In this thesis, we consider a capacity allocation problem in flexible manufacturing systems. We assume limited time and tool magazine capacities on the Computer Numerically Controlled (CNC) machines. We have a set of operations that have to be assigned to the machines and each operation requires a set of tools to be processed. Our problem is to allocate the available capacity of the CNC machines to operations and their required tools. We consider two problems in this study: maximizing the total weight of operations where there are a limited number of tools of each type available and maximizing total weight minus total tooling cost where the tools can be used or purchased at a cost. We model the problems as Integer Linear Programs and show that they are NP-hard in the strong sense. For the total weight problem, we propose upper bounds, branch and bound algorithm for exact solutions and several heuristics for approximate solutions. For the bicriteria problem, we use Lagrangean relaxation technique to obtain lower and upper bounds. Our computational results have revealed that all solution approaches give satisfactory results in reasonable times.

The novel designs of circular microstrip antennas have been investigated in this dissertation. In the linearly polarized designs, the study of single-feed dual-frequency circular microstrip antenna with an open-ring slot has been firstly presented. As for the broadband circular microstrip antenna designs, antennas with two open-ring slots, embedded reactive loading by probe feed and microstrip-line feed have been presented. The antenna bandwidth of them can be enhanced about 4% to 6%. In the circularly polarized designs, we have proposed a circularly polarized microstrip antenna with a spur line. By choosing a suitable length of the spur line, CP operation can be obtained. And then, such a design can be applied to a compact circular patch antenna with bent slots. These reduced the antenna size to be 40%~50% of that of the simple case. Finally, we use the ideas of CP operation with elliptic patch and dual-frequency operation with stacked patch to propose a dual-band circularly polarized stacked elliptic microstrip antenna design. The frequency ratio of this design is about 1.39.

Abstract To pursue continuous growth, enterprises have to draft out various development strategies of their operation management. Nevertheless, whether the development strategies can achieve the co-understanding and supports from the members of the organization and whether they can be really executed have to depend on systematic methods for implementation. Balanced scorecard is a kind of management system that makes the organizational strategies realized. It was originated from the balanced scorecard of the United States in 1990. It emphasized that the assessment standards for the performance on the four aspects of an enterprise (the aspect of finance, the aspect of customers, the aspect of internal procedures, and the aspect of innovation and learning) should be originated from their strategies, and should be linked with the rewarding system of the enterprise. It referred that balanced scorecard is not merely a performance assessment system, but also a management tool linked with strategies and rewarding system. This research takes the case of a company, being a distributor of high-technological material, as an example to understand the structural process of its embedding of ¡§balanced scorecard.¡¨ Secondly, through evidential analysis, we can understand the high- and low-rank staff¡¦s different extents of agreement to balanced scorecard ever since it was embedded in the company. Finally, according to the analytic results, the research points out the relevant problems encountered in the process of embedding and gives suggestions, which can be a reference guide for the analyzed company and other companies planning to embed balanced scorecard. The conclusions of the research are as follows: In spite of having received guidance from a professional consulting company in the embedding process of a series of organizational reform plans, the analyzed company was confronted with a lot of problems over the promotion of balanced scorecard. This is closely related to the enterprise culture, value judgment, organizational climate and leadership style deeply cultivated in the company for a long time. Therefore, it is not a problem of system itself, but a problem of execution. Apart from supporting the promotion of the system, high-rank and leading grades should hold positive attitude and take initiative action to participate the promotion of the system, and cultivate correct enterprise culture, value judgment, organizational climate and leadership style. In this way, the implementation of the system can be sustained continuously, and the future value of the enterprise can thus be created.

To increase the allowable capacity of wind generation and system reliability of distribution system for islanding operation, an actual Taipower feeder has been selected for computer simulation. The voltage enhancement of distribution feeders with fixed speed wind generator has been obtained by using the static synchronous compensator(STATCOM). The model of Doubly-Fed induction generator(DFIG) in Matlab/Simulink has also been applied in the feasibility study of islanding operation for Taipower feeder. The critical clearing time of fault contingency is solved by considering the low voltage ride through (LVRT) capability of wind generators (WG) and the CBEMA curve of sensitive loads. In this way, feeder circuit breaker(CB) can be tripped in time to achieve islanding operation of distribution feeders without causing the tripping of WG due to voltage disturbance for the system fault contingency. To restore the stable operation of distribution feeders after being isolated from the rest of the power system, an adaptive load shedding scheme has been presented to disconnect the proper amount of system loading to achieve the balance of wind power generation and load demand according to the variations of feeder load profile and wind speed. It is found that system voltage sag problem due to severe fault contingency can be mitigated effectively by using the STATCOM for the support of low voltage ride through capability of WG. With the proper design of protection relay settings for feeder CB tripping and load shedding scheme, the WG and critical loads can be prevented from tripping during transient disturbance to ensure the successful islanding operation of distribution system.

This paper adopts a dual-point measurement technique to predict the resonance frequency and operation modes of a high speed rotor at different operating speed. The effect of balance policy on the operating mode shapes of a rotor has also been investigated. Displacement signals measured at two different points of a rotating shaft are used to estimate the operation mode shapes at the main operating frequency based on the definition of transmissibility function. To verify the feasibility of this technique, the dynamic parameters, i.e. natural frequencies, damping ratio and normal modes of a stationary rotor are measured in advance by applying the traditional frequency response method for comparison. The values of modal assurance criterion (MAC) and mode shape diagrams indicate that both methods are in a good agreement on the normal modes when the system is undamped or lightly damped. However, a significant difference is observed for highly damped modes. The dual-point measurement technique is applicable to investigate the effect of rotating speed on measured operation modes at different speed. Results indicate that the rotating speed may affect the dynamic parameters of a rotating shaft significantly. Furthermore, the dynamic unbalance effect on the response of a rotating shaft has also been studied in this thesis. Results indicate that the position of the unbalance is quite sensitive to the response of a rotating shaft. The sensitivity of unbalance and its position is dependent on the operation mode correspondence to the driving speed. The measured results indicate the dual-point measurement is quite available to study the dynamic responses of a rotating shaft or rotor.

Thesis (doctoral)--Universität, Heidelberg, 2001.

Zugl.: Leipzig, Univ., Habil.-Schrift, 2009

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