ISSN 
2004 Vol. 33, No. 3
2004, 33(3): 225-227.
Abstract:
This article researches the combination of fractionally spaced equalizer (FSE) and decision feedback equalizer(DFE) applied in MIMO frequency selective channels. This kind of equalizer has low sensitivity to the receiver's sampling phase, and it can eliminate the ISI without adding noise gain. This paper analyses and compares the FSE-DFE applying two adaptive algorithms:least mean squares (LMS) algorithm and constant modulus algorithm (CMA). Through the simulation results, their respective advantages and disadvantages are presented. Based on these algorithms, a new hybrid algorithm possessing the advantages of LMS and CMA is proposed. This algorithm requires only a few training sequences and performs better than CMA.
This article researches the combination of fractionally spaced equalizer (FSE) and decision feedback equalizer(DFE) applied in MIMO frequency selective channels. This kind of equalizer has low sensitivity to the receiver's sampling phase, and it can eliminate the ISI without adding noise gain. This paper analyses and compares the FSE-DFE applying two adaptive algorithms:least mean squares (LMS) algorithm and constant modulus algorithm (CMA). Through the simulation results, their respective advantages and disadvantages are presented. Based on these algorithms, a new hybrid algorithm possessing the advantages of LMS and CMA is proposed. This algorithm requires only a few training sequences and performs better than CMA.
2004, 33(3): 228-230，253.
Abstract:
In this paper, the effects of third order dispersion on characteristic of high speed dispersion managed soliton transmission are studied by split-step fast fourier transformed method. Through compared with transmission figures in different system conditions, the performance of dispersion managed soliton system is better than common soliton system, the results of this paper have valuable reference in designing the dispersion managed soliton system.
In this paper, the effects of third order dispersion on characteristic of high speed dispersion managed soliton transmission are studied by split-step fast fourier transformed method. Through compared with transmission figures in different system conditions, the performance of dispersion managed soliton system is better than common soliton system, the results of this paper have valuable reference in designing the dispersion managed soliton system.
2004, 33(3): 231-234,238.
Abstract:
The instantaneous feature parameters of received signal are extracted using digital signal processing, the eliminating correlation and dimensionality reduction for these feature parameters are realized using the principal component analysis approach. The classification and recognition of modulation of signal are designed by template matching of statistical pattern recognition. The simulation results show the approach proposed in this paper is efficient.
The instantaneous feature parameters of received signal are extracted using digital signal processing, the eliminating correlation and dimensionality reduction for these feature parameters are realized using the principal component analysis approach. The classification and recognition of modulation of signal are designed by template matching of statistical pattern recognition. The simulation results show the approach proposed in this paper is efficient.
2004, 33(3): 235-238.
Abstract:
Aim at the case that the practical DS/CDMA system often is asynchronous DS/CDMA system in multipath fading channel, some conventional blind multi-user detection algorithms, which were applied to synchronous DS/CDMA system in AWGN channel, are modified, and to use them to asynchronous DS/CDMA system in multipath fading channel,these modified algorithms have good performance.Theoretical analysis and computer simulation confirm that these modified methods are available.
Aim at the case that the practical DS/CDMA system often is asynchronous DS/CDMA system in multipath fading channel, some conventional blind multi-user detection algorithms, which were applied to synchronous DS/CDMA system in AWGN channel, are modified, and to use them to asynchronous DS/CDMA system in multipath fading channel,these modified algorithms have good performance.Theoretical analysis and computer simulation confirm that these modified methods are available.
2004, 33(3): 239-242.
Abstract:
In this paper, both tracking errorsdue to multipath effects considered autocorrelation sidelobe in GPS and the effect of different early-late spacing are studied. Based on noncoherent DLL and arctan carrier PLL, the curves of tracking errors in general forms are given after a series of computing and simulation.It is shown that tracking errors are different in different regions; autocorrelation sidelobe affects the code phase and carrier phase tracking errors of the longer time reative multipath delay; a smaller early-late spacing can reduce the tracking errors both of code phase and of carrier phase.
In this paper, both tracking errorsdue to multipath effects considered autocorrelation sidelobe in GPS and the effect of different early-late spacing are studied. Based on noncoherent DLL and arctan carrier PLL, the curves of tracking errors in general forms are given after a series of computing and simulation.It is shown that tracking errors are different in different regions; autocorrelation sidelobe affects the code phase and carrier phase tracking errors of the longer time reative multipath delay; a smaller early-late spacing can reduce the tracking errors both of code phase and of carrier phase.
2004, 33(3): 243-246.
Abstract:
In this paper, an adaptive time-varying wavelet packet transform (WPT) excision algorithm is proposed for time-varying narrowband interference (TVNBI) in DSSS communication. Based on time decomposition, this method takes advantage of multi-resolution capability and favorable time-frequency character of WPT to perform frequency decomposition, separate desirable signal from jamming signal, the DS signal is recovered by wavelet reconstruction after setting zeros to polluted frequency sub-band. Computer simulation results show that compared with the non-time-varying WPT technique, this method could efficiently search and locate the TVNBI, provide satisfied bit error rate (BER) performance at the cost of increasing computation.
In this paper, an adaptive time-varying wavelet packet transform (WPT) excision algorithm is proposed for time-varying narrowband interference (TVNBI) in DSSS communication. Based on time decomposition, this method takes advantage of multi-resolution capability and favorable time-frequency character of WPT to perform frequency decomposition, separate desirable signal from jamming signal, the DS signal is recovered by wavelet reconstruction after setting zeros to polluted frequency sub-band. Computer simulation results show that compared with the non-time-varying WPT technique, this method could efficiently search and locate the TVNBI, provide satisfied bit error rate (BER) performance at the cost of increasing computation.
2004, 33(3): 247-249.
Abstract:
Based on the fraction Fouier transform and subspace orthogonality,an approach,which detects and estimates the parameters of the low SNR LFM signal,is proposed in this paper.The LFM signal is first transformed into a complex sinusoidal signal in term of the fraction Fourier transform,and then using the orthogonality between the subspace of noise and the subspace of the transformed signal,the detection and parameters estimation of LFM signal is achieved by finding the minimum/maximum. Computer simulation confirms its availability.
Based on the fraction Fouier transform and subspace orthogonality,an approach,which detects and estimates the parameters of the low SNR LFM signal,is proposed in this paper.The LFM signal is first transformed into a complex sinusoidal signal in term of the fraction Fourier transform,and then using the orthogonality between the subspace of noise and the subspace of the transformed signal,the detection and parameters estimation of LFM signal is achieved by finding the minimum/maximum. Computer simulation confirms its availability.
2004, 33(3): 250-253.
Abstract:
The paper mainly deals with following three aspects:offering a frame of filtering system in collecting high-precision data of weak signals when strong electromagnetic interferes and analyzing the corresponding errors, discussing common digital filtering theory and its realization with field programmable gate array, applying self-adaptive theory to reducing noise. Since the system has such advantages as running independently, writing program easily, and digital filtering, it is to be put into widespread use in collecting and controlling signals.
The paper mainly deals with following three aspects:offering a frame of filtering system in collecting high-precision data of weak signals when strong electromagnetic interferes and analyzing the corresponding errors, discussing common digital filtering theory and its realization with field programmable gate array, applying self-adaptive theory to reducing noise. Since the system has such advantages as running independently, writing program easily, and digital filtering, it is to be put into widespread use in collecting and controlling signals.
2004, 33(3): 254-257.
Abstract:
After analyzing recently common methods of calculating the largest Lyapunov exponent from small data sets, the irreversible property of time trajectories is studied and extended method for calculating the largest Lyapunov exponent of chaotic system is proposed based on backward or bi-direction search phase point. The computer simulation shows some valuable conclusions that the novel method is more anti-noise and precise that the old ones.
After analyzing recently common methods of calculating the largest Lyapunov exponent from small data sets, the irreversible property of time trajectories is studied and extended method for calculating the largest Lyapunov exponent of chaotic system is proposed based on backward or bi-direction search phase point. The computer simulation shows some valuable conclusions that the novel method is more anti-noise and precise that the old ones.
2004, 33(3): 258-261.
Abstract:
Characteristics of ion noise in a traveling wave tube (TWT) focused by periodic permanent magnets (PPM) have been discussed by means of a hybrid model. One dimension Particle-in-Cell method (PIC) simulation code is developed. Compare to uniform magnetic field focus system the noise frequency is lower and the spectrum is wider by the PPM focus system. From the analysis results we find decreasing the axial electrostatic potential well would reduce this noise.
Characteristics of ion noise in a traveling wave tube (TWT) focused by periodic permanent magnets (PPM) have been discussed by means of a hybrid model. One dimension Particle-in-Cell method (PIC) simulation code is developed. Compare to uniform magnetic field focus system the noise frequency is lower and the spectrum is wider by the PPM focus system. From the analysis results we find decreasing the axial electrostatic potential well would reduce this noise.
2004, 33(3): 262-265.
Abstract:
Maths model of nonlinear electric pulse generated by PCSS's is built. Transmission Characteristics of various waveforms of it are deduced theoretically and analysised numerically. Compared with rectangle and isosceles trapezoid electric pulses,it is indicated that transmission Characteristics of Nonlinear Electric Pulse is more closer to that of rectangle pulse,when the risetime is shorter and the beeline is more horizontal. Theoretical basis is provided for applications of nonlinear photoconductive switches in the transmission of electromagnetic energy.
Maths model of nonlinear electric pulse generated by PCSS's is built. Transmission Characteristics of various waveforms of it are deduced theoretically and analysised numerically. Compared with rectangle and isosceles trapezoid electric pulses,it is indicated that transmission Characteristics of Nonlinear Electric Pulse is more closer to that of rectangle pulse,when the risetime is shorter and the beeline is more horizontal. Theoretical basis is provided for applications of nonlinear photoconductive switches in the transmission of electromagnetic energy.
2004, 33(3): 266-269.
Abstract:
Based on the Maxwell's equation, the finite-difference time-domain method presented in this paper is efficient and accuracy for modeling and analyzing the micro-electro-mechanical systems multiplayer microstrip patch antenna studied by our lab. The antenna characteristic parameters are discussed by the result of simulation. It implements relatively compatible absorbing boundary conditions. Saving the computer memory and CPU time.
Based on the Maxwell's equation, the finite-difference time-domain method presented in this paper is efficient and accuracy for modeling and analyzing the micro-electro-mechanical systems multiplayer microstrip patch antenna studied by our lab. The antenna characteristic parameters are discussed by the result of simulation. It implements relatively compatible absorbing boundary conditions. Saving the computer memory and CPU time.
2004, 33(3): 270-272.
Abstract:
Nowadays, Internet is more and more widely used. WWW has been a largely distributed information space and provided a valuable information resource for users. How get the information rapidly and accurately makes information filtrating become the focus of Internet. Based on these, the paper analysis the vector space model, Boolean logic model and the latent semantic index model in common use in the information filtrating and problems in existence. And the paper presents an accurate and better information filtrating model based on the blur muster.
Nowadays, Internet is more and more widely used. WWW has been a largely distributed information space and provided a valuable information resource for users. How get the information rapidly and accurately makes information filtrating become the focus of Internet. Based on these, the paper analysis the vector space model, Boolean logic model and the latent semantic index model in common use in the information filtrating and problems in existence. And the paper presents an accurate and better information filtrating model based on the blur muster.
2004, 33(3): 273-277.
Abstract:
The steady-state optimization problem is optimizing objective functions based on mathematical model under constrained conditions, in fact the large-scale industrial processes are often nonlinear and slowly time varying. In allusion to dynamic nonlinear large-scale industrial processes, to bring up gained the method of decentralized identification for the strong consistency estimates of the divisible steady-state models, it is used that property of polynomial can infinitely approach to the nonlinear function and in optimization processes use step signals as input signals, the divisible steady-state models of dynamic nonlinear large-scale industrial processes, and the cognizable conditions are obtained.
The steady-state optimization problem is optimizing objective functions based on mathematical model under constrained conditions, in fact the large-scale industrial processes are often nonlinear and slowly time varying. In allusion to dynamic nonlinear large-scale industrial processes, to bring up gained the method of decentralized identification for the strong consistency estimates of the divisible steady-state models, it is used that property of polynomial can infinitely approach to the nonlinear function and in optimization processes use step signals as input signals, the divisible steady-state models of dynamic nonlinear large-scale industrial processes, and the cognizable conditions are obtained.
2004, 33(3): 278-281.
Abstract:
A design principle of refrigerator vaporizer pipeline capability is developed. The pipeline resistance synthesis parameter is affected by temperature and pressure based on theory of carrent in pipeline. The test method of pipeline resistance synthesis parameter and leakage factor is expounded. The test system of pipeline is developed based on sunsamg microcomputer.
A design principle of refrigerator vaporizer pipeline capability is developed. The pipeline resistance synthesis parameter is affected by temperature and pressure based on theory of carrent in pipeline. The test method of pipeline resistance synthesis parameter and leakage factor is expounded. The test system of pipeline is developed based on sunsamg microcomputer.
2004, 33(3): 282-284.
Abstract:
Atmospheric turbulence flux data and land surface temperature data of Tibet are analyzed in this paper. A new term, the character estimation of land surface temperature,is proposed to get the relationship. By the time series analysis, the transfer function model between turbulence flux and land surface temperature is found out. This model is the base to discuss the temporal scaling effect and the temporal lag effect of land surface temperature.
Atmospheric turbulence flux data and land surface temperature data of Tibet are analyzed in this paper. A new term, the character estimation of land surface temperature,is proposed to get the relationship. By the time series analysis, the transfer function model between turbulence flux and land surface temperature is found out. This model is the base to discuss the temporal scaling effect and the temporal lag effect of land surface temperature.
2004, 33(3): 285-288.
Abstract:
In this paper, the characteristics of SYN flooding attack are explored, some key metrics of judging this kind of attack are proposed. Thereafter, an introduction of the architecture of network measurement system is introduced. Then the detecting method with the features of service-protected and attack-removed, the method of tracing the source of attack are expatiated in detail. Finally, the experiments for validating the mechanisms of detecting and tracing attacks are given.
In this paper, the characteristics of SYN flooding attack are explored, some key metrics of judging this kind of attack are proposed. Thereafter, an introduction of the architecture of network measurement system is introduced. Then the detecting method with the features of service-protected and attack-removed, the method of tracing the source of attack are expatiated in detail. Finally, the experiments for validating the mechanisms of detecting and tracing attacks are given.
2004, 33(3): 289-292.
Abstract:
This paper designs an Agent-based Distributed Intrusion Detection System. The DIDS system combines host-based intrusion detection and network-based intrusion detection functions. It can be used to protect large area network and have relatively good expansibility. This paper also discusses the implementation of BP neural network in intrusion detection. Because of the traditional BP NN's weakness in learning time and performance, variable learning rate BP regression neural network (batch and momentum techniques are also used) are designed. The algorithm has been tested on a network data set. The result showed that it had much better performance than traditional BP NN.
This paper designs an Agent-based Distributed Intrusion Detection System. The DIDS system combines host-based intrusion detection and network-based intrusion detection functions. It can be used to protect large area network and have relatively good expansibility. This paper also discusses the implementation of BP neural network in intrusion detection. Because of the traditional BP NN's weakness in learning time and performance, variable learning rate BP regression neural network (batch and momentum techniques are also used) are designed. The algorithm has been tested on a network data set. The result showed that it had much better performance than traditional BP NN.
2004, 33(3): 293-296.
Abstract:
A rate-distortion computation model is established for approximately estimating the total quantization distortion of one frame, and a new real time Intra-update criterion is proposed. Through comparing the increased quantization distortion and reduced propagation distortion by intra-updating, the encoder can quickly decide which macroblock need to be intra-updated. Simulation results show that the performance of proposed algorithm, which reduces the computational complexity significantly, achieves the same or even better gains over traditional rate-distortion based Intra-update methods.
A rate-distortion computation model is established for approximately estimating the total quantization distortion of one frame, and a new real time Intra-update criterion is proposed. Through comparing the increased quantization distortion and reduced propagation distortion by intra-updating, the encoder can quickly decide which macroblock need to be intra-updated. Simulation results show that the performance of proposed algorithm, which reduces the computational complexity significantly, achieves the same or even better gains over traditional rate-distortion based Intra-update methods.
2004, 33(3): 297-300.
Abstract:
Considering many separated maintenance databases of the airline companies, this paper presents a solution based on the C/A/S construction of EASERVER application server. The solution is applied in the troubleshooting expert system.It optimizes the software construction of the expert system, and avoids upgrade of hardware so as to reduce the cost. By combining NVO(Non Visual Object) with DATAWINDOW, it solves the problem of dealing with and sharing a lot of data in the expert system.
Considering many separated maintenance databases of the airline companies, this paper presents a solution based on the C/A/S construction of EASERVER application server. The solution is applied in the troubleshooting expert system.It optimizes the software construction of the expert system, and avoids upgrade of hardware so as to reduce the cost. By combining NVO(Non Visual Object) with DATAWINDOW, it solves the problem of dealing with and sharing a lot of data in the expert system.
2004, 33(3): 301-304.
Abstract:
National security is a foundation which a nation has been existing and developing. Building a national security pre-warning system which bases on new international situations and national security traits is a important measure by which many nations will safeguard national sovereighty and interests. The theory gist the system based on will be analysed from new point of view.The paper will put forward national security factor's levels and their interactional mathematics model; and will summarize briefly the system's function and characteristic; and will show emphases on the building plan and task and list of the system.
National security is a foundation which a nation has been existing and developing. Building a national security pre-warning system which bases on new international situations and national security traits is a important measure by which many nations will safeguard national sovereighty and interests. The theory gist the system based on will be analysed from new point of view.The paper will put forward national security factor's levels and their interactional mathematics model; and will summarize briefly the system's function and characteristic; and will show emphases on the building plan and task and list of the system.
2004, 33(3): 305-308.
Abstract:
An optimization scheme design of BOM management was proposed, with a manufacturing enterprise which based on customer's order as object, aimed at the characteristics and difficulty in the material management. This paper constructed a transformable structure of the products, accounting for the functions and characteristics of the system; brought forward a referenced optimization scheme for implementation. Via this scheme, we reduced the amount of the products and the BOM, improved the efficiency of the BOM regeneration and the accuracy of costing. And with more careful configuration of the product structure, the manufacture process can be managed more accurately.
An optimization scheme design of BOM management was proposed, with a manufacturing enterprise which based on customer's order as object, aimed at the characteristics and difficulty in the material management. This paper constructed a transformable structure of the products, accounting for the functions and characteristics of the system; brought forward a referenced optimization scheme for implementation. Via this scheme, we reduced the amount of the products and the BOM, improved the efficiency of the BOM regeneration and the accuracy of costing. And with more careful configuration of the product structure, the manufacture process can be managed more accurately.
2004, 33(3): 309-311,315.
Abstract:
After Tl(I)-morpholine-4-carbodithioate complex is formed by the complex reaction of Tl(I) with morpholine-4-carbodithioate, the Tl(I) complex is quantitatively adsorbed onto microcrystalline naphthalene in the range of pH=5~10.The trace amount of thallium is determined by differential pulse polarography on DME after the adsorption of its morpholine-4-carbodithioate is decomposed in 15 ml of 1.5 mol/L HCl. The detection limit of thallium is 0.025 μg/ml and the linear range of concentration is 0.05~10 μg/ml with a correlation coefficient of 0.999 5 and a relative standard deviation of ±0.90.
After Tl(I)-morpholine-4-carbodithioate complex is formed by the complex reaction of Tl(I) with morpholine-4-carbodithioate, the Tl(I) complex is quantitatively adsorbed onto microcrystalline naphthalene in the range of pH=5~10.The trace amount of thallium is determined by differential pulse polarography on DME after the adsorption of its morpholine-4-carbodithioate is decomposed in 15 ml of 1.5 mol/L HCl. The detection limit of thallium is 0.025 μg/ml and the linear range of concentration is 0.05~10 μg/ml with a correlation coefficient of 0.999 5 and a relative standard deviation of ±0.90.
2004, 33(3): 312-315.
Abstract:
A new algorithm for finding the inverse of a nonsingular r-circulant matrix is presented by the Euclid algorithm of polynomial. Extension is made to compute the group inverse and the Moore-Penrose inverse of a singular r-circulant matrix. Finally, numerical examples are given.
A new algorithm for finding the inverse of a nonsingular r-circulant matrix is presented by the Euclid algorithm of polynomial. Extension is made to compute the group inverse and the Moore-Penrose inverse of a singular r-circulant matrix. Finally, numerical examples are given.
2004, 33(3): 316-318,330.
Abstract:
Friedman viewed that the number of bidders in bidding submit Poisson Distribution. On the aboue assumption, this paper studies reservation value setting and draws conclusions that reservation value has no pertinence with the expected number of bidders while the expected number of bidders affect expected revenue of the auctioneer. Meanwhile this paper gets a formula to calculate reservation value, thus brings forward a way for design of bidding meechanism, which further approaches actual conditions.
Friedman viewed that the number of bidders in bidding submit Poisson Distribution. On the aboue assumption, this paper studies reservation value setting and draws conclusions that reservation value has no pertinence with the expected number of bidders while the expected number of bidders affect expected revenue of the auctioneer. Meanwhile this paper gets a formula to calculate reservation value, thus brings forward a way for design of bidding meechanism, which further approaches actual conditions.
2004, 33(3): 319-321.
Abstract:
The article puts forward a approach of third-degree price discrimination decision of monopolist in uncertain demand,according to the disparity between the existing theory of price of monopolist and their practice.A new decision model was found based on the third-degree price discriminarion decision model in certain demand.Sametime the article gives us a way of solving the decision model by computer simulation.And it analyses the results of simulation,the results show that this method expand the theory of price of monopolist and improve the utilization of the theory as well.
The article puts forward a approach of third-degree price discrimination decision of monopolist in uncertain demand,according to the disparity between the existing theory of price of monopolist and their practice.A new decision model was found based on the third-degree price discriminarion decision model in certain demand.Sametime the article gives us a way of solving the decision model by computer simulation.And it analyses the results of simulation,the results show that this method expand the theory of price of monopolist and improve the utilization of the theory as well.
2004, 33(3): 322-326.
Abstract:
Fuzzy pattern recognition is one of the most useful methods in quantitative analysis of company market competition orientation. But its uniqueness of deciding grade of membership makes this method lose its fuzzy meaning. In this paper, cloud model is built and applied to rectify the shortage of the above by using the normal cloud instead of membership function, make the recognition results of company market competition orientation more reasonable and actual, and try to explore the application of Cloud Theory in the field of economic management.
Fuzzy pattern recognition is one of the most useful methods in quantitative analysis of company market competition orientation. But its uniqueness of deciding grade of membership makes this method lose its fuzzy meaning. In this paper, cloud model is built and applied to rectify the shortage of the above by using the normal cloud instead of membership function, make the recognition results of company market competition orientation more reasonable and actual, and try to explore the application of Cloud Theory in the field of economic management.
2004, 33(3): 327-330.
Abstract:
As economic society develops, the marketing strategies changes constantly while the marketing theory innovates unceasingly in practical use. With an analysis of the content,characters and advantages of the traditional 4Ps marketing strategies, 4Cs marketing strategies in the well as 4Rs and 4Vs marketing strategies recently put forward, this paper proposes the applicable market environments and ranges that the above marketing strategies can be put into by combining Chinese marketing environment and its enterprises' characteristics. It helps instruct Chinese enterprises how to understand and apply those marketing strategies appropriately.
As economic society develops, the marketing strategies changes constantly while the marketing theory innovates unceasingly in practical use. With an analysis of the content,characters and advantages of the traditional 4Ps marketing strategies, 4Cs marketing strategies in the well as 4Rs and 4Vs marketing strategies recently put forward, this paper proposes the applicable market environments and ranges that the above marketing strategies can be put into by combining Chinese marketing environment and its enterprises' characteristics. It helps instruct Chinese enterprises how to understand and apply those marketing strategies appropriately.
2004, 33(3): 331-333.
Abstract:
This paper considers a cold standby system consisting of two different units with t delay repair. Assuming that the working life, the delay repair time and the repair time are general distributions, some main reliability quantities, such as MTTFF, availability and average failure number, are analyzed by Markov renewal process and Laplace transform. Some important reliability results are obtained.
This paper considers a cold standby system consisting of two different units with t delay repair. Assuming that the working life, the delay repair time and the repair time are general distributions, some main reliability quantities, such as MTTFF, availability and average failure number, are analyzed by Markov renewal process and Laplace transform. Some important reliability results are obtained.
2004, 33(3): 334-337.
Abstract:
A relation of equivalence on a finite set is discussed, and it is transformed into the number of solutions of an indefinite system of equations. Formula and their combinatorial meaning of nonnegative integral solution of such equations are given.
A relation of equivalence on a finite set is discussed, and it is transformed into the number of solutions of an indefinite system of equations. Formula and their combinatorial meaning of nonnegative integral solution of such equations are given.
