scholarly journals Uma Nova Metodologia para formação de Grupos em VANETs

Author(s):  
André Vieira ◽  
Claudio Farias ◽  
Wilson Melo Jr.

This work proposes a new methodology to create groups in intervehicular networks as a basis for complex applications involving smart vehicles. We proposed a distributed protocol whose purpose is to build a higher number of groups in less time, keeping the vehicles grouped for most of their journey. We implement our proposal in two versions. The first one considers only the interaction among vehicles. The second includes a group merge functionality. We validate both versions of our protocol using simulation with real traffic data. We evaluate the amount of created groups and their persistence and size.

Author(s):  
Lu Sun ◽  
Jie Zhou

Empirical speed–density relationships are important not only because of the central role that they play in macroscopic traffic flow theory but also because of their connection to car-following models, which are essential components of microscopic traffic simulation. Multiregime traffic speed– density relationships are more plausible than single-regime models for representing traffic flow over the entire range of density. However, a major difficulty associated with multiregime models is that the breakpoints of regimes are determined in an ad hoc and subjective manner. This paper proposes the use of cluster analysis as a natural tool for the segmentation of speed–density data. After data segmentation, regression analysis can be used to fit each data subset individually. Numerical examples with three real traffic data sets are presented to illustrate such an approach. Using cluster analysis, modelers have the flexibility to specify the number of regimes. It is shown that the K-means algorithm (where K represents the number of clusters) with original (nonstandardized) data works well for this purpose and can be conveniently used in practice.


2002 ◽  
Vol 49 (1-4) ◽  
pp. 147-163 ◽  
Author(s):  
Mengzhi Wang ◽  
Anastassia Ailamaki ◽  
Christos Faloutsos

2004 ◽  
Vol 27 (1) ◽  
pp. 9-31 ◽  
Author(s):  
John Soldatos ◽  
Evangelos Vayias ◽  
Panagiotis Stathopoulos ◽  
Nikolas Mitrou

2021 ◽  
Vol 11 (21) ◽  
pp. 9914
Author(s):  
Aleksandra Romanowska ◽  
Kazimierz Jamroz

The fundamental relationship of traffic flow and bivariate relations between speed and flow, speed and density, and flow and density are of great importance in transportation engineering. Fundamental relationship models may be applied to assess and forecast traffic conditions at uninterrupted traffic flow facilities. The objective of the article was to analyze and compare existing models of the fundamental relationship. To that end, we proposed a universal and quantitative method for assessing models of the fundamental relationship based on real traffic data from a Polish expressway. The proposed methodology seeks to address the problem of finding the best deterministic model to describe the empirical relationship between fundamental traffic flow parameters: average speed, flow, and density based on simple and transparent criteria. Both single and multi-regime models were considered: a total of 17 models. For the given data, the results helped to identify the best performing models that meet the boundary conditions and ensure simplicity, empirical accuracy, and good estimation of traffic flow parameters.


2019 ◽  
Vol 145 (4) ◽  
pp. 04019010
Author(s):  
Alberto E. García-Moreno ◽  
Carlos Rosa-Jiménez ◽  
Carlos Prados-Gómez ◽  
María José Márquez-Ballesteros ◽  
Pedro Lázaro ◽  
...  
Keyword(s):  

2017 ◽  
Vol 3 (3) ◽  
pp. 195-210 ◽  
Author(s):  
Abdul Hafidz Abdul Hanan ◽  
Mohd. Yazid Idris ◽  
Omprakash Kaiwartya ◽  
Mukesh Prasad ◽  
Rajiv Ratn Shah

Author(s):  
Jinning Li ◽  
Liting Sun ◽  
Wei Zhan ◽  
Masayoshi Tomizuka

Abstract Autonomous vehicles (AVs) need to interact with other traffic participants who can be either cooperative or aggressive, attentive or inattentive. Such different characteristics can lead to quite different interactive behaviors. Hence, to achieve safe and efficient autonomous driving, AVs need to be aware of such uncertainties when they plan their own behaviors. In this paper, we formulate such a behavior planning problem as a partially observable Markov Decision Process (POMDP) where the cooperativeness of other traffic participants is treated as an unobservable state. Under different cooperativeness levels, we learn the human behavior models from real traffic data via the principle of maximum likelihood. Based on that, the POMDP problem is solved by Monte-Carlo Tree Search. We verify the proposed algorithm in both simulations and real traffic data on a lane change scenario, and the results show that the proposed algorithm can successfully finish the lane changes without collisions.


2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Ying Zhuo ◽  
Lan Yan ◽  
Wenbo Zheng ◽  
Yutian Zhang ◽  
Chao Gou

Autonomous driving has become a prevalent research topic in recent years, arousing the attention of many academic universities and commercial companies. As human drivers rely on visual information to discern road conditions and make driving decisions, autonomous driving calls for vision systems such as vehicle detection models. These vision models require a large amount of labeled data while collecting and annotating the real traffic data are time-consuming and costly. Therefore, we present a novel vehicle detection framework based on the parallel vision to tackle the above issue, using the specially designed virtual data to help train the vehicle detection model. We also propose a method to construct large-scale artificial scenes and generate the virtual data for the vision-based autonomous driving schemes. Experimental results verify the effectiveness of our proposed framework, demonstrating that the combination of virtual and real data has better performance for training the vehicle detection model than the only use of real data.


Sign in / Sign up

Export Citation Format

Share Document