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Ultra High Frequency (UHF) band is increasingly widely used in military maritime satellite communications due to its good communication performance. When the electromagnetic wave reaches the sea surface, it is reflected. The reflected wave and direct wave enter the receiver in the form of a superimposed vector, which will inevitably produces multipath fading at the receiving end. This paper followed the general principles of modeling in multipath effects, and the UHF band multipath effects of sea surface were studied. The judgment basis was obtained which determines whether the specula reflected wave dominates in the reflected wave based on Rayleigh criterion, and then the reflection coefficient of sea surface were calculated. Finally, the power attenuation of reflected wave relative to direct wave for different wind speeds were simulated and analyzed.

This paper taked Xinxue River constructed wetland of Nansi Lake as the study object , researched the boundary problem in the process of modeling and prediction of water quality and quantity. Furthermore, all data collected were expanded, and virtual data points were increased to broaden the range of the model value. Therefore boundary problem was solved effectively, and mode accuracy was also improved.

The morphological filter as a nonlinear filtering method has been widely used for image (or signal) processing. Unlike the traditional digital filters, mathematical morphological operations are shape-based computing. Feature extraction of signals is entirely in the time domain without the transforming of the signal from the time domain to frequency domain. The vibration signal contaminated with noise is processed using morphological filter and Butterworth filter respectively. To compare the outputs of the two filters, we find that morphological filter shows better performance. It is effective in suppressing noise while maintaining the original signal both in the time and frequency domain. In addition, an outstanding advantage of morphological filter is its ability to keep the phase of the original signal. Its computing speed is faster. In the end, its low-pass characteristic is verified by processing vibration signal.

This paper designed a signal acquisition and analysis system based on the characteristics of the graphical programming language of LabVIEW. The system adopted NI USB -9234 data collection card, applied with the virtual instrument and related technology for the signal collecting and processing system. The system also has dual-channel data acquisition, real time data acquisition, signal analysis in time domain and frequency domain, FFT implementation Waterfall conversion, signal simulation capabilities. On the basis of analysis the systems functional requirements, a detailed description of the functional programming and design of the front panel is approached. At last the feasibility of system is experimental inspected and detailed. Experiments have shown that the virtual instrument is a good solution to the efficient implementation of various missions.

The tension of warp and weft run through the whole weaving process in knitted carpet weaving equipment. The performance of delivering warp mechanism and guiding weft mechanism in this kind of equipment influences the quality of carpet directly. A self-adjusting delivering warp mechanism is designed in this thesis, which is used in knitted carpet weaving equipment or other textile equipment that delivers warp by warp-spindle and demands even warp tension. The self-adjusting delivering warp mechanism consists of the device for setting and detecting warp tension, the device for driving warp-spindle in different speed, and the device for transmitting warp-spindle movement. The device for setting and detecting warp tension can determine initialization tension of warp, according to the technical requirements, can detect and feed back warp tension in real time. The device for driving warp-spindle in different speed makes the rotating speed of warp-spindle change according to the warp tension. The self-adjusting delivering warp mechanism realizes the function on controlling the rotating speed of warp-spindle in closed loop, and on stabilizing delivering warp tension.