Table of Content

20 June 2005 Volume 32 Issue 3

  

Original Articles

Analysis of the seizure-preventing reliability of synchronous gears in the deployment mechanism of a large satellite antenna


CHENG Jian-jun;ZHANG Jian-guo;DUAN Bao-yan;WANG Xiao-bing;DU Lei

J4. 2005, 32(3):  329-334. 

Abstract ( 1830 )   Save

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Gears are often used in the deployment mechanism of a large satellite antenna to spread the truss synchronously, and seizure is a main invalidation of a pair of synchronous gears in the deployment mechanism. From the ultimate position of the gearing mesh, the seizure-preventing condition for the gear pair is given in this paper. Then, with gears’ mismachining tolerances and fitting allowances and the space temperature cosidered synchetically, an analystical model of seizure-preventing reliability of the gear pair is presneted, and the movement function of the gearing mesh is obtained, which is expressed by the tooth clearance. With the true dimensions of the shape and position of a gear regarded as random variables, the formula of the gear’s degree of seizure-preventing reliability is derived by the method of second-order moment. Finally, a real satellite antenna with hoop-truss is calculated and some conclusions are obtained as follows: 1) the effect of thermal loads on the seizure-preventing reliability of synchronous gears deserves not to be ignored; 2) if two gears are fixed at the normal center-to-center distance, the thermal distortion in the space will obviously lower their performance; 3) properly adopting the method to fix the gear pair at the normal-shifted center-to-center distance, and preventing the deployment mechanism from working at high temperature can improve the degree of seizure-preventing reliability. Computational results show that the analytical model of seizure-preventing reliability in this paper is reasonable and efficient.


Uncertainty analysis for multidisciplinary systems based on convex models

CAO Hong-jun;DUAN Bao-yan

J4. 2005, 32(3):  335-338. 

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The convex model theory is implemented to handle the uncertain parameters of multidisciplinary systems. Two types of convex models are considered simultaneously to account for the uncertainties: the ellipsoid convex model and the uniform bound convex model (or interval variables). In order to improve computing efficiency, the first-order Taylor approximation combined with global sensitivity equations (GSE) is used to estimate the intervals of the end performance of multidisciplinary systems. The sensitivity information needed in this method is often a byproduct for many gradient-based optimization algorithms, so this approach can be easily integrated with a non-deterministic optimization framework to perform the robust design for multidisciplinary systems. The method is validated using the Monte Carlo simulation in application to an electronic packaging problem. Results show that it can give a good approximation for the uncertainty intervals of the coupling variables with a small amount of calculation when the uncertainty level is low.


Upper limit of embedded strength of transformation domain digital watermarking under invisible target of improved image fidelity constraint


YIN Zhong-hai1;2;JIAN Jian-feng1;ZHOU Li-hua1;CHEN Jie1;JI Hong1

J4. 2005, 32(3):  339-343. 

Abstract ( 1649 )   Save

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The upper limit of embedded strength of transformation domain digital watermarking under the invisible target of improved image fidelity constraint is discussed. Also, the evaluation expression of embedded strength under the above constraint is presented. This conclusion and its inference can be regarded as a sufficient requirement, used to determine the embedding parameters of watermarking such as the embedded strength maxΔFuv and the number of embedded editions r. The experimental results have proved the validity of the conclusion.


Higher performance V-BLAST system complemented by ML detection

SU Xin;SUN Yong-jun;YI Ke-chu

J4. 2005, 32(3):  344-347. 

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A modified detection algorithm for the V-BLAST (Vertical Bell Labs Layered Space-Time) system is presented. The reveived signal vector is feedforward filtered by QR factorization of the sorted channel matrix. The ranked layers are divided into serveral groups. The layers within the same group are detected using the maximum likelihood (ML) algorithm while the decision feedback interference cancellation are performed between groups. Based on the assumption of QPSK modulation and the quasi-static flat fading channel, simulations are made to testify the performance of the proposed algorithm. Results show that the algorithm outperforms the original V-BLAST and ML-DFE(Maximum Likelihood-Decision Feedback Equalization) algorithm dramatically in bit error ratio (BER) performance. Specifically, signal-to-noise ratio (SNR) improvement of 1.6~2.8dB is obtained for BER of 10^-2, while maintaining a reasonable complexity.


A low voltage and high accuracy CMOS bandgap reference by considering mismatch of MOSFETs

LIU Lian-xi;YANG Yin-tang;ZHU Zhang-ming

J4. 2005, 32(3):  348-352. 

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The principle of the influence on the offset caused by MOSFET mismatch is analysed. The mechanism of the chopped modulator technology to decrease the offset and increase the accuracy of a BGR is introduced. A design of a low voltage bandgap reference (BGR) is implemented by considering these mechanisms and the chip layout is presented. To compensate the error caused by the offset of an opamp, the chopper modulator is used in the BGR circuit. Considering that the mismatch of current-mirror and differential input pairs is ±2%, the peak-to-peak value of the output ripple is 0.31mV. The relative accuracy is increased by 86 times compared with the BGR without chopped modulators. The temperature coefficient is about 12×10^-6/℃ at temperature range from 0℃ to 80℃. The area of the layout is 0.3mm×0.4mm with a standard 0.25μm 2P5M CMOS process.


Roles of Mg addition in perovskite oxygen sensing materials

CAO Quan-xi;DENG Liang-xiong;YANG Peng;HUANG Yun-xia;WANG Yu-peng

J4. 2005, 32(3):  353-356. 

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The roles and effects of Mg addition in perovskite oxygen sensing ceramic are studied. The Mg contents in SrTiO₃ are taken as different. It was measured that the dependence of resistance on temperature and oxygen sensing behavior at different temperatures and oxygen partial pressures. The characteristic of adsorbed oxygen on the specimens is investigated by means of TPD. Where there is substitution of Mg²⁺ at the Ti⁴⁺ site, the p-type region of SrTiO₃ ceramic can be expanded, extrinsic oxygen vacancy can be produced and solid solubility limit of acceptor can be raised simultaneously. The exchange quantity of oxygen is increased between specimen and ambient, so it is possible to obtain SrTiO₃ exhibiting high oxygen sensitivity. However, a part of addition of Mg above 20mol% increases resistivity because of Sr₂TiO₄ segregation.


Application of DSSS based layered space-time architecture to downlink correlated fading MIMO systems

LI Yong-zhao1;LIAO Gui-sheng1;WANG Feng2

J4. 2005, 32(3):  357-361. 

Abstract ( 1781 )   Save

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To improve the performance of LSTA(Layered Space-Time Architecture) in downlink correlated fading MIMO (Multiple-Input Mulitple-Output) systems, a novel DSSS(Direct Sequence Spread Spectrum) based LSTA combining eigenbeamforming is proposed. The transmitter takes advantage of the eigenvectors of the SCM(Spatial Covariance Matrix) of the correlated channels to spread and weigh the signals of each layer. The spatial eigenbeams are formed to carry the signals being spread. The receiver distinguishes the signals from different beams via dispreading operations; therefore co-channel interferences are eliminated effectively. The proposed scheme has the some advantage of dispensing with designing OSS and can be applied to downlink transmission at the cost of loss in the spreading spectrum. Simulation results show that the new scheme greatly outperforms ZF-LSTA(LSTA using ZF algorithm).


A receiver-driven multicast congestion control algorithm for streaming media applications

ZHANG Bing;XU Ya-yan;LIU Zeng-ji;LI Zhen

J4. 2005, 32(3):  362-366. 

Abstract ( 1941 )   Save

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A TCP-friendly single rate multicast congestion control for streaming media applications called the Binomial congestion control at Receivers for Multicast(BARM) is proposed. The protocol maintains a congestion window independently at each receiver instead of at the sender, and adopts the binomial algorithm to adjust the congestion window from which an expected receiving rate of the receiver is calculated. To suppress feedback implosion, the representative approach is used. The protocol improves the scalability and reduces the impact of the LPM problem greatly. Simulations indicate that BARM shows good TCP-friendliness, smoothness, scalability, and acceptable responsiveness.


A sub-１V PTAT voltage reference based on the bulk-driven technique


ZHU Zhang-ming;YANG Yin-tang

J4. 2005, 32(3):  367-369. 

Abstract ( 1889 )   Save

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The fundamental principles of the bulk-driven MOSFET are discussed, with the analysis and simulation of its low voltage characteristics also made. Based on the PMOS bulk-driven and current feedback technique an sub 1V low power PTAT voltage reference is proposed. At a 0.8V power supply with 0~100℃ temperature range, the temperature coefficient of the voltage reference is 0.926mV/K, and the supply current is about 4.5μA. When the power supply ranges between 0.7~1.0V, the voltage reference is about 302mV at the room temperature.


A multi-resolution indexing method for high-dimensional image databases using the wavelet transform

CUI Jiang-tao;SUN Jun-ding;ZHOU Li-hua

J4. 2005, 32(3):  370-373. 

Abstract ( 1614 )   Save

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In order to reduce the “curse of dimensionality” faced by the traditional indexing method at high dimensionality, a new MRVA-File(Multi-Resolution Vector Approximation File) approach is proposed. In the new approach, a multi-resolution data structure is built using the wavelet transform, and low-dimensional distance measure between the candidate vector and query vector can be obtained at a low-resolution level. When doing the nearest neighbor search, the lower bounds of distance is computed at each level and compared with the latest nearest neighbor distance, starting from the low-resoltuion level. If it is larger than the latest nearest neighbor distance, the candidate can be removed without calculating the distance in the high-dimensional space at the high-resolution level. By doing this, the total computational complexity can be dramatically reduced. Experimental results on large image databases show that the new approach provides a faster search speed than the VA-File approach.


New method for joint estimation of array parameters based on forth-order cumulants

WANG Lan-mei1;2;WANG Hong-yang1;LIAO Gui-sheng1

J4. 2005, 32(3):  374-377. 

Abstract ( 1408 )   Save

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The problem of joint estimation of the frequency, angle of arrival and polarization with crossed dipoles is investigated. The proposed method overcomes the disadvantage of most existing methods in which only the eigenvector of the forth-order cumulant matrix is used, thereby greatly reducing the computation burden. Finally, simulation results verify the efficacy of this method.


External illuminator based continuous wave radar clutter canceling algorithm using arrival time estimation by fractional interpolation


WANG Jun;SHUI Peng-lang;BAO Zheng;ZHANG Shou-hong

J4. 2005, 32(3):  378-382. 

Abstract ( 1642 )   Save

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The detecting performance of the external illuminator base bistatistic continuous wave radar system is greatly influenced by the direct signal and the multipath reflected clutter received by the main receiving channel. This paper presents an effective external illuminator based bistatistic continuous wave radar clutter canceling algorithm to overcome the problem. The presented algorithm employs the auxiliary receiving channel reference signal to adaptively cancel the direct signal and multipath reflected clutter by using the fractional interpolated arrival time interval of such clutters. Experimental results on real collected data show the method improves the detecting performance for a moving target by offering an average detection gain of about 45dB.


A monopulse angle measurement method for multiple targets

ZHAO Yong-bo1;GU Hong2;ZHANG Shou-hong1

J4. 2005, 32(3):  383-386. 

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For the purpose of improving the angle measurement performance in the case of multiple targets, a modified monopulse method is proposed. Instead of using the discrete Fourier transform (DFT) filters, the proposed method uses some special Doppler filters to process the received data according to target' Doppler frqeuency. Then the processed data are used by the monopulse method to measure the angle. Because the special Doppler filters can greatly reduce the influences between targets, the proposed method performs significantly better than the conventional monpulse method. Simulation results show its merits.


Clipping noise cancellation in the OFDM system using the code restriction technique


YANG Gang;CHEN Yuan-yuan;LI Yu-shan

J4. 2005, 32(3):  387-391. 

Abstract ( 1660 )   Save

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According to the higher PAPR in the OFDM system, by analyzing the frequency distribution of constellation points after clipping, the code restriction technique is adopted to combat the effect of clipping the OFDM signal in the digital part of the transmitter. The code restriction technique is adopted to constrain every constellation point in the certain region, and lessen ICI or ISI through modulation. The code restriction technique and clipping are combined to achieve higher PAPR reduction and better BER, which can be seen from the simulation results of CCDF and BER based on MATLAB.


Research on the FPA imaging character based on microscanning

WANG Xiao-rui1;2;HU Fang-ming1;ZHANG Jian-qi1;FENG Zhuo-xiang2

J4. 2005, 32(3):  392-395. 

Abstract ( 1899 )   Save

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Based on the analysis of the microscanning imaging principle, sampling-averaging MTF at the inherent Nyquist frequency is used as a figure of merit to characterize quantitatively the improvement on the FPA imaging quality of typical microscanning modes, and the optimum corresponding relationship between the microscanning modes and detector fill factor is obtained. Then, taking a spoke image with 768×768 pixels as the original input, imaging processes with different microscanning modes are simulated with the pixel processing method for detectors with a fill factor of 100% and 50% respectively. Simulation results show a good agreement with those by theoretical analysis.


Study of temperature properties of the SiC CMOS inverter

WANG Ping;YANG Yin-tang;WANG Xu

J4. 2005, 32(3):  396-399. 

Abstract ( 1553 )   Save

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Based on the relevant models of 6H-SiC material and devices, the temperature properties of the submicron 6H-SiC CMOS inverter proposed in this paper are investigated with the 2-Dimentional device simulator MEDICI. Simulation results show that the inverter can operate at 600K and has better voltage transfer and transient characteristics. The calculated switching threshold voltage of the inverter varies from 1.218V to 1.274V in the temperature range of 300~600K with a 5V power supply and its change is not significant. All this provides a valuable reference for the design of and the research on more complicated high temperature 6H-SiC CMOS circuits.


A D-S evidence theory based trust model for the P2P network

WEN Hao-yu;REN Xiao-long;XU Guo-hua

J4. 2005, 32(3):  400-402. 

Abstract ( 1876 )   Save

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Along with the wide application of the P2P network in various areas, it is necessary to establish the trust mechanism of the P2P network. According to the equal relationship and loose coupling characteristics among peers in a P2P network, a Dempster-Shafer evidence theory based trust model for the P2P network is proposed. The frame of trust discernment, the basic trust probability assignment and the trust interval are defined in this model, on the basis of which the trust transfer mechanism and the clustering mechanism are established. Application of this model in P2P-based manufacturing resource networks (PMRN) proves its correctness and reasonableness.


Infrared image target detection based on FPGA

WANG Yan1;BAO Jian-yue2;LIN Xiao-chun3;GUO Run-qiu1

J4. 2005, 32(3):  403-407. 

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During the infrared image target detection, a great deal of data needs to be stored and processed with high speed. An image processing system based on DSP and FPGA is presented in this paper. After the discussion of the LoG filter and its design, a detailed description of how to realize the infrared target detection in FPGA through the LoG filtering though FPGA follows. With the use of FPGA in target detection, high-speed can be reached to satisfy the real-time desire of the infrared image processing system.


Study of electromagnetic scattering from the rough surface using the small slope approximation

GUO Li-xin;CHEN Jian-jun;WEI Guo-hui;WU Chun-yu

J4. 2005, 32(3):  408-413. 

Abstract ( 1651 )   Save

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Electromagnetic scattering from the rough surface using the small slope approximation is investigated, which gives a systematic expansion of the scattering cross section that can be interpreted as a series in the generalized surface slope, with the bistatic scattering cross sections for the Gaussian conducting rough surface under the first, second and third-order small slope approximation obtained. The results by the small slope approximation are also compared with those of the Kirchhoff approximation with the shadowing effect considered and the experimnetal data, which shows that the small slope approximation is more accurate for the whole region of the incident angle and the numerical results also show good agreement with the experimental data for the large scattering angle.


The fast computation and analysis of RCS for large objects

LI Jian-ying;TANG Song;LIU Qi-zhong

J4. 2005, 32(3):  414-417. 

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The fast mutipole method (FMM) and multilevel fast-multipole algorithm(MLFMA) are investigated first for analyzing the radar cross section from large and complex structure objects fast and effectively. And the incomplete LU factorization (ILU) method is employed to reduce the iterative times while the fast algorithms are used. The fast algorithms combine with the ILU to make the simulation speed improve largely. Then the emphasis was put on simulating and studying the RCS from a aircraft of special structure. Theoretical results are very useful for investigating this type of aircraft.


Scalar multiplication of hyperelliptic curves with the efficient algorithm for inversion

HAO Yan-hua;JIANG Zheng-tao;WANG Yu-min

J4. 2005, 32(3):  418-422. 

Abstract ( 1401 )   Save

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In hyperelliptic curve croptosystem, the most important and computationally costliest operation is the scalar multiplication. To speed up, an efficient algorithm for simultaneously obtaining the inverses of a list of underlying field elements is given. The feature of the algorithm is that the later arithmetics make efficient use of the results of the former ones. The algorithm decreases the number of arithmetics and saves time. The scalar multiplication algorithm with the efficient algorithm for inversion is 32%~35% faster than the scalar multiplication algorithm given by Lange and 49%~53% or 6%~7% faster than the improved scalar multiplication algorithms given by Mishra and others, and provides protection agatinst side-channel attacks.


A method to find optimal period interleaver

WANG Ying;WANG Yu-min

J4. 2005, 32(3):  423-426. 

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For finding the optimal period interleaver, we rearrange the information polynomial of Turbo codes as a matrix based on the divisibility between the information polynomial and the feedback polynomial. Any column of the matrix can be permuted randomly, and the permutation between columns should satisfy the form which is the automorphism group of the binary cyclic Turbo code generated by the feedback polynomial. According to this idea a method to find the form of the optimal period interleaver is given. From the computer simulation we find that such an interleaver can improve the BER performance of Turbo codes.


An ID-based aggregate signature scheme from m-torsion groups

CHENG Xiang-guo;LIU Jing-mei;WANG Xin-mei

J4. 2005, 32(3):  427-431. 

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Based on the ID-based signature scheme given by Cha and Cheon, we propose an ID-based aggregate signautre scheme from m-torsion groups of elliptic curves. It is provably secure in the random oracle model. Due to the nice properties of m-torsion groups and the base scheme, it turns out that our scheme is as efficient as the base scheme. An ID-based aggregate signature provides the one-time verification of many different ID-based signautres on many diferent messages by many users.


Study of the SiGe HBT based on the self-alignment and air-bridge


LIU Dao-guang1;2;3;HAO Yue1;XU Shi-liu2;3;LI Kai-cheng2;3;LIU Yu-kui2;3;LIU Rong-kan2;3;ZHANG Jing2;3;HU Hui-yong1 LI Pei-xian1;ZHANG Xiao-ju1;XU Xue-liang2;3

J4. 2005, 32(3):  432-434. 

Abstract ( 1525 )   Save

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By using base-emitter self-alignment and air-bridge technology, the base resistance of SiGe heterojunction bipolar transistors(HBT) together with the capacitance between collector and base is reduced; in addition, the maximum oscillation frequency (f_max) is improved. In this paper, SiGe HBT f_max of 124.2GHz has been obtained based on MBE SiGe materials.


Optimal jamming waveforms based on spot jamming to TDRSS


LI Peng;JI Hong-bing

J4. 2005, 32(3):  435-438. 

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A new analytic technique for optimal jamming waveforms is presented. Based on the performance of TDRSS S-band spread spectrum links, according to the theory of optimal jamming, the spot jamming equation is presented based on the correlation function between signal waveforms and jamming codes waveforms. Then it is proved that the jamming equation in the sense of the equal value is the optimal jamming waveform condition. Finally, the Monte-carlo simulation results illustrate that the optimal jamming waveform is a square waveform, because its equal value of jamming equation is larger.


The classifier of car types using BP neural networks

HU Fang-ming;JIA Qin;ZHANG Xiu-jun

J4. 2005, 32(3):  439-442. 

Abstract ( 1621 )   Save

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In view of the features of car types, this paper proposes a recognition method based on the BP neural network: first, pick up feature vectors of car types; then, we design the classifier using BP, and train it effectively; finally, this BP classifier can recognize the test samples. This paper mainly trains networks using the SCG algorithm. This algorithm can make the network converge quickly, thus solving the limitation of slow convergence of the common algorithm.


Sidelobe suppression for color television signals

SUN Xiao-wen;LIU Li-dong;WU Shun-jun

J4. 2005, 32(3):  443-446. 

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Pulse compression for color television signals is investigated. A mismatch filter is used to suppress the sidelobe resulting from pulse compression of color television signals. By using the mismatch filter, the sidelobes of pulse compression are suppressed and the unambiguity range of radar using color television signals as an illuminator is enlarged.


A method for ICA for complex-valued sources

LI Xiao-jun1;LOU Shun-tian1;ZHANG Xian-da2

J4. 2005, 32(3):  447-451. 

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ICA is used to get the complex-valued signals. ICA is a statistical method for transforming an observed random vector into components that are as mutually independent as possible. By changing the extended Hebbian learning and directly using the nonline function, blind separation of complex-valued signals will be obtained. By using this method, the algorithm based on the gradient steepest ascent is proposed, with its computational efficiency shown by simulations.


A list-decoding-based soft GMD algorithm


XU Chao-jun;WANG Xin-mei

J4. 2005, 32(3):  452-456. 

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A list-decoding-based soft-GMD algorithm is provided. Based on the Koetter-Vardy algorithm, the proposed algorithm performs sucessive erasure-and-error decoding according to the reliability metric of each interpolation points subset. Simulation results show that to obtain the same coding gains, the soft-GMD algorithm leads to a factor of 90%~985% reduction in complexity for RS codes of length 15 and a factor of about 46% reduction in complexity for RS(255, 239) code, as compared with the Koetter-Vardy algorithm.


The application of support vector machines in detection of images steganography

YANG Xiao-yuan1;2;WANG Zhi-gang1;WANG Yu-min2

J4. 2005, 32(3):  457-459. 

Abstract ( 1921 )   Save

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The Support Vector Machines is a new machines learning algorithm based on the Statistical Learning Theory. It has found important applications in pattern discrimination of high dimensions Character vectors. The algorithm of Support Vector Macnines has been studied in this paper, and the detection algorithm of steganography based on the Support Vector Machines has been put forward. For this detection algorithm, we select two kinds of steganography software F5r11 and Jsteg41 to make a large number of experiments. In quadratic programming, we find that the penalty gene C is important to experimental results, and therefore, we show different detection results of different Cs, and the results show that the detection rate of this algorithm improves evidently compared with the Fisher Linear Discrimination.


Study of the stock market tendency based on the neural network


LONG Jian-cheng1;2;LI Xiao-ping2

J4. 2005, 32(3):  460-463. 

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A model of stock exchange is built based on the nonlinear dynamics theory. The parallel nerve network is used for network study that extracts a standard model and undertakes pattern identification. The results of pattern classification and stock market tendency prediction testify the validity of this method.


Design of a dish-shaped sub-mini underwater vehicle

ZHAI Yu-yi;LIU Liang;CHEN Wei-hua;GONG Zhen-bang

J4. 2005, 32(3):  464-467. 

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In the special case, the sub-mini underwater vehicle (SMUV) is only asked to perform transverse movement. But because of the limited size, the requirement is difficultly realized or the cost is dear. This paper expounds upon the design scheme of a kind of dish-shaped SMUV. It enables the vehicle to fulfill many degrees of freedom of movement in many directions. The mechanical structure designs fulfill the SMUV movements. Compared with those common SMUVs, the characteristics of this vehicle are that it adopts revocable properller with two rotated axises to accomplish synchronously the robot ascending and descending and direction changing. And the relationship between movements and conditions of control forces is derived. An expression for ensuring the normal function of the dish-shaped SMUV is obtained.


A rapid evaluation formula for electromagnetic scattering of arbitrary shaped conducting targets with partial coating


GUO Hui-ping1;LIU Xue-guan1;2;YIN Hong-cheng2;HUANG Pei-kang2

J4. 2005, 32(3):  468-471. 

Abstract ( 1884 )   Save

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A rapid evaluation formula for the PO method on electromagnetic scattering by arbitrary shaped conducting targets with partial coating is obtained by approximating electrically large scale objects with polygons, based on the theory of equivalent currents on the arbitrary RAM surface with the infinite metal substrate. It makes the calculation high efficient as there are only simple algebraic operations without integration in our formula. This establishes a basis for the RCS rapid evaluation of the electrically large scale conducting bodies with partial coating.


The research on impairment of frequency hopping communication systems

ZHANG Yi;YAO Fu-qiang

J4. 2005, 32(3):  472-476. 

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The primary reasons for leading to the impairment of frequency hopping communication system are studied, the analytic relations between the impairment ratio and the parameters of the frquency hopping system are given, and the low bound of the frequency hopping system loss is achieved. The conclusion not only explains the difference in performance between frequency hopping communication and frequency fixing communication, but also clarifies the misunderstanding about FH systems.


Image object tracking algorithms analysis

MA Ben;SHI Zhong-ke;PI Yan-ni

J4. 2005, 32(3):  477-480. 

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The study of image object tracking algorithm is a key technique in the object tracking system. The theory of gate tracking and correlation tracking is introduced, and several image-based tracking algorithms are analyzed in detail, which include the segmentation-based cancroids tracking algorithm, the edge-based difference tracking algorithm and matching tracking algorithm.


Continuous wavelet transforms in a special abstract function space


QU Han-zhang;HAN Jun-gang

J4. 2005, 32(3):  481-488. 

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A special abstract function L²⁽R,H) is discussed, the continuous wavelet transform on L²(R) is generalized to that on L²(R,H), and the reconstruct formula produced by the integral kernel of the abstract transform function is discussed. The conditions which make the reconstrcution formula true not only in the weak topology but also in the strong topology are discussed. Generally speaking, there does not exist the reconstruction formula. The condition of abstract functions which makes the reconstruction formula the simplest is obtained. A method of finding the abstract functions which make the reconstruction formula the simplest is given.


A serial dynamic multidimensional assignment algorithm


HE You;YI Xiao;GUAN Xin

J4. 2005, 32(3):  489-493. 

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The static assignment algorithm is generalized to the dynamic tracking circumstance. A serial dynamic multidimensional assignment algorithm is proposed. And the models for deciding the delegate of the associated measurements, track initiation, eliminating of the ghost assignments are given. Finally, a Monte Carlo simulation is used to analyze the performance of the method. Simulation results show that the proposed algorithm can steadily track multiple targets.