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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

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

Automatic Transmission Gear Ratio Optimization and Monte Carlo Simulation of Fuel Consumption with Parasitic Loss Uncertainty

2015-04-14
2015-01-1145
An enterprise approach for vehicle fleet balancing of fuel consumption objectives based upon selection of automatic transmission gearing strategy is presented. Monte Carlo simulations for the influence of parasitic loss uncertainty for the automatic transmissions selected from the generalized DOE were conducted to determine the range of fuel consumption that might be realized in production. ...Automatic transmission gearing parameter selection was unaffected by the variation introduced by the Monte Carlo simulations, but did show fuel consumption performance to vary upwards of 9 g CO2/km depending on applications and to have a direct impact on powertrain operating parameters.
Technical Paper

An Inexpensive, All Solid-state Video and Data Recorder for Accident Reconstruction

1999-03-01
1999-01-1299
A video and data recording is very helpful for accurate accident reconstruction. We have made a prototype of a “personal eye witness”: a small video camera with solid state memory and a short recording time. ...The camera records continuously until it senses an accident, then it saves a video record of the events surrounding the accident in time. Since video is available from both before and after the collision, accident reconstruction becomes easier. ...Since video is available from both before and after the collision, accident reconstruction becomes easier. The camera uses only solid state memory with no moving parts, can be manufactured inexpensively, and can be packaged in a crash-resistant and tamper-resistant module.
Technical Paper

State-of-the-Art-Motor Vehicle Accident Studies

1970-02-01
700437
The studies referenced deal with mass statistics, the in-depth clinical analysis of selected accidents or accident factors, or the application of a combination of both. These studies are directed toward: epidemiology and causes of accidents, injury patterns attributable to given components of the interior (or exterior), and component failures contributing to the accident or injuries. ...The basic objectives of the paper are to trace the history of motor vehicle accident studies, assess the present state-of-the-art, and discuss the problems that exist. The emphasis is on the method of collection and techniques for analysis of accident and resultant injury data. ...The emphasis is on the method of collection and techniques for analysis of accident and resultant injury data. The studies referenced deal with mass statistics, the in-depth clinical analysis of selected accidents or accident factors, or the application of a combination of both.
Technical Paper

A Personal Computer Program for Drawing Accident Sites

1988-02-01
880068
Its use with other computer accident reconstruction programs is illustrated. It is seen that the scaled accident site diagram provides an important element to the reconstruction, both as an analytical tool as well as a presentation tool. ...Standard features are explained and features unique to the needs of the accident reconstructionist, such as photogrammetry and a built-in accident site template, are presented. ...A personal computer program for drawing accident sites is described. The program design is reviewed and hardware requirements are defined.
Technical Paper

Computer Program for Reconstruction of Highway Accidents

1973-02-01
730980
In one of the presented applications to a staged collision, the initial conditions were kept unknown until completion of the reconstruction process. Results of sample applications to actual highway accidents are included. ...The Simulation Model of Automobile Collisions (SMAC) computer program has been developed for the purpose of achieving uniformity in the use of analytical techniques for interpretation of physical evidence in investigations of highway accidents. The comprehensive output information of the SMAC program (kinematics, tire tracks, and vehicle damage) permits extensive, detailed comparisons with physical evidence in the iterative runs used to achieve a “best fit,” and the predicted vehicle responses provide a basis for relatively refined categorization of occupant exposures. ...Computer graphics displays of reconstructed accidents, including rest positions, tracks, and damage, are presented.
Technical Paper

Computer Assisted Single-View Photogrammetry for Accident Scene Documentation

1985-02-25
850067
Accurate documentation of traffic accidents is a prerequisite for accident research as well as traffic jurisdiction. As an important part of accident documentation, stereo-photogrammetry is recognised to be an excellent tool for providing accurate and complete scaled maps of accident scenes. ...ACCURATE AND COMPLETE documentation of traffic accidents is the basis of accident research and analysis. Likewise, it is important for traffic jurisdiction. ...Accordingly, the city police of Zurich introduced stereophotogrammetry as a routine tool for accident documentation purposes as early as 1934 (1)*. Apart from its value for accident jurisdiction, stereophotogrammetry proved to be indispensible for a reliable accident reconstruction and analysis.
Technical Paper

ACCIDENT INFORMATION SYSTEM (AIS)

2009-12-13
2009-28-0029
Suppose a vehicle crashes down due to an accident, an immediate information in the form of message regarding the accident bearing the vehicle number and the area name in which the accident has occurred will be sent to the rescue service centre. ...As it is rightly said by the adage “NECESSITY IS THE MOTHER OF INVENTION”, it has become an obligation for the innovators to design some novel concepts for the sake of safety as well. Accidents have become a major havoc to the lives of mankind. Luxury has steered people to some unknown block outs which has taken out lives together. ...Our innovation deals in providing the necessary service in case of accidents even in isolated rural areas. Now-a-days air bags have been provided only in branded vehicles but our system is adaptable to all heavy vehicles.
Technical Paper

Random Fatigue Load History Reconstruction

1994-03-01
940247
A concise method for modeling nonstationary fatigue loading histories is presented. The mininum number of model parameters is achieved by fitting the variations in mean and variance by a truncated Fourier series. An autoregressive moving average (ARMA) model is used to describe the stationary component. Justification of the method is made by comparing fatigue relevant parameters obtained when subjected to the original and reconstructed histories. In spite of a relatively small number of parameters required, the model is shown to give good results that fall within the bounds predicted by the orginal history.
Journal Article

Reconstruction of Wheel Forces Using an Intelligent Bearing

2016-04-05
2016-01-0092
Active vehicle safety and driving assistance systems can be made more efficient, more robust and less complex if wheel load information would be available. Although this information could be determined via numerous different methods, due to various reasons, no commercially feasible approach has yet been introduced. In this paper the approach of bearing load estimation is topic of interest. Using the bearing for load measurement has considerable advantages making it commercially attractive as: i) it can be performed on a non-rotating part, ii) all wheel loads can be measured and iii) usually the bearing serves the entire lifetime of the vehicle. This paper proposes a novel approach for the determination of wheel loading. This new approach, based on the strain variance on the surface of the bearing outer ring, is tested on a dedicated bearing test setup.
Technical Paper

Failure Analysis in Support of Aircraft Accident Investigations

2000-04-11
2000-01-2102
Subsequent to determination of component failure cause, corrective actions and development of field inspection methods are often imperative to preventing accident recurrence. Examples from several analyses of both military and commercial accident hardware are presented. ...High-speed ground impact, fire, secondary damage and the loss of components during an accident greatly hinder component failure analysis efforts and root cause determination. Careful evaluation of unfailed components can often give accident investigators the information needed to fill in gaps and determine the mishap sequence or cause. ...Careful evaluation of unfailed components can often give accident investigators the information needed to fill in gaps and determine the mishap sequence or cause.
Technical Paper

Engine Fault Detection Using Vibration Signal Reconstruction in the Crank-Angle Domain

2011-05-17
2011-01-1660
Moreover, the results have shown the crank-angle domain analysis using sinc interpolation for signal reconstruction to be more precise than that using linear or cubic spline interpolation. This improved precision enables better fault detection with a more accurate measure of the severity of the fault condition.
Technical Paper

Uncertainty of CRASH3 ΔV and Energy Loss for Frontal Collisions

2012-04-16
2012-01-0608
An understanding of the nature of such uncertainties is of particular importance as both the ΔV and EC are frequently used as inputs to reconstruction methods and become variations in the reconstruction process. These variations lead to uncertainties in the results of the reconstruction which are generally the preimpact speed of one or both of the vehicles involved in the collision. ...These variations then are used in the CRASH3 damage algorithm, through the use of Monte Carlo analysis, to calculate the uncertainty in the ΔV and EC for each of the six vehicle models colliding with a fixed, rigid barrier. ...These variations lead to uncertainties in the results of the reconstruction which are generally the preimpact speed of one or both of the vehicles involved in the collision.
Technical Paper

Determination of the Critical Correlation Coefficient to Establish a Good Fit for Weibull and Log-Normal Failure Distributions

1999-03-01
1999-01-0057
Most software packages calculate the correlation coefficient, r, or the coefficient of determination, r2. Monte Carlo simulation was used to create and analyze several thousand data sets. By comparing r from a given sample to results obtained from Monte Carlo simulation, the goodness of fit of the sample can be determined. ...By comparing r from a given sample to results obtained from Monte Carlo simulation, the goodness of fit of the sample can be determined.
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