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    Information & Control
    A Customized Routing Backup Mechanism for IPv6
    ZENG Rong-fei, ZHANG De-yong, WANG Xing-wei, HUANG Min
    2020, 41 (10):  1369-1376.  DOI: 10.12068/j.issn.1005-3026.2020.10.001
    Abstract ( 634 )   HTML   PDF (696KB) ( 710 )  
    In order to solve the problems of network customization capability and reliable routing, a customized routing backup mechanism for IPv6 was proposed. Considering the requirements of various applications, a routing customization process was designed to consider the maximum satisfaction of both users and ISP(Internet service provider) about the network, and design a route backup mechanism in conjunction with the new IPv6 header format to enhance the reliability of the network. Simulation experiments and performance analysis showed that this mechanism balanced the utility of users and network service providers when routing through a two-person game, so that routing has the ability to customize. In terms of reliability, compared with the traditional IPv6 routing without customization, the mechanism reserves the backup path resource and reduces the routing recovery response time by more than 15% with a 16.8% increase of routing time overhead.
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    Network Anomaly Detection Method for Intentional Attack
    ZHAO Hai, ZHENG Chun-yang, WANG Jin-fa, SI Shuai-zong
    2020, 41 (10):  1376-1381.  DOI: 10.12068/j.issn.1005-3026.2020.10.002
    Abstract ( 660 )   HTML   PDF (646KB) ( 722 )  
    The anomaly triggered by intentional attack in complex networks is common but most existing detection methods ignore the global topology mutation feature. To solve this problem, based on the abnormal evolution characteristics of the global network topology, a network path change coefficient (r) was proposed to quantify the change of the transmission path between nodes. The Fibonacci evolution region was derived from the Fibonacci sequence to distinguish normal and abnormal evolution. r was used as the core measurement parameter to construct the Fibonacci evolution region, form a network anomaly detection method, and realize the determination of anomalies. The results showed that the average accuracy of the detection method is more than 90%, which is higher than the accuracies of MCS (maximum common subgraph) and GED (graph edit distance), which proves the effectiveness of the proposed detection method.
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    Entity Recognition Method for Judicial Documents Based on BERT Model
    CHEN Jian, HE Tao, WEN Ying-you, MA Lin-tao
    2020, 41 (10):  1382-1387.  DOI: 10.12068/j.issn.1005-3026.2020.10.003
    Abstract ( 913 )   HTML   PDF (531KB) ( 1282 )  
    Using manual analysis of case files, it is easy to cause the problem of case entity omission and low efficiency of feature extraction. Therefore, the bidirectional encoder representation from transformers pre-training model based on the traditional long short-term memory networks and conditional random fields was used to fine tune the model parameters on the manually labeled corpus for entity recognition. And then the semantic coding output from the previous layer was decoded by the long short-term memory networks and conditional random fields to complete entity extraction. The pre-training model has the advantages of huge parameters, powerful feature extraction ability and multi-dimensional semantic representation of entities, which can effectively improve the effect of entity extraction. The experimental results showed that the proposed model can achieve more than 89% entity extraction accuracy, which is significantly better than the traditional recurrent neural network and convolutional neural network model.
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    H Congestion Tracking Control for TCP/AWM Network Systems
    JING Yuan-wei, QI Xue-lei, SHEN Jin-dong, JING Jiang-shan
    2020, 41 (10):  1388-1393.  DOI: 10.12068/j.issn.1005-3026.2020.10.004
    Abstract ( 560 )   HTML   PDF (519KB) ( 542 )  
    For the TCP/AWM network system congestion tracking control problem, a congestion control strategy design idea based on AWM mechanism was proposed. For the nonlinear model of the network system, the coordinate transformation was used to transform it into an error model with a lower triangle form. An H controller was designed using backstepping technology. Considering the interference situation of UDP flow in the system, an H performance function was designed to inhibit the interference effect. A sufficient condition was obtained for the stability of the error system by combining the backstepping technology with the H performance function. The simulation results showed that the proposed control method can quickly stabilize the queue length, and is still effective when the UDP stream occupies nearly half of the link bandwidth.
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    Materials & Metallurgy
    Effect of Extrusion-Forging Temperature on Microstructure and Mechanical Properties of Solid State Regenerated H11 Steel
    LIU Xing-gang, WANG Ya-qin, MA Zhao-jun, ZHANG De-liang
    2020, 41 (10):  1394-1401.  DOI: 10.12068/j.issn.1005-3026.2020.10.005
    Abstract ( 572 )   HTML   PDF (2945KB) ( 595 )  
    Using the powders from the recovered machining chips of H11 steel as raw materials, the samples were prepared by powder compacting and extrusion-forging processes. Using tensile test, hardness test, XRD, SEM, TEM and etc., the effects of different extrusion-forging temperatures in a range of 1100~1220℃ on the microstructure and mechanical properties of solid regenerated H11 steel were studied. The results show that the sample has a good consolidation effect. When the extrusion-forging temperature is 1220℃, the density of the sample can reach up to 95.8%. After the temperature is over 1140℃, the Fe7C3 phase precipitates in the matrix. With increasing extrusion-forging temperature from 1100℃ to 1220℃, the hardness along the extrusion direction increases from 2.5GPa to 4.4GPa and the tensile strength increases from 451MPa to 808MPa, while the elongation decreases from 3.1% to 0.7%.
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    Modeling and Analysing Leakage of Heating Pipe Network in Park
    LI Guo-jun, LI Yi-qing, QIU Yong
    2020, 41 (10):  1402-1409.  DOI: 10.12068/j.issn.1005-3026.2020.10.006
    Abstract ( 611 )   HTML   PDF (1178KB) ( 650 )  
    In order to improve the safety of heating system and the accuracy of fault diagnosis system, hydraulic characteristics of a park’s heating pipe network under leakage conditions were modeled based on the graph theory, and the indoor-user temperature under different conditions was solved from the energy-balance equations of the pipe network. The effects of different leakage conditions on hydraulic and thermal characteristics of heating network were analyzed. The results show that the leakage faults at any point in heating pipe network will affect hydraulic characteristics of the system, and the closer the leakage point is to the circulating water pump, the greater impact on the flow of heating system pipe. Moreover, the change of hydraulic characteristics of heating pipe network can cause a coupling effect on thermal characteristics. The results can provide a guidance for the prediction of leakage accidents and fault diagnosis of heating pipe networks.
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    Molten Iron Powders Trapping and Recovering Palladium in Spent Catalyst
    ZHU Xiao-ping, SUN Shu-chen, TU Gan-feng, SUN Ting
    2020, 41 (10):  1410-1415.  DOI: 10.12068/j.issn.1005-3026.2020.10.007
    Abstract ( 645 )   HTML   PDF (1336KB) ( 614 )  
    According to the isothermal phase diagram of a slag system calculated from FactSage 6.4 software, a high-aluminum system with w(Al2O3)about 30% was chosen as the target slag. The recovery of palladium from spent catalyst was carried out by using iron powers as the collector and smelting in MF induction furnace. The effects of binary basicity of the slag system and the amount of collector on the recovery rate of palladium were studied, and the composition and micro-morphology of the alloy and tail slag were analyzed. The results show that when the smelting temperature is 1550℃, the binary basicity(mCaO/mSiO2)of the slag system is 0.6, and when the mass ratio between the iron powder and spent catalyst is 0.2, the recovery rate of palladium is up to 99%, leading to the greatest recovery efficiency. The tailings stand a dark green glass state with the palladium content less than 5g/t, and the mass fraction of palladium enriched in the ferroalloy is 0.76%. The results indicate the recovery of palladium resources in spent catalyst can be realized efficiently.
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    Materials & Metallurgy
    Effect of SO2-4 on Preparation of Magnesium Hydroxide by Electrode Position
    DI Yue-zhong, MA Guang-chao, SHEN Zi-qiang, CUI Zhi-chun
    2020, 41 (10):  1415-1420.  DOI: 10.12068/j.issn.1005-3026.2020.10.008
    Abstract ( 593 )   HTML   PDF (2330KB) ( 571 )  
    Using the by-product of magnesium chloride from titanium sponge as a raw material, the magnesium hydroxide [Mg(OH)2] prepared by the aqueous solution electrode position method was agglomerated dramatically and it was difficult to fall from the electrode plate. By adding a certain amount of SO2-4 into the electrolyte to improve the dispersion of Mg(OH)2, the serious agglomeration can be avoided effectively. The effect of SO2-4 on the shedding performance, product morphology and growth mode of Mg(OH)2 was studied. The results show that the SO2-4 concentration has a great influence on the initial shedding time of Mg(OH)2. When the SO2-4 concentration is 0.45g/L, the performance of Mg(OH)2 is the best, associated with the initial shedding time about 10min. When the Mg(OH)2 crystals grow on the electrode plate, the growth mode is the layered-island composite growth. Meanwhile, it is also found that the addition of SO2-4 can induce the Mg(OH)2 to grow in a stepped manner.
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    Mechanical Engineering
    Analytical Modeling of Inherent Characteristics of Bolted Joint Composite Plates Based on Virtual Materials
    SUN Wei, FANG Zi-wen, LIU Xiao-feng
    2020, 41 (10):  1421-1426.  DOI: 10.12068/j.issn.1005-3026.2020.10.009
    Abstract ( 517 )   HTML   PDF (686KB) ( 615 )  
    To improve the efficiency of dynamic analysis of the composite material structure with bolts, a corresponding analytical model was established on the basis of the virtual material model, and the inherent characteristics of the structure were solved. An energy analysis of the bolted joint composite plate structure was carried out, a dynamic analysis model of bolted joint composite plates was established by using Lagrange’s equation, and the natural frequencies and modal shapes of the structure were solved. The decomposition-based multi-objective evolutionary algorithm (MOEA/D) was used to determine the parameters of the virtual materials in the model to achieve the purpose of model modification. A case study was conducted on bolted TC500 carbon fiber/resin plates. The results showed that the application of this virtual material model can reproduce the vibration characteristics of bolted composite plate structures. After the model correction, the maximum deviation of the first 6 natural frequencies obtained from the simulation calculation and the measured value is 2.83%, which proves the rationality of the proposed modeling method.
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    Analysis of Molten Pool Temperatures and Convection Caused by Laser Cladding
    SONG Bo-xue, YU Tian-biao, JIANG Xing-yu, XI Wen-chao
    2020, 41 (10):  1427-1431.  DOI: 10.12068/j.issn.1005-3026.2020.10.010
    Abstract ( 1092 )   HTML   PDF (728KB) ( 1065 )  
    Complicated heat and mass transfer exist inside the molten pool generated by laser cladding. Since the scale of the molten pool is so small that it is difficult to monitor it in real time, a numerical model of laser cladding was constructed, and the temperature distribution and convection mode inside the molten pool were simulated and analyzed. The results showed that the temperature gradient in the molten pool is very large, and the part of the molten pool bottom that extends to the matrix will re-austenitize due to high temperatures. The fluid flow in the molten pool is mainly driven by Marangoni movement, and the convection in the molten pool is annular convection with a maximum flow rate of 0.1m/s. The research results can provide a reliable theoretical basis for the forming process of the cladding layer and the transmission process of the alloy powder in the molten pool.
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    Identification of Instantaneous Cutting Force Coefficients for Helical Milling of Carbon Fiber Composite Materials
    WANG Hai-yan, WANG Jian-yu, TAO Ke-xin
    2020, 41 (10):  1432-1437.  DOI: 10.12068/j.issn.1005-3026.2020.10.011
    Abstract ( 574 )   HTML   PDF (729KB) ( 573 )  
    The special tool orbits around the axis of the hole while rotating with its own axis and feeds in the axial direction in the helical milling process. Based on the cutting mechanism of the helical milling process, considering the effect of the side edges and bottom edges on the major cutting during the feed process and the anisotropic characteristics of the composite material, a cutting force analytical model was established in the helical milling of carbon fiber reinforced plastics (CFRP). According to the composite material helical milling test data under the full factor condition, the data fitting method was used to identify the bottom edge cutting force coefficient, and the instantaneous cutting force method was used to identify the side edge cutting force coefficient. The results showed that the simulated cutting force can better fit the experimental value.
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    Resources & Civil Engineering
    Isolation of Cultivable Bacteria in Coal Gangue Spontaneous Combustion Weathered Soil and Phosphate-Solubilizing and Cadmium-Resistant Characteristics
    JIANG Bin-hui, JIANG Qi, ZHOU Xing-xing, SHI Yang
    2020, 41 (10):  1438-1444.  DOI: 10.12068/j.issn.1005-3026.2020.10.012
    Abstract ( 605 )   HTML   PDF (1396KB) ( 575 )  
    Using plate coating separation method, 3 strains of bacteria were isolated and purified from coal gangue weathered soil (MF) and coal gangue spontaneously weathered soil (MZ) in Fushun West Open-pit Coal Mine, labeled as MF2, MZ1 and MZ2. Using 16S rRNA gene sequence detection, the strains of bacteria were species identified and classified according to bacterial morphology and physiological and biochemical characteristics, of which strain MF2 is Paenarthrobacter sp., MZ1 is Acinetobacter radioresistens, MZ2 is Bacillus paramycoides. The strains’ abilities of phosphate-solubilizing and cadmium tolerance were respectively investigated. The results showed that the maximum phosphate-solubilizing capacity of the three bacteria is MF2 (72h, 71.76mg·L-1)> MZ2 (96h, 55.48mg·L-1)> MZ1 (120h, 5.79mg·L-1), and the maximum tolerated dose of Cd2+ is ranked as MZ2 (100mg·L-1)>MZ1 (50mg·L-1)>MF2 (10mg·L-1). The B. paramycoides MZ2 not only has strong ability to dissolve phosphorus, but also has high tolerance to heavy metal Cd2+ among three strains.
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    Deformation Monitoring of High Steep Slope in Open-Pit Mine with Multi-Orbit SBAS
    WEI Lian-huan, FENG Qiu-yue, MAO Ya-chun, LIU Shan-jun
    2020, 41 (10):  1445-1451.  DOI: 10.12068/j.issn.1005-3026.2020.10.013
    Abstract ( 577 )   HTML   PDF (3680KB) ( 692 )  
    For deep open pit deformation monitoring, three Sentinel-1 datasets were analyzed by the small baseline subset method for deformation monitoring of the high steep slope in Dagushan Open-pit Iron Mine. A slope deformation retrieval method based on topographic features was studied. Three groups of LOS deformation were transformed to slope deformation respectively. Three groups of monitoring results are in good agreement with terrestrial measurements, and there is a certain correlation with precipitation. Northwest slope of the open-pit is the main deformation area threatening mine safety. The results showed that rock mass structure, lithology and precipitation are main factors affecting the stability of deep open-pit mines. Multi-orbit SBAS can be used as a routine tool for deformation monitoring of high steep slopes in deep open-pit mines, providing technical support for disaster prevention and mitigation.
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    Critical Curve of Rainfall Intensity-Time for Saturated-Zone in Unsaturated Soil Slope
    WANG Shu-hong, HE Jian, LIU Huan, HAN Wen-shuai
    2020, 41 (10):  1452-1458.  DOI: 10.12068/j.issn.1005-3026.2020.10.014
    Abstract ( 535 )   HTML   PDF (1238KB) ( 551 )  
    In order to study the critical condition of rainfall-induced saturated-zone forming, the soil saturation based on the MVG model was used to characterize the calculation equations of rainfall intensity. When the surface saturation of the soil reaches above 0.9 for the first time, the saturation is continuously stable at 0.9 ± 0.005 as the critical criterion of the saturated-zone. The numerical calculation method was used to obtain the critical rainfall intensity and rainfall time in the saturated-zone of the soil column and slope. Through the data fitting, a rainfall intensity-time critical curve model of the saturated zone was constructed, and the influence of different slope and effective rainfall intensity on the critical curve was analyzed. The results showed that the calculation method of saturation characterizing rainfall intensity can make the soil surface saturation reach a predetermined value, with an average accuracy of -0.008. When the effective rainfall intensity is large, the greater the slope, the shorter the time consuming to produce the saturated zone for the slope of 50°~60°,on the contrary, the longer it takes. A slope of 30°~40° is a “dangerous slope” prone to shallow landslides.
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    Pipe-Soil Contact State and Jacking Force Prediction of Rectangular Pipe Jacking
    JIAO Cheng-long, ZHAO Xin, NIU Fu-jun
    2020, 41 (10):  1459-1464.  DOI: 10.12068/j.issn.1005-3026.2020.10.015
    Abstract ( 633 )   HTML   PDF (1557KB) ( 721 )  
    The experience of rectangular pipe jacking for exit and entrance of metro station in Tianjin is limited, especially for pipes with large diameter. Considering the factors such as stoppages, pipe buoyancy and lubrication volumes, a jacking force calculation model of the coupled finite difference method and jacking force-jacking path control method was proposed and applied to the estimation of jacking force of rectangular pipe jacking. In view of the stratum situation in Tianjin, this model was used to estimate the jacking force in the construction of pipe jacking at the entrance and exit of metro stations. The field test and monitoring data proved the correctness of the jacking force prediction model. It is helpful for the design optimization of the back wall of the jacking working well and the layout of the long-distance large-diameter jacking construction relay room.
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    Experimental Research on Seismic Behavior of High Strength Bar Concrete Beam-Column Joints Reinforced by Steel Fiber
    ZHANG Jian-xin, ZHANG Biao, RONG Xian, DING Chuan-lin
    2020, 41 (10):  1465-1475.  DOI: 10.12068/j.issn.1005-3026.2020.10.016
    Abstract ( 674 )   HTML   PDF (2471KB) ( 574 )  
    In order to investigate the seismic behavior and shear bearing capacity of HRB600 high strength bar concrete beam-column joints reinforced by steel fiber, a quasi-static test of 10 beam-column edge joints was carried out. The influence of axial compression ratio, shear compression ratio, stirrup ratio, concrete type and reinforced range of steel fiber concrete on the seismic behavior index of HRB600 reinforced concrete beam and column joints was studied. The results show that the hysteresis curve of the HRB600 reinforced concrete beam-column joint with overall/local steel fiber is fuller, the rate of stiffness degradation is slower, and the energy consumption is higher. The steel fiber reinforced concrete can significantly improve the failure mode of the specimen and reduce the cumulative damage of the joints. When the formula of “Code for Seismic Design of Buildings” is used to calculate the shear bearing capacity of HRB600 high strength bar concrete beam-column joints reinforced by steel fiber, it is more conservative for specimens with a lower stirrup ratio, closer to the experimental value for high stirrup ratio. The predictions calculated by ACI 352—02 have a higher safety margin than the predictions given by “Code for Seismic Design of Buildings”.
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    Williams Element with Generalized Degrees of Freedom for SIFs Analysis in Functionally Graded Material Plate with Cracks
    XU Hua, YANG Tao, HAN Lin-jun, YANG Lu-feng
    2020, 41 (10):  1476-1483.  DOI: 10.12068/j.issn.1005-3026.2020.10.017
    Abstract ( 513 )   HTML   PDF (736KB) ( 562 )  
    According to the Williams series displacement field, only considering the elastic modulus E as a function of coordinate, a new format of Williams element with generalized degrees of freedom for the thin plane fracture analysis in a functionally graded material plate is derived by changing the integration mode of the overall stiffness of the crack tip in the singular region. Combined with a inclined crack and an edge crack contained in a functionally graded material plate, the influence of the distribution form of the elastic modulus E, the crack inclination angle and the crack length on the stress intensity factor at the crack tip is analysed. The results show that the method can directly and efficiently solve the crack tip stress intensity factor of the functionally graded material with cracks. When the elastic modulus E changes monotonically and its gradient is parallel to or vertical to the load direction, the stress intensity factors of mode I or mode II at the two crack-tips of the central inclined crack are different, and the distribution of stress intensity factors with the crack inclination angle is not affected by the distribution form of elastic modulus E.
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    Management Science
    Vector-Type Two-Tuple Semantic Density Weighted Operator and Its Application
    YI Ping-tao, WANG Lu, LI Wei-wei
    2020, 41 (10):  1483-1490.  DOI: 10.12068/j.issn.1005-3026.2020.10.018
    Abstract ( 494 )   HTML   PDF (446KB) ( 498 )  
    Aiming at the problem of multi-attribute decision making, two-tuple semantic information in the form of vector is integrated and an information aggregation method of vector-type two-tuple semantic density weighted averaging (V-TDWA) operator is proposed. Firstly, the basic idea of the vector-type two-tuple semantic weighted operator and its synthetic operators are introduced, and then their properties are analyzed. Secondly, based on the density of information distribution, the clustering problem of the vector-type two-tuple semantic information is discussed, and a clustering method based on vector similarity is given. Based on the clustering group, the maximum entropy value method is used to solve the density weight of different clustering groups. Finally, an example is given to briefly explain the application of the vector-type two-tuple semantic density aggregation operator.
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    Concept Definition and Scale Development of Organizational Resilience
    ZHANG Lan-xia, WANG Le-le, ZHANG Qin, JIA Ming-mei
    2020, 41 (10):  1491-1499.  DOI: 10.12068/j.issn.1005-3026.2020.10.019
    Abstract ( 941 )   HTML   PDF (644KB) ( 849 )  
    The concept of organizational resilience was defined by collating and summarizing the existing related theories and literatures, and the qualitative data was collected through an open questionnaire. The structure of organizational resilience was explored using the grounded theory, and the two dimensions of organizational internal resilience and organizational external resilience were refined, based on which an initial scale of organizational resilience was developed. The item analysis, exploratory factor analysis and confirmatory factor analysis were used to revise and verify the scale. Finally, an organizational resilience measurement scale with 15 items and good reliability and validity was obtained, which laid the foundation for subsequent research.
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    Analysis of Community Structures and Systemic Risks in China’s Stock Market Under Extreme Conditions
    LI Yan-shuang, ZHUANG Xin-tian, WANG Jian, ZHANG Wei-ping
    2020, 41 (10):  1500-1508.  DOI: 10.12068/j.issn.1005-3026.2020.10.020
    Abstract ( 587 )   HTML   PDF (809KB) ( 521 )  
    Two domestic stock market disasters in 2008 and 2015 were selected as the background to construct China’s stock market network community structures before, during and after the disasters. The node systemic importance index and the systemic risk index of stock market were constructed to analyze the core stocks, industries, stock portfolios and their changes within the network communities in each period, and to explore the correlation between systemic risks and network topological indicators and macroeconomic indicators. The results showed that the industrial sector suffer severe setbacks, and the raw materials, financial real estates, medical and health sectors play a role in protecting the market and repairing stock indexes during the stock market disasters. Three kinds of special community structures are found and some of them have a tendency to merge with each other. During the periods of extreme stock index fluctuations, the systemic risk of China’s stock market is significantly correlated with some network topological indicators and macroeconomic indicators.
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    Fuzzy Criteria Method of Level of Service for Bus Rapid Transit
    HUO Yue-ying, LI Wen-quan, LI Xiao-juan, CHEN Guo-qing
    2020, 41 (10):  1509-1516.  DOI: 10.12068/j.issn.1005-3026.2020.10.021
    Abstract ( 517 )   HTML   PDF (1061KB) ( 587 )  
    The method of establishing fuzzy levels of service (LOS) criteria for bus rapid transit (BRT) was developed, whose steps included classifying measures, constructing membership matrix and drawing membership function diagrams. Select arrival time, waiting time and bus speed as evaluation indicators. BRT passenger travel surveys were conducted using a self-developed transit travel survey system. Based on the data collected from the surveys, BRT fuzzy LOS criteria were established using the developed method. Some findings were concluded by comparing the hard LOS criteria currently used worldwide:fuzzy LOS criteria eliminate clear boundaries and use membership to reflect to what extent the measures belong to different LOS grades; the changes of LOS due to the changes of measure values can be reflected by continuous changes of membership, thus fuzzy LOS criteria can avoid the shortcomings of the hard LOS criteria.
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    Mathematics
    Lipschitz Continuity of Martingale’s Limit Density Function in Galton-Watson Processes
    HOU Wan-ting, ZHANG Mei-juan
    2020, 41 (10):  1517-1520.  DOI: 10.12068/j.issn.1005-3026.2020.10.022
    Abstract ( 769 )   HTML   PDF (301KB) ( 532 )  
    Considering the total number Zn of the n-th generation particles in the supercritical Galton-Watson process, let W denote the limit of martingale Wn=Zn/mn. Aiming at the Lipschitz continuity problem of the density function ω(x) of W, based on the Kesten-Stigum theorem, a more complete proof and supplement were proposed. A series of discussions on the limit properties of martingales were also conducted. First, the previous method of proof was modified, and it was obtained that in the case of δ≠1,ω(x) is Lipschitz continuous in [ε,), and the order is δ′=min(δ,1).When δ=1, the order of Lipschitz continuity of ω(x) is 1/2, thus ensuring the completeness of the conclusion.
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