2006 Vol.12

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Microwave Equivalent Model of Tuned MEMS Shunt-Capacitive Switches LI Yue-fei;YANG Xue-xia;ZHANG Wen-jun Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 111-115.   Abstract （1996）            Knowledge map    Save By analyzing electromagnetic characteristics of a microwave equivalent circuit model, the offstate resonance choice formulation and on-state impedance matching formulation of tuned MEMS shunt-capacitive switches is presented. A design method of tuned MEMS shunt-capacitive switches is developed based on an analysis of the microwave equivalent circuit. Numerical results of the circuit simulation of a MEMS switch for the X band based on these design models are described. Electromagnetic characteristics of the switch are confirmed with a high frequency full-wave simulation software. This is useful in designing high-performance RF MEMS switches. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Stereo Video Object Segmentation Based on Disparity and Change Detection GAO Xin;AN Ping;LIU Jia;ZHANG Zhaoyang; Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 116-119.   Abstract （2089）            Knowledge map    Save Stereo video object segmentation is a key technology in the new generation video coding, video browsing, and Internet multimedia interacting, etc. In this paper, a stereo video object segmentation algorithm that combines various sources of information is proposed. Estimation of disparity based on edge character restriction is first adopted to obtain reliable disparity scene. The disparity information is used to initialize segmentation. Change detection information is then integrated to modify boundaries of disparity segmentation. Experimental results show effectiveness of the algorithm in the case of multiple object overlapping. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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All-Optical Gain-Clamped EDFA with High Gain and Low Noise Factor SONG Ying-xiong;LI Ying-chun;CHEN Jian;LIN Ru-jian Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 120-124.   Abstract （2351）            Knowledge map    Save A novel alloptical EDFA with flat and clamped gain is presented. By using a 2-stage amplifier and adding fiber grating and a gain-flattening filter at the output port, high gain and low noise factor are obtained. Flatness and clamping gain in the C band and the cost is also considered. Simulation results show that this configuration has a good gain-clamping characteristic. When some wavelengths are added or dropped, the gain of remaining channels keeps constant. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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UWB Printed Antenna with a Wing-Shaped Ground Plate BAI Xiao-feng;ZHONG Shun-shi;LIANG Xian-ling Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 125-128.   Abstract （2059）            Knowledge map    Save A novel ultra-wide band (UWB) printed antenna with a semi-circular metal patch and a wing-shaped metal ground plate is presented. The proposed planar antenna has an ultra-wide band and small size. It has a simple structure, therefore is easy to fabricate. Its measured -10 dB return loss bandwidth covers a frequency range between 3.6 GHz and 11.0 GHz. In other words, the ratio impedance bandwidth reaches 3∶1. This type of antenna is suitable for short-distance UWB communications. Related Articles | Metrics | Comments（0） Cited: Baidu(8)

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A Novel Defected Ground Structure and Its Application to Lowpass Filter ZHONG Xiao-ming;LI Guo-hui Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 129-132.   Abstract （2209）            Knowledge map    Save A novel defected ground structure (DGS) is proposed and the effect of the defect parameters on its performances is presented. A lowpass filter is designed using the proposed DGS. Experimental results confirm that the lowpass filter can provide a very wide stopband with 20 dB bandgap, which is approximately 3.7 times of the cutoff frequency. Therefore the higher order harmonic responses are effectively suppressed. In addition, the highimpedance inductances are realized by using DGS so that highpower handling capability is improved. Related Articles | Metrics | Comments（0） Cited: Baidu(29)

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Design of Coherent Information Protection Equipment DING Xiao-qing;LING Yong;CHEN Hui-min Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 133-135.   Abstract （1838）            Knowledge map    Save A piece of correlative information protection equipment is designed for information security. Electromagnetic emissions are protected through correlative interference. An implementation of correlative information protection is described. The design procedure is presented, and performances are tested. Related Articles | Metrics | Comments（0）

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Simulation Model of Ink-Wash Effect Based on a Dynamic Diffusion Mechanism CHEN Feng;ZHANG Wen-jun;ZHANG Mu Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 136-140.   Abstract （2023）            Knowledge map    Save Digitalization of the inkwash diffusion effect is a key in simulating ink-wash by computer graphics. Based on an analysis of the relationship between water, ink and rice paper, an improved method that is token the mechanism of ink-wash dynamic diffusion by these relations is presented. Assuming that ink-wash consists of water and ink molecules and by constructing a rice paper structure, a simulation model using a particle system is established. The process of dynamic diffusion and its simulation are simplified. Simulation experiments on Maya show that the diffusion effect of ink-wash using this model is more realistic. Randomness and mobility of the ink-wash dynamic diffusion is visibly improved. In this way, controllability of particles is enhanced, and the amount of computation is reduced. This model is more flexible for the implementation of various styles of ink-wash simulation. Related Articles | Metrics | Comments（0） Cited: Baidu(3)

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Software Development for Digital Control and Measurementof JIC Based on DOLI System HUANG Xing;MA Hang;CHENG Chang-jun Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 141-145.   Abstract （1950）            Knowledge map    Save This work expands the function of testing machines with a DOLI system, and provides a platform for teaching and research. Based on the function library of DOLI system and MFC Class Libraries provided by Microsoft, software for digital control has been developed, and measurement of the ductile fracture toughness (JIC) performed by modularized design. The software development makes use of techniques such as multi-thread, serial communication in Win32, object oriented programming, etc. The JIC of 12Cr1MoV and 20Mn steel was measured using the three-point bending specimens. The result shows that the software not only operates stably and reliably and can accurately control the testing machine in realtime, but can also measure JIC and carry out digital analysis. Related Articles | Metrics | Comments（0）

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Adaptive Edge Detection Using a Half-Neighborhood Algorithm XU Wei-dian;XU Li-chun;HU Yue-li Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 146-149.   Abstract （2217）            Knowledge map    Save Edges in image is important for object recognition and computer analysis, and a large number of edge extraction algorithms are available. This paper proposes an improved method on the basis of a half-neighborhood operator. In order to decide whether a pixel belongs to an edge, a 3-by-3 block centered at the pixel is chosen, and the maximum, minimum, mean, and standard deviation are calculated. The standard deviation is used as a threshold value, and at the same time, the ability of human eyes in distinguishing gray-level differences is taken into consideration. Edges in a number of images are extracted using the described method, and the results show validity of the method. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Advances in Theoretical Study and Engineering-Application of Nano-Actuators ZHANG Yong-yu;CHEN Xiao-yang Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 150-157.   Abstract （2143）            Knowledge map    Save Nano-actuators are devices and structure that can be actuated in the range of 0.1～100 nm. Nano-actuators are sorted into conventional dimension nano-actuators, micro scale nano-actuators and nano-machine actuators. The same characteristic is the nano-scale precision of driving and positioning. Research statusand main accomplishments of nano-actuators are summarized in detail. In particular, typical driving mechanisms of micro-scale nano-actuators appeared in the recent years are introduced. In addition, the key technology, existing problems and application prospect of nanoactuators are analyzed. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Nonlinear Decoupling Control of Hybrid ExcitationPermanent Magnet Synchronous Motor XIE Qi-yue;KANG Hui-jun Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 158-161.   Abstract （2048）            Knowledge map    Save In practical operation of hybrid excitation permanent magnet synchronous motor (HPMSM), a thirdorder formation is modeled under the condition that the additional exciting current is stable. Using differential geometry, decoupling control and complete linearization of HPMSM are realized. Simulation shows that HPMSM control based on nonlinear decoupling control theory has good performance. Related Articles | Metrics | Comments（0）

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Ultrasonic Nondestructive Evaluation of Average Grain Size of Cr-Mo Steel ZHANG Hong-da;MA Shi-wei Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 162-165.   Abstract （1971）            Knowledge map    Save This paper describes a high frequency ultrasonic testing of Cr-Mo steel samples heat-treated at high temperature. Reflected echoes were analyzed both in the time and frequency domains. Ultrasonic characteristics such as attenuation coefficient, velocity and frequency of samples being tested were obtained. Relationships between these parameters and the average grain diameter of samples were also obtained. These results are useful in early assessment of material thermal fatigue development based on ultrasonic pulseecho techniques. Related Articles | Metrics | Comments（0） Cited: Baidu(7)

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Digital Monitoring System for High-Speed Press Using CMOS Image Sensor SUN Xu-sheng;XU Yao-liang;LI Yu-zeng;WANG Da-wei Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 166-169.   Abstract （1699）            Knowledge map    Save An image monitoring system for high-speed press is outlined. Based on analysis of drawbacks of traditional monitor systems, a new digital image monitoring system is designed. The system includes a CMOS image sensor, a high-speed microprocessor, an USB2.0 chip and a SRAM frame memory. Considerations in the system design are described. The system has been installed in a high-speed press with satisfactory results. Related Articles | Metrics | Comments（0）

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Uniformization for Authentication Codes YANG Jian-sheng;QI Tao Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 170-173.   Abstract （1792）            Knowledge map    Save By constructing a new coding algorithm, called uniformization, it is proved that all authentication codes, or systematic authentication codes, can be uniformized into a new class of authentication codes, called uniformized authentication codes, or uniformized systematic authentication codes. With these codes a new lower bound of maximum probabilities of a successful impersonation for all general codes is derived if encoding rule distributions are equiprobable. Related Articles | Metrics | Comments（0） Cited: Baidu(2)

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Scheduling of Goods Loading and Unloading within Common Due Window LU Yan-ping;SUN Shi-jie;TAN Fang Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 174-180.   Abstract （2035）            Knowledge map    Save This paper studies the following relationship between shipowner and harbor in loading and unloading goods: n ships arrive at the same harbor at time zero. It is hoped to finish loading and unloading goods within the same due window ［d,D］. If a ship finishes its work after D, the ship owner will penalize the harbor. If a ship finishes its work before d, the ship owner will reward the harbor. Thus the harbor needs to arrange the loading and unloading sequence in an optimal manner for these ships so that the total cost is minimized. To deal wit h such an NPhard problem, the paper proposes two dynamic programming algorithm s, a branch and bound algorithm with a polynomial solvable case. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Hedging European Contingent Claims at Higher Interest Rate for Borrowing with Transaction Costs TANG Mao-ning;ZHAO Fei Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 181-185.   Abstract （1875）            Knowledge map    Save This paper studies the problem of hedging European Contingent Claims (ECCs) in the market that has frictions in the form of percentage management costs for holding or borrowing risk assets and a higher interest rate for borrowing than for lending. The upper-hedging price of an ECC is obtained by introducing a family of auxiliary frictionless financial markets Existence of an optimal portfolio for hedging contingent claims is shown. A similar method can be used to get a lower-hedging price and then an arbitrage-free interval. Related Articles | Metrics | Comments（0）

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Three Dimensional Numerical Simulation and Flow Analysis of DoubleSuction Pumps ZHANG Ji-guang;CHEN Hong-xun;MA Zheng;SHI Fa-jia;WEI Pei-ru Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 186-190.   Abstract （2281）            Knowledge map    Save Numerical simulation of internal flow within double-suction pump is carried out based on the Reynolds Average Navier-Stokes equation and k-ε model with a simple algorithm. According to the simulation results, the internal flow and the calculated performance of doublesuction pumps are analyzed. The calculated results of performance prediction of the pump are compared with experimental results, showing good agreement under large flow conditions. The flow field simulation provides a useful basis to optimize design of double-suction pumps. Related Articles | Metrics | Comments（0）

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Evaluation of Energies and Intensities of γ Rays from 233 92U 141 αParticle Decay LUO Wen-yun;LI Xin-nian;LIU Jing-yi Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 191-195.   Abstract （2119）            Knowledge map    Save 233U is a fissionable material that can be used as nuclear fuels. However, no results of decay data evaluation have been published since 1990. As some recent measurements have become available, it is necessary to update the evaluation. Based on a search of the new measurement results from the Nuclear Science References File (NSRF), evaluation of decay data of 233U is recommended in this paper. Related Articles | Metrics | Comments（0）

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Determination of Methanol During Fermentation of Pichia Pastoris by Chromotropic Acid Spectrophotography YU Bo;DAI Xiao-feng;ZHANG She;CHEN Yu-guang Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 196-199.   Abstract （2356）            Knowledge map    Save Methanol in acid solution was oxidized to formaldehyde, which interacts with chromotropic acid, and a purple compound with a characteristic absorption peak at 574 nm is formed. Based on the above reaction principle, a novel method, chromotropic acid spectrophotography, was established to determine methanol content during fermentation of Pichia Pastoris. In methanol determination (0.05%～0.5%(m/V)), the method is good in the sense of linearity (R2＝0.999). The recovery ratio of methanol is between 99.4%～103.8%, and the relative standard deviation of determination is less than 1.49%. Compared with a result of gas chromatography (GC), the coincidence indicator is over 95.0%. The results suggest that the method is simple, fast and low priced for methanol determination. Related Articles | Metrics | Comments（0） Cited: Baidu(13)

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Determination of High Calcium Content in Milk Powder Using Incomplete DigestionFlame AAS Method XU Yin-juan;ZHANG Lan-man;YUAN Hui-juan;TANG Wei-li Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 200-202.   Abstract （2090）            Knowledge map    Save A method of incomplete digestion with flame atomic absorption spectrometry (FAAS) for the determination of high calcium content in milk powder is reported. The sample milk powder was incompletely digested with HNO 3H 2 O 2 in a pressurized vessel. Emulsifier OP-10 and releasing agent lanthanum were added for FAAS determination of calcium. Parameters were optimized. Recovery of the method was in the range of 101%～104% with RSD 0.29%. Related Articles | Metrics | Comments（0）

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Optimal Portfolio Choice with Fixed Consumption under CEV Model PENG Wang-xiang;QIN Cheng-lin Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 203-206.   Abstract （1798）            Knowledge map    Save The method of stochastic control, Bellman equation and the maximum rules are used to settle down the problem of optimal portfolio choice with fixed consumption. A cyclic solution to the equation is obtained. The conclusion is economically meaningful for private investors, management of pension fund, and insurance companies in portfolio choice. Related Articles | Metrics | Comments（0）

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Optimal XL Reinsurance Using Mean-Variance Premium Principle WANG Ai-xiang;QIN Cheng-lin Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 207-210.   Abstract （2439）            Knowledge map    Save The optimal dynamic unlimited excess of loss reinsurance using the meanvariance premium principle is studied. Following Hipp's theory, a corresponding HamiltonJacobiBellman equation is obtained to minimize the ruin probability, and existence and optimality of the solution is proved. Related Articles | Metrics | Comments（0） Cited: Baidu(8)

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Purification of Cytosolic APX from Barley Leaves, Preparation of Antibodies and Effect of AMD on APX Activities CHEN Qin;WANG Wei;LIU You-liang Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 211-215.   Abstract （1965）            Knowledge map    Save Ascorbate peroxidase (APX，EC1.11.1.11) was purified to homogeneity from barley (Hordeum vulgare L.) leaves. APX was determined as a monomer with a molecular mass of about 29 kD by SDS-polyacrylamide gel electrophoresis. Western blot analysis using polyclonal antibodies raised against barley APX revealed that there exists immune cross-reaction of APX between Jian 4 and Kepin 7, and APX contents of two barley cultivars differing in NaCl sensitivity changed in the course of NaCl stress. Changes in APX contents showed the same trends as that of APX activities. APX activities in leaves of barley seedlings were inhibited by Actinomycin D (AMD) at different concentration. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Empirical Research on Production Function of Chinese Commercial Banks Based on DEA Regression MAO Ding-xiang Journal of Shanghai University（Natural Science Edition）    2006, 12 (2): 216-220.   Abstract （2025）            Knowledge map    Save This paper uses a DEA-regression model to establish a production function of commercial banks in China. The output elasticity coefficient and comprehensive operating efficiency coefficient of 14 Chinese banks are then studied empirically using this function. The result indicates that to make a joint stock bank a listed company is an effective pattern of reform for the Chinese banking industry.  Related Articles | Metrics | Comments（0）

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Steganography Using DualModulo Arithmetic without Introducing Histogram Abnormality WANG Wei-na;ZHOU Zhen-yu;WANG Shuo-zhong Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 331-337.   Abstract （2089）            Knowledge map    Save A new steganographic embedding technique based on pixel pairs is described. The proposed method involves two modulo operations on the difference between pixels in each pixel pair and the gray-value of a pixel, respectively, hence the name modulo gray-value modulo difference(MGMD). The number of bits to be embedded into each pair is determined by the pixel difference. The secret data and the results of two modulo operations are combined and used to modify the host pixel pair such that the gray level difference is kept unchanged. MGMD embedding causes no histogram abnormality as often encountered in other pixel pairbased techniques such as PVD and SM. It can also resist the popular RS and χ2 analyses. Security of the method is confirmed in experiments on a large number of images. Related Articles | Metrics | Comments（0）

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Biorthogonal Multiwavelet Packet Theory CHEN Jun-li;LU En-bo;CAO Wen-jia Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 338-341.   Abstract （1970）            Knowledge map    Save Multiwavelet can simultaneously posses many desired properties such as short support, orthogonality, symmetry and high vanishing moments, which a single wavelet cannot posses. Multiwavelet has increasingly attracted attention in the research community. The goal of this paper is to generalize the notions and properties of wavelet packet to produce biorthogonal multiwavelet packet, and to develop the theoretical framework of biorthogonal multiwavelet packet, which makes more kinds of signals for analysis with multiwavelet. A proof is given. Related Articles | Metrics | Comments（0）

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Comprehensive Improvement of MLFMA CHEN Xiao-xin;ZHANG Hong-xia;NI Wei-li Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 342-346.   Abstract （1981）            Knowledge map    Save This paper proposes three methods for improvement of MLFMA including fixed side-length subdivision, assignment of weight of translation factor, and optimization for storing kernel arrays. Using these methods, one can reduce memory requirements and accelerate matrixvector multiplication. Numerical results show the validity of the optimizing methods. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Face Recognition Based on Computation of Variance Similarity HUANG Cui-rong;YAN Pei-min;SHI Lu-ming Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 347-350.   Abstract （2294）            Knowledge map    Save This paper deals with image match for face recognition. Variances of feature vectors are computed, giving the weights of similarity after certain translation to the variations. This method is beneficial in increasing the face recognition rate due to its stability and accuracy. Experiments are carried out using the face database developed in the authors' laboratory. The recognition results are satisfactory, indicating validity of the proposed method. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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Design of Precision GPS Compass SHI Hai;CUI Wen-nan Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 351-353.   Abstract （2192）            Knowledge map    Save GPS compass is a new kind of navigation equipment, which overcomes the shortcomings of traditional compasses and provides accurate navigation data anywhere, anytime. Software and hardware are designed, with error of single spot location less than 10 mm, and that of course attitude angle less than 1.0°. Experiments show that this low priced GPS compass has high precision and reliability. Related Articles | Metrics | Comments（0）

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Classification of Breast Cancer Genes with a Simplified Fuzzy ARTMAP Approach CHEN Zhi-hong;YAN Zhuang-zhi;LIU Shu-peng Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 354-358.   Abstract （2134）            Knowledge map    Save This paper presents a gene expression-based classification method for hereditary breast cancer, using a simplified fuzzy ART map. The method was tested on gene expression profiles with BRCA1 and BRCA2, respectively, from Hedenfalk's experiment. The results show that the method has a hit rate of 78% estimated by leave one out method. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A Triple-Band Slot-Loaded Patch Antenna GUAN Zhong-wei;WU Di Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 359-361.   Abstract （1948）            Knowledge map    Save This paper presents a new method for designing a triple-band microstrip patch antenna. By etching two asymmetrical narrow slots close to the radiating edges of a rectangular patch, the antenna shows similar radiation properties at three resonant frequencies and achieves tri-band operation. Results of experiments on a designed antenna show validity of the method.  Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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A Valve Shuttered Electronic Expansion Valve TAO Ji-ming;HE Kui;LI Yang Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 362-365.   Abstract （1916）            Knowledge map    Save Discharge characteristic of the cone valve structure is studied. Based on this, a new structure of electronic expansion valve (EEV) is proposed. The new structure can improve discharge characteristics. It also has some additional merits including low leakage and good linearity. All these provide a platform to control flux accurately. It is useful in improving performance of air conditioning systems. Related Articles | Metrics | Comments（0）

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Improvement of AR Registration Accuracy with a Non-linear Camera Model DING Wei-qi;WU Jia-qi;YUAN Zheng-peng;CHEN Jin-bo Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 366-370.   Abstract （2148）            Knowledge map    Save Registration is a key technique in an augmented reality (AR) system. A recent registration method based on fundamental matrix does not need auxiliary instruments and manmade markers, therefore is easily implemented and widely adaptable. However its registration accuracy needs improvement. In this paper the Tsai algorithm is used to introduce a non-linear camera model and correct distortion in the image feature points. The corrected feature points are then applied to the registration method based on a fundamental matrix. Experimental results show that the new registration technique provides better accuracy than the original method. Related Articles | Metrics | Comments（0）

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An Improved Two-Dimensional Optimal Information Diffusion Method ZHANG Jing-jing;HE You-hua;WANG Qiao-lan;XIN Li-li Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 371-375.   Abstract （1903）            Knowledge map    Save By improving the method for two-dimensional information diffusion that is governed by a single parameter, a new type of diffusion function is obtained. Based on the new diffusion function, an optimized parametric model is proposed for information diffusion under some criteria based on real situations. An example using the proposed method is given, which results in better results with a small sample. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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MiRdetector: A Computational Tool to Predict and Detect miRNA Genes ZHANG Dong-ning;LIU Yang;WANG Yi-fei Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 376-382.   Abstract （2129）            Knowledge map    Save MicroRNA (miRNA) are a class of endogenous 21～24 nucleotide non-coding small RNAs. They may participate in a wide range of genetic regulatory pathways and play an important role in the development of both animals and plants. The number of miRNA genes in every species is still unknown. Bioinformatics analytic method has been used to find novel miRNA genes. In this study, a computational system called MiRdetector is developed, which is used to predict and identify miRNA genes. The computational system is based on homology search and prediction of stem-loop structure. Oryza sativa miRNA genes were used to examine the prediction quality. In total, 140 in 155 samples were correctly identified. The prediction accuracy reaches 90.32%. Moreover, detected 95 potential miRNA genes were detected. The false positive rate was low, so the data set of candidate miRNA genes can well be used for further verification in experiments. Related Articles | Metrics | Comments（0） Cited: Baidu(5)

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Double Wronskian Solution to the Modified Korteweg-de Vries Equation LU Lili;HAO Honghai;BI Jinbo;CHEN Dengyuan Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 383-388.   Abstract （1782）            Knowledge map    Save The mKdV equation is solved using the Hirotas's direct method and the Wronskian technique.The generalized double Wronskian solution is derived through generalized conditions satisfied by Wronskian entries. Related Articles | Metrics | Comments（0） Cited: Baidu(1)

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A Rigorous Method for Solving 0-1 Polynomial Knapsack Problem SHENG Hong-bo;SUN Juan;SUN Xiao-ling Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 389-393.   Abstract （2214）            Knowledge map    Save This paper proposes a rigorous algorithm for solving the 0-1 polynomial knapsack problem. The algorithm uses a branch-and-bound method based on Lagrangian relaxation and dual search. The upper bounds are computed with the outer approximation method where Lagrangian relaxations are solved with the maximumflow algorithm. Heuristic procedures are derived to search for feasible solutions, and some variables in the optimal solution are determined before the branch-and-bound process, thus improving performance of the algorithm. Promising computational results are reported for test problems. Related Articles | Metrics | Comments（0）

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Chord-Integrals of Star Bodies LI Yu-hong;\UAN Jun;LENG Gang-song Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 394-398.   Abstract （1941）            Knowledge map    Save The i th chord-integrals of star bodies are introduced, and some inequalities and propositions for the chord-integrals of star bodies established. Asan application, the Brunn-Minkowski inequality for star duality of intersection bodies is obtained. Related Articles | Metrics | Comments（0） Cited: Baidu(8)

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Rebalance Timing of Index Tracking LIU Shaolin;QIN Chenglin Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 399-402.   Abstract （1504）            Knowledge map    Save The rebalance timing of index tracking with proportional transaction c osts is studied. We make use of linear tracking error (MAD) first introduced by Markus Rudolf. There are two cases in the rebalancing: periodical adjustment and aperiodical adjustment. The latter case is studied. Results of numerical experi ments on these two adjustment methods for the 30 indices of Dow Jones Industrial Average in two months are given.  Related Articles | Metrics | Comments（0）

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Identification of Modal Parameters of Multiple DegreeofFreedom  System Based on HilbertHuang Transform DUAN Xibo;ZHANG Jiguang;;YAN Yong Journal of Shanghai University（Natural Science Edition）    2006, 12 (4): 403-407.   Abstract （1989）            Knowledge map    Save For adaptively analyzing nonstationary and nonlinear signals, Hilber t Huang transform (HHT) has been developed recently. An HHT based method is prop o sed to identify modal frequency and damping ratio, in which the measured respons e data polluted by noise are first decomposed into modal responses using empiric al mode decomposition (EMD). HHT is then applied to each modal response to obtai n the instantaneous amplitude and phase angle time histories. Linear leastsqua r e fitting is carried out to identify the natural frequency and damping ratio fro m the instantaneous amplitude and phase angle for each modal response. Experimen tal results show the validity of the algorithm.  Related Articles | Metrics | Comments（0）

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