5,357 research outputs found
Are speed enforcement cameras more effective than other speed management measures? The impact of speed management schemes on 30mph roads.
This paper presents the results of an evaluation of the impact of various types of speed management schemes on both traffic speeds and accidents. The study controls for general trends in accidents, regression-to-mean effects and migration, separately estimating the accident
changes attributable to the impact of the schemes on traffic speed and on traffic volume. It was found that, when judged in absolute terms, all types of speed management scheme have remarkably similar effects on accidents, with an average fall in personal injury accidents of about 1 accident/km/year. In terms of the percentage accident reduction, however, engineering schemes incorporating vertical deflections (such as
speed humps or cushions) offer the largest benefits: at 44%, the average reduction in personal injury accidents attributable to such schemes, is twice that at sites where safety cameras were used to control speeds (22%) and they were the only type of scheme to have a significant
impact on fatal and serious accidents. Other types of engineering scheme (with a fall of 29% in personal injury accidents) were on average less effective in reducing accidents than schemes with vertical features but more effective than cameras. All types of scheme were generally
effective in reducing speeds, with the largest reductions tending to be obtained with vertical deflections and the smallest with other types of engineering schemes
Commuting charges and symmetric spaces
Every classical sigma-model with target space a compact symmetric space
(with classical) is shown to possess infinitely many local, commuting,
conserved charges which can be written in closed form. The spins of these
charges run over a characteristic set of values, playing the role of exponents
of , and repeating modulo an integer which plays the role of a Coxeter
number.Comment: LaTeX, 16 pages; v2: footnote adde
Conserved Charges and Supersymmetry in Principal Chiral Models
We report on investigations of local (and non-local) charges in bosonic and
supersymmetric principal chiral models in 1+1 dimensions. In the bosonic PCM
there is a classically conserved local charge for each symmetric invariant
tensor of the underlying group. These all commute with the non-local Yangian
charges. The algebra of the local charges amongst themselves is rather more
subtle. We give a universal formula for infinite sets of mutually commuting
local charges with spins equal to the exponents of the underlying classical
algebra modulo its Coxeter number. Many of these results extend to the
supersymmetric PCM, but with local conserved charges associated with
antisymmetric invariants in the Lie algebra. We comment briefly on the quantum
conservation of local charges in both the bosonic and super PCMs.Comment: 18 pages, LaTeX. Revised and up-dated version based on conference
talks by JME and NJ
Electronic Medical Record in the Simulation Hospital: Does It Improve Accuracy in Charting Vital Signs, Intake, and Output?
The introduction of electronic health records has created a shift in the way nursing care is delivered (McBride, Delaney, & Tietze, 2012; Furukawa, Raghu, & Shao, 2010). A factor which heavily influences a nurse’s ability to navigate and utilize EMR is adequate education in the use of computerized documentation (McBride, et al., 2012). There is an increased risk for error at the bedside without the correct knowledge and skills regarding EMR documentation (Kelly, Brandon, & Docherty, 2011). This skill should be introduced during the pre-licensure education of the nurse.
Two groups of associate degree nursing students attending a small community college in Northern California were examined to determine if introduction of EMR in the simulation hospital increased accuracy in documenting vital signs, intake, and output. The first group of students charted using paper- pencil during simulation; the second group used an academic EMR. Each group was evaluated during their preceptor rotation at two local inpatient facilities. Registered nurse preceptors provided information by responding to a 10 question survey regarding the use of student EMR documentation during the 120 hour preceptor rotation.
The implementation of the EMR into the simulation hospital, although a complex undertaking, provided students a safe environment in which to practice using technology and receive feedback from faculty regarding accurate documentation
The Psychological Impact of Investigating Crime Scenes
The goal of this study was to determine if there are stressful or psychological impacts from investigating crime scenes. This was accomplished by analyzing ninety-four anonymous surveys that had been distributed to various law enforcement agencies across the country. The surveys asked professional crime scene processors various questions about their careers, home life, and wellbeing. IBM SPSS Statistics was used to analyze questions about physical health, mental health, job position, duties, schedule, and crimes investigated. The surveys were thirty-seven questions each, with several having multiple answer options. The study found the majority of participants did not have any diagnosed disorders but did desire to either quit or retire due to impact on family life or from repeated exposure to tragic violence. Most agencies offer some type of post-crime counseling, but the bulk of participants did not utilize this resource. However, the vast majority of participants did think that counseling would be helpful and favored having the option in their career field
Invariant tensors and Casimir operators for simple compact Lie groups
The Casimir operators of a Lie algebra are in one-to-one correspondence with
the symmetric invariant tensors of the algebra. There is an infinite family of
Casimir operators whose members are expressible in terms of a number of
primitive Casimirs equal to the rank of the underlying group. A systematic
derivation is presented of a complete set of identities expressing
non-primitive symmetric tensors in terms of primitive tensors. Several examples
are given including an application to an exceptional Lie algebra.Comment: 11 pages, LaTeX, minor changes, version in J. Math. Phy
Enhanced star formation: The importance of bars in spiral galaxies
It was found that among an IR luminous subset of nearby spiral galaxies, nearly all of the systems with IRAS colors and luminosities indicative of enhanced star formation are barred. Radio continuum and IR spectroscopic results support the hypothesis that this emission originates within the central 2 kpc; possibly in a circumnuclear ring. It was also found that outer rings are over represented among these barred systems and suggest possible reasons for this phenomena
Databases and Inter-Connectivity in Ground-Based Astronomy
Optical and infrared ground-based astronomy is undergoing a renaissance. Advances in material technology, system modeling, and the ability to correct atmospheric distortions in real time have produced a new generation of powerful, large telescopes. An equally profound revolution stems from the availability of large observational databases that span the electromagnetic spectrum. The increased use of such databases as well as the need to operate the new telescopes efficiently requires the development of a National or International Virtual Observatory to set standards for astronomical database formats, data quality assurance, and access protocols, and also to provide all-inclusive centers for data products
A Global Photometric Analysis of 2MASS Calibration Data
We present results from the application of a global photometric calibration
(GPC) procedure to calibration data from the first 2 years of The Two Micron
All Sky Survey (2MASS). The GPC algorithm uses photometry of both primary
standards and moderately bright `tracer' stars in 35 2MASS calibration fields.
During the first two years of the Survey, each standard was observed on
approximately 50 nights, with about 900 individual measurements. Based on the
photometry of primary standard stars and secondary tracer stars and under the
assumption that the nightly zeropoint drift is linear, GPC ties together all
calibration fields and all survey nights simultaneously, producing a globally
optimized solution. Calibration solutions for the Northern and Southern
hemisphere observatories are found separately, and are tested for global
consistency based on common fields near the celestial equator.
Several results from the GPC are presented, including establishing candidate
secondary standards, monitoring of near-infrared atmospheric extinction
coefficients, and verification of global validity of the standards. The
solution gives long-term averages of the atmospheric extinction coefficients,
A_J=0.096, A_H=0.026, A_{K_s}=0.066 (North) and A_J=0.092, A_H=0.031,
A_{K_s}=0.065 (South), with formal error of 0.001. The residuals show small
seasonal variations, most likely due to changing atmospheric content of water
vapor. Extension of the GPC to approximately 100 field stars in each of the 35
calibration fields yields a catalog of more than two thousand photometric
standards ranging from 10th to 14th magnitude, with photometry that is globally
consistent to .Comment: 19 pages, 10 figures; Submitted to AJ. The table of secondary
standards is available from ftp://nova.astro.umass.edu/pub/nikolaev/ or
ftp://anon-ftp.ipac.caltech.edu/pub/2mass/globalcal
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