The expected effectivity of the dynamic speed limit algorithm SPECIALIST - A field data evaluation method

Author(s):  
A. Hegyi ◽  
S.P. Hoogendoorn ◽  
M. Schreuder ◽  
H. Stoelhorst
2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Huixuan Ye ◽  
Lili Tu ◽  
Jie Fang

Variable Speed Limit (VSL) control contributes to potential crash risk reduction by suggesting a suitable dynamic speed limit to achieve more stable and uniform traffic flow. In recent studies, researchers adopted macroscopic traffic flow models and perform prediction-based optimal VSL control. The response of drivers to the advised VSL is one of the most critical parameters in VSL-controlled speed dynamics modeling, which significantly affects the accuracy of traffic state prediction as well as the control reliability and performance. Nevertheless, the variations of driver responses were not explicitly modeled. Thus, in this research, the authors proposed a dynamic driver response model to formulate how the drivers respond to the advised VSL during various traffic conditions. The model was established and calibrated using field data to quantitatively analyze the dynamics of drivers’ desired speed regarding the advised VSL and current traffic state variables. A proactive VSL control algorithm incorporating the established driver response model was designed and implemented in field-data-based simulation study. The design proactive control algorithm modifies VSL in real-time according to the traffic state prediction results, aiming to reduce potential crash risks over the experiment site. By taking into account the real-time driver response variations, the VSL-controlled traffic state dynamics was more accurately predicted. The experimental results illustrated that the proposed control algorithm effectively reduces the crash probabilities in the traffic network.


Author(s):  
Kai Lin ◽  
Min Chen ◽  
Joel J. P. C. Rodrigues ◽  
Hongwei Ge

Body Sensor Networks (BSNs) are formed by the equipped or transplanted sensors in the human body, which can sense the physiology and environment parameters. As a novel e-health technology, BSNs promote the deployment of innovative healthcare monitoring applications. In the past few years, most of the related research works have focused on sensor design, signal processing, and communication protocol. This chapter addresses the problem of system design and data fusion technology over a bandwidth and energy constrained body sensor network. Compared with the traditional sensor network, miniaturization and low-power are more important to meet the requirements to facilitate wearing and long-running operation. As there are strong correlations between sensory data collected from different sensors, data fusion is employed to reduce the redundant data and the load in body sensor networks. To accomplish the complex task, more than one kind of node must be equipped or transplanted to monitor multi-targets, which makes the fusion process become sophisticated. In this chapter, a new BSNs system is designed to complete online diagnosis function. Based on the principle of data fusion in BSNs, we measure and investigate its performance in the efficiency of saving energy. Furthermore, the authors discuss the detection and rectification of errors in sensory data. Then a data evaluation method based on Bayesian estimation is proposed. Finally, the authors verify the performance of the designed system and the validity of the proposed data evaluation method. The chapter is concluded by identifying some open research issues on this topic.


2016 ◽  
Vol 37 (4) ◽  
pp. 555-560 ◽  
Author(s):  
Jin Qiuyu ◽  
Ma Fei ◽  
Liu Entao ◽  
Wang Yun ◽  
Zhao Weiqian

1994 ◽  
Vol 27 (15) ◽  
pp. 4391-4396 ◽  
Author(s):  
Gabriele Feldmann ◽  
Alisa Winsauer ◽  
Jiri Pfleger ◽  
Wolfram Schnabel

2013 ◽  
Vol 842 ◽  
pp. 733-736
Author(s):  
Zhao Yan Li ◽  
Zhuo Shi Chen

CPT is a kind of relatively superior field test technology, which is one of important the liquefaction in-situ test at home and abroad. In 1987, China has formed the national standard CPT liquefaction evaluation method, which predominantly from 1976 Tangshan earthquake liquefaction data, and then has not been tested. Recently by the 40 CPT liquefaction field data of Bachu earthquake obtained a liquefied evaluation formula. Due to comparing the liquefied evaluation methods at home and abroad, found the national standard CPT liquefied critical curve is qualitatively distinct to the others liquefied evaluation methods. If it is wrong about the code of CPT liquefied evaluation method, which the liquefied critical curve will be smaller along with the direction of the depth, will direct the liquefied evaluation critically be conservative and the depth liquefaction evaluation clearly be hazardous. In theory, this problem can be attributed to the influence of sand depth for liquefied evaluation, worthy of further discussion.


2019 ◽  
Vol 31 (5) ◽  
pp. 465-474 ◽  
Author(s):  
D. Sommermann ◽  
T. Triller ◽  
W. Köhler

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