Vehicle Accident Reconstruction Using Basic Energy Analysis Techniques

Author(s):  
Randall Noon
2018 ◽  
Vol 10 (12) ◽  
pp. 4448 ◽  
Author(s):  
Samuel Domínguez-Amarillo ◽  
Jesica Fernández-Agüera ◽  
Juan Sendra ◽  
Susan Roaf

Although energy analysis techniques can contribute to substantial energy savings in housing stock retrofitting operations, the outcomes often deviate significantly from the predicted results, which tend to overestimate potential savings by overestimating the starting energy baselines, particularly in southern Europe. This deviation can be largely attributed to occupant practice relating to the use of air conditioning facilities and the temperatures at which occupants feel comfortable. The patterns observed differed widely from standard values. In this study environmental variables, primarily indoor air temperature both with and without HVAC, were monitored in occupied dwellings for a full year. The data gathered were supplemented with surveys on occupants’ temperature-related behaviour to define comfort patterns. The findings show that the standards in place are not consistent with actual comfort-accepted patterns in medium- to low-income housing in southern Spain, where energy consumption was observed to be lower than expected, mostly because occupants endure unsuitable, even unhealthy, conditions over long periods of time. A new user profile, better adjusted to practice in southern Europe, particularly in social housing, is proposed to reflect the current situation.


Author(s):  
Xiaoyun Zhang ◽  
Zhen Hu ◽  
Xiaoping Du

Inverse simulation is an inverse process of direct simulation. It determines unknown input variables of the direct simulation for a given set of simulation output variables. Uncertainties usually exist, making it difficult to solve inverse simulation problems. The objective of this research is to account for uncertainties in inverse simulation in order to produce high confidence in simulation results. The major approach is the use of the maximum likelihood methodology, which determines not only unknown deterministic input variables but also the realizations of random input variables. Both types of variables are solved on the condition that the joint probability density of all the random variables is maximum. The proposed methodology is applied to a traffic accident reconstruction problem where the simulation output (accident consequences) is known and the simulation input (velocities of the vehicle at the beginning of crash) is sought.


2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Xiaoyun Zhang ◽  
Zhen Hu ◽  
Xiaoping Du

Inverse simulation is an inverse process of direct simulation. It determines unknown input variables of the direct simulation for a given set of simulation output variables. Uncertainties usually exist, making it difficult to solve inverse simulation problems. The objective of this research is to account for uncertainties in inverse simulation in order to produce high confidence in simulation results. The major approach is the use of the maximum probability density function (PDF), which determines not only unknown deterministic input variables but also the realizations of random input variables. Both types of variables are solved on the condition that the joint probability density of all the random variables is maximum. The proposed methodology is applied to a traffic accident reconstruction problem where the simulation output (accident consequences) is known and the simulation input (velocities of the vehicle at the beginning of crash) is sought.


2014 ◽  
Vol 641-642 ◽  
pp. 799-804 ◽  
Author(s):  
Yong Gang Zhang ◽  
Jian Min Xu ◽  
Tie Fang Zou ◽  
Yu Liu

To reconstruct accident succinctly and scientifically, four steps of vehicle-vehicle impact accident reconstruction based on Pc-Crash were discussed, including accident scene reconstruction, vehicle modeling, accident reconstruction, result analysis and verification. Three accident scene reconstruction methods were proposed. Key attention was paid to methods which can reduce difficulties of accident reconstruction, such as drive model, equivalent energy speed (EES) database and collision optimizer. Finally, a case study was conducted, which confirmed that the proposed four steps can simplify vehicle-vehicle accident reconstruction while maintaining satisfying objectivity and reliability. This paper can contribute to the better application of Pc-Crash to traffic accident reconstruction.


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