Table of Content

28 February 2015, Volume 49 Issue 02 Previous Issue    Next Issue

Automation Technique, Computer Technology

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Stereo Correction of Binocular Images with Optical Axes Divergent Arrangement JING Xu1,QIU Shiguang1,YIN Xuyue1,FAN Xiumin1,2,HE Qichang1,2 2015, 49 (02):  141-149.  Abstract ( 997 )   Save Abstract： The traditional stereo correction method based on epipolar geometry is difficult to apply to the binocular imaging and display system with optical axes divergent arrangement for wide field of view. To address this problem, using 3D reconstruction error, a stereo image correction method was proposed based on the disparity characteristics of the binocular images. First, the features of horizontal and vertical disparity of the images captured by binocular imaging system with divergent optical axes was analyzed. Then, based on these characteristics, a pair of affine transformation was proposed for the position error between the optical centers of the binocular cameras and the corresponding projection centers of the wide vision HMD(Head Mounted Display), and two functions of horizontal disparity distortion correction and vertical disparity correction were proposed for the angular deviation between the optical axes of binocular cameras and the corresponding visual axes of the wide vision HMD. Finally, the stereo correction parameters were calculated using the optimization solution with 3D reprojection errors of a set of 3D spatial points. Simulation results show that this method can effectively eliminate the effects on the stereo disparity of the binocular images caused by the position error of optical center and the angular deviation of optical axes when the divergent angle of visual axes is up to 30 °. Real image correction experiment results show that the corrected images have small horizontal distortion, and can provide correct 3D senses with a wide field of view. Key words： References | Related Articles | Metrics

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Adaptive N Tree Anti-Collision Algorithm Based on Bitmap Construction WANG Xin1,JIA Qingxuan1,GAO Xin1,CHEN Gang1,ZHAO Bing2 2015, 49 (02):  150-157.  Abstract ( 711 )   Save Abstract： Aimed at the RFID (radio frequency identification) collision problem caused by multiple access of shared channel, this paper proposed two RFID adaptive N tree anticollision algorithms based on bitmap construction, single frame bitmap track N tree algorithm (SFBTNA) and multiframe bitmap track N tree algorithm(MFBTNA). First of all, the two methods take advantage of the maximum likelihood tag numbers estimation method (MLBE) that can effectively estimate the number of tags. Secondly, based on the MLBE, it put forward the probe method construct bitmap. The SFBTNA adaptively adjusts the optimization value of N and builds N trees on one frame based on bitmap. The MFBTNA adaptively adjusts optimization value of N and builds N trees frame by frame. At the same time, the SFBTNA and MFBTNA identify the subtrees using collision track tree algorithm (CT). The combination of bitmap and CT greatly reduces the impact of collision time slot. Theoretical analysis and simulation experiments show that the performance of the two algorithms is higher than that of the other existing anticollision algorithms. References | Related Articles | Metrics

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A Novel Algorithm for Improving the Accuracy of  Attitude and Heading Angle Measurement  of Electronic Compass HU Chao1,2,AI Guoxiang1,PANG Feng1,2,LI Shengming1,MA Lihua1 2015, 49 (02):  158-163.  Abstract ( 1105 )   Save Abstract： This paper studied the measurement precision of the electronic compass used in VSAT(very small aperture terminal). The basic principle of the measurement was discussed in detail, and the error mathematical model of the measurement was derived. The cause for the increase of the roll angle measurement error with the increases of the pitch angle was analyzed and a novel method for improving the measurement precision was proposed based on the above analysis. The simulation and experiment results show that the novel method can remove the influence of pitch angle on the roll angle measurement and can improve the accuracy of heading measurement effectively. The application of the novel method shows that the roll angle accuracy is approximately 0.2° and the heading angle accuracy is approximately 0.5°with a turntable pitch angle of 30 °. References | Related Articles | Metrics

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Design of a Modified ArctangentBased Tracking Differentiator BU Xiangwei,WU Xiaoyan，MA Zhen,ZHONG Yu 2015, 49 (02):  164-168.  Abstract ( 938 )   Save Abstract： A modified arctangentbased tracking differentiator (MATD) was designed to improve the performance of arctangentbased tracking differentiator with the difficulty of parameter adjustment and poor ability of noise restraint. First, the tracking function of MATD was constructed by introducing the nonlinear function and reducing design parameters, and its global uniformly asymptotical stability was proved. Then, the improvement mechanism of MATD was shown based on the convergence analysis of the tracking function of MATD. Finally, the parameter adjustment rule of MATD was obtained via analyzing the effects parameters on frequency domain characteristics. Simulation results demonstrate that MATD has the advantages of fast response, high precision and strong ability of noise restraint. References | Related Articles | Metrics

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Real-time Human Activity Pattern Recognition Based on Time Domain Features of Acceleration LIU Yu,JIANG Hongyi,WANG Shiliang,WANG Yibing,CHEN Yanping 2015, 49 (02):  169-172.  Abstract ( 1201 )   Save Abstract： An algorithm of activity pattern recognition based on the time domain feature of acceleration was proposed for realtime human activity pattern recognition with high accuracy. Time-domain analysis was used as the only method for extracting features. Computation of feature extraction was simplified to achieve realtime recognition of activity, and the ideal result with high accuracy was acquired at the same time. The data tests on Android smart phone indicate that the average accuracy of realtime activity recognition is above 80%. The result proves that this algorithm has a much more high accuracy of realtime recognition compared with the existing algorithms, which has great application prospect in hand-held terminal areas. References | Related Articles | Metrics

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Dynamic Binary Translation Algorithm Based on Characteristic of Transfer Instructions LI Zhanhui1,MENG Jianyi2,CHEN Zhijian1,YAN Xiaolang1,2 2015, 49 (02):  173-177.  Abstract ( 846 )   Save Abstract： The traditional dynamic binary translator(DBT) deals with different kinds of transfer instructions in the same way, which leads to great performance loss of DBT. This paper proposed a novel DBT algorithm composed of directmapping and transfertypeinheriting mechanism to efficiently handle transfer translation，based on the distinctive characteristics between innerfunction and outerfunction transfers. Innerfunction transfers were exactly mapped to the same type of transfers in the source machine, which not only reduced the transfers induced by conditional branches, but also avoids memory synchronizations. Outerfunction transfers were dealt with differently to pass function callreturn attributes from source code to translation code, thus improving the hit rate of the target machine branch predictor. The experiment results from EEMBC(embedded microprocessor benchmark consortium) show that the instructions executed in translation code of transfers has been reduced by 58.9%, the branch predictor hit rate has been increased by 80.7%, and the overall DBT performance has been improved by 12.3%. References | Related Articles | Metrics

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Dynamic Optimization and Simulation of Urban Domestic Water Based on Logistic and C-D Function LI Kebai 2015, 49 (02):  178-183.  Abstract ( 666 )   Save Abstract： The problem of dynamic optimization of urban domestic water input was studied to optimally adapt to the changes of urban population under the process of urbanization. The product of logistic equation and per capita water demand was used to denote domestic water demand, and CD production function was used to denote water supply. Through the dynamic coordination of capital and labor input, the urban water supply dynamic was made to meet domestic water demand, realizing dynamic optimal configuration of water supply input. The system simulation show that expanding the scope of the value of capital and labor input can accelerate up the narrow urban domestic water supply and demand balance and achieve equilibrium. References | Related Articles | Metrics

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MPSoC Communication Optimization Strategy Based on Integer Linear Programming HUANG Kai1a,ZHANG Xiaoxu1b,ZHANG Xiaomeng1b,XIU Siwen2, MEI Lingqi1a,YU Min1a,YAN Xiaolang1b 2015, 49 (02):  184-190.  Abstract ( 694 )   Save Abstract： To solve the problem of the overuse of communication optimization techniques—communication pipeline and message aggregation—in MPSoC (Multiprocessor System-on-chip), which may increase the synchronization cost and lead to system performance degradation, an ILP (integer linear programming) based strategy was proposed. The strategy can employ communication pipeline and message aggregation techniques appropriately, considering communication optimization as well as synchronization optimization, to achieve optimal system performance. Experimental results show that the proposed strategy can take the advantage of the communication optimization techniques and obtain significant performance improvements. References | Related Articles | Metrics

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Multivariate Responses Analysis for Model Validation of Dynamic Systems ZHENG Kai1，HU Jie1，ZHAN Zhenfei2，QI Jin1，PENG Yinghong1 2015, 49 (02):  191-195.  Abstract ( 763 )   Save Abstract： In order to analyze the multiple dynamic responses for model validation of multiple dynamic systems, this paper proposed the analysis method based on the enhanced error assessment of response time histories (EEARTH) and the analytic hierarchy process (AHP). The EEARTH method was used to calculate the characteristic errors of the multivariate dynamic time series. The errors had to be translated into scores between 0 and 100% because they had different value ranges. The AHP method was performed to determine the weights of the three EEARTH scores and the weight of each response on the overall AHPEEARTH score according to the knowledge of experts. Moreover, the AHPEEARTH score of a multiple dynamic system was computed. Furthermore, a driver side occupant restraint system mathematical dynamic model (MADYMO) model was used to demonstrate the validity of the proposed method for model validation of multivariate dynamic systems. Key words： References | Related Articles | Metrics

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Moving Targets CopyMove Forgery Detection in Video Sequences ZHANG Luboa,SUN Tanfenga,b,c,JIANG Xinghaoa,b,c 2015, 49 (02):  196-201.  Abstract ( 818 )   Save Abstract： In this paper, a novel technique to detect moving targets copy-move forgery in video sequences based on LK optical flow and the pre-screening mechanism of moving targets was proposed. The proposed scheme is a coarse-to-fine approach and composed of moving targets detection and tracking, candidate motion sequences selection, and spatial matching. In the pre-processing round, the visual background extractor (ViBe) mechanism and Kalman filter were used to detect and tracking moving objects. To screen duplicated candidates in the temporal domain, the optical flow features in each motion sequences were obtained using the Lucas_Kanade algorithm and calculate their correlation. To evaluate the similarity of image content, the scale invariant feature transform (SIFT) algorithm was used to measure spatial correlation of each corresponding frame between the motion sequences. The experimental results show that the proposed scheme can detect moving targets copy-move forgery well in homologous video. Key words： References | Related Articles | Metrics

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Control of Small Scale Quad-Rotor Helicopter Using Adaptive Control-Optimization LI Jinsonga，YANG Lianb，WANG Letiana 2015, 49 (02):  202-208.  Abstract ( 920 )   Save Abstract： A novel method was proposed in this paper in view of the problem of stability and translation tracking control of small scale quadrotor helicopter. A dynamic model of the quad-rotor helicopter was established based on Newton Euler equation and the rigid body theory. A model of the relationship between lift and input control signal is established by secondary fitting. The adaptive control-optimization (ACO) method is applied to the control system for the first time, by which the attitude stability and translation tracking control of the quad-rotor helicopter was realized. The results of realflight experiment show that adaptive controloptimization (ACO) method has better robustness and real-time performance on attitude and translation control in comparison with common adaptive control methods. References | Related Articles | Metrics

Radiao Electronics, Telecommunication Technology

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Cross-Domain Path Computation Strategy with Multi-Parameter Fitting in Large-Scale Optical Networks WU Dapeng1，ZHANG Lei1，L Yi1，XIONG Yu1,2 2015, 49 (02):  209-213.  Abstract ( 626 )   Save Abstract： In order to overcome the long-time routing and high traffic blocking in complex multidomain optical networks, a path computation strategy was proposed based on the least square. First, the multidomain networks were abstracted into a low complex virtual topology through single node topology convergence. Then the more than one domain sequences from source node to destination node were calculated using the minimum number of hops. Secondly, based on the least square method, these domain sequences were fitted to some different centre points by jointly considering multiple inter-domain resources. Furthermore, the optimal centre point, that is the optimal domain sequence, was selected using the weighting formula. Finally, the route was computed according to the selected domain sequence. Simulation results indicate that the proposed strategy not only ensures a shorter path computation time but also reduces the traffic blocking effectively. Key words： References | Related Articles | Metrics

Communication and Transportation

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Prediction of Fatigue Life Reliability for Ship Details Based on Crack Growth YAN Xiaoshun,HUANG Xiaoping 2015, 49 (02):  214-219.  Abstract ( 953 )   Save Abstract： In this paper, a limit state equation was derived by using an improved model of Paris law. A more efficient numerical integration method was described and the verification showed that the result of this method was in good agreement with that of the cyclebycycle method. A flowchart for prediction of fatigue life reliability of ship details by using Monte Carlo simulation was given. Based on this procedure, a demonstration was done for predicting the fatigue life reliability of a detail on deck of a container ship. In addition, the influences of variables on prediction result were discussed. It is shown that the improved Paris model can reduce the variation of predicted fatigue life. Initial crack size affects the results a lot while the critical crack size does not. The method proposed can provide reference for fast prediction of fatigue life or obtaining reliability of other engineering structures. References | Related Articles | Metrics

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Deflection Measurement Methods Based on Velocities of Pavement Deflections ZHANG Dejin1,LI Qingquan1,CAO Min2,LIN Hong2 2015, 49 (02):  220-226.  Abstract ( 1067 )   Save Abstract： To meet the demands of continuous deflection measurement at a traffic speed of 20~80 km/h, a novel method was proposed which substituted velocities of pavement deflections for absolute deflection. The measurement method and retrieve algorithm of velocities of pavement deflections with the standard loads were studied by using Doppler laser sensor. Based on the BernoulliEuler beam theory on an elastic foundation, the twoparameter solutions of deflection basin curve were deduced. Pavement deflection was inversed using velocities of pavement deflections with Newton Iteration method. The prototype system based on this method was applied to totally 40 000 km in Xinjiang, Shaanxi, Gansu, Tianjin, Hubei and other provinces in 2014. A large number of experimental data showed that the data repeatability could reach more than 95%. Compared with experimental data by Benkelman beam, its dependency was more than 90%. The method requires only a single measurement sampling and is independent to the curvature of the road, which is suitable for highspeed, nondestructive measurement. The proposed method can meet the requirements of lane by lane, continuous, non-destructive, high-density, high-speed measurement at road network level,  and has extensive promotion value. References | Related Articles | Metrics

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Accessibility Analysis of Ship Evacuation Network Model LIAO Quanmi,HUANG Sheng,WANG Yu,ZHENG Mao 2015, 49 (02):  227-232.  Abstract ( 175 )   Save Abstract： To study the accessibility of large ships, a computational model for emergency evacuation was established based on the differences between naval ships and passenger ships. The minimum evacuation time and optimal watertight are two goals of the model. By using genetic algorithms, the evacuation routes for functional groups in different locations were calculated and selected, considering the capacity constraints and influence of encounter flow and counter flow. The comparison with the method based on the shortest path implied that the shortest path is not necessarily the optimal path of ship evacuation. References | Related Articles | Metrics

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Analysis of RC Arch Strengthen by Bonded FRP Under Initial Stress REN Wei1,GAI YiTing2,ZHANG Gang1 2015, 49 (02):  232-238.  Abstract ( 126 )   Save Abstract： The paper aims at the drawbacks and difficulties in nonlinear numerical simulation of pasting FRP to reinforce concrete arch structure. Based on 3 FRP reinforced test of concrete arch structure, it introduces technologies such as the concrete plastic damage model, cohesive behavior, embedded and model change etc into nonlinear numerical analysis, realizing the simulation of some key mechanical properties such as concrete damage, FRPconcrete interface paste slip and initial load, etc. The comparison of reinforced test and numerical simulation that the ultimate bearing capacity of the structure by adopting cross section reinforcement, is increased by 14.47%, the ultimate bearing capacity of the structure is increased by 27.60%, and analytical error of cracking load is within 7.79%, analytical error of ultimate load is relatively small, and the maximum value is 4.88% which shows that the numerical analysis method proposed in the paper is feasible, and can provide basis for further research on pasting FRP to reinforce concrete arch structure. References | Related Articles | Metrics

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Experimental Study of Hydrodynamic Performance of Unmanned Wave Glide Vehicle LIU Penga,SU Yumina，LIAO Yuleia,GUO Chunyub 2015, 49 (02):  239-244.  Abstract ( 121 )   Save Abstract： The prototype of unmanned wave glide vehicle (UWGV)——“Voyager I” was designed and built. Experiments were conducted including the resistance tests in calm water, the selfpropulsion tests in regular wave and the freedom sailing tests in regular wave. The resistance composition of UWGV in calm water was studied. Besides, the effect of wave length and amplitude on heaving amplitude, pitching angle, thrust of wave glider propulsor (WGP) and the freedom sailing velocity of the UWGV were analyzed. The changing tendency of was obtained with wave length and amplitude. The experiment result provides a new direction for numerical calculation and a foundation for development of unmanned surface vehicle with long voyage and low carbon. References | Related Articles | Metrics

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Model-Based Controller Design for an Electronic Throttle of Gasoline ZHANG Hu,ZHANG Yong,LIANG Junyi,YIN Chengliang 2015, 49 (02):  245-249.  Abstract ( 107 )   Save Abstract： Electronic throttle is a key actuator of the gasoline engine. Due to the effects of frictions and the nonlinear return spring, the throttle control system design is difficult. In this paper, an electronic throttle system model was constructed and system parameters were identified through the system identification method. Then, a feedforward compensation controller was designed based on the model of friction and nonlinear return spring. And an H infinity controller was designed based on the compensated system which was modeled as a linear system. After that, the H infinity controller was discretized for implementation. Because of the controller discretization, the performance of the H infinity controller declined slightly, and, therefore, a proportional control was added to improve the control performance. Finally, experimental verification was conducted which showed that the designed electronic throttle control system could meet the design requirements. References | Related Articles | Metrics

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Adaptive Fuzzy Compensation Control for Nonlinear Ship CourseKeeping ZHU Dongjiana,MA Ninga,b,GU Xiechonga,b 2015, 49 (02):  250-254.  Abstract ( 143 )   Save Abstract： The problem of ship linear and harmonic course-keeping control was discussed. Based on Lyapunov stability theory, the adaptive fuzzy compensation technology was applied to the nonlinear ship response model. A robust adaptive fuzzy compensation based tracking controller including a second-order filter with physical constraints was proposed with the help of the universal approximation theory creating fuzzy systems as approximator of unknown nonlinearities in the system. The response model takes account of the modeling errors and external disturbances. The fuzzy systems can approach the nonlinear system effectively. The controller can track the designed heading angle and turning rate accurately. The rudder control was connected with the rudder servo system, making the steering in keeping with physical reality. Simulation results demonstrate the effectiveness and superiority of the adaptive fuzzy controller compared with the traditional PD control under the same control parameters. Key words： References | Related Articles | Metrics

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Scale Effect of Appendage Resistance of TwinScrew Ship WANG Zhanzhi1,XIONG Ying1，SUN Haitao2,HUANG Zheng1，WANG Rui1 2015, 49 (02):  255-261.  Abstract ( 199 )   Save Abstract： A flat plate was studied for the validation of the numerical method in high Reynolds number condition, based on which, the viscous flow field of different scale model including full scale ship of DTMB5415 bare and appendaged hull were solved numerically by RANS (Reynolds Averaged Navier-Stokes) method and SST k－ω (Shear-Stress Transport k-ω) turbulence model without considering the free surface effect, and the scale effect of appendage resistance of twinscrew ship was analyzed in detail. It shows that the scale effect is quite different for individual appendages. The scale effect of appendage resistance cannot be ignored due to the large proportion in total resistance for twinscrew ship. The appendage resistance correction factor was introduced for the extrapolation of appendage resistance from model scale to full scale ship, and it is found that the cubic polynomial function is fit perfectly for the relationship of the appendage resistance correction factor and the Reynolds number in the logarithmic scales. Key words： References | Related Articles | Metrics

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Numerical Simulation Analysis of Unsteady Cavitation Performance of a Pump-jet Propulsor LU Lin,PAN Guang 2015, 49 (02):  262-268.  Abstract ( 152 )   Save Abstract： The steady cavitating flows of NACA66 hydrofoil were investigated numerically based on the RANS equations of homogeneous multiphase using high quality multiblock structure grid, combined with SST k－ω   turbulence model and Z-G-B cavitation model. Numerical simulation results are in good agreement with the experimental data. Consequently, it is indicated that the numerical simulation method is applicable and reliable. Furthermore, URANS equations and sliding mesh method were applied to the numerical predictions of unsteady cavitation performance for pump-jet propulsor on UUV. The results show that the numerical simulations accurately predict the cavitation inception and extension, shape and location. When cavitation phenomenon appears, the efficiency of pumpjet propulsor drops significantly, even  up to more 20%. The obtained pressure distributions of UUV surface, rotor and stator blades are reasonable and consistent with the cavitation phenomenon. Additionally, the pressure difference of pressure side and suction side of rotor blade causes tip vortex and tip clearance cavitation, which result in a further drop in efficiency of pump-jet propulsor. References | Related Articles | Metrics

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Numerical Prediction of Propulsive Performance with an Iterative Body-Force Propeller Model ZHENG Yanga,CHEN Zuogangb,DAI Yib 2015, 49 (02):  269-274.  Abstract ( 129 )   Save Abstract： The research of self-propulsion performance plays a vital role in the ship-design and the development of the novel ship. To achieve the prompt prediction of propulsive performance, this paper simulated hull/propeller interaction using a convenient prescribed bodyforce method and computational fluid dynamics (CFD).The free surface viscous flow around MOERI container ship (KCS) was simulated at the selfpropulsion point. An iterative bodyforce method which couples the Vortex Lattice Method (VLM) of the propeller lifting surface with the RANS solver was presented.  Both the force and moment computed by VLM were input to RANS as the source term while the inflow to the propeller computation from the viscous velocity subtracted the induced velocity at the propeller plane.  The iterations between the VLM and RANS were prosecuted until the propeller thrust and torque coefficients were converged within a specific tolerance. All the progress was done automatically by an integrated program which coupled RANS/VLM solvers. The computed results agree well with the measured data. The method adopted in this paper predicts the performance of selfpropulsion accurately and efficiently. References | Related Articles | Metrics

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Application of Improved FAHP in Evaluation of AUV Overall Performance WANG Jian1，PANG Yongjie1，YANG Zhuoyi1，HU Zhonghui2 2015, 49 (02):  275-280.  Abstract ( 133 )   Save Abstract： In order to evaluate the AUV overall performance and select the excellent design scheme, the evaluation system of AUV overall performance was built based on expert advices. The weight coefficient of the evaluation indicators were solved by the method of the improved FAHP. Then, the applied research to evaluate the AUV overall performance was conducted. The results shows that the evaluation model can objectively reflect the AUV overall performance clearly. This evaluation method can effectively transform the multiobjective problem into a single objective problem. It can be used for evaluation of the AUV performance and optimization of AUV design scheme. References | Related Articles | Metrics

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Complex Network Short-Term Traffic Forecasting Based on Lasso-NN Model JIANG Shizheng,XU Rong,CHEN Qimei 2015, 49 (02):  281-286.  Abstract ( 183 )   Save Abstract： Traditional traffic forecasting models are transforming from single section historical data processing to multi-section and multi-timing historical data processing. However, when considering the influence between each section, the fickle traffic condition tends to complicate the forecasting model. Therefore, this paper introduced the Lasso method used in multivariable linear regression and utilized its excellent ability of variable selection. It selected partial high correction sections from a complex multi-section road network. Combined with the non-linear neural network, a new LassoNN model was proposed. The result shows that the LassoNN model has an overall lower error rate. In the intersection region of the road network, the error rate is less than 9.2% and in the nonintersection region, it is less than 6.7%. References | Related Articles | Metrics

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A Prediction Model for Traffic Accident Proneness Caused by Drunk Driving via Numerical Characteristics of Drivers’ EEGs ZHONG Mingen1,WU Pingdong2，PENG Junqiang3,HONG Hanchi1 2015, 49 (02):  287-292.  Abstract ( 137 )   Save Abstract： This paper introduces the establishment of a predicting model for normalized traffic accident proneness (NAP) after drinking. Eighteen drivers’ EEGs and traffic accident proneness were measured respectively in different drunken states. Considering the instant complexity and longterm periodicity of EEGs measured from the left frontal lobe, the power gain of δ wave and fuzzy entropy of EEG were invented and calculated. A hybrid SigmaPi neural network was introduced and studied to help building the predict model for NAP from the aspects of both power gain of δ wave and fuzzy entropy of EEG. Experiments proved that the predicted values of NAP  accord with the actual values, with a consistent increase and decrease characteristic. When the amount of the alcohol drunk is less than 50% of the subjective maximum alcohol to drink, the errors were very small, but when the amount of the alcohol drunk is more than 50%, the errors became bigger along with the increase volume of alcohol to drink. References | Related Articles | Metrics