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1997 Vol. 19, No. 6
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1997, 19(6): 721-728.
Abstract:
This paper presents two binary track correlation algorithms applying to distributed multisensor data fusion. In the paper, these two binary track correlation criteria are described in detail,and track correlation mass design, multivalency processing methods and miss correlation probability estimation methods are discussed as well. Moreover, they are compared with two classical methods through simulation. The simulation results show that the performance of the two binary track correlation algorithms is much better than that of the classical methods in dense multitarget environments, more cross, split and maneuvering track situations. Under above situation their correct correlation rate is improved about 35 per cent over teh classical methods.
This paper presents two binary track correlation algorithms applying to distributed multisensor data fusion. In the paper, these two binary track correlation criteria are described in detail,and track correlation mass design, multivalency processing methods and miss correlation probability estimation methods are discussed as well. Moreover, they are compared with two classical methods through simulation. The simulation results show that the performance of the two binary track correlation algorithms is much better than that of the classical methods in dense multitarget environments, more cross, split and maneuvering track situations. Under above situation their correct correlation rate is improved about 35 per cent over teh classical methods.
1997, 19(6): 729-732.
Abstract:
Short-term statistical characteristics of moving sequences is discussed in this paper. To get reasonable results, real time motion image sequences are used, bit numbers of each macroblock after encoding using MPEG(Moving Pictures Experts Group) compression algrithom is analyzed.In the mean time, the effect of quantiser scale and quantiser matrix to the statistical property is also researched. Simulation result shows that quantiser scale plays a important role in the statistical property, while quantiser matrix has little influence. If small quantiser scale is adopted, image contents will affect the probability distribution at low bit end, and its influence decreases as the quantiser scale is relatively large.
Short-term statistical characteristics of moving sequences is discussed in this paper. To get reasonable results, real time motion image sequences are used, bit numbers of each macroblock after encoding using MPEG(Moving Pictures Experts Group) compression algrithom is analyzed.In the mean time, the effect of quantiser scale and quantiser matrix to the statistical property is also researched. Simulation result shows that quantiser scale plays a important role in the statistical property, while quantiser matrix has little influence. If small quantiser scale is adopted, image contents will affect the probability distribution at low bit end, and its influence decreases as the quantiser scale is relatively large.
1997, 19(6): 733-738.
Abstract:
In this paper, a new method for solving multiscale difference equation by the M-band wavelet neural networks is proposed. It is shown that the methods in the paper have many advantages over existed methods and enlarge the range of the solvable equations by the theoretical proofs and computer simulations.
In this paper, a new method for solving multiscale difference equation by the M-band wavelet neural networks is proposed. It is shown that the methods in the paper have many advantages over existed methods and enlarge the range of the solvable equations by the theoretical proofs and computer simulations.
1997, 19(6): 739-744.
Abstract:
This paper first discusses the structure, principle and learning algorithm of Elman neural network model. A modified Ehnan neural network model is then proposed by adding new adjustable weights between the context nodes and the output nodes to enhance its dynamical character. The corresponding learning algorithm is also derived by using steepest descent principle. Theoretical analysis and simulation results show that this kind of modified Ehnan neural network learns much faster than the original model.
This paper first discusses the structure, principle and learning algorithm of Elman neural network model. A modified Ehnan neural network model is then proposed by adding new adjustable weights between the context nodes and the output nodes to enhance its dynamical character. The corresponding learning algorithm is also derived by using steepest descent principle. Theoretical analysis and simulation results show that this kind of modified Ehnan neural network learns much faster than the original model.
1997, 19(6): 745-750.
Abstract:
In the array processing problem, the high-order cumulants not only are capable to reduce the Gaussian noises but also have the aperture extension property. The method of the aperture extension using the fourth-order cumulants are studied and the structure of the corresponding virtual array are presented in this paper. The fourth-order coherent problem in the application in the narrow-band direction-finding system is given and analyzed. We obtain the array aperture extension condition of the fourth-order cumulant-based method to the multiple sources case. The numerical results support the analytic results.
In the array processing problem, the high-order cumulants not only are capable to reduce the Gaussian noises but also have the aperture extension property. The method of the aperture extension using the fourth-order cumulants are studied and the structure of the corresponding virtual array are presented in this paper. The fourth-order coherent problem in the application in the narrow-band direction-finding system is given and analyzed. We obtain the array aperture extension condition of the fourth-order cumulant-based method to the multiple sources case. The numerical results support the analytic results.
1997, 19(6): 751-755.
Abstract:
In this paper, a new recursive algorithm for adaptive array weight vectors and its systolic array implementing structure are proposed, which are based on the QR factorization algorithms and the idea of the algorithmic engineering. The algorithm can realize fully parallel and pipeline processing.
In this paper, a new recursive algorithm for adaptive array weight vectors and its systolic array implementing structure are proposed, which are based on the QR factorization algorithms and the idea of the algorithmic engineering. The algorithm can realize fully parallel and pipeline processing.
1997, 19(6): 756-761.
Abstract:
Because the impulse response of an acoustic echo path may be several hundred milliseconds long, acoustic echo cancellation is a long-stranding problem and has not been solved effectively. In order to solve this problem an acoustic echo canceller is presented and a new algorithm, self-orthogonalizing alternative constrained Partitioned Block Frequency-domain LMS (PBFLMS) algorithm, is put forward in this paper. This algorithm has good convergence ability, small misadjustment, low computation complexity and small delay. In addition, according to the application on the acoustic echo canceller, this algorithm is modified. Finally the whole echo canceller is implemented by using a single TMS320C30 processor in the ATD-C30 simulator and satisfying results are acquired.
Because the impulse response of an acoustic echo path may be several hundred milliseconds long, acoustic echo cancellation is a long-stranding problem and has not been solved effectively. In order to solve this problem an acoustic echo canceller is presented and a new algorithm, self-orthogonalizing alternative constrained Partitioned Block Frequency-domain LMS (PBFLMS) algorithm, is put forward in this paper. This algorithm has good convergence ability, small misadjustment, low computation complexity and small delay. In addition, according to the application on the acoustic echo canceller, this algorithm is modified. Finally the whole echo canceller is implemented by using a single TMS320C30 processor in the ATD-C30 simulator and satisfying results are acquired.
1997, 19(6): 762-767.
Abstract:
A criterion called Sliding Window Predictive Least-Squares (SWPLS) order selection criterion is presented in this paper by comparison of several typical criteria of AR model order selection. In addition to property of fine order selection the criterion has advantage of good tracking property and can be easily implemented on-line in real time. The effectiveness of SWPLS criterion is verified by simulation experiment of order selection for models of time-varying parameter and time-varying order.
A criterion called Sliding Window Predictive Least-Squares (SWPLS) order selection criterion is presented in this paper by comparison of several typical criteria of AR model order selection. In addition to property of fine order selection the criterion has advantage of good tracking property and can be easily implemented on-line in real time. The effectiveness of SWPLS criterion is verified by simulation experiment of order selection for models of time-varying parameter and time-varying order.
1997, 19(6): 768-772.
Abstract:
With reference to the air target detected by ultra-wideband(UWB)/impulse radar,this paper discussed transient signal processing techniques.In weak UWB signal detection,wavelet transforms and high order spectrum estimation were preferred.In target characteristics analysis,a time domain bispectrum estimation algorithm was presented,which could estimate accurately local scattering distribution of complex target.A free field experimental impulse radar system was introduced in this paper.With this system,the response of several canonical target models and scale aircraft were measured and processed.
With reference to the air target detected by ultra-wideband(UWB)/impulse radar,this paper discussed transient signal processing techniques.In weak UWB signal detection,wavelet transforms and high order spectrum estimation were preferred.In target characteristics analysis,a time domain bispectrum estimation algorithm was presented,which could estimate accurately local scattering distribution of complex target.A free field experimental impulse radar system was introduced in this paper.With this system,the response of several canonical target models and scale aircraft were measured and processed.
PERFORMANCE ANALYSIS OF CYCLIC ESTIMATORS FOR HARMONICS IN MULTIPLICATIVE AND COMPLEX ADDITIVE NOISE
1997, 19(6): 773-779.
Abstract:
The concern here is retrieval of harmonic observed in multiplicative and complex additive noises. Cyclic mean and correlation statistics have proved to be useful for harmonic retrieval in the presence of real-valued multiplicative and complex-valued additive noise of arbitrary color and distribution. Performance analysis of cyclic estimators is carried through both for nonzero and zero mean multiplicative noises. Cyclic estimators are shown to be asymptotically equivalent to certain nonlinear least squares estimators, and large sample variance expressions of the cyclic estimators are derived. Simulations validate the large sample performance analysis.
The concern here is retrieval of harmonic observed in multiplicative and complex additive noises. Cyclic mean and correlation statistics have proved to be useful for harmonic retrieval in the presence of real-valued multiplicative and complex-valued additive noise of arbitrary color and distribution. Performance analysis of cyclic estimators is carried through both for nonzero and zero mean multiplicative noises. Cyclic estimators are shown to be asymptotically equivalent to certain nonlinear least squares estimators, and large sample variance expressions of the cyclic estimators are derived. Simulations validate the large sample performance analysis.
1997, 19(6): 780-785.
Abstract:
Two methods of distance measuring for sparse-array Synthetic Impulse and Aperture Radar(SIAR) are described, by which a high precision is obtained without high frequency sampling. The effect of errors in angle measuring on distance measuring is discussed in the process of time-space 3D matched filtering. Computer simulation results show these methods are effective.
Two methods of distance measuring for sparse-array Synthetic Impulse and Aperture Radar(SIAR) are described, by which a high precision is obtained without high frequency sampling. The effect of errors in angle measuring on distance measuring is discussed in the process of time-space 3D matched filtering. Computer simulation results show these methods are effective.
1997, 19(6): 786-791.
Abstract:
The probability distribution of the location error based on range differences is presented first. After having the relationship between two common criteria for measuring location accuracy and the error covariance matrix, the optimal constellation is obtained for the case in which the radars are constrained in a sysmmetic area to locate a target in space by use of the minimum error ellipsoid criterion. Finally, some calculation results are given.
The probability distribution of the location error based on range differences is presented first. After having the relationship between two common criteria for measuring location accuracy and the error covariance matrix, the optimal constellation is obtained for the case in which the radars are constrained in a sysmmetic area to locate a target in space by use of the minimum error ellipsoid criterion. Finally, some calculation results are given.
1997, 19(6): 792-796.
Abstract:
Autofocus is an important technique in high resolution Synthetic Aperture Radar(SAR). When autofocus is needed by real-time SAR imaging processing, it must be very computationally effective. Shift and correlate algorithm is such an algorithm. It was first presented by Jorgen, (1991). In this paper, we analyze its essence and make some advance on it.
Autofocus is an important technique in high resolution Synthetic Aperture Radar(SAR). When autofocus is needed by real-time SAR imaging processing, it must be very computationally effective. Shift and correlate algorithm is such an algorithm. It was first presented by Jorgen, (1991). In this paper, we analyze its essence and make some advance on it.
1997, 19(6): 797-802.
Abstract:
A new approximation method to distribution function of conductivity for electrical impedance tomography image reconstruction algorithm is proposed in this paper. This method is called continuous interpolation function method. Compared with the conventional piecewise constant method, the image reconstructed by this method is much better, while the amount of computation is not increased or even decreased because the good property of finite element method has been used sufficently.
A new approximation method to distribution function of conductivity for electrical impedance tomography image reconstruction algorithm is proposed in this paper. This method is called continuous interpolation function method. Compared with the conventional piecewise constant method, the image reconstructed by this method is much better, while the amount of computation is not increased or even decreased because the good property of finite element method has been used sufficently.
1997, 19(6): 803-809.
Abstract:
The developments of Personal Communication and Mobile Computing stimulate the introducation of integrated traffics into mobile communication. CDMA is suitable for transmission of integrated traffics. In this paper, we introduced an admission control algorithm. Under this algorithm, the capacity of a CDMA system for integrated traffics is evaluted. Users with different QoS requirements are allocated different power. To solve the problem of higher-rate traffics using higher powers, wider bandwidth to higher-rate traffics is given. All the traffics are transmitted in the same frequency band. Finally, according to the measured data of CODIT, we derived the capacity of different traffics in different environments.
The developments of Personal Communication and Mobile Computing stimulate the introducation of integrated traffics into mobile communication. CDMA is suitable for transmission of integrated traffics. In this paper, we introduced an admission control algorithm. Under this algorithm, the capacity of a CDMA system for integrated traffics is evaluted. Users with different QoS requirements are allocated different power. To solve the problem of higher-rate traffics using higher powers, wider bandwidth to higher-rate traffics is given. All the traffics are transmitted in the same frequency band. Finally, according to the measured data of CODIT, we derived the capacity of different traffics in different environments.
1997, 19(6): 810-813.
Abstract:
This paper constructs the Hash algorithm based on strong one-way permutation by the composition of one-way permutation and perfect permutation on n and proves that its security is equivalent to the one-way permutation that can not be inversed in polynomial time.
This paper constructs the Hash algorithm based on strong one-way permutation by the composition of one-way permutation and perfect permutation on n and proves that its security is equivalent to the one-way permutation that can not be inversed in polynomial time.
1997, 19(6): 814-819.
Abstract:
In this paper, the mean cycle times of the slotted access channel are analyzed by using the average cycle method. Analytic formulae for mean values of a successful period, a colliding period and an idle period are derived. Also, the upper bounds on the throughput of the system with capture effect and packet conflict resolution are provided. Finally, the simulation results of the slotted access channel are given.
In this paper, the mean cycle times of the slotted access channel are analyzed by using the average cycle method. Analytic formulae for mean values of a successful period, a colliding period and an idle period are derived. Also, the upper bounds on the throughput of the system with capture effect and packet conflict resolution are provided. Finally, the simulation results of the slotted access channel are given.
1997, 19(6): 820-823.
Abstract:
This paper proposes a method to improve H.261 video coder by modifying the block matching motion estimation algorithm. We think that the traditional block matching algorithm based on the least mean square error or absolute error criteria is not suitable for H.261 video coder. The good criteria must consider not only the error energy, but also the bit number for encoding motion vectors as well as the interframe prediction error. Experimental results show that the performance of H.261 coder is improved greatly by using the proposed implementation method.
This paper proposes a method to improve H.261 video coder by modifying the block matching motion estimation algorithm. We think that the traditional block matching algorithm based on the least mean square error or absolute error criteria is not suitable for H.261 video coder. The good criteria must consider not only the error energy, but also the bit number for encoding motion vectors as well as the interframe prediction error. Experimental results show that the performance of H.261 coder is improved greatly by using the proposed implementation method.
1997, 19(6): 824-827.
Abstract:
In this paper, Chua s circuit is modified by adding an RC parallel circuit into the L-arm in Chua s circuit. The bifurcation, control and synchronization of the modified Chua s circuit have been studied by computer simulation.
In this paper, Chua s circuit is modified by adding an RC parallel circuit into the L-arm in Chua s circuit. The bifurcation, control and synchronization of the modified Chua s circuit have been studied by computer simulation.
1997, 19(6): 828-835.
Abstract:
By applying switch-signal theory, the theory of transmission current-switches based on symmetric ternary logic is proposed, this theory is suitable to design symmetric ternary current-mode CMOS circuits. The symmetric ternary current-mode CMOS circuits designed by using this theory not only have simpler circuit structures and correct logic functions, but also can process two-way signal.
By applying switch-signal theory, the theory of transmission current-switches based on symmetric ternary logic is proposed, this theory is suitable to design symmetric ternary current-mode CMOS circuits. The symmetric ternary current-mode CMOS circuits designed by using this theory not only have simpler circuit structures and correct logic functions, but also can process two-way signal.
1997, 19(6): 843-846.
Abstract:
Through selecting the network s competition rules by the nature of layout problem, an algorithm based on the competitive learning and self-organization characteristics of Self-Organization Feature Mapping(SOFM) neural network for gate matrix layout is put forward in this paper. Experiments show that the achieved results can be quite approximate to the lower limit of the optimum solutions. The time complexity of this algorithm is O(np2ln p), here n and p are the number of nets and dominant gates, respectively.
Through selecting the network s competition rules by the nature of layout problem, an algorithm based on the competitive learning and self-organization characteristics of Self-Organization Feature Mapping(SOFM) neural network for gate matrix layout is put forward in this paper. Experiments show that the achieved results can be quite approximate to the lower limit of the optimum solutions. The time complexity of this algorithm is O(np2ln p), here n and p are the number of nets and dominant gates, respectively.
1997, 19(6): 847-851.
Abstract:
In this article, self-rotation-shrinking-series of m-series are introduced; their elegant algebraic structure and nice cryptic features are discussed. For practical application, a linking scheme with a little stores and judgements is proposed.
In this article, self-rotation-shrinking-series of m-series are introduced; their elegant algebraic structure and nice cryptic features are discussed. For practical application, a linking scheme with a little stores and judgements is proposed.
1997, 19(6): 852-854.
Abstract:
Construction and enumeration of correlation-immune Boolean functions of m-order are discussed in this paper and the formula of lower bounds given by the authors (1997) formerly is improved greatly.
Construction and enumeration of correlation-immune Boolean functions of m-order are discussed in this paper and the formula of lower bounds given by the authors (1997) formerly is improved greatly.
1997, 19(6): 836-842.
Abstract:
This paper reports on current developments in the area of very low bit-rate video coding, including algorithms and standardization. The advances are summarized in several areas, among them motion compensation/transformation (MC/T)techniques, model-based video coding, fractal IFS coding, H.263 and MPEG4. The future developments are discussed.
This paper reports on current developments in the area of very low bit-rate video coding, including algorithms and standardization. The advances are summarized in several areas, among them motion compensation/transformation (MC/T)techniques, model-based video coding, fractal IFS coding, H.263 and MPEG4. The future developments are discussed.
