scholarly journals Diffusion Model of a Non-Integer Order PIγ Controller with TCP/UDP Streams

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 619
Author(s):  
Dariusz Marek ◽  
Adam Domański ◽  
Joanna Domańska ◽  
Jakub Szyguła ◽  
Tadeusz Czachórski ◽  
...  
Keyword(s):  
Diffusion Model ◽  
Traffic Congestion ◽  
Queue Management ◽  
Transport Protocols ◽  
Ip Routers ◽  
Control Traffic ◽  
The Impact ◽  
Mutually Independent ◽  
Fractional Controller ◽  
Management Algorithms

In this article, a way to employ the diffusion approximation to model interplay between TCP and UDP flows is presented. In order to control traffic congestion, an environment of IP routers applying AQM (Active Queue Management) algorithms has been introduced. Furthermore, the impact of the fractional controller PIγ and its parameters on the transport protocols is investigated. The controller has been elaborated in accordance with the control theory. The TCP and UDP flows are transmitted simultaneously and are mutually independent. Only the TCP is controlled by the AQM algorithm. Our diffusion model allows a single TCP or UDP flow to start or end at any time, which distinguishes it from those previously described in the literature.

scholarly journals Fluid flow approximation of time-limited TCP/UDP/XCP streams

2014 ◽  
Vol 62 (2) ◽  
pp. 217-225 ◽  
Author(s):  
J. Domańska ◽  
A. Domański ◽  
T. Czachórski ◽  
J. Klamka
Keyword(s):  
Fluid Flow ◽  
Traffic Congestion ◽  
Time Moment ◽  
Active Queue Management ◽  
Queue Management ◽  
Flow Approximation ◽  
Ip Routers ◽  
Control Traffic ◽  
Management Algorithms

Abstract This article presents the use of fluid flow approximation to model interactions between a set of TCP, UDP and XCP flows in the environment of IP routers using AQM (Active Queue Management) algorithms to control traffic congestion. In contrast to other works, independent UDP and TCP streams are considered and the model allows to start and end data transmissions in TCP, UDP and XCP streams at any time moment. It incorporates several Active Queue Management mechanisms: RED, NLRED, CHOKe.

scholarly journals A review on Queue Management Algorithms in Large Networks

2021 ◽  
Vol 1076 (1) ◽  
pp. 012034
Author(s):  
Mustafa Maad Hamdi ◽  
Hussain Falih Mahdi ◽  
Mohammed Salah Abood ◽  
Ruaa Qahtan Mohammed ◽  
Abdulkareem Dawah Abbas ◽  
...  
Keyword(s):  
Queue Management ◽  
Large Networks ◽  
Management Algorithms

scholarly journals Behavior of Traffic Congestion and Public Transport in Eight Large Cities in Latin America during the COVID-19 Pandemic

2021 ◽  
Vol 11 (10) ◽  
pp. 4703
Author(s):  
Renato Andara ◽  
Jesús Ortego-Osa ◽  
Melva Inés Gómez-Caicedo ◽  
Rodrigo Ramírez-Pisco ◽  
Luis Manuel Navas-Gracia ◽  
...  
Keyword(s):  
Latin American ◽  
Public Transport ◽  
Public Transportation ◽  
Traffic Congestion ◽  
Urban Transport ◽  
Control Measures ◽  
Johns Hopkins Hospital ◽  
Large Cities ◽  
Public Data ◽  
The Impact

This comparative study analyzes the impact of the COVID-19 pandemic on motorized mobility in eight large cities of five Latin American countries. Public institutions and private organizations have made public data available for a better understanding of the contagion process of the pandemic, its impact, and the effectiveness of the implemented health control measures. In this research, data from the IDB Invest Dashboard were used for traffic congestion as well as data from the Moovit© public transport platform. For the daily cases of COVID-19 contagion, those published by Johns Hopkins Hospital University were used. The analysis period corresponds from 9 March to 30 September 2020, approximately seven months. For each city, a descriptive statistical analysis of the loss and subsequent recovery of motorized mobility was carried out, evaluated in terms of traffic congestion and urban transport through the corresponding regression models. The recovery of traffic congestion occurs earlier and faster than that of urban transport since the latter depends on the control measures imposed in each city. Public transportation does not appear to have been a determining factor in the spread of the pandemic in Latin American cities.

scholarly journals An Efficiency Enhancing Methodology for Multiple Autonomous Vehicles in an Urban Network Adopting Deep Reinforcement Learning

2021 ◽  
Vol 11 (4) ◽  
pp. 1514 ◽  
Author(s):  
Quang-Duy Tran ◽  
Sang-Hoon Bae
Keyword(s):  
Reinforcement Learning ◽  
Traffic Congestion ◽  
Autonomous Vehicles ◽  
Penetration Rate ◽  
Autonomous Vehicle ◽  
Effective Means ◽  
Urban Network ◽  
Learning Agents ◽  
Policy Optimization ◽  
The Impact

To reduce the impact of congestion, it is necessary to improve our overall understanding of the influence of the autonomous vehicle. Recently, deep reinforcement learning has become an effective means of solving complex control tasks. Accordingly, we show an advanced deep reinforcement learning that investigates how the leading autonomous vehicles affect the urban network under a mixed-traffic environment. We also suggest a set of hyperparameters for achieving better performance. Firstly, we feed a set of hyperparameters into our deep reinforcement learning agents. Secondly, we investigate the leading autonomous vehicle experiment in the urban network with different autonomous vehicle penetration rates. Thirdly, the advantage of leading autonomous vehicles is evaluated using entire manual vehicle and leading manual vehicle experiments. Finally, the proximal policy optimization with a clipped objective is compared to the proximal policy optimization with an adaptive Kullback–Leibler penalty to verify the superiority of the proposed hyperparameter. We demonstrate that full automation traffic increased the average speed 1.27 times greater compared with the entire manual vehicle experiment. Our proposed method becomes significantly more effective at a higher autonomous vehicle penetration rate. Furthermore, the leading autonomous vehicles could help to mitigate traffic congestion.

An improved car-following model considering the impact of safety messages

2018 ◽  
Vol 32 (32) ◽  
pp. 1850398 ◽  
Author(s):  
Tenglong Li ◽  
Fei Hui ◽  
Xiangmo Zhao
Keyword(s):  
Traffic Congestion ◽  
Dominant Factor ◽  
Velocity Difference ◽  
Car Following ◽  
Safety Message ◽  
Warning Messages ◽  
Gray Correlation ◽  
Car Following Model ◽  
The Stability ◽  
The Impact

The existing car-following models of connected vehicles commonly lack experimental data as evidence. In this paper, a Gray correlation analysis is conducted to explore the change in driving behavior with safety messages. The data mining analysis shows that the dominant factor of car-following behavior is headway with no safety message, whereas the velocity difference between the leading and following vehicle becomes the dominant factor when warning messages are received. According to this result, an extended car-following model considering the impact of safety messages (IOSM) is proposed based on the full velocity difference (FVD) model. The stability criterion of this new model is then obtained through a linear stability analysis. Finally, numerical simulations are performed to verify the theoretical analysis results. Both analytical and simulation results show that traffic congestion can be suppressed by safety messages. However, the IOSM model is slightly less stable than the FVD model if the average headway in traffic flow is approximately 14–20 m.

scholarly journals Le port de Montréal à la veille de l’ouverture de la nouvelle voie navigable du Saint-Laurent

2005 ◽  
Vol 3 (5) ◽  
pp. 85-95
Author(s):  
Pierre Camu
Keyword(s):  
Great Lakes ◽  
Traffic Congestion ◽  
Royal Commission ◽  
Different Types ◽  
Mcgill University ◽  
General Cargo ◽  
The Impact

A few months before the opening of the new St. Lawrence Seaway, the author reappraises the effects of the Project on the Port of Montréal. Analysing the conclusions and recommendations of three studies published in 1957 and 1958, the Report of the ToIIs Committee of the St. Lawrence Seaway, the Report of the Royal Commission on Coastal Trade, and the report published by the Faculty of Commerce of McGill University, The Impact of the St. Lawrence Seaway on the Montréal Area, one comes to the conclusion that the Port of Montréal will remain a grain transhipment centre, but will lose a good part of its general cargo trade to Great Lakes ports. The loss of general cargo tonnage is estimated at 650,000 tons. In conclusion, several factors that may contribute to keep Montréal the leading oceanic port on the Seaway are stressed : 1. the imponderables ; 2. the Lachine rapids that are reduced in size by the new canal, but do not disappear; 3. competition between different types of vessels ; and, 4. traffic congestion in the waterway.

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