Abstract:With the rapid development of society, it becomes a tendency to guarantee the safe train operation, improve the ride comfort and reduce energy consumption as well. Therefore, a holistic automatic train control system is of great significance. The core of automatic train control system lies in establishing an effective train model and designing an appropriate speed tracking controller. This paper introduces the main components and basic principle for automatic train control system. Then the dynamic modeling methods and speed control ap- proaches for trains are mainly induced and analyzed. Finally, the future research trend is presented.

Abstract:Hump shunting is a common way of shunting operations by using the gravity of a vehicle to carry out shunting operations, but derailment accidents often happen at the turnout zone of hump yard. In this paper, a test was designed in hump yard. The horizontal force and vertical force of the 6# ballast in the hump yard were test- ed under the three conditions of the multi-hook slide on the sunny day, the multi-hook slide besides friction control on the rainy day and the entire column slide besides friction control on the rainy day. The influence of marshalling mode on the vehicle derailment coefficient at the turnout zone of hump yard was also analyzed. The research results show that the derailment coefficient of empty vehicles is about 12% higher than that of the load vehicles. The impact of the mixed sequence of empty and load vehicles on empty vehicles and load vehicles are different. The sequence can change the derailment coefficient of load vehicles slightly. The sequence of empty and load vehicles should be selected according to different working conditions. The order of the load vehicles before the empty vehicles can reduce the derailment coefficient of the empty vehicles by 16% under the condi- tion of the friction control on rainy days. The entire column slide mode would greatly improve the derailment co- efficient of vehicles. For load vehicles, it is increased by 41%; for empty vehicles, it is increased by 38%. Then, long marshalling should be avoided. To ensure the safety of the vehicle and the efficiency of marshalling, it is recommended that 8 cars should be thrown each time. For daily maintenance work, the high rail and switch rail at the turnout zone should be paid more attention to.

Abstract:Previous studies have shown that the static side pressure of the granular goods transported by railway truck is a triangular linear distribution along the height of the loose particles, but the calculated results are often inconsistent with the actual results. With the development of computer technology, simulation analysis and nu- merical calculation become important research methods. Based on particle flow theory, the model of railway truck granule material was established. The static side pressure of granular goods with different bulk density and dif- ferent internal friction angle was simulated and analyzed. Then, the simulation value was compared with coulomb force, and the reliability of the simulation results was verified by experiments.

Abstract:According to the existing national codes Code for Design of High Speed Railway, Code for Design of Railway Station and Terminal and Code for Design of Metro, this paper analyzed the influencing factors for the distance between turnout and horizontal curve of rail transit in city region. The calculation methods and results of distance between turnout and horizontal curves of rail transit in city region were calculated by considering railway vehicle parameters of Wenzhou, target speed of the railway line, extra height and width of turnout con- nected with curves, turnout size and the structure of frog, line property of turnout laying, and the impacts of rail structure on distance between main line portion of turnout, auxiliary line turnout, yard track turnout and horizon- tal curves.

Abstract:The ANSYS and the ETABS were adopted to establish finite element model for the Ganjiang bridge in Fushan in this paper. The program compiled by MATLAB was applied to solve the dynamic equation of vehicle bridge coupling. The dynamic response and dynamic impact coefficient of large span continuous box girder bridge with corrugated steel webs under the action of vehicle speed and pavement serviceability were analyzed, and the obtained results were compared with the calculated value in accordance with the current codes. The re- search results show that the effect of vehicle speed on the impact coefficient of large span continuous box girder bridge with corrugated steel webs is complex, and the impact coefficient does not increase linearly with the in- crease of velocity. Besides, the worse the pavement condition is, the more obvious the influence of pavement ser- viceability on impact coefficient of bridge is. For the multi-span continuous box girder bridge with corrugated steel webs, as the vehicle speed and pavement serviceability remain unchanged, the impact coefficients of differ- ent main spans are different. It is suggested that the maximum impact coefficient of main span should be used to design this type of bridge.

Abstract:The later constructed railway may have great influence on the former constructed shield tunnel. For this case, the paper analyzed two types of foundation treatment measures, including cement mixing pile and pile- plank structure. According to the results of theoretical calculation and numerical simulation, the deformation of shield tunnel with cement mixing pile reinforcement is above the protection standard of subway while the defor- mation of shield tunnel with pile-plank reinforcement can control the deformation of the tunnel. The research may provide reference for similar projects in the future.

Abstract:To rationally optimize the location of logistics distribution centers, the related characteristics and ap- plication of Voronoi diagram were introduced to realize the dynamic division of the logistics node service range. Considering the influencing factors which affect the logistics node location, and giving the corresponding weight value, this paper established the improved P-median model, and built up the objective function with the mini- mum total service cost. Combining Voronoi diagram with the improved P-median model, based on dynamic ser- vice range division of the logistics node in the Voronoi diagram, the optimization algorithm of the model with Matlab programming was used to solve the optimal node location layout of the whole logistics system through continuous iteration. The research results show that the optimization method of logistics node based on Voronoi diagram is reasonable, which can make the total distribution cost minimum, reduce the logistics cost and improve the logistics efficiency.

Abstract:Chinese ports are in a critical period of transforming development and realizing the transformation and upgrading. It is an urgent demand for the development of ports to scientifically define the influencing factors of transformation and upgrading. However, the factors influencing port transformation and upgrading are complex, multi-layered and difficult to quantify. In this article, various influencing factors and their relationships were ex- plored comprehensively, and a structural equation model for the influencing factors of transformation and up- grading of ports was established based on the sampling data and the questionnaire survey. The effect of each in- fluencing factor on port transformation and upgrading was quantitatively analyzed. Besides, a set of key factors were set up. The conclusion may provide theoretical and decision-making basis for port transformation and up- grading.

Abstract:The focus for the current freight reform of national railway is to break down the boundaries not only between railway bureaus but also between railways and ports, thus dredging the regional railway freight channels and cutting down the energy consumption and the carbon emissions of rail freight. The profit allocation method is the key among various influencing factors for forming regional alliance of railway freight. Taking into account the irrationality during the profit allocation of regional alliance of railway freight, this paper firstly constructed a mathematical programming model based on the least square method, then solved the quadratic programming model to determine players’ imputations after the cooperation. Finally, a numerical example was given to show the applicability and advantages of the model and the proposed method.

Abstract:Public bikes (PB), a kind of transport, play an important role in improving public transit system (PTS) and promoting city development. According to shortcomings in previous researches concerning the selection and layout of rental stations (RSSL) for urban public bike system(PBS), this paper conducted some researches on the model. Then, on the basis of proposing the Gather Effect (GE), the Lag Effect (LE) and the Life Circle (LC), it developed a mixed-integer?programming model for RSSL problems so as to minimize the bilateral cost, which is subjected to the demand of renting and returning, turnover rate and weighted average walking of users. By solv- ing the model, the spatial position of rental stations may be actually set up, and the number of bikes and lock- stakes can be calculated.

Abstract:Large-scale compression test for the improved filler from blast furnace slag by the large direct shear apparatus was carried out, and the confining deformation modulus of different stages in the loading, unloading and reloading was obtained. The research results show that water content has little influence on the compress- ibility of the filler, as there are few fine particles in the filler and the coarse particles have good water stability. Compression in the first stage of loading mainly results from smash of edges and corners and breaking off of long flat shape particles. The settlement calculation of the foundation should refer to the deformation modulus at the stage of reloading when the foundation is constructed by dynamic consolidation. The content of fine particles should be increased for the improved filler from blast furnace slag to reduce stress concentration of coarse parti- cles and make the best use of coherence of the flyash.

Abstract:Tunneling in completely weathered granite and its residual soil ground with compressed air can pre- vent seepage of groundwater into the tunnel and improve the stability of tunnel face. However, some problems exist such as the air pressure control in head chamber, and it is necessary to evaluate the rate of air loss with shield method using compressed air. In view of compressed air tunneling for a subway tunnel in Guangzhou, ac- cording to the characteristics of gas and soil movement in the soil and considering the strongly nonlinear of air and water conduction function in unsaturated soil, a three-dimensional finite element seepage model of layered homogeneity and isotropic soil was established by using TOUGH2 software. The basic rule of gas and water mi- gration in the stratum with A-EPB shield method was revealed. The research results show that an unsaturated zone has been formed and this zone progressively develops with time until it connects with the surface and forms a funnel shaped steady seepage channel. The calculated air losses are within the range from the field date, which verifies the rationality of this model. Finally, an exponential relationship has been conducted between permeabil- ity coefficient of soil and quantity flow of air seepage, and the air injection quantity of different soil layers has been suggested.

Abstract:The current researches of coating cracking control of laser deposition were reviewed in this paper. The characteristics of coating cracking control methods were analyzed in details. Based on the mechanism of coating crack, the cracking control methods can be divided into stress control, coating strengthening and double control on the strength and stress of coating. It maintains that the composite laser deposition method can be considered as an effective method for coating cracking control.

Abstract:This paper presented a prediction method based on the regression sliding average (ARMA) model to achieve the vibrational data prediction of rolling bearings. Firstly, the early failure data of the full life cycle for the rolling bearings were selected as samples to calculate the autocorrelation coefficient and the deviation corre- lation coefficient of its truncated sequence. Then, the minimum information criterion (AIC) was adopted to order the ARMA model. By using the least square estimation parameter, the ARMA model was established. And the bearing data under the same and similar working conditions were input to the established ARMA model. The comparison between prediction data and the actual failure data was made to calculate the prediction accuracy. The research results show that this method can accurately predict the actual state of the bearing and the predic- tion result of the same working condition is better than that of the similar working condition.

Abstract:In view of the fact that the existing phase mode transformation matrix can not satisfy the decoupling calculation of the multi-line system of the traction network with the line frequency parameters, this paper pre- sented a method of calculating the phase mode transformation matrix, i.e. the approximate iteration of the eigen- vector was realized by the LM (Levenberg-Marquardt) algorithm based on the mathematical relationship between the eigenvector and the eigenvalue. The research results show that the smooth continuity of the phase mode transformation matrix in the frequency domain can be guaranteed, and the feasibility and accuracy of the method are verified through the phase velocity obtained by other phase matrix transformation methods.

Abstract:Aiming at the problems of software encryption including the excessive use of host system resources, complex data processing, and slow encryption speed, a method of hardware encryption was proposed. Hardware encryption has the advantages of low cost and fast encryption speed, which can reduce the burden of CPU and improve service performance. By using Vivado 2016.3 development tools and Verilog HDL hardware description language, this paper completed the SMS4 algorithm design input, functional testing and timing simulation, and encapsulated them into independent IP core. The testing system was designed on ZYNQ chip, the user-defined IP was called through ARM processor and the verification of the algorithm in actual application was finished. The research results show that the designed algorithm has the correct function and good performance. In the ac- tual hardware test process, the algorithm is running correctly with the maximum working frequency of 200 MHz and the data throughput rate of 800 Mbps.

Abstract:To obtain better structural performance by exploiting the advantages of different materials, a topologi- cal design method of thermo-mechanical coupling structure using multiple materials under non-uniform temper- ature field is proposed in this study. The objective function was developed by minimizing the strain energy to satisfy the stiffness requirements, and the structure volume was restricted. The multi-material topology optimiza- tion model of thermo-mechanical coupling structure subjected to non-uniform temperature field was also estab- lished. The sensitivities of the objective function and the constraint were solved by the adjoint matrix approach. The Heaviside filter technique was adopted to modify the sensitivities in to avoid the phenomenon of numerical instability and the method of moving asymptotes was used to solve the topological optimization problem. The nu- merical examples were given to illustrate that the proposed method is correct and effective.

Abstract:The experimental process of extracting furfural from walnut nutshell powder by using the two -step method was studied in this paper. Firstly, the xylose extract was obtained by acid hydrolysis. Then, the influence of the single factor including the liquid ratio to material, hydrolysis reaction time and hydrolysis reaction temper- ature on the extraction rate of xylose was explored. Then, the above hydrolysis reaction was optimized by the combination experiment of the Box-Behnken center and response surface methodology based on the single factor. The optimum reaction conditions are found as follows: the ratio of the reaction liquid to the material is 24.48 mL/ g, the reaction time being 3.17 h, and the reaction temperature is 119.92 °C. The furfural was obtained from the above xylose extract using carbon -based solid acid catalyst at the second step with the furfural yield up to 15.74%. The experimental results provide theoretical and experimental basis for the high value-added use of walnut nutshell.

Abstract:To study the autobiographical digital characteristics of random process and its expansibility, the rela- tionship among process elements was analyzed by using the principle of extended analysis of primitives. By con- sidering features of process element and the correlation and implication on these features, this paper concluded that when the amount of a characteristic in the process element changed, the value of other features in the pro- cess element would bring about conduction transformation, which produced the concept of the conduction corre- lation function and the self covariance function. The case study of the carrier landing system shows that this method provides possibility for solving a class of contradictory problems involving digital characteristics of ran- dom process.

Abstract:Aiming at the problems of low efficiency, long cycle time and high cost for traditional single car brake experiment training, this paper designed and developed a single car brake training system of virtual and reality combination based on Unity3D engine. Taking C64 single car as the object, by using Maya software to build a model and adopting NGUI, DoTween animation, C # and other plug-ins and scripting languages, it created a three-dimensional virtual interactive environment. Meanwhile, the single-chip technology and the serial commu- nication technology were adopted to establish the single car brake experimental training system of virtual and re- ality combination with the simulation of a single car tester and brake experiment as the core. The research re- sults show that compared with the traditional single car brake experiment training method, this system has good operation convenience and learning efficiency, which can meet the needs of users for single car brake experiment training.