4,227 research outputs found
Analysis of Traffic Crash Data in Kentucky (2013-2017)
Executive Summary
This report documents an analysis of traffic crash data in Kentucky for the years of 2013-2017. A primary objective of this study was to determine average crash statistics for Kentucky highways. Rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.
Average and critical numbers and rates of crashes were calculated for various types of highways in rural and urban areas. These rates used crashes identified on highways where traffic volumes were available. Improved methods of identifying crash locations have resulted in higher rates for the last couple of years. The crash rate data can be used in Kentucky’s procedure to identify locations that have abnormal rates or numbers of crashes.
The other primary objective of this study was to provide data that can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway Safety Plan. County and city crash statistics were analyzed. A summary of results and recommendations in several problem identification areas is presented. These general areas include; alcohol involvement, occupant protection, speed, teenage drivers, pedestrians, bicycles, motorcycles, trucks, and vehicle defects. Other areas included in the analysis for which specific recommendations were not made include, school bus crashes and train crashes.
The crash data are stored in the Collision Report Analysis for Safer Highways (CRASH) database. This database is updated daily so the number of crashes in a given calendar year will continue to change for a substantial time after the end of that year
Analysis of Traffic Crash Data in Kentucky (2012-2016)
This report documents an analysis of traffic crash data in Kentucky for the years of 2012 through 2016. A primary objective of this study was to determine average crash statistics for Kentucky highways. Rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.
The other primary objective of this study was to provide data that can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway Safety Plan. County and city crash statistics were analyzed. A summary of results and recommendations in several problem identification areas is presented
The weight for random quark masses
In theories in which the parameters of the low energy theory are not unique,
perhaps having different values in different domains of the universe as is
possible in some inflationary models, the fermion masses would be distributed
with respect to some weight. In such a situation the specifics of the fermion
masses do not have a unique explanation, yet the weight provides the visible
remnant of the structure of the underlying theory. This paper introduces this
concept of a weight for the distribution of masses and provides a quantitative
estimate of it from the observed quarks and leptons. The weight favors light
quark masses and appears roughly scale invariant (rho ~ 1/m). Some relevant
issues, such as the running of the weight with scale and the possible effects
of anthropic constraints, are also discussed.Comment: 35pages, 19 figure
A Note On R-Parity Violation and Fermion Masses
We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs
models in which R-parity is violated through bilinear Higgs-lepton
interactions. The required, due to R-parity violation, higgs-lepton rotations
introduce an alternative way to generate the phenomenologically desirable
fermion mass matrix structures independently of the equality of Yukawas,
possibly imposed by superstring or other unification.Comment: 8 pages, uses LaTeX2
Ionized Ultraviolet and Soft-X-ray Absorptions in the Low Redshift Active Galactic Nucleus PG1126-041
We present here the analysis of ultraviolet spectra from IUE and an X-ray
spectrum from ROSAT PSPC observations of the X-ray weak, far-infrared loud AGN,
PG 1126-041 (Mrk 1298). The first UV spectra taken in June 1992, simultaneously
with ROSAT, show strong absorption lines of NV, CIV and SiIV, extending over a
velocity range from -1000 to -5000 km/s with respect to the corresponding line
centre. Our analysis shows that the Broad Emission Line Region (BELR) is, at
least partially, covered by the material causing these absorption lines. In the
IUE spectrum taken in Jan. 1995, the continuum was a factor of two brighter and
the UV absorption lines are found to be considerably weaker than in 1992, but
only little variation in the emission line fluxes is found. With UV spectral
indices of A_{uv} \simeq 1.82 and 1.46 for the 1992 and 1995 data, the far UV
spectrum is steep. Based on the emission line ratios and the broad band
spectral energy distribution, we argue that the steepness of the UV spectrum is
unlikely to be due to reddening. The soft X-ray emission in the ROSAT band is
weak. A simple power-law model yields a very poor fit with a UV-to-X-ray
spectral index A_{uvx}=2.32. Highly ionized (warm) absorption is suggested by
the ROSAT data. After correcting for a warm absorber, the optical to X-ray
spectral slope is close to the average of A{uvx}\simeq 1.67 for radio quiet
quasars.Comment: 8 pages, 9 postscript figures. Mon. Not. Roy. Astr. Soc., accepte
Fermion masses and mixing angles from gauge symmetries
The structure of the quark and lepton masses and mixing angles provides one
of the few windows we have on the underlying physics generating the \sm. In an
attempt to identify the underlying symmetry group we look for the simplest
gauge extension of the SUSY standard model capable of generating the observed
structure. We show that the texture structure and hierarchical form found in
the (symmetric) quark and lepton mass matrices follows if one extends the gauge
group of the standard model to include an horizontal gauge factor,
constrained by the need for anomaly cancellation. This symmetry is
spontaneously broken slightly below the unification/string scale leaving as its
only remnant the observed structure of masses and mixings. Anomaly cancellation
is possible only in the context of superstring theories via the Green Schwarz
mechanism with .Comment: 19 pages, preprint numbers OUTP-9403 and FTUAM-94/7, LaTe
Hierarchies of R-violating interactions from Family Symmetries
We investigate the possibility of constructing models of R-violating LQD
Yukawa couplings using a single U(1) flavour-symmetry group and supermultiplet
charge assignments that are compatible with the known hierarchies of quark and
lepton masses. The mismatch of mass and current eigenstates inferred from the
known charged-current mixing induces the propagation of strong phenomenological
constraints on some R-violating couplings to many others. Applying these
constraints, we look for flavour-symmetry models that are consistent with
different squark-production hypotheses devised to explain the possible HERA
large-Q^2 anomaly. The e^+ d -> stop interpretation of the HERA data is
accommodated relatively easily, at the price of postulating an extra parity.
The e^+ s -> stop interpretation of the events requires models to have only
small (2,3) mixing in the down quark sector. The e^+ d -> scharm mechanism
cannot be accommodated without large violations of squark-mass universality,
due to the very strong experimental constraints on R-violating operators. We
display a model in which baryon decay due to dangerous dimension-five operators
is automatically suppressed.Comment: 21 pages, Latex file, no figure
Finiteness and anomalies in (4,0) supersymmetric sigma models
Power-counting arguments based on extended superfields have been used to
argue that two-dimensional supersymmetric sigma models with (4,0) supersymmetry
are finite. This result is confirmed up to three loop order in pertubation
theory by an explicit calculation using (1,0) superfields. In particular, it is
shown that the finite counterterms which must be introduced into the theory in
order to maintain (4,0) supersymmetry are precisely the terms that are required
to establish ultra-violet finiteness.Comment: 19 page
Temporal variability and statistics of the Strehl ratio in adaptive-optics images
We have investigated the temporal variability and statistics of the
"instantaneous" Strehl ratio. The observations were carried out with the 3.63-m
AEOS telescope equipped with a high-order adaptive optics system. In this paper
Strehl ratio is defined as the peak intensity of a single short exposure. We
have also studied the behaviour of the phase variance computed on the
reconstructed wavefronts. We tested the Marechal approximation and used it to
explain the observed negative skewness of the Strehl ratio distribution. The
estimate of the phase variance is shown to fit a three-parameter Gamma
distribution model. We show that simple scaling of the reconstructed wavefronts
has a large impact on the shape of the Strehl ratio distribution.Comment: submitted to PAS
Anthropometric measures in relation to Basal Cell Carcinoma: a longitudinal study
BACKGROUND: The relationship between anthropometric indices and risk of basal cell carcinoma (BCC) is largely unknown. We aimed to examine the association between anthropometric measures and development of BCC and to demonstrate whether adherence to World Health Organisation guidelines for body mass index, waist circumference, and waist/hip ratio was associated with risk of BCC, independent of sun exposure. METHODS: Study participants were participants in a community-based skin cancer prevention trial in Nambour, a town in southeast Queensland (latitude 26°S). In 1992, height, weight, and waist and hip circumferences were measured for all 1621 participants and weight was remeasured at the end of the trial in 1996. Prevalence proportion ratios were calculated using a log-binomial model to estimate the risk of BCC prior to or prevalent in 1992, while Poisson regression with robust error variances was used to estimate the relative risk of BCC during the follow-up period. RESULTS: At baseline, 94 participants had a current BCC, and 202 had a history of BCC. During the 5-year follow-up period, 179 participants developed one or more new BCCs. We found no significant association between any of the anthropometric measures or indices and risk of BCC after controlling for potential confounding factors including sun exposure. There was a suggestion that short-term weight gain may increase the risk of developing BCC for women only. CONCLUSION: Adherence to World Health Organisation guidelines for body mass index, waist circumference and waist/hip ratio is not significantly associated with occurrence of basal cell carcinomas of the skin
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