Abstract:Considering employing the electric vehicles to deliver parts to stations for assembly lines based on point-to-point delivery strategy，an improved multi-objective cuckoo search algorithm is presented. First，the scheduling problem of material delivery is formally described，and the number of electric vehicles and the maximum handling time are selected as the components of the objective function based on overall consideration of power limit and on-time delivery requirements. After that，a fusion encoding mechanism reflecting directly the vehicle and sequence of the delivery is put forward in the algorithm. Then，a task allocation rule is designed to generate the initial solutions，and Gaussian mutation and elite selection strategy are incorporated into the search process based on chaotic dynamic step size to improve global search ability of the algorithm as well as the quality of the solutions. Furthermore, two local search operators are proposed to enhance the algorithm′s ability for deep optimization. Finally，the simulation results verify the feasibility and effectiveness of the proposed scheduling algorithm.

Abstract:For distributed drive electric vehicles，less attention is paid to the inhibition of lateral torque distribution on wheel slip ratio and its improvement on cornering performance. To solve this problem，taking the advantage of the independently controllable torque，a torque vectoring control method based on tire longitudinal stiffness estimation and optimal slip ratio identification was proposed to reduce the average slip ratio of the driving-axle. According to the simplified adhesion characteristics of the tire and the road，the impact of torque vectoring on the average slip ratio of the driving-axle was theoretically analyzed. An estimator based on Recursive Least Square method（RLS） was designed to estimate the tire longitudinal stiffness in real time. On the basis of the estimated tire longitudinal stiffness and identified optimal slip ratio，an torque vectoring control method was developed. The simulation results show that，the proposed torque vectoring control method not only can obviously decrease the average slip ratio of the driving-axle by more than 10%，but also can reduce the steering wheel angle input by about 14%，which achieves the dual purpose including the improvement of cornering efficiency and the enhancement of steering maneuverability.

Abstract:With respect to several drawbacks such as easily causing the loss of experts' risk assessment information，overlooking the failure mode and effect analysis（FMEA） team member's bounded rational behaviors and the relative importance among risk factors in traditional FMEA method. a probabilistic linguistic FMEA risk evaluation method based on regret theory and Complex Proportional Assessment（COPRAS） method was proposed. Firstly，the probabilistic linguistic term sets（PLTS） was used to characterize the ambiguity and uncertainty of experts risk assessment information；Secondly，the risk factor weights were determined by using comprehensive weighting method based on the probabilistic linguistic multiplicative Analytic Hierarchy Process（PL-MAHP） and the maximum deviation method；Thirdly，taking experts′ psychological behaviors into account，regret theory and COPRAS were adopted to prioritize failure modes. Finally，an empirical case concerning the risk evaluation of the grinding wheel frame was presented to demonstrate the practicality and effectiveness of the proposed method. Results derived from comparative and sensitivity analyses fully show that the risk priority ranking order determined by the proposed FMEA method is shown to be more rational and reliable by comparing with other existing methods.

Abstract:Engineering application problem analysis often involves multi-body dynamics and fluid-solid coupling joint simulation，and the problem of pedestrian wading in wet road is a typical one. Multi-system co-simulation modeling and integral shoe “wading-outlet” process simulation analysis have a good reference value for the analysis of similar complex coupling problems in engineering applications. In this paper，a multi-body dynamic model of human lower limbs based on Adams/View was established to simulate pedestrian gait and then used as the boundary condition of shoe motion. A fluid-solid coupling model of shoe wading process was established，and the detailed “wading-outlet” process of the shoe was visually analyzed using the coupled Euler-Lagrange（CEL） method. It was found that the whole process can be divided into five stages：drainage，water pushing，water film formation，water film rupture and complete water discharge. Finally，wading simulation of sport shoes and flat shoes was performed，the volume fraction cloud map，water velocity map and system kinetic energy changes at various stages were compared，and the wading time and energy consumption were used as the evaluation index of wading performance，it can be found that the wading performance of flat shoes is weaker than that of sports shoes.

Abstract:This paper presented an experimental investigation on the dynamic characteristic of nested compression spring gas foil bearings（NSFBs）. A test rig was built to test the dynamic characteristic of the NSFB. Impact load tests with stationary rotor and rotating rotor（24.00 kr/min） were conducted，respectively. The dynamic stiffness and equivalent viscous damping coefficients of the studied bearing were extracted from the results of impact load tests. Bearings with different spring numbers were tested and their dynamic coefficient were compared. Static load tests were conducted to measure the real clearance of the test bearings after assembling. And then the diameter of the rotor in the impact load tests was calculated based on the tested real bearing clearance to confirm that the nominal clearance for the test bearings with different spring numbers are the same under the impact loads. For both the tests with stationary rotor and rotating rotor，the direct stiffness coefficients，direct equivalent viscous coefficients，and loss factor increasd as the spring number increased. However，the direct stiffness and equivalent viscous coefficients for the test with rotating rotor were smaller than the results of the test with stationary rotor.

Abstract:To improve the service performance of the dry disc brakes for tracked vehicles，a novel pressurized structure based on the taper roller is proposed and studied. The extension of generatrix is intersected with the axis of pressurized structure to guarantee the pure rolling condition for the taper roller and brake. The full arc convex and arc modified form are given to improve the mechanical performance of tapered roller. Based on penalty contact algorithm，the circular arc，tapered roller and improved types are analyzed and compared using explicit finite element method under typical brake condition. Numerical simulation results show that the stress state is great improved because the proposed roller is line contact instead of point contact of spherical billiard. The full arc convex and arc modified form can eliminate the boundary effect of roller. Not only the maximum effective stress is reduced，but also the uniform stress along axis is guaranteed for the full arc convex roller.

Abstract:In order to solve the problems of poor accuracy and low efficiency in manual detection of foreign matters in the internal and external wall groove of zirconium tube，a visual detection method based on the average template is proposed in the paper. In this method，compound light source is used to image the conical surface of the groove on the inner and outer walls of zirconium tube，and the obtained image is unfolded into rectangle image.Based on the threshold setting，the similarity comparison and replacement of the gray value of the column pixels are carried out，and then the average template of the groove without foreign matters is designed. The suspected foreign matters are located by the difference detection between the template and the real image. Finally，the foreign matters are identified according to the actual criterion rules. Experimental test and enterprise application show that the method can effectively detect the small size foreign matters in the groove of zirconium tube，with an accuracy of 99.6%，and an detection efficiency of 1.84 s/piece，and the corresponding equipment runs well in the enterprise.

Abstract:As an excellent ATPG toll，TetraMAX ATPG enable to generate a test pattern set with high fault coverage in a short time. In this paper，by re-modeling the basic test pattern set generated by TetraMAX ATPG，a method for computing an optimal test pattern set based on minimum set covering problem is proposed. This method models the test pattern set reduction problem as an instance of set coverage problem. It can effectively reduce the scale of test set on the basis of guaranteeing the invariable fault coverage of test set，thereby reducing the test cost of the circuit testing. According to the stuck-at fault and the IDDQ Fault，the experimentd results show that the method has good reduction effect on both of them.

Abstract:Accidental fall seriously threatens the health and safety of the elderly. Accurately identify the behavior of human falls and giving timely alerts are effective means to reduce the damage of accidental fall-wound. In this paper，we present a new fall detection method. In our method，dynamic characteristics of human tilt posture are extracted from the key points of the human body based on OpenPose deep convolutional network，the dynamic characteristics are then used for Linear SVM to detect falls，a judgment based on human descending posture is made to exclude confusing human behavior and improve the recall rate. Our method has achieved 97.33% accuracy and 94.80% precision on the human motion dataset，which is better than the current image-based falling behavior recognition method. Being suitable for monocular RGB camera make our method superior in practicality to the existing falling behavior recognition methods that require Kinect cameras.

Abstract:In order to accurately predict the demand for bike-sharing in different regions of a city and solve the problem of imbalance between supply and demand，the travel distribution law of bike-sharing in Shanghai were studied based on the visualization analysis of spatio-temporal characteristics. In view of the non-strict periodicity of time travel distribution，Attention Mechanism was introduced into the Long-short Term Memory （LSTM） network to build a demand forecasting model named AM-LSTM. Spearman correlation analysis method was used to analyze characteristic influencing factors and extract model characteristic values. The prediction models of different input sequences were constructed and compared with the traditional time series prediction models. The results showed that the input sequence with a time interval of 30 min had a higher prediction accuracy. AM-LSTM model can better predict the travel demand of bike-sharing，and the prediction accuracy was higher than that of the single LSTM model. Finally，the correlation analysis of the prediction curve was conducted to verify the prediction performance of AM-LSTM model，which can provide effective information for the scheduling and distribution of urban bike-sharing.

Abstract:Nowadays a large amount of manpower and material resources are required for mechanical reading，and thus an automatic mechanical watch accuracy measurement method based on machine vision is proposed in this paper. Firstly，a hardware system for image acquisition is designed，and then the improved mask-rcnn network is used to extract the mechanical pointer area and other area on the captured image. Secondly，the canny operator is used to extract the edge of the dial，and the centroid of each connected domain is determined. According to the distance relationship between the centroids and the midpoint of the line between the 12 o′clock and the 6 o'clock，the scale centroid is selected and used to fit the inner circle of the dial to determine the position of the center of the dial. Subsequently，the connection between the center and the center of 12 o′clock is used as the reference line for measurement，and the center line of each pointer is then extracted by the RANSAC least squares method. By calculating the angular relationship between the reference and center line，the purpose of using the machine to read the time is achieved. At the same time，as for the reading of the mechanical watch，the error correction principle is proposed，which greatly improves the efficiency of the mechanical watch accuracy measurement.

Abstract:Users and traffics of mobile communication is growing rapidly along with the application of 5G，but pilot resources are still restricted to limited ranges，which leads to the scarcity of pilots in cellular mobile communications. Under the urgent requirement of higher efficiency on pilot utilisation，a small-scale method based on the classical large-scale strategy is proposed. This method divides a cell into several regions in shape of rings，and diversifies the reuse factor to multiple values in a cell. Every user is allocated to a specified reuse factor according to its attached ring. To decrease the effect of interference，users near the edge of a cell have smaller reuse factors than those in the central region，whose higher degrees of reuse save the occupancy of pilot resources. Although the distribution of small-scale strategy is more complex than that of large-scale way，it has better performance on balancing the communication quality and pilot consumptions in a system. Meanwhile，it offers more precise adjustments on the extent of reuse. The simulation results verify the improvement on pilot reuse，utilising distinct factors and adjusting coverages of rings adaptively according to the number of terminals. Influences of some system configurations and extrinsic factors obtained from the simulation provide references for the implementations of small-scale reuses.

Abstract:As the reliability analysis for modular multilevel converter（MMC） usually ignores the correlation between control module and submodules. Firstly， the reliability model of single submodule（SM） and control module is established based on submodule topology analysis. Secondly， considering the interaction of the service life between the SMs and control module， this paper selects the Copula function in accordance with the special application scenario according to the construction method of Copula theory multi-variable joint probability distribution function. Thirdly，taking into account the premise of the correlation of all modules， the MMC reliability analysis model is established with redundant configuration based on k/n（G） model. Finally，taking the flexible DC transmission project in Nanhui Shanghai as an example，the variation law of MMC reliability under different conditions of operation years， correlation degree，requisite SM count and redundant SM count are analyzed. The results show that the model can meet the MMC reliability assessment requirements better and provide the necessary information for MMC topology design and redundancy configuration.

Abstract:There will be multiple photo voltaic（PV） users in the same distribution network area， and building a PV user group is one of the effective ways to manage them. In order to further promote the stability and development of the PV user group， it is necessary to evaluate the importance of users within the group. This paper analyzes the nature of the operator's revenue for the PV user group that implements the internal electricity price， and proposes a method for calculating the contribution value of the user to the operator's revenue based on the cooperative game theory. From the three aspects of users， operators and power grids， the importance evaluation indicators of users are defined， and then the importance evaluation and ranking of users in the PV user group are carried out based on the TOPSIS method in multi-criteria decision making. Simulation examples verify the effectiveness of the comprehensive evaluation method.

Abstract:In order to ensure the using safety of lithium-ion batteries，an online battery condition monitoring method based on the Fading Extended Kalman Filter（FEKF） was proposed. A first-order equivalent circuit model of the lithium battery was established，the state parameters of the lithium battery were identified online using the recursive least squares method，and the state equation was established; the optimal dissipative factor was then introduced to construct the FEKF to obtain the terminal voltage residual，The terminal voltage residual sequence was used to construct the diagnostic function of χ2 distribution，and the error detection rate and the abnormal threshold of state parameters were then calculated by using the function. The experimental results showed that the residuals error generated by FEKF can alert abnormal conditions earlier，which proved that FEKF method method can significantly improve the accuracy of the χ2 test in terms of judging the abnormal internal abnormal state of lithium batteries.

Abstract:In order to trace EMT status of lung cancer A549 cells，we constructed a lentiviral plasmid carrying E-cadherin gene promoter，which was co-transfected with packaging plasmids pVSVG and Δ8.91 into HEK 293T cells to produce active lentivirus. Then the A549 cells were infected by the collected lentivirus，and the success of infection was examined by flow-cytometry and Western blot. Afterwards，TGF-β was used to treat the infected A549 cell，and the expression of GFP and E-cadherin in those cells was detected by the fluorescence observation，RT-PCR and Western blot. We found that after 48 hours of TGF-β induction，the morphology of A549 cells changed from cobblestone to long fusiform. Fluorescence microscopy showed that fluorescence signal of A549 cells was significantly decreased in the induction group compared with untreated cells，and RNA levels and protein levels of GFP and E-cadherin were decreased as well. This indicated that the EMT tracer system was established successfully. In conclusion，we established a EMT tracer system using lentivirus in the A549 cells，providing materials for further study of EMT process of lung cancer.

Abstract:In order to investigate the effects of Litsea cubeba essential oil （LCEO） on the proliferation and apoptosis of Spodoptera litura （SL） cells cultured in vitro and preliminarily determine the main toxic activity component，the CCK，MTT assay and flow cytometry were used to study the inhibitory effects of different concentrations of LCEO on SL cells. The effect of different concentrations of citral on the apoptosis of SL cells was verified by flow cell method. The results showed LCEO can inhibit the proliferation of SL cells，and with the increase of the concentration of LCEO and the prolongation of treatment time，the survival rate of SL cells decreased. When the concentration of LCEO was increased to 0.015%，the survival rate of SL cells was significantly lower （P<0.01）. And the treatment time reached 72 h，the survival rate of SL cells decreased significantly. As the main active component of LCEO，citral has obvious inhibitory effect on SL cells，and the dose is positively correlated. In addition，the citral concentration was greater than 0.015%，the survival rate of SL cells was significantly decreased （P<0.01）. It is indicated that LCEO and citral can effectively promote cell apoptosis and show dose dependence，and citral is the main active ingredient of LCEO to promote apoptosis of SL cells. So，it also provides a basis for the development and utilization of new plant-derived pesticides based on LCEO.