Advanced Materials Research Vols. 424-425

Abstract: Power semiconductor devices and its control circuit in inverter of motor speed regulation system is the weak link most likely occurs fault. Fault feature extraction is the key to fault diagnosis.Regarding inverter’s output voltage signal as the characteristic parameters,extracting inverter’s voltage spectrum by using improved windowed STFT,fault detection and diagnosis can be achieved.Simulation results demonstrate the effectiveness of this method

Abstract: The sewage should be filtered to prevent the blockage of the heat exchanger before using. And the anti-blocking machine is the key device to prevent blocking in sewage source heat pump system. The paper introduces the development of the anti-blocking machine: intermittent backwashing, flat continuous backing, cylindrical with external baffle continuous backwashing, double-stage continuous backwashing without external baffle. Also, it describes the principle of the anti-blocking machine, the key technologies and the necessity of choosing double-stage pump in sewage source heat pump system with anti-blocking machine. The paper concludes the technical characteristics, the advantages and disadvantages of the double-stage sewage source heat pump system and introduces the selecting principle of the double-stage pump. The paper clarifies some misunderstanding about anti-blocking machine and double-stage pump.

Abstract: In order to help vehicle users to save fuel cost, combining the refueling with transportation task, this paper provided a scientific solution of gas station selection during transportation task. Considering users’ personalized requirements, gasoline price, etc, this paper established a multi-objective decision-making model based on the aims of the shortest distance and minimum cost of given refueling volume. The model can be resolved by the algorithm designed. In order to improve its practical applicability, a visual decision support system which can show the gas station selected and route had been developed based on GIS. This system can provide selection of gas station which meets user’s personalized requirements and make the objective function optimal

Abstract: Due to rapid developments in computer networking and communi- cation technology, users have begun to use personal computers to transmit images through the internet. However, this activity puts users at risk of hacker attacks and theft. Although single pixel position shuffling can eliminate an image’s contour, it cannot hide the characteristics of the grey-level spectrum. Because the dynamic trajectories of a chaotic system are highly sensitive to the initial values of the system, applying chaotic-ciphering to the image will result in a good encryption effect, and significantly enhance the key space of the encrypted image. For these reasons, this paper propose a novel and simple Bit-Chaotic-Shuffle (BCS) technique for encryption on color images that is based on multi chaotic systems. This technique not only eliminates image contours, but also disorders the characteristics of the RGB-level spectrum. This encryption method also adopts three chaotic systems in which the key space reaches 10137, thoroughly preventing decryption by an exhaustive attack. This paper further applies the correction coefficient and Mean Square Error (MSE) methods to prove the encryption and the high security performance of the proposed encryption system

Abstract: Metallization treating on the plastic surface without the mask technology was created by using a new method combining the laser technique with the electroless copper deposition,this method get rid of palladium as catalyzer in the traditional chemical plating which is high cost and environment unfriendly. The samples are examined carefully by the scanning electron microscopy; resistance and adherence of the Cu plating were inspected and analysised. The result indicated that it was feasible to fabricate compact,uniform,and good conductive Cu plating on the plastic substrate by using potassium sodium tartrate and EDTA2Na as chelating agent; the resistivity of plating is related to the deposition time; adherence is influenced by laser power,the excellent adherence to plastics surface are obtained when the laser power exceeds 5W.

Abstract: A cost-effective energy recovery (ER) circuit for plasma display is proposed in this paper. Besides main full-bridge sustain switches, the ER circuit should be included in the sustain driver for plasma display to reduce the power loss. The proposed ER circuit consists of four diodes and a single external inductor. Due to a simpler structure than the conventional ER circuit, the efficiency can be improved and the overall cost is reduced. Theoretical analysis and performance of the proposed ER circuit were verified on an experimental prototype operating at 200 kHz switching frequency

Abstract: According to the characteristics of wavelet packet decomposition and reconstruction, an image enhancement method is put forward by decomposing wavelet packet and adjusting enhancement coefficient of band signal by the energy size. First, borehole peep images were decomposed by wavelet packet, and obtained the signal bandwidth of each layer after wavelet packet decomposition combined with Fourier transform. Secondly, energy of each band signal was calculated, wavelet packet decomposition coefficients according to the size of band energy were enhanced and weakened. Finally, the wavelet packet images were reconstructed. Project case indicates that this method can effectively enhance the images, especially the information of fractured surrounding rock.

Abstract: A non-isolated single-switch step up/down converter with wide conversion range is proposed in this paper. In the porposed converter, a boost converter and a single-ended primary inductor converter (SEPIC) are connected in cascade. Due to the cascade connection of a boost converter and SEPIC, wide conversion range is achieved. By utilizing a single switch, a complex control circuitry problem of conventional cascade converters is solved. The boost converter at the input stage can provide a continuous input current. The operation principle and steady-state analysis of the proposed converter are provided. A prototype of the proposed converter is developed, and its experimental results are presented for validation

Abstract: New complex inorganic ion exchanger Li_1.2Zn_0.9PO₄ is synthesized. Chemical composition, structure and some related properties and complex mechanism of this ion exchanger are investigated by electron microscopic, X-ray diffraction and chemical methods. The ion exchange behavior of Li_1.2Zn_0.9PO₄ has been studied in detail. Results of column test indicated, that the exchange capacity obtained from tests for Li⁺ in 0.1mol /L HNO₃ solution is 6.3mmol/g.

Abstract: Based on the algorithm of Scale invariant feature transform SIFT, informed a method to detection the airport runway foreign objects based on the algorithm of improved SIFT, first roughly extracts object through the image segmentation algorithm, then match the object on it’s SIFT features, ensure it’s features stability, enhance the matching accuracy. Experimental results show that this method can not only handle the problems of tar-get losing evidently, which are induced by objects rotation and translation, but also has nice robustness to the conjunction of multi-targets in the process of object tracking