Abstract:This paper discusses the progress of ultrasonic cleaning technologies in theoretical research and equipment application. Firstly， the observation of cavitation effect， the motion characteristics of cavitation bubble and the measurement of cavitation intensity in ultrasonic cleaning are discussed， and the effects of frequency， power， temperature and other factors on the effect of ultrasonic cleaning are mainly introduced from numerical simulation and experimental analysis. Then， the research on the directivity and impedance matching of transducer in cleaning equipment and the research status of frequency automatic tracking technology in recent years are discussed， and the application of different ultrasonic cleaning technology in various fields is introduced. Finally， in view of the existing problems in the research of ultrasonic cleaning technology， the paper puts forward the future research suggestions of ultrasonic cleaning technology and the direction of equipment development.

Abstract:Mobile rail profile detectors can obtain high-precision three-dimensional image of rail shape with accurate mileage position by measuring the whole section rail profile continually and frequently. However，there is no exiting mature method to use these data for accurate rail grinding. The paper proposes an accurate method for rail grinding based on data measured with high frequency，getting an accurate scheme of rail grinding in the whole test region through fine partition of rail head and segment of mileage after obtaining the curve of grinding amount varying with mileage by comparing the measured profile with the target profile. The method was proved by field test on Beijing-Shanghai high-speed railway of Shanghai Hongqiao Station Line，which achieved accurate rail grinding. Finally，a PSI (profile similarity index) is put forward to evaluate the quality of rail grinding. The results show that PSI can quantify the similarity between the measured profile and the target one，and evaluate the grinding quality directly and accurately.

Abstract:Based on the overhaul operation of CRTSI slab replacement by rail lining of Shanghai-Nanjing intercity passenger dedicated line, a three dimensional finite element model of the high-speed railway rail-fastening coupled systemis established. The validity of the modelwas verified by comparing the simulation results with the field measured data, and the model was used to investigate and analyze the influence of the temperature difference between the constructed rail and the locked rail on the stress and deformation of the rails in the straight segment and the curved segment with a radius of 7000m. According to the temperature difference-stress variation obtained from the model analysis, based on the rail allowable stress limit of 377.78 MPa, in the straight segments, the temperature difference between the construction rail and the locked rail should be in the range of-33.46~43.95 °C, in the curved segments, temperature differenceshould be in the range of -23.35~42.78 °C of inner railand -25.69~39.08 °C of outer rail.

Abstract:With the continuous increase of subway lines in China，infrastructures such as reinforced concrete and buried pipelines are widely used in subway systems. The leakage of stray current in the subway will cause serious damage to the infrastructures，and the corrosion of concrete reinforcement and buried metals deserves high attention of the urban operation and maintenance departments. This paper introduces the current status and progress of researches on stray current metal corrosion at home and abroad from the aspects of metal corrosion and stray current modeling under stray current. Finally，the system comparison and prospect of the stray current modeling schemes are discussed.

Abstract:The existing damage identification methods are faced with the problem that the processing capacity of a large number of bridge health monitoring data is limited and the extracted information cannot fully reflect the health status of the bridge. Based on the advantage of deep learning in big data，a method of bridge structure damage location identification based on stacked denoising auto-encoder is proposed. The method is verified by a finite element model of a simply supported beam bridge. The vertical acceleration time history response value at L / 5，2 L / 5，3 L / 5，4 L / 5 of the bridge are extracted. The acceleration matrix (4 x 1) at every moment is established，then the preprocessed matrix is sent to the stacked denoising auto-encoder for feature extraction to complete the model training. Finally，the test samples are sent to the model for classification to complete the task of damage location identification. The results show that the proposed method has the advantages of high positioning accuracy and good anti-noise performance compared with the traditional machine learning method，and has certain reference value in the field of bridge structure damage identification in the future.

Abstract:Track irregularity is the main source of train vibration, which has a direct impact on the safety of train operation and passengers’comfort. On the basis of measured track irregularities, combined with the structural characteristics of high-speed maglev TR08 vehicle and the basic principle of deep neural network, TensorFlow neural network is used to characterize the relationship between track irregularities and vehicle vibration accele ration. In this paper, a method of detecting irregularities by measuring vibration acceleration and constructing neural network is proposed. The research results show that the relative accuracy of the predicted track irregularity value and the real value by the depth neural network is more than 99%, and it can measure the height and level irregularity at the same time, which provides a theoretical basis for the new method of track irregularity measurement.

Abstract:In order to better deal with the local disasters of urban road network, it is necessary to evaluate the resilience of urban road network. The concept of the resilience of road network was summarized based on the literature reviews of relevant published papers. According to topological structure and traffic characteristics of the road network, the concept “resilience indicator of road network” (RIRN) was proposed, and two quantitative methods were given: (1) Based on the complex network theory, the characteristics of the topological structure of urban road network was analyzed and a topological index was structured associated with node degree, intermediate centrality and closeness centrality;(2) Meanwhile, a traffic index was structured associated with traffic volume and surplus saturation degree. A calculating method of RIRN was proposed and applied to the network in Jinshan Area of Fuzhou, China, for purpose of illustration. This paper highlights the effects of traffic characteristics on the resilience of road network and extends the research method in planning urban road networks, traffic management and disaster prevention.

Abstract:Flat organization structure is an important means to improve the management efficiency of railway freight car production enterprises. This paper uses the structure entropy model to analyze the order degree of the traditional organization and the flat organization structure, and calculates the time-efficient entropy sum of the two organizational structures. It is found that the flat entropy and quality entropy of the flat organizational structure are higher than those of the traditional organizational structure. The actual operation shows that the flat organizational structure can be restructured by rebuilding the salary distribution system, integrating relevant functions, improving the production rhythm, and reducing the production employment, which can solve the problem of imbalance in salary distribution among enterprises and some overlapping management functions among departments and workshops, thus reducing manufacturing costs.

Abstract:The competition and cooperation of radiation domain reflects the competitiveness of the airports in the multi-airport system. Based on Lotka-Volterra model, this paper studies the competition equilibrium of the cross hinterland for the regional multi-airport system. Taking the comprehensive strength of airports as the influencing factor, the market share of each airport in the cross hinterland is selected as the dependent variable to solve the competitive stable state and the required conditions between the two airports. Taking the cross hinterland of Nanjing Lukou Airport and Hangzhou Xiaoshan Airport in the Yangtze river delta airport group as an example, the numerical simulation is carried out. The results show that when the comprehensive strength ratio of the two airports is greater than the demand of the corresponding airport in the hinterland cross region, the two airports achieve the competition equilibrium in the cross region of the radiation domain.This provides a theoretical analysis method for an airport to improve its competitiveness in a regional multi-airport system.

Abstract:The railway logistics center is the hub connecting the railway freight and the outside world. Its internal layout is related to the efficiency of the operation of goods in it, which has a crucial impact on the fluency of the entire railway freight. Based on the functional division of the railway logistics center, this paper compares and analyzes the layout method of the functional area, and proposes a functional area layout method based on improved SLP. Taking the maximum mutual relationship and the minimum overall transportation cost as the optimization goal, the two aspects of the function are constrained, the multi-objective optimization model is established, and the NSGA -Ⅱ is used to solve the problem, and the optimal solution set is obtained. Finally, the AHP fuzzy comprehensive evaluation method is used to compare and evaluate, and the optimal layout scheme is selected. Taking the S city railway logistics center as an example, the scientific and feasibility of the method are verified.

Abstract:Based on DEA, this paper evaluates the matching of urban rail transit stations and analyzes the influencing factors. Five non-transfer stations of urban rail transit in Dalian were selected as the research objects, relevant data were obtained through field investigation, and the matching of station facilities and equipment were analyzed. The results showed that the main reasons for the low comprehensive efficiency of station facilities were insufficient passenger flow output and waste of resources in the station equipment and facilities. By analyzing the sensitivity of the index, it is concluded that the number of escalators, the width of stairs and the matching degree of the capacity of escalators have an impact on the matching degree of urban rail transit stations, among which the width of stairs has the greatest influence.

Abstract:Point merge system(PMS)， a new approach flight procedure proposed by the European Control Experiment Center in 2006, has attracted extensive international attention. The design applications of point merge system are summarized in this paper. Firstly, the elements of point merge system are introduced and its design parameters are analyzed from the aspects of height, speed, angles and distance. Secondly, the global cases of point merge system are reviewed. The actual design parameters and design principles are explored and the implementation effect of point merge system is summarized. The future development trend of point merge system is speculated from multilayer point merge system, point merge system based on CDA and point merge system based on 4D track.

Abstract:In order to realize the accurate simulation of concrete crack propagation, a two-dimensional concrete mesoscopic modeling method based on the geometric of actual aggregate is proposed. The method obtained actual aggregate geometric by image processing, and formed the random growth of actual aggregate through the random movement of aggregate contour points in the plane. In addition, the front polygons-rear circumcircle criteria was proposed, which simplified the conflict and overlap process between complex polygons. Using this method, threepoint bending beam tests were carried out to analyze the influence of aggregate shape on crack propagation and macroscopic properties. The results show that the larger the aggregate ovality is, the smaller the bending ultimate strength of the beam is, and the more obvious guiding and blocking effect is.

Abstract:In this paper, a pneumatic active accompaniment deburring tool design is proposed, and the modeling simulation and experimental comparison analysis is carried out. The designed tool is actively controllable in both axial and radial direction. Linear pneumatic actuators are used to control axial forces and integrated with linear encoders to measure the axial height. The radial force control is achieved by pneumatic ring driver integrated with angle sensor and two compliant systems realize hybrid control through a universal joint structure. The dynamic modeling and analysis of the tool are carried out and the Arruda-Boyce constitutive model is adopted according to the hyperelasticity theory. The axial and radial stiffness are determined based on the force exerted on the tool tip and the displacement caused by the force. The stiffness simulation is performed by ANSYS Workbench and the simulation results are verified by experiments. It is proved that the deburring tool can float freely during operation, has active compliance, and can also provide the corresponding stiffness according to the pressure in the axial and radial directions that can reduce the vibration and interference in the operation and ensure the machining accuracy.

Abstract:The multi-Agent system can effectively solve distribution problems, and the electric power system belongs to the distributed structure. This paper takes the intelligent substation as the research object, combines the Agent technology with IEC61850 standard, and analyzes how the Agent technology is used to solve the possible conflicts of IEC61850 communication. In the same LAN, IED device is used as Agent to avoid communication confusion by implementing multi-Agent autonomous algorithm coordination system, setting message filtering and creating polling Agent. Between different LANs, the complex distributed communication problem of substation is solved by using TCP/IP protocol to transmit messages, which has high practical value.

Abstract:In the traditional way, the structural analysis and optimization of the complex shield cutter parameterization model requires a lot of manual intervention, and the whole analysis process is tedious and inefficient. Aiming at this defect, the parameterized design and automatic analysis and optimization method of the cutter head structure are proposed. Based on the parameterized shield cutter head modeling system, through the simplified rules and evaluation criteria, the parameterized model of the shield cutter head was automatically simplified. The secondary development principle and database technology were applied to develop the information data interface between SolidWorks and ANSYS. By use of this interface, the integration of parametric design and finite element analysis can be realized. The test example shows that the developed system can not only complete the structural design of the entire shield cutter head, but also realize the structural analysis and structural optimization of the model, greatly reducing the workload of product design and optimization, and shortening the development cycle of the product.

Abstract:The traditional linear discriminant analysis(LDA)algorithm does not consider the similarity between the samples embedded from the high-dimensional space to the low-dimensional space. Therefore, it often fails to achieve good results for non-Gaussian data. In this paper, a self-weight linear discriminant analysis algorithm is proposed. The new model assigns weights of the sample pairs by measuring the Euclidean distance between the sample pairs to differentiate the importance of each data point so that the underlying local manifold structure can be discovered, which can improve the ability of the model to process non- Gaussian data. Extensive experiments conducted on synthetic and real data demonstrate that the proposed algorithmhas improved the dimension reduction performance of traditional LDA in processing non-Gaussian data to some extent.