Current Issue |
|
|||
May 30,2009 Volume 2,Issue 10 Pages 1000-1116 Subject Area:Basic Subject of Aviation,Highway Signs, Signals, Monitoring Project |
||||
Title: Experimental research on two-phase flow pattern of boiling water flowing in a horizontal pipe under Hi-G condition | ||||
Authors: YAO Qiuping, SONG Baoyin, ZHAO Mei PP: 1111~1116 Abstract: The experiment for investigating steam-water two-phase flow patterns under high gravity (Hi-G) condition was conducted on a self built rotational platform, on which a steam-water two-phase flow system was installed. The typical photos of two-phase flow pattern of boiling water flowing in a pipe were obtained under the same heating condition during increasing the platform’s rotational speed from 0 to 57 r/min (i.e. the change of dynamic load at middle section of test pipe is from 0 to 2 times of acceleration of gravity) and decreasing the speed from 57 r/min to 0 (i.e. the change of dynamic load at middle section of test pipe is from 2 times to 0 of acceleration). The new flow patterns were found and defined as impact flow, high impact mixing flow and low impact mixing flow. The effects of gravity and centrifugal force on bubble and boiling flow patterns were investigated. The reason for the asymmetrical phenomena of flow pattern transition in acceleration and deceleration processes was analyzed from the point of view of the forces exerted on the fluid particles in the pipe. Keywords: basic subject of aeronautics and astronautics science and technology; steam-water two-phase flow; high gravity; horizontal pipe; boiling; flow pattern |
||||
Title: Study on collision early warning of space obstacle based on GUI | ||||
Authors: SONG Lei, YANG Jianying PP: 1103~1110 Abstract: As the total number of orbital objects increase rapidly, it is now necessary to establish certain maneuver for the spacecraft to avoid collision. This paper dealt with the collision avoidance for spacecraft. A new early warning method was developed. The method was based on calculation of collision probability and orbit prediction. The method combined a simple method of orbit prediction with newly developed collision probability method, which could take advantage of both methods and quantify the risk degree that the spacecraft faced in outer space, thereby increasing accuracy and effectiveness of the collision early warning. Finally, the whole early warning process was realized by use of the graphical user interface (GUI) in Matlab. Keywords: basic subject of aeronautics and astronautics science and technology; collision avoidance; collision probability; early warning; orbit prediction; space obstacle |
||||
Title: The application of fractal geometry theory in the research of aggregate gradation of asphalt mixture | ||||
Authors: JIANG Shuangquan, ZHANG Zhengqi PP: 1095~1102 Abstract: This paper introduced the fractal geometry theory, and established the relations of the asphalt mixture aggregate gradation distribution and the fractal dimension values D according to the fractal geometry theory. A method of calculating the fractal dimension values of asphalt mixture aggregate gradation was proposed. In addition, the paper analyzed the influence of fractal dimension values on the compaction characteristics, and indicated that the fractal dimension values was the representation of gradation, the gradations with different fractal dimension values had different compaction process and energy dissipation, but the trend of compaction curve was consilient. The paper proposed the approach which using the fractal dimension values to quantitatively predict and evaluate anti-rutting performance and uniformity of asphalt mixture. The experiment indicated that the fractal dimension values had good relevance to the anti-rutting performance and uniformity of asphalt mixture. The massive researches indicated that the method which using fractal geometry theory to study the relationship between the micro-structure and pavement performance of asphalt mixture is reasonable and effective. Keywords: road engineering; asphalt mixture; aggregate gradation; fractal geometry; compaction characteristics; rutting; uniformity |
||||
Title: Analysis on the effect of the Internet on traditional freight forwarder (railway transportation) | ||||
Authors: AO Chen PP: 1090~1094 Abstract: In order to adapt to the change of market environment made by the application and development of Internet, seek stable growth of the profits, and further promote the development of freight forwarding industry, this paper introduces the characteristics and development status of railway freight forwarding enterprise and makes analysis on the effect of Internet and e-commerce environment on the market structure, organization mode, technical support system and marketing mode of traditional freight forwarding (railway transport) puts forward the development strategies for railway freight forwarding enterprise under the e-commerce environment, including establishing management information system, developing network marketing, building marketing database, optimizing business process and extending to logistics service. Keywords: transportation engineering; the freight forwarder; railway transportation; e-commerce; Internet |
||||
Title: Brief discussion of the logistics expanding strategy on port railway together with the state-owned railway | ||||
Authors: YANG Mei PP: 1085~1089 Abstract: Based on the sufficient analysis of the current situation and existing problems of port railway, this paper made a research on the need and the benefits of bringing the port railway into the state-owned railway logistics management system, and used the game model to study the feasibility of the merger decision. Finally it put forward the logistics expanding strategies on the railway logistics to achieve resource sharing, raise the key competitive power of railway logistics, and realize the economic benefit maximization. Keywords: railway transport; port railway; railway logistics; expanding strategy |
||||
Title: Investigation on the cantilever device of catenary by simulation and experiment | ||||
Authors: ZHOU Ning, ZHANG Weihua PP: 1079~1084 Abstract: In this paper, all of the cantilever structure is considered as a whole. Three-dimension finite element model is built. Contact algorithm is employed to describe the connection relations among all parts. With the finite element method, the intensity and vibration characteristics of the structure are analyzed, the deformation and stress results are obtained under static and dynamic loads, and design parameter of the cantilever structure is verified. Also, comparison with experimental results indicates that the simulation results with the software meet the requirements of accuracy in engineering applications. Keywords: railway transport; cantilever device; finite element; intensity; vibration |
||||
Title: System design based on safe automobile traffic on highway in foggy days | ||||
Authors: LEI Jintao, WANG Yan PP: 1074~1078 Abstract: In order to overcome the influence of heavy fog on the highway traffic safety, an intelligent traffic control system for uncommon sections capable of ensuring safe transportation even in heavy fog is introduced. The paper introduces the hardware and software parts of the system. The system comprises a short-wave signal emission part, an information acquisition and processing part, and an on-vehicle graphical information display and alarm part. The system is capable of decreasing danger brought by the heavy fog by real-time renewing information, thereby improving the transportation safety quality, and bringing great social and economic benefits. Keywords: intelligent transportation; cluster fog; short-wave emission; traffic information; real-time control; special monitoring |
||||
Title: Research on control method for automotive active engine mount with electromagnetic-actuator | ||||
Authors: DING Shiwen,SHI Wenku,LIANG Tianye PP: 1066~1073 Abstract: In order to achieve the ideal isolation effects of engine mount, the working principle of electromagnetic actuators and active mount are introduced respectively, the two-degree-of-freedom vibration isolation system is modeled, a study on the control of active engine mount with electromagnetic-actuator is carried out by applying proportion integration differentiation(PID) control method, Fuzzy control method and Fuzzy/PI parallel control method, then a simulation is conducted using the three control methods and the vibration isolation performances of the engine mount are compared with each other. The results indicate that Fuzzy/PI parallel control method has a better performance in contrast to PID control method and fuzzy control method. Keywords: highway transportation; active engine mount with electromagnetic-actuator; proportion integration differentiation control method; fuzzy control method; Fuzzy/PI parallel control method |
||||
Title: A research of automotive integrated display & control system based on dual-core embedded systems and CAN bus | ||||
Authors: CHEN Yunxing, HUANG Jian, WANG Hongzhi PP: 1062~1065 Abstract: The rapid development of embedded systems and the successful application of coutroller area network (CAN) bus provide a platform on which vehicle can achieve intellectualization, systematization and networking. With the use of dual-core embedded systems and CAN bus to design automotive integrated pisplay & control system, realizing the integration of vehicle control, virtual instrument display, traffic information display, fault diagnosis and alarm, as well as globla positioning system(GPS) positioning and wireless networks, it is conducive to the overall optimization of system and the realization of achieving greater information processing and controlling with less room for the automotive electronic control system. The article designed the system in a modular pattern based on the demand, and described the system’s hardware structure, the requirements of the various units, as well as the realization of the software process control. Keywords: vehicle engineering; dual-core embedded system; controller area network bus; integrated display & control |
||||
Title: Dynamic simulation analysis of regenerative brake control strategy for hybrid electric car | ||||
Authors: WANG Pengyu, WANG Qingnian, DUAN Youhua PP: 1057~1061 Abstract: The paper introduced three typical regenerative brake control strategies, including parallel brake, ideal brake and maximum energy recycling brake. A dynamic simulation model for the brake system of the hybrid electric car was established under Matlab/Simulink environment. On the basis of this model, three regenerative brake control strategies were simulated and analyzed. Results of the simulation showed that the model could simulate the dynamic response of the brake system, providing a platform for the simulation and revision of control strategy. Keywords: highway transportation; hybrid electric car; regenerative brake; control strategy; simulation |
||||
Title: Study on the change of streams and riverbed erosion and deposition in reclamation engineering | ||||
Authors: LI Dan PP: 1051~1056 Abstract: To demonstrate the rationality of the design of closure in reclamation engineering, taking the Zoumadai closure work as example, by the overall physical model experiment, this paper studied and determined the change of water level inside and outside the port under different closure gap scales during the closure construction period, the change of velocity and flow pattern, and the depth, shape and scope of the maximum scour pit on the beach around closure gap under the construction water flow condition. The change law of streams and riverbed erosion and deposition in reclamation engineering was obtained, The conclusion provides scientific basis for the construction design and the optimization of engineering scheme. It also provides the optimized scheme of closure procedures, which is beneficial to the safe and steady performance of engineering, and lays a theoretical foundation for the reclamation engineering practice in the future. Keywords: water transportation; streams; silt movement; riverbed erosion and deposition; construction design |
||||
Title: Ship automatic navigation and collision avoidance using harmonic potential field | ||||
Authors: SHI Chaojian, ZHANG Mingming PP: 1043~1050 Abstract: Ship automatic navigation technology is a promising approach for reducing human errors in maritime accidents. Artificial potential field method has been successfully employed for path planning of automatic mobile robot, and it is also effective for ship navigation and collision avoidance at sea. The problem of local minima, however, should be properly tackled. Harmonic functions can be used to solve the problem. In this paper, harmonic functions were used in defining the potential field. Proper boundary conditions were chosen to solve the navigation planning problem for ships. With the harmonic potential field, ship navigation route could be generated automatically in constrained water areas as well as at open sea, and the tracks of the ships could follow the navigational regulations and general practices of seaman in specific water areas. Computer simulations were applied in two typical water areas including traffic lane and narrow channel. The simulations illustrated satisfying results for path planning of ship navigation and collision avoidance. Keywords: waterway transportation; ship automatic navigation; collision avoidance; potential field; harmonic function; motion planning |
||||
Title: A new license plate location method based on edge detection | ||||
Authors: REN Wenlong, ZHANG Xiaohang, JU Yongfeng PP: 1035~1042 Abstract: This paper studies license plate location. The image processing and image analysis technology and the license plate location problem itself were studied in detail, and a new license plate location method was brought forward. First, edge information was extracted by edge detection operator (sobel operator) and applied with binary processing; and then the vertical and horizontal positions of the license plate were determined separately by vertical and horizontal projections to the edge information, thereby positioning the license plate. Various edge detection operators were simulated by use of Matlab 6.5. The results proved that this method was feasible and applicable. Keywords: traffic information engineering and control; license plate automatic recognition; edge detection; projection; license plate location |
||||
Title: Application of landlord port mode in Chinese ports | ||||
Authors: ZHOU Xiang, CHEN Ning PP: 1029~1034 Abstract: China has rich port resources, but insufficient construction funds. In order to solve the problem that the port construction requires a huge amount of money, this paper summarizes the problem in the investment and financing and the management mode of the Chinese ports, compares the landlord port financing mode with the new port project financing mode, compares the landlord port management mode with the Chinese port management mode, analyzes the necessity and feasibility of the application of the landlord port mode in Chinese ports, and finally gives some suggestions on application and development of the landlord port mode in Chinese ports. The landlord port mode has a wide application prospect in China. Keywords: waterway transportation; landlord port; investment and financing; management mode |
||||
Title: Analysis of the relationship between transportation investment and economic growth | ||||
Authors: YU Weifeng, CHEN Senfa PP: 1023~1028 Abstract: This paper establishes a dynamic adjusting and controlling model of transportation infrastucture investment and economic growth using pole placement theory and complex system modeling method. The relation among transportation infrastucture investment, transportation demand and economic growth is evaluated on quantitative analysis, and the relationship between transportation infrastucture investment and economic growth shows nonlinear relation significantly based the linear relation among transportation volume, gross domestic prodact (GDP) and transportation demand volume. Especially, transportation infrastucture investment support should be strengthened during the period of rapid economic growth. These conclusions are in correspondence with the present status of transportation industry and the national transportation development strategy in China. Finally, some suggestions on strategy and tactics for current transportation development of China are raised. Keywords: transportation systems engineering; economic growth; compatibility; pole placement |
||||
Title: Research on a combined model of dynamic user optimal departure time and route selection | ||||
Authors: LONG Jiancheng, GAO Ziyou, REN Hualing PP: 1015~1022 Abstract: In this paper, a bi-level programming model is proposed to represent dynamic user optimal (DUO) departure time and route selection problem. The upper level is a dynamic departure time selection model, and the lower level is a DUO dynamic route selection model. An improved cell transmission model is used to calculate practical running time at dynamical road network condition. A discretization process is applied to the investigation time to solve the proposed model. The Frank-Wolfe algorithm is used to solve the lower DUO route selection problem. Furthermore, an improved genetic algorithm is designed in detail to solve the proposed bi-level programming model. Keywords: dynamic traffic assignment; bi-level programming; cell transmission model; genetic algorithm |
||||
Title: A review on the heuristic algorithms for the VRP | ||||
Authors: YANG Yanxuan, SONG Shiji, JI Pengcheng PP: 1000~1014 Abstract: Vehicle routing problem is a NP-hard problem with great research and application significance. In this research, the definition and basic description of the problem are first presented and the existed heuristic algorithms for the problem are classified into three categories: constructive. heuristic algorithm, improved heuristic algorithm and artificial intelligent algorithm. Then the typical algorithms of each category are introduced, and the application and research situation of the algorithms are investigated and summarized. Finally, the further research directions are given. Keywords: traffic transportation safety engineering;traffic transportation economics; revew; vehicle routing problem; scheduling; heuristic algorithm |
||||