Archive

24 December 2013, Volume 13 Issue 6 Previous Issue    Next Issue
---
Decision-making Forum



For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Decision-making Forum

Select

Contemporary Situations and Tasks of Transport of China JIA Shun-ping 2013, 13(6): 1-10.  Abstract ( )   PDF (514KB) ( )   The Eighth Advanced Forum on Transport of China sets its theme as “contemporary situations and tasks of transport of China”. Five subjects are involved such as “construct the system and mechanism of integrated transport”, “collaborative innovation mechanism and policy of integrated transport system”, “theory and methodology of transportation planning”, “applications of intelligent transportation systems” and “transportation energy saving method and strategy implementation”. The experts from government, university, research institution and industrial circle are invited. With the problem of transportation systematic of China, several issues are discussed, such as strengthen the theory of transportation system, construction and perfection of transport system, promoting the management system reform of transportation field, perfecting the management system of transportation systematic, coordination layout of transportation system, increase construction of traffic node, coordination national energy strategy and traffic development strategy. The forum also emphasizes the importance of environmental protection, constructs ecological traffic, and making related system to guarantee. Related Articles | Metrics

Select

Several Key Fields and Inspiration of Transportation Economics Research YUAN Chang-wei,WU Qun-qi 2013, 13(6): 11-17.  Abstract ( )   PDF (451KB) ( )   Transport economics need to focus on the core titles such as transport policy goals, demand, subsidy, regulation and so on. But the domestic transport economics research is difficult to fuse with the mainstream economics for a long time, and is lack of analysis and interpretation of practice issues. This paper reviews the research fields and progress in the international transport economics. It also traces the development and prospect of the several key issues of transport economics, such as policy subjective, scale and cost, regulation reform, on the basis of reviewing the evolution of the transportation economics. With the description and summary of the key issues, focusing on domestic transport development, in order to provide the relevant references for domestic transport economics research and practice, which includes speed and risk, space factor, coordination and so on. References | Related Articles | Metrics

Select

Incentive compatible Mechanism Model of Entrusted Transportation Management for Joint-venture Railway PENG Hui, ZHAO Jun-feng, WANG Ai-yun, CHEN Guo-dong 2013, 13(6): 18-22.  Abstract ( )   PDF (575KB) ( )   Entrusted transportation management model is an important form of joint venture railway in China. To establish a macro, reasonable and effective management mechanism of entrusted transportation management model for joint venture railway, the principal agent theory is used on the bases of Douglas function. The optimal incentive compatible mechanism is constructed on the case of symmetric and asymmetric information. On the basis of survey data of Xi’an Railway Bureau and Xiyan Joint venture Railway Company. It analyzes the model and obtains that the coefficient of excitation intensity is 7.2%, and also demonstrates operation management mechanism and incentive compatible policy on the basis of entrusted transportation model of joint venture railway. Finally, from Railway Bureau and joint railway company, it puts forward the strategies to construct incentivecompatible mechanism of joint venture railway by analyzing the potential problems of incentive compatible mechanism, and provides the theoretical analysis method for the joint venture railway of entrusted transportation management model. References | Related Articles | Metrics

Select

Calculating Method of Urban Public Transport Finance Subsidy WANG Hai-yan， YU Rong， WANG Guo-xiang， ZHENG Ji-yuan 2013, 13(6): 23-26.  Abstract ( )   PDF (356KB) ( )   The social benefits of urban public transportation in some extent determine the losses of bus enterprises. Financial subsidies have become the important measure for government to develop the public transport. This paper uses utility function to analyze three agents—government, enterprises and passengers. A model is established that containing passenger utility, enterprise cost and government finance subsidy. It also analyzes the advantages of the classification subsidies, scientifically calculus the finance subsidy amount. Then taking Nanjing as an example calculus the finance subsidy combined with the survey data. Results show that the classification subsidies and calculation model can effectively measure bus financial subsidies amount. The method of Classified Calculating public financial subsidies proposes a new idea for urban public transport subsidies. References | Related Articles | Metrics

Select

The Influence of Transport Infrastructure on Urban Size SUN Ying-ying，JI Da-peng，XIAO Zhong-bin 2013, 13(6): 27-31.  Abstract ( )   PDF (367KB) ( )   Transport infrastructure is one of the important influences on urban size. In certain stage of urban involution, status of transport infrastructure always indicates the size of urban area. This paper will do research into the relationship between transport infrastructure and urban involution; quantify indicators such as layout and scale of transport infrastructure, node compatibility and accessibility. Then based on the consideration of economic development towards urban size, the model about relationship between transport infrastructure and urban size is structured, and part of parameters is evaluated. Finally, it takes Shuyang as an example, researches the reasonable urban size under the established scale of transport infrastructure, and compares with its current size. References | Related Articles | Metrics

Select

Research on the Maritime Cluster Competition Based on Ecological Niche Theory JIN Jia-chen，ZHEN Hong 2013, 13(6): 32-36.  Abstract ( )   PDF (362KB) ( )   In order to study the relations between maritime clusters, by using the theoretical models about the relationship between species in ecology, competition relation, mutually beneficial relation and dominance relation is considered as chief relations on the basis of facts and characteristics of maritime cluster. And three theory models of maritime cluster with ecological equilibrium condition are also given. With forward, reverse and comparative niche overlap methods, a case study of ecological competition between Shanghai and Ningbo maritime cluster is carried out, making it clear that Shanghai and Ningbo maritime cluster has high overlap in container development, and Shanghai has stronger competitive advantages, considering Shanghai and Ningbo maritime cluster must speed up the realization of “dislocation competition, complementary advantages”. References | Related Articles | Metrics

Select

Optimal Space Allocation of Logistics Capital Based on the Regional Cooperation XING Hu-song, LIU Kai, DENG Yuan-hui 2013, 13(6): 37-43.  Abstract ( )   PDF (565KB) ( )   In the background of the regional logistics integration of China, In order to effectively solve the problems of repetitive construction of logistics infrastructure and malignant competition of logistics market among the adjoining areas, regional logistics cooperation are considered to be an important means to realize regional logistics integration and used widely. This paper tries to solve the problem that how to allocate the logistics capital effectively among the different administrative areas in the regional logistics cooperation process, discusses the principle of an optimal space allocation, studies the processes and methods of space allocation of logistics capital, and applies it to the cooperation practice of Shenzhen Dongguan and Huizhou (SGH for short) . It’s not only beneficial to raise utilization efficiency and intensive development of capital resources, but also beneficial to the health and coordinated development of regional logistics, which can provide theoretical reference and basis of the planning and development of regional logistics in our country. References | Related Articles | Metrics

Select

Analysis of Micro-cars’Influence on Traffic Network Using a Microscopic Simulator MU Rui, YAMAMOTO Toshiyuki 2013, 13(6): 44-51.  Abstract ( )   PDF (2674KB) ( )   The environmental effects and network performance of mixed traffic, consisting of micro-cars and conventional cars, on a small network are investigated using microscopic simulations. After calibrating the simulation model, the effects of three assumptions concerning micro-car speeds are investigated using the model. First, the parameters needed for network performance evaluation are determined iteratively. The power required to meet total travel demand is then computed to predict emissions. A higher ratio of micro-cars in the traffic reduces emissions, as does a lower micro-car speed. To investigate travel efficiency, the main parameters used are average speed, total travel time and total delay time. The results suggest that a higher ratio of micro-cars has a positive effect on the network when their speed is the same as or a slightly lower than that of conventional cars, while a higher ratio of micro-cars has a negative effect when their speed is close to the average traffic speed of the base model. To obtain a suitable balance between desired environmental effects and road network performance, we recommend that the desired speed of micro-cars be set to 40-45 km/h on a small urban traffic network. References | Related Articles | Metrics

Select

Traffic Incident Prediction on Intersections Based on HMM ZHOU Jun, CHENG Lin, ZHOU Ling-yun, CHU Zhao-ming 2013, 13(6): 52-59.  Abstract ( )   PDF (1028KB) ( )   The intersection is an area where many accidents occur. Reasons for accidents are due to complicated intersection designs and the congested travel conditions. For these reasons, traffic incident detection is more complicated. This paper uses the intersections of Huaihai South Road and Jiefang Road as an example. According to the vehicle operation and phase timing, the situations of two vehicle's relative movement on four phase intersections are summarized. The motion vectors of the conflicting vehicle are quantized on the basis of vehicle tracking. Then, the HMM is used to classify the traffic conflicts of the intersection. Finally, numerical experiments verify that the algorithm is able to classify the conflict when the traffic is normal. Furthermore, the algorithm can forecast the traffic accidents (such as bumping, tandem, and stop) which occurred in the intersection. References | Related Articles | Metrics

Select

Urban Road Short-term Traffic Flow Forecasting Based on the Delay and Nonlinear Grey Model GUO Huan1,XIAO Xin-ping1,Jeffrey Forrest2 2013, 13(6): 60-66.  Abstract ( )   PDF (486KB) ( )   Concerning the delay and nonlinear properties of traffic flow in urban road systems, this paper forecasts the short-term traffic flow based on the grey model. Firstly, the delay factor is determined by the speed-flow relationship when volume is greater than it capacity. Then, the nonlinear parameter is determined by a particle swarm optimization algorithm, where the prediction effect is unsurpassed. Finally, verification of this model is done by collecting traffic flow data on one section of Youyi Avenue and comparing the prediction value of with and SVM. The results show that the prediction effect of model for short-term traffic flow is significantly improved, which plays an important role in intelligent traffic systems. References | Related Articles | Metrics

Select

The Recovery Algorithm for Road Traffic Parameters Based on Compressive Sensing XU Dong-wei, DONG Hong-hui, LI Hai-jian, JIA Li-min 2013, 13(6): 67-72.  Abstract ( )   PDF (398KB) ( )   To solve the road traffic parameters data problems (data invalid or data deletion) when a part of traffic states detectors in the road network break down, an algorithm based on compressive sensing is presented to repair traffic parameters of the road traffic network in this paper. Firstly, the road traffic parameters data are decomposed and approximated. Then the road traffic parameters recovery approach is presented based on compressive sensing, and the parameters setting referred in this road traffic parameters estimation approach based on compressive sensing is discussed. Finally, one typical road network in Beijing is adopted for the experiments analysis. The results show that this traffic states data recovery approach based on compressive sensing is feasible and can achieve a high accuracy. References | Related Articles | Metrics

Select

A Method to Identify Public Transit Transfers Based on IC and AVL Data LI Hai-bo，CHEN Xue-wu 2013, 13(6): 73-79.  Abstract ( )   PDF (857KB) ( )   The behavior characteristics of public transit transfers are important to the planning and operation of public transit transfer hubs, which are the key nodes of multi-mode urban public transportation systems. This paper analyzes bus trip process and describes it as a serial of time points. Considering the features of current public transportation system data, it is possible to calculate previous alighting time and arrival time at transfer stations by combining IC data with AVL data. According to the assumption that bus passengers will get on the first bus arriving at the transfer station, we can determine whether a bus passenger is a transfer or not by just comparing his/her previous alighting time and arrival time at transfer stations with bus arrival time at the transfer station. Finally, it takes two continuous transaction records of an actual bus passenger from Suzhou as an example to examine the feasibility and efficiency of the method. The result indicates that the improved method is much more reasonable and accurate. References | Related Articles | Metrics

Select

An Improved FVD Model for Intersection ZHI Liang，SHI Zhong-ke，LIU Tong 2013, 13(6): 80-85.  Abstract ( )   PDF (866KB) ( )   In order to study the car-following behavior of the intersection accurately, based on the analysis of driving behavior characteristics on the condition of car-following, combine with real data of traffic flow and verify the Full Velocity Difference model (FVDM). In terms of the problem that the frequency response of FVDM is inaccurate, considering the velocity and front distance of the moving vehicles, an improved model is proposed based on maximum optimal speed. The improved optimal velocity is determined by the front distance and velocity of the two vehicles, thus reflects the expected moving speed of drivers (the optimization speed) more comprehensively and accurately. Using the data collected by taking videos at the intersection verify the improved model. It analyzes the verification results and compares with the one of original model, it also comes out that the improved model is more corresponded to the actual driving behavior at the intersection. References | Related Articles | Metrics

Select

Effects of Friends’ Information Interaction on Travel Decisions LIU Tian-liang,ZHANG Chong,WANG Tian-ge,WU Guo-jun 2013, 13(6): 86-93.  Abstract ( )   PDF (522KB) ( )   Many existing studies focus on the effects of traffic information from ATIS on travel choices. Research on the effect of friends’ travel information on people’s travel choice is uncommon, yet needed. In this paper, behavioral experiments are conducted to discuss what the effects of information interaction with friends can bring on individual travel decision behavior. The experimental results concluded that when the rate of friends’ information interaction reaches 33.3%, the whole system is at an optimal level. Furthermore, users reach an optimum when the rate of friends’ travel information interaction is 75%. The average time and cost per person is increasing when the whole system optimum transfers to the user optimum. Moreover, adjustments of departure time at the system optimum are more dispersed than at the user optimum, while travel choice changes are more concentrated. References | Related Articles | Metrics

Select

Least-time Path Algorithm Based on Missile Guidance GONG Yan1, LI Su-jian1, XING En-hui2 2013, 13(6): 94-100.  Abstract ( )   PDF (498KB) ( )   A dynamic and real-time single-vehicle path algorithm considering system optimization is proposed by the method of simulating missile guidance. Targeted at minimizing the run-time of a single vehicle, the algorithm plans a path for the vehicle to avoid traffic congestion and help optimize the overall traffic state. This algorithm begins with preliminary path planning to find the points from which ideal paths that help balance the vehicle traffic flow can be generated. Then the algorithm plans for the ideal paths before the actual path is derived from the ideal ones. Throughout the driving process, the algorithm dynamically and cyclically plans the path in real-time, and dynamically revises the plan of the path covering the sections ahead based on the traffic state . Simulation showed that the proposed algorithm effectively enables vehicles to avoid congestion and save travel time, and helps balance the vehicle traffic flow and optimize the traffic state. References | Related Articles | Metrics

Select

A Probability Model of Bicycles Crossing Vehicle-bicycle Separation Lines ZHANG Shui-chao,HE Kang-kang,YANG Ren-fa ZHANG Shui-chao,HE Kang-kang,YANG Ren-fa 2013, 13(6): 101-104.  Abstract ( )   PDF (473KB) ( )   Vehicle-bicycle separation lines are frequently used to isolate motor vehicles from bicycles on China’s urban roads. Conflict between motor vehicles and bicycles exists in these road sections. It is regularly caused by bicycles crossing the vehicle-bicycle separation line onto the motor vehicle lane. Thus, it is imperative to research the probability of crossing travel of bicycles. First, two presumptions for bicycles to cross travel are stated. One is that bicycles need to cross the traffic marking; the other is that the space among the adjacent motor vehicle flows is available for bicycles to cross. With this observation, the probability of conflicts between motor vehicles and bicycles can be obtained as a product of their probabilities. Based on this probability, the result was summarized as follows: the probability for bicycles crossing the traffic marking obeys a negative exponential distribution, which is derived. The result was shown by theoretical analysis and was compared to actual survey data. The available probability for bicycles entering into motor vehicle flow was found by the use of a traffic survey. Therefore, a probability function was proposed with different spaces that led to a probability model for vehicle-bicycle conflicts. At last, using the survey data, the probability model proved to be correct. References | Related Articles | Metrics

Select

Application Research on Improved FP-tree Algorithm in EMU’s Fault Diagnosis ZHONG Yan， MA Hai-man， ZHANG Chun， ZHAO Huai-xin 2013, 13(6): 105-111.  Abstract ( )   PDF (630KB) ( )   From the point view of acquiring fault diagnosis knowledge using EMU’s mass operation and maintenance data, through the study of FP-tree algorithm which is an association rule algorithm of data mining, combining with the requirement of EMU’s fault diagnosis, the FP-tree algorithm is improved from the aspect of spanning tree and searching for frequent items, and an improved algorithm is put forward that called NP-FP-tree algorithm. In the stage of spanning tree, EMU’s fault information is put in the top, in searching for frequent items, all searches are carried out to the top. Finally, the NP-FP-tree algorithm is applied to mining of association rule of EMU’s fault information and state information. Through carefully analyzing and testing the performance of NP-FP-tree algorithm, it proves that the improved algorithm is better than the original one in the aspect of time consumption and space consumption. References | Related Articles | Metrics

Select

Synergy Evaluation Method and Empirical Application for Joint-Service System of Containerized Liner Shipping CHEN Ji-hong,HU Zhi-hua,HE Xin-hua, HAN Ling-bing 2013, 13(6): 112-119.  Abstract ( )   PDF (760KB) ( )   Focusing on the problem of synergy operation performance of joint-service system of containerized liner shipping, this paper puts forward corresponding synergy evaluation method and models with empirical examples. In view of the international shipping business status, it establishes the synergy mechanism framework of joint-service system of containerized liner shipping through the synergy theory and method. It selects associated operation indexes for joint service of liner shipping, and formulates synergy evaluation models and the evaluation system. Moreover, the synergy degree is used to measure the synergistic effect of joint-service system of containerized liner shipping. The typical CKYH joint-service system of containerized liner shipping is taken as an example for case study to verify the method and models. The results show that the synergy degree of joint-service system of containerized liner shipping system is reflected in the interaction of the each component and elements of the system. The proposed method can effectively measure the synergy status of the joint-service system. The case study results are also consistent with the actual practice of shipping, which examines the validity of the method. References | Related Articles | Metrics

Select

Stochastic User Equilibrium Evolutionary Model with Elastic Demand and Advanced Traveler Information Systems DU Wei,HUANG Chong-chao,XIAO Hai-yan,WANG Xian-jia 2013, 13(6): 120-126.  Abstract ( )   PDF (1065KB) ( )   The paper investigates the dynamic behavior of urban network traffic flow. In the evolution process of traffic flow in the urban network, travelers adjust the day-to-day route choice. In a traffic network served by advanced traveler information systems (ATIS), travelers always choose their routes based on experiments on traffic condition and current network information provided by the ATIS. With different attitudes toward ATIS service, the paper divides all the travelers into two types, namely optimism and conservatism, and then examine their travel time determination. Integrateing the Logit dynamics with the above work, this study further develops the network traffic flow evolutionary model considering stochastic user equilibrium with elastic demand with ATIS. In the last section, a numerical example is given to illustrate the evolution process of the model. Simulation results indicate the proportion of conservative travelers exerts effects on the final state of traffic flow. References | Related Articles | Metrics

Select

Bus Travel Algorithm Based on Vector Matching in Sparsely Populated Areas ZHANG Kai,ZHANG Qiang,ZHUANG Liang 2013, 13(6): 127-133.  Abstract ( )   PDF (1069KB) ( )   People in sparsely populated areas such as suburbs and new cities traveling by bus have much inconvenience. To eliminate the defect of bus travel in these areas, a travel algorithm research is conducted. This paper proposes two algorithms, vector matching and pick-up path. Firstly, to match the direction between traveler’s departure and destination location information and main road network route of service area. Secondly, a global optimal path planning is conducted for all successful matched request location information. Finally, experimental data analysis and conclusion are given based on the road network model and travel algorithm. The result shows that travel algorithm have the characteristic of humanized and point-to-point services to be different form regular bus, service quality is high, and travel cost is cheaper compared with taxi fee. In addition, average traveler’s journey time is also within acceptable range, passenger satisfaction is higher, and the algorithm can well satisfy the wishes of people to travel conveniently and quickly. References | Related Articles | Metrics

Select

Railway Assignment Model with Vehicle Capacity Constraints ZHU Yu-ting, MAO Bao-hua, LI Ming-gao, GAN Tian-tian, ZHAO Yu-gang 2013, 13(6): 134-139.  Abstract ( )   PDF (888KB) ( )   This paper extends the physical nodes and physical arcs, and builds a time-expanded network. Then a schedule-based quasi-dynamic assignment model is proposed with the expanded network. The model takes into account vehicle capacities explicitly and individually, and passengers are loaded on a first-come-first-serve principle. Then, the method of successive averages (MSA) is used to solve the problem. Numerical example empirically demonstrated that the algorithm converges to an equilibrium solution. And the result shows that the arrival distribution of passenger flow can be divided into three types: bimodal pattern, unimodal pattern and non-peak pattern. With the improvement of service level, the arrival distribution change from bimodal pattern to unimodal pattern, finally to the non-peak pattern. References | Related Articles | Metrics

Select

Fleet Scheduling Problem with Time Windows Based on FCFS Strategy XUAN Hua XUAN Hua 2013, 13(6): 140-146.  Abstract ( )   PDF (493KB) ( )   It helps improve resource utilization and realize scientific transportation to schedule freight vehicle and transportation tasks effectively. A fleet scheduling problem with time windows is analyzed, and then formulated as a mathematical programming model. A heuristic algorithm is designed because of it is difficult to solve the model using traditional algorithms, where the vehicle is assigned to the transportation tasks using FCFS method. The vehicle label is devised to represent the location and the arrival time of the vehicle. A sub-tour is devised to contain a sequence of chained vehicle-task assignment. Finally, the fleet scheduling solution is proposed. A case validates the feasibility of this algorithm. References | Related Articles | Metrics

Select

Evaluation of Air Traffic Control Sector Complexity WANG Hong-yong, ZHAO Yi-fei,WANG Fei, WEN Rui-ying 2013, 13(6): 147-153.  Abstract ( )   PDF (3026KB) ( )   The number of aircraft as a crude sector capacity metric is not enough to fully account for the controller’s workload. Based air traffic complexity, the capability evaluation of airspace system is becoming a new hot research in the field of air traffic management. This paper discusses the concept of approach effect of pairwise aircrafts by taking relative approach degree, relative approach rate as evaluation index. On this basis, the index of conflict resolution is further presented and an intrinsic complexity model of pairwise aircrafts is constructed. Utilizing this model, a method is introduced to calculate sector complexity of aircraft disturbance and sector geographical distribution. And then, the corresponding complexity map is presented, which can provide leverage for accurate insight into the capability of airspace system. Simulated some traffic situation with different traffic flow and different airspace structure, the simulation experimental results indicated that the complexity-based model represented the microscopic characteristics of the complex traffic situation in sector better than the aircraft count-based model. The proposed model can provide scientific evidence for adopting effective air traffic management measures. References | Related Articles | Metrics

Select

Real-time Fault Diagnosis of Urban Train Brake System Based on LMI YU Bo,JI Chang-xu,JIA Li-min,LONG Jing,CHEN Xi-jun 2013, 13(6): 154-160.  Abstract ( )   PDF (546KB) ( )   Real-time fault diagnosis of urban rail train braking system is an important means for the stable and safe operation of urban rail transit. Based on the real time data acquisition of urban rail train braking system, a braking system control model is established with linear matrix inequality (LMI) theory, and then a residual generator is designed for system control output. It calibrates the key parameters of the residual generator and threshold of the fault residual generator, based on the application of control theory. A real-time fault diagnosis method is put forward for urban rail train. Simulation results show that the fault diagnosis method is real-time and availability. References | Related Articles | Metrics

Select

Impact Factors of Travel Intention During the Toll Road Being Free on the Major Holidays HUANG Chun-hui, WU Jin-feng, ZHANG Fei, ZHU Dong-hong 2013, 13(6): 161-168.  Abstract ( )   PDF (535KB) ( )   Based on the objective reality of the toll road being free on the major holidays, the research objects of this paper are the travelers who have their own private cars. This paper, by the method of empirical, researches the interaction among all impact factors. By using survey data collected from 261 travelers who have the experience traveled on the toll road being free on the major holidays, it builds a concept model based on the theory of planned behavior (TPB), and designs the measurement scale about travel attitude and intention. Through the research of this paper, on one hand, it is possible to expand basic research theory in the field in domestic, and on the other hand，it also reveals mechanism of action of the policy of free toll road to the travel intention. The results show that the perceived service quality, the positive utility have a positive impact on the traveler’s travel attitude, and the negative utility has a negative impact on the traveler’s travel attitude. The travel attitude, perceived behavioral control and subjective norm will affect travelers travel intention. References | Related Articles | Metrics

Select

Research on Free Flight Conflict Detection Based on K-Nearest Neighbor ZHAO Yuan-di, SUN He, WANG Jie-ning 2013, 13(6): 169-175.  Abstract ( )   PDF (1405KB) ( )   In order to detect aircraft conflicts under the condition of free flight in three-dimensional space, a conflict detection method based on K-Nearest Neighbor is proposed. On the basis of establishing distance matrix by K-Nearest Neighbor, the aircraft conflicts are detected according to the conflict decision rules. The presented method can detect conflicts among several aircraft simultaneously with computation complexity O(n), which improves the computational efficiency compared with traditional methods. The distance matrix only needs to be modified locally in order to redetect conflicts when the positions of some aircraft change. Besides, an adaptive calculation method of K is proposed for avoiding unnecessary distance detection. Simulation experiments on many aircraft in the airspace demonstrate that the proposed method can detect the aircraft conflicts rapidly and accurately, so it can reduce the workload of controllers effectively. References | Related Articles | Metrics

Select

Layout Optimization of the Feeder Bus Routes Connecting Subways at Bus Stops CUI Yuan，CHEN Shao-kuan， LIU Jian-feng 2013, 13(6): 176-183.  Abstract ( )   PDF (1077KB) ( )   Aiming at unreasonable distribution of feeder bus lines which leads to unbalanced utilization rate of bus stops and the low level of passenger service, an optimization model is established to obtain the shortest total passenger’s transfer distance and the minimum the total time of all buses dwelling at bus stops. This paper gives Pareto frontiers by constraint approach and employs weight coefficients to indicate the preference of decision makers. Case studies of the Xiyuan Station in Beijing are implemented to verify the validity and practicability. The results from case studies shows that the proposed model is capable of optimizing the layout of the feeder bus routes connecting subways at bus stops and improving the level of public transit service and the operational efficiency of buses. References | Related Articles | Metrics

Select

Railway Coal Dispatched Volume Prediction Based on Maximum Lyapunov Exponent WU Hua-wen, WANG Fu-zhang 2013, 13(6): 184-190.  Abstract ( )   PDF (2445KB) ( )   The phase space reconstruction method of chaos theory is used to analyze the three groups of time series associated with railway coal dispatched volume. The embedded time-delay, embedded dimension, correlation dimension and the maximum Lyapunov exponent of each time series are separately calculated. The results are used to judge the chaotic characteristic of time series. The analytical results show as follows: the growth amount and growth rate of railway coal dispatched volume have chaotic characteristics while the coal dispatched volume doesn’t. The maximum Lyapunov exponent method and BP neural network are separately used to forecast the growth amount and growth rate of railway coal dispatched volume. The result shows that the predicted data using maximum Lyapunov exponent method is anastomotic with the real data. The maximum Lyapunov exponent method is better than BP neural network in prediction. The maximum Lyapunov exponent prediction of chaos theory has extensive and practical value in railway coal dispatched volume time series prediction. References | Related Articles | Metrics

Select

Price Evolution Trends, Problems and Countermeasures of China Road Freight Market GU Jing-yan, WU Qun-qi 2013, 13(6): 191-197.  Abstract ( )   PDF (683KB) ( )   With the market-oriented reforms since the 80’s of the last century, the supply and demand relationship in road freight market has undergone tremendous changes. The supply of the generate cargo transport capacities is greater than demand of them. The road freight costs continue to rise. At the same time, the road freight price fell into a prolonged slump. The distorted price system and the imbalance structure between supply and demand led to resources allocation disorders of the freight market. These problems cause a lot of the contradiction which impact freight market healthy and stable development. In this paper, the deeper reason about the road freight market price mechanism disorders is analyzed based on the comprehensive review of the prices evolution trends of the road freight market. The policy and recommendations are put forward to promoting the healthy and stable development of the road freight market. References | Related Articles | Metrics

Select

Statistical Analysis of Weighted Complex Network in Beijing Public Transit Routes System Based on Passenger Flow HUANG Ai-ling，GUAN Wei，MAO Bao-hua，ZANG Guang-zhi 2013, 13(6): 198-204.  Abstract ( )   PDF (683KB) ( )   Urban public transit network is a typical mixed complex network with dynamic weights. In order to understand its essence and evolving mechanism, we should not only study its static topological network, but also explore its structural characteristics when the passenger flow is distributed in the network. This paper models a weighted complex network for public transit routes based on passenger flow, and collects related data in Beijing to study its structure and complex characteristics. The statistical analysis shows that in the weighted complex network for Beijing public transit routes, the node degree and strength distribution all obey power-law functions, and clustering coefficient and average path length are relative small, therefore, the weighted network is a scale-free network, and it is disassortative mixing, which is similar to the technical network. What we have done could provide some references to design and optimize urban public transit routes. References | Related Articles | Metrics