Current North American operational satellite passive microwave snow water equivalent (SWE) retrieval algorithms consistently underestimate SWE levels for tundra environments when compared to four years of regional snow surveys conducted in the Northwest Territories and northern Manitoba, Canada. Almost all contemporary SWE algorithms are based on the brightness temperature difference between the 37GHz and 19GHz frequencies found onboard both past and present spaceborne sensors. This underestimation is likely a result of the distribution and deposition of the tundra snow, coupled with the influence of tundra lakes on brightness temperatures at the 19GHz frequency. To better our understanding concerning the underestimation of passive microwave SWE retrievals on the tundra, Environment Canada collected in situ measurements of SWE, snow depth, and density at 87 sites within a 25km by 25km study domain located near Churchill, Manitoba in March 2006. Coincident multi-scale passive microwave airborne (70m & 500m resolution) and spaceborne (regridded to 12.5km & 25km resolution depending on frequency) data were measured at 6.9GHz, 19GHz, 37GHz and 89 GHz frequencies during the same time period. The snow survey data highlighted small-scale localized patterns of snow distribution and deposition on the tundra that likely influences current SWE underestimation. Snow from the open tundra plains is re-distributed by wind into small-scale vegetated features and micro-topographic depressions such as narrow creekbeds, lake edge willows, small stands of coniferous trees and polygonal wedge depressions. The very large amounts of snow deposited in these spatially-constrained features has little influence on the microwave emission measured by large-scale passive microwave spaceborne sensors and is therefore unaccounted for in current methods of satellite SWE estimation. The analysis of the passive microwave airborne data revealed that brightness temperatures at the 19GHz were much lower over some tundra lakes, effectively lowering SWE at the satellite scale by reducing the 37-19GHz brightness temperature difference used to estimate SWE. The unique emission properties of lakes in the wide open expanse of the tundra plains, coupled with an insensitivity to the large amounts of SWE deposited in small-scale features provides an explanation for current passive microwave underestimation of SWE in the tundra environment.

Conventionally, metal halide lamps were struck by voltages higher than those required for breaking down the electrodes to ensure successful ignition. These high ignition voltages may hurt the electrodes to some extent, leading to a shorter lamp lifecycle. In practice, the breakdown voltage can be affected by the dark current which occurs when a voltage is applied on lamp before the electrodes have been broken down. A lamp model to account for the dark current is derived from the test results. Three ignition schemes with single-pulse, multiple pulses and step voltage are used for describing the effect of the dark current on the breakdown voltage. Experimental results exhibit that the breakdown voltage can be lowered by applying a higher dark current or allotting more times of dark current to the lamp. The investigation provides useful information for the design of the ignition circuit.

The purpose of this study was to determine how well the Monte Carlo transport code FLUKA can simulate a tissue-equivalent proportional counter (TEPC) and produce the expected delta ray events when exposed to high energy heavy ions (HZE) like in the galactic cosmic ray (GCR) environment. Accurate transport codes are desirable because of the high cost of beam time, the inability to measure the mixed field GCR on the ground and the flexibility they offer in the engineering and design process. A spherical TEPC simulating a 1 um site size was constructed in FLUKA and its response was compared to experimental data for an 56Fe beam at 360 MeV/nucleon. The response of several narrow beams at different impact parameters were used to explain the features of the response of the same detector exposed to a uniform field of radiation. Additionally, an investigation was made into the effect of the wall thickness on the response of the TEPC and the range of delta rays in the tissue-equivalent (TE) wall material. A full impact parameter test (from IP = 0 to IP = detector radius) was performed to show that FLUKA produces the expected wall effect. That is, energy deposition in the gas volume can occur even when the primary beam does not pass through the gas volume. A final comparison to experimental data was made for the simulated TEPC exposed to various broad beams in the energy range of 200 - 1000 MeV/nucleon. FLUKA overestimated energy deposition in the gas volume in all cases. The FLUKA results differed from the experimental data by an average of 25.2 % for yF and 12.4 % for yD. It is suggested that this difference can be reduced by adjusting the FLUKA default ionization potential and density correction factors.

The Coffin-Manson equations of Sn/Ag/Cu and Sn/Pb solder joints are presented in this thesis. The experimental results of CSP thermal cycle fatigue test and ball shear test are used to formulate Coffin-Manson equations. The maximum amplitude of equivalent plastic shear strain corresponding to these two experiments are employed. The MARC finite element package is used to calculate the plastic shear strain. Different published fatigue experiment results have been used to show the accuracy and the feasibility of these proposed equations. The 3-D finite element models of the BGA type¡¦s CSP and VCSEL assembly are employed to simulate the thermal cycling fatigue. Results indicate that the fatigue lifes of solder predicted by using the proposed equations have good agreement with those measured from experimental tests.

The objective of this thesis is to report the concept of driving a non-contacting steel plate conveyance system with a DSP-based closed-loop control structure. The lift force of the system is first estimated from the magnetic equivalent circuit (MEC) analysis, and the estimation results have been verified through three-dimensional finite element analysis (3-D FEA). Based on the force calculations and the fuzzy control theory, a closed-loop control structure has been designed. Through accurate signal detections, a real-time lift force control of the conveyance system can be realized. Finally, by feeding AC sources with DC bias to the stator windings of the motor, the lift and propulsive forces can be supplied to the steel plate simultaneously.

Because the metal enclosure with apertures is the structure of the cavity form, FDTD method belonging to full-wave analytical algorithm isn¡¦t efficient for analyzing such case. Thereby the ETL method belonging to analytical formulation provides another way to analyze it. Although the structure which it can apply to isn¡¦t as complex as that in full-wave analytical algorithm, the computing time is shorter than FDTD. In contrast, the method can¡¦t get good agreement. Thus two improved ways are introduced in this paper. One is to make the suitable structure wider and the other is to consider the higher mode original ETL method isn¡¦t included to improve the accuracy. Further these two ways make the suitable range of the method wider and the method has good practicability.

Economics Value Added has two major characteristics that differ from the traditional accounting measure. First, the process of counting EVA includes the cost of equity. Second, it corrects distortion of Generally Accepted Accounting Principles¡]GAAP¡^by equity equivalent reserves. The purpose of this study is to test the relationship between performance measure EVA and stock return. Furthermore, we investigate if conbining these two parts provides additional information. In addition, the difference between literature and the study is that we use not only OLS regression model but also Panel Data Model. We choose a more suitable model to analyze our sample data. Our main finding is as follows¡G 1. Since sample data involve cross-section and time-series data. The result of test is that the Fixed Effect Model of Panel Data Model is more suitable for sample data. 2. Base on the Fixed Effect Model, the relationship between EVA and stock return is positive. 3. Considering the cost of equity and equity equivalent reserves increases the R-square respectively by 2.408% and 1.915%. It doesn¡¦t increase much power to explain stock return apparently. However, by F test, we find these two independent variables are obviously explainable. In a word, base on the Fixed Effect Model, there is relationship between EVA and stock return. Moreover, the joining of the variables of the cost of equity and equity equivalent reserves can explain contemporaneous stock return a little more.

This dissertation presents two kinds of model extraction approaches, direct extraction and adaptive rational approximation methods, for establishing a novel broadband model, the modified T-equivalent circuit. Both methods skillfully use the simplified and decomposed schemes to dramatically reduce the complexity of modeled parameter extraction procedures and the needed computational efforts. As a result, any two-port microwave passive components or networks can be modeled efficiently using the proposed fully-analytical mathematic extraction formulations. In comparison with other broadband modeling techniques, the modified T-equivalent circuit can be constructed with much less elements. Model with such a compact character attributes the frequency responses of two decomposed circuits having obvious resonances to be identified and utilized for constituting equivalent circuits using only necessary elements. It is worth to note that the modified T-equivalent circuit model can utilize two expandable multilayer resonators to achieve very wide bandwidth but maintain model still in a single-stage equivalent circuit. Several successful modeling examples verified on the LTCC- and organic- embedded type of band-pass filters and inductors, the most crucial passive components to affect the performances of RF communication system, demonstrate the presented model with the superior character of accuracy and broadband indeed.

This thesis focuses on the structures of plated through holes in organic substrate, and discusses the high-frequency electrical characteristics of various plated through hole structures. This thesis consists of four parts. The first part introduces various kinds of vias in multilayer substrate. This content includes substrate drilling processes and capabilities, and discussions on plated through hole structures and their manufacture concerns. The second part focuses on actual measurement of plated through holes, and introduces high-frequency double-side probing technique. The difference from traditional high-frequency coplanar probing measurement is also discussed. The third part focuses on the high-frequency simulation by full-wave software ¡V Ansoft HFSS, and discusses the effects of various excited source and model structures on simulations. Part4 focuses on developing the broadband equivalent circuit model based on the physical structures, and discusses the electrical characterization of different plated through holes, and provides the related design concept.

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