ISSN 
2005 Vol. 34, No. 2
2005, 34(2): 145-147,209.
Abstract:
This article discusses the character of range-dechirped spotlight SAR signal, analyzes the time and frequency domain character of dechirp SAR signal, presents imaging method of spotlight range-dechirped raw data.The new algorithm combines the advantages of two processing approaches:the efficiency of SPECAN algorithm and the precision of stripmap focusing technique, the first step of the proposed algorithm implements deramp technique representing a simplified version of the SPECAN approach, the second processing carries out the residual focusing via the use of a conventional stripmap processing procedure,in comparison with the range doppler method,this algorithm decreases the processed data with a little amount of calculation increased.The Ku band airborne spotlight SAR imaging experiment confirms its availability.
This article discusses the character of range-dechirped spotlight SAR signal, analyzes the time and frequency domain character of dechirp SAR signal, presents imaging method of spotlight range-dechirped raw data.The new algorithm combines the advantages of two processing approaches:the efficiency of SPECAN algorithm and the precision of stripmap focusing technique, the first step of the proposed algorithm implements deramp technique representing a simplified version of the SPECAN approach, the second processing carries out the residual focusing via the use of a conventional stripmap processing procedure,in comparison with the range doppler method,this algorithm decreases the processed data with a little amount of calculation increased.The Ku band airborne spotlight SAR imaging experiment confirms its availability.
2005, 34(2): 148-151.
Abstract:
Based on the construction theory of optical orthogonal hopping codes, constructed the two dimensions MPC/OOC combination codes for the wireless-OCDMA system with the modified prime code as time spreading codes and the optical orthogonal codes as frequency hopping codes. This coding scheme has large code's capacity compared with the two dimensional codes in existence. By grouping, the MPC/OOC code has good performance in auto-correlation and cross-correlation with still quite large codes capacity. Designed the tunable FBG encoder and decoder to the construction example.
Based on the construction theory of optical orthogonal hopping codes, constructed the two dimensions MPC/OOC combination codes for the wireless-OCDMA system with the modified prime code as time spreading codes and the optical orthogonal codes as frequency hopping codes. This coding scheme has large code's capacity compared with the two dimensional codes in existence. By grouping, the MPC/OOC code has good performance in auto-correlation and cross-correlation with still quite large codes capacity. Designed the tunable FBG encoder and decoder to the construction example.
2005, 34(2): 152-155.
Abstract:
In this paper, the basic principle of decimation-in-frequnency radix-2 FFT algorithm is briefly presented. Then, the design and realization methods of hardware system with FPGA are thoroughly discussed, with which it is easy to implement the FFT algorithm of large points-4 096 points. The FFT-speed of many groups of large points is accelerated greatly through ping-pong-ram. Finally, this hardware system is turned out to be feasible and accurate through the FFT algorithm experiment. Furthermore, the real-time imaging procession of airborne SAR can be accomplished successfully by this hardware system.
In this paper, the basic principle of decimation-in-frequnency radix-2 FFT algorithm is briefly presented. Then, the design and realization methods of hardware system with FPGA are thoroughly discussed, with which it is easy to implement the FFT algorithm of large points-4 096 points. The FFT-speed of many groups of large points is accelerated greatly through ping-pong-ram. Finally, this hardware system is turned out to be feasible and accurate through the FFT algorithm experiment. Furthermore, the real-time imaging procession of airborne SAR can be accomplished successfully by this hardware system.
2005, 34(2): 156-159.
Abstract:
The computational load in Matching Pursuit (MP) of images is very huge, and this is the main drawback with MP of images. In this paper, a new fast algorithm is presented to speed up MP of images. Energy distribution of atoms used in MP is studied and most of computational loads can therefore be avoided by making use of the atom energy property. Experimental results show that the MP algorithm developed according to this property is many times faster than the conventional MP method and at the same time the quality of reconstructed images by the new algorithm is as good as by the conventional MP method.
The computational load in Matching Pursuit (MP) of images is very huge, and this is the main drawback with MP of images. In this paper, a new fast algorithm is presented to speed up MP of images. Energy distribution of atoms used in MP is studied and most of computational loads can therefore be avoided by making use of the atom energy property. Experimental results show that the MP algorithm developed according to this property is many times faster than the conventional MP method and at the same time the quality of reconstructed images by the new algorithm is as good as by the conventional MP method.
2005, 34(2): 160-163.
Abstract:
The main shortcoming of the strap-down inertial navigation system (SINS) is the increasing navigation positioning errors with time. Double-star positioning system is one regional satellite positioning system built up by our country, and can output horizon position information with high accuracy, but the double-star positioning system has the characteristic of output position lag and bad concealment. This paper studies the filtering method for this integration system aiming at the position lag, and puts forward the statistical model of the measurement noise of integration system for the first time, at the same time designs the time of integration in order to compensate for the bad concealment. The simulating results show this filtering method is feasible, which has better value of engineering application.
The main shortcoming of the strap-down inertial navigation system (SINS) is the increasing navigation positioning errors with time. Double-star positioning system is one regional satellite positioning system built up by our country, and can output horizon position information with high accuracy, but the double-star positioning system has the characteristic of output position lag and bad concealment. This paper studies the filtering method for this integration system aiming at the position lag, and puts forward the statistical model of the measurement noise of integration system for the first time, at the same time designs the time of integration in order to compensate for the bad concealment. The simulating results show this filtering method is feasible, which has better value of engineering application.
2005, 34(2): 164-167.
Abstract:
Automatic threshold choice is difficult and important to color images edge detection, First of all, on the base of human visual properties, threshold versus intensity function of human visual system are researched and analyzed, by using method of mathematic modeling and the result of saturation research, function of least color difference that can be perceptible by visual systems in detecting edge is given. Finally, we use the principle of wavelet edge detection and suggest an algorithm of automatic threshold choice according to difference color background in wavelet edge detection. Emulate experiments demonstrate good adaptability and edge recognition effeteness of the algorithm.
Automatic threshold choice is difficult and important to color images edge detection, First of all, on the base of human visual properties, threshold versus intensity function of human visual system are researched and analyzed, by using method of mathematic modeling and the result of saturation research, function of least color difference that can be perceptible by visual systems in detecting edge is given. Finally, we use the principle of wavelet edge detection and suggest an algorithm of automatic threshold choice according to difference color background in wavelet edge detection. Emulate experiments demonstrate good adaptability and edge recognition effeteness of the algorithm.
2005, 34(2): 168-171.
Abstract:
This paper introduces the authentication and the architecture of IEEE802.1x Wireless Local Area Network based on the RADIUS/EAP, with respect to the characteristics of three parties coloration in accessing to WLAN, analyses the security mechanism, indicates that there would exist six security crushers either by the protocol defects or by the inadequate usage and deteriorating and it is necessary to fully utilize the data frame in the RADIUS/EAP structure for the encryption and authentication as well as to design the double-doors authenticated access mechanism. The four common authentication solutions are compared and the corresponding security functions in certain different extents are evaluated.
This paper introduces the authentication and the architecture of IEEE802.1x Wireless Local Area Network based on the RADIUS/EAP, with respect to the characteristics of three parties coloration in accessing to WLAN, analyses the security mechanism, indicates that there would exist six security crushers either by the protocol defects or by the inadequate usage and deteriorating and it is necessary to fully utilize the data frame in the RADIUS/EAP structure for the encryption and authentication as well as to design the double-doors authenticated access mechanism. The four common authentication solutions are compared and the corresponding security functions in certain different extents are evaluated.
2005, 34(2): 172-174.
Abstract:
Most previous authenticated encryption schemes have a problem that the recipient can not prove the dishonesty to any verifier if the signer denies his signatures. An efficient solving scheme has been presented in this paper. The new scheme requires less computational costs and lower communication than other previous convertible authenticated encryption schemes and the conventional signature-then-encryption approaches. In the proposed scheme, if the signer repudiates the signature, the recipient can convert this signature into an ordinary one without the cooperation of the signer. Furthermore, the message is not disclosed to any verifier during verification.
Most previous authenticated encryption schemes have a problem that the recipient can not prove the dishonesty to any verifier if the signer denies his signatures. An efficient solving scheme has been presented in this paper. The new scheme requires less computational costs and lower communication than other previous convertible authenticated encryption schemes and the conventional signature-then-encryption approaches. In the proposed scheme, if the signer repudiates the signature, the recipient can convert this signature into an ordinary one without the cooperation of the signer. Furthermore, the message is not disclosed to any verifier during verification.
2005, 34(2): 175-178.
Abstract:
Fractional Hilbert transform, a generalization of Hilbert transform from integral order to fractional order, extends the application fields. Firstly, generalized Hilbert transform is defined in the frequency domain, and it can be used to construct a new kind of analytic signal——generalized analytic signal. Then basic properties and digital realization of ideal generalized digital Hilbert transformer are investigated from the viewpoint of digital signal processing. Finally digital FIR filter design using window method and frequency sampling method are studied, and error analysis is given.
Fractional Hilbert transform, a generalization of Hilbert transform from integral order to fractional order, extends the application fields. Firstly, generalized Hilbert transform is defined in the frequency domain, and it can be used to construct a new kind of analytic signal——generalized analytic signal. Then basic properties and digital realization of ideal generalized digital Hilbert transformer are investigated from the viewpoint of digital signal processing. Finally digital FIR filter design using window method and frequency sampling method are studied, and error analysis is given.
2005, 34(2): 179-182.
Abstract:
The paper describes a fast start-up equalizer which firstly uses the semi-extended Neuman-Hoffman sequence to estimate the time varying channel impulse response, and then a initial DFE tap value to preload the the equalizer. The performance of the equalizer is confirmed by simulation in the 802.16 channel model, and it is fund that the convergence speed is comparable with the recursive least squares (RLS) adaptive algorithm.
The paper describes a fast start-up equalizer which firstly uses the semi-extended Neuman-Hoffman sequence to estimate the time varying channel impulse response, and then a initial DFE tap value to preload the the equalizer. The performance of the equalizer is confirmed by simulation in the 802.16 channel model, and it is fund that the convergence speed is comparable with the recursive least squares (RLS) adaptive algorithm.
2005, 34(2): 183-185.
Abstract:
A mutual authentication scheme and key exchange based on public key encryption is presented for mobile communication system. This scheme can realize mutual authentication and generate a session key confirmed by both sides of communication. The generation of session key has no third party involved. Besides, non-repudiation of data sent by both sides is provided with digital signature. By performance analysis, this scheme has a simple structure and high efficiency.
A mutual authentication scheme and key exchange based on public key encryption is presented for mobile communication system. This scheme can realize mutual authentication and generate a session key confirmed by both sides of communication. The generation of session key has no third party involved. Besides, non-repudiation of data sent by both sides is provided with digital signature. By performance analysis, this scheme has a simple structure and high efficiency.
2005, 34(2): 186-189.
Abstract:
The military security model (MSM) is a multilevel security model which used to control information flows within an information system with secret (such as government department, military etc.). In the old model, it depends on product lattice of linear lattice and subset lattice for information flow control. But relationships described in this model exists drawbacks in applications. In the new model, the product lattice which is a sensitivity lattice multiplying by organization level lattice is mapped to level relations with sensitivity within an organizations. Then, a more proper relationships which is multiplying the product lattice by lattice of information subset are formed for access control and flow control. So it make the new model more suitable to control the information flow security for information systems of military, government departments or various organizations.
The military security model (MSM) is a multilevel security model which used to control information flows within an information system with secret (such as government department, military etc.). In the old model, it depends on product lattice of linear lattice and subset lattice for information flow control. But relationships described in this model exists drawbacks in applications. In the new model, the product lattice which is a sensitivity lattice multiplying by organization level lattice is mapped to level relations with sensitivity within an organizations. Then, a more proper relationships which is multiplying the product lattice by lattice of information subset are formed for access control and flow control. So it make the new model more suitable to control the information flow security for information systems of military, government departments or various organizations.
2005, 34(2): 190-193.
Abstract:
Power grid analysis is an important issue for circuit design and verification. With the increasing number of transistors on a chip, the size of the power networks has grown so large as to make the verification task very challenging. Fast and memory-saving power analysis algorithms are needed. In this paper, we present a fast power grid analyzer using multigrid technique, which speed up the convergence of sparse iterative solver. we proposed a simple and intuitive restriction and interpolation scheme, which is based on the electric distance between the nodes in the power grid network. The convergence can be controlled by a user specified threshold parameter and pre/post smoothing iterations. Experimental results show the efficiency of the new method.
Power grid analysis is an important issue for circuit design and verification. With the increasing number of transistors on a chip, the size of the power networks has grown so large as to make the verification task very challenging. Fast and memory-saving power analysis algorithms are needed. In this paper, we present a fast power grid analyzer using multigrid technique, which speed up the convergence of sparse iterative solver. we proposed a simple and intuitive restriction and interpolation scheme, which is based on the electric distance between the nodes in the power grid network. The convergence can be controlled by a user specified threshold parameter and pre/post smoothing iterations. Experimental results show the efficiency of the new method.
2005, 34(2): 194-197.
Abstract:
In this paper, the data path of a high performance reconfigurable DSP processor is introduced. Based on its several 16-bit fixed-point computational units with powerful functions, the data path forms a 16-bit high-speed signal processing platform. By SIMD means, it can flexibly support computations of multi-dimension vector. By the way of reconfiguration, it can efficiently support 32-bit data processing.
In this paper, the data path of a high performance reconfigurable DSP processor is introduced. Based on its several 16-bit fixed-point computational units with powerful functions, the data path forms a 16-bit high-speed signal processing platform. By SIMD means, it can flexibly support computations of multi-dimension vector. By the way of reconfiguration, it can efficiently support 32-bit data processing.
2005, 34(2): 198-201.
Abstract:
In this paper, we integrate feature-based image matching method with feature-based one. Zero-crossing edge points are first extracted from image pairs with the Gauss-Laplace operator caculating. They are matched according some constraint conditions. Then, being looked as symmetries, image pairs' other point to point correspondences are searched from two directions by pixel neighbor area correlation values. Applying this approach, we have designed Visual C++ programs for rectified image pairs and extracted their condense disparity map not only fast but also efficiently.
In this paper, we integrate feature-based image matching method with feature-based one. Zero-crossing edge points are first extracted from image pairs with the Gauss-Laplace operator caculating. They are matched according some constraint conditions. Then, being looked as symmetries, image pairs' other point to point correspondences are searched from two directions by pixel neighbor area correlation values. Applying this approach, we have designed Visual C++ programs for rectified image pairs and extracted their condense disparity map not only fast but also efficiently.
2005, 34(2): 202-205.
Abstract:
The effects of the difference of circuit parameters or capacitances and inductances on the quantum fluctuations in the non-resonant damped mesoscopic coupled electric circuits were studied. In the calculations, the physical mechanism of the generation of the resistance or the interaction between electrons and phonons was considered. The difference of the circuit parameters in the two component circuits makes the quantum fluctuations in one component circuit smaller and that in the other larger. The results also show that both capacitance coupling and inductance coupling will cause the quantum fluctuations of the electric charge in the coupling part squeezed. But there is no squeezing for the electric current in the coupling part.
The effects of the difference of circuit parameters or capacitances and inductances on the quantum fluctuations in the non-resonant damped mesoscopic coupled electric circuits were studied. In the calculations, the physical mechanism of the generation of the resistance or the interaction between electrons and phonons was considered. The difference of the circuit parameters in the two component circuits makes the quantum fluctuations in one component circuit smaller and that in the other larger. The results also show that both capacitance coupling and inductance coupling will cause the quantum fluctuations of the electric charge in the coupling part squeezed. But there is no squeezing for the electric current in the coupling part.
2005, 34(2): 206-209.
Abstract:
In the paper, we extend the definition of traditional image edge to morphology edge, derive a series of new morphological operators which are enlightened by semi-increasing and semi-continuation and first time bring forward double-structure element used in morphological processing at one time. These new morphological operators can resist noise and have good merit which not only have good location but keep image detail. Experiments have shown that better image edge detection results will be produced by these operators than otherwise by traditional methods, moreover, the edge thus detected is basically continuous with single-resolution-widths.
In the paper, we extend the definition of traditional image edge to morphology edge, derive a series of new morphological operators which are enlightened by semi-increasing and semi-continuation and first time bring forward double-structure element used in morphological processing at one time. These new morphological operators can resist noise and have good merit which not only have good location but keep image detail. Experiments have shown that better image edge detection results will be produced by these operators than otherwise by traditional methods, moreover, the edge thus detected is basically continuous with single-resolution-widths.
2005, 34(2): 210-212,232.
Abstract:
A global and local two-level cooperation scheduling (TCS) algorithm is presented. In order to improve the scheduling precision, the global scheduling considers both the service states and system states to choose a suitable site to serve; Based on the global scheduling, the local scheduling adjusts the service quality and service states to guarantee no rejection of client request, and feeds back the service states to improve the correctness of global scheduling. The theoretical and simulated results show that, with the similar efficiency, the proposed algorithm owns higher reliability compared with the traditional distributed scheduling algorithms.
A global and local two-level cooperation scheduling (TCS) algorithm is presented. In order to improve the scheduling precision, the global scheduling considers both the service states and system states to choose a suitable site to serve; Based on the global scheduling, the local scheduling adjusts the service quality and service states to guarantee no rejection of client request, and feeds back the service states to improve the correctness of global scheduling. The theoretical and simulated results show that, with the similar efficiency, the proposed algorithm owns higher reliability compared with the traditional distributed scheduling algorithms.
2005, 34(2): 213-216.
Abstract:
Aiming at the characteristics of the LAN of fast Ethernet and distributed parallel server system, a novel distributed operating system transport protocol (DOSTP) is proposed in this paper. The goal of this work is to study how to reduce the communication software overheads in the distributed parallel server system with off-shelf equipments, moreover to keep the common programming interfaces. Several measurements, such as decreasing redundant operations at underlying protocol stack, reducing OS interventions and the overheads of protocol self-maintenance, are used to improve the performance. Experiments have been done on the server of 8 PⅢ PC nodes and 100Mbps Ethernet with switches. Compared with UDP/IP, DOSTP decreases round-trip time of 20% for 64 bytes packets under the same application conditions.
Aiming at the characteristics of the LAN of fast Ethernet and distributed parallel server system, a novel distributed operating system transport protocol (DOSTP) is proposed in this paper. The goal of this work is to study how to reduce the communication software overheads in the distributed parallel server system with off-shelf equipments, moreover to keep the common programming interfaces. Several measurements, such as decreasing redundant operations at underlying protocol stack, reducing OS interventions and the overheads of protocol self-maintenance, are used to improve the performance. Experiments have been done on the server of 8 PⅢ PC nodes and 100Mbps Ethernet with switches. Compared with UDP/IP, DOSTP decreases round-trip time of 20% for 64 bytes packets under the same application conditions.
2005, 34(2): 217-220.
Abstract:
Based on the study of HFC MAC protocol over contention/reservation scheme, an efficient method, which worked on random contention and polling model has been proposed in this article to meet the needs of a multi-priority service access control system. The computer simulating shows the service with higher priority would have the better performance of throughput and delay.
Based on the study of HFC MAC protocol over contention/reservation scheme, an efficient method, which worked on random contention and polling model has been proposed in this article to meet the needs of a multi-priority service access control system. The computer simulating shows the service with higher priority would have the better performance of throughput and delay.
2005, 34(2): 221-224.
Abstract:
This paper points out the deficiency in detecting the unknown Trojan horse of the present anti-virus software at first, introduces the advantage of artificial immune system in self-adaptability aspect, and points out the feasibility of artificial immunity mechanism in Trojan horses detection; Then through an analysis about the new technology of Trojan horses, proves the deficiency of current computer security system with a Trojan horses model, presents the transfer of Trojan horses detection from the anti-virus software to the subsystem of immune IDS, improves the self-adaptive capacity of Trojan horses detection with its immune mechanism; Finally, a behavior mode is put forward, which is mapped from the using situation of process systematic resource to the process systematic call, and by this means, a Trojan horse detection model based on artificial immunity mechanism is set up.
This paper points out the deficiency in detecting the unknown Trojan horse of the present anti-virus software at first, introduces the advantage of artificial immune system in self-adaptability aspect, and points out the feasibility of artificial immunity mechanism in Trojan horses detection; Then through an analysis about the new technology of Trojan horses, proves the deficiency of current computer security system with a Trojan horses model, presents the transfer of Trojan horses detection from the anti-virus software to the subsystem of immune IDS, improves the self-adaptive capacity of Trojan horses detection with its immune mechanism; Finally, a behavior mode is put forward, which is mapped from the using situation of process systematic resource to the process systematic call, and by this means, a Trojan horse detection model based on artificial immunity mechanism is set up.
2005, 34(2): 225-228.
Abstract:
Researching many cache invalidation strategies, we propose a performance analyzing model which can evaluate the cache schemes in the mobile computing environments. Based on some parameters-the update rate, the hitting "hot spot" rate, the bandwidth of the wireless, the overhead of the uplink and downlink, etc., the throughput of cache strategies can be computed. Using this model, we evaluate the performance of four schemas-no caching, ideal strategies, timestamp, mobile agent. Our study shows that this model is intensive practicability.
Researching many cache invalidation strategies, we propose a performance analyzing model which can evaluate the cache schemes in the mobile computing environments. Based on some parameters-the update rate, the hitting "hot spot" rate, the bandwidth of the wireless, the overhead of the uplink and downlink, etc., the throughput of cache strategies can be computed. Using this model, we evaluate the performance of four schemas-no caching, ideal strategies, timestamp, mobile agent. Our study shows that this model is intensive practicability.
2005, 34(2): 229-232.
Abstract:
The LogP model has more parameters and more complicated arithmetic. The simple LogP model divided the deferent data to two parts to make algorithmic analyses simple. For simulating simple LogP model's parameters, we supply one method to test idiographic environment's parameters of model, which can help us to design and analyze parallel arithmetic. And we respectively use the single machine and multiply machines to test the model's parameters of LogP. According to the test data, we analyzed the network delay and the software expense. Then we get an empirical formula for simple LogP model's parameters.
The LogP model has more parameters and more complicated arithmetic. The simple LogP model divided the deferent data to two parts to make algorithmic analyses simple. For simulating simple LogP model's parameters, we supply one method to test idiographic environment's parameters of model, which can help us to design and analyze parallel arithmetic. And we respectively use the single machine and multiply machines to test the model's parameters of LogP. According to the test data, we analyzed the network delay and the software expense. Then we get an empirical formula for simple LogP model's parameters.
2005, 34(2): 233-235,276.
Abstract:
In this paper, an intelligence home network based on multi-agent system is brought up by analyzing the intelligence demand of home network. It realizes the control and manage of different function unit with Agent, and builds up the Intelligent Home Network model by the thinking, method and architecture of MAS. It also gives all the composed parts of MAIHN model, analyzes the function design and implement model in Agent, researches the collaboration and correspond strategy of multi-Agent in MAIHN model. At last this article construct the experimental archetype of MAIHN model.
In this paper, an intelligence home network based on multi-agent system is brought up by analyzing the intelligence demand of home network. It realizes the control and manage of different function unit with Agent, and builds up the Intelligent Home Network model by the thinking, method and architecture of MAS. It also gives all the composed parts of MAIHN model, analyzes the function design and implement model in Agent, researches the collaboration and correspond strategy of multi-Agent in MAIHN model. At last this article construct the experimental archetype of MAIHN model.
2005, 34(2): 236-239.
Abstract:
Coverage testing is a basic method for dynamic software testing. An algorithm is proposed for calculating the branch routes of an embedded assembly program in software coverage testing. The correctness of the algorithm is verified on a sample assembly program and it's time complexity is analyzed also.
Coverage testing is a basic method for dynamic software testing. An algorithm is proposed for calculating the branch routes of an embedded assembly program in software coverage testing. The correctness of the algorithm is verified on a sample assembly program and it's time complexity is analyzed also.
2005, 34(2): 240-243.
Abstract:
The access control of local area network is a common security problem which involved the resource protection of local area network. In this paper, a project of access control of local area network based on ARP protocol is presented. It can be used to detect and refuse the illegal computers that try to log on and access the local area network by capturing and analyzing the network packets. On the other hand, through the authentication of the local area network server and based on the ARP buffer principle, it can be also used to control the access between the legal computers of the local area network. So that it is an effective way to protect the resource of local area network. The project is convenient and useful.
The access control of local area network is a common security problem which involved the resource protection of local area network. In this paper, a project of access control of local area network based on ARP protocol is presented. It can be used to detect and refuse the illegal computers that try to log on and access the local area network by capturing and analyzing the network packets. On the other hand, through the authentication of the local area network server and based on the ARP buffer principle, it can be also used to control the access between the legal computers of the local area network. So that it is an effective way to protect the resource of local area network. The project is convenient and useful.
2005, 34(2): 244-247.
Abstract:
A system of fuzzy stator direct torque control for induction motor based is introduced. A novel of fuzzy stator resistance estimator on-line is proposed. It can improve the performance at low speeds and the response of the system. By estimating Flux-chain and speed, a fuzzy direct torque control system based on TMS320F240 is made. The experiment result shows that scheme is reliable.
A system of fuzzy stator direct torque control for induction motor based is introduced. A novel of fuzzy stator resistance estimator on-line is proposed. It can improve the performance at low speeds and the response of the system. By estimating Flux-chain and speed, a fuzzy direct torque control system based on TMS320F240 is made. The experiment result shows that scheme is reliable.
2005, 34(2): 248-250,284.
Abstract:
The key techniques in the development of digital storage oscilloscope (DSO), a product type project taken by the authors, are discussed, of which the concept and the theory of the system design, the high-speed data acquisition technique based on the devices with lower operation speed, the equivalent sampling technique based on Random sampling are expatiated. The 200 ps time resolution and 5 GSPS equivalent sampling rate are gotten by using large-scale time expander, so the DSO can observe 100 MHz (-3 dB) seasonal signal. The results of experiment and application are presented in the end.
The key techniques in the development of digital storage oscilloscope (DSO), a product type project taken by the authors, are discussed, of which the concept and the theory of the system design, the high-speed data acquisition technique based on the devices with lower operation speed, the equivalent sampling technique based on Random sampling are expatiated. The 200 ps time resolution and 5 GSPS equivalent sampling rate are gotten by using large-scale time expander, so the DSO can observe 100 MHz (-3 dB) seasonal signal. The results of experiment and application are presented in the end.
2005, 34(2): 251-253.
Abstract:
This paper constructs risk factors base on SSE-CMM, and Presents a scientific exploration of the analysis and assessment of e-government information system's risk by applying the methods of system engineering and ISM. It focuses on the application of the methods and the result analysis in the actual case. Some proposals and solutions for the risk are also raised in the paper.
This paper constructs risk factors base on SSE-CMM, and Presents a scientific exploration of the analysis and assessment of e-government information system's risk by applying the methods of system engineering and ISM. It focuses on the application of the methods and the result analysis in the actual case. Some proposals and solutions for the risk are also raised in the paper.
2005, 34(2): 254-257.
Abstract:
This paper deals with the tracking control problem of a rigid-flexible manipulator system with unknown and changing dynamics. Lagrange-Euler formulation is used to establish the dynamics of the robotic system. Because of the characteristics of high non-linearity and complexity of the robotic system, intelligent control strategy is proposed to control the system in this study, in which a fuzzy logic controller in the feedback configuration and an efficient dynamic recurrent neural network in the feedforward configuration are developed. Simulations are carried out for both the fuzzy logic controller and the proposed intelligent controller under the condition of three groups of step inputs. Results demonstrate that the performance of the system is greatly improved by using the proposed controller.
This paper deals with the tracking control problem of a rigid-flexible manipulator system with unknown and changing dynamics. Lagrange-Euler formulation is used to establish the dynamics of the robotic system. Because of the characteristics of high non-linearity and complexity of the robotic system, intelligent control strategy is proposed to control the system in this study, in which a fuzzy logic controller in the feedback configuration and an efficient dynamic recurrent neural network in the feedforward configuration are developed. Simulations are carried out for both the fuzzy logic controller and the proposed intelligent controller under the condition of three groups of step inputs. Results demonstrate that the performance of the system is greatly improved by using the proposed controller.
2005, 34(2): 258-260.
Abstract:
One of the open problems in the graph theory is to find the minimum number of edges required for a graph of order n. A class of graphs with connectivity of at least k and k-diameter of at most d is studied in this paper, and an upper and a lower bound of the minimum edges of the graphs under general conditions are offered. Based on this, the calculation formulas of the minimum edges in two specific situations are also given. In addition we suggest the approaches to costruct the minimum networks as mentioned above.
One of the open problems in the graph theory is to find the minimum number of edges required for a graph of order n. A class of graphs with connectivity of at least k and k-diameter of at most d is studied in this paper, and an upper and a lower bound of the minimum edges of the graphs under general conditions are offered. Based on this, the calculation formulas of the minimum edges in two specific situations are also given. In addition we suggest the approaches to costruct the minimum networks as mentioned above.
2005, 34(2): 261-264.
Abstract:
In this paper, the problem of K-stability for general neural network with time-delay was studied. By the method of variation of the parameters and inequality analysis and some properties of differential equations, sufficient delay-dependent conditions of K-stability and K-exponentially stability for general neural network with time-delay are established.
In this paper, the problem of K-stability for general neural network with time-delay was studied. By the method of variation of the parameters and inequality analysis and some properties of differential equations, sufficient delay-dependent conditions of K-stability and K-exponentially stability for general neural network with time-delay are established.
2005, 34(2): 265-268.
Abstract:
This paper presented a new ideas for resolving linear matrix inequalities using evolutionary computation, which decides the stability of the fuzzy model-based control. Experiments proved it is a effective algorithm to achieve gain scheduling and stability checking of fuzzy controllor. In the end,two examples conducted in simulations demonstrated the effectiveness of the proposed algorithm for solving matrix inequalities.
This paper presented a new ideas for resolving linear matrix inequalities using evolutionary computation, which decides the stability of the fuzzy model-based control. Experiments proved it is a effective algorithm to achieve gain scheduling and stability checking of fuzzy controllor. In the end,two examples conducted in simulations demonstrated the effectiveness of the proposed algorithm for solving matrix inequalities.
2005, 34(2): 269-272.
Abstract:
In the paper, a class of Schrödinger equation with harmonic Potential, which concerns Bose-Einstin condensates, is investigated. Now that the equation of Bose-einstin condensates describes lot of phenomena, that we research it has special significance. With the help of using energy conservative law and quality conservative law as well as knowledge of vector analysis, integral and differential inequality, we prove that the solution to the Cauchy's problem will blow up in finite time in case initial value satisfy with some conditions. As the equation in the paper is more general, we have got extensive conclusion, by means of which we may deeply understand the aggregative phenomena on energy and quality.
In the paper, a class of Schrödinger equation with harmonic Potential, which concerns Bose-Einstin condensates, is investigated. Now that the equation of Bose-einstin condensates describes lot of phenomena, that we research it has special significance. With the help of using energy conservative law and quality conservative law as well as knowledge of vector analysis, integral and differential inequality, we prove that the solution to the Cauchy's problem will blow up in finite time in case initial value satisfy with some conditions. As the equation in the paper is more general, we have got extensive conclusion, by means of which we may deeply understand the aggregative phenomena on energy and quality.
2005, 34(2): 273-276.
Abstract:
Another concept of generalized diagonal dominance for nonlinear functions (i.e. quasi-generalized nonlinear diagonal dominance) is introduced. This concept includes as special case generalized nonlinear diagonal dominance, possess much of important properties of generalized nonlinear diagonal dominance, easy to judge a nonlinear function is quasi-generalized nonlinear diagonally dominant if its derivative is a generalized diagonally dominant matrix on an convex set in Rn.
Another concept of generalized diagonal dominance for nonlinear functions (i.e. quasi-generalized nonlinear diagonal dominance) is introduced. This concept includes as special case generalized nonlinear diagonal dominance, possess much of important properties of generalized nonlinear diagonal dominance, easy to judge a nonlinear function is quasi-generalized nonlinear diagonally dominant if its derivative is a generalized diagonally dominant matrix on an convex set in Rn.
2005, 34(2): 277-280.
Abstract:
The paper aims at the unfair which the marginal cost transfer pricing method on firm's profit assignment. By inducting the thoughts of cooperation game, we put forward to divide the firm's total profit use Shapley value of cooperation game based on marginal cost transfer pricing method. The operation steps are the upstream divisions supply the intermediate products on marginal cost price firstly. Secondly, the headquarters divides the total profit with Shapley value method. At last, the headquarters assesses the performance and reward on base of the redistribution profit to the divisions' managers. The conclusion is that any division's profit of redistributed is exceed the independent profit. So implementing the marginal cost pricing strategy and redistribution the revenue, can get the internal targets coincidence and improve the total profit of the firm.
The paper aims at the unfair which the marginal cost transfer pricing method on firm's profit assignment. By inducting the thoughts of cooperation game, we put forward to divide the firm's total profit use Shapley value of cooperation game based on marginal cost transfer pricing method. The operation steps are the upstream divisions supply the intermediate products on marginal cost price firstly. Secondly, the headquarters divides the total profit with Shapley value method. At last, the headquarters assesses the performance and reward on base of the redistribution profit to the divisions' managers. The conclusion is that any division's profit of redistributed is exceed the independent profit. So implementing the marginal cost pricing strategy and redistribution the revenue, can get the internal targets coincidence and improve the total profit of the firm.
2005, 34(2): 281-284.
Abstract:
Ant Colony Algorithm is a brand-new bionic simulated evolutionary algorithm, which has been applied to many fields. Multi-objective optimization problems are very important optimization problems. It's hard to optimized or solved. An improved Ant Colony Algorithm to solve Multi-objective optimization problems is introduced. After setting up a set of weight for the parameters, the algorithm uses some ants search in the solution space first in a stochastic way then stimulate the food searching behavior of real ants to guide the search by the pheromone. The new algorithm is explained in details and some simulations show the algorithm is very effective in finding global optimizations.
Ant Colony Algorithm is a brand-new bionic simulated evolutionary algorithm, which has been applied to many fields. Multi-objective optimization problems are very important optimization problems. It's hard to optimized or solved. An improved Ant Colony Algorithm to solve Multi-objective optimization problems is introduced. After setting up a set of weight for the parameters, the algorithm uses some ants search in the solution space first in a stochastic way then stimulate the food searching behavior of real ants to guide the search by the pheromone. The new algorithm is explained in details and some simulations show the algorithm is very effective in finding global optimizations.
2005, 34(2): 285-288.
Abstract:
This paper applies the real-option approach to study the capacity decision in supply chain management under perfect competitive markets. Through analyzing the value of capacity investment decision, we give some rules of the capacity decision with flexibility. We also analyze the influence of three main factors upon the investment decision, which include the property of market evolvement, investment cost, and out of stock cost. The results show that a more (less) risky market, a higher (lower) capacity investment cost, or a lower (higher) out of stock cost is likely to postpone (advance) the implementing of capacity expansion.
This paper applies the real-option approach to study the capacity decision in supply chain management under perfect competitive markets. Through analyzing the value of capacity investment decision, we give some rules of the capacity decision with flexibility. We also analyze the influence of three main factors upon the investment decision, which include the property of market evolvement, investment cost, and out of stock cost. The results show that a more (less) risky market, a higher (lower) capacity investment cost, or a lower (higher) out of stock cost is likely to postpone (advance) the implementing of capacity expansion.
