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Sample records for aircraft crash hit

  1. Crash hit frequency analysis of aircraft overflights of the Nevada Test Site (NTS) and the Device Assembly Facility (DAF)

    SciTech Connect

    Kimura, C. Y.; Sanzo, D. L.; Sharirli, M.

    1998-12-16

    Aircraft crashes are an element of external events required to be analyzed and documented in Facility Safety Analysis Reports (SARs) and Nuclear Explosive Safety Studies (NESS). Aircraft crashes into DOE facilities are of concern due to effects related to impact and fire that can potentially lead to penetration of the facility, disruption of operations, and the potential of release of radioactive and/or hazardous materials subsequent to the aircraft impact. Recent changes in the control of the airspace were not considered in previous safety studies of aircraft flights over the NTS [Refs. 4,5,6]. The Airspace changes have warranted review of the effects of the issued MOU on the Device Assembly Facility (DAF) Authorization Basis Documents [Refs. 4,5], the underlying analysis assumptions, and results relevant to aircraft crash. This report documents the review and analysis of aircraft crash hit frequency on the DAF within NTS. It focuses on the impact of airspace changes based on the MOU. The frequency of an aircraft crashing and hitting the DAF is in the 1 E-7 to E-8 range. While this is considered to be acceptably small, it should not be considered an upper bound. This conclusion should not be interpreted to mean that no further work need be done. The results of the analysis are highly dependent on the assumptions made and the available data. There is considerable uncertainty in the number of overflights which are taking place over the NTS and restricted airspace R-4808N. To reduce this uncertainty, additional follow-on work should be done to activate the monitor in the CP at NTS which is to receive information from the Nellis Range control station, to monitor the level of air activity in R-4808N and to recalculate the aircraft crash hit frequency on the DAF when better overflight estimates are obtained. Finally, to reduce the human error component, the process by which the DOE notifies the USAF of �no-fly� periods for R-4808N during which SNM is present in the

  2. Crash hit frequency analysis of aircraft overflights of the Nevada Test Site (NTS) and the Device Assembly Facility (DAF)

    SciTech Connect

    Kimura, C. Y.; Sanzo, D. L.; Sharirli, M.

    1998-07-09

    Aircraft crashes are an element of external events required to be analyzed and documented in Facility Safety Analysis Reports (SARs) and Nuclear Explosive Safety Studies (NESS). Aircraft crashes into DOE facilities are of concern due to effects related to impact and fire that can potentially lead to penetration of the facility, disruption of operations, and the potential of release of radioactive and/or hazardous materials subsequent to the aircraft impact. Recent changes in the control of the airspace were not considered in previous safety studies of aircraft flights over the NTS [Refs. 4,5,6]. The Airspace changes have warranted review of the effects of the issued MOU on the Device Assembly Facility (DAF) Authorization Basis Documents [Refs. 4,5], the underlying analysis assumptions, and results relevant to aircraft crash. This report documents the review and analysis of aircraft crash hit frequency on the DAF within NTS. It focuses on the impact of airspace changes based on the MOU. The frequency of an aircraft crashing and hitting the DAF is in the 1 E-7 to E-8 range. While this is considered to be acceptably small, it should not be considered an upper bound. This conclusion should not be interpreted to mean that no further work need be done. The results of the analysis are highly dependent on the assumptions made and the available data. There is considerable uncertainty in the number of overflights which are taking place over the NTS and restricted airspace R-4808N. To reduce this uncertainty, additional follow-on work should be done to activate the monitor in the CP at NTS which is to receive information from the Nellis Range control station, to monitor the level of air activity in R-4808N and to recalculate the aircraft crash hit frequency on the DAF when better overflight estimates are obtained. Finally, to reduce the human error component, the process by which the DOE notifies the USAF of "no-fly" periods for R-4808N during which SNM is present in the DAF

  3. Simulation of aircraft crash and its validation

    NASA Technical Reports Server (NTRS)

    Alfaro-Bou, E.; Hayduk, R. J.; Thomson, R. G.; Vaughan, V. L., Jr.

    1975-01-01

    A joint FAA/NASA program is discussed which is aimed at developing a reliable technology for the design of crashworthy light aircraft. This program encompasses the development of analytical methods, the definition of a survivable crash envelope, and the design of improved seat and restraint systems. A facility for full-scale crash-simulation testing is described along with the test method and results of five full-scale crash tests of twin-engine light aircraft. The major goals of the analytical portion of the program are outlined, including the development and validation of the analytical technique using simplified structural specimens that approximate aircraft components, as well as the mathematical modeling of the complete airframe and its subsequent dynamic analysis by substructuring and matrix reduction techniques.

  4. An Approach to Estimate the Localized Effects of an Aircraft Crash on a Facility

    SciTech Connect

    Kimura, C; Sanzo, D; Sharirli, M

    2004-04-19

    Aircraft crashes are an element of external events required to be analyzed and documented in facility Safety Analysis Reports (SARs) and Nuclear Explosive Safety Studies (NESSs). This paper discusses the localized effects of an aircraft crash impact into the Device Assembly Facility (DAF) located at the Nevada Test Site (NTS), given that the aircraft hits the facility. This was done to gain insight into the robustness of the DAF and to account for the special features of the DAF that enhance its ability to absorb the effects of an aircraft crash. For the purpose of this paper, localized effects are considered to be only perforation or scabbing of the facility. This paper presents an extension to the aircraft crash risk methodology of Department of Energy (DOE) Standard 3014. This extension applies to facilities that may find it necessary or desirable to estimate the localized effects of an aircraft crash hit on a facility of nonuniform construction or one that is shielded in certain directions by surrounding terrain or buildings. This extension is not proposed as a replacement to the aircraft crash risk methodology of DOE Standard 3014 but rather as an alternate method to cover situations that were not considered.

  5. Offsite radiological consequence analysis for the bounding aircraft crash accident

    SciTech Connect

    OBERG, B.D.

    2003-03-22

    The purpose of this calculation note is to quantitatively analyze a bounding aircraft crash accident for comparison to the DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', Appendix A, Evaluation Guideline of 25 rem. The potential of aircraft impacting a facility was evaluated using the approach given in DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities''. The following aircraft crash frequencies were determined for the Tank Farms in RPP-11736, ''Assessment Of Aircraft Crash Frequency For The Hanford Site 200 Area Tank Farms'': (1) The total aircraft crash frequency is ''extremely unlikely.'' (2) The general aviation crash frequency is ''extremely unlikely.'' (3) The helicopter crash frequency is ''beyond extremely unlikely.'' (4) For the Hanford Site 200 Areas, other aircraft type, commercial or military, each above ground facility, and any other type of underground facility is ''beyond extremely unlikely.'' As the potential of aircraft crash into the 200 Area tank farms is more frequent than ''beyond extremely unlikely,'' consequence analysis of the aircraft crash is required.

  6. Aircraft-crash-locating transmitter features design improvements

    NASA Technical Reports Server (NTRS)

    Manoli, R.; Ulrich, B. R.

    1971-01-01

    Crash locater is automatically ejected from aircraft at time of crash and begins transmitting at emergency radio frequencies monitored by all airports and airport control towers. Advantages are smaller size, simpler design and installation, extended transmitting range and life, greater deployment reliability and increased crash resistance.

  7. Mechanism of Start and Development of Aircraft Crash Fires

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irving; Preston, G. Merritt; Pesman, Gerard J.

    1952-01-01

    Full-scale aircraft crashes were made to investigate the mechanism of the start and development of aircraft crash fires. The results are discussed herein. This investigation revealed the characteristics of the ignition sources, the manner in which the combustibles spread, the mechanism of the union of the combustibles and ignition sources, and the pertinent factors governing the development of a crash fire as observed in this program.

  8. Mechanism of Start and Development of Aircraft Crash Fires

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irving; Preston, G. Merritt; Pesman, Gerard J.

    1952-01-01

    Full-scale aircraft crashes, devised to give surge fuel spillage and a high incidence of fire, were made to investigate the mechanism of the start and development of aircraft crash fires. The results are discussed. herein. This investigation revealed the characteristics of the ignition sources, the manner in which the combustibles spread., the mechanism of the union of the combustibles and ignition sources, and the pertinent factors governing the development of a crash fire as observed in this program.

  9. Aircraft crash caused by stress corrosion cracking

    SciTech Connect

    Kolkman, H.J.; Kool, G.A.; Wanhill, R.J.H.

    1996-01-01

    An aircraft crash in the Netherlands was caused by disintegration of a jet engine. Fractography showed that the chain of events started with stress corrosion cracking (SCC) of a pin attached to a lever arm of the compressor variable vane system. Such a lever arm-pin assembly costs only a few dollars. Investigation of hundreds of pins from the accident and a number of identical engines revealed that this was not an isolated case. Many pins exhibited various amounts of SCC. The failed pin in the accident engine happened to be the first fractured one. SCC requires the simultaneous presence of tensile stress, a corrosive environment, and a susceptible material. In this case the stress was a residual stress arising from the production method. There was a clear correlation between the presence of salt deposits on the levers and SCC of the pins. It was shown that these deposits were able to reach the internal space between the pin and lever arm, thereby initiating SCC in this space. The corrosive environment in Western Europe explains why the problem manifested itself in the Netherlands at a relatively early stage in engine life. The main point is, however, that the manufacturer selected an SCC-prone material in the design stage. The solution has been to change the pin material.

  10. Aircraft subfloor response to crash loadings

    NASA Technical Reports Server (NTRS)

    Carden, H. D.; Hayduk, R. J.

    1981-01-01

    Results are presented of an experimental and analytical study of the dynamic response to crash loadings of five different load-limiting subfloors for general aviation aircraft. These subfloors provide a high-strength structural floor platform to retain the seats and a crushable zone to absorb energy and limit vertical loads. Experimental static load-deflection data and dynamic deceleration response data for the five subfloors indicated that the high-strength floor platform performed well in that structural integrity and residual strength was maintained throughout the loading cycle. The data also indicated that some of the subfloor crush zones were more effective than others in providing nearly constant load for a range of displacement. The analytical data was generated by characterizing the nonlinear crush zones of the subfloor with static load-deflection data and using the DYCAST nonlinear finite element computer program. Comparisons between experimental and analytical data showed good correlation for the subfloors in which the static deformation mode closely approximated the dynamic deformation mode.

  11. Aircraft-mounted crash-activated transmitter device

    NASA Technical Reports Server (NTRS)

    Manoli, R.; Ulrich, B. R. (Inventor)

    1976-01-01

    An aircraft crash location transmitter tuned to transmit on standard emergency frequencies is reported that is shock mounted in a sealed circular case atop the tail of an aircraft by means of a shear pin designed to fail under a G loading associated with a crash situation. The antenna for the transmitter is a metallic spring blade coiled like a spiral spring around the outside of the circular case. A battery within the case for powering the transmitter is kept trickle charged from the electrical system of the aircraft through a break away connector on the case. When a crash occurs, the resultant ejection of the case from the tail due to a failure of the shear pin releases the free end of the antenna which automatically uncoils. The accompanying separation of the connector effects closing of the transmitter key and results in commencement of transmission.

  12. A review of the analytical simulation of aircraft crash dynamics

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Carden, Huey D.; Boitnott, Richard L.; Hayduk, Robert J.

    1990-01-01

    A large number of full scale tests of general aviation aircraft, helicopters, and one unique air-to-ground controlled impact of a transport aircraft were performed. Additionally, research was also conducted on seat dynamic performance, load-limiting seats, load limiting subfloor designs, and emergency-locator-transmitters (ELTs). Computer programs were developed to provide designers with methods for predicting accelerations, velocities, and displacements of collapsing structure and for estimating the human response to crash loads. The results of full scale aircraft and component tests were used to verify and guide the development of analytical simulation tools and to demonstrate impact load attenuating concepts. Analytical simulation of metal and composite aircraft crash dynamics are addressed. Finite element models are examined to determine their degree of corroboration by experimental data and to reveal deficiencies requiring further development.

  13. The Pope Air Force Base aircraft crash and burn disaster.

    PubMed

    Mozingo, David W; Barillo, David J; Holcomb, John B

    2005-01-01

    This report describes the initial hospital and burn center management of a mass casualty incident resulting from an aircraft crash and fire. One hundred thirty soldiers were injured, including 10 immediate fatalities. Womack Army Medical Center at Fort Bragg, North Carolina, managed the casualties and began receiving patients 15 minutes after the crash. As a result of repetitive training that included at least two mass casualty drills each year, the triage area and emergency department were cleared of all patients within 2 hours. Fifty patients were transferred to burn centers, including 43 patients to the US Army Institute of Surgical Research. This constitutes the largest single mass casualty incident experienced in the 57-year history of the Institute. All patients of the US Army Institute of Surgical Research survived to hospital discharge, and 34 returned to duty 3 months after the crash. The scenario of an on-ground aircraft explosion and fire approximates what might be seen as a result of an aircraft hijacking, bombing, or intentional crash. Lessons learned from this incident have utility in the planning of future response to such disasters. PMID:15756114

  14. An assessment of the crash fire hazard of liquid hydrogen fueled aircraft

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The crash fire hazards of liquid hydrogen fueled aircraft relative to those of mission equivalent aircraft fueled either with conventional fuel or with liquefied methane were evaluated. The aircraft evaluated were based on Lockheed Corporation design for 400 passenger, Mach 0.85, 5500 n. mile aircraft. Four crash scenarios were considered ranging from a minor incident causing some loss of fuel system integrity to a catastrophic crash. Major tasks included a review of hazardous properties of the alternate fuels and of historic crash fire data; a comparative hazard evluation for each of the three fuels under four crash scenarios a comprehensive review and analysis and an identification of areas further development work. The conclusion was that the crash fire hazards are not significantly different when compared in general for the three fuels, although some fuels showed minor advantages in one respect or another.

  15. Assessment of aircraft crash frequency for the Hanford site 200 Area tank farms

    SciTech Connect

    OBERG, B.D.

    2003-03-22

    Two factors, the near-airport crash frequency and the non-airport crash frequency, enter into the estimate of the annual aircraft crash frequency at a facility. The near-airport activities, Le., takeoffs and landings from any of the airports in a 23-statute-mile (smi) (20-nautical-mile, [nmi]) radius of the facilities, do not significantly contribute to the annual aircraft crash frequency for the 200 Area tank farms. However, using the methods of DOE-STD-3014-96, the total frequency of an aircraft crash for the 200 Area tank farms, all from non-airport operations, is calculated to be 7.10E-6/yr. Thus, DOE-STD-3014-96 requires a consequence analysis for aircraft crash. This total frequency consists of contributions from general aviation, helicopter activities, commercial air carriers and air taxis, and from large and small military aircraft. The major contribution to this total is from general aviation with a frequency of 6.77E-6/yr. All other types of aircraft have less than 1E-6/yr crash frequencies. The two individual aboveground facilities were in the realm of 1E-7/yr crash frequencies: 204-AR Waste Unloading Facility at 1.56E-7, and 242-T Evaporator at 8.62E-8. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', states that external events, such as aircraft crashes, are referred to as design basis accidents (DBA) and analyzed as such: ''if frequency of occurrence is estimated to exceed 10{sup -6}/yr conservatively calculated'' DOE-STD-3014-96 considers its method for estimating aircraft crash frequency as being conservative. Therefore, DOE-STD-3009-94 requires DBA analysis of an aircraft crash into the 200 Area tank farms. DOE-STD-3009-94 also states that beyond-DBAs are not evaluated for external events. Thus, it requires only a DBA analysis of the effects of an aircraft crash into the 200 Area tank farms. There are two attributes of an aircraft crash into a Hanford waste storage tank

  16. Safety Analysis of Dual Purpose Metal Cask Subjected to Impulsive Loads due to Aircraft Engine Crash

    NASA Astrophysics Data System (ADS)

    Shirai, Koji; Namba, Kosuke; Saegusa, Toshiari

    In Japan, the first Interim Storage Facility of spent nuclear fuel away from reactor site is being planned to start its commercial operation around 2010, in use of dual-purpose metal cask in the northern part of Main Japan Island. Business License Examination for safety design approval has started since March, 2007. To demonstrate the more scientific and rational performance of safety regulation activities on each phase for the first license procedure, CREPEI has executed demonstration tests with full scale casks, such as drop tests onto real targets without impact limiters(1) and seismic tests subjected to strong earthquake motions(2). Moreover, it is important to develop the knowledge for the inherent security of metal casks under extreme mechanical-impact conditions, especially for increasing interest since the terrorist attacks from 11th September 2001(3)-(6). This paper presents dynamic mechanical behavior of the metal cask lid closure system caused by direct aircraft engine crash and describes calculated results (especially, leak tightness based on relative dynamic displacements between metallic seals). Firstly, the local penetration damage of the interim storage facility building by a big passenger aircraft engine crash (diameter 2.7m, length 4.3m, weight 4.4ton, impact velocity 90m/s) has been examined. The reduced velocity is calculated by the local damage formula for concrete structure with its thickness of 70cm. The load vs. time function for this reduced velocity (60m/s) is estimated by the impact analysis using Finite Element code LS-DYNA with the full scale engine model onto a hypothetically rigid target. Secondly, as the most critical scenarios for the metal cask, two impact scenarios (horizontal impact hitting the cask and vertical impact onto the lid metallic seal system) are chosen. To consider the geometry of all bolts for two lids, the gasket reaction forces and the inner pressure of the cask cavity, the detailed three dimensional FEM models are

  17. Analytical modeling of transport aircraft crash scenarios to obtain floor pulses

    NASA Technical Reports Server (NTRS)

    Wittlin, G.; Lackey, D.

    1983-01-01

    The KRAS program was used to analyze transport aircraft candidate crash scenarios. Aircraft floor pulses and seat/occupant responses are presented. Results show that: (1) longitudinal only pulses can be represented by equivalent step inputs and/or static requirements; (2) the L1649 crash test floor longitudinal pulse for the aft direction (forward inertia) is less than 9g static or an equivalent 5g pulse; aft inertia accelerations are extremely small ((ch76) 3g) for representative crash scenarios; (3) a viable procedure to relate crash scenario floor pulses to standard laboratory dynamic and static test data using state of the art analysis and test procedures was demonstrated; and (4) floor pulse magnitudes are expected to be lower for wide body aircraft than for smaller narrow body aircraft.

  18. Origin and Prevention of Crash Fires in Turbojet Aircraft

    NASA Technical Reports Server (NTRS)

    Pinkel, I Irving; Weiss, Solomon; Preston, G Merritt; Pesman, Gerard J

    1957-01-01

    The manner in which the jet engine may start a crash fire was explored in test-stand and full-scale crash studies. On the basis of these studies, a method was devised for inserting and cooling the engine parts that may serve as ignition sources in crash. This method was tried successfully in full-scale crashes of jet-powered airplanes carrying engines in pod nacelles and engines buried within the airplane structure.

  19. Data development technical support document for the aircraft crash risk analysis methodology (ACRAM) standard

    SciTech Connect

    Kimura, C.Y.; Glaser, R.E.; Mensing, R.W.; Lin, T.; Haley, T.A.; Barto, A.B.; Stutzke, M.A.

    1996-08-01

    The Aircraft Crash Risk Analysis Methodology (ACRAM) Panel has been formed by the US Department of Energy Office of Defense Programs (DOE/DP) for the purpose of developing a standard methodology for determining the risk from aircraft crashes onto DOE ground facilities. In order to accomplish this goal, the ACRAM panel has been divided into four teams, the data development team, the model evaluation team, the structural analysis team, and the consequence team. Each team, consisting of at least one member of the ACRAM plus additional DOE and DOE contractor personnel, specializes in the development of the methodology assigned to that team. This report documents the work performed by the data development team and provides the technical basis for the data used by the ACRAM Standard for determining the aircraft crash frequency. This report should be used to provide the generic data needed to calculate the aircraft crash frequency into the facility under consideration as part of the process for determining the aircraft crash risk to ground facilities as given by the DOE Standard Aircraft Crash Risk Assessment Methodology (ACRAM). Some broad guidance is presented on how to obtain the needed site-specific and facility specific data but this data is not provided by this document.

  20. Crash response data system for the controlled impact demonstration (CID) of a full scale transport aircraft

    NASA Astrophysics Data System (ADS)

    Calloway, Raymond S.; Knight, Vernie H., Jr.

    NASA Langley's Crash Response Data System (CRDS) which is designed to acquire aircraft structural and anthropomorphic dummy responses during the full-scale transport CID test is described. Included in the discussion are the system design approach, details on key instrumentation subsystems and operations, overall instrumentation crash performance, and data recovery results. Two autonomous high-environment digital flight instrumentation systems, DAS 1 and DAS 2, were employed to obtain research data from various strain gage, accelerometer, and tensiometric sensors installed in the B-720 test aircraft. The CRDS successfully acquired 343 out of 352 measurements of dynamic crash data.

  1. Crash response data system for the controlled impact demonstration (CID) of a full scale transport aircraft

    NASA Technical Reports Server (NTRS)

    Calloway, Raymond S.; Knight, Vernie H., Jr.

    1986-01-01

    NASA Langley's Crash Response Data System (CRDS) which is designed to acquire aircraft structural and anthropomorphic dummy responses during the full-scale transport CID test is described. Included in the discussion are the system design approach, details on key instrumentation subsystems and operations, overall instrumentation crash performance, and data recovery results. Two autonomous high-environment digital flight instrumentation systems, DAS 1 and DAS 2, were employed to obtain research data from various strain gage, accelerometer, and tensiometric sensors installed in the B-720 test aircraft. The CRDS successfully acquired 343 out of 352 measurements of dynamic crash data.

  2. Soil analyses and evaluations at the impact dynamics research facility for two full-scale aircraft crash tests

    NASA Technical Reports Server (NTRS)

    Cheng, R. Y. K.

    1977-01-01

    The aircraft structural crash behavior and occupant survivability for aircraft crashes on a soil surface was studied. The results of placement, compaction, and maintenance of two soil test beds are presented. The crators formed by the aircraft after each test are described.

  3. Assessment of methodologies for analysis of the dungeness B accidental aircraft crash risk.

    SciTech Connect

    LaChance, Jeffrey L.; Hansen, Clifford W.

    2010-09-01

    The Health and Safety Executive (HSE) has requested Sandia National Laboratories (SNL) to review the aircraft crash methodology for nuclear facilities that are being used in the United Kingdom (UK). The scope of the work included a review of one method utilized in the UK for assessing the potential for accidental airplane crashes into nuclear facilities (Task 1) and a comparison of the UK methodology against similar International Atomic Energy Agency (IAEA), United States (US) Department of Energy (DOE), and the US Nuclear Regulatory Commission (NRC) methods (Task 2). Based on the conclusions from Tasks 1 and 2, an additional Task 3 would provide an assessment of a site-specific crash frequency for the Dungeness B facility using one of the other methodologies. This report documents the results of Task 2. The comparison of the different methods was performed for the three primary contributors to aircraft crash risk at the Dungeness B site: airfield related crashes, crashes below airways, and background crashes. The methods and data specified in each methodology were compared for each of these risk contributors, differences in the methodologies were identified, and the importance of these differences was qualitatively and quantitatively assessed. The bases for each of the methods and the data used were considered in this assessment process. A comparison of the treatment of the consequences of the aircraft crashes was not included in this assessment because the frequency of crashes into critical structures is currently low based on the existing Dungeness B assessment. Although the comparison found substantial differences between the UK and the three alternative methodologies (IAEA, NRC, and DOE) this assessment concludes that use of any of these alternative methodologies would not change the conclusions reached for the Dungeness B site. Performance of Task 3 is thus not recommended.

  4. Factors associated with pilot fatalities in work-related aircraft crashes--Alaska, 1990-1999.

    PubMed

    2002-04-26

    Despite its large geographic area, Alaska has only 12,200 miles of public roads, and 90% of the state's communities are not connected to a highway system. Commuter and air-taxi flights are essential for transportation of passengers and delivery of goods, services, and mail to outlying communities (Figure 1). Because of the substantial progress in decreasing fatalities in the fishing and logging industries, aviation crashes are the leading cause of occupational death in Alaska. During 1990-1999, aircraft crashes in Alaska caused 107 deaths among workers classified as civilian pilots. This is equivalent to 410 fatalities per 100,000 pilots each year, approximately five times the death rate for all U.S. pilots and approximately 100 times the death rate for all U.S. workers. As part of a collaborative aviation safety initiative that CDC's National Institute for Occupational Safety and Health (NIOSH) is implementing with the Federal Aviation Administration (FAA), the National Transportation Safety Board (NTSB), and the National Weather Service, CDC analyzed data from NTSB crash reports to determine factors associated with pilot fatalities in work-related aviation crashes in Alaska. This report summarizes the result of this analysis, which found that the following factors were associated with pilot fatalities: crashes involving a post-crash fire, flights in darkness or weather conditions requiring instrument use, crashes occurring away from an airport, and crashes in which the pilot was not using a shoulder restraint. Additional pilot training, improved fuel systems that are less likely to ignite in crashes, and company policies that discourage flying in poor weather conditions might help decrease pilot fatalities. More detailed analyses of crash data, collaborations with aircraft operators to improve safety, and evaluation of new technologies are needed. PMID:12004985

  5. Impact dynamics research facility for full-scale aircraft crash testing

    NASA Technical Reports Server (NTRS)

    Vaughan, V. L. J.; Alfaro-Bou, E.

    1976-01-01

    An impact dynamics research facility (IDRF) was developed to crash test full-scale general aviation aircraft under free-flight test conditions. The aircraft are crashed into the impact surface as free bodies; a pendulum swing method is used to obtain desired flight paths and velocities. Flight paths up to -60 deg and aircraft velocities along the flight paths up to about 27.0 m/s can be obtained with a combination of swing-cable lengths and release heights made available by a large gantry. Seven twin engine, 2721-kg aircraft were successfully crash tested at the facility, and all systems functioned properly. Acquisition of data from signals generated by accelerometers on board the aircraft and from external and onboard camera coverage was successful in spite of the amount of damage which occurred during each crash. Test parameters at the IDRF are controllable with flight path angles accurate within 8 percent, aircraft velocity accurate within 6 percent, pitch angles accurate to 4.25 deg, and roll and yaw angles acceptable under wind velocities up to 4.5 m/s.

  6. Structural dynamics research in a full-scale transport aircraft crash test

    NASA Technical Reports Server (NTRS)

    Mccomb, H. G., Jr.; Hayduk, R. J.; Thomson, R. G.

    1986-01-01

    A remotely piloted air-to-ground crash test of a full-scale transport aircraft was conducted for the first time for two purposes: (1) to demonstrate performance of an antimisting fuel additive in suppressing fire in a crash environment, and (2) to obtain structural dynamics data under crash conditions for comparison with analytical predictions. The test, called the Controlled Impact Demonstration (CID), was sponsored by FAA and NASA with cooperation of industry, the Department of Defense, and the British and French governments. The test aircraft was a Boeing 720 jet transport. The aircraft impacted a dry lakebed at Edwards Air Force Base, CA. The purpose of this paper is to discuss the structural aspects of the CID. The fuselage section tests and the CID itself are described. Structural response data from these tests are presented and discussed. Nonlinear analytical modeling efforts are described, and comparisons between analytical results and experimental results are presented.

  7. Evaluation of aircraft crash hazard at Los Alamos National Laboratory facilities

    SciTech Connect

    Selvage, R.D.

    1996-07-01

    This report selects a method for use in calculating the frequency of an aircraft crash occurring at selected facilities at the Los Alamos National Laboratory (the Laboratory). The Solomon method was chosen to determine these probabilities. Each variable in the Solomon method is defined and a value for each variable is selected for fourteen facilities at the Laboratory. These values and calculated probabilities are to be used in all safety analysis reports and hazards analyses for the facilities addressed in this report. This report also gives detailed directions to perform aircraft-crash frequency calculations for other facilities. This will ensure that future aircraft-crash frequency calculations are consistent with calculations in this report.

  8. Experimental Photogrammetric Techniques Used on Five Full-Scale Aircraft Crash Tests

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.

    2016-01-01

    Between 2013 and 2015, full-scale crash tests were conducted on five aircraft at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). Two tests were conducted on CH-46E airframes as part of the Transport Rotorcraft Airframe Crash Testbed (TRACT) project, and three tests were conduced on Cessna 172 aircraft as part of the Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project. Each test served to evaluate a variety of crashworthy systems including: seats, occupants, restraints, composite energy absorbing structures, and Emergency Locator Transmitters. As part of each test, the aircraft were outfitted with a variety of internal and external cameras that were focused on unique aspects of the crash event. A subset of three camera was solely used in the acquisition of photogrammetric test data. Examples of this data range from simple two-dimensional marker tracking for the determination of aircraft impact conditions to entire full-scale airframe deformation to markerless tracking of Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) during the crash event. This report describes and discusses the techniques used and implications resulting from the photogrammetric data acquired from each of the five tests.

  9. Probabilistic model, analysis and computer code for take-off and landing related aircraft crashes into a structure

    SciTech Connect

    Glaser, R.

    1996-02-06

    A methodology is presented that allows the calculation of the probability that any of a particular collection of structures will be hit by an aircraft in a take-off or landing related accident during a specified window of time with a velocity exceeding a given critical value. A probabilistic model is developed that incorporates the location of each structure relative to airport runways in the vicinity; the size of the structure; the sizes, types, and frequency of use of commercial, military, and general aviation aircraft which take-off and land at these runways; the relative frequency of take-off and landing related accidents by aircraft type; the stochastic properties of off-runway crashes, namely impact location, impact angle, impact velocity, and the heading, deceleration, and skid distance after impact; and the stochastic properties of runway overruns and runoffs, namely the position at which the aircraft exits the runway, its exit velocity, and the heading and deceleration after exiting. Relevant probability distributions are fitted from extensive commercial, military, and general aviation accident report data bases. The computer source code for implementation of the calculation is provided.

  10. Origin and Prevention of Crash Fires in Turbojet Aircraft

    NASA Technical Reports Server (NTRS)

    Pinkel, I. Irvin; Weiss, Solomon; Preston, G. Merritt; Pesman, Gerard J.

    1958-01-01

    The tendency for the jet engine rotor to continue to rotate after crash presents the probability that crash-spilled combustibles suspended in the air or puddled on the ground at the engine inlet may be sucked into the engine. Studies with jet engines operating on a test stand and full-scale crashes of turbojet-powered airplanes showed that combustibles drawn into the engine in this way ignite explosively within the engine. Experiment showed that the gas flow through the engine is too rapid to permit the ignition of ingested combustibles on the hot metal in contact with the main gas stream. Ignition will occur on those hot surfaces not in the main gas stream. The portion of the engine airflow is diverted for cooling and ventilation to these zones where the gas moves slowly enough for ignition to occur.

  11. Assessment of crash fire hazard of LH sub 2 fueled aircraft

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Wittlin, G.; Versaw, E. F.; Parmley, R.; Cima, R.; Walther, E. G.

    1981-01-01

    The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously.

  12. Frequency Estimates for Aircraft Crashes into Nuclear Facilities at Los Alamos National Laboratory (LANL)

    SciTech Connect

    George D. Heindel

    1998-09-01

    In October 1996, the Department of Energy (DOE) issued a new standard for evaluating accidental aircraft crashes into hazardous facilities. This document uses the method prescribed in the new standard to evaluate the likelihood of this type of accident occurring at Los Alamos National Laboratory's nuclear facilities.

  13. Factors associated with pilot fatality in work-related aircraft crashes, Alaska, 1990-1999.

    PubMed

    Bensyl, D M; Moran, K; Conway, G A

    2001-12-01

    Work-related aircraft crashes are the leading cause of occupational fatality in Alaska, with civilian pilots having the highest fatality rate (410/100,000/year). To identify factors affecting survivability, the authors examined work-related aircraft crashes that occurred in Alaska in the 1990s (1990-1999), comparing crashes with pilot fatalities to crashes in which the pilot survived. Using data from National Transportation Safety Board reports, the authors carried out logistic regression analysis with the following variables: age, flight experience, use of a shoulder restraint, weather conditions (visual flight vs. instrument flight), light conditions (daylight vs. darkness), type of aircraft (airplane vs. helicopter), postcrash fire, crash location (airport vs. elsewhere), and state of residence. In the main-effects model, significant associations were found between fatality and postcrash fire (adjusted odds ratio (AOR) = 6.43, 95% confidence interval (CI): 2.38, 17.37), poor weather (AOR = 4.11, 95% CI: 2.15, 7.87), and non-Alaska resident status (AOR = 2.10, 95% CI: 1.05, 4.20). Protective effects were seen for shoulder restraint use (AOR = 0.40, 95% CI: 0.21, 0.77) and daylight versus darkness (AOR = 0.50, 95% CI: 0.25, 0.99). The finding that state of residence was associated with survivability offers new information on pilot survivability in work-related aircraft crashes in Alaska. These results may be useful in targeting safety interventions for pilots who fly occupationally in Alaska or in similar environments. PMID:11724720

  14. Energy absorption studied to reduce aircraft crash forces

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The NASA/FAA aircraft safety reseach programs for general aviation aircraft are discussed. Energy absorption of aircraft subflooring and redesign of interior flooring are being studied. The testing of energy absorbing configurations is described. The three NASA advanced concepts performed at neary the maximum possible amount of energy absorption, and one of two minimum modifications concepts performed well. Planned full scale tests are described. Airplane seat concepts are being considered.

  15. Failure behavior of generic metallic and composite aircraft structural components under crash loads

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.; Robinson, Martha P.

    1990-01-01

    Failure behavior results are presented from crash dynamics research using concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. To achieve desired new designs incorporating improved energy absorption capabilities often requires an understanding of how more conventional designs behave under crash loadings. Experimental and analytical data are presented which indicate some general trends in the failure behavior of a class of composite structures including individual fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame-stringer arrangement. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.

  16. Unique failure behavior of metal/composite aircraft structural components under crash type loads

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.

    1990-01-01

    Failure behavior results are presented on some of the crash dynamics research conducted with concepts of aircraft elements and substructure which have not necessarily been designed or optimized for energy absorption or crash loading considerations. To achieve desired new designs which incorporate improved energy absorption capabilities often requires an understanding of how more conventional designs behave under crash type loadings. Experimental and analytical data are presented which indicate some general trends in the failure behavior of a class of composite structures which include individual fuselage frames, skeleton subfloors with stringers and floor beams but without skin covering, and subfloors with skin added to the frame-stringer arrangement. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models. It is believed that the thread of similarity in behavior is telling the designer and dynamists a great deal about what to expect in the crash behavior of these structures and can guide designs for improving the energy absorption and crash behavior of such structures.

  17. A History of Full-Scale Aircraft and Rotorcraft Crash Testing and Simulation at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.; Lyle, Karen H.

    2004-01-01

    This paper summarizes 2-1/2 decades of full-scale aircraft and rotorcraft crash testing performed at the Impact Dynamics Research Facility (IDRF) located at NASA Langley Research Center in Hampton, Virginia. The IDRF is a 240-ft.-high steel gantry that was built originally as a lunar landing simulator facility in the early 1960's. It was converted into a full-scale crash test facility for light aircraft and rotorcraft in the early 1970 s. Since the first full-scale crash test was preformed in February 1974, the IDRF has been used to conduct: 41 full-scale crash tests of General Aviation (GA) aircraft including landmark studies to establish baseline crash performance data for metallic and composite GA aircraft; 11 full-scale crash tests of helicopters including crash qualification tests of the Bell and Sikorsky Advanced Composite Airframe Program (ACAP) prototypes; 48 Wire Strike Protection System (WSPS) qualification tests of Army helicopters; 3 vertical drop tests of Boeing 707 transport aircraft fuselage sections; and, 60+ crash tests of the F-111 crew escape module. For some of these tests, nonlinear transient dynamic codes were utilized to simulate the impact response of the airframe. These simulations were performed to evaluate the capabilities of the analytical tools, as well as to validate the models through test-analysis correlation. In September 2003, NASA Langley closed the IDRF facility and plans are underway to demolish it in 2007. Consequently, it is important to document the contributions made to improve the crashworthiness of light aircraft and rotorcraft achieved through full-scale crash testing and simulation at the IDRF.

  18. Ames T-3 fire test facility - Aircraft crash fire simulation

    NASA Technical Reports Server (NTRS)

    Fish, R. H.

    1976-01-01

    There is a need to characterize the thermal response of materials exposed to aircraft fuel fires. Large scale open fire tests are costly and pollute the local environment. This paper describes the construction and operation of a subscale fire test that simulates the heat flux levels and thermochemistry of typical open pool fires. It has been termed the Ames T-3 Test and has been used extensively by NASA since 1969 to observe the behavior of materials exposed to JP-4 fuel fires.

  19. Impact Analyses and Tests of Metal Cask Considering Aircraft Engine Crash - 12308

    SciTech Connect

    Lee, Sanghoon; Choi, Woo-Seok; Kim, Ki-Young; Jeon, Je-Eon; Seo, Ki-Seog

    2012-07-01

    The structural integrity of a dual purpose metal cask currently under development by the Korea Radioactive Waste Management Cooperation (KRMC) is evaluated through analyses and tests under a high-speed missile impact considering the targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from the literature. The missile impact velocity was set at 150 m/s, and two impact orientations were considered. A simplified missile simulating a commercial aircraft engine is designed from an impact load history curve provided in the literature. In the analyses, the focus is on the evaluation of the containment boundary integrity of the metal cask. The analyses results are compared with the results of tests using a 1/3 scale model. The results show very good agreements, and the procedure and methodology adopted in the structural analyses are validated. While the integrity of the cask is maintained in one evaluation where the missile impacts the top side of the free standing cask, the containment boundary is breached in another case in which the missile impacts the center of the cask lid in a perpendicular orientation. A safety assessment using a numerical simulation of an aircraft engine crash into spent nuclear fuel storage systems is performed. A commercially available explicit finite element code is utilized for the dynamic simulation, and the strain rate effect is included in the modeling of the materials used in the target system and missile. The simulation results show very good agreement with the test results. It is noted that this is the first test considering an aircraft crash in Korea. (authors)

  20. Instrumentation and data acquisition for full-scale aircraft crash testing

    NASA Technical Reports Server (NTRS)

    Jones, Lisa E.; Fasanella, Edwin L.

    1993-01-01

    The Landing and Impact Dynamics Branch of the NASA Langley Research Center has been conducting full-scale aircraft crash tests since the 1970s. Using a pendulum method, aircraft are suspended by cables from a 240-ft high gantry and swung into the impact surface at various attitudes and velocities. Instrumentation for these tests include on-board high-speed cameras, strain gages, load cells, displacement transducers, and accelerometers. Transducers in the aircraft are hard-wired through a long umbilical cable to the data acquisition room. Up to 96 channels of data can be collected at a typical rate of 4000 samples per second. Data acquisition using an FM multiplexed analog system and a high-speed personal computer based digital system is described.

  1. An overview of the crash dynamics failure behavior of metal and composite aircraft structures

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.

    1991-01-01

    An overview of failure behavior results is presented from some of the crash dynamics research conducted with concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. Experimental and analytical data are presented that indicate some general trends in the failure behavior of a class of composite structures that includes fuselage panels, individual fuselage sections, fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame stringer structure. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.

  2. Crash Testing and Simulation of a Cessna 172 Aircraft: Pitch Down Impact Onto Soft Soil

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Jackson, Karen E.

    2016-01-01

    During the summer of 2015, NASA Langley Research Center conducted three full-scale crash tests of Cessna 172 (C-172) aircraft at the NASA Langley Landing and Impact Research (LandIR) Facility. The first test represented a flare-to-stall emergency or hard landing onto a rigid surface. The second test, which is the focus of this paper, represented a controlled-flight-into-terrain (CFIT) with a nose-down pitch attitude of the aircraft, which impacted onto soft soil. The third test, also conducted onto soil, represented a CFIT with a nose-up pitch attitude of the aircraft, which resulted in a tail strike condition. These three crash tests were performed for the purpose of evaluating the performance of Emergency Locator Transmitters (ELTs) and to generate impact test data for model validation. LS-DYNA finite element models were generated to simulate the three test conditions. This paper describes the model development and presents test-analysis comparisons of acceleration and velocity time-histories, as well as a comparison of the time sequence of events for Test 2 onto soft soil.

  3. The annual probability of an aircraft crash on the US Department of Energy reservation in Oak Ridge, Tennessee

    SciTech Connect

    Seigler, R.S.; Luttrell, L.J.

    1992-11-01

    Aircraft hazards were evaluated to determine the total annual probability of an aircraft crash occurring at any structure located on the US Department of Energy (DOE) reservation in Oak Ridge, Tennessee. This report documents the use of an accepted methodology for calculating the probability of an aircraft crash as applied to the three Oak Ridge plant sites including the adjoining facilities. Based on the data contained herein, the evaluation concluded that the probability of an aircraft crash occurrence at a single facility is generally considered ``not credible`` as defined in DOE/OR-901. Additionally, reevaluation of probabilities would be necessary if significant changes were made to local air traffic. The probability of an aircraft crash could increase as a result of the opening of any new airport or heliport in the vicinity; a greater volume of air traffic from McGhee Tyson airport in Knoxville, should the airport status change from feeder airport to hub airport; the rerouting of commercial and/or military flights at the McGhee Tyson airport; and finally, a change in direction or the addition of a federal airway. At one time, DOE planned to establish a zone of prohibited airspace over the Y-12 plant; if the plans are enacted in the future, the probability of an aircraft crash at the Y-12 plant could decrease. Pilots since have been voluntarily requested not to fly below 3000 feet over the Y-12 plant. Also, the Federal Aviation Administration plans to reroute air traffic in the spring of 1993 on federal airway V16. However, the section of V16 which traverses the three plant sites and five adjoining facilities will not be altered. If this plan is implemented, the air traffic over the Oak Ridge facilities would not be affected significantly, and the probability of an aircraft crash as determined herein would be unchanged.

  4. Crash Simulation of a Vertical Drop Test of a Commuter-Class Aircraft

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    A finite element model of an ATR42-300 commuter-class aircraft was developed and a crash simulation was executed. Analytical predictions were correlated with data obtained from a 30-ft/s (9.14-m/s) vertical drop test of the aircraft. The purpose of the test was to evaluate the structural response of the aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with seats, dummies, luggage, and other ballast. The wings were filled with 8,700 lb. (3,946 kg) of water to represent the fuel. The finite element model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry. The seats, dummies, luggage, fuel, and other ballast were represented using concentrated masses. The model was executed in LS-DYNA, a commercial code for performing explicit transient dynamic simulations. Predictions of structural deformation and selected time-history responses were generated. The simulation was successfully validated through extensive test-analysis correlation.

  5. Occupant injury and fatality in general aviation aircraft for which dynamic crash testing is certification-mandated.

    PubMed

    Boyd, Douglas D

    2015-06-01

    Towards further improving general aviation aircraft crashworthiness, multi-axis dynamic tests have been required for aircraft certification (14CFR23.562) since 1985. The objective of this study was to determine if occupants in aircraft certified to these higher crashworthiness standards show a mitigated fraction of fatal accidents and/or injury severity. The NTSB aviation database was queried for accidents occurring between 2002 and 2012 involving aircraft certified to, or immune from, dynamic crash testing and manufactured after 1999. Only operations conducted under 14CFR Part 91 were considered. Statistical analysis employed proportion tests and logistic regression. Off-airport landings are associated with high decelerative forces; however for off-airport landings, the fraction of fatal accidents for aircraft subject to, or exempt from, dynamic crash testing was similar (0.53 and 0.60, respectively). Unexpectedly, for on-airport landings a higher fraction of fatalities was evident for aircraft whose certification mandated dynamic crash testing. Improved crashworthiness standards would be expected to translate into a reduced severity of accident injuries. For all accidents, as well as for those deemed survivable, the fraction of minor and serious injuries was reduced for occupants in aircraft certified to the higher crashworthiness standards. Surprisingly, the fraction of occupants fatally injured was not decreased for aircraft subject to dynamic crash tests. To shed light on this unexpected finding flight history, airman demographics and post-impact fires for aircraft for which dynamic crash testing is mandatory or exempt was examined. For the former cohort the median distance of the accident flight was nearly 44% higher. Aircraft subject to dynamic crash testing were also involved in a greater fraction (0.25 versus 0.12, respectively) of post-impact fires. Our data suggest that while the more stringent crashworthiness standards have mitigated minor and serious

  6. Crash Testing and Simulation of a Cessna 172 Aircraft: Hard Landing Onto Concrete

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2016-01-01

    A full-scale crash test of a Cessna 172 aircraft was conducted at the Landing and Impact Research Facility at NASA Langley Research Center during the summer of 2015. The purpose of the test was to evaluate the performance of Emergency Locator Transmitters (ELTs) that were mounted at various locations in the aircraft and to generate impact test data for model validation. A finite element model of the aircraft was developed for execution in LSDYNA to simulate the test. Measured impact conditions were 722.4-in/s forward velocity and 276-in/s vertical velocity with a 1.5deg pitch (nose up) attitude. These conditions were intended to represent a survivable hard landing. The impact surface was concrete. During the test, the nose gear tire impacted the concrete, followed closely by impact of the main gear tires. The main landing gear spread outward, as the nose gear stroked vertically. The only fuselage contact with the impact surface was a slight impact of the rearmost portion of the lower tail. Thus, capturing the behavior of the nose and main landing gear was essential to accurately predict the response. This paper describes the model development and presents test-analysis comparisons in three categories: inertial properties, time sequence of events, and acceleration and velocity time-histories.

  7. Heat shields for aircraft - A new concept to save lives in crash fires.

    NASA Technical Reports Server (NTRS)

    Neel, C. B.; Parker, J. A.; Fish, R. H.; Henshaw, J.; Newland, J. H.; Tempesta, F. L.

    1971-01-01

    A passenger compartment surrounded by a fire-retardant shell, to protect the occupants long enough for the fire to burn out or for fire-fighting equipment to reach the aircraft and extinguish it, is proposed as a new concept for saving lives in crash fires. This concept is made possible by the recent development of two new fire-retardant materials: a very lightweight foam plastic, called polyisocyanurate foam, and an intumescent paint. Exposed to heat, the intumescent paint expands to many times its original thickness and insulates the surface underneath it. Demonstration tests are illustrated, described and discussed. However, some problems, such as preventing fuselage rupture and protecting windows, must be solved before such a system can be used.

  8. Aircraft mishap investigation with radiology-assisted autopsy: helicopter crash with control injury.

    PubMed

    Folio, R Les; Harcke, H Theodore; Luzi, Scott A

    2009-04-01

    Radiology-assisted autopsy traditionally has been plain film-based, but now is being augmented by computed tomography (CT). The authors present a two-fatality rotary wing crash scenario illustrating application of advanced radiographic techniques that can guide and supplement the forensic pathologist's physical autopsy. The radiographic findings also have the potential for use by the aircraft mishap investigation board. Prior to forensic autopsy, the two crash fatalities were imaged with conventional two-dimensional radiographs (digital technique) and with multidetector CT The CT data were used for multiplanar two-dimensional and three-dimensional (3D) image reconstruction. The forensic pathologist was provided with information about skeletal fractures, metal fragment location, and other pathologic findings of potential use in the physical autopsy. The radiologic autopsy served as a supplement to the physical autopsy and did not replace the traditional autopsy in these cases. Both individuals sustained severe blunt force trauma with multiple fractures of the skull, face, chest, pelvis, and extremities. Individual fractures differed; however, one individual showed hand and lower extremity injuries similar to those associated with control of the aircraft at the time of impact. The concept of "control injury" has been challenged by Campman et al., who found that control surface injuries have a low sensitivity and specificity for establishing who the pilot was in an accident. The application of new post mortem imaging techniques may help to resolve control injury questions. In addition, the combination of injuries in our cases may contribute to further understanding of control surface injury patterns in helicopter mishaps. PMID:19378913

  9. Accident-precipitating factors for crashes in turbine-powered general aviation aircraft.

    PubMed

    Boyd, Douglas D; Stolzer, Alan

    2016-01-01

    General aviation (14CFR Part 91) accounts for 83% of civil aviation fatalities. While much research has focused on accident causes/pilot demographics in this aviation sector, studies to identify factors leading up to the crash (accident-precipitating factors) are few. Such information could inform on pre-emptive remedial action. With this in mind and considering the paucity of research on turbine-powered aircraft accidents the study objectives were to identify accident-precipitating factors and determine if the accident rate has changed over time for such aircraft operating under 14CFR Part 91. The NTSB Access database was queried for accidents in airplanes (<12,501lb) powered by 1-2 turbine engines and occurring between 1989 and 2013. We developed and utilized an accident-precipitating factor taxonomy. Statistical analyses employed logistic regression, contingency tables and a generalized linear model with Poisson distribution. The "Checklist/Flight Manual Not Followed" was the most frequent accident-precipitating factor category and carried an excess risk (OR 2.34) for an accident with a fatal and/or serious occupant injury. This elevated risk reflected an over-representation of accidents with fatal and/or serious injury outcomes (p<0.001) in the "non-adherence to V Speeds" sub-category. For accidents grouped in the "Inadequate Pre-Flight Planning/Inspection/Procedure" the "inadequate weather planning" sub-category accounted (p=0.036) for the elevated risk (OR 2.22) of an accident involving fatal and/or serious injuries. The "Violation FARs/AIM Deviation" category was also associated with a greater risk for fatal and/or serious injury (OR 2.59) with "Descent below the MDA/failure to execute the missed approach" representing the largest sub-category. Accidents in multi-engine aircraft are more frequent than their single engine counterparts and the decline (50%) in the turbine aircraft accident rate over the study period was likely due, in part, to a 6-fold

  10. Behavior of composite/metal aircraft structural elements and components under crash type loads: What are they telling us

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.

    1990-01-01

    Failure behavior results are presented from crash dynamics research using concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. To achieve desired new designs which incorporate improved energy absorption capabilities often requires an understanding of how more conventional designs behave under crash loadings. Experimental and analytical data are presented which indicate some general trends in the failure behavior of a class of composite structures which include individual fuselage frames, skeleton subfloors with stringers and floor beams but without skin covering, and subfloors with skin added to the frame-stringer arrangement. Although the behavior is complex, a strong similarity in the static and dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models. It is believed that the similarity in behavior is giving the designer and dynamists much information about what to expect in the crash behavior of these structures and can guide designs for improving the energy absorption and crash behavior of such structures.

  11. Crash Test of Three Cessna 172 Aircraft at NASA Langley Research Center's Landing and Impact Research Facility

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.

    2015-01-01

    During the summer of 2015, three Cessna 172 aircraft were crash tested at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). The three tests simulated three different crash scenarios. The first simulated a flare-to-stall emergency or hard landing onto a rigid surface such as a road or runway, the second simulated a controlled flight into terrain with a nose down pitch on the aircraft, and the third simulated a controlled flight into terrain with an attempt to unsuccessfully recover the aircraft immediately prior to impact, resulting in a tail strike condition. An on-board data acquisition system captured 64 channels of airframe acceleration, along with acceleration and load in two onboard Hybrid II 50th percentile Anthropomorphic Test Devices, representing the pilot and co-pilot. Each test contained different airframe loading conditions and results show large differences in airframe performance. This paper presents test methods used to conduct the crash tests and will summarize the airframe results from the test series.

  12. Non-invasive examination of a skull fragment recovered from a World War Two aircraft crash site.

    PubMed

    Gapert, René; Rieder, Kurt

    2013-09-01

    The discovery of human remains dating to the time of the Second World War is a common occurrence in Europe and the Pacific regions. This case report demonstrates the analysis of a bone fragment recovered from a Luftwaffe crash site in Austria during the summer of 2007. Eye-witness statements and official reports were used to reconstruct the historical background of the case. A recovered German military identity tag helped to identify the pilot. Aircraft parts, also discovered at the crash site in 2007, aided the identification of the aircraft type and corroborated the eye-witness reports of the final moments before and during the crash. The bone was analyzed chiefly to establish its human or non-human origin and to identify from which anatomic region the fragment could have arisen. It was identified as part of a human adult skull which exhibited peri-mortem fractures and heat damage as well as post-mortem vegetation staining. The historical background information in connection with the morphological analysis led to the presumptive identification of the cranial fragment as belonging to a downed German pilot. PMID:23238939

  13. Effect of crash pulse shape on seat stroke requirements for limiting loads on occupants of aircraft

    NASA Technical Reports Server (NTRS)

    Carden, Huey D.

    1992-01-01

    An analytical study was made to provide comparative information on various crash pulse shapes that potentially could be used to test seats under conditions included in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats, show the effects that crash pulse shape can have on the seat stroke requirements necessary to maintain a specified limit loading on the seat/occupant during crash pulse loadings, compare results from certain analytical model pulses with approximations of actual crash pulses, and compare analytical seat results with experimental airplace crash data. Structural and seat/occupant displacement equations in terms of the maximum deceleration, velocity change, limit seat pan load, and pulse time for five potentially useful pulse shapes were derived; from these, analytical seat stroke data were obtained for conditions as specified in Federal Regulations Part 23 Paragraph 23.562(b)(1) for dynamic testing of general aviation seats.

  14. Technical Seminar: "Crash Safety"""

    NASA Video Gallery

    This seminar addresses the history and successful progress in predicting and improving the crash safety characteristics of vehicles, with particular emphasis on rotary wing aircraft and composite s...

  15. Test-Analysis Correlation of a Crash Simulation of a Vertical Drop Test of a Commuter-Category Aircraft

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    A finite element model of an ATR42-300 commuter-class aircraft was developed and a crash simulation was executed. Analytical predictions were correlated with data obtained from a 30-feet per second (9.14-meters per second) vertical drop test of the aircraft. The purpose of the test was to evaluate the structural response of the aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with seats, dummies, luggage, and other ballast. The wings were filled with 8,700 lb. (3,946 kilograms) of water to represent the fuel. The finite element model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry. The seats, dummies, luggage, simulated engines and fuel, and other ballast were represented using concentrated masses. The model was executed in LS-DYNA, a commercial finite element code for performing explicit transient dynamic simulations. Analytical predictions of structural deformation and selected time-history responses were correlated with experimental data from the drop test to validate the simulation.

  16. Radiological analysis of hand and foot injuries after small aircraft crashes.

    PubMed

    Kubat, Bela; Korthout, Tessa; van Ingen, Gert; Rietveld, Louk A C; de Bakker, Henri M

    2014-09-01

    Medico-legal investigation of fatal aviation accidents should contribute to the reconstruction of the accident in addition to providing the usual information about cause and manner of death. In cases with more than one fatality, the question of who was flying the plane at the time of the crash may need to be answered. In such cases the identification of "control injuries" plays an important role. This study aims to investigate whether specific patterns of skeletal hand and foot injuries could assist in the identification of the pilot. The analysis of radiological investigations of hands and feet of 27 fatalities from 18 accidents showed that foot injuries are more frequent than hand injuries in pilots and passengers, dislocations of feet were more frequent in passengers, and right-sided injuries were more frequent in pilots. Injuries of the distal parts of the hand were slightly more frequent in the pilot group. The limited numbers in the study do not allow definitive conclusions and further investigations are needed. However, the study yields interesting results and shows that radiological examination should be included in the medico-legal air crash investigation. PMID:24985317

  17. AP1000{sup R} design robustness against extreme external events - Seismic, flooding, and aircraft crash

    SciTech Connect

    Pfister, A.; Goossen, C.; Coogler, K.; Gorgemans, J.

    2012-07-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel

  18. Death and injury in aerial spraying: pre-crash, crash, and post-crash prevention strategies.

    PubMed

    Richter, E D; Gordon, M; Halamish, M; Gribetz, B

    1981-01-01

    To prevent crash-related death and injury among spray pilots, a program including pre-crash, crash and post-crash stages of intervention for aircraft, physical environment, and pilots and ground crews was proposed in accordance with a matrix of options derived from road crash epidemiology. In addition to the dangers of fixed obstacles, low-altitude runs, and heavy work schedules, work hazards included combined exposures to noise, vibration, G forces, heat stress, pesticides, and dehydration. Together, these exposures were believed to have produced slight, but crucial decreases in pilot performance, alertness and skill. For aircraft, the major pre-crash measure was cockpit air cooling, with filter technologies to prevent in-flight pesticide exposure. Crash and post-crash design changes to reduce energy transfers to the pilot's body (thermal, kinetic) were the most important recommendations, because absolute prevention of the crash event was unlikely. For the environment, pre-crash recommendations included marking fixed obstacles, such as power and telephone lines, but preferably their elimination. Other measures included drainage pits with sodium hydroxide points to neutralize parathion and prevent dispersion of parathion-containing mists. Pilot pre-crash measures (more fluid intake, biological monitoring--EMG, urinary alkyl phosphate, cholinesterase testing) required special organizational arrangements. Systematic application of options from the foregoing matrix suggest that the high risk of death and injury from aerial spraying is unnecessary. PMID:7213290

  19. Impact Landing Dynamics Facility Crash Test

    NASA Technical Reports Server (NTRS)

    1975-01-01

    By 1972 the Lunar Landing Research Facility was no longer in use for its original purpose. The 400-foot high structure was swiftly modified to allow engineers to study the dynamics of aircraft crashes. 'The Impact Dynamics Research Facility is used to conduct crash testing of full-scale aircraft under controlled conditions. The aircraft are swung by cables from an A-frame structure that is approximately 400 ft. long and 230 foot high. The impact runway can be modified to simulate other grand crash environments, such as packed dirt, to meet a specific test requirement.' 'In 1972, NASA and the FAA embarked on a cooperative effort to develop technology for improved crashworthiness and passenger survivability in general aviation aircraft with little or no increase in weight and acceptable cost. Since then, NASA has 'crashed' dozens of GA aircraft by using the lunar excursion module (LEM) facility originally built for the Apollo program.' This photograph shows Crash Test No. 7.

  20. The application of EOQ and lead time crashing cost models in material with limited life time (Case study: CN-235 Aircraft at PT Dirgantara Indonesia)

    NASA Astrophysics Data System (ADS)

    Agustina Hidayat, Yosi; Ria Kasanah, Aprilia; Yudhistira, Titah

    2016-02-01

    PT. Dirgantara Indonesia, one of State Owned Enterprises engaging in the aerospace industry, targets to control 30% of world market for light and medium sized aircraft. One type of the aircrafts produced by PT. DI every year is CN-235. Currently, the cost of material procurement reaches 50% of the total cost of production. Material has a variety of characteristics, one of which is having a lifetime. The demand characteristic of the material with expiration for the CN-235 aircraft is deterministic. PT DI does not have any scientific background for its procurement of raw material policy. In addition, there are two methods of transportation used for delivering materials, i.e. by land and air. Each method has different lead time. Inventory policies used in this research are deterministic and probabilistic. Both deterministic and probabilistic single and multi-item inventory policies have order quantity, time to order, reorder point, and lead time as decision variables. The performance indicator for this research is total inventory cost. Inventory policy using the single item EOQ and considering expiration factor inventory results in a reduction in total costs up to 69.58% and multi item results in a decrease in total costs amounted to 71.16%. Inventory policy proposal using the model of a single item by considering expiration factor and lead time crashing cost results in a decrease in total costs amounted to 71.5% and multi item results in a decrease in total costs amounted to 71.62%. Subsequently, wasted expired materials, with the proposed models have been successfully decreased to 95%.

  1. Development of an LS-DYNA Model of an ATR42-300 Aircraft for Crash Simulation

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    This paper describes the development of an LS-DYNA simulation of a vertical drop test of an ATR42-300 twin-turboprop high-wing commuter-class airplane. A 30-ft/s drop test of this aircraft was performed onto a concrete impact surface at the FAA Technical Center on July 30, 2003. The purpose of the test was to evaluate the structural response of a commuter-class aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with crew and passenger seats, anthropomorphic test dummies, forward and aft luggage, instrumentation, and onboard data acquisition systems. The wings were filled with approximately 8,700 lb. of water to represent the fuel and the aircraft weighed a total of 33,200 lb. The model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry, over a period of approximately 8 months. The seats, dummies, luggage, fuel, and other ballast were represented using concentrated masses. Comparisons were made of the structural deformation and failure behavior of the airframe, as well as selected acceleration time history responses.

  2. Nonlinear transient analysis by energy minimization: A theoretical basis for the ACTION computer code. [predicting the response of a lightweight aircraft during a crash

    NASA Technical Reports Server (NTRS)

    Kamat, M. P.

    1980-01-01

    The formulation basis for establishing the static or dynamic equilibrium configurations of finite element models of structures which may behave in the nonlinear range are provided. With both geometric and time independent material nonlinearities included, the development is restricted to simple one and two dimensional finite elements which are regarded as being the basic elements for modeling full aircraft-like structures under crash conditions. Representations of a rigid link and an impenetrable contact plane are added to the deformation model so that any number of nodes of the finite element model may be connected by a rigid link or may contact the plane. Equilibrium configurations are derived as the stationary conditions of a potential function of the generalized nodal variables of the model. Minimization of the nonlinear potential function is achieved by using the best current variable metric update formula for use in unconstrained minimization. Powell's conjugate gradient algorithm, which offers very low storage requirements at some slight increase in the total number of calculations, is the other alternative algorithm to be used for extremely large scale problems.

  3. The search and rescue satellite mission - A basis for international cooperation. [in aircraft crash and marine distress

    NASA Technical Reports Server (NTRS)

    Redisch, W. N.; Trudell, B. J.

    1978-01-01

    The use of geostationary and polar-orbiting satellites to monitor and locate signals of the Emergency Locator Transmitter (ELT) and Emergency Position Indicating Radio Beacon (EPIB) of general aviation aircraft and inspected marine vessels respectively is described. The joint U.S. Canada/France SARSAT demonstration program will require a minimum of four minutes of mutual visibility of distress transmitter, local user terminal and satellite to obtain a location by Doppler tracking. The program consisting of placing instrumentation on-board three of the Tiros-N series of NOAA operational satellites is attracting interest also from other countries including the USSR, Norway, Australia, and Japan.

  4. Impact Landing Dynamics Facility Crash Test

    NASA Technical Reports Server (NTRS)

    1975-01-01

    By 1972 the Lunar Landing Research Facility was no longer in use for its original purpose. The 400-foot high structure was swiftly modified to allow engineers to study the dynamics of aircraft crashes. The Impact Dynamics Research Facility is used to conduct crash testing of full- scale aircraft under controlled conditions. The aircraft are swung by cables from an A-frame structure that is approximately 400 ft. long and 230 foot high. The impact runway can be modified to simulate other grand crash environments, such as packed dirt, to meet a specific test requirement. In 1972, NASA and the FAA embarked on a cooperative effort to develop technology for improved crashworthiness and passenger survivability in general aviation aircraft with little or no increase in weight and cceptable cost. Since then, NASA has 'crashed' dozens of GA aircraft by using the lunar excursion module (LEM) facility originally built for the Apollo program.

  5. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  6. Aircraft

    DOEpatents

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  7. Crash involvement of drivers with multiple crashes.

    PubMed

    Chandraratna, Susantha; Stamatiadis, Nikiforos; Stromberg, Arnold

    2006-05-01

    A goal for any licensing agency is the ability to identify high-risk drivers. Kentucky data show that a significant number of drivers are repeatedly involved in crashes. The objective of this study is the development of a crash prediction model that can be used to estimate the likelihood of a driver being at fault for a near future crash occurrence. Multiple logistic regression techniques were employed using the available data for the Kentucky licensed drivers. This study considers as crash predictors the driver's total number of previous crashes, citations accumulated, the time gap between the latest two crashes, crash type, and demographic factors. The driver's total number of previous crashes was further disaggregated into the drivers' total number of previous at-fault and not-at-fault crashes. The model can be used to correctly classify at-fault drivers up to 74.56% with an overall efficiency of 63.34%. The total number of previous at-fault crash involvements, and having previous driver license suspensions and traffic school referrals are strongly associated with a driver being responsible for a subsequent crash. In addition, a driver's likelihood to be at fault in a crash is higher for very young or very old, males, drivers with both speeding and non-speeding citations, and drivers that had a recent crash involvement. Thus, the model presented here enables agencies to more actively monitor the likelihood of a driver to be at fault in a crash. PMID:16405858

  8. Best Practices for Crash Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Jackson, Karen E.

    2002-01-01

    Aviation safety can be greatly enhanced by the expeditious use of computer simulations of crash impact. Unlike automotive impact testing, which is now routine, experimental crash tests of even small aircraft are expensive and complex due to the high cost of the aircraft and the myriad of crash impact conditions that must be considered. Ultimately, the goal is to utilize full-scale crash simulations of aircraft for design evaluation and certification. The objective of this publication is to describe "best practices" for modeling aircraft impact using explicit nonlinear dynamic finite element codes such as LS-DYNA, DYNA3D, and MSC.Dytran. Although "best practices" is somewhat relative, it is hoped that the authors' experience will help others to avoid some of the common pitfalls in modeling that are not documented in one single publication. In addition, a discussion of experimental data analysis, digital filtering, and test-analysis correlation is provided. Finally, some examples of aircraft crash simulations are described in several appendices following the main report.

  9. Crash Tests of Protective Airplane Floors

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1986-01-01

    Energy-absorbing floors reduce structural buckling and impact forces on occupants. 56-page report discusses crash tests of energy-absorbing aircraft floors. Describes test facility and procedures; airplanes, structural modifications, and seats; crash dynamics; floor and seat behavior; and responses of anthropometric dummies seated in airplanes. Also presents plots of accelerations, photographs and diagrams of test facility, and photographs and drawings of airplanes before, during, and after testing.

  10. 14 CFR 29.952 - Fuel system crash resistance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system crash resistance. 29.952 Section 29.952 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.952 Fuel system crash resistance. Unless other means...

  11. 14 CFR 27.952 - Fuel system crash resistance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system crash resistance. 27.952 Section 27.952 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.952 Fuel system crash resistance. Unless other means acceptable...

  12. ELT antenna gain distributions under simulated crash conditions

    NASA Technical Reports Server (NTRS)

    Estep, H.

    1984-01-01

    A study of the relative merits of ELT antenna positions, when mounted on a small aircraft, is presented. The gain distribution of the best antenna position together with the worst crash scenario is also given.

  13. Overview Of Structural Behavior and Occupant Responses from Crash Test of a Composite Airplane

    NASA Technical Reports Server (NTRS)

    Jones, Lisa E.; Carden, Huey D.

    1995-01-01

    As part of NASA's composite structures crash dynamics research, a general aviation aircraft with composite wing, fuselage and empennage (but with metal subfloor structure) was crash tested at the NASA Langley Research Center Impact Research Facility. The test was conducted to determine composite aircraft structural behavior for crash loading conditions and to provide a baseline for a similar aircraft test with a modified subfloor. Structural integrity and cabin volume were maintained. Lumbar loads for dummy occupants in energy absorbing seats wer substantially lower than those in standard aircraft seats; however, loads in the standard seats were much higher that those recorded under similar conditions for an all-metallic aircraft.

  14. Gender and Age Differences among Teen Drivers in Fatal Crashes.

    PubMed

    Swedler, David I; Bowman, Stephen M; Baker, Susan P

    2012-01-01

    To identify age and gender differences among teen drivers in fatal crashes, we analyzed FARS data for 14,026crashes during 2007-2009. Compared with female teenagers, crashes of male teenagers were significantly more likely to involve BACs of 0.08% or more (21% vs. 12%), speeding (38% vs. 25%), reckless driving (17% vs. 14%), night driving (41% vs. 36%) and felony crashes (hit-and-run, homicide, or manslaughter) (8% vs. 6%) (all χ(2) p<0.001). Conversely, crashes of female teenagers were more likely to involve right angle ("t-bone") crashes (23% vs. 17%). Some crash characteristics associated with males and known to play a major role in crash causation also are more common in the youngest teenagers; for example, crashes of drivers age 15 or 16 were more likely than crashes of older teens to involve speeding or reckless driving. Crashes of drivers with BACs of 0.08% or higher increased with age in both genders. Some age effects differed by gender: for example, the proportion of crashes of female teens that involved speeding dropped from 38% to 22% between ages 15 and 19, while for males about 38% of crashes at each age involved speeding. The gender and age differences observed in teen drivers suggest opportunities for targeted driver training - for example, simulator training modules specifically tailored for male or female teenagers. Technology-based tools could also be developed to help parents to focus on the reckless driving tendencies of their sons. Insurance companies should consider ways to incentivize young males to drive more responsibly. PMID:23169121

  15. Designing for aircraft structural crashworthiness

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Caiafa, C.

    1981-01-01

    This report describes structural aviation crash dynamics research activities being conducted on general aviation aircraft and transport aircraft. The report includes experimental and analytical correlations of load-limiting subfloor and seat configurations tested dynamically in vertical drop tests and in a horizontal sled deceleration facility. Computer predictions using a finite-element nonlinear computer program, DYCAST, of the acceleration time-histories of these innovative seat and subfloor structures are presented. Proposed application of these computer techniques, and the nonlinear lumped mass computer program KRASH, to transport aircraft crash dynamics is discussed. A proposed FAA full-scale crash test of a fully instrumented radio controlled transport airplane is also described.

  16. CID Aircraft post-impact lakebed skid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Moments after hitting and sliding through the wing openers the aircraft burst into flame, with a spectacular fireball seen emanating from the right inboard engine area. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four

  17. Crash Rates of Scheduled Commuter and Air Carrier Flights Before and After a Regulatory Change

    PubMed Central

    Baker, Susan P.; Groff, Loren; Haaland, Wren; Qiang, Yandong; Rebok, George W.; Li, Guohua

    2010-01-01

    Introduction In 1997, in an effort to reduce the crash rate of scheduled commuter flights, the FAA required aircraft with 10–30 passenger seats to operate under stricter rules. Training and other requirements of 14 CFR Part 121 rules were applied to these midsize commuters, which previously had operated under the less strict Part 135 rules. Published crash rates obscured changes related to aircraft size. This research was undertaken to determine whether the rule change affected crash rates of aircraft with 10–30 passenger seats. Method We determined the number of passenger seats on each Part 135 or Part 121 aircraft that crashed between 1983 and 2007. For aircraft with < 10, 10–30, and > 30 seats, we estimated the numbers of departures and crash rates, adjusting for changes in total departures and numbers of in-service aircraft. Results The Part 135 crash rate tripled in 1997 when commuters with 10–30 seats were excluded, reflecting the administrative change. However, the crash rate of aircraft with 10–30 passenger seats began to decline 4 yr before the rule change; thereafter, their rate was lower than for larger aircraft. The fleet size of aircraft with 10–30 passenger seats increased from 1983 to 1997, then declined as they were replaced with larger aircraft in response to the rule change. Discussion No effect of the rule change on crash rates of 10–30-seat aircraft was apparent. The decline in their crash rates began before the rule change and may have been related to the 1992 requirement for ground proximity warning devices. PMID:19378909

  18. CID Aircraft pre-impact lakebed skid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The B-720 is seen viewed moments after impact and just before hitting the wing openers. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1, 1984, more than four years of effort passed trying to set-up final impact conditions considered survivable by the FAA. During those years while 14 flights with crews were flown the following major efforts were underway: NASA Dryden developed the remote piloting techniques necessary for the B-720 to fly as a drone aircraft; General Electric installed and tested four degraders (one on each engine); and the FAA refined AMK (blending, testing, and

  19. NASA/FAA general aviation crash dynamics program

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Hayduk, R. J.; Carden, H. D.

    1981-01-01

    The program involves controlled full scale crash testing, nonlinear structural analyses to predict large deflection elastoplastic response, and load attenuating concepts for use in improved seat and subfloor structure. Both analytical and experimental methods are used to develop expertise in these areas. Analyses include simplified procedures for estimating energy dissipating capabilities and comprehensive computerized procedures for predicting airframe response. These analyses are developed to provide designers with methods for predicting accelerations, loads, and displacements on collapsing structure. Tests on typical full scale aircraft and on full and subscale structural components are performed to verify the analyses and to demonstrate load attenuating concepts. A special apparatus was built to test emergency locator transmitters when attached to representative aircraft structure. The apparatus is shown to provide a good simulation of the longitudinal crash pulse observed in full scale aircraft crash tests.

  20. Factors associated with hit-and-run pedestrian fatalities and driver identification.

    PubMed

    MacLeod, Kara E; Griswold, Julia B; Arnold, Lindsay S; Ragland, David R

    2012-03-01

    As hit-and-run crashes account for a significant proportion of pedestrian fatalities, a better understanding of these crash types will assist efforts to reduce these fatalities. Of the more than 48,000 pedestrian deaths that were recorded in the United States between 1998 and 2007, 18.1% of them were caused by hit-and-run drivers. Using national data on single pedestrian-motor vehicle fatal crashes (1998-2007), logistic regression analyses were conducted to identify factors related to hit-and-run and to identify factors related to the identification of the hit-and-run driver. Results indicate an increased risk of hit-and-run in the early morning, poor light conditions, and on the weekend. There may also be an association between the type of victim and the likelihood of the driver leaving and being identified. Results also indicate that certain driver characteristics, behavior, and driving history are associated with hit-and-run. Alcohol use and invalid license were among the leading driver factor associated with an increased risk of hit-and-run. Prevention efforts that address such issues could substantially reduce pedestrian fatalities as a result of hit-and-run. However, more information about this driver population may be necessary. PMID:22269520

  1. Estimate of air carrier and air taxi crash frequencies from high altitude en route flight operations

    SciTech Connect

    Sanzo, D.; Kimura, C.Y.; Prassinos, P.G.

    1996-06-03

    In estimating the frequency of an aircraft crashing into a facility, it has been found convenient to break the problem down into two broad categories. One category estimates the aircraft crash frequency due to air traffic from nearby airports, the so-called near-airport environment. The other category estimates the aircraft crash frequency onto facilities due to air traffic from airways, jet routes, and other traffic flying outside the near-airport environment The total aircraft crash frequency is the summation of the crash frequencies from each airport near the facility under evaluation and from all airways, jet routes, and other traffic near the facility of interest. This paper will examine the problems associated with the determining the aircraft crash frequencies onto facilities outside the near-airport environment. This paper will further concentrate on the estimating the risk of aircraft crashes to ground facilities due to high altitude air carrier and air taxi traffic. High altitude air carrier and air taxi traffic will be defined as all air carrier and air taxi flights above 18,000 feet Mean Sea Level (MSL).

  2. Post-crash fuel dispersal

    SciTech Connect

    Tieszen, S.R.

    1997-03-01

    This paper is a brief overview of work over the last several decades in understanding what occurs to jet fuel stored in aircraft fuel tanks on impact with the ground. Fuel dispersal is discussed in terms of the overall crash dynamics process and impact regimes are identified. In a generic sense, the types of flow regimes which can occur are identified and general descriptions of the processes are given. Examples of engineering level tools, both computational and experimental, which have applicability to analyzing the complex environments are presented. Finally, risk based decision is discussed as a quick means of identifying requirements for development of preventative or mitigation strategies, such as further work on the development of an anti-misting agent.

  3. Critical market crashes

    NASA Astrophysics Data System (ADS)

    Sornette, D.

    2003-04-01

    This review presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. We start by discussing the limitation of standard analyses for characterizing how crashes are special. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are “outliers”: they form a class of their own as can be seen from their statistical signatures. If large financial crashes are “outliers”, they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the narrow confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. A first model posits that the crash hazard drives the market price. The crash hazard may sky-rocket at some times due to the collective behavior of “noise traders”, those who act on little information, even if they think they “know”. A second version inverses the logic and posits that prices drive the crash hazard. Prices may skyrocket at some times again due to the speculative or imitative behavior of investors. According the rational expectation model, this entails automatically a corresponding increase of the probability for a crash. We also review two other models including the competition between imitation and contrarian behavior and between value investors and technical analysts. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory

  4. Survey of NASA research on crash dynamics

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.; Carden, H. D.; Hayduk, R. J.

    1984-01-01

    Ten years of structural crash dynamics research activities conducted on general aviation aircraft by the National Aeronautics and Space Administration (NASA) are described. Thirty-two full-scale crash tests were performed at Langley Research Center, and pertinent data on airframe and seat behavior were obtained. Concurrent with the experimental program, analytical methods were developed to help predict structural behavior during impact. The effects of flight parameters at impact on cabin deceleration pulses at the seat/occupant interface, experimental and analytical correlation of data on load-limiting subfloor and seat configurations, airplane section test results for computer modeling validation, and data from emergency-locator-transmitter (ELT) investigations to determine probable cause of false alarms and nonactivations are assessed. Computer programs which provide designers with analytical methods for predicting accelerations, velocities, and displacements of collapsing structures are also discussed.

  5. Pilot ejection, parachute, and helicopter crash injuries.

    PubMed

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. PMID:25399374

  6. The SVT Hit Buffer

    SciTech Connect

    Belforte, S.; Dell`Orso, M.; Donati, S.

    1996-06-01

    The Hit Buffer is part of the Silicon Vertex Tracker, a trigger processor dedicated to the reconstruction of particle trajectories in the Silicon Vertex Detector and the Central Tracking Chamber of the Collider Detector at Fermilab. The Hit Buffer is a high speed data-traffic node, where thousands of words are received in arbitrary order and simultaneously organized in an internal structured data base, to be later promptly retrieved and delivered in response to specific requests. The Hit Buffer is capable of processing data at a rate of 25 MHz, thanks to the use of special fast devices like Cache-Tag RAMs and high performance Erasable Programmable Logic Devices from the XILINX XC7300 family.

  7. But Can You Hit?

    ERIC Educational Resources Information Center

    Johnson, R. E.

    2009-01-01

    The author shares a story told to him by a colleague more than thirty years ago. The dean of a midsized American university was explaining the path to tenure to a roomful of newly appointed assistant professors. "We know you boys can all "field"," he declared. "Now we want to see if you can hit." A lot has changed over the intervening decades. If…

  8. Solid state crash survivable flight data recorders for mishap investigation

    NASA Astrophysics Data System (ADS)

    Ask, H. R.

    1981-11-01

    The state of the art in solid state memories, microprocessors and crash survival is reviewed. Flight recorders for small and large civil transport aircraft are described. Heat flow problems with crash survivable designs are solved, using an intumescent outer layer for the enclosure. This provides heat absorbtion during a phase change, followed by creation of a passive insulation layer formed by the charred residue. An aluminum alloy housing under the intumescent layer is the primary rigid structure for penetration, shock and static crush resistance. The small aircraft system has a 131 kbit memory, providing 30 min of prior flight data with 100% reserve, using data compression. It protects airborne and on ground signal goodness data and is nondeployable. The large aircraft system stores the 21 min of raw input data and the last 15 hr of data in memory with data compression possible. It protects in memory two flight cycles of any duration, with total elapsed time 25 hr possible.

  9. Annoyance by aircraft noise and fear of overflying aircraft in relation to attitudes toward the environment and community

    NASA Technical Reports Server (NTRS)

    Loeb, M.; Moran, S. V.

    1977-01-01

    It has been suggested that expressions of annoyance attributable to aircraft noise may reflect in part fear of aircraft overflights and possible crashes. If this is true, then residents of areas where crashes have occurred should express more annoyance. To test this hypothesis, 50 residents of an Albany, New York area where an aircraft crash producing fatalities recently occurred and 50 residents of a comparable nearby area without such a history, were asked to respond to a 'Quality of Life Questionnaire.' Among the items were some designed to test annoyance by noise and fear of aircraft overflights. It was predicted that those in the crash area would express more fear and would more often identify aircraft as a noise source. These hypotheses were sustained. A near-replication was carried out in Louisville, Kentucky; results were much the same. Analyses indicated that for the crash-area groups, there was associating of aircraft fear and noise annoyance responses; this was true to an apparently lesser extent for non-crash groups. The greater annoyance of crash groups by aircraft community noise apparently does not carry over to situations in which aircraft noise is assessed in the laboratory.

  10. Pilot Age and Error in Air-Taxi Crashes

    PubMed Central

    Rebok, George W.; Qiang, Yandong; Baker, Susan P.; Li, Guohua

    2010-01-01

    Introduction The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air-taxi crashes. Methods Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. Results Of the 1751 air-taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air-taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. Conclusions Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air-taxi crashes. Lack of age-related differences in pilot error may be attributable to the “safe worker effect.” PMID:19601508

  11. Reading as Wedding Crashing

    ERIC Educational Resources Information Center

    Newkirk, Thomas

    2014-01-01

    Grappling with difficult texts can make readers feel as though they're crashing a party that wasn't meant for them. They don't know the occasion. They don't know the guests. They have a hard time fitting in. In this article, Thomas Newkirk suggests several reasons why students find texts difficult to understand. Students may be…

  12. General aviation crash safety program at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Thomson, R. G.

    1976-01-01

    The purpose of the crash safety program is to support development of the technology to define and demonstrate new structural concepts for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: full-scale crash simulation testing, nonlinear structural analyses necessary to predict failure modes and collapse mechanisms of the vehicle, and evaluation of energy absorption concepts for specific component design. Both analytical and experimental methods are being used to develop expertise in these areas. Analyses include both simplified procedures for estimating energy absorption capabilities and more complex computer programs for analysis of general airframe response. Full-scale tests of typical structures as well as tests on structural components are being used to verify the analyses and to demonstrate improved design concepts.

  13. Sikorski - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Roof instrument panel between pilot stations - left view. Photographed at the Impact Dynamics Research Facility, building 1297.

  14. Sikorski - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Roof instrument panel between pilot stations, right view. Photographed at the Impact Dynamics Research Facility, building 1297.

  15. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Left view of cockpit showing manikin head against panel. Photographed at the Impact Dynamics Research Facility, building 1297.

  16. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Right view of cabin showing troop seat fabric failure. Photographed at the Impact Dynamics Research Facility, building 1297.

  17. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Sub-floor, inside view showing details of limited crushing. Photographed at the Impact Dynamics Research Facility, building 1297.

  18. Delamination Modeling of Composites for Improved Crash Analysis

    NASA Technical Reports Server (NTRS)

    Fleming, David C.

    1999-01-01

    Finite element crash modeling of composite structures is limited by the inability of current commercial crash codes to accurately model delamination growth. Efforts are made to implement and assess delamination modeling techniques using a current finite element crash code, MSC/DYTRAN. Three methods are evaluated, including a straightforward method based on monitoring forces in elements or constraints representing an interface; a cohesive fracture model proposed in the literature; and the virtual crack closure technique commonly used in fracture mechanics. Results are compared with dynamic double cantilever beam test data from the literature. Examples show that it is possible to accurately model delamination propagation in this case. However, the computational demands required for accurate solution are great and reliable property data may not be available to support general crash modeling efforts. Additional examples are modeled including an impact-loaded beam, damage initiation in laminated crushing specimens, and a scaled aircraft subfloor structures in which composite sandwich structures are used as energy-absorbing elements. These examples illustrate some of the difficulties in modeling delamination as part of a finite element crash analysis.

  19. Compressible magnetohydrodynamic sawtooth crash

    NASA Astrophysics Data System (ADS)

    Sugiyama, Linda E.

    2014-02-01

    In a toroidal magnetically confined plasma at low resistivity, compressible magnetohydrodynamic (MHD) predicts that an m = 1/n = 1 sawtooth has a fast, explosive crash phase with abrupt onset, rate nearly independent of resistivity, and localized temperature redistribution similar to experimental observations. Large scale numerical simulations show that the 1/1 MHD internal kink grows exponentially at a resistive rate until a critical amplitude, when the plasma motion accelerates rapidly, culminating in fast loss of the temperature and magnetic structure inside q < 1, with somewhat slower density redistribution. Nonlinearly, for small effective growth rate the perpendicular momentum rate of change remains small compared to its individual terms ∇p and J × B until the fast crash, so that the compressible growth rate is determined by higher order terms in a large aspect ratio expansion, as in the linear eigenmode. Reduced MHD fails completely to describe the toroidal mode; no Sweet-Parker-like reconnection layer develops. Important differences result from toroidal mode coupling effects. A set of large aspect ratio compressible MHD equations shows that the large aspect ratio expansion also breaks down in typical tokamaks with rq =1/Ro≃1/10 and a /Ro≃1/3. In the large aspect ratio limit, failure extends down to much smaller inverse aspect ratio, at growth rate scalings γ =O(ɛ2). Higher order aspect ratio terms, including B˜ϕ, become important. Nonlinearly, higher toroidal harmonics develop faster and to a greater degree than for large aspect ratio and help to accelerate the fast crash. The perpendicular momentum property applies to other transverse MHD instabilities, including m ≥ 2 magnetic islands and the plasma edge.

  20. Resisting "Crash Diet" Staff Development

    ERIC Educational Resources Information Center

    Dana, Nancy Fichtman; Yendol-Hoppey, Diane

    2008-01-01

    People often respond to the pressure of attending a high school reunion or their child's wedding by going on a crash diet to get quick results. In response, friends may marvel about how good they look on the outside. But what folks don't acknowledge is that, in the name of getting results, crash dieters have done some very unhealthy things to…

  1. The Cleveland Aircraft Fire Tests

    NASA Technical Reports Server (NTRS)

    Brenneman, James J.; Heine, Donald A.

    1968-01-01

    On June 30 and July 1, 1966, tests were conducted to evaluate high expansion foam's ability to extend the time for which an aircraft passenger cabin environment would remain survivable during a post-crash fire. While some results tend to confirm those of similar tests, others may shed new light on the problem.

  2. Hurricane Iris Hits Belize

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hurricane Iris hit the small Central American country of Belize around midnight on October 8, 2001. At the time, Iris was the strongest Atlantic hurricane of the season, with sustained winds up to 225 kilometers per hour (140 mph). The hurricane caused severe damage-destroying homes, flooding streets, and leveling trees-in coastal towns south of Belize City. In addition, a boat of American recreational scuba divers docked along the coast was capsized by the storm, leaving 20 of the 28 passengers missing. Within hours the winds had subsided to only 56 kph (35 mph), a modest tropical depression, but Mexico, Guatemala, El Salvador, and Honduras were still expecting heavy rains. The above image is a combination of visible and thermal infrared data (for clouds) acquired by a NOAA Geostationary Operational Environmental Satellite (GOES-8) on October 8, 2001, at 2:45 p.m., and the Moderate-resolution Imaging Spectroradiometer (MODIS) (for the color of the ground). The three-dimensional view is from the south-southeast (north is towards the upper left). Belize is off the image to the left. Image courtesy Marit Jentoft-Nilsen, NASA GSFC Visualization Analysis Lab

  3. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Top view from gantry, showing helicopter in final position after sliding 23 feet from initial impact. Photographed at the Impact Dynamics Research Facility, building 1297.

  4. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Overall view of the nose landing gear (originally from Sikorsky S-76 helicopter). Photographed at the Impact Dynamics Research Facility, building 1297.

  5. Sikorsky - (ACAP) - helicopter crash test

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sikorsky - Advanced Composite Airframe Program (ACAP) - helicopter crash test. Sub-floor, inside view between station 175 and 143, showing limited crushing. Photographed at the Impact Dynamics Research Facility, building 1297.

  6. Distracted Driving Raises Crash Risk

    MedlinePlus

    ... Raises Crash Risk Video technology and in-vehicle sensors showed that distracted driving, especially among new drivers, ... whenever the cars were moving. A suite of sensors recorded acceleration, sudden braking or swerving, and other ...

  7. Suicide by use of aircraft in the United States, 1979-1989.

    PubMed

    Ungs, T J

    1994-10-01

    Intentional aircraft crashes are a dramatic cause of death. The entire set of fatalities due to this cause of death in the United States has not been described. Mortality data from aircraft crashes determined as being due to suicide were obtained from National Center for Health Statistics (NCHS) and National Transportation Safety Board (NTSB) data sources. The NCHS reported that, between 1979 and 1989, ten persons committed suicide by aircraft crashes. Twenty aircraft crash fatalities were also reported during the period in which the intent of death could not be determined as either suicide, homicide, or accidental. White middle-aged males accounted for the majority of deaths. The NTSB reported, for the years 1979-89, that nine fatal aircraft accidents were suicide. All fatalities were male pilots operating small fixed wing aircraft. NTSB investigations identified evidence for important adverse psychologic factors in most pilots. PMID:7832739

  8. Helicopter In-Flight Tracking System (HITS) for the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Martone, Patrick; Tucker, George; Aiken, Edwin W. (Technical Monitor)

    2001-01-01

    The National Aeronautics and Space Administration (NASA) Ames Research Center (ARC) is sponsoring deployment and testing of the Helicopter In-flight Tracking System (HITS) in a portion of the Gulf of Mexico offshore area. Using multilateration principles, HITS determines the location and altitude of all transponder-equipped aircraft without requiring changes to current Mode A, C or S avionics. HITS tracks both rotary and fixed-wing aircraft operating in the 8,500 sq. mi. coverage region. The minimum coverage altitude of 100 ft. is beneficial for petroleum industry, allowing helicopters to be tracked onto the pad of most derricks. In addition to multilateration, HITS provides surveillance reports for aircraft equipped for Automatic Dependent Surveillance - Broadcast (ADS-B), a new surveillance system under development by the Federal Aviation Administration (FAA). The U.S. Department of Transportation (DOT) Volpe National Transportation Systems Center (Volpe Center) is supporting NASA in managing HITS installation and operation, and in evaluating the system's effectiveness. Senses Corporation is supplying, installing and maintaining the HITS ground system. Project activities are being coordinated with the FAA and local helicopter operators. Flight-testing in the Gulf will begin in early 2002. This paper describes the HITS project - specifically, the system equipment (architecture, remote sensors, central processing system at Intracoastal City, LA, and communications) and its performance (accuracy, coverage, and reliability). The paper also presents preliminary results of flight tests.

  9. NASA technical advances in aircraft occupant safety

    NASA Technical Reports Server (NTRS)

    Enders, J. H.

    1978-01-01

    A NASA program to improve aircraft safety is discussed in terms of three areas of concentration: unexpected turbulence encounters, fire, and crash impact. To provide warning of clear air turbulence (CAT) so that the pilot can take evasive action, a laser Doppler system is described, which functions by measuring backscatter frequency radiation occurring in aerosols ahead of the aircraft. The system was found able to detect CAT, but at shorter than optimal ranges (10 km as opposed to 32 km). Fire safety has focused on both the early detection of fires through improved sensing methods, and on the development of fire-retardant materials, i.e., intumescent char-forming protective coatings. Crashworthiness is discussed in terms of the development of a survivable crash envelope and improved seat and restraint systems. To evaluate an aircraft for crashworthiness, finite-element computer programs are currently being developed which analyze both aircraft structural configurations and the intrinsic strength of aircraft materials.

  10. Heat Waves Hit Seniors Hardest

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_160425.html Heat Waves Hit Seniors Hardest Risk of high-temperature trouble ... much of the Northeast struggles with a heat wave that isn't expected to ease until the ...

  11. Development and use of computational techniques in Army Aviation research and development programs for crash resistant helicopter technology

    NASA Astrophysics Data System (ADS)

    Burrows, Leroy T.

    1993-08-01

    During the 1960's over 30 full-scale aircraft crash tests were conducted by the Flight Safety Foundation under contract to the Aviation Applied Technology Directorate (AATD) of the U.S. Army Aviation Systems Command (AVSCOM). The purpose of these tests were to conduct crash injury investigations that would provide a basis for the formulation of sound crash resistance design criteria for light fixed-wing and rotary wing aircraft. This resulted in the Crash Survival Design Criteria Designer's Guide which was first published in 1967 and has been revised numerous times, the last being in 1989. Full-scale aircraft crash testing is an expensive way to investigate structural deformations of occupied spaces and to determine the decelerative loadings experienced by occupants in a crash. This gave initial impetus to the U.S. Army to develop analytical methods to predict the dynamic response of aircraft structures in a crash. It was believed that such analytical tools could be very useful in the preliminary design stage of a new helicopter system which is required to demonstrate a level of crash resistance and had to be more cost effective than full-scale crash tests or numerous component design support tests. From an economic point of view, it is more efficient to optimize for the incorporation of crash resistance features early in the design stage. However, during preliminary design it is doubtful if sufficient design details, which influence the exact plastic deformation shape of structural elements, will be available. The availability of simple procedures to predict energy absorption and load-deformation characteristics will allow the designer to initiate valuable cost, weight, and geometry tradeoff studies. The development of these procedures will require some testing of typical specimens. This testing should, as a minimum, verify the validity of proposed procedures for providing pertinent nonlinear load-deformation data. It was hoped that through the use of these

  12. Development and use of computational techniques in Army Aviation research and development programs for crash resistant helicopter technology

    NASA Technical Reports Server (NTRS)

    Burrows, Leroy T.

    1993-01-01

    During the 1960's over 30 full-scale aircraft crash tests were conducted by the Flight Safety Foundation under contract to the Aviation Applied Technology Directorate (AATD) of the U.S. Army Aviation Systems Command (AVSCOM). The purpose of these tests were to conduct crash injury investigations that would provide a basis for the formulation of sound crash resistance design criteria for light fixed-wing and rotary wing aircraft. This resulted in the Crash Survival Design Criteria Designer's Guide which was first published in 1967 and has been revised numerous times, the last being in 1989. Full-scale aircraft crash testing is an expensive way to investigate structural deformations of occupied spaces and to determine the decelerative loadings experienced by occupants in a crash. This gave initial impetus to the U.S. Army to develop analytical methods to predict the dynamic response of aircraft structures in a crash. It was believed that such analytical tools could be very useful in the preliminary design stage of a new helicopter system which is required to demonstrate a level of crash resistance and had to be more cost effective than full-scale crash tests or numerous component design support tests. From an economic point of view, it is more efficient to optimize for the incorporation of crash resistance features early in the design stage. However, during preliminary design it is doubtful if sufficient design details, which influence the exact plastic deformation shape of structural elements, will be available. The availability of simple procedures to predict energy absorption and load-deformation characteristics will allow the designer to initiate valuable cost, weight, and geometry tradeoff studies. The development of these procedures will require some testing of typical specimens. This testing should, as a minimum, verify the validity of proposed procedures for providing pertinent nonlinear load-deformation data. It was hoped that through the use of these

  13. Full-Scale Crash Tests and Analyses of Three High-Wing Single

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Littell, Justin D.; Stimson, Chad M.; Jackson, Karen E.; Mason, Brian H.

    2015-01-01

    The NASA Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project was initiated in 2014 to assess the crash performance standards for the next generation of ELT systems. Three Cessna 172 aircraft have been acquired to conduct crash testing at NASA Langley Research Center's Landing and Impact Research Facility. Testing is scheduled for the summer of 2015 and will simulate three crash conditions; a flare to stall while emergency landing, and two controlled flight into terrain scenarios. Instrumentation and video coverage, both onboard and external, will also provide valuable data of airframe response. Full-scale finite element analyses will be performed using two separate commercial explicit solvers. Calibration and validation of the models will be based on the airframe response under these varying crash conditions.

  14. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    SciTech Connect

    Fenimore, Edward E.; Kunkle, Thomas David; Stead, Richard J.

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  15. Application of Probability Methods to Assess Crash Modeling Uncertainty

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Stockwell, Alan E.; Hardy, Robin C.

    2003-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stress-strain behaviors, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the effects of finite element modeling assumptions on the predicted responses. The vertical drop test of a Fokker F28 fuselage section will be the focus of this paper. The results of a probabilistic analysis using finite element simulations will be compared with experimental data.

  16. Application of Probability Methods to Assess Crash Modeling Uncertainty

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Stockwell, Alan E.; Hardy, Robin C.

    2007-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stress-strain behaviors, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the effects of finite element modeling assumptions on the predicted responses. The vertical drop test of a Fokker F28 fuselage section will be the focus of this paper. The results of a probabilistic analysis using finite element simulations will be compared with experimental data.

  17. "Crashing the gates" - selection criteria for television news reporting of traffic crashes.

    PubMed

    De Ceunynck, Tim; De Smedt, Julie; Daniels, Stijn; Wouters, Ruud; Baets, Michèle

    2015-07-01

    This study investigates which crash characteristics influence the probability that the crash is reported in the television news. To this purpose, all news items from the period 2006-2012 about traffic crashes from the prime time news of two Belgian television channels are linked to the official injury crash database. Logistic regression models are built for the database of all injury crashes and for the subset of fatal crashes to identify crash characteristics that correlate with a lower or higher probability of being reported in the news. A number of significant biases in terms of crash severity, time, place, types of involved road users and victims' personal characteristics are found in the media reporting of crashes. More severe crashes are reported in the media more easily than less severe crashes. Significant fluctuations in media reporting probability through time are found in terms of the year and month in which the crash took place. Crashes during week days are generally less reported in the news. The geographical area (province) in which the crash takes place also has a significant impact on the probability of being reported in the news. Crashes on motorways are significantly more represented in the news. Regarding the age of the involved victims, a clear trend of higher media reporting rates of crashes involving young victims or young fatalities is observed. Crashes involving female fatalities are also more frequently reported in the news. Furthermore, crashes involving a bus have a significantly higher probability of being reported in the news, while crashes involving a motorcycle have a significantly lower probability. Some models also indicate a lower reporting rate of crashes involving a moped, and a higher reporting rate of crashes involving heavy goods vehicles. These biases in media reporting can create skewed perceptions in the general public about the prevalence of traffic crashes and eventually may influence people's behaviour. PMID:25909390

  18. Watch for those fragments of evidence: the use of an automatic timepiece to help correlate a helicopter crash site from the Vietnam War.

    PubMed

    Tuller, Hugh; Paolello, Josephine M

    2012-01-01

    This case study illustrates the use of the date function on an automatic wristwatch to help identify a Vietnam War helicopter crash site. The location of a crash incident can sometimes be uncertain because of inadequate or inaccurate wartime records and the passage of time. Artifacts recovered from a prospective crash scene are regularly used to correlate the loss incident. In this case study, a recovered automatic watch displayed a date 2 days later than the reported loss incident. Although the date conflicts with the aircraft crash incident report, it is observed that a fully wound automatic watch continues to work for c. 2 days after movement of the watch ceases. Thus, the watch's date in fact correlates with the aircraft crash incident report. It is noted that automatic watches may also be used to date scenes of crime. PMID:21939442

  19. CDC Vital Signs: Motor Vehicle Crash Deaths

    MedlinePlus

    ... Press Kit Read the MMWR Science Clips Motor Vehicle Crash Deaths How is the US doing? Language: ... Sweden, Switzerland, and the United Kingdom. Problem Motor vehicle crash deaths in the US are still too ...

  20. NASA technical advances in aircraft occupant safety. [clear air turbulence detectors, fire resistant materials, and crashworthiness

    NASA Technical Reports Server (NTRS)

    Enders, J. H.

    1978-01-01

    NASA's aviation safety technology program examines specific safety problems associated with atmospheric hazards, crash-fire survival, control of aircraft on runways, human factors, terminal area operations hazards, and accident factors simulation. While aircraft occupants are ultimately affected by any of these hazards, their well-being is immediately impacted by three specific events: unexpected turbulence encounters, fire and its effects, and crash impact. NASA research in the application of laser technology to the problem of clear air turbulence detection, the development of fire resistant materials for aircraft construction, and to the improvement of seats and restraint systems to reduce crash injuries are reviewed.

  1. General Models for Assessing Hazards Aircraft Pose to Surface Facilities

    SciTech Connect

    G.E. Ragan

    2002-11-18

    This paper derives formulas for estimating the frequency of accidental aircraft crashes into surface facilities. Objects unintentionally dropped from aircraft are also considered. The approach allows the facility to be well within the flight area; inside the flight area, but close to the edge; or completely outside the flight area.

  2. Car Hits Boy on Bicycle

    ERIC Educational Resources Information Center

    Ruiz, Michael J.

    2005-01-01

    In this article we present the fascinating reconstruction of an accident where a car hit a boy riding his bicycle. The boy dramatically flew several metres through the air after the collision and was injured, but made a swift and complete recovery from the accident with no long-term after-effects. Students are challenged to determine the speed of…

  3. Can-Filled Crash Barrier

    NASA Technical Reports Server (NTRS)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  4. IDENTIFICATION OF AIRCRAFT HAZARDS

    SciTech Connect

    K.L. Ashley

    2005-03-23

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

  5. Identification of Aircraft Hazards

    SciTech Connect

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  6. Nonfatal motor-vehicle animal crash-related injuries--United States, 2001-2002.

    PubMed

    2004-08-01

    In 2000, an estimated 6.1 million light-vehicle (e.g., passenger cars, sport utility vehicles, vans, and pickup trucks) crashes on U.S. roadways were reported to police. Of these reported crashes, 247,000 (4.0%) involved incidents in which the motor vehicle (MV) directly hit an animal on the roadway. Each year, an estimated 200 human deaths result from crashes involving animals (i.e., deaths from a direct MV animal collision or from a crash in which a driver tried to avoid an animal and ran off the roadway). To characterize nonfatal injuries from these incidents, CDC analyzed data from the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP). This report summarizes the results of that analysis, which indicated that, during 2001-2002, an estimated 26,647 MV occupants per year were involved in crashes from encounters with animals (predominantly deer) in a roadway and treated for nonfatal injuries in U.S. hospital emergency departments (EDs). Cost-effective measures targeting both drivers (e.g., speed reduction and early warnings) and animals (e.g., fencing and underpasses) are needed to reduce injuries associated with MV collisions involving animals. PMID:15295310

  7. Full-scale crash test of a CH-47C helicopter

    NASA Technical Reports Server (NTRS)

    Castle, C. B.

    1976-01-01

    A full-scale crash test of a large troop/cargo carrying CH-47C helicopter was conducted at the Langley impact dynamics research facility. The crash test of this large helicopter was performed as part of a joint U.S. Army-NASA helicopter test program to provide dynamic structural and seat response data. The test, the procedures employed, the instrumentation, a general assessment of the resulting damage, and typical levels of accelerations experienced during the crash are reported. Various energy-absorbing seating systems for crew and troops were installed and instrumented to provide data for use in the development of design criteria for future aircraft. The crash conditions were selected to simulate known crash conditions and are representative of the 95th percentile accident environment for an autorotating helicopter. Visual examination of the crashed test specimen indicated irreparable damage to many of the structural components. The highest accelerations were recorded by the accelerometers located on the cabin floor in the aft section of the helicopter, directly above the primary impact location and on the floor of the cockpit above the secondary impact location(s).

  8. Impact of pavement conditions on crash severity.

    PubMed

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

    Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses. PMID:23892046

  9. Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks

    PubMed Central

    Bock, Joel R.; Maewal, Akhilesh; Gough, David A.

    2012-01-01

    Data analysis is used to test the hypothesis that “hitting is contagious”. A statistical model is described to study the effect of a hot hitter upon his teammates’ batting during a consecutive game hitting streak. Box score data for entire seasons comprising streaks of length games, including a total observations were compiled. Treatment and control sample groups () were constructed from core lineups of players on the streaking batter’s team. The percentile method bootstrap was used to calculate confidence intervals for statistics representing differences in the mean distributions of two batting statistics between groups. Batters in the treatment group (hot streak active) showed statistically significant improvements in hitting performance, as compared against the control. Mean for the treatment group was found to be to percentage points higher during hot streaks (mean difference increased points), while the batting heat index introduced here was observed to increase by points. For each performance statistic, the null hypothesis was rejected at the significance level. We conclude that the evidence suggests the potential existence of a “statistical contagion effect”. Psychological mechanisms essential to the empirical results are suggested, as several studies from the scientific literature lend credence to contagious phenomena in sports. Causal inference from these results is difficult, but we suggest and discuss several latent variables that may contribute to the observed results, and offer possible directions for future research. PMID:23251507

  10. Full-Scale Crash Test of an MD-500 Helicopter

    NASA Technical Reports Server (NTRS)

    Littell, Justin

    2011-01-01

    A full-scale crash test was successfully conducted in March 2010 of an MD-500 helicopter at NASA Langley Research Center s Landing and Impact Research Facility. The reasons for conducting this test were threefold: 1 To generate data to be used with finite element computer modeling efforts, 2 To study the crashworthiness features typically associated with a small representative helicopter, and 3 To compare aircraft response to data collected from a previously conducted MD-500 crash test, which included an externally deployable energy absorbing (DEA) concept. Instrumentation on the airframe included accelerometers on various structural components of the airframe; and strain gages on keel beams, skid gear and portions of the skin. Three Anthropomorphic Test Devices and a specialized Human Surrogate Torso Model were also onboard to collect occupant loads for evaluation with common injury risk criteria. This paper presents background and results from this crash test conducted without the DEA concept. These results showed accelerations of approximately 30 to 50 g on the airframe at various locations, little energy attenuation through the airframe, and moderate to high probability of occupant injury for a variety of injury criteria.

  11. A Study of Transport Airplane Crash-Resistant Fuel Systems

    NASA Technical Reports Server (NTRS)

    Jones, Lisa (Technical Monitor); Robertson, S. H.; Johnson, N. B.; Hall, D. S.; Rimson, I. J.

    2002-01-01

    This report presents the results of a study, funded by the Federal Aviation Administration (FAA), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S. Army, which ultimately led to the current state of the art in CRFS technology. It describes the basic research, testing, field investigations and production efforts which have led to the highly successful military CRFS, which has saved many lives and reduced costs of accidents. Current CRFS technology used in transport category airplanes is defined and compared to the available state-of-the-art technology. The report provides information to the FAA and other government organizations which can help them plan their efforts to improve the state of crash fire protection in the transport airplane fleet. The report provides guidance to designers looking for information about CRFS design problems, analysis tools to use for product improvement, and a summary of current and proposed regulations for transport category airplane fuel systems.

  12. Naturalistic Assessment of Novice Teenage Crash Experience

    PubMed Central

    Lee, Suzanne E.; Simons-Morton, Bruce G.; Klauer, Sheila E.; Ouimet, Marie Claude; Dingus, Thomas A.

    2011-01-01

    Background Crash risk is highest during the first months after licensure. Current knowledge about teenagers’ driving exposure and the factors increasing their crash risk is based on self-reported data and crash database analyses. While these research tools are useful, new developments in naturalistic technologies have allowed researchers to examine newly-licensed teenagers’ exposure and crash risk factors in greater detail. The Naturalistic Teenage Driving Study (NTDS) described in this paper is the first study to follow a group of newly-licensed teenagers continuously for 18 months after licensure. The goals of this paper are to compare the crash and near-crash experience of drivers in the NTDS to national trends, to describe the methods and lessons learned in the NTDS, and to provide initial data on driving exposure for these drivers. Methods A data acquisition system was installed in the vehicles of 42 newly-licensed teenage drivers 16 years of age during their first 18 months of independent driving. It consisted of cameras, sensors (accelerometers, GPS, yaw, front radar, lane position, and various sensors obtained via the vehicle network), and a computer with removable hard drive. Data on the driving of participating parents was also collected when they drove the instrumented vehicle. Findings The primary findings after 18 months included the following: (1) crash and near-crash rates among teenage participants were significantly higher during the first six months of the study than the final 12 months, mirroring the national trends; (2) crash and near-crash rates were significantly higher for teenage than adult (parent) participants, also reflecting national trends; (3) teenaged driving exposure averaged between 507-710 kilometers (315-441 miles) per month over the study period, but varied substantially between participants with standard errors representing 8-14 percent of the mean; and (4) crash and near-crash types were very similar for male and female

  13. CID Aircraft slap-down

    NASA Technical Reports Server (NTRS)

    1984-01-01

    In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1

  14. Deployable System for Crash-Load Attenuation

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Jackson, Karen E.

    2007-01-01

    An externally deployable honeycomb structure is investigated with respect to crash energy management for light aircraft. The new concept utilizes an expandable honeycomb-like structure to absorb impact energy by crushing. Distinguished by flexible hinges between cell wall junctions that enable effortless deployment, the new energy absorber offers most of the desirable features of an external airbag system without the limitations of poor shear stability, system complexity, and timing sensitivity. Like conventional honeycomb, once expanded, the energy absorber is transformed into a crush efficient and stable cellular structure. Other advantages, afforded by the flexible hinge feature, include a variety of deployment options such as linear, radial, and/or hybrid deployment methods. Radial deployment is utilized when omnidirectional cushioning is required. Linear deployment offers better efficiency, which is preferred when the impact orientation is known in advance. Several energy absorbers utilizing different deployment modes could also be combined to optimize overall performance and/or improve system reliability as outlined in the paper. Results from a series of component and full scale demonstration tests are presented as well as typical deployment techniques and mechanisms. LS-DYNA analytical simulations of selected tests are also presented.

  15. Improvements to the stand and hit algorithm

    SciTech Connect

    Boneh, A.; Boneh, S.; Caron, R.; Jibrin, S.

    1994-12-31

    The stand and hit algorithm is a probabilistic algorithm for detecting necessary constraints. The algorithm stands at a point in the feasible region and hits constraints by moving towards the boundary along randomly generated directions. In this talk we discuss methods for choosing the standing point. As well, we present the undetected first rule for determining the hit constraints.

  16. Re-visiting crash-speed relationships: A new perspective in crash modelling.

    PubMed

    Imprialou, Maria-Ioanna M; Quddus, Mohammed; Pitfield, David E; Lord, Dominique

    2016-01-01

    Although speed is considered to be one of the main crash contributory factors, research findings are inconsistent. Independent of the robustness of their statistical approaches, crash frequency models typically employ crash data that are aggregated using spatial criteria (e.g., crash counts by link termed as a link-based approach). In this approach, the variability in crashes between links is explained by highly aggregated average measures that may be inappropriate, especially for time-varying variables such as speed and volume. This paper re-examines crash-speed relationships by creating a new crash data aggregation approach that enables improved representation of the road conditions just before crash occurrences. Crashes are aggregated according to the similarity of their pre-crash traffic and geometric conditions, forming an alternative crash count dataset termed as a condition-based approach. Crash-speed relationships are separately developed and compared for both approaches by employing the annual crashes that occurred on the Strategic Road Network of England in 2012. The datasets are modelled by injury severity using multivariate Poisson lognormal regression, with multivariate spatial effects for the link-based model, using a full Bayesian inference approach. The results of the condition-based approach show that high speeds trigger crash frequency. The outcome of the link-based model is the opposite; suggesting that the speed-crash relationship is negative regardless of crash severity. The differences between the results imply that data aggregation is a crucial, yet so far overlooked, methodological element of crash data analyses that may have direct impact on the modelling outcomes. PMID:26571206

  17. Crash energy absorption of two-segment crash box with holes under frontal load

    NASA Astrophysics Data System (ADS)

    Choiron, Moch. Agus; Sudjito, Hidayati, Nafisah Arina

    2016-03-01

    Crash box is one of the passive safety components which designed as an impact energy absorber during collision. Crash box designs have been developed in order to obtain the optimum crashworthiness performance. Circular cross section was first investigated with one segment design, it rather influenced by its length which is being sensitive to the buckling occurrence. In this study, the two-segment crash box design with additional holes is investigated and deformation behavior and crash energy absorption are observed. The crash box modelling is performed by finite element analysis. The crash test components were impactor, crash box, and fixed rigid base. Impactor and the fixed base material are modelled as a rigid, and crash box material as bilinear isotropic hardening. Crash box length of 100 mm and frontal crash velocity of 16 km/jam are selected. Crash box material of Aluminum Alloy is used. Based on simulation results, it can be shown that holes configuration with 2 holes and ¾ length locations have the largest crash energy absorption. This condition associated with deformation pattern, this crash box model produces axisymmetric mode than other models.

  18. Hitting is contagious in baseball: evidence from long hitting streaks.

    PubMed

    Bock, Joel R; Maewal, Akhilesh; Gough, David A

    2012-01-01

    Data analysis is used to test the hypothesis that "hitting is contagious". A statistical model is described to study the effect of a hot hitter upon his teammates' batting during a consecutive game hitting streak. Box score data for entire seasons comprising [Formula: see text] streaks of length [Formula: see text] games, including a total [Formula: see text] observations were compiled. Treatment and control sample groups ([Formula: see text]) were constructed from core lineups of players on the streaking batter's team. The percentile method bootstrap was used to calculate [Formula: see text] confidence intervals for statistics representing differences in the mean distributions of two batting statistics between groups. Batters in the treatment group (hot streak active) showed statistically significant improvements in hitting performance, as compared against the control. Mean [Formula: see text] for the treatment group was found to be [Formula: see text] to [Formula: see text] percentage points higher during hot streaks (mean difference increased [Formula: see text] points), while the batting heat index [Formula: see text] introduced here was observed to increase by [Formula: see text] points. For each performance statistic, the null hypothesis was rejected at the [Formula: see text] significance level. We conclude that the evidence suggests the potential existence of a "statistical contagion effect". Psychological mechanisms essential to the empirical results are suggested, as several studies from the scientific literature lend credence to contagious phenomena in sports. Causal inference from these results is difficult, but we suggest and discuss several latent variables that may contribute to the observed results, and offer possible directions for future research. PMID:23251507

  19. Identification of a crash model

    NASA Astrophysics Data System (ADS)

    Mizzi, J. P.; Jezequel, L.

    1992-11-01

    Our knowledge of the behaviour of passenger cars and road safety systems during a crash trial is based on experimental studies. A survey was carried out on the modelling of the front compartment of a passenger car: the model will make it possible to enlarge the conclusions drawn from a test by extending the results to different situations. We have designed a mathematical spring-masses model which simulates the behaviour of a passenger car during various frontal crash configurations. However, the main difficulty is to know perfectly the laws of behaviour of the springs. That is why an identification methodology was envisaged from the configuration of the experimental results. To know the vehicle's real behaviour during a crash trial, it is necessary to have experimental devices which make it possible to rebuild the space kinematics of the components. We thus designed, in each case, suitable acquisition and processing software. Different non-parametric and parametric identification methods were then tested on simple and then complex models. The results have permitted us to determine which is the best adapted to solve our problem.

  20. Research on antimisting fuel for suppression of postcrash aircraft fires

    NASA Technical Reports Server (NTRS)

    Sarohia, V.; Parikh, P.; Yavrouian, A.; Matthys, E.

    1986-01-01

    Recent experimental results in the field of post-crash aircraft fire suppression are reviewed, with emphasis given to antimisting kerosene fuel (AMK). Findings in three major areas of study are presented, including: rheological studies (skin friction, and heat transfer); fuel breakup processes and nozzle spray combustion; and the development of inline blenders for production of AMK at the refueling point. An interpretation of the results of the FAA/NASA Controlled Impact Demonstration of AMK fuel is also presented. It is concluded that AMK is a sound concept and offers several advantages over conventional fuels in any crash scenario involving post-crash fires.

  1. Crash Types: Markers of Increased Risk of Alcohol-Involved Crashes Among Teen Drivers*

    PubMed Central

    Bingham, C. Raymond; Shope, Jean T.; Parow, Julie E.; Raghunathan, Trivellore E.

    2009-01-01

    Objective: Teens drink/drive less often than adults but are more likely to crash when they do drink/drive. This study identified alcohol-related crash types for which teen drivers were at greater risk compared with adults. Method: Michigan State Police crash records for drivers ages 16-19 (teens) and 45-65 years (adults) who experienced at least one crash from 1989 to 1996 were used to create alcohol crash types consisting of alcohol-related crashes that included specific combinations of other crash characteristics, such as drinking and driving at night (i.e., alcohol/nighttime). These data were combined with data from the 1990 and 1995 National Personal Travel Surveys and the 2001 National Household Travel Survey to estimate rates and rate ratios of alcohol-related crash types based on person-miles driven. Results: Teens were relatively less likely than adults to be involved in alcohol-related crashes but were significantly more likely to be in alcohol-related crashes that included other crash characteristics. Teen males' crash risk was highest when drinking and driving with a passenger, at night, at night with a passenger, and at night on the weekend, and casualties were more likely to result from alcohol-related nighttime crashes. All the highest risk alcohol-related crash types for teen female drinking drivers involved casualties and were most likely to include speeding, passenger presence, and nighttime driving. Conclusions: The frequency with which passengers, nighttime or weekend driving, and speeding occurred in the highest risk alcohol-related crash types for teens suggests that these characteristics should be targeted by policies, programs, and enforcement to reduce teen alcohol-related crash rates. PMID:19515292

  2. Simulation of Aircraft Landing Gears with a Nonlinear Dynamic Finite Element Code

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Jackson, Karen E.; Fasanella, Edwin L.

    2000-01-01

    Recent advances in computational speed have made aircraft and spacecraft crash simulations using an explicit, nonlinear, transient-dynamic, finite element analysis code more feasible. This paper describes the development of a simple landing gear model, which accurately simulates the energy absorbed by the gear without adding substantial complexity to the model. For a crash model, the landing gear response is approximated with a spring where the force applied to the fuselage is computed in a user-written subroutine. Helicopter crash simulations using this approach are compared with previously acquired experimental data from a full-scale crash test of a composite helicopter.

  3. Crash pulse recorder--validation in full scale crash tests.

    PubMed

    Kullgren, A; Lie, A; Tingvall, C

    1995-10-01

    Estimation of the accident severity is a fundamental requirement in accident reconstruction and analysis. Accident severity can be measured in many different ways, but in frontal collisions change of velocity, energy equivalent speed or equivalent barrier speed are frequently used parameters. These parameters are most often estimated from vehicle deformation. It is known, however, that the quality of these estimates is limited if compared with these obtained in laboratory test conditions. To be able to achieve almost the same measurements and measurement accuracy in real-life accidents as in the laboratory, where the acceleration time history is measured, an on-board measurement technique is required. This presentation gives results of tests of a low cost device for measuring the crash pulse for a car involved in an accident, concerning systematic and random error. The device, called the Crash Pulse Recorder (CPR), has been tested previously in several sled tests. The CPR is based on measurement of the movement of the mass in a spring mass system in a collision. A brief description of its construction is also included. The CPR is an integral part of a large accident data collection system including interior and exterior deformation measurements and evaluation of injury outcome. This report presents the results of several full-scale crash tests, undertaken to evaluate the accuracy and precision of the CPR in cars in different impact modes. The tests comprised both offset and angled collisions. Most of the tests were car to car collisions, but barrier tests were also performed. The random error of the CPR was found to be 2.2 km/hr for the delta V measurements and 0.6 g for mean acceleration. PMID:8579702

  4. A multivariate spatial crash frequency model for identifying sites with promise based on crash types.

    PubMed

    Jonathan, Aguero-Valverde; Wu, Kun-Feng Ken; Donnell, Eric T

    2016-02-01

    Many studies have proposed the use of a systemic approach to identify sites with promise (SWiPs). Proponents of the systemic approach to road safety management suggest that it is more effective in reducing crash frequency than the traditional hot spot approach. The systemic approach aims to identify SWiPs by crash type(s) and, therefore, effectively connects crashes to their corresponding countermeasures. Nevertheless, a major challenge to implementing this approach is the low precision of crash frequency models, which results from the systemic approach considering subsets (crash types) of total crashes leading to higher variability in modeling outcomes. This study responds to the need for more precise statistical output and proposes a multivariate spatial model for simultaneously modeling crash frequencies for different crash types. The multivariate spatial model not only induces a multivariate correlation structure between crash types at the same site, but also spatial correlation among adjacent sites to enhance model precision. This study utilized crash, traffic, and roadway inventory data on rural two-lane highways in Pennsylvania to construct and test the multivariate spatial model. Four models with and without the multivariate and spatial correlations were tested and compared. The results show that the model that considers both multivariate and spatial correlation has the best fit. Moreover, it was found that the multivariate correlation plays a stronger role than the spatial correlation when modeling crash frequencies in terms of different crash types. PMID:26615494

  5. CDC Vital Signs: Motor Vehicle Crash Injuries: Costly but Preventable

    MedlinePlus

    ... Press Kit Read the MMWR Science Clips Motor Vehicle Crash Injuries Costly but Preventable Language: English Español ( ... and how to prevent future crashes. Problem Motor vehicle crashes are a leading cause of injury in ...

  6. Bibliography on aircraft fire hazards and safety. Volume 2: Safety. Part 1: Key numbers 1 to 524

    NASA Technical Reports Server (NTRS)

    Pelouch, J. J., Jr. (Compiler); Hacker, P. T. (Compiler)

    1974-01-01

    Bibliographic citations are presented to describe and define aircraft safety methods, equipment, and criteria. Some of the subjects discussed are: (1) fire and explosion suppression using whiffle balls, (2) ultraviolet flame detecting sensors, (3) evaluation of flame arrestor materials for aircraft fuel systems, (4) crash fire prevention system for supersonic commercial aircraft, and (5) fire suppression for aerospace vehicles.

  7. HITS - The Navy's new DATPG system

    NASA Astrophysics Data System (ADS)

    Hosley, L.; Modi, M.

    A new digital automatic test program generation standard called HITS (Hierarchical Integrated Test Simulator), developed by the U.S. Navy as the answer to digital LSI/VLSI circuit technology is discussed. Three major areas of the HITS program which include system flow/unique capabilities, modeling language structures, and management of HITS are preseented. HITS contains the following major software modules: the primary model processor, the secondary model processor, the test language processor, the simulator, and the tester output generator. The functions performed by the individual system modules are described. A circuit description language, which provides user flexibility when describing complex circuit models, and its components are considered. The major areas of HITS management include: (1) HITS accessibility, distribution, and availability; (2) user support; (3) advanced development; and (4) Navy/DOD coordination and standardization.

  8. Seat Design for Crash Worthiness

    NASA Technical Reports Server (NTRS)

    Pinkel, I Irving; Rosenberg, Edmund G

    1957-01-01

    A study of many crash deceleration records suggested a simplified model of a crash deceleration pulse, which incorporates the essential properties of the pulse. The model pulse is considered to be composed of a base pulse on which are superimposed one or more secondary pulses of shorter duration. The results of a mathematical analysis of the seat-passenger deceleration in response to the airplane deceleration pulse are provided. On the basis of this information, presented as working charts, the maximum deceleration loads experienced by the seat and passenger in response to the airplane deceleration pulse can be computed. This maximum seat-passenger deceleration is found to depend on the natural frequency of the seat containing the passenger, considered as a mass-spring system. A method is presented that shows how to arrive at a combination of seat strength, natural frequency, and ability to absorb energy in deformation beyond the elastic limit that will allow the seat to serve without failure during an airplane deceleration pulse taken as the design requirement.

  9. Crashes involving motorised rickshaws in urban India: Characteristics and injury patterns

    PubMed Central

    Schmucker, Uli; Dandona, Rakhi; Kumar, G. Anil; Dandona, Lalit

    2011-01-01

    Introduction Motorised three-wheeled vehicles (motorised rickshaw) are popular in Asian countries including India. This study aims to describe the crash characteristics and injury patterns for motorised rickshaw occupants and the road users hit-by-motorised rickshaw in urban India. Methods Consecutive cases of road traffic crashes involving motorised rickshaw, irrespective of injury severity, whether alive or dead, presenting to the emergency departments of two large government hospitals and three branches of a private hospital in Hyderabad city were recruited. Crash characteristics, details of injuries, injury severity parameters and outcome were documented in detailed interviews. Results A total of 139 (18%) of the 781 participants recruited were injured as a motorised rickshaw occupant (11%) or were hit by a motorised rickshaw (7%) in 114 crashes involving motorised rickshaw. Amongst motorised rickshaw occupants, single-vehicle collisions (54%) were more frequent than multi-vehicle collisions (46%), with overturning of motorised rickshaw in 73% of the single-vehicle collisions. Mortality (12%), the mean Injury Severity Score (5.8) and rate of multiple injured (60%) indicated a substantial trauma load. No significant differences in injury pattern were found between motorised rickshaw occupants and hit-by-motorised rickshaw subjects, with the pattern being similar to that of the pedestrians and two-wheeled vehicle users. With bivariate analysis for motorised rickshaw occupants, the risk of fatal outcome (odds ratio (OR) 2.60, 95% confidence interval (CI): 0.64–10.54), upper limb injury (OR 2.25, 95% CI: 0.94–5.37) and multiple injuries (OR 2.03, 95% CI 0.85–4.83) was high, although not statistically significant in multi-motorised-vehicle collisions as compared with the single-vehicle collisions or overturning. The risk of having multiple injuries (OR 4.55, 95% CI: 1.15–17.95) was significantly higher in motorised rickshaw occupants involved in front

  10. Adverse Pregnancy Outcomes Following Motor Vehicle Crashes

    PubMed Central

    Vladutiu, Catherine J.; Marshall, Stephen W.; Poole, Charles; Casteel, Carri; Menard, M. Kathryn; Weiss, Harold B.

    2013-01-01

    Background Motor vehicle crashes are a leading cause of serious trauma during pregnancy, but little is known about their relationships with pregnancy outcomes. Purpose To estimate the association between motor vehicle crashes and adverse pregnancy outcomes. Methods A retrospective cohort study of 878,546 pregnant women, aged 16–46 years, who delivered a singleton infant in North Carolina (NC) from 2001 to 2008. Pregnant drivers in crashes were identified by probabilistic linkage of vital records and crash reports. Poisson regression modeled the association among crashes, vehicle safety features, and adverse pregnancy outcomes. Analyses were conducted in 2012. Results In 2001–2008, 2.9% of pregnant NC women were drivers in one or more crashes. After a single crash, compared to not being in a crash, pregnant drivers had slightly elevated rates of preterm birth (adjusted rate ratio, aRR=1.23, 95% CI=1.19, 1.28); placental abruption (aRR=1.34, 95% CI=1.15, 1.56); and premature rupture of the membranes (PROM; aRR=1.32, 95% CI=1.21, 1.43). Following a second or subsequent crash, pregnant drivers had more highly elevated rates of preterm birth (aRR=1.54, 95% CI=1.24, 1.90); stillbirth (aRR=4.82, 95% CI=2.85, 8.14); placental abruption (aRR=2.97, 95% CI=1.60, 5.53); and PROM (aRR=1.95, 95% CI=1.27, 2.99). Stillbirth rates were elevated following crashes involving unbelted pregnant drivers (aRR=2.77, 95% CI=1.22, 6.28) compared to belted pregnant drivers. Conclusions Crashes while driving during pregnancy were associated with elevated rates of adverse pregnancy outcomes, and multiple crashes were associated with even higher rates of adverse pregnancy outcomes. Crashes were especially harmful if drivers were unbelted. PMID:24139777

  11. Developing Health Information Technology (HIT) Programs and HIT Curriculum: The Southern Polytechnic State University Experience

    ERIC Educational Resources Information Center

    Zhang, Chi; Reichgelt, Han; Rutherfoord, Rebecca H.; Wang, Andy Ju An

    2014-01-01

    Health Information Technology (HIT) professionals are in increasing demand as healthcare providers need help in the adoption and meaningful use of Electronic Health Record (EHR) systems while the HIT industry needs workforce skilled in HIT and EHR development. To respond to this increasing demand, the School of Computing and Software Engineering…

  12. Hitting Is Contagious: Experience and Action Induction

    ERIC Educational Resources Information Center

    Gray, Rob; Beilock, Sian L.

    2011-01-01

    In baseball, it is believed that "hitting is contagious," that is, probability of success increases if the previous few batters get a hit. Could this effect be partially explained by action induction--that is, the tendency to perform an action related to one that has just been observed? A simulation was used to investigate the effect of inducing…

  13. Recognition of Hits in a Target

    NASA Astrophysics Data System (ADS)

    Semerak, Vojtech; Drahansky, Martin

    This paper describes two possible ways of hit recognition in a target. First method is based on frame differencing with use of a stabilization algorithm to eliminate movements of a target. Second method uses flood fill with random seed point definition to find hits in the target scene.

  14. Factors Contributing to Crashes among Young Drivers

    PubMed Central

    Bates, Lyndel J.; Davey, Jeremy; Watson, Barry; King, Mark J.; Armstrong, Kerry

    2014-01-01

    Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures. PMID:25097763

  15. Statistical Detection of Atypical Aircraft Flights

    NASA Technical Reports Server (NTRS)

    Statler, Irving; Chidester, Thomas; Shafto, Michael; Ferryman, Thomas; Amidan, Brett; Whitney, Paul; White, Amanda; Willse, Alan; Cooley, Scott; Jay, Joseph; Rosenthal, Loren; Swickard, Andrea; Bates, Derrick; Scherrer, Chad; Webb, Bobbie-Jo; Lawrence, Robert; Mosbrucker, Chris; Prothero, Gary; Andrei, Adi; Romanowski, Tim; Robin, Daniel; Prothero, Jason; Lynch, Robert; Lowe, Michael

    2006-01-01

    A computational method and software to implement the method have been developed to sift through vast quantities of digital flight data to alert human analysts to aircraft flights that are statistically atypical in ways that signify that safety may be adversely affected. On a typical day, there are tens of thousands of flights in the United States and several times that number throughout the world. Depending on the specific aircraft design, the volume of data collected by sensors and flight recorders can range from a few dozen to several thousand parameters per second during a flight. Whereas these data have long been utilized in investigating crashes, the present method is oriented toward helping to prevent crashes by enabling routine monitoring of flight operations to identify portions of flights that may be of interest with respect to safety issues.

  16. Assessment of aircraft impact possibilities at the Idaho Chemical Processing Plant on the INEL Site

    SciTech Connect

    Lee, L.G.; Mines, J.M.; Webb, B.B.

    1993-08-01

    The concern of this study was the possibility of an aircraft collision with facilities at the Idaho Chemical Processing Plant (ICPP). Two sets of data were combined in calculating the probability of this event. The first was from the Nuclear Regulatory Commission. The Nuclear Regulatory Commission data is used to check the adequacy of nuclear power plant location relative to aircraft crashes. For neighboring airport scenarios, the accepted rate unit is fatal crashes per square mile. For in-flight crash scenarios, a total loss of control crash rate (where the pilot was completely out of control) is used for evaluating nuclear reactors. Numbers were given per linear mile of flight. The other set of data was obtained from the National Transportation Safety Board`s annual review. These data points show higher crash frequencies because crashes in which the pilot maintained some control have not been excluded. By including this data set, the evaluation gained two advantages. First, the data are separated by type of aircraft, which makes frequencies for specific flight paths more meaningful. Second, the data are given year by year over a ten-year time span. Therefore, it is possible to gain a sense of the variability in crash frequencies from one year to another.

  17. Cost of crashes related to road conditions, United States, 2006.

    PubMed

    Zaloshnja, Eduard; Miller, Ted R

    2009-10-01

    This is the first study to estimate the cost of crashes related to road conditions in the U.S. To model the probability that road conditions contributed to the involvement of a vehicle in the crash, we used 2000-03 Large Truck Crash Causation Study (LTCCS) data, the only dataset that provides detailed information whether road conditions contributed to crash occurrence. We applied the logistic regression results to a costed national crash dataset in order to calculate the probability that road conditions contributed to the involvement of a vehicle in each crash. In crashes where someone was moderately to seriously injured (AIS-2-6) in a vehicle that harmfully impacted a large tree or medium or large non-breakaway pole, or if the first harmful event was collision with a bridge, we changed the calculated probability of being road-related to 1. We used the state distribution of costs of fatal crashes where road conditions contributed to crash occurrence or severity to estimate the respective state distribution of non-fatal crash costs. The estimated comprehensive cost of traffic crashes where road conditions contributed to crash occurrence or severity was $217.5 billion in 2006. This represented 43.6% of the total comprehensive crash cost. The large share of crash costs related to road design and conditions underlines the importance of these factors in highway safety. Road conditions are largely controllable. Road maintenance and upgrading can prevent crashes and reduce injury severity. PMID:20184840

  18. Crash Videos Spark Inelastic Collisions Interest

    NASA Astrophysics Data System (ADS)

    Bart, George R.

    2006-12-01

    There are many popular dramatic crash videos available on the Internet. Introductory physics student interest about the details of inelastic collisions can be significantly aroused by the use of these videos. Sources of the videos will be provided and some of truck crashes will be shown. One dramatic one will be analyzed. It involves MJ of kinetic energy and MN of force. More detail with references is found at http://faculty.ccc.edu/gbart/crashvideo/.

  19. Marijuana Use and Motor Vehicle Crashes

    PubMed Central

    Li, Mu-Chen; Brady, Joanne E.; DiMaggio, Charles J.; Lusardi, Arielle R.; Tzong, Keane Y.; Li, Guohua

    2012-01-01

    Since 1996, 16 states and the District of Columbia in the United States have enacted legislation to decriminalize marijuana for medical use. Although marijuana is the most commonly detected nonalcohol drug in drivers, its role in crash causation remains unsettled. To assess the association between marijuana use and crash risk, the authors performed a meta-analysis of 9 epidemiologic studies published in English in the past 2 decades identified through a systematic search of bibliographic databases. Estimated odds ratios relating marijuana use to crash risk reported in these studies ranged from 0.85 to 7.16. Pooled analysis based on the random-effects model yielded a summary odds ratio of 2.66 (95% confidence interval: 2.07, 3.41). Analysis of individual studies indicated that the heightened risk of crash involvement associated with marijuana use persisted after adjustment for confounding variables and that the risk of crash involvement increased in a dose-response fashion with the concentration of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol detected in the urine and the frequency of self-reported marijuana use. The results of this meta-analysis suggest that marijuana use by drivers is associated with a significantly increased risk of being involved in motor vehicle crashes. PMID:21976636

  20. A disaggregate approach to crash rate analysis.

    PubMed

    Kam, Booi Hon

    2003-09-01

    This paper presents a disaggregate approach to crash rate analysis. Enumerating crash rates on a per trip-kilometer basis, the proposed method removes the linearity assumption inherent in the conventional quotient indicator of accidents per unit travel distance. The approach involves combining two disparate datasets on a geographic information systems (GIS) platform by matching accident records to a defined travel corridor. As an illustration of the methodology, travel information from the Victorian Activity and Travel Survey (VATS) and accident records contained in CrashStat were used to estimate the crash rates of Melbourne residents in different age-sex groups according to time of the day and day of the week. The results show a polynomial function of a cubic order when crash rates are plotted against age group, which contrasts distinctly with the U-shape curve generated by using the conventional aggregate quotient approach. Owing to the validity of the many assumptions adopted in the computation, this study does not claim that the results obtained are conclusive. The methodology, however, is seen as providing a framework upon which future crash risk measures could be based as the use of spatial tracking devises become prevalent in travel surveys. PMID:12850070

  1. Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

    2003-01-01

    A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

  2. Occupant Responses in a Full-Scale Crash Test of the Sikorsky ACAP Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard; McEntire, Joseph; Lewis, Alan

    2002-01-01

    A full-scale crash test of the Sikorsky Advanced Composite Airframe Program (ACAP) helicopter was performed in 1999 to generate experimental data for correlation with a crash simulation developed using an explicit nonlinear, transient dynamic finite element code. The airframe was the residual flight test hardware from the ACAP program. For the test, the aircraft was outfitted with two crew and two troop seats, and four anthropomorphic test dummies. While the results of the impact test and crash simulation have been documented fairly extensively in the literature, the focus of this paper is to present the detailed occupant response data obtained from the crash test and to correlate the results with injury prediction models. These injury models include the Dynamic Response Index (DRI), the Head Injury Criteria (HIC), the spinal load requirement defined in FAR Part 27.562(c), and a comparison of the duration and magnitude of the occupant vertical acceleration responses with the Eiband whole-body acceleration tolerance curve.

  3. The microburst - Hazard to aircraft

    NASA Technical Reports Server (NTRS)

    Mccarthy, J.; Serafin, R.

    1984-01-01

    In encounters with microbursts, low altitude aircraft first encounter a strong headwind which increases their wing lift and altitude; this phenomenon is followed in short succession by a decreasing headwind component, a downdraft, and finally a strong tailwind that catastrophically reduces wing lift and precipitates a crash dive. It is noted that the potentially lethal low altitude wind shear of a microburst may lie in apparently harmless, rain-free air beneath a cloud base. Occasionally, such tell-tale signs as localized blowing of ground dust may be sighted in time. Microbursts may, however, occur in the heavy rain of a thunderstorm, where they will be totally obscured from view. Wind shear may be detected by an array of six anemometers and vanes situated in the vicinity of an airport, and by Doppler radar equipment at the airport or aboard aircraft.

  4. Aircraft-assisted pilot suicides in the United States, 1993-2002.

    PubMed

    Lewis, Russell J; Johnson, Robert D; Whinnery, James E; Forster, Estrella M

    2007-01-01

    Our laboratory was interested in epidemiological and toxicological findings from aircraft-assisted pilot suicides. Between 1993-2002 there were 3,648 fatal aviation accidents. The NTSB determined that 16 were aircraft-assisted suicides; 15 from intentional crashing of an aircraft and 1 from exiting the aircraft while in-flight. All pilots involved in these aircraft-assisted suicides were male, with a median age of 40 years. Seven of the 14 pilots for which specimens were available were positive for disqualifying substances. Based on the few cases conclusively attributed to suicide, death by the intentional crashing of an aircraft appears to be an infrequent and uncommon event. PMID:17453693

  5. Rising Blood Sugar Hitting More Obese Adults

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159853.html Rising Blood Sugar Hitting More Obese Adults To curb diabetes, researchers ... HealthDay News) -- Among obese American adults, control of blood sugar is worsening, leading to more diabetes and heart ...

  6. Vehicular crash data used to rank intersections by injury crash frequency and severity.

    PubMed

    Liu, Yi; Li, Zongzhi; Liu, Jingxian; Patel, Harshingar

    2016-09-01

    This article contains data on research conducted in "A double standard model for allocating limited emergency medical service vehicle resources ensuring service reliability" (Liu et al., 2016) [1]. The crash counts were sorted out from comprehensive crash records of over one thousand major signalized intersections in the city of Chicago from 2004 to 2010. For each intersection, vehicular crashes were counted by crash severity levels, including fatal, injury Types A, B, and C for major, moderate, and minor injury levels, property damage only (PDO), and unknown. The crash data was further used to rank intersections by equivalent injury crash frequency. The top 200 intersections with the highest number of crash occurrences identified based on crash frequency- and severity-based scenarios are shared in this brief. The provided data would be a valuable source for research in urban traffic safety analysis and could also be utilized to examine the effectiveness of traffic safety improvement planning and programming, intersection design enhancement, incident and emergency management, and law enforcement strategies. PMID:27508245

  7. Assessment of aircraft impact probabilities at the Idaho Chemical Processing Plant. Revision 1

    SciTech Connect

    Lee, L.G.; Mines, J.M.; Webb, B.B.

    1994-06-01

    The purpose of this study is to evaluate the possibility of an aircraft crash into a facility at the Idaho Chemical Processing Plant (ICPP). The ICPP is part of the Idaho National Engineering Laboratory (INEL). Based on the data used in this study, an air crash into any single facility at the ICPP is incredible. An air crash into aggregate areas incorporating the following is extremely unlikely: (1) ICPP radiological materials storage facilities, (2) ICPP major processing facilities, and (3) the ICPP land surface area, which excludes buildings. According to Westinghouse Idaho Nuclear Company safety analysis procedures, if the probability of a radiological release event is determined to be incredible, no further review is required. Therefore, an aircraft crash scenario is not required in the safety analysis for a single facility but should be discussed relative to the ICPP aggregate areas.

  8. Thoracolumbar Spine Fractures in Frontal Impact Crashes

    PubMed Central

    Pintar, Frank A.; Yoganandan, Narayan; Maiman, Dennis J.; Scarboro, Mark; Rudd, Rodney W.

    2012-01-01

    There is currently no injury assessment for thoracic or lumbar spine fractures in the motor vehicle crash standards throughout the world. Compression-related thoracolumbar fractures are occurring in frontal impacts and yet the mechanism of injury is poorly understood. The objective of this investigation was to characterize these injuries using real world crash data from the US-DOT-NHTSA NASS-CDS and CIREN databases. Thoracic and lumbar AIS vertebral body fracture codes were searched for in the two databases. The NASS database was used to characterize population trends as a function of crash year and vehicle model year. The CIREN database was used to examine a case series in more detail. From the NASS database there were 2000–4000 occupants in frontal impacts with thoracic and lumbar vertebral body fractures per crash year. There was an increasing trend in incidence rate of thoracolumbar fractures in frontal impact crashes as a function of vehicle model year from 1986 to 2008; this was not the case for other crash types. From the CIREN database, the thoracolumbar spine was most commonly fractured at either the T12 or L1 level. Major, burst type fractures occurred predominantly at T12, L1 or L5; wedge fractures were most common at L1. Most CIREN occupants were belted; there were slightly more females involved; they were almost all in bucket seats; impact location occurred approximately half the time on the road and half off the road. The type of object struck also seemed to have some influence on fractured spine level, suggesting that the crash deceleration pulse may be influential in the type of compression vector that migrates up the spinal column. Future biomechanical studies are required to define mechanistically how these fractures are influenced by these many factors. PMID:23169137

  9. The sensitivity and specificity of control surface injuries in aircraft accident fatalities.

    PubMed

    Campman, Steven C; Luzi, Scott A

    2007-06-01

    Among the important determinations that aircraft crash investigators try to make is which occupant of an aircraft was attempting to control the aircraft at the time of the crash. The presence or absence of certain injuries of the extremities is used to help make this determination. These "control surface injuries" reportedly occur when crash forces are applied to a pilot's hands and feet through the aircraft's controls. We sought to clarify the significance of these injuries and the frequency with which their presence indicates that the decedent was the person that might have been trying to control the aircraft, questions that are frequently asked of the examining pathologist. We studied sequential fatalities of airplane and helicopter crashes in which autopsies were performed by the Office of the Armed Forces Medical Examiner, excluding those that were known to have been incapacitated before the crash and those that were known to have attempted to escape from the aircraft, collecting 100 "qualified" crash decedents. The incidence of control surface injuries was determined for both pilots and passengers. The sensitivity and specificity of control surface injuries were calculated by classifying the decedents into a 4-cell diagnostic matrix. The positive and negative predictive values for control surface injuries were also calculated. Injuries that met the published definitions of control surface injuries had high incidences in passengers, as well as pilots, giving the term control surface injury a diagnostically unacceptable sensitivity and specificity for indicating "a pilot attempting to control an aircraft." We offer caveats and refinements to the definition of these injuries that help to increase the sensitivity and specificity of this term. PMID:17525559

  10. Gasoline prices and their relationship to drunk-driving crashes.

    PubMed

    Chi, Guangqing; Zhou, Xuan; McClure, Timothy E; Gilbert, Paul A; Cosby, Arthur G; Zhang, Li; Robertson, Angela A; Levinson, David

    2011-01-01

    This study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by several crash types and demographic groups at the monthly level from 2004 to 2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk-driving crashes among young and adult drivers, among male and female drivers, and among white and black drivers. Results from negative binomial regression models show that when gas prices are higher, there are fewer drunk-driving crashes, particularly among property-damage-only crashes. When alcohol consumption levels are higher, there are more drunk-driving crashes, particularly fatal and injury crashes. The effects of gasoline prices and alcohol consumption are stronger on drunk-driving crashes than on all crashes. The findings do not vary much across different demographic groups. Overall, gasoline prices have greater effects on less severe crashes and alcohol consumption has greater effects on more severe crashes. PMID:21094313

  11. Effect of electronic stability control on automobile crash risk.

    PubMed

    Farmer, Charles

    2004-12-01

    Per vehicle crash involvement rates were compared for otherwise identical vehicle models with and without electronic stability control (ESC) systems. ESC was found to affect single-vehicle crashes to a greater extent than multiple-vehicle crashes, and crashes with fatal injuries to a greater extent than less severe crashes. Based on all police-reported crashes in 7 states over 2 years, ESC reduced single-vehicle crash involvement risk by approximately 41 percent (95 percent confidence limits 3348) and single-vehicle injury crash involvement risk by 41 percent (2752). This translates to an estimated 7 percent reduction in overall crash involvement risk (310) and a 9 percent reduction in overall injury crash involvement risk (314). Based on all fatal crashes in the United States over 3 years, ESC was found to have reduced single-vehicle fatal crash involvement risk by 56 percent (3968). This translates to an estimated 34 percent reduction in overall fatal crash involvement risk (2145). PMID:15545069

  12. Emergency Locator Transmitter System Performance During Three Full-Scale General Aviation Crash Tests

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.; Stimson, Chad M.

    2016-01-01

    Full-scale crash tests were conducted on three Cessna 172 aircraft at NASA Langley Research Center's Landing and Impact Research facility during the summer of 2015. The purpose of the three tests was to evaluate the performance of commercially available Emergency Locator Transmitter (ELT) systems and support development of enhanced installation guidance. ELTs are used to provide location information to Search and Rescue (SAR) organizations in the event of an aviation distress situation, such as a crash. The crash tests simulated three differing severe but survivable crash conditions, in which it is expected that the onboard occupants have a reasonable chance of surviving the accident and would require assistance from SAR personnel. The first simulated an emergency landing onto a rigid surface, while the second and third simulated controlled flight into terrain. Multiple ELT systems were installed on each airplane according to federal regulations. The majority of the ELT systems performed nominally. In the systems which did not activate, post-test disassembly and inspection offered guidance for non-activation cause in some cases, while in others, no specific cause could be found. In a subset of installations purposely disregarding best practice guidelines, failure of the ELT-to-antenna cabling connections were found. Recommendations for enhanced installation guidance of ELT systems will be made to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 229 for consideration for adoption in a future release of ELT minimum operational performance specifications. These recommendations will be based on the data gathered during this test series as well as a larger series of crash simulations using computer models that will be calibrated based on these data

  13. Motor vehicle-bicycle crashes in Beijing: irregular maneuvers, crash patterns, and injury severity.

    PubMed

    Yan, Xinping; Ma, Ming; Huang, Helai; Abdel-Aty, Mohamed; Wu, Chaozhong

    2011-09-01

    This research presents a comprehensive analysis of motor vehicle-bicycle crashes using 4 years of reported crash data (2004-2007) in Beijing. The interrelationship of irregular maneuvers, crash patterns and bicyclist injury severity are investigated by controlling for a variety of risk factors related to bicyclist demographics, roadway geometric design, road environment, etc. Results show that different irregular maneuvers are correlated with a number of risk factors at different roadway locations such as the bicyclist age and gender, weather and traffic condition. Furthermore, angle collisions are the leading pattern of motor vehicle-bicycle crashes, and different irregular maneuvers may lead to some specific crash patterns such as head-on or rear-end crashes. Orthokinetic scrape is more likely to result in running over bicyclists, which may lead to more severe injury. Moreover, bicyclist injury severity level could be elevated by specific crash patterns and risk factors including head-on and angle collisions, occurrence of running over bicyclists, night without streetlight, roads without median/division, higher speed limit, heavy vehicle involvement and older bicyclists. This study suggests installation of median, division between roadway and bikeway, and improvement of illumination on road segments. Reduced speed limit is also recommended at roadway locations with high bicycle traffic volume. Furthermore, it may be necessary to develop safety campaigns aimed at male, teenage and older bicyclists. PMID:21658503

  14. Predicting crash risk and identifying crash precursors on Korean expressways using loop detector data.

    PubMed

    Kwak, Ho-Chan; Kho, Seungyoung

    2016-03-01

    In order to improve traffic safety on expressways, it is important to develop proactive safety management strategies with consideration for segment types and traffic flow states because crash mechanisms have some differences by each condition. The primary objective of this study is to develop real-time crash risk prediction models for different segment types and traffic flow states on expressways. The mainline of expressways is divided into basic segment and ramp vicinity, and the traffic flow states are classified into uncongested and congested conditions. Also, Korean expressways have irregular intervals between loop detector stations. Therefore, we investigated on the effect and application of the detector stations at irregular intervals for the crash risk prediction on expressways. The most significant traffic variables were selected by conditional logistic regression analysis which could control confounding factors. Based on the selected traffic variables, separate models to predict crash risk were developed using genetic programming technique. The model estimation results showed that the traffic flow characteristics leading to crashes are differed by segment type and traffic flow state. Especially, the variables related to the intervals between detector stations had a significant influence on crash risk prediction under the uncongested condition. Finally, compared with the single model for all crashes and the logistic models used in previous studies, the proposed models showed higher prediction performance. The results of this study can be applied to develop more effective proactive safety management strategies for different segment types and traffic flow states on expressways with loop detector stations at irregular intervals. PMID:26710266

  15. Aircraft fires, smoke toxicity, and survival.

    PubMed

    Chaturvedi, A K; Sanders, D C

    1996-03-01

    In-flight fires in modern aircraft are rare, but post-crash fires do occur. Cabin occupants frequently survive initial forces of such crashes but are incapacitated from smoke inhalation. According to an international study, there were 95 fire-related civil passenger aircraft accidents worldwide over a 26-yr period, claiming approximately 2400 lives. Between 1985 and 1991, about 16% (32 accidents) of all U.S. transport aircraft accidents involved fire and 22% (140 fatalities) of the deaths in these accidents resulted from fire/smoke toxicity. Our laboratory analyses of postmortem blood samples (1967-93) indicate that 360 individuals in 134 fatal fire-related civil aircraft (air carrier and general aviation) accidents had carboxyhemoglobin saturation levels (> or = 20%), with or without blood cyanide, high enough to impair performance. Combustion toxicology is now moving from a descriptive to a mechanistic phase. Methods for gas analyses have been developed and combustion/animal-exposure assemblies have been constructed. Material/fire-retardant toxicity and interactions between smoke gases are being studied. Relationships between gas exposure concentrations, blood levels, and incapacitation onset are being established in animal models. Continuing basic research in smoke toxicity will be necessary to understand its complexities, and thus enhance aviation safety and fire survival chances. PMID:8775410

  16. HIT: time to end behavioral health discrimination.

    PubMed

    Rosenberg, Linda

    2012-10-01

    While the Health Information Technology for Economic and Clinical Health Act, enacted as part of the American Recovery and Reinvestment Act of 2009, provided $20.6 billion for incentive payments to support the adoption and meaningful use of health information technology (HIT), behavioral health organizations were not eligible to receive facility payments. The consequences of excluding behavioral health from HIT incentive payments are found in the results of the "HIT Adoption and Meaningful Use Readiness in Community Behavioral Health" survey. The survey found that only 2% of community behavioral health organizations are able to meet federal meaningful use (MU) requirements-compare this to the 27% of Federally Qualified Health Centers and 20% of hospitals that already meet some level of MU requirements. Behavioral health organizations, serving more than eight million adults, children, and families with mental illnesses and addiction disorders, are ready and eager to adopt HIT to meet the goals of better healthcare, better health, and lower costs. But reaching these goals may prove impossible unless behavioral health achieves "parity" within healthcare and receives resources for the adoption of HIT. PMID:22956203

  17. Drinking-Driving and Fatal Crashes: A New Perspective

    ERIC Educational Resources Information Center

    Zylman, Richard

    1975-01-01

    Discusses the relationship between alcohol and fatal automobile crashes. Stresses the need for controlled studies in order to determine the correlation between drunk drivers and fatal accidents and to obtain dependable statistics on alcohol-related crashes. (BD)

  18. ATD Occupant Responses from Three Full-Scale General Aviation Crash Tests

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.; Annett, Martin S.

    2016-01-01

    During the summer of 2015, three Cessna 172 General Aviation (GA) aircraft were crash tested at the Landing and Impact Research (LandIR) Facility at NASA Langley Research Center (LaRC). Three different crash scenarios were represented. The first test simulated a flare-to-stall emergency or hard landing onto a rigid surface such as a road or runway. The second test simulated a controlled flight into terrain with a nose down pitch of the aircraft, and the third test simulated a controlled flight into terrain with an attempt to unsuccessfully recover the aircraft immediately prior to impact, resulting in a tail strike condition. An on-board data acquisition system (DAS) captured 64 channels of airframe acceleration, along with accelerations and loads in two onboard Hybrid II 50th percentile Anthropomorphic Test Devices (ATDs) representing the pilot and copilot. Each of the three tests contained different airframe loading conditions and different types of restraints for both the pilot and co-pilot ATDs. The results show large differences in occupant response and restraint performance with varying likelihoods of occupant injury.

  19. Ball lightning risk to aircraft

    NASA Astrophysics Data System (ADS)

    Doe, R.; Keul, A.

    2009-04-01

    Lightning is a rare but regular phenomenon for air traffic. Aircraft are designed to withstand lightning strikes. Research on lightning and aircraft can be called detailed and effective. In the last 57 years, 18 reported lightning aviation disasters with a fatality figure of at least 714 persons occurred. For comparison, the last JACDEC ten-year average fatality figure was 857. The majority encountered lightning in the climb, descent, approach and/or landing phase. Ball lightning, a metastable, rare lightning type, is also seen from and even within aircraft, but former research only reported individual incidents and did not generate a more detailed picture to ascertain whether it constitutes a significant threat to passenger and aircraft safety. Lacking established incident report channels, observations were often only passed on as "air-travel lore". In an effort to change this unsatisfactory condition, the authors have collected a first international dataset of 38 documented ball lightning aircraft incidents from 1938 to 2001 involving 13 reports over Europe, 13 over USA/Canada, and 7 over Russia. 18 (47%) reported ball lightning outside the aircraft, 18 (47%) inside, 2 cases lacked data. 8 objects caused minor damage, 8 major damage (total: 42%), only one a crash. No damage was reported in 18 cases. 3 objects caused minor crew injury. In most cases, ball lightning lasted several seconds. 11 (29%) incidents ended with an explosion of the object. A cloud-aircraft lightning flash was seen in only 9 cases (24%) of the data set. From the detailed accounts of air personnel in the last 70 years, it is evident that ball lightning is rarely, but consistently observed in connection with aircraft and can also occur inside the airframe. Reports often came from multiple professional witnesses and in several cases, damages were investigated by civil or military authorities. Although ball lightning is no main air traffic risk, the authors suggest that incident and accident

  20. Factors Affecting Ejection Risk in Rollover Crashes

    PubMed Central

    Funk, James R.; Cormier, Joseph M.; Bain, Charles E.; Wirth, Jeffrey L.; Bonugli, Enrique B.; Watson, Richard A.

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 – 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  1. Conscientious personality and young drivers’ crash risk

    PubMed Central

    Ehsani, Johnathon P.; Li, Kaigang; Simons-Morton, Bruce; Tree-McGrath, Cheyenne Fox; Perlus, Jessamyn; O’Brien, Fearghal; Klauer, Sheila G.

    2015-01-01

    Introduction Personality characteristics are associated with many risk behaviors. However, the relationship between personality traits, risky driving behavior, and crash risk is poorly understood. The purpose of this study was to examine the association between personality, risky driving behavior and crashes and near-crashes, using naturalistic driving research methods. Method Participants’ driving exposure, kinematic risky driving (KRD), high-risk secondary task engagement, and the frequency of crashes and near-crashes (CNC) were assessed over the first 18 months of licensure using naturalistic driving methods. A personality survey (NEO-Five Factor Inventory) was administered at baseline. The association between personality characteristics, KRD rate, secondary task engagement rate and CNC rate was estimated using a linear regression model. Mediation analysis was conducted to examine if participants’ KRD rate or secondary task engagement rate mediated the relationship between personality and CNC. Data were collected as part of the Naturalistic Teen Driving Study. Results Conscientiousness was marginally negatively associated with CNC (path c = −0.034, p = .09) and both potential mediators KRD (path a = −0.040, p = .09) and secondary task engagement while driving (path a = −0.053, p = .03). KRD, but not secondary task engagement, was found to mediate (path b = 0.376, p = .02) the relationship between conscientiousness and CNC (path c’ = −0.025, p = .20). Conclusions Using objective measures of driving behavior and a widely used personality construct, these findings present a causal pathway through which personality and risky driving are associated with CNC. Specifically, more conscientious teenage drivers engaged in fewer risky driving maneuvers, suffered fewer CNC. Practical Applications Part of the variability in crash-risk observed among newly licensed teenage drivers can be explained by personality. Parents and driving instructors may take teenage

  2. Factors affecting ejection risk in rollover crashes.

    PubMed

    Funk, James R; Cormier, Joseph M; Bain, Charles E; Wirth, Jeffrey L; Bonugli, Enrique B; Watson, Richard A

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 - 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  3. Costs of Alcohol-Involved Crashes, United States, 2010

    PubMed Central

    Zaloshnja, Eduard; Miller, Ted R.; Blincoe, Lawrence J.

    2013-01-01

    This paper estimates total and unit costs of alcohol-involved crashes in the U.S. in 2010. With methods from earlier studies, we estimated costs per crash survivor by MAIS, body part, and fracture/dislocation involvement. We multiplied them times 2010 crash incidence estimates from NHTSA data sets, with adjustments for underreporting of crashes and their alcohol involvement. The unit costs are lifetime costs discounted at 3%. To develop medical costs, we combined 2008 Health Care Utilization Program national data for hospitalizations and ED visits of crash survivors with prior estimates of post-discharge costs. Productivity losses drew on Current Population Survey and American Time Use Survey data. Quality of life losses came from a 2011 AAAM paper and property damage from insurance data. We built a hybrid incidence file comprised of 2008–2010 and 1984–86 NHTSA crash surveillance data, weighted with 2010 General Estimates System weights. Fatality data came from the 2010 FARS. An estimated 12% of 2010 crashes but only 0.9% of miles driven were alcohol-involved (BAC > .05). Alcohol-involved crashes cost an estimated $125 billion. That is 22.5% of the societal cost of all crashes. Alcohol-attributable crashes accounted for an estimated 22.5% of US auto liability insurance payments. Alcohol-involved crashes cost $0.86 per drink. Above the US BAC limit of .08, crash costs were $8.37 per mile driven; 1 in 788 trips resulted in a crash and 1 in 1,016 trips in an arrest. Unit costs for crash survivors by severity are higher for impaired driving than for other crashes. That suggests national aggregate impaired driving cost estimates in other countries are substantial underestimates if they are based on all-crash unit costs. PMID:24406941

  4. Application of Probabilistic Analysis to Aircraft Impact Dynamics

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Padula, Sharon L.; Stockwell, Alan E.

    2003-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stressstrain behaviors, laminated composites, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the uncertainty in the simulated responses. Several criteria are used to determine that a response surface method is the most appropriate probabilistic approach. The work is extended to compare optimization results with and without probabilistic constraints.

  5. Aircraft Design

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  6. Aircraft Noise

    NASA Astrophysics Data System (ADS)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  7. Hitting is contagious: experience and action induction.

    PubMed

    Gray, Rob; Beilock, Sian L

    2011-03-01

    In baseball, it is believed that "hitting is contagious," that is, probability of success increases if the previous few batters get a hit. Could this effect be partially explained by action induction--that is, the tendency to perform an action related to one that has just been observed? A simulation was used to investigate the effect of inducing stimuli on batting performance for more-experienced (ME) and less-experienced (LE) baseball players. Three types of inducing stimuli were compared with a no-induction condition: action (a simulated ball traveling from home plate into left, right, or center field), outcome (a ball resting in either left, right, or center field), and verbal (the word "left", "center", or "right"). For both ME and LE players, fewer pitchers were required for a successful hit in the action condition. For ME players, there was a significant relationship between the inducing stimulus direction and hit direction for both the action and outcome prompts. For LE players, the prompt only had a significant effect on batting performance in the action condition, and the magnitude of the effect was significantly smaller than for ME. The effect of the inducing stimulus decreased as the delay (i.e., no. of pitches between prompt and hit) increased, with the effect being eliminated after roughly 4 pitches for ME and 2 pitches for LE. It is proposed that the differences in the magnitude and time course of action induction as a function of experience occurred because ME have more well-developed perceptual-motor representations for directional hitting. PMID:21443380

  8. Investigative and autopsy findings in sport aircraft-related deaths in southwest Florida.

    PubMed

    Wolf, Barbara C; Harding, Brett E

    2008-09-01

    Aircraft designated for sport or recreational use only, including ultralights, experimental aircraft and light-sport aircraft, have become increasingly popular. Because of their relative safety and the rarity of fatalities resulting from crashes of these aircraft, the forensic literature contains little information concerning the pathologic findings in such deaths. We report 9 deaths resulting from 6 sport aircraft crashes in southwest Florida, 6 pilots and 3 passengers. The vehicles involved 3 experimental aircraft, 1 ultralight and 2 "ultralight-like" aircraft. The patterns of injuries included trauma predominantly to the chest (3 cases), abdomen (1) or head (1), as well as multiple blunt force injuries involving the chest and abdomen (1) or the head and torso (3). Extremity fractures were found in only 2 cases, whereas injuries to the symphysis pubis were found in six. No "control-type" injuries were identified. These cases illustrate the varied pathologies associated with deaths due to crashes of sport aircraft and reveal the lack of uniformity associated with the investigations of such deaths. PMID:18725774

  9. Child Passengers Injured in Motor Vehicle Crashes

    PubMed Central

    Romano, Eduardo; Kelley-Baker, Tara

    2015-01-01

    Introduction—During 2010, 171,000 children aged 0-14 were injured in motor vehicle crashes. Despite the severity of the problem, research has been limited, and most of what we know about these children emanates from fatal crash databases. Method—Using information from the General Estimates System, this effort examines the occurrence of non-fatal crashes among children aged 0-14 over the last decade. Results—We found about 1% of the non-injured children in the file had been driven by a driver who was positive for alcohol. This percentage climbed to about 2% among children who had suffered injuries. Compared with the proportion of alcohol-positive drivers at the time of the crash, the proportion of drivers who sped or failed to obey a traffic signal were significantly higher. Practical Applications—The finding that drinking and driving with children did not decrease over time questions the adequacy of the extant child endangerment laws. PMID:25662876

  10. Robotics and Design: An Interdisciplinary Crash Course

    ERIC Educational Resources Information Center

    Bonarini, A.; Romero, M.

    2013-01-01

    The authors designed and ran a crash course on emotional robotics involving students from both the Information Engineering School and the Design School of Politecnico di Milano, Milan, Italy. The course consisted of two intensive days of short introductory lessons and lab activity, done in interdisciplinary groups and supported by a well-equipped…

  11. Analysis of Large Truck Rollover Crashes

    PubMed Central

    McKnight, A. James; Bahouth, George T.

    2008-01-01

    The Large Truck Crash Causation Study undertaken by the Federal Motor Carrier Safety Administration describes 239 crashes in which a truck rolled over. In-depth analysis revealed almost half resulted from failing to adjust speed to curves in the road, (mostly on-and off-ramps), the load being carried, condition of the brakes, road surface, and intersection conditions. A second major crash contributor involved attention: simply being inattentive, dozing or falling asleep, and distraction, all leading to situations where a sudden direction change resulted in a rollover. The third large crash contributor involved steering: over-steering to the point of rolling over, not steering enough to stay in lane, and overcorrecting to the point of having to counter-steer to remain on the road. Finally, loads are a frequent problem when drivers fail to take account of their weight, height or security, or when loading takes place before they are assigned. Instruction in rollover prevention, like most truck driver training, comes through printed publications. The use of video would help drivers recognize incipient rollovers while currently available simulation would allow drivers to experience the consequences of mistakes without risk. PMID:19026244

  12. CRASH3: cosmological radiative transfer through metals

    NASA Astrophysics Data System (ADS)

    Graziani, L.; Maselli, A.; Ciardi, B.

    2013-05-01

    Here we introduce CRASH3, the latest release of the 3D radiative transfer code CRASH. In its current implementation, CRASH3 integrates into the reference algorithm the code CLOUDY to evaluate the ionization states of metals, self-consistently with the radiative transfer through H and He. The feedback of the heavy elements on the calculation of the gas temperature is also taken into account, making CRASH3 the first 3D code for cosmological applications which treats self-consistently the radiative transfer through an inhomogeneous distribution of metal-enriched gas with an arbitrary number of point sources and/or a background radiation. The code has been tested in idealized configurations, as well as in a more realistic case of multiple sources embedded in a polluted cosmic web. Through these validation tests, the new method has been proven to be numerically stable and convergent. We have studied the dependence of the results on a number of physical quantities such as the source characteristics (spectral range and shape, intensity), the metal composition, the gas number density and metallicity.

  13. Statistical Properties and Pre-Hit Dynamics of Price Limit Hits in the Chinese Stock Markets

    PubMed Central

    Wan, Yu-Lei; Xie, Wen-Jie; Gu, Gao-Feng; Jiang, Zhi-Qiang; Chen, Wei; Xiong, Xiong; Zhang, Wei; Zhou, Wei-Xing

    2015-01-01

    Price limit trading rules are adopted in some stock markets (especially emerging markets) trying to cool off traders’ short-term trading mania on individual stocks and increase market efficiency. Under such a microstructure, stocks may hit their up-limits and down-limits from time to time. However, the behaviors of price limit hits are not well studied partially due to the fact that main stock markets such as the US markets and most European markets do not set price limits. Here, we perform detailed analyses of the high-frequency data of all A-share common stocks traded on the Shanghai Stock Exchange and the Shenzhen Stock Exchange from 2000 to 2011 to investigate the statistical properties of price limit hits and the dynamical evolution of several important financial variables before stock price hits its limits. We compare the properties of up-limit hits and down-limit hits. We also divide the whole period into three bullish periods and three bearish periods to unveil possible differences during bullish and bearish market states. To uncover the impacts of stock capitalization on price limit hits, we partition all stocks into six portfolios according to their capitalizations on different trading days. We find that the price limit trading rule has a cooling-off effect (object to the magnet effect), indicating that the rule takes effect in the Chinese stock markets. We find that price continuation is much more likely to occur than price reversal on the next trading day after a limit-hitting day, especially for down-limit hits, which has potential practical values for market practitioners. PMID:25874716

  14. Statistical properties and pre-hit dynamics of price limit hits in the Chinese stock markets.

    PubMed

    Wan, Yu-Lei; Xie, Wen-Jie; Gu, Gao-Feng; Jiang, Zhi-Qiang; Chen, Wei; Xiong, Xiong; Zhang, Wei; Zhou, Wei-Xing

    2015-01-01

    Price limit trading rules are adopted in some stock markets (especially emerging markets) trying to cool off traders' short-term trading mania on individual stocks and increase market efficiency. Under such a microstructure, stocks may hit their up-limits and down-limits from time to time. However, the behaviors of price limit hits are not well studied partially due to the fact that main stock markets such as the US markets and most European markets do not set price limits. Here, we perform detailed analyses of the high-frequency data of all A-share common stocks traded on the Shanghai Stock Exchange and the Shenzhen Stock Exchange from 2000 to 2011 to investigate the statistical properties of price limit hits and the dynamical evolution of several important financial variables before stock price hits its limits. We compare the properties of up-limit hits and down-limit hits. We also divide the whole period into three bullish periods and three bearish periods to unveil possible differences during bullish and bearish market states. To uncover the impacts of stock capitalization on price limit hits, we partition all stocks into six portfolios according to their capitalizations on different trading days. We find that the price limit trading rule has a cooling-off effect (object to the magnet effect), indicating that the rule takes effect in the Chinese stock markets. We find that price continuation is much more likely to occur than price reversal on the next trading day after a limit-hitting day, especially for down-limit hits, which has potential practical values for market practitioners. PMID:25874716

  15. Improvements of HITS Algorithms for Spam Links

    NASA Astrophysics Data System (ADS)

    Asano, Yasuhito; Tezuka, Yu; Nishizeki, Takao

    The HITS algorithm proposed by Kleinberg is one of the representative methods of scoring Web pages by using hyperlinks. In the days when the algorithm was proposed, most of the pages given high score by the algorithm were really related to a given topic, and hence the algorithm could be used to find related pages. However, the algorithm and the variants including Bharat's improved HITS, abbreviated to BHITS, proposed by Bharat and Henzinger cannot be used to find related pages any more on today's Web, due to an increase of spam links. In this paper, we first propose three methods to find “linkfarms,” that is, sets of spam links forming a densely connected subgraph of a Web graph. We then present an algorithm, called a trust-score algorithm, to give high scores to pages which are not spam pages with a high probability. Combining the three methods and the trust-score algorithm with BHITS, we obtain several variants of the HITS algorithm. We ascertain by experiments that one of them, named TaN+BHITS using the trust-score algorithm and the method of finding linkfarms by employing name servers, is most suitable for finding related pages on today's Web. Our algorithms take time and memory no more than those required by the original HITS algorithm, and can be executed on a PC with a small amount of main memory.

  16. Precise timing when hitting falling balls

    PubMed Central

    Brenner, Eli; Driesen, Ben; Smeets, Jeroen B. J.

    2014-01-01

    People are extremely good at hitting falling balls with a baseball bat. Despite the ball's constant acceleration, they have been reported to time hits with a standard deviation of only about 7 ms. To examine how people achieve such precision, we compared performance when there were no added restrictions, with performance when looking with one eye, when vision was blurred, and when various parts of the ball's trajectory were hidden from view. We also examined how the size of the ball and varying the height from which it was dropped influenced temporal precision. Temporal precision did not become worse when vision was blurred, when the ball was smaller, or when balls falling from different heights were randomly interleaved. The disadvantage of closing one eye did not exceed expectations from removing one of two independent estimates. Precision was higher for slower balls, but only if the ball being slower meant that one saw it longer before the hit. It was particularly important to see the ball while swinging the bat. Together, these findings suggest that people time their hits so precisely by using the changing elevation throughout the swing to adjust the bat's movement to that of the ball. PMID:24904380

  17. Precise timing when hitting falling balls.

    PubMed

    Brenner, Eli; Driesen, Ben; Smeets, Jeroen B J

    2014-01-01

    People are extremely good at hitting falling balls with a baseball bat. Despite the ball's constant acceleration, they have been reported to time hits with a standard deviation of only about 7 ms. To examine how people achieve such precision, we compared performance when there were no added restrictions, with performance when looking with one eye, when vision was blurred, and when various parts of the ball's trajectory were hidden from view. We also examined how the size of the ball and varying the height from which it was dropped influenced temporal precision. Temporal precision did not become worse when vision was blurred, when the ball was smaller, or when balls falling from different heights were randomly interleaved. The disadvantage of closing one eye did not exceed expectations from removing one of two independent estimates. Precision was higher for slower balls, but only if the ball being slower meant that one saw it longer before the hit. It was particularly important to see the ball while swinging the bat. Together, these findings suggest that people time their hits so precisely by using the changing elevation throughout the swing to adjust the bat's movement to that of the ball. PMID:24904380

  18. Science hit by US government crisis

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2013-11-01

    A 16-day government shutdown last month hit the US physics community hard as research projects ranging from space missions to polar geophysics were closed down after Congress failed to vote on its budget for the financial year 2014, which started on 1 October.

  19. Escorting commercial aircraft to reduce the MANPAD threat

    NASA Astrophysics Data System (ADS)

    Hock, Nicholas; Richardson, M. A.; Butters, B.; Walmsley, R.; Ayling, R.; Taylor, B.

    2005-11-01

    This paper studies the Man-Portable Air Defence System (MANPADS) threat against large commercial aircraft using flight profile analysis, engagement modelling and simulation. Non-countermeasure equipped commercial aircraft are at risk during approach and departure due to the large areas around airports that would need to be secured to prevent the use of highly portable and concealable MANPADs. A software model (CounterSim) has been developed and was used to simulate an SA-7b and large commercial aircraft engagement. The results of this simulation have found that the threat was lessened when a escort fighter aircraft is flown in the 'Centreline Low' position, or 25 m rearward from the large aircraft and 15 m lower, similar to the Air-to-Air refuelling position. In the model a large aircraft on approach had a 50% chance of being hit or having a near miss (within 20m) whereas escorted by a countermeasure equipped F-16 in the 'Centerline Low' position, this was reduced to only 14%. Departure is a particularly vulnerable time for large aircraft due to slow climb rates and the inability to fly evasive manoeuvres. The 'Centreline Low' escorted departure greatly reduced the threat to 16% hit or near miss from 62% for an unescorted heavy aircraft. Overall the CounterSim modelling has showed that escorting a civilian aircraft on approach and departure can reduce the MANPAD threat by 3 to 4 times.

  20. Survivors’ experiences from a train crash

    PubMed Central

    Saveman, Britt-Inger

    2011-01-01

    Rarely described are people's lived experiences from severe injury events such as train crashes. The number of train crashes named disasters with ≥10 killed and/or ≥100 nonfatally injured grows globally and the trend shows that more people survive these disasters today than did so in the past. This results in an increased number of survivors needing care. The aim of the study was to explore survivors’ experiences from a train crash. Narrative interviews were performed with 14 passengers 4 years after a train crash event. Qualitative content analysis was used to analyse the interviews. Experiences were captured in three main themes: (1) Living in the mode of existential threat describes how the survivors first lost control, then were thrown into a state of unimaginable chaos as they faced death. (2) Dealing with the unthinkable described how survivors restored control, the central role of others, and the importance of reconstructing the event to move forward in their processing. (3) Having cheated death shows how some became shackled by their history, whereas others overcame the haunting of unforgettable memories. Furthermore, the result shows how all experienced a second chance in life. Experiencing a train crash meant that the passengers experienced severe vulnerability and a threat to life and interdependence turned out to play a crucial role. Focusing on helping other passengers on site was one way to regain the loss of control and kept the chaos at bay. Family, friends, and fellow passengers turned out to be extremely important during the recovery process why such closeness should be promoted and facilitated. PMID:22125573

  1. Defining and screening crash surrogate events using naturalistic driving data.

    PubMed

    Wu, Kun-Feng; Jovanis, Paul P

    2013-12-01

    Naturalistic driving studies provide an excellent opportunity to better understand crash causality and to supplement crash observations with a much larger number of near crash events. The goal of this research is the development of a set of diagnostic procedures to define, screen, and identify crash and near crash events that can be used in enhanced safety analyses. A way to better understand crash occurrence and identify potential countermeasures to improve safety is to learn from and use near crash events, particularly those near crashes that have a common etiology to crash outcomes. This paper demonstrates that a multi-stage modeling framework can be used to search through naturalistic driving data, extracting statistically similar crashes and near crashes. The procedure is tested using data from the VTTI 100-car study for road departure events. A total of 63 events are included in this application. While the sample size is limited in this empirical study, the authors believe the procedure is ready for testing in other applications. PMID:23177902

  2. Characteristics of the Injury Environment in Far-Side Crashes

    PubMed Central

    Digges, K.; Gabler, H; Mohan, P.; Alonso, B.

    2005-01-01

    The population of occupants in far-side crashes that are documented in the US National database (NASS/CDS) was studied. The annual number of front seat occupants with serious or fatal injuries in far-side planar and rollover crashes was 17,194. The crash environment that produces serious and fatal injuries to belted front seat occupants in planar far-side crashes was investigated in detail. It was found that both the change in velocity and extent of damage were important factors that relate to crash severity. The median severity for crashes with serious or fatal injuries was a lateral delta-V of 28 kph and an extent of damage of CDC 3.6. Vehicle-to-vehicle impacts were simulated by finite element models to determine the intrusion characteristics associated with the median crash condition. These simulations indicated that the side damage caused by the IIHS barrier was representative of the damage in crashes that produce serious injuries in far-side crashes. Occupant simulations of the IIHS barrier crash at 28 kph showed that existing dummies lack biofidelity in upper body motion. The analysis suggested test conditions for studying far-side countermeasures and supported earlier studies that showed the need for an improved dummy to evaluate safety performance in the far-side crash environment. PMID:16179148

  3. How similar are two-unit bicycle and motorcycle crashes?

    PubMed

    Haworth, Narelle; Debnath, Ashim Kumar

    2013-09-01

    This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation. PMID:23689202

  4. Real World Crash Evaluation of Vehicle Stability Control (VSC) Technology

    PubMed Central

    Bahouth, G.

    2005-01-01

    This study quantifies the effect of Vehicle Stability Control (VSC) in reducing crash involvement rates for a subset of vehicles in the US fleet. Crash rates for a variety of impact types before and after VSC technology was implemented are compared. Police-reported crashes from six available US state files from 1998–2002 were analyzed including 13,987 crash-involved study vehicles not equipped with the technology and 5,671 crashes of vehicles equipped with VSC as a standard feature. Overall, an 11.2% (95% CI: 2.4%, 21.1%) reduction in multi-vehicle frontal crash involvement was identified for VSC-equipped vehicles. A 52.6% (95% CI: 42.5%, 62.7%) reduction in single-vehicle crash rates was found. PMID:16179137

  5. Hitting and trapping times on branched structures.

    PubMed

    Agliari, Elena; Sartori, Fabio; Cattivelli, Luca; Cassi, Davide

    2015-05-01

    In this work we consider a simple random walk embedded in a generic branched structure and we find a close-form formula to calculate the hitting time H(i,f) between two arbitrary nodes i and j. We then use this formula to obtain the set of hitting times {H(i,f)} for combs and their expectation values, namely, the mean first-passage time, where the average is performed over the initial node while the final node f is given, and the global mean first-passage time, where the average is performed over both the initial and the final node. Finally, we discuss applications in the context of reaction-diffusion problems. PMID:26066144

  6. Probability of Brownian motion hitting an obstacle

    SciTech Connect

    Knessl, C.; Keller, J.B.

    2000-02-01

    The probability p(x) that Brownian motion with drift, starting at x, hits an obstacle is analyzed. The obstacle {Omega} is a compact subset of R{sup n}. It is shown that p(x) is expressible in terms of the field U(x) scattered by {Omega} when it is hit by plane wave. Therefore results for U(x), and methods for finding U(x) can be used to determine p(x). The authors illustrate this by obtaining exact and asymptotic results for p(x) when {Omega} is a slit in R{sup 2}, and asymptotic results when {Omega} is a disc in R{sup 3}.

  7. Hitting and trapping times on branched structures

    NASA Astrophysics Data System (ADS)

    Agliari, Elena; Sartori, Fabio; Cattivelli, Luca; Cassi, Davide

    2015-05-01

    In this work we consider a simple random walk embedded in a generic branched structure and we find a close-form formula to calculate the hitting time H (i ,f ) between two arbitrary nodes i and j . We then use this formula to obtain the set of hitting times {H (i,f)} for combs and their expectation values, namely, the mean first-passage time, where the average is performed over the initial node while the final node f is given, and the global mean first-passage time, where the average is performed over both the initial and the final node. Finally, we discuss applications in the context of reaction-diffusion problems.

  8. A model of traffic crashes in New Zealand.

    PubMed

    Scuffham, P A; Langley, J D

    2002-09-01

    The aim of this study was to examine the changes in the trend and seasonal patterns in fatal crashes in New Zealand in relation to changes in economic conditions between 1970 and 1994. The Harvey and Durbin (Journal of the Royal Statistical Society 149 (3) (1986) 187-227) structural time series model (STSM), an 'unobserved components' class of model, was used to estimate models for quarterly fatal traffic crashes. The dependent variable was modelled as the number of crashes and three variants of the crash rate (crashes per 10,000 km travelled, crashes per 1,000 vehicles, and crashes per 1000 population). Independent variables included in the models were unemployment rate (UER), real gross domestic product per capita, the proportion of motorcycles, the proportion of young males in the population, alcohol consumption per capita, the open road speed limit, and dummy variables for the 1973 and 1979 oil crises and seat belt wearing laws. UERs, real GDP per capita, and alcohol consumption were all significant and important factors in explaining the short-run dynamics of the models. In the long-run, real GDP per capita was directly related to the number of crashes but after controlling for distance travelled was not significant. This suggests increases in income are associated with a short-run reduction in risk but increases in exposure to a crash (i.e. distance travelled) in the long-run. A 1% increase in the open road speed limit was associated with a long-run 0.5% increase in fatal crashes. Substantial reductions in fatal crashes were associated with the 1979 oil crisis and seat belt wearing laws. The 1984 universal seat belt wearing law was associated with a sustained 15.6% reduction in fatal crashes. These road policy factors appeared to have a greater influence on crashes than the role of demographic and economic factors. PMID:12214962

  9. Database improvements for motor vehicle/bicycle crash analysis

    PubMed Central

    Lusk, Anne C; Asgarzadeh, Morteza; Farvid, Maryam S

    2015-01-01

    Background Bicycling is healthy but needs to be safer for more to bike. Police crash templates are designed for reporting crashes between motor vehicles, but not between vehicles/bicycles. If written/drawn bicycle-crash-scene details exist, these are not entered into spreadsheets. Objective To assess which bicycle-crash-scene data might be added to spreadsheets for analysis. Methods Police crash templates from 50 states were analysed. Reports for 3350 motor vehicle/bicycle crashes (2011) were obtained for the New York City area and 300 cases selected (with drawings and on roads with sharrows, bike lanes, cycle tracks and no bike provisions). Crashes were redrawn and new bicycle-crash-scene details were coded and entered into the existing spreadsheet. The association between severity of injuries and bicycle-crash-scene codes was evaluated using multiple logistic regression. Results Police templates only consistently include pedal-cyclist and helmet. Bicycle-crash-scene coded variables for templates could include: 4 bicycle environments, 18 vehicle impact-points (opened-doors and mirrors), 4 bicycle impact-points, motor vehicle/bicycle crash patterns, in/out of the bicycle environment and bike/relevant motor vehicle categories. A test of including these variables suggested that, with bicyclists who had minor injuries as the control group, bicyclists on roads with bike lanes riding outside the lane had lower likelihood of severe injuries (OR, 0.40, 95% CI 0.16 to 0.98) compared with bicyclists riding on roads without bicycle facilities. Conclusions Police templates should include additional bicycle-crash-scene codes for entry into spreadsheets. Crash analysis, including with big data, could then be conducted on bicycle environments, motor vehicle potential impact points/doors/mirrors, bicycle potential impact points, motor vehicle characteristics, location and injury. PMID:25835304

  10. Visual factors in hitting and catching.

    PubMed

    Regan, D

    1997-12-01

    To hit or catch an approaching ball, it is necessary to move a bat or hand to the right place at the right time. The performance of top sports players is remarkable: positional errors of less than 5 cm and temporal errors of less than 2 or 3 ms are reliably maintained. There are three schools of thought about how this is achieved. One holds that predictive visual information about where the ball will be at some future instance (when) is used to achieve the hit or catch. The second holds that the bat or hand is moved to the correct position by exploiting some relation between visual information and the required movement. The third focuses on the use of prior knowledge to supplement inadequate visual information. For a rigid spherical ball travelling at constant speed along or close to the line of sight, the retinal images contain both binocular and monocular correlates of the ball's instantaneous direction of motion in depth. Also, the retinal images contain both binocular and monocular information about time of arrival. Humans can unconfound and use this visual information, but they are unable to estimate the absolute distance of the ball or its approach speed other than crudely. In cricket, this visual inadequacy allows a slow bowler to cause the batsman to misjudge where the ball will hit the ground. Such a bowler uses a three-pronged strategy: first, to deliver the ball in such a way as to prevent the batsman from obtaining the necessary visual information until it is too late to react; secondly, to force the batsman to rely entirely on inadequate retinal image information; thirdly, to allow the batsman to learn a particular relationship between the early part of the ball's flight and the point where the ball hits the ground, and then to change the relationship with such skill that the batsman does not detect the change. PMID:9486432

  11. Boolean computation of optimum hitting sets

    SciTech Connect

    Hulme, B.L.; Baca, L.S.; Shiver, A.W.; Worrell, R.B.

    1984-04-01

    This report presents the results of computational experience in solving weighted hitting set problems by Boolean algebraic methods. The feasible solutions are obtained by Boolean formula manipulations, and the optimum solutions are obtained by comparing the weight sums of the feasible solutions. Both the algebra and the optimization can be accomplished using the SETS language. One application is to physical protection problems. 8 references, 2 tables.

  12. Rollover crashes: predicting serious injury based on occupant, vehicle, and crash characteristics.

    PubMed

    Conroy, Carol; Hoyt, David B; Eastman, A Brent; Erwin, Steve; Pacyna, Sharon; Holbrook, Troy Lisa; Vaughan, Teresa; Sise, Michael; Kennedy, Frank; Velky, Tom

    2006-09-01

    The purpose of this research was to determine occupant, vehicle, and crash characteristics predicting serious injury during rollover crashes. We compared 27 case occupants with serious or greater severity injuries with 606 control occupants without injury or with only minor or moderate injury. Odds ratios (OR) for individual variables and logistic regression were used to identify predictive variables for serious injury associated with rollovers. Cases more often had thorax, spine, or head injury compared to controls that more often had extremity injuries. Intrusion (especially roof rail or B-pillar intrusion) at the occupant's position, the vehicle interior side and roof as sources of injury, and improper safety belt use were significantly associated with serious injury. Even when safety belt use or proper use was controlled for, occupants with greater magnitude of intrusion at their seat position were about 10 times more likely to receive serious injury. Although prevention of rollover crashes is the ultimate goal, it is important to develop safer vehicles and safety systems to better protect occupants who are involved in rollover crashes. This also requires improvement in data collection systems documenting these types of crashes. PMID:16540073

  13. Explaining Differences in Crash and Injury Crash Outcomes in Red Light Camera Studies.

    PubMed

    Langland-Orban, Barbara; Pracht, Etienne E; Large, John T; Zhang, Nanhua; Tepas, Joseph T

    2016-06-01

    Evaluations of red light camera (RLC) traffic safety programs have produced mixed results. Some conclude RLCs were associated with significant increases in motor vehicle crashes and injury crashes, whereas other research reports safety benefits. To understand the difference in findings, the present analysis assessed whether standards required for internal validity in quasi-experimental public health program evaluations were adhered to in frequently cited RLC analyses. Four evaluation standards were identified and used to assess the RLC analyses: lack of bias in the selection of both (a) treated sites and (b) comparison sites, (c) integration of relevant control variables in the analysis, and (d) full disclosure of results of the statistical analysis. Six leading RLC studies were then critiqued. Only two of the six studies adhered to the four standards and both concluded RLCs were associated with significant increases in crashes and injury or possible injury crashes. A third study reported an increase in fatal/injury crashes but did not test for statistical significance. Three studies reported equivocal findings; however, each failed to adhere to most standards. Differences in findings were attributed to the evaluation methods used. If implementing an RLC program, communities should use sound public health evaluation methods to assess effectiveness. PMID:25007792

  14. Predicting severe head injury after light motor vehicle crashes: implications for automatic crash notification systems.

    PubMed

    Talmor, Daniel; Thompson, Kimberly M; Legedza, Anna T R; Nirula, Ram

    2006-07-01

    Motor vehicle crashes (MVC) are a leading public health problem. Improving notification times and the ability to predict which crashes will involve severe injuries may improve trauma system utilization. This study was undertaken to develop and validate a model to predict severe head injury following MVC using information readily incorporated into an automatic crash notification system. A cross-sectional study with derivation and validation sets was performed. The cohort was drawn from drivers of vehicles involved in MVC obtained from the National Automotive Sampling System (NASS). Independent multivariable predictors of severe head injury were identified. The model was able to stratify drivers according to their risk of severe head injury indicating its validity. The areas under the receiver-operating characteristic (ROC) curves were 0.7928 in the derivation set and 0.7940 in the validation set. We have developed a prediction model for head injury in MVC. As the development of automatic crash notification systems improves, models such as this one will be necessary to permit triage of what would be an overwhelming increase in crash notifications to pre-hospital responders. PMID:16530717

  15. Hitting a baseball: a biomechanical description.

    PubMed

    Welch, C M; Banks, S A; Cook, F F; Draovitch, P

    1995-11-01

    A tremendous amount of time and energy has been dedicated to the development of conditioning programs, mechanics drills, and rehabilitation protocols for the throwing athlete. In comparison, a significantly smaller amount has been spent on the needs of the hitting athlete. Before these needs can be addressed, an understanding of mechanics and the demands placed on the body during the swing must be developed. This study uses three-dimensional kinematic and kinetic data to define and quantify biomechanics during the baseball swing. The results show that a hitter starts the swing with a weight shift toward the rear foot and the generation of trunk coil. As the hitter strides forward, force applied by the front foot equal to 123% of body weight promotes segment acceleration around the axis of the trunk. The hip segment rotates to a maximum speed of 714 degrees/sec followed by a maximum shoulder segment velocity of 937 degrees/sec. The product of this kinetic link is a maximum linear bat velocity of 31 m/sec. By quantifying the hitting motion, a more educated approach can be made in developing rehabilitation, strength, and conditioning programs for the hitting athlete. PMID:8580946

  16. Dynamic model for automotive side impact crashes

    NASA Astrophysics Data System (ADS)

    Sun, Ludong; Taghvaeeyan, Saber; Rajamani, Rajesh

    2014-07-01

    A rigid body model to represent a side impact crash is constructed using five degrees-of-freedom (dof) for the vehicle and three dof for each occupant in the vehicle. Nonlinear stiffness and damping elements and the presence of physical gaps between several components make the model highly nonlinear. The model is validated using experimental crash test data from a National Highway Traffic Safety Administration (NHTSA) database. To simplify the parameter identification process and reduce the number of parameters to be identified at each stage, a two-step process is adopted in which the vehicle is first assumed to be unaffected by the presence of the occupants, and its model parameters are identified. Subsequently, the parameters in the occupant models are identified. The active set method with a performance index that includes both the L2 and L∞ norms is used for parameter identification. A challenge is posed by the fact that the optimisation problem involved is non-convex. To overcome this challenge, a large set of random initial values of parameter estimates is generated and the optimisation method is applied with all these initial conditions. The values of parameters that provide the minimal performance index from the entire set of initial conditions are then chosen as the best parameter values. The optimal parameters values thus identified are shown to significantly improve the match between the model responses and the experimentally measured sensor signals from the NHTSA crash test.

  17. Modeling situation awareness and crash risk.

    PubMed

    Fisher, Donald L; Strayer, David L

    2014-01-01

    In this article we develop a model of the relationship between crash risk and a driver's situation awareness. We consider a driver's situation awareness to reflect the dynamic mental model of the driving environment and to be dependent upon several psychological processes including Scanning the driving environment, Predicting and anticipating hazards, Identifying potential hazards in the driving scene as they occur, Deciding on an action, and Executing an appropriate Response (SPIDER). Together, SPIDER is important for establishing and maintaining good situation awareness of the driving environment and good situation awareness is important for coordinating and scheduling the SPIDER-relevant processes necessary for safe driving. An Order-of-Processing (OP) model makes explicit the SPIDER-relevant processes and how they predict the likelihood of a crash when the driver is or is not distracted by a secondary task. For example, the OP model shows how a small decrease in the likelihood of any particular SPIDER activity being completed successfully (because of a concurrent secondary task performance) would lead to a large increase in the relative risk of a crash. PMID:24776225

  18. Safer Roadside Crash Walls Would Limit Deceleration

    NASA Technical Reports Server (NTRS)

    Schneider, William C.; Locke, James P.

    2003-01-01

    The figure depicts the aspects of a proposed deceleration-limiting design for crash walls at the sides of racetracks and highways. The proposal is intended to overcome the disadvantages of both rigid barriers and kinetic-energy-absorbing barriers of prior design. Rigid barriers can keep high-speed crashing motor vehicles from leaving roadways and thereby prevent injury to nearby persons and objects, but they can also subject the occupants of the vehicles to deceleration levels high enough to cause injury or death. Kinetic-energy-absorbing barriers of prior design reduce deceleration levels somewhat, but are not designed to soften impacts optimally; moreover, some of them allow debris to bounce back onto roadways or onto roadside areas, and, in cases of glancingly incident vehicles, some of them can trap the vehicles in such a manner as to cause more injury than would occur if the vehicles were allowed to skid along the rigid barriers. The proposed crash walls would (1) allow tangentially impacting vehicles to continue sliding along the racetrack without catching them, (2) catch directly impacting vehicles to prevent them from injuring nearby persons and objects, and (3) absorb kinetic energy in a more nearly optimum way to limit decelerations to levels that human occupants could survive.

  19. Modeling Situation Awareness and Crash Risk

    PubMed Central

    Fisher, Donald L.; Strayer, David. L.

    2014-01-01

    In this article we develop a model of the relationship between crash risk and a driver’s situation awareness. We consider a driver’s situation awareness to reflect the dynamic mental model of the driving environment and to be dependent upon several psychological processes including Scanning the driving environment, Predicting and anticipating hazards, Identifying potential hazards in the driving scene as they occur, Deciding on an action, and Executing an appropriate Response (SPIDER). Together, SPIDER is important for establishing and maintaining good situation awareness of the driving environment and good situation awareness is important for coordinating and scheduling the SPIDER-relevant processes necessary for safe driving. An Order-of-Processing (OP) model makes explicit the SPIDER-relevant processes and how they predict the likelihood of a crash when the driver is or is not distracted by a secondary task. For example, the OP model shows how a small decrease in the likelihood of any particular SPIDER activity being completed successfully (because of a concurrent secondary task performance) would lead to a large increase in the relative risk of a crash. PMID:24776225

  20. The Stock Market Crashes of 1929 and 1987: Linking History and Personal Finance Education

    ERIC Educational Resources Information Center

    Lopus, Jane S.

    2005-01-01

    This article discusses two twentieth-century stock market crashes: the crash of 1929 and the crash of 1987. When this material is presented to students, they see important parallels between the two historical events. But despite remarkable similarities in the severity and many other aspects of the two crashes, the crash of 1929 was followed by the…

  1. Identifying Critical Road Geometry Parameters Affecting Crash Rate and Crash Type

    PubMed Central

    Othman, Sarbaz; Thomson, Robert; Lannér, Gunnar

    2009-01-01

    The objective of this traffic safety investigation was to find critical road parameters affecting crash rate (CR). The study was based on crash and road maintenance data from Western Sweden. More than 3000 crashes, reported from 2000 to 2005 on median-separated roads, were collected and combined with road geometric and surface data. The statistical analysis showed variations in CR when road elements changed confirming that road characteristics affect CR. The findings indicated that large radii right-turn curves were more dangerous than left curves, in particular, during lane changing manoeuvres. However sharper curves are more dangerous in both left and right curves. Moreover, motorway carriageways with no or limited shoulders have the highest CR when compared to other carriageway widths, while one lane carriageway sections on 2+1 roads were the safest. Road surface results showed that both wheel rut depth and road roughness have negative impacts on traffic safety. PMID:20184841

  2. A tree-structured crash surrogate measure for freeways.

    PubMed

    Kuang, Yan; Qu, Xiaobo; Wang, Shuaian

    2015-04-01

    In this paper, we propose a novel methodology to define and estimate a surrogate measure. By imposing a hypothetical disturbance to the leading vehicle, the following vehicle's action is represented as a probabilistic causal model. After that, a tree is built to describe the eight possible conflict types under the model. The surrogate measure, named Aggregated Crash Index (ACI), is thus proposed to measure the crash risk. This index reflects the accommodability of freeway traffic state to a traffic disturbance. We further apply this measure to evaluate the crash risks in a freeway section of Pacific Motorway, Australia. The results show that the proposed indicator outperforms the three traditional crash surrogate measures (i.e., Time to Collision, Proportion of Stopping Distance, and Crash Potential Index) in representing rear-end crash risks. The applications of this measure are also discussed. PMID:25710638

  3. STOL Aircraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Michael E. Fisher, President of AeroVisions International, has introduced the Culex light twin engine aircraft which offers economy of operation of a single engine plane, the ability to fly well on one engine, plus the capability of flying from short, unimproved fields of takeoff and landing distances less than 35 feet. Key element of design is an airfoil developed by Langley. Culex was originally intended to be factory built aircraft for special utility markets. However, it is now offered as a build-it-yourself kit plane.

  4. Relating crash frequency and severity: evaluating the effectiveness of shoulder rumble strips on reducing fatal and major injury crashes.

    PubMed

    Wu, Kun-Feng; Donnell, Eric T; Aguero-Valverde, Jonathan

    2014-06-01

    To approach the goal of "Toward Zero Deaths," there is a need to develop an analysis paradigm to better understand the effects of a countermeasure on reducing the number of severe crashes. One of the goals in traffic safety research is to search for an effective treatment to reduce fatal and major injury crashes, referred to as severe crashes. To achieve this goal, the selection of promising countermeasures is of utmost importance, and relies on the effectiveness of candidate countermeasures in reducing severe crashes. Although it is important to precisely evaluate the effectiveness of candidate countermeasures in reducing the number of severe crashes at a site, the current state-of-the-practice often leads to biased estimates. While there have been a few advanced statistical models developed to mitigate the problem in practice, these models are computationally difficult to estimate because severe crashes are dispersed spatially and temporally, and cannot be integrated into the Highway Safety Manual framework, which develops a series of safety performance functions and crash modification factors to predict the number of crashes. Crash severity outcomes are generally integrated into the Highway Safety Manual using deterministic distributions rather than statistical models. Accounting for the variability in crash severity as a function geometric design, traffic flow, and other roadway and roadside features is afforded by estimating statistical models. Therefore, there is a need to develop a new analysis paradigm to resolve the limitations in the current Highway Safety Manual methods. We propose an approach which decomposes the severe crash frequency into a function of the change in the total number of crashes and the probability of a crash becoming a severe crash before and after a countermeasure is implemented. We tested this approach by evaluating the effectiveness of shoulder rumble strips on reducing the number of severe crashes. A total of 310 segments that have

  5. Natural laminar flow hits smoother air

    NASA Technical Reports Server (NTRS)

    Holmes, B. J.

    1985-01-01

    Natural laminar flow (NLF) may be attained in aircraft with lower cost, weight, and maintenance penalties than active flow laminarization by means of a slot suction system. A high performance general aviation jet aircraft possessing a moderate degree of NLF over wing, fuselage, empennage and engine nacelles will accrue a 24 percent reduction in total aircraft drag in the cruise regime. NASA-Langley has conducted NLF research centered on the use of novel airfoil profiles as well as composite and milled aluminum alloy construction methods which minimize three-dimensional aerodynamic surface roughness and waviness. It is noted that higher flight altitudes intrinsically reduce unit Reynolds numbers, thereby minimizing turbulence for a given cruise speed.

  6. Crash Culpability and the Role of Driver Blood Alcohol Levels

    PubMed Central

    Kufera, Joseph A.; Soderstrom, Carl A.; Dischinger, Patricia C.; Ho, Shiu M.; Shepard, Angela

    2006-01-01

    Twenty years ago the American Medical Association reported the relationship between blood alcohol concentration (BAC) and crash causation. This study addresses culpability, age, gender and BAC in a population of drivers injured in motor vehicle crashes. Five years of hospital and crash data were linked, using probabilistic techniques. Trends in culpability were analyzed by BAC category. Given BAC level, the youngest and oldest drivers were more likely to have caused their crash. Women drivers had significantly higher odds of culpability at the highest BAC levels. Seatbelt use was also associated with culpability, perhaps as a marker for risk-taking among drinkers. PMID:16968631

  7. Older driver population and crash involvement trends, 1974-1988.

    PubMed

    Stutts, J C; Martell, C

    1992-08-01

    North Carolina motor vehicle crash data for even-numbered years 1974-1988, inclusive, are analyzed in conjunction with North Carolina population, licensed driver, and mileage data to examine trends in motor vehicle crash involvement by driver age, sex, and race. Crash rates per licensed driver are presented along with crash rates per estimated vehicle miles travelled calculated on the basis of induced exposure. Results focus particularly on older drivers. They show that older drivers' representation in the licensed driver population has increased at a greater rate than their representation in either the census or crash involvement populations. These trends are particularly strong for females and for nonwhites. Furthermore, crash rates have declined more for drivers aged 55 and older than for younger drivers. The greatest declines, both in terms of crashes per licensed driver and crashes per estimated miles travelled, have been experienced by drivers age 65 and older, particularly nonwhites. Males show higher overall crash rates per miles travelled than females, but this effect decreases with age and disappears entirely in the oldest age categories. Results are discussed in light of the changing nature of the overall driving population and the cohort of older drivers in particular. PMID:1605814

  8. Development of crashworthy passenger seats for general-aviation aircraft

    NASA Technical Reports Server (NTRS)

    Reilly, M. J.; Tanner, A. E.

    1979-01-01

    Two types of energy absorbing passenger seat concepts suitable for installation in light twin-engine fixed wing aircraft were developed. An existing passenger seat for such an aircraft was used to obtain the envelope constraints. Ceiling suspended and floor supported seat concept designs were developed. A restraint system suitable for both concepts was designed. Energy absorbing hardware for both concepts was fabricated and tension and compression tests were conducted to demonstrate the stroking capability and the force deflection characteristics. Crash impact analysis was made and seat loads developed. The basic seat structures were analyzed to determine the adequacy of their strength under impact loading.

  9. Aircraft cybernetics

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  10. Health Information Technology Knowledge and Skills Needed by HIT Employers

    PubMed Central

    Fenton, S.H.; Gongora-Ferraez, M.J.; Joost, E.

    2012-01-01

    Objective To evaluate the health information technology (HIT) workforce knowledge and skills needed by HIT employers. Methods Statewide face-to-face and online focus groups of identified HIT employer groups in Austin, Brownsville, College Station, Dallas, El Paso, Houston, Lubbock, San Antonio, and webinars for rural health and nursing informatics. Results HIT employers reported needing an HIT workforce with diverse knowledge and skills ranging from basic to advanced, while covering information technology, privacy and security, clinical practice, needs assessment, contract negotiation, and many other areas. Consistent themes were that employees needed to be able to learn on the job and must possess the ability to think critically and problem solve. Many employers wanted persons with technical skills, yet also the knowledge and understanding of healthcare operations. Conclusion The HIT employer focus groups provided valuable insight into employee skills needed in this fast-growing field. Additionally, this information will be utilized to develop a statewide HIT workforce needs assessment survey. PMID:23646090

  11. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    PubMed

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  12. Female involvement in U.S. nonfatal crashes under a three-level hierarchical crash model.

    PubMed

    Kelley-Baker, Tara; Romano, Eduardo

    2010-11-01

    Men have long held the lead in motor-vehicle crashes; however, research indicates that women are closing the gap. To further investigate this problem, we applied a hierarchical model to investigate female involvement in fatal crashes in the United States. The hierarchical model recognizes that decisions at higher levels affect the decisions at lower levels. At the top level, the model assumes that the driver's condition (e.g., inattention, fatigue, impairment) affects the next level (e.g., speeding or other failures to obey traffic laws), which subsequently affects the basic maneuvering skills (i.e., the lowest level) were either nonexistent, or largely explained by gender differences in alcohol consumption. We found that although female involvement in skill-related crashes was not different from that of males, females were more likely than males to apply wrong maneuvers when speeding was involved. We also found that the most important contributing factor to gender differences in nonfatal crashes can be traced back to gender-based differences in alcohol consumption. PMID:20728655

  13. Planar impacts in rollover crashes: significance, distribution and injury epidemiology.

    PubMed

    Bose, Dipan; Kerrigan, Jason R; Foster, Jonathan B; Crandall, Jeff R; Tobaru, Shigeo

    2011-01-01

    While one third of all fatal motor vehicle crashes involve rollover of the vehicle, a substantially large portion of these rollover crashes involve planar impacts (e.g., frontal, side or rear impact) that influence the crash kinematics and subsequently the injury outcome. The objective of the study was to evaluate the distribution of planar impacts in rollover crashes, and in particular, to describe the differences in the underlying crash kinematics, injury severity and the regional distribution of injuries when compared to the rollover-dominated crashes without significant planar impact (i.e., primary rollovers). Sampled cases (n=6,900) from the U.S. National Automotive Sampling System - Crashworthiness Data System, representing approximately 3.3 million belted drivers involved in a rollover crash in years 1998-2008, were analyzed. Single vehicle rollover crashes with significant planar impact (21% of all rollover crashes) were in general more likely to result in occupant fatality and involved higher incidence of moderate to severe injuries compared to single vehicle primary rollovers (p<0.05). A substantial proportion of the planar impact rollovers ended in single quarter turn crashes (30%), mostly resulting from a frontal impact (59%). While chest was the most frequently injured body region among all rollover victims sustaining severe injuries, severe injuries sustained in primary rollovers were more isolated (single body region) in comparison to the ones sustained in rollovers with planar impacts. The results emphasize the higher risk of rollover victims sustaining an injury and the differences in distribution of injuries sustained when a planar impact is associated with the rollover crash. PMID:22105400

  14. Planar Impacts in Rollover Crashes: Significance, Distribution and Injury Epidemiology

    PubMed Central

    Bose, Dipan; Kerrigan, Jason R.; Foster, Jonathan B.; Crandall, Jeff R.; Tobaru, Shigeo

    2011-01-01

    While one third of all fatal motor vehicle crashes involve rollover of the vehicle, a substantially large portion of these rollover crashes involve planar impacts (e.g., frontal, side or rear impact) that influence the crash kinematics and subsequently the injury outcome. The objective of the study was to evaluate the distribution of planar impacts in rollover crashes, and in particular, to describe the differences in the underlying crash kinematics, injury severity and the regional distribution of injuries when compared to the rollover-dominated crashes without significant planar impact (i.e., primary rollovers). Sampled cases (n=6,900) from the U.S. National Automotive Sampling System – Crashworthiness Data System, representing approximately 3.3 million belted drivers involved in a rollover crash in years 1998–2008, were analyzed. Single vehicle rollover crashes with significant planar impact (21% of all rollover crashes) were in general more likely to result in occupant fatality and involved higher incidence of moderate to severe injuries compared to single vehicle primary rollovers (p<0.05). A substantial proportion of the planar impact rollovers ended in single quarter turn crashes (30%), mostly resulting from a frontal impact (59%). While chest was the most frequently injured body region among all rollover victims sustaining severe injuries, severe injuries sustained in primary rollovers were more isolated (single body region) in comparison to the ones sustained in rollovers with planar impacts. The results emphasize the higher risk of rollover victims sustaining an injury and the differences in distribution of injuries sustained when a planar impact is associated with the rollover crash. PMID:22105400

  15. Cutaneous presentation of Double Hit Lymphoma

    PubMed Central

    Khelfa, Yousef; Lebowicz, Yehuda

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), representing approximately 25% of diagnosed NHL. DLBCL is heterogeneous disease both clinically and genetically. The 3 most common chromosomal translocations in DLBCL involve the oncogenes BCL2, BCL6, and MYC. Double hit (DH) DLBCL is an aggressive form in which MYC rearrangement is associated with either BCL2 or BCL6 rearrangement. Patients typically present with a rapidly growing mass, often with B symptoms. Extranodal disease is often present. Though there is a paucity of prospective trials in this subtype, double hit lymphoma (DHL) has been linked to very poor outcomes when patients are treated with standard R-CHOP. There is, therefore, a lack of consensus regarding the standard treatment for DHL. Several retrospective analyses have been conducted to help guide treatment of this disease. These suggest that DA EPOCH-R may be the most promising regimen and that achievement of complete resolution predicts better long-term outcomes. PMID:27115017

  16. 77 FR 32639 - HIT Standards Committee and HIT Policy Committee; Call for Nominations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... Committee was established under the American Recovery and Reinvestment ] Act 2009 (ARRA)(Pub. L. 111-5... participating in payment reform initiatives, accountable care organizations, pharmacists, behavioral health.... The HIT Policy Committee was established under the American Recovery and Reinvestment Act 2009...

  17. HitKeeper, a generic software package for hit list management

    PubMed Central

    Hau, Jörg; Muller, Michael; Pagni, Marco

    2007-01-01

    Background The automated annotation of biological sequences (protein, DNA) relies on the computation of hits (predicted features) on the sequences using various algorithms. Public databases of biological sequences provide a wealth of biological "knowledge", for example manually validated annotations (features) that are located on the sequences, but mining the sequence annotations and especially the predicted and curated features requires dedicated tools. Due to the heterogeneity and diversity of the biological information, it is difficult to handle redundancy, frequent updates, taxonomic information and "private" data together with computational algorithms in a common workflow. Results We present HitKeeper, a software package that controls the fully automatic handling of multiple biological databases and of hit list calculations on a large scale. The software implements an asynchronous update system that introduces updates and computes hits as soon as new data become available. A query interface enables the user to search sequences by specifying constraints, such as retrieving sequences that contain specific motifs, or a defined arrangement of motifs ("metamotifs"), or filtering based on the taxonomic classification of a sequence. Conclusion The software provides a generic and modular framework to handle the redundancy and incremental updates of biological databases, and an original query language. It is published under the terms and conditions of version 2 of the GNU Public License and available at . PMID:17391514

  18. 77 FR 23250 - HIT Standards Committee; Schedule for the Assessment of HIT Policy Committee Recommendations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... timeline, which may also account for NIST testing, where appropriate, and include dates when the HIT... timeline provided by the subcommittee, and, if necessary, revise it; and (2) Assign subcommittee(s) to... in a timely manner. (C) Advise the National Coordinator, consistent with the accepted timeline in...

  19. 76 FR 25355 - HIT Standards Committee; Schedule for the Assessment of HIT Policy Committee Recommendations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... gaps; and (3) A timeline, which may also account for NIST testing, where appropriate, and include dates...) Upon receipt of a subcommittee report, the HIT Standards Committee will: (1) Accept the timeline... timely manner. (C) Advise the National Coordinator, consistent with the accepted timeline in (B)(1)...

  20. Effect of bus size and operation to crash occurrences.

    PubMed

    Chimba, Deo; Sando, Thobias; Kwigizile, Valerian

    2010-11-01

    This paper evaluates roadway and operational factors considered to influence crashes involving buses. Factors evaluated included those related to bus sizes and operation services. Negative binomial (NB) and multinomial logit (MNL) models were used in linearizing and quantifying these factors with respect to crash frequency and injury severities, respectively. The results showed that position of the bus travel lane, presence or absence of on-street shoulder parking, posted speed limit, lane width, median width, number of lanes per direction and number of vehicles per lane has a higher influence on bus crashes compared to other roadway and traffic factors. Wider lanes and medians were found to reduce probability of bus crashes while more lanes and higher volume per lane were found to increase the likelihood of occurrences of bus-related crashes. Roadways with higher posted speed limits excluding freeways were found to have high probability of crashes compared to low speed limit roadways. Buses traveling on the inner lanes and making left turns were found to have higher probability of crashes compared to those traveling on the right most lanes. The same factors were found to influence injury severity though with varying magnitudes compared to crash frequency. PMID:20728663

  1. Innovative Anti Crash Absorber for a Crashworthy Landing Gear

    NASA Astrophysics Data System (ADS)

    Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano

    2014-06-01

    This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.

  2. Analyzing angle crashes at unsignalized intersections using machine learning techniques.

    PubMed

    Abdel-Aty, Mohamed; Haleem, Kirolos

    2011-01-01

    A recently developed machine learning technique, multivariate adaptive regression splines (MARS), is introduced in this study to predict vehicles' angle crashes. MARS has a promising prediction power, and does not suffer from interpretation complexity. Negative Binomial (NB) and MARS models were fitted and compared using extensive data collected on unsignalized intersections in Florida. Two models were estimated for angle crash frequency at 3- and 4-legged unsignalized intersections. Treating crash frequency as a continuous response variable for fitting a MARS model was also examined by considering the natural logarithm of the crash frequency. Finally, combining MARS with another machine learning technique (random forest) was explored and discussed. The fitted NB angle crash models showed several significant factors that contribute to angle crash occurrence at unsignalized intersections such as, traffic volume on the major road, the upstream distance to the nearest signalized intersection, the distance between successive unsignalized intersections, median type on the major approach, percentage of trucks on the major approach, size of the intersection and the geographic location within the state. Based on the mean square prediction error (MSPE) assessment criterion, MARS outperformed the corresponding NB models. Also, using MARS for predicting continuous response variables yielded more favorable results than predicting discrete response variables. The generated MARS models showed the most promising results after screening the covariates using random forest. Based on the results of this study, MARS is recommended as an efficient technique for predicting crashes at unsignalized intersections (angle crashes in this study). PMID:21094345

  3. Formulation of the Multi-Hit Model With a Non-Poisson Distribution of Hits

    SciTech Connect

    Vassiliev, Oleg N.

    2012-07-15

    Purpose: We proposed a formulation of the multi-hit single-target model in which the Poisson distribution of hits was replaced by a combination of two distributions: one for the number of particles entering the target and one for the number of hits a particle entering the target produces. Such an approach reflects the fact that radiation damage is a result of two different random processes: particle emission by a radiation source and interaction of particles with matter inside the target. Methods and Materials: Poisson distribution is well justified for the first of the two processes. The second distribution depends on how a hit is defined. To test our approach, we assumed that the second distribution was also a Poisson distribution. The two distributions combined resulted in a non-Poisson distribution. We tested the proposed model by comparing it with previously reported data for DNA single- and double-strand breaks induced by protons and electrons, for survival of a range of cell lines, and variation of the initial slopes of survival curves with radiation quality for heavy-ion beams. Results: Analysis of cell survival equations for this new model showed that they had realistic properties overall, such as the initial and high-dose slopes of survival curves, the shoulder, and relative biological effectiveness (RBE) In most cases tested, a better fit of survival curves was achieved with the new model than with the linear-quadratic model. The results also suggested that the proposed approach may extend the multi-hit model beyond its traditional role in analysis of survival curves to predicting effects of radiation quality and analysis of DNA strand breaks. Conclusions: Our model, although conceptually simple, performed well in all tests. The model was able to consistently fit data for both cell survival and DNA single- and double-strand breaks. It correctly predicted the dependence of radiation effects on parameters of radiation quality.

  4. Effect of vehicular size on chain-reaction crash

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-11-01

    We present the dynamic model of the chain-reaction crash to take account of the vehicular size. Drivers brake according to taillights of the forward vehicle. We investigate the effect of the vehicular size on the chain-reaction crash (multiple-vehicle collision) in the traffic flow controlled by taillights. In the multiple-vehicle collision, the first crash induces more collisions. We investigate how the first collision induces the chain-reaction crash numerically. We derive, analytically, the transition points and the region maps for the chain-reaction crash in the traffic flow of vehicles with finite sizes. We clarify the effect of the vehicular size on the multiple-vehicle collision.

  5. Comprehensive and Human Capital Crash Costs by Maximum Police-Reported Injury Severity Within Selected Crash Types

    PubMed Central

    Zaloshnja, Eduard; Miller, Ted; Council, Forrest; Persaud, Bhagwant

    2004-01-01

    This paper presents estimates for both the economic and comprehensive costs per crash for three police-coded severity groupings within 16 selected crash types and within two speed limit categories (<=45 and >=50 mph). The economic costs are hard dollar costs. The comprehensive costs include economic costs and quality of life losses. We merged previously developed costs per victim keyed on the Abbreviated Injury Scale (AIS) into US crash data files that scored injuries in both the AIS and police-coded severity scales to produce per crash estimates. The most costly crashes were non-intersection fatal/disabling injury crashes on a road with a speed limit of 50 miles per hour or higher where multiple vehicles crashed head-on or a single vehicle struck a human (over 1.69 and $1.16 million per crash, respectively). The annual cost of police-reported run-off-road collisions, which include both rollovers and object impacts, represented 34% of total costs. PMID:15319129

  6. Annoyance and acceptability judgements of noise produced by three types of aircraft by residents living near JFK Airport

    NASA Technical Reports Server (NTRS)

    Borsky, P. N.

    1974-01-01

    A random sample of selected communities near JFK Airport were interviewed. Subsamples, with differing feelings of fear of aircraft crashes and different locations of residence were invited to participate in a laboratory experiment. The subjects were exposed to tape recordings of simulated flyovers of aircraft in approach and departure operations at nominal distances from the airport. The subjects judged the extent of noise annoyance and acceptability of the aircraft noises. Results indicate that level of noise is most significant in affecting annoyance judgements. Subjects with feelings of high fear report significantly more annoyance and less acceptability of aircraft noise than subjects with feelings of low fear.

  7. Vanadium Nitrogenase: A Two-Hit Wonder?

    PubMed Central

    Hu, Yilin; Lee, Chi Chung; Ribbe, Markus W.

    2013-01-01

    Nitrogenase catalyzes the biological conversion of atmospheric dinitrogen to bioavailable ammonia. The molybdenum (Mo)- and vanadium (V)-dependent nitrogenases are two homologous members of this metalloenzyme family. However, despite their similarities in structure and function, the characterization of V-nitrogenase has taken a much longer and more winding path than that of its Mo-counterpart. From the initial discovery of this nitrogen-fixing system, to the recent finding of its CO-reducing capacity, V-nitrogenase has proven to be a two-hit wonder in the over-a-century-long research of nitrogen fixation. This perspective provides a brief account of the catalytic function and structural basis of V-nitrogenase, as well as a short discussion of the theoretical and practical potentials of this unique metalloenzyme. PMID:22101422

  8. Vanadium nitrogenase: a two-hit wonder?

    PubMed

    Hu, Yilin; Lee, Chi Chung; Ribbe, Markus W

    2012-01-28

    Nitrogenase catalyzes the biological conversion of atmospheric dinitrogen to bioavailable ammonia. The molybdenum (Mo)- and vanadium (V)-dependent nitrogenases are two homologous members of this metalloenzyme family. However, despite their similarities in structure and function, the characterization of V-nitrogenase has taken a much longer and more winding path than that of its Mo-counterpart. From the initial discovery of this nitrogen-fixing system, to the recent finding of its CO-reducing capacity, V-nitrogenase has proven to be a two-hit wonder in the over-a-century-long research of nitrogen fixation. This perspective provides a brief account of the catalytic function and structural basis of V-nitrogenase, as well as a short discussion of the theoretical and practical potentials of this unique metalloenzyme. PMID:22101422

  9. A Two-Hit Model of Autism: Adolescence as the Second Hit

    PubMed Central

    Picci, Giorgia; Scherf, K. Suzanne

    2015-01-01

    Adolescence brings dramatic changes in behavior and neural organization. Unfortunately, for some 30% of individuals with autism, there is marked decline in adaptive functioning during adolescence. We propose a two-hit model of autism. First, early perturbations in neural development function as a “first hit” that sets up a neural system that is “built to fail” in the face of a second hit. Second, the confluence of pubertal hormones, neural reorganization, and increasing social demands during adolescence provides the “second hit” that interferes with the ability to transition into adult social roles and levels of adaptive functioning. In support of this model, we review evidence about adolescent-specific neural and behavioral development in autism. We conclude with predictions and recommendations for empirical investigation about several domains in which developmental trajectories for individuals with autism may be uniquely deterred in adolescence. PMID:26609500

  10. Modeling Programs Increase Aircraft Design Safety

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the

  11. Daedalus Project's Light Eagle - Human powered aircraft

    NASA Technical Reports Server (NTRS)

    1987-01-01

    autopilot that could be used on high altitude or human powered aircraft, and determining the power required to fly the Daedalus aircraft. The research flights began in late December 1987 with a shake-down of the Light Eagle instrumentation and data transfer links. The first flight of the Daedalus 87 also occurred during this time. On February 7, 1988, the Daedalus 87 aircraft crashed on Rogers Dry Lakebed. The Daedalus 88, which later set the world record, was then shipped from MIT to replace the 87's research flights, and for general checkout procedures. Due to the accident, flight testing was extended four weeks and thus ended in mid-March 1988 after having achieved the major goals of the program; exploring the dynamics of low Reynolds number aircraft, and investigating the aeroelastic behavior of lightweight aircraft. The information obtained from this program had direct applications to the later design of many high-altitude, long endurance aircraft.

  12. A reexamination of the small overlap frontal crash.

    PubMed

    Scullion, Paul; Morgan, Richard M; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 - 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 - 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study-following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC-suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  13. Requirements for the Crash Protection of Older Vehicle Passengers

    PubMed Central

    Morris, Andrew; Welsh, Ruth; Hassan, Ahamedali

    2003-01-01

    This study compares injury outcomes in vehicle crashes involving different age groups of belted passengers. Two datasets were considered. Firstly, UK national data revealed that younger passengers are much more likely to be involved in crashes per million miles travelled compared to older passengers although older passengers are much more likely to be killed or seriously injured compared to younger passengers. Secondly, in-depth vehicle crash injury data were examined to determine some of the underlying reasons for the enhanced injury risk amongst older passengers. In crashes of approximately equal severity, the older passenger group were significantly more likely to be fatally injured in frontal crashes (p<0.001). However young passengers were as equally likely to be killed in struck-side crashes compared to the older group. The results also showed that older passengers sustained more serious injuries to the chest region in frontal crashes compared with the younger aged group (p<0.0001) and it is this body region that is particularly problematic. When the data were analysed further, it was found that a large proportion of passengers were female and that in the majority of cases, the seat belt was responsible for injury. Since by the year 2030, 1 in 4 persons will be aged over 65 in most OECD countries, the results suggest a need for intervention through vehicle design including in-vehicle crashworthiness systems that take into account reduced tolerance to impact with ageing. PMID:12941224

  14. Driver air bag effectiveness by severity of the crash.

    PubMed Central

    Segui-Gomez, M

    2000-01-01

    OBJECTIVES: This analysis provided effectiveness estimates of the driver-side air bag while controlling for severity of the crash and other potential confounders. METHODS: Data were from the National Automotive Sampling System (1993-1996). Injury severity was described on the basis of the Abbreviated Injury Scale, Injury Severity Score, Functional Capacity Index, and survival. Ordinal, linear, and logistic multivariate regression methods were used. RESULTS: Air bag deployment in frontal or near-frontal crashes decreases the probability of having severe and fatal injuries (e.g., Abbreviated Injury Scale score of 4-6), including those causing a long-lasting high degree of functional limitation. However, air bag deployment in low-severity crashes increases the probability that a driver (particularly a woman) will sustain injuries of Abbreviated Injury Scale level 1 to 3. Air bag deployment exerts a net injurious effect in low-severity crashes and a net protective effect in high-severity crashes. The level of crash severity at which air bags are protective is higher for female than for male drivers. CONCLUSIONS: Air bag improvement should minimize the injuries induced by their deployment. One possibility is to raise their deployment level so that they deploy only in more severe crashes. PMID:11029991

  15. External validation of the HIT Expert Probability (HEP) score.

    PubMed

    Joseph, Lee; Gomes, Marcelo P V; Al Solaiman, Firas; St John, Julie; Ozaki, Asuka; Raju, Manjunath; Dhariwal, Manoj; Kim, Esther S H

    2015-03-01

    The diagnosis of heparin-induced thrombocytopenia (HIT) can be challenging. The HIT Expert Probability (HEP) Score has recently been proposed to aid in the diagnosis of HIT. We sought to externally and prospectively validate the HEP score. We prospectively assessed pre-test probability of HIT for 51 consecutive patients referred to our Consultative Service for evaluation of possible HIT between August 1, 2012 and February 1, 2013. Two Vascular Medicine fellows independently applied the 4T and HEP scores for each patient. Two independent HIT expert adjudicators rendered a diagnosis of HIT likely or unlikely. The median (interquartile range) of 4T and HEP scores were 4.5 (3.0, 6.0) and 5 (3.0, 8.5), respectively. There were no significant differences between area under receiver-operating characteristic curves of 4T and HEP scores against the gold standard, confirmed HIT [defined as positive serotonin release assay and positive anti-PF4/heparin ELISA] (0.74 vs 0.73, p = 0.97). HEP score ≥ 2 was 100 % sensitive and 16 % specific for determining the presence of confirmed HIT while a 4T score > 3 was 93 % sensitive and 35 % specific. In conclusion, the HEP and 4T scores are excellent screening pre-test probability models for HIT, however, in this prospective validation study, test characteristics for the diagnosis of HIT based on confirmatory laboratory testing and expert opinion are similar. Given the complexity of the HEP scoring model compared to that of the 4T score, further validation of the HEP score is warranted prior to widespread clinical acceptance. PMID:25588983

  16. Educating with Aircraft Models

    ERIC Educational Resources Information Center

    Steele, Hobie

    1976-01-01

    Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

  17. Overview of the Transport Rotorcraft Airframe Crash Testbed (TRACT) Full Scale Crash Tests

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    The Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate Anthropomorphic Test Devices (ATD) responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 ATDs were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the horizontal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  18. Evaluation of the Second Transport Rotorcraft Airframe Crash Testbed (TRACT 2) Full Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin; Littell, Justin

    2015-01-01

    Two Transport Rotorcraft Airframe Crash Testbed (TRACT) full-scale tests were performed at NASA Langley Research Center's Landing and Impact Research Facility in 2013 and 2014. Two CH-46E airframes were impacted at 33-ft/s forward and 25-ft/s vertical combined velocities onto soft soil, which represents a severe, but potentially survivable impact scenario. TRACT 1 provided a baseline set of responses, while TRACT 2 included retrofits with composite subfloors and other crash system improvements based on TRACT 1. For TRACT 2, a total of 18 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and activation of emergency locator transmitters and crash sensors. Combinations of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. The structural response of the airframe was assessed based on accelerometers located throughout the airframe and using three-dimensional photogrammetric techniques. Analysis of the photogrammetric data indicated regions of maximum deflection and permanent deformation. The response of TRACT 2 was noticeably different in the longitudinal direction due to changes in the cabin configuration and soil surface, with higher acceleration and damage occurring in the cabin. Loads from ATDs in energy absorbing seats and restraints were within injury limits. Severe injury was likely for ATDs in forward facing passenger seats.

  19. Crash test for the Copenhagen problem.

    PubMed

    Nagler, Jan

    2004-06-01

    The Copenhagen problem is a simple model in celestial mechanics. It serves to investigate the behavior of a small body under the gravitational influence of two equally heavy primary bodies. We present a partition of orbits into classes of various kinds of regular motion, chaotic motion, escape and crash. Collisions of the small body onto one of the primaries turn out to be unexpectedly frequent, and their probability displays a scale-free dependence on the size of the primaries. The analysis reveals a high degree of complexity so that long term prediction may become a formidable task. Moreover, we link the results to chaotic scattering theory and the theory of leaking Hamiltonian systems. PMID:15244719

  20. Countermeasures for Reducing Alcohol-Related Crashes.

    PubMed

    Voas, R B

    2000-01-01

    Programs to prevent alcohol-related crashes occur at several levels. Although most of the public thinks of drunk-driving prevention only in terms of the criminal justice system, much can be done to prevent alcohol-related highway deaths before the drinking-and-driving offender gets on the road. In recent years, the field of alcohol safety has merged with the area of public health concerned with preventing alcohol- and drug-related traumatic injury and death. This paper provides an overview of the status of road safety programs directed at reducing impaired driving. It covers ten topics falling into the three levels of prevention: primary programs to reduce alcohol consumption; secondary programs to prevent driving after drinking; and tertiary programs to prevent recidivism among convicted drinking drivers. PMID:26256029

  1. Crash Testing of Helicopter Airframe Fittings

    NASA Technical Reports Server (NTRS)

    Clarke, Charles W.; Townsend, William; Boitnott, Richard

    2004-01-01

    As part of the Rotary Wing Structures Technology Demonstration (RWSTD) program, a surrogate RAH-66 seat attachment fitting was dynamically tested to assess its response to transient, crash impact loads. The dynamic response of this composite material fitting was compared to the performance of an identical fitting subjected to quasi-static loads of similar magnitude. Static and dynamic tests were conducted of both smaller bench level and larger full-scale test articles. At the bench level, the seat fitting was supported in a steel fixture, and in the full-scale tests, the fitting was integrated into a surrogate RAH-66 forward fuselage. Based upon the lessons learned, an improved method to design, analyze, and test similar composite material fittings is proposed.

  2. Effect of horizontal curves on urban arterial crashes.

    PubMed

    Banihashemi, Mohamadreza

    2016-10-01

    The crash prediction models of the Highway Safety Manual (HSM), 2010 estimate the expected number of crashes for different facility types. Models in Part C Chapter 12 of the first edition of the HSM include crash prediction models for divided and undivided urban arterials. Each of the HSM crash prediction models for highway segments is comprised of a "Safety Performance Function," a function of AADT and segment length, plus, a series of "Crash Modification Factors" (CMFs). The SPF estimates the expected number of crashes for the site if the site features are of base condition. The effects of the other features of the site, if their values are different from base condition, are carried out through use of CMFs. The existing models for urban arterials do not have any CMF for horizontal curvature. The goal of this research is to investigate if the horizontal alignment has any significant effect on crashes on any of these types of facilities and if so, to develop a CMF for this feature. Washington State cross sectional data from the Highway Safety Information System (HSIS), 2014 was used in this research. Data from 2007 to 2009 was used to conduct the investigation. The 2010 data was used to validate the results. As the results showed, the horizontal curvature has significant safety effect on two-lane undivided urban arterials with speed limits of 35 mph and higher and using a CMF for horizontal curvature in the crash prediction model of this type of facility improves the prediction of crashes significantly, for both tangent and curve segments. PMID:27376485

  3. Emerging technology for vehicular safety and emergency response to roadway crashes.

    PubMed

    Champion, H R; Cushing, B

    1999-12-01

    Emerging technology for vehicular safety and emergency response to roadway crashes is the topic of this article. Reduction in emergency medical services system notification time, improvements in vehicular safety, crash avoidance and protection, post-crash injury control, triage, national automatic crash notification systems, and technologic improvements in emergency diagnostics and treatment during the past year are discussed. PMID:10625974

  4. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 34-MOTOR VEHICLE MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  5. Use of Real-Time Ground-To-Air Video during Aeromedical Response to Traffic Crashes

    NASA Astrophysics Data System (ADS)

    Perina, D.

    2002-08-01

    The purpose of this feasibility study was to determine whether the use of ground-based video imaging by local rescue squad personnel, along with real-time transmission of this information to the Pegasus helicopter medical crew, is technically feasible and of sufficient quality to be used as a tool to improve pre-hospital care provided to crash victims. The scope of this project was to investigate various types of existing technology and equipment that may allow for the desired communication linkage between aircraft and ground responders either as is or with achievable modifications. Additionally, other stakeholder entities in this project would be identified and approached to solicit cooperation in the subsequent deployment of the equipment.

  6. NASA's Research in Aircraft Vulnerability Mitigation

    NASA Technical Reports Server (NTRS)

    Allen, Cheryl L.

    2005-01-01

    Since its inception in 1958, the National Aeronautics and Space Administration s (NASA) role in civil aeronautics has been to develop high-risk, high-payoff technologies to meet critical national aviation challenges. Following the events of Sept. 11, 2001, NASA recognized that it now shared the responsibility for improving homeland security. The NASA Strategic Plan was modified to include requirements to enable a more secure air transportation system by investing in technologies and collaborating with other agencies, industry, and academia. NASA is conducting research to develop and advance innovative and commercially viable technologies that will reduce the vulnerability of aircraft to threats or hostile actions, and identify and inform users of potential vulnerabilities in a timely manner. Presented in this paper are research plans and preliminary status for mitigating the effects of damage due to direct attacks on civil transport aircraft. The NASA approach to mitigation includes: preventing loss of an aircraft due to a hit from man-portable air defense systems; developing fuel system technologies that prevent or minimize in-flight vulnerability to small arms or other projectiles; providing protection from electromagnetic energy attacks by detecting directed energy threats to aircraft and on/off-board systems; and minimizing the damage due to high-energy attacks (explosions and fire) by developing advanced lightweight, damage-resistant composites and structural concepts. An approach to preventing aircraft from being used as weapons of mass destruction will also be discussed.

  7. Energy Absorbing Seat System for an Agricultural Aircraft

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Jones, Lisa E. (Technical Monitor)

    2002-01-01

    A task was initiated to improve the energy absorption capability of an existing aircraft seat through cost-effective retrofitting, while keeping seat-weight increase to a minimum. This task was undertaken as an extension of NASA ongoing safety research and commitment to general aviation customer needs. Only vertical crash scenarios have been considered in this task which required the energy absorbing system to protect the seat occupant in a range of crash speeds up to 31 ft/sec. It was anticipated that, the forward and/or side crash accelerations could be attenuated with the aid of airbags, the technology of which is currently available in automobiles and military helicopters. Steps which were followed include, preliminary crush load determination, conceptual design of cost effective energy absorbers, fabrication and testing (static and dynamic) of energy absorbers, system analysis, design and fabrication of dummy seat/rail assembly, dynamic testing of dummy seat/rail assembly, and finally, testing of actual modified seat system with a dummy occupant. A total of ten full scale tests have been performed including three of the actual aircraft seat. Results from full-scale tests indicated that occupant loads were attenuated successfully to survivable levels.

  8. Projecting Fatalities in Crashes Involving Older Drivers, 2000-2025

    SciTech Connect

    Hu, P.S.

    2001-03-23

    As part of this research effort, we developed a new methodology for projecting elderly traffic crash fatalities. This methodology separates exposure to crashes from crash risk per se, and further divides exposure into two components, the number of miles driven and the likelihood of being a driver. This component structure permits conceptually different determinants of traffic fatalities to be projected separately and has thorough motivation in behavioral theory. It also permits finer targeting of particular aspects of projections that need improvement and closer linking of projections to possible policy instruments for influencing them.

  9. Crash Certification by Analysis - Are We There Yet?

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.

    2006-01-01

    This paper addresses the issue of crash certification by analysis. This broad topic encompasses many ancillary issues including model validation procedures, uncertainty in test data and analysis models, probabilistic techniques for test-analysis correlation, verification of the mathematical formulation, and establishment of appropriate qualification requirements. This paper will focus on certification requirements for crashworthiness of military helicopters; capabilities of the current analysis codes used for crash modeling and simulation, including some examples of simulations from the literature to illustrate the current approach to model validation; and future directions needed to achieve "crash certification by analysis."

  10. Crash tests of four low-wing twin-engine airplanes with truss-reinforced fuselage structure

    NASA Technical Reports Server (NTRS)

    Williams, M. S.; Fasanella, E. L.

    1982-01-01

    Four six-place, low-wing, twin-engine, general aviation airplane test specimens were crash tested under controlled free flight conditions. All airplanes were impacted on a concrete test surface at a nomial flight path velocity of 27 m/sec. Two tests were conducted at a -15 deg flight path angle (0 deg pitch angle and 15 deg pitch angle), and two were conducted at a -30 deg flight path angle (-30 deg pitch angle). The average acceleration time histories (crash pulses) in the cabin area for each principal direction were calculated for each crash test. In addition, the peak floor accelerations were calculated for each test as a function of aircraft fuselage longitudinal station number. Anthropomorphic dummy accelerations were analyzed using the dynamic response index and severity index (SI) models. Parameters affecting the dummy restraint system were studied; these parameters included the effect of no upper torso restraint, measurement of the amount of inertia-reel strap pullout before locking, measurement of dummy chest forward motion, and loads in the restraints. With the SI model, the dummies with no shoulder harness received head impacts above the concussive threshold.

  11. Crash Simulation of a Vertical Drop Test of a B737 Fuselage Section with Overhead Bins and Luggage

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    The focus of this paper is to describe a crash simulation of a 30-ft/s vertical drop test of a Boeing 737 (B737) fuselage section. The drop test of the 10-ft. long fuselage section of a B737 aircraft was conducted in November of 2000 at the FAA Technical Center in Atlantic City, NJ. The fuselage section was outfitted with two different commercial overhead stowage bins. In addition, 3,229-lbs. of luggage were packed in the cargo hold to represent a maximum take-off weight condition. The main objective of the test was to evaluate the response and failure modes of the overhead stowage bins in a narrow-body transport fuselage section when subjected to a severe, but survivable, impact. A secondary objective of the test was to generate experimental data for correlation with the crash simulation. A full-scale 3-dimensional finite element model of the fuselage section was developed and a crash simulation was conducted using the explicit, nonlinear transient dynamic code, MSC.Dytran. Pre-test predictions of the fuselage and overhead bin responses were generated for correlation with the drop test data. A description of the finite element model and an assessment of the analytical/experimental correlation are presented. In addition, suggestions for modifications to the model to improve correlation are proposed.

  12. Improved Curveball Hitting through the Enhancement of Visual Cues.

    ERIC Educational Resources Information Center

    Osborne, Kurt; And Others

    1990-01-01

    The study investigated the effectiveness of using visual cues to highlight the seams of baseballs, to improve the hitting of curveballs by five undergraduate varsity baseball team candidates. Results indicated that subjects hit a greater percentage of marked than unmarked balls. (Author/DB)

  13. Infants' Reactions to Object Collision on Hit and Miss Trajectories

    ERIC Educational Resources Information Center

    Schmuckler, Mark A.; Collimore, Lisa M.; Dannemiller, James L.

    2007-01-01

    This experiment investigated the impact of the path of approach of an object, from head on versus from the side, and the type of imminent contact with that object, a hit versus a miss, on young infants' perceptions of object looming. Consistent with earlier studies, we found that 4- to 5-month-old infants do indeed discriminate hits versus misses.…

  14. Object Rotation Effects on the Timing of a Hitting Action

    ERIC Educational Resources Information Center

    Scott, Mark A.; van der Kamp, John; Savelsbergh, Geert J. P.; Oudejans, Raoul R. D.; Davids, Keith

    2004-01-01

    In this article, the authors investigated how perturbing optical information affects the guidance of an unfolding hitting action. Using monocular and binocular vision, six participants were required to hit a rectangular foam object, released from two different heights, under four different approach conditions, two with object rotation (to perturb…

  15. Optoelectronic hit/miss transform for screening cervical smear slides

    NASA Astrophysics Data System (ADS)

    Narayanswamy, R.; Turner, R. M.; McKnight, D. J.; Johnson, K. M.; Sharpe, J. P.

    1995-06-01

    An optoelectronic morphological processor for detecting regions of interest (abnormal cells) on a cervical smear slide using the hit/miss transform is presented. Computer simulation of the algorithm tested on 184 Pap-smear images provided 95% detection and 5% false alarm. An optoelectronic implementation of the hit/miss transform is presented, along with preliminary experimental results.

  16. Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test

    NASA Technical Reports Server (NTRS)

    Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph

    2014-01-01

    In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy

  17. Effect of Advanced Location Methods on Search and Rescue Duration for General Aviation Aircraft Accidents in the Contiguous United States

    ERIC Educational Resources Information Center

    Wallace, Ryan J.

    2013-01-01

    The purpose of this study was to determine the impact of advanced search and rescue devices and techniques on search duration for general aviation aircraft crashes. The study assessed three categories of emergency locator transmitters, including 121.5 MHz, 406 MHz, and GPS-Assisted 406 MHz devices. The impact of the COSPAS-SARSAT organization…

  18. Facilities and Methods Used in Full-scale Airplane Crash-fire Investigation

    NASA Technical Reports Server (NTRS)

    Black, Dugald O.

    1952-01-01

    The facilities and the techniques employed in the conduct of full scale airplane crash-fire studies currently being conducted at the NACA Lewis laboratory are discussed herein. This investigation is part of a comprehensive study of the airplane crash-fire problem. The crash configuration chosen, the general physical layout of the crash site, the test methods, the instrumentation, the data-recording systems, and the post-crash examination procedure are described

  19. Antarctic ozone hole hits record depth

    SciTech Connect

    Not Available

    1991-10-18

    A bad year for the ozone over Antarctica looked like a good bet this year. For the past 2 years, stratospheric ozone destruction has equaled the record set in 1987. Now things look even worse, with a record-setting ozone hole. In 1987, 1989, and 1990, the minimum amount of ozone over Antarctica early each October was 120 to 125 Dobson units compared to the typical level of 220 that prevailed before manmade Chlorofluorocarbons (CFCs) began eating into the ozone layer. The depletion allowed as much as twice the usual amount of biologically damaging ultraviolet light to reach the earth's surface. But researchers took some comfort in the fact that the hole seemed to have hit a barrier to further losses. Now that barrier may have been breached. On 6 October, the satellite-borne Total Ozone Mapping Spectrometer detected an ozone minimum of 110 Dobson units. The region of the lower stratosphere where icy cloud particles and the chlorine of CFCs combine to destroy ozone - between 14 and 24 kilometers - looks much the same as it did in 1987.

  20. 42 CFR 495.340 - As-needed HIT PAPD update and as-needed HIT IAPD update requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... update or a HIT IAPD no later than 60 days after the occurrence of project changes including but not... document or the HIT implementation advance planning document. (d) A change in implementation concept or a change to the scope of the project. (e) A change to the approved cost allocation methodology....

  1. Frequency Analysis of Aircraft hazards for License Application

    SciTech Connect

    K. Ashley

    2006-10-24

    The preclosure safety analysis for the monitored geologic repository at Yucca Mountain must consider the hazard that aircraft may pose to surface structures. Relevant surface structures are located beneath the restricted airspace of the Nevada Test Site (NTS) on the eastern slope of Yucca Mountain, near the North Portal of the Exploratory Studies Facility Tunnel (Figure 1). The North Portal is located several miles from the Nevada Test and Training Range (NTTR), which is used extensively by the U.S. Air Force (USAF) for training and test flights (Figure 1). The NTS airspace, which is controlled by the U.S. Department of Energy (DOE) for NTS activities, is not part of the NTTR. Agreements with the DOE allow USAF aircraft specific use of the airspace above the NTS (Reference 2.1.1 [DIRS 103472], Section 3.1.1 and Appendix A, Section 2.1; and Reference 2.1.2 [DIRS 157987], Sections 1.26 through 1.29). Commercial, military, and general aviation aircraft fly within several miles to the southwest of the repository site in the Beatty Corridor, which is a broad air corridor that runs approximately parallel to U.S. Highway 95 and the Nevada-California border (Figure 2). These aircraft and other aircraft operations are identified and described in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Sections 6 and 8). The purpose of this analysis is to estimate crash frequencies for aircraft hazards identified for detailed analysis in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Section 8). Reference 2.1.3, Section 8, also identifies a potential hazard associated with electronic jamming, which will be addressed in this analysis. This analysis will address only the repository and not the transportation routes to the site. The analysis is intended to provide the basis for: (1) Categorizing event sequences related to aircraft hazards; (2) Identifying design or operational requirements related to aircraft hazards.

  2. The Behavioral Contributors to Highway Crashes of Youthful Drivers.

    PubMed Central

    McKnight, A. James; McKnight, A. Scott

    2000-01-01

    The per-mile crash rate of drivers under age 20 is over five times that of the adult population in general, while that of 16-year-old novices is approximately ten times that of adults. Reports of over 2,000 non-fatal crashes involving young drivers were analyzed for behavioral crash contributors as a step in orienting preventive efforts. The great majority of non-fatal crashes resulted from errors in attention, visual search, speed relative to conditions, hazard recognition, and emergency maneuvers, with high speeds and patently risky behavior accounting from but a small minority. The pattern of errors for novices did not differ significantly from that of more experienced youth. PMID:11558091

  3. Crash in Australian outback ends NASA ballooning season

    NASA Astrophysics Data System (ADS)

    Harris, Margaret

    2010-06-01

    NASA has temporarily suspended all its scientific balloon launches after the balloon-borne Nuclear Compton Tele scope (NCT) crashed during take-off, scattering a trail of debris across the remote launch site and overturning a nearby parked car.

  4. Methodology for estimating thoracic impact response in frontal crash tests.

    PubMed

    Thor, Craig P; Gabler, Hampton C

    2007-01-01

    This study has investigated the feasibility of estimating chest acceleration from the pelvic acceleration and shoulder belt forces measured on a vehicle occupant exposed to a frontal crash. The method of estimating chest acceleration is based upon a simple two-mass one-dimensional model of a vehicle occupant in which pelvic acceleration and shoulder belt force are applied as forcing functions. The predictive power of the model was evaluated by comparing the estimated and measured chest acceleration of 18 Hybrid-III crash test dummies subjected to 56 km/hr full frontal barrier crash tests. The crashtest dummies were restrained by airbags and three-point belt systems with pretensioners and load-limiting shoulder belts. The combined loads exerted on the chest by the pelvis and the shoulder belts were shown to be a reasonable estimate of force on the chest early in the crash event prior to significant airbag loading. PMID:17487104

  5. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights

    PubMed Central

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  6. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    PubMed

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  7. Heavy Vehicle Crash Characteristics in Oman 2009–2011

    PubMed Central

    Al-Bulushi, Islam; Edwards, Jason; Davey, Jeremy; Armstrong, Kerry; Al-Reesi, Hamed; Al-Shamsi, Khalid

    2015-01-01

    In recent years, Oman has seen a shift in the burden of diseases towards road accidents. The main objective of this paper, therefore, is to describe key characteristics of heavy vehicle crashes in Oman and identify the key driving behaviours that influence fatality risks. Crash data from January 2009 to December 2011 were examined and it was found that, of the 22,543 traffic accidents that occurred within this timeframe, 3,114 involved heavy vehicles. While the majority of these crashes were attributed to driver behaviours, a small proportion was attributed to other factors. The results of the study indicate that there is a need for a more thorough crash investigation process in Oman. Future research should explore the reporting processes used by the Royal Oman Police, cultural influences on heavy vehicle operations in Oman and improvements to the current licensing system. PMID:26052451

  8. Bayesian log-periodic model for financial crashes

    NASA Astrophysics Data System (ADS)

    Rodríguez-Caballero, Carlos Vladimir; Knapik, Oskar

    2014-10-01

    This paper introduces a Bayesian approach in econophysics literature about financial bubbles in order to estimate the most probable time for a financial crash to occur. To this end, we propose using noninformative prior distributions to obtain posterior distributions. Since these distributions cannot be performed analytically, we develop a Markov Chain Monte Carlo algorithm to draw from posterior distributions. We consider three Bayesian models that involve normal and Student's t-distributions in the disturbances and an AR(1)-GARCH(1,1) structure only within the first case. In the empirical part of the study, we analyze a well-known example of financial bubble - the S&P 500 1987 crash - to show the usefulness of the three methods under consideration and crashes of Merval-94, Bovespa-97, IPCMX-94, Hang Seng-97 using the simplest method. The novelty of this research is that the Bayesian models provide 95% credible intervals for the estimated crash time.

  9. Structure and dynamics of sawteeth crashes in ASDEX Upgrade

    SciTech Connect

    Igochine, V.; Guenter, S.; Lackner, K.; Pereverzev, G.; Zohm, H.; Boom, J.; Classen, I.; Dumbrajs, O.

    2010-12-15

    The crash phase of the sawteeth in ASDEX Upgrade tokamak [Herrmann et al., Fusion Sci. Technol. 44(3), 569 (2003)] is investigated in detail in this paper by means of soft x-ray (SXR) and electron cyclotron emission (ECE) diagnostics. Analysis of precursor and postcursor (1,1) modes shows that the crash does not affect the position of the resonant surface q=1. Our experimental results suggest that sawtooth crash models should contain two ingredients to be consistent with experimental observations: (1) the (1,1) mode structure should survive the crash and (2) the flux changes should be small to preserve the position of the q=1 surface close to its original location. Detailed structure of the reconnection point was investigated with ECE imaging diagnostic. It is shown that reconnection starts locally. The expelled core is hot which is consistent with SXR tomography results. The observed results can be explained in the framework of a stochastic model.

  10. Structure and dynamics of sawteeth crashes in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Igochine, V.; Boom, J.; Classen, I.; Dumbrajs, O.; Günter, S.; Lackner, K.; Pereverzev, G.; Zohm, H.; ASDEX Upgrade Team

    2010-12-01

    The crash phase of the sawteeth in ASDEX Upgrade tokamak [Herrmann et al., Fusion Sci. Technol. 44(3), 569 (2003)] is investigated in detail in this paper by means of soft x-ray (SXR) and electron cyclotron emission (ECE) diagnostics. Analysis of precursor and postcursor (1,1) modes shows that the crash does not affect the position of the resonant surface q =1. Our experimental results suggest that sawtooth crash models should contain two ingredients to be consistent with experimental observations: (1) the (1,1) mode structure should survive the crash and (2) the flux changes should be small to preserve the position of the q =1 surface close to its original location. Detailed structure of the reconnection point was investigated with ECE imaging diagnostic. It is shown that reconnection starts locally. The expelled core is hot which is consistent with SXR tomography results. The observed results can be explained in the framework of a stochastic model.

  11. Relationship between organisational safety culture dimensions and crashes.

    PubMed

    Varmazyar, Sakineh; Mortazavi, Seyed Bagher; Arghami, Shirazeh; Hajizadeh, Ebrahim

    2016-01-01

    Knowing about organisational safety culture in public transportation system can provide an appropriate guide to establish effective safety measures and interventions to improve safety at work. The aim of this study was investigation of association between safety culture dimensions (leadership styles and company values, usage of crashes information and prevention programmes, management commitment and safety policy, participation and control) with involved self-reported crashes. The associations were considered through Spearman correlation, Pearson chi-square test and logistic regression. The results showed an association among self-reported crashes (occurrence or non-occurrence) and factors including leadership styles and company values; management commitment and safety policy; and control. Moreover, it was found a negative correlation and an odds ratio less than one between control and self-reported crashes. PMID:25494102

  12. A study on crashes related to visibility obstruction due to fog and smoke.

    PubMed

    Abdel-Aty, Mohamed; Ekram, Al-Ahad; Huang, Helai; Choi, Keechoo

    2011-09-01

    Research on weather effects has focused on snow- or rain-related crashes. However, there is a lack of understanding of crashes that occur during fog or smoke (FS). This study presents a comprehensive examination of FS-related crashes using crash data from Florida between 2003 and 2007. A two-stage research strategy was implemented (1) to examine FS-related crash characteristics with respect to temporal distribution, influential factors and crash types and (2) to estimate the effects of various factors on injury severity given that a FS-related crash has occurred. The morning hours from December to February are the prevalent times for FS-related crashes. Compared to crashes under clear-visibility conditions, FS-related crashes tend to result in more severe injuries and involve more vehicles. Head-on and rear-end crashes are the two most common crash types in terms of crash risk and severity. These crashes were more prevalent on high-speed roads, undivided roads, roads with no sidewalks and two-lane rural roads. Moreover, FS-related crashes were more likely to occur at night without street lighting, leading to more severe injuries. PMID:21658500

  13. Light airplane crash tests at three pitch angles

    NASA Technical Reports Server (NTRS)

    Vaughan, V. L., Jr.; Alfaro-Bou, E.

    1979-01-01

    Three similar twin-engine general aviation airplane specimens were crash tested at an impact dynamics research facility at 27 m/sec, a flight path angle of -15 deg, and pitch angles of -15 deg, 0 deg, and 15 deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  14. Generalized nonlinear models for rear-end crash risk analysis.

    PubMed

    Lao, Yunteng; Zhang, Guohui; Wang, Yinhai; Milton, John

    2014-01-01

    A generalized nonlinear model (GNM)-based approach for modeling highway rear-end crash risk is formulated using Washington State traffic safety data. Previous studies majorly focused on causal factor identification and crash risk modeling using Generalized linear Models (GLMs), such as Poisson regression, Logistic regression, etc. However, their basic assumption of a generalized linear relationship between the dependent variable (for example, crash rate) and independent variables (for example, contribute factors to crashes) established via a link function can be often violated in reality. Consequently, the GLM-based modeling results could provide biased findings and conclusions. In this research, a GNM-based approach is developed to utilize a nonlinear regression function to better elaborate non-monotonic relationships between the independent and dependent variables using the rear end accident data collected from 10 highway routes from 2002 through 2006. The results show for example that truck percentage and grade have a parabolic impact: they increase crash risks initially, but decrease them after the certain thresholds. Such non-monotonic relationships cannot be captured by regular GLMs which further demonstrate the flexibility of GNM-based approaches in the nonlinear relationship among data and providing more reasonable explanations. The superior GNM-based model interpretations help better understand the parabolic impacts of some specific contributing factors for selecting and evaluating rear-end crash safety improvement plans. PMID:24125803

  15. Car insurance and the risk of car crash injury.

    PubMed

    Blows, Stephanie; Ivers, Rebecca Q; Connor, Jennie; Ameratunga, Shanthi; Norton, Robyn

    2003-11-01

    Despite speculation about the role of vehicle insurance in road traffic accidents, there is little research estimating the direction or extent of the risk relationship. Data from the Auckland Car Crash Injury Study (1998-1999) were used to examine the association between driving an uninsured motor vehicle and car crash injury. Cases were all cars involved in crashes in which at least one occupant was hospitalized or killed anywhere in the Auckland region. Controls were 588 drivers of randomly selected cars on Auckland roads. Participants completed a structured interview. Uninsured drivers had significantly greater odds of car crash injury compared to insured drivers after adjustment for age, sex, level of education, and driving exposure (odds ratio 4.77, 95% confidence interval 2.94-7.75). The causal mechanism for insurance and car crash injury is not easily determined. Although we examined the effects of multiple potential confounders in our analysis including socioeconomic status and risk-taking behaviours, both of which have been previously observed to be associated with both insurance status and car crash injury, residual confounding may partly explain this association. The estimated proportion of drivers who are uninsured is between 5 and 15% in developed countries, representing a significant public health problem worthy of further investigation. PMID:12971933

  16. Macroscopic spatial analysis of pedestrian and bicycle crashes.

    PubMed

    Siddiqui, Chowdhury; Abdel-Aty, Mohamed; Choi, Keechoo

    2012-03-01

    This study investigates the effect of spatial correlation using a Bayesian spatial framework to model pedestrian and bicycle crashes in Traffic Analysis Zones (TAZs). Aggregate models for pedestrian and bicycle crashes were estimated as a function of variables related to roadway characteristics, and various demographic and socio-economic factors. It was found that significant differences were present between the predictor sets for pedestrian and bicycle crashes. The Bayesian Poisson-lognormal model accounting for spatial correlation for pedestrian crashes in the TAZs of the study counties retained nine variables significantly different from zero at 95% Bayesian credible interval. These variables were - total roadway length with 35 mph posted speed limit, total number of intersections per TAZ, median household income, total number of dwelling units, log of population per square mile of a TAZ, percentage of households with non-retired workers but zero auto, percentage of households with non-retired workers and one auto, long term parking cost, and log of total number of employment in a TAZ. A separate distinct set of predictors were found for the bicycle crash model. In all cases the Bayesian models with spatial correlation performed better than the models that did not account for spatial correlation among TAZs. This finding implies that spatial correlation should be considered while modeling pedestrian and bicycle crashes at the aggregate or macro-level. PMID:22269522

  17. Three Cases of Spine Fractures after an Airplane Crash.

    PubMed

    Lee, Han Joo; Moon, Bong Ju; Pennant, William A; Shin, Dong Ah; Kim, Keung Nyun; Yoon, Do Heum; Ha, Yoon

    2015-10-01

    While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings. PMID:27169094

  18. Three Cases of Spine Fractures after an Airplane Crash

    PubMed Central

    Lee, Han Joo; Moon, Bong Ju; Pennant, William A.; Shin, Dong Ah; Kim, Keung Nyun; Yoon, Do Heum

    2015-01-01

    While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings. PMID:27169094

  19. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  20. World commercial aircraft accidents

    SciTech Connect

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accident is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.

  1. Ozone loss hits us where we live

    SciTech Connect

    Appenzeller, T.

    1991-11-01

    The news about Earth's ozone layer just keeps getting worse. Three weeks ago, NASA researchers reported that the ozone hole over the Antarctic hit a record depth this year. Now comes the United Nations Environment Program, together with the World Meteorological Organization, with an even more distressing assessment of the state of the ozone layer. For the first time, the 80-member UN panel said, measurements show the ozone shield is eroding over temperate latitudes in summer, exposing crops and people to a larger dose of ultraviolet light just when they are most vulnerable. For a small group of atmospheric modelers, though, the bad news is bittersweet. Four months ago researchers predicted summertime ozone losses of just the magnitude the UN panel has now reported: about 3% over the past decade for northern temperate latitudes. Ozone modelers are encouraged by the agreement, particularly because other models are now yielding the same result. The modeling effort was spurred by earlier measurements showing a serious erosion of ozone at midlatitudes, mainly in winter. In 1988, an analysis of data collected from the ground showed that ozone levels at the latitude of the US were dropping by about 1% to 3% per decade; last April, an analysis of measurements from the satellite-borne Total Ozone Mapping Spectrometer boosted that figure to between 4% and 5%. Those findings raised the question: What mechanisms could be driving the midlatitude losses The fact that the losses seemed to be concentrated in winter suggested one possibility. The winter ozone losses at the poles are driven by chemical reactions taking place on the surface of ice crystals in polar stratospheric clouds. Such clouds don't form at temperate latitudes. But some researchers suggested that masses of air already depleted in ozone or enriched in reactive chlorine by the chemistry in the polar clouds might be escaping to temperate latitudes during the winter.

  2. Aircraft vulnerability analysis by modeling and simulation

    NASA Astrophysics Data System (ADS)

    Willers, Cornelius J.; Willers, Maria S.; de Waal, Alta

    2014-10-01

    Infrared missiles pose a significant threat to civilian and military aviation. ManPADS missiles are especially dangerous in the hands of rogue and undisciplined forces. Yet, not all the launched missiles hit their targets; the miss being either attributable to misuse of the weapon or to missile performance restrictions. This paper analyses some of the factors affecting aircraft vulnerability and demonstrates a structured analysis of the risk and aircraft vulnerability problem. The aircraft-missile engagement is a complex series of events, many of which are only partially understood. Aircraft and missile designers focus on the optimal design and performance of their respective systems, often testing only in a limited set of scenarios. Most missiles react to the contrast intensity, but the variability of the background is rarely considered. Finally, the vulnerability of the aircraft depends jointly on the missile's performance and the doctrine governing the missile's launch. These factors are considered in a holistic investigation. The view direction, altitude, time of day, sun position, latitude/longitude and terrain determine the background against which the aircraft is observed. Especially high gradients in sky radiance occur around the sun and on the horizon. This paper considers uncluttered background scenes (uniform terrain and clear sky) and presents examples of background radiance at all view angles across a sphere around the sensor. A detailed geometrical and spatially distributed radiometric model is used to model the aircraft. This model provides the signature at all possible view angles across the sphere around the aircraft. The signature is determined in absolute terms (no background) and in contrast terms (with background). It is shown that the background significantly affects the contrast signature as observed by the missile sensor. A simplified missile model is constructed by defining the thrust and mass profiles, maximum seeker tracking rate, maximum

  3. Analysis of Pregnant Occupant Crash Exposure and the Potential Effectiveness of Four-Point Seatbelts in Far Side Crashes

    PubMed Central

    Duma, Stefan M.; Moorcroft, David M.; Gabler, Hampton C.; Manoogian, Sarah M.; Stitzel, Joel D.; Duma, Greg G.

    2006-01-01

    The purpose of this paper is to present the crash exposure patterns of pregnant occupants and to evaluate the effectiveness of restraint systems, including four-point seatbelts, in far side crashes. The NASS CDS database revealed that 53.0 % of pregnant occupants are exposed to frontal crashes while 13.5 % are exposed to far side impacts. Given that far side crashes were the second leading crash mode after frontal impacts, a previously validated MADYMO computer model of a 30 week pregnant occupant was utilized to investigate pregnant occupant biomechanics in far side crashes. Three impact speeds (5, 15, and 25 mph) were simulated with four restraint conditions: unbelted, lap-belt only, three-point belt, and a four-point belt. Direct abdominal contact from the shoulder strap of the three-point or four-point belt caused uterine-placental strain in contrast to the inertial loading induced strain in the lap-belt and unbelted cases. Overall, the three-point and four-point belt systems provide superior restraint effectiveness for the pregnant occupant compared to the lap-belt and no restraint cases. The four-point resulted in slightly better performance than the three-point belt by reducing the fetal injury risk and occupant excursion. PMID:16968637

  4. Wealth inhomogeneity applied to crash rate theory.

    PubMed

    Shuler, Robert L

    2015-11-01

    A crash rate theory based on corporate economic utility maximization is applied to individual behavior in U.S. and German motorway death rates, by using wealth inhomogeneity data in ten-percentile bins to account for variations of utility maximization in the population. Germany and the U.S. have similar median wealth figures, a well-known indicator of accident risk, but different motorway death rates. It is found that inhomogeneity in roughly the 10(th) to 30(th) percentile, not revealed by popular measures such as the Gini index which focus on differences at the higher percentiles, provides a satisfactory explanation of the data. The inhomogeneity analysis reduces data disparity from a factor of 2.88 to 1.75 as compared with median wealth assumed homogeneity, and further to 1.09 with average wealth assumed homogeneity. The first reduction from 2.88 to 1.75 is attributable to inequality at lower percentiles and suggests it may be as important in indicating socioeconomic risk as extremes in the upper percentile ranges, and that therefore the U.S. socioeconomic risk may be higher than generally realized. PMID:27441226

  5. Modeling Composite Laminate Crushing for Crash Analysis

    NASA Technical Reports Server (NTRS)

    Fleming, David C.; Jones, Lisa (Technical Monitor)

    2002-01-01

    Crash modeling of composite structures remains limited in application and has not been effectively demonstrated as a predictive tool. While the global response of composite structures may be well modeled, when composite structures act as energy-absorbing members through direct laminate crushing the modeling accuracy is greatly reduced. The most efficient composite energy absorbing structures, in terms of energy absorbed per unit mass, are those that absorb energy through a complex progressive crushing response in which fiber and matrix fractures on a small scale dominate the behavior. Such failure modes simultaneously include delamination of plies, failure of the matrix to produce fiber bundles, and subsequent failure of fiber bundles either in bending or in shear. In addition, the response may include the significant action of friction, both internally (between delaminated plies or fiber bundles) or externally (between the laminate and the crushing surface). A figure shows the crushing damage observed in a fiberglass composite tube specimen, illustrating the complexity of the response. To achieve a finite element model of such complex behavior is an extremely challenging problem. A practical crushing model based on detailed modeling of the physical mechanisms of crushing behavior is not expected in the foreseeable future. The present research describes attempts to model composite crushing behavior using a novel hybrid modeling procedure. Experimental testing is done is support of the modeling efforts, and a test specimen is developed to provide data for validating laminate crushing models.

  6. Posttraumatic Growth After Motor Vehicle Crashes.

    PubMed

    Wu, Kitty K; Leung, Patrick W L; Cho, Valda W; Law, Lawrence S C

    2016-06-01

    The relationship between sub-dimensions of posttraumatic growth (PTG) and distress was investigated for survivors of motor vehicle crashes (MVC). PTG and symptoms of posttraumatic stress disorder (PTSD) for 1045 MVC survivors who attended the Accident and Emergency Services were examined with the Chinese versions of the Posttraumatic Growth Inventory (PTGI) and the Impact of Event Scale-Revised 1 week after the experience of a MVC. A factor structure, which was different from both the original English version of the PTGI and the Chinese version of PTGI for cancer survivors, was identified. Factors extracted were: (1) Life and Self Appreciation; (2) New Commitments; (3) Enlightenment; and (4) Relating to Others. However, correlation analyses indicated a functional similarity between factors from this study and those from previous studies. Relations between PTG sub-dimensions and PTSD symptoms were identified. Results from hierarchical multiple regression analysis and structural equation modeling show that there were different predictors for different PTG sub-dimensions. Findings suggest that different modes of relationship between PTSD symptoms and PTG sub-dimensions may co-exist. PMID:27040687

  7. Cervical spine response in frontal crash.

    PubMed

    Panzer, Matthew B; Fice, Jason B; Cronin, Duane S

    2011-11-01

    Predicting neck response and injury resulting from motor vehicle accidents is essential to improving occupant protection. A detailed human cervical spine finite element model has been developed, with material properties and geometry determined a priori of any validation, for the evaluation of global kinematics and tissue-level response. Model validation was based on flexion/extension response at the segment level, tension response of the whole ligamentous cervical spine, head kinematic response from volunteer frontal impacts, and soft tissue response from cadaveric whole cervical spine frontal impacts. The validation responses were rated as 0.79, assessed using advanced cross-correlation analysis, indicating the model exhibits good biofidelity. The model was then used to evaluate soft tissue response in frontal impact scenarios ranging from 8G to 22G in severity. Disc strains were highest in the C4-C5-C6 segments, and ligament strains were greatest in the ISL and LF ligaments. Both ligament and disc fiber strain levels exceeded the failure tolerances in the 22G case, in agreement with existing data. This study demonstrated that a cervical spine model can be developed at the tissue level and provide accurate biofidelic kinematic and local tissue response, leading to injury prediction in automotive crash scenarios. PMID:21665513

  8. Flight-crash events in turbulence.

    PubMed

    Xu, Haitao; Pumir, Alain; Falkovich, Gregory; Bodenschatz, Eberhard; Shats, Michael; Xia, Hua; Francois, Nicolas; Boffetta, Guido

    2014-05-27

    The statistical properties of turbulence differ in an essential way from those of systems in or near thermal equilibrium because of the flux of energy between vastly different scales at which energy is supplied and at which it is dissipated. We elucidate this difference by studying experimentally and numerically the fluctuations of the energy of a small fluid particle moving in a turbulent fluid. We demonstrate how the fundamental property of detailed balance is broken, so that the probabilities of forward and backward transitions are not equal for turbulence. In physical terms, we found that in a large set of flow configurations, fluid elements decelerate faster than accelerate, a feature known all too well from driving in dense traffic. The statistical signature of rare "flight-crash" events, associated with fast particle deceleration, provides a way to quantify irreversibility in a turbulent flow. Namely, we find that the third moment of the power fluctuations along a trajectory, nondimensionalized by the energy flux, displays a remarkable power law as a function of the Reynolds number, both in two and in three spatial dimensions. This establishes a relation between the irreversibility of the system and the range of active scales. We speculate that the breakdown of the detailed balance characterized here is a general feature of other systems very far from equilibrium, displaying a wide range of spatial scales. PMID:24794529

  9. A crash-prediction model for road tunnels.

    PubMed

    Caliendo, Ciro; De Guglielmo, Maria Luisa; Guida, Maurizio

    2013-06-01

    Considerable research has been carried out into open roads to establish relationships between crashes and traffic flow, geometry of infrastructure and environmental factors, whereas crash-prediction models for road tunnels, have rarely been investigated. In addition different results have been sometimes obtained regarding the effects of traffic and geometry on crashes in road tunnels. However, most research has focused on tunnels where traffic and geometric conditions, as well as driving behaviour, differ from those in Italy. Thus, in this paper crash prediction-models that had not yet been proposed for Italian road tunnels have been developed. For the purpose, a 4-year monitoring period extending from 2006 to 2009 was considered. The tunnels investigated are single-tube ones with unidirectional traffic. The Bivariate Negative Binomial regression model, jointly applied to non-severe crashes (accidents involving material-damage only) and severe crashes (fatal and injury accidents only), was used to model the frequency of accident occurrence. The year effect on severe crashes was also analyzed by the Random Effects Binomial regression model and the Negative Multinomial regression model. Regression parameters were estimated by the Maximum Likelihood Method. The Cumulative Residual Method was used to test the adequacy of the regression model through the range of annual average daily traffic per lane. The candidate set of variables was: tunnel length (L), annual average daily traffic per lane (AADTL), percentage of trucks (%Tr), number of lanes (NL), and the presence of a sidewalk. Both for non-severe crashes and severe crashes, prediction-models showed that significant variables are: L, AADTL, %Tr, and NL. A significant year effect consisting in a systematic reduction of severe crashes over time was also detected. The analysis developed in this paper appears to be useful for many applications such as the estimation of accident reductions due to improvement in existing

  10. United States Navy - Canadian forces solid state flight data recorder/crash position locator experiment on the B-720 controlled impact demonstration

    NASA Technical Reports Server (NTRS)

    Watters, D. M.

    1986-01-01

    The operation of a radio beacon position locator during and after the remotely controlled transport aircraft is discussed. The radio beacon transmission was actuated and was picked up by the Navy P-3A chase aircraft for a short time, after which reception was lost. The pilot reported that he received a signal on both 121.5 MHz and 243 MHz for a period of approximately 5 seconds. Five minutes after the crash a portable direction finding unit located on the roof of the NASA Dryden Flight Research Facility, 4 miles distant from the crash, was unable to pick up the beacon transmission. The fire crews started fighting the fires approximately 90 seconds after the time of impact. Navy personnel access to the crash site was allowed on the morning of December 2, 1984. Radio beacon locator was found resting top side up, 15 feet forward and 13 feet perpendicular from the tray location the starboard side of the aircraft. An immediate inspection indicated the airfoil suffered moderate fire damage with paint peeling but not intumescing. The visual marker strobe lamp housings were intact but extensively burned such that it was impossible to see if the lamps had survived. The airfoil suffered minor structural damage, with assorted dents, etc. The extended plunger on the ARU-21 release unit indicated that the pyrotechnic deployment system operated. The radio beacon base (tray) suffered some heat and fire damage, and was charred and blackened by smoke. The frangible switch in the nose survived and the switch in the belly was recovered and found to have actuated. It is assumed that this switch fired the ARU-21 squib. There were no other release switches installed in the normally open system in the aircraft.

  11. Baseline monitoring using aircraft laser ranging. [spaceborne laser simulation and aircraft laser tracking

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Hoge, F. E.; Martin, C. F.

    1982-01-01

    The use of aircraft laser ranging for the determination of baselines between ground based retroreflectors was investigated via simulations and with tests at Wallops Flight Center using the Airborne Oceanographic Lidar (AOL) on the Wallops C-54 aircraft ranging to a reflector array deployed around one of the Wallops runways. The aircraft altitude and reflector spacing were chosen on the basis of scaled down modeling of spacecraft tracking from 1000 km of reflectors separated by some 52 km, or of high altitude (10 km) aircraft tracking of reflectors separated by some 500 m. Aircraft altitudes flown for different passes across the runway reflector array varied from 800 m to 1350 m, with 32 reflectors deployed over an approximtely 300 m x 500 m ground pattern. The AOL transmitted 400 pulses/sec with a scan rate of 5/sec in a near circular pattern, so that the majority of the pulses were reflected by the runway surface or its environs rather than by retroreflectors. The return pulse characteristics clearly showed the high reflectivity of portions of the runway, with several returns indistinguishable in amplitude from reflector returns. For each pass across the reflector field, typically six to ten reflector hits were identified, consistent with that predicted by simulations and the observed transmitted elliptical pulse size.

  12. Concussion Study Shows Player-To-Player Hits Most Damaging

    MedlinePlus

    ... Study Shows Player-to-Player Hits Most Damaging Running longer before the contact happens also spells more ... the University of Georgia. "We also found that running a long distance before colliding with an opponent ...

  13. People with learning disabilities are hit hard by funding cutbacks.

    PubMed

    Hughes, Charlie

    Thank you for publishing Ken Mack's letter (March 5) drawing attention to the suffering and distress caused by welfare reforms and cutbacks, and how people with disabilities and their families are being hit particularly hard. PMID:24617400

  14. Even Mild Football Head Hits Can Harm Vision

    MedlinePlus

    ... www.nlm.nih.gov/medlineplus/news/fullstory_158807.html Even Mild Football Head Hits Can Harm Vision Study of college players raises concerns about repetitive non-concussive impacts To use the sharing features on ...

  15. The Chelyabinsk Meteorite Hits an Anomalous Zone in the Urals

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2013-09-01

    The Chelyabinsk meteorite is "strange" because it hits an area in the Urals where anomalous events are observed: shining skies, light balls, UFOs, electrphonic bolids. The area tectonically occurs at the intersection of two fold belts: Urals and Timan.

  16. Even Mild Football Head Hits Can Harm Vision

    MedlinePlus

    ... html Even Mild Football Head Hits Can Harm Vision Study of college players raises concerns about repetitive ... Repeated blows to the head can cause near vision to blur slightly, even if the individual impacts ...

  17. A Reexamination of the Small Overlap Frontal Crash

    PubMed Central

    Scullion, Paul; Morgan, Richard M.; Mohan, Pradeep; Kan, Cing-Dao; Shanks, Kurt; Jin, Wook; Tangirala, Ravi

    2010-01-01

    The objective of this study was to examine and rank the Small Overlap Frontal Crash as one of the eight-group taxonomy proposed by Ford. The Ford taxonomy classifies real-world frontal-impact crashes based on the National Automotive Sampling System (NASS). Frontally-impacted vehicles were identified for 1985 – 2008 model year passenger vehicles with Collision Deformation Classification (CDC) data from the 1995 – 2008 years of NASS. Small overlap frontal cases were identified where there was no engagement of the vehicle frame rails, and the direct damage was located entirely outside of the vehicle frame rails. The results are that full engagement and offset (offset category means the direct damage overlaps the vehicle frame rail, with the center of direct damage between the frame rails) were the most frequent crashes contributing 35% each. The frequency of the small overlap frontal was 6%. The risks of injury (AIS ≥ 2) for the full engagement, offset, and small overlap were 8%, 6%, and 3% respectively. For this study, the number of small overlap vehicles was 1,118 and the number of injured nearside occupants was 100. This study—following the Ford approach and reasonably identifying the location of the longitudinal rails based on CDC—suggests that the small overlap is at worst a moderately dangerous crash in the overall scheme of frontal crashes. The implications of this study are that the safety community should reexamine the significance of the small overlap frontal crash against an overall taxonomy of crashes. PMID:21050598

  18. Mopeds and Scooters: Crash Outcomes in a High Traffic State

    PubMed Central

    Miggins, Makesha; Lottenberg, Lawrence; Liu, Huazhi; Moldawer, Lyle; Efron, Philip; Ang, Darwin

    2014-01-01

    Background Moped and scooter crash outcomes in the United States were last reported over 20 years ago. These vehicles have experienced resurgence in popularity with sales that have increased up to 60% in recent years. The purpose of this study is to identify risk factors between severe and non-severe driver related injuries and to identify modifiable risk factors. Methods The Florida Traffic Crash Records Database (FTCRD) was used to identify all crashes involving mopeds and scooters occurring between 2002 and 2008. A total of 5,660 moped crashes were evaluated. Multivariate logistic regression was used to determine the strength of association of severe injury for each risk factor. Results Over 90% of drivers involved in moped or scooter crashes were uninsured. Only 17% of all drivers wore helmets. Alcohol and drug use was a significant risk factor severe and lethal crashes OR 2.09, 95% CI (1.64, 2.66). Risk factors amenable for state intervention and associated with increased severe or lethal injury were unpaved roads OR 1.57, 95% CI (1.30, 1.88); driving speeds > 20 mph OR 2.02, 95% CI (1.73, 2.36); posted speed limits >30 mph OR 1.40, 95% CI (1.22, 1.62); major roadways with 4 or more lanes OR 1.83, 95% CI (1.04, 3.21); and poor lighting conditions OR 1.69, 95% CI (1.23, 2.32). Conclusions These results suggest that most of the traffic infrastructure does not accommodate the safety of moped and scooter drivers. Focused interventions and further investigation into statewide traffic rules may improve moped crash outcomes. PMID:21399547

  19. Compulsive Cell Phone Use and History of Motor Vehicle Crash

    PubMed Central

    O’Connor, Stephen S.; Whitehill, Jennifer M.; King, Kevin M.; Kernic, Mary A.; Boyle, Linda Ng; Bresnahan, Brian; Mack, Christopher D.; Ebel, Beth E.

    2013-01-01

    Introduction Few studies have examined the psychological factors underlying the association between cell phone use and motor vehicle crash. We sought to examine the factor structure and convergent validity of a measure of problematic cell phone use and explore whether compulsive cell phone use is associated with a history of motor vehicle crash. Methods We recruited a sample of 383 undergraduate college students to complete an on-line assessment that included cell phone use and driving history. We explored the dimensionality of the Cell Phone Overuse Scale (CPOS) using factor analytic methods. Ordinary least squares regression models were used to examine associations between identified subscales and measures of impulsivity, alcohol use, and anxious relationship style to establish convergent validity. We used negative binomial regression models to investigate associations between the CPOS and motor vehicle crash incidence. Results We found the CPOS to be comprised of four subscales: anticipation, activity interfering, emotional reaction, and problem recognition. Each displayed significant associations with aspects of impulsivity, problematic alcohol use, and anxious relationship style characteristics. Only the anticipation subscale demonstrated statistically significant associations with reported motor vehicle crash incidence, controlling for clinical and demographic characteristics (RR 1.13, CI 1.01 to 1.26). For each one-point increase on the 6-point anticipation subscale, risk for previous motor vehicle crash increased by 13%. Conclusions Crash risk is strongly associated with heightened anticipation about incoming phone calls or messages. The mean score on the CPOS is associated with increased risk of motor vehicle crash but does not reach statistical significance. PMID:23910571

  20. Spatial regression analysis of traffic crashes in Seoul.

    PubMed

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. PMID:26994374

  1. Fluid-Solid Interactive Methodology for Prognosis of Passenger Jet Structural Damage in Water Crash Landing

    NASA Astrophysics Data System (ADS)

    Bayandor, Javid

    2010-11-01

    Today, crashworthiness studies constitute a major part of modern aerospace design and certification processes. Of important consideration is the assessment of structural damage tolerance in terms of the extent of progressive damage and failure caused by aircraft emergency ditching on soft terrain or on water. Although a certification requirement, full scale crash landings are rarely tested using fully functional prototypes due to their high associated costs. This constraint makes it difficult for all crashworthy features of the design to be identified and fine-tuned before the commencement of the manufacturing phase. The current study presents aspects of a numerical methodology that can drastically subside the dependency of the certification assessments to full scale field trials. Interactive, fully nonlinear, solid-structure and fluid- structure analyses have been proposed using coupled Lagrangian- Eulerian and independent meshless Lagrangian approaches that run on a combined finite element-computational fluid dynamics platform. Detailed analysis of a key landing scenario pertaining to a large passenger jet will be provided to determine the relevance and accuracy of the proposed method. The work further identifies state-of-the-art computational approaches for modeling fluid-solid interactive systems that can help improve aircraft structural responses to soft impact and water ditching.

  2. Combined hit theory-microdosimetric explanation of cellular radiobiological action

    SciTech Connect

    Bond, V.P.; Varma, M.N.

    1983-01-01

    Hit theory is combined with microdosimetry in a stochastic approach that explains the observed responses of cell populations exposed in radiation fields of different qualities. The central thesis is that to expose a population of cells in a low-level radiation field is to subject the cells to the potential for interaction with charged particles in the vicinity of the cells, quantifiable in terms of the charged particle fluence theta. When such an interaction occurs there is a resulting stochastic transfer of energy to a critical volume (CV) of cross section sigma, within the cell(s). The severity of cell injury is dependent on the amount of energy thus imparted, or the hit size. If the severity is above some minimal level, there is a non-zero probability that the injury will result in a quantal effect (e.g., a mutational or carcinogenic initial event, cell transformation). A microdosimetric proportional counter, viewed here as a phantom cell CV that permits measurements not possible in the living cell, is used to determine the incidence of hit cells and the spectrum of hit sizes. Each hit is then weighted on the basis of an empirically-determined function that provides the fraction of cells responding quantally, as a function of hit size. The sum of the hits so weighted provides the incidence of quantally-responding cells, for any amount of exposure theta in a radiation field of any quality or mixture qualities. The hit size weighting function for pink mutations in Tradescantia is discussed, as are its implications in terms of a replacement for RBE and dose equivalent. 14 references, 9 figures.

  3. Do pigeons prefer alternatives that include near-hit outcomes?

    PubMed

    Stagner, Jessica P; Case, Jacob P; Sticklen, Mary F; Duncan, Amanda K; Zentall, Thomas R

    2015-07-01

    Pigeons show suboptimal choice on a gambling-like task similar to that shown by humans. Humans also show a preference for gambles in which there are near hits (losses that come close to winning). In the present research, we asked if pigeons would show a preference for alternatives with near-hit-like trials. In Experiment 1, we included an alternative that presented a near hit, in which a stimulus associated with reinforcement (a presumed conditioned reinforcer) changed to a stimulus associated with the absence of reinforcement (a presumed conditioned inhibitor). The pigeons tended to avoid this alternative. In Experiment 2, we varied the duration of the presumed conditioned reinforcer (2 vs. 8 s) that changed to a presumed conditioned inhibitor (8 vs. 2 s) and found that the longer the conditioned reinforcer was presented, the more the pigeons avoided it. In Experiment 3, the near-hit alternative involved an ambiguous stimulus for 8 s that changed to a presumed conditioned reinforcer (or a presumed conditioned inhibitor) for 2 s, but the pigeons still avoided it. In Experiment 4, we controlled for the duration of the conditioned reinforcer by presenting it first for 2 s followed by the ambiguous stimulus for 8 s. Once again, the pigeons avoided the alternative with the near-hit trials. In all 4 experiments, the pigeons tended to avoid alternatives that provided near-hit-like trials. We concluded that humans may be attracted to near-hit trials because near-hit trials give them the illusion of control, whereas this does not appear to be a factor for pigeons. PMID:26167775

  4. Correlation and assessment of structural airplane crash data with flight parameters at impact

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1982-01-01

    Crash deceleration pulse data from a crash dynamics program on general aviation airplanes and from transport crash data were analyzed. Structural airplane crash data and flight parameters at impact were correlated. Uncoupled equations for the normal and longitudinal floor impulses in the cabin area of the airplane were derived, and analytical expressions for structural crushing during impact and horizontal slide out were also determined. Agreement was found between experimental and analytical data for general aviation and transport airplanes over a relatively wide range of impact parameter. Two possible applications of the impulse data are presented: a postcrash evaluation of crash test parameters and an assumed crash scenario.

  5. Superfast Cosmic Jet "Hits the Wall"

    NASA Astrophysics Data System (ADS)

    1999-01-01

    -288. The jet travelled quickly until its advance suddenly was stopped and the endpoint of the jet became brighter than the core. "This fast-moving material obviously hit something," Hjellming said. What did it it hit? "Probably a mixture of external material plus material from a previous jet ejection." Further studies of the collision could yield new information about the physics of cosmic jets. Such jets are believed to be powered by black holes into which material is being drawn. The exact mechanism by which the black hole's gravitational energy accelerates particles to nearly the speed of light is not well understood. There is even dispute about the types of particles ejected. Competing models call for either a mixture of electrons and protons or a mixture of electrons and positrons. Because protons are more than 1,800 times more massive than electrons or positrons (the positively-charged antiparticle of the electron), the electron-proton mixture would be much more massive than the electron-positron pair. Thus, an electron-proton jet is called a heavy jet and an electron-positron jet is called a light jet. A light jet would be much more easily slowed or stopped by tenuous interstellar material than a heavy jet, so the collision of XTE J1748-288's jet may indicate that it is a light jet. "There's still a lot more work to do before anyone can conclude that, but the collision offers the possibility of answering the light-heavy jet question," Hjellming said. A 1998 VLA study by John Wardle of Brandeis University and his colleagues indicated that the jet of a distant quasar is a light, electron-positron jet. Though the black holes in quasars are supermassive, usually millions of times more massive than the Sun, the physics of jet production in them is thought to be similar to the physics of jet production by smaller black holes, only a few times more massive than the sun, such as the one possibly in XTE J1748-288. The VLA is an instrument of the National Radio Astronomy

  6. Thomson Scattering Measurements on HIT-SI3

    NASA Astrophysics Data System (ADS)

    Everson, C. J.; Morgan, K. D.; Jarboe, T. R.

    2015-11-01

    A multi-point Thomson Scattering diagnostic has been implemented on HIT-SI3 (Helicity Injected Torus - Steady Inductive 3) to measure electron temperature. The HIT-SI3 experiment is a modification of the original HIT-SI apparatus that uses three injectors instead of two. This modification alters the configuration of magnetic fields and thus the plasma behavior in the device. The scientific aim of HIT-SI3 is to develop a deeper understanding of how injector behavior and interactions influence current drive and plasma performance in the spheromak. The Thomson Scattering system includes a 20 J (1 GW pulse) Ruby laser that provides the incident beam, and collection optics that are installed such that measurements can be taken at four spatial locations in HIT-SI3 plasmas. For each measurement point, a 3-channel polychromator is used to detect the relative level of scattering. These measurements allow for the presence of temperature gradients in the spheromak to be investigated. Preliminary HIT-SI3 temperature data are presented and can be compared to predictions from computational models. Work supported by the D.O.E.

  7. Propulsion controlled aircraft computer

    NASA Technical Reports Server (NTRS)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  8. Motor Vehicle Crash Severity Estimations by Physicians and Prehospital Personnel

    PubMed Central

    Cleveland, Nathan; Colwell, Christopher; Douglass, Erica; Hopkins, Emily; Haukoos, Jason S.

    2016-01-01

    Objective To determine whether emergency physicians (EPs) and prehospital emergency medical services (EMS) personnel differ in their assessment of motor vehicle crash (MVC) severity and the potential for serious injury when viewing crash scene photographs. Methods Attending and resident EPs, paramedics, and emergency medical technicians (EMTs) from a single emergency medicine system used a web-based survey platform to rate the severity of 100 crash photographs on a 10-point Likert scale (Crash Score) and the potential for serious injury on a 0–100% scale (Injury Score). Serious injury was defined as skull fracture or intracranial bleeding, spine fracture or spinal cord injury, intrathoracic or intraabdominal injury, or long bone fracture. Crash and Injury Scores were stratified into EP and paramedic/EMT (EMS) groups and the mean score was calculated for each photo. Spearman rank correlation coefficients with 95% confidence intervals (95% CI) and Bland-Altman plots were constructed to assess agreement. Secondary analyses were performed after categorizing data into quartiles based on participants’ estimations of MVC severity. Results A total of 54 attending and 53 resident EPs, 156 paramedics, and 34 EMTs were invited to participate in the survey. Of these, 39 (72%) attending and 46 (87%) resident EPs, 107 (69%) paramedics, and 17 (50%) EMTs completed the survey. A total of 183 (88%) surveys were completed in full. The overall Crash Score correlation coefficient between EPs and EMS was 0.98 (95% CI, 0.97–0.99). The Crash Score correlation coefficients for each quartile were 0.86 (0.57–0.97), 0.93 (0.85–0.96), 0.58 (0.16–0.85), and 0.88 (0.66–0.97), respectively. The overall Injury Score correlation coefficient between EPs and EMS was 0.98 (0.88–0.97). The Injury Score correlation coefficients for each quartile were 0.94 (0.48–0.91), 0.76 (0.50–0.92), 0.80 (0.69–1.00), and 0.94 (0.57–0.97), respectively. Conclusion Although overall agreement

  9. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

    PubMed

    Kusano, Kristofer D; Gabler, Hampton C

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G's to 0.8 G's while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G's. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% - 50% and avoid 0% - 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%. PMID:21050603

  10. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes

    PubMed Central

    Kusano, Kristofer D.; Gabler, Hampton C.

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G’s to 0.8 G’s while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G’s. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% – 50% and avoid 0% – 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%. PMID:21050603

  11. Injury Differences Between Small and Large Overlap Frontal Crashes

    PubMed Central

    Hallman, Jason J.; Yoganandan, Narayan; Pintar, Frank A.; Maiman, Dennis J.

    2011-01-01

    Because small overlap impacts have recently emerged as a crash mode posing great injury risk to occupants, a detailed analysis of US crash data was conducted using the NASS/CDS and CIREN databases. Frontal crashes were subcategorized into small overlap impact (SOI) and large overlap impact (LOI) using crash and crush characteristics from the datasets. Injuries to head, spine, chest, hip and pelvis, and lower extremities were parsed and compared between crash types. MAIS 3+ occupants in NASS/CDS and CIREN demonstrated increased incidence of head, chest, spine, and hip/pelvis injuries in SOI compared to LOI. In NASS/CDS, subgaleal hematoma represented 48.6% of SOI head injury codes but 27.6% in LOI. Cervical spine posterior element fractures also represented greater proportions of SOI spine injuries (e.g., facet fractures: 27.8 vs. 14.0%), and proximal femur fractures represented a greater proportion of hip/pelvis injuries (e.g., intertrochanteric fracture: 32.5 vs. 11.8%). Tarsal/metatarsal fractures were a lesser proportion of lower extremity injuries in SOI compared to LOI. Occupant contact points inducing these injuries were observed in CIREN cases in some instances without compartment intrusion. These injuries suggest the substantial role of occupant kinematics in SOI which may induce suboptimal occupant restraint interaction. PMID:22105392

  12. The tole of towing services at motor vehicle crashes.

    PubMed

    Dean, L; Jame, W; Ryan, G A

    1975-08-16

    A survey of tow truck services operating in a defined area of the south-east suburbs of Melbourne was undertaken to determine their potential for delivering emergency medical care at the scene of crashes. Most towing firms have an association with a panel-beating shop, and operate within a limited area of one to three miles radius. The rapid response of tow trucks to crash scenes is due to their well-developed intelligence network of "spotters" and the short distances the trucks travel. Very little first aid is provided by the drivers, although one-fifth had some first aid training at some time. In about one-half of the calls to crashes a damaged vehicle is still at the scene, in about 20% an ambulance is called, and in about 5% a hospital admission occurs. Direct observation of 22 crashes suggests that on average, tow trucks arrive at a crash scene five minutes before the ambulance, and fifteen minutes before the police. There is a good case for making first aid training a preerequisite for issue of a tow truck operator's license. PMID:1160789

  13. Motor vehicle drivers' injuries in train-motor vehicle crashes.

    PubMed

    Zhao, Shanshan; Khattak, Aemal

    2015-01-01

    The objectives of this research were to: (1) identify a more suitable model for modeling injury severity of motor vehicle drivers involved in train-motor vehicle crashes at highway-rail grade crossings from among three commonly used injury severity models and (2) to investigate factors associated with injury severity levels of motor vehicle drivers involved in train-motor vehicle crashes at such crossings. The 2009-2013 highway-rail grade crossing crash data and the national highway-rail crossing inventory data were combined to produce the analysis dataset. Four-year (2009-2012) data were used for model estimation while 2013 data were used for model validation. The three injury severity levels-fatal, injury and no injury-were based on the reported intensity of motor-vehicle drivers' injuries at highway-rail grade crossings. The three injury severity models evaluated were: ordered probit, multinomial logit and random parameter logit. A comparison of the three models based on different criteria showed that the random parameter logit model and multinomial logit model were more suitable for injury severity analysis of motor vehicle drivers involved in crashes at highway-rail grade crossings. Some of the factors that increased the likelihood of more severe crashes included higher train and vehicle speeds, freight trains, older drivers, and female drivers. Where feasible, reducing train and motor vehicle speeds and nighttime lighting may help reduce injury severities of motor vehicle drivers. PMID:25463957

  14. Urban sprawl as a risk factor in motor vehicle crashes

    USGS Publications Warehouse

    Ewing, Reid; Hamidi, Shima; Grace, James B.

    2016-01-01

    A decade ago, compactness/sprawl indices were developed for metropolitan areas and counties which have been widely used in health and other research. In this study, we first update the original county index to 2010, then develop a refined index that accounts for more relevant factors, and finally seek to test the relationship between sprawl and traffic crash rates using structural equation modelling. Controlling for covariates, we find that sprawl is associated with significantly higher direct and indirect effects on fatal crash rates. The direct effect is likely due to the higher traffic speeds in sprawling areas, and the indirect effect is due to greater vehicle miles driven in such areas. Conversely, sprawl has negative direct relationships with total crashes and non-fatal injury crashes, and these offset (and sometimes overwhelm) the positive indirect effects of sprawl on both types of crashes through the mediating effect of increased vehicle miles driven. The most likely explanation is the greater prevalence of fender benders and other minor accidents in the low speed, high conflict traffic environments of compact areas, negating the lower vehicle miles travelled per capita in such areas.

  15. Injury Risk Functions in Frontal Impacts Using Data from Crash Pulse Recorders

    PubMed Central

    Stigson, Helena; Kullgren, Anders; Rosén, Erik

    2012-01-01

    Knowledge of how crash severity influences injury risk in car crashes is essential in order to create a safe road transport system. Analyses of real-world crashes increase the ability to obtain such knowledge. The aim of this study was to present injury risk functions based on real-world frontal crashes where crash severity was measured with on-board crash pulse recorders. Results from 489 frontal car crashes (26 models of four car makes) with recorded acceleration-time history were analysed. Injury risk functions for restrained front seat occupants were generated for maximum AIS value of two or greater (MAIS2+) using multiple logistic regression. Analytical as well as empirical injury risk was plotted for several crash severity parameters; change of velocity, mean acceleration and peak acceleration. In addition to crash severity, the influence of occupant age and gender was investigated. A strong dependence between injury risk and crash severity was found. The risk curves reflect that small changes in crash severity may have a considerable influence on the risk of injury. Mean acceleration, followed by change of velocity, was found to be the single variable that best explained the risk of being injured (MAIS2+) in a crash. Furthermore, all three crash severity parameters were found to predict injury better than age and gender. However, age was an important factor. The very best model describing MAIS2+ injury risk included delta V supplemented by an interaction term of peak acceleration and age. PMID:23169136

  16. 42 CFR 495.344 - Approval of the State Medicaid HIT plan, the HIT PAPD and update, the HIT IAPD and update, and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) STANDARDS AND CERTIFICATION STANDARDS FOR THE ELECTRONIC HEALTH RECORD TECHNOLOGY INCENTIVE PROGRAM... include all of the information required under this subpart. ... 42 Public Health 5 2010-10-01 2010-10-01 false Approval of the State Medicaid HIT plan, the...

  17. AIRCRAFT DEPAINTING TECHNOLOGY

    EPA Science Inventory

    Chemical paint strippers historically used for aircraft contained toxic and hazardous components; aircraft depainting operations are a major source of hazardous waste generation in DOD. Federal and state agencies have begun to restrict using these hazardous materials and Governme...

  18. Impact and Injury Patterns in Between-Rails Frontal Crashes of Vehicles with Good Ratings for Frontal Crash Protection

    PubMed Central

    Morgan, Richard M.; Cui, Chongzhen; Digges, Kennerly H.; Cao, Libo; Kan, Cing-Dao (Steve)

    2012-01-01

    This research investigated (1) what are the key attributes of the between-rail, frontal crash, (2) what are the types of object contacted, and (3) what is the type of resulting trauma. The method was to study with both weighted and in-depth case reviews of NASS-CDS crash data with direct damage between the longitudinal rails in frontal crashes. Individual case selection was limited to belted occupants in between-rail, frontal impacts of good-rated, late-model vehicles equipped with air bags. This paper evaluates the risk of trauma for drivers in cars and LTVs in between-rail, frontal crashes, and suggests the between-rail impact is more dangerous to car drivers. Using weighted data—representing 227,305 tow-away crashes—the resulting trauma to various body regions was analyzed to suggest greatest injury is to the chest, pelvis/thigh/knee/leg, and foot/ankle. This study analyzed the type of object that caused the direct damage between the rails, including small tree or post, large tree or pole, and another vehicle; and found that the struck object was most often another vehicle or a large tree/pole. Both the extent of damage and the occupant compartment intrusion were explored, and suggest that 64% of the serious injuries are associated with increasing intrusion. Individual NASS cases were reviewed to gain a deeper understanding of the mechanical particulars in the between-rail crash. PMID:23169135

  19. Estimating national road crash fatalities using aggregate data.

    PubMed

    Ahmed, Anwaar; Khan, Beenish Akbar; Khurshid, Muhammad Bilal; Khan, Muhammad Babar; Waheed, Abdul

    2016-09-01

    Injuries and fatalities from road traffic crashes have emerged a major public health challenge in Pakistan. Reliable estimates of road crash fatalities (RCF) of a country, is a vital element needed for identification and control of key risk factors, road-safety improvement efforts and prioritizing national health. Reliability of current annual RCF estimates for Pakistan becomes highly questionable due to serious underreporting. This study aimed to predict annual RCF for Pakistan using data from World Health Organization and International Road Federation sources. An ordinary least square (OLS) regression model that relates fatality rate with different explanatory variables was developed. RCF were predicted for Pakistan for year 2012 and 2013, and results were compared with national police reported estimates. Study results indicated that there is serious underreporting of RCF in Pakistan and immediate measures are needed to improve the existing road crash recording and reporting system at the national and subnational levels. PMID:25571957

  20. Chain-reaction crash on a highway in high visibility

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2016-05-01

    We study the chain-reaction crash (multiple-vehicle collision) in high-visibility condition on a highway. In the traffic situation, drivers control their vehicles by both gear-changing and braking. Drivers change the gears according to the headway and brake according to taillights of the forward vehicle. We investigate whether or not the first collision induces the chain-reaction crash numerically. It is shown that dynamic transitions occur from no collisions, through a single collision, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We compare the multiple-vehicle collisions in high-visibility with that in low-visibility. We derive the transition points and the region maps for the chain-reaction crash in high visibility.

  1. An improved human display model for occupant crash simulation programs

    NASA Technical Reports Server (NTRS)

    Willmert, K. D.; Potter, T. E.

    1975-01-01

    An improved three-dimensional display model of a human being which can be used to display the results of three-dimensional simulation programs that predict the positions of an occupant during impact of a vehicle was presented. The model allows the user to view the occupant from any orientation in any position during the crash. The display model assumes the usual break up of the body into rigid segments which is normal for occupant crash simulation programs, but the shape of the segments in the display model are not necessarily the same as those used in the crash simulation. The display model is proportioned so as to produce a realistic drawing of the human body in any position. Joints connecting the segments are also drawn to improve realism.

  2. Option pricing during post-crash relaxation times

    NASA Astrophysics Data System (ADS)

    Dibeh, Ghassan; Harmanani, Haidar M.

    2007-07-01

    This paper presents a model for option pricing in markets that experience financial crashes. The stochastic differential equation (SDE) of stock price dynamics is coupled to a post-crash market index. The resultant SDE is shown to have stock price and time dependent volatility. The partial differential equation (PDE) for call prices is derived using risk-neutral pricing. European call prices are then estimated using Monte Carlo and finite difference methods. Results of the model show that call option prices after the crash are systematically less than those predicted by the Black-Scholes model. This is a result of the effect of non-constant volatility of the model that causes a volatility skew.

  3. Evaluation of Test/Analysis Correlation Methods for Crash Applications

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Bark, Lindley W.; Jackson, Karen E.

    2001-01-01

    A project has been initiated to improve crash test and analysis correlation. The work in this paper concentrated on the test and simulation results for a fuselage section. Two drop tests of the section were conducted. The first test was designed to excite the linear structural response for comparison with finite element modal analysis results. The second test was designed to provide data for correlation with crash simulations. An MSC.Dytran model was developed to generate nonlinear transient dynamic results. Following minor modifications, the same model was executed in MSC.Nastran to generate modal analysis results. The results presented in this paper concentrate on evaluation of correlation methodologies for crash test data and finite element simulation results.

  4. Road traffic crashes managed by Rescue 1122 in Lahore, Pakistan.

    PubMed

    Tahir, Navid; Naseer, Rizwan; Khan, Samina Mohsin; Macassa, Gloria; Hashmi, Waseem; Durrani, Mohsin

    2012-01-01

    The objective of this retrospective study was to describe demographic characteristics, injury patterns and causes of road traffic crashes (RTCs) managed by Rescue 1122 in Lahore, Pakistan during the period 2005-2010. In total 123,268 RTCs were reported and responded by Rescue 1122 ambulance service during the study period. Of the 132,504 victims of RTCs, there were 67% male and 33% female subjects, and the maximum share (65%) was reported among people aged 16-35 years. Motorcyclists were involved in 45% of crashes, with over-speeding (40%) found to be the major reason of these collisions. Similarly, minor injuries (65%) and fractures (25%) were the most reported outcome of these crashes. It is concluded that data from ambulance services, if appropriately collected, can provide valuable epidemiological information to monitor RTCs in developing countries. However, in Pakistan, the collection of data as well as the registration process needs further improvement. PMID:22047006

  5. U.S. Car Crash Deaths Down, but Still Surpass Other Nations

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159736.html U.S. Car Crash Deaths Down, But Still Surpass Other Nations ... 6, 2016 WEDNESDAY, July 6, 2016 (HealthDay News) -- Car crash deaths on American roads fell nearly one- ...

  6. U.S. Car Crash Deaths Down, but Still Surpass Other Nations

    MedlinePlus

    ... medlineplus/news/fullstory_159736.html U.S. Car Crash Deaths Down, But Still Surpass Other Nations Decline of ... WEDNESDAY, July 6, 2016 (HealthDay News) -- Car crash deaths on American roads fell nearly one-third over ...

  7. Modeling crash spatial heterogeneity: random parameter versus geographically weighting.

    PubMed

    Xu, Pengpeng; Huang, Helai

    2015-02-01

    The widely adopted techniques for regional crash modeling include the negative binomial model (NB) and Bayesian negative binomial model with conditional autoregressive prior (CAR). The outputs from both models consist of a set of fixed global parameter estimates. However, the impacts of predicting variables on crash counts might not be stationary over space. This study intended to quantitatively investigate this spatial heterogeneity in regional safety modeling using two advanced approaches, i.e., random parameter negative binomial model (RPNB) and semi-parametric geographically weighted Poisson regression model (S-GWPR). Based on a 3-year data set from the county of Hillsborough, Florida, results revealed that (1) both RPNB and S-GWPR successfully capture the spatially varying relationship, but the two methods yield notably different sets of results; (2) the S-GWPR performs best with the highest value of Rd(2) as well as the lowest mean absolute deviance and Akaike information criterion measures. Whereas the RPNB is comparable to the CAR, in some cases, it provides less accurate predictions; (3) a moderately significant spatial correlation is found in the residuals of RPNB and NB, implying the inadequacy in accounting for the spatial correlation existed across adjacent zones. As crash data are typically collected with reference to location dimension, it is desirable to firstly make use of the geographical component to explore explicitly spatial aspects of the crash data (i.e., the spatial heterogeneity, or the spatially structured varying relationships), then is the unobserved heterogeneity by non-spatial or fuzzy techniques. The S-GWPR is proven to be more appropriate for regional crash modeling as the method outperforms the global models in capturing the spatial heterogeneity occurring in the relationship that is model, and compared with the non-spatial model, it is capable of accounting for the spatial correlation in crash data. PMID:25460087

  8. Variability in Crash and Near-Crash Risk among Novice Teenage Drivers: A Naturalistic Study

    PubMed Central

    Guo, Feng; Simons-Morton, Bruce G.; Klauer, Sheila E.; Ouimet, Marie Claude; Dingus, Thomas A.; Lee, Suzanne E.

    2013-01-01

    Objective Using video monitoring technologies, we investigated teenage driving risk variation during the first 18 months of independent driving. Study design Driving data were collected on 42 teenagers whose vehicles were instrumented with sophisticated video and data recording devices. Surveys on demographic and personality characteristics were administered at baseline. Drivers were classified into three risk groups using a K-mean clustering method based on crash and near-crash (CNC) rate. The change in CNC rates over time was evaluated by mixed-effect Poisson models. Results Compared with the first three months after licensure (first quarter), the CNC rate for participants during the third, fourth and fifth quarters decreased significantly to 59%, 62%, and 48%, respectively. Three distinct risk groups were identified with CNC rates of 21.8 (high-risk), 8.3 (moderate-risk), and 2.1 (low-risk) per 10000 kilometers traveled. High- and low-risk drivers showed no significant change in CNC rates throughout the 18-month study period. CNC rates for moderate-risk drivers decreased substantially from 8.8 per 10000 kilometers in the first quarter to 0.8 and 3.2 in the fourth and fifth quarters, respectively. The three groups were not distinguishable with respect to personality characteristics. Conclusion Teenage CNC rates varied substantially, with distinct high-, moderate-, and low-risk groups. Risk declined over time only in the moderate-risk group. The high-risk drivers appeared to be insensitive to experience, with CNC rates consistently high throughout the 18-month study period, and the moderate-risk group appeared to learn from experience. PMID:23992677

  9. Aircraft noise problems

    NASA Astrophysics Data System (ADS)

    1981-01-01

    The problems related to aircraft noise were studied. Physical origin (sound), human reaction (noise), quantization of noise and sound sources of aircraft noise are discussed. Noise abatement at the source, technical, fleet-political and air traffic measures are explained. The measurements and future developments are also discussed. The position of Lufthansa as regards aircraft noise problems is depicted.

  10. Unmanned aircraft systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  11. A fuzzy logic approach to modeling a vehicle crash test

    NASA Astrophysics Data System (ADS)

    Pawlus, Witold; Karimi, Hamid; Robbersmyr, Kjell

    2013-03-01

    This paper presents an application of fuzzy approach to vehicle crash modeling. A typical vehicle to pole collision is described and kinematics of a car involved in this type of crash event is thoroughly characterized. The basics of fuzzy set theory and modeling principles based on fuzzy logic approach are presented. In particular, exceptional attention is paid to explain the methodology of creation of a fuzzy model of a vehicle collision. Furthermore, the simulation results are presented and compared to the original vehicle's kinematics. It is concluded which factors have influence on the accuracy of the fuzzy model's output and how they can be adjusted to improve the model's fidelity.

  12. Modular disposable can (MODCAN) crash cushion: A concept investigation

    NASA Technical Reports Server (NTRS)

    Knoell, A.; Wilson, A.

    1976-01-01

    A conceptual design investigation of an improved highway crash cushion system is presented. The system is referred to as a modular disposable can (MODCAN) crash system. It is composed of a modular arrangement of disposable metal beverage cans configured to serve as an effective highway impact attenuation system. Experimental data, design considerations, and engineering calculations supporting the design development are presented. Design performance is compared to that of a conventional steel drum system. It is shown that the MODCAN concepts offers the potential for smoother and safer occupant deceleration for a larger class of vehicle impact weights than the steel drum device.

  13. Analysis of NTSB Aircraft-Assisted Pilot Suicides: 1982-2014.

    PubMed

    Politano, P Michael; Walton, Robert O

    2016-04-01

    On March 24, 2015, a Germanwings aircraft crashed in the Alps. The suicidal copilot killed himself and 150 others. Pilot suicide is rare, but does happen. This research analyzed the National Transportation Safety Board's accident database (eADMS) looking for pilots who died by suicide in flight. Fifty-one suicides were identified. Gender, age, and other characteristics were examined. Average age of suicidal pilots was 38, significantly different from the average age of 45 for all male pilots involved in aircraft accidents. A discriminant function accurately identified suicidal incidents at 96%. There was a high false-positive rate limiting the usefulness of the discriminant function. PMID:27094027

  14. Prevalence and factors associated with road traffic crash among bus drivers in Hanoi, Vietnam.

    PubMed

    La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

    2013-01-01

    Bus provides a main mode of public transport in Vietnam, but the risk of road traffic crash for bus drivers is unknown. This retrospective study estimated the crash prevalence among bus drivers in Hanoi, Vietnam, and identified driver characteristics affecting their crashes. Information on bus crashes for the period 2006-2009 was collected by interviewing drivers from five bus companies in Hanoi using a structured questionnaire. Logistic regression analysis was performed to determine pertinent risk factors affecting the crash prevalence for bus drivers. Of the total 365 participants recruited, 73 drivers reported 76 crashes, giving an overall crash prevalence of 20%. Among the crashed group, three drivers (4%) were involved in two crashes during the past 3 years. Crashes mainly occurred on streets or local roads (81%). Migrant worker (adjusted odds ratio (OR) 4.26, 95% confidence interval (CI) 2.20-8.25) and insufficient income perceived (OR 2.60, 95% CI 1.37-4.93) were identified to be significantly associated with the crash risk. Further prospective and qualitative studies are needed to provide detailed crash characteristics as well as behaviour and perception of bus drivers, so that an effective intervention can be developed to improve road safety and to prevent traffic injury of these drivers. PMID:23190322

  15. 41 CFR 102-34.295 - To whom do we send crash reports?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION PERSONAL PROPERTY 34-MOTOR VEHICLE MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false To whom do we send...

  16. Characteristics of Crashes with Farm Equipment that Increase Potential for Injury

    ERIC Educational Resources Information Center

    Peek-Asa, Corinne; Sprince, Nancy L.; Whitten, Paul S.; Falb, Scott R.; Madsen, Murray D.; Zwerling, Craig

    2007-01-01

    Context: Crash fatality and injury rates are higher on rural roadways than other roadway types. Although slow-moving farm vehicles and equipment are risk factors on rural roads, little is known about the characteristics of crashes with farm vehicles/equipment. Purpose: To describe crashes and injuries for the drivers of farm vehicles/equipment and…

  17. A computer simulation of aircraft evacuation with fire

    NASA Technical Reports Server (NTRS)

    Middleton, V. E.

    1983-01-01

    A computer simulation was developed to assess passenger survival during the post-crash evacuation of a transport category aircraft when fire is a major threat. The computer code, FIREVAC, computes individual passenger exit paths and times to exit, taking into account delays and congestion caused by the interaction among the passengers and changing cabin conditions. Simple models for the physiological effects of the toxic cabin atmosphere are included with provision for including more sophisticated models as they become available. Both wide-body and standard-body aircraft may be simulated. Passenger characteristics are assigned stochastically from experimentally derived distributions. Results of simulations of evacuation trials and hypothetical evacuations under fire conditions are presented.

  18. Aircraft landing gear systems

    NASA Technical Reports Server (NTRS)

    Tanner, John A. (Editor)

    1990-01-01

    Topics presented include the laboratory simulation of landing gear pitch-plane dynamics, a summary of recent aircraft/ground vehicle friction measurement tests, some recent aircraft tire thermal studies, and an evaluation of critical speeds in high-speed aircraft. Also presented are a review of NASA antiskid braking research, titanium matrix composite landing gear development, the current methods and perspective of aircraft flotation analysis, the flow rate and trajectory of water spray produced by an aircraft tire, and spin-up studies of the Space Shuttle Orbiter main gear tire.

  19. Improved curveball hitting through the enhancement of visual cues.

    PubMed

    Osborne, K; Rudrud, E; Zezoney, F

    1990-01-01

    This study investigated the effectiveness of using visual cues to highlight the seams of baseballs to improve the hitting of curveballs. Five undergraduate varsity baseball team candidates served as subjects. Behavior change was assessed through an alternating treatments design involving unmarked balls and two treatment conditions that included baseballs with 1/4-in. and 1/8-in. orange stripes marking the seams of the baseballs. Results indicated that subjects hit a greater percentage of marked than unmarked balls. These results suggest that the addition of visual cues may be a significant and beneficial technique to enhance hitting performance. Further research is suggested regarding the training procedures, effect of feedback, rate of fading cues, generalization to live pitching, and generalization to other types of pitches. PMID:2249972

  20. Influence of Running on Pistol Shot Hit Patterns.

    PubMed

    Kerkhoff, Wim; Bolck, Annabel; Mattijssen, Erwin J A T

    2016-01-01

    In shooting scene reconstructions, risk assessment of the situation can be important for the legal system. Shooting accuracy and precision, and thus risk assessment, might be correlated with the shooter's physical movement and experience. The hit patterns of inexperienced and experienced shooters, while shooting stationary (10 shots) and in running motion (10 shots) with a semi-automatic pistol, were compared visually (with confidence ellipses) and statistically. The results show a significant difference in precision (circumference of the hit patterns) between stationary shots and shots fired in motion for both inexperienced and experienced shooters. The decrease in precision for all shooters was significantly larger in the y-direction than in the x-direction. The precision of the experienced shooters is overall better than that of the inexperienced shooters. No significant change in accuracy (shift in the hit pattern center) between stationary shots and shots fired in motion can be seen for all shooters. PMID:26331462

  1. Small transport aircraft technology

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1983-01-01

    Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

  2. Integrated Dataset of Screening Hits against Multiple Neglected Disease Pathogens

    PubMed Central

    Nwaka, Solomon; Besson, Dominique; Ramirez, Bernadette; Maes, Louis; Matheeussen, An; Bickle, Quentin; Mansour, Nuha R.; Yousif, Fouad; Townson, Simon; Gokool, Suzanne; Cho-Ngwa, Fidelis; Samje, Moses; Misra-Bhattacharya, Shailja; Murthy, P. K.; Fakorede, Foluke; Paris, Jean-Marc; Yeates, Clive; Ridley, Robert; Van Voorhis, Wesley C.; Geary, Timothy

    2011-01-01

    New chemical entities are desperately needed that overcome the limitations of existing drugs for neglected diseases. Screening a diverse library of 10,000 drug-like compounds against 7 neglected disease pathogens resulted in an integrated dataset of 744 hits. We discuss the prioritization of these hits for each pathogen and the strong correlation observed between compounds active against more than two pathogens and mammalian cell toxicity. Our work suggests that the efficiency of early drug discovery for neglected diseases can be enhanced through a collaborative, multi-pathogen approach. PMID:22247786

  3. Interval Throwing and Hitting Programs in Baseball: Biomechanics and Rehabilitation.

    PubMed

    Chang, Edward S; Bishop, Meghan E; Baker, Dylan; West, Robin V

    2016-01-01

    Baseball injuries from throwing and hitting generally occur as a consequence of the repetitive and high-energy motions inherent to the sport. Biomechanical studies have contributed to understanding the pathomechanics leading to injury and to the development of rehabilitation programs. Interval-based throwing and hitting programs are designed to return an athlete to competition through a gradual progression of sport-specific exercises. Proper warm-up and strict adherence to the program allows the athlete to return as quickly and safely as possible. PMID:26991569

  4. Direct determination of the hit locations from experimental HPGe pulses

    NASA Astrophysics Data System (ADS)

    Désesquelles, P.; Boston, A. J.; Boston, H. C.; Cresswell, J. R.; Dimmock, M. R.; Lazarus, I. H.; Ljungvall, J.; Nelson, L.; Nga, D.-T.; Nolan, P. J.; Rigby, S. V.; Simpson, J.; Van-Oanh, N.-T.

    2013-11-01

    The gamma-tracking technique optimises the determination of the energy and emission angle of gamma-rays detected by modern segmented HPGe detectors. This entails the determination, using the delivered pulse shapes, of the interaction points of the gamma-ray within the crystal. The direct method presented here allows the localisation of the hits using only a large sample of pulses detected in the actual operating conditions. No external crystal scanning system or pulse shape simulation code is needed. In order to validate this method, it is applied to sets of pulses obtained using the University of Liverpool scanning system. The hit locations are determined by the method with good precision.

  5. Multi-hit time-to-amplitude CAMAC module (MTAC)

    SciTech Connect

    Kang, H.

    1980-10-01

    A Multi-Hit Time-to-Amplitude Module (MTAC) for the SLAC Mark III drift chamber system has been designed to measure drift time by converting time-proportional chamber signals into analog levels, and converting the analog data by slow readout via a semi-autonomous controller in a CAMAC crate. The single width CAMAC module has 16 wire channels, each with a 4-hit capacity. An externally generated common start initiates an internal precision ramp voltage which is then sampled using a novel shift register gating scheme and CMOS sampling switches. The detailed design and performance specifications are described.

  6. Design of Thomson Scattering Diagnostic for HIT-SI

    NASA Astrophysics Data System (ADS)

    Morgan, Kyle; Fryett, Taylor; Golingo, Raymond; Jarboe, Tom; Victor, Brian

    2012-10-01

    Steady Inductive Helicity Injection (SIHI) is used to create a spheromak inside the HIT-SI machine. A multi-point Thomson scattering diagnostic has been designed and is under construction for the HIT-SI experiment. The system uses a 20J Ruby Laser with 20ns pulse length. The collection system allows for eight spatial measurement locations, with four being active at any time. Four polychromators are being used to spectrally resolve the scattered light. Present Langmuir probe measurements show an electron temperature of about 12eV, within the range the polychromators can resolve. Properties of system and expected measurement are given.

  7. Thermal performance of aircraft polyurethane seat cushions

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1982-01-01

    Measurements were conducted on 7.6 x 7.6 cm samples of polyurethane seat cushion material in a modified National Bureau of Standards smoke density chamber to simulate real life conditions for an onboard aircraft fire or post-crash fire. In this study, a non-flaming heat radiation condition was simulated. Two aluminized polymeric fabrics (Norfab 11HT-26-A and Preox 1100-4) and one neoprene type material in two thicknesses (Vonar 2 and 3) were tested as heat blocking layers to protect the urethane foam from rapid heat degradation. Thermogravimetric analysis and differential scanning calorimetry were performed to characterize thermally the materials tested. It was found that Vonar 2 or 3 provided approximately equal thermal protection to F.R. urethane as the aluminized fabrics, but at a significant weight penalty. The efficiency of the foams to absorb heat per unit mass loss when protected with the heat blocking layer decreases in the heating range of 2.5-5.0 W/sq cm, but remains unchanged or slightly increases in the range of 5.0-7.5 W/sq cm. The results show that at all heat flux ranges tested the usage of a heat blocking layer in aircraft seats significantly improves their thermal performance.

  8. Lidar wind shear detection for commercial aircraft

    NASA Astrophysics Data System (ADS)

    Targ, Russell; Bowles, Roland L.

    1991-08-01

    National attention has focused on the critical problem of detecting and avoiding windshear since the crash on August 2, 1985, of a Lockheed L-1011 at Dallas/Fort Worth International Airport. As part of The NASA/FAA National Integrated Windshear Program, the authors have defined a measurable windshear hazard index that can be remotely sensed from an aircraft, to give the pilot information about the wind conditions he will experience at some later time if he continues along the present flight path. The technology analysis and end- to-end performance simulation, which measures signal-to-noise ratios and resulting wind velocity errors for competing coherent lidar systems, shows that a Ho:YAG lidar at a wavelength of 2.1 micrometers and a CO2 lidar at 10.6 micrometers can give the pilot information about the line-of-sight component of a windshear threat in a region extending from his present position to 2 to 4 km in front of the aircraft. This constitutes a warning time of 20 to 40 s, even under conditions of moderately heavy precipitation. Using these results, a Coherent Lidar Airborne Shear Sensor (CLASS), using a Q-switched CO2 laser at 10.6 micrometers , is being designed and developed for flight evaluation in early 1992.

  9. Car-Crash Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Ball, Penny L.; And Others

    1974-01-01

    Describes an interesting, inexpensive, and highly motivating experiment to study uniform and accelerated motion by measuring the position of a car as it crashes into a rigid wall. Data are obtained from a sequence of pictures made by a high speed camera. (Author/SLH)

  10. MADYMO crash victim simulations: A flight safety application

    NASA Astrophysics Data System (ADS)

    Wismans, J.; Griffioen, J. A.

    1988-12-01

    MADYMO is a computer program for two- or three-dimensional simulation of human body gross motions. The program was designed particularly for crash analyses. In the past years the program was applied and validated extensively for vehicle safety research. An application is described in the field of flight safety: the simulation of a space shuttle crew escape system.

  11. Magnetorheological impact seat suspensions for ground vehicle crash mitigation

    NASA Astrophysics Data System (ADS)

    Bai, Xian-Xu; Wereley, Norman M.

    2014-04-01

    Semi-active magnetorheological energy absorbers (MREAs) are one type of the most promising actuator for both the vibration and shock control. This paper investigates the frontal crash mitigation performance of semi-active MR impact seat suspensions for ground vehicles. The characteristics of two MREAs, a conventional MREA and an MREA with an internal bypass, with an identical volume, are theoretically evaluated and compared. To explore the control effectiveness of MREAs in the shock control systems, the mechanical model of a 4-degree-of-freedom (4DOF) sliding seat suspension system with MREAs is constructed. An optimal Bingham number control, which is to minimize the crash pulse loads transmitted to occupants by utilizing maximum stroke of the MREAs based on initial velocity of crash pulse, mass, and damping, is proposed and developed to improve the crash mitigation performance of the 4DOF MR sliding seat suspension control systems. The simulated control performances of the mitigation systems based on the MREAs with different functional structures are evaluated, compared, and analyzed. The research results indicate that (1) the constant stroking load velocity range of the MREAs is of significance to evaluate the controllability of the MREAs (i.e., the effectiveness of the semi-active shock control systems), and (2) suboptimal Bingham number control cannot realize "soft landing" (i.e., either an end-stop impact or incomplete utilization of the MREA stroke happens).

  12. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air bag... conditions specified in 49 CFR 571.214 for a moving deformable barrier test. (c) The data elements required... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash...

  13. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air bag... conditions specified in 49 CFR 571.214 for a moving deformable barrier test. (c) The data elements required... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash...

  14. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air bag... conditions specified in 49 CFR 571.214 for a moving deformable barrier test. (c) The data elements required... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash...

  15. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air bag... conditions specified in 49 CFR 571.214 for a moving deformable barrier test. (c) The data elements required... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash...

  16. How Well Do Parents Manage Young Driver Crash Risks?

    ERIC Educational Resources Information Center

    Simons-Morton, Bruce G.; Hartos, Jessica L.

    2003-01-01

    Discusses strategies to guide the parents of newly licensed young drivers. Describes some of the effects of the Checkpoints program in Connecticut and Maryland on traffic citations, motor-vehicle crashes, and family management of teenage driving. (Contains 1 figure and 42 references.) (WFA)

  17. STOCK MARKET CRASH AND EXPECTATIONS OF AMERICAN HOUSEHOLDS*

    PubMed Central

    HUDOMIET, PÉTER; KÉZDI, GÁBOR; WILLIS, ROBERT J.

    2011-01-01

    SUMMARY This paper utilizes data on subjective probabilities to study the impact of the stock market crash of 2008 on households’ expectations about the returns on the stock market index. We use data from the Health and Retirement Study that was fielded in February 2008 through February 2009. The effect of the crash is identified from the date of the interview, which is shown to be exogenous to previous stock market expectations. We estimate the effect of the crash on the population average of expected returns, the population average of the uncertainty about returns (subjective standard deviation), and the cross-sectional heterogeneity in expected returns (disagreement). We show estimates from simple reduced-form regressions on probability answers as well as from a more structural model that focuses on the parameters of interest and separates survey noise from relevant heterogeneity. We find a temporary increase in the population average of expectations and uncertainty right after the crash. The effect on cross-sectional heterogeneity is more significant and longer lasting, which implies substantial long-term increase in disagreement. The increase in disagreement is larger among the stockholders, the more informed, and those with higher cognitive capacity, and disagreement co-moves with trading volume and volatility in the market. PMID:21547244

  18. Drowsy Driving Causes 1 in 5 Fatal Crashes: Report

    MedlinePlus

    ... FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Latest Health News → Article URL of this page: https://medlineplus.gov/news/fullstory_160312.html Drowsy Driving Causes 1 in 5 Fatal Crashes: Report Teens and young adults, shift- ...

  19. Orthopaedic trauma from road crashes: is enough being done?

    PubMed

    Donaldson, Lachlan H; Brooke, Kathryn; Faux, Steven G

    2009-02-01

    A file review of patients presenting to the Emergency Department of St Vincent's Hospital with fractures sustained in a road crash was completed to describe patterns of orthopaedic injury, acute intervention and separation as well as the cost of care for adult road crash victims. One-hundred and eighty-seven patients were included. 65.8% were male; 48.1% were pedestrians. Differing patterns of injury corresponded to the role of the patient in the road crash (eg, pedestrian, driver of vehicle, etc). The mean length of stay was 8.8 days. 35.2% of patients were prescribed a different analgesic at discharge to that which they had received in the previous 24 hours. 35.8% had a documented discussion regarding insurance matters, usually with a social worker. 11.9% were discharged to inpatient rehabilitation. 56.2% had orthopaedic follow-up arranged at discharge, while 4.8% were discharged to an outpatient rehabilitation clinic. The mean overall cost was $13 336, with patients aged over 65 costing the most. The quality of acute care for fractures sustained in road crashes could be improved with evidence-based analgesia management, increased screening for psychiatric sequelae, enhanced assistance with insurance matters and vocational issues, and closer follow-up. Further research into the impact of these factors on long-term recovery is warranted. PMID:19203336

  20. 49 CFR 563.10 - Crash test performance and survivability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this section when tested according to S8, S16, and S18 of 49 CFR 571.208. (b) Each vehicle subject to the requirements of 49 CFR 571.214, Side impact protection, that meets a trigger threshold or has a frontal air...

  1. Investigation of work zone crash casualty patterns using association rules.

    PubMed

    Weng, Jinxian; Zhu, Jia-Zheng; Yan, Xuedong; Liu, Zhiyuan

    2016-07-01

    Investigation of the casualty crash characteristics and contributory factors is one of the high-priority issues in traffic safety analysis. In this paper, we propose a method based on association rules to analyze the characteristics and contributory factors of work zone crash casualties. A case study is conducted using the Michigan M-94/I-94/I-94BL/I-94BR work zone crash data from 2004 to 2008. The obtained association rules are divided into two parts including rules with high-lift, and rules with high-support for the further analysis. The results show that almost all the high-lift rules contain either environmental or occupant characteristics. The majority of association rules are centered on specific characteristics, such as drinking driving, the highway with more than 4 lanes, speed-limit over 40mph and not use of traffic control devices. It should be pointed out that some stronger associated rules were found in the high-support part. With the network visualization, the association rule method can provide more understandable results for investigating the patterns of work zone crash casualties. PMID:27038500

  2. Teenaged Drivers and Fatal Crash Responsibility. Preliminary Report.

    ERIC Educational Resources Information Center

    Williams, Allan F.; Karpf, Ronald S.

    According to data obtained for the year 1978 from the Fatal Accident Reporting System (FARS) and from state governments under contract to the National Highway Traffic Safety Administration, teenaged drivers (especially males) have much higher rates of fatal crash involvement than older drivers. In addition, teenaged drivers are more likely than…

  3. Finite pressure effects on the tokamak sawtooth crash

    SciTech Connect

    Nishimura, Yasutaro

    1998-07-01

    The sawtooth crash is a hazardous, disruptive phenomenon that is observed in tokamaks whenever the safety factor at the magnetic axis is below unity. Recently, Tokamak Test Fusion Reactor (TFTR) experimental data has revealed interesting features of the dynamical pressure evolution during the crash phase. Motivated by the experimental results, this dissertation focuses on theoretical modeling of the finite pressure effects on the nonlinear stage of the sawtooth crash. The crash phase has been studied numerically employed a toroidal magnetohydrodynamic (MHD) initial value code deduced from the FAR code. For the first time, by starting from a concentric equilibrium, it has been shown that the evolution through an m/n = 1/1 magnetic island induces secondary high-n ballooning instabilities. The magnetic island evolution gives rise to convection of the pressure inside the inversion radius and builds up a steep pressure gradient across the island separatrix, or current sheet, and thereby triggers ballooning instabilities below the threshold for the axisymmetric equilibrium. Due to the onset of secondary ballooning modes, concomitant fine scale vortices and magnetic stochasticity are generated. These effects produce strong flows across the current sheet, and thereby significant modify the m = 1 driven magnetic reconnection process. The resultant interaction of the high-n ballooning modes with the magnetic reconnection process is discussed.

  4. Crash simulations of wheelchair-occupant systems in transport.

    PubMed

    Kang, W; Pilkey, W D

    1998-01-01

    A nonlinear multirigid body dynamic computer model has been developed to simulate the dynamic responses of a wheelchair-occupant system in a vehicle during a crash. The occupant, restrained by safety belts, is seated in a wheelchair that is, in turn, tied down in a vehicle. Validated extensively by crash sled tests at three laboratories, this model has been used to predict the responses of wheelchair-occupant systems in various crash environments. To evaluate the crashworthiness of different wheelchair tie-downs, the sensitivity of several design parameters, such as tiedown stiffness, wheel stiffness, and tiedown positions, has been studied using this model, and optimal values of these parameters for the wheelchair-occupant system have been obtained. Moreover, the model has been used to study the sensitivity of crash sled test pulse corridors in an effort to develop a sled test standard. It has been found that an existing ISO corridor allows large variation and should be "tightened." The model was implemented using a version of the multibody dynamic simulator, the Articulated Total Body program. PMID:9505255

  5. Maxillofacial and ocular injuries in motor vehicle crashes.

    PubMed Central

    Brookes, Christopher Noel

    2004-01-01

    BACKGROUND: Injuries from motor vehicle crashes constitute a leading cause of death in the young and a high degree of morbidity and mortality in all age groups. Facial trauma has been consistently shown to be the single most common injury to the occupants of vehicles involved in crashes. This has been confirmed by more recent studies which have demonstrated a continuing high incidence of facial fractures amongst belted drivers. Airbags have been advocated as a supplemental restraint system. However, their deployment can cause injury particularly if the driver is of short stature, unrestrained or out of position within the vehicle. METHODS: The Crash Injury Research Engineering Network (CIREN) project aims to correlate the injuries received by occupants in vehicle crashes with the biomechanics of vehicle deformation. All cases of facial injury which presented to the University of Michigan Medical Center, USA in 1999 were retrospectively evaluated with reference to the methods of occupant restraint and to the correlation between the injuries sustained and vehicle deformation. RESULTS AND CONCLUSIONS: The case analysis confirmed the value of airbags to the safety of vehicle occupants but reinforced the conclusion that they must still be considered supplemental restraint systems. New generation airbags will minimise the risk of injury even to small stature or out of position occupants as they will prevent deployment in situations where they may have an adverse effect. PMID:15140296

  6. School Bus Crash Rates on Routine and Nonroutine Routes

    ERIC Educational Resources Information Center

    O'Neal, Elizabeth; Ramirez, Marizen; Hamann, Cara; Young, Tracy; Stahlhut, Mary; Peek-Asa, Corinne

    2014-01-01

    Background: Although prior research has established that school buses are a safe form of transportation, crashes can produce catastrophic consequences. School buses have 2 types of routes: predictable, routine routes that take children to and from school and less predictable, nonroutine routes for school events. No studies have examined school bus…

  7. Aurora Flight Sciences' Perseus B Remotely Piloted Aircraft in Flight

    NASA Technical Reports Server (NTRS)

    1998-01-01

    project. The Perseus Proof-Of-Concept aircraft first flew in November 1991 and made three low-altitude flights within a month to validate the Perseus aerodynamic model and flight control systems. Next came the redesigned Perseus A, which incorporated a closed-cycle combustion system that mixed oxygen carried aboard the aircraft with engine exhaust to compensate for the thin air at high altitudes. The Perseus A was towed into the air by a ground vehicle and its engine started after it became airborne. Prior to landing, the engine was stopped, the propeller locked in horizontal position, and the Perseus A glided to a landing on its unique bicycle-type landing gear. Two Perseus A aircraft were built and made 21 flights in 1993-1994. One of the Perseus A aircraft reached over 50,000 feet in altitude on its third test flight. Although one of the Perseus A aircraft was destroyed in a crash after a vertical gyroscope failed in flight, the other aircraft completed its test program and remains on display at Aurora's facility in Manassas. Perseus B first flew Oct. 7, 1994, and made two flights in 1996 before being damaged in a hard landing on the dry lakebed after a propeller shaft failure. After a number of improvements and upgrades-including extending the original 58.5-foot wingspan to 71.5 feet to enhance high-altitude performance--the Perseus B returned to Dryden in the spring of 1998 for a series of four flights. Thereafter, a series of modifications were made including external fuel pods on the wing that more than doubled the fuel capacity to 100 gallons. Engine power was increased by more than 20 percent by boosting the turbocharger output. Fuel consumption was reduced with fuel control modifications and a leaner fuel-air mixture that did not compromise power. The aircraft again crashed on Oct. 1, 1999, near Barstow, California, suffering moderate damage to the aircraft but no property damage, fire, or injuries in the area of the crash. Perseus B is flown remotely by a pilot

  8. Effects of Enforcement Intensity on Alcohol Impaired Driving Crashes

    PubMed Central

    Fell, James C.; Waehrer, Geetha; Voas, Robert B.; Auld-Owens, Amy; Carr, Katie; Pell, Karen

    2014-01-01

    Background Research measuring levels of enforcement has investigated whether increases in police activities (e.g., checkpoints, driving-while-intoxicated [DWI] special patrols) above some baseline level are associated with reduced crashes and fatalities. Little research, however, has attempted to quantitatively measure enforcement efforts and relate different enforcement levels to specific levels of the prevalence of alcohol-impaired driving. Objective The objective of this study was to investigate the effects of law-enforcement intensity in a sample of communities on the rate of crashes involving a drinking driver. We analyzed the influence of different enforcement strategies and measures: (1) specific deterrence -annual number of driving-under-the-influence (DUI) arrests per capita; (2) general deterrence -frequency of sobriety checkpoint operations; (3) highly visible traffic enforcement -annual number of traffic stops per capita; (4) enforcement presence - number of sworn officers per capita; and (5) overall traffic enforcement - the number of other traffic enforcement citations per capita (i.e., seat belt citations, speeding tickets, and other moving violations and warnings) in each community. Methods We took advantage of nationwide data on the local prevalence of impaired driving from the 2007 National Roadside Survey (NRS), measures of DUI enforcement activity provided by the police departments that participated in the 2007 NRS, and crashes from the General Estimates System (GES) in the same locations as the 2007 NRS. We analyzed the relationship between the intensity of enforcement and the prevalence of impaired driving crashes in 22 to 26 communities with complete data. Log-linear regressions were used throughout the study. Results A higher number of DUI arrests per 10,000 driving-aged population was associated with a lower ratio of drinking-driver crashes to non-drinking-driver crashes (p=0.035) when controlling for the percentage of legally intoxicated

  9. Traffic Crash Risks in Morbidly Obese Drivers Before and After Weight Loss Surgery.

    PubMed

    Bhatti, Junaid A; Nathens, Avery B; Redelmeier, Donald A

    2016-08-01

    Morbidly obese drivers have a higher risk of road crashes because of associated conditions such as obstructive sleep apnea. We assessed whether weight loss surgery has an impact on subsequent road crash risks in morbidly obese drivers. Our longitudinal self-matched cohort analyses suggest that road crash risks are three times higher in morbidly obese drivers than the population norm. Yet, weight loss surgery yields no significant reductions in crash risks. We found similar results in patients not previously diagnosed with sleep disorders, suggesting the need to clarify the relationship of obesity with road crash risk. PMID:27216732

  10. Pulmonary fat and bone marrow embolism in aircraft accident victims.

    PubMed

    Bierre, A R; Koelmeyer, T D

    1983-04-01

    On 28 November 1979, an Air New Zealand DC10 aircraft crashed into Mt Erebus, Antarctica with the loss of 257 passengers and crew. Postmortem examinations were carried out on 231 victims in Auckland, 4641 kilometres north of the crash site, and lung tissue was present in 205 cases. Pulmonary fat emboli were present in 134 cases (65%), pulmonary bone marrow emboli in 60 (29%) and pulmonary edema in 76 cases (37%). Clear relationships were demonstrated, firstly between the extent of fat and bone marrow embolism, secondly between the extent of fat and bone marrow embolism and the presence of pulmonary edema, and thirdly between the extent of fat and bone marrow embolism and the extent of cardiovascular damage. It was apparent that death had occurred immediately following impact, and the extent of fat and bone marrow embolism varied inversely with the severity of the injuries found. The most severely injured victims were those seated in the rear cabin of the aircraft suggesting that this was the site of impact with the ground. Our studies show that pulmonary fat embolism occurs very rapidly after severe injury and is followed by increasing numbers of fat and bone marrow emboli depending on the nature of the mortal injuries. PMID:6888959

  11. The risk of groundling fatalities from unintentional airplane crashes.

    PubMed

    Thompson, K M; Rabouw, R F; Cooke, R M

    2001-12-01

    The crashes of four hijacked commercial planes on September 11, 2001, and the repeated televised images of the consequent collapse of the World Trade Center and one side of the Pentagon will inevitably change people's perceptions of the mortality risks to people on the ground from crashing airplanes. Goldstein and colleagues were the first to quantify the risk for Americans of being killed on the ground from a crashing airplane for unintentional events, providing average point estimates of 6 in a hundred million for annual risk and 4.2 in a million for lifetime risk. They noted that the lifetime risk result exceeded the commonly used risk management threshold of 1 in a million, and suggested that the risk to "groundlings" could be a useful risk communication tool because (a) it is a man-made risk (b) arising from economic activities (c) from which the victims derive no benefit and (d) exposure to which the victims cannot control. Their results have been used in risk communication. This analysis provides updated estimates of groundling fatality risks from unintentional crashes using more recent data and a geographical information system approach to modeling the population around airports. The results suggest that the average annual risk is now 1.2 in a hundred million and the lifetime risk is now 9 in ten million (below the risk management threshold). Analysis of the variability and uncertainty of this estimate, however, suggests that the exposure to groundling fatality risk varies by about a factor of approximately 100 in the spatial dimension of distance to an airport, with the risk declining rapidly outside the first 2 miles around an airport. We believe that the risk to groundlings from crashing airplanes is more useful in the context of risk communication when information about variability and uncertainty in the risk estimates is characterized, but we suspect that recent events will alter its utility in risk communication. PMID:11824678

  12. Safety performance functions for crash severity on undivided rural roads.

    PubMed

    Russo, Francesca; Busiello, Mariarosaria; Dell'Acqua, Gianluca

    2016-08-01

    The objective of this paper is to explore the effect of the road features of two-lane rural road networks on crash severity. One of the main goals is to calibrate Safety Performance Functions (SPFs) that can predict the frequency per year of injuries and fatalities on homogeneous road segments. It was found that on more than 2000km of study-road network that annual average daily traffic, lane width, curvature change rate, length, and vertical grade are important variables in explaining the severity of crashes. A crash database covering a 5-year period was examined to achieve the goals (1295 injurious crashes that included 2089 injuries and 235 fatalities). A total of 1000km were used to calibrate SPFs and the remaining 1000km reflecting the traffic, geometric, functional features of the preceding one were used to validate their effectiveness. A negative binomial regression model was used. Reflecting the crash configurations of the dataset and maximizing the validation outcomes, four main sets of SPFs were developed as follows: (a) one equation to predict only injury frequency per year for the subset where only non-fatal injuries occurred, (b) two different equations to predict injury frequency and fatality frequency per year per sub-set where at least one fa tality occurred together with one injury, and (c) only one equation to predict the total frequency per year of total casualties correlating accurate percentages to obtain the final expected frequency of injuries and fatalities per year on homogeneous road segments. Residual analysis confirms the effectiveness of the SPFs. PMID:27177393

  13. A model-based, multichannel, real-time capable sawtooth crash detector

    NASA Astrophysics Data System (ADS)

    van den Brand, H.; de Baar, M. R.; van Berkel, M.; Blanken, T. C.; Felici, F.; Westerhof, E.; Willensdorfer, M.; The ASDEX Upgrade Team; The EUROfusion MST1 Team

    2016-07-01

    Control of the time between sawtooth crashes, necessary for ITER and DEMO, requires real-time detection of the moment of the sawtooth crash. In this paper, estimation of sawtooth crash times is demonstrated using the model-based interacting multiple model (IMM) estimator, based on simplified models for the sawtooth crash. In contrast to previous detectors, this detector uses the spatial extent of the sawtooth crash as detection characteristic. The IMM estimator is tuned and applied to multiple ECE channels at once. A model for the sawtooth crash is introduced, which is used in the IMM algorithm. The IMM algorithm is applied to seven datasets from the ASDEX Upgrade tokamak. Five crash models with different mixing radii are used. All sawtooth crashes that have been identified beforehand by visual inspection of the data, are detected by the algorithm. A few additional detections are made, which upon closer inspection are seen to be sawtooth crashes, which show a partial reconnection. A closer inspection of the detected normal crashes shows that about 42% are not well fitted by any of the full reconnection models and show some characteristics of a partial reconnection. In some case, the measurement time is during the sawtooth crashes, which also results in an incorrect estimate of the mixing radius. For data provided at a sampling rate of 1 kHz, the run time of the IMM estimator is below 1 ms, thereby fulfilling real-time requirements.

  14. Influence of the strain path on crash properties of a crash-box structure by experimental and numerical approaches

    NASA Astrophysics Data System (ADS)

    Durrenberger, L.; Even, D.; Molinari, A.; Rusinek, A.

    2006-08-01

    In order to reduce the gas emission without decreasing the passengers safety, the UHSS (Ultra High Strength Steel) steels are more and more used in the automotive industry. The very high mechanical characteristics of these steels allow to reduce the car weight thanks to the thickness reduction of the structure parts. The aim of this study is to analyse the plastic pre-strain effect (forming) on the crash properties of a crash-box structure. In order to achieve this goal, experimental rheological tests have been performed by combining quasi-static tensile tests followed by dynamic tensile test (8.10 - 3 s - 1 ≤ dot{\\varepsilon} ≤ 1000 s - 1) for a TRIP steel produced by ARCELOR. The combination of these results allows to obtain a better understanding of the steel behaviour in dynamic loading under different strain paths. All these information are necessary for an efficient simulation of crash test by including a pertinent material response. A special attention is given to the influence of the previous forming process on the dynamical response of crash boxes.

  15. Computer simulations and experimental study on crash box of automobile in low speed collision

    NASA Astrophysics Data System (ADS)

    Liu, Yanjie; Ding, Lin; Yan, Shengyuan; Yang, Yongsheng

    2008-11-01

    Based on the problems of energy-absorbing components in the automobile low speed collision process, according to crash box frontal crash test in low speed as the example, the simulation analysis of crash box impact process was carried out by Hyper Mesh and LS-DYNA. Each parameter on the influence modeling was analyzed by mathematics analytical solution and test comparison, which guaranteed that the model was accurate. Combination of experiment and simulation result had determined the weakness part of crash box structure crashworthiness aspect, and improvement method of crash box crashworthiness was discussed. Through numerical simulation of the impact process of automobile crash box, the obtained analysis result was used to optimize the design of crash box. It was helpful to improve the vehicles structure and decrease the collision accident loss at most. And it was also provided a useful method for the further research on the automobile collision.

  16. Injury severity in delivery-motorcycle to vehicle crashes in the Seoul metropolitan area.

    PubMed

    Chung, Younshik; Song, Tai-Jin; Yoon, Byoung-Jo

    2014-01-01

    More than 56% of motorcycles in Korea are used for the purpose of delivering parcels and food. Since such delivery requires quick service, most motorcyclists commit traffic violations while delivering, such as crossing the centerline, speeding, running a red light, and driving in the opposite direction down one-way streets. In addition, the fatality rate for motorcycle crashes is about 12% of the fatality rate for road traffic crashes, which is considered to be high, although motorcycle crashes account for only 5% of road traffic crashes in South Korea. Therefore, the objective of this study is to analyze the injury severity of vehicle-to-motorcycle crashes that have occurred during delivery. To examine the risk of different injury levels sustained under all crash types of vehicle-to-motorcycle, this study applied an ordered probit model. Based on the results, this study proposes policy implications to reduce the injury severity of vehicle-to-motorcycle crashes during delivery. PMID:24161584

  17. [Strategy of molecular drug design: hits, leads and drug candidates].

    PubMed

    Guo, Zong-ru

    2008-09-01

    Hits, leads and drug candidates constitute three millstones in the course of drug discovery and development. The definition of drug candidates is a critical point in the value chain of drug innovation, which not only differentiates the research and development stages, but more importantly, determines the perspective and destiny of the pre-clinical and clinical studies. All outcomes from the development stage are actually attributed to the chemical structure of candidates. The quality of candidates, however, is restricted by the drug-likeness of lead compounds, which in turn is decided by the characteristics of hits. The hit-to-lead is to provide a promising and druggable structure for further development, whereas the optimization of lead compounds is a process to transform an active compound into a drug, which in essence is molecular manipulation in multi-dimensional space related to pharmacodynamic, pharmacokinetic, physico-chemical, and safety properties. This review discusses the strategic principles in hit discovery, lead identification and optimization, as well as drug candidate definition with practical examples. PMID:19048779

  18. 42 CFR 495.342 - Annual HIT IAPD requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) STANDARDS AND CERTIFICATION STANDARDS FOR THE ELECTRONIC HEALTH RECORD TECHNOLOGY INCENTIVE... delays in meeting target dates in the approved HIT technology PAPD/IAPD and approved changes to it. (c) A... status which consists of a detailed accounting of all expenditures for project development over the...

  19. Plans for Federal Reading Panel Hit a New Roadblock

    ERIC Educational Resources Information Center

    Manzo, Kathleen Kennedy

    2007-01-01

    After several years of planning and a series of false starts, a new federal venture to review reading research has hit another bureaucratic hurdle--one that could keep it from ever getting off the ground. A planned announcement last week of the membership of the Commission on Reading Research was put on hold by the National Institute for Literacy…

  20. 42 CFR 495.342 - Annual HIT IAPD requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Annual HIT IAPD requirements. 495.342 Section 495.342 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... status which consists of a detailed accounting of all expenditures for project development over the...

  1. Assessing the lipophilicity of fragments and early hits.

    PubMed

    Mortenson, Paul N; Murray, Christopher W

    2011-07-01

    A key challenge in many drug discovery programs is to accurately assess the potential value of screening hits. This is particularly true in fragment-based drug design (FBDD), where the hits often bind relatively weakly, but are correspondingly small. Ligand efficiency (LE) considers both the potency and the size of the molecule, and enables us to estimate whether or not an initial hit is likely to be optimisable to a potent, druglike lead. While size is a key property that needs to be controlled in a small molecule drug, there are a number of additional properties that should also be considered. Lipophilicity is amongst the most important of these additional properties, and here we present a new efficiency index (LLE(AT)) that combines lipophilicity, size and potency. The index is intuitively defined, and has been designed to have the same target value and dynamic range as LE, making it easily interpretable by medicinal chemists. Monitoring both LE and LLE(AT) should help both in the selection of more promising fragment hits, and controlling molecular weight and lipophilicity during optimisation. PMID:21614595

  2. Hit Identification and Optimization in Virtual Screening: Practical Recommendations Based Upon a Critical Literature Analysis

    PubMed Central

    Zhu, Tian; Cao, Shuyi; Su, Pin-Chih; Patel, Ram; Shah, Darshan; Chokshi, Heta B.; Szukala, Richard; Johnson, Michael E.; Hevener, Kirk E.

    2013-01-01

    A critical analysis of virtual screening results published between 2007 and 2011 was performed. The activity of reported hit compounds from over 400 studies was compared to their hit identification criteria. Hit rates and ligand efficiencies were calculated to assist in these analyses and the results were compared with factors such as the size of the virtual library and the number of compounds tested. A series of promiscuity, drug-like, and ADMET filters were applied to the reported hits to assess the quality of compounds reported and a careful analysis of a subset of the studies which presented hit optimization was performed. This data allowed us to make several practical recommendations with respect to selection of compounds for experimental testing, defining hit identification criteria, and general virtual screening hit criteria to allow for realistic hit optimization. A key recommendation is the use of size-targeted ligand efficiency values as hit identification criteria. PMID:23688234

  3. Spatial panel analyses of alcohol outlets and motor vehicle crashes in California: 1999–2008

    PubMed Central

    Ponicki, William R.; Gruenewald, Paul J.; Remer, Lillian G.

    2014-01-01

    Although past research has linked alcohol outlet density to higher rates of drinking and many related social problems, there is conflicting evidence of density’s association with traffic crashes. An abundance of local alcohol outlets simultaneously encourages drinking and reduces driving distances required to obtain alcohol, leading to an indeterminate expected impact on alcohol-involved crash risk. This study separately investigates the effects of outlet density on (1) the risk of injury crashes relative to population and (2) the likelihood that any given crash is alcohol-involved, as indicated by police reports and single-vehicle nighttime status of crashes. Alcohol outlet density effects are estimated using Bayesian misalignment Poisson analyses of all California ZIP codes over the years 1999–2008. These misalignment models allow panel analysis of ZIP-code data despite frequent redefinition of postal-code boundaries, while also controlling for overdispersion and the effects of spatial autocorrelation. Because models control for overall retail density, estimated alcohol-outlet associations represent the extra effect of retail establishments selling alcohol. The results indicate a number of statistically well-supported associations between retail density and crash behavior, but the implied effects on crash risks are relatively small. Alcohol-serving restaurants have a greater impact on overall crash risks than on the likelihood that those crashes involve alcohol, whereas bars primarily affect the odds that crashes are alcohol-involved. Off-premise outlet density is negatively associated with risks of both crashes and alcohol involvement, while the presence of a tribal casino in a ZIP code is linked to higher odds of police-reported drinking involvement. Alcohol outlets in a given area are found to influence crash risks both locally and in adjacent ZIP codes, and significant spatial autocorrelation also suggests important relationships across geographical units

  4. Crash risk analysis for Shanghai urban expressways: A Bayesian semi-parametric modeling approach.

    PubMed

    Yu, Rongjie; Wang, Xuesong; Yang, Kui; Abdel-Aty, Mohamed

    2016-10-01

    Urban expressway systems have been developed rapidly in recent years in China; it has become one key part of the city roadway networks as carrying large traffic volume and providing high traveling speed. Along with the increase of traffic volume, traffic safety has become a major issue for Chinese urban expressways due to the frequent crash occurrence and the non-recurrent congestions caused by them. For the purpose of unveiling crash occurrence mechanisms and further developing Active Traffic Management (ATM) control strategies to improve traffic safety, this study developed disaggregate crash risk analysis models with loop detector traffic data and historical crash data. Bayesian random effects logistic regression models were utilized as it can account for the unobserved heterogeneity among crashes. However, previous crash risk analysis studies formulated random effects distributions in a parametric approach, which assigned them to follow normal distributions. Due to the limited information known about random effects distributions, subjective parametric setting may be incorrect. In order to construct more flexible and robust random effects to capture the unobserved heterogeneity, Bayesian semi-parametric inference technique was introduced to crash risk analysis in this study. Models with both inference techniques were developed for total crashes; semi-parametric models were proved to provide substantial better model goodness-of-fit, while the two models shared consistent coefficient estimations. Later on, Bayesian semi-parametric random effects logistic regression models were developed for weekday peak hour crashes, weekday non-peak hour crashes, and weekend non-peak hour crashes to investigate different crash occurrence scenarios. Significant factors that affect crash risk have been revealed and crash mechanisms have been concluded. PMID:26847949

  5. Comparison of pregnant and non-pregnant occupant crash and injury characteristics based on national crash data.

    PubMed

    Manoogian, Sarah

    2015-01-01

    The objective of this study was to provide specific characteristics of injuries and crash characteristics for pregnant occupants from the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) database for pregnant women as a group, broken down by trimester, and compared to non-pregnant women. Using all NASS/CDS cases collected between the years 2000 and 2012 with at least one pregnant occupant, the entire pregnant data set included 321,820 vehicles, 324,535 occupants, and 640,804 injuries. The pregnant occupant data were compared to the characteristics of NASS/CDS cases for 14,719,533 non-pregnant females 13-44 years old in vehicle crashes from 2000 to 2012. Sixty five percent of pregnant women were located in the front left seat position and roughly the same percentage of pregnant women was wearing a lap and shoulder belt. The average change in velocity was 11.6 mph for pregnant women and over 50% of crashes for pregnant women were frontal collisions. From these collisions, less than seven percent of pregnant women sustained MAIS 2+ injuries. Minor differences between the pregnant and non-pregnant occupants were identified in the body region and source of injuries sustained. However, the data indicated no large differences in injury or crash characteristics based on trimester of pregnancy. Moreover, the risk of an MAIS 2+ level injury for pregnant occupants is similar to the risk of injury for non-pregnant occupants based on the total vehicle change in velocity. Overall this study provides useful data for researchers to focus future efforts in pregnant occupant research. Additionally, this study reinforces that more detailed and complete data on pregnant crashes needs to be collected to understand the risk for pregnant occupants. PMID:25463946

  6. Raptors and aircraft

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Johnson, T.H.

    1988-01-01

    Less than 5% of all bird strikes of aircraft are by raptor species, but damage to airframe structure or jet engine dysfunction are likely consequences. Beneficial aircraft-raptor interactions include the use of raptor species to frighten unwanted birds from airport areas and the use of aircraft to census raptor species. Many interactions, however, modify the raptor?s immediate behavior and some may decrease reproduction of sensitive species. Raptors may respond to aircraft stimuli by exhibiting alarm, increased heart rate, flushing or fleeing and occasionally by directly attacking intruding aircraft. To date, most studies reveal that raptor responses to aircraft are brief and do not limit reproduction; however, additional study is needed.

  7. A comparison of age level on baseball hitting kinematics.

    PubMed

    Escamilla, Rafael F; Fleisig, Glenn S; DeRenne, Coop; Taylor, Marcus K; Moorman, Claude T; Imamura, Rodney; Barakatt, Edward; Andrews, James R

    2009-08-01

    We propose that learning proper hitting kinematics should be encouraged at a young age during youth baseball because this may help reinforce proper hitting kinematics as a player progresses to higher levels of baseball in their adult years. To enhance our understanding between youth and adult baseball hitting, kinematic and temporal analyses of baseball hitting were evaluated with a high-speed motion analysis system between 12 skilled youth and 12 skilled adult baseball players. There were only a small number of temporal differences between youth and adult hitters, with adult hitters taking significantly greater time than youth hitters during the stride phase and during the swing. Compared with youth hitters, adult hitters a) had significantly greater (p < .01) lead knee flexion when the hands started to move forward; b) flexed the lead knee over a greater range of motion during the transition phase (31 degrees versus 13 degrees); c) extended the lead knee over a greater range of motion during the bat acceleration phase (59 degrees versus 32 degrees); d) maintained a more open pelvis position at lead foot off ground; and e) maintained a more open upper torso position when the hands started to move forward and a more closed upper torso position at bat-ball contact. Moreover, adult hitters had greater peak upper torso angular velocity (857 degrees/s versus 717 degrees/s), peak left elbow extension angular velocity (752 degrees/s versus 598 degrees/s), peak left knee extension angular velocity (386 degrees/s versus 303 degrees/s), and bat linear velocity at bat-ball contact (30 m/s versus 25 m/s). The numerous differences in kinematic and temporal parameters between youth and adult hitters suggest that hitting mechanics are different between these two groups. PMID:19827470

  8. One-hit models of carcinogenesis: conservative or not

    SciTech Connect

    Bailar, J.C. III; Crouch, E.A.C.; Shaikh, R.; Spiegelman, D.

    1988-12-01

    One-hit formulas are widely believed to be conservative when used to analyze carcinogenesis bioassays, in the sense that they will rarely underestimate risks of cancer at low exposures. Such formulas are generally applied to the lifetime incidence of cancer at a specific site, with risks estimated from animal data at zero dose (control), and two or more additional doses that are appreciable fractions of a maximum tolerated dose. No empirical study has demonstrated that the one-hit formula is conservative in the sense described. The Carcinogenesis Bioassay Database System contains data on 1212 separate bioassays of 308 chemical substances tested at exactly three evaluable doses. These provided sufficient data to examine 8432 specific combination of cancer site with sex, species, and chemical. For each of these they fitted a one-hit formula to the zero and maximum dose data points, then examined the relation of the fitted curve to the incidence rate observed at the mid-dose, with and without adjustment for intercurrent mortality. Both underestimates and overestimates of risk at mid-dose occurred substantially more often than expected by chance. They cannot tell whether such underestimates would occur at lower doses, but offer six biological reasons why underestimates might be expected. In a high percentage of animal bioassays, the one-hit formula is not conservative when applied in the usual way to animal data. It remains possible that the one-hit formula may indeed be conservative at sufficiently low doses (below the observational range), but the usual procedure, applied to the usual dose range, can be nonconservative in estimating the slope of the formula at such low doses. Risk assessments for regulation of carcinogens should incorporate some measure of additional uncertainty.

  9. Lightning effects on aircraft

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

  10. Aircraft fire safety research

    NASA Technical Reports Server (NTRS)

    Botteri, Benito P.

    1987-01-01

    During the past 15 years, very significant progress has been made toward enhancing aircraft fire safety in both normal and hostile (combat) operational environments. Most of the major aspects of the aircraft fire safety problem are touched upon here. The technology of aircraft fire protection, although not directly applicable in all cases to spacecraft fire scenarios, nevertheless does provide a solid foundation to build upon. This is particularly true of the extensive research and testing pertaining to aircraft interior fire safety and to onboard inert gas generation systems, both of which are still active areas of investigation.

  11. Hypersonic aircraft design

    NASA Technical Reports Server (NTRS)

    Alkamhawi, Hani; Greiner, Tom; Fuerst, Gerry; Luich, Shawn; Stonebraker, Bob; Wray, Todd

    1990-01-01

    A hypersonic aircraft is designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and it was decided that the aircraft would use one full scale turbofan-ramjet. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic region. After considering aerodynamics, aircraft design, stability and control, cooling systems, mission profile, and landing systems, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets are also taken into consideration in the final design. A hypersonic aircraft was designed which uses scramjets to accelerate from Mach 6 to Mach 10 and sustain that speed for two minutes. Different propulsion systems were considered and a full scale turbofan-ramjet was chosen. Two solid rocket boosters were added to save fuel and help the aircraft pass through the transonic reqion. After the aerodynamics, aircraft design, stability and control, cooling systems, mission profile, landing systems, and their physical interactions were considered, a conventional aircraft configuration was chosen over that of a waverider. The conventional design was chosen due to its landing characteristics and the relative expense compared to the waverider. Fuel requirements and the integration of the engine systems and their inlets were also considered in the designing process.

  12. Social costs of road crashes: An international analysis.

    PubMed

    Wijnen, Wim; Stipdonk, Henk

    2016-09-01

    This paper provides an international overview of the most recent estimates of the social costs of road crashes: total costs, value per casualty and breakdown in cost components. The analysis is based on publications about the national costs of road crashes of 17 countries, of which ten high income countries (HICs) and seven low and middle income countries (LMICs). Costs are expressed as a proportion of the gross domestic product (GDP). Differences between countries are described and explained. These are partly a consequence of differences in the road safety level, but there are also methodological explanations. Countries may or may not correct for underreporting of road crashes, they may or may not use the internationally recommended willingness to pay (WTP)-method for estimating human costs, and there are methodological differences regarding the calculation of some other cost components. The analysis shows that the social costs of road crashes in HICs range from 0.5% to 6.0% of the GDP with an average of 2.7%. Excluding countries that do not use a WTP- method for estimating human costs and countries that do not correct for underreporting, results in average costs of 3.3% of GDP. For LMICs that do correct for underreporting the share in GDP ranges from 1.1% to 2.9%. However, none of the LMICs included has performed a WTP study of the human costs. A major part of the costs is related to injuries: an average share of 50% for both HICs and LMICs. The average share of fatalities in the costs is 23% and 30% respectively. Prevention of injuries is thus important to bring down the socio-economic burden of road crashes. The paper shows that there are methodological differences between countries regarding cost components that are taken into account and regarding the methods used to estimate specific cost components. In order to be able to make sound comparisons of the costs of road crashes across countries, (further) harmonization of cost studies is recommended. This can be

  13. Fatal Traffic Crashes Involving Drinking Drivers: What have we Learned?

    PubMed Central

    Fell, James C.; Tippetts, A. Scott; Voas, Robert B.

    2009-01-01

    Alcohol involvement in fatal crashes (any driver with a blood alcohol concentration [BAC] = .01g/dL or greater) in 2007 was more than three times higher at night (6 p.m.–6 a.m.) than during the day (6 a.m.–6 p.m.) (62% versus 19%). Alcohol involvement was 35% during weekdays compared to 54% on weekends. Nearly one in four drivers (23%) of personal vehicles (e.g., passenger cars or light trucks) and more than one in four motorcyclists (27%) in fatal crashes were intoxicated (i.e., had a BAC equal to or greater than the .08 g/dL illegal limit in the United States). In contrast, only 1% of the commercial drivers of heavy trucks had BACs equal to .08 g/dL or higher. More than a quarter (26%) of the drivers with high BACs (≥.15 g/dL) did not have valid licenses. The 21- to 24-age group had the highest proportion (35%) of drivers with BACs≥.08 g/dL, followed by the 25- to 34-age group (29%). The oldest and the youngest drivers had the lowest percentages of BACs≥ .08 g/dL: those aged 75 or older were at 4%, and those aged 16 to 20 were at 17%. Utah had the lowest rate of intoxicated drivers in fatal crashes at one in every eight drivers (12%), followed by Kentucky, Indiana, Iowa, New Hampshire, and Kansas, all at 17%. Montana (31%), South Carolina (31%), and North Dakota (39%) all had more than 3 in 10 drivers in fatal crashes who were intoxicated in 2007. The United States enjoyed a remarkable downward trend in alcohol-related crashes between 1982 and 1995, which has since leveled off. That trend coincided with a period during which per capita national alcohol consumption declined, the number of young drivers decreased, and the proportion of female drivers increased. Those factors alone, however, did not appear to account for the overall reduction. This provides further evidence that impaired-driving laws and safety program activity may have been responsible for at least some of the decline. However, there was a general worldwide decline in alcohol

  14. CID-720 aircraft Langley Research Center preflight hardware tests: Development, flight acceptance and qualification

    NASA Technical Reports Server (NTRS)

    Pride, J. D.

    1986-01-01

    The testing conducted on LaRC-developed hardware for the controlled impact demonstration transport aircraft is discussed. To properly develop flight qualified crash systems, two environments were considered: the aircraft flight environment with the focus on vibration and temperature effects, and the crash environment with the long pulse shock effects. Also with the large quantity of fuel in the wing tanks the possibility of fire was considered to be a threat to data retrieval and thus fire tests were included in the development test process. The aircraft test successfully demonstrated the performance of the LaRC developed heat shields. Good telemetered data (S-band) was received during the impact and slide-out phase, and even after the aircraft came to rest. The two onboard DAS tape recorders were protected from the intense fire and high quality tape data was recovered. The complete photographic system performed as planned throughout the 40.0 sec of film supply. The four photo power distribution pallets remained in good condition and all ten onboard 16 mm high speed (400 frames/sec) cameras produced good film data.

  15. Single- versus multi-vehicle bicycle road crashes in Victoria, Australia.

    PubMed

    Boufous, Soufiane; de Rome, Liz; Senserrick, Teresa; Ivers, Rebecca Q

    2013-10-01

    The aim of the study is to compare trends, circumstances and outcomes of single- versus multi-vehicle bicycle on-road crashes in Victoria, Australia, through the analysis of police records and hospital admissions between January 2004 and December 2008. The results show that over 80% of on-road single-vehicle bicycle crashes occurred as a result of the cyclist losing control of the bicycle with the remainder involving collisions with objects. Compared with multi-vehicle crashes, single-vehicle crashes were more likely to occur in the dark, in wet conditions and in rural areas. Over half of the cyclists hospitalised as result of on-road crashes were injured in single-vehicle crashes and this proportion seems to be increasing over time. Single-vehicle crashes were associated with hospitalised injuries as severe as those resulting from multivehicle crashes. The findings highlight the significant burden of serious injury associated with single-vehicle bicycle road crashes. Further research is needed to investigate in greater detail the risk factors of these crashes and the effectiveness of countermeasures to reduce their burden. PMID:23435306

  16. Motor Vehicle Crash-Related Subdural Hematoma from Real-World Head Impact Data

    PubMed Central

    Urban, Jillian E.; Whitlow, Christopher T.; Edgerton, Colston A.; Powers, Alexander K.; Maldjian, Joseph A.

    2012-01-01

    Abstract Approximately 1,700,000 people sustain a traumatic brain injury (TBI) each year and motor vehicle crashes (MVCs) are a leading cause of hospitalization from TBI. Acute subdural hematoma (SDH) is a common intracranial injury that occurs in MVCs associated with high mortality and morbidity rates. In this study, SDH volume and midline shift have been analyzed in order to better understand occupant injury by correlating them to crash and occupant parameters. Fifty-seven head computed tomography (CT) scans were selected from the Crash Injury Research Engineering Network (CIREN) with Abbreviated Injury Scale (AIS) level 3+ SDH. Semi-automated methods were used to isolate the intracranial volume. SDH and additional occupant intracranial injuries were segmented across axial CT images, providing a total SDH injury volume. SDH volume was correlated to crash parameters and occupant characteristics. Results show a positive correlation between SDH volume and crash severity in near-side and frontal crashes. Additionally, the location of the resulting hemorrhage varied by crash type. Those with greater SDH volumes had significantly lower Glasgow Coma Scale (GCS) scores at the crash site in near-side crashes. Age and fracture type were found to be significant contributors to SDH volume. This study is a volumetric analysis of real world brain injuries and known MVC impacts. The results of this study demonstrate a relationship among SDH volume, crash mechanics, and occupant characteristics that provide a better understanding of the injury mechanisms of MVC-associated TBI. PMID:22928543

  17. Motor vehicle crash-related subdural hematoma from real-world head impact data.

    PubMed

    Urban, Jillian E; Whitlow, Christopher T; Edgerton, Colston A; Powers, Alexander K; Maldjian, Joseph A; Stitzel, Joel D

    2012-12-10

    Abstract Approximately 1,700,000 people sustain a traumatic brain injury (TBI) each year and motor vehicle crashes (MVCs) are a leading cause of hospitalization from TBI. Acute subdural hematoma (SDH) is a common intracranial injury that occurs in MVCs associated with high mortality and morbidity rates. In this study, SDH volume and midline shift have been analyzed in order to better understand occupant injury by correlating them to crash and occupant parameters. Fifty-seven head computed tomography (CT) scans were selected from the Crash Injury Research Engineering Network (CIREN) with Abbreviated Injury Scale (AIS) level 3+ SDH. Semi-automated methods were used to isolate the intracranial volume. SDH and additional occupant intracranial injuries were segmented across axial CT images, providing a total SDH injury volume. SDH volume was correlated to crash parameters and occupant characteristics. Results show a positive correlation between SDH volume and crash severity in near-side and frontal crashes. Additionally, the location of the resulting hemorrhage varied by crash type. Those with greater SDH volumes had significantly lower Glasgow Coma Scale (GCS) scores at the crash site in near-side crashes. Age and fracture type were found to be significant contributors to SDH volume. This study is a volumetric analysis of real world brain injuries and known MVC impacts. The results of this study demonstrate a relationship among SDH volume, crash mechanics, and occupant characteristics that provide a better understanding of the injury mechanisms of MVC-associated TBI. PMID:22928543

  18. Investigating driver injury severity patterns in rollover crashes using support vector machine models.

    PubMed

    Chen, Cong; Zhang, Guohui; Qian, Zhen; Tarefder, Rafiqul A; Tian, Zong

    2016-05-01

    Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns. PMID:26938584

  19. What do cyclists need to see to avoid single-bicycle crashes?

    PubMed

    Schepers, Paul; den Brinker, Berry

    2011-04-01

    The number of single-bicycle crash victims is substantial in countries with high levels of cycling. To study the role of visual characteristics of the infrastructure, such as pavement markings, in single-bicycle crashes, a study in two steps was conducted. In Study 1, a questionnaire study was conducted among bicycle crash victims (n = 734). Logistic regression was used to study the relationship between the crashes and age, light condition, alcohol use, gaze direction and familiarity with the crash scene. In Study 2, the image degrading and edge detection method (IDED-method) was used to investigate the visual characteristics of 21 of the crash scenes. The results of the studies indicate that crashes, in which the cyclist collided with a bollard or road narrowing or rode off the road, were related to the visual characteristics of bicycle facilities. Edge markings, especially in curves of bicycle tracks, and improved conspicuity of bollards are recommended. STATEMENT OF RELEVANCE: Elevated single-bicycle crash numbers are common in countries with high levels of cycling. No research has been conducted on what cyclists need to see to avoid this type of crash. The IDED-method to investigate crash scenes is new and proves to be a powerful tool to quantify 'visual accessibility'. PMID:21491274

  20. Multivariate spatial models of excess crash frequency at area level: case of Costa Rica.

    PubMed

    Aguero-Valverde, Jonathan

    2013-10-01

    Recently, areal models of crash frequency have being used in the analysis of various area-wide factors affecting road crashes. On the other hand, disease mapping methods are commonly used in epidemiology to assess the relative risk of the population at different spatial units. A natural next step is to combine these two approaches to estimate the excess crash frequency at area level as a measure of absolute crash risk. Furthermore, multivariate spatial models of crash severity are explored in order to account for both frequency and severity of crashes and control for the spatial correlation frequently found in crash data. This paper aims to extent the concept of safety performance functions to be used in areal models of crash frequency. A multivariate spatial model is used for that purpose and compared to its univariate counterpart. Full Bayes hierarchical approach is used to estimate the models of crash frequency at canton level for Costa Rica. An intrinsic multivariate conditional autoregressive model is used for modeling spatial random effects. The results show that the multivariate spatial model performs better than its univariate counterpart in terms of the penalized goodness-of-fit measure Deviance Information Criteria. Additionally, the effects of the spatial smoothing due to the multivariate spatial random effects are evident in the estimation of excess equivalent property damage only crashes. PMID:23872657

  1. Investigating the Effects of Side Airbag Deployment in Real-World Crashes Using Crash Comparison Techniques

    PubMed Central

    Loftis, Kathryn L.; Weaver, Ashley A.; Stitzel, Joel D.

    2011-01-01

    The objective of this study was to investigate side airbag (SAB) deployment in near side crashes and compare injuries and contact points between occupants with and without SAB deployment. Using NASS 2000–2008 and selecting for near side cases, with PDOF ± 20 degrees from 90 or 270, for non-pregnant adult belted occupants, there were 20,253 (weighted) SAB deployments. NASS showed that SABs have been increasing within the fleet, comprising 2% of airbags in 2000 and increasing to 33% of airbags in 2008. To investigate deployed SABs, we developed a three-step methology to pair CIREN cases to study the effects of deployment on occupant outcome. The first step involved extracting near side impacts from CIREN with adult, non-pregnant occupants seated in row 1 (drivers or right front passengers). In the second step, each case was quantitatively compared to FMVSS 214 barrier test standards using a 6 point similarity scoring system. Cases scoring at least 3 points were then qualitatively analyzed and 33 pairs of cases of the same vehicle make/model but opposite SAB status were chosen. Occupants with deployed SAB had reduced occurrences and severity of head and face, neck and cervical spine, and thoracic injuries and fewer injurious contacts to side components including the door, a-pillar, and window sill. SAB deployment was statistically significant for reducing occupant MAIS and ISS and thorax airbags were statistically significant for reducing thoracic and neck/cervical spine injury severity. The average ISS with SAB deployment was 21, while the average ISS of those without was 33. This study establishes methods for performing comparisons between CIREN cases based on regulatory conditions and shows injury reduction in key body regions with SAB deployment. PMID:22105386

  2. Protection of rear seat occupants in frontal crashes, controlling for occupant and crash characteristics.

    PubMed

    Sahraei, Elham; Soudbakhsh, Damoon; Digges, Kennerly

    2009-11-01

    In this study, the level of protection offered to rear seat occupants in frontal crashes is investigated. The Fatality Analysis Reporting System (FARS) and National Automotive Sampling System Crashworthiness Data System (NASS CDS) databases were used for the analyses. The investigation focused on: 1- estimating the fatality protection effectiveness of the rear seat position relative to the right front seat position, using the double paired comparison method, 2- evaluating the effect of control group selection method on effectiveness predictions, and 3- identifying trends in rear seat occupant protection over model years of vehicles. By applying a uniform control group to the double paired comparison analysis of FARS data, this study suggests that all ages of occupants are safer in the rear seat than in the right front seat. Effectiveness estimates ranged from 5.9% to 82% for different age groups of occupants. Results indicate that although occupants overall benefit from sitting in the rear seat compared to the right front seat, for all model year vehicles, the protective effect of the rear seat relative to that of the right front seat has decreased in the newer model year vehicles. The reduction in the effectiveness was 43.7% for unbelted occupants and 33.5% for belted occupants. Logistic regression analysis on NASS CDS data shows that vehicle model year has a significant effect (p-value = 0.0043) on increasing the risk of injury for belted rear seat occupants. Considering these results, protection of rear seat occupants deserves more attention from the automotive industry and government agencies. PMID:20058551

  3. Investigation of time and weather effects on crash types using full Bayesian multivariate Poisson lognormal models.

    PubMed

    El-Basyouny, Karim; Barua, Sudip; Islam, Md Tazul

    2014-12-01

    Previous research shows that various weather elements have significant effects on crash occurrence and risk; however, little is known about how these elements affect different crash types. Consequently, this study investigates the impact of weather elements and sudden extreme snow or rain weather changes on crash type. Multivariate models were used for seven crash types using five years of daily weather and crash data collected for the entire City of Edmonton. In addition, the yearly trend and random variation of parameters across the years were analyzed by using four different modeling formulations. The proposed models were estimated in a full Bayesian context via Markov Chain Monte Carlo simulation. The multivariate Poisson lognormal model with yearly varying coefficients provided the best fit for the data according to Deviance Information Criteria. Overall, results showed that temperature and snowfall were statistically significant with intuitive signs (crashes decrease with increasing temperature; crashes increase as snowfall intensity increases) for all crash types, while rainfall was mostly insignificant. Previous snow showed mixed results, being statistically significant and positively related to certain crash types, while negatively related or insignificant in other cases. Maximum wind gust speed was found mostly insignificant with a few exceptions that were positively related to crash type. Major snow or rain events following a dry weather condition were highly significant and positively related to three crash types: Follow-Too-Close, Stop-Sign-Violation, and Ran-Off-Road crashes. The day-of-the-week dummy variables were statistically significant, indicating a possible weekly variation in exposure. Transportation authorities might use the above results to improve road safety by providing drivers with information regarding the risk of certain crash types for a particular weather condition. PMID:25190632

  4. Evaluation of the predictability of real-time crash risk models.

    PubMed

    Xu, Chengcheng; Liu, Pan; Wang, Wei

    2016-09-01

    The primary objective of the present study was to investigate the predictability of crash risk models that were developed using high-resolution real-time traffic data. More specifically the present study sought answers to the following questions: (a) how to evaluate the predictability of a real-time crash risk model; and (b) how to improve the predictability of a real-time crash risk model. The predictability is defined as the crash probability given the crash precursor identified by the crash risk model. An equation was derived based on the Bayes' theorem for estimating approximately the predictability of crash risk models. The estimated predictability was then used to quantitatively evaluate the effects of the threshold of crash precursors, the matched and unmatched case-control design, and the control-to-case ratio on the predictability of crash risk models. It was found that: (a) the predictability of a crash risk model can be measured as the product of prior crash probability and the ratio between sensitivity and false alarm rate; (b) there is a trade-off between the predictability and sensitivity of a real-time crash risk model; (c) for a given level of sensitivity, the predictability of the crash risk model that is developed using the unmatched case-controlled sample is always better than that of the model developed using the matched case-controlled sample; and (d) when the control-to-case ratio is beyond 4:1, the increase in control-to-case ratio does not lead to clear improvements in predictability. PMID:27332063

  5. Human Factors In Aircraft Automation

    NASA Technical Reports Server (NTRS)

    Billings, Charles

    1995-01-01

    Report presents survey of state of art in human factors in automation of aircraft operation. Presents examination of aircraft automation and effects on flight crews in relation to human error and aircraft accidents.

  6. Crash test for the restricted three-body problem.

    PubMed

    Nagler, Jan

    2005-02-01

    The restricted three-body problem serves to investigate the chaotic behavior of a small body under the gravitational influence of two heavy primary bodies. We analyze numerically the phase space mixing of bounded motion, escape, and crash in this simple model of (chaotic) celestial mechanics. The presented extensive numerical analysis reveals a high degree of complexity. We extend the recently presented findings for the Copenhagen case of equal main masses to the general case of different primary body masses. Collisions of the small body onto the primaries are comparatively frequent, and their probability displays a scale-free dependence on the size of the primaries as shown for the Copenhagen case. Interpreting the crash as leaking in phase space the results are related to both chaotic scattering and the theory of leaking Hamiltonian systems. PMID:15783407

  7. Transient analysis techniques in performing impact and crash dynamic studies

    NASA Technical Reports Server (NTRS)

    Pifko, A. B.; Winter, R.

    1989-01-01

    Because of the emphasis being placed on crashworthiness as a design requirement, increasing demands are being made by various organizations to analyze a wide range of complex structures that must perform safely when subjected to severe impact loads, such as those generated in a crash event. The ultimate goal of crashworthiness design and analysis is to produce vehicles with the ability to reduce the dynamic forces experienced by the occupants to specified levels, while maintaining a survivable envelope around them during a specified crash event. DYCAST is a nonlinear structural dynamic finite element computer code that started from the plans systems of a finite element program for static nonlinear structural analysis. The essential features of DYCAST are outlined.

  8. Correlation Analysis of Automobile Crash Responses Based on Wavelet Decompositions

    NASA Astrophysics Data System (ADS)

    Cheng, Z. Q.; Pellettiere, J. A.

    2003-11-01

    Wavelets are used to analyse automobile crash responses. Crash signals are decomposed into a wavelet or wavelet packet basis, which provide an intuitive vision of impact behaviour of the vehicle structure and occupants. The decomposed signals are further divided into segments that represent vibrations occurring in certain time spans. A correlation analysis is then performed on the decomposed and segmented signals in order to determine the dynamic relationship between different parts of the structure or different segments of the body. The structural responses and the occupant responses in a full frontal impact test are analysed. It is shown that when the gross motions of the structural components are superimposed with significant short time vibrations, the occupant forward motion is basically a rigid body motion. Published by Elsevier Science Ltd.

  9. Epidemiology, causes and prevention of car rollover crashes with ejection.

    PubMed

    El-Hennawy, Hm; El-Menyar, A; Al-Thani, H; Tuma, M; Parchani, A; Abdulrahman, H; Peralta, R; Asim, M; Zarour, A; Latifi, R

    2014-07-01

    Rollover crashes (ROCs) are responsible for almost a third of all highway vehicle occupant fatalities. Although ROCs are common and serious mechanism of injury, ROCs are under-reported. To analyze the causes, mechanism, impact and prevention of ROCs, we reviewed the literature between 1984 and 2013. By utilizing the search engines PubMed, MEDLINE and EMBASE by using key words "ROCs" "Ejection" and "vehicle" the initial search yielded 241 abstracts, of which 58 articles were relevant. Most of the articles were either retrospective or experimental studies funded by automobile companies. All vehicles are susceptible to rollovers to certain extents. Despite continuing innovation in vehicles' safety, human factor is pivotal in prevention of ROCs. Distracted driving, speeding and drinking escalate the chances of rollover crashes. Wearing a seatbelt greatly improves the chances of surviving a ROC. PMID:25221693

  10. Abnormal statistical properties of stock indexes during a financial crash

    NASA Astrophysics Data System (ADS)

    Li, Wei-Shen; Liaw, Sy-Sang

    2015-03-01

    We investigate minute indexes of stock markets in 10 countries during financial crashes by dividing them into several stages according to their stock price tendencies: plunging stage (stage 1), fluctuating or rebounding stage (stage 2), and soaring stage (stage 3). The tail distributions of the returns satisfy a power law for developed markets but show a dual power-law structure for emerging markets. Prominent dual fractal structures are found during the plunging stage in developed markets, and after the plunging stage in emerging markets. The fractal analysis on the sign series of the returns yields similar dual fractal properties. The magnitude series of the returns provides surprising results during a crash. We find that developed markets have strong and weak long-range persistence in plunging and soaring stage respectively, while emerging markets behave oppositely. These results indicate that different types of markets are influenced strongly by the external shock of a crisis at different stages.

  11. Image qualification of high-speed film for crash tests

    NASA Astrophysics Data System (ADS)

    Oleksy, Jerry E.; Choi, James H.

    1994-10-01

    The Department of Transportation, National Highway Traffic Safety Administration (NHTSA) desires to develop qualifications for the film received from independent organizations that perform automobile collision performance tests. All crash tests are recorded on high-speed film. Running 18 cameras at frame rates up to 1000 frames per second is not uncommon. Some of the films acquired during the 150 to 200 ms time-frame of the actual crash are used for computation of both human and vehicle kinematics. Detailed recommendations for performing the tests are outlined by NHTSA in SAE documents. However, no specifications for film quality are defined. Problems arise when unclear and/or incorrectly exposed films result in images unsuitable for analysis. Aspects of the optical data channel that are evaluated in this paper include lighting, lenses, cameras, film, film processing, and timing. Recommendations for reliable data acquisition as well as a set of criteria are also developed.

  12. Epidemiology, Causes and Prevention of Car Rollover Crashes with Ejection

    PubMed Central

    El-Hennawy, HM; El-Menyar, A; Al-Thani, H; Tuma, M; Parchani, A; Abdulrahman, H; Peralta, R; Asim, M; Zarour, A; Latifi, R

    2014-01-01

    Rollover crashes (ROCs) are responsible for almost a third of all highway vehicle occupant fatalities. Although ROCs are common and serious mechanism of injury, ROCs are under-reported. To analyze the causes, mechanism, impact and prevention of ROCs, we reviewed the literature between 1984 and 2013. By utilizing the search engines PubMed, MEDLINE and EMBASE by using key words “ROCs” “Ejection” and “vehicle” the initial search yielded 241 abstracts, of which 58 articles were relevant. Most of the articles were either retrospective or experimental studies funded by automobile companies. All vehicles are susceptible to rollovers to certain extents. Despite continuing innovation in vehicles’ safety, human factor is pivotal in prevention of ROCs. Distracted driving, speeding and drinking escalate the chances of rollover crashes. Wearing a seatbelt greatly improves the chances of surviving a ROC. PMID:25221693

  13. Determinants of road traffic crash fatalities across Indian States.

    PubMed

    Grimm, Michael; Treibich, Carole

    2013-08-01

    This article explores the determinants of road traffic crash fatalities in India. In addition to income, the analysis considers the sociodemographic population structure, motorization levels, road and health infrastructure and road rule enforcement as potential factors. An original panel data set covering 25 Indian states is analyzed using multivariate regression analysis. Time and state fixed-effects account for unobserved heterogeneity across states and time. The rising motorization, urbanization and accompanying increase in the share of vulnerable road users, that is, pedestrians and two-wheelers, are the major drivers of road traffic crash fatalities in India. Among vulnerable road users, women form a particularly high-risk group. Higher expenditure per police officer is associated with a lower fatality rate. The results suggest that India should focus, in particular, on road infrastructure investments that allow the separation of vulnerable from other road users on improved road rule enforcement and should pay special attention to vulnerable female road users. PMID:22936645

  14. Light airplane crash tests at three flight-path angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1978-01-01

    Three similar twin engine general aviation airplane specimens were crash tested at Langley impact dynamics research facility at 27 m/sec and at flight-path angles of -15 deg, -30 deg, and -45 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  15. Light airplane crash tests at three roll angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1979-01-01

    Three similar twin engine general aviation airplanes were crash tested at the Langley impact dynamics research facility at 27 m/sec and at nominal roll angles of 0 deg, -15 deg, and -30 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  16. Car Crashes and Central Disorders of Hypersomnolence: A French Study

    PubMed Central

    Lopez, Regis; Pesenti, Carole; Plazzi, Giuseppe; Drouot, Xavier; Leu-Semenescu, Smaranda; Beziat, Severine; Arnulf, Isabelle; Dauvilliers, Yves

    2015-01-01

    Background Drowsiness compromises driving ability by reducing alertness and attentiveness, and delayed reaction times. Sleep-related car crashes account for a considerable proportion of accident at the wheel. Narcolepsy type 1 (NT1), narcolepsy type 2 (NT2) and idiopathic hypersomnia (IH) are rare central disorders of hypersomnolence, the most severe causes of sleepiness thus being potential dangerous conditions for both personal and public safety with increasing scientific, social, and political attention. Our main objective was to assess the frequency of recent car crashes in a large cohort of patients affected with well-defined central disorders of hypersomnolence versus subjects from the general population. Methods We performed a cross-sectional study in French reference centres for rare hypersomnia diseases and included 527 patients and 781 healthy subjects. All participants included needed to have a driving license, information available on potential accident events during the last 5 years, and on potential confounders; thus analyses were performed on 282 cases (71 IH, 82 NT2, 129 NT1) and 470 healthy subjects. Results Patients reported more frequently than healthy subjects the occurrence of recent car crashes (in the previous five years), a risk that was confirmed in both treated and untreated subjects at study inclusion (Untreated, OR = 2.21 95%CI = [1.30–3.76], Treated OR = 2.04 95%CI = [1.26–3.30]), as well as in all disease categories, and was modulated by subjective sleepiness level (Epworth scale and naps). Conversely, the risk of car accidents of patients treated for at least 5 years was not different to healthy subjects (OR = 1.23 95%CI = [0.56–2.69]). Main risk factors were analogous in patients and healthy subjects. Conclusion Patients affected with central disorders of hypersomnolence had increased risk of recent car crashes compared to subjects from the general population, a finding potentially reversed by long-term treatment. PMID:26052938

  17. On the Fatal Crash Experience of Older Drivers

    PubMed Central

    Kent, Richard; Henary, Basem; Matsuoka, Fumio

    2005-01-01

    This study describes the fatal crash experiences of older drivers. Data from two U.S. databases (NASS-CDS and FARS) were used. Several crash, vehicle, and occupant characteristics were compared across age groups, including vehicle type, crash direction (PDOF), severity (ΔV), and injured body region. A sub-set of 97 fatally injured drivers was chosen for a detailed case study. The mean travel speed, ΔV, and airbag deployment rate decreased significantly with age (p<0.001 unless noted). Mortality rate increased significantly with age. Older drivers killed were significantly more likely to die of a chest injury (47.3% vs. 24.0% in youngest group) and less likely to die of a head injury (22.0% vs. 47.1% in youngest group). Older drivers were more likely to die at a date after the crash date (“delayed death”), as were males (p=0.003). A 16-year-old driver had a 10.8%–12.0% probability of delayed death, while a 75-year-old had a 20.7%–22.7% probability. For those having a delayed death, the length of the delay increased significantly with age (2.9 days for age 16 vs. 7.9 for age 75). A subjective assessment of the case files indicated that frailty or a pre-existing health condition played a role in 4.3% of the younger drivers’ deaths, but 50.0% of the older group. PMID:16179160

  18. A Crash Course in using Pulsars to Detect Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Lommen, Andrea N.; NANOGrav

    2014-01-01

    A collection of well-timed millisecond pulsars makes a “pulsar timing array”, an “observatory” capable of detecting and characterizing small perturbations in spacetime called gravitational waves. In this 12-minute crash course you will learn how pulsars are timed, how you can use them to detect gravitational waves, who and what telescopes are engaged in this international enterprise, and how you can get involved.

  19. General Aviation Aircraft Reliability Study

    NASA Technical Reports Server (NTRS)

    Pettit, Duane; Turnbull, Andrew; Roelant, Henk A. (Technical Monitor)

    2001-01-01

    This reliability study was performed in order to provide the aviation community with an estimate of Complex General Aviation (GA) Aircraft System reliability. To successfully improve the safety and reliability for the next generation of GA aircraft, a study of current GA aircraft attributes was prudent. This was accomplished by benchmarking the reliability of operational Complex GA Aircraft Systems. Specifically, Complex GA Aircraft System reliability was estimated using data obtained from the logbooks of a random sample of the Complex GA Aircraft population.

  20. Cable Tensiometer for Aircraft

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2008-01-01

    The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

  1. Lightning protection of aircraft

    NASA Technical Reports Server (NTRS)

    Fisher, F. A.; Plumer, J. A.

    1977-01-01

    The current knowledge concerning potential lightning effects on aircraft and the means that are available to designers and operators to protect against these effects are summarized. The increased use of nonmetallic materials in the structure of aircraft and the constant trend toward using electronic equipment to handle flight-critical control and navigation functions have served as impetus for this study.

  2. Civil aircraft accident investigation.

    PubMed

    Haines, Daniel

    2013-01-01

    This talk reviews some historic aircraft accidents and some more recent. It reflects on the division of accident causes, considering mechanical failures and aircrew failures, and on aircrew training. Investigation results may lead to improved aircraft design, and to appropriate crew training. PMID:24057309

  3. Digital video data archive for crash test systems

    NASA Astrophysics Data System (ADS)

    Hock, Christian

    1997-04-01

    Kayser-Threde has been invested many years in developing technology used in crash testing, data acquisition and test data archiving. Since 1976 the department Measurement Systems has ben supplying European car manufacturers and test houses with ruggedized on-board data acquisition units for use in safety tests according to SAE J 211. The integration of on-board high-speed digital cameras has completed the data acquisition unit. Stationary high-speed cameras for external observation are also included in the controlling and acquisition system of the crash test site. The occupation of Kayser-Threde's department High Speed Data Systems is the design and integration of computerized data flow systems under real-time conditions. The special circumstances of crash test applications are taken into account for data acquisition, mass storage and data distribution. The two fundamental components of the video data archiving systems are, firstly, the recording of digital high-speed images as well as digital test data and secondly, an organized filing in mass archiving systems with the capability of near on-line access. In combination with sophisticated and reliable hardware components Kayser-Threde is able to deliver high performance digital data archives with storage capacities of up to 2600 TeraBytes.

  4. 75 FR 32472 - Office of the National Coordinator for Health Information Technology; HIT Standards Committee...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... HUMAN SERVICES Office of the National Coordinator for Health Information Technology; HIT Standards... Information Technology AGENCY: Office of the National Coordinator for Health Information Technology, HHS... Information Technology (ONC). Name of Committee: HIT Standards Committee. General Function of the...

  5. 77 FR 66617 - HIT Policy and Standards Committees; Workgroup Application Database

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... HUMAN SERVICES HIT Policy and Standards Committees; Workgroup Application Database AGENCY: Office of the... Application Database. The Office of the National Coordinator (ONC) has launched a new Health Information Technology Federal Advisory Committee Workgroup Application Database. Name of Committees: HIT...

  6. Aircraft operations management manual

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

  7. Why aircraft disinsection?

    PubMed Central

    Gratz, N. G.; Steffen, R.; Cocksedge, W.

    2000-01-01

    A serious problem is posed by the inadvertent transport of live mosquitoes aboard aircraft arriving from tropical countries where vector-borne diseases are endemic. Surveys at international airports have found many instances of live insects, particularly mosquitoes, aboard aircraft arriving from countries where malaria and arboviruses are endemic. In some instances mosquito species have been established in countries in which they have not previously been reported. A serious consequence of the transport of infected mosquitoes aboard aircraft has been the numerous cases of "airport malaria" reported from Europe, North America and elsewhere. There is an important on-going need for the disinsection of aircraft coming from airports in tropical disease endemic areas into nonendemic areas. The methods and materials available for use in aircraft disinsection and the WHO recommendations for their use are described. PMID:10994283

  8. Hypersonic reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Bulk, Tim; Chiarini, David; Hill, Kevin; Kunszt, Bob; Odgen, Chris; Truong, Bon

    1992-01-01

    A conceptual design of a hypersonic reconnaissance aircraft for the U.S. Navy is discussed. After eighteen weeks of work, a waverider design powered by two augmented turbofans was chosen. The aircraft was designed to be based on an aircraft carrier and to cruise 6,000 nautical miles at Mach 4;80,000 feet and above. As a result the size of the aircraft was only allowed to have a length of eighty feet, fifty-two feet in wingspan, and roughly 2,300 square feet in planform area. Since this is a mainly cruise aircraft, sixty percent of its 100,000 pound take-off weight is JP fuel. At cruise, the highest temperature that it will encounter is roughly 1,100 F, which can be handled through the use of a passive cooling system.

  9. Manual laterality and hitting performance in major league baseball.

    PubMed

    Grondin, S; Guiard, Y; Ivry, R B; Koren, S

    1999-06-01

    Asymmetrical hand function was examined in the context of expert sports performance: hitting in professional baseball. An archival study was conducted to examine the batting performance of all Major League Baseball players from 1871 to 1992, focusing on those who batted left (n = 1,059) to neutralize the game asymmetry. Among them, left-handers (n = 421) were more likely to hit with power and to strike out than right-handers (n = 638). One possible account, based on the idea of hand dominance and an analogy to tennis, is that batting left involves a double-handed forehand for left-handers and a weaker and more reliable double-handed backhand for right-handers. The results are also interpretable in the light of Y. Guiard's (1987) kinematic chain model of a between-hands asymmetrical division of labor, which provides a detailed account of why left batting is optimal for left-handers. PMID:10385985

  10. A memory model for internet hits after media exposure

    NASA Astrophysics Data System (ADS)

    Chessa, Antonio G.; Murre, Jaap M. J.

    2004-02-01

    We present a cognitive model, based on the mathematical theory of point processes, which extends the results of two studies by Johansen (Physica A 276 (2000) 338; Physica A 296 (2001) 539) on download relaxation dynamics. Responses from subjects are considered as single events, which are received from original listeners or readers and from a network of social contacts, through which a message may propagate further. We collected data on the number of daily visits at our web site after a radio interview with the second author, in which the name of the web site was mentioned. A model based on an exponential hit time distribution and a homogeneous point process for regular visitors fits our data and Johansen's very well and is superior to both the power law and the logarithmic function. The fits suggest that hit data from different sources share the same cognitive mechanism, which are controlled merely by the encoding and retrieval of the target information memorised.

  11. A Quantum Algorithm for Estimating Hitting Times of Markov Chains

    NASA Astrophysics Data System (ADS)

    Narayan Chowdhury, Anirban; Somma, Rolando

    We present a quantum algorithm to estimate the hitting time of a reversible Markov chain faster than classically possible. To this end, we show that the hitting time is given by an expected value of the inverse of a Hermitian matrix. To obtain this expected value, our algorithm combines three important techniques developed in the literature. One such a technique is called spectral gap amplification and we use it to amplify the gap of the Hermitian matrix or reduce its condition number. We then use a new algorithm by Childs, Kothari, and Somma to implement the inverse of a matrix, and finally use methods developed in the context of quantum metrology to reduce the complexity of expected-value estimation for a given precision. The authors acknowledge support from AFOSR Grant Number FA9550-12-1-0057 and the Google Research Award.

  12. A hit-and-run giant impact scenario

    NASA Astrophysics Data System (ADS)

    Reufer, Andreas; Meier, Matthias M. M.; Benz, Willy; Wieler, Rainer

    2012-09-01

    The formation of the Moon from the debris of a slow and grazing giant impact of a Mars-sized impactor on the proto-Earth (Cameron and Ward [1976]. Lunar Planet. Sci. Conf.; Canup and Asphaug [2001]. Nature 412, 708) is widely accepted today. We present an alternative scenario with a hit-and-run collision (Asphaug [2010]. Chem. Erde 70, 199) with a fractionally increased impact velocity and a steeper impact angle.

  13. Hitting moving targets with a continuously changing temporal window.

    PubMed

    de la Malla, Cristina; López-Moliner, Joan

    2015-09-01

    Hitting a moving target requires that we do not miss the target when it is around the aimed position. The time available for us not to miss the target when it is at the position of interest is usually called the time window and depends on target's speed and size. These variables, among others, have been manipulated in previous studies but kept constant within the same trial or session. Here, we present results of a hitting task in which targets underwent simple harmonic motion, which is defined by a sinusoidal function. Target velocity changes continuously in this motion and so does the time window which is shorter in the centre (peak velocity) and longer at the turning points (lowest velocity) within a single trial. We studied two different conditions in which the target moved with a reliable (across trials) amplitude displacement or reliable peak velocity, respectively, and subjects were free to decide where and when to hit it. Results show that subjects made a compromise between maximum and minimum target's speed, so that they did hit the target at intermediate speed values. Interestingly, the reliability of target peak velocity (or displacement) modulated the point of interception. When target's peak velocity was more reliable, subjects intercepted the target at positions with smaller temporal windows and the reverse was true when displacement was reliable. Subjects adapted the interceptive behaviour to the underlying statistical structure of the targets. Finally, in a control condition in which the temporal window also depended on the instant size and not only on speed, subjects intercepted the target when it moved at similar speeds than when the size was constant. This finding suggests that velocity rather than the temporal window contributed more to controlling the interceptive movements. PMID:26003129

  14. Fatalities of Pedestrians, Bicycle Riders, and Motorists Due to Distracted Driving Motor Vehicle Crashes in the U.S., 2005–2010

    PubMed Central

    Wilson, Fernando A.; Muelleman, Robert L.

    2013-01-01

    Objective Distracted driving is an increasingly deadly threat to road safety. This study documents trends in and characteristics of pedestrian, bicycle rider, and other victim deaths caused by distracted drivers on U.S. public roads. Methods We obtained data from the Fatality Analysis Reporting System database from 2005 to 2010 on every crash that resulted in at least one fatality within 30 days occurring on public roads in the U.S. Following the definition used by the National Highway Traffic Safety Administration, we identified distracted driving based on whether police investigators determined that a driver had been using a technological device, including a cell phone, onboard navigation system, computer, fax machine, two-way radio, or head-up display, or had been engaged in inattentive or careless activities. Results The rate of fatalities per 10 billion vehicle miles traveled increased from 116.1 in 2005 to 168.6 in 2010 for pedestrians and from 18.7 in 2005 to 24.6 in 2010 for bicyclists. Pedestrian victims of distracted driving crashes were disproportionately male, 25–64 years of age, and non-Hispanic white. They were also more likely to die at nighttime, be struck by a distracted driver outside of a marked crosswalk, and be in a metro location. Bicycling victims of distracted crashes were disproportionately male, non-Hispanic white, and struck by a distracted driver outside of a crosswalk. Compared with pedestrians, bicyclists were less likely to be hit in early morning. Conclusions Distracted drivers are the cause of an increasing share of fatalities found among pedestrians and bicycle riders. Policies are needed to protect pedestrians and bicycle riders as they cross intersections or travel on roadways. PMID:24179255

  15. Cognitive orientations in marathon running and "hitting the wall"

    PubMed Central

    Stevinson, C. D.; Biddle, S. J.

    1998-01-01

    OBJECTIVES: To investigate whether runners' cognitions during a marathon are related to "hitting the wall". To test a new and more comprehensive system for classifying cognition of marathon runners. METHODS: Non-elite runners (n = 66) completed a questionnaire after finishing the 1996 London marathon. The runners were recruited through the charity SPARKS for whom they were raising money by running in the race. RESULTS: Most runners reported that during the race their thoughts were internally associative, with internally dissociative thoughts being the least prevalent. Runners who "hit the wall" used more internal dissociation than other runners, indicating that it is a hazardous strategy, probably because sensory feedback is blocked. However, internal association was related to an earlier onset of "the wall", suggesting that too much attention on physical symptoms may magnify them, thereby exaggerating any discomfort. External dissociation was related to a later onset, probably because it may provide a degree of distraction but keeps attention on the race. CONCLUSIONS: "Hitting the wall" for recreational non-elite marathon runners is associated with their thought patterns during the race. In particular, "the wall" is associated with internal dissociation. 




 PMID:9773172

  16. Progress on the HIT-SI3 Experiment

    NASA Astrophysics Data System (ADS)

    Golingo, R. P.; Rogers, J. A.; Ennis, D. A.; Hansen, C. J.; Hossack, A. C.; Jarboe, T. R.; Nelson, B. A.; Marklin, G. J.; Victor, B. S.

    2012-10-01

    The HIT-SI program at the University of Washington is investigating the formation and sustainment of toroidal current using steady inductive helicity injection (SIHI). The HIT-SI experiment consists of a bow tie shaped flux conserver with two helicity injectors on opposite sides of the machine. All plasma facing surfaces are coated with an insulting material to prevent arcing. The injectors are driven 90 degrees out of phase leading to a constant rate of helicity injection. Presently toroidal currents up to three times the injector current are created in the device. Discoveries made during the operation have guided the design of an improved injection geometry. Three injectors, which will operate with 120 degree phase differences, are presently being assembled to be mounted on one side of the device. These injectors will have the same preferred direction and produce a rotating structure with less n=1 than presently used. The injectors will operate at a higher frequency. The IDCD model predicts this will lead to a further reduction of the perturbations in the confinement volume. Additional diagnostic access has been gained by placing the injectors on one of the device. The present assembly status of the injectors and additional diagnostics for HIT-SI3 will be presented.

  17. Effective progression of nuclear magnetic resonance-detected fragment hits.

    PubMed

    Eaton, Hugh L; Wyss, Daniel F

    2011-01-01

    Fragment-based drug discovery (FBDD) has become increasingly popular over the last decade as an alternate lead generation tool to HTS approaches. Several compounds have now progressed into the clinic which originated from a fragment-based approach, demonstrating the utility of this emerging field. While fragment hit identification has become much more routine and may involve different screening approaches, the efficient progression of fragment hits into quality lead series may still present a major bottleneck for the broadly successful application of FBDD. In our laboratory, we have extensive experience in fragment-based NMR screening (SbN) and the subsequent iterative progression of fragment hits using structure-assisted chemistry. To maximize impact, we have applied this approach strategically to early- and high-priority targets, and those struggling for leads. Its application has yielded a clinical candidate for BACE1 and lead series in about one third of the SbN/FBDD projects. In this chapter, we will give an overview of our strategy and focus our discussion on NMR-based FBDD approaches. PMID:21371601

  18. Carbon/graphite fiber risk analysis and assessment study: An assessment of the risk to Douglas commercial transport aircraft

    NASA Technical Reports Server (NTRS)

    Schjelderup, H. C.; Cook, C. Q.; Snyder, E.; Henning, B.; Hosford, J.; Gilles, D. L.; Swanstrom, C. W.

    1980-01-01

    The potential hazard to electrical and electronic devices should there be a release of free carbon fibers due to an aircraft crash and fire was assessed. Exposure and equipment sensitivity data were compiled for a risk analysis. Results are presented in the following areas: DC-9/DC-10 electrical/electronic component characterization; DC-9 and DC-10 fiber transfer functions; potential for transport aircraft equipment exposure to carbon fibers; and equipment vulnerability assessment. Results reflect only a negligible increase in risk for the DC-9 and DC-10 fleets either now or projected to 1993.

  19. Driver crash risk factors and prevalence evaluation using naturalistic driving data

    PubMed Central

    Dingus, Thomas A.; Guo, Feng; Lee, Suzie; Antin, Jonathan F.; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-01-01

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk. PMID:26903657

  20. Driver crash risk factors and prevalence evaluation using naturalistic driving data.

    PubMed

    Dingus, Thomas A; Guo, Feng; Lee, Suzie; Antin, Jonathan F; Perez, Miguel; Buchanan-King, Mindy; Hankey, Jonathan

    2016-03-01

    The accurate evaluation of crash causal factors can provide fundamental information for effective transportation policy, vehicle design, and driver education. Naturalistic driving (ND) data collected with multiple onboard video cameras and sensors provide a unique opportunity to evaluate risk factors during the seconds leading up to a crash. This paper uses a National Academy of Sciences-sponsored ND dataset comprising 905 injurious and property damage crash events, the magnitude of which allows the first direct analysis (to our knowledge) of causal factors using crashes only. The results show that crash causation has shifted dramatically in recent years, with driver-related factors (i.e., error, impairment, fatigue, and distraction) present in almost 90% of crashes. The results also definitively show that distraction is detrimental to driver safety, with handheld electronic devices having high use rates and risk. PMID:26903657

  1. The role of exposure in comparisons of crash risk among different drivers and driving environments.

    PubMed

    Chipman, M L; MacGregor, C G; Smiley, A M; Lee-Gosselin, M

    1993-04-01

    Crash rates based on drivers, driver-kilometers, and driver-days in the denominator were compared, using survey estimates of time and distance driven and the annual frequency of traffic crashes in Ontario. Rates by age, sex, and region were computed for all crashes and for crashes resulting in injury or fatality. Young male drivers remained at high risk for all types of denominator; older women had high rates when distance was included in the denominator. When time spent driving was substituted, men and women drivers over 60 had very similar rates. For comparisons of rural residents with urban and northern residents, time and distance give equivalent results. These findings suggest that apparent differences in crash risk per kilometre, whether for older women or for urban drivers, is explained by differences in typical driving speed and environment. Exposure time is better than distance to explain crash risk among drivers and regions with very different driving patterns and environments. PMID:8471119

  2. An examination of the environmental attributes associated with pedestrian-vehicular crashes near public schools.

    PubMed

    Clifton, Kelly J; Kreamer-Fults, Kandice

    2007-07-01

    This paper examines pedestrian-vehicular crashes in the vicinity of public schools, the severity of injuries sustained, and their relationship to the physical and social attributes near the schools. Multivariate models of crash severity and crash risk exposure were estimated as a function of social and physical characteristics of the area immediately surrounding schools in Baltimore City, Maryland. Results show that the presence of a driveway or turning bay on the school entrance decreases both crash occurrence and injury severity. Conversely, the presence of recreational facilities on the school site is positively associated with crash occurrence and injury severity of crashes. Findings related to neighborhood characteristics were mixed but the significant variables - transit access, commercial access, and population density - are generally associated with increased pedestrian demand and should be interpreted with care. The results of this study are relevant for Safe Routes to School projects and point to areas meriting further study. PMID:17174259

  3. The effectiveness of antilock brake systems on motorcycles in reducing real-life crashes and injuries.

    PubMed

    Rizzi, Matteo; Strandroth, Johan; Tingvall, Claes

    2009-10-01

    This study set out to evaluate the effectiveness of antilock brake system (ABS) technology on motorcycles in reducing real-life injury crashes and to mitigate injury severity. The study comprised an analysis of in-depth fatal crash data in Sweden during 2005-2008 to investigate the potential of ABS as well an estimate of the effectiveness of ABS in crash reduction in Sweden between 2003 and 2008 using induced exposure methods. Findings show that head-on collisions were the least ABS-affected crash types and collisions at intersections the most influenced. Induced exposure analysis showed that the overall effectiveness of ABS was 38 percent on all crashes with injuries and 48 percent on all severe and fatal crashes, with a minimum effectiveness of 11 and 17 percent, respectively. The study recommends the fitment of ABS on all new motorcycles as soon as possible and that customers only purchase motorcycles with ABS. PMID:19746312

  4. Investigation of dynamics of ELM crashes and their mitigation techniques

    SciTech Connect

    Pankin, Alexei Y.

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  5. Improving Trauma Triage Using Basic Crash Scene Data

    PubMed Central

    Ryb, Gabriel E.; Dischinger, Patricia C.

    2011-01-01

    Objective: to analyze the occurrence of severe injuries and deaths among crash victims transported to hospitals in relation to occupant and scene characteristics, including on-scene patient mobility, and their potential use in triaging patients to the appropriate level of care. Methods: the occurrence of death and ISS>15 were studied in relation to occupant, crash and mobility data readily available to EMS at the scene, using weighted NASS-CDS data. Data set was randomly split in two for model development and evaluation. Characteristics were combined to develop new triage schemes. Overtriage and undertriage rates were calculated for the NASS-CDS case trauma center allocation and for the newly developed triage schemes. Results: Compared to the NASS-CDS distribution, a scheme using patient mobility alone showed lower overtriage of those with ISS≤15 (38.8% vs. 55.5%) and lower undertriage of victims who died from their crash-related injuries (2.34% vs. 21.47%). Undertriage of injuries with ISS> 15 was similar (16.0 vs. 16.9). A scheme based on the presence of one of many scene risk factors (age>55, GCS<14, intrusion ≥18”, near lateral impact, far lateral impact with intrusion ≥12”, rollover or lack of restraint use) resulted in an undertriage of 0.86% (death) and 10.5% (ISS>15) and an overtriage of 63.4%. The combination of at least one of the scene risk factors and mobility status greatly decreased overtriage of those with ISS<15 (24.4%) with an increase in death undertriage (3.19%). Further combination of mobility and scene factors allowed for maintenance of a low undertriage (0.86%) as well as an acceptable overtriage (48%). Conclusion: Patient mobility data easily obtained at the scene of a crash allows triaging of injured patients to the appropriate facility with a high sensitivity and specificity. The addition of crash scene data to scene mobility allows further reductions on undertriaging or overtriaging. PMID:22105408

  6. Involvement rate in two-car crashes versus driver age and car mass of each involved car.

    PubMed

    Evans, L

    1985-04-01

    This work was performed to investigate how the likelihood of a two-car crash depends on the driver age and car mass for each of the two involved cars, and also to examine the special case of cars of similar mass crashing into each other. Data on 108 044 cars involved in police reported two-car crashes occurring in New York State in 1971 and 1972 were fitted to a function of the driver age and car mass for each of the two involved cars. Car registrations are used to estimate exposure. The special case of crashes between cars of similar mass is considered because of prior results on driver injuries in such crashes. It is found that "small-small" crashes (defined as a 900 kg car crashing into another 900 kg car) are about 0.3 times as likely as "big-big" crashes (an 1800 kg car crashing into another 1800 kg car), assuming equal numbers of cars driven by drivers of the same age. Combining the present results with earlier findings of increased injury risk in small-small crashes gives that such crashes injure about 70% as many drivers as big-big crashes when normalized for numbers of cars and driver age. That is, it is concluded that small-small crashes produce 30% fewer injuries than do big-big crashes. PMID:4096783

  7. An Active Flow Circulation Controlled Flap Concept for General Aviation Aircraft Applications

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Viken, Sally A.; Washburn, Anthony E.; Jenkins, Luther N.; Cagle, C. Mark

    2002-01-01

    A recent focus on revolutionary aerodynamic concepts has highlighted the technology needs of general aviation and personal aircraft. New and stringent restrictions on these types of aircraft have placed high demands on aerodynamic performance, noise, and environmental issues. Improved high lift performance of these aircraft can lead to slower takeoff and landing speeds that can be related to reduced noise and crash survivability issues. Circulation Control technologies have been around for 65 years, yet have been avoided due to trade offs of mass flow, pitching moment, perceived noise etc. The need to improve the circulation control technology for general aviation and personal air-vehicle applications is the focus of this paper. This report will describe the development of a 2-D General Aviation Circulation Control (GACC) wing concept that utilizes a pulsed pneumatic flap.

  8. To Err is Human Case Reports of Two Military Aircraft Accidents

    PubMed Central

    Dikshit, Mohan B

    2010-01-01

    It has been postulated that pilot error or in-flight incapacitation may be the main contributory factors to 70–80% of aircraft accidents. Two fatal aircraft accidents are presented in which either of the above possibilities may have played a role. The first case report describes an erroneous decision by a fighter pilot to use a seat position adjustment of the ejection seat leading to fatal injuries when he had to eject from his aircraft. Injuries to the body of the pilot, and observations on the state of his flying clothing and the ejection seat were used to postulate the mechanism of fatal injury and establish the cause of the accident. The second case report describes the sequence of events which culminated in the incapacitation of a fighter pilot while executing a routine manouevre. This resulted in a fatal air crash. Possible contributions of environmental factors which may have resulted in failure of his physiological mechanisms are discussed. PMID:21509093

  9. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false State Medicaid health information technology (HIT... Medicaid health information technology (HIT) plan requirements. Each State Medicaid HIT plan must include... Medicaid Information Technology Architecture (MITA) principles as described in the Medicaid...

  10. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false State Medicaid health information technology (HIT... Medicaid health information technology (HIT) plan requirements. Each State Medicaid HIT plan must include... Medicaid Information Technology Architecture (MITA) principles as described in the Medicaid...

  11. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false State Medicaid health information technology (HIT... Medicaid health information technology (HIT) plan requirements. Each State Medicaid HIT plan must include... Medicaid Information Technology Architecture (MITA) principles as described in the Medicaid...

  12. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false State Medicaid health information technology (HIT... Medicaid health information technology (HIT) plan requirements. Each State Medicaid HIT plan must include... Medicaid Information Technology Architecture (MITA) principles as described in the Medicaid...

  13. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false State Medicaid health information technology (HIT... Medicaid health information technology (HIT) plan requirements. Each State Medicaid HIT plan must include... Medicaid Information Technology Architecture (MITA) principles as described in the Medicaid...

  14. 77 FR 2448 - Special Local Regulation; HITS Triathlon; Corpus Christi Bayfront, Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; HITS Triathlon; Corpus Christi... from portions of the Corpus Christi Bayfront area during the HITS Triathlon on February 18th and 19th, 2012. This Special Local Regulation is necessary to ensure the safety of HITS Triathlon...

  15. Teachers' Perspectives on Hitting Back in School: Between Inexcusable Violence and Self-Defense

    ERIC Educational Resources Information Center

    Fleischmann, Amos

    2015-01-01

    Israeli schools expressly forbid a student to hit back after being attacked. In semistructured interviews, 71 Israeli educators were asked for their views on the hitting-back tactic. The interviews compared their attitude toward hitting back as teachers with their take on the matter as parents. The results, analyzed using grounded theory, show…

  16. Dissimilar Teen Crash Rates in Two Neighboring Southeastern Virginia Cities with Different High School Start Times

    PubMed Central

    Vorona, Robert Daniel; Szklo-Coxe, Mariana; Wu, Andrew; Dubik, Michael; Zhao, Yueqin; Ware, J. Catesby

    2011-01-01

    Study Objectives: Early high school start times may contribute to insufficient sleep leading to increased teen crash rate. Virginia Beach (VB) and Chesapeake are adjacent, demographically similar cities. VB high schools start 75-80 minutes earlier than Chesapeake's. We hypothesized that VB teens would manifest a higher crash rate than Chesapeake teens. Methods: The Virginia Department of Motor Vehicles (DMV) provided de-identified, aggregate 2008 and 2007 data for weekday crashes and crash times in VB and Chesapeake for drivers aged 16-18 years (“teens”), and provided 2008 and 2007 crash data for all drivers. Data allowed comparisons of VB versus Chesapeake crash rates for teens (overall and hour-by-hour), and teens versus all other ages. We compared AM and PM traffic congestion (peak hours) in the two cities. Results: In 2008, there were 12,916 and 8,459 Virginia Beach and Chesapeake 16- to 18-year-old drivers, respectively. For VB and Chesapeake, teen drivers' crash rates in 2008 were 65.8/1000 and 46.6/1000 (p < 0.001), respectively, and in 2007 were 71.2/1000 and 55.6/1000. Teen drivers' crash peaks in the morning occurred one hour earlier in VB than Chesapeake, consistent with school commute time. Congestion data for VB and Chesapeake did not explain the different crash rates. Conclusions: A significantly increased teen crash rate for both 2008 and 2007 occurred in VB, the city with earlier high school start times. Future studies using individual level data may clarify if sleep restriction, circadian dyssynchrony, and sleep inertia might contribute to this increased crash rate. Citation: Vorona RD; Szklo-Coxe M; Wu A; Dubik M; Zhao Y; Ware JC. Dissimilar teen crash rates in two neighboring southeastern Virginia cities with different high school start times. J Clin Sleep Med 2011;7(2):145-151. PMID:21509328

  17. Evaluation of Emergency-Locator-Transmitter performance in real and simulated crash tests

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1981-01-01

    Emergency locator transmitter (ELT) activation problems were investigated by testing a sampling of ELT units in actual crashes and in a special test apparatus which simulated longitudinal crash pulses with superimposed local structural resonances. The probable causes of excessive false alarms and nonactivation of ELT's during crash situations were determined. Solutions to operational and technical problems were also examined as well as the sensitivity of ELT impact switches to orientation and to local structural vibrations.

  18. Analysis of work zone rear-end crash risk for different vehicle-following patterns.

    PubMed

    Weng, Jinxian; Meng, Qiang; Yan, Xuedong

    2014-11-01

    This study evaluates rear-end crash risk associated with work zone operations for four different vehicle-following patterns: car-car, car-truck, truck-car and truck-truck. The deceleration rate to avoid the crash (DRAC) is adopted to measure work zone rear-end crash risk. Results show that the car-truck following pattern has the largest rear-end crash risk, followed by truck-truck, truck-car and car-car patterns. This implies that it is more likely for a car which is following a truck to be involved in a rear-end crash accident. The statistical test results further confirm that rear-end crash risk is statistically different between any two of the four patterns. We therefore develop a rear-end crash risk model for each vehicle-following pattern in order to examine the relationship between rear-end crash risk and its influencing factors, including lane position, the heavy vehicle percentage, lane traffic flow and work intensity which can be characterized by the number of lane reductions, the number of workers and the amount of equipment at the work zone site. The model results show that, for each pattern, there will be a greater rear-end crash risk in the following situations: (i) heavy work intensity; (ii) the lane adjacent to work zone; (iii) a higher proportion of heavy vehicles and (iv) greater traffic flow. However, the effects of these factors on rear-end crash risk are found to vary according to the vehicle-following patterns. Compared with the car-car pattern, lane position has less effect on rear-end crash risk in the car-truck pattern. The effect of work intensity on rear-end crash risk is also reduced in the truck-car pattern. PMID:25150525

  19. Predicting visibility of aircraft.

    PubMed

    Watson, Andrew; Ramirez, Cesar V; Salud, Ellen

    2009-01-01

    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration. PMID:19462007

  20. Predicting Visibility of Aircraft

    PubMed Central

    Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen

    2009-01-01

    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration. PMID:19462007

  1. Injury severity data for front and second row passengers in frontal crashes.

    PubMed

    Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud

    2016-06-01

    The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the years 2008-2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief. PMID:27077084

  2. Relationship between crash rate and hourly traffic flow on interurban motorways.

    PubMed

    Martin, Jean-Louis

    2002-09-01

    This paper describes the relationship between crash incidence rates and hourly traffic volume and discusses the influence of traffic on crash severity, based on observations made on 2000 km of French interurban motorways over 2 years. Incidence rates involving property damage-only crashes and injury-crashes are highest when traffic is lightest (under 400 vehicles/h). These incidence rates are at their lowest when traffic flows at a rate of 1000-1500 vehicles/h. For heavier traffic flows, crash incidence rates increase steadily as traffic increases on 2- and 3-lane motorways and inflect on 2-lane motorways when traffic increases to a level of 3000 vehicles/h. For an equivalent light traffic level, the number of crashes is higher on three-lane than on 2-lane motorways and higher at weekends (when truck traffic is restricted) than on weekdays. In heavy traffic, the number of crashes is higher on weekdays. We found no significant difference between the number of daytime and night-time crashes, whatever the traffic. No difference was observed in crash severity by number of lanes or period in the week for a given level of traffic. However, severity is greater at night and when hourly traffic is light. Compared to the number of vehicles on the road, light traffic is a safety problem in terms of frequency and severity, and road safety campaigns targeting motorway users to influence their behavior in these driving conditions should be introduced. PMID:12214956

  3. Using Crash Data to Develop Simulator Scenarios for Assessing Novice Driver Performance

    PubMed Central

    McDonald, Catherine C.; Tanenbaum, Jason B.; Lee, Yi-Ching; Fisher, Donald L.; Mayhew, Daniel R.; Winston, Flaura K.

    2013-01-01

    Teenage drivers are at their highest crash risk in their first 6 months or first 1,000 mi of driving. Driver training, adult-supervised practice driving, and other interventions are aimed at improving driving performance in novice drivers. Previous driver training programs have enumerated thousands of scenarios, with each scenario requiring one or more skills. Although there is general agreement about the broad set of skills needed to become a competent driver, there is no consensus set of scenarios and skills to assess whether novice drivers are likely to crash or to assess the effects of novice driver training programs on the likelihood of a crash. The authors propose that a much narrower, common set of scenarios can be used to focus on the high-risk crashes of young drivers. Until recently, it was not possible to identify the detailed set of scenarios that were specific to high-risk crashes. However, an integration of police crash reports from previous research, a number of critical simulator studies, and a nationally representative database of serious teen crashes (the National Motor Vehicle Crash Causation Survey) now make identification of these scenarios possible. In this paper, the authors propose this novel approach and discuss how to create a common set of simulated scenarios and skills to assess novice driver performance and the effects of training and interventions as they relate to high-risk crashes. PMID:23543947

  4. Overtaking, rear-end, and door crashes involving bicycles: an empirical investigation.

    PubMed

    Pai, Chih-Wei

    2011-05-01

    Recent emphasis on bicycling as an alternative to automobile transportation has underscored the need for research efforts directed at bicycle safety when sharing roadways with motorised vehicles. Much of the research attention is focused on junction accidents where motorists tend to infringe upon bicycles' right of way. Non-junction accidents where a motorist strikes a bicycle while overtaking it, or crashes into the rear of the bicycle, have been less frequently researched. Another common crash type is a door crash that involves a bicycle striking an open door of an automobile. Using British Stats19 accident data, the present study estimates a mixed multinomial model to predict the likelihood of a non-junction crash being of a certain crash type (out of three possible types). The methodological approach adopted allows for the individuals within the observations to have different parameter estimates (as opposed to a single parameter representing all observations). Main findings include that buses/coaches as collision partners were associated with overtaking crashes; and bicycles' traversing manoeuvres were associated with overtaking and rear-end collisions. Given a crash where a bicycle collides with a motorcycle/taxi, it is more likely a rear-end crash and a door crash, respectively. Implications of the research findings, the concluding remarks, and recommendations for future research are finally provided. PMID:21376922

  5. Injury severity data for front and second row passengers in frontal crashes

    PubMed Central

    Atkinson, Theresa; Leszek Gawarecki; Tavakoli, Massoud

    2016-01-01

    The data contained here were obtained from the National Highway Transportation Safety Administration׳s National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 2008–2014. This publically available data set monitors motor vehicle crashes in the United States, using a stratified random sample frame, resulting in information on approximately 5000 crashes each year that can be utilized to create national estimates for crashes. The NASS-CDS data sets document vehicle, crash, and occupant factors. These data can be utilized to examine public health, law enforcement, roadway planning, and vehicle design issues. The data provided in this brief are a subset of crash events and occupants. The crashes provided are exclusively frontal crashes. Within these crashes, only restrained occupants who were seated in the right front seat position or the second row outboard seat positions were included. The front row and second row data sets were utilized to construct occupant pairs crashes where both a right front seat occupant and a second row occupant were available. Both unpaired and paired data sets are provided in this brief. PMID:27077084

  6. Ambulance Crash Characteristics in the US Defined by the Popular Press: A Retrospective Analysis

    PubMed Central

    Sanddal, Teri L.; Sanddal, Nels D.; Ward, Nicolas; Stanley, Laura

    2010-01-01

    Ambulance crashes are a significant risk to prehospital care providers, the patients they are carrying, persons in other vehicles, and pedestrians. No uniform national transportation or medical database captures all ambulance crashes in the United States. A website captures many significant ambulance crashes by collecting reports in the popular media (the website is mentioned in the introduction). This report summaries findings from ambulance crashes for the time period of May 1, 2007 to April 30, 2009. Of the 466 crashes examined, 358 resulted in injuries to prehospital personnel, other vehicle occupants, patients being transported in the ambulance, or pedestrians. A total of 982 persons were injured as a result of ambulance crashes during the time period. Prehospital personnel were the most likely to be injured. Provider safety can and should be improved by ambulance vehicle redesign and the development of improved occupant safety restraints. Seventy-nine (79) crashes resulted in fatalities to some member of the same groups listed above. A total of 99 persons were killed in ambulance crashes during the time period. Persons in other vehicles involved in collisions with ambulances were the most likely to die as a result of crashes. In the urban environment, intersections are a particularly dangerous place for ambulances. PMID:22046532

  7. Effects of red light cameras on violations and crashes: a review of the international literature.

    PubMed

    Retting, Richard A; Ferguson, Susan A; Hakkert, A Shalom

    2003-03-01

    Red light running is a frequent cause of motor vehicle crashes and injuries. A primary countermeasure for red light running crashes is police traffic enforcement. In recent years, many police agencies have begun using automated red light cameras as a supplement to conventional enforcement methods. The present study reviewed and evaluated available evidence in the international literature regarding the effectiveness of cameras to reduce both red light violations and crashes. Camera enforcement generally reduces violations by an estimated 40-50%. In terms of crash effects, most studies contain methodological flaws that, to varying degrees, either overestimate (failure to adjust for regression to the mean) or underestimate (comparison with nearby signalized intersections affected by cameras) crash effects. Mindful of these limitations, the research generally indicates that camera enforcement can significantly reduce injury crashes at signalized intersections, in particular right-angle injury crashes. Most studies reported increases in rear-end crashes following camera installation. Taken together the studies indicate that, overall, injury crashes, including rear-end collisions, were reduced by 25-30% as a result of camera enforcement. PMID:14522657

  8. An Index For Rating the Total Secondary Safety of Vehicles from Real World Crash Data

    PubMed Central

    Newstead, S.; Watson, L.; Cameron, M.

    2007-01-01

    This study proposes a total secondary safety index for light passenger vehicles that rates the relative performance of vehicles in protecting both their own occupants and other road users in the full range of real world crash circumstances. The index estimates the risk of death or serious injury to key road users in crashes involving light passenger vehicles across the full range of crash types. The proposed index has been estimated from real world crash data from Australasia and was able to identify vehicles that have superior or inferior total secondary safety characteristics compared with the average vehicle. PMID:18184497

  9. Evaluation of emergency-locator-transmitter performance in real and simulated crash tests

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1981-01-01

    Emergency locator transmitter (ELT) activation problems were investigated by testing a sampling of ELT units in actual airplane crashes and in a special test apparatus which simulated longitudinal crash pulses with superimposed local structural resonances. Probable causes of excessive false alarms and nonactivations of ELT's during crash situations were determined and solutions to the current operational and technical problems were obtained. The results, which considered placement, mounting, and activation of ELT's under simulated crash impacts, and an evaluation of the sensitivity of ELT impact switches to orientation and to local structural vibrations are discussed.

  10. Prevalence and factors associated with road traffic crash among taxi drivers in Hanoi, Vietnam.

    PubMed

    La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

    2013-01-01

    Injury due to road traffic crash is a major cause of ill health and premature deaths in developing countries. Taxis provide a main mode of public transport in Vietnam but there has been little research on the risk of crash for taxi drivers. This retrospective study collected information on taxi crashes for the period 2006-2009 by interviewing drivers from five taxi companies in Hanoi, Vietnam, using a structured questionnaire. Of the total 1214 participants recruited, 276 drivers reported at least one crash, giving an overall crash prevalence of 22.7%. Among the crashed group, 50 drivers (18.1%) were involved in two to four crashes. Logistic regression analysis further identified age of driver, type of driving licence, employment status, perceived sufficiency of income, seat-belt usage, and traffic infringement history to be significantly associated with the crash risk. Further prospective and qualitative studies are recommended to provide detailed crash characteristics as well as behaviour and perception of taxi drivers, so that an effective intervention can be developed to improve road safety and to prevent injury of these commercial drivers. PMID:22683278

  11. The effects of roadway characteristics on farm equipment crashes: A GIS approach

    NASA Astrophysics Data System (ADS)

    Greenan, Mitchell Joseph

    Tractors and other self-propelled farm equipment, such as combines, sprayers, and towed grain carts, are often used on public roadways as the primary means for traveling from homestead to homestead or from homestead to a distributer. Increased roadway exposure has led to a growing concern for crashes involving farm equipment on the public roadway. A handful of studies exist examining public roadway crashes involving farm equipment using crash data, but none thus far have evaluated road segment data to identify road-specific risk factors. The objective of this study is to identify if roadway characteristics (traffic density, speed limit, road type, surface type, road width, and shoulder width) affect the risk of a crash involving farm equipment on Iowa public roadways. A retrospective cohort study of Iowa roads was conducted to identify the types of roads that are at an increased risk of having a farm-equipment crash on them. Crash data from the Iowa Department of Transportation (to identify crashes) were spatial linked to Iowa roadway data using Geographic Information Systems (GIS). Logistic regression was used to calculate ORs and 95% CL. Out of 319,705 road segments in Iowa, 0.4% segments (n=1,337) had a farm equipment crash from 2005-2011. The odds of having a farm equipment crash were significantly higher for road segments with increased traffic density and speed limit. Roads with an average daily traffic volume of at least 1,251 vehicles were at a 5.53 times greater odds of having a crash than roads with a daily traffic volume between 0-30 vehicles. (CI: 3.90-7.83). Roads with a posted speed limit between 50mph and 60mph were at a 4.88 times greater odds of having a crash than roads with a posted speed limit of 30mph or less. (CI: 3.85-6.20). Specific roadway characteristics such as roadway and shoulder width were also associated with the risk of a crash. For every 5 foot increase in road width, the odds for a crash decreased by 6 percent (CI: 0.89-0.99) and

  12. Comparative analysis of PA-31-350 Chieftain (N44LV) accident and NASA crash test data

    NASA Technical Reports Server (NTRS)

    Hayduk, R. J.

    1979-01-01

    A full scale, controlled crash test to simulate the crash of a Piper PA-31-350 Chieftain airplane is described. Comparisons were performed between the simulated crash and the actual crash in order to assess seat and floor behavior, and to estimate the acceleration levels experienced in the craft at the time of impact. Photographs, acceleration histories, and the tested airplane crash data is used to augment the accident information to better define the crash conditions. Measured impact parameters are presented along with flight path velocity and angle in relation to the impact surface.

  13. Loftin Collection - Boeing Aircraft

    NASA Technical Reports Server (NTRS)

    1933-01-01

    Either a F2B-1 or F3B-1, both aircraft were built by Boeing and both were powered by Pratt and Whitney Wasp engines. These fighters were intended for Navy shipboard use. Boeing F3B-1: While most Boeing F3B-1s served the U. S. Navy aircraft carriers the Lexington and the Saratoga, this example flew in NACA hands at the Langley Memorial Aeronautical Laboratory in the late 1920's. Also known as the Boeing Model 77, the aircraft was the next to last F3B-1 build in November 1928.

  14. OVRhyp, Scramjet Test Aircraft

    NASA Technical Reports Server (NTRS)

    Aslan, J.; Bisard, T.; Dallinga, S.; Draper, K.; Hufford, G.; Peters, W.; Rogers, J.

    1990-01-01

    A preliminary design for an unmanned hypersonic research vehicle to test scramjet engines is presented. The aircraft will be launched from a carrier aircraft at an altitude of 40,000 feet at Mach 0.8. The vehicle will then accelerate to Mach 6 at an altitude of 100,000 feet. At this stage the prototype scramjet will be employed to accelerate the vehicle to Mach 10 and maintain Mach 10 flight for 2 minutes. The aircraft will then decelerate and safely land.

  15. Some fighter aircraft trends

    NASA Technical Reports Server (NTRS)

    Spearman, L.

    1985-01-01

    Some basic trends in fighters are traced from the post World II era. Beginning with the first operational jet fighter, the P-80, the characteristics of subsequent fighter aircraft are examined for performance, mission capability, effectiveness, and cost. Characteristics presented include: power loading, wing loading, maximum speed, rate of climb, turn rate, weight and weight distribution, cost and cost distribution. The characteristics of some USSR aircraft are included for comparison. The trends indicate some of the rationale for certain fighter designs and some likely characteristics to be sought in future fighter aircraft designs.

  16. Tropospheric sampling with aircraft

    SciTech Connect

    Daum, P.H.; Springston, S.R.

    1991-03-01

    Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.

  17. Aircraft compass characteristics

    NASA Technical Reports Server (NTRS)

    Peterson, John B; Smith, Clyde W

    1937-01-01

    A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

  18. Microwave imaging of aircraft

    NASA Astrophysics Data System (ADS)

    Steinberg, Bernard D.

    1988-12-01

    Three methods of imaging aircraft from the ground with microwave radar with quality suitable for aircraft target recognition are described. The imaging methods are based on a self-calibration procedure called adaptive beamforming that compensates for the severe geometric distortion inherent in any imaging system that is large enough to achieve the high angular resolution necessary for two-dimensional target imaging. The signal processing algorithm is described and X-band (3-cm)-wavelength experiments demonstrate its success on commercial aircraft flying into Philadelphia International Airport.

  19. Aircraft accident report: NASA 712, Convair 990, N712NA, March Air Force Base, California, July 17, 1985, facts and analysis

    NASA Technical Reports Server (NTRS)

    Batthauer, Byron E.; Mccarthy, G. T.; Hannah, Michael; Hogan, Robert J.; Marlow, Frank J.; Reynard, William D.; Stoklosa, Janis H.; Yager, Thomas J.

    1986-01-01

    On July 17, l985, at 1810 P.d.t., NASA 712, a Convair 990 aircraft, was destroyed by fire at March Air Force Base, California. The fire started during the rollout after the pilot rejected the takeoff on runway 32. The rejected takeoff was initiated during the takeoff roll because of blown tires on the right landing gear. During the rollout, fragments of either the blown tires or the wheel/brake assemblies penetrated a right-wing fuel tank forward of the right main landing gear. Leaking fuel ignited while the aircraft was rolling, and fire engulfed the right wing and the fuselage after the aircraft was stopped on the runway. The 4-man flightcrew and the 15 scientists and technicians seated in the cabin evacuated the aircraft without serious injury. The fire was not extinguished by crash/rescue efforts and the aircraft was destroyed.

  20. Aircraft electromagnetic compatibility

    NASA Technical Reports Server (NTRS)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.