ISSN 
2004 Vol. 33, No. 4
2004, 33(4): 341-344.
Abstract:
Spectral purity and frequency capacity are performance barriers of Direct Digital Frequency Synthesizers (DDS) that designers are striving to break. Traditionally, spurious signals are reduced by ways of better algorithms and improvements on DDS structure. In this paper a novel spur reduction method, DDS array method, is proposed and its performance is analyzed. And an experiment on the technology is operated to verify its feasibility.
Spectral purity and frequency capacity are performance barriers of Direct Digital Frequency Synthesizers (DDS) that designers are striving to break. Traditionally, spurious signals are reduced by ways of better algorithms and improvements on DDS structure. In this paper a novel spur reduction method, DDS array method, is proposed and its performance is analyzed. And an experiment on the technology is operated to verify its feasibility.
2004, 33(4): 345-348.
Abstract:
This paper describes models and algorithms for realizing the reference model proposed in ITU-R M.1225 for each test-operating environment including indoor office, outdoor-to-indoor/pedestrian and vehicular. Besides the brief description of the scheme as a whole, we discuss two algorithms in detail that are adapted to be realized in real time:shaping of slow fading with correlation and generation of frequency-selected multipath fading. The numerical results and simulation statistics given in the end show that the simulator gives good simulations of the first-order and second-order statistic characteristics.
This paper describes models and algorithms for realizing the reference model proposed in ITU-R M.1225 for each test-operating environment including indoor office, outdoor-to-indoor/pedestrian and vehicular. Besides the brief description of the scheme as a whole, we discuss two algorithms in detail that are adapted to be realized in real time:shaping of slow fading with correlation and generation of frequency-selected multipath fading. The numerical results and simulation statistics given in the end show that the simulator gives good simulations of the first-order and second-order statistic characteristics.
2004, 33(4): 349-352.
Abstract:
A novel difference-spectrum hybrid numerical technique is proposed in this paper. In this method, each time dependent variable in Maxwell's equations is periodically continued with proper approximation, which results in the conversion of the continuous-spectrum problem to a discrete one by virtue of the consistent of solution before and after periodical continuation in the first period. The discrete spectra of the field quantities after continuation are obtained from difference Maxwell curl equations in frequency-domain and the time-domain solution of the original problem is derived from their inverse Fourier transforms. The strong point of the proposed method is its high capability of calculating any dispersive media and utilizing PML boundary condition without additional codes. Due to its unconditional stability, this technique excels Yee's FDTD in dealing with electromagnetic problems where the characteristic sizes of the scatter are much larger than the wavelength of the stimulant source. Numerical experiments demonstrate its effectiveness, easy implementation and high precision.
A novel difference-spectrum hybrid numerical technique is proposed in this paper. In this method, each time dependent variable in Maxwell's equations is periodically continued with proper approximation, which results in the conversion of the continuous-spectrum problem to a discrete one by virtue of the consistent of solution before and after periodical continuation in the first period. The discrete spectra of the field quantities after continuation are obtained from difference Maxwell curl equations in frequency-domain and the time-domain solution of the original problem is derived from their inverse Fourier transforms. The strong point of the proposed method is its high capability of calculating any dispersive media and utilizing PML boundary condition without additional codes. Due to its unconditional stability, this technique excels Yee's FDTD in dealing with electromagnetic problems where the characteristic sizes of the scatter are much larger than the wavelength of the stimulant source. Numerical experiments demonstrate its effectiveness, easy implementation and high precision.
2004, 33(4): 353-356.
Abstract:
An electromagnetic simulation software is developed. The software is based on the finite-difference time-domain (FDTD) method and can handle objects with curved surfaces and edges.The program includes a Visual Basic(VB) graphical user interface for graphically inputting object geometries and setting source and boundary conditions, and uses Fortran language to compute with a data file from VB. Examples that show the applications of the software for antennas and resonators are presented, and the results show good agreement with those reported in the published papers.
An electromagnetic simulation software is developed. The software is based on the finite-difference time-domain (FDTD) method and can handle objects with curved surfaces and edges.The program includes a Visual Basic(VB) graphical user interface for graphically inputting object geometries and setting source and boundary conditions, and uses Fortran language to compute with a data file from VB. Examples that show the applications of the software for antennas and resonators are presented, and the results show good agreement with those reported in the published papers.
2004, 33(4): 357-360.
Abstract:
The attenuation of the electromagnetic wave in the non-uniform plasma slab cling to a metal plane is studying in this paper. The plasma slab is divided into a number of sub-slabs each of which is dealt with as a uniform slab. Detailed numerical calculations are conducted on Epstein-distributions. The effects of electron number density, momentum transfer collision rate, magnetic field and angle of incidence on the attenuation are taken into account, and get the character of plasma's absorbing electromagnetic wave.
The attenuation of the electromagnetic wave in the non-uniform plasma slab cling to a metal plane is studying in this paper. The plasma slab is divided into a number of sub-slabs each of which is dealt with as a uniform slab. Detailed numerical calculations are conducted on Epstein-distributions. The effects of electron number density, momentum transfer collision rate, magnetic field and angle of incidence on the attenuation are taken into account, and get the character of plasma's absorbing electromagnetic wave.
2004, 33(4): 361-363,390.
Abstract:
A novel dual-koch fractal antenna with sleeves is presented, and dependences of its resonant parameters on the indentation angles, the half cone angles, the sleeve space and the sleeve height are investigated by using the method of moment. Based on these discussions, a double-band unipole antenna for application of GSM/DCS is designed by using the genetic algorithm. All the analyses show that dual-Koch fractal antenna has much lower resonant frequency than single-koch fractal antenna, and the resonant frequency decreases with increase of the indentation angle. The sleeves can effectively improve the performance of the fractal antenna at high resonant frequency. That is, its space and its height have excellent ability to tune at high resonant frequency.
A novel dual-koch fractal antenna with sleeves is presented, and dependences of its resonant parameters on the indentation angles, the half cone angles, the sleeve space and the sleeve height are investigated by using the method of moment. Based on these discussions, a double-band unipole antenna for application of GSM/DCS is designed by using the genetic algorithm. All the analyses show that dual-Koch fractal antenna has much lower resonant frequency than single-koch fractal antenna, and the resonant frequency decreases with increase of the indentation angle. The sleeves can effectively improve the performance of the fractal antenna at high resonant frequency. That is, its space and its height have excellent ability to tune at high resonant frequency.
2004, 33(4): 364-367.
Abstract:
Two models for analyzing both the cross-couplings and their phase relationships and the implementation in cavity-filters by establishing auxiliary signal passages and adding control parts between non-adjacent resonators to both introduce finite transmission zeroes and optimize the performance of filters are proposed. The feasibility and practicability of the method are validated by design examples based on the presented models.
Two models for analyzing both the cross-couplings and their phase relationships and the implementation in cavity-filters by establishing auxiliary signal passages and adding control parts between non-adjacent resonators to both introduce finite transmission zeroes and optimize the performance of filters are proposed. The feasibility and practicability of the method are validated by design examples based on the presented models.
2004, 33(4): 368-370.
Abstract:
Many DOA estimation algorithms, reported in the past literature, are presented and used with the problem that the elements of smart antenna arrays are usually of no direction. The paper analyzes the influence to DOA estimation by MUSIC algorithm when the antenna elements have direction. The effect of mutual coupling is calibrated and some factors that influence the DOA resolution are analyzed. The simulation results are compared and the conclusion is reached that element direction, the direction of array and SNR have great effect on DOA resolution.
Many DOA estimation algorithms, reported in the past literature, are presented and used with the problem that the elements of smart antenna arrays are usually of no direction. The paper analyzes the influence to DOA estimation by MUSIC algorithm when the antenna elements have direction. The effect of mutual coupling is calibrated and some factors that influence the DOA resolution are analyzed. The simulation results are compared and the conclusion is reached that element direction, the direction of array and SNR have great effect on DOA resolution.
2004, 33(4): 371-373.
Abstract:
The coupling gap between traditional open-loop microstrip resonators of high temperature superconductivity filter is too narrow to be fabricated with normal photolithography technology. This paper studies the mixed coupling of high temperature superconductivity open-loop microstrip resonators and presents a new improved resonator structure which can be fabricated with normal photolithography technology. A six-pole high temperature superconductivity linear phase filter is designed with this new structure and simulated results are also presented here.
The coupling gap between traditional open-loop microstrip resonators of high temperature superconductivity filter is too narrow to be fabricated with normal photolithography technology. This paper studies the mixed coupling of high temperature superconductivity open-loop microstrip resonators and presents a new improved resonator structure which can be fabricated with normal photolithography technology. A six-pole high temperature superconductivity linear phase filter is designed with this new structure and simulated results are also presented here.
2004, 33(4): 374-377.
Abstract:
The concepts of optical orthogonal code and two-dimensional optical orthogonal code are introduced, and their performance is analysed.The paper analyses three types of two-dimensional optical code-division multiple access communication systems:T/S OCDMA、WDM+OCDMA、MW OCDMA, and compares their performance. The design of two-dimensional optical orthogonal code fiber delay line encoder and decoder, and the scheme of the encoder based on fiber grating is presented.
The concepts of optical orthogonal code and two-dimensional optical orthogonal code are introduced, and their performance is analysed.The paper analyses three types of two-dimensional optical code-division multiple access communication systems:T/S OCDMA、WDM+OCDMA、MW OCDMA, and compares their performance. The design of two-dimensional optical orthogonal code fiber delay line encoder and decoder, and the scheme of the encoder based on fiber grating is presented.
2004, 33(4): 378-382.
Abstract:
The system of synchronous CDMA has large capacity, however it is difficult to implement in mobile satellite condition. So we consider establishing quasi-synchronous system. In this paper, the effect of quasi-synchronous error to broadband CDMA mobile satellite system is analyzed through computer simulation. The performance of CDMA system is improved distinctively in the condition of quasi-synchronous. This paper presented one strategy to realize quasi-synchronous in satellite environment, and discussed its feasibility. After analysis, we find that this strategy is feasible and implemented easier with the increase of orbit elevation.
The system of synchronous CDMA has large capacity, however it is difficult to implement in mobile satellite condition. So we consider establishing quasi-synchronous system. In this paper, the effect of quasi-synchronous error to broadband CDMA mobile satellite system is analyzed through computer simulation. The performance of CDMA system is improved distinctively in the condition of quasi-synchronous. This paper presented one strategy to realize quasi-synchronous in satellite environment, and discussed its feasibility. After analysis, we find that this strategy is feasible and implemented easier with the increase of orbit elevation.
2004, 33(4): 383-386,394.
Abstract:
Usually modular inverse operation becomes bottlenecked in realizing the public key cryptosystem. The method commonly used leads to a lot of division operation. The modular inverse operation by extended Euclidean algorithm and the binary extended Euclidean algorithm are analyzed, and the improved modular inverse operation by binary extended Euclidean algorithm is presented in this paper. The result shows that the new algorithm runs faster than the old one under the given testing environment. Furthermore it has much more feasibility in hardware realization.
Usually modular inverse operation becomes bottlenecked in realizing the public key cryptosystem. The method commonly used leads to a lot of division operation. The modular inverse operation by extended Euclidean algorithm and the binary extended Euclidean algorithm are analyzed, and the improved modular inverse operation by binary extended Euclidean algorithm is presented in this paper. The result shows that the new algorithm runs faster than the old one under the given testing environment. Furthermore it has much more feasibility in hardware realization.
2004, 33(4): 387-390.
Abstract:
Providing a low-cost solution on static image procession. In this system, digital signal processor(DSP) is the core of high performance compression and image data procession. The system uses CCD for getting digital image, uses a 16 bit fix-point DSP to perform fast discret cosine transform(DCT) arithmetic and image encoding and realizes a fast image compression in end. The compression result testifies the high performance of the system.
Providing a low-cost solution on static image procession. In this system, digital signal processor(DSP) is the core of high performance compression and image data procession. The system uses CCD for getting digital image, uses a 16 bit fix-point DSP to perform fast discret cosine transform(DCT) arithmetic and image encoding and realizes a fast image compression in end. The compression result testifies the high performance of the system.
2004, 33(4): 391-394.
Abstract:
The close-opening or open-closing filter based on the morphological filter with the same size structuring element cannot remove all the positive or negative impulse noise effectively. To improve the performance of these two kinds of filter, the generalized close-opening and open-closing filter based on the morphological filter with the different size structuring element are put forward. Based on the generalized morphological filter, this paper suggests a kind of designing project of the filter that applies a new structuring element to the generalized morphological filter. The theory analysis and the simulation experiments of the image processing indicate that this kind of filter can not only remove noise effectively but also keep the details of the image sufficiently.
The close-opening or open-closing filter based on the morphological filter with the same size structuring element cannot remove all the positive or negative impulse noise effectively. To improve the performance of these two kinds of filter, the generalized close-opening and open-closing filter based on the morphological filter with the different size structuring element are put forward. Based on the generalized morphological filter, this paper suggests a kind of designing project of the filter that applies a new structuring element to the generalized morphological filter. The theory analysis and the simulation experiments of the image processing indicate that this kind of filter can not only remove noise effectively but also keep the details of the image sufficiently.
2004, 33(4): 395-398.
Abstract:
Bluetooth is a short range and low power wireless network technology.The remote controller of portable radio station needs a wireless link. In this paper, a hardware and software designing of Bluetooth remote controller system is presented, which is implemented through embedding bluetooth technology to radio station, using bluetooth module along with personal digital assistant (PDA) module. With this solution, remote interface of radio station is improved, bluetooth remote controller makes it more portable and its operation more convenient for portable radio station.
Bluetooth is a short range and low power wireless network technology.The remote controller of portable radio station needs a wireless link. In this paper, a hardware and software designing of Bluetooth remote controller system is presented, which is implemented through embedding bluetooth technology to radio station, using bluetooth module along with personal digital assistant (PDA) module. With this solution, remote interface of radio station is improved, bluetooth remote controller makes it more portable and its operation more convenient for portable radio station.
2004, 33(4): 399-402.
Abstract:
A new low-loss wide-angle Y branches is proposed based on the graded-index waveguides in this paper. The Results of theoretical analysis and the simulations by finite-difference beam propagation method (FDBPM) show that the radiation losses can be less than 0.18 dB even if a branching angle is as large as 10°. Compared with traditional Y branches, the new Y branches is characteristic with low losses and simple structure.
A new low-loss wide-angle Y branches is proposed based on the graded-index waveguides in this paper. The Results of theoretical analysis and the simulations by finite-difference beam propagation method (FDBPM) show that the radiation losses can be less than 0.18 dB even if a branching angle is as large as 10°. Compared with traditional Y branches, the new Y branches is characteristic with low losses and simple structure.
2004, 33(4): 403-406.
Abstract:
The research of anomaly detection now focuses on four aspects:selection of data source, specification of behavior, normal behavior learning, behavior matching. For the first aspect, a new data source, which is based on linux security modules, is presented in paper. In order to test its effect, we employ two kinds of method:information-theoretic measures and Markov chains model, and we also compare the result with data of system call. The conclusion of experiment indicates that this data source is useful and even better than data of system call under certain condition.
The research of anomaly detection now focuses on four aspects:selection of data source, specification of behavior, normal behavior learning, behavior matching. For the first aspect, a new data source, which is based on linux security modules, is presented in paper. In order to test its effect, we employ two kinds of method:information-theoretic measures and Markov chains model, and we also compare the result with data of system call. The conclusion of experiment indicates that this data source is useful and even better than data of system call under certain condition.
2004, 33(4): 407-409.
Abstract:
This paper provides a fast and accurate algorithm of multi-face detection that is robust to the change of background and light. Because the multi-template matching algorithm based on Hausdorff Distance is very complex, many resolution techniques, such as decrease the dimension of model, find the area of interest, and get the fittest model based on the distance between transformation, have been used to advance the computation efficiency. The algorithm's performance was proved by experiment results.
This paper provides a fast and accurate algorithm of multi-face detection that is robust to the change of background and light. Because the multi-template matching algorithm based on Hausdorff Distance is very complex, many resolution techniques, such as decrease the dimension of model, find the area of interest, and get the fittest model based on the distance between transformation, have been used to advance the computation efficiency. The algorithm's performance was proved by experiment results.
2004, 33(4): 410-413.
Abstract:
A new automatic image registration method was presented in this paper, which was based on projection technique and suitable for functional magnetic resonance imaging times series images. The binary times series images were projected onto the horizontal orientation or the vertical orientation, and the arguments of rotation and translation were calculated according to the elements of the projection vectors. The method wad proved to be validated by the results of the simulation experiment and the application of functional magnetic resonance imaging data.
A new automatic image registration method was presented in this paper, which was based on projection technique and suitable for functional magnetic resonance imaging times series images. The binary times series images were projected onto the horizontal orientation or the vertical orientation, and the arguments of rotation and translation were calculated according to the elements of the projection vectors. The method wad proved to be validated by the results of the simulation experiment and the application of functional magnetic resonance imaging data.
2004, 33(4): 414-418.
Abstract:
Presented is an analytic signal model Va=GVu + W with Va and Vu corresponding to the event-related potentials (ERPs) evoked by attended and unattended visual stimuli, respectively. A total least square algorithm is utilized to get the G and W, then the effect of attention is decomposed into two aspects:attention induced activities (W) and a gain control (G) of unattended. Applied to a spatial attention ERP data, an integrated concept of selective attention is suggested that the early gain amplification (G>1.0) and newly involved neuron activities (W) before 200 ms after the stimulus onset mainly aim at obtaining an improved signal/noise ratio, the late gain supression (GW) after 200 ms aim at specific cognitive processing of the selectively enhanced signal.
Presented is an analytic signal model Va=GVu + W with Va and Vu corresponding to the event-related potentials (ERPs) evoked by attended and unattended visual stimuli, respectively. A total least square algorithm is utilized to get the G and W, then the effect of attention is decomposed into two aspects:attention induced activities (W) and a gain control (G) of unattended. Applied to a spatial attention ERP data, an integrated concept of selective attention is suggested that the early gain amplification (G>1.0) and newly involved neuron activities (W) before 200 ms after the stimulus onset mainly aim at obtaining an improved signal/noise ratio, the late gain supression (GW) after 200 ms aim at specific cognitive processing of the selectively enhanced signal.
2004, 33(4): 419-422.
Abstract:
Flexible intrusion detection and response system (ID&R) needs to maximize security while minimizing cost and making response automatically. A multi-agents based response system, CI2D&R, the cost-based intelligent intrusion detection and response system, is proposed in this paper, which is originally developed as a facility to deal with network-based attacks and to take effective response automatically and intelligently. The networking environment deployed with the CI2D&R consists of two major parts:Guard, which runs on the specific guarded host (GH), and Spy, which runs in guarded network (GN). The components of the CI2D&R are introduced, which include intrusion detection, attack classification, damage analysis, attack path rebuilding, resources automatically safeguarding, disaster recovery, and security management. The several kinds of data flow in CI2D&R are discussed, too. While CI2D&R is only a prototype, some special safety considerations of agents are also addressed.
Flexible intrusion detection and response system (ID&R) needs to maximize security while minimizing cost and making response automatically. A multi-agents based response system, CI2D&R, the cost-based intelligent intrusion detection and response system, is proposed in this paper, which is originally developed as a facility to deal with network-based attacks and to take effective response automatically and intelligently. The networking environment deployed with the CI2D&R consists of two major parts:Guard, which runs on the specific guarded host (GH), and Spy, which runs in guarded network (GN). The components of the CI2D&R are introduced, which include intrusion detection, attack classification, damage analysis, attack path rebuilding, resources automatically safeguarding, disaster recovery, and security management. The several kinds of data flow in CI2D&R are discussed, too. While CI2D&R is only a prototype, some special safety considerations of agents are also addressed.
2004, 33(4): 423-426.
Abstract:
Network quality of service in future needs to consider the impact of inherent self-similar. Traditional networks ignore this. The paper utilizes Fractional Brownian Motion model to build a network model, which improves statistical multiplexing efficiency by controlling effective bandwidth and provides services by admission control. Experiment verifies that FBM model can realistically describe packet traffic flows, predict their performance, make full use of network recourses, and make up the deficiency of conventional queue models.
Network quality of service in future needs to consider the impact of inherent self-similar. Traditional networks ignore this. The paper utilizes Fractional Brownian Motion model to build a network model, which improves statistical multiplexing efficiency by controlling effective bandwidth and provides services by admission control. Experiment verifies that FBM model can realistically describe packet traffic flows, predict their performance, make full use of network recourses, and make up the deficiency of conventional queue models.
2004, 33(4): 427-429,433.
Abstract:
The article presents a multicast routing algorithm that meets three constraint conditions in the multicast application. The algorithm comprises two steps. First the algorithm is based on MPH and adjusts the nodes' rank in the current multicast tree, and gradually gets the low cost and hop constrained multicast tree by selecting the destination node with minimum cost to current multicast tree in turn. Then some relay nodes, which is not fit for the requirement of the resource consumption, is deleted. The rest of the relay nodes makes up of the final multicast tree, which consumes the least time slot.
The article presents a multicast routing algorithm that meets three constraint conditions in the multicast application. The algorithm comprises two steps. First the algorithm is based on MPH and adjusts the nodes' rank in the current multicast tree, and gradually gets the low cost and hop constrained multicast tree by selecting the destination node with minimum cost to current multicast tree in turn. Then some relay nodes, which is not fit for the requirement of the resource consumption, is deleted. The rest of the relay nodes makes up of the final multicast tree, which consumes the least time slot.
2004, 33(4): 430-433.
Abstract:
This paper analyzes the existing P2P soft wares and their deficiency and inability to transmit data efficiently and hereby presents a new kind of P2P file transmission system architecture. This architecture is based on the existent IPv4 network,working on a unique three leveled multistage RootServer-GroupServer-User structure to improve efficiency. UDP-tunnel technology is employed to solve the problem in realizing the NAT-NAT data transmission. A new search-mode is adopted, files are well classified and indexed, and all of the processes of file transferring are properly monitored in this architecture. The results of the running of the system prove that the system makes an efficient use of the network bandwidth and the efficiency of file transmission is highly increased.
This paper analyzes the existing P2P soft wares and their deficiency and inability to transmit data efficiently and hereby presents a new kind of P2P file transmission system architecture. This architecture is based on the existent IPv4 network,working on a unique three leveled multistage RootServer-GroupServer-User structure to improve efficiency. UDP-tunnel technology is employed to solve the problem in realizing the NAT-NAT data transmission. A new search-mode is adopted, files are well classified and indexed, and all of the processes of file transferring are properly monitored in this architecture. The results of the running of the system prove that the system makes an efficient use of the network bandwidth and the efficiency of file transmission is highly increased.
2004, 33(4): 434-437.
Abstract:
The paper is dealing with the IPSec Protocols and analysing the structure and key technology of security association, authentication header, encapsulating security payload and Internet key exchange. On the basis of the discussion, it presents the practical design of IPSec, which can effectively ensure the security of data transmission in IPv6. In practice, there are two models can be selected, transmission model and tunnel model, transmission model can only be used on condition that IPSec is applied to the systems of the sender and the receiver. Therefore, in most cases, tunnel model is used because it is not necessary to make any change to the user's system.
The paper is dealing with the IPSec Protocols and analysing the structure and key technology of security association, authentication header, encapsulating security payload and Internet key exchange. On the basis of the discussion, it presents the practical design of IPSec, which can effectively ensure the security of data transmission in IPv6. In practice, there are two models can be selected, transmission model and tunnel model, transmission model can only be used on condition that IPSec is applied to the systems of the sender and the receiver. Therefore, in most cases, tunnel model is used because it is not necessary to make any change to the user's system.
2004, 33(4): 438-441.
Abstract:
Fault-tolerant real-time scheduling algorithm through time redundancy, whose schedulability bound is based on the worst execution time of tasks and the time reserved for tasks' fault-tolerant operation, has high rejection rate and low resource utilization. This paper presents fault-tolerant rate-monotonic scheduling with resource reclaim, based on FT-RM, to improve resource utilization and tasks throughoutput. This algorithm makes use of the attribute that the actual execution time of task is shorter than the worst execution time, to reclaim and reuse the resource released by the ended task. At last, the performance simulation and analysis of the scheduling algorithm are presented and factors that affect performance are investigated.
Fault-tolerant real-time scheduling algorithm through time redundancy, whose schedulability bound is based on the worst execution time of tasks and the time reserved for tasks' fault-tolerant operation, has high rejection rate and low resource utilization. This paper presents fault-tolerant rate-monotonic scheduling with resource reclaim, based on FT-RM, to improve resource utilization and tasks throughoutput. This algorithm makes use of the attribute that the actual execution time of task is shorter than the worst execution time, to reclaim and reuse the resource released by the ended task. At last, the performance simulation and analysis of the scheduling algorithm are presented and factors that affect performance are investigated.
2004, 33(4): 442-445.
Abstract:
Conception of secure labels is analyzed, and defined by formalization, subsequently the lattice model theory of labels for dynamic multi-level security is established, which shows that the set of secure labels for dynamic multi-level security comes into being "lattice order" in math, and solves the existence of g.l.b and l.u.b when one secure label compares to other, and establishes the theoretical basis for change from static multi-level security to dynamic multi-level security according to the history sensitivity.
Conception of secure labels is analyzed, and defined by formalization, subsequently the lattice model theory of labels for dynamic multi-level security is established, which shows that the set of secure labels for dynamic multi-level security comes into being "lattice order" in math, and solves the existence of g.l.b and l.u.b when one secure label compares to other, and establishes the theoretical basis for change from static multi-level security to dynamic multi-level security according to the history sensitivity.
2004, 33(4): 446-448.
Abstract:
The image is segmented to Bi-value image with max variance algorithm, and then the edge is detected by a series of image morphology algorithm including grads, thinning and cutting. The eleven point curvature-computing method is used to locate the area of corner and point of tangency. An improved algorithm based on least square fitting is given to search corner and point of tangency. This algorithm is applied to the cutting tools measurement system based on image processing and the actual result proves it has a good noise-resisted performance and can detect feature points accurately.
The image is segmented to Bi-value image with max variance algorithm, and then the edge is detected by a series of image morphology algorithm including grads, thinning and cutting. The eleven point curvature-computing method is used to locate the area of corner and point of tangency. An improved algorithm based on least square fitting is given to search corner and point of tangency. This algorithm is applied to the cutting tools measurement system based on image processing and the actual result proves it has a good noise-resisted performance and can detect feature points accurately.
2004, 33(4): 449-452.
Abstract:
Basing on the methods of production determining to the peak-load demand, the paper studies the models of production determining according to the demand that the manufacture facing with uncertain multi-peak-load. The paper establishes the model of production determining under demand with multi-peak-load and presents the methods of production determining under demand with multi-peak-load. The methods can apply to the production pricing especially to the electric power industry.
Basing on the methods of production determining to the peak-load demand, the paper studies the models of production determining according to the demand that the manufacture facing with uncertain multi-peak-load. The paper establishes the model of production determining under demand with multi-peak-load and presents the methods of production determining under demand with multi-peak-load. The methods can apply to the production pricing especially to the electric power industry.
2004, 33(4): 453-456.
Abstract:
In order to track Doppler signal effectively, a linear discrete-time tracking-differentiator is designed. For the integral-bounded input signal on an arbitrarily finite field, the progressive stabilization and the rapidity of this kind of tracking-differentiator are proved from mathematical analysis and the result of simulation. The obvious error occurred in difference method can be basically removed by using this kind of linear discrete-time tracking-differentiator and the design process is simple.
In order to track Doppler signal effectively, a linear discrete-time tracking-differentiator is designed. For the integral-bounded input signal on an arbitrarily finite field, the progressive stabilization and the rapidity of this kind of tracking-differentiator are proved from mathematical analysis and the result of simulation. The obvious error occurred in difference method can be basically removed by using this kind of linear discrete-time tracking-differentiator and the design process is simple.
2004, 33(4): 457-460.
Abstract:
A new fast algorithm for calculating the coefficients of ideal digital fractional differentiator is presented. It is difficult to compute directly the coefficients from the integral formula, since the integral function in the formula of the ideal digital fractional differentiator is a high-order oscillating function. Based on the properties of the integral formula, it's easy to convert the oscillating factor to the integral upper limit. Therefore a set of recursive expressions for calculating coefficients of ideal digital fractional differentiator are introduced in this paper. The experimental result shows that the new algorithm decreases the amount of operation greatly, at the same time promotes the algorithm's efficiency as well as avoid integral of high-order oscillating function.
A new fast algorithm for calculating the coefficients of ideal digital fractional differentiator is presented. It is difficult to compute directly the coefficients from the integral formula, since the integral function in the formula of the ideal digital fractional differentiator is a high-order oscillating function. Based on the properties of the integral formula, it's easy to convert the oscillating factor to the integral upper limit. Therefore a set of recursive expressions for calculating coefficients of ideal digital fractional differentiator are introduced in this paper. The experimental result shows that the new algorithm decreases the amount of operation greatly, at the same time promotes the algorithm's efficiency as well as avoid integral of high-order oscillating function.
2004, 33(4): 461-463,484.
Abstract:
By using a classical screened Coulomb potential with two phase factors and adopting classical analytical methods, the predictive descriptions on the energy level and spectrum of anti-hydrogen atom are given. As a result, the great differences of the energy level and spectrum between anti-hydrogen atom and hydrogen atom are found. The main quantum number n is a fraction less than 1 and the spectrum of the anti-hydrogen atom occurs only when the positron transits from ground state to excitation state, which is just contrary to the luminescent mechanism of an hydrogen atom.
By using a classical screened Coulomb potential with two phase factors and adopting classical analytical methods, the predictive descriptions on the energy level and spectrum of anti-hydrogen atom are given. As a result, the great differences of the energy level and spectrum between anti-hydrogen atom and hydrogen atom are found. The main quantum number n is a fraction less than 1 and the spectrum of the anti-hydrogen atom occurs only when the positron transits from ground state to excitation state, which is just contrary to the luminescent mechanism of an hydrogen atom.
2004, 33(4): 464-467.
Abstract:
In the paper, a new increment method of data mining is presented. Based on encoding the transaction data item set, the original data is transformed into a integral variable series is proved to be a Markov chain in theory. And instead of transfer probability, frequency is used in transfer probability matrix. Then a module is built for trend analysis.The analysis for the sale data of supermarket indicates that the method is fine, and a nice result that customs choice is same to different bland of one product is received.
In the paper, a new increment method of data mining is presented. Based on encoding the transaction data item set, the original data is transformed into a integral variable series is proved to be a Markov chain in theory. And instead of transfer probability, frequency is used in transfer probability matrix. Then a module is built for trend analysis.The analysis for the sale data of supermarket indicates that the method is fine, and a nice result that customs choice is same to different bland of one product is received.
2004, 33(4): 468-470.
Abstract:
A feasible trust algorithm which used maxim-entropy methods, a class of max-min problems with nonlinear constraints turn into nonlinear programming problems with inequality constraints is proposed. The algorithm which resolve general max-min problems is global convergent. Preliminary numerical experiments show that the proposed algorithm is effective.
A feasible trust algorithm which used maxim-entropy methods, a class of max-min problems with nonlinear constraints turn into nonlinear programming problems with inequality constraints is proposed. The algorithm which resolve general max-min problems is global convergent. Preliminary numerical experiments show that the proposed algorithm is effective.
2004, 33(4): 471-473.
Abstract:
Using the linear transformation method, this paper gives the necessary and sufficient conditions for Stein equation to have unique solution.The unique solution is also obtained. The method in this paper is elementary and the results are richer than the conclusion quoted from the references of this pojoer. The method in this paper can also be used to deal with mtrix equations on general field, which supplies a new method to cryptography.
Using the linear transformation method, this paper gives the necessary and sufficient conditions for Stein equation to have unique solution.The unique solution is also obtained. The method in this paper is elementary and the results are richer than the conclusion quoted from the references of this pojoer. The method in this paper can also be used to deal with mtrix equations on general field, which supplies a new method to cryptography.
2004, 33(4): 474-477.
Abstract:
In this paper, the effect of gas slippage in low permeation gas reservoirs is researched. Firstly, as the phenomenon of gas slippage has effected to the rate of permeation in gas measure, the mathematical model of nonlinear parabolic partial differential equation which reflects the rule of low permeation porous medium gas permeance is built according to the effect. Then the well posed of the solution to the nonlinear partial differential equation model in the condition of nonlinear boundary is analyzed in mathematical way. We also theoretically prove the existence, unique and stability of the solution to the model. Those results build the foundation for numerical calculation.
In this paper, the effect of gas slippage in low permeation gas reservoirs is researched. Firstly, as the phenomenon of gas slippage has effected to the rate of permeation in gas measure, the mathematical model of nonlinear parabolic partial differential equation which reflects the rule of low permeation porous medium gas permeance is built according to the effect. Then the well posed of the solution to the nonlinear partial differential equation model in the condition of nonlinear boundary is analyzed in mathematical way. We also theoretically prove the existence, unique and stability of the solution to the model. Those results build the foundation for numerical calculation.
2004, 33(4): 478-480.
Abstract:
In this paper, the signal majority domination number of graphs is generalized to strict majority domination number of graphs. We investigated the strict majority domination number of some unions of graphs based on the signal majority domination number of graphs. According to study for strict majority domination number of some unions of graphs, we determined the strict majority domination number of some unions of graphs and discuss relation the strict majority domination number of some unions of graphs and order number of graphs.
In this paper, the signal majority domination number of graphs is generalized to strict majority domination number of graphs. We investigated the strict majority domination number of some unions of graphs based on the signal majority domination number of graphs. According to study for strict majority domination number of some unions of graphs, we determined the strict majority domination number of some unions of graphs and discuss relation the strict majority domination number of some unions of graphs and order number of graphs.
2004, 33(4): 481-484.
Abstract:
The relativistic integral invariants of Birkhoffian systems are studied. The simultaneous variant equations and non-simultaneous variant equations to the relativistic Birkhoffian systems are constructed respectively. we demonstrate a theorem, i.e. by virtue of a given first integral of the system, a integral invariant of system may be constructed, and further give it's inverse theorem.
The relativistic integral invariants of Birkhoffian systems are studied. The simultaneous variant equations and non-simultaneous variant equations to the relativistic Birkhoffian systems are constructed respectively. we demonstrate a theorem, i.e. by virtue of a given first integral of the system, a integral invariant of system may be constructed, and further give it's inverse theorem.
