ISSN 
2012 Vol. 41, No. 3
2012, 41(3): 322-335.
doi: 10.3969/j.issn.1001-0548.2012.03.001
Abstract:
In this paper we present a very expressive fuzzy description logic framework, L-SROIQ(D), based on certainty lattices, which is a fuzzy extension of the description logic SROIQ(D) (theoretical basis of the ontology language OWL 2). Some logical properties of L-SROIQ(D) are researched and the decidability of L-SROIQ(D) is proved in case of linearly ordered lattices.
In this paper we present a very expressive fuzzy description logic framework, L-SROIQ(D), based on certainty lattices, which is a fuzzy extension of the description logic SROIQ(D) (theoretical basis of the ontology language OWL 2). Some logical properties of L-SROIQ(D) are researched and the decidability of L-SROIQ(D) is proved in case of linearly ordered lattices.
2012, 41(3): 336-341.
doi: 10.3969/j.issn.1001-0548.2012.03.002
Abstract:
This paper presents a new method in structure learning of Bayesian network based on dependency analysis and scoring function. Through analyzing the dependent relationship between variables and accessing to undirected graph, the prior sequence of all of the nodes in Bayesian network structure is obtained. The optimal structure of the Bayesian network is then generated by heuristic-search method. The new algorithm has been applied to the diagnostic system of mild cognitive impairment. The experimental results show that the new algorithm can better predict the possibility of mild cognitive impairment under the similar complexity, and further assist the diagnosis of doctor.
This paper presents a new method in structure learning of Bayesian network based on dependency analysis and scoring function. Through analyzing the dependent relationship between variables and accessing to undirected graph, the prior sequence of all of the nodes in Bayesian network structure is obtained. The optimal structure of the Bayesian network is then generated by heuristic-search method. The new algorithm has been applied to the diagnostic system of mild cognitive impairment. The experimental results show that the new algorithm can better predict the possibility of mild cognitive impairment under the similar complexity, and further assist the diagnosis of doctor.
2012, 41(3): 342-347.
doi: 10.3969/j.issn.1001-0548.2012.03.003
Abstract:
Considering the small synchronization range of code-aided (CA) carrier recovery algorithms at low signal to noise ratio (SNR), a pilot-code joint assisted carrier synchronization algorithm is proposed. Firstly, through analyzing the impact of pilot structure on synchronization range and accuracy of coarse estimation, a new algorithm for estimating pilot structure and coarse frequency offset is proposed and its mean squared error (MSE) is also derived. And then a pilot-code joint assisted synchronization with large synchronization range and high estimation accuracy is achieved by using pilot symbols with simplified expectation maximization (EM) fine synchronization. Simulations verify that the new algorithm can increase synchronization range greatly without accuracy decrease, which can achieve perfect synchronization with a certain amount of pilot symbols.
Considering the small synchronization range of code-aided (CA) carrier recovery algorithms at low signal to noise ratio (SNR), a pilot-code joint assisted carrier synchronization algorithm is proposed. Firstly, through analyzing the impact of pilot structure on synchronization range and accuracy of coarse estimation, a new algorithm for estimating pilot structure and coarse frequency offset is proposed and its mean squared error (MSE) is also derived. And then a pilot-code joint assisted synchronization with large synchronization range and high estimation accuracy is achieved by using pilot symbols with simplified expectation maximization (EM) fine synchronization. Simulations verify that the new algorithm can increase synchronization range greatly without accuracy decrease, which can achieve perfect synchronization with a certain amount of pilot symbols.
2012, 41(3): 348-354.
doi: 10.3969/j.issn.1001-0548.2012.03.004
Abstract:
A new kind of improved two-step approach for underdetermined blind separation of dynamic sources and mixing matrix is proposed in the paper. Firstly, the change time of the mixing matrix is estimated based on planar minimum offset angle of sparse domain. The mixing matrix is then estimated and the dynamic number of sources is determined. Secondly, the source signals are recovered by pseudo extraction vector method, and the underdetermined blind separation of source signals is achieved by applying linear programming method. Results show that not only the proposed method can accomplish underdetermined blind separation of dynamic sources and mixing matrix but also its velocity of separation is ten times of the methods based on linear programming.
A new kind of improved two-step approach for underdetermined blind separation of dynamic sources and mixing matrix is proposed in the paper. Firstly, the change time of the mixing matrix is estimated based on planar minimum offset angle of sparse domain. The mixing matrix is then estimated and the dynamic number of sources is determined. Secondly, the source signals are recovered by pseudo extraction vector method, and the underdetermined blind separation of source signals is achieved by applying linear programming method. Results show that not only the proposed method can accomplish underdetermined blind separation of dynamic sources and mixing matrix but also its velocity of separation is ten times of the methods based on linear programming.
2012, 41(3): 355-358.
doi: 10.3969/j.issn.1001-0548.2012.03.005
Abstract:
The opportunistic beamforming system can achieve the same throughput with channel singular value decomposition, and doesn't need perfect channel-state information. Opportunistic multi-beamforming improve system throughput by transmitting orthogonal beam, when increasing transmit beam number, the space-reuse gain will improve and the interference between beams will increase, which is contradict. To obtain the optimum number of transmitting beams, the paper analyze the throughput of MISO opportunistic beamforming system's capacity when adopt different number of transmitting beams. The results show that the optimum transmitting beam number is increased with users number, decreased with the average SNR.
The opportunistic beamforming system can achieve the same throughput with channel singular value decomposition, and doesn't need perfect channel-state information. Opportunistic multi-beamforming improve system throughput by transmitting orthogonal beam, when increasing transmit beam number, the space-reuse gain will improve and the interference between beams will increase, which is contradict. To obtain the optimum number of transmitting beams, the paper analyze the throughput of MISO opportunistic beamforming system's capacity when adopt different number of transmitting beams. The results show that the optimum transmitting beam number is increased with users number, decreased with the average SNR.
2012, 41(3): 359-363.
doi: 10.3969/j.issn.1001-0548.2012.03.006
Abstract:
A new adaptive Kalman filtering algorithm is presented. The new algorithm assumes that the variance relationship between process noise and measurement noise is known, but both kinds of variance are unknown and varying with time. At first, let the process noise variance at the current time point be equal to that at the prior time point. Applying the method of variational Bayesian approximation, the measurement noise variance and state estimation are solved under the framework of Kalman filter, and then a new process noise variance is obtained via the function relationship. After the process above is implemented for some runs, the final state estimation and covariance are obtained. Experimental results show that the new algorithm has higher accuracy; Furthermore, the new algorithm still has strong robustness when the assumption is uncertain.
A new adaptive Kalman filtering algorithm is presented. The new algorithm assumes that the variance relationship between process noise and measurement noise is known, but both kinds of variance are unknown and varying with time. At first, let the process noise variance at the current time point be equal to that at the prior time point. Applying the method of variational Bayesian approximation, the measurement noise variance and state estimation are solved under the framework of Kalman filter, and then a new process noise variance is obtained via the function relationship. After the process above is implemented for some runs, the final state estimation and covariance are obtained. Experimental results show that the new algorithm has higher accuracy; Furthermore, the new algorithm still has strong robustness when the assumption is uncertain.
2012, 41(3): 364-367.
doi: 10.3969/j.issn.1001-0548.2012.03.007
Abstract:
This paper first demonstrats that signal subspace has finite dimensions from signal model. A conclusion is obtained by simulation test that both eigenvalues of signal subspace and noise subspace can't be evaluated precisely due to small size data. Then signal subspace dimensions are estimated accurately with Modified-AIC criterion using likelihood function depending only on noise space eigenvalues. A new robust SNR estimation method is proposed with the application of modified-AIC criterion. Regarding a variety of SNR and data size, simulation results show that the new method can be applied in lower SNR and shorter data samples environment.
This paper first demonstrats that signal subspace has finite dimensions from signal model. A conclusion is obtained by simulation test that both eigenvalues of signal subspace and noise subspace can't be evaluated precisely due to small size data. Then signal subspace dimensions are estimated accurately with Modified-AIC criterion using likelihood function depending only on noise space eigenvalues. A new robust SNR estimation method is proposed with the application of modified-AIC criterion. Regarding a variety of SNR and data size, simulation results show that the new method can be applied in lower SNR and shorter data samples environment.
2012, 41(3): 368-372.
doi: 10.3969/j.issn.1001-0548.2012.03.008
Abstract:
An approach of wideband beamforming to achieve accurate beam direction was pursued by the designers of the wideband digital array radar. According to the characteristics of the wideband digital array radar sampling in the Radio Frequency(RF) part, a real time and efficient digital time delay beam forming method based on the Variable Fractional Delay (VFD) filter is presented. The method proposes that the VFD filter can be integrated with the decimation anti-aliasing filter to design a dual-purpose filter and reduce the processing modules, and the polyphase structure is combined with the Farrow Structure to configure the key filter proposed above. This approach can realize the decimation and variable fractional delay in real time and achieve the accurate beam direction, which isn't affected when the signal frequency varies. The computer simulation result shows that, compared with unit delay beamforming approach, this optimized approach can improve the beam pointing accuracy effectively.
An approach of wideband beamforming to achieve accurate beam direction was pursued by the designers of the wideband digital array radar. According to the characteristics of the wideband digital array radar sampling in the Radio Frequency(RF) part, a real time and efficient digital time delay beam forming method based on the Variable Fractional Delay (VFD) filter is presented. The method proposes that the VFD filter can be integrated with the decimation anti-aliasing filter to design a dual-purpose filter and reduce the processing modules, and the polyphase structure is combined with the Farrow Structure to configure the key filter proposed above. This approach can realize the decimation and variable fractional delay in real time and achieve the accurate beam direction, which isn't affected when the signal frequency varies. The computer simulation result shows that, compared with unit delay beamforming approach, this optimized approach can improve the beam pointing accuracy effectively.
2012, 41(3): 373-377.
doi: 10.3969/j.issn.1001-0548.2012.03.009
Abstract:
To study the scattering mechanism of radar terrain returned in vertical incidence region, an experimental program to measure the scattering coefficients of terrain including farmland and sand in vertical incidence region was carried out by using S and 8mm Linear Frequency Modulated Continuous Wave Radar scatterometers. A terrain scattering return database connected with radar frequency, altitude, antenna pattern, incidence angle, and the roughness and permittivity of ground surface was established. The return data processing approach is provided, the theoretical scattering model of rough terrain surface is derived, and then the measured data is fitted by the model. The experimental results show that the measured scattering coefficients agree with the given model, the radar cross section per unit area at vertical incidence of sand is 2~3dB larger than that of farmland, and the scattering coefficients at 8mm is 18~20dB larger than that at S frequency-band.
To study the scattering mechanism of radar terrain returned in vertical incidence region, an experimental program to measure the scattering coefficients of terrain including farmland and sand in vertical incidence region was carried out by using S and 8mm Linear Frequency Modulated Continuous Wave Radar scatterometers. A terrain scattering return database connected with radar frequency, altitude, antenna pattern, incidence angle, and the roughness and permittivity of ground surface was established. The return data processing approach is provided, the theoretical scattering model of rough terrain surface is derived, and then the measured data is fitted by the model. The experimental results show that the measured scattering coefficients agree with the given model, the radar cross section per unit area at vertical incidence of sand is 2~3dB larger than that of farmland, and the scattering coefficients at 8mm is 18~20dB larger than that at S frequency-band.
2012, 41(3): 378-383.
doi: 10.3969/j.issn.1001-0548.2012.03.010
Abstract:
One-step system based on the semi-implicit Runge-Kutta method and simple iteration is designed for simplifying computation and avoiding the distortion of simulation results caused by shock response in solving a set of nonlinear coupled equations of fiber Bragg grating (FBG). The feasibility of the design is verified by comparing with other calculation methods and experimental results. The computational workload is greatly reduced when the same accuracy is required in simulating. Unified numerical simulation model based on physical process of optical wave transmission in grating is established under static and dynamic circumstances. Smoothing skills in simulation are researched. Nonlinear transmission characteristics of FBGs are studied numerically when continuous wave (CW) and pulse were input. The results show that the switching threshold power of phase-shift grating is lower than of uniform grating and all-optically tuned delay can be achieved by nonlinear effect in fiber Bragg grating.
One-step system based on the semi-implicit Runge-Kutta method and simple iteration is designed for simplifying computation and avoiding the distortion of simulation results caused by shock response in solving a set of nonlinear coupled equations of fiber Bragg grating (FBG). The feasibility of the design is verified by comparing with other calculation methods and experimental results. The computational workload is greatly reduced when the same accuracy is required in simulating. Unified numerical simulation model based on physical process of optical wave transmission in grating is established under static and dynamic circumstances. Smoothing skills in simulation are researched. Nonlinear transmission characteristics of FBGs are studied numerically when continuous wave (CW) and pulse were input. The results show that the switching threshold power of phase-shift grating is lower than of uniform grating and all-optically tuned delay can be achieved by nonlinear effect in fiber Bragg grating.
2012, 41(3): 384-387.
doi: 10.3969/j.issn.1001-0548.2012.03.011
Abstract:
This paper reported a new kind of micro fiber ring resonator (MFR) temperature sensor. Due to its sub-wavelength diameter, the micro fiber ring resonator has a high Q factor, and hence it can be used for high-precision optical sensing and measurement. The refractive index of the MFR varies with temperature, which can be detected by measuring its change in optical spectrum. Experimental results show that the temperature sensitivity of the MNFR is~19 pm/℃ within 20℃~30℃. Such a type of MFR temperature sensors has the advantages of very simple fabrication, extremely small size, quite low cost, and easy to be integrated, et al.
This paper reported a new kind of micro fiber ring resonator (MFR) temperature sensor. Due to its sub-wavelength diameter, the micro fiber ring resonator has a high Q factor, and hence it can be used for high-precision optical sensing and measurement. The refractive index of the MFR varies with temperature, which can be detected by measuring its change in optical spectrum. Experimental results show that the temperature sensitivity of the MNFR is~19 pm/℃ within 20℃~30℃. Such a type of MFR temperature sensors has the advantages of very simple fabrication, extremely small size, quite low cost, and easy to be integrated, et al.
Non-Contact Detecting Method of the Stability of Switching Power by Using Magnetic Leakage Radiation
2012, 41(3): 388-391.
doi: 10.3969/j.issn.1001-0548.2012.03.012
Abstract:
Aiming at solving the problem of the complicated tests of the stability of switching power supplies, a non-contact testing method of qualitative analysis for the stability of switching power supplies is presented. Several issues are discussed, including the stable principles of switching power closed-loop model, the coil model, and the radiation signal processing, etc. Coil is utilized to detect magnetic leakage radiation of magnetic elements of switching power, and the stability working information of switching power supplies is achieved via amplifying, transmitting and processing of the radiation signals. The validity of the methodology is verified by experiments.
Aiming at solving the problem of the complicated tests of the stability of switching power supplies, a non-contact testing method of qualitative analysis for the stability of switching power supplies is presented. Several issues are discussed, including the stable principles of switching power closed-loop model, the coil model, and the radiation signal processing, etc. Coil is utilized to detect magnetic leakage radiation of magnetic elements of switching power, and the stability working information of switching power supplies is achieved via amplifying, transmitting and processing of the radiation signals. The validity of the methodology is verified by experiments.
Hybrid Analysis for Electromagnetic Characteristics of Through Vias in Microwave Multilayer Circuits
2012, 41(3): 392-396.
doi: 10.3969/j.issn.1001-0548.2012.03.013
Abstract:
The single through-via structure can be divided into two parts, interior structure and the exterior structure, based on physical modeling. The improved matrix-penciled moment method (MPMM) is applied to the analysis of the exterior structure. The equivalent circuit method which takes into account the parallel plate effect is applied to the analysis of the interior structure for structural features. The scattering parameters of the complete structure are obtained by the microwave network cascade theory. The hybrid analysis method is verified by comparing with the commercial simulation software HFSS in different boundary conditions. The computational efficiency of the hybrid analysis method is improved five times faster than that of the commercial simulation software benefitting from the combination of the field analysis method and the circuit analysis method.
The single through-via structure can be divided into two parts, interior structure and the exterior structure, based on physical modeling. The improved matrix-penciled moment method (MPMM) is applied to the analysis of the exterior structure. The equivalent circuit method which takes into account the parallel plate effect is applied to the analysis of the interior structure for structural features. The scattering parameters of the complete structure are obtained by the microwave network cascade theory. The hybrid analysis method is verified by comparing with the commercial simulation software HFSS in different boundary conditions. The computational efficiency of the hybrid analysis method is improved five times faster than that of the commercial simulation software benefitting from the combination of the field analysis method and the circuit analysis method.
2012, 41(3): 401-404.
doi: 10.3969/j.issn.1001-0548.2012.03.015
Abstract:
Internal field emission breakdown in the electro-dynamic structures of high-power microwave devices can seriously limit the devices' output power and pulse duration. Increasing the diameter of the electro-dynamic structure beyond the cut-off radius can reduce these internal fields to below critical breakdown levels, but may introduce mode competition as unwanted side effects. An over-sized backward wave oscillator with rectangular profile corrugations is designed to produce TM01 high power microwave radiation without mode-competition. The slow wave structure and the reflector are matched to achieve mode selection and enhance interaction efficiency. The physical mechanism for mode selection is explored both in theoretical investigation and particle in cell simulation.
Internal field emission breakdown in the electro-dynamic structures of high-power microwave devices can seriously limit the devices' output power and pulse duration. Increasing the diameter of the electro-dynamic structure beyond the cut-off radius can reduce these internal fields to below critical breakdown levels, but may introduce mode competition as unwanted side effects. An over-sized backward wave oscillator with rectangular profile corrugations is designed to produce TM01 high power microwave radiation without mode-competition. The slow wave structure and the reflector are matched to achieve mode selection and enhance interaction efficiency. The physical mechanism for mode selection is explored both in theoretical investigation and particle in cell simulation.
2012, 41(3): 405-407.
doi: 10.3969/j.issn.1001-0548.2012.03.016
Abstract:
Based on the cluster approach, the high-order perturbation formulas for a 3d9 ion in tetragonal octahedral are established and applied to the studies of the spin Hamiltonian parameters of the g facts g|| and g⊥ and the hyperfine structure constants A|| and A⊥. In these formulas, the contributions to the g factors from the tetragonal distortion are characterized by the tetragonal field parameters DS and Dt. Since the spin Hamiltonian parameters are sensitive to the local structure of a paramagnetic impurity center, the defect structure of Cu2+ center in Ca(OD)2 crystal is estimated, the oxygen octahedron is found to undergo the local elongation ΔZ (0.008 3 nm) along the C4 axis. Based on the above local structure, the calculated results show good agreement with the experimental data, and the defect structure of Cu2+ center in Ca(OD)2 crystal.
Based on the cluster approach, the high-order perturbation formulas for a 3d9 ion in tetragonal octahedral are established and applied to the studies of the spin Hamiltonian parameters of the g facts g|| and g⊥ and the hyperfine structure constants A|| and A⊥. In these formulas, the contributions to the g factors from the tetragonal distortion are characterized by the tetragonal field parameters DS and Dt. Since the spin Hamiltonian parameters are sensitive to the local structure of a paramagnetic impurity center, the defect structure of Cu2+ center in Ca(OD)2 crystal is estimated, the oxygen octahedron is found to undergo the local elongation ΔZ (0.008 3 nm) along the C4 axis. Based on the above local structure, the calculated results show good agreement with the experimental data, and the defect structure of Cu2+ center in Ca(OD)2 crystal.
2012, 41(3): 408-411.
doi: 10.3969/j.issn.1001-0548.2012.03.017
Abstract:
In this paper, 3D symmetric computation algorithm with finite element method for electron optic system is presented. The symmetric boundary conditions for the electric field and the electron trajectories are derived in detail. The algorithm is implemented in electron optics simulator (EOS). The Comparison of symmetric computation and full computation shows that the symmetric computation can reduce the computational time and the computer memory effectively without decreasing the computational accuracy.
In this paper, 3D symmetric computation algorithm with finite element method for electron optic system is presented. The symmetric boundary conditions for the electric field and the electron trajectories are derived in detail. The algorithm is implemented in electron optics simulator (EOS). The Comparison of symmetric computation and full computation shows that the symmetric computation can reduce the computational time and the computer memory effectively without decreasing the computational accuracy.
2012, 41(3): 412-417.
doi: 10.3969/j.issn.1001-0548.2012.03.018
Abstract:
A fault diagnosis approach for analog circuits based on minimum spanning tree (MST) support vector machine (SVM) is proposed. Fault features of analog circuits are extracted by wavelet analysis method. By taking separability measure of fault classes as weights of edges in feature space, the MST is generated and the sub-class separation for fault groups with clustering property is achieved. The node distribution of fault decision tree is then optimized. Hierarchical multi-class SVMs with large margins are constituted according to the structure of MST, which can effectively improve the fault diagnosis accuracy of analog circuits. The presented approach simplifies the structure of multiclass SVMs. Case study shows that our approach achieves more precision and higher efficiency comparing with other conventional SVM methods in analog circuit fault diagnosis.
A fault diagnosis approach for analog circuits based on minimum spanning tree (MST) support vector machine (SVM) is proposed. Fault features of analog circuits are extracted by wavelet analysis method. By taking separability measure of fault classes as weights of edges in feature space, the MST is generated and the sub-class separation for fault groups with clustering property is achieved. The node distribution of fault decision tree is then optimized. Hierarchical multi-class SVMs with large margins are constituted according to the structure of MST, which can effectively improve the fault diagnosis accuracy of analog circuits. The presented approach simplifies the structure of multiclass SVMs. Case study shows that our approach achieves more precision and higher efficiency comparing with other conventional SVM methods in analog circuit fault diagnosis.
2012, 41(3): 418-423.
doi: 10.3969/j.issn.1001-0548.2012.03.019
Abstract:
A method to realize the sampling and reconstruction of the sparse signals is proposed in this paper based on minimum L1 normal. According to the feature of periodic non-uniform sampling that it needs multiple channels,the sampling and reconstruction of signals are transformed into matrix and vector operations by using theory of union of subspaces. Necessary condition of reconstruction is analyzed. Finally, taking multi-band sinusoidal signals as an example, we prove that the method can achieve the sampling and reconstruction of sparse signals.
A method to realize the sampling and reconstruction of the sparse signals is proposed in this paper based on minimum L1 normal. According to the feature of periodic non-uniform sampling that it needs multiple channels,the sampling and reconstruction of signals are transformed into matrix and vector operations by using theory of union of subspaces. Necessary condition of reconstruction is analyzed. Finally, taking multi-band sinusoidal signals as an example, we prove that the method can achieve the sampling and reconstruction of sparse signals.
2012, 41(3): 424-428.
doi: 10.3969/j.issn.1001-0548.2012.03.020
Abstract:
Prediction of the traffic mutation in network for mine monitoring can enhance quality of service (QoS) and reduce network congestion. In view of the characteristics of traffic in mine monitoring network, data acquisition (SCADA) information is selected as indicator of chaotic signal and Lyapunov exponent method is used to verify the chaotic characters of the indicator. Duffing oscillator is employed to calculate the amplitude of the critical threshold of the oscillator ad and a predicting model is constructed. The error between simulation results and real data is between ±0.036 632, validating the accuracy and reliability of the predicting method.
Prediction of the traffic mutation in network for mine monitoring can enhance quality of service (QoS) and reduce network congestion. In view of the characteristics of traffic in mine monitoring network, data acquisition (SCADA) information is selected as indicator of chaotic signal and Lyapunov exponent method is used to verify the chaotic characters of the indicator. Duffing oscillator is employed to calculate the amplitude of the critical threshold of the oscillator ad and a predicting model is constructed. The error between simulation results and real data is between ±0.036 632, validating the accuracy and reliability of the predicting method.
2012, 41(3): 429-434.
doi: 10.3969/j.issn.1001-0548.2012.03.021
Abstract:
The next generation automotive electronics architecture defines ECU software architecture and new development process. Runtime environment is critical to implement the above purposes. Based on the research of AUTOSAR virtual functional bus communication semantics, combining the requirements of application deployment, the communication problem of runtime environment in the next generation architecture is proposed and its corresponding algorithms are designed. The experimental results show that the designed communication algorithms implement all the communication semantics of virtual function bus.
The next generation automotive electronics architecture defines ECU software architecture and new development process. Runtime environment is critical to implement the above purposes. Based on the research of AUTOSAR virtual functional bus communication semantics, combining the requirements of application deployment, the communication problem of runtime environment in the next generation architecture is proposed and its corresponding algorithms are designed. The experimental results show that the designed communication algorithms implement all the communication semantics of virtual function bus.
2012, 41(3): 435-440.
doi: 10.3969/j.issn.1001-0548.2012.03.022
Abstract:
In the real world many data sources exist in the form of tensor, so the learning algorithm based on tensor space can describe the semantic information of data sources better. This paper presents a new tensor correlation analysis algorithm, with which we can directly analyze the tensor data. Because of the large reduction of the dimension of eigenvalue decomposition covariance matrix, the algorithm can effectively reduce the computing complexity and avoid the covariance matrix singular problem. The effectiveness of this method can be proved at YALE, ORL face database.
In the real world many data sources exist in the form of tensor, so the learning algorithm based on tensor space can describe the semantic information of data sources better. This paper presents a new tensor correlation analysis algorithm, with which we can directly analyze the tensor data. Because of the large reduction of the dimension of eigenvalue decomposition covariance matrix, the algorithm can effectively reduce the computing complexity and avoid the covariance matrix singular problem. The effectiveness of this method can be proved at YALE, ORL face database.
2012, 41(3): 441-446.
doi: 10.3969/j.issn.1001-0548.2012.03.023
Abstract:
Considering that greedy routing may fail due to routing voids on random network topologies, greedy routing's deliverability is defined and studied in a typical hemi-sphere 3D sensor network deployment scenario. Based on nodes' distribution characteristics, the relationship between the sensor transmission radius and the probability of guaranteed delivery for greedy routing is analyzed. A very tight analytical upper bound on the sensor transmission radius to ensure the designed deliverability probability is derived, and the corresponding numerical solution of this upper bound is proposed. The correctness and tightness of the derived upper bound are verified by extensive simulations, and hence the results can be used to design the minimal transmission for actual sensor network deployment.
Considering that greedy routing may fail due to routing voids on random network topologies, greedy routing's deliverability is defined and studied in a typical hemi-sphere 3D sensor network deployment scenario. Based on nodes' distribution characteristics, the relationship between the sensor transmission radius and the probability of guaranteed delivery for greedy routing is analyzed. A very tight analytical upper bound on the sensor transmission radius to ensure the designed deliverability probability is derived, and the corresponding numerical solution of this upper bound is proposed. The correctness and tightness of the derived upper bound are verified by extensive simulations, and hence the results can be used to design the minimal transmission for actual sensor network deployment.
2012, 41(3): 447-452.
doi: 10.3969/j.issn.1001-0548.2012.03.024
Abstract:
To resolve the conflict within the massive rules in enterprise, this paper proposes a fast rule conflict-detection algorithm named multi_slot sub_bucket conflict cetection (MSSB) based on multi_slot and sub_bucket. It turns rule's complexity conflict detection into result of non-conflict rules in lineartime by the theorem of non-conflict. First, this research proposed the concepts of general rule's conflict and non-conflict, and proves three propositions and the theorem of non-conflict. Then it proposes the MSSB algorithm by the structure of Huffman tree and Triangular matrix. Extensive experiments over real data of Hub Airport show the effectiveness of new proposed MSSB algorithm. The average space complexity is decreased 33.6% and matching time is decreased 36.2% compared with traditional linear detection and policytree.
To resolve the conflict within the massive rules in enterprise, this paper proposes a fast rule conflict-detection algorithm named multi_slot sub_bucket conflict cetection (MSSB) based on multi_slot and sub_bucket. It turns rule's complexity conflict detection into result of non-conflict rules in lineartime by the theorem of non-conflict. First, this research proposed the concepts of general rule's conflict and non-conflict, and proves three propositions and the theorem of non-conflict. Then it proposes the MSSB algorithm by the structure of Huffman tree and Triangular matrix. Extensive experiments over real data of Hub Airport show the effectiveness of new proposed MSSB algorithm. The average space complexity is decreased 33.6% and matching time is decreased 36.2% compared with traditional linear detection and policytree.
2012, 41(3): 453-458.
doi: 10.3969/j.issn.1001-0548.2012.03.025
Abstract:
An intrusion detection gray space model is presented based on rough set theory. Information gain is used to equivalence rule discovery and reduction algorithm. As a result, a new intrusion detection model is designed. According to the analyses and validation based on KDDCUP 99, the experimental results show that the model is good for networks intrusion detection with simple classification rules, short detection time and high detection accuracy, and it overcomes the bottleneck that the detection system can not effectively determine the unknown behavior.
An intrusion detection gray space model is presented based on rough set theory. Information gain is used to equivalence rule discovery and reduction algorithm. As a result, a new intrusion detection model is designed. According to the analyses and validation based on KDDCUP 99, the experimental results show that the model is good for networks intrusion detection with simple classification rules, short detection time and high detection accuracy, and it overcomes the bottleneck that the detection system can not effectively determine the unknown behavior.
2012, 41(3): 459-462.
doi: 10.3969/j.issn.1001-0548.2012.03.026
Abstract:
Based on the similar structure and similar kernel function of the solutions for a type of boundary value problems of the composite normalized modified Bessel differential equation, a new algorithm, called similar constructive algorithm, is proposed for solving this type of boundary value problems. This algorithm is an algebraic method without the need of calculus operations, and therefore, it is an effective but simple approach to the studies of engineering and science problems.
Based on the similar structure and similar kernel function of the solutions for a type of boundary value problems of the composite normalized modified Bessel differential equation, a new algorithm, called similar constructive algorithm, is proposed for solving this type of boundary value problems. This algorithm is an algebraic method without the need of calculus operations, and therefore, it is an effective but simple approach to the studies of engineering and science problems.
2012, 41(3): 463-466.
doi: 10.3969/j.issn.1001-0548.2012.03.027
Abstract:
In this paper, the influence of thermally poling and corona charging on electric properties of PVDF films was investigated by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), ferroelectric hysteresis loops and leakage current measurement. The results showed that the ferroelectric properties of PVDF films were both improved by thermally poling and corona charging, but the leakage properties of PVDF films were distinct due to different poling temperatures, poling electric fields and poling times. With the effect of high electric field at high temperature in thermally poling, the dipoles were oriented along the direction of electric field completely, which caused more polar β crystalline transited from non-polar α crystalline. So it was found that the crystalline degree, β crystalline content and remanent polarization of thermally poled PVDF films were higher than those of corona charged PVDF films. The reason that caused leakage current was also analyzed. The space charges injected during the poling process were stored in the shallow traps of PVDF films for corona poling and in the deep traps for thermally poling, respectively. Therefore, the leakage current of corona poled PVDF was unstable than that of thermally poled PVDF films.
In this paper, the influence of thermally poling and corona charging on electric properties of PVDF films was investigated by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), ferroelectric hysteresis loops and leakage current measurement. The results showed that the ferroelectric properties of PVDF films were both improved by thermally poling and corona charging, but the leakage properties of PVDF films were distinct due to different poling temperatures, poling electric fields and poling times. With the effect of high electric field at high temperature in thermally poling, the dipoles were oriented along the direction of electric field completely, which caused more polar β crystalline transited from non-polar α crystalline. So it was found that the crystalline degree, β crystalline content and remanent polarization of thermally poled PVDF films were higher than those of corona charged PVDF films. The reason that caused leakage current was also analyzed. The space charges injected during the poling process were stored in the shallow traps of PVDF films for corona poling and in the deep traps for thermally poling, respectively. Therefore, the leakage current of corona poled PVDF was unstable than that of thermally poled PVDF films.
2012, 41(3): 467-470.
doi: 10.3969/j.issn.1001-0548.2012.03.028
Abstract:
The Ni/4H-SiC Schottky diode ionization radiation detector was fabricated and measured with different radiation sources. Under radiation from 63Ni and gamma-ray, the detectors show sensitive current response. After 1 Mrad(Si) gamma-ray radiation, the signal current has no obvious degradation. After 1 Mrad(Si) gamma-ray and 100 Mrad(Si) electron radiation respectively, the dark current of detectors under different radiation bias voltage has slightly degradation. The resluts show that Ni/4H-SiC Schottky diode ionization radiation detector has low dark current, high sensitivity and high radiation hardness and can be applied in high radiation environment for a long time.
The Ni/4H-SiC Schottky diode ionization radiation detector was fabricated and measured with different radiation sources. Under radiation from 63Ni and gamma-ray, the detectors show sensitive current response. After 1 Mrad(Si) gamma-ray radiation, the signal current has no obvious degradation. After 1 Mrad(Si) gamma-ray and 100 Mrad(Si) electron radiation respectively, the dark current of detectors under different radiation bias voltage has slightly degradation. The resluts show that Ni/4H-SiC Schottky diode ionization radiation detector has low dark current, high sensitivity and high radiation hardness and can be applied in high radiation environment for a long time.
2012, 41(3): 471-476.
doi: 10.3969/j.issn.1001-0548.2012.03.029
Abstract:
When using optimization techniques to solve non-rigid image registration, improper initial values often cause the optimization process to converge to a local minima and lead to a failed image registration. In order to solve this problem, we propose a new non-rigid image registration procedure which is guided by a pair of matched feature points. Firstly, an initial local region is determined according to the pair of matched feature points. Secondly, the local registration region expands gradually to cover the whole image as the optimization process continues. In the process that the initial local registration region is determined and expanded, the values of the deformation parameter vector are estimated according to the spatial locations of the matched feature point pair and the statistical prior that the deformation field is a Gaussian Markov random field (GMRF). The parameter vector of the deformation field in the local registration region is solved by using the registration method based on the image's intensity statistical information. Experimental results show that the proposed approach can effectively overcome the problem that the non-rigid registration method is liable to be trapped in a local minimum.
When using optimization techniques to solve non-rigid image registration, improper initial values often cause the optimization process to converge to a local minima and lead to a failed image registration. In order to solve this problem, we propose a new non-rigid image registration procedure which is guided by a pair of matched feature points. Firstly, an initial local region is determined according to the pair of matched feature points. Secondly, the local registration region expands gradually to cover the whole image as the optimization process continues. In the process that the initial local registration region is determined and expanded, the values of the deformation parameter vector are estimated according to the spatial locations of the matched feature point pair and the statistical prior that the deformation field is a Gaussian Markov random field (GMRF). The parameter vector of the deformation field in the local registration region is solved by using the registration method based on the image's intensity statistical information. Experimental results show that the proposed approach can effectively overcome the problem that the non-rigid registration method is liable to be trapped in a local minimum.
2012, 41(3): 477-480.
doi: 10.3969/j.issn.1001-0548.2012.03.030
Abstract:
The activity pattern in human visual cortex is studied and the common feature of volunteers is extracted based on analysis of regions of interest (ROI). By combining physiological structure and Talairach coordinates system, the same ROIs are obtained from the three-dimensional cortical model of each volunteer, these ROIs is then projected into the two-dimensional cortical model with the same topology, and the maximum activation intensity of each ROI is extracted. The common activation feature of volunteers is drawn and described via statistical analysis of ROIs. Experiment results show that the proposed method overcomes the limitation of traditional voxel-based analysis in extracting the common activation feature of volunteers.
The activity pattern in human visual cortex is studied and the common feature of volunteers is extracted based on analysis of regions of interest (ROI). By combining physiological structure and Talairach coordinates system, the same ROIs are obtained from the three-dimensional cortical model of each volunteer, these ROIs is then projected into the two-dimensional cortical model with the same topology, and the maximum activation intensity of each ROI is extracted. The common activation feature of volunteers is drawn and described via statistical analysis of ROIs. Experiment results show that the proposed method overcomes the limitation of traditional voxel-based analysis in extracting the common activation feature of volunteers.
