This dissertation aims to address two optimization problems involving power system reliabilty analysis, namely multi-area power system adequacy planning and transformer maintenance optimization. A new simulation method for power system reliability evaluation is proposed. The proposed method provides reliability indexes and distributions which can be used for risk assessment. Several solution methods for the planning problem are also proposed. The first method employs sensitivity analysis with Monte Carlo simulation. The procedure is simple yet effective and can be used as a guideline to quantify effectiveness of additional capacity. The second method applies scenario analysis with a state-space decomposition approach called global decomposition. The algorithm requires less memory usage and converges with fewer stages of decomposition. A system reliability equation is derived that leads to the development of the third method using dynamic programming. The main contribution of the third method is the approximation of reliability equation. The fourth method is the stochastic programming framework. This method offers modeling flexibility. The implementation of the solution techniques is presented and discussed. Finally, a probabilistic maintenance model of the transformer is proposed where mathematical equations relating maintenance practice and equipment lifetime and cost are derived. The closed-form expressions insightfully explain how the transformer parameters relate to reliability. This mathematical model facilitates an optimum, cost-effective maintenance scheme for the transformer.

Taiwan became a member of the WTO in November last year. This helped push Taiwan to the International business circle successfully; also it helped all the Taiwanese businesses to grow positively, but Taiwan would face strong international competition as well. This essay is about how Taiwan¡¦s rice policy will react and adjust to the strong international competition after joining the WTO. Also we will talk about how the rice policy of Taiwan revolves into what it is today since WWII. We will look at the good and the bad from previous policies, so we can create better agricultural policies for now, and better the economy of Taiwan¡¦s rice business for the future. The problem that Taiwan is facing now is the policy of limited quota. We have to follow the rule of ¡¥minimum access¡¦ once we join the WTO. The import number of brown rice in 2002 is 8% of the total amount consumed in Taiwan from 1990 to 1992. According to the statistics from the Food Bureau of Taiwan, The total consumption of brown rice in Taiwan in 1990, 1991, and 1992 are; 1,834 thousand tons, 1,897 thousand tons, and 1,694 tons. If we count the grain it would be approximately 2,260 thousand tons. If we use the minimum access policy, 8% of it would be 180 thousand tons of grain. If we do not have the proper ¡¥Tie-in sales¡¦, the price of local rice sales and the amount the farmers earn would fall drastically. Tie-in sale is actually a short-term solution. In the long term, Taiwan¡¦s rice policy will lead to results with tariff. At this moment, the price of Taiwanese rice would not be under any protection, so the most important thing is to raise the ability to compete internationally for Taiwan¡¦s rice. The result, after a careful examination, is that Taiwan is no competition with the U.S., Thailand, and China on the price aspect. Besides from that, the personnel and the space of land cost much higher than the other countries make Taiwan hard to compete. The only way is to raise the quality above the other competition then we can actually have a place to compete with the rest of them. At the same time, if we can create a large-scale center for tie-in sales, it should help lowering the base cost of grain rice. As for the government, it should change the policies to assist with the rice farmers. Transform the current guaranteed purchasing policy for guaranteed price , to direct payment , which should help Taiwan¡¦s rice market to market suitable diversion and reduction ,would minimize the impact actually. . In the future, the rice farmers will grow rice for consumers, not for the needs of the government. The agriculture of rice will go back to the natural market rule; the rice farmers will work with the government to develop higher quality rice. Joining the WTO brings both good and bad to the grain rice industry, so if we can take chances at the right times and avoid risks, we can be in the business for a long time.

Thesis (B.A.)--Haverford College, Dept. of Mathematics, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--Open University. BLDSC no. D52160/84. / Consultation copy in 2 volumes.

Thesis (M.B.A.)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Ken Doerr, Phil Candreva. Includes bibliographical references (p. 76-77). Also available online.

Thesis--M. Phil., University of Hong Kong, 1986.

Thesis--Ph. D., University of Hong Kong. / Mimeographed.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 61-65).

This thesis is concerned with the dissipative control and filtering problems of singular systems. Four classes of singular systems are considered: delay-free singular systems, singular systems with constant time-delay, uncertain singular systems with time-varying delay and sensor failures, and singular Markovian jump systems with actuator failures. For delay-free singular systems, the system augmentation approach is employed to study the dissipative control and filtering problems. First, the approach is used to solve the dissipative control problem by static output-feedback for standard state-space systems which are the special cases of singular systems. For a continuous-time standard state-space system, the closed-loop system is represented in an augmented system form. Based on the augmented system, a necessary and sufficient dissipativity condition is proposed, which decouples the Lyapunov matrix and controller matrix. To further separate the Lyapunov matrix and the system matrices, an equivalent condition is obtained by introducing some slack matrices. Then, a necessary and sufficient condition for the existence of a static output-feedback controller is proposed, and an iterative algorithm is given to solve the condition. For discrete-time singular systems, by giving an equivalent representation of the solution set, a necessary and sufficient dissipativity condition is proposed in terms of strict linear matrix inequality (LMI) which can be easily solved by standard commercial software. Then a state-feedback controller design method is given based on the augmentation system approach. The method is extended to the static output-feedback control problem and the reduced-order dissipative filtering problem. For continuous-time singular time-delay systems, the problem of state-feedback dissipative control is considered. An improved delay-dependent dissipativity condition in terms of LMIs is established by employing the delay-partitioning technique, which guarantees a singular system to be admissible and dissipative. Based on this, a delay-dependent sufficient condition for the existence of a state-feedback controller is proposed to guarantee the admissibility and dissipativity of the closed-loop system. In addition to delay-dependence, the obtained results are also dependent on the level of dissipativity. Moreover, the results obtained unify existing results on H∞ performance analysis and passivity analysis for singular systems. For discrete-time singular systems with polytopic uncertainties, time-varying delay and sensor failures, the problem of robust reliable dissipative filtering is considered. The filter is designed by the reciprocally convex approach such that the filtering error singular system is admissible and strictly (Q, S, R)-dissipative. For singular systems with time-varying delay and sensor failures, a sufficient condition of reliable dissipative analysis is obtained in terms of LMIs. Then the result is extended to the uncertain case by introducing some variables to decouple the Lyapunov matrices and the filtering error system matrices. Moreover, a desired filter for uncertain singular systems with time-varying delay and sensor failures is obtained by solving a set of LMIs. For continuous-time singular Markovian jump systems with actuator failures, the problem of reliable dissipative control is addressed. Attention is focused on the state-feedback controller design method such that the closed-loop system is admissible and strictly (Q, S, R)-dissipative. A sufficient condition is obtained in terms of strict LMIs. Moreover, the results obtained unify existing results on H∞control and passive control on singular Markovian jump systems. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Conceptual data schema is constructed from the analysis of the business forms which are used in an enterprise. In order to peform the analysis a data model, a forms model, and heuristics to map from the forms model to the data model are developed. The data model we use is an extended version of the Entity-Relationship Model. Extensions include the addition of the min-max cardinalities and generalization hierarchy. By extending the min-max cardinalities to attributes we capture a number of significant characteristics of the entities in a concise manner. We introduce a hierarchical model of forms. The model specifies various properties of each form field within the form such as their origin, hierarchical structure, and cardinalities. The inter-connection of the forms is expressed by specifying which form fields flow from one form to another. The Expert Database Design System creates a conceptual schema by incrementally integrating related collections of forms. The rules of the expert system are divided into six groups: (1) Form Selection, (2) Entity Identification, (3) Attribute Attachment, (4) Relationship Identification, (5) Cardinality Identification, and (6) Integrity Constraints. The rules of the first group use knowledge about the form flow to determine the order in which forms are analyzed. The rules in other groups are used in conjunction with a designer dialogue to identify entities, relationships, and attributes of a schema that represents the collection of forms.