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    Development of IT Industry in China in the New Age
    JIANG Ze-min
    Journal of Shanghai Jiaotong University   
    Abstract16883)            Save
    The article explains the role and future trend of IT industry, and states that information technology represented by the internet and computers has brought about the third industrial revolution in history. An important impetus for economic growth in modern times, the IT industry has greatly promoted sustainable development and is profoundly changing mankind’s way of life and production. In discussing the development trend of world IT industry, the article suggests that with potential new breakthroughs in IT technology, the trend of agglomeration and integration of industries has become increasingly obvious, competition of intellectual properties and strandards is intensifying and ubiquitous networks is taking shape. It points out that China should bring into better play the role of IT industry as an “amplifier” in economic growth, a “transformer” in development mode and a “propeller” in industrial upgrading. It is important to follow a policy that emphasizes indepandent innovation, marketdriven approach, open and compatible technologies, integrated and comprehensive application, and serving both military and civil purposes, so that a quantum leap of IT industry will be achieved. China should advance industrialization with IT technologles and promote the IT industry in the course of industrialization in an effort to build an IT industry with Chinese characteristics. Greater efforts should be made to develop such core sectors as microelectronics, computer, software, key components and materials, as well as sectors with international competitiveness, including broadband mobile communication, nextgeneration network and information services. Continued improvement should be made in the policies guiding the development of IT industry with a view to making China a country with a strong IT industry by 2020.
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    Modeling and Stability Analysis of a Pressure Compensator for Flow-Control Valve
    JIA Wen-Hua- , YIN Chen-Bo
    Journal of Shanghai Jiaotong University    2011, 45 (04): 561-564.  
    Abstract5687)            Save
    The forces acting on the load-sensing compensated valve were illustrated and analyzed, the mathematical model was generated using classical momentum principles, while the linear analysis of this was carried out using the Taylor expansions. The valve motion of the system was described by presenting the equation of motion, the stability condition was given by Routh-Hurwitz stability criterion and the dynamic properties of the compensator were studied. The CFD analysis of the compensator was described to study the effect of the force acting on the bottom of the compensator. The pressure along the bottom wall was noted and its variation was plotted against the geometrical position of the bottom wall that it acted on. Noted that this pressure remain constant along the wall. Then, some plots describe the flow induced forces and coefficients used to understand the stability of the compensator itself.
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    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
    Abstract3932)   HTML321)    PDF(pc) (1383KB)(1422)       Save

    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.

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    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
    Abstract4180)   HTML108)    PDF(pc) (2567KB)(1326)       Save

    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.

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    Elastified Procedure for the Formfound Equilibrium State  and Zero-stress State of Cable-net Structure
    CHEN Wu-Jun, ZHANG Li-Mei, DONG Shi-Lin
    Journal of Shanghai Jiaotong University    2011, 45 (04): 523-527.  
    Abstract5154)            Save
    Six states and five analysis processes were pointed out for the whole numerical analysis process of cable-net structure. The six states are initial geometry state, form-found equilibrium state, elastified form-found equilibrium state, zero-stress (unstressed) state, pre-stress state and loading state, respectively. The five analysis process are form-finding analysis, elastified cable analysis, pre-stress analysis, inverse analysis and loading analysis. And the state parameters were clarified, also for the analytical model of different analysis procedures. The real zero-stress state does not exist generally, the assumed approximated zero-stress state is usually employed. On the basis of elastified form-found equilibrium state, the bestfit reasonable zero-stress state can be found through inverse analysis. The numerical algorithm and procedure was proposed for the ANSYS and EASY for cable-net analysis, and the emphasis is focused on the zero-stress state assumption. Finally, the numerical analysis was exemplified for two cablenet structures. The results demonstrate the significant difference with different zero-stress state assumption and the corresponding numerical analysis approaches.
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    Adaptive Consensus Fusion Estimation for Mobile Sensor Networks
    Wang-Lin, ZHANG Guo-Zhong, ZHU Hua-Yong, SHEN Lin-Cheng
    Journal of Shanghai Jiaotong University    2011, 45 (03): 383-0387.  
    Abstract4524)            Save
    To the problem of distributed estimation for mobile sensor networks(MSN)with communication delays and switching network topologies, a novel distributed fusion estimation algorithm, named adaptive consensus based bistributed unscented information filter(AC_DUIF), was presented. The proposed algorithm was based on unscented information filter, adaptive consensus algorithm, as well as a new fusion framework for the consideration of the communication delays. An application of target tracking using an air mobile sensor networks with dynamically switched network topologies was employed to illustrate the performance of the proposed algorithm. The simulation results show that the proposed method can significantly improve the accuracy of target position estimation of each sensor node in a distributed fashion, when the distributed consensus between each nodes and the adaptability of the communication delays are assured.
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    A Method for Multitarget Passive Location by a Movable Single Station  Based on Weighted MUSIC Algorithm in FRFT Domain
    HE Wei-Yan, JIN Rong-Hong, GENG Jun-Ping, LIANG Xian-Ling
    Journal of Shanghai Jiaotong University    2011, 45 (03): 345-0349.  
    Abstract4464)            Save

    Aiming at the situation of multiple linear frequency modulation(LFM) signal sources, by analyzing the Doppler shift of received signals, a multicomponent LFM signal model for the antenna array on a movable single station was built. Then a method for multitarget passive location based on weighted MUSIC algorithm in fractional Fourier transformation(FRFT) domain was presented, which implements the detection and DOA estimation of multitarget signals at low SNR. The simulation results show that  multiple targets with similar frequency and close space can be distinguished in a high accuracy.
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    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
    Abstract4277)   HTML953)    PDF(pc) (2106KB)(1271)       Save

    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.

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    A SINS Coning Compensation Algorithm Based  on Gyro Error PostCompensation
    LI Zong-Tao-a, b , WU Tie-Jun-b, MA Long-Hua-b
    Journal of Shanghai Jiaotong University    2011, 45 (03): 388-0392.  
    Abstract5246)            Save
     The coning compensation computation in strapdown inertial navigation system(SINS) attitude updating algorithms is based on the use of compensated gyros incremental angle outputs,  the gyro output errors compensation has to be performed at the high rate of gyro output sampling,thus increasing the throughout of the navigation compater. A postcompensation algorithm was proposed to solve this problem by calculating the coning compensation with uncompensated gyros incremental angle outputs and then compensating for gyros output errors at the updating rate of coning compensation that is lower than the gyro output sampling rate. The simulation results show that the coning compensation accuracy of the proposed postcompensation algorithm is almost the same as that of traditional precompensation algorithms, but the throughput of the navigation computer is significantly reduced.
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    Adaptive limited feedback for MUMIMO system
    WU Youlong,LUO Hanwen,LIU Wei,DING Ming,Wang Hailong
    Journal of Shanghai Jiaotong University    2011, 45 (03): 313-0320.  
    Abstract4596)            Save
    The limited feedback in multiuser MultipleInput MultipleOutput (MUMIMO) systems is addressed in this paper. In order to reduce the feedback overhead in the uplink channel, we analyze the relation between user’s feedback bits and rate, deduce the optimal solution for adaptive limited feedback, and propose a suboptimal feedback scheme which is more practical. In this scheme, users choose the feedback bits according to both their channel gains and the average gain of the system. Users with high SNR are assigned with more feedback bits than the lowSNR users so as to improve the feedback efficiency. Simulation results and analysis show that the proposed scheme is easytoimplement and can enhance the throughput with no additional feedback overhead.
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    The Influence of Formation Manner of Component on Signal Processing Effect of Singular Value Decomposition
    ZHAO Xue-Zhi, YE Bang-Yan
    Journal of Shanghai Jiaotong University    2011, 45 (03): 368-0374.  
    Abstract4525)            Save
     Aimed at the formation manner of component signal in singular value decomposition (SVD), the difference of signal processing effect between the simple manner and the average manner was studied. Firstly, for the average manner, a convenient algorithm to get the average of matrix elements is proposed according to the characteristic of Hankel matrix. Secondly, it is proved that the original signal can be decomposed into the linear sum of a series of component signals by SVD with both manners, and a parameter called loss ratio is proposed to evaluate the signal processing effect of both manners. The studying results show that for sine signals, there is no difference between the processing effects of the two manners, while for frequency change signals, the average manner has the advantage of the simple one, however, both manners have extracted the modulated signal caused by the damage in roll track from the complicated vibration signal of a bearing, but the computation amount of the average manner is much larger than that of the simple one. It is recommended that except frequency change signal, for other common signals the simple method should be prior used.
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    ClosedForm BER Analysis of DSUWB Systems Using Narrowband Interference Suppression Technology
    GONG Ling-Song, WANG Cheng, YANG Yu-Hang, ZHU Rong-Bo
    Journal of Shanghai Jiaotong University    2011, 45 (03): 358-0362.  
    Abstract3996)            Save
    In order to accurately evaluate the bit error rate(BER) of DSUWB systems with narrowband interference suppressor, a method based on characteristic function (CF) is proposed for precisely calculating the BER of DSUWB systems using twosided transversal filters for rejection of single tone interference. We derive a mathematical expression called interference suppression factor of twosided transversal filters. In addition, theory analyses show that with sufficiently large tap number, the tone interference could be almost cancelled totally. The simulation and numerical results validate the accuracy and effectiveness of analytical BER derivations.
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    An Identification Method for DC-Link Capacitor Capacitance of Grid Connected Inverter
    ZHU Chenghao, WANG Han, SUN Guoqi, WEI Xiaobin, WANG Fuwen, CAI Xu
    Journal of Shanghai Jiao Tong University    2022, 56 (6): 693-700.   DOI: 10.16183/j.cnki.jsjtu.2021.515
    Abstract1066)   HTML1284)    PDF(pc) (5050KB)(1249)       Save

    DC-link for the capacitor is one of the most vulnerable components of the grid connected converter, whose capacitance identification will help to improve the system reliability by finding and replacing the aging capacitor in time. An identification method for the DC-link capacitor capacitance of the grid connected inverter based on pre-charging circuit is proposed. By analyzing the relationship between the capacitance and the charging current, charging voltage during pre-charging process, and combining the historical operating data, the set of capacitance state feature vector is built. The support vector regression (SVR) model is trained and the regression prediction relationship between the state value and the capacitance is set. The model is optimized by using the particle swarm optimization (PSO) algorithm, which can be used for capacitance identification of the DC-link capacitor. Simulation and experiments results show that the proposed method can implement the accurate capacitance identification of the DC-link capacitor of the grid connected inverter, with an identification error of less than 0.95%. This method does not need to add hardware circuit and change the control algorithm, and has a certain practical value.

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    Frequency Planning in RelayAided Cellular Network
    LIN Yi-Ru-1, GUO Jia-1, LUO Han-Wen-1, ZHOU Xiao-Lin-2
    Journal of Shanghai Jiaotong University    2011, 45 (03): 336-0339.  
    Abstract4485)            Save
    This paper proposes a new frequency planning scheme for the proposed cellular wireless system using fix relay. Our scheme improves the frequency efficiency, while relatively improving the CEU’s SIR through frequency planning based on fractional frequency reuse. The simulation results show that it can improve the performance of frequency efficiency compared with others scheme, CEU’s average throughput is improved.
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    Fast Approximate Clustering Algorithm and Its Application in Image Retrieval
    GU Wangyi,ZHU Lin,YANG Jie
    Journal of Shanghai Jiaotong University    2011, 45 (02): 149-0153.  
    Abstract5523)            Save
    The fast approximate Kmeans algorithm (FAKM) was proposed to solve the limitations of traditional Kmeans algorithm in the large scale database. Based on the approximate Kmeans algorithm (AKM), FAKM classifies the cluster centers according to cluster results. This new algorithm filters out the cluster centers with few samples, and makes good use of those with intensive and stable samples, and thus the number of samples and clusters will reduce in each iteration. Accordingly it can improve the speed of this algorithm and refine the cluster result. Several experimental results in image retrieval system are presented to demonstrate its average advantage over Kmeans and AKM in the clustering time, retrieval time and the robustness capability of retrieval accuracy.
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    Grating Lobe Suppression for Contiguous Subarray with Uniform Structure
    CHEN Bi-Xian, JIN Rong-Hong, GENG Jun-Ping, LIANG Xian-Ling
    Journal of Shanghai Jiaotong University    2011, 45 (03): 340-0344.  
    Abstract5330)            Save
     When large scale arrays are divided into subarrays of equal sizes a difficulty with grating lobes is encountered during scanning. The condition of producing the grating lobe was discussed at first, and on this basis, a new method of beam scanning at uniform subarray level was proposed for the purpose of reducing the grating lobe by dividing the scanning region. The fundamental rules of scanning regional division and how to optimize the weights of all angles in each scanning region at elements level and subarray level by particle swarm optimization (PSO) were also discussed. As an example, an array of three subarray with four elements was simulated and the results show that the maximum sidelobe level can be reduced to -22 dB in each scanning region. This approach also can be used for multibeam forming.
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    Twodimensional Cross Entropy Thresholding Based on Chaotic Resilient Particle Swarm Optimization or Decomposition
    WU Yi-Quan, ZHANG Xiao-Jie, WU Shi-Hua
    Journal of Shanghai Jiaotong University    2011, 45 (03): 301-0307.  
    Abstract4401)            Save
    A twodimensional cross entropy image thresholding method based on chaotic resilient particle swarm optimization (CRPSO) or decomposition was proposed. Firstly, chaotic resilient particle swarm optimization was used to find the optimal threshold of twodimensional cross entropy method. The recursive algorithm was adopted to avoid the repetitive computation of fitness function in iterative procedure. As a result, the computing speed was improved greatly. Then, the computation of twodimensional cross entropy method was converted into two onedimensional spaces, which made the computation complexity further reduce from O(L2) to O(L). The experimental results show that, the two methods proposed in this paper can greatly reduce the running time while the segmented result is as good as or better than the existing twodimensional cross entropy thresholding method.
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    Experimental Study on Resistance Reduction of Displacement Type Deep-V Hull Model Using Stern Flap
    ZHENG Yi, DONG Wen-Cai, YAO Chao-Bang
    Journal of Shanghai Jiaotong University    2011, 45 (04): 475-480.  
    Abstract5986)            Save
    Model tests of kiloton displacement type deep V ship series using stern flap for resistance reduction were carried through. The flap chord varies from 0.010 Lwl to 0.023 Lwl, install angle changes from 3° to 10°, and the test speed range from Fr=0.12 to 0.52. The influence of ship speed, flap chord and install angle on resistance reduction rate and running trim were investigated based on test data. Optimized stern flap parameters with application range were obtained for this particular ship form.
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    Calculation of HighPrecision Pseudocritical Temperatures for Transcritical Transient Analysis
    FU Sheng-Wei, ZHOU Chong, YANG Yan-Hua, CHENG Xu
    Journal of Shanghai Jiaotong University    2011, 45 (03): 413-417.  
    Abstract4482)            Save
    The development of thermalhydraulic system code applicable for transcritical transients’ calculation requires the support of a pseudocritical temperature calculating module with high precision. Based on the accurate data of pseudocritical temperatures obtained by the IAPWSIF97 thermalphysical property equations, the relation between pseudocritical temperature and pressure was fitted. The fitting equations are capable of providing pseudocritical temperatures with good precision. This paper presented the implementation of the fitting equations into a thermalhydraulic system code, as well as simulation of some simple transcritical transients. The results indicate that the pseudocritical temperature calculating method developed in this paper is applicable.
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    A User Pairing Algorithm for Virtual MIMO Systems
    Jiang-Wu-Yang, LIU Wei, DING Ming, LUO Han-Wen
    Journal of Shanghai Jiaotong University    2011, 45 (03): 350-0353.  
    Abstract4583)            Save
    A novel user pairing algorithm for virtual MIMO systems was proposed based on semiorthogonal user selection (SUS) with partial inverse selection. To solve the problem that users with bad channel condition suffer from low throughput in the traditional SUS algorithm, this paper proposed a mechanism called ‘inverse selection’, which is derived from the analysis of the MMSE receiver. The simulation results show that the new algorithm largely improves the throughput of users with poor SINR at a reasonable cost of the overall throughput decrease, thus achieving a profitable tradeoff between system throughput and user fairness.
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    A Multiuser Scheduling Algorithm for MIMO Broadcast Channels with Limited Feedback
    LI Jun-Fei, YU Hui, LUO Han-Wen, DING Ming
    Journal of Shanghai Jiaotong University    2011, 45 (03): 379-0382.  
    Abstract4416)            Save
    This paper addresses the issue of multiuser scheduling with limited feedback in MIMO broadcast channels. A new user selection algorithm was proposed. In order to exploit multiuser diversity, users feedback the estimation of the available transmit rates as well as the channel directional information. At first, the transmitter divides all the codewords into groups according to their crosscorrelation coefficients. When scheduling, the users are assigned to different groups corresponding to different code regions and then the active user group is selected among the groups. Simulation results show that the presented algorithm can achieve good sumrate performance and obtain the optimal multiuser diversity, with low computational complexity.
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    Challenges of Distributed Green Energy Carbon Trading Mechanism and Carbon Data Management
    LI Xingzhi, HAN Bei, LI Guojie, WANG Keyou, XU Jin
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 977-993.   DOI: 10.16183/j.cnki.jsjtu.2021.450
    Abstract1038)   HTML893)    PDF(pc) (2604KB)(1210)       Save

    To achieve the double carbon goal of “carbon peaking and carbon neutrality”, the construction of the power system which is based on the green energy needs to be accelerated. With the growth of the system scale, the distributed green energy carbon trading mechanism and the carbon data management technology based on the blockchain technology can effectively encourage the development of green energy and become effective means for the implementation of low-carbon electricity. The accurate and real-time carbon emission calculation will further provide data support for the accuracy and security of carbon trading information. First, the current research status of green certificate trading and carbon asset management is introduced. Next, the adaptability analysis of the key technologies of the blockchain technology in the four directions of green electricity traceability, green certificate trading, carbon trading, and joint market of green certificate and carbon assets is performed. Afterwords, the specific mathematical models of carbon emission calculation is studied, and the data availability of carbon source traceability methods applicable to the blockchain architecture are discussed. Finally, some suggestions for the future development of carbon emission flow analysis are proposed.

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    A Relay Scheduling Algorithm in DualHop Wireless Networks
    Zhang-Yu, LUO Han-Wen, ZHOU Xiao-Lin
    Journal of Shanghai Jiaotong University    2011, 45 (03): 331-0335.  
    Abstract3912)            Save
    This paper proposed a relay node iterative scheduling algorithm based on the channel capacity maximization for dualhop wireless networks. Based on the amplifyandforward relay protocol, the proposed algorithm selects relay nodes iteratively according to the criterion which makes the instantaneous capacity maximal when the destination node performs the joint decoding. The selection process continues until the number of the selected relays is equal to the number of source transmitting antennas or the channel capacity does not increase anymore. The simulation results show that under different conditions including total number of relay nodes, number of source transmitting antennas and signal to noise ratios of the forward and backward channels, the algorithm can obtain greater capacity gains and multirelay diversity gains over conventional algorithms and can reach the upper bound of the informationtheoretic capacity more closely.
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    Research of Sliding Mode Controller for Flight Simulator Based  on Disturbance Observer
    LIU Xiao-Dong, WU Yun-Jie, TIAN Da-Peng, WANG Jun-Feng
    Journal of Shanghai Jiaotong University    2011, 45 (03): 393-397.  
    Abstract5068)            Save
    Because disturbance observer (DOB) underestimates the equivalent disturbances in flight simulator system, one sliding mode variable structure controller (SMVSC) based on DOB was proposed. The controller introduces additional compensation for disturbances, velocity and acceleration of tracking signals, and a new sliding approach law for the SMVSC was defined, then the system meets the conditions for the existence of generalized sliding mode. The experiments on one singleaxis flight simulator show that the proposed control scheme improves the tracking performance with more robustness against parameter uncertainty and extern disturbance, contrasted with the traditional PD+DOB scheme.
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    Algorithm for Relative Position and Attitude of  RVD Based on Dualquaternion
    ZHANG Ze, DUAN Guang-Ren, SUN Yong
    Journal of Shanghai Jiaotong University    2011, 45 (03): 398-402.  
    Abstract4216)            Save
    Traditional algorithm for the determination of relative position and attitude between target spacecraft and tracking spacecraft of RVD is to obtain the direction cosine matrix and translation vector respectively, but this method can not hold the integrity of the rigid body motion, and also, the solving speed and convergence influence the realtime characteristic and the accuracy of the measurement. This paper proposed a new algorithm based on dualquaternion to overcome the disadvantage of the traditional method. The integrity of the relative rotation and translation between the two coordinates is considered. At last, the simulation results show the effectiveness of the new algorithm.
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    Three-Dimensional Numerical Analysis of Soil Nailing for Deep Excavation
    DING Yong-chun, ZHOU Shun-xin, WANG Jian-hua
    Journal of Shanghai Jiao Tong University    2011, 45 (04): 547-552.   DOI: 10.16183/j.cnki.jsjtu.2011.04.019
    Abstract5132)   HTML427)    PDF(pc) (1058KB)(1192)       Save

    In order to investigate the deformation characteristics and load transfer mechanism of deep excavation, a numerical model considering the process of stepped excavating and soil nailing was established by FLAC 3D. The lateral displacement of excavation surface and outside soil, the shear strain increment of soil, and the axial force distribution of nail were analyzed. The results show that, the maximum lateral displacement appears close to slope toe, meanwhile, outside corner is the most disadvantageous location of deflection, and the multilevel platforms have positive effects on controlling soil deformation. Tensile failure and shear failure are the two main failure modes of excavation slope. The location of potential sliding surface can be indicated by shear strain increment contour, and the location moves toward the outside end of soil nail due to soil nail reinforcement effects. The maximum axial force of soil nail appears near the middle and the relative minimum value near the two ends, and the distribution of maximum axial force agrees well with the potential sliding surface.

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    Autonomous Orbit Determination of Satellite Navigation System
    Based on Unscented Kalman Filter
    ZHAO Xiao-Fang, LIU Sheng-Gang, HAN Chao
    Journal of Shanghai Jiaotong University    2011, 45 (03): 433-438.  
    Abstract4198)            Save
    In accordance with the highly nonlinear of orbit dynamics and the precision requirement of the autonomous orbit determination for navigation constellation, a parallel autonomous orbit determination method based on the dual direction range measurement was proposed. In this method, the unscented Kalman filter is used as the onboard estimation algorithm for each satellite to get its own state and the extra covariance used in this filter which is introduced by the priori orbit is given to ensure the filter stability. The simulation results show that the new method can maintain the long term autonomous orbit determination and the precision of the satellite orbits.
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    An Algorithm of Optimizing Throughput in Multi-relay Cooperativ Networks
    LI Qian-Wen, JIANG Ling-Ge, HE Chen, ZHAN Ao
    Journal of Shanghai Jiaotong University    2011, 45 (03): 363-0367.  
    Abstract4839)            Save
     This paper considers a wireless network with single sourcedestination pair and multiple potential relays, in which each node accumulates the received information to recover source information, then based on dynamic decode and for ward(DDF) protocol, a relay selection and transmission algorithm is proposed. Firstly, a corresponding mathematical problem of minimizing information’s transmission time is exactly formulated. Moreover, it is proved to be a nondeterministic polynomial complete (NPC ) problem. Secondly, a suboptimal distributed greedy algorithm is proposed, which synthetically considess the chosen relay’s uplink and downlink gains. Not only the chosen relay is ensured to estimate the source information easily but also the network terminal is guaranteed to receive more effective decoding information. Finally, simulation results show that the proposed algorithm almost achieves the optimal network performance. Meanwhile its distributed implement decreases system overhead efficiently.
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    Potential Energy Study of Mooring System Based on Catenary Method
    YUAN Meng, FAN Ju, ZHU Ren-Chuan, MIAO Guo-Ping
    Journal of Shanghai Jiaotong University    2011, 45 (04): 597-603.  
    Abstract3999)            Save
    To understand the mooring energy during positioning, the configuration and tension of three types of mooring lines were derived using catenary formula. The gravitational and elastic potential energy distributions of a single mooring line with the lower end fixed were calculated for different upper end positions. The horizontal force calculated from potential energy was compared with that of calculation directly, and the results show good agreement, and satisfy the law of conservation of energy and also prove the correctness of the results of potential energy. For a deep-water platform moored by nine composite mooring lines, the potential energy distributions of the mooring system were analyzed, and the offset-lateral force relations were compared in different directions. They are found to meet each other very well, which indicates a balanced performance of the mooring system. The potential energy distributions and the offsetlateral force relations in different wave directions were calculated for the damaged case. From the results, it can be found that the potential energy distribution can reflect the performance of the mooring system in all directions effectively, which has important practical value in ocean engineering.
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    Energy Consumption Analysis and Improvement Strategy for ClusterHead Rotation in Wireless Sensor Networks
    DENG Han-Lin, LI Lei, HUANG He-Qing, YUAN Xiao-Bing, WANG Ying-Guan
    Journal of Shanghai Jiaotong University    2011, 45 (03): 321-0326.  
    Abstract4275)            Save
    To design a more energyefficient cluster head rotation (CHR) strategy for wireless sensor networks, this paper built an analytical model for the energy consumption of contentionbased CHR, analyzed the energy consumption ratio between data gathering and CHR, and proposed a schedulebased CHR, which could remove the energy consumption in CHR. The simulation results show that the schedulebased CHR obviously improves energy efficiency and energy consumption balance in the cluster.
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    A Novel ICI Cancellation Algorithm Based on Channel Segmentationcascade in OFDM System
    XU Xing-Hui, HE Chen
    Journal of Shanghai Jiaotong University    2011, 45 (03): 308-0312.  
    Abstract3869)            Save
     For Orthogonal Frequency Division Multiplexing (OFDM) wireless systems with high frequency, deficiencies caused by Doppler frequency offset and the carrier phase noise are much higher,which will introduce InterCarrier Interference (ICI) and degrade the performance. Using channel segmentation,an equivalent method was presented in this paper,which transfers linear timevariant channel into the cascading of timeinvariant channel and timevariant channel with no delay. Then onedimensional equalization can be achieved at the receiver to suppress ICI, avoiding calculating the frequency domain channel response matrix and its inverse matrix. The analysis and simulation results show that, the proposed algorithm can effectively reduce the complexity to O(N) with almost no performance loss, compared to the existing low complexity MMSE.
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    Sliding Mode Variable Structure Control Based
     on Multimodel Online Identification
    DUAN Chao-Yang, ZHANG Yan, SHAO Lei, LEI Hu-Min, CHEN Zong-Ji
    Journal of Shanghai Jiaotong University    2011, 45 (03): 403-407.  
    Abstract3722)            Save
     In order to improve the control effect of traditional sliding mode variable structure control system for nonlinear uncertain systems, a new control scheme was proposed, which combines the multimodel online identification with sliding mode variable structure. Firstly, based on the inputoutput data, multiple local models was constructed by online clustering, and the local models are updated. Then, the model of the nonlinear system is given by the combination of all weighted local models. Finally, a sliding mode controller based on reaching law is designed according to the online indentificated system model. The simulation results show the robustness of the proposed scheme to the uncertainty of system model.
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    Experimental and Numerical Analysis for Floatover Installation on Jacket
    XU Xin, YANG Jian-Min, LV Hai-Ning
    Journal of Shanghai Jiaotong University    2011, 45 (04): 439-445.  
    Abstract5669)            Save
    This paper investigated the floatover installation process on a jacket with numerical and experimental analysis. Numerical analyses in both frequency and time domain were carried out for typical configurations during floatover operation. Corresponding model tests were also performed in ocean engineering basin. The comparison between numerical and experimental results shows that the response amplitude operator and time series agree quite well. The barge has favorable hydrodynamic behavior in considered sea state and the loads of equipments are allowable. The floatover operation on the jacket is feasible.
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    Application of HybridModel Method in UltraLarge Water Conveyance Tunnel
    YANG Yan-Zhi, JIN Xian-Long, GU Bin, QIAO Zong-Zhao, YANG Zhi-Hao
    Journal of Shanghai Jiaotong University    2011, 45 (04): 534-538.  
    Abstract3544)            Save
    This paper proposed a hybridmodel method based on an ultralarge water conveyance tunnel under construction, which directly performs global simulation and local simulation together, and can avoid the deviation brought by boundary condition gained from global simulation. Using the explicit algorithm and related technologies, it proves this method is feasible through the actual calculation and application.
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    The Wave Loads and Outrigger Hulls’ Position Optimization for Trimaran Traveling in Waves
    XU Min, ZHANG Shi-Lian
    Journal of Shanghai Jiaotong University    2011, 45 (04): 470-474.  
    Abstract4096)            Save
    Because of the interaction between the main hull and the outrigger hulls the wave loads will be quite different by different arrangement. Based on the threedimensional potential theory and Green’s function, the wave loads, including vertical shear force end vertical bending moment at different locations on the main hull with respect to different staggers and clearances, were derived by the spectral analysis. Several ship speeds and wave headings were also considered. A suitable arrangement was got by comparison.
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    Numerical Simulation of Wind Loading Shape Coefficient  on a New Airport Terminal
    CHEN Xiang-Qiao, TU Jia-Huang, ZHOU Dai, ZHU Zhong-Yi, QIN Kai
    Journal of Shanghai Jiaotong University    2011, 45 (04): 517-522.  
    Abstract4961)            Save
    Based on the project of new Kunming Airport Terminal, the wind field and wind pressure distribution of structural surface was simulated by commercial computational software with standard kε turbulent model, while parameter analysis such as coming wind angle was carried out. The investigation indicates that the numerical results of wind pressure distribution on the roof are somewhat greater than the wind tunnel experiment results and the wind loading shape coefficients vary greatly with the coming wind angles. It should be mentioned that the most unfavorable wind pressure distribution should be obtained according to local wind environment, in order to provide a reference for windresistant design of practical eningeering project.
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    Study on Multi-objective Optimization of a New Side-load Spring  for MacPherson Suspensions
    LIU Jiang, WANG Yu-Shun, YU Fan
    Journal of Shanghai Jiaotong University    2011, 45 (04): 464-469.  
    Abstract5046)            Save
    Aiming at decreasing shock absorber’s side load in the MacPherson suspension system, improving suspension performances and reducing manufacture cost, a multiobjective optimization approach was proposed. This virtualprototypebased approach combines the penalty function algorithms SUMT, vehicle system dynamics simulation and finite Element Analysis. Taking a small passenger car as an example, structure parameters were optimized for this curved side load spring. The results of vehicle dynamics simulation, the experimental data of test rig and on road test indicate the improvement of ride performances, in which the side load on damper rod reduces almost to zero and the first resonance peak amplitude of the body acceleration decreases by nearly 24.37%. Besides, the average weight of spring samples also reduces by 2.71% so as to save the manufacture cost.
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    Non-fragile Optimal H2/LQR Control with Regional Pole Placement for Hypersonic Vehicle
    HUANG Yi-Qing, WANG Li, SUN Chang-Yin
    Journal of Shanghai Jiaotong University    2011, 45 (03): 423-428.  
    Abstract4329)            Save
    A kind of robust mixed nonfragile optimal H2/LQR control with regional pole placement was proposed for an airbreathing hypersonic vehicle (AHV). A new linear uncertain model was developed according to a nonlinear longitudinal model of an AHV and then  a multiobjective nonfragile controller was designed that includes regional pole placement, robust guaranteed cost control and optimal H2 control performance indexes for the proposed linear uncertain model. The paper also took the gain variation of the controller into account due to parametric uncertainties of an AHV flight condition and the errors  existed in modeling. The existed conditions of the multiobjective nonfragile controller were deduction by linear matrix inequalities (LMIs). Finally, the simulation comparisons between nonfragile controller and traditional controller that without considering the gain variation illustrate the advantages and effectiveness of our approach.
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    Identification of Response Models of Ship Manoeuvring Motion Using Support Vector Regression
    ZHANG Xin-Guang, ZOU Zao-Jian
    Journal of Shanghai Jiaotong University    2011, 45 (04): 501-504.  
    Abstract4455)            Save
    Abstract: By applying the LSsupport vector regression to analyze the data of rudder angle and yaw rate obtained from the deformed zigzag test of freerunning model, the manoeuvrability indexes in the response models of ship manoeuvring motion were identified. The obtained response models were solved numerically by RungeKutta method to simulate the deformed zigzag manoeuvres. The prediction results of heading angle and yaw rate were compared with the test data to verify the proposed method.
    Key words: ship manoeuvring; response model; parameter identification; support vector regression
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    Retarded Motion in Approach and Glide Speed Measurement  with TwoStations for Carrier Aircraft
    YU Tao
    Journal of Shanghai Jiaotong University    2011, 45 (03): 429-432.  
    Abstract3829)            Save
    The motion law in approach for carrier aircraft was analyzed by applying Doppler shift. When carrier aircraft is in uniform glide motion, the proportional navigation guidance law can be derived according to the condition that Doppler changing rate tends towards zero. Then, the retarded motion at equal proportion is emphatically researched and the conclusion is obtained that adjacent Doppler changing rate tends to equal. Based on the fact that the approach for carrier aircraft must be practically a retarded motion, this paper presented an engineering solution detecting glide angle and velocity of carrier aircraft in mobile platform. As opposed to the available multistation measurement mode, the analytic equation of velocity vector of carrier aircraft from Doppler shift equation can be directly derived making use of angle transformation introduced by directionfinding although the location parameter is unknown. The analog calculation verifies that the derived formula of velocity vector is errorless. The error analysis shows that the measuring error of velocity vector is less than 0.1 m/s if the rms value of measurement error of the velocity for aircraft carrier is less than 0.1 m/s.
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