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: The present disclosure provides a multi-factor quantitative analysis method for deformation of a neighborhood tunnel. The method includes the following steps: analyzing monitoring data generated at a tunnel site; simulating collapse occurring at a shallow buried section of a tunnel; determining the degree of influence of each factor on the tunnel and a stratum; and determining quantitative influence of each factor on tunnel deformation. The present disclosure can not only provide an accurate theoretical basis for the construction of the shallow buried section of the small-distance tunnel, but also guarantee safety and cost saving during tunnel construction.

Abstract: An encoding method includes pre-encoding a current video frame in a video stream, to obtain a pre-encoded current video frame, when there is no I frame in M encoded video frames that have been encoded before the current video frame, determining whether the current video frame is a scene switching frame in which scene switching has occurred relative to a previous video frame, based on the pre-encoded current video frame and a pre-encoded previous video frame to the current video frame, M being a preset positive integer, and encoding the current video frame into an I frame when the current video frame is the scene switching frame, and encoding the current video frame into a P frame when the current video frame is not the scene switching frame.

Abstract: A video processing collaboration method includes transmitting a video processing capability request and a video analysis capability request to a terminal device, receiving video processing capability information and video analysis capability information from the terminal device based on the video processing capability request and the video analysis capability request, determining a video processing collaboration configuration based on the video processing capability information and a video analysis collaboration configuration based on the video analysis capability information, allocating an image processing task to the terminal device, to the cloud server, or to both the terminal device and the cloud server, based on the video processing collaboration configuration, and allocating an image analysis task to the terminal device, to the cloud server, or to both the terminal device and the cloud server, based on the video analysis collaboration configuration.

Abstract: A calibration system for magnetometers includes magnetometers configured to measure a magnetic field to be measured; a magnetometer holder fixedly mounted on the magnetometer holder; at least one magnetic field generating device having its position fixed relative to the magnetometers, and used to generate a calibration magnetic field distribution in a space to be measured; and a calculation device configured to calculate the magnitudes of magnetic field vectors at the positions of the magnetometers according to the calibration magnetic field distribution generated by the at least one magnetic field generating device in the space to be measured, receive measured magnitudes of the magnetic field vectors from the magnetometers, and calculate detection gain values of the magnetometers on the basis of the calculated magnitudes of the magnetic field vectors and the measured magnitudes of the magnetic field vector.

Abstract: A system and a method for spatial positioning of magnetometers. Said system includes: magnetometers, a magnetometer support, first positioning markers, a photogrammetry system, and a controller. The first positioning markers are a non-rotationally-symmetrical pattern. The photogrammetry system includes photographing devices configured to photograph, at at least two of a plurality of photographing sites, first image data of the first positioning markers by means of one or more photographing devices. The controller is configured to receive data of the first image photographed by the photographing devices, calculate spatial positions of the first positioning markers on the basis of pre-obtained system parameters and the first image data, and then calculate spatial positions and spatial orientations of the magnetometers.