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2004 Vol. 26, No. 8
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2004, 26(8): 1177-1182.
Abstract:
Ant Colony Optimization (ACO) is a novel evolutionary algorithm derived from the foraging behavior of real ants of nature, which can find the shortest path between a food source and their nest. The main characteristics of ACO are robustness, positive feedback and distributed computation. And at the same time, Support Vector Machine (SVM), based on structure risk minimization principle, has the better performance and the better generalization ability. According to these, a gender classification using SVM and ACO is presented. Firstly, to reduce the dimensionality of the face images, the principal component coefficients of all images are calculated through Karhunen Loeve transform. Then, the eigenvectors are sorted in the descending order of eigenvalues. Secondly, ACO decides which eigenvectors will be used. After ACOs feature selection, the SVMs are trained and tested for gender classification. Deserving the best optimal features with highest accuracy rate, the next validation is continued until 10-fold cross-validations are completed. The experiments indicate that the proposed gender classification system based on ACO and SVM is more practical and efficient in comparison with others.
Ant Colony Optimization (ACO) is a novel evolutionary algorithm derived from the foraging behavior of real ants of nature, which can find the shortest path between a food source and their nest. The main characteristics of ACO are robustness, positive feedback and distributed computation. And at the same time, Support Vector Machine (SVM), based on structure risk minimization principle, has the better performance and the better generalization ability. According to these, a gender classification using SVM and ACO is presented. Firstly, to reduce the dimensionality of the face images, the principal component coefficients of all images are calculated through Karhunen Loeve transform. Then, the eigenvectors are sorted in the descending order of eigenvalues. Secondly, ACO decides which eigenvectors will be used. After ACOs feature selection, the SVMs are trained and tested for gender classification. Deserving the best optimal features with highest accuracy rate, the next validation is continued until 10-fold cross-validations are completed. The experiments indicate that the proposed gender classification system based on ACO and SVM is more practical and efficient in comparison with others.
2004, 26(8): 1183-1189.
Abstract:
Grid feature is a popular feature extraction scheme in image recognition, and usually higher performance could be obtained with the help of deformable template, espe-cially in such difficult image recognition tasks as character recognition, digit recognition, logo recognition etc. The critical shortcoming of deformable template is time-consuming. In this paper the method of deformable grid is proposed to compensate for the shortcoming of deformable template. Firstly certain grid must be superimposed on image, then unlike de-formable template where deformation is applied to image, various deformations are applied to grid. Because the number of grid is much less than that of pixels in image, the method is much more timesaving comparing to deformable template. The approximate equality of deformable template and deformable gird is also analyzed. The method is evaluated by two image recognition experiments, namely, logo recognition and off-line Chinese character recognition. The improvements in recognition rate by 7.3% in first experiment, and 5.8% in second one are obtained by the use of deformable grid.
Grid feature is a popular feature extraction scheme in image recognition, and usually higher performance could be obtained with the help of deformable template, espe-cially in such difficult image recognition tasks as character recognition, digit recognition, logo recognition etc. The critical shortcoming of deformable template is time-consuming. In this paper the method of deformable grid is proposed to compensate for the shortcoming of deformable template. Firstly certain grid must be superimposed on image, then unlike de-formable template where deformation is applied to image, various deformations are applied to grid. Because the number of grid is much less than that of pixels in image, the method is much more timesaving comparing to deformable template. The approximate equality of deformable template and deformable gird is also analyzed. The method is evaluated by two image recognition experiments, namely, logo recognition and off-line Chinese character recognition. The improvements in recognition rate by 7.3% in first experiment, and 5.8% in second one are obtained by the use of deformable grid.
2004, 26(8): 1190-1195.
Abstract:
On the basis of information fusion, an Evolutionary Algorithm based on Helrnholtz Machine and Kalman Filter (KFHMEA) is proposed. In KFHMEA, the population is divided into several sub-populations and Helmholtz machine is used to estimate the state of each sub-population. Then the information of these states is fused using a Kalman filter, and the fused information is feed back to the sub-populations. Experimental results demonstrate that KFHMEA outperforms HMEA in the stability and global search ability.
On the basis of information fusion, an Evolutionary Algorithm based on Helrnholtz Machine and Kalman Filter (KFHMEA) is proposed. In KFHMEA, the population is divided into several sub-populations and Helmholtz machine is used to estimate the state of each sub-population. Then the information of these states is fused using a Kalman filter, and the fused information is feed back to the sub-populations. Experimental results demonstrate that KFHMEA outperforms HMEA in the stability and global search ability.
2004, 26(8): 1196-1202.
Abstract:
Target tracking with angle only measurements is quite difficult, but there is a strong application potential. Based on the example of two passive sensors respectively on two moving platforms, this paper systematically analyzes the fusion method in such a circumstance. For sensors without spurious responses, the sensor availability matrix is put forward and the fusion estimate equation is established. For the circumstance of dense spu-rious responses, the idea of tracking fusion gate for application of PDAF filter are proposed for single target tracking. Simulation result verified the novel method.
Target tracking with angle only measurements is quite difficult, but there is a strong application potential. Based on the example of two passive sensors respectively on two moving platforms, this paper systematically analyzes the fusion method in such a circumstance. For sensors without spurious responses, the sensor availability matrix is put forward and the fusion estimate equation is established. For the circumstance of dense spu-rious responses, the idea of tracking fusion gate for application of PDAF filter are proposed for single target tracking. Simulation result verified the novel method.
2004, 26(8): 1203-1209.
Abstract:
In the field of data mining, it is often encountered to perform cluster analysis on large data sets with mixed numerical and categorical values. However, most existing clustering algorithms are only efficient for the numerical data rather than the mixed data set. For this purpose, this paper presents a novel clustering algorithm for these mixed data sets by modifying the common cost function, trace of the within cluster dispersion matrix. The Genetic Algorithm (GA) is used to optimize the new cost function to obtain valid clustering result. Experimental result illustrates that the GA-based new clustering algorithm is feasible for the large data sets with mixed numerical and categorical values.
In the field of data mining, it is often encountered to perform cluster analysis on large data sets with mixed numerical and categorical values. However, most existing clustering algorithms are only efficient for the numerical data rather than the mixed data set. For this purpose, this paper presents a novel clustering algorithm for these mixed data sets by modifying the common cost function, trace of the within cluster dispersion matrix. The Genetic Algorithm (GA) is used to optimize the new cost function to obtain valid clustering result. Experimental result illustrates that the GA-based new clustering algorithm is feasible for the large data sets with mixed numerical and categorical values.
2004, 26(8): 1210-1217.
Abstract:
This paper analyzes the model and algorithm of Nonlinear Blind Source Sepa-ration(NBSS) systematically, proposes a novel NBSS algorithm based on mutual cumulates, and puts forward a new optimum method using Multi-universe Parallel Quantum Genetic Algorithm(MPQGA). The simulation result demonstrates the effectiveness of the algorithm.
This paper analyzes the model and algorithm of Nonlinear Blind Source Sepa-ration(NBSS) systematically, proposes a novel NBSS algorithm based on mutual cumulates, and puts forward a new optimum method using Multi-universe Parallel Quantum Genetic Algorithm(MPQGA). The simulation result demonstrates the effectiveness of the algorithm.
2004, 26(8): 1218-1223.
Abstract:
Blind multiuser detection in multipath fading channel is an interesting topic in code division multiple access systems. In this paper a blind adaptive multiuser detector based on Minimum Mean Square Error (MMSE) criterion is proposed. In order to guarantee that the algorithm converges to the desired user, a new linear constraint technique that limits the searching space is developed. The new constraint can guarantee that the algorithm converges to the global MMSE optimal solution. Besides, an efficient iterative implementation that provides very fast convergence is proposed. Simulation results show the efficiency of the proposed algorithm.
Blind multiuser detection in multipath fading channel is an interesting topic in code division multiple access systems. In this paper a blind adaptive multiuser detector based on Minimum Mean Square Error (MMSE) criterion is proposed. In order to guarantee that the algorithm converges to the desired user, a new linear constraint technique that limits the searching space is developed. The new constraint can guarantee that the algorithm converges to the global MMSE optimal solution. Besides, an efficient iterative implementation that provides very fast convergence is proposed. Simulation results show the efficiency of the proposed algorithm.
2004, 26(8): 1224-1231.
Abstract:
This paper presents a new approch for estimating the multipath time delay of signals with unknown shape from observations received by one sensor. In th? paper, a frequency domain model for the received data is developed, and multipath timo delay estimation using this model is found to be similar to DOA estimation using an array. Thus, an algorithm for estimating time delays is derived based on the ESPRIT algorithm for DOA estimation. Ambiguities arising from the model have also been analyzed, and solutions to them are provided. Simulation results verify the efficiency of this method.
This paper presents a new approch for estimating the multipath time delay of signals with unknown shape from observations received by one sensor. In th? paper, a frequency domain model for the received data is developed, and multipath timo delay estimation using this model is found to be similar to DOA estimation using an array. Thus, an algorithm for estimating time delays is derived based on the ESPRIT algorithm for DOA estimation. Ambiguities arising from the model have also been analyzed, and solutions to them are provided. Simulation results verify the efficiency of this method.
2004, 26(8): 1232-1236.
Abstract:
In processing of array signal, Direction Of Arrival(DOA) of target can be ob-tained by extracting spatial frequency of echo. This article mainly proposes a new method of beam-forming using continuous wavelet transform. It is based on the traditional beam-forming method with STFT. In the paper, the theory frames and the simulation results are given. Prom the results it can be concluded that, the method based on WT is more effective than that on STPT. This effect is determined by the advantages of wavelet transform in time-frequency analysis.
In processing of array signal, Direction Of Arrival(DOA) of target can be ob-tained by extracting spatial frequency of echo. This article mainly proposes a new method of beam-forming using continuous wavelet transform. It is based on the traditional beam-forming method with STFT. In the paper, the theory frames and the simulation results are given. Prom the results it can be concluded that, the method based on WT is more effective than that on STPT. This effect is determined by the advantages of wavelet transform in time-frequency analysis.
2004, 26(8): 1237-1244.
Abstract:
So far many fruitful results have been obtained for stability of equilibrium points of Bidirectional Associative Memory (BAM) neural networks with axonal signal transmission delays (DBAM). A novel neural network model named as Standard Neural Network Model (SNNM) is advanced. By using state affine transformation, the DBAM neural networks arc converted to SNNMs with time delays (DSNNMs). Based on some results of DSNNMs stability, some sufficient conditions for the globally asymptotical stability of DBAM neural networks are derived, which are formulated as linear matrix inequalities (LMIs), which can be verified easily and whose conservativeness is lower. The approach proposed extends the known stability results, and can also be applied to other forms of Recurrent Neural Networks (RNNs) with (or without) time delays.
So far many fruitful results have been obtained for stability of equilibrium points of Bidirectional Associative Memory (BAM) neural networks with axonal signal transmission delays (DBAM). A novel neural network model named as Standard Neural Network Model (SNNM) is advanced. By using state affine transformation, the DBAM neural networks arc converted to SNNMs with time delays (DSNNMs). Based on some results of DSNNMs stability, some sufficient conditions for the globally asymptotical stability of DBAM neural networks are derived, which are formulated as linear matrix inequalities (LMIs), which can be verified easily and whose conservativeness is lower. The approach proposed extends the known stability results, and can also be applied to other forms of Recurrent Neural Networks (RNNs) with (or without) time delays.
2004, 26(8): 1245-1249.
Abstract:
High Performance Computing (HPC) system is an important part of a modern SAR processing system. SAR imaging has its specific characteristics compared with other HPC problems. It performs with great difference on different HPC architectures. The effects on SAR imaging performance by every part of the HPC architecture are analyzed on this paper. Based on this analysis, some benchmarking could be made to more accurately predict the SAR imaging performance on a multi-nodes environment. Prom these benchmarks, the effective way to optimize the SAR imaging could be found.
High Performance Computing (HPC) system is an important part of a modern SAR processing system. SAR imaging has its specific characteristics compared with other HPC problems. It performs with great difference on different HPC architectures. The effects on SAR imaging performance by every part of the HPC architecture are analyzed on this paper. Based on this analysis, some benchmarking could be made to more accurately predict the SAR imaging performance on a multi-nodes environment. Prom these benchmarks, the effective way to optimize the SAR imaging could be found.
2004, 26(8): 1250-1255.
Abstract:
A method of simulating distributed targets raw data of spaceborne SAR is given. Based on the theory of Kirchhoff approach and facet, the algorithm of computing the facets backscatter coefficients is discussed. Then the echo signal model of the distributed target consisted of facets is introduced. And the method and whole procedure of simulating distributed targets raw data are described. After the analysis of the compressed image of raw data simulated, the conclusion can be reached that the method of simulating raw data of distributed target is right.
A method of simulating distributed targets raw data of spaceborne SAR is given. Based on the theory of Kirchhoff approach and facet, the algorithm of computing the facets backscatter coefficients is discussed. Then the echo signal model of the distributed target consisted of facets is introduced. And the method and whole procedure of simulating distributed targets raw data are described. After the analysis of the compressed image of raw data simulated, the conclusion can be reached that the method of simulating raw data of distributed target is right.
2004, 26(8): 1256-1261.
Abstract:
For Ultra WideBand (UWB) communication technology, the design of Time-Hopping (TH) sequences is a critical point and good TPI correlation property is desired. In this paper, through analyzing TH correlation property, the TH correlation function is defined. Based on the definition, the limits of TH correlation property are obtained, and the-relation between TH correlation function and Frequency-Hopping (FH) correlation function is derived. In addition, this paper presents a method that improves TH correlation property.
For Ultra WideBand (UWB) communication technology, the design of Time-Hopping (TH) sequences is a critical point and good TPI correlation property is desired. In this paper, through analyzing TH correlation property, the TH correlation function is defined. Based on the definition, the limits of TH correlation property are obtained, and the-relation between TH correlation function and Frequency-Hopping (FH) correlation function is derived. In addition, this paper presents a method that improves TH correlation property.
2004, 26(8): 1269-1275.
Abstract:
Low-Density Parity-Check (LDPC) codes are a class of channel codes based on graphs and iterative decoding whose performance is very close to the Shannon limit with low complexity and have strong error control strength. In this paper, encoding and decoding principles of LDPC codes are deeply studied. At the same time, this coding scheme is applied in image transmission system over Rayieigh fading channel. The simulation results indicate that LDPC codes can make the quality of the image highly improved with rather low system complexity and short decoding time delay.
Low-Density Parity-Check (LDPC) codes are a class of channel codes based on graphs and iterative decoding whose performance is very close to the Shannon limit with low complexity and have strong error control strength. In this paper, encoding and decoding principles of LDPC codes are deeply studied. At the same time, this coding scheme is applied in image transmission system over Rayieigh fading channel. The simulation results indicate that LDPC codes can make the quality of the image highly improved with rather low system complexity and short decoding time delay.
2004, 26(8): 1276-1281.
Abstract:
In spread spectrum system, frequency-domain interference suppression algo-rithms always use data windows to reduce the spectral leakage associated with truncation, and employ overlap to lessen the SNR degradation due to windowing. In this paper, the windowing degradation and the data composing are studied. An improved method has been put forward to compose the data after overlap based on Capozzas(2000) method. The ana-lyzed and simulated results show that the new method leads to a less SNR degradation than Capozzas method at the cost of a few more addition.
In spread spectrum system, frequency-domain interference suppression algo-rithms always use data windows to reduce the spectral leakage associated with truncation, and employ overlap to lessen the SNR degradation due to windowing. In this paper, the windowing degradation and the data composing are studied. An improved method has been put forward to compose the data after overlap based on Capozzas(2000) method. The ana-lyzed and simulated results show that the new method leads to a less SNR degradation than Capozzas method at the cost of a few more addition.
2004, 26(8): 1282-1287.
Abstract:
Multiple outputs logic function is an important tool for constructing cryptog-raphy systems, and correlation immunity is a critical criterion in designing secure logic functions. In this paper, a very simple method is used to prove that two descriptions of cor-relation immunity of multiple outputs logic function are equivalent indeed. The correlation properties of a kind of keystream generator are analyzed, which is defined by multiple out-puts logic functions. It is found that this constructing method is wrong, which means that the immunity expected by the construction cannot be obtained. Walsh transform technique and linear sequential circuit approximation method are applied to find the weakness of this kind keystream generator respectively. That is to say the keystream generator constructed by this method is vulnerable.
Multiple outputs logic function is an important tool for constructing cryptog-raphy systems, and correlation immunity is a critical criterion in designing secure logic functions. In this paper, a very simple method is used to prove that two descriptions of cor-relation immunity of multiple outputs logic function are equivalent indeed. The correlation properties of a kind of keystream generator are analyzed, which is defined by multiple out-puts logic functions. It is found that this constructing method is wrong, which means that the immunity expected by the construction cannot be obtained. Walsh transform technique and linear sequential circuit approximation method are applied to find the weakness of this kind keystream generator respectively. That is to say the keystream generator constructed by this method is vulnerable.
2004, 26(8): 1288-1293.
Abstract:
Verifiable secret sharing widely applies in the areas such as safeguarding and legal use of confidential information, key escrow, group oriented cryptography, secured mul-tiparty computation, access control and electronic commerce. In this paper, the problem of verifiable secret sharing on vector space access structures is studied. An information-theoretical secure verifiable secret sharing protocol on this kind of access structures is pro-posed. Compared with generalized verifiable secret sharing protocols available, the newly proposed protocol has not only a higher information rate, but also a far lower cost of com-putation and communication.
Verifiable secret sharing widely applies in the areas such as safeguarding and legal use of confidential information, key escrow, group oriented cryptography, secured mul-tiparty computation, access control and electronic commerce. In this paper, the problem of verifiable secret sharing on vector space access structures is studied. An information-theoretical secure verifiable secret sharing protocol on this kind of access structures is pro-posed. Compared with generalized verifiable secret sharing protocols available, the newly proposed protocol has not only a higher information rate, but also a far lower cost of com-putation and communication.
2004, 26(8): 1294-1299.
Abstract:
In this paper, combining both neural networks and fuzzy systems merits, a chaotic sequence generation model is proposed and constructed on the basis of Adaptive Neural Fuzzy Inference System(ANPIS) firstly. Its basic system parameters are adjusted by genetic algorithm. The correlation property and balance performance of chaotic sequences generated by this model is tested. The result shows performances of these chaotic sequences are as good as, or better than that of chaotic sequences directly by chaotic map, which possess very high complexity and suit to act as spread-spectrum communication applications pseudo code.
In this paper, combining both neural networks and fuzzy systems merits, a chaotic sequence generation model is proposed and constructed on the basis of Adaptive Neural Fuzzy Inference System(ANPIS) firstly. Its basic system parameters are adjusted by genetic algorithm. The correlation property and balance performance of chaotic sequences generated by this model is tested. The result shows performances of these chaotic sequences are as good as, or better than that of chaotic sequences directly by chaotic map, which possess very high complexity and suit to act as spread-spectrum communication applications pseudo code.
2004, 26(8): 1300-1305.
Abstract:
By extending MPAS technology to subcarrier domain, a novel broadband op-tical network scheme to fuse TV networks and optical internet with high efficiency-multi-protocol subcarrier/lambda label switching networks based on subcarrier label and switching interfaces, is proposed. By utilizing new compound label and basing on two-layer subcar-rier/lambda switching frame, a multi-layer dynamic Traffic Engineering(TE) and a flexible QoS guarantee are realized, which use wavelengths in a economical way. The structure of two-layer label switching router and its performance are analyzed and some key problems facing by this scheme and related solutions are presented.
By extending MPAS technology to subcarrier domain, a novel broadband op-tical network scheme to fuse TV networks and optical internet with high efficiency-multi-protocol subcarrier/lambda label switching networks based on subcarrier label and switching interfaces, is proposed. By utilizing new compound label and basing on two-layer subcar-rier/lambda switching frame, a multi-layer dynamic Traffic Engineering(TE) and a flexible QoS guarantee are realized, which use wavelengths in a economical way. The structure of two-layer label switching router and its performance are analyzed and some key problems facing by this scheme and related solutions are presented.
2004, 26(8): 1306-1311.
Abstract:
DCF performs unfairly within multi-rate wireless LAN. Higher rate stations occupy channel for less time, and they can only obtain the same throughput as lower rate stations. This paper presents fair-time-share MDCF, which sets different initial contention windows for stations with different rates. Theoretical analysis and simulation results both show that MDCF can greatly improve the time-fairness and throughput of multi-rate wireless LAN.
DCF performs unfairly within multi-rate wireless LAN. Higher rate stations occupy channel for less time, and they can only obtain the same throughput as lower rate stations. This paper presents fair-time-share MDCF, which sets different initial contention windows for stations with different rates. Theoretical analysis and simulation results both show that MDCF can greatly improve the time-fairness and throughput of multi-rate wireless LAN.
2004, 26(8): 1312-1318.
Abstract:
To improve the spectral efficiency for wireless data transmissions, a subband-by-subband adaptive turbo coded modulation scheme based on capacity evaluation is proposed for Orthogonal Frequency Division Multiplexing (OFDM). The target is to optimize the overall throughput under constant transmit power and target Bit-Error-Rate (BER). Sim-ulation results show that the adaptive OFDM scheme exhibits a 2.5~5 dB Signal to Noise Ratio (SNR) gain relative to fixed threshold adaptive turbo coded modulation when the transmitter knows the perfect channel information. However, the adaptation performance is degraded due to the feedback delay in time-varying channels. Then, the investigation indicates that decreasing the amounts of subbands, and utilizing the diversity characteristic adequately in frequency domain of OFDM is an effective approach to reduce the performance degradation.
To improve the spectral efficiency for wireless data transmissions, a subband-by-subband adaptive turbo coded modulation scheme based on capacity evaluation is proposed for Orthogonal Frequency Division Multiplexing (OFDM). The target is to optimize the overall throughput under constant transmit power and target Bit-Error-Rate (BER). Sim-ulation results show that the adaptive OFDM scheme exhibits a 2.5~5 dB Signal to Noise Ratio (SNR) gain relative to fixed threshold adaptive turbo coded modulation when the transmitter knows the perfect channel information. However, the adaptation performance is degraded due to the feedback delay in time-varying channels. Then, the investigation indicates that decreasing the amounts of subbands, and utilizing the diversity characteristic adequately in frequency domain of OFDM is an effective approach to reduce the performance degradation.
2004, 26(8): 1319-1324.
Abstract:
The frequency source in Global Positioning System (GPS) receiver has a great many influence on the whole performance of the receiver. Based on the analysis of error characteristics and performance effect of the mostly used crystal oscillator, a method to simulate the frequency error of crystal oscillator is proposed. The major idea is to determine the Allan variance parameter of each main stochastic error component at the given sampling interval at first, then to deduct a set of corresponding frequency error series and superpose them together. The computer numerical simulation approach and the experimental results are given. This research provides related both theoretical reference and practical design for the development of an integrated design, test and evaluation platform such as a GPS signal simulator.
The frequency source in Global Positioning System (GPS) receiver has a great many influence on the whole performance of the receiver. Based on the analysis of error characteristics and performance effect of the mostly used crystal oscillator, a method to simulate the frequency error of crystal oscillator is proposed. The major idea is to determine the Allan variance parameter of each main stochastic error component at the given sampling interval at first, then to deduct a set of corresponding frequency error series and superpose them together. The computer numerical simulation approach and the experimental results are given. This research provides related both theoretical reference and practical design for the development of an integrated design, test and evaluation platform such as a GPS signal simulator.
2004, 26(8): 1325-1331.
Abstract:
A novel current-mode CMOS parallel structure is proposed. This parallel switch structure allows current-mode CMOS circuits to perform under lower source voltage which makes low power consuming possible. Beside, the current-mode circuits based on the pro-posed parallel structure have smaller propagation delay time than its counterpart which use cascade switches under the same source voltage. PSPICE simulation proves that circuits designed with the proposed structure can perform under low source voltage while holding short propagation delay time.
A novel current-mode CMOS parallel structure is proposed. This parallel switch structure allows current-mode CMOS circuits to perform under lower source voltage which makes low power consuming possible. Beside, the current-mode circuits based on the pro-posed parallel structure have smaller propagation delay time than its counterpart which use cascade switches under the same source voltage. PSPICE simulation proves that circuits designed with the proposed structure can perform under low source voltage while holding short propagation delay time.
2004, 26(8): 1332-1339.
Abstract:
Quantum Neural Networks (QNN) is a promising area which integrates Arti-ficial Neural Netowrk(ANN) with quantum computing. The field of QNN is discussed, in particular, the motivation of ANN towards QNN, the advantages and the possible candi-dates for the implementation of QNN. Several QNN models are introduced in details and their architecture, learning algorithms and some properties are explored. The applications to pattern recognition, computing entanglement and multivariable functions approximation are analyzed.
Quantum Neural Networks (QNN) is a promising area which integrates Arti-ficial Neural Netowrk(ANN) with quantum computing. The field of QNN is discussed, in particular, the motivation of ANN towards QNN, the advantages and the possible candi-dates for the implementation of QNN. Several QNN models are introduced in details and their architecture, learning algorithms and some properties are explored. The applications to pattern recognition, computing entanglement and multivariable functions approximation are analyzed.
2004, 26(8): 1340-1344.
Abstract:
The fair exchange protocols are classified. Based on publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchange protocol with an off-line Semi-Trusted Third Party(off-STTP) is presented. The off-STTP intervenes into the exchange in case of problems. That the off-STTP can decipher a sub-secret key makes sure the confidentiality of exchange data and the true fairness of the barter. The participants can barter with others at their will and the exchange topology is unknown to others including the off-STTP.
The fair exchange protocols are classified. Based on publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchange protocol with an off-line Semi-Trusted Third Party(off-STTP) is presented. The off-STTP intervenes into the exchange in case of problems. That the off-STTP can decipher a sub-secret key makes sure the confidentiality of exchange data and the true fairness of the barter. The participants can barter with others at their will and the exchange topology is unknown to others including the off-STTP.
2004, 26(8): 1262-1268.
Abstract:
A twice-correlate code-acquisition circuit and a rapid acquisition algorithm are proposed according to the characteristics of multi-code and time-limited acquisition for Phys-ical Random Access Channel (PRACH) preamble part in WCDMA reverse link. Compared with the conventional matched-filter and parallel acquisition methods, this scheme has lower complexity with fast series correlate calculation for multiple codes in the fcwice-correlate cir-cuit. The proposed acquisition algorithm uses the information of multiple paths to achieve higher detection probability in multi-path fading environments than that in single patli fad-ing channel. Performance analysis with theory expressions and numerical results is provided.
A twice-correlate code-acquisition circuit and a rapid acquisition algorithm are proposed according to the characteristics of multi-code and time-limited acquisition for Phys-ical Random Access Channel (PRACH) preamble part in WCDMA reverse link. Compared with the conventional matched-filter and parallel acquisition methods, this scheme has lower complexity with fast series correlate calculation for multiple codes in the fcwice-correlate cir-cuit. The proposed acquisition algorithm uses the information of multiple paths to achieve higher detection probability in multi-path fading environments than that in single patli fad-ing channel. Performance analysis with theory expressions and numerical results is provided.
