Table of Content

28 February 2020, Volume 54 Issue 2 Previous Issue    Next Issue

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A Network Maximum Flow Based Approach for Author Name Disambiguation QUAN Jinqi,FU Luoyi,GAN Xiaoying,WANG Xinbing 2020, 54 (2):  111-116.  doi: 10.16183/j.cnki.jsjtu.2020.02.001 Abstract ( 1087 )   PDF (616KB) ( 665 )   Save In order to reduce the influence of sharing features (organizations, conferences, etc.) among different author entities on author name disambiguation, an algorithm based on network maximum flow is proposed in this paper. The algorithm puts the paper entities and features into a network graph, and sets the capacity of feature nodes based on the sharing degree. And then, it calculates maximum flow between each paper nodes and does clustering based on maximum flow. The experiment results show that the proposed algorithm has a more balanced performance on accuracy and recall, and has better overall performance. References | Related Articles | Metrics

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Intent-Aware Search Snippet Text Highlighting Method ZHANG Hui,MA Shaoping 2020, 54 (2):  117-125.  doi: 10.16183/j.cnki.jsjtu.2020.02.002 Abstract ( 946 )   PDF (4139KB) ( 376 )   Save The efficiency of information retrieval from web depends largely on the search engine results page (SERP) that obtained by searchers, especially the highlighting text. At present, the SERP of commercial search engines usually uses query terms highlighting strategy. However, the query words can be ambiguous and even contain noise, which may be incompletely consistent with the search intention of users. In order to highlight the most important terms that describe the search information clearly, this paper proposes a new key term highlighting strategy based on the results of manual annotation. Then this paper generates highlighting terms based on four machine learning algorithms, including structured support vector machine, hidden Markov model, max-margin Markov networks and conditional random field algorithm. In addition, this paper also proposes a new method which called the joint sequence labeling (JSL) algorithm to combine these four structured learning algorithms. Moreover, this paper conducts search experiments by using JSL algorithm. Experimental results show that the JSL algorithm provides more accurate solutions compared with the baselines and its search accuracy achieves 9330%. And the results of search experiments show that the key term highlighting strategy achieves better performance and users’satisfactory than traditional query terms highlighting strategy. References | Related Articles | Metrics

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Scheduling of Multi-Load Rail Guided Vehicles in AS/RS with Collision Avoidance Constrains MA Changpu，ZHOU Binghai 2020, 54 (2):  126-134.  doi: 10.16183/j.cnki.jsjtu.2020.02.003 Abstract ( 890 )   PDF (1085KB) ( 379 )   Save To deal with the problems of cargo loading/unloading sequence constraint and impending collision between rail guided vehicles (RGVs) in automated storage and retrieval system (AS/RS), the concepts of the conflicts of cargo loading/unloading sequence and collision are introduced. And a mathematical programming model considering the characteristics of eliminating the conflicts is established to minimize the total complete time. CPLEX is employed to optimally solve the small-scale problems, and a modified harmony search(MHS) algorithm is constructed for medium to large scale problems. In the algorithm design, the harmony memory is repeatedly divided and regrouped to accelerate the searching process, and four variable neighborhood search strategies and a mutation operation are integrated to overcome the deficiencies of the basic harmony search algorithm, such as limited search depth and tendencies to trap into local optimum. Simulation experiments of the MHS algorithm are compared with other evolution algorithms, and the simulation results show that the algorithm has high solution quality and good convergence performance, and can improve the running speed and the practicality of the AS/RS. References | Related Articles | Metrics

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Development and Application of Revit-Abaqus Model Exchange Interface WANG Xuanxuan, HUANG Yulin, ZHAO Jincheng, DUAN Liping 2020, 54 (2):  135-143.  doi: 10.16183/j.cnki.jsjtu.2020.02.004 Abstract ( 2614 )   PDF (6141KB) ( 848 )   Save In order to solve the difficulties of modeling complex building structures in Abaqus and improve modeling efficiency, the Revit-Abaqus model exchange interface was developed. Based on Revit API, the components’ coordinates, geometry size, section type and direction, material parameters, boundary conditions and load information of the Revit structural model, which were required for structural analysis in Abaqus, were obtained by using C# language on the Visual Studio 2015 platform. In the exchange program, all components were automatically meshed, and an Abaqus-aware INP file was generated. Afterwards, the reliability and correctness of the interface were verified by a multi-layer steel frame. Finally, it was applied to the 3D modeling and structural analysis of the integral steel platform for the core tube construction of a super high-rise building in Shanghai. This exchange interface bridged the data barriers between Revit and Abaqus, and realized the goal of structural analysis by introducing the complex structural model of Revit into Abaqus, and it greatly improved the efficiency of modeling and calculation of complex structures. References | Related Articles | Metrics

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Adaptive Terminal Sliding Mode Control of a Howitzer Shell Transfer Arm with Friction Compensation YAO Laipeng, HOU Baolin, LIU Xi 2020, 54 (2):  144-151.  doi: 10.16183/j.cnki.jsjtu.2020.02.005 Abstract ( 907 )   PDF (3150KB) ( 458 )   Save To deal with the fast position control problem of a howitzer shell transfer arm with load change and nonlinear friction disturbance, a nonsingular fast terminal sliding mode control strategy is designed combined with adaptive control. The dynamical equations of shell transfer arm with load change and nonlinear friction are established. To avoid singular problem of the control law and improve the convergence rate of reaching the sliding surface, a new nonsingular fast terminal sliding mode control strategy is used to design the control law of the howitzer shell transfer arm. An adaptive law is presented to estimate the unknown upper bound of the uncertain disturbance which is difficult to obtain. The state of the closed-loop system is finite time convergence based on the Lyapunov theory. In order to realize the friction compensation control, a genetic algorithm is used to identify the Stribeck model parameters of the system. The experiment results of shell transfer arm under three different load conditions show that the controller designed in this paper can position accurately, and it has a good robustness against load change and nonlinear friction. The correctness and effectiveness of the proposed control strategy are proved by experimental results. References | Related Articles | Metrics

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Optimization of a Powering Coil Onboard a Dime-Size Inchworm-Like Robot for Exploring the Intestine GAO Jinyang, YAN Guozheng, SHI Yunbo, LIU Jun 2020, 54 (2):  152-159.  doi: 10.16183/j.cnki.jsjtu.2020.02.006 Abstract ( 1158 )   PDF (6572KB) ( 384 )   Save A dime-size inchworm-like robot, which adopts wireless power transmission for power supply, has a great potential for a minimally invasive intestinal exploration. The powering coil onboard the robot is usually composed of a ring-shaped ferrite core and a ring-shaped winding. This paper presents a fast design method for power coil. Firstly, the integrated environment model of the powering coil is established by modeling the geometry of the ring-shaped winding, measuring the permeability distribution of the ferrite core, and analyzing the influence of eddy-current effect of the metal parts on the powering coil. Then, by referring to electromagnetic theory, the equivalent series resistance and mutual inductance of the powering coil are calculated. Finally, axial location, number of layers, number of turns, and wire diameter of the winding are optimized, with an aim of maximizing the output power of the powering coil and with a consideration of temperature rise safety and limited space. And some guiding rules for selecting the design parameters are obtained. The optimized winding, having a compact size of (12.0—12.4)mm×9.9mm, can output an electric power of 1478.3mW. References | Related Articles | Metrics

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Impact of Vane Friction Coefficient on Cam-Rotor Motor’s Torque Performance TAN Dun，TAO Jianfeng，CHEN Liangshen,WANG Xuyong 2020, 54 (2):  160-166.  doi: 10.16183/j.cnki.jsjtu.2020.02.007 Abstract ( 944 )   PDF (6532KB) ( 252 )   Save In order to study the influence of the blade friction coefficient on the torque performance of the hydraulic cam-rotor servo motor, a mechanical model of the vane motor torque is established. By analyzing the force on the vane, the relationship between the positive pressure exerted by the cam-rotor on the vane and the friction coefficient between the vane and the vane groove are derived. Based on this, the analytical formula between the friction coefficient and the resistance torque applied by the vane to the cam-rotor is derived. The MATLAB is used to simulate the mechanical model. The results show that the increase of the friction coefficient between the vane and the vane groove will reduce the positive pressure between the vanes, and increase the resistance torque of the vane to the cam-rotor, resulting in significant fluctuation of the motor output torque. The maximum and average values of the resistance torque are roughly linear to the friction coefficient. Reducing the geometrical tolerance and surface roughness between the vane and the vane groove can improve the low speed characteristics of the servo motor. References | Related Articles | Metrics

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Influence of Double Circular Arc Harmonic Transmission Profile Parameters on Flexspline Stress JIANG Qianqian,WANG Jiaxu,LI Junyang,XIAO Ke,TANG Ting,WANG Cheng 2020, 54 (2):  167-175.  doi: 10.16183/j.cnki.jsjtu.2020.02.008 Abstract ( 956 )   PDF (3506KB) ( 353 )   Save In view of the influence of tooth profile parameters on the fatigue life of flexspline without considering the tooth profile parameters in the design specifications, the enveloping method is used to design the double tangent conjugate tooth profile without common tangent, and the multi-body contact finite element analysis is carried out. The response surface model of tooth profile parameter and flexspline stress is established, and the influence law of each tooth profile parameter on the flexspline stress is analyzed. The results show that the flexspline stress is more sensitive to the change of tooth profile parameters due to the deforming of the flexspline caused by the meshing teeth between the circular spline and the flexspline; the harmonic drive is more tooth meshing transmission, so the single contact tooth is less loaded and the load has less effect on the stress of the flexspline. The ratio of tooth thickness has the greatest effect on the flexspline stress. The teeth height coefficient and the root fillet radius have the second impact, and the dedendum high coefficient has the least impact. The flexspline stress decreases with the increase of root radius and root height coefficient and then increases, and the other factors are inversely proportional to the stress of the flexspline. References | Related Articles | Metrics

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Modal Analysis of Wake Induced Vibration Transient Process Based on POD and DMD XIE Hairun,WU Yadong,OUYANG Hua,WANG Anzheng 2020, 54 (2):  176-185.  doi: 10.16183/j.cnki.jsjtu.2020.02.009 Abstract ( 1773 )   PDF (3428KB) ( 717 )   Save Wake induced vibration is a common phenomenon in the field of aeroelasticity which can cause forced vibrations of the structure. This phenomenon can endanger the integrity and the fatigue life of the excited structure. In this paper, wake induced vibration is studied by an approximate model with upstream cylinder and downstream blade. The cylinder in freestream produces Karman vortex street with a specific frequency. When the cylinder wake encounters the downstream blade, continuous pulse excitation is applied to the blade. Two-dimension numerical simulation based on Fluent illustrates the shedding vortex and transient process of blade from static to vibration at its natural frequency, and the detail information of transient flow field is obtained. Based on the unsteady transient results, proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) are applied for the decomposition and the reconstruction of the pressure field near the vibrating blade. The modal frequency and the evolution process are extracted to capture the main flow structure of wake induced vibration. The comparison of two modal analysis methods shows that POD reconstruction has a smaller maximum residual than DMD, and DMD has more advantages in single frequency mode extraction and corresponding evolution analysis. References | Related Articles | Metrics

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Lightweight Design for Improving Aeroengine Fan Blade Impact Resistance Capability CHAI Xianghai，ZHANG Zhinan，YAN Jun，LIU Chuanxin 2020, 54 (2):  186-192.  doi: 10.16183/j.cnki.jsjtu.2020.02.010 Abstract ( 1600 )   PDF (8907KB) ( 519 )   Save In order to improve the impact resistance of fan blades, this paper optimizes the innovative configuration design of fan blades with the constraint of the hollow ratio. The feasibility rationality of the optimized solution was verified through the processing of test pieces and performance evaluation. The static equivalent method of transient impact load was established to obtain the optimal mass distribution of the fan blade that can effectively resist bird impact load under working conditions. Based on the optimization results, the fan blade topology optimization was reconstructed, and the geometric configuration of fan blade with low mass and high impact resistance was established. Based on 3D printed fan blade to optimize the configuration test sample, the feasibility of the processing technology and the mechanical properties of the optimized configuration of fan blades were evaluated by 3D printing. The process reliability, static force and bird impact resistance of the optimized design were verified. The results show that the proposed optimization method can be used for the design of hollow fan blades of aero engine with a hollow ratio of over 45%, and the impact resistance of the blades is significantly improved. References | Related Articles | Metrics

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Parametric Study and Displacement Response of Steel Pipeline Subjected to Surface Explosion WANG Yaguang，LIAO Chencong，ZHANG Qi 2020, 54 (2):  193-199.  doi: 10.16183/j.cnki.jsjtu.2020.02.011 Abstract ( 955 )   PDF (9984KB) ( 734 )   Save A coupled numerical model is established by adopting the u-p model. The dynamic response of pipe jacking in saturated soil under surface explosion is investigated in detail. A comprehensive parametric study is carried out to study effect of explosive charge, explosion offset, embedment depth and radius of the pipe jacking. The results show that the vertical displacement of pipe jacking increases with explosive charge. The stability capacity of the pipe jacking under surface explosion decreases as the pipe radius increases. Increasing the buried depth of pipe jacking can significantly enhance the anti-explosion ability of pipe jacking under surface explosion. In additioin, the vertical displacment of the pipe jacking decreases as the off-set distance increases. The pipe jacking rises slightly under surface explosion eventually. And the horizontal displacement increases firstly and then decreases as off-set distance increases. References | Related Articles | Metrics

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Experimental Study on the Behavior of Piezoelectric Micro-Droplet Ejection in a Coaxial Airflow ZHOU Jian,PEI Zeguang 2020, 54 (2):  200-210.  doi: 10.16183/j.cnki.jsjtu.2020.02.012 Abstract ( 1102 )   PDF (1744KB) ( 6005 )   Save The aim of this study is to investigate the effects of coaxial airflow on micro-droplet ejection process. A coaxial airflow assisted piezoelectric printhead is designed and fabricated, and a micro-droplet ejection and observation system is constructed. A bipolar trapezoidal wave is adopted as the waveform of driving signal, and droplet images at different time are obtained by a CCD camera. Then the behavior of piezoelectric micro-droplet ejection based on the reproducibility of the droplet ejection process is studied. The results have shown that with the increase of coaxial airflow intensity, the liquid ligament length increases without the change of time for its breakup at the nozzle exit, while the breakup time of its head and tail is delayed. Meanwhile, the volume of a liquid drop ejected decreases slightly followed by a decreased primary droplet and an increased satellite droplet. Velocities of the leading and trailing ends of both the primary and satellite droplets tend to increase. The velocity fluctuations of the trailing ends of both the primary and satellite droplets are both decreased in amplitude and frequency. And a higher airflow pressure also leads to flattened shapes of the primary and satellite droplets, decreased equivalent diameters of the former, and increased ones of the latter. The study elucidates the behavior of micro-droplet ejection driven by a combination of the pressure wave and the coaxial airflow, reveals the mechanism of coaxial airflow in the process of extension, breakup and flight of micro-droplets, and provides the basis for design of coaxial airflow assisted piezoelectric printhead. References | Related Articles | Metrics

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Dynamic Research on Dual Array Towed System for Breaking Situations WANG Fei,TU Weimin,DENG Deheng,WU Xiaofeng 2020, 54 (2):  211-220.  doi: 10.16183/j.cnki.jsjtu.2020.02.013 Abstract ( 999 )   PDF (10677KB) ( 247 )   Save This paper plans to research the dynamics of a dual array towed system at and after breaking sonar array conditions, and a mathematical model and the numerical solving method are developed, which are used to intensively analyze the system’s dynamic and kinematic responses at different conditions. In this paper, the cable is modeled by the lumped mass method, and the underwater towed body, as an essential part, is described by the 6-degree-of-freedom maneuverability equation of submarines, while coupling conditions between them are given to form the whole system’s governing equations set, which is solved by 4th order Runge-Kutta method in time domain. The numerical implement of breaking array is also given. Some numerical simulations are carried out to analyze the system’s responses at different maneuvering conditions, which include instantaneous response and after response of breaking array, some meaningful conclusions are drawn. The numerical result shows that the system may move above the water surface at high speed with long array breaking, and impact and entanglement may occur when a array breaks during loop maneuvers. References | Related Articles | Metrics