Table of Content

25 April 2019, Volume 47 Issue 4

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Electronics, Communication & Automation Technology

SISR Reconstruction Method of Image Structure Perception Based on Hidden Topic Probability Model



MA Lihong WANG Xiaoe TIAN Jing ZHANG Yu

2019, 47(4):  1-9.  doi:10.12141/j.issn.1000-565X.180321

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In the process of single image super-resolution reconstruction (SISR) based on learning from examples， the mapping relation was assumed one-to-one from a low-resolution (LR) input to a high-resolution (HR) image patch． But in fact，one LR patch may relate to many HR patches，and thus leads to matching errors． To solve the mismatch problem of restored patch，the probability model of LR patch topic pattern was derived to express new observation information for hidden topics in LR signals． Then a structure-aware recovery mechanism with topic differences and context maximum probability was proposed，and LR manifold description was formed by relating topic modes to LR neighbor contents． The HR signal was accurately distinguished and reconstructed from similar LR manifold signals via an adaptive selection of topic decision trees and regression matrix of nodes． The topic mo- del optimization experiment demonstrates that the peak signal-to-noise ratio (PSNR) of our topic constraint SISR method is improved by 0. 25dB compared to that of the decision tree based SISR algorithm without introducing hid- den topics． In the comparative experiment of five algorithms，the average PSNR value of our SISR approach is im- proved by 0. 92dB compared to that of the sparse dictionary based SISR method． So the introduced hidden topic in- formation and topic-manifold structure identification are feasible．

Recognition of Passengers＇Abnormal Behavior on the Escalator Based on Human Skeleton Sequence



TIAN Lianfang WU Qichao DU Qiliang HUANG Liguang LI Miao ZHANG Daming

2019, 47(4):  10-19.  doi:10.12141/j.issn.1000-565X.180186

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The research on recognition of passengers＇ abnormal behavior on the escalator is of great significance． The traditional behavior recognition algorithm can not accurately recognize the multi-target in real time，and the re- cognition result is easily affected by the environment change． So an algorithm for recognizing passengers＇abnormal behavior on the escalator based on human skeleton sequences was proposed． Firstly，the passenger＇s face was de- tected by the support vector machine and tracked by the improved kernelized correlation filter to obtain the trajecto- ries of the passengers． Then，the human skeleton sequences of passengers were extracted by the convolutional neu- ral network． After that，the abnormal behavior skeleton sequences were detected from the human skeleton se- quences of passengers through template matching． Finally，the abnormal behavior was recognized by matching its skeleton sequence with all kinds of abnormal behavior skeleton sequences through dynamic time warping． The re- sults of experiment on 10 escalator videos show that the algorithm achieves a processing speed of 10 frames per se- cond and the recognition accuracy rate is 93. 2%，so it can accurately recognize a variety of passenger＇s abnormal behaviors in real time．

Prediction of Chaotic Sequence with the Adaptive Moment Estimation Algorithm Based on Maximum Correntropy Criterion



WANG Shiyuan WANG Wenyue QIAN Guobing

2019, 47(4):  20-26,34.  doi:10.12141/j.issn.1000-565X.180404

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A novel adaptive moment estimation algorithm based on maximum correntropy criterion (AdamMCC) was proposed to improve the prediction accuracy of chaotic sequence in the non-Gaussian noises． The maximum correntropy criterion was chosen as the cost function of the proposed AdamMCC owing to its robustness against non- Gaussian noises． The first and second moments of gradients in the cost function were used to adjust the weight of the parameters in the algorithm，which provides a better search direction for the optimal weight，thus improved the prediction performance of the proposed AdamMCC． Simulations on the prediction of the Mackey-Glass chaotic time sequence and Lorenz chaotic time sequence illustrate that the proposed AdamMCC can achieve better prediction performance with affordable computational complexity and maintain robustness，compared with the least mean square algorithm (LMS)，the maximum correntropy criterion algorithm (MCC)，and the fractional-order maxi- mum correntropy criterion algorithm (FMCC) in the presence of non-Gaussian noises．

Iterative Correlation Noise Refinement for Unidirectional Distributed Video Coding



WANG Jianpeng SONG Juan LIU Huan

2019, 47(4):  27-34.  doi:10.12141/j.issn.1000-565X.180566

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An iterative correlation noise refinement (CNR) method was proposed for unidirectional distributed video coding (UDVC)． In the iterative decoding process，the correlation noise was refined by using the previously reconstructed coefficients to improve the accuracy of correlation noise modeling． During the refinement，the correla- tion noise residuals were classified according to the decoding reliability and weighted refined respectively in order to avoid misleading refinement caused by wrongly decoded coefficients． Experimental results show that the reconstruc- tion quality is greatly improved after CNR． The average peak signal-to-noise ratio (PSNR) of reconstructed WZ frames from different video sequences is improved by 0. 32 ～ 0. 13 dB． Compared with UDVC without CNR，the average PSNR of the proposed UDVC with CNR is improved by 0. 21dB．

Joint Adaptive Interference Management of Hybrid Cellular Networks



XIAO Liyuan LI Zhao CUI Sha

2019, 47(4):  35-43,60.  doi:10.12141/j.issn.1000-565X.180285

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A joint adaptive interference management (JAIM) mechanism exploiting multi-dimensional resources was proposed for downlink transmission in hybrid cellular networks consisting of overlapping macrocells and pico- cells by taking practical factors such as path loss，distance between base stations and transmit power difference into account． The scheme manages the interference from macro base station to picocell user equipment． Firstly，the efficiency of interference management was defined，and based on which the criterion for adaptive interference ma- nagement was derived． Then，the design of JAIM was elaborated by taking interference neutralization (IN) and zero-forcing (ZF) reception as an example． The theoretical analysis and simulation results show that by exploiting multi-dimensional resource the proposed mechanism can avoid the dependence of single interference management method on specific resources，and improve the picocell users＇spectral efficiency without influencing the macrocell users＇．

Lithium Battery Internal Temperature Estimation Based on Simplified Variable Parameter Thermal Model



LIU Xintian ZHANG Sheng HE Yao ZHENG Xinxin LIU Xingtao WANG Shoumo

2019, 47(4):  44-52.  doi:10.12141/j.issn.1000-565X.180464

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The accurate estimation of the internal temperature of lithium battery is the key to realize the safe and re- liable thermal management of the battery． In order to accurately estimate the internal temperature of the lithium battery，considering the influence of the identification error of each thermoelectric parameter in the existing battery thermal model on the internal temperature estimation accuracy，a method for estimating the internal temperature of a lithium battery based on a simplified variable parameter thermal model was proposed． By identifying the internal heat capacity and external thermal resistance of lithium battery at different ambient temperatures，a variable inter- nal heat capacity and external thermal resistance estimation model was established to analyze the model mechanism， and the influence of external environment on internal heat capacity and external thermal resistance． The reliablity of the model was verified by experiments． Finally，the extended temperature Kalman filter (EKF) algorithm was used to estimate the internal temperature． The constant current discharge experiment and simulation results under different temperature gradients prove that the model is suitable for the lithium battery thermal model under different ambient temperatures，and it has improved the internal temperature estimation accuracy．

Square Root UKF Algorithm Based on Fuzzy Logical Quaternion



WANG Dandan TAN Kaituo GAO Suling YUAN Gannan

2019, 47(4):  53-60.  doi:10.12141/j.issn.1000-565X.180476

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An attitude estimation algorithm based on fuzzy logic square root quaternion UKF is proposed in order to solve the problems such as the filtering accuracy of target continuous state estimation by discrete sensors observation is too low for navigation solution and the traditional quaternion extended Kalman filtering algorithm can not meet the precision requirement of target attitude measurement． The algorithm takes quaternion as the state of fuzzy logic UKF filter，and the measured time rate is used to complete the time update and measurement update of the filter． The square root covariance form of fuzzy logic is used as the update parameter，which reduces the calculation amount and complexity of the algorithm，and ensures the stability of the value． Taking near-earth satellite as an example， simulation experiments were carried out on Matlab and C + + software． The experimental results show that the pro- posed algorithm could guarantee the accuracy of attitude control for robots and features． It can also track and locate the target in real time and update the measurement，which suppress the problem of attitude error divergence．

Traffic & Transportation Engineering

Evaluation of the Metro＇s In-vehicle Congestion Parameters Based on Random Parameters Logit Model



LIU Jianrong HAO Xiaoni

2019, 47(4):  61-66,75.  doi:10.12141/j.issn.1000-565X.180512

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There is significant heterogeneity among travelers＇evaluation on in-vehicle congestion． The impact of in- vehicle congestion was studied with the random parameters Logit model． In view of the impact of the latent psycho- logical factor on travelers＇mode choice，travelers＇demand of comfort was taken into account ． The results show that the random parameters Logit model fit the data much better than the traditional discrete choice model． From the re- sult，it can be concluded that，the parameters of price and in-vehicle time are non-random． However，the parame- ter of in-vehicle congestion is random，and it is affected by travelers＇demand of comfort when traveling and in-vehi- cle time． The impact of in-vehicle congestion increases as travelers＇ demand of comfort increases，and decreases when in-vehicle time increases．

Customer Segmentation of Railway Egress Shuttle System Based on Latent Class Mixed Logit Model



ZHU Hai LUO Xia CHEN Xin LIU Yonghong

2019, 47(4):  67-75.  doi:10.12141/j.issn.1000-565X.180357

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Customer segmentation of railway egress shuttle system is one of the fundamental work for the optimiza- tion of intermodal connectivity for railway hubs． A latent class mixed Logit model for customer segmentation，which can realize the function of customer classification and behavior analysis at one time，was constructed by collabora- ting the likelihood function of latent class model with that of disaggregate mixed Logit model． With the settings of random preference parameters in the latent classes，it can accommodate the resembling but not homogeneous prefe- rences that customers have on attributes in the same sub-market． An example was given with the stated preference data collected towards the arrival passengers at Chengdu East Railway Station for their egress mode choices． NLogit software was used in the process of model testing and parameter estimation． Direct and cross elastics for time and cost of different egress modes were calculated and corresponding management policies were proposed to improve egress shuttle services． The results show that the market is segmented into 4 sub-markets that are “transit pre- ferred”，“private car preferred”，“taxi preferred”and“car-hailing preferred”，and each sub-market exhibits di- fferent market occupation rates，parameter significance levels，as well as attribute preferences． It proves the model ＇s feature of integrating both exogenous and endogenous variables in market segmentation as well as its powerful econometrical explanation ability in market analysis．

Resource Allocation Model Based on Multi-objective Path Planning in Emergency Management



ZHAO Xing JI Kang LIN Hao XU Peng

2019, 47(4):  76-82.  doi:10.12141/j.issn.1000-565X.180437

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With the increasing emergencies，resource allocation in emergency management is vital for fast rescue operation and reducing property loss． A resource allocation model was constructed based on multi-objective path planning，aiming at solving two problems: path planning and resource allocation． Considering impacts of emergen- cies on the road network，the model conducted path planning with two optimization goals: (1) timeliness: obtain the path travel time based on BPR (Bureau of Public Road of United States) road impedance function; (2) relia- bility: evaluate the path travel time reliability degree based on historical traffic volume data． An algorithm integra- ting Tabu Search and non-dominated sorting was devised to acquire the Pareto solution set． By setting index weights，the optimal paths from dispatch centers to emergency areas could be determined． Secondly，according to the optimal paths and the level of emergencies，utility coefficient was introduced to establish the total resource utili- ty function． To achieve the maximum total resource utilization benefits，Lingo was used to obtain the optimal re- source allocation scheme． At last，a cases study which verified the effectiveness of the proposed model and solving method，was presented based on the historical data of Wuxi road network．

Short-term Prediction of Passenger Flow on Bus Routes Based on K-means Clustering Combination Models



CHEN Weiya PAN Xin FANG Xiaoping

2019, 47(4):  83-89,113.  doi:10.12141/j.issn.1000-565X.180489

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The prediction of the short-term passenger flow on a bus route plays a key role in the daily dynamic bus dispatching system． A combined forecasting model based on K-means clustering algorithm was constructed through analyzing passenger flow characteristics． The historical short-term passenger demand data was divided into different clusters by using K-means algorithm according to the similarity of time-varying demand． Each cluster of the passen- ger demand was predicted individually by using Least Squares Support Vector Machine (LSSVM)，Back Propaga- tion Neural Network (BPNN) and Auto-regressive Moving Average (ARMA)． The parameters of LSSVM and BPNN were optimized by the genetic algorithms． The weather effects on passenger flow were also considered． The combination models were formed by a combination of the best prediction models for each cluster． The passenger flow data of Route 104 in Changsha of China was used for the case studies． The results show that the model combinations depend on the differences of the time-varying passenger flow． The K-means clustering method has the ability to classify the time-varying passenger flow data in different periods，which is conducive to improving the prediction performance． The K-means clustering combination models are a promising tool to predict the short-term passenger flow on a bus route，especially when considering the weather effects．

Simplified Dynamic Model for Cable-Stayed Bridge with Longitudinal Viscous Damper



XU Yan TONG Chuan LI Jianzhong

2019, 47(4):  90-98.  doi:10.12141/j.issn.1000-565X.180118

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Longitudinal viscous dampers are usually installed between tower and girder to control the girder＇s longi- tudinal vibration，which is the dominated mode to the dynamic reactions of a floating-system cable-stayed bridge， and the rationale damper parameter has to be determined through complicated FEM analysis． In the light of the dominated vibration mode contribution in floating system，a 3 DOFs simplified dynamic model considering the su- pplemental viscous damper that improves the mechanical behavior of 2 DOFs model was proposed，and the formula- tions for calculating the dynamic responses subjected to pulse dominated near-fault ground motions were deduced． Finally，with an actual bridge project as an example，through comparing the difference between the various simpli- fied model and the whole bridge model，it was proved that the 3 DOFs simplified dynamic model can not only effec- tively calculate the seismic dynamic response of cable-stayed bridge under the action of impulsive earthquake，but also provide a more accurate relative displacement difference and velocity difference between the tower and girder． It is conducive to a more reasonable and accurate design damper parameters，and the rationality of the model is verified．

Special Welding Robot

Multi-objective Path Planning of Welding Robot Based on DMOEA/D-ET Algorithm



WANG Xuewu XIA Zelong GU Xingsheng

2019, 47(4):  99-106.  doi:10.12141/j.issn.1000-565X.180652

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The arc welding robot can improve the production efficiency in the actual production process． The path length and energy consumption during the welding process were optimized，and an adaptive neighborhood discrete multi-objective optimization algorithm based on event triggering (DMOEA/D-ET) was proposed． The algorithm uses the updated particle ratio as the event trigger mechanism to coordinate the global search and the local search through the event trigger mechanism． The grid method was used for global search and MOEA/D for local search． The problem of uneven distribution of MOEA/D algorithm was improved by adopting adaptive neighborhood stra- tegy． By comparing with the other five algorithms on three TSPLIB problems，the experimental results show that the proposed algorithm has better performance． Finally，multi-objective optimization was carried out for the wel- ding process of the balanced beam model． Compared with the other five multi-objective algorithms，the results show that the proposed algorithm is closer to the real frontier and has better distribution of the solution．

Arc Shape and Weld Pool Behavior in Low-frequency Pulse TIG Backing Welding for Medium and Thick Plates



SHI Yu WANG Kaifei ZHANG Gang ZHU Yingrui

2019, 47(4):  107-113.  doi:10.12141/j.issn.1000-565X.180653

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The pulse TIG welding with low frequency and large duty cycle was used to realize single-side welding without subtrate and double-side forming of 16MnR steel plates with 5mm large blunt edge，in view of the low effi- ciency，complex process and poor stability in traditional manual welding with subtract for medium and thick plates backing welding． The compression process of welding arc passing through the molten hole was captured by a high- speed camera． And the correlation between deflection angle and length of arc tail flame and weld penetration at a certain welding speed was analyzed． The results show that a hole-shaped weld pool is formed under a certain para- meters，and the deflection angle and length of the arc tail flame passing through the hole is negatively correlated with the welding speed，and positively correlated with the weld penetration． By observing the size of the arc tail flame，the weld penetration can be estimated，and the stirring and convection of liquid in weld pool is enhanced un- der the thermo-mechanical coupling effect of periodic arc． Under the combined action of surface tension，gravity， arc force and gas blowing force，the liquid metal on the side wall of the welding hole flows to the edge and bottom， which enhances the heat conduction in the weld pool and effectively increases the weld penetration．

Effect of Compensating Gas Jet Impinging Molten Pool on Pulsed MIG High Speed Welding of Stainless Steel



DONG Changwen JIN Li XUE Jiaxiang

2019, 47(4):  114-119,126.  doi:10.12141/j.issn.1000-565X.180658

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A new idea of artificial interference in the movement of weld pool after welding was put forward to im- prove the welding speed of stainless steel and restrain the hump weld bead and undercut defects． Compensating gas jet was introduced to impact the high temperature unsettled weld pool，and the weld formation was improved by in- terfering pulsed MIG weld pool of stainless steel． A self-made pulsed MIG weld pool compensating gas jet test plat- form was used to test different welding speeds and different compensating gas jet flow rates with 304 stainless steel as welding workpiece under the same energy input． The results show that the welding speed can be increased by more than 2 times with the method of compensating gas jet，and the welding seam is straight，uniform and beautiful without hump and undercut defects． The cross-section analysis of welding seam shows that the adjustment rate of liquid metal accumulated in hump by this method reaches 78. 63%，and the thermal efficiency of base metal increa- ses to 74. 36%．

Ultrasonic Echo Signal Analysis of Oil Pipeline Corrosion Based on 1. 5-D Spectrum Estimation



TANG Jian JIAO Xiangdong DAI Bo DING Xuepeng

2019, 47(4):  120-126.  doi:10.12141/j.issn.1000-565X.180657

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The frequently used second-order statistics represented by fast Fourier transform often cause many errors in processing the ultrasonic echo signals of pipeline corrosion． To solve the problem，the formation principle of the pipeline ultrasonic echo signal was studied，and the characteristics of the echo signal were analyzed with the wave theory． A processing method of non-minimum phase system and non-Gaussian signal based on 1. 5-D spectrum esti- mation was proposed． Scanning detection and ultrasonic echo signal analysis were carried out for the normal location of pipe wall，the location of inner wall corrosion and outer wall corrosion respectively． And a special method of echo signal processing for the critical location of corrosion on pipe wall was given． Experimental results of single-point detection and multi-point continuous detection show that 1. 5-D spectrum estimation algorithm can effectively over- come the shortcomings of fast Fourier transform algorithm when analyzing the ultrasonic echo signal of the oil pipe- line corrosion． The relative error of wall thickness obtained is less than 2%． C-scan image can clearly show pipe- line corrosion，which meets the detection requirements of the residual wall thickness of the oil pipeline corrosion．

Droplet Transfer Behavior of High-current GMAW and Its Control



XIAO Lei FAN Ding ZHENG Falei HUANG Jiankang YANG Wenyan

2019, 47(4):  127-131,137.  doi:10.12141/j.issn.1000-565X.180654

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Single wire high-current GMAW welding methods with steady metal transfer processes has irreplaceable advan- tages over other high-efficiency GMAW welding methods． Based on the high-speed photography and electric signals se- lecting technology in metal transfer process of GMAW，the differences between MIG and MAG welding were discussed， and the impacts of current or shielding gas constitution on transfer frequency were highlighted． The results indicate that metal transfer style of high-current MIG welding is rotating spray transfer，and the rotating frequency of MIG welding de- crease at first and then increase with the increase of welding current; while in the MAG welding，it becomes a mixing rotating and swing transfer style，and the rotating frequency or swing frequency increases when the flow beam contacts with the weld pool in high current condition． In addition，the external magnetic field can change the rotation direction of large current GMAW flow beam and arc，and reduce the rotation angle． This discovery provides a new idea for the research and development of high efficiency GMAW welding process with single wire over 400A．

Weld Seam Feature Point Recognition Analysis Based on Improved Mean-shift Algorithm



GAO Xiangdong LI Yangjin LIU Xiuhang ZHANG Yanxi YOU Deyong

2019, 47(4):  132-137.  doi:10.12141/j.issn.1000-565X.180656

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A fast and accurate weld seam feature point recognition is the key of the weld seam tracking system based on structured light sensing． For the streak discontinuity caused by the deformation of structured light stripe line at the weld，tracking tests were carried on butt and lap welds of stainnless steel board，and an improved mean-shift algorithm was proposed to extract the feature point of a weld seam． Unlike the traditional algorithm，the improved algorithm eliminated the process of extracting fringe center line and fitting fringe lineand the feature points of welding seam are identified by drift． In order to prevent from back-shifting，the search direction of the algorithm was limited． To improve the running efficiency，a shifting accelerating factor was introduced． The test shows that the improved mean-shift algorithm can effectively recognize the feature point of a weld seam and saliently improve the accuracy and real-time performance．

Effect of the Direction of Droplet Impingement on the Bead Quality



ZHANG Zhanhui XUE Jiaxiang

2019, 47(4):  138-144.  doi:10.12141/j.issn.1000-565X.180655

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Bead-on-plate welding was conducted on a 6061 aluminum alloy sheet by pulsed gas metal arc welding (P-GMAW) with welding torch inclined in transverse plate，in order to investigate the effect of droplet impingement direction on spatters，profile of welding pool，microstructure，porosities and cracks． Results show that when the torch is inclined，the spatter is dramatically increased and is on the same side with the inclined torch． Meanwhile， the grains can be refined by the effect of droplet impingement． Taking the welding torch inclined to right-hand as an example，because of an asymmetric driving forces within the molten pool，the highest point of the bead does not co- incide with the center line of the lower penetration; the biggest deviation from the bottom center line is 20. 1% of the maximum bead width． Heat affected zone and the micro-hardness zone are wider on the right side that the left． Porosity and crack distribute separately on the two sides of the bead，respectively． Most pores are formed and trapped on the left side，while a substantial number of cracks emerge on the right side． This distribution of porosity and crack is attributed to the molten metal flow pattern which is driven by droplet impingement． The molten metal flow prevents the air hole from escaping on the left side，but facilitates the cracks to appear on the right side．