Bøger af Jianhua Wang

H.264/AVC(Advanced Video Coding) is a more advanced international video coding standard, which increases the compression ratio and video quality, at the same time, it also causes much memory access because of its frequent table look-up UVLT (Unstructured Variable Length Tables) operations. High memory access can cause high power consumption in CAVLC decoding. Aiming to solve the problem of high table memory access due to frequent table look-up operations, thereby reducing its power consumption, a high-efficient table memory access saving algorithm based on program code is presented in this book. In our scheme, we mainly use program code to fully realize the expression of all the UVLT in CAVLC decoding. As a result, our proposed scheme can completely realize the searching of decoded codewords in UVLT by a program execution way instead of sequential table look-up, which can save a lot of memory access because there is no frequent look-up of UVLT in CAVLC decoding We used series of experiments to verify the effectiveness of our proposed methods in this book by comparing them with current methods.

Vacuum circuit breakers are widely used in distribution power systems for their advantages such as maintenance free and eco-friendly. Nowadays, most circuit breakers used at transmission voltage level are SF6 circuit breakers, but the SF6 they emit is one of the six greenhouse gases defined in Kyoto Protocol. Therefore, the development of transmission voltage level vacuum circuit breaker can help the environment. The switching arc phenomena in transmission voltage level vacuum circuit breakers are key issues to explore. This book focuses on the high-current vacuum arcs phenomena at transmission voltage level, especially on the anode spot phenomena, which significantly influence the success or failure of the short circuit current interruption. Then, it addresses the dielectric recovery property in current interruption. Next it explains how to determine the closing/opening displacement curve of transmission voltage level vacuum circuit breakers based on the vacuum arc phenomena. After that, it explains how to determine key design parameters for vacuum interrupters and vacuum circuit breakers at transmission voltage level. At the end, the most challenging issue for vacuum circuit breakers, capacitive switching in vacuum, is addressed. The contents of this book will benefit researchers and engineers in the field of power engineering, especially in the field of power circuit breakers and power switching technology.