Abstract: The present disclosure provides a risk assessment method of water inrush in tunnels constructed in water-rich grounds. The method includes the following steps: simulating a tunnel excavation process by finite element software MIDAS GTS NX and fluid-structure interaction; according to a research method of control variables, analyzing effects of a groundwater level, an elastic modulus and advanced pipe shed grouting on the stability of surrounding rock, and improving an algorithm of a radial basis function (RBF) neural network using a Grey Relation Analysis (GRA)-based Partitioning Around Medoid (PAM) clustering algorithm to assess risks of water inrush occurring in Qingdao area.

Abstract: Disclosed is a mobile broadcast signal demodulation chip for location. The demodulation chip includes a reception demodulation and module and a measurement module, where the reception and demodulation module is configured to demodulate a spread spectrum signal for positioning inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information; and the measurement module is configured to measure and acquire location characteristic parameters. The demodulation chip is not only capable of demodulating broadcast data in a mobile broadcast signal, but also capable of demodulating a spread spectrum signal for positioning-inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information and location characteristic parameters, thereby effectively improving location accuracy.

Abstract: The present invention, pertaining to the field of mobile broadcast television technologies, discloses a method and apparatus for generating a broadcast positioning signal, and a positioning method. According to the present invention, a broadcast positioning signal is generated by inserting a spread spectrum signal and a first spread spectrum signal in an orthogonal frequency-division multiplexing (OFDM) signal, and a receiver is positioned according to broadcast positioning signals from at least three different senders.

Abstract: The present invention, pertaining to the field of wireless communications, discloses a mobile broadcast signal demodulation chip for location. The demodulation chip includes a reception and demodulation module and a measurement module, where the reception and demodulation module is configured to demodulate a location spreading signal inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information; and the measurement module is configured to measure and acquire location characteristic parameters. The demodulation chip is not only capable of demodulating broadcast data in a mobile broadcast signal, but also capable of demodulating a location spreading signal inserted in the header of a time slot or in the header of a transmission frame of a received mobile broadcast signal to acquire navigation message information and location characteristic parameters, thereby effectively improving location accuracy.

Abstract: The present invention, pertaining to the field of mobile broadcast television technologies, discloses a method and apparatus for generating a broadcast positioning signal, and a positioning method. According to the present invention, a broadcast positioning signal is generated by inserting a spread spectrum signal and a first spread spectrum signal in an orthogonal frequency-division multiplexing (OFDM) signal, and a receiver is positioned according to broadcast positioning signals from at least three different senders.