Table of Content

25 September 2007, Volume 35 Issue 9

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Electronics, Communication & Automation Technology

Protocol of Wireless Data Transmission in Åutomobile Braking Performance Monitoring System

Lin Tu-sheng li lin-feng

2007, 35(9):  1-5. 

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In order to resolve the data conf1ict in real-time transmission of braking signals sent by tire-mounted accelerators, a protocol of wireless data transmission of the non-contact automobile braking performance monitoring system (BPMS) was investigated. According to the features of braking signals and the conf1ict sources during the signal transmission in BPMS , the methods to resolve the data conf1ict in current tire pressure monitoring system ( TPMS) were analyzed and compared , and a new protocol of multi -slaver circular transmission chain for real-time wireless data transmission was proposed. Moreover , the principle and realization of the protocol were discussed and communicating experiments were performed to verify the effectiveness of the proposed protocol in resolving the data conflict in wireless data transmission in BPMS.

Design of Radio Frequency Identification Tag Antenna Based on Slot Antenna

Zhou Yong-ming Lai Xiao-zheng Lai Sheng-li Zhang Rui-na

2007, 35(9):  6-10. 

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In order to apply the slot .antenna to the Radio Frequency Identification (RFID) tag , a new method to design the slot antenna for RFID tag is first proposed. In this method , the impedance expression of mutual-patch antenna is adopted to calculate the impedance of mutual-patch dipole antenna according to the impedance of the slot antenna to be designed. Next , the profile of the dipole antenna is determined , and two slot antennas respectively with even and odd symmetries are presented for RFID tag at ultra-high frequency band. Then , the simulation is performed to present the curves of impedance and retum coefficient (S lI) versus frequency and the radiated pattem. Fabricated antennas are finally produced according to the simulated results. The results of design , simulation and measurement indicate that the design method is simple , clear and efficient , that the performance of the odd-symmetry slot antenna is better than that of the even-symmetry one , and that the simulated results accord well with the measured ones.

Performance of MIMO-OFDM System ßased on Subcarrier Grouping in Multipath Fading

Yu Hua -wen Yin jun-xun Lai Guo-ting

2007, 35(9):  11-15. 

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In the space-time-frequency-coded MIMO-OFDM system , the scheme of subcarrier grouping is adopted to divide the pilot sequence into independent subchannels , and the channel estimation is extended from the spacefrequency dimensions to the space-time-frequency dimensions , thus reducing the complexity of the system codingl decoding and the pilot sequence design. Then , the close-form solution to the Chemoff upper bound of the pairwise error probability is derived for the MIMO-OFDM system with imperfect channel information. The results of the theoretical analysis and numerical simulation show that , in the fading channels , the proposed subcarrier grouping scheme with equal intervals is of good performance because it can attain the results with low coding and decoding complexity by reducing the matrix scale.

Iterative Maximum Likelihood Channel Estimation of OFDM Systems via Superimposed Training Sequence

Hou Wei-kun Ye Wu Feng Sui-li Ke Feng

2007, 35(9):  16-19,35. 

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Although Orthogonal Frequency Division Multiplexing (OFDM) system with superimposed training sequence is bandwidth-efficient , the effectiveness of the conventional channel estimation method by utilizing the firstorder statistic is restricted by the power allocation ratio and noise. In order to solve this problem , by considering the property that the training sequence and data signal are arithmetically added and experience the same channel , a maximum likelihood channel estimation scheme is proposed for OFDM systems using the superimposed training sequence. In the proposed scheme , the transmitted data signals are considered as Gaussian variables to establish the likelihood function related to the channel parameter , and an iterative maximum likelihood estimation (MLE) algorithm is derived by means of the cyclic minimizing technology. Afterwards , the lower bound of the variance is obtained and the convergence of the algorithm is analyzed. Simulated results show that the proposed scheme is of better performance in the mean square error and the symbol error rate due to the simultaneous use of the first-order and the second-order statistics of the received signals.

Method to Extrapolate HRTF at Low Elevation of Median Plane by Means of Neural Network

Zhong Xiao-li

2007, 35(9):  20-25. 

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In order to construct a continuous head-related transfer function (HRTF) along elevation , a method to extrapolate the HRTF at low elevation of the median plane is proposed based on the radial basis function (RBF) neural network. Then , according to the data of KEMAR mannequin and a human being , the performances of the proposed method in three network input methods are analyzed. The results show that the correlative coefficient between he extrapolated and the measured HRTFs is as high as O. 93 , that the extrapolation accuracy can be improved by increasing the data of network input and by reducing the spatial distance between the extrapolated and the known directions , and that the extrapolation error increases with frequency.

Transient-State Analysis of Closed -Loop PWM DC-DC Converter System via Symbolic Method

Ding Yue-hua Chen Yan-feng Chen lin-feng

2007, 35(9):  26-30. 

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In order to more efficiently guide the analysis and design of a circuit , this paper presents a method to obtain the analytical solutions to transient-state responses and steady-state ripples of closed-loop Pulse-Width Modulation (PWM) DC-DC converter systems in CCM mode (Continuous Conduction Mode) , and extends the equivalent small parameter (ESP) method in combination with the multiple-scale method to the transient-state analysis of the closed-loop PWM DC-DC converter systems. According to the simulated results , the method of symbolic analysis may result in a simulation waveform similar to that obtained by the method based on the circuit principle , which verifies the effectiveness of the proposed method. Moreover , all the results in symbolic form can provide theoretical guidance for the circuit design and the analysis of nonlinear stability.

Design Scheme of Secure Communication System for Image Based on CNN and DES

Xiang Fei Xiao Hui-juan Qiu Shui-sheng

2007, 35(9):  31-35. 

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In order to overcome the deficiency of the key space of chaotic encryption system and to protect the Data Encryption Standard (DES) algo出hm from being attacked , this paper proposes a secure communication scheme for images by combining the cellular neural network (CNN) with DES algorithm. In the proposed scheme , the original chaotic signal generated by CNN is rounded , taken module , squared , extracted , magnified and excursed. Mter that , a new chaotic pseudo-random sequence is obtained and is used to encrypt the image. Then , the image is encrypted again with DES algorithm. The realization of the secure communication system is also discussed in this paper. Simulated results show that the proposed scheme is of good encηption and decryption efficiency and improves security performance , and that the decrypted results are highly sensitive to the initial condition of CNN and the key of DES. In addition , the traditional cryptanalysis is hardly useful for the proposed encryption system due to the random perturbation in hardware implementation.

Image Segmentation Algorithm ßased on Snake Model of Local Statistical Characteristic Restriction

Lü Pei-zhuo Lai Sheng-li Hu Rong Chen Jia-yang

2007, 35(9):  36-39,59. 

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In order to clarify the fuzzy boundary of intravascular ultrasound (IVUS) image , an image segmentation algorithm based on the Snake model of local statistical characteristic restriction is presented. In this algorithm , the prior knowledge of IVUS image is used to establish the statistical information of image characteristics , with which the expanding force is set up and the intemal balance force of the contour is proposed to construct a new Snake model. The newly constructed model is then adopted to segment the IVUS image. Experimental results show that the proposed Snake model is little dependent on the initial contour and is not sensitive to noise. Thus , the target image with fuzzy boundalγcan be accurately segmented.

Edge Detection of Complex Scenes Based on Bayesian Statistical Inference

Zhang Hao Cai Jin-hui Huang Ping-jie Zhou Ze-kui

2007, 35(9):  40-44. 

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The traditional edge detectors are inefficient in the image detection in complex scenes due to the disturbances of noise and texture. In order to solve this problem , a multi -information fusion edge detection algorithm based on Bayesian statistical inference theory is proposed. This algorithm fuses the output responses of four operators , such as the gradient operator , the Laplacian operator and the ratio of average (ROA) operators at two scales , achieves the optimal discretization for the continuous attributes of feature vector by maximizing the class-attribute mutual information , employs the nonparametric histogram method to estimate the class-conditional probability density functions , and adopts the principle of Bayes Risk Minimization to complete the edge detection of new images. Experimental results show that the proposed algorithm is feasible , with a Bhattacharyya error bound of 0. 093 and area under the receiver operating characteristic carve (AUC) of 0.958. The comparison of the detection results obtained respectively from the proposed algorithm and from the classical detectors also shows that the proposed algorithm is robust to the noise and texture in images.

Face Recognition via DT-CWT Feature-Based Orthogonal Neighborhood Preserving Projections

Sun Yue-hui Du Ming-hui

2007, 35(9):  45-49. 

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In order to efficiently accomplish the face recognition using dual-tree complex-wavelet transform (DTCWT), a method composed of DT-CWT and orthogonal neighborhood preserving projections (ONPP) is proposed. In this method , a feature vector with desirable characteristics including spatial locality , frequency and orientation selectivity is obtained by DT-CWT. Then , the dimension of the vector is linearly reduced by ONPP, thus effectively preserving the intrinsic neighborhood geometry of the vector and the global geometry. So , the recognition can be easily performed. Experimental results demonstrate that the proposed ONPP based on DT -CWT can accomplish the face recognition well with the feature dimension being effectively reduced.

Output-Feedback Variable-Structure Sliding-Mode Control of Stochastic System with Uncertainties

Peng Yun-jian Deng Fei-qi

2007, 35(9):  50-54. 

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The paper aims at the problem of output-feedback-based stabilizing control of an Itô's stochastic system with time-varying uncertainties , and at the design of a robust stabilization controller mainly adopting variable-structure sliding-mode control (SMC) techniques. By presupposing the system uncertainties satisfying certain matching conditions , a sliding-mode switching manifold and a SMC law are proposed , which are invariable to the structural uncertainties and possess the parameters without stochastic noise. Then , the accessibility of the sliding mode and the stability of the closed-loop system are analyzed , and some necessary conditions are further obtained to select the parameters for the SMC law. By the simulation of an illustrative example system , the correctness and effectiveness of the proposed controlling scheme are finally verified.

An Adaptive Friction Compensation Method for High-Precision Turntable System

Wang Zhong-shan Wang Yi Su Bao-ku

2007, 35(9):  55-59. 

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In order to eliminate the nonlinear dynamic friction force in a high-precision tumtable system and to improve the position-tracking accuracy of the tumtable in swing motion , a novel adaptive friction compensation method is developed , in which Lugre's dynamic friction model is adopted to characterize the friction torque. In this proposed method , the nonlinear observer/filter structure is used to compensate the uncertainty of friction parameters ,and dual nonlinear filters are introduced to improve the position-tracking performance of the tumtable system by adjusting the gains of the filters. The asymptotic stability of the closed-Ioop system is then proved by a Lyapunov-like argument , and the effectiveness of the proposed approach is finally verified by simulation.

Computer Science & Technology

Design and Implementation of Stochastic Model Algorithm for Dynamic Power Management

Liu Fa-gui Mai Wei-peng Huang Kai-yao

2007, 35(9):  60-64. 

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The policy-optimizing algorithms based on stochastic model can effectively reduce the power consumption of power state transitions for dynamic power management (DPM) and work out a better strategy. In this paper , a stochastic model based on Markov decision processes was established for the DPM system , and the corresponding algorithm was implemented in a material DPM architecture. Then , experiments for the algorithm were carried out. The results indicate that , with the proposed algorithm , different optimized policies satisfying performance requirements can be worked out in different power consumptions , that is , the algorithm strikes a balance between the performance and energy consumption. All this means that the algorithm implementation is feasible.

Coarsening and Refining of Extended Subjective Logic

Su Jin-dian Guo He-qing Gao Ying

2007, 35(9):  65-69,84. 

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In order to improve the extensibility and flexibility of the subjective logic , an extended subjective logic is proposed based on the temary events incorporating the evidence theory and the belief structure. By redefining the mapping relationship between the opinion space and the evidence space and by presenting the coarsening and refining mappings as well as the computation rules , the extended subjective logic can offer discemment frames with different details according to the practical requirements of the environment , and can combine the belief functions via the coarsening and refining mappings. The results of combination can also map back to the original discemment frame. Experimental and analytical results show that the proposed extended subjective logic can solve the problem of trust information fusion between different discemment frames.

Classification for Close Short Shot in Soccer Video

Zhao Pi-xi Li Qi-dian Wang Xiu-kun wang Wei Li Guo-hui

2007, 35(9):  70-73. 

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Video shot type can bridge the gap between the low-level features and the high-level semantics and helps to detect highlights. In this paper , a new method for the classification of the close short shot in soccer video is proposed , which classifies the shot into close-up shot or out-of-field audiences' shot. In the proposed method , a component image with the minimal summation in all pixel values is selected from the key frame of a close short shot in RGB color space , and the size of the image is then normalized. After that , the isotropic Sobel operator and the closed operation are adopted to obtain the corresponding binarization edge image , and the classification decision is made by calculating the amount of black blocks in the binarization edge image. Experimental results finally reveal the validity and practicality of the proposed method.

Evolution Analysis of Open Source Software Linux Kernel

Zheng Wei Xu Min-hong

2007, 35(9):  74-77. 

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The source code and related development information of the open-source software with various versions are important data sources for software engineering researchers to investigate the software evolution. This paper analyzes the evolution law of Linux , summarizes the corresponding data sources and date-collecting methods , proposes a method to analyze the software evolution of Linux kernel , and gives the related analytical results. Moreover , a method is presented to fast measure the complexity of large-scale open-source software. It is concluded that Linux is now in a super-linear evolution , the main reason of which is that Linux should adapt to the evolution of hardware resource.

DOMulti: A Delay-Optimized P2P Application Layer Multicast Protocol

Lin Long-xin Zhou Jie Zhang Ling Ye Zhao

2007, 35(9):  78-84. 

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In the existing structured peer-to-peer (P2P) application layer multicast schemes , the end-to-end delay from the source to group members is high and the multicast delivelγtree is unstable. In order to overcome these demerits , this paper presents a new P2P application layer multicast protocol named DOMulti. In this protocol , the Tapestry routing and the data location service are utilized to construct a multicast delivelγtree with bounded depth and constrained out-degree of node. As there are no non-group members in the deliverγtree ， the transmission delay between the source and group members can be optimized and the stability of the tree can be improved. Simulated results indicate that , as compared with the existing protocol , DOMulti is of distinct advantages in terms of end-toend delay and is more suitable for the delay-sensitive multicast applications in P2P environment.

Network Flowrate Control Model ßased on Game Theory

Zhong Bo-cheng Han Jiang-hong

2007, 35(9):  85-89. 

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Traditional flowrate control schemes require the cooperation of traffic sources to achieve an optimal network performance. However , all of such schemes will lead inevitably to a congestion collapse in the presence of noncooperative end-users. In order to solve this problem , a flowrate control framework is proposed based on the noncooperative game theory. In this scheme , the idea of the Nash solution from noncooperative game theory is taken into account , and each user has to pay for the network and has to choose a willingness-to-pay to maximize his own net profit. Moreover , a pricing mechanism for network bandwidth is designed to drive the user flow to the social optimal solution. The results prove that the proposed flowrate control game admits a unique Nash equilibrium point ,at which the bandwidth allocation is efficient and fair.

Information Extraction from Chinese Research Papers Based on Conditional Random Fields

Yu Jiang-de Fan xiao-zhong yin ji-hao

2007, 35(9):  90-94,106. 

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The information of headers and citations of research papers is necessaηfor many applications , such asthe field-based paper search , the paper statistics and the citation analysis. In order to enhance the utilization ofcontext features for information extraction which is greatly restricted by the hidden Markov model (HMM) , a methodbased on the conditional random fields (CRFs) is proposed to extract the information of paper header and citationfrom Chinese research papers. The proposed method , whose key is the parameter estimation and the feature selection, employs L-BFGS algorithm for the estimation of model parameters in the experiment and selects the categoriesfeatures of location , layout , lexicon and state transition as the feature set of the model. During the information extraction, the format information about list separators and special-labels is used to segment the text , and then CRFsare applied to the extraction in special fields. Experimental results show that the proposed method possesses betterperformance than that based on the HMM , and that the performance improvement varies with the features sets.

Optimization of Bilateral and Multi-Issue Negotiation Model Based on Concurrent Options

Peng Zhi-ping Peng Hong

2007, 35(9):  95-100. 

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In order to break the deadlocks in the bilateral and multi-issue negotiation , a method to optimize the negotiation model is proposed based on concurrent Options. In this method , the reserved values of several issues related to the deadlock issue can be dynamically optimized in parallel without reducing the bilateral utility. As illustrated by an example of E-commerce , the proposed optimization method is effective. It significantly outperforms the methods based on standard Options and Q-leaming in terms of the leaming efficiency as well as the optimization degree and generalization capacity of the leamed policies for solving negotiation deadlocks.

Scheduling of Flexible Manufacturing System Based on Cooperative Game

Liu Jian-guo Li Qing-song Wang Ning-sheng

2007, 35(9):  101-106. 

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For adapting to the agile manufacturing , an effective and real-time manufacturing scheduling is necessary to the flexible manufacturing system with multi-machining and multi-assemble equipment , as well as with many machining and assembly processes. This paper brings forward a new scheduling algorithm to decompose the assembly structure of the products , obtain simple problems easy to schedule and form the corresponding Agents. Then , by applying the cooperative game theory , the importance and restriction of each Agent are taken into account to obtain an order of simple scheduling problem. In this order, the scheduling of sub-questions can be implemented in term of rules , and the almost optimal scheduling results meeting the restriction can be obtained. Experimental results finally verify the effectiveness of the proposed scheduling algorithm.

Multi-Agent-Based Distributed Monitoring and Controlling System for Hazard Installations

Zhou lian-feng Chen Guo-hua Wan Mu-sheng Chen Qing-guang

2007, 35(9):  107-112. 

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The distrihuted and remote monitoring and controlling system for hazard installations , especially for fatal hazard installations , is of great importance to the prevention of major accidents , the succor of people and properties in emergency and the management of hazard installations. In this paper , the concept and model of multi-Agent group (MAG) are first proposed hased on the multi-Agent technology. Then , the characteristics of the MAG model
and the differences hetween MAG and multi-Agent system (MAS) are discussed. Moreover , a MAG model for monitoring and controlling hazard installations is estahlished hased on task analyses , in which the tasks are decomposed into 5 Agents including the Monitoring and Control Agent , the Remote Communication Agent , the Feature Extraction Agent , the Early-Waming Analysis Agent and the User Interface Agent. The 5 Agents operate independently and they synergetically compose a multiple distrihuted MAGs system to perform distrihuted monitoring and controlling for hazard installations. Finally , a monitoring and controlling system for LPG storage is presented hased on the proposed MAG model and the architecture of the distrihuted monitoring and controlling system , and the main functions of the agents are also analyzed.

Adaptive General Particle Swarm Optimization for One-Dimension Cutting Stock Problem

Shen Xian-jun Yang Jin-cai Ying Wei-qin Zheng Bo-jin Li Yuan-xiang

2007, 35(9):  113-117. 

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In the existing particle swarm optimization algorithms , the iteration of particle velocities is difficult to define for combinatorial optimization problems. In order to solve this problem , this paper proposes a general particle swarm optimization algorithm to solve the one-dimension cutting stock problem. In the proposed algorithm , the existing particle swarm optimization algorithm is combined with the genetic algorithm , the crossover operator and the
mutation operator in genetic algorithm are employed , and an adaptive strategy based on the simulated annealing algorithm is introduced to avoid the premature convergence of particle swarm. Simulated results demonstrate that the proposed algorithm is effective and robust in solving the one-dimension cutting stock problem.

Ontology Partition Method Based on Improved Particle Swarm Optimization Algorithm

Xie Qiang Zhang Lei Zhou Liang

2007, 35(9):  118-122. 

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In order to overcome the difficulty in the use of huge Ontology , a method of automatic Ontology partition is proposed based on the improved particle swarm optimization algorithm. In this method , the probability of the concept to fall into a certain sub-Ontology is taken as the particle speed according to the Ontology partition request , and the digital string of the number of the sub-Ontology is taken as the particle. Mterwards , the fitness degree function of the particle swarm optimization algorithm is designed , and the concrete steps of the Ontology partition are presented. According to the correlation contrast experiment , it is finally found that the proposed partition method is of better division effect than tlre other methods.