In the present study, a fifth-order weighted essentially non-oscillatory (WENO) scheme was built for solving the surface-capturing level-set equation. Combined with the level-set equation, the three-dimensional Reynolds averaged Navier-Stokes (RANS) equations were employed for the prediction of nonlinear wave-interaction and wave-breaking phenomena over sloping beaches. In the level-set finite-analytic Navier-Stokes (FANS) method, the free surface is represented by the zero level-set function, and the flows are modeled as immiscible air-water two phase flows. The Navier-Stokes equations for air-water two phase flows are formulated in a moving curvilinear coordinate system and discretized by a 12-point finite-analytical scheme using the finite-analytic method on a multi-block over-set grid system. The Pressure Implicit with Splitting of Operators / Semi-Implicit Method for Pressure-Linked Equation Revised (PISO/SIMPLER) algorithm was used to determine the coupled velocity and pressure fields. The evolution of the level-set method was solved using the third-order total variation diminishing (TVD) Runge-Kutta method and fifth-order WENO scheme. The accuracy was confirmed by solving the Zalesak's problem. Two major subjects are discussed in the present study. First, to identify the WENO scheme as a more accurate scheme than the essentially non-oscillatory scheme (ENO), the characteristics of a nonlinear monochromatic wave were studied systematically and comparisons of wave profiles using the two schemes were conducted. To eliminate other factors that might produce wave profile fluctuation, different damping functions and grid densities were studied. To damp the reflection waves efficiently, we compared five damping functions. The free-surface elevation data collected from gauges distributed evenly in a numerical wave tank are analyzed to demonstrate the damping effect of the beach. Second, as a surface-tracking numerical method built on curvilinear coordinates, the level-set RANS model was tested for nonlinear bichromatic wave trains and breaking waves on a sloping beach with a complex free surface. As the wave breaks, the velocity of the fluid flow surface became more complex. Numerical modeling was performed to simulate the two-phase flow velocity and its corresponding surface and evolution when the wave passed over different sloping beaches. The breaking wave test showed that it is an efficient technique for accurately capturing the breaking wave free surface. To predict the breaking points, different wave heights and beach slopes are simulated. The results show that the dependency of wave shape and breaking characteristics to wave height and beach slope match the results provided by experiments.

The field of Computational Fluid Dynamics (CFD) is in a continual state of advancement due to new numerical techniques, optimization of existing codes, and the increase in memory and processing speeds of computers. In this thesis, the solution technique for a pre-existing Navier-Stokes flow solver is adapted from an explicit Runge Kutta method to a Lower-Upper Symmetric Gauss-Seidel (LU-SGS) implicit time integration method. Explicit time integration methods were originally used in CFD codes because these methods require less memory. Information needed to advance the flow in time is localized to each grid point. These explicit methods are, however, restricted by time step sizes due to stability criteria. In contrast, implicit methods are unaffected by a large time step sizes but are restricted by memory requirements due to the complexities of unstructured grids. The implementation of LU-SGS performs grid re-ordering for unstructured meshes because of the coupling of grid points in the integration method's solution. The explicit and implicit flow solvers were tested for inviscid flows in incompressible, compressible, and transoinc flow regimes. The results found by comparing the implicit and explicit algorithms revealed a significant speed up in convergence to steady state by the LU-SGS method in terms of iteration number and CPU time per iteration.

In this thesis, we propose the predictive multicast polling scheme for medium access control in wireless networks with multipacket reception capability. We concentrate on the case in which the packet arrival process is general and the maximum queue size is finite but larger than one. We derive both analytical results and simulation results. We use the theory of discrete-time Markov chain to analyze the evolution of the system state. In addition, we propose to use Markov reward processes to calculate the throughput. Furthermore, we obtain the average system size, the packet blocking probability, and the average packet delay. The proposed analysis approach is applicable no matter whether perfect state information is available to the controller or not. We also use simulation results to justify the usage of the proposed approach. Our study shows that the system performance can be significantly improved with a few additional buffers in the queues. The proposed medium access control scheme can be used in the single-hop wireless local area networks and the multi-hop wireless mesh networks.

Small and Medium Business Credit Guarantee Fund (SMEG) is the sole non-profit credit guarantee providing organization in Taiwan. The mission of the fund is to help small and medium enterprises in need of capital obtain bank loans, and, hopefully, to promote the domestic economy as well as create the empolyment opportunities. In essence the fund facilitates the implementation of public policy. As the business environment is completely changed, the goals of handling fund were shifted from a financial perspective to a business perspective. The demand for the credit guarantee of the bank loan has substantially increased. In order to meet the growing demand, the effective risk management becomes an important issue. This study examines the overdue ratio and the effect of the risk management from the perspectives of enterprises, banks and the macroeconomics. Findings include the following:(a)some certain affiliated trades and some scales of loans are associated with high overdue ratio; (b) lowering the rate of guarantee can reduce the overdue ratio; (c) there is a significant difference between the characters of the bank and the overdue ratio of SMEG; (d) in macroeconomics, the overdue rate of the SMEG are highly related to the economic indicators such as economic growth rate, money supply, heavy discount rate and unemployment rate. The previous indicators can be the reference indicator of the risk management of SMEG.

Leisure is most basically defined as the time free from work. The ancient conception and forms of leisure were quite different from the modern ones, which came into discussion during the industrial era. The Roman society was highly stratified and comprised of diverse social classes for which leisure acquired different forms and meanings. Every stratum of the Roman society enjoyed the possibilities and pleasures of leisure proportional to its hierarchy in the social system, so that leisure can be investigated in both public and private contexts in the Roman world. This study aims to investigate leisure, which was one of the main driving social forces in the Roman society, in spatial terms with reference to Roman domestic architecture. The study focuses on central Italy and particularly on Ephesus, the latter of which is a good example to discuss how the Roman conception of leisure was spatially materialized in a provincial private setting since a group of well studied, documented, and published houses constitute an appropriate comparative sample and context in Ephesus. The spatial organization and characteristics of the spaces housing leisurely activities are discussed on the basis of an axes-scheme that regulated and even dictated the visual and bodily interaction of the participants with certain spaces and elements during leisure activities either in a static state (sitting, reclining), or a kinetic one (walking, perambulating). The visual axes are those perceived in either of these states, along which the eye is directed towards a visual focal point, whereas the dynamic axes are those along which people move during a kinetic leisurely activity. The location, architecture, and use of leisure-oriented spaces in the Roman period houses in Ephesus, such as triclinium, exedra, oecus, museion, and peristyle courtyard are examined with reference to the proposed axes-scheme to present and compare the operation of leisure in the Roman provincial and private setting.

The objective of this thesis is to present the algorithm of achieving speed and lift force controls of transverse flux linear switched-reluctance machine (LSRM) simultaneously. A high-speed digital signal processor based (DSP-based) switching controller will be implemented, and the desired speed control objective is realized by using a fuzzy control scheme. On the other hand, by using an indirect field-oriented control scheme, the LSRM reluctance forces, which are magnetically decoupled and position dependent, can be projected onto sets of stationary axes that are aligned with the motor fixed secondary poles. Hence by controlling flux on the specific stationary axis, the machine lift force can be properly controlled. Finally, adequate duty cycle distribution will be discussed and examined to asynchronously supply the required speed and lift force control objectives simultaneously.

Two significant differences were found between theoretical expectation and empirical results to budgetary slack in managerial accounting study. First, subjects under the slack-inducing pay schemes set their budgets well above zero regardless of their risk-neutral or risk-averse characteristics, although their maximum rewards arise from setting their budgets at zero (Waller, 1988; Chow, Cooper, and Waller, 1988; Chow, Cooper, and Haddad, 1991). Second, theoretically subjects operating under truth-inducing pay schemes set budgets at their best estimate performance, that is, no budgetary slack. But in violation of traditional economic theory, truth-inducing pay schemes have not been found to drive all slack out of the budget (Chow, Cooper, and Haddad, 1991). These results suggest that the existence of other non-pecuniary factors impacting slack, such as personal integrity and conscience, or social pressure (Chow, Cooper, and Waller, 1988). Moreover, the other potential causes in methodology may affect the congruence with theoretical expectation: (1) single-period experimental setting may limit the subjects¡¦ learning effect (Chow, Cooper, and Haddad, 1991), or (2) social pressure that was not controlled between subjects results in measurement errors. This study investigates the impacts of pay scheme, social pressure, internal norm and organizational commitment on budgetary slack in the participative budgeting setting. Specifically, this research executes an experimental test of the effects of a truth-inducing pay scheme, superior-generated social pressure, and subordinates¡¦ intern norm and their organizational commitment on the propensity to set their budgets below expected performance. In the experimental setting budgets were participatively set under three kinds of pay scheme and under the condition of either existence of social pressure or no social pressure. Pay schemes are categorized by three factors: truth-inducing pay scheme, fixed-pay-plus-bonus pay scheme, and fixed-pay-plus-bonus pay scheme with ratchet. The social pressure manipulation involved having subordinates either personally submit their budgets and performance to a superior, or enter their budgets into a computer with no personal interaction. Moreover, internal norm and organizational commitment are measured by questionnaires built in the personal computer. The experiment was conducted by computerizing the multi-period task on the screen of man-machine interactive personal computer. To eliminate the potential social pressure, subjects in the group with no social pressure executed the computerized procedure to create a ¡¨doubled-blinded¡¨ environment where there was inter-participant anonymity (anonymity between subjects) and experimenter-participant anonymity (anonymity between experimenter and subjects), hence the effects of internal norm and organizational commitment on budgetary slack were investigated. This study tested the following hypotheses with 120 production unit managers that sampled from one manufacturing company in Kaohsiung. (1) Managers will build the least slack into their budget under a truth-inducing pay scheme, the second slack under a fixed-pay-plus-bonus pay scheme with ratchet, and the most slack under a fixed-pay-plus-bonus pay scheme. (2) Managers will build less slack into their budget as social pressure from superior is increased. (3) The difference in budgetary slack between the truth-inducing pay scheme and fixed-pay-plus-bonus pay scheme with ratchet will be reduced as social pressure from superior is increased. That is, there is an interaction between pay scheme and social pressure. (4) The level of slack built into the budget will be negatively correlated with the managers¡¦ degree of internal norm in condition of no social pressure. (5) The level of slack built into the budget will be negatively correlated with the managers¡¦ degree of organizational commitment in condition of no social pressure. The test result verified the mentioned-above hypotheses except item (1) that is partially supported. This study not only extends the management accounting literature that investigates the effects of pay schemes, but also further examines the potential effects of social pressure from superior, subordinates¡¦ internal norm and organizational commitment on budgetary slack. Especially, the results that isolated the effects of internal norm from social pressure on budgetary slack have shown the implications of personnel recruitment and managerial style in the enterprises organization.

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MPLS, a next generation backbone architecture, can speed up packet forwarding to destination by label switching. However, if there exists no backup LSP when the primary LSP fails, MPLS frames cannot be forwarded to destination. Therefore, fault recovery has become an important research area in MPLS Traffic Engineering. Makam approach and Haskin approach are the most famous two among the previous literatures. Besides, IETF has made strict definitions for MPLS Recovery in RFC 3469 in February, 2003. We propose a Reverse Labeling Scheme to handle fault recovery in this thesis. We establish a virtual reverse LSP along the completely reverse direction of the primary path. When there is a link failure in the primary LSP, LSR will forward packets back to Ingress by virtual reverse LSP instead of using the primary LSP. This idea of building virtual reverse LSP makes Haskin approach practical in implementation. In addition, we save network resources by designing a scheme such that LSR is easier to convert from the primary LSP to the backup LSP. In order to solve the out-of-order packets in Haskin approach, Hundessa adds buffering on every LSR. The buffer can temporarily store the packets once a link failure has been detected. By adopting the basic idea of Hundessa approach, we embed our Reverse Labeling Scheme and implement it on Linux platform. We also make some modifications to solve the buffering problems. Finally, we demonstrate this Reverse Labeling Scheme by several experiments. We not only show the low packet loss rate, but also solve the packet out-of-order problems. The significant decrease of out-of-order packets can further improve the efficiency of TCP flow transmission.

For a back-light module with multiple cold cathode fluorescent lamps (CCFLs) in mid-size or large size liquid crystal displays, a balance scheme must be included to have approximately equal currents among the lamps and hence to output equal brightness. In this thesis, a half-bridge inverter is adopted to drive multiple step-up transformers with the same turn ratio, in which the primary windings of the transformers are connected in series whereas the second windings drive CCFLs in parallel. Due to the series connection of the transformer sets, the current going through the primary windings is identical, so that the lamp currents from second windings tend to be equal. A driver circuit with the proposed scheme is designed for 8 U-type cold cathode fluorescent lamps in a 32-inch backlight module. The simulation and experimental results demonstrate the effectiveness of the balance scheme, even for the lamps operating at low current.