1. This book gives the reader a comprehensive and in-depth introduction to the variable gain control and details a series of related innovative technologies. Instead of reading various relevant books, this book enables readers to establish an overall understanding of variable gain control methods for different systems. 2. The goal of this book is to interpret complex control knowledge in simple terms. It is easy to understand and needs little background knowledge. 3. It highlights the practical applications of variable gain control in energy conversation. The designed variable gain control has a simple form and is convenient for engineering applications. 4. Discussion remarks are provided in each chapter with new contributions to emphasize the novelty of the presented design and analysis methods. Moreover, a number of interesting remaining problems in the related topics, which are worthy of further investigation, are discussed in this book. 5. Simulation results are given in each chapter, sometimes in a comparative manner, to show the effectiveness of these methods.

The publication in 1934 of Yang Chengfu's book, Essence and Applications of Taijiquan (Taijiquan Tiyong Quanshu) marked a milestone in the modern evolution of the art of taijiquan. Using what is best-termed demonstration narrative, the author presents form postures and suggested applications from his own perspective, as he performed them. This methodology renders Yang Chengfu's direct, hands-on teaching of the art with such immediacy and liveliness that the reader experiences the master's teaching much as his students did.
This English translation finally makes Yang Chengfu's classic work available to taijiquan enthusiasts in the West. It includes notes and commentary that clarify the author's frequent classical and literary turns of phrase and elucidate the philosophical and political underpinnings that shape the text. The translator investigates and compares several early taijiquan books in order to help explain the roles played by two of Yang Chengfu's students, Dong Yingjie and Zheng Manqing, in bringing Yang Chengfu's words and teachings into print.
Serious students of taijiquan, and those wishing to deepen their knowledge of taijiquan history and theory, will find this seminal work indispensable to their study and practice.