2,117,819 research outputs found
Developing safety performance functions for railway grade crossings: A case study of Canada
No full textAlthough accident frequencies at railway grade crossings have shown a decreasing trend over the last two decades (partly due to implemented safety improvements and technological advances), safety at grade crossings is still a major concern since crossing accidents are usually associated with devastating consequences. This paper investigates the effect of various site attributes on railway crossing safety outcomes using recent Canada wide data from a 6-year period (2008-2013). The new data sets allow adjusting previous accident models according to latest circumstances (e.g., vehicles' improved safety features) affecting safety dynamics at crossings. Employing Bayesian hierarchical models including the non-conventional Poisson-Weibull model, different safety performance functions were separately developed for crossings with the following major warning systems: (1) flashing light and bell (FLB), (2) flashing light, bell, and gate (FLBG), (3) standard reflectorized crossing sign (SRCS), and (4) standard reflectorized crossing sign and stop sign (SRCS & STOP). Among other findings, the results indicated that traffic exposure (product of train and vehicle), number of lanes, whistle prohibition, train speed, and road speed were the most important factors affecting accident frequencies at Canadian railway crossings. It should be also noted that safety performance functions vary, in terms of independent variables and their associated coefficients, between the aforementioned warning devices.</p
Liping Zhu Interview, July 22, 1998
No full textLiping Zhu describes the experiences of Chinese immigrants in the American West in the last 19th and early 20th centuries. He describes the employment open to Chinese immigrants, including mining and railroad construction, the reasons for their high mortality rates, and cultural exchanges. Zhu discusses Chinese funerals, the fall of the Ching Dynasty, Chinese food, fireworks, and the tight-knit community of the Chinese immigrants in the West.https://scholarworks.umt.edu/fareast_oldwest_oralhistory/1010/thumbnail.jp
Church in Liping
No full textPhotograph from Liping of Liping Qiao Street Church. This church is located in Liping, Qiandongnan Miao and Dong Autonomous Prefecture, Guizhou Province Liping.https://scholarlycommons.pacific.edu/kam-photos/2998/thumbnail.jp
A resource optimization framework for improving railway-highway grade crossing safety in Canada
No full textThis paper presents a new approach to address the problem of allocating federal resources and identifying upgrading projects for improving the safety of at-grade crossings in Canada. The proposed approach is unique in two key aspects. First, a risk-based network screening process is adopted to identify the priority sites for providing a justifiable basis for distributing the total budget at a regional level as well as narrowing the search space in the subject optimization step. Secondly, a mathematical programming approach is applied to formalize the resource allocation process with explicit consideration of the expected benefits - risk reduction and the costs of implementing the projects. This approach is expected to improve the process of identifying the optimal set of upgrading projects within each region, thus maximizing the return of investment. A full-scale case study from the Canadian crossing network is conducted to demonstrate the application of the proposed approach
GUO-Liping/Rockfall_motion_analysis: Rockfall motion analysis
No full textRockfall motion analysis: Added an icon to GUI
Meeting Liping Ma
No full textRecenze knihy MA, Liping. Znát a učit elementární matematiku. Jak učitelé v Číně a ve Spojených státech rozumí základní matematice. Praha: Academia, 2021. Jubilejní vydání
Meeting Liping Ma
No full textsummary:Recenze knihy MA, Liping. Znát a učit elementární matematiku. Jak učitelé v Číně a ve Spojených státech rozumí základní matematice. Praha: Academia, 2021. Jubilejní vydání
Identifying areas of high risk for collisions: A Canda-wide study of grade crossing safety
No full textRanking sites and identifying high-crash risk locations based on various safety performance measures (e.g. expected crash frequency) are among the key tasks of the safety management program, enabling an effective allocation of funds for safety improvement projects. While several studies have discussed the issues relating to the hotspot identification process at a micro-level (e.g., intersections or highway segments), less attention is given to the macro-level hotspot identification issue: how to identify areas or regions with the highest risk of crashes. In this research, we introduce a Bayesian multilevel (hierarchical) model for estimating the regional differences while controlling for other important site attributes. The proposed method is illustrated using a case study on railway grade crossings in Canada. While accommodating the spatial dependencies of crash risk, our method allows a fair comparison of different regions by adjusting for the effect of covariates such as traffic exposure. In particular, we compute pairwise probabilities of crash risk for each province in Canada compared to all others. We are therefore able to draw inferences about regional safety performances under similar circumstances. Our findings indicate the need for further investigation to identify the possible reasons for inter-region variations in grade crossing safety across Canada. Our approach could be useful to guide safety policy development and resource allocation.</p
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