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Technical Paper

Use of Monte Carlo Simulation Techniques in Accident Reconstruction

1994-03-01
940719
This paper describes a straight-forward, automated approach to performing sensitivity analyses using Monte Carlo simulation techniques. Probability distributions are assigned to key input parameters, and results are expressed in the form of probability distributions of each of the desired output parameters. ...The approach is fast and automated, and provides a rational basis for dealing with uncertainty and ranges of parameters in accident reconstruction analyses.
Technical Paper

Considerations for Applying and Interpreting Monte Carlo Simulation Analyses in Accident Reconstruction

2007-04-16
2007-01-0741
One popular method of examining and quantifying the uncertainty within an analysis is the use of Monte Carlo simulation techniques. The methods have been well established and published over the last several years by numerous authors. ...One of the key factors underlying the Monte Carlo analysis is the assumed probability distribution of the individual factors within the analysis. ...However, the literature to date has not examined how the assumption of a distribution affects the resulting probability distribution of the Monte Carlo analysis. This paper attempts to address this issue. Furthermore, with the large number of samples typically considered during a Monte Carlo analysis, the resulting probability distribution tends to be normal and lends itself well to statistical interpretation as to the “most likely” range of the desired parameter.
Journal Article

Sensitivity of Monte Carlo Modeling in Crash Reconstruction

2010-04-12
2010-01-0071
The Monte Carlo method is a well-known technique for propagating uncertainty in complex systems and has been applied to traffic crash reconstruction analysis. The Monte Carlo method is a probabilistic technique that randomly samples input distributions and then combines these samples according to a deterministic model. ...The Monte Carlo method is a well-known technique for propagating uncertainty in complex systems and has been applied to traffic crash reconstruction analysis. ...The computed sensitivity values were obtained using analytical derivatives which only required a single Monte Carlo simulation. The analytical derivative values are compared to a finite difference value to demonstrate numerical accuracy.
Journal Article

Monte Carlo Techniques for Correlated Variables in Crash Reconstruction

2009-04-20
2009-01-0104
Therefore, a discussion of uncertainty propagation techniques with correlation and Monte Carlo simulation of correlated variables is presented in this paper. The idea that measuring a parameter with a common instrument induces correlation is explored by examining the process of determining vehicle weights. ...However, the examples provided are aimed at introducing the concept of correlation in Monte Carlo simulation and determining the practical significance of correlation have yet to be determined. ...Furthermore, interpreting and presenting results from simple Monte Carlo analysis of a momentum problem requires using the concepts of joint, marginal, and conditional distributions to fully understand the results.
Technical Paper

Conducting Monte Carlo Analysis with Spreadsheet Programs

2003-03-03
2003-01-0487
Monte Carlo analysis has been shown to be a powerful tool for evaluating confidence limits and probability distributions for values calculated during the analysis of vehicle accidents. ...This paper presents a method of using the tools provided with most simple spreadsheet programs to conduct Monte Carlo analysis with both evenly distributed and normally distributed variables for cases where the equations can be expressed in closed form. ...Monte Carlo analysis has been shown to be a powerful tool for evaluating confidence limits and probability distributions for values calculated during the analysis of vehicle accidents. Using this tool has generally required specialized software. This paper presents a method of using the tools provided with most simple spreadsheet programs to conduct Monte Carlo analysis with both evenly distributed and normally distributed variables for cases where the equations can be expressed in closed form.
Technical Paper

Determination of Vehicle Velocities and Collision Location by Means of Monte Carlo Simulation Method

2006-04-03
2006-01-0907
“collision from the right-hand side of the center line” – “collision from the left-hand side of the center line”, or “the accident could have been avoided” – “the accident could not be avoided”). The aim of the paper was to present a method of collision reconstruction calculation using the principle of conservation of momentum, the principle of energy conservation, and the principle of kinetic energy and work equivalence (energy balance) (Marquard), taking into consideration Monte Carlo simulation method. ...The aim of the paper was to present a method of collision reconstruction calculation using the principle of conservation of momentum, the principle of energy conservation, and the principle of kinetic energy and work equivalence (energy balance) (Marquard), taking into consideration Monte Carlo simulation method. The applicability of the method in determination of distribution function for vehicle collision velocities was proved and, what is more important, its practical uselessness in determination of collision location. ...In road accident analysis the problem of uncertainty of calculation results becomes essential particularly when modification of input values within the adopted ranges leads to diametric change of the answer to the question posed by the court of justice (e.g.
Journal Article

A Bayesian Approach to Cross-Validation in Pedestrian Accident Reconstruction

2011-04-12
2011-01-0290
In statistical modeling, cross-validation refers to the practice of fitting a model with part of the available data, and then using predictions of the unused data to test and improve the fitted model. In accident reconstruction, cross-validation is possible when two different measurements can be used to estimate the same accident feature, such as when measured skidmark length and pedestrian throw distance each provide an estimate of impact speed. ...In accident reconstruction, cross-validation is possible when two different measurements can be used to estimate the same accident feature, such as when measured skidmark length and pedestrian throw distance each provide an estimate of impact speed. ...An actual measurement falling in an extreme tail of the predictive distribution suggests a weakness in the assumptions governing the reconstruction. This paper describes an implementation of these ideas using the Bayesian freeware WinBUGS.
Technical Paper

Evaluating the Uncertainty in Various Measurement Tasks Common to Accident Reconstruction

2002-03-04
2002-01-0546
This paper presents the results of recent tests conducted to obtain sample distributions of some common parameters, including measurements made with tapes, measurements made with roller-wheels, skidmark measurements, yawmark measurements, estimation of crush damage from photographs, and drag factors, that can be used to evaluate the uncertainty in an accident reconstruction analysis. The paper also reviews the distributions of some pertinent data reported by other researchers. ...When performing calculations pertaining to the analysis of motor vehicle accidents, investigators must often select appropriate values for a number of parameters. The uncertainty of the final answers is a function of the uncertainty of each parameter involved in the calculation.
Journal Article

Probabilistic Reanalysis Using Monte Carlo Simulation

2008-04-14
2008-01-0215
PRA calculates very efficiently the system reliability or the average value of an attribute of a design for many probability distributions of the input variables, by performing a single Monte Carlo simulation. In addition, PRA calculates the sensitivity derivatives of the reliability to the parameters of the probability distributions.
Technical Paper

Application of Monte Carlo Analysis to Life Cycle Assessment

1999-03-01
1999-01-0011
This paper demonstrates the use of Monte Carlo Analysis to track and measure the propagation of uncertainty in LCA studies. The Monte Carlo technique basically consists of running repeated assessments using random input values chosen from a specified probable range. ...While measuring the overall LCA uncertainty, the Monte Carlo technique also measures the uncertainty contribution of each unit process within the system being considered. ...The Monte Carlo technique basically consists of running repeated assessments using random input values chosen from a specified probable range.
Technical Paper

Monte Carlo Based Predictive Models for Total Flux Output of Multi-LED Array Designs

2011-04-12
2011-01-0118
Monte Carlo simulations are shown to be a useful tool when determining the flux output of LED arrays during the design phase. ...The results of Monte Carlo simulations are able to show the statistical distribution of output flux based on multi-LED arrays, thus allowing engineers to optimise their design, rather than using worst case scenario design principles.
Journal Article

Managing the Computational Cost of Monte Carlo Simulation with Importance Sampling by Considering the Value of Information

2013-04-08
2013-01-0943
Although it is significantly more efficient than standard Monte Carlo simulation if a suitable sampling distribution is used, in many design problems it is too expensive. ...The authors have previously proposed a method to manage the computational cost in standard Monte Carlo simulation that views design as a choice among alternatives with uncertain reliabilities.
Technical Paper

Predicting Weight Distribution from Occupant Load Using a Monte Carlo Method

2012-09-24
2012-01-1925
Actual occupant weight distributions versus certified weight per occupant seat causes a potential conflict between a vehicle's in-use weight versus its certified GVWR. A Monte Carlo method using a midsized bus example was conducted to determine the statistical probability that adult passengers and rated cargo would result in weight distributions that exceeded tire load capability, Gross Axle Weight Rating (GAWR), or GVWR.
Technical Paper

Monte Carlo Direct Simulation of Axisymmetric Rarefied Gas Flows Through Thruster Nozzles for Spacecrafts

1991-09-01
912062
Axial symmetric flows of a mono-atomic rarefied gas exhausted through the thruster nozzle of an artificial satellite were numerically simulated by the Direct Simulation Monte Carlo method, since the transitional flow regime occurs at altitudes where the enhancement region is several orders of magnitude larger than the nozzle throat diameter of the thruster (high altitude rocket).
Journal Article

Estimation of One-Sided Lower Tolerance Limits for a Weibull Distribution Using the Monte Carlo Pivotal Simulation Technique

2013-04-08
2013-01-0329
This paper introduces a methodology to calculate confidence bounds for a normal and Weibull distribution using Monte Carlo pivotal statistics. As an example, a ready-to-use lookup table to calculate one-sided lower confidence bounds is established and demonstrated for normal and Weibull distributions. ...Lieberman in 1958 (later modified by Link in 1985 and Wei in 2012), and has been widely used in the automotive industry because of the easy-to-use lookup tables. Monte Carlo simulation methods presented here are more accurate as they eliminate assumptions and approximations inherent in existing approaches by using random experiments.
Technical Paper

Tools and Devices for Accident Investigation and Reconstruction

1990-02-01
900372
Over the last several years, many active participants in the accident investigation and reconstruction field have accumulated items useful in the analysis of motor vehicle traffic accidents. ...Accident investigators and reconstructionists typically accumulate tools and devices useful to them in the course of their work. ...Over the last several years, many active participants in the accident investigation and reconstruction field have accumulated items useful in the analysis of motor vehicle traffic accidents. The purpose of this paper is to disseminate a list of available tools and devices to the investigation community.
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