scholarly journals A new strategy for synchronizing traffic flow on a distributed simulation using SUMO

10.29007/1x48 ◽  
2018 ◽  
Author(s):  
Nicolas Arroyo ◽  
Andrés Acosta ◽  
Jairo Espinosa ◽  
Jorge Espinosa
Keyword(s):  
Management Strategy ◽  
Distributed Simulation ◽  
Urban Traffic ◽  
Network Partitioning ◽  
Incoming Edge ◽  
New Strategy ◽  
Python Programming ◽  
And Control ◽  
The City ◽  
Modelling Simulation

The Project Modelling and Control of Urban Traffic in the City of Medell ́ın (MOY- COT) has produced multiple results in modelling, simulation and control of multimodal urban traffic using the SUMO simulator. As the simulations became more complex the necessity to distribute the computational load rose. Therefore, an approach for network partitioning and border edges management was introduced. In this paper a new border edge management strategy is presented for distributed simulation with SUMO. Unlike the previous approaches, which were developed in Python programming language using the corresponding TraCI client and tools such as sumolib, the strategy presented in this work was developed in C++ using the TraCI client for this language. Additionally, this strategy involves a simplified process for network partitioning since the border edges are preserved in every partition, without the need of splitting them. In this case, neighboring partitions behave in a master-slave fashion, depending on whether the border edge is an incoming edge or an outgoing edge. Concretely, a given partition is a master for its incoming edges and a slave for its outgoing ones. Furthermore, all the vehicles are found in the master and the slave partitions, where the master partition controls its slaves through the TraCI commands slowDown and moveTo that correct the position of these vehicles. Simulation results show that this new strategy presents better precision than the previous one. The description of the new procedure for border edge management is detailed. Finally, it is compared with the previous approach and the non-distributed simulation using a free flow scenario and a scenario with queue formation is presented.

On-Surface Radical Oligomerisation: A New Approach to STM Tip-Induced Reactions

2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  
Keyword(s):  
Sample Surface ◽  
Scanning Tunnelling Microscope ◽  
Transfer Event ◽  
New Approach ◽  
The Past ◽  
Organic Nanostructures ◽  
Scanning Tunnelling ◽  
New Strategy ◽  
Surface Fabrication ◽  
And Control

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.

scholarly journals Evaluating the Impact of Floods on Housing Price Using a Spatial Matching Difference-In-Differences (SM-DID) Approach

2021 ◽  
Vol 13 (2) ◽  
pp. 804
Author(s):  
Jean Dubé ◽  
Maha AbdelHalim ◽  
Nicolas Devaux
Keyword(s):  
Housing Price ◽  
Hedonic Pricing ◽  
Environmental Amenities ◽  
Sale Price ◽  
Difference In Differences ◽  
Hedonic Pricing Model ◽  
The Difference ◽  
And Control ◽  
The Impact ◽  
The City

Many applications have relied on the hedonic pricing model (HPM) to measure the willingness-to-pay (WTP) for urban externalities and natural disasters. The classic HPM regresses housing price on a complete list of attributes/characteristics that include spatial or environmental amenities (or disamenities), such as floods, to retrieve the gradients of the market (marginal) WTP for such externalities. The aim of this paper is to propose an innovative methodological framework that extends the causal relations based on a spatial matching difference-in-differences (SM-DID) estimator, and which attempts to calculate the difference between sale price for similar goods within “treated” and “control” groups. To demonstrate the potential of the proposed spatial matching method, the researchers present an empirical investigation based on the case of a flood event recorded in the city of Laval (Québec, Canada) in 1998, using information on transactions occurring between 1995 and 2001. The research results show that the impact of flooding brings a negative premium on the housing price of about 20,000$ Canadian (CAN).

scholarly journals A new model for COVID-19 control and its implementation in the city of Honghu, China: a case report

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
He-ran Wang ◽  
Meng-chun Gong ◽  
Jing-Yuan Sun ◽  
Jian Sun ◽  
Yi Guo ◽  
...  
Keyword(s):  
Management Strategy ◽  
Human Infection ◽  
Public Health Emergency ◽  
Medical Resources ◽  
Case Presentation ◽  
Management Measures ◽  
Rapid Spread ◽  
Medical Teams ◽  
Novel Coronavirus ◽  
The City

Abstract Background Novel coronavirus pneumonia has been the most serious worldwide public health emergency since being identified in December 2019. The rapid spread of the pandemic and the strong human to human infection rate of COVID-19 poses a great prevention challenge. There has been an explosion in the number of confirmed cases in several cities near Wuhan, including the highest in Honghu, Jinzhou. Owing to the limited admission capacity and medical resources, increasing numbers of suspected cases of COVID-19 infection were difficult to confirm or treat. Case presentation Following the arrival of the Guangdong medical aid team on 11 February, 2020, COVID-19 care in Honghu saw changes after a series of solutions were implemented based on the ‘Four-Early’ and ‘Four-centralization’ management measures. The ‘Four-Early’ measures are: early detection, early reporting, early quarantine, and early treatment for meeting an urgent need like the COVID-19 pandemic. ‘Four-centralization’ refers to the way in which recruited medical teams can make full use of medical resources to give patients the best treatment. These solutions successfully increased the recovery rate and reduced mortality among patients with COVID-19 in Honghu. Conclusions This management strategy is called the ‘Honghu Model’ which can be generalized to enable the prevention and management of COVID-19 worldwide.

scholarly journals SARS-CoV-2 Epidemics in Retirement and Nursing Homes in Italy: A New Preparedness Assessment Model after the First Epidemic Wave

2021 ◽  
Vol 18 (11) ◽  
pp. 5712
Author(s):  
Carmelo Gugliotta ◽  
Davide Gentili ◽  
Silvia Marras ◽  
Marco Dettori ◽  
Pietro Paolo Muglia ◽  
...  
Keyword(s):  
Nursing Homes ◽  
Perceived Risk ◽  
Assessment Tool ◽  
Resident Training ◽  
Assessment Model ◽  
Infection Prevention And Control ◽  
Field Assessment ◽  
Italian Context ◽  
And Control ◽  
The City

The aim of the study is to evaluate the preparedness of retirement and nursing homes in the city of Sassari at the end of the first wave of the severe acute respiratory syndrome coronavirus 2 epidemic, first by investigating the risk perception of epidemic outbreaks by the facility managers and subsequently by carrying out a field assessment of these facilities. To perform the field assessment, a checklist developed by the CDC (Infection Prevention and Control Assessment Tool for Nursing Homes Preparing for COVID-19) and adapted to the Italian context was used. Fourteen facilities took part in the survey (87.5%). The application of good practices for each survey area was expressed as a percentage with the following median values: restriction policies (87.5%), staff training (53.8%), resident training (67.6%), availability of personal protective equipment (41.7%), infection control practices (73.5%) and communication (80%). Among the facilities, considerable variability was observed in these evaluation fields: only the restriction policies and communication activities were applied uniformly. A discrepancy was found between perceived risk and real danger in the facilities, requiring targeted communication actions. At present, it is necessary to promote a new approach based on the prediction of critical events, thereby providing the means to effectively address them.

scholarly journals Measurements of urban traffic parameters before and after road reconstruction

2021 ◽  
Vol 11 (1) ◽  
pp. 365-376
Author(s):  
Andrzej Bąkowski ◽  
Leszek Radziszewski
Keyword(s):  
Urban Traffic ◽  
Noise Model ◽  
Vehicle Traffic ◽  
The Road ◽  
Passenger Vehicles ◽  
Before And After ◽  
Traffic Volumes ◽  
National Road ◽  
The City ◽  
Good Agreement

Abstract The study analyzed the parameters of vehicle traffic and noise on the national road in the section in the city from 2011 to 2016. In 2013–2014 this road was reconstructed. It was found that in most cases, the distribution of the tested variable was not normal. The median and selected percentiles of vehicle traffic parameters and noise were examined. The variability and type A uncertainty of the results were described and evaluated. The results obtained for the data recorded on working and non-working days were compared. The vehicle cumulative speed distributions, for two-way four-lane road segments in both directions were analyzed. A mathematical model of normalized traffic flow has been proposed. Fit factor R2 of the proposed equations to the experimental data for passenger vehicles ranges from 0.93 to 0.99. It has been shown that two years after the road reconstruction, the median noise level did not increase even though traffic volumes and vehicle speeds increased. The Cnossos noise model was validated for data recorded over a period of 6 years. A very good agreement of the medians determined according to the Cnossos-EU model and the measured ones was obtained. It should be noted, however, that for the other analyzed percentiles, e.g. 95%, the discrepancies are larger.

TripRes

2021 ◽  
Vol 17 (2) ◽  
pp. 1-21
Author(s):  
Xiaolong Xu ◽  
Zijie Fang ◽  
Lianyong Qi ◽  
Xuyun Zhang ◽  
Qiang He ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Discrete Distribution ◽  
Resource Provisioning ◽  
Path Selection ◽  
Urban Traffic ◽  
Traffic Flows ◽  
Multimedia Services ◽  
Traffic Flow Prediction ◽  
The City ◽  
Multimedia Surveillance

The Internet of Vehicles (IoV) connects vehicles, roadside units (RSUs) and other intelligent objects, enabling data sharing among them, thereby improving the efficiency of urban traffic and safety. Currently, collections of multimedia content, generated by multimedia surveillance equipment, vehicles, and so on, are transmitted to edge servers for implementation, because edge computing is a formidable paradigm for accommodating multimedia services with low-latency resource provisioning. However, the uneven or discrete distribution of the traffic flow covered by edge servers negatively affects the service performance (e.g., overload and underload) of edge servers in multimedia IoV systems. Therefore, how to accurately schedule and dynamically reserve proper numbers of resources for multimedia services in edge servers is still challenging. To address this challenge, a traffic flow prediction driven resource reservation method, called TripRes, is developed in this article. Specifically, the city map is divided into different regions, and the edge servers in a region are treated as a “big edge server” to simplify the complex distribution of edge servers. Then, future traffic flows are predicted using the deep spatiotemporal residual network (ST-ResNet), and future traffic flows are used to estimate the amount of multimedia services each region needs to offload to the edge servers. With the number of services to be offloaded in each region, their offloading destinations are determined through latency-sensitive transmission path selection. Finally, the performance of TripRes is evaluated using real-world big data with over 100M multimedia surveillance records from RSUs in Nanjing China.

Sign in / Sign up

Export Citation Format

Share Document