Search

The theories about the eight diagrams and the five elements were first recorded in I Ching. In the ancient China, the enthronement of emperors faced southward, which is called “Becoming an Emperor Facing Southward”. The directions and modern maps in the eight diagrams of The Book of Changes and in the theories on FengShui are the opposite to the aerial diagram, the cadastral diagram, the measurement diagram, the navigation diagram, the tourist diagram and architectural diagram of China. This is also one of the problems that scholars and users to solve. With the mathematical deduction method and according to the realities, this paper demonstrates the “heaven in the south and earth in the north” in The Book of Changes and explains the philosophical problems that have remained unsolved for years. In this way, it aims to allow researchers to analyze problems with appropriate principles and provide some help for researchers and users.

The identifiability of spatial variable coefficients for vibration string and Euler-Bernoulli beam are considered. It is shown that the coefficients can be determined by means of boundary control and observation in finite time duration. These results can be considered as the generalization of infinite time coefficients identifiability through the application of Ingham-Beurling theorem.

The identifiability of spatial variable coefficients for the vibrating string and Euler-Bernoulli beam are considered. It is shown that the coefficients can be determined by means of boundary control and observation in a finite time duration. These results can be considered as the generalization of infinite-time coefficients identifiability through the application of the Ingham-Beurling theorem.