Table of Content

25 November 2019, Volume 47 Issue 11

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Traffic & Transportation Engineering

Effects of Guide Distance and Initial Speed on Driving Behavior at Expressway Exit



FU Xinsha DU Jintao HE Shijian

2019, 47(11):  1-9.  doi:10.12141/j.issn.1000-565X.190032

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The influence of guide distance and initial speed on driving behavior is directly related to the traffic safety in expressway exit． In order to analyze the effects of different combinations of the two factors on driving behavior，na- turalistic driving experiments under nine combination conditions were carried out on the exit section of a mountainous expressway service area with the design speed of 100 km/h． The combination conditions contained three kinds of exit guide distances ( 700，500 and 300m) and three initial speeds ( 110，100 and 90 km/h) ． The driving behavior cha- racteristic parameters such as the speed at the portal of the starting of deceleration lane，the maximum deceleration and the starting position of lane-changing behavior，were collected and analyzed． The results show that both the exit guide distance and the initial speed have a significant effect on the speed at the portal of the starting of deceleration lane，which is 8 ～18km/h lower than the design speed under all combination conditions． The maximum deceleration is significantly affected by the initial speed but not by the exit guide distance． When the exit guide distance is 700m and the initial speed is 100km/h or 110km/h，there is a twice deceleration phenomenon which differs from that under other conditions． Exit guide distance is the key factor to influence the starting position of lane-changing behavior． Specifically，when the exit guide distance is 300m，the initial speed could obviously influence the starting position of lane-changing; while the influence became less obvious as the exit guide distance increase． The results can provide a reference for understanding the changing rules of expressway driving behavior and optimizing export design．

Experimental Investigation into Vehicle Drag Deduction Based on Plasma Flow Control



HU Xingjun, HUI Zheng, GUO Peng, et al

2019, 47(11):  10-15.  doi:10.12141/j.issn.1000-565X.180514

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A dielectric barrier discharge ( DBD) plasma actuator was placed near the flow separation point at the end of the 25° Ahmed automobile model． Through wind tunnel test，the effects of different excitation voltages on the aerodynamic drag coefficient of the model when the excitation frequency was 9 kHz，the maximum drag reduction rate when the wind speed was 10 ～ 25 m /s and the optimum excitation voltage corresponding to this time were stu- died． The flow field map measured by PIV and the pressure value of the tail bevel measured by PSI pressure scan- ning system shows that when DBD is switched on，the flow velocity around the exciter and near the wall surface of the inclined surface is increased，the tail flow separation area is decreased，and the pressure at the pressure mea- surement point on the tail bevel is increased． According to the measurement results of the balance sensor，the maxi- mum drag reduction rate ( 7． 28% ) can be obtained when the experimental wind speed is 15 m /s and the corre- sponding optimal excitation voltage is18． 5 kV． The DBD exciter has an effect of drag reduction by reducing the pressure drag of the model． With the increase of the excitation voltage，the aerodynamic drag coefficient presents a tendency that decreases first and then keeps steady． Therefore，there was an optimum excitation． With the increas- ing wind speed，a higher excitation voltage is required to achieve a better drag reduction effect．

Road Friction Condition Identification Based on Tire Lateral Stiffness Estimation



LIN Fen, ZHANG Huada, ZHAO Youqun, et al

2019, 47(11):  16-24.  doi:10.12141/j.issn.1000-565X.180433

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Accurate and real-time access to road adhesion information is the premise of the operation of the vehicle active safety control system． The roughness and wet condition of road have great influence on lateral stiffness． Based on this，road adhesion condition can be identified by estimating the lateral stiffness of tire under the steady- state cornering． First，the lateral force and slip angles of front and rear axle were obtained from the two-degree-of- freedom vehicle model． Considering the load transfer，the vertical tire vertical force was obtained． With the diffe- rence between the front and back axes，the sideslip angle which is more difficult to get was eliminated． Finally，the normalized tire lateral stiffness was estimated by the recursive least square method，and the estimated results under different road adhesion conditions were compared． Different from previous lateral stiffness estimation methods，the proposed method does not need to measure or estimate the sideslip angle，so it does not need expensive extra sen- sors． Moreover，the influence of load transfer on the estimation of cornering stiffness was taken into account． The proposed algorithm was verified through simulation and electric model vehicle road test． The simulation and experi- mental results show that the proposed identification algorithm can identify the road adhesion conditions when consi- dering load transfer．

Short-Turn Vehicles Departure Strategy Considering Ｒeliability of Bus Operation



YAN Hai LIU Ｒunkun

2019, 47(11):  25-32,43.  doi:10.12141/j.issn.1000-565X.190154

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The operation of short-turn buses will affect the operation state of full-length buses． The reliability of bus operation system can be improved by properly designing a short-turn departure strategy． Given the operation of short-turn buses，a bus operation state model was established． And the departure strategy was designed with the cu- mulative sum ( CUSUM) method． In addition，based on the real-time IC data of bus No． 973 in Beijing，the influ- ence of different short-turn bus departure strategies on the operation state of full-length buses and passenger's average waiting time were studied by numerical simulation method． The simulation results show that the bus depar- ture strategy developed by this method can not only improve the bus operation reliability，but also greatly reduce the passenger＇s average waiting time; improper departure time arrangement have a negative impact on the operation reli- ability of other full-length vehicles．

Longitudinal Stimuli-Based Classification and Ｒecognition Method for Driving Styles



SUN Bohua, DENG Weiwen, HE Rui, et al

2019, 47(11):  33-43.  doi:10.12141/j.issn.1000-565X.180618

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A research on longitudinal stimuli-based classification and recognition for driving style were carried out to make Advanced Driver Assistance System ( ADAS) work in a more human-like or personalized way and to im- prove the safety and comfort for intelligent vehicles． Six typical longitudinal driving stimuli of the leading vehicle were designed based on the periodicity and mutability of the leading vehicle's speed，and data collection for 64 dri- vers was conducted in field test． The corresponding driving style was defined and classified by combining particle swarm optimization clustering ( PSO-Clustering) method with subjective questionnaire． The optimal longitudinal stimulus set，the Sine NO． 3 and Step NO． 3，was obtained by comparing the classification results under different stimulus． The recognition model for driving styles based on the multi-dimension Gaussian hidden Markov process ( MGHMP) was modeled． And the optimal model input set was obtained based on the recognition accuracy and key parameters were optimized by the orthogonal test method． Ｒesults show that the longitudinal stimuli based classifica- tion and recognition for driving styles can achieve better classification and identification accuracy．

Real-Time Optimization of Equivalent Factor for Plug-in Hybrid Electric Vehicle



YAO Mingyao ZHANG Xiaoxing QIN Datong

2019, 47(11):  44-53.  doi:10.12141/j.issn.1000-565X.190066

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The real-time optimization method of adaptive equivalent factors was studied，in oder to achieve a SOC balance and reduce fuel consumption and thus further improve the fuel economy of plug-in hybrid electric vehicles． The driving cycle NEDC was taken as an example and was decomposed into different basic driving-cycle block． The relationship curves between the equivalent factors and fuel consumption and SOC variation of each basic driving-cy- cle block were linearly fitted． The real-time optimization problem of equivalent factors was transformed into a simple linear programming problem，and the real-time optimization model of equivalent factors based on linear program- ming was constructed． Then a adaptive equivalent fuel consumption minimization strategy ( A-ECMS) based on li- near programming was proposed． Hardware-in-loop tests show that the real-time optimization method of equivalent factors based on linear programming model can meet the real-time online control requirements of vehicle controller， and it is feasible to apply it in real vehicles． The test and simulation results show that A-ECMS based on linear pro- gramming model can maintain a SOC balance and achieve a fuel economy which is close to the global optimal energy management strategy under different operating conditions． It verifies that the real-time optimization model has prac- tical application value and potential．

Brittle Nodes Identification of Navigation System in Traffic Flow Intensive Waters in Emergency Situations



CHEN Yongjun, LIU Qing, WAN Chengpeng, et al

2019, 47(11):  54-61,70.  doi:10.12141/j.issn.1000-565X.190007

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In order to improve the emergency response ability in the traffic-intensive waters，a brittle node identifi- cation method for navigation system based on different attack strategies was proposed． Firstly，based on the original mapping method，the topological structure of the navigation system in traffic-intensive waters was modeled，and the network topology statistical characteristics of the navigation system were analyzed． Then the brittle node of the sys- tem was identified by analyzing the changes of global network efficiency in traffic-intensive waters under different at- tack strategies． Taking the navigation system of the Yangtze Ｒiver estuary as an example，a case study on the brittle node identification of the traffic flow in traffic-intensive waters was carried out． The research results show that the identification of the brittle nodes of navigation systems in traffic-intensive waters with the complex network method and the analysis of the nodes and brittle nodes of navigation system under different attack strategies can effectively identify the key vulnerabilities that affect the reliability of the ship navigation system． By effectively pre-controlling the identified key nodes and routes，it can help to reduce the vulnerability of the whole navigation system．

Biotechnology

Asymmetric Oxidation of Ｒacemic 1-Phenyl-1，2-Ethanediol Using Immobilized Kurthia gibsonii SC0312 Cells in DESs-Containing System



LOU Wenyong ZHAO Ying PENG Fei

2019, 47(11):  62-70.  doi:10.12141/j.issn.1000-565X.190101

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Highly efficient asymmetric oxidation of racemic 1-phenyl-1，2-ethanediol ( PED) was successfully con- ducted to prepare enantiomerically pure ( S) -PED with immobilized Kurthia gibsonii SC0312 cells in non-aqueous system containing DESs． Among the 4 kind of tested ionic liquids and 2 kind of deep eutectic solvents，［ChCl］［U］ manifested better biocompatibility with Kurthia gibsonii SC0312 cells，and it can appropriately change the cell membrane integrity，thereby effectively improve the catalytic efficiency of this reaction． When ［ChCl］［U］content is 4% ( volume fraction) ，buffer pH is 7． 5，reaction temperature is 35 ℃，cell concentration is 60 mg /mL，and substrate concentration is 100 mmol /L，the initial reaction rate reaches 8． 25 mmol /( L·h) ，and after 7 hours' re- action，the yield rate and ( S) -PED e． e． value reach 49． 6% and 99． 9% ，respectively．

Application of Sequence Alignment-Free Comparison-Based SeqDistK to Microbial Flora Clustering



LIU Xuemei HUANG Guanda HUANG Tianlai

2019, 47(11):  71-77.  doi:10.12141/j.issn.1000-565X.190224

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Using sequence alignment-free comparison method to study microbial flora classification is a hot topic in bioinformatics． In this paper，SeqDistK，the sequence alignment-free comparison software based on k-mer statis- tics，is presented． The open source software package can be obtained from https: ∥github． com /htczero /SeqDistK． SeqDistK has the advantages of fast calculation and high accuracy in microbial flora classification，and has the po- tential to adapt to large-scale data research． By adopting SeqDistK to cluster 63 distance matrices of 16S rＲNA gene sequences，it is found that the clustering results are basically consistent with the existing classifications，which means that SeqDistK can accurately classify microbial flora clustering samples and provides effective software for phylogenetic analysis in molecular biology．

Coexpression Analysis of Gene Pairs with Protein-Protein Interaction in Cancers



MENG Yuhuan, BAI Yunmeng, CUI Ying, et al

2019, 47(11):  78-88.  doi:10.12141/j.issn.1000-565X.180374

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The relativity of protein-protein interaction ( PPI) can be reflected by the gene coexpression correlation． The study of global PPIs in cancer cells or tissues will facilitate the understanding of the relationship between geno- types and phenotypes，as well as the mechanisms of cancer development in normal and abnormal cells or tissues． The mRNA expression profile data and clinical information was collected from the Cancer Genome Atlas ( TCGA) ，including 5726 samples across 11 human cancers type． Combining with PPI gene pairs of Human from STRING and HPRD databases，Pearson correlation coefficients ( PCC) was used to calculate the gene coexpression coefficients of tissue-specific PPIs in normal samples and cancer samples at different stages，and then the cancer-disordered and cancer-specific PPI gene pairs were obtained． With the different gene expression and survival analysis，PPI gene pairs which may affect the development of cancer were found out． Result shows that: the gene coexpression coeffi- cient of PPI gene pairs in cancer samples is significantly lower than normal samples． There are 2812 pairs of can- cer-disordered PPI genes，among which LRSAM1，ATXN1，SMAＲCC2 and SMARCA2 appear in multiple cancers interacted and clustered into a network module，and they may play an important role in caner． There are 31 pairs of cancer-specific PPI genes，among which BMP1 and COL1A1 may interact to promote tumorous migration and infil- tration． In addition，113 pairs of PPI genes with differential expression were selected from cancer-disordered and cancer-specific genes． Among them，16 pairs show significantly survival difference in 7 cancers．


Architecture & Civil Engineering

Modified TCK Constitutive Model Applied to Inorganic Glass Materials



WEI Demin LI Dong

2019, 47(11):  89-94.  doi:10.12141/j.issn.1000-565X.190036

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The Taylor-Chen-Kuszmaul model，which is rate dependent and used to ceramic material，was modified and applied to glass materials so as to investigate the tensile damage characteristics of inorganic glass materials un- der impact loads． The modified TCK constitutive model was used to simulate the edge-on impact test of glass plate． Simulation results show that the modified TCK constitutive model can accurately simulate the propagation velocity of the stress wave，the size and location of the damage area，and the damage propagation velocity of glass materials．

Calculation Model and Empirical Investigation of Thermal Balance of Pervious Ground



LUO Jianhe, LIAO Xiaoqin, SHI Gang, et al

2019, 47(11):  95-103.  doi:10.12141/j.issn.1000-565X.190198

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Pervious ground temperature is difficult to estimate because it can be affected by many factors，such as solar radiation，surface convection heat transfer，evaporation and heat dissipation． Based on the heat and humidity control equation，the heat transfer process between the permeable surface and the surrounding environment was nu- merically analyzed，and the hourly temperature calculation model at different depths of the permeable surface was deduced． Then the calculation program was compiled to calculate the permeable surface temperature． The calcula- ted temperature was compared with the measured surface temperature． The results show that the numerical calcula- tion value is basically in accordance with the measured value，and the maximum relative error is less than 3． 5% ． the study shows that the derived numerical method can be used as an effective method to predict the permeable sur- face temperature． Based on this，the equivalent solar radiation absorption coefficient concept is proposed，which can be directly used to evaluate the solar heat gain of permeable surface with different water content．

Optimal Arrangement of Dampers Based on Coarse-Grained Parallel Genetic Algorithm



MA Hongwei CHEN Fengshou

2019, 47(11):  104-112.  doi:10.12141/j.issn.1000-565X.190051

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A coarse-grained parallel genetic algorithm was proposed to optimize the damper arrangement in passive controlled structures． According to the algorithm，a population is divided into several sub-populations，which can independently complete the operation of genetic algorithm． For a given gene coding individual，the INP model files are firstly generated，numerical analysis is conducted in ABAQUS environment and the result data is read and transmitted in Python environment by using Matlab programming． Through the interactive use of Matlab-ABAQUS- Python，the value of objective function is figured out． A 10-story passive-controlled steel frame structure is selected as the research object，and the optimal design of damper arrangement is conducted by taking the inter-story drift an- gle as the control objective． The results show that the algorithm can not only improve the diversity of population compared with the classical genetic algorithm，but also accelerate the convergence speed of population． Compared with the results of the structure with the dampers placed in every two storeys，the inter-story drift reduction ratio of the structure equipped with the new algorithm can be increased by 19． 3% ，which indicates that the seismic re- sponse reduction ratio of the structure is greatly improved by using the algorithm．

Compressive Behavior of Plate-Ｒeinforced Square Hollow Section T-Joints



CHANG Hongfei, ZUO Wenkang, REN Tenglong, et al

2019, 47(11):  113-121,139.  doi:10.12141/j.issn.1000-565X.180636

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A series of finite element models were established and verified to study the compressive behavior of doubler or collar plate-reinforced square hollow section T-joints． The influence of the width of the brace and the thickness of the reinforcement plate was investigated． The control failure modes as well as the design formulas of the compressive capacity of reinforced T-joints were summarized． The parametric analysis indicates that the width of the brace and the thickness of the reinforcement plate are key parameters that influence the compressive behavior of doubler and collar plate，and they also determine the failure mode of the reinforced T-joints． When the width ratio of brace and chord exceeds 0． 8，or the thickness ratio of plate and chords more than 2． 2，the failure of the joint is dominated by the buckling of the chord side wall． Under this condition，it is unnecessary to further increase the thickness of the reinforcement plate． The proposed novel reinforcement method with collar plate is efficient to rein- force the flange and side wall of the chord，thus to prevent or delay the side wall buckling of the chord． The exist- ing design formulas from the literatures were finally introduced to calculate the compressive capacity of the plate re- inforced joints，and the applicability of each formula is checked and discussed

Static Elasto-Plastic Analysis of Tensegrity Structures Based on Co-Ｒotational Formulation



FENG Xiaodong, LUO Yaozhi, DING Yi, et al

2019, 47(11):  122-129.  doi:10.12141/j.issn.1000-565X.180557

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To investigate the static elasto-plastic properties of tensegrity structures，an efficient finite element me- thod—co-rotational ( CＲ) formulation，which is suitable to solve large rotation and small strain problems，was in- troduced． Large displacement of a space rod element was decomposed into a rigid body motion in the global coordi- nate system and a pure small deformation in the local coordinate system． A new form of tangent stiffness matrix was derived based on the proposed approach． An incremental-iterative solution strategy in conjunction with the Newton- Ｒaphson method was employed to study the geometrical nonlinear elasto-plastic properties of a quadruplex tensegrity unit． Ｒesearch results shows that the CＲ approach is computationally more efficient than the traditional TL and UL formulations． The rigidity of lower“fibers”is larger than that of upper“fibers”in the quadruplex unit． With the increase of the self-stress coefficient，the tensegrity unit becomes stiffer，and this is more obvious when the struc- ture is under compression than under tension． Compared with the elasto-plastic response of structure，the self-stress coefficient plays a more important role in elastic responses．

Experimental Investigation into Dynamic Elastic Modulus and Damping Ｒatio in Transient Saturated Zone of Ｒed Sandstone Residual Soil Subgrade



DING Yu, CHEN Xiaobin, WANG Xuan, et al

2019, 47(11):  130-139.  doi:10.12141/j.issn.1000-565X.190091

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The red sandstone residual soil subgrade after a continuous rainfall will form a transient saturated zone， and the soil backbone curve，dynamic elastic modulus and damping ratio are the key factors for analyzing the dy- namic characteristics of the subgrade． In order to study the dynamic characteristics of red sandstone residual soil subgrade in transient saturated zone under heavy-haul train load conditions，dynamic tri-axial tests were carried out with sand and different content of red clay remolded soil samples． The effects of fines content and confining pressure on backbone curve，dynamic elastic modulus and damping ratio of soil in transient saturated zone were discussed． The results show that: the backbone curve of sand with fines content conforms to Konder hyperbolic model; the in- fluence of fines content on the dynamic elastic modulus and damping ratio is not monotonic，but there is a threshold ( about 20% ) ; the variation trends of dynamic elastic modulus and damping ratio negatively related with fines con- tent around the threshold; confining pressure has a significant effect on dynamic elastic modulus and damping ratio of soil: with the increase of confining pressure，the dynamic elastic modulus increases and the damping ratio de- creases．

Study on the External Excitation Input Methods for Porous Medium



HU Dan, ZHANG Kaiyin, SUN Liang, et al

2019, 47(11):  140-146.  doi:10.12141/j.issn.1000-565X.180628

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The numerical methods have been widely used to solve the structure-foundation interaction problems in which the semi-infinite medium simulation and the external excitation input method are of most concern． The com- monly used external excitation input methods include the wave method，the artificial boundary substructure method and the domain reduction method ( DＲM) ，etc． Firstly，the applicability of different wave input methods for single- phase media e are compared by virtue of FLAC3D and Matlab，and the results show that the free field response ob- tained by the DＲM method match well with the one-dimensional analytical solution． Further，the artificial boundary substructure method and DＲM method are applied to porous medium，respectively，and the formula to transfer ex- ternal excitation into equivalent force and equivalent discharge are proposed． Finally，the feasibility of two methods are compared and verified with the elastic semi-infinite saturated foundation response under the effect of vertical seismic wave． The results indicate that the free field response value obtained by the DＲM method is consistent with the one-dimensional analytical solution，however，the response value obtained by the artificial boundary substruc- ture method is much smaller．