As IC technology moves into the deep submicrometer regime in high performance ULSI circuits, it is required to decrease the metal pitch and to increase the number of metal layers for interconnect to accommodate the increased packing density and functional complexity. But the signal propagation delay in the interconnect becomes an appreciable fraction of the total time delay. Use of low dielectric constant material (low-k) as the intermetal dielectric (IMD) results in low inter-line capacitance and therefore high performance in speed, low power dissipation, and low cross-talk noise. During various low dielectric materials, porous silica film is one of the possible candidates with an inherent low dielectric constant. In this thesis, the intrinsic properties such as fundamental physical, electrical, thermal stability of the spin on glass (SOG) have been investigated. We also study the properties of the SOG film with various plasma and treatments. An inherent low dielectric constant of 1.9 is achieved for high porosity of the porous silica film and the leakage current density keep at a level of ~10-9 A/cm2 at 1MV/cm electric field strength. After O2 plasma treatment, the Si-C and C-H bonds of the film are almost eliminated, thus the dielectric constant and leakage current are rapid increase than that of those untreated films. We find that H2 plasma can passivate the porous silica surface so that the leakage current can be kept at acceptable range, however, the dielectric constant increase slightly. Moreover, the etching issues were also investigated in this study. The mask undercutting on sidewall was observed due to the spontaneous reaction between the porous silca film and fluorocarnbon plasma. Therefore, H2 plasma treatment was provided to suppress this phenomenon. In this study, the intrinsic properties such as fundamental physical, electrical, and thermal properties of the porous silica have been investigated. The compatibility of the porous silica with integration processes also has been studied comprehensively. We have proposed H2 plasma treatments to improve the dielectric properties of porous silica after photoresist removal. Material and electrical analyses were used to interpret these improvements.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 129-137). Available also in a digital version from Dissertation Abstracts.

Nonlinearity accompanied with stiffness in atmospheric boundary layer physical parameterizations is a well-known concern in numerical weather prediction (NWP) models. Nonlinear diffusion equations, furthermore, are a class of equations which are extensively applicable in different fields of science and engineering. Numerical stability and accuracy is a common concern in this class of equation. In the present research, a comprehensive effort has been made toward the temporal integration of such equations. The main goal is to find highly stable and accurate numerical methods which can be used specifically in atmospheric boundary layer simulations in weather and climate prediction models, and extensively in other models where nonlinear differential equations play an important role, such as magnetohydrodynamics and Navier-Stokes equations. A modified extended backward differentiation formula (ME BDF) scheme is adapted and proposed at the first stage of this research. Various aspects of this scheme, including stability properties, linear stability analysis, and numerical experiments, are studied with regard to applications for the time integration of commonly used nonlinear damping and diffusive systems in atmospheric boundary layer models. A new temporal filter which leads to significant improvement of numerical results is proposed. Nonlinear damping and diffusion in the turbulent mixing of the atmospheric boundary layer is dealt with in the next stage by using optimally stable singly-diagonally-implicit Runge-Kutta (SDIRK) methods, which have been proved to be effective and computationally efficient for the challenges mentioned in the literature. Numerical analyses are performed, and two schemes are modified to enhance their numerical features and stability. Three-stage third-order diagonally-implicit Runge-Kutta (DIRK) scheme is introduced by optimizing the error and linear stability analysis for the aforementioned nonlinear diffusive system. The new scheme is stable for a wide range of time steps and is able to resolve different diffusive systems with diagnostic turbulence closures, or prognostic ones with a diagnostic length scale, with enhanced accuracy and stability compared to current schemes. The procedure implemented in this study is quite general and can be used in other diffusive systems as well. As an extension of this study, high-order low-dissipation low-dispersion diagonally implicit Runge-Kutta schemes are analyzed and introduced, based on the optimization of amplification and phase errors for wave propagation, and various optimized schemes can be obtained. The new scheme shows no dissipation. It is illustrated mathematically and numerically that the new scheme preserves fourth-order accuracy. The numerical applications contain the wave equation with and without a stiff nonlinear source term. This shows that different optimized schemes can be investigated for the solution of systems where physical terms with different behaviours exist.

Thesis (M.Com. (Finance))--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Economic and Business Sciences, 2016 / This study aims to investigate the presence of the low market risk (beta) anomaly in the Johannesburg Stock Market (JSE). Finance theory suggests that with higher return comes higher risk. However, several studies have reported evidence of low risk anomaly in global markets where portfolios containing low beta shares delivers superior risk adjusted returns compared to market index and high beta shares' portfolio. This study will explore various risk return relationships on the JSE and test a variety of potential explanations of the anomalous behaviour of the low beta premium. Three explanations have been identified as potential factors that contribute to the persistence of the Low Beta Anomaly. These include; Net International Equity flows (NIEF), Idiosyncratic Risk and Market Concentration. The results are consistent with international literature indicating a persistent Low Beta Anomaly on the JSE. However, the results also indicate that in periods of turmoil, high beta shares outperform low beta shares i.e. during the Global Financial Crisis. Although some significant relationships are found between the low minus high beta differential and NIEF. NIEF is unable to suitably explain the anomaly. Idiosyncratic risk results are mixed depending on the model used to calculate the idiosyncratic risk estimates. Despite being a significant issue on the JSE, Market concentration does not explain the Low Beta Anomaly. As the superior performance of the low beta portfolios remains once the portfolios returns have been adjusted for the different variables however magnitude ofthe outperformance ofthe low beta portfolio was to a lesser degree. / AC2016

Wong Pui On Raymond. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 105-120). / Abstracts in English and Chinese. / Contents --- p.i / Abstract --- p.vi / Statement of originality --- p.xii / Acknowledgments --- p.xiii / List of figures and tables --- p.xiv / Abbreviations --- p.xvii / Publications --- p.xx / Text / Chapter Chapter 1: --- Introduction and Objectives --- p.1 / Chapter 1.1 --- Neonatal Sepsis --- p.2 / Chapter 1.2 --- Markers of Infection --- p.4 / Chapter 1.2-1 --- Clinical markers for sepsis --- p.4 / Chapter 1.2-2 --- Cytokines as markers of sepsis --- p.7 / Chapter 1.2-3 --- Cell surface receptors as markers of sepsis --- p.8 / Chapter 1.3 --- The immune system in response to pathogen challenge --- p.10 / Chapter 1.3-1 --- Source of cytokines --- p.11 / Chapter 1.4 --- General outline of cytokines implicated in sepsis --- p.12 / Chapter 1.4-1 --- IL-2 --- p.13 / Chapter 1.4-2 --- IL-4 --- p.15 / Chapter 1.4-3 --- IL-5 --- p.16 / Chapter 1.4-4 --- IL-6 --- p.17 / Chapter 1.4-5 --- IL-10 --- p.18 / Chapter 1.4-6 --- IFN-γ --- p.19 / Chapter 1.4-7 --- TNF-α --- p.21 / Chapter 1.5 --- General outline of cell surface receptors implicated in sepsis --- p.23 / Chapter 1.5-1 --- CDllb --- p.23 / Chapter 1.5-2 --- CD64 --- p.24 / Chapter 1.5-3 --- CD45RO --- p.25 / Chapter 1.5-4 --- CD25 --- p.26 / Chapter 1.6 --- Aims of study --- p.27 / Chapter Chapter 2: --- Materials and methods --- p.31 / Chapter 2.1 --- Patients inclusion criteria and classification --- p.32 / Chapter 2.2 --- Sample collection and sepsis screening --- p.33 / Chapter 2.3 --- Quantitation of cell surface antigens --- p.35 / Chapter 2.3-1 --- Cell acquisition and calculation --- p.37 / Chapter 2.4 --- Quantitation of plasma cytokines --- p.38 / Chapter 2.4-1 --- Cytometric Beads Array assay --- p.40 / Chapter 2.5 --- Statistical Analysis --- p.41 / Chapter Chapter 3: --- "Cell surface and plasma cytokine markers for the diagnosis of late-onset sepsis in preterm, very low birthweight (VLBW) infants" --- p.51 / Chapter 3.1 --- Results --- p.52 / Chapter 3.1-1 --- Lymphocyte markers: CD25 and CD45RO --- p.52 / Chapter 3.1-2 --- Neutrophil markers --- p.53 / Chapter 3.1-2a --- CD64 --- p.54 / Chapter 3.1-2b --- CDllb --- p.55 / Chapter 3.1-3 --- Purified CDllb --- p.56 / Chapter 3.1-4 --- Comparison of cell surface markers --- p.56 / Chapter 3.1-5 --- Interluekin 6 (IL-6) and C-Reactive Protein (CRP) --- p.57 / Chapter 3.2 --- Combined analysis of diagnostic markers --- p.58 / Chapter 3.3 --- Discussion --- p.58 / Chapter Chapter 4: --- Proinflammatory and anti-inflammatory cytokine response in preterm very low birthweight infants (VLBW) with systemic infections --- p.82 / Chapter 4.1 --- Results --- p.83 / Chapter 4.1-1 --- Correlation of cytokine levels in infected patients --- p.84 / Chapter 4.2 --- Subgroup analysis --- p.85 / Chapter 4.2-1 --- Proinflammatory and anti-inflammatory cytokine ratios --- p.85 / Chapter 4.2.2 --- The deceased case --- p.86 / Chapter 4.3 --- Discussion --- p.87 / Chapter Chapter 5: --- General Discussion and Conclusions --- p.97 / Chapter 5.1 --- General Discussion --- p.98 / Chapter 5.1-1 --- Cell surface markers --- p.98 / Chapter 5.1-2 --- Infection markers with prognostic significance --- p.100 / Chapter 5.1-3 --- Limitations of infection markers in clinical applications --- p.100 / Chapter 5.2 --- Conclusions and future development --- p.102 / Chapter 5.2-1 --- Conclusions --- p.102 / Chapter 5.2-2 --- The future development --- p.102 / References --- p.105

No description available.

A clock driver that works on the principle of charging and discharging the clock network in a VLSI circuit in two steps is investigated in a few different configurations. The aim of the design is twofold: to reduce the power consumption to reduce the third harmonic of the clock signal, and thereby the EMI (electromagnetic interference) emitted by the clock network. The first should be possible to accomplish as the clock interconnect network gets charged by half the voltage during each rising transition, and the second should be possible to accomplish by carefully time the rising and falling transitions, so that the third Fourier coefficient of the resulting wave form cancels. The drivers are loaded by eight 16-bit adders. The drivers’ power consumption, and the spectrum of the output signal, are investigated under varying clock frequencies, power supply voltage, and driver architecture. The results are compared to a conventional square wave clock. The results are that while the third harmonics of the resulting output sees an improvement in all the investigated cases over the square wave clock, the power savings are, for higher clock frequencies, more than completely canceled by the extra power needed in the logic stage which controls these drivers. On the other hand, the power consumption of the new driver appears to drop below that of the conventional driver when the clock frequency drops below approximately 100MHz. A few suggestions for further investigations of new designs and clock wave forms are given.

Purpose: The prevalence of age-related visual impairment is projected to increase as the Canadian population ages. As a result, the demand for low vision service is also projected to increase. However, there is a lack of healthcare planning regarding vision rehabilitation in Canada. The current study is the first study that describes optometric low vision services across Canada. The primary purposes of this study were to determine the provision of low vision services by optometrists in Canada, the barriers to providing low vision services and the pattern and perception of referrals to specialised low vision services. The secondary purposes of this study were to examine regional differences in low vision practice and referral patterns, and to identify predictive factors associated with the extent of optometric low vision care. Methods: Practising optometrists across Canada (n=1839 or 40.5% of the Canadian optometric population) were randomly sampled so as to obtain approximately equal responses from the Western Provinces, Ontario, Quebec and the Eastern provinces. Between October 2010 to January 2011, optometrists were invited to participate in a 30-item questionnaire that included questions on personal profile, primary practice profile, types of patients seen, levels of low vision services offered, patterns of referral and barriers to provision of low vision care. Descriptive statistics were used to describe the current landscape of optometric low vision care. Chi-square analyses were used to identify any regional differences in pattern of low vision provision and/or referrals. Multivariate logistic regression was used to determine the predictive factors associated with the extent of optometric low vision care. Written comments on low vision education and provision of low vision services were first coded to represent relevant categories of information emerging from the written data. Then the patterns of coding were grouped into common themes. Results: A total of 459 optometrists responded (24.8%). Optometrists estimated that 1% (range 0-100%) of their patients were patients with low vision, yet also estimated that 10% of their patients had a best corrected visual acuity of ???6/12. Almost three-quarters of respondents would manage a hypothetical patient with minimal visual disabilities and simple visual goals with high-powered additions and lighting; however, the proportion of those who would manage with the same patient with magnifiers and filter lenses dropped to 43%. The most frequently cited barriers to providing more extensive low vision services were found to be related to financial non-viability, lack of affordability by the patient and the time-consuming nature of conducting a low vision assessment. The percentage of respondents who cited no interest in low vision was 33.5%. Many respondents would like to see more continuing education on low vision, preferably through a hands-on approach. The most frequent site of referral was CNIB (81.9%), although most of the respondents (57.1%) rarely (0-5% of the time) or almost never (0-25% of the time) received a written report from the low vision service providers. Chi-square analyses revealed that optometrists in Quebec tended to refer eligible patients to government-sponsored vision rehabilitation centres, while optometrists in Eastern provinces tended to manage patients on their own. The predictive factors associated with the extent of optometric low vision care were advanced years of practice (16+ years), having local low vision optometrists/ophthalmologists within one-day???s travel, working in a practice within a population of less than 50,000 and working in a non-solo practice. Conclusions: This study documents that optometrists may be undertaking more low vision (LV) in patients with relatively good vision than they tend to label as LV. Vision rehabilitation is of interest to a large portion of optometrists across Canada. To translate the interest into practice, barriers identified by the current study must be addressed.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Accompanying booklets in pockets. Includes bibliographical references (leaves 110-121). Also available via the Internet.

Inaug.-Diss.--Leipzig. / Lebenslauf. "Litteratur": p. [6].