Traffic Management Bureau

Beijing, China

Traffic Management Bureau

Beijing, China
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Liang G.-H.,Chang'an University | Liang G.-H.,University of Louisiana at Lafayette | Zhang J.-F.,Traffic Management Bureau | Ma R.-G.,Chang'an University
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2013

Based on the concept of highway network equilibrium scale, the second-class highway was taken as the standard grade highway, the calculation method of equivalent mileage and equivalent coefficient was proposed, and the regressing model of terrain correction coefficient for highway network was established. The shortcomings and characteristics of traditional methods such as territory coefficient method and connectivity method were analyzed. The traditional calculation method of highway network equilibrium scale was adjusted. The minimum comprehensive Gini coefficient was taken as judging criterion, the range of equilibrium scale interval was adjusted, the calculation flow of equilibrium scale proportion was established, the systematic determination method of equilibrium scale for highway network was proposed, and example verification was carried out by using the highway network in Yunnan Province. Analysis result shows that the terrain correction coefficient of freeway in Qujing is the minimum, and is 1.12. The terrain correction coefficient of the fourth-class highway and substandard highway in Diqing is the maximum, and is 1.92. The equilibrium scale mileage in Nujiang is the minimum, and is 549 km. The equilibrium scale mileage in Qujing is the maximum, and is 4753 km. By using the proposed method, the Gini coefficients of population, economy and area for highway network in Yunnan Province are 0.02, 0.19, 0.15, reduce by 0.15, 0.29, 0.18 respectively, the three Gini coefficients meet absolute equilibrium standard.


Cao P.,Tsinghua University | Jin F.,Tsinghua University | Feng D.,Harbin Institute of Technology | Zhou C.,Dalian University of Technology | Hu W.,Traffic Management Bureau
Construction and Building Materials | Year: 2016

Asphalt mixture usually needs compaction prior to servicing in field. Traditionally, finite element methods cannot simulate the compaction of asphalt mixture in field. Although discrete element methods (DEM) are able to describe such a process, the intrusion among aggregates always exists and influences the calculation accuracy. Additionally, the central difference method used in DEM requires very fine elements, which significantly jeopardizes the calculation efficiency. This study proposed an innovative systematic method to generate virtual asphalt mixture based on random aggregate modeling method and virtual physics engine theory. The aggregates were virtually generated with random aggregate modeling methods and imported into the virtual physics engine, where the movements of aggregates in asphalt concrete during compaction was simulated. The coordinates of aggregates after compaction were extracted, which were incorporated into the Convex Hull Algorithm to determine the new locations of aggregates after compaction. The original contribution of this study is that a pre-processing method of generating virtual asphalt concrete was proposed, which can successfully introduce compaction of asphalt mixture into finite element models and solve the intrusion problem of aggregates. The dynamic modulus of asphalt concrete simulated in finite element method (FEM) based on this modeling method was found much closer to the experimental results, comparing to the traditional analytic methods. It indicates the proposed method valid in generating virtual asphalt concrete in FEM. © 2016 Elsevier Ltd


Liu Y.-H.,Sun Yat Sen University | Bi S.-Y.,Sun Yat Sen University | Zhou B.,Traffic Management Bureau | Wang C.,Sun Yat Sen University | And 3 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2010

To improve air quality during the 2010 Asian Games, temporal traffic control measures were made that some vehicles was banned to drive in certain roads in central district of Foshan from December 26 to 29 in 2009. The rate of vehicular emissions reduction was calculated, according to traffic flow parameters on-road including volume of traffic, speeds, the proportion of different vehicular types and vehicular emission factors. These traffic flow parameters were made based on traffic investigation, while vehicular emission factors related to vehicular emission standards, speed and vehicular types on-road were calculated after running the European COPERT model. The results showed that during temporal traffic control measures, the average volume of traffic on all roads in central district reduced by 35.2%, and the proportion of different vehicular types changed greatly, and volume of motorcycle decreased significantly. But the reduction rate of emissions of CO, NOx, VOC, and PM were unequal. So according to this reduction rate of volume of traffic, the average annual emissions of CO, NOx, VOC, PM on all roads in central district would decrease respectively by 48.1%, 39.2%, 43.6%, 49.2%.


Meng L.,Fujian Police College | Zhang W.,Traffic Management Bureau | Meng P.,Chinese People's Public Security University | Zhu B.,Fujian Police College | Zheng K.,Fujian Police College
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2015

Two microextraction techniques based on hollow fiber liquid-phase microextraction (HF-LPME) and ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) had been applied for the determination of drugs of abuse (methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, methcathinone, ketamine, meperidine, and methadone) in urine and blood samples by gas chromatography-mass spectrometry. Parameters affecting extraction efficiency have been investigated and optimized for both methods. Under the optimum conditions, linearities were observed for all analytes in the range 0.0030-10. μg/ml with the correlation coefficient (R) ranging from 0.9985 to 0.9995 for HF-LPME and in the range 0.0030-10. μg/ml with the R ranging from 0.9985 to 0.9994 for DLLME. The recovery of 79.3-98.6% with RSDs of 1.2-4.5% was obtained for HF-LPME, and the recovery of 79.3-103.4% with RSDs of 2.4-5.7% was obtained for DLLME. The LODs (S/N. =. 3) were estimated to be in the range from 0.5 to 5. ng/ml and 0.5 to 4. ng/ml, respectively. Compared with HF-LPME, the UA-LDS-DLLME technique had the advantages of less extraction time, suitability for batches of sample pretreatment simultaneously, and higher extraction efficiency, while HF-LPME has excellent sample clean-up effect, and is a robust and suitable technique for various sample matrices with better repeatability. Both methods were successfully applied to the analysis of drugs of abuse in real human blood sample. © 2015 Elsevier B.V.


Meng L.,Fujian Police College | Zhu B.,Fujian Police College | Zheng K.,Fujian Police College | Zhang W.,Traffic Management Bureau | Meng P.,Chinese People's Public Security University
Chinese Journal of Chromatography (Se Pu) | Year: 2015

A novel microextraction technique based on ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) has been developed for the determination of multiple drugs of abuse in biological samples by gas chromatography-triple quadrupole mass spectrometry (GC-QQQ-MS). A total of 100 μL of toluene as extraction solvent was dropped into the sample solution. Then the mixture was sonicated drastically in an ultrasonic bath for 3 min with occasional manual shaking to form a cloudy suspension. After centrifugation at 10 000 r/min for 3 min, the upper layer of low-density extractant was withdrawn and injected into the GC-QQQ-MS for analysis. The parameters affecting extraction efficiency have been investigated and optimized. Under the optimum conditions, good linearities were observed for all analytes with the correlation coefficients ranging from 0.998 4 to 0.999 4. The recoveries of 79.3%-100.3%with RSDs<5.7% were obtained. The LODs (S/N = 3) were in the range from 0.05 to 0.40 μg/L. UA-LDS-DLLME technique has the advantages of less extraction time, suitable for batches of sample pretreatment simultaneously, and higher extraction efficiency. It was successfully applied to the analysis of amphetamines in real human urine samples.


PubMed | Fujian Police College, Traffic Management Bureau and Chinese People's Public Security University
Type: | Journal: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences | Year: 2015

Two microextraction techniques based on hollow fiber liquid-phase microextraction (HF-LPME) and ultrasound-assisted low-density solvent dispersive liquid-liquid microextraction (UA-LDS-DLLME) had been applied for the determination of drugs of abuse (methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, methcathinone, ketamine, meperidine, and methadone) in urine and blood samples by gas chromatography-mass spectrometry. Parameters affecting extraction efficiency have been investigated and optimized for both methods. Under the optimum conditions, linearities were observed for all analytes in the range 0.0030-10 g/ml with the correlation coefficient (R) ranging from 0.9985 to 0.9995 for HF-LPME and in the range 0.0030-10 g/ml with the R ranging from 0.9985 to 0.9994 for DLLME. The recovery of 79.3-98.6% with RSDs of 1.2-4.5% was obtained for HF-LPME, and the recovery of 79.3-103.4% with RSDs of 2.4-5.7% was obtained for DLLME. The LODs (S/N=3) were estimated to be in the range from 0.5 to 5 ng/ml and 0.5 to 4 ng/ml, respectively. Compared with HF-LPME, the UA-LDS-DLLME technique had the advantages of less extraction time, suitability for batches of sample pretreatment simultaneously, and higher extraction efficiency, while HF-LPME has excellent sample clean-up effect, and is a robust and suitable technique for various sample matrices with better repeatability. Both methods were successfully applied to the analysis of drugs of abuse in real human blood sample.


Zhuge C.,Beijing Jiaotong University | Shao C.,Beijing Jiaotong University | Zheng C.,Traffic Management Bureau | Liang Q.,Traffic Management Bureau | Gao J.,Beijing Jiaotong University
Journal of Software | Year: 2013

With the VMS (Variable Message Signs) gradually and extensively used in major cities, it is necessary to develop a related evaluation system to evaluate its guidance effect systematically and efficiently. This paper primarily studies on developing a system to make the evaluation work more simply and quickly, and it chiefly contains the following five aspects: Firstly, conducting the system requirement analysis. Secondly, designing the overall system framework; Thirdly, designing and achieving every module's function; Fourthly, study on the main models used in the system; Finally, applying the evaluation system to practice by taking one road network of Beijing as an example. As a result, it indicates that the system can be successfully applied in practice. In addition, it can also save time and money. © 2013 ACADEMY PUBLISHER.


Zhuge C.,Beijing Jiaotong University | Shao C.,Beijing Jiaotong University | Zheng C.,Traffic Management Bureau | Qiao L.,Traffic Management Bureau
Advances in Intelligent and Soft Computing | Year: 2012

With the VMS gradually extensively used in major cities, it is necessary to evaluate its guiding result scientifically and systematically. This paper studies on the effect evaluating system of VMS, mainly includes evaluation index and comprehensive evaluation two parts. First, the evaluation index is made up of five indexes which are network, economy, environment, safety and driver. Second, compare the common comprehensive evaluation method and the Grey relational analysis is finally chose. Finally, take one region network of Beijing as an example to apply the evaluation system and prove its efficiency. © 2012 Springer-Verlag GmbH.

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