ABSTRACT For the 3-D system of wave motion consisted of a free-surface progressive gravity wave train propagating over a two side ripple bottom , a perturbation expansion procedure is developed to second order. The mechanism and the properity of the induced wave motion by the effect of the ripple bottom on the free-surface progressive gravity waves , including the resonance and non-resonance case , is described. To the induced resonance wave motion to the second order of the solution , the growth of its energy flux with time , and consequently the growth for the transmission speed of its energy flux are vividly demonstrated. Furthermore , the relation between the transmission speed in time and space is also established. Finally , the growth of the induced resonance wave motion with its propagating distance in the region of the ripple bottom located is emphasized. The variation and growth of the whole flow field of the wave motion system in time and space is therefore presented. To ascertain the accuracy and the generality of the analytical result , it was verified not only to by reducing which the solution of the one side wavy bottom, but also conform to the three kinds of the actual physical situation.

Recently, the ripple phenomena of liquid crystal display module were occurred frequently after burning machine test. The phenomena were mainly caused by the non-uniformity of the flatness of light guide plate. But, it is difficult to detect the ripple phenomena when the light guide plate is in a free state. It is usually can be detected until the burning machine test of liquid crystal display module was finished. But it will cost massive manpower and the physical resource wasting in this process. In this study, the through analyses of flatness variations of light guide plate in its free state, in the back light module, and in the liquid crystal display module after the burning machine test, respectively, were executed. Also, the effects of variations of process factors of a light guide plate on the ripple phenomena were studied. It is hoped to achieve the purpose that one can control the flatness of light guide plate in the initial stage so that the ripple phenomena will no longer occur.

Graduation date: 1978

No description available.

For the 2-D system of wave motion, consider a free surface progressive gravity wave train propagating over a random ripple seabed and there will be an interaction between surface wave and seabed. By spectrum analysis, getting the components of ripple seabed to make a Fourier form and a perturbation expansion procedure will be developed to second order to solve the flow field. Because the different type of spectrum will make different ripple seabed, the affect made by components of ripple seabed will change with the type and it¡¦s bandwidth, and the resoults predicted in model of this paper can become systematic .It is helpful for design of engineer.

This thesis examines the use of ripple correlation control as a maximum power point tracking algorithm with an interleaved SEPIC converter for use with a solar array. The suitability of existing topologies for use with photovoltaic applications and the tradeoffs involved are discussed. The advantages of interleaving in converters are examined and the benefits it provides to photovoltaic applications are discussed. An interleaved SEPIC converter operated in interleaved mode with a photovoltaic array is studied. The operation of ripple correlation control as a maximum power point tracking technique applied to the interleaved SEPIC converter is examined and simulations with results are presented. / text

Thesis (Ph. D.)--University of Adelaide, School of Civil and Environmental Engineering, 2005. / "June 2005." Bibliography: p. 157-165.

Proefschrift--Leyden. "Literatuurlijst": p. 155-156. / Pages 5-156 have also continuous paging, 235-386. Summary in English.

Proefschrift--Leyden. "Literatuurlijst": p. 155-156. / Pages 5-156 have also continuous paging, 235-386. Summary in English.

Due to its cheap production costs, simple construction, and robustness, switched reluctance machines are viable candidates for traction motor drive applications in the electrification of transportation. However, high torque ripple and acoustic noise limit the performance of switched reluctance motors (SRM). This thesis considers control methods to reduce the electromagnetic torque ripple in SRM, while also analyzing the impact of these control methods on other aspect of machine performance, such as copper losses and radial force production. Traditionally, SRM is controlled using rectangular current profiles which are excited using discrete pulsations. Timing of these pulsations is quantified with conduction angles, and the performance of the machine at a given operating point can be optimized by carefully choosing these conduction angles. This thesis starts the analysis on controls of SRM using the conduction angle parameters to determine a baseline of torque ripple performance for comparison against advanced control techniques developed afterwards. Recently, current profiling techniques have been developed, and have been shown to have high performance for torque ripple reduction. In this thesis, one such technique is proposed in the form of an optimization problem where the solution of this problem yields an optimized current profile that both minimizes torque ripple while reducing copper losses. The proposed current profiling technique ensures good current tracking, which allow for optimal control performance over a wide speed range. Finally, this thesis shows the torque more generally as one component of the nodal forces in SRM. The other component of the nodal forces is the radial forces, which contributes to the noise, vibrations, and harshness of the machine. In this thesis, modeling of the radial forces has been conducted, and effects of the proposed current profiling technique on radial forces have been shown to comprehensively illustrate the performance of the current profiling technique. / Thesis / Master of Applied Science (MASc)