Wang F.,Jackson State University |
Bu L.,Jackson State University |
Li C.,Civil Aviation Engineering Consulting Company of China |
Rong J.,Beijing University of Technology |
Guo R.,Tsinghua University
Transportation Research Record | Year: 2014
Emergency evacuation traffic is simulated in response to an assumed chlorine gas spill incident in downtown Jackson, Mississippi. The best evacuation corridors are identified, and possible effective traffic management strategies are compared to increase the cumulative number of vehicles evacuated out of the protective action zone and to decrease the average travel times for evacuees. To relieve the heavy traffic congestion around the spill location caused by the sudden increase in demand, traffic management strategies (law enforcement for traffic control, contraflow oPerations, and variable message signs) are tested on the three major arterial streets in the protective action zone to improve evacuation performance over a baseline traffic management strategy. A multiway analysis of variance was conducted for the simulation results to numerically assess the effect of each factor that might contribute to the performance of the short-notice evacuation. Results of a comparison of evacuation scenarios used to determine evacuation effectiveness and statistical analysis indicated that (a) selection of a best contraflow operation route depends on interference from intersecting links and the cost of deploying traffic management and (b) the use of both contraflow and variable message sigas could improve evacuation performance over using neither or only one of the two strategies.
Tan H.,Beijing Institute of Technology |
Feng J.,CAS Institute of Automation |
Feng G.,Civil Aviation Engineering Consulting Company of China |
Wang W.,Beijing Institute of Technology |
Zhang Y.-J.,Tsinghua University
Mathematical Problems in Engineering | Year: 2013
Traffic volume data is already collected and used for a variety of purposes in intelligent transportation system (ITS). However, the collected data might be abnormal due to the problem of outlier data caused by malfunctions in data collection and record systems. To fully analyze and operate the collected data, it is necessary to develop a validate method for addressing the outlier data. Many existing algorithms have studied the problem of outlier recovery based on the time series methods. In this paper, a multiway tensor model is proposed for constructing the traffic volume data based on the intrinsic multilinear correlations, such as day to day and hour to hour. Then, a novel tensor recovery method, called ADMM-TR, is proposed for recovering outlier data of traffic volume data. The proposed method is evaluated on synthetic data and real world traffic volume data. Experimental results demonstrate the practicability, effectiveness, and advantage of the proposed method, especially for the real world traffic volume data. © 2013 Huachun Tan et al.
Luo Y.-Z.,Zhejiang University |
Sun B.,Zhejiang University |
Sun B.,Civil Aviation Engineering Consulting Company of China |
Hong J.-B.,Hanjia Design Group Co.
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013
Wind tunnel tests in smooth and turbulent flows with and without a building were performed to detect static pressure fields here. A dimensionless method was proposed to solve a problem that static pressures could hardly be measured exactly, therefore the distributions of static pressure fields were investigated, dynamic characteristics of different flow areas around a building were analyzed in details with amplitude domain and frequency domain analysis methods, distribution function formulas of a static pressure field in main directions were given, and then its static and dynamic boundaries were figured out. The study results indicated that the natural vibration modes of a gas column in the wind tunnel may be evidently excited in some conditions and then the test results may be misled; the pressure fluctuating in the windward area of a building depends on the velocity fluctuating of an approach flow; the pressure fluctuating in the leeward area is close to the static pressure fluctuating of a turbulent approach flow but there are more non-Gaussian characteristics in the leeward area; a periodic vibration with a small amplitude of static pressure turns to a random vibration with a larger amplitude in the crosswind area with surface roughness rising; the more rough the surface, the smaller the static force action but the bigger the dynamic action of the whole static pressure field. The proposed distribution function formulas could be used for many purposes, such as, measuring a reference static pressure in full-scale filed tests and investigating a wind-induced interference effect among buildings.
Xu J.-L.,Chang'an University |
Lei B.,Chang'an University |
Lei B.,Xian Metro Co. |
Li N.,Civil Aviation Engineering Consulting Company of China
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2013
The traffic composition, heavy vehicle power, load mass and mass-to-power ratio of expressway in Inner Mongolia were analyzed, and the typical vehicle on expressway uphill section was determined. Based on the corrected speed prediction model, the operating speed curves of typical vehicle under different slope gradients(1%-6%), slope lengths, load masses(30, 40, 50, 55 t), mass-to-power ratios(80, 120, 160, 200 kg·kW-1) and initial speeds into slope(0, 20, 40, 60 km·h-1) were drawn, and the reasons of curve changes from vehicle dynamics perspective were studied. Analysis result shows that Foton Auman ETX9 heavy truck is the typical vehicle on the expressway for coal transportation in Inner Mongolia. When heavy vehicle runs on a certain slope, the vehicle speed will not decrease with the increase of slope length after reaching balancing speed. The bigger the slope gradient is, the faster the vehicle speed drops, the lower the final balancing speed is. The bigger the load mass is, the faster the vehicle speed drops. The smaller the mass-to-power ratio is, the better the vehicle climbing performance is. The higher the initial speed is, the longer the distance for vehicle to reach balancing speed is.
Zhang H.-J.,Beijing Institute of Technology |
Zhang H.-J.,Civil Aviation Engineering Consulting Company of China |
Zhang Q.,Beijing Institute of Technology
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2010
Under the assumption that the domain of the undetermined parameters can vary is known, the existence of simple Berge equilibrium for non-cooperative games is investigated. Based on the concept of simple Berge equilibrium and NS-equilibrium introduced by Zhukovskii for non-cooperative games, the notions of Pareto simple Berge equilibrium (PSBE) and Weak Pareto simple Berge equilibrium (WPSBE) are defined, and theorems of existence of the equilibrium are also provided by means of the Ky Fan inequality. Finally, a numeric example is raised to illustrate the proposed method's feasibility.
Guan X.,Tongji University |
Ge C.,Civil Aviation Engineering Consulting Company of China |
Wang X.,Tongji University |
Wang G.,East Carolina University
Human and Ecological Risk Assessment | Year: 2013
This article examines the location-allocation of emergency service facilities as a research subject. The research presents the setup of the single allocation set covering location-allocation models for emergency service facilities under strong time constraints, in view of the shortage of hub & spoke network bypass. The article also presents an extension to the single allocation set covering location-allocation model (SASCP) and the SASCP model with bypass constraints (γ-SASCP) for emergency service facilities under large-scale emergency requirements. For the two models, an improved genetic algorithm was designed and the two models were respectively solved, with the effectiveness of the algorithm verified by a specific example. The impacts of change of parameters such as time discount rate, maximum time constraints, and bypass ratio on the model's results are compared and analyzed, based on solved results by the specific example. © 2013 Copyright Taylor and Francis Group, LLC.
Zhang Y.,Chang'an University |
Guo Q.,Civil Aviation Engineering Consulting Company of China |
Ji X.,Chang'an University
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2016
The sodium silicate, organic silicone resin and silane coupling agent were used to enhance the performances of recycled aggregate(RA). The performances of RAs with and without enhancement were investigated, including crushing value, abrasion value, water absorption and adhesion in order to select out the best enhancer. The surface microscopic morphology of RAs with and without enhancement was observed by SEM and further the enhancing mechanism of enhancer on RA was investigated. The recycled coarse aggregate and natural fine aggregate were used to make up asphalt treated recycled aggregate(ATRA), and laboratory experiments were conducted including rutting test, water stability test and low-temperature bending test, and then the road performances of ATRAs were investigated. The results show that RA has large crushing value, abrasion value and water absorption and poor adhesion due to the voids and micro-cracks that exist in RA. The enhancing effect of organic silicone resin on comprehensive performances of RA is superior over that of sodium silicate and silane coupling agent. Most voids in RA are effectively blocked and micro-cracks are repaired in a certain extent when RA is enhanced by organic silicone resin, and the anti-crushed and adhesion of RA are improved and the water absorption of RA is reduced. When the RA without enhancement is used in ATRA, the average bending strain, residual stability and freeze-thaw splitting strength ratio of ATRA can't meet the requirements of JTG F40-2004. Moreover, When the RA enhanced by 2%(by mass) organic silicone resin is used in ATRA, the road performances of ATRA can be greatly improved and meet regulatory requirements of JTG F40-2004. © 2016, Editorial Department of Journal of Building Materials. All right reserved.
Zheng P.,Beijing Institute of Technology |
Li J.,Beijing Institute of Technology |
Liang Y.H.,Civil Aviation Engineering Consulting Company of China
Applied Mechanics and Materials | Year: 2014
Airport gate assignment is to appoint a gate for the arrival or leave flight and to ensure that the flight is on schedule. Assigning the airport gate with high efficiency is a key task among the airport ground busywork. As the core of airport operation, aircraft gate assignment is known as a kind of complicated combinatorial optimization problem. In this paper, we consider the over-constrained Airport Gate Assignment Problem where the number of flights exceeds the number of gates available, and where the objective is to minimize the overall variance of slack time (OVST). According to the intrinsic characteristics of the objective function itself, we design a meta-heuristic method and simulated annealing to solve the problem. Finally, the illustrative examples show the validity of the proposed approach. © (2014) Trans Tech Publications, Switzerland.
Bian J.,Shenyang University of Chemical Technology |
Bai Q.,Shenyang University of Technology |
Shi Q.,Civil Aviation Engineering Consulting Company of China
Advanced Materials Research | Year: 2012
Along with the fast increasing of maintenance demand, the problems associated with maintenance and reinforcement decision-making for deteriorating bridges such as maintenance strategy optimization have been present research focus. The solutions to these problems have inspired a considerable amount of research, one particular area being the application of evolutionary search algorithms such as the genetic algorithm (GA). This paper begins with a brief overview of bridge maintenance strategy optimization followed by a review of the current state of research in applying evolutionary techniques to solving this problem.
Luo Y.-Z.,Zhejiang University |
Sun B.,Zhejiang University |
Sun B.,Civil Aviation Engineering Consulting Company of China
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2013
The static pressure field around a cube in turbulent flow was detected in wind tunnel, and computational fluid dynamics (CFD) numerical simulation was conducted. Comparison between the results from the computation and the wind tunnel test was performed, which indicated that the precision of CFD technology is enough to compute static pressure field distributions around buildings. Then the full-scale cube and more types of full-scale buildings were simulated by CFD method. Results show that static pressure distribution patterns of different buildings are similar. The same formulas can be given to describe main directions of static pressure fields around dissimilar buildings, and the boundaries are concluded. More investigations of static pressure fields reveal that there are two narrow strips of regions near a building which can be used to quickly measure reference static pressure and so be named "static pressure corridor", and the method to find their positions and directions is proposed.