Top Read Articles

    Published in last 1 year |  In last 2 years |  In last 3 years |  All
    Please wait a minute...
    For Selected: Toggle Thumbnails
    Optimization of Active Distribution Network Operation Considering Decarbonization Endowment from 5G Base Stations
    ZENG Bo, MU Hongwei, DONG Houqi, ZENG Ming
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 279-292.   DOI: 10.16183/j.cnki.jsjtu.2021.367
    Abstract3384)   HTML7)    PDF (3102KB)(128)      

    The massive access of 5G base stations (5G BSs) provides new possibilities for the low-carbon development of future power systems. By incentivizing 5G BSs to participate in demand response and incorporating them into the existing active distribution network (ADN) operation framework, the cost of the electricity consumption of 5G BSs can be reduced while promoting the consumption and efficient use of renewable energy sources (RES). This paper proposes a multi-objective interval optimization model for ADN operation considering low-carbon empowerment of 5G BSs. Based on the interaction mode between 5G BSs and the distribution network, a 5G BSs operating flexibility description model is constructed, and the system dynamics method is used to reveal the mechanism of 5G BSs on carbon emission reduction on the distribution side. Taking the minimization of system operating cost and carbon emissions as the goals, and considering the constraints for both the distribution network and the communication network, a multi-objective optimization model for ADN operation with 5G BSs is established. The model cooptimizes the dispatch of RES and 5G equipment, and adopts an interval method to consider the uncertainty of RES output and communication loads, which can achieve simultaneous optimization of system economy and low-carbon benefits. Combining the equivalent transformation and the non-dominated sorting genetic algorithm to solve the problem, the results of numerical studies prove the effectiveness of the proposed method.

    Table and Figures | Reference | Related Articles | Metrics
    Low-Carbon Transformation of the Power System in the Guangdong-Hong Kong-Macao Greater Bay Area
    ZHANG Pengfei, XU Jingyi, GUO Wei, WU Wei, ZHONG Chen, WEI Wendong
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 293-302.   DOI: 10.16183/j.cnki.jsjtu.2021.436
    Abstract3304)   HTML5)    PDF (2818KB)(145)      

    China’s “carbon peaking and carbon neutrality” goal relies greatly on the low-carbon transition of the power system, but the existing research rarely explores the low-carbon transition of the regional power system. By using the intergovernmental panel on climate change (IPCC) greenhouse gas inventory compilation method and the network model analysis, the carbon emissions caused by the power generation and the power consumption in Guangdong-Hong Kong-Macao Greater Bay Area (the Greater Bay Area) was quantified. The logarithmic mean Divisia index (LMDI) method was used to quantify the influence of socio-economic factors on the electricity-related carbon emissions in the Greater Bay Area. The results show that Hong Kong and Macao have made slow progress in the low-carbon transition of the power system, and Guangdong’s share of the low-carbon power continues to increase. The rapidly expanding economic scale and the power demand were the most important drivers of the emissions growth in the Greater Bay Area. The low-carbon electricity imported from outside regions and the improved efficiency in the sectoral electricity consumption offset part of the emission growth.

    Table and Figures | Reference | Related Articles | Metrics
    Control Strategies for Suppressing Frequency Oscillation of Doubly-Fed Wind Farms Connected to Grid
    LIU Xinyu, LU Xinyan, ZENG Long, HAO Zhenghang, ZHAO Qifang, LI Xianwei, HAO Tongmeng
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 303-311.   DOI: 10.16183/j.cnki.jsjtu.2021.437
    Abstract3298)   HTML4)    PDF (1481KB)(112)      

    Aimed at the problem of low-frequency oscillations caused by cross-region power transmissioin of large-scale wind farms, a single neuron adaptive proportion integration differentiation (PID) additional damping control strategy for low-frequency oscillations of the damping system is proposed in this paper. By analyzing the dynamic frequency response characteristics of doubly-fed wind turbines, a wind farm damping system oscillation controller is constructed by introducing quadratic performance indicators into the single neuron adaptive PID control algorithm. By adaptively adjusting the excitation frequency converter, the wind farm can quickly generate active power and the maximum positive damping, and suppress the low-frequency oscillation of the damping system. MATLAB is used to build a four-machine two-region power system simulation model with a wind farm. The comparison verifies that the method proposed in this paper can effectively suppress the swing of the power angle of the synchronous generator when low-frequency oscillation occurs in the system, improve the inertial response of the system, and reduce the risk of low-frequency oscillation in the power grid.

    Table and Figures | Reference | Related Articles | Metrics
    State of Health Estimation of Lithium-Ion Batteries Based on Dual Charging State
    LU Dihua, CHEN Ziqiang
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 342-352.   DOI: 10.16183/j.cnki.jsjtu.2021.027
    Abstract3277)   HTML8)    PDF (8000KB)(38)      

    Aimed at the uncertainty of charging starting and ending point caused by incomplete charging and discharging in practical applications of lithium-ion battery, an estimation method of battery health based on dual charging state factors is proposed. A battery aging experiment bench is built, and eight nickel-cobalt-manganese lithium-ion batteries are subjected to aging test. Different from the traditional single state factor estimation, the average value of equal time difference current at the front end of constant voltage charging curve and the equal amplitude voltage charging time at the end of constant current charging curve are selected under different aging conditions to construct health factors. The corresponding relationship between state of charge (SOC) and open circuit voltage (OCV) of the experimental battery in different aging states is analyzed and the correctness of health factor is proved by theoretical deduction and experimental results. An improved support vector regression model with a strong generalization ability is established, and the hyperparameters of the model are optimized through the particle swarm optimization algorithm. The results show that the proposed dual-charging health factor is closely related to battery capacity aging and attenuation. The improved support vector regression model can estimate the health status in different aging states in real time, and has the ability to characterize local capacity rebound change, which can be used as an effective method for estimating the state of health of an embedded battery management system.

    Table and Figures | Reference | Related Articles | Metrics
    Uncertainty Analysis of Offshore Platform Wind Load Tests
    DAI Yi, CHEN Zuogang, WANG Fei
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 361-367.   DOI: 10.16183/j.cnki.jsjtu.2021.066
    Abstract3210)   HTML8)    PDF (2064KB)(68)      

    The superstructures of offshore platforms are usually complex in shape, and wind tunnel test is the most reliable method to obtain the wind loads. Few researches about the procedures of uncertainty analysis (UA) and key points have been conducted, and the influences of error sources are not clear. The UA of an offshore platform wind load tests is first performed based on the International Towing Tank Conference (ITTC) recommended procedures. According to the wind load test procedure of the offshore platform, the uncertainties due to many error sources are analyzed. In order to obtain the remark of all error sources and propose the approach of reducing uncertainties, error sources are evaluated and graded. The results show that the wind profile, the accuracy of the model, the air pressure measurement, and the balance measuring state have a great influence on wind load coefficients, which contribute to 96.13% of the combined uncertainty. The uncertainties can be effectively reduced by model simplification, high quality wind profile, high precision air pressure measurement, and stable measurement state.

    Table and Figures | Reference | Related Articles | Metrics
    Numerical Simulation and Analysis of Cylindrical Ice Impacting Problem
    WANG Chao, YANG Bo, ZHANG Yuan, GUO Chunyu, YE Liyu
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 368-378.   DOI: 10.16183/j.cnki.jsjtu.2020.278
    Abstract3190)   HTML6)    PDF (4968KB)(228)      

    In order to study the application characteristics of the peridynamics (PD) method in the field of ice mechanical behavior and the sensitivity analysis of parameter changes in the numerical prediction of ice failure, the ordinary state-based peridynamic method is employed to systematically analyze the impact failure process of cylindrical ice in the present work. The results show that the simulated ice impact process by the proposed method is basically consistent with the test results, and the calculation results converge under the selected time step and particle spacing. The impact velocity, Poisson’s ratio, and the elastic modulus of the ice have remarkable effects on the impact process of ice cylinder, while the size and fracture toughness of the ice only have little influence. The innovation of this paper lies in the fact that the state-based PD method is applied to study the ice impact problem, which compensate for the shortcomings of the bond-based PD method that limits the Poisson’s ratio of the ice.

    Table and Figures | Reference | Related Articles | Metrics
    Influence of Pressurization Methods on Cryogenic Helium Pressurization in Rocket Fuel Tank
    ZOU Zhenfeng, REN Feng, LI Xiaoci, DUAN Haiyang, DU Hailang, HUANG Yonghua
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 386-394.   DOI: 10.16183/j.cnki.jsjtu.2020.265
    Abstract3146)   HTML10)    PDF (13239KB)(34)      

    To verify the technical scheme of cryogenic helium pressurization in the fuel tank of liquid oxygen (LOX)-kerosene rocket, a test device was established and the ground simulation test was conducted. The influences of different pressurization methods on pressure control stability, ullage temperature distribution in tank, helium consumption, gas-liquid mixture, and liquid freezing of pressurized drainage process were investigated. The pressurization method specifically includes pressurization outlet position, diffuser form, and pressurant flow rate. The results show that when pressurized from the liquid zone, the heat exchange of pressurized gas is more sufficient, which reduced the gas consumption by 33.1% compared with that in the ullage zone. However, the stability of pressure control is less satisfying. The form of diffuser has little influence on the gas consumption and the temperature distribution of ullage. The helium consumption for pressurization at a small flow rate is less than that at a high flow rate. For example, when the drainage flow is 10 L/s, the helium consumption can be reduced by 20% compared with that at 40 L/s. Under all experimental conditions, neither ice due to local supercooling in the tank nor bubbles in the drainage pipeline are observed. The test results verify the feasibility of the proposed scheme, and provide a reference for structural design and working condition regulation of the cryogenic helium pressurization system in rocket.

    Table and Figures | Reference | Related Articles | Metrics
    A Suppression Strategy for Subsequent Commutation Failures Considering Commutation Capability of Recovery Process
    CONG Xinpeng, ZHENG Xiaodong, CAO Yaqian, TAI Nengling, MIAO Yuancheng, LI Ke
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 333-341.   DOI: 10.16183/j.cnki.jsjtu.2021.004
    Abstract3124)   HTML4)    PDF (1969KB)(83)      

    In order to suppress subsequent commutation failures of high voltage direct current (HVDC), the dynamic process of electrical and control quantities during system recovery is studied, and the main reason for subsequent commutation failures is proposed in the paper. During the recovery process, the voltage of the converter bus after the fault is in a state of drop, the actual firing angle of the inverter is in overshoot, and direct current continues to rise. These factors result in an insufficient system commutation capability to complete the transfer of valve arm inductance energy during the commutation process. A suppression strategy for subsequent commutation failure considering the commutation capability of the system recovery process is proposed. By limiting the direct current (DC) when the firing angle is in overshoot, the system commutation capability is increased, and subsequent commutation failures are suppressed. In addition, the DC system is effectively recovered. The proposed theory is tested and verified based on the HVDC CIGRE Benchmark in PSCAD/EMTDC.

    Table and Figures | Reference | Related Articles | Metrics
    Dynamics Modeling and Validation of Coaxial Lifting Rotors
    HU Jinshuo, HUANG Jianzhe
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 395-402.   DOI: 10.16183/j.cnki.jsjtu.2021.044
    Abstract3079)   HTML10)    PDF (2567KB)(419)      

    The dynamics model for coaxial lifting rotors can be used to study the controller design and flight simulation for coaxial-rotor aerial vehicles. However, both the computational efficiency and the accuracy should be considered. First, the computational model of the induced velocity of lifting rotor everywhere including the wake region is derived based on adjoint theorem. Then, the finite state dynamics model for coaxial lifting rotors with wake skew considered is developed by extending the finite state inflow model for single rotor. Finally, the equations for calculating the thrust of coaxial lifting rotors in the hover condition are given, and the test is conducted. The results show that the computational complexity of the proposed dynamics model for coaxial lifting rotors is acceptable, and the computational thrusts are almost close to the test results when the rotational speed is within a certain range, which can also reflect the trend of the thrust lost for coaxial lifting rotors.

    Table and Figures | Reference | Related Articles | Metrics
    A Review of Coupled Electricity and Hydrogen Energy System with Transportation System Under the Background of Large-Scale New Energy Vehicles Access
    LI Jiaqi, XU Xiaoyuan, Yan Zheng
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 253-266.   DOI: 10.16183/j.cnki.jsjtu.2021.464
    Abstract3061)   HTML80)    PDF (2106KB)(348)      

    The large-scale utilization of renewable energy is an important way to achieve the “double carbon targets”. The technology of coupled renewable energy with hydrogen system can improve the consumption rate of renewable energy and the penetration of new energy vehicles. The coupling between the electricity-hydrogen energy system and the transportation system will be even closer in the future. Based on the access of large-scale new energy vehicles, first, the development of the electricity and hydrogen energy system was summarized, and the three working modes of electricity-hydrogen coupling system including hydrogen production, output smoothing, and coordinated operation with electricity network were introduced. Then, the research status of the electricity-transportation coupling system on planning and optimal operation, and the problems of hydrogen-transportation coupling system on hydrogen refueling station optimization and hydrogen transportation were analyzed. Finally, in combination with the existing bottlenecks, the future feasible research directions such as dynamic model construction and the influence of uncertain factors were proposed.

    Table and Figures | Reference | Related Articles | Metrics
    Journal of Diagnostics Concepts & Practice    2021, 20 (04): 317-337.  
    Abstract3042)      PDF (18564KB)(3175)      
    Related Articles | Metrics
    Performance Evaluation Index and Method of Micro-Grid Distributed Electricity Trading Under the Background of “Carbon Peaking and Carbon Neutrality”
    WANG Wenbin, ZHENG Shujiang, FAN Ruixiang, CHEN Wen, ZHOU Shiyang
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 312-324.   DOI: 10.16183/j.cnki.jsjtu.2021.391
    Abstract2882)   HTML7)    PDF (2446KB)(71)      

    With the rapid development of distributed power generation research and application, the distributed trading market, as a new type of power trading mode, can effectively increase the consumption rate of renewable energy and is an important means to promote the realization of the goal of “carbon peaking and carbon neutrality”. Introducing the market evaluation mechanism into distributed transactions will prompt users to consider the impact of the market evaluation mechanism on their trading strategies and promote the sound development of the distributed transaction market. The distributed power trading market among micro-grid users is studied in this paper. First, taking the market participants and transaction supporting software and hardware as the research object, a multi-dimensional performance evaluation index system is established from the aspects of power supply capacity, user satisfaction, and platform security. Next, the research status of distributed power trading market evaluation methods is summarized. The key technologies of distributed power trading performance evaluation are analyzed from the establishment of index system, the index calculation method, and the comprehensive evaluation method. Finally, in combination with the current development status, the research direction of the distributed power trading performance evaluation in the future is prospected.

    Table and Figures | Reference | Related Articles | Metrics
    Review of Research on Condition Assessment of Nuclear Power Plant Equipment Based on Data-Driven
    XU Yong, CAI Yunze, SONG Lin
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 267-278.   DOI: 10.16183/j.cnki.jsjtu.2021.502
    Abstract2818)   HTML18)    PDF (1383KB)(326)      

    The condition assessment of the entire life cycle of nuclear power equipment has a significant impact on improving the safety and economy of nuclear power plants. In the past, operation and maintenance of systems, equipment, and structures of domestic nuclear power plants, mostly relied on the alarm mechanism of equipments, the simple threshold judgments of parameters, or the empirical judgments of engineers. With the implementation of online monitoring system in nuclear power plants, a large number of equipment operation data have been accumulated, and the use of data-driven technology to assess the health of equipment has become the focus of attention in the industry. In this paper, the current situation of the online monitoring system of nuclear power equipment was introduced and the common malfunction of nuclear power equipment was analyzed. The condition assessment of nuclear power equipment were categorized into three major problems (i.e., anomaly detection, life prediction, and fault diagnosis), the situation of research and application were summarized respectively, and the application potential of deep learning technology in this field was emphasized. Based on this, the challenges and possible solutions to the condition assessment of nuclear power plant equipment were further analyzed.

    Table and Figures | Reference | Related Articles | Metrics
    A Dual Cooperative Optimization for Optimal Redundancy Quantity of MMC Submodules of Flexible Controller
    MA Zhoujun, WANG Yong, WANG Jie, CHEN Shaoyu
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 325-332.   DOI: 10.16183/j.cnki.jsjtu.2021.444
    Abstract2750)   HTML7)    PDF (922KB)(89)      

    The failure of modular multilevel converter (MMC) submodules in the flexible direct current (DC) system affects the normal operation of the system, and the mutual restriction of reliability and economy is one of the key issues of MMC redundancy configuration optimization. A multi-objective optimization function of MMC reliability and economy mathematical model with redundant submodules was established. Based on the weight coefficient and NSGAII multi-objective optimization methods, a dual collaborative optimization for redundancy quantity of flexible controller was proposed. Combining the advantages of the two methods, the intersection of the two optimization results was calculated under the same redundancy quantity selection preference. A model based on a DC project in a flexible station area of Nanjing was built in MATLAB. The simulation results prove that the proposed method can not only meet the reliability of the flexible DC system, but also significantly improve the economy. It provides ideas for redundancy quantity of MMC submodules in the actual flexible DC project.

    Table and Figures | Reference | Related Articles | Metrics
    Optimization of Control Scheme for Large Flow Seawater Cooling System Based on FloMaster-Simulink Co-Simulation
    WANG Ning, FU Yunpeng, LI Ting, LI Tie, YI Ping
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 379-385.   DOI: 10.16183/j.cnki.jsjtu.2021.023
    Abstract2729)   HTML9)    PDF (1498KB)(147)      

    Large-scale marine equipment will overheat if it works for a long time and a cooling system is necessary to be established to ensure that the equipment works in a safe range of temperature. To meet the cooling requirements of a large-scale marine equipment, a model of seawater cooling system is established in FloMaster, and simulations under dynamic conditions are conducted. According to the temperature of the coolant (glycol solution) in the front or back of the room of the heat exchanger, the pump speed or valve opening is changed to realize automatic control of seawater flow. Three control schemes are proposed, and the control effects are evaluated by the response characteristics and operating characteristics of the system under variable working conditions using the FloMaster-Simulink co-simulation method. The results show that when the pump speed is controlled by both the open loop and closed loop, the best control effect and lower energy consumption can be achieved.

    Table and Figures | Reference | Related Articles | Metrics
    An Improved TDOA Lightning Location Approach Considering L-M Algorithm and Acoustics
    LUO Yaoying, BIAN Hongzhi, LIU Quanzhen, LIU Baoquan, FU Zhengcai, ZHANG Jianxun, LIU Yakun
    Journal of Shanghai Jiao Tong University    2022, 56 (3): 353-360.   DOI: 10.16183/j.cnki.jsjtu.2020.301
    Abstract2475)   HTML10)    PDF (3403KB)(58)      

    In the conventional lightning location system (LLS) based on time difference of arrival (TDOA), the nonlinear equations in lightning location calculation easily get to be divergent when the time information acquired from electromagnetic sensors is redundant. The LLS setup in lightning-sensitive regions in China usually experiences a development from detecting the thunderclap signal to the electromagnetic signal, such as the LLSs in oil tank farms. Therefore, an improved TDOA lightning location approach was proposed considering the acoustic and electromagnetic information emitted from lightning discharges. The targeted lightning monitoring region was divided into 16 sub-regions according to the location of the existing detection stations. The lightning location was calculated based on the Levenberg-Marquardt (L-M) iterative algorithm, which improves the lightning location accuracy and the resistance ability to measuring errors. The results show that the average error of the traditional lightning location method is 203.2 m. In contrast, the proposed approach can reduce the lightning location error to 108.4 m by considering the acoustic information and L-M iteration algorithm. The location accuracy at the edge of the targeted area is improved by 51.2%. This research can be potentially counseled in the improvement of existing LLSs and making an effective use of acoustic information.

    Table and Figures | Reference | Related Articles | Metrics
    Design of a Virtual Assembly Gesture Library and Optimization of Ergonomics Evaluation
    GUO Jiawei, XU Zhijie, HE Qichang
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 127-133.   DOI: 10.16183/j.cnki.jsjtu.2021.095
    Abstract1116)   HTML23)    PDF (7083KB)(83)      

    In view of the low efficient of virtual human upper limb simulation in the virtual assembly environment and the inaccurate evaluation of ergonomics, this paper analyzes hand assembly action, defines hand joint structure, arm and hand size, establishes a parametric assembly gesture model, and forms a gesture library. The fuzzy algorithm is used to improve the rapid upper limb assessment (RULA) method. The trapezoidal function is used to optimize the evaluation score when the joint angle is at the critical value. The final evaluation result is obtained through the rule base. Strain index(SI) is used to evaluate the risk of musculoskeletal operations such as hands and wrists, and the comprehensive score is weighted with fuzzy RULA evaluation. The ergonomics of the virtual hand assembly process is continuously evaluated to capture the risk posture in the assembly operation. Finally, the above methods are integrated based on the 3D Experience platform and verified by the assembly of mobile communication components.

    Table and Figures | Reference | Related Articles | Metrics
    A Multi-Feature Particle Filter Vehicle Tracking Algorithm Based on Adaptive Interpolation Moth-Flame Optimization
    HUANG He, WU Kun, LI Xinrui, WANG Jun, WANG Huifeng, RU Feng
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 143-155.   DOI: 10.16183/j.cnki.jsjtu.2021.037
    Abstract946)   HTML11)    PDF (33546KB)(48)      

    In order to solve the problem of low accuracy and the poor global searching ability of the moth-flame optimization algorithm, an improved adaptive interpolation moth-flame optimization algorithm is proposed, which is embedded into multi-feature particle filter to optimize. Besides, a multi-feature particle filter vehicle tracking algorithm based on adaptive interpolation moth-flame optimization is constructed. First, adaptive weights are added to the moths’ position updating mechanism to improve the global searching ability of the proposed algorithm. Next, the adaptive interpolation moth-flame optimization algorithm is used to optimize the sampling process. Then, in combination with the multi-feature adaptive fusion particle filter vehicle tracking algorithm, the particle distribution according to the latest observation information is continuously adjusted, so that the particles in the low weight layer can move to the area with higher weight to enhance the particle quality and avoid sample degradation. The experimental results show that the proposed algorithm can effectively reduce the number of sample particles required for state prediction, improve the tracking performance of the algorithm, and track the target vehicle accurately and stably under the interferences of occlusion, illumination, attitude, and scale changes.

    Table and Figures | Reference | Related Articles | Metrics
    Underwater Image Enhancement Based on Generative Adversarial Networks
    LI Yu, YANG Daoyong, LIU Lingya, WANG Yiyin
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 134-142.   DOI: 10.16183/j.cnki.jsjtu.2021.075
    Abstract881)   HTML22)    PDF (22386KB)(73)      

    This paper proposes an underwater image correction and enhancement algorithm based on generative adversarial networks. In this algorithm, the multi-scale kernel is applied to the improved residual module to construct a generator, which realizes the extraction and fusion of multiple receptive fields feature information. The discriminator design considers the relationship between global information and local details, and establishes a global-region dual discriminator structure, which can ensure the consistency of overall style and edge texture. An unsupervised loss function based on human visual sensory system is proposed. Reference image constraints are not required, and the confrontation loss and the content loss are jointly optimized to obtain better color and structure performance. Experimental evaluations on multiple data sets show that the proposed algorithm can better correct color deviation and contrast, protect details from loss, and is superior to typical algorithms in subjective and objective indexes.

    Table and Figures | Reference | Related Articles | Metrics
    Neural-Network-Based Adaptive Feedback Linearization Control for 6-DOF Wave Compensation Platform
    DING Ming, MENG Shuai, WANG Shuheng, XIA Xi
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 165-172.   DOI: 10.16183/j.cnki.jsjtu.2020.424
    Abstract703)   HTML6)    PDF (1175KB)(80)      

    Ocean resource exploration expands into deep and ultra-deep waters, which has posed great challenges to the 6-DOF parallel platform that requires to finish the long-span and high-velocity wave compensation task with high precision and anti-interference ability. The control strategy employed in the asymmetric hydraulic system of large aspect ratio requires more careful considerations when operating in the harsh and severe environment. An adaptive feedback linearization control strategy was proposed by employing the radial basis function neural network (RBFNN) for identification. First, a nonlinear model of the asymmetric hydraulic system was established. Then, an adaptive controller was designed based on RBFNN and feedback linearization. Finally, simulations were performed by using MATLAB/Simulink under the five-stage wave environment at a 90° wave encounter angle and under the external interference condition. The result shows that this method has a good traceability and robustness compared to classic PID and sliding mode control methods, which is more suitable in control of the wave compensation platform in complex sea conditions. The new controller can significantly increase the compensation accuracy and anti-interference ability, and provide a workbench for the 6-DOF parallel platform operation in deep waters.

    Table and Figures | Reference | Related Articles | Metrics
    A Modified Migrating Birds Optimization for Multi-Objective Lot Streaming Hybrid Flowshop Scheduling
    TANG Hongtao, WANG Dannan, SHAO Yiping, ZHAO Wenbin, JIANG Weiguang, CHEN Qingfeng
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 201-213.   DOI: 10.16183/j.cnki.jsjtu.2020.435
    Abstract654)   HTML7)    PDF (1462KB)(105)      

    This paper proposes an adaptive migrating birds optimization (AMBO) method based on variable neighborhood search to solve the inequal lot streaming hybrid flowshop scheduling problem (ILS-HFSP) for a 2+1+1 hybrid flowshop, which realizes multi-objective optimization of minimizing makespan and minimum average work in process. Compared with the original migrating birds optimization, the AMBO algorithm adopts the variable neighborhood search strategy with an adaptive selection probability of neighborhood operator that is adaptively adjusted with the number of iterations. Besides, a time-window operator is adopted to improve the search performance of exchange operators and convergence rate. Several orders of different scales generated randomly are studied, and the results show that the AMBO algorithm has a higher solution quality and a better convergence performance than the migrating birds optimization algorithm and the genetic algorithm, thereby verifying the effectiveness of the AMBO algorithm.

    Table and Figures | Reference | Related Articles | Metrics
    A Fault Diagnosis Method Based on Feature Pyramid CRNN Network
    LIU Xiuli, XU Xiaoli
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 182-190.   DOI: 10.16183/j.cnki.jsjtu.2021.001
    Abstract632)   HTML9)    PDF (7606KB)(49)      

    Aimed at the problems that the proportion and position of different fault characteristics of equipment components under variable working conditions and variable load in the signal are not fixed, and include the multi-scale complexity of the original vibration signal in a large number of different scenarios, a convolutional recurrent neural network (CRNN) rolling bearing fault diagnosis method based on feature pyramid network (FPN) was proposed. Using the convolution neural network (CNN) framework, the convolution layer of CNN and the long and short-term memory (LSTM) layer of recurrent neural network (RNN) were connected in parallel to form a new CRNN, so as to make full use of the learning ability of CNN to spatial domain information and RNN to time domain information. The weights were shared in each layer to reduce network parameters. A novel feature map was constructed using FPN, and one-dimensional signal and two-dimensional signal formed after stacking were input to extract the feature of the signal collected by the sensor, and realize fault diagnosis. The average diagnostic accuracy of this method is 99.20%, which is at least 3.62% higher than that of the basic neural network model, indicating that this method has a high diagnostic accuracy and a strong robustness. Using the bearing data set of Case Western Reserve University, it is proved that the method has a good universality. The t-SNE method was used to visually analyze the feature learning effect of the model. The results show that different fault category features have good clustering effect.

    Table and Figures | Reference | Related Articles | Metrics
    Static Output Feedback Control of Vehicle Active Front Steering Considering Multiple Performance Constraints
    MAO Yingzhong, FENG Zhiyong, GUO Huiru
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 156-164.   DOI: 10.16183/j.cnki.jsjtu.2021.073
    Abstract632)   HTML6)    PDF (1328KB)(70)      

    To enable the vehicle to accurately track the ideal yaw rate, thereby improving the vehicle path tracking ability, this paper proposes a static output feedback (SOF) control method for active front steering (AFS) considering multiple performance constraints. Since the cornering stiffness of vehicle tire is a strong nonlinear parameter, the cornering stiffness is taken as the uncertainty parameter of the model. In addition, the two-degree-of-freedom poly-topic model of the vehicle dynamics is established based on the saturated linear tire model to deal with the parameter uncertainty. Moreover, the design of robust SOF controllers with regional pole configuration constraints and H performance constraints are considered for this type of uncertain system. Furthermore, the linear matrix inequality (LMI) sufficient conditions for this type of uncertain system are given, and a coordinate transformation matrix(CTM) optimization method is used to iteratively solve the obtained LMI conditions for the first time. Thus, the robust optimal H SOF controller for this type of uncertain system is obtained. Co-simulation results of MATLAB/Simulink and CarSim show that the designed SOF controller can significantly improve the tracking performance of the desired yaw rate and improve the vehicle path tracking ability. In addition, the controller has a good robustness to the uncertainties of vehicle model parameters.

    Table and Figures | Reference | Related Articles | Metrics
    Shift Strategy of Electric Drive Loader with Compound Control of Motor and Clutch
    REN Haoling, CAI Shaole, CHEN Qihuai, LIN Tianliang, LANG Bin
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 173-181.   DOI: 10.16183/j.cnki.jsjtu.2020.409
    Abstract595)   HTML7)    PDF (6683KB)(208)      

    To give full play to the advantages of pure electric drive, and aimed at the transmission system of electric loader, the low efficiency hydraulic torque converter and reverse direction clutch of traditional models are cancelled. By analyzing the shift law of the pure electric drive system, the electro-hydraulic shift control system is used to control the wet clutch, and based on the feedback of pressure and speed, combined with the driving motor active working in the speed and torque mode, the matching of torque and speed in the process of clutch engagement and disengagement is realized. For a 50-type pure electric drive loader, a shift control strategy of pure electric drive loader based on composite control of drive motor and clutch pressure is proposed. The result of vehicle test shows that the proposed control strategy can give full play to the advantages of pure electric drive. The shift time is reduced by about 50%, the sliding friction work is greatly reduced, and the maximum shift impact is 14.08 m/s3, which is within the recommended limit value of 17.64 m/s3 for Chinese vehicles.

    Table and Figures | Reference | Related Articles | Metrics
    Weekly Physician Scheduling for Emergency Departments with Time-Varying Demands of Patients with Revisits
    WANG Zixiang, WU Zerui, LIU Ran
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 242-252.   DOI: 10.16183/j.cnki.jsjtu.2020.328
    Accepted: 08 June 2021

    Abstract488)   HTML4)    PDF (1266KB)(95)      

    To solve the flexible scheduling problem of emergency departments, a method based on the queuing theory and the fluid model for approximating the patient waiting length of a time-varying queuing system with returns for a given scheduling plan is proposed. A mixed-integer programming model, which considers the real constraints of physician scheduling, is then proposed and solved by using a tabu search algorithm. Numerical experiments show that the proposed method can effectively approximate the waiting queue length of patients and the scheduling plan computed by the proposed algorithm can effectively reduce the total waiting queue length of patients.

    Table and Figures | Reference | Related Articles | Metrics
    Development Pathway of China’s Clean Electricity Under Carbon Peaking and Carbon Neutrality Goals
    HUANG Qiang, GUO Yi, JIANG Jianhua, MING Bo
    Journal of Shanghai Jiao Tong University    2021, 55 (12): 1499-1509.   DOI: 10.16183/j.cnki.jsjtu.2021.272
    Abstract476)   HTML66)    PDF (1849KB)(248)      

    Nowadays, the third energy revolution has taken place. Many developed countries have formulated clean energy development strategies and announced the time for phasing out thermal and nuclear power to reduce carbon emissions. Meanwhile, China has made a commitment to the world that the carbon emissions of China will peak before 2030, and the carbon neutrality will be achieved before 2060. Therefore, it is of great significance to study the development pathway of clean electricity of China. The reserves and characteristics of clean energy such as hydro, wind, and solar in China are analyzed. The medium and long-term power demand of China is projected, and the power system structure in 2030 and 2050 are respectively estimated based on the electric power and energy balance equations. In addition, the trend of carbon emissions is also analyzed. Some suggestions are proposed to guide the development of China’s clean electricity. The results indicate that the “carbon peaking” of China’s power system would arrive in 2027, and the clean electricity of China is projected to exceed 50% of the total energy production in 2030. Thermal and nuclear power can be replaced by clean electricity such as hydro, wind, and solar energy in 2050, the power industry will achieve “zero CO2 emission”, and the transformation of the green power system will be achieved in response to carbon peaking and carbon neutrality goals.

    Table and Figures | Reference | Related Articles | Metrics
    Decoupling of Vibration and Temperature Signals of Fiber Bragg Grating Sensor
    LI Han, ZHANG Botao, WANG Junjie, SUN Yunda, GONG Shengjie
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 214-222.   DOI: 10.16183/j.cnki.jsjtu.2020.313
    Abstract468)   HTML5)    PDF (3613KB)(139)      

    This paper uses a single fiber bragg grating (FBG) sensor to implement an experiment to measure vibration and temperature signals at the same time, and proposes a MATLAB-based decoupling method to separate vibration and temperature signals. The experimental results show that under the condition of single signal measurement, the static temperature measurement error of the FBG sensor is within ±0.4 ℃ and the relative error of the dynamic measurement of the main frequency of vibration is 0.5%. The FBG sensor measures the composite signal of vibration and temperature. The relative error of the main vibration frequency obtained by the decoupling method proposed in this experiment is 0.65%, the relative error of the vibration amplitude is 7.14%, and the temperature signal error is within ±3.3 ℃.

    Table and Figures | Reference | Related Articles | Metrics
    Stability of Orthogonal Cutting System Considering Nonlinear Stiffness
    SHI Huirong, WANG Haixing, LI Zonggang
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 191-200.   DOI: 10.16183/j.cnki.jsjtu.2020.413
    Abstract462)   HTML6)    PDF (2857KB)(31)      

    In order to accurately predict the stability of orthogonal cutting of cylindrical workpiece, a nonlinear orthogonal cutting system model is established, which includes the nonlinear stiffness caused by the surface wave of work as well as the deformation of the tool and work. The multi-scale method is used to solve the system. The effect of machining parameters and system parameters on the stability of the primary resonance and 1/2 subresonance is analyzed to gain the overall stability cloud map compared with the lobe diagrams of linear approximation system. The results show that the instability of primary resonance, 1/2, 1/3, and 1/4 subresonance occur in the orthogonal cutting system with the quadratic nonlinearity and cubic nonlinearities stiffness, which makes the system have period-doubling, quasi-periodic, and chaotic operation behavior. The comparison indicates that the dynamics model of nonlinear orthogonal cutting can accurately predict the stability of the system.

    Table and Figures | Reference | Related Articles | Metrics
    Distributed Photovoltaic Net Load Forecasting in New Energy Power Systems
    LIAO Qishu, HU Weihao, CAO Di, HUANG Qi, CHEN Zhe
    Journal of Shanghai Jiao Tong University    2021, 55 (12): 1520-1531.   DOI: 10.16183/j.cnki.jsjtu.2021.244
    Abstract438)   HTML22)    PDF (69168KB)(257)      

    To respond to the demand of achieving carbon peaking and carbon neutrality goals, and to construct a complete “source-grid-load-storage” new energy power system, a distributed photovoltaic net load forecasting model based on Hamiltonian Monte Carlo inference for deep Gaussian processes (HMCDGP) is proposed. First, direct and indirect forecasting methods are used to examine the accuracy of the proposed model and to obtain spot forecasting results. Then, the proposed model is used to perform probability forecasting experiments and produce interval prediction results. Finally, the superiority of the proposed model is verified through the comparative experiments based on the net load data of 300 households recorded by Australia Grid. After obtaining the exact net load probabilistic forecasting results, the photovoltaic production can be fully utilized via power dispatch, which can reduce the use of fossil energy and further reduce the carbon emission.

    Table and Figures | Reference | Related Articles | Metrics
    An Accuracy Dynamically Configurable FFT Processor Based on Approximate Computing
    MA Liping, ZHANG Xiaoyu, BAI Yuxin, CHEN Xin, ZHANG Ying
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 223-230.   DOI: 10.16183/j.cnki.jsjtu.2020.430
    Abstract432)   HTML7)    PDF (5962KB)(192)      

    In order to meet the different requirements of circuit targets in various scenarios, an accuracy configurable fast Fourier transform (FFT) processor based on the concept of approximate circuit is proposed. A configurable approximate butterfly unit which can truncate the carry chain is proposed at the butterfly node and a bit-width configurable multiplier is proposed at the rotation factor multiplication node. MATLAB is adopted to develop an error analysis platform. After analyzing the sensitivity of each butterfly node and rotation factor node to approximate calculations, five calculation modes of the accuracy configurable FFT processor are determined, which can achieve dynamic balance among performance, power consumption, and accuracy. Finally, based on the 180 nm complementary metal oxide semiconductor (CMOS) technology of Taiwan Semiconductor Manufacturing Company (TSMC), the proposed processor is implemented with the standard procedure of ultra-large-scale digital integrated circuits. The performance results are obtained by professional electronic design automation (EDA) tools. Compared with the precise mode, the maximum operating frequency of the processor in the approximate mode is increased by 14.33%, and the power consumption is reduced by 15.61% when the operating frequency is 60 MHz.

    Table and Figures | Reference | Related Articles | Metrics
    Design of Light Fireproof Enclosure Bulkheads Based on Topography Optimization for Cruise Ships
    ZHANG Fan, YANG Deqing, QIU Weiqiang
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1175-1187.   DOI: 10.16183/j.cnki.jsjtu.2020.201
    Accepted: 08 June 2021

    Abstract419)   HTML222)    PDF (19957KB)(538)      

    In order to develop a new lightweight enclosure structure with an excellent fireproof and bearing performance, and to replace the traditional stiffened fire enclosure bulkheads in the superstructure area, a design method of light fireproof enclosure bulkheads for cruise ship based on the topography optimization technology was proposed. The location and numbers of corrugated beads in lightweight wall designed by this method were generated according to the requirements of load bearing capacity and manufacturing process, and this method overcomes the disadvantages that the location and numbers of beads in the design of conventional corrugated wall have to be determined in advance. Aimed at the specified design regions, the lightweight of cruise fireproof enclosure bulkheads (CFEB) structure was taken as the objective function while the stress in the weld zone, the stress in the nonweld zone, and the first-order buckling factor of CFEB were taken as constraints. Then, the topography design models of CFEB were established and solved. Feasible configurations were obtained by topography optimization, and the final configurations of CFEB were formed by secondary design. The mechanical properties of the final configurations were compared with the traditional stiffened fireproof bulkheads. It is concluded that the new CFEB has advantages of lightweight and good strength compared with the traditional stiffened fireproof bulkheads.

    Table and Figures | Reference | Related Articles | Metrics
    Decision-Making Method of Intelligent Vehicles: A Survey
    HU Yikai, WANG Chunxiang, YANG Ming
    Journal of Shanghai Jiao Tong University    2021, 55 (8): 1035-1048.   DOI: 10.16183/j.cnki.jsjtu.2020.387
    Accepted: 08 June 2021

    Abstract409)   HTML12)    PDF (1687KB)(378)      

    Combined with the current research status of the intelligent vehicle decision-making methods at home and abroad, this paper classifies and summarizes decision-making methods from four aspects: decision input and output, environment interaction, and algorithm types. Besides, it analyzes their advantages and disadvantages, and evaluates applicable scenarios. Moreover, it surveyes the common data sets and current evaluation standards which are used for decision-making researches. Furthermore it discusses the technical difficulties faced by current decision-making methods and future development trends.

    Table and Figures | Reference | Related Articles | Metrics
    A High Quality Algorithm of Time-Frequency Analysis and Its Application in Radar Signal Target Detection via LMSCT
    HAO Guocheng, ZHANG Bichao, GUO Juan, ZHANG Yabing, SHI Guangyao, WANG Panpan, ZHANG Wei
    Journal of Shanghai Jiao Tong University    2022, 56 (2): 231-241.   DOI: 10.16183/j.cnki.jsjtu.2020.432
    Abstract401)   HTML8)    PDF (8925KB)(24)      

    Aimed at the fact that the chirplet rate parameter of the chirplet transform (CT) cannot match the instantaneous frequency of the signal completely, and that the anti-noise performance of the algorithm is poor, this paper proposes a high-quality local maximum synchrosqueezing chirplet transform (LMSCT) algorithm to improve the deviation of energy diffusion amplitude in CT time-frequency (TF)distribution. The main idea of this algorithm is to reallocate CT frequency points by local maximum synchrosqueezing operation. The experiment results show that the LMSCT algorithm has a higher TF concentration and a strong ability to suppress the interference of noise. The method can maintain a better resolution of TF representation at a low signal-to-noise ratio. In the application analysis of IPIX processing radar signals, the LMSCT algorithm can clearly describe the TF joint distribution characteristic of target signal and determine the distance unit of target, which provides the judgement basis for small target detection of IPIX radar signal in the background of sea clutter.

    Table and Figures | Reference | Related Articles | Metrics
    Medical Application of 3D Printing:A Powerful Tool for Personalised Treatment
    DAI Kerong (戴尅戎), XU Feng (许锋)
    J Shanghai Jiaotong Univ Sci    2021, 26 (3): 257-258.   DOI: 10.1007/s12204-021-2290-8
    Abstract378)      PDF (86KB)(181)      
    We are in an era of technological revolutions promoting personalised healthcare. Advances in medical imaging techniques with 3D imaging software and 3D printing have allowed healthcare professionals to view and document various geometrical structures in a brand-new way, enabling them to make meaningful 3D measurements more accurately by generating both virtual and physical models used for preoperative planning,physician-patient communication, and fabrication of surgical guides, instruments, and implants[1-5]. With improvements in cost-effectiveness, efficiency, and mechanical properties, 3D printing technologies have become a powerful tool for physicians to meet clinical requirements. Furthermore, biological tissues made from 3D printing may eventually provide patients with required human organs in the future[6-7].
    Although both medical communities and socialmedia spare no effort to highlight the prospects of 3D printing technologies in healthcare and popularise this innovative new method through Web-based approaches to promote its application in personalised treatment, to date, not a single healthcare organisation has yet released new technologies, disseminated findings in peerreviewed
    literature, or clarified the role and aims of 3D printing in healthcare. This, in turn, has left much of the current research and development to medical device companies, expecting them to meet individual clinical requests. Therefore, at present and in the future, it is critical to have a clear understanding of the clinical implementation of 3D printing for both traditional and personalised healthcare.
    The first step in the entire 3D printing process starts with medical imaging, in which professionals with expertise
    in radiology and imaging processing have conducted many investigations to identify and quantify patient-specific anatomical areas and geometrical structures before designing and manufacturing personalised medical models, surgical guides, medical instruments,
    and devices using 3D printing[8-11]. It must be noted that 3D printing usually starts with conventional clinical images, and errors cannot be avoided with several more complex steps involved in image processing. Traditionally,medical images have been acquired in radiology departments by trained radiologists using special software packages. With the help of commercial medical imaging processing software, such as MIMICS,Analyze, and MeDraw, many physicians from different specialties, with little engineering background, are able to perform these analyses by themselves and develop their preoperative planning software tailored to special
    medical treatments. Understandably, the development of software tailored to 3D printing needed in medicine could accelerate and promote its popularity in clinical practice.
    Organised by Journal of Shanghai Jiao Tong University (Science), this special issue, authored by a group of physicians and engineers with diverse and interdisciplinary backgrounds and insights, is intended to introduce their research topics in the most hotly debated areas where medical 3D printing is used in patient care,especially focusing on medical and dental applications.
    The issue also presents some related topics about imaging generation and processing, material properties, and biomechanics, among others. However, it is difficult to cover all the 3D printing fundamentals.
    In the current special issue, some interesting studies provide details regarding how to apply 3D printing to medical or dental personalised healthcare, which could be invaluable for physicians who would like to find their own methods of developing personalised routines by applying 3D printing in daily practice. The issue also includes some dedicated studies that focus
    on imaging and software applications, which are indispensable for those who are eager to enter the field of pre-processing in 3D printing. Last but not least, some studies discussing material properties and biomechanics with in-depth insights regarding the safety and reliability of 3D printing technology in the manufacturing of medical devices can be found in this issue. As authors
    and advocates of personalised treatment, we are interested in promoting 3D printing from its current niche applications to more widespread use in the medical community. Thus, this special issue also includes studies on some of these niche applications. Since 3D printing technology is now growing at an exponential rate, it is definitely a very challenging task to organise issues on 3D printing in personalised patient care. In this issue, we attempt to inspire our readers by choosing some clinical examples in several representative areas to show how 3D printing positively influences personalised healthcare.
    There is no doubt that 3D printing is truly one of the leading technologies of the 21st century and praised as a key feature of the fourth industrial revolution. We hope this special issue could provide essential information to help you understand the role that 3D printing plays in personalised patient care with the purpose of improving clinical outcomes and quality of life for patients in China and around the world. Finally, we genuinely hope that people with lofty ideals from both medical and engineering fields who are interested in 3D printing technologies notice this special issue and join us to enter the field with your meaningful contributions.
    Reference | Related Articles | Metrics
    Numerical Simulation and Experimental Research of Sheet Hemming Forming Based on Adhesive Filling
    TANG Genglin, LI Jianjun, LI Yuanhui, ZHANG Longyao, ZHU Wenfeng
    Journal of Shanghai Jiao Tong University    2022, 56 (4): 523-531.   DOI: 10.16183/j.cnki.jsjtu.2020.429
    Accepted: 08 June 2021

    Abstract377)   HTML1)    PDF (11461KB)(253)      

    The filling rate of adhesive is defined based on the geometric dimensions of the hemming model, and the numerical simulation model of the hemming process with adhesive is established by using the finite element method-smoothed particle hydrodynamics (FEM-SPH) method. By comparing and verifying with the hemming experiment with adhesive, the quantitative study of the influences of the hemming adhesive diameter, the edge distance, and the hemming thickness on the filling rate is realized. The research results show that the flow state and the final filling state of the adhesive layer obtained in the experiment are similar to the numerical simulation results, and the filling rate of the adhesive layer obtained in the experiment is highly consistent with the numerical simulation result, which verifies the feasibility and accuracy of the numerical simulation model. Further analysis shows that the influences of the hemming adhesive diameter, the edge distance, and the hemming thickness on the filling rate decrease in order, and the relationship formulas between the filling rate and process parameters, such as the hemming adhesive diameter, the edge distance, and the hemming thickness, are obtained by fitting, which provides a basis for the optimization design of the hemming process with adhesive of the automobile body sheet.

    Table and Figures | Reference | Related Articles | Metrics
    Contemporary Foreign Languages Studies    2021, 454 (4): 50-61.   DOI: 10.3969/j.issn.1674-8921.2021.04.007
    Abstract376)   HTML12)    PDF (2011KB)(57)      
    Reference | Related Articles | Metrics
    Comparative Analysis of Technical Standards for Offshore Wind Power via VSC-HVDC
    YU Hao, ZHANG Zhemeng, PENG Sui, ZHANG Zhiqiang, REN Wanxin, LI Canbing
    Journal of Shanghai Jiao Tong University    2022, 56 (4): 403-412.   DOI: 10.16183/j.cnki.jsjtu.2021.465
    Abstract368)   HTML37)    PDF (1110KB)(100)      

    This paper introduces the current situation of domestic and foreign offshore wind power grid-connected via voltage source converter based high voltage direct current(VSC-HVDC) transmission standards, and selects representative standards of offshore wind power grid-connected via VSC-HVDC. It also compares the domestic and foreign offshore wind power grid in terms of power control, fault ride-through, power quality, stability, etc., and analyzes the development trend of offshore wind power grid-connected via VSC-HVDC standards. In order to promote the development of offshore wind power industry, it provides reasonable suggestions for the formulation and revision of Chinese offshore wind power grid-connected via VSC-HVDC standards.

    Table and Figures | Reference | Related Articles | Metrics
    State of Health Estimation of Lithium-ion Battery Using a CS-SVR Model Based on Evidence Reasoning Rule
    XU Hongdong, GAO Haibo, XU Xiaobin, LIN Zhiguo, SHENG Chenxing
    Journal of Shanghai Jiao Tong University    2022, 56 (4): 413-421.   DOI: 10.16183/j.cnki.jsjtu.2021.345
    Abstract342)   HTML8)    PDF (1150KB)(19)      

    The state of health (SOH) estimation accuracy of lithium-ion battery affects the safety and service life of batteries. Aimed at the problem in SOH estimation of lithium-ion battery, a cuckoo search support vector regression (CS-SVR) model based on the evidence reasoning (ER) rule was proposed for SOH estimation. The lithium-ion battery data from NASA Ames Center was used to perform the SOH estimation test. In this method, the average voltage and average temperature of battery discharge cycles were taken as model input, and a fusion belief degree matrix of input data was obtained by the ER rule. The SOH estimation result of the battery was obtained by inputting a fusion belief degree matrix into the SVR model optimized by the CS algorithm. The results show that the CS-SVR algorithm based on the ER rule has a better estimation performance than the five existing models.

    Table and Figures | Reference | Related Articles | Metrics
    On Strategies for Interpreting Metaphors in Diplomatic Discourse for Political Equivalence: A Case Study of Chinese Foreign Ministry's 2019 Regular Press Conferences
    REN Dongsheng, JI Xiumei
    Contemporary Foreign Languages Studies    2021, 453 (3): 84-95.   DOI: 10.3969/j.issn.1674-8921.2021.03.009
    Abstract342)   HTML15)    PDF (1764KB)(40)      

    Metaphor is of great importance in the major-country diplomatic discourse system with Chinese characteristics for its vital role in the expressiveness and functionality of diplomatic discourse. Studies on the translation strategies of metaphors contribute significantly to facilitating the effective communication of diplomatic discourse and enhancing China's international discourse power. This paper conducts a case study of Chinese Foreign Ministry's 2019 regular press conferences on strategies for interpreting metaphors in diplomatic discourses from the perspective of political equivalence Yang Mingxing proposed as a criterion for the translation of diplomatic discourse. The metaphors employed in 2019 regular press conferences can be categorized into two types: shared and non-shared metaphors between China and the West. The former includes metaphors of the same source domain and metaphors of different source domains. It is advisable to retain or convert metaphors with comprehensive consideration of the number and political connotations of metaphors and the usages of the source and target languages. The latter includes new metaphors for the target audiences and metaphors originating from Chinese neologisms. The authors propose a strategy of retaining the metaphors plus explanation in the target text for consideration of the audiences' understanding of the cultural and political connotations of the metaphors.

    Table and Figures | Reference | Related Articles | Metrics
    Journal of Diagnostics Concepts & Practice    2021, 20 (04): 138-.   DOI: 10.16150/j.1671-2870.2021.02.004
    Abstract342)      PDF (676KB)(535)      
    Related Articles | Metrics