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Wyszukujesz frazę "traffic engineering" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Simulation and Comparison of Two Fusion Methods for Macroscopic Fundamental Diagram Estimation
Autorzy:
Lin, Xiaohui
Xu, Jianmin
Cao, Chengtao
Powiązania:
https://bibliotekanauki.pl/articles/224073.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
Inżynieria ruchu
Opis:
Accurate estimation of macroscopic fundamental diagram (MFD) is the precondition of MFD’s application. At present, there are two traditional estimation methods of road network’s MFD, such as the loop detector data (LDD) estimation method and the floating car data (FCD) estimation method, but there are limitations in both traditional estimation methods. In order to improve the accuracy of road network MFD estimation, a few scholars have studied the fusion method of road network MFD estimation, but there are still some shortcomings on the whole. However, based on the research of adaptive weighted averaging (AWA) fusion method for MFD estimation of road network, I propose to use the MFD’s two parameters of road network obtained by LDD estimation method and FCD estimation method, and establish a back-propagation neural network data fusion model for MFD parameters of road network (BPNN estimation fusion method), and then the micro-traffic simulation model of connected-vehicle network based on Vissim software is established by taking the intersection group of the core road network in Tianhe District of Guangzhou as the simulation experimental area, finally, compared and analyzed two MFD estimation fusion methods of road network, in order to determine the best MFD estimation fusion method of road network. The results show that the mean absolute percent error (MAPE) of the parameters of road network’s MFD and the average absolute values of difference values of the state ratio of road network’s MFD are both the smallest after BPNN estimation fusion, which is the closest to the standard MFD of road network. It can be seen that the result of BPNN estimation fusion method is better than that of AWA estimation fusion method, which can improve the accuracy of road network MFD estimation effectively.
Źródło:
Archives of Transport; 2019, 51, 3; 35-48
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Evaluation of Preemption Algorithms in MPLS Networks
Autorzy:
Kaczmarek, S.
Nowak, K.
Powiązania:
https://bibliotekanauki.pl/articles/226477.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MPLS
preemption
algorithms
traffic engineering
Opis:
Preemption is a traffic engineering technique in Multiprotocol Switching Network that enables creation of high priority paths when there is not enough free bandwidth left on the route. Challenging part of any preemption method is to select the best set of paths for removal. Several heuristic methods are available but no wider comparison had been published before. In this paper, we discusses the dilemmas in implementing preemption methods are presented the simulation studyof well known existing algorithms. Based on the results, we provide recommendations for deployment of preemption for the two most common evaluation criteria: number of preemption and preempted bandwidth.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 2; 169-175
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The road safety at turbo roundabouts in Poland
Autorzy:
Macioszek, E.
Powiązania:
https://bibliotekanauki.pl/articles/223668.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
turbo roundabouts
road safety
traffic engineering
rondo turbo
bezpieczeństwo ruchu drogowego
inżynieria ruchu
Opis:
There are to two groups of turbo roundabouts used currently in Poland. The first group is turbo roundabouts with geometry and traffic organization designed following the model of Dutch turbo roundabouts with raised lane dividers. The other group is turbo roundabouts with traffic organization which entirely or partly corresponds to traffic organization of conventional turbo roundabouts, but with lane dividers not present, with their function performed by a single continuous line of P-2 type. Turbo roundabouts in the world are considered as solutions which are characterized by a high level of road safety and allow for effective flow at substantial traffic intensities. The data about turbo roundabouts in Poland analysed by the author show that there are substantially more turbo roundabouts without raised lane dividers. The paper attempts to answer to the question of whether turbo roundabouts with lane dividers in the form of a single continuous line ensure the appropriate level of road safety. Furthermore, the comparison of the level of road safety in turbo roundabouts equipped in raised lane dividers with turbo roundabouts with lane separators in the form of continuous line revealed that turbo roundabouts with raised lane dividers are safer solutions than turbo roundabouts with traffic lane dividers in the form of continuous line.
Źródło:
Archives of Transport; 2015, 33, 1; 57-67
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of driver behaviour at turbo-roundabouts
Autorzy:
Chodur, J.
Bąk, R.
Powiązania:
https://bibliotekanauki.pl/articles/223750.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
road safety
turbo-roundabout
separation of traffic lanes
inżynieria ruchu
bezpieczeństwo na drodze
turborondo
rozdzielenie pasów ruchu
Opis:
The article presents the results of preliminary research into the behaviour of drivers at turbo-roundabouts. The subject of the research included the frequency of driver behaviour against the traffic rules, and the speed at which vehicles drive through turbo-roundabouts. One of the crucial problems which was analysed was the influence of different kinds of traffic lane division on the behaviour of drivers. The analysis results affirm that the raised lane dividers can visibly improve the propensity of drivers to stay within the designated traffic corridor. However, it does not eliminate the phenomenon of improper lane changing on circulatory roadway. The physical separation of traffic lanes has not been determined to introduce any additional hazard. The speed of vehicles encroaching upon the neighbouring traffic corridor is visibly higher than this of vehicles following traffic rules. Using crash prediction models developed for single- and multi-lane roundabouts, the authors of the research estimated that lane dividers may reduce the number of crashes from about 10% to 17%.
Źródło:
Archives of Transport; 2016, 38, 2; 17-28
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carpooling Scheme Selection for Taxi Carpooling Passengers: a Multi-Objective Model and Optimisation Algorithm
Autorzy:
Xiao, Q.
He, R.-C.
Powiązania:
https://bibliotekanauki.pl/articles/223987.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
taxi carpooling
multi-objective optimisation
information entropy
inżynieria ruchu
system carpooling
wspólne dojazdy
infrastruktura transportowa
optymalizacja
Opis:
Carpooling has been long deemed a promising approach to better utilizing existing transportation infrastructure, the carpooling system can alleviate the problems of traffic congestion and environmental pollution effectively in big cities. However, algorithmic and technical barriers inhibit the development of taxi carpooling, and it is still not the preferred mode of commute. In order to improve carpooling efficiency in urban, a taxi carpooling scheme based on multi-objective model and optimisation algorithm is presented. In this paper, urban traffic road network nodes were constructed from the perspective of passenger carpooling. A multi-objective taxi carpooling scheme selection model was built based on an analysis of the main influences of carpooling schemes on passengers. This model aimed to minimise get-on-and-get-off distance, carpooling waiting time and arriving at the destination. Furthermore, a two-phase algorithm was used to solve this model. A rapid searching algorithm for feasible routes was established, and the weight vector was assigned by introducing information entropy to obtain satisfying routes. The algorithm is applied to the urban road, the Simulation experimental result indicates that the optimisation method presented in this study is effective in taxi carpooling passengers.
Źródło:
Archives of Transport; 2017, 42, 2; 85-92
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comprehensive service quality evaluation of public transit based on extension cloud model
Autorzy:
Hu, Xinghua
Chen, Xinghui
Zhao, Jiahao
Yu, Kun
Long, Bing
Dai, Gao
Powiązania:
https://bibliotekanauki.pl/articles/2173929.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
public transit
urban traffic congestion
service quality
optimization
sustainable development
inżynieria ruchu
transport publiczny
zatory komunikacyjne
ocena jakości usług
optymalizacja
zrównoważony rozwój
Opis:
Prioritizing the development of public transit and enhancing its attractiveness is an important way to solve the problem of urban traffic congestion and achieve sustainable development. To improve the service quality and overall operational efficiency of urban public transit, an evaluation index system related to the comprehensive experience of passengers, service supply quality of public transit enterprises, and supervision of management departments was introduced from both the demand and the supply of public transit travel services. Based on the data distribution characteristics of the boxplot in statistics, the evaluation level and corresponding value range of each index were determined, and the comprehensive weight of the index was determined using the linear weighting method combining the analytic hierarchy process and the entropy weight method, so as to reduce the influence of single weighting method on the evaluation results of comprehensive service quality of public transit. An evaluation method of public transit comprehensive service quality based on the extension cloud model was established. The evaluation results of the model were obtained by calculating the cloud affiliation and comprehensive certainty, and a reliability factor was used to test the evaluation results, which solved the problem of randomness and fuzziness in the process of comprehensive service quality evaluation of public transportation and made the evaluation results closer to the reality. Finally, the established comprehensive evaluation model was applied to a city for example analysis, and the corresponding evaluation level was obtained as good. The value of the reliability factor in the model was less than 0.01, indicating that the model has good applicability and a certain application value for the comprehensive service quality evaluation of public transit. The evaluation method fully considered a variety of evaluation indicators, specified the evaluation level of comprehensive service quality of public transit, and the evaluation results provide a theoretical basis for public transport enterprise to make targeted improvement measures.
Źródło:
Archives of Transport; 2022, 61, 1; 103--115
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the road linear optimization design of bridge and tunnel connecting segment in the canyon
Autorzy:
Wang, Lu
Liu, Yuwen
Chen, Xiaoxin
Powiązania:
https://bibliotekanauki.pl/articles/223553.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
curved road
simulation experiment
radius of curve
bridge
tunnel
traffic safety
inżynieria ruchu
łuk drogi
eksperyment symulacyjny
promień łuku
most
tunel
bezpieczeństwo na drodze
Opis:
It is easy to skid and roll by centrifugal force and wind, which affects the safety of the vehicle. At the same time, the special location of bridge and tunnel connecting segment in the canyon will accelerate the wind, and make the transverse wind play a more important role in driving vehicles. Based on the acceleration effect of canyons on wind, the vehicle model is simulated by Carsim software, and the road and wind models are established. It is studied that the vehicle has different radius of circular curve under different wind levels, corresponding to different superelevation. The lateral acceleration, lateral deflection and transverse force coefficient are selected as the running state of the vehicle at different speeds to research the linear optimization design of bridge and tunnel connecting segment in the canyon. The result shows that when the wind force exceeds the fifth grade, it is possible for the vehicle to overturn under the limit minimum radius required by the standard value. In order to ensure the stability and safety of the vehicle, this paper considers the geographical position of bridge and tunnel connecting segment in the canyon and the relationship between the radius of the superelevation and circular curve. What’s more, it puts forward the optimal limit minimum radius of the circular curve with different wind grades of 5-9 grades. At the same time, when the road alignment cannot be optimized under the condition, this paper puts forward the speed limit that the vehicle safety can be guaranteed under different wind speed conditions. The speed limit can provide reference for traffic management and safety guarantee of mountain expressway.
Źródło:
Archives of Transport; 2019, 52, 4; 81-93
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Road network partitioning method based on Canopy-Kmeans clustering algorithm
Autorzy:
Lin, Xiaohui
Xu, Jianmin
Powiązania:
https://bibliotekanauki.pl/articles/949836.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
road network
road network partition
Canopy-Kmeans algorithm
macroscopic fundamental diagram
inżynieria ruchu
sieć drogowa
sterowanie siecią drogową
algorytm Canopy-Kmeans
Opis:
With the increasing scope of traffic signal control, in order to improve the stability and flexibility of the traffic control system, it is necessary to rationally divide the road network according to the structure of the road network and the characteristics of traffic flow. However, road network partition can be regarded as a clustering process of the division of road segments with similar attributes, and thus, the clustering algorithm can be used to divide the sub-areas of road network, but when Kmeans clustering algorithm is used in road network partitioning, it is easy to fall into the local optimal solution. Therefore, we proposed a road network partitioning method based on the Canopy-Kmeans clustering algorithm based on the real-time data collected from the central longitude and latitude of a road segment, average speed of a road segment, and average density of a road segment. Moreover, a vehicle network simulation platform based on Vissim simulation software is constructed by taking the real-time collected data of central longitude and latitude, average speed and average density of road segments as sample data. Kmeans and Canopy-Kmeans algorithms are used to partition the platform road network. Finally, the quantitative evaluation method of road network partition based on macroscopic fundamental diagram is used to evaluate the results of road network partition, so as to determine the optimal road network partition algorithm. Results show that these two algorithms have divided the road network into four sub-areas, but the sections contained in each sub-area are slightly different. Determining the optimal algorithm on the surface is impossible. However, Canopy-Kmeans clustering algorithm is superior to Kmeans clustering algorithm based on the quantitative evaluation index (e.g. the sum of squares for error and the R-Square) of the results of the subareas. Canopy-Kmeans clustering algorithm can effectively partition the road network, thereby laying a foundation for the subsequent road network boundary control.
Źródło:
Archives of Transport; 2020, 54, 2; 95-106
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feedforward feedback iterative learning control method for the multilayer boundaries of oversaturated intersections based on the macroscopic fundamental diagram.
Autorzy:
Lin, Xiaohui
Xu, Jianmin
Powiązania:
https://bibliotekanauki.pl/articles/224037.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
oversaturated intersection
multilayer boundary
macroscopic fundamental diagram
feedforward feedback
iterative control
inżynieria ruchu
przesycone skrzyżowanie
granica wielowarstwowa
makroskopowy diagram fundamentalny
sprzężenie zwrotne
Opis:
The feedback control based on the model and method of iterative learning control, which in turn is based on the macroscopic fundamental diagram (MFD), mostly belongs to the classification of single-layer boundary control method. However, the feedback control method has the problem of time delay. Therefore, a feed forward feedback iterative learning control (FFILC) method based on MFD of the multi-layer boundary of single-area oversaturated intersections is proposed. The FFILC method can improve the effectiveness of boundary control and avoid the time-delay problem of feedback control. Firstly, MFD theory is used to determine the MFD of the control area; the congestion zone and the transition zone of the control area are identified; and the two-layer boundary of the control area is determined. Then, the FFILC controllers are established at the two-layer boundary of the control area. When the control area enters into a congestion state, the control ratio of traffic flow in and out of the two-layer boundary is adjusted. The cumulative number of vehicles in the control area continues to approach the optimal cumulative number of vehicles, and it maintains high traffic efficiency with high flow rates. Finally, The actual road network is taken as the experimental area, and the road network simulation platform is built. The controller of the feedforward iterative learning control (FILC) is selected as the comparative controller and used to analyse the iterative effect of FFILC. Improvements in the use of traffic signal control indicators for the control area are analysed after the implementation of the FFILC method. Results show that the FFILC method considerably reduces the number of iterations, and it can effectively improve convergence speed and the use of traffic signal evaluation indicators for the control area.
Źródło:
Archives of Transport; 2020, 53, 1; 67-87
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved mathematical model for vehicle crashagainst highway guardrails
Autorzy:
He, L.
Lin, X.
Powiązania:
https://bibliotekanauki.pl/articles/224317.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
roadway engineering
mechanical model
roadway guardrail
traffic safety
lateral rotation
vehicle crash
inżynieria drogowa
model mechaniczny
bariera drogowa
poręcz autostradowa
bezpieczeństwo na drodze
Opis:
Highway guardrail is a kind of important road traffic safety facility. When a vehicle is travelling on a highway, it can lose control because of accident. The guardrail can prevent the vehicle from rushing directly out of the road, so as to reduce the injury to the driver in the vehicle. Therefore, the guiding performance, anti-collision performance and buffer performance of the guardrail are important indexes to reflect the highway guardrail safety in the traffic accidents between vehicle and guardrail. The process of collisions between vehicles and guardrails is a complex motion, affected by multiple factors such as the movement patterns and types of vehicles, the types of guardrail, the bending stiffness of the beams, the speed of collision, the angle of collision, etc. The accuracy of energy estimation when vehicle collides with guardrail is the foundation of highway guardrail design, installation and improvement. Many experts and scholars at home and abroad have done a lot of theoretical research and experimental verifications on the safety performance of highway guardrail, and analyzed the anti-collision ability and energy absorption effect of highway guardrail. Single degree of freedom model is the most widely used mathematical model of vehicle collision in highway guardrail. The traditional model is more suitable for calculating the maximum impact force of small vehicles, but it is not accurate for large vehicles. However, due to the unreasonableness of the model in the theoretical derivation process, there is a large error in the mathematical model, especially in estimating the accuracy of the energy value of the large vehicle collision guardrail. Practice shows that the current guardrail cannot withstand the impact of large vehicles. Once large vehicles collide with the corrugated beam guardrail, the guardrail will collapse in most cases, and the vehicle will rush out of the road directly, so it is very difficult to exert the protective function of the guardrail. The anti-collision performance of guardrail is poor, which is related to the existing calculation model, which results in insufficient strength in the design of guardrail.
Źródło:
Archives of Transport; 2018, 48, 4; 41-49
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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