Advanced Materials Research Vols. 834-836

Abstract: A new digital camouflage design scheme is presented by exploiting the visual perception of images. Firstly, the proposed scheme used color similarity and k-mean clustering to extract dominant background colors in RGB color space. Then pixels in the target selected by users were replaced with dominant colors under the control of color similarity. So the camouflage image was generated after the fusion of the target and the background. Experimental results show that the algorithm is effective and the camouflages have pleasant visual quality.

Abstract: LED Display-Screen is widely used as one of display Terminals to reveal the information in all aspects. With the improvement of living standards, people demand LED display screen to work with the high quality, high speed and high intelligence. The paper presents a method to design LED display-Screen with TMS320F2812 DSP chip of TI, Meanwhile it uses GPRS to communicate with the telephone and the information platform for convenient remote control, it can constitute a large LED display with the CAN bus and so on. The test shows that the system is reasonable, realizable, operated easily, flexible, adaptable to environment, low price, and it is useful in practice after being proved in the practical system. Key words: Display-Screen;TMS320F2812;DSP ;GPRS;

Abstract: Bi-frequency modulation can effectively solve the contradiction between high frequency and efficiency, but it will bring the problem of the current ripple. In this paper, use Buck circuit as the prototype, adopt phase shift parallel technology, make theoretical analysis and simulation studies on the bi-frequency circuit that the high and low frequencies units are operating in a state of continuous inductor current. Analysis and simulation results show that phase shift parallel can effectively inhibit the output current ripple. ^aMitsui86425@163.com ^bZ1960113@VIP.sina.com ^cdepkia@163.com

Abstract: A higher order sliding mode control algorithm is proposed to design and analyze for a class of MIMO nonlinear systems with unknown nonlinearities. The proposed control scheme based on geometric homogeneity and sliding mode control provides a general approach to design controller for near space vehicle system. Simulation example results demonstrate the advantages of the strategy.

Abstract: With more and more wide application of distributed power generation system, it is necessary to explore its impact on the power grid. The first residential user of distributed photovoltaic power generation system in China has recently connected to the power grid. A series of experiments were carried out by State grid metering center to detect status of the residential users system. The testing method of distributed photovoltaic power generation system and the results of field test are briefly introduced in this paper. Through the analysis of the test results, the characteristics of photovoltaic power generation system are discussed, in order to carry out further research of measurement technology.

Abstract: Design a DC/AC converter based on simplex single voltage source high frequency pulse DC loop technology, the output is 115V400Hz, 0.9KVA and the input is three phase alternating current. The forward part is DC/DC converter which provides pulse D.C. to the back part DC/AC converter. Implement soft-switch by changing the on-off state of switching tubes on the inversion arm path at the zero-voltage instant of the pulse direct current, no need of the auxiliary resonant net. The system takes three-state DPM current hysteresis control mode, gets good performance on output wave and efficiency.

Abstract: In order to filter, we use the coupling methods of line defects and point defects in photonic crystals to verity through theories and experimentations, get micro-cavity center frequency and wavelength of the main waveguide frequency resonance, and the same frequency lights will enter micro-cavity. Results show waveguides and micro-cavity can support its modes within in their deficiencies, but defects still can transfer energies through the evanescent coupling, the evanescent coupling is the role of the photonic crystals to the integration of device.

Abstract: A novel octave or fractional octave filter design method is presented here. In this method, a cascaded IIR filter is applied to overcome the Finite Word-Length Effect. Compared with the traditional octave filter bank, this method does not require 1/2 extraction or a corresponding anti-aliasing filter. The filter frequency response is improved. Filter attenuation values conform to the standard IEC1260-1995 defined class 0 filters. Simulation and experimental studies shows that the filter bank obtains a more accurate result than does the traditional method, especially in the low-frequency part. The 1/3 octave filter bank can analyze speech signals effectively.

Abstract: Solar energy is a kind of renewable energy, it‘s abundant, clean and environmental protection. In the current theme that calls for saving energy and reducing pollution, it’s undoubtedly of great significance to make full use of solar energy. In order to effectively use solar energy, we developed an automatic sunlight tracking solar panel system based on single chip microcomputer. We use MC9S12XS128 single chip microcomputer as the main control chip, and acquire signal with the sensor composed of photoconductive resistances. According to the signal collected by sensors, the control signal drives step motor to rotate, so that the system can follow the sun, ensuring that solar panel is always vertical to the sunlight, so it can absorb and convert solar energy to the maximum extent.

Abstract: A novel coupled-line structure is proposed to design dual-band and high-power Gysel power dividers. Based on traditional even-and odd-mode technique, the analytical design theory is given and the electrical parameters analysis is provided. Four numerical examples are presented to demonstrate the flexible dual-band applications. A practical power divider operating at 1GHz and 2 GHz is designed. The calculated and full-wave simulated results verify our proposed idea.