In this thesis, we demonstrated the effectiveness and the accuracy of the FD-FD method for complex optical waveguide structures such as the micro ring resonator, micro disk resonator, tapered waveguides and waveguides terminated with tilted facets. We are able to achieve the goals by deriving the following modification/extension of the original FD-FD methods. In frequency domain, we can build an accurate frequency-domain modal absorbing boundary condition (ABC) for both the homogeneous region and for the layered background. This allows us to connect the analytical modal solutions with FD solutions and thus reduce the area of the FD domain. In addition, we adopt an effective index averaging method for representing equivalent material for grid cells containing more than one kind of materials. For the TM case, for each grid cell we need to compute effective indices for all four surrounding cells (left, right, up, and down). For the TE case, we need to compute just one effective index within each grid cell. Note that we employ two different averaging schemes for the TE and the TM cases. To solve the huge block tri-diagonal matrix equation (derived from the FD-FD approximation) we modified the Thomas method and we were able to obtain the solutions of linear equations involving more than a hundred thousand variables under a few minutes. We used our method to analyze optical micro-ring waveguides, micro-disk cavities, adiabatic tapered waveguides and waveguides terminated with tilted facets. The simulated results include the reflection coefficients, transmission coefficients and field distribution.

This thesis aims to implement a linear wireless transmitter based on the envelope-following architecture. A class-E PA is utilized to replace the linear PA used in the traditional envelope-following transmitter for enhancing the average efficiency. The transmitter relies on a digital processor realized by FPGA to generate the baseband IQ signal and corresponding envelope signal. This way can not only achieve more accurate modulation accuracy and wider modulation bandwidth, but also use less analog components for the future convenience of realizing single-chip integration when compared to the traditional envelope-following transmitter. Furthermore, this thesis implements a predistorter in the digital processor to compensate the Vdd/AM distortion of class-E amplifier. Therefore, this transmitter can simultaneously achieve high efficiency and high linearity over a wide input power range. From the results measured in transmitting a QPSK-modulated CDMA2000 1x signal at a chip rate of 1.2288 Mcps, the transmitter incorporating an InGaAs pHEMT class-E PA can achieve 30~44 % in average efficiency (23~38 % in average PAE) with above 44 dBc in ACPR and below 4 % in EVM in the average modulated output power range from 7 to 21 dBm, while the transmitter incorporating a GaAs HBT can achieve 20~40 % in average efficiency (16~35 % in average PAE) with above 43 dBc in ACPR and below 5 % in EVM in the average modulated output power range from 4 to 18.5 dBm.

Abstract Background and Objectives: Since 1894, open appendectomy (OA) has been the treatment of choice for acute appendicitis. In 1981 Semm performed the first laparoscopic appendectomy (LA). More than 2 decades later, the benefits of LA are still controversial. The goal of the present investigation was to compare the effectiveness of LA and OA based on a large administrative (The Bureau of National Health Insurance, BNHI) Research Database. The source of data analyzed was the administrative claims data from the BNHI Research Database. Methods: The objective of this retrospective study was based on the ICD-9-CM procedure code of 4701 (Laparoscopic appendectomy, LA) and 4709 (Open appendectomy, OA) respectively from a database of 20 million insurance population, Separate analyses were performed for uncomplicated (ICD-9-CM, 540.9) and complicated (presence of appendiceal perforation or abscess; ICD-9-CM 540.0 and 540.1) appendicitis. Exclusive criteria were: (1) Average length of stay exceeds 3 S.D. (n=1,262). (2) Gender unmentioned (n=243). All these data will analyze in multiple dimensions including length of hospital stay, in-hospital complications, in-hospital mortality, and rate of routine discharge between laparoscopic (LA) and open appendectomy (OA) based on The Bureau of National Health Insurance (BNHI) database. Results: We enrolled 11,118 patients underwent LA and 47,725 patients underwent OA during 2004 to 2007. The prevalence of LA increases gradually from 6.97 per 100,000 populations in 2004 to 21 per 100,000 populations in 2007. The prevalence of OA decreases gradually from 57.5 per 100,000 populations in 2004 to 44.86 per 100,000 populations in 2007. Patients underwent LA (3.25¡Ó1.51day) have significant lower length of hospital stay than OA (3.57¡Ó1.49 day) (p<0.001). We also found the trend that the annual medical expenditure of LA increases gradually but OA decreases gradually. In general, LA spends higher medical expenditure than OA. With respect to medical expenditure, higher length of hospital stay and co-morbidity are associated with more medical expenditure significantly. Conclusions: LA is the current developing trend of surgical treatments for appendicitis. LA can reduce length of hospital stay significantly. OA can reduce the medical expenditure in Taiwan. In our opinion, the results represent the native data in Taiwan and are very important for a good administration of public resources distribution.

Investors should seriously assess and consider investment objects when they are proceeding domestically newly-issued equity funds investment. According to this study, the returns of domestically newly-issued equity funds are negative whether they are invested locally or overseas. If we take excess returns into account, the returns rate will be lower. General excess returns¡]systematic risk BETA¡^¡Bnet flow rate ¡]Flow¡^¡Bequity funds turnover rate¡]Turn¡^¡Baverage investment amount per person¡]AVG¡^etc. four factors are listed in this study. The past ten-year excess returns of domestically newly-issued equity funds are researched the correlationship of these variables. The empirical results show:there is a positively significant relationship risk, the higher the systematic risk is, the better the funds¡¦ performance is. Funds excess returns are positively significantly related with equity funds turnover rate; the situation represents: the more active this month investment objects are the better this month performance is. The relationship between equity funds excess returns and net flow rate is statistically insignificant; no matter what the net buying amount of this month is higher or lower than last month funds assets scale, the performance of the funds is not affected. The relationship between funds excess returns and investment amount is statistically insignificant. As far as domestically newly-issued international equity funds are concerned, funds excess returns are statistically insignificant with systematic risk, net flow rate and funds turnover rate, that is, the performance of international equity funds is not affected by domestical systematic risk, net flow rate and fund turnover rate. Funds excess return rate is negatively significantly related with the investment amount per person, that is, the bigger the net funds assets scale or the smaller the beneficiaries of the funds is, the worse the performance of the funds is. In other words, when topical news¡]for example BDI index fluctuations¡B the rise of BRICs¡B the large scale epidmic¡^ferment,the international equity funds commodity which is enjoying busy trading will result in loss in the first year-end after investing, it verifies the proverb¡XDon¡¦t go to the place where many persons gatter.

In the past decade, there has been great motivation to improve the efficiency of power amplifiers (PAs) in handset transmitter systems in order to address critical issues such as poor battery life and excessive heat. Currently, the focus lies on high data rate applications such as wideband code division multiple access (WCDMA) and long term evolution (LTE) standards due to the stringent efficiency and linearity requirements on the PA. This thesis describes a simulation-based study of techniques for enhancing the efficiency of a CMOS power amplifier for WCDMA and LTE applications. The primary goal is to study the concepts of envelope and average power tracking in simulation and to demonstrate the effectiveness of these supply modulation techniques on a CMOS PA design. The P1dB and IMD performance of a Class A/AB CMOS PA has been optimized to operate with high peak-to-average modulation with WCDMA and LTE signals. Behavioral models of envelope and average power tracking are implemented using proposed algorithms, and a system-level analysis is performed. Envelope tracking is seen to offer a peak PAE improvement of 15% for WCDMA, versus a fixed voltage supply, while average power tracking renders a maximum efficiency gain of 9.8%. Better than -33dBc adjacent channel leakage-power ratio (ACLR) at 5MHz offset and EVM below 4% are observed for both supply tracking techniques. For LTE, envelope and average power tracking contribute to a peak PAE enhancement of 15.3% and 7%, respectively. LTE ACLR begins failing the -30dBc specification above 22.5dBm output power during envelope tracking operation in the PA implementation described here. / text

1. Introduction Pastaraisiais metais, ypač reformuojant stacionarinę sveikatos priežiūrą, vis didesnis dėmesys skiriamas ligoninių veiklos vertinimui daugelyje šalių, nes stacionarinei sveikatos priežiūrai skiriama 45-75% visų sveikatos priežiūrai skirtų lėšų (1). Vertinant ligoninės veiklos rodiklius, dažniausiai apsiribojama pagrindine jos funkcija - paslaugų teikimu (2-4). Tradiciškai sveikatos priežiūros organizacijų veikla yra vertinama pagal paslaugų apimtis (5), o gydytų pacientų skaičius yra labiausiai paplitęs stacionarinių sveikatos priežiūros įstaigų veiklos rodiklis. Nepaisant to, kad šiuolaikiniai sveikatos priežiūros organizacijų veiklos vertinimo modeliai apima daug įvairių aspektų ir dimensijų (tokių kaip paslaugų kokybė, pajėgumas gauti reikiamus išteklius, pajėgumas reaguoti į visuomenės poreikius, veiklos efektyvumas, veiksmingumas, produktyvumas, našumas, organizacijos kultūra ir pan.), sveikatos priežiūros įstaigų veiklos vertinimas pagal pacientų (paslaugų atvejų) skaičių išlieka kaip vienas pagrindinių rodiklių jau vien dėl to, kad daugumoje sveikatos sistemų apmokėjimas sveikatos priežiūros organizacijoms yra pagrįstas gydytų pacientų ar suteiktų paslaugų apimtimis (6,7). Tačiau analizuojant vien tik stacionarinėje asmens sveikatos priežiūros įstaigoje (ASPĮ) gydytų pacientų (atvejų) skaičių per tam tikrą laiko periodą, daryti išvadas apie ligoninės veiklą ir ypač lyginti su kitomis ligoninėmis yra pakankamai sudėtinga ir net nevisiškai objektyvu... [to full text]

Three key questions are identified and answered in this paper. Firstly, have the average annual temperatures in the Prince George Region changed in recent years? Secondly, have the seasonal flow rates changed for local waterways? Lastly, have the timing of the annual flood cycles in the Prince George, British Columbia changed? By reviewing data from local weather and hydrological monitoring stations, this paper identifies that the average annual temperature in Prince George, British Columbia has not only increased but also shifted to a pattern of warmer winters and cooler summers. The flow rates for the region were seen to have been altered as well, indicating increased flow rates in the winter and early spring and decreased flow rates in the summer and early fall. The magnitude of flood frequency events such as the 10, 25 and 100 year flood occurrence does not seem to have the increased in recent years.

This thesis deals with modeling, simulation and operating limits of high-voltage direct-current (HVDC) transmission systems that employ voltage-source converters (VSCs) as their building blocks. This scheme is commonly known as the VSC-HVDC transmission. A simulation-based study is undertaken in which detailed electromagnetic transient (EMT) models are developed for a back-to-back VSC-HVDC transmission system. Different control strategies are implemented and their dynamic performances are investigated in the PSCAD/EMTDC EMT simulator. The research presented in this thesis firstly specifies the factors that limit the operating points of a VSC-HVDC system with particular emphasis on the strength of the terminating ac system. Although the EMT model shows these limits it provides little analytical reason for their presence and extent. A phasor-based quasi-steady state model of the system including the phase-locked loop firing control mechanism is proposed to determine and characterize the factors contributing to these operating limits. Stability margins and limits on the maximum available power are calculated, taking into consideration the maximum voltage rating of the VSC. The variations of ac system short-circuit ratio (SCR) and transformer impedance are proven to significantly impact the operating limits of the VSC-HVDC system. The results show how the power transfer capability reduces as the SCR decreases. The analysis shows that VSC-HVDC converters can operate into much weaker networks, and with less sensitivity, than the conventional line commutated converters (LCC-HVDC). Also for a given SCR the VSC-HVDC system has a significantly larger maximum available power in comparison with LCC-HVDC. A second research thrust of the thesis is introduction of a simplified converter model to reduce the computational intensity of its simulation. This is associated with the admittance matrix inversions required to simulate high-frequency switching of the converter valves. This simplified model is based on the concept of dynamic average-value modelling and provides the ability to generate either the full spectrum or the fundamental-frequency component of the VSC voltage. The model is validated against the detailed VSC-HVDC circuit and shows accurate matching during steady state and transient operation. Major reductions of 50-70% in CPU-time in repetitive simulation studies such as multiple runs and optimization-based controller tuning are achieved.

In order to achieve enhanced and cost-effective performance of engineering components, Surface Engineering embraces traditional and innovative surface technologies which modify the surface properties of metallic and non-metallic engineering components for specific and sometime unique engineering purposes. The surface roughness of an engineered surface may be classified as: the random surface roughness which is a product of surface finishing and the deterministic surface roughness which is engineered to increase the lubrication characteristics of the hydro dynamically lubricated thrust ring. The effect of stochastic/random roughness can not be ignored when the roughness is of the same amplitude as that of fluid film thickness. Average flow model derived in terms of flow factors which are functions of the roughness characteristics is used to study the random surface roughness effects on hydrodynamic lubrication of deterministic asperity. In addition, the effect of boundary conditions on flow factors is studied by calculating the pressure and shear flow factor using two different new boundary conditions. The results are obtained for random surface roughness having a Gaussian distribution of roughness heights.

Minicell-based manufacturing system is used in identifying best minicell designs. The existing method of minicell design generates best minicell designs by designing and scheduling minicells simultaneously. While in this research designing of minicells and scheduling of jobs in minicells is done separately. This research evaluates the effectiveness of hierarchical approach and compares with simultaneous method. Minicell designs with respect to average flow times and machine capacities and both are identified in a multi-stage flow shop environment. Rules for the extraction of good minicell designs in mass customization manufacturing systems are also established.