Evaluation of 2009 Oregon crash data reported to the Motor Carrier Management Information System Crash File

This report is part of a series evaluating the data reported to the Motor Carrier Management Information System (MCMIS) Crash File undertaken by the Center for National Truck and Bus Statistics at the University of Michigan Transportation Research Institute. Earlier studies have shown that reporting to the MCMIS Crash File was generally incomplete. This report examines reporting by the State of Oregon. Because key variables used in the evaluation process are not recorded in the computerized state data files, it was not possible to calculate an overall reporting rate for Oregon. It appears that Oregon reported 28 of 30 qualifying vehicles in fatal crashes, and the 1,120 total vehicles actually reported is reasonably close to the number predicted by a model that estimates the number of vehicles reportable to the MCMIS Crash file. However, it was not possible to evaluate the extent of underreporting or overreporting. An evaluation of timeliness in reporting shows that Oregon tended to upload records to the MCMIS Crash file well after the 90-day grace period ended. Only about 5 percent of records submitted were uploaded within the grace period. Missing data rates are low for most variables, though specific problems were noted with the hazmat variables. Corresponding data elements in the MCMIS and Oregon crash files were reasonably consistent except as noted with the straight truck and truck tractor configurationsFederal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89597/1/102789.pd

Evaluation of 2009 Virginia crash data reported to the Motor Carrier Management Information System Crash File

This report is part of a series evaluating the data reported to the Motor Carrier Management Information System (MCMIS) Crash File undertaken by the Center for National Truck and Bus Statistics at the University of Michigan Transportation Research Institute. Earlier studies have shown that reporting to the MCMIS Crash File was generally incomplete. This report examines the factors that are associated with reporting rates for the State of Virginia. MCMIS Crash File records were matched to the Virginia Crash file to determine the nature and extent of underreporting. Overall, it appears that Virginia is reporting 75.2 percent of crash involvements that should be reported to the MCMIS Crash file. Because police officers are instructed to code tractors with trailers as single unit trucks with three axles, reporting rates by truck configuration were not calculated, but the reporting rate for all trucks is 76.1 percent, and the reporting rate for buses is 67.4 percent. The reporting rate for fatal crashes is 84.1 percent, 77.3 percent for injured/transported crashes, and 73.0 percent for towed/disabled crashes. The Virginia Police Crash Report form has a Commercial Motor Vehicle Section and it appears that the data recorded in this section plays a major role in determining what information gets uploaded to the MCMIS Crash file. Missing data rates are low for most variables. Corresponding data elements in the MCMIS and Virginia Crash files were reasonably consistent for several variables examined.Federal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89600/1/102792.pd

Tunable far-infrared laser spectroscopy of deuterated isotopomers of Ar–H2O

Several far-infrared vibration-rotation-tunneling transitions have been measured in deuterated isotopomers of Ar–H2O for the first time. These experimental results will enable the generation of improved intermolecular potential energy surfaces for the Ar–H2O system when combined with existing microwave, far-infrared, and infrared data

Radiative instabilities in simulations of spherically symmetric supernova blast waves

High-resolution simulations of the cooling regions of spherically symmetric supernova remnants demonstrate a strong radiative instability. This instability, whose presence is dependent on the shock velocity, causes large-amplitude fluctuations in the shock velocity. The fluctuations begin almost immediately after the radiative phase begins (upon shell formation) if the shock velocity lies in the unstable range; they last until the shock slows to speeds less than approximately 130 km/s. We find that shock-velocity fluctuations from the reverberations of waves within the remnant are small compared to those due to the instability. Further, we find (in plane-parallel simulations) that advected inhomogeneities from the external medium do not interfere with the qualitative nature of the instability-driven fluctuations. Large-amplitude inhomogeneities may alter the phases of shock-velocity fluctuations, but do not substantially reduce their amplitudes.Comment: 18 pages text, LaTeX/AASTeX (aaspp4); 10 figures; accepted by Ap

A New Model of Crash Severities Reportable to the MCMIS Crash File

The Motor Carrier Management Information system (MCMIS) Crash file has been developed by the Federal Motor Carrier Safety Administration (FMCSA) to serve as a census file of trucks and buses involved in traffic crashes meeting a specific crash severity threshold. Each state is responsible for identifying cases that meet the MCMIS Crash file criteria and reporting the required data through the SafetyNet system. The present report is an addition to three previous reports describing models to predict the number of crash involvements a state should be reporting. The model has been updated and changed over time as more data becomes available from additional states. In each state, the number of fatal involvements is well-known, so all states will start with a known quantity, the number of fatal truck and bus crash involvements. The new model also incorporates a rural/urban (RU) factor that accounts for the relative proportion of rural to urban truck travel in a state. In the new model, data from 16 states that provide all the information necessary to identify MCMIS-reportable cases were used. A log-linear model is fit to MCMIS data for the states that have information recorded for both fatal and nonfatal crashes. The model is then used to predict the number of nonfatal crashes for a new state in which the number of fatal crashes and the RU factor are known. Ninety percent prediction intervals provide a range of nonfatal crash values to be used for guidance. The new model provides more accurate prediction than previous models and is expected to be updated as data from additional states become availableFederal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89595/1/102787.pd

Chandra X-ray and Hubble Space Telescope Imaging of Optically Selected kiloparsec-Scale Binary Active Galactic Nuclei I. Nature of the Nuclear Ionizing Sources

Kiloparsec-scale binary active galactic nuclei (AGNs) signal active supermassive black hole (SMBH) pairs in merging galaxies. Despite their significance, unambiguously confirmed cases remain scarce and most have been discovered serendipitously. In a previous systematic search, we optically identified four kpc-scale binary AGNs from candidates selected with double-peaked narrow emission lines at redshifts of 0.1--0.2. Here we present Chandra and Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging of these four systems. We critically examine and confirm the binary-AGN scenario for two of the four targets, by combining high angular resolution X-ray imaging spectroscopy with Chandra ACIS-S, better nuclear position constraints from WFC3 F105W imaging, and direct starburst estimates from WFC3 F336W imaging; for the other two targets, the existing data are still consistent with the binary-AGN scenario, but we cannot rule out the possibility of only one AGN ionizing gas in both merging galaxies. We find tentative evidence for a systematically smaller X-ray-to-[O III] luminosity ratio and/or higher Compton-thick fraction in optically selected kpc-scale binary AGNs than in single AGNs, possibly caused by a higher nuclear gas column due to mergers and/or a viewing angle bias related to the double-peak narrow line selection. While our result lends some further support to the general approach of optically identifying kpc-scale binary AGNs, it also highlights the challenge and ambiguity of X-ray confirmation.Comment: 18 emulateapj pages, 5 figures, ApJ in pres

Where, when, and how well people park: a phone survey and field measurements

AVM and Low Speed Maneuvers: Human Factors Issues ProjectTwo evaluations were completed to characterize where, how often, and how accurately people normally park. A telephone survey of 30 drivers examined where people park most frequently and the problems drivers have parking. The focus was on executing maneuvers, not the availability of parking. Depending on how the question was asked, approximately 74 to 84 percent of the parking events involved perpendicular parking. Of the 8 parking-related crashes reported by subjects, 6 involved backing, usually with a vehicle traveling down an aisle or backing up from a parking stall. A field survey examined the parking accuracy of 102 vehicles in Ann Arbor, Michigan, a college town. For parallel parking, drivers parked about 4 in from the curb in spaces averaging 24 feet long. For angle parking, distances to the front of the space were bimodal, with some drivers parking about 10 inches from the end of the space and others overlapping by 10 in on average. Overall, drivers parked slightly to the right of center (by 1 inch for parallel parking and 4 inches for perpendicular parking) for 8.5 feet wide spaces. Yaw angles were almost always less than 1 degree for perpendicular and angle parking, but as much as 3 degrees for parallel parking, which is a more difficult task. The data from this experiment provide both a basis for establishing the conditions for parking experiments and baseline data on how well people park without assistance.Nissan Research Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/87990/1/102765.pd

Herschel Observations and Updated Spectral Energy Distributions of Five Sunlike Stars with Debris Disks

Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R > 100 AU. Here we present new Herschel PACS and re-analyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper belt size to R > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14" along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS PSF size (50% of energy enclosed within radius 4.23"). HD 105211 also has a 24-micron infrared excess that was previously overlooked because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius ~3 microns, though the minimum grain gradius is larger than the radiation pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of model blackbody disks. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 0.00002 <= L/L* <= 0.0002, consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.Comment: Accepted for publication in ApJ. 18 pages, including 10 figures and 3 table