ISSN 
2009 Vol. 38, No. 4
2009, 38(4): 481-484.
doi: 10.3969/j.issn.1001-0548.2009.04.001
Abstract:
Interleave division multiple access (IDMA) is a multiple access system with low rate codes and random interleavers, which is the only method to separate different users. Compared with code division multiple access (CDMA) systems, IDMA systems can provide more efficient scheme for multiple user detection (MUD). And IDMA can achieve the optimal combination between coding gain and multipath gain. In research area, IDMA system is looked as a special case of CDMA system and has the same channel capacity with CDMA system. But this issue is not proved from the viewpoint of information theory. Based on the code definition of IDMA, we introduce the average mutual information to measure the channel capacity. The capacity region achieved by IDMA with K users is proved with random encoding and jointly typical sequences. We prove that IDMA has the same capacity limitation with CDMA. Thus, it is proved that IDMA is a special case of CDMA from the view of information theory.
Interleave division multiple access (IDMA) is a multiple access system with low rate codes and random interleavers, which is the only method to separate different users. Compared with code division multiple access (CDMA) systems, IDMA systems can provide more efficient scheme for multiple user detection (MUD). And IDMA can achieve the optimal combination between coding gain and multipath gain. In research area, IDMA system is looked as a special case of CDMA system and has the same channel capacity with CDMA system. But this issue is not proved from the viewpoint of information theory. Based on the code definition of IDMA, we introduce the average mutual information to measure the channel capacity. The capacity region achieved by IDMA with K users is proved with random encoding and jointly typical sequences. We prove that IDMA has the same capacity limitation with CDMA. Thus, it is proved that IDMA is a special case of CDMA from the view of information theory.
2009, 38(4): 485-488.
doi: 10.3969/j.issn.1001-0548.2009.04.002
Abstract:
A novel multi-focus image fusion algorithm is proposed for multi-focus image fusion. Pulse coupled neural network (PCNN) and rough set theory are employed to solve the problem of multi-focus image fusion. The clarity of original image is calculated and processed by PCNN. The original image pixels are classified based on rough set theory. Finally, a fusion image is created according to the classified results. Experiments indicate that the proposed method is superior to traditional algorithms with good anti-noise performance.
A novel multi-focus image fusion algorithm is proposed for multi-focus image fusion. Pulse coupled neural network (PCNN) and rough set theory are employed to solve the problem of multi-focus image fusion. The clarity of original image is calculated and processed by PCNN. The original image pixels are classified based on rough set theory. Finally, a fusion image is created according to the classified results. Experiments indicate that the proposed method is superior to traditional algorithms with good anti-noise performance.
2009, 38(4): 489-492.
doi: 10.3969/j.issn.1001-0548.2009.04.003
Abstract:
Aimming at the problems of traditional transmission control protocol (TCP) congestion control protocol in the wired/wireless heterogeneous networks, an innovative link equivalent noise model is proposed. In this method, the background traffic of TCP link is equivalent to the additive noise. The end-to-end link bandwidth estimation methods are researched based on the equivalent noise model. An improved TCP congestion control algorithm, TCP protocol based on noise model (N-TCP), is proposed. The results of simulation and theoretical analysis show that the proposed method is valid for bandwidth estimation and therefore suitable for the application since its good compatibility to the traditional TCP protocol and characteristics of fairness for allocating bandwidth and resisting random packet loss.
Aimming at the problems of traditional transmission control protocol (TCP) congestion control protocol in the wired/wireless heterogeneous networks, an innovative link equivalent noise model is proposed. In this method, the background traffic of TCP link is equivalent to the additive noise. The end-to-end link bandwidth estimation methods are researched based on the equivalent noise model. An improved TCP congestion control algorithm, TCP protocol based on noise model (N-TCP), is proposed. The results of simulation and theoretical analysis show that the proposed method is valid for bandwidth estimation and therefore suitable for the application since its good compatibility to the traditional TCP protocol and characteristics of fairness for allocating bandwidth and resisting random packet loss.
2009, 38(4): 493-495.
doi: 10.3969/j.issn.1001-0548.2009.04.004
Abstract:
Antenna mutual coupling (MC) is considered and the general coupling coefficients matrix from the equivalent network model of the multiple-antenna is obtained. Indoor multiple input multiple output (MIMO) wireless channel model is extended by using mutual coupling compensation method, and the effects of MC on the capacity of indoor MIMO channels are analyzed numerically. The conditions that MC has no effect on the spatial correlation are identified. Simulation results show that MC can cause the antenna pattern distortion which brings angel diversity and low correlation so as to improve channel capacity.
Antenna mutual coupling (MC) is considered and the general coupling coefficients matrix from the equivalent network model of the multiple-antenna is obtained. Indoor multiple input multiple output (MIMO) wireless channel model is extended by using mutual coupling compensation method, and the effects of MC on the capacity of indoor MIMO channels are analyzed numerically. The conditions that MC has no effect on the spatial correlation are identified. Simulation results show that MC can cause the antenna pattern distortion which brings angel diversity and low correlation so as to improve channel capacity.
2009, 38(4): 496-500.
doi: 10.3969/j.issn.1001-0548.2009.04.005
Abstract:
A new algorithm is proposed to enable GPS positioning with acceptable accuracy based on less-than-three available satellites in insufficient condition caused by temporal signal blockage. Tests in real data demonstrate that the proposed algorithm offers significant improvement of GPS availability by providing location results suitable for navigation applications in temporal insufficient condition more than one minute. The algorithm does not need extra sensors or support of digital maps, meanwhile the increased gross system cost is neglectable.
A new algorithm is proposed to enable GPS positioning with acceptable accuracy based on less-than-three available satellites in insufficient condition caused by temporal signal blockage. Tests in real data demonstrate that the proposed algorithm offers significant improvement of GPS availability by providing location results suitable for navigation applications in temporal insufficient condition more than one minute. The algorithm does not need extra sensors or support of digital maps, meanwhile the increased gross system cost is neglectable.
2009, 38(4): 501-504.
doi: 10.3969/j.issn.1001-0548.2009.04.006
Abstract:
Communication systems always suffer the in-band distortion, spectrum regrowth, and BER degradation since the nonlinear effect of high power amplifier (HPA). This paper proposes a new joint nonlinearity reduction method by combining the predistorter and tone reservation using null subcarriers (TRNS) method. Tone reservation method is used to reduce the peak-to-average power ratio of the transmitted signal, while predistorter is applied to extend the dynamic range of HPA. Simulation results show that the proposed method can improve the total performance, especially, under low input back-off (IBO).
Communication systems always suffer the in-band distortion, spectrum regrowth, and BER degradation since the nonlinear effect of high power amplifier (HPA). This paper proposes a new joint nonlinearity reduction method by combining the predistorter and tone reservation using null subcarriers (TRNS) method. Tone reservation method is used to reduce the peak-to-average power ratio of the transmitted signal, while predistorter is applied to extend the dynamic range of HPA. Simulation results show that the proposed method can improve the total performance, especially, under low input back-off (IBO).
2009, 38(4): 505-508.
doi: 10.3969/j.issn.1001-0548.2009.04.007
Abstract:
A serial concatenated coding method is presented based on low-density parity-check (LDPC) codes and vertical single-parity-check (VSPC) product codes. By applying the decoded result of LDPC codes instead of the horizontal checks of conventional product codes, the performance of the component SPC product codes can be improved with the reduced complexity. The performance of the new concatenated codes is analyzed. Simulation results show that the proposed concatenated codes significantly outperform LDPC codes alone on AWGN channels and Raleigh fading channels, and the additional decoding complexity is very low. Moreover, the error floors of LDPC codes can be impaired effectively.
A serial concatenated coding method is presented based on low-density parity-check (LDPC) codes and vertical single-parity-check (VSPC) product codes. By applying the decoded result of LDPC codes instead of the horizontal checks of conventional product codes, the performance of the component SPC product codes can be improved with the reduced complexity. The performance of the new concatenated codes is analyzed. Simulation results show that the proposed concatenated codes significantly outperform LDPC codes alone on AWGN channels and Raleigh fading channels, and the additional decoding complexity is very low. Moreover, the error floors of LDPC codes can be impaired effectively.
2009, 38(4): 509-512.
doi: 10.3969/j.issn.1001-0548.2009.04.008
Abstract:
A method for estimating carrier parameters is proposed by using extended Kalman filter (EKF) when the amplitude of the received signal is unknown. In the method, the state vector of EKF is composed of the carrier phase, the frequency and the product of the signal amplitude and auto-correlation of PN code. Theoretical analysis illustrates that the method is essentially the joint estimation of amplitude-locked loop and phase-locked loop with variable gains. The closed-form expression of transform function and equivalent noise bandwidth are obtained. Numerical simulation shows that the method proposed can obtain the high accuracy of estimation and the short convergent time.
A method for estimating carrier parameters is proposed by using extended Kalman filter (EKF) when the amplitude of the received signal is unknown. In the method, the state vector of EKF is composed of the carrier phase, the frequency and the product of the signal amplitude and auto-correlation of PN code. Theoretical analysis illustrates that the method is essentially the joint estimation of amplitude-locked loop and phase-locked loop with variable gains. The closed-form expression of transform function and equivalent noise bandwidth are obtained. Numerical simulation shows that the method proposed can obtain the high accuracy of estimation and the short convergent time.
2009, 38(4): 513-516.
doi: 10.3969/j.issn.1001-0548.2009.04.009
Abstract:
Based on the mobile Ad hoc networks with the group mobility model, the principle of the original landmark hierarchical routing protocol (LANMAR) is analyzed. On the basis of the landmark routing protocol, a physical hierarchical structure with backbone nodes, including channel setting and access methods, is designed, which can satisfy the requirements of the mobile Ad hoc network. A novel LANMAR protocol with designated clusterheads is proposed, which is called designated clusterhead LANMAR (DC-LANMAR). The clusterhead has powerful radios and use high quality backbone links to communicate among groups to reduce hop distances. The main performances of LANMAR and DC-LANMAR are compared through computer simulations. The results verifies the feasibility and effectiveness of DC-LANMAR protocol.
Based on the mobile Ad hoc networks with the group mobility model, the principle of the original landmark hierarchical routing protocol (LANMAR) is analyzed. On the basis of the landmark routing protocol, a physical hierarchical structure with backbone nodes, including channel setting and access methods, is designed, which can satisfy the requirements of the mobile Ad hoc network. A novel LANMAR protocol with designated clusterheads is proposed, which is called designated clusterhead LANMAR (DC-LANMAR). The clusterhead has powerful radios and use high quality backbone links to communicate among groups to reduce hop distances. The main performances of LANMAR and DC-LANMAR are compared through computer simulations. The results verifies the feasibility and effectiveness of DC-LANMAR protocol.
2009, 38(4): 517-520.
doi: 10.3969/j.issn.1001-0548.2009.04.010
Abstract:
The velocity estimation and SAR imaging are the two significant topics for the forward-looking ground penetrating radar (FLGPR). This paper presents a fast subsurface SAR imaging algorithm with nonstationary filtering matrix for FLGPR. The target image is reconstructed from FLGPR received data after a nonstationary convolution filtering in the Fourier domain. And the velocity of the electromagnetic wave propagating under ground is estimated by using the image gray variance after synthetic aperture imaging with various velocities. The effectiveness of the approach is demonstrated with simulated data and experimental data set.
The velocity estimation and SAR imaging are the two significant topics for the forward-looking ground penetrating radar (FLGPR). This paper presents a fast subsurface SAR imaging algorithm with nonstationary filtering matrix for FLGPR. The target image is reconstructed from FLGPR received data after a nonstationary convolution filtering in the Fourier domain. And the velocity of the electromagnetic wave propagating under ground is estimated by using the image gray variance after synthetic aperture imaging with various velocities. The effectiveness of the approach is demonstrated with simulated data and experimental data set.
2009, 38(4): 521-524.
doi: 10.3969/j.issn.1001-0548.2009.04.011
Abstract:
A complete and effective design is introduced to realize the 0805 size of standard packaging laminated low pass filter (LPF) using the technology of low temperature co-fired ceramic (LTCC). The three-stage laminated LPF with 200 MHz cut-off frequency is successfully manufactured using the ceramic green tape with relative permittivity of 14 and tape-casting thickness of 25 μm. Testing results show that the three-order LPF sample can achieve a 3 dB return loss at 200 MHz and a 26 dB return loss at 500 MHz by Agilent 8722ES. And the measured results agree well with the simulated data. This method illustrates a way to resolve the consistency problems between simulation and manufacture.
A complete and effective design is introduced to realize the 0805 size of standard packaging laminated low pass filter (LPF) using the technology of low temperature co-fired ceramic (LTCC). The three-stage laminated LPF with 200 MHz cut-off frequency is successfully manufactured using the ceramic green tape with relative permittivity of 14 and tape-casting thickness of 25 μm. Testing results show that the three-order LPF sample can achieve a 3 dB return loss at 200 MHz and a 26 dB return loss at 500 MHz by Agilent 8722ES. And the measured results agree well with the simulated data. This method illustrates a way to resolve the consistency problems between simulation and manufacture.
2009, 38(4): 525-528.
doi: 10.3969/j.issn.1001-0548.2009.04.012
Abstract:
The good spatial-frequencial localization characteristic of wavelet transform make the energy of image congregate mostly in lower frequency subimage. Based on this characteristic, a coding algorithm which combines embedded zerotree wavelet (EZW) coding method with predicting coding method is presented to fit the limited computer resources in small-satellites. Heavyweight higher frequency coefficients are selected and coded by EZW coding algorithm and lower frequency coefficients are coded by predicting coding algorithm. The result indicates that with this coding algorithm the speed of image compression can be increased with good compression effect.
The good spatial-frequencial localization characteristic of wavelet transform make the energy of image congregate mostly in lower frequency subimage. Based on this characteristic, a coding algorithm which combines embedded zerotree wavelet (EZW) coding method with predicting coding method is presented to fit the limited computer resources in small-satellites. Heavyweight higher frequency coefficients are selected and coded by EZW coding algorithm and lower frequency coefficients are coded by predicting coding algorithm. The result indicates that with this coding algorithm the speed of image compression can be increased with good compression effect.
2009, 38(4): 529-532.
doi: 10.3969/j.issn.1001-0548.2009.04.013
Abstract:
In Lambda-grids, advance reservation is one of important methods to guarantee QoS for grid computing applications. However, it would bring many resource fragmentations, which have greatly effect on resource utilization. This paper discusses the key problems existing in advance reservation-based RWA algorithm, i.e., not considering resource fragmentation and its impacts to new arriving traffic request. Based on layered-graph model, a heuristic routing and wavelength assignment algorithm is proposed to support advance reservation with less resource fragmentations, named Less Resource Fragmentations based on Layered Graph (LG-LRF). The algorithm directly considers resource fragmentations as link weights of layered wavelength-plane graph, and therefore, can resolve routing and wavelength assignment at the same time, and avoid the wavelength continuity constraint and some side-effects on new arriving traffic request. Simulation results show that LG-LRF outperforms the conventional heuristic RWA algorithms in terms of blocking probability of traffic requests and resource fragmentations ratio, and is more suitable for advance reservation for lambda-grids.
In Lambda-grids, advance reservation is one of important methods to guarantee QoS for grid computing applications. However, it would bring many resource fragmentations, which have greatly effect on resource utilization. This paper discusses the key problems existing in advance reservation-based RWA algorithm, i.e., not considering resource fragmentation and its impacts to new arriving traffic request. Based on layered-graph model, a heuristic routing and wavelength assignment algorithm is proposed to support advance reservation with less resource fragmentations, named Less Resource Fragmentations based on Layered Graph (LG-LRF). The algorithm directly considers resource fragmentations as link weights of layered wavelength-plane graph, and therefore, can resolve routing and wavelength assignment at the same time, and avoid the wavelength continuity constraint and some side-effects on new arriving traffic request. Simulation results show that LG-LRF outperforms the conventional heuristic RWA algorithms in terms of blocking probability of traffic requests and resource fragmentations ratio, and is more suitable for advance reservation for lambda-grids.
2009, 38(4): 533-536.
doi: 10.3969/j.issn.1001-0548.2009.04.014
Abstract:
Combining blind signature with certificateless cryptology, a certificateless blind signature scheme is proposed. This scheme solves the escrow problem and retains the merits of blind signature with no deed of certificate. This scheme includes various functional algorithms such as system initialization, partial-key-extract, set-secret-value, set-public-key, set-private-key, and so on. Finally, an analysis of the scheme's security is presented. The results demonstrate its capability of achieving high level of security.
Combining blind signature with certificateless cryptology, a certificateless blind signature scheme is proposed. This scheme solves the escrow problem and retains the merits of blind signature with no deed of certificate. This scheme includes various functional algorithms such as system initialization, partial-key-extract, set-secret-value, set-public-key, set-private-key, and so on. Finally, an analysis of the scheme's security is presented. The results demonstrate its capability of achieving high level of security.
2009, 38(4): 537-541.
doi: 10.3969/j.issn.1001-0548.2009.04.015
Abstract:
The nodes of wireless sensor network are very limited in its processing power, storage capacity and communications capability, so it is usually to be considered unsuitable for the use of public key cryptography technology. However, in recent years many research results indicated that some optimized public-key algorithm can provide much more security for wireless sensor networks (WSN). The identity-based public system simplifies the certificates management which is cumbersome in certificate based public key system. According to the features of WSN, the security model of identity-based public-key system is modified. A new identity-based signature (IBS) system is presented and proved secure in the new security model without random oracle. Storage requirement in previous IBS systems is directly related to message length, but it is constant in our new system, so the new system is more suitable for wireless sensor networks.
The nodes of wireless sensor network are very limited in its processing power, storage capacity and communications capability, so it is usually to be considered unsuitable for the use of public key cryptography technology. However, in recent years many research results indicated that some optimized public-key algorithm can provide much more security for wireless sensor networks (WSN). The identity-based public system simplifies the certificates management which is cumbersome in certificate based public key system. According to the features of WSN, the security model of identity-based public-key system is modified. A new identity-based signature (IBS) system is presented and proved secure in the new security model without random oracle. Storage requirement in previous IBS systems is directly related to message length, but it is constant in our new system, so the new system is more suitable for wireless sensor networks.
2009, 38(4): 542-545.
doi: 10.3969/j.issn.1001-0548.2009.04.016
Abstract:
A blind image watermarking algorithm based on the multiresolution sub-band decomposition-fast independent component analysis (MSD-FICA) is proposed. In this scheme, the watermark bits are embedded in the middle-frequency components and the low-frequency components simultaneously. The middle-frequency components are selected by adopting the sorting scheme among the high-frequency components. In watermarking extraction, primary component analysis (PCA) is applied for preprocess, then the watermark is extracted by FICA. The experimental results show that the proposed algorithm is robust against JPEG compression, Gaussian noise, and median filtering. The comparison analysis demonstrates that our scheme has better performance than the QIM watermarking scheme.
A blind image watermarking algorithm based on the multiresolution sub-band decomposition-fast independent component analysis (MSD-FICA) is proposed. In this scheme, the watermark bits are embedded in the middle-frequency components and the low-frequency components simultaneously. The middle-frequency components are selected by adopting the sorting scheme among the high-frequency components. In watermarking extraction, primary component analysis (PCA) is applied for preprocess, then the watermark is extracted by FICA. The experimental results show that the proposed algorithm is robust against JPEG compression, Gaussian noise, and median filtering. The comparison analysis demonstrates that our scheme has better performance than the QIM watermarking scheme.
2009, 38(4): 546-548.
doi: 10.3969/j.issn.1001-0548.2009.04.017
Abstract:
In an infinite dimensional Hilbert space, the normal Mann's iterative algorithm has only weak convergence, in general, even for non-expansive mappings. In order to get a strong convergence result, the normal Mann's iterative algorithm is modified by using a suitable convex combination of a fixed vector and a sequence in a closed convex subset of a real Hilbert space. A strong convergence theorem is established by means of a new Ishikawa-like iterative algorithm for κ-strict pseudo-contractions in Hilbert spaces. The results presented in this paper have extended and improved some recent results.
In an infinite dimensional Hilbert space, the normal Mann's iterative algorithm has only weak convergence, in general, even for non-expansive mappings. In order to get a strong convergence result, the normal Mann's iterative algorithm is modified by using a suitable convex combination of a fixed vector and a sequence in a closed convex subset of a real Hilbert space. A strong convergence theorem is established by means of a new Ishikawa-like iterative algorithm for κ-strict pseudo-contractions in Hilbert spaces. The results presented in this paper have extended and improved some recent results.
2009, 38(4): 549-552.
doi: 10.3969/j.issn.1001-0548.2009.04.018
Abstract:
The theoretical study and simulation of Cherenkov radiation of a charged particle which moves uniformly in magnetized plasma are carried out. The analytical expression of radiated field, eigenvalue, and radiated conditions are obtained. Numerical calculations of the eigenvalues and contour map of radiated field are presented. It is found that the cyclotron frequency and plasma frequency affect the distribution of the eigenvalue. Then the PIC-simulation is applied to analyze the characteristics of this radiation. The results show that the amplitude of confinement magnetic field influences the radiation angle and the amplitude of radiation field. And the wakefield is found in the simulation.
The theoretical study and simulation of Cherenkov radiation of a charged particle which moves uniformly in magnetized plasma are carried out. The analytical expression of radiated field, eigenvalue, and radiated conditions are obtained. Numerical calculations of the eigenvalues and contour map of radiated field are presented. It is found that the cyclotron frequency and plasma frequency affect the distribution of the eigenvalue. Then the PIC-simulation is applied to analyze the characteristics of this radiation. The results show that the amplitude of confinement magnetic field influences the radiation angle and the amplitude of radiation field. And the wakefield is found in the simulation.
2009, 38(4): 553-558.
doi: 10.3969/j.issn.1001-0548.2009.04.019
Abstract:
A new method for analog circuit fault diagnosis is presented based on genetic algorithm optimized support vector machine multi-class decision tree (GADT-SVM). The design idea and algorithm principle of GADT-SVM is introduced firstly; then model of analog circuit is built by transfer function, and fault characteristic is picked-up by wavelet energy distribution of impulse response. Finally, fault samples are recognized by GADT-SVM. Experiment results show that our method can depress error accumulation phenomena of diagnosis and have stronger error control ability compared with the traditional DAG-SVM and DT-SVM.
A new method for analog circuit fault diagnosis is presented based on genetic algorithm optimized support vector machine multi-class decision tree (GADT-SVM). The design idea and algorithm principle of GADT-SVM is introduced firstly; then model of analog circuit is built by transfer function, and fault characteristic is picked-up by wavelet energy distribution of impulse response. Finally, fault samples are recognized by GADT-SVM. Experiment results show that our method can depress error accumulation phenomena of diagnosis and have stronger error control ability compared with the traditional DAG-SVM and DT-SVM.
2009, 38(4): 559-563.
doi: 10.3969/j.issn.1001-0548.2009.04.020
Abstract:
The stochastic nonlinear large-scale systems with time-varying delays in the strict-feedback form is researched. The interconnections satisfy linear increase restriction. By using backstepping algorithms, decentralized output feedback controllers are designed through choosing appropriate state observers and employing guartic control Lyapunov-Krasovskii function. The numerical simulation shows that the closed-loop system is asymptotically stable and the effectiveness of our design is verified.
The stochastic nonlinear large-scale systems with time-varying delays in the strict-feedback form is researched. The interconnections satisfy linear increase restriction. By using backstepping algorithms, decentralized output feedback controllers are designed through choosing appropriate state observers and employing guartic control Lyapunov-Krasovskii function. The numerical simulation shows that the closed-loop system is asymptotically stable and the effectiveness of our design is verified.
2009, 38(4): 564-568.
doi: 10.3969/j.issn.1001-0548.2009.04.021
Abstract:
A new three-dimensional piecewise-linear chaotic system is proposed. Some dynamical characteristics of this system including symmetry and invariance, dissipativity and existence of attractor, equilibrium, and stability are investigated in detail. By numerical simulating with Lyapunov exponent spectrum, bifurcation diagram, Poincaré mapping, and phase portrait, this paper verifies that the proposed system has abundant dynamical behaviors. It can operate on chaotic and periodic orbits and can evolve into chaos with difform chaotic attractor or period or limited point by a constant controller.
A new three-dimensional piecewise-linear chaotic system is proposed. Some dynamical characteristics of this system including symmetry and invariance, dissipativity and existence of attractor, equilibrium, and stability are investigated in detail. By numerical simulating with Lyapunov exponent spectrum, bifurcation diagram, Poincaré mapping, and phase portrait, this paper verifies that the proposed system has abundant dynamical behaviors. It can operate on chaotic and periodic orbits and can evolve into chaos with difform chaotic attractor or period or limited point by a constant controller.
2009, 38(4): 569-572.
doi: 10.3969/j.issn.1001-0548.2009.04.022
Abstract:
Digital oscilloscope can not measure week singal in chaotic background. A method using Elman neural network is described to achieve signal parameter detection in chaotic background. With the phase space reconstruction theory on time series, the embedded dimension is calculated and used as the in-put dimension of a neural network considered. By adopting the single-step prediction method, the weak signals are detected directly and their waveforms can be gained as well in the chaotic state. Result shows that the method studied in this paper is superior to the existing detection principles. Its feasibility and practicability have been proved by the experiments.
Digital oscilloscope can not measure week singal in chaotic background. A method using Elman neural network is described to achieve signal parameter detection in chaotic background. With the phase space reconstruction theory on time series, the embedded dimension is calculated and used as the in-put dimension of a neural network considered. By adopting the single-step prediction method, the weak signals are detected directly and their waveforms can be gained as well in the chaotic state. Result shows that the method studied in this paper is superior to the existing detection principles. Its feasibility and practicability have been proved by the experiments.
2009, 38(4): 573-577.
doi: 10.3969/j.issn.1001-0548.2009.04.023
Abstract:
In order to obtain the horizontal restriction of any two aircraft, a method of the assignment problem (AP) of flight level is presented. Based on the expanded efficiency matrix of generalized assignment problem (GAP), Hungarian algorithm provides a solution for the optimization of the vertical trajectory with the efficiency matrix of the flight level from one single aircraft to multiple aircraft in the same flight level. It also provides a general method to convert the indeterminate mode of assignment problem to determinant mode when the efficient matrix varies. The case study shows that the direct or indirect Hungarian algorithm is efficient in real time optimal use of flight level in air traffic control.
In order to obtain the horizontal restriction of any two aircraft, a method of the assignment problem (AP) of flight level is presented. Based on the expanded efficiency matrix of generalized assignment problem (GAP), Hungarian algorithm provides a solution for the optimization of the vertical trajectory with the efficiency matrix of the flight level from one single aircraft to multiple aircraft in the same flight level. It also provides a general method to convert the indeterminate mode of assignment problem to determinant mode when the efficient matrix varies. The case study shows that the direct or indirect Hungarian algorithm is efficient in real time optimal use of flight level in air traffic control.
2009, 38(4): 578-582.
doi: 10.3969/j.issn.1001-0548.2009.04.024
Abstract:
The paper constructs a remote sensing model of the forest canopy rainfall interception in the upstream of Minjiang Valley based on the principle of the forest water content balance and research on the orientation observation. The enhanced thematic mapper (ETM) and various data from remote sensing, practical measurement and routine observation are fully utilized in this model. By taking one pixel of the remote sensing images as the calculating unit, the model parameters, including vegetation coverage, leaf area index (LAI), and leaf rainfall interception are calculated, and the inverse calculation of the interception rainfall quantity of the forest coronal in the Maoergai Region of Minjiang Valley is given and analyzed. The results show that the inversion model can better reflect the true condition of the forest canopy rainfall interception in the research area.
The paper constructs a remote sensing model of the forest canopy rainfall interception in the upstream of Minjiang Valley based on the principle of the forest water content balance and research on the orientation observation. The enhanced thematic mapper (ETM) and various data from remote sensing, practical measurement and routine observation are fully utilized in this model. By taking one pixel of the remote sensing images as the calculating unit, the model parameters, including vegetation coverage, leaf area index (LAI), and leaf rainfall interception are calculated, and the inverse calculation of the interception rainfall quantity of the forest coronal in the Maoergai Region of Minjiang Valley is given and analyzed. The results show that the inversion model can better reflect the true condition of the forest canopy rainfall interception in the research area.
2009, 38(4): 583-587.
doi: 10.3969/j.issn.1001-0548.2009.04.025
Abstract:
The three-party password-based authenticated key exchange protocol based on the CCDH assumption is analyzed. It is demonstrated that this protocol has security vulnerabilities from on-line guessing attack and lacks a perfect authentication mechanism. This paper presents an attack scheme to the protocol. Our attack scheme shows that an adversary can get other legitimate user's password successfully by on-line guessing cyclically.
The three-party password-based authenticated key exchange protocol based on the CCDH assumption is analyzed. It is demonstrated that this protocol has security vulnerabilities from on-line guessing attack and lacks a perfect authentication mechanism. This paper presents an attack scheme to the protocol. Our attack scheme shows that an adversary can get other legitimate user's password successfully by on-line guessing cyclically.
2009, 38(4): 588-591.
doi: 10.3969/j.issn.1001-0548.2009.04.026
Abstract:
According to the analysis of the implicit parallelism in algorithms, a physical model of implicit parallelism in algorithm is proposed. The uncertainty and high entropy state of algorithm bring forward implicit parallelism, but the implicit parallelism of algorithms may cause the uncertainty of algorithm results. In the proposed model, the search direction in result space is decided by the apriori knowledge and the high speed parallel search ability is decided by the implicit parallelism. The implicit parallelism of genetic algorithm and simulated annealing algorithm are analyzed by this model.
According to the analysis of the implicit parallelism in algorithms, a physical model of implicit parallelism in algorithm is proposed. The uncertainty and high entropy state of algorithm bring forward implicit parallelism, but the implicit parallelism of algorithms may cause the uncertainty of algorithm results. In the proposed model, the search direction in result space is decided by the apriori knowledge and the high speed parallel search ability is decided by the implicit parallelism. The implicit parallelism of genetic algorithm and simulated annealing algorithm are analyzed by this model.
2009, 38(4): 592-595.
doi: 10.3969/j.issn.1001-0548.2009.04.027
Abstract:
Since the electronic evidence is difficult to collect in the computer crime in morden society, a new high-performance algorithm for mining association rules based on the construction of the FP-array is proposed according to the discuss of the maximal frequent patterns (FP-Max) algorithm based on FP-tree. Five kinds of common data of computer-related crime are mined successfully by using the new algorithm. The mining results can provide important reference in actual detection process.
Since the electronic evidence is difficult to collect in the computer crime in morden society, a new high-performance algorithm for mining association rules based on the construction of the FP-array is proposed according to the discuss of the maximal frequent patterns (FP-Max) algorithm based on FP-tree. Five kinds of common data of computer-related crime are mined successfully by using the new algorithm. The mining results can provide important reference in actual detection process.
2009, 38(4): 596-599.
doi: 10.3969/j.issn.1001-0548.2009.04.028
Abstract:
For energy management and optimization of wireless sensor network (WSN) nodes, a power state transition model of WSN node is proposed through the analysis of the operation of the main energy consuming components within the node. The model describes the relations and conditions of the transitions of WSN node between different states with different power levels. Since more energy can be reserved when the node is scheduled into the appropriate states with lower power level, a method is introduced to determine the time thresholds for the state transitions. The optimal decision of the time thresholds is based on Markov strategy with certainty. This model can supply a good reference for the design of the dynamic power management of WSN nodes.
For energy management and optimization of wireless sensor network (WSN) nodes, a power state transition model of WSN node is proposed through the analysis of the operation of the main energy consuming components within the node. The model describes the relations and conditions of the transitions of WSN node between different states with different power levels. Since more energy can be reserved when the node is scheduled into the appropriate states with lower power level, a method is introduced to determine the time thresholds for the state transitions. The optimal decision of the time thresholds is based on Markov strategy with certainty. This model can supply a good reference for the design of the dynamic power management of WSN nodes.
2009, 38(4): 600-604.
doi: 10.3969/j.issn.1001-0548.2009.04.029
Abstract:
The validity of the provable security of counter with cipher block chaining message authentication code (CCM) mode and cipher-based message authentication code (CMAC) mode was studied and proved. The illustrations of different communications' encryption have been developed. The security of the novel authentication operation mode is demonstrated with flowing chart. The standardized operation modes of block cipher are proved to be safe in various environments. The proposed procedure is also applicable to Galois/counter mode (GCM) operation mode published in July, 2007. The provable security is a necessary process for a new mode of block cipher.
The validity of the provable security of counter with cipher block chaining message authentication code (CCM) mode and cipher-based message authentication code (CMAC) mode was studied and proved. The illustrations of different communications' encryption have been developed. The security of the novel authentication operation mode is demonstrated with flowing chart. The standardized operation modes of block cipher are proved to be safe in various environments. The proposed procedure is also applicable to Galois/counter mode (GCM) operation mode published in July, 2007. The provable security is a necessary process for a new mode of block cipher.
2009, 38(4): 605-608.
doi: 10.3969/j.issn.1001-0548.2009.04.030
Abstract:
An integrated classified Web software package protection scheme based on chaos encrypting alogrithm is proposed. It creates download rights in user LAN according to the significance grade and safe scale of the protected software package. According to the uncertainty and initial value sensitivity of chaotic systems, the exclusive registered code of the protected software package with different safe scale is created based on chaos encryption algorithm of Logistic maps. The proposed protection scheme yields an improvement in efficiency and security.
An integrated classified Web software package protection scheme based on chaos encrypting alogrithm is proposed. It creates download rights in user LAN according to the significance grade and safe scale of the protected software package. According to the uncertainty and initial value sensitivity of chaotic systems, the exclusive registered code of the protected software package with different safe scale is created based on chaos encryption algorithm of Logistic maps. The proposed protection scheme yields an improvement in efficiency and security.
2009, 38(4): 609-612.
doi: 10.3969/j.issn.1001-0548.2009.04.031
Abstract:
A mathematical model of controller parameter tuning based on immune theory is established. Antibody, antigen, and affinity of the parameter tuning problem are defined. The process of parameter tuning based on immune principles is discussed in detail. The method is used to optimize the three parameters of proportion-integral-derivative (PID) controller for the control of high-order process, large time delay process, and non-minimum phase process. The results compared with some other tuning methods show the effectiveness of the proposed method is effective.
A mathematical model of controller parameter tuning based on immune theory is established. Antibody, antigen, and affinity of the parameter tuning problem are defined. The process of parameter tuning based on immune principles is discussed in detail. The method is used to optimize the three parameters of proportion-integral-derivative (PID) controller for the control of high-order process, large time delay process, and non-minimum phase process. The results compared with some other tuning methods show the effectiveness of the proposed method is effective.
2009, 38(4): 613-616.
doi: 10.3969/j.issn.1001-0548.2009.04.032
Abstract:
A new small moving target detection algorithm in infrared image sequences is presented to reduce the energy scattering in dynamic programming-based algorithm. Based on the property of target motion, a Gaussian template is built to model target position in the next frame. Our algorithm uses probability not hard constrain, so it can overcome the randomicity of target motion. Experiments with real infrared image sequences show our algorithm can greatly reduce the energy scattering in dynamic programming-based algorithm.
A new small moving target detection algorithm in infrared image sequences is presented to reduce the energy scattering in dynamic programming-based algorithm. Based on the property of target motion, a Gaussian template is built to model target position in the next frame. Our algorithm uses probability not hard constrain, so it can overcome the randomicity of target motion. Experiments with real infrared image sequences show our algorithm can greatly reduce the energy scattering in dynamic programming-based algorithm.
2009, 38(4): 617-620.
doi: 10.3969/j.issn.1001-0548.2009.04.033
Abstract:
micro zooming super-resolution imaging is difficult for interpolation and reconstruction, and there are some limitations in the frequency domain model and space domain model based on LSE (least squares estimation). By referring to the mathematical concept of Delaunay triangulation and randomized incremental algorithm, an interpolation algorithm based on Delaunay triangulation in the course of image reconstruction is defined for both real time and accuracy of super-resolution imaging. This algorithm can improve the resolution and reduce the amount of calculation. The results of simulation experiment show that this method is better than the method based on conjugate gradient least square (CGLS) in the speed and error of image reconstruction.
micro zooming super-resolution imaging is difficult for interpolation and reconstruction, and there are some limitations in the frequency domain model and space domain model based on LSE (least squares estimation). By referring to the mathematical concept of Delaunay triangulation and randomized incremental algorithm, an interpolation algorithm based on Delaunay triangulation in the course of image reconstruction is defined for both real time and accuracy of super-resolution imaging. This algorithm can improve the resolution and reduce the amount of calculation. The results of simulation experiment show that this method is better than the method based on conjugate gradient least square (CGLS) in the speed and error of image reconstruction.
2009, 38(4): 621-625.
doi: 10.3969/j.issn.1001-0548.2009.04.034
Abstract:
The perception of motion-in-depth is still in research. The influence of motion direction on the perception is unclear and not reported. By an experiment paradigm close to human's practical visual experience, this paper presents a detail spatio-temporal analysis of the 128-channels event-related potential (ERP) data under two conditions. The results illustrate that same or similar brain areas are activated in both conditions, but the emphasis brain areas are not same when processing different motion direction, and some significant difference on their temporal course can be observed.
The perception of motion-in-depth is still in research. The influence of motion direction on the perception is unclear and not reported. By an experiment paradigm close to human's practical visual experience, this paper presents a detail spatio-temporal analysis of the 128-channels event-related potential (ERP) data under two conditions. The results illustrate that same or similar brain areas are activated in both conditions, but the emphasis brain areas are not same when processing different motion direction, and some significant difference on their temporal course can be observed.
2009, 38(4): 626-630.
doi: 10.3969/j.issn.1001-0548.2009.04.035
Abstract:
A novel method, which is based on the zero-crossing points combined with Gaussian filter, is developed to estimate the cartilage thickness of hip joint automatically in magnetic resonance imaging (MRI). A 2D mathematical model for simulating human hip joint femoral cartilage distribution is founded. Based on the model, a point spread function (PSF) is applied to simulate the MR imaging process, and then the one-dimensional profile of MR intensity values along the normal direction of the sheet structure can be performed. The simulation experiment demonstrates that the thickness of sheet structure can be accurately measured by using the zero-crossing method, where the thickness of sheet structure is defined as the distance between zero-crossing points of the Gaussian second derivatives along the normal direction. Plastic sheet simulation and the vivo experiment verify the validity of the method.
A novel method, which is based on the zero-crossing points combined with Gaussian filter, is developed to estimate the cartilage thickness of hip joint automatically in magnetic resonance imaging (MRI). A 2D mathematical model for simulating human hip joint femoral cartilage distribution is founded. Based on the model, a point spread function (PSF) is applied to simulate the MR imaging process, and then the one-dimensional profile of MR intensity values along the normal direction of the sheet structure can be performed. The simulation experiment demonstrates that the thickness of sheet structure can be accurately measured by using the zero-crossing method, where the thickness of sheet structure is defined as the distance between zero-crossing points of the Gaussian second derivatives along the normal direction. Plastic sheet simulation and the vivo experiment verify the validity of the method.
2009, 38(4): 631-635.
doi: 10.3969/j.issn.1001-0548.2009.04.036
Abstract:
The key issues of machine vision system is the speed, accuracy and stability of image processing. To make the machine vision system of automatic screw-classifying devices to monitor the geometric parameters, the image edge and its detection stability are enhanced by the Curvelet transform and the speed of image processing is accelerated by the program optimized by MMX, SSE, and IPP functions. The application shows that the image processing speed of the system can reach 25 ms per frame with repeat accuracy of 8 μm. So the system can meet the requirements of stability and real-time monitoring geometric parameters.
The key issues of machine vision system is the speed, accuracy and stability of image processing. To make the machine vision system of automatic screw-classifying devices to monitor the geometric parameters, the image edge and its detection stability are enhanced by the Curvelet transform and the speed of image processing is accelerated by the program optimized by MMX, SSE, and IPP functions. The application shows that the image processing speed of the system can reach 25 ms per frame with repeat accuracy of 8 μm. So the system can meet the requirements of stability and real-time monitoring geometric parameters.
2009, 38(4): 636-640.
doi: 10.3969/j.issn.1001-0548.2009.04.037
Abstract:
A transient fuel film model is established by four-stroke gasoline engine as the research object. The recursive least square algorithm is used to identify parameters of the film. The simulation model of engine air-fuel ratio is established. The identified model is used to simulate transient operating conditions which are compared with the actual acquisition of the air-fuel ratio. The results show that identified parameters of the film can meet the requirements of actual control using recursive least squares algorithm.
A transient fuel film model is established by four-stroke gasoline engine as the research object. The recursive least square algorithm is used to identify parameters of the film. The simulation model of engine air-fuel ratio is established. The identified model is used to simulate transient operating conditions which are compared with the actual acquisition of the air-fuel ratio. The results show that identified parameters of the film can meet the requirements of actual control using recursive least squares algorithm.
