| 1. |
- Nie, Jin, et al.
(författare)
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A comparative study of head dynamic response and fatality risk of pedestrian and bicyclist in vehicle collisions
- 2014
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Ingår i: Hunan Daxue Xuebao/Journal of Hunan University Natural Sciences. - 1674-2974. ; 41:2, s. 64-72
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to compare the casualty risk of pedestrians and bicyclists in urban traffic through an analysis of real-world accident data in China. For this purpose, 438 cases were selected as samples from the accidents collected by in-depth investigation of vehicle accidents in China. A statistic measurement of the fatality risk with respect to impact speed was carried out by logistic regression analysis. Then, 21 pedestrian and 24 bicyclist accidents were further selected for reconstruction with MADYMO program. A comparative analysis was conducted on the basisi of the results from accident analysis and computer reconstructions for the fatality risk and the head dynamic response of pedestrians and bicyclists. The results have indicated that the vehicle impact speed has a significant relationship with the fatality risk of both pedestrians and bicyclists and bicyclists suffered slightly lower fatality risk compared to pedestrians. Besides, the head impact conditions such as head impact speed and impact angle between pedestrians and bicyclists are also obviously different. These findings can contribute to the setting of a more reasonable speed limit for urban traffic in China and generate strategies for bicyclist and pedestrian head protection.
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| 2. |
- Yang, Jikuang, 1948
(författare)
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Injury Biomechanics and Protective Systems in Car-to-Pedestrian Collisions
- 2001
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Ingår i: Hunan Daxue Xuebao/Journal of Hunan University Natural Sciences. - 1674-2974. ; 28:3, s. 69-78
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Tidskriftsartikel (refereegranskat)abstract
- The injury biomechanics of pedestrians in vehicle impacts and research approaches are described in this paper. Of which include identification of injury patterns in car pedestrian collisions, determination of injury mechanisms and body segment tolerance levels, development of method and techniques for injury assessment and safety system evaluation. The possible protective countermeasures are summarized and further studies on pedestrian protection are proposed.
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| 3. |
- Yang, Jikuang, 1948, et al.
(författare)
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Study of the structural response and occupant injury in side pole impact to a passenger car
- 2011
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Ingår i: Hunan Daxue Xuebao/Journal of Hunan University Natural Sciences. - 1674-2974. ; 38:1, s. 23-28
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Tidskriftsartikel (refereegranskat)abstract
- Based on the occupant injury severity in side pole impact, this paper conducted a computer simulation study on the side pole impact of a passenger car. The injury criterion and parameters of dummy, the side structure deformation and acceleration of the car body were thoroughly analyzed in terms of the crash characteristics of the car in side pole impact. The countermeasures for improving the strength of the door-sill-beam and the floor cross member were presented. Simulation results have shown that the side pole impact increases occupant injury risk and makes more intrusion on the side structure of the body, compared with car to barrier side impact. The passenger car safety performance can be improved in side pole impact by strengthening the door-sill-beam and the floor cross member.
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| 4. |
- Zhu, Huiming, et al.
(författare)
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Bayesian Analysis of a Stochastic Volatility Model Using Gibbs Sampling
- 2008
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Ingår i: Hunan Daxue Xuebao (Ziran Kexue Ban). - 1674-2974. ; 35:12
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Tidskriftsartikel (refereegranskat)abstract
- After exploring the statistical structure of the stochastic volatility model, its likelihood functions concrete form is derived, and its parameters conjugate priors are constructed. Then, using the Bayesian theorem, the conditional posterior distributions are derived. In order to obtain the Baysian parameters estimators and their intervals, we develop a Markov chain Monte Carlo algorithm procedure with Gibbs sampling. Finally, using the Shanghai stocks comprehensive index and the Shenzhen stocks composition index, we give an empirical example to illustrate how to use the proposed method. This paper provides a new approach to establish Bayesian models for financial stochastic volatilities with random parameters.
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| 5. |
- Zhu, Huiming, et al.
(författare)
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Bayesian multivariate monitoring models for process mean vectors based on multistage predictive distributions
- 2011
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Ingår i: Hunan Daxue Xuebao (Ziran Kexue Ban). - 1674-2974. ; 38:3, s. 82-86
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper is to utilize sample information in different stages and solve the parameter uncertainty risk in statistical process control. This paper introduces a reference prior distribution for the parameters in quality models, and constructs the warning lines and action lines to monitor the mean vectors change according to the predictive distribution as well as the relationship between the multivariate t distribution and F distribution. When the current stage is under control, the parametric posterior distribution is considered to be their priori distribution in the next stage, in which the sequential Bayesian mean vector control method is established.
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