ISSN 
2001 Vol. 30, No. 4
2001, 30(4): 331-334.
Abstract:
This paper presents a new fast coding method of wavelet image with zerotree encoding. Based on the definition of multi-stage zerotree root and encoding imformation form, using optimized scalar quantization, this paper adopts different thresholds and different size of quantization codebood to each wavelet subband and confficients of each directions. It fully employs the importance degree of the subband coefficients and visual characteristic of mankind, which can compress the high frequency wavelet coefficients efficiently.The method only makes one time zerotree encoding, thus greatly reduces the encoding time.
This paper presents a new fast coding method of wavelet image with zerotree encoding. Based on the definition of multi-stage zerotree root and encoding imformation form, using optimized scalar quantization, this paper adopts different thresholds and different size of quantization codebood to each wavelet subband and confficients of each directions. It fully employs the importance degree of the subband coefficients and visual characteristic of mankind, which can compress the high frequency wavelet coefficients efficiently.The method only makes one time zerotree encoding, thus greatly reduces the encoding time.
2001, 30(4): 335-339.
Abstract:
This paper studies the survival performance of WDM optical networks based on wavelength routing. In order to reduce cost and make full use of finite resource of WDM optical networks, a survival scheme of WDM optical network based on self-healing ring in combination with mesh network is put forward. The scheme can dynamically allocate networks(optical fiber and wavelength resource according to concrete situation of network traffic and failure, and enhance flexibility and survivability of WDM OTN, which satisfies different user service for real time demand of survival performance.
This paper studies the survival performance of WDM optical networks based on wavelength routing. In order to reduce cost and make full use of finite resource of WDM optical networks, a survival scheme of WDM optical network based on self-healing ring in combination with mesh network is put forward. The scheme can dynamically allocate networks(optical fiber and wavelength resource according to concrete situation of network traffic and failure, and enhance flexibility and survivability of WDM OTN, which satisfies different user service for real time demand of survival performance.
2001, 30(4): 340-345.
Abstract:
In this paper, a 16QAM in BC of HFC is studied, and the effects of noise and channel characteristic on QAM are analyzed. A scheme of improving the quality of QAM by adopting adaptive equalizer is put forward, which is fulfilled with CPLD devices. The technology can improve the credibility of the equalizer and reduce the period of design. At present, the datum about the technology of the equalization of complex signal is very less, while the complex of equalizer can be apply to the system of communication. So it is a feasible technology method.
In this paper, a 16QAM in BC of HFC is studied, and the effects of noise and channel characteristic on QAM are analyzed. A scheme of improving the quality of QAM by adopting adaptive equalizer is put forward, which is fulfilled with CPLD devices. The technology can improve the credibility of the equalizer and reduce the period of design. At present, the datum about the technology of the equalization of complex signal is very less, while the complex of equalizer can be apply to the system of communication. So it is a feasible technology method.
2001, 30(4): 346-349.
Abstract:
It is very important of optical cross-connect (OXC) in OTN based on WDM, which is correlated with resource distribution, flexibility, survivability of OTN. A kind of OXC architecture is presented in this paper. The architecture is capable of flexible routing and cross-connecting for optical-channels, which is proved by means of photonic transmission design suite(PTDS) software. The parameters of insertion-loss and cross-talking meet with the requests.
It is very important of optical cross-connect (OXC) in OTN based on WDM, which is correlated with resource distribution, flexibility, survivability of OTN. A kind of OXC architecture is presented in this paper. The architecture is capable of flexible routing and cross-connecting for optical-channels, which is proved by means of photonic transmission design suite(PTDS) software. The parameters of insertion-loss and cross-talking meet with the requests.
2001, 30(4): 350-354.
Abstract:
Based on the definition of cable modem and the comparison of several demodulators, a novel burst mode differential quadrature phase shift keying (DQPSK) demodulator for the up-stream channel of hybrid fiber-coax networks is given. The scheme achieves bit-timing recovery prior to carrier recovery. Simulation results demonstrate that the proposed scheme can greatly reduce the required preamble length and its bit error rate (BER) performance in the AWGN channel is close to the theoretical performance of static DQPSK demodulator.
Based on the definition of cable modem and the comparison of several demodulators, a novel burst mode differential quadrature phase shift keying (DQPSK) demodulator for the up-stream channel of hybrid fiber-coax networks is given. The scheme achieves bit-timing recovery prior to carrier recovery. Simulation results demonstrate that the proposed scheme can greatly reduce the required preamble length and its bit error rate (BER) performance in the AWGN channel is close to the theoretical performance of static DQPSK demodulator.
2001, 30(4): 355-358.
Abstract:
The performance of turbo codes on frequency non-selective slow Rayleigh fading channels is investigated in this paper. The turbo decoder which performs maximum-likelihood(ML) decoding using the modified Euclidean distance metric and channel state information is considered. Based on the union bound and code weight distributions, the exact upper limit of turbo codes performance on fully interleaved Rayleigh fading channel is derived. A efficient tool for the design and analysis of turbo codes on Rayleigh fading channels is presented.
The performance of turbo codes on frequency non-selective slow Rayleigh fading channels is investigated in this paper. The turbo decoder which performs maximum-likelihood(ML) decoding using the modified Euclidean distance metric and channel state information is considered. Based on the union bound and code weight distributions, the exact upper limit of turbo codes performance on fully interleaved Rayleigh fading channel is derived. A efficient tool for the design and analysis of turbo codes on Rayleigh fading channels is presented.
2001, 30(4): 359-362.
Abstract:
This paper studies the digital moving picture definition and the method of test. The test pattern sequences of different rotate speeds are designed and created to measure the picture definition in all directions. The definition of static and moving pictures are measured and compared quantificationally. The definition of digital TV system using different code parameters of MPEG-2 is also given in this paper.
This paper studies the digital moving picture definition and the method of test. The test pattern sequences of different rotate speeds are designed and created to measure the picture definition in all directions. The definition of static and moving pictures are measured and compared quantificationally. The definition of digital TV system using different code parameters of MPEG-2 is also given in this paper.
2001, 30(4): 363-366.
Abstract:
An associated pseudorandom sequences technique,which is used in encryption watermark embedding and dedecting is proposed for multimedia copyright protection.Since the embedded data is associated with the embedded position,the watermark is not easy to be attacked.Covariance is used to detect watermark,which may reduce the influence of chaos.The discussion of the watermark's hidden ability and robustness shows that the technique has satisfied result,so it can be widely used.
An associated pseudorandom sequences technique,which is used in encryption watermark embedding and dedecting is proposed for multimedia copyright protection.Since the embedded data is associated with the embedded position,the watermark is not easy to be attacked.Covariance is used to detect watermark,which may reduce the influence of chaos.The discussion of the watermark's hidden ability and robustness shows that the technique has satisfied result,so it can be widely used.
2001, 30(4): 367-370.
Abstract:
A temperature detect scheme of hot-wire method with electronic switching is given in this paper. The change of heating state and sensing state for thermocouple is completed successfully. The comparator controlling circuit and detecting circuit are analyzed. The inline error decreases with linear alignment circuit. A mesentery system composed of an 8031 single-chip is established. The methods which stabilize the switching voltage are used in order to increase the measurement accuracy. Besides, sample hold circuit and digital display circuit are used in the scheme. The feasibility of the detecting instrument is also proved with experiments.
A temperature detect scheme of hot-wire method with electronic switching is given in this paper. The change of heating state and sensing state for thermocouple is completed successfully. The comparator controlling circuit and detecting circuit are analyzed. The inline error decreases with linear alignment circuit. A mesentery system composed of an 8031 single-chip is established. The methods which stabilize the switching voltage are used in order to increase the measurement accuracy. Besides, sample hold circuit and digital display circuit are used in the scheme. The feasibility of the detecting instrument is also proved with experiments.
2001, 30(4): 371-374.
Abstract:
According to the relation of image quality and its signal-to-noise ratio, the system behavior with frequency modulation is forecasted theoretically. By the use of current technologies, an analogue communication system at W-band is developed, which can be applied to video link. System experiment results are also given. The scheme and the essential technology of the system are recommended. The levels of millimeter-wave components applied to the system are described, which include oscillator, mixer, duplexer and antenna, et al. The system is cost-effective, stable and reliable, and its communication distance exceeds 8 km with image quality of 4.5-class.
According to the relation of image quality and its signal-to-noise ratio, the system behavior with frequency modulation is forecasted theoretically. By the use of current technologies, an analogue communication system at W-band is developed, which can be applied to video link. System experiment results are also given. The scheme and the essential technology of the system are recommended. The levels of millimeter-wave components applied to the system are described, which include oscillator, mixer, duplexer and antenna, et al. The system is cost-effective, stable and reliable, and its communication distance exceeds 8 km with image quality of 4.5-class.
2001, 30(4): 375-378.
Abstract:
In this paper, the microstrip patch antennae are simulated with FDTD method to discuss the effect of superstrate and air gap. The resonant frequency are calculated as well. It is shown that the numerical results are identical with experimental results. The radiation pattern and bandwidth are also predicted and discussed.
In this paper, the microstrip patch antennae are simulated with FDTD method to discuss the effect of superstrate and air gap. The resonant frequency are calculated as well. It is shown that the numerical results are identical with experimental results. The radiation pattern and bandwidth are also predicted and discussed.
2001, 30(4): 379-382.
Abstract:
The structure and dielectric properties of the BaO-TiO2-Nd2O3-La2O3(BTNL)system are investigated in this paper. BTNL system is the result of La2O3 partly replacing Nd2O3 in the BaO-TiO2-Nd2O3(BTN) system. By analyzing XRD diffractogram, it is proved that the temperature coefficient ((decreases with the increase of molar ratio of La2O3 and Nd2O3, because of the increase of the crystalline phases of BaLa2Ti4O12 and La2Ti2O7. Adding proper quantities additions into the BTNL system, the microwave ceramic material with ultra low loss can be achieved sintered at middle temperature, which can be used to prepare microwave monolithic capacitor.
The structure and dielectric properties of the BaO-TiO2-Nd2O3-La2O3(BTNL)system are investigated in this paper. BTNL system is the result of La2O3 partly replacing Nd2O3 in the BaO-TiO2-Nd2O3(BTN) system. By analyzing XRD diffractogram, it is proved that the temperature coefficient ((decreases with the increase of molar ratio of La2O3 and Nd2O3, because of the increase of the crystalline phases of BaLa2Ti4O12 and La2Ti2O7. Adding proper quantities additions into the BTNL system, the microwave ceramic material with ultra low loss can be achieved sintered at middle temperature, which can be used to prepare microwave monolithic capacitor.
2001, 30(4): 383-386.
Abstract:
In this paper, a simple 3-bus power system model which includes a dynamic induction motor model is analyzed and simulated to study voltage collapse. Voltage collapse means the voltage of the electrical system suddenly declines to an unacceptable level. The system parameter analysis shows that the initial conditions, parameters and change of the demand of electrical can result in voltage collapse. When perturbation is applied to the system, voltage collapse can be delayed or controlled. Simulation results show the feasibility of the method.
In this paper, a simple 3-bus power system model which includes a dynamic induction motor model is analyzed and simulated to study voltage collapse. Voltage collapse means the voltage of the electrical system suddenly declines to an unacceptable level. The system parameter analysis shows that the initial conditions, parameters and change of the demand of electrical can result in voltage collapse. When perturbation is applied to the system, voltage collapse can be delayed or controlled. Simulation results show the feasibility of the method.
2001, 30(4): 387-390.
Abstract:
This paper expounds the work principle and the torque measuring as well as rotating speed measuring methods used by the sensor which are based on the phase difference. The system scheme of the measurements is proposed, which is based on PC for controlling. The hardware electric circuit and the software designing idea are discussed in detail. The experiment and practical test results show the validity of the design and the reliability of the performance of the system.
This paper expounds the work principle and the torque measuring as well as rotating speed measuring methods used by the sensor which are based on the phase difference. The system scheme of the measurements is proposed, which is based on PC for controlling. The hardware electric circuit and the software designing idea are discussed in detail. The experiment and practical test results show the validity of the design and the reliability of the performance of the system.
2001, 30(4): 391-395.
Abstract:
A serve-accelerometer is a kind of sensor for acceleration measuremnent. By using a servo-accelerometer, the measurements of the inclination angle along its sensing axis can be easily got. This paper presents theoretical analysis for a servo-accelerometer with flexible quartz and experimental study of the device output voltages with different inclination angles, which proves that the inclination angle measurements with high accuracy by means of sensing characteristics of the device are very feasible. The servo-accelerometer with flexible quarts, which is connected to a signal processor including the technology of extro-low frequency filtering, 16-bit A/D transformation and CPU controlled by a software, becomes a high accuracy intrument for inclination angle measurements.
A serve-accelerometer is a kind of sensor for acceleration measuremnent. By using a servo-accelerometer, the measurements of the inclination angle along its sensing axis can be easily got. This paper presents theoretical analysis for a servo-accelerometer with flexible quartz and experimental study of the device output voltages with different inclination angles, which proves that the inclination angle measurements with high accuracy by means of sensing characteristics of the device are very feasible. The servo-accelerometer with flexible quarts, which is connected to a signal processor including the technology of extro-low frequency filtering, 16-bit A/D transformation and CPU controlled by a software, becomes a high accuracy intrument for inclination angle measurements.
2001, 30(4): 396-400.
Abstract:
Based on the fieldbus, an architecture of the most economical intelligent realization of the control system is put forward, and the economic goal function of the control system is presented in this paper. The intelligent optimization of the design of the system structure and the local controller parameters are discussed as well. The application indicates that the method can shorten the designing circle, improve the reliability of the system and gain conspicuous social economic benefits.
Based on the fieldbus, an architecture of the most economical intelligent realization of the control system is put forward, and the economic goal function of the control system is presented in this paper. The intelligent optimization of the design of the system structure and the local controller parameters are discussed as well. The application indicates that the method can shorten the designing circle, improve the reliability of the system and gain conspicuous social economic benefits.
2001, 30(4): 401-406.
Abstract:
Using Maxwell(s equations and the linear theory, the dispersion equations of wave propagation along the waveguide filled with radially and inhomogeneously unmagnetized plasma are deduced in this paper. Its propagation characteristics are discussed. The wave dispersion curves under radially linear and parabola plasma distribution are calculated quantitatively. The principles of variation compared with homogeneous conditions are discovered:the cut-off frequencies of HE waves decrease, while the cut-off frequencies of EH waves increase.
Using Maxwell(s equations and the linear theory, the dispersion equations of wave propagation along the waveguide filled with radially and inhomogeneously unmagnetized plasma are deduced in this paper. Its propagation characteristics are discussed. The wave dispersion curves under radially linear and parabola plasma distribution are calculated quantitatively. The principles of variation compared with homogeneous conditions are discovered:the cut-off frequencies of HE waves decrease, while the cut-off frequencies of EH waves increase.
2001, 30(4): 407-413.
Abstract:
Software agents are becoming an important design paradigm for inter-operating open, distributed systems. Mobile agents and intelligent agents are obviously different in origins, emphases, implementation and application platforms and interests of the supporting communities. But both mobile agents and intelligent agents paradigms are targeting adaptive and flexible co-operation, particularly for interoperability between or within distributed systems in a dynamically changing environment. In this paper, the similarities and differences, advantages and disadvantages of the OMG mobile agent and FIPA intelligent agent approaches in specific application context are analyzed. Based on the analysis, two ACL based possibilities are discussed for harmonizing and integrating the two standards and a MASIF-FIPA addon is also developed.
Software agents are becoming an important design paradigm for inter-operating open, distributed systems. Mobile agents and intelligent agents are obviously different in origins, emphases, implementation and application platforms and interests of the supporting communities. But both mobile agents and intelligent agents paradigms are targeting adaptive and flexible co-operation, particularly for interoperability between or within distributed systems in a dynamically changing environment. In this paper, the similarities and differences, advantages and disadvantages of the OMG mobile agent and FIPA intelligent agent approaches in specific application context are analyzed. Based on the analysis, two ACL based possibilities are discussed for harmonizing and integrating the two standards and a MASIF-FIPA addon is also developed.
2001, 30(4): 414-418.
Abstract:
The data integrity is an important content of the database protection. In view of database application from one-tier architecture to multi-tier architecture, this paper analyzes the tiered models of the access to database by database application. The realization of the data integrity at each tier is discussed and the examples for the realization in three tiers of database, data module and user interface are given to prove the discussion. Therefore the data integrity can be kept at tiers whenever the access of the data is realized in different process.
The data integrity is an important content of the database protection. In view of database application from one-tier architecture to multi-tier architecture, this paper analyzes the tiered models of the access to database by database application. The realization of the data integrity at each tier is discussed and the examples for the realization in three tiers of database, data module and user interface are given to prove the discussion. Therefore the data integrity can be kept at tiers whenever the access of the data is realized in different process.
2001, 30(4): 419-423.
Abstract:
This paper of studies the characteristics of the regional allocations of FDI in China based on the data of 1999. Furthermore, it makes the statistical test and practical analysis on the influential factors to the regional allocations of FDI on the basis of linear regression models. Thus, it is concluded that the present regional allocation of FDI is quite out of balances mainly caused by different economic strength, investment climate and geographical locations. It is of major task for the western regions to improve the investment climate. It is also suggested that some policies should be made on how to attract more FDI for the western regions.
This paper of studies the characteristics of the regional allocations of FDI in China based on the data of 1999. Furthermore, it makes the statistical test and practical analysis on the influential factors to the regional allocations of FDI on the basis of linear regression models. Thus, it is concluded that the present regional allocation of FDI is quite out of balances mainly caused by different economic strength, investment climate and geographical locations. It is of major task for the western regions to improve the investment climate. It is also suggested that some policies should be made on how to attract more FDI for the western regions.
2001, 30(4): 424-428.
Abstract:
In this paper, a kind of the problems with respect to the moment complete convergence of martingale random variables is discussed. Under certain moment condition, based on high order moment and inequality of supmartingale and other relevant analytical methods, the sufficient condition of the moment complete convergence for martingale random variables is obtained. Therefor, the relation between moment and complete convergence for martingale random variables is revealed with a satisfying result.
In this paper, a kind of the problems with respect to the moment complete convergence of martingale random variables is discussed. Under certain moment condition, based on high order moment and inequality of supmartingale and other relevant analytical methods, the sufficient condition of the moment complete convergence for martingale random variables is obtained. Therefor, the relation between moment and complete convergence for martingale random variables is revealed with a satisfying result.
2001, 30(4): 429-433.
Abstract:
This paper investigates the L2-gain stability of perturbed neural networks by analyzing finite-gain stability of control systems. Using the method of variations of the parameters, the method of Liapunov function and the method of inequality analysis, an sufficient condition guaranteeing networks L2-gain stability is given, when networks are affected by inner and external perturbation.
This paper investigates the L2-gain stability of perturbed neural networks by analyzing finite-gain stability of control systems. Using the method of variations of the parameters, the method of Liapunov function and the method of inequality analysis, an sufficient condition guaranteeing networks L2-gain stability is given, when networks are affected by inner and external perturbation.
