --- Ambient-layers model / Chapter 6.2.1 --- Parameter generator / Chapter 6.2.2 --- Least square fitting / Chapter 6.2.3 --- Choice of error function / Chapter CHAPTER 7. --- EXPERIMENTAL RESULT / Chapter Section 7.1 --- Spectra of Refractive index / Chapter 7.1.1 --- Low temperature MBE growth GaAs / Chapter 7.1.2 --- Amorphous Carbon / Chapter 7.1.3 --- High order x AlxGa1-xAs with different cooling rate / Chapter Section 7.2 --- Comparison of ellipsometric spectrum of SOI samples / Chapter 7.2.1 --- Difficulty in the analysis of multi-layer structure / Chapter 7.2.2 --- Silicon on insulator (SOI) / Chapter 7.2.2.1 --- The beam current effects / Chapter 7.2.2.2 --- Annealing after implantation / Chapter CHAPTER 8. --- CONCLUSION / Chapter Section8.1 --- Summary of the results / Chapter Section8.2 --- Suggestions for future work / REFERENCE / APPENDIX(A)MARQUART ALGORITHM / Chapter (B) --- CIRCUIT DIAGRAM

O objetivo deste artigo é avaliar previsões da inflação brasileira a partir do método não-paramétrico de Análise Espectral Singular (SSA). O exercício de previsão utiliza o esquema de janelas rolantes. Diferentes estratégias de combinação de previsões e procedimentos de seleção de variáveis para métodos multivariados foram contempladas. Para robustez, cinco horizontes de previsão foram utilizados. A avaliação das previsões considera diversos procedimentos e medidas estatísticas para oferecer conclusões confiáveis, incluindo razões de erro quadrático médio de previsão, teste de igualdade condicional de habilidade preditiva, diferenças de erro quadrático médio de previsão cumulativas e Model Confidence Set. Os resultados mostram que o SSA supera consistentemente os métodos competidores. Quase todas as previsões SSA superam os competidores em termos de erro quadrático médio de previsão, e em vários casos, com significância estatística. A análise da porção fora da amostra indica superioridade em performance relativa do SSA, especialmente no período de choque nos preços de energia elétrica. Adicionalmente, métodos SSA sempre foram incluídos no conjunto superior do Model Confidence Set. A falta de estudos relacionados com previsão da inflação brasileira e a relativa escassez de análises de previsões via métodos não-paramétricos ressaltam a relevância deste artigo. Não existem pesquisas na literatura de previsão de inflação brasileira aplicando SSA. Uma das estratégias de combinação de previsões aplicadas neste artigo não é comumente encontrada na literatura, na medida em que envolve combinações de diferentes especificações para cada método de previsão. Adicionalmente, restrições de parâmetros foram impostas nas previsões SSA, uma prática não reportada na literatura. / The purpose of this paper is to evaluate Brazilian inflation forecasts produced by the nonparametric method Singular Spectrum Analysis (SSA). This forecasting exercise employs rolling windows scheme. Different strategies of forecast combinations and variable selection procedures for multivariate methods were contemplated. For robustness, five forecast horizons were used. The forecast evaluation considers several statistical measures and procedures to offer reliable conclusions, including mean squared forecast error ratios, tests of equal conditional predictive ability, cumulative square forecast error difference and Model Confidence Set. The results show that SSA consistently outperforms the competitive methods. Almost all SSA forecasts outperforms the competitors in the mean squared forecast error sense, and several with statistical significance. Analysis of the out-of-sample portion indicates relative superior performance of SSA, especially over the period of electricity shock of prices. SSA methods were always included in the superior set of Model Confidence Set procedures. The lack of studies related to Brazilian inflation forecasting and the relative scarcity of nonparametric methods of forecasting analysis highlights the relevance of this paper. There is no research in Brazilian inflation literature applying SSA. One of the forecast combination strategies applied in this paper is not commonly found in the literature, as it involves combinations of different specifications for each forecast method. Additionally, parameter restrictions on SSA forecasts were imposed, a practice which is not reported in the literature.

by Raymon, Wai-man Chan. / "March 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese. / by Raymon, Wai-man Chan.

by Bai Tao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 1-21). / PART I : A new approach to identification by infrared spectrometry / Chapter Chapter 1: --- Introduction --- p.1 / Chapter Chapter 2 : --- Coding system of IR spectra --- p.13 / Chapter Chapter 3 : --- Library search system of IR spectra --- p.46 / Chapter Chapter 4 : --- Identification of pharmaceuticals by the IR database of pharmaceuticals --- p.64 / Chapter Chapter 5 : --- Identification of Chinese mineral drugs by the IR database of Chinese mineral drugs --- p.85 / Chapter Chapter 6 : --- Identification of Chinese herbal drugs by the IR database of Chinese herbal drugs --- p.114 / Chapter Chapter 7 : --- Coding and library search system for IR spectra of some Chinese mineral drugs with no apparent absorption peaks --- p.133 / Chapter Chapter 8: --- Conclusion to Part I --- p.150 / PART II : A new approach to quantification of solid samples by infrared spectrometry / Chapter Chapter 1: --- Introduction --- p.152 / Chapter Chapter 2: --- Derivative method for the IR spectrometric determination of solid samples using polyethylene film as internal standard(DISPE method) --- p.163 / Chapter Chapter 3: --- The IRQA software for quantitative analysis using IR spectrometry --- p.178 / Chapter Chapter 4: --- IR for the quantitative analysis of some Chinese mineral drugs based on the proposed DISPE method --- p.190 / Chapter Chapter 5: --- Determination of iron-containing species in inorganic mixtures using the proposed DISPE method --- p.204 / Chapter Chapter 6: --- Conclusion to Part II --- p.217 / References for Part I / References for Part II / Appendix I for Part I / Appendix II for Part II

Few and many-body systems usually feature interesting and novel behaviors compared with their counterparts in three dimensions. On one hand, low dimensional physics presents challenges due to strong interactions and divergences in the perturbation theory; On the other hand, there exist powerful theoretical tools such as the renormalization group and the Bethe ansatz. In this thesis, I discuss two examples: three interacting bosons in two dimensions and interacting bosons/fermions in one dimension. In both examples, there are intraspecies repulsion as well as interspecies attraction, producing a rich spectrum of phenomena. In the former example, a universal curve of three-body binding energies versus scattering lengths is obtained efficiently by evolving a matrix renormalization group equation. In the latter example, exact solutions for the BCS-BEC crossover are obtained and the unexpected robust features in their excitation spectra are explained by a comprehensive semiclassical analysis.

The abundance of molecular hydrogen (H2), the primary coolant in primordial gas, is critical for the thermodynamic evolution and star–formation histories in early protogalaxies. Suppression of H2–cooling in early protogalaxies can occur via photodissociation of H2 (by ultraviolet Lyman–Werner [LW] photons) or by photodetachment of H−, a precursor in H2 formation (by infrared [IR] photons). It is widely believed that the formation of the first massive black hole “seeds,” with masses 104−6 M⊙, in primordial halos may be enabled if H2–cooling is suppressed. We study the radiative feedback processes that suppress H2–cooling in primordial proto- galaxies. Previous studies have typically adopted idealized spectra, with a blackbody or a power–law shape, in modeling the chemistry of metal–free protogalaxies, and utilized a single parameter, the critical UV flux, or Jcrit, to determine whether H2–cooling is prevented. This can be misleading, as independent of the spectral shape, there is a a critical curve in the (kLW,kH−) plane, where kLW and kH− are the H2–dissociation rates by LW and IR photons, which determines whether a protogalaxy can cool below ∼ 1000 Kelvin. In Chapter 1, we use a one–zone model to follow the chemical and thermal evolution of gravitationally collapsing protogalactic gas, to compute this critical curve, and provide an accurate analytical fit for it. We improve on previous works by considering a variety of more realistic Pop III or Pop II-type spectra from population synthesis models and perform fully frequency–dependent calculations of the H2–photodissociation rates for each spectrum. We compute the ratio kLW/kH− for each spectrum, as well as the minimum stellar mass M∗, for various IMFs and metallicities, required to prevent cooling in a neighboring halo a distance d away. We provide critical M∗/d2 values for suppression of H2–cooling, with analytic fits, which can be used in future studies. Determining the photodissociation rate of H2 by an incident LW flux is crucial, but prohibitively expensive to calculate on the fly in simulations. The rate is sensitive to the H2 rovibrational distribution, which in turn depends on the gas density, temperature, and incident LW radiation field. In Chapter 2, we use the publicly available cloudy package to model primordial gas clouds and compare exact photodissociation rate calculations to commonly–used fitting formulae. We find the fit from Wolcott-Green et al. (2011) is most accurate for moderate densities n ∼ 103cm−3 and temperatures, T ∼ 103K, and we provide a new fit, which captures the increase in the rate at higher densities and temperatures, owing to the increased excited rovibrational populations in this regime. Our new fit has typical errors of a few percent percent up to n ≤ 107 cm−3, T ≤ 8000K, and H2 column density NH2 ≤ 1017 cm−2, and can be easily utilized in simulations. We also show that pumping of the excited rovibrational states of H2 by a strong LW flux further modifies the level populations when the gas density is low, and noticeably decreases self-shielding for J21 > 103 and n < 102cm−3. This may lower the “critical flux” at which primordial gas remains H2–poor in some protogalaxies, enabling massive black hole seed formation. In Chapter 3, we study the thermal evolution of UV–irradiated atomic cooling halos using high–resolution three–dimensional hydrodynamic simulations. We consider the effect of H− photodetachment by Lyα cooling radiation in the optically–thick cores of three such halos, a process which has not been included in previous simulations. H− is a precursor of molecular hydrogen, and therefore, its destruction can diminish the H2 abundance and cooling. We find that the critical UV flux for suppressing H2–cooling is decreased by up to a factor of a few when H− photodetachment by Lyα is included. In a more conservative estimate of the trapped Lyα energy density, we find the critical flux is decreased by ∼ 15 − 50 per cent. Our results suggest that Lyα radiation may have an important effect on the thermal evolution of UV–irradiated halos, and therefore on the potential for massive black hole formation.

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