Examination of the Transferability of Safety Performance Functions for Developing Crash Modification Factors: Using the Empirical Bayes Method

Author(s):  
Jung-Han Wang ◽  
Mohamed Abdel-Aty ◽  
Jaeyoung Lee
2019 ◽  
Vol 9 (17) ◽  
pp. 3614
Author(s):  
Jaisung Choi ◽  
Richard Tay ◽  
Sangyoup Kim ◽  
Seungwon Jeong ◽  
Jeongmin Kim ◽  
...  

Hard shoulder running (HSR) has been increasingly used as a sustainable and viable way to increase road capacity. This study investigated the safety effect of HSR on freeways in South Korea using the empirical Bayes method. This study found an increase in the total number of crashes. In terms of crash severity, a higher proportion of crashes (25.3%) on 2(3)-lane sections were found to be serious (involving injuries and/or fatalities) compared to those on 4(5)-lane sections (3.6%). Also, a positive relationship was found between the length of the hard shoulder running and changes in crash frequencies. Thus, hard shoulder running on lengthy 2(3)-lane freeways should be avoided.


1996 ◽  
Vol 15 (17) ◽  
pp. 1875-1884 ◽  
Author(s):  
XIAO-HUA ZHOU ◽  
B. P. KATZ ◽  
E. HOLLEMAN ◽  
C. A. MELFI ◽  
R. DITTUS

Author(s):  
Erik Kristiansson ◽  
Anders Sjögren ◽  
Mats Rudemo ◽  
Olle Nerman

In microarray experiments quality often varies, for example between samples and between arrays. The need for quality control is therefore strong. A statistical model and a corresponding analysis method is suggested for experiments with pairing, including designs with individuals observed before and after treatment and many experiments with two-colour spotted arrays. The model is of mixed type with some parameters estimated by an empirical Bayes method. Differences in quality are modelled by individual variances and correlations between repetitions. The method is applied to three real and several simulated datasets. Two of the real datasets are of Affymetrix type with patients profiled before and after treatment, and the third dataset is of two-colour spotted cDNA type. In all cases, the patients or arrays had different estimated variances, leading to distinctly unequal weights in the analysis. We suggest also plots which illustrate the variances and correlations that affect the weights computed by our analysis method. For simulated data the improvement relative to previously published methods without weighting is shown to be substantial.


2017 ◽  
Vol 21 ◽  
pp. 114-129 ◽  
Author(s):  
Evangelos Evangelou ◽  
Vasileios Maroulas

2014 ◽  
Vol 2433 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Xiaoduan Sun ◽  
Subasish Das ◽  
Zhongjie Zhang ◽  
Fan Wang ◽  
Charles Leboeuf

2017 ◽  
Vol 22 (2) ◽  
pp. 804-812 ◽  
Author(s):  
Yoon Hwan Choi ◽  
Sung Ho Park ◽  
Hangeom Ko ◽  
Kyung Hyun Kim ◽  
Ilsoo Yun

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