Coal-gangue interface detection during top-coal caving mining is a challenging problem. This paper proposes a new empirical approach to detect the coal-gangue interface based on vibration signal analysis of the tail boom support of the longwall mining machine. Due to nonstationary characteristics in vibration signals in this complicated environment, the empirical mode decomposition is used to decompose the original vibration signals into intrinsic mode functions. The associated Hilbert transform calculates the instantaneous frequency and amplitude of the selected intrinsic mode functions, providing a novel Hilbert spectrum in the time-frequency domain. The distribution of the Hilbert spectrum of top-coal caving is found to be more uniform than that of coal-gangue caving. A method of vibration feature extraction based on the information entropy of the Hilbert spectrum is presented. The Mahalanobis distance function is used to classify the caving states. Experimental results show that the Mahalanobis distance measure applied to the information entropy of the Hilbert spectrum of vibration signals from the tail boom support of a longwall mining machine is effective for coal-gangue interface detection.

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IntroductionFor the nano-area analysis of materials, it is necessary to evaluate all data obtained by HRTEM, EDS, EELS, and/or Energy Filter. Up till now, each analytical/imaging instrument required its original computer control system. Thus, the total operational environment for the nano-area analysis was not convenient for us. Recent progress of computer technology provides the ability to build a high performance environment for seamless operation by Client/Server design.We have developed computer controlled high-throughput integration system based on PC, called FasTEM system, having seamless integration function and real-time remote control function of all instruments related to nano-area analysis. The FasTEM system is composed of Windows NT based Server PC System that is connected to the target TEM via RS232C for integrated operation, and Client PC SYSTEM connected to the Server PC via TCP/IP for remote operation (Fig.l).Seamless Integration FunctionAll user interfaces of the analytical/imaging instruments, such as HRTEM, STEM BF/DF, EDS, PEELS and GIF can be seamlessly integrated into the Server PC.

Coal-gangue interface detection during top-coal caving mining is a challenging problem. This paper proposes a new vibration signal analysis approach to detecting the coal-gangue interface based on singular value decomposition (SVD) techniques and support vector machines (SVMs). Due to the nonstationary characteristics in vibration signals of the tail boom support of the longwall mining machine in this complicated environment, the empirical mode decomposition (EMD) is used to decompose the raw vibration signals into a number of intrinsic mode functions (IMFs) by which the initial feature vector matrices can be formed automatically. By applying the SVD algorithm to the initial feature vector matrices, the singular values of matrices can be obtained and used as the input feature vectors of SVMs classifier. The analysis results of vibration signals from the tail boom support of a longwall mining machine show that the method based on EMD, SVD, and SVM is effective for coal-gangue interface detection even when the number of samples is small.

An TM switching system should be capable of handling multimedia traffic, which has different bit-rates and diversiied quality requirements. A self-routing switch is a key piece of equipment for attaining this goal. This paper proposes. a new switch construction and describes its LSI design and fabrication.The proposed switch, which is a memory switch with dynamic link speed control, can dynamically change link speeds according to traffic flow, thereby achieving high performance in any imbalanced traffic condition. The switch element also functions as a multiplexer/demultiplexer and an inserter/dropper. Thus, the proposed LSI is expected to be a key component in ATM-based equipment.A 4x4 memory switch LSI using 0.8-pm BiCMOS technology is developed, and a switching network with a capacity of 256 155-Mb/s lines is tested. Results show that the proposed LSI makes possible a compact, economical ATM switching system.