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20 December 2010, Volume 21 Issue 6
Low complexity DCT-based distributed source coding with Gray code for hyperspectral images
Rongke Liu, Jianrong Wang, and Xuzhou Pan
2010, 21(6):  927-933.  doi:10.3969/j.issn.1004-4132.2010.06.001
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To compress hyperspectral images, a low complexity discrete cosine transform (DCT)-based distributed source coding (DSC) scheme with Gray code is proposed. Unlike most of the existing DSC schemes, which utilize transform in spatial domain, the proposed algorithm applies transform in spectral domain.Set-partitioning-based approach is applied to reorganize DCT coefficients into waveletlike tree structure and extract the sign, refinement, and significance bitplanes. The extracted refinement bits are Gray encoded. Because of the dependency along the line dimension of hyperspectral images, low density paritycheck-(LDPC)-based Slepian-Wolf coder is adopted to implement the DSC strategy. Experimental results on airborne visible/infrared
imaging spectrometer (AVIRIS) dataset show that the proposed paradigm achieves up to 6 dB improvement over DSC-based coders which apply transform in spatial domain, with significantly reduced computational complexity and memory storage.

Super-resolution image reconstruction based on three-step-training neural networks
Fuzhen Zhu, Jinzong Li, Bing Zhu, and Dongdong Ma
2010, 21(6):  934-940.  doi:10.3969/j.issn.1004-4132.2010.06.002
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A new method of super-resolution image reconstruction is proposed, which uses a three-step-training error backpropagation neural network (BPNN) to realize the super-resolution reconstruction (SRR) of satellite image. The method is based on BPNN. First, three groups learning samples with different resolutions are obtained according to image observation model, and then vector mappings are respectively used to those three group
learning samples to speed up the convergence of BPNN, at last, three times consecutive training are carried on the BPNN. Training samples used in each step are of higher resolution than those used in the previous steps, so the increasing weights store a great amount of information for SRR, and network performance and generalization ability are improved greatly. Simulation and generalization tests are carried on the well-trained three-step-training NN respectively, and the reconstruction results with higher resolution images verify the effectiveness and validity of this method.

SRV constraint based FIB design for wideband linear array
Peng Chen, Yihui Liang, Chaohuan Hou, Xiaochuan Ma, and Dapeng Liu
2010, 21(6):  941-947.  doi:10.3969/j.issn.1004-4132.2010.06.003
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Frequency-invariant beamformer (FIB) design is a key issue in wideband array signal processing. To use commonly wideband linear array with tapped delay line (TDL) structure and complex weights, the FIB design is provided according to the rule of minimizing the sidelobe level of the beampattern at the reference frequency while keeping the distortionless response constraint in the mainlobe direction at the reference frequency, the norm constraint of the weight vector and the amplitude constraint of the averaged spatial response variation (SRV). This kind of beamformer design problem can be solved with the interior-point method after being converted to the form of standard second order cone programming (SOCP). The computer simulations are presented which illustrate the effectiveness of our FIB design method for the wideband linear array with TDL structure and complex weights.

Fast method for spreading sequence estimation of DSSS signal based on maximum likelihood function
Yanhua Peng, Bin Tang, and Ming Lü
2010, 21(6):  948-953.  doi:10.3969/j.issn.1004-4132.2010.06.004
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To estimate the spreading sequence of the direct sequence spread spectrum (DSSS) signal, a fast algorithm based on maximum likelihood function is proposed, and the theoretical derivation of the algorithm is provided. By simplifying the objective function of maximum likelihood estimation, the algorithm can realize sequence synchronization and sequence estimation via adaptive iteration and sliding window.since it avoids the correlation matrix computation, the algorithm significantly reduces the storage requirement and the computation complexity. Simulations show that it is a fast convergent algorithm, and can perform well in low signal to noise ratio (SNR).

Adaptive detector design of MIMO radar with unknown covariance matrix
Lingjiang Kong, Guolong Cui, Xiaobo Yang, and Jianyu Yang
2010, 21(6):  954-960.  doi:10.3969/j.issn.1004-4132.2010.06.005
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The problem of detecting signal with multiple input multiple output (MIMO) radar in correlated Gaussian clutter dominated scenario with unknown covariance matrix is dealt with. The general MIMO model, with widely separated sub-arrays and co-located antennas at each sub-array, is adopted. Firstly, the generalized likelihood ratio test (GLRT) with known covariance matrix is obtained, and then the Rao and Wald detectors are devised, which have proved that the Rao and Wald test coincide with GLRT detector.To make the detectors fully adaptive, the secondary data with signal-free will be collected to estimate the covariance. The performance of the proposed detector is analyzed, however, it is just ancillary. A thorough performance assessment by several numerical examples is also given, which has considered the sense with co-located antennas configure of transmitters and receivers array.The results show that the performance the proposed adaptive detector is better than LJ-GLRT, and the loss can be acceptable in comparison to their non-adaptive counterparts.

Hierarchical interacting multiple model algorithm based on improved current model
Xianghua Wang, Xinyu Yang, Zheng Qin, and Huijie Yang
2010, 21(6):  961-967.  doi:10.3969/j.issn.1004-4132.2010.06.006
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Interacting multiple models is the hotspot in the research of maneuvering target models at present. A hierarchical idea is introduced into IMM algorithm. The method is that the whole models are organized as two levels to co-work, and each cell model is an improved “current” statistical model. In the improved model, a kind of nonlinear fuzzy membership function is presented to get over the limitation of original model, which can not track weak maneuvering target precisely. At last, simulation experiments prove the efficient of the novel algorithm compared to interacting multiple model and hierarchical interacting multiple model based original “current” statistical model in tracking precision.

Instantaneous measurement for radar target polarization scattering matrix
Yong Liu, Yongzhen Li, and Xuesong Wang
2010, 21(6):  968-974.  doi:10.3969/j.issn.1004-4132.2010.06.007
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 Adopting“simultaneous transmitting, simultaneous receiving”operational scheme, instantaneous polarization radar (IPR) can measure target polarization scattering matrix (PSM) using only once target echoes in two orthogonal polarization channels. Firstly, signal model and signal process are advanced under narrowband condition. Secondly, measurement performances of two typical IPR waveforms are analyzed in detail. At last, field experiments are carried out using X-band IPR system designed by National University of Defense Technology (NUDT), China. Compared with results obtained by alternative polarization measurement scheme, following results can be obtained: the difference of relative amplitude measurement results is smaller than 2 dB and that of relative phase measurement results is smaller than 10?, verifying the validity of instantaneous polarization measurement scheme.

Dynamic programming methodology for multi-criteria group decision-making under ordinal preferences
Wu Li, Guanqi Guo, Chaoyuan Yue, and Yong Zhao
2010, 21(6):  975-980.  doi:10.3969/j.issn.1004-4132.2010.06.008
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A method of minimizing rankings inconsistency is proposed for a decision-making problem with rankings of alternatives given by multiple decision makers according to multiple criteria. For each criteria, at first, the total inconsistency between the rankings of all alternatives for the group and the ones for every decision maker is defined after the decision maker weights in respect to the criteria are considered. Similarly, the otal nconsistency between their final rankings for the group and the ones under every criteria is determined after the criteria weights are taken into account. Then two nonlinear integer programming models minimizing respectively the two total inconsistencies above are developed and then transformed to two dynamic programming models to obtain separately the rankings of all alternatives for the group with respect to each criteria and their final rankings. A supplier selection case illustrated the proposed method, and some discussions on the results verified its effectiveness. This work develops a new measurement of ordinal preferences’ inconsistency in multi-criteria group decision-making (MCGDM) and extends the cook-seiford social selection function to MCGDM considering weights of criteria and decision makers and can obtain unique ranking result.

Robust data envelopment analysis based MCDM with the consideration of uncertain data
Ke Wang, and Fajie Wei
2010, 21(6):  981-989.  doi:10.3969/j.issn.1004-4132.2010.06.009
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The application of data envelopment analysis (DEA) as a multiple criteria decision making (MCDM) technique has been gaining more and more attention in recent research. In the practice of applying DEA approach, the appearance of uncertainties on input and output data of decision making unit (DMU) might make the nominal solution infeasible and lead to the efficiency scores meaningless from practical view. This paper analyzes the
impact of data uncertainty on the evaluation results of DEA, and proposes several robust DEA models based on the adaptation of recently developed robust optimization approaches, which would be immune against input and output data uncertainties. The robust DEA models developed are based on input-oriented and outputoriented
CCR model, respectively, when the uncertainties appear in output data and input data separately. Furthermore, the robust DEA models could deal with random symmetric uncertainty and unknown-but-bounded uncertainty, in both of which the distributions of the random data entries are permitted to be unknown. The robust DEA models are implemented in a numerical example and the efficiency scores and rankings of these models are compared.
The results indicate that the robust DEA approach could be a more reliable method for efficiency evaluation and ranking in MCDM problems.

Linear goal programming approach to obtaining the weights of intuitionistic fuzzy ordered weighted averaging operator
Yejun Xu, Chao Huang, Qingli Da, and Xinwang Liu
2010, 21(6):  990-994.  doi:10.3969/j.issn.1004-4132.2010.06.010
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The multiple attribute decision making problems are studied, in which the information about attribute weights is partly known and the attribute values take the form of intuitionistic fuzzy numbers. The operational laws of intuitionistic fuzzy numbers are introduced, and the score function and accuracy function are presented to compare the intuitionistic fuzzy numbers. The intuitionistic fuzzy ordered weighted averaging (IFOWA) operator which is an extension of the well-known ordered weighted averaging (OWA) operator is investigated to aggregate the intuitionistic fuzzy information. In order to determine the weights of intuitionistic fuzzy ordered weighted averaging operator, a linear goal programming procedure is proposed for learning the weights from data. Finally,
an example is illustrated to verify the effectiveness and practicability of the developed method.

Attributes reduct and decision rules optimization based on maximal tolerance classification in incomplete information systems with fuzzy decisions
Fang Yang, Yanyong Guan, Shujin Li, and Lei Du
2010, 21(6):  995-999.  doi:10.3969/j.issn.1004-4132.2010.06.011
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A new approach to knowledge acquisition in incomplete information system with fuzzy decisions is proposed. In such incomplete information system, the universe of discourse is classified by the maximal tolerance classes, and fuzzy approximations are defined based on them. Three types of relative reducts of maximal tolerance classes are then proposed, and three types of fuzzy decision rules based on the proposed attribute description
are defined. The judgment theorems and approximation discernibility functions with respect to them are presented to compute the relative reduct by using Boolean reasoning techniques, from which we can derive optimal fuzzy decision rules from the systems. At last, three types of relative reducts of the system and their computing methods are given.

New type of conjugate gradient algorithms for unconstrained optimization problems
Caiying Wu and Guoqing Chen
2010, 21(6):  1000-1007.  doi:10.3969/j.issn.1004-4132.2010.06.012
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Two new formulaes of the main parameter βk of the conjugate gradient method are presented, which espectively can be seen as the modifications of method HS and PRP. In comparison with classic conjugate  gradient methods, the new methods take both available gradient and function value information. Furthermore,
their modifications are proposed. These methods are shown to be global convergent under some assumptions. Numerical results are also reported.

Human resources allocation for aircraft maintenance with predefined sequence
Zhaodong Huang, Wenbing Chang, Yiyong Xiao, Yuchun Xu, and Rui Liu
2010, 21(6):  1008-1013.  doi:10.3969/j.issn.1004-4132.2010.06.013
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There are always large-scale items in the maintenances schedule of aircraft system, many of which have been fixed to be done in predefined sequences, which leads the workflow to be systematically complex and makes this kind of problem quite different from all sorts of existing job-selection modes. On the other hand, the human resources are always limited and men have different working capabilities on different items, which make the allocation operation of human resources be much roomy. However, the final total time span of maintenance is often required to be as short as possible in many practices, in order to suffer only the lowest cost of loss while the system is stopping. A new model for optimizing the allocation if aircraft maintenance human resources with the constraint of predefined sequence is presented. The genetic algorithm is employed to find the optimal solution that holds the shortest total time span of maintenance. To generate the ultimate maintenance work items and the human resource array, the sequences among all maintenance work items are considered firstly, the work item array is then generated through traversal with the constraint of maintenance sequence matrix, and the human resources are finally allocated according to the work item array with the constraint of the maintenance capability. An example is demonstrated to show that the model and algorithm behave a satisfying performance on finding the optimal solution as expected.

DTHMM based delay modeling and prediction for networked control systems
Shuang Cong, Yuan Ge, Qigong Chen, Ming Jiang, and Weiwei Shang
2010, 21(6):  1014-1024.  doi:10.3969/j.issn.1004-4132.2010.06.014
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In the forward channel of a networked control system (NCS), by defining the network states as a hidden Markov chain and quantizing the network-induced delays to a discrete sequence distributing over a finite time interval, the relation between the network states and the network-induced delays is modelled as a discrete-time hidden Markov model (DTHMM). The expectation maximization (EM) algorithm is introduced to derive the maximumlikelihood estimation (MLE) of the parameters of the DTHMM.Based on the derived DTHMM, the Viterbi algorithm is introduced to predict the controller-to-actuator (C-A) delay during the current sampling period. The simulation experiments demonstrate the effectiveness of the modelling and predicting methods proposed.

Quantized dynamic output feedback control for networked control systems
Chong Jiang, Dexin Zou, Qingling Zhang, and Song Guo
2010, 21(6):  1025-1032.  doi:10.3969/j.issn.1004-4132.2010.06.015
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The problem of the quantized dynamic output feedback controller design for networked control systems is mainly discussed. By using the quantized information of the system measurement output and the control input, a novel networked control system model is described. This model includes many networkinduced features, such as multi-rate sampled-data, quantized signal, time-varying delay and packet dropout. By constructing suitable Lyapunov-Krasovskii functional, a less conservative stabilization criterion is established in terms of linear matrix inequalities. The quantized control strategy involves the updating values of the quantizer parameters μi(i = 1, 2)(μi take on countable sets of values which dependent on the information of the system measurement outputs and the control inputs). Furthermore, a numerical example is given to illustrate the effectiveness of the proposed method.

Diffserv AQM algorithm for edge and core routers
Yang Xiao, Lingyun Lu, and Kiseon Kim
2010, 21(6):  1033-1040.  doi:10.3969/j.issn.1004-4132.2010.06.016
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The existing active queue management (AQM) algorithm acts on subscribers and edge routers only, it does not support differentiate-serve (Diffserv) quality of service (QoS), while the existing diffserv QoS has not considered the link capacities between edge routers and connected core routers. When a core router in a two layers’ network experiences congestion, the connected edge routers have no ability to adjust their access data rates. Thus, it is difficult to achieve the congestion control for the large scale network with many edge routers and core routers. To solve these problems, two difffserve AQM algorithms are proposed for the congestion control of multilayer network. One diffserv AQM algorithm implements fair link capacities of edge routers, and the other one implements unequal link capacities of edge routers, but it requires the core routers to have multi-queues buffers and Diffserv AQM to support. The proposed algorithms achieve the network congestion control by operating AQM parameters on the conditions of proposed three theorems for core and edge routers. The dynamic simulation results demonstrate the proposed control algorithms for core and edge routers to be valid.

Filtering of long-term dependent fractal noise in fiber optic gyroscope
Chunhong Hua, Zhang Ren, and Minhu Zhang
2010, 21(6):  1041-1045.  doi:10.3969/j.issn.1004-4132.2010.06.017
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Stochastic noises of fiber optic gyroscope (FOG) mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filtering methodology is proposed.Firstly, fractional differencing (FD) method is introduced to transform fractal noise into fractional white noise based on the estimation of Hurst exponent for long-term dependent fractal process, which together with the existing white noise make up of a generalized white noise. Further, an improved denoising algorithm of wavelet maxima is developed to suppress the generalized white noise. Experimental results show that the basic noise terms of FOG greatly decrease, and especially the slow drift is restrained effectively. The proposed methodology provides a promising approach for filtering long-term dependent fractal noise.

Novel adaptive Hatch filter to mitigate the effects of ionosphere and multipath on LAAS
Lin Zhao, Liang Li, Ming Sun, and Xiaoxu Wang
2010, 21(6):  1046-1053.  doi:10.3969/j.issn.1004-4132.2010.06.018
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It has been proven that carrier smoothing and differential global positioning system (DGPS) are effective to improve the accuracy of pseudorange by reducing the noise in it and eliminating almost all the common mode errors between the ground station and user. However, another issue coming with local area augmentation system (LAAS) is how to find an adaptive smoothing window width to minimize the error on account of ionosphere delay and multipath. Based on the errors analysis in carrier smoothing process, a novel algorithm is formulated to design adaptive Hatch filter whose smoothing window width flexibly varies with the characteristic of ionosphere delay and multipath in the differential carrier smoothing process. By conducting the simulation in LAAS and after compared with traditional Hatch filers, it reveals that not only the accuracy of differential correction, but also the accuracy and the robustness of positioning results are significantly improved by using the designed adaptive Hatch filter.

New type of adaptive control for a class of distributed time-delay systems with adaptation regard to delay parameter
Lin Chai, Shumin Fei, Haiyan Jin, Ruimin Wang, and Yanhong Li
2010, 21(6):  1054-1062.  doi:10.3969/j.issn.1004-4132.2010.06.019
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The problem on stabilization for the system with distributed delays is researched. The distributed time-delay under consideration is assumed to be a constant time-delay, but not known exactly. A design method is proposed for a memory proportional and integral (PI) feedback controller with adaptation to distributed time-delay. The feedback controller with memory simultaneously contains the current state and the past distributed
information of the addressed systems. The design for adaptation law to distributed delay is very concise. The controller can be derived by solving a set of linear matrix inequalities (LMIs). Two numerical examples are given to illustrate the effectiveness of the design method.

Control of static unstable airframes
Junfang Fan, Defu Lin, Zhong Su, and Qing Li
2010, 21(6):  1063-1071.  doi:10.3969/j.issn.1004-4132.2010.06.020
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The challenge and control problems of static unstable missiles are presented. The steady-state benefits of static instability are illustrated, while the corresponding control challenge is described both by the characteristic lag of airframe and the increment of necessary control usage. Control limitation led by unstable zero-pole pair is analyzed for preliminary design and evaluation. Linear control strategy is examined wherein two and three loop acceleration autopilots with different control usages are developed using an optimal control approach combined with frequency domain constraint. The weights selection and relation with system performance are detailed. Then the nonlinear backstepping recursive method is detailed to determine how well it is able to follow command and its engineering feasibility. The results show that a static unstable missile is controllable, while the actuator bandwidth is the crucial limited factor. There should be a compromise between overall performance and actuator payment.

Adaptive integral dynamic surface control based on fully tuned radial basis function neural network
Li Zhou, Shumin Fei, and Changsheng Jiang
2010, 21(6):  1072-1078.  doi:10.3969/j.issn.1004-4132.2010.06.021
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An adaptive integral dynamic surface control approach based on fully tuned radial basis function neural network
(FTRBFNN) is presented for a general class of strict-feedback nonlinear systems, which may possess a wide class of uncertainties that are not linearly parameterized and do not have any prior knowledge of the bounding functions. FTRBFNN is employed to approximate the uncertainty online, and a systematic framework for adaptive controller design is given by dynamic surface control. The control algorithm has two outstanding features, namely, the neural network regulates the weights, width and center of Gaussian function simultaneously, which ensures the control system has perfect ability of restraining different unknown uncertainties and the integral term of tracking error introduced in the control law can eliminate the static error of the closed loop system effectively.
As a result, high control precision can be achieved. All signals in the closed loop system can be guaranteed bounded by Lyapunov approach. Finally, simulation results demonstrate the validity of the control approach.

Parameter estimation for multirate multi-input systems using auxiliary model and multi-innovation
Lili Han and Feng Ding
2010, 21(6):  1079-1083.  doi:10.3969/j.issn.1004-4132.2010.06.022
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The multirate multi-input systems have different updating periods and sampling periods such that the conventional identification algorithms cannot be used to identify such multirate systems. By using the auxiliary model identification idea, the multiinnovation stochastic gradient algorithm is developed to estimate the parameters of multirate systems. Finally, an illustrative example is given to verify the effectiveness of the proposed algorithm.

Finite time stability and stabilization of hybrid dynamic systems
Guopei Chen, Junmin Li, and Ying Yang
2010, 21(6):  1084-1089.  doi:10.3969/j.issn.1004-4132.2010.06.023
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Finite time stability and stabilization are studied for hybrid dynamic systems. By combining multiple Lyapunov function and finite time Lyapunov function, a sufficient condition of finite time stability is given for the system. Compared with the previous works, our results have less conservativeness. Furthermore, based on the state partition of continuous and resetting parts of system, a hybrid feedback controller is constructed, which stabilizes
the closed-loop systems in finite time. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed method.

Stabilizing model predictive control scheme for piecewise affine systems with maximal positively invariant terminal set
Fu Chen, Guangzhou Zhao, and Xiaoming Yu
2010, 21(6):  1090-1094.  doi:10.3969/j.issn.1004-4132.2010.06.024
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An efficient algorithm is proposed for computing the solution to the constrained finite time optimal control (CFTOC) problem for discrete-time piecewise affine (PWA) systems with a quadratic performance index. The maximal positively invariant terminal set, which is feasible and invariant with respect to a feedback control law, is computed as terminal target set and an associated Lyapunov function is chosen as terminal cost. The combination of these two components guarantees constraint satisfaction and closed-loop stability for all time. The proposed algorithm combines a dynamic programming strategy with a multi-parametric quadratic programming solver and basic polyhedral manipulation. A numerical example shows that a larger stabilizable set of states can be obtained by the proposed algorithm than precious work.

Joint channel assignment and cross-layer routing protocol for multi-radio multi-channel Ad Hoc networks
Yang Lu, Junming Guan, Zhen Wei, and Qilin Wu
2010, 21(6):  1095-1102.  doi:10.3969/j.issn.1004-4132.2010.06.025
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To study multi-radio multi-channel (MR-MC) Ad Hoc networks based on 802.11, an efficient cross-layer routing protocol with the function of joint channel assignment, called joint channel assignment and cross-layer routing (JCACR), is presented. Firstly, this paper introduces a new concept called channel utilization percentage (CUP), which is for measuring the contention level of different channels in a node’s neighborhood, and deduces its optimal value for determining whether a channel is overloaded or not. Then, a metric parameter named channel selection metric (CSM) is designed, which actually reflects not only the channel status but also corresponding node’s capacity to seize it. JCACR evaluates channel assignment by CSM, performs a local optimization by assigning each node a channel with the smaller CSM value, and changes the working channel dynamically when the channel is overloaded. Therefore, the network load balancing can be achieved. In addition, simulation shows that, when compared with the protocol of weighted cumulative expected transfer time (WCETT), the new protocol can improve the network throughput and reduce the end-to-end average delay with fewer overheads.

Fast motion estimation algorithm for H.264/AVC based on centered prediction
Wei Zhou, Zhemin Duan, and Hongqi Hu
2010, 21(6):  1103-1110.  doi:10.3969/j.issn.1004-4132.2010.06.026
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H.264/AVC video coding standard can achieve roughly half of the bit-savings over MPEG2 and MPEG4 for a given quality. However, this comes at a cost in considerably increased complexity at the encoder and thus increases the difficulty in hardware implementation. The high redundancy that exists between the successive frames of a video sequence makes it possible to achieve a high data compression ratio. Motion estimation (ME) plays an important role in motion compensated video coding. A fast motion estimation algorithm for H.264/AVC is proposed based on centered prediction, called centered prediction based fast mixed search algorithm (CPFMS). It makes use of the spatial and temporal correlation in motion vector (MV) fields and feature of all-zero blocks to accelerate the searching process. With the initialized searching point prediction, adaptive search window changing and searching direction decision, CPFMS is provided to reduce computation in block-matching process. The experimental results show that the speed of CPFMS is nearly 12 times of FS with a negligible peak signal-noise ratio (PSNR) loss. Also, the efficiency of CPFMS outperforms some popular fast algorithms such as hybrid unsymmetrical cross multi-hexagongrid search and a novel multidirectional gradient descent search evidently.

Improved clustering method based on artificial immune
Lin Zhu and Bo Li
2010, 21(6):  1111-1115.  doi:10.3969/j.issn.1004-4132.2010.06.027
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An improved clustering method based on artificial immune is proposed. To obtain the better initial solution, the initial antibody network is introduced by self organizing map (SOM) method. In the process of the clustering iteration, a series of optimization and evolution strategies are designed, such as clustering satisfaction, the threshold design of scale compression, the learning rate, the clustering monitoring points and the clustering evaluations indexes. These strategies can make the clustering thresholds be quantified and reduce the operator’s subjective factors. Thus, the local optimal and the global optimal clustering simultaneously are proposed by the synthesized function of these strategies. Finally, the experiment and the comparisons demonstrate the proposed method effectiveness.