4,556 research outputs found
The Perceptions of Emergency Vehicle Drivers Using Simulation in Driver Training
The number of accidents over the past decade involving emergencyvehicles is a major concern for emergency service providers. This study assessedthe perception of adding a driving simulator to a traditional training program. Thesample population consisted of Emergency Medical Technician students attendingthe National EMS Academy in Lafayette, LA. The group self-scheduled whichday they would attend the driving portion of the class. This resulted in 52participants in the control group and 50 participants in the treatment group. Thetreatment group used a driving simulator prior to driving on the competencycourse.Surveys were used to assess the emergency vehicle operatorsâ perceptions ofusing a driving simulator as part of an emergency vehicle training course. Thesimulator allowed the treatment group to understand the course prior to actuallydriving the course. The control group thought the simulator would have affordedthem the opportunity to learn the course before actually driving the course. Bothgroups thought the simulator should be a part of the driver training course, but didnot see the simulator replacing actual driving experience. Emergency MedicalTechnician students in both the treatment and control group thought the simulatorwould improve their driving ability
Cleaning the USNO-B Catalog through automatic detection of optical artifacts
The USNO-B Catalog contains spurious entries that are caused by diffraction
spikes and circular reflection halos around bright stars in the original
imaging data. These spurious entries appear in the Catalog as if they were real
stars; they are confusing for some scientific tasks. The spurious entries can
be identified by simple computer vision techniques because they produce
repeatable patterns on the sky. Some techniques employed here are variants of
the Hough transform, one of which is sensitive to (two-dimensional)
overdensities of faint stars in thin right-angle cross patterns centered on
bright (<13 \mag) stars, and one of which is sensitive to thin annular
overdensities centered on very bright (<7 \mag) stars. After enforcing
conservative statistical requirements on spurious-entry identifications, we
find that of the 1,042,618,261 entries in the USNO-B Catalog, 24,148,382 of
them (2.3 \percent) are identified as spurious by diffraction-spike criteria
and 196,133 (0.02 \percent) are identified as spurious by reflection-halo
criteria. The spurious entries are often detected in more than 2 bands and are
not overwhelmingly outliers in any photometric properties; they therefore
cannot be rejected easily on other grounds, i.e., without the use of computer
vision techniques. We demonstrate our method, and return to the community in
electronic form a table of spurious entries in the Catalog.Comment: published in A
A new species in the major malaria vector complex sheds light on reticulated species evolution
Complexes of closely related species provide key insights into the rapid and independent evolution of adaptive traits. Here, we described and studied Anopheles fontenillei sp.n., a new species in the Anopheles gambiae complex that we recently discovered in the forested areas of Gabon, Central Africa. Our analysis placed the new taxon in the phylogenetic tree of the An. gambiae complex, revealing important introgression events with other members of the complex. Particularly, we detected recent introgression, with Anopheles gambiae and Anopheles coluzzii, of genes directly involved in vectorial capacity. Moreover, genome analysis of the new species allowed us to clarify the evolutionary history of the 3La inversion. Overall, An. fontenillei sp.n. analysis improved our understanding of the relationship between species within the An. gambiae complex, and provided insight into the evolution of vectorial capacity traits that are relevant for the successful control of malaria in Africa
Snapshots in time: MicroCT scanning of pottery sherds determines early domestication of sorghum (Sorghum bicolor) in East Africa
MicroCT visualisations of organic inclusions within pottery sherds from Khashm el Girba 23 (KG23), Sudan, reveal domesticated sorghum (Sorghum bicolor subsp. bicolor) at c. 3700â2900 BCE. The percentage of non-shattering spikelet bases was c. 73% of identifiable visualizations, with c. 27% representing wild types. These analyses demonstrate the domestication of sorghum is significantly earlier than suggested by previous archaeological research. These results also demonstrate that microCT scanning is a major qualitative and quantitative advance on pre-existing methods for the investigation of crop remains in pottery sherds, which hitherto have been reliant on surface impressions; it is non-destructive, provides higher resolution 3D imaging of organic inclusions, and enables greater archaeobotanical recovery of inclusions within a sherd. MicroCT analysis of ceramics, mudbrick and other building materials has considerable potential for improving the chronologies and resolution for the domestication of other cereals in the past
Chiral molecules split light: Reflection and refraction in a chiral liquid
A light beam changes direction as it enters a liquid at an angle from another
medium, such as air. Should the liquid contain molecules that lack mirror
symmetry, then it has been predicted by Fresnel that the light beam will not
only change direction, but will actually split into two separate beams with a
small difference in the respective angles of refraction. Here we report the
observation of this phenomenon. We also demonstrate that the angle of
reflection does not equal the angle of incidence in a chiral medium. Unlike
conventional optical rotation, which depends on the path-length through the
sample, the reported reflection and refraction phenomena arise within a few
wavelengths at the interface and thereby suggest a new approach to polarimetry
that can be used in microfluidic volumes
Large Faraday rotation of resonant light in a cold atomic cloud
We experimentally studied the Faraday rotation of resonant light in an
optically-thick cloud of laser-cooled rubidium atoms. Measurements yield a
large Verdet constant in the range of 200 000 degrees/T/mm and a maximal
polarization rotation of 150 degrees. A complete analysis of the polarization
state of the transmitted light was necessary to account for the role of the
probe laser's spectrum
Comment on "On the importance of the free energy for elasticity under pressure"
Marcus et al. (Marcus P, Ma H and Qiu S L 2002 J. Phys.: Condens. Matter 14
L525) claim that thermodynamic properties of materials under pressure must be
computed using the Gibbs free energy , rather than the internal energy .
Marcus et al. state that ``The minima of , but not of , give the
equilibrium structure; the second derivatives of , but not of , with
respect to strains at the equilibrium structure give the equilibrium elastic
constants.'' Both statements are incorrect.Comment: Commen
Theoretical Properties of Projection Based Multilayer Perceptrons with Functional Inputs
Many real world data are sampled functions. As shown by Functional Data
Analysis (FDA) methods, spectra, time series, images, gesture recognition data,
etc. can be processed more efficiently if their functional nature is taken into
account during the data analysis process. This is done by extending standard
data analysis methods so that they can apply to functional inputs. A general
way to achieve this goal is to compute projections of the functional data onto
a finite dimensional sub-space of the functional space. The coordinates of the
data on a basis of this sub-space provide standard vector representations of
the functions. The obtained vectors can be processed by any standard method. In
our previous work, this general approach has been used to define projection
based Multilayer Perceptrons (MLPs) with functional inputs. We study in this
paper important theoretical properties of the proposed model. We show in
particular that MLPs with functional inputs are universal approximators: they
can approximate to arbitrary accuracy any continuous mapping from a compact
sub-space of a functional space to R. Moreover, we provide a consistency result
that shows that any mapping from a functional space to R can be learned thanks
to examples by a projection based MLP: the generalization mean square error of
the MLP decreases to the smallest possible mean square error on the data when
the number of examples goes to infinity
Worker heterogeneity, new monopsony, and training
A worker's output depends not only on his/her own ability but also on that of colleagues, who can facilitate the performance of tasks that each individual cannot accomplish on his/her own. We show that this common-sense observation generates monopsony power and is sufficient to explain why employers might expend resources on training employees even when the training is of use to other firms. We show that training will take place in better-than-average or âgoodâ firms enjoying greater monopsony power, whereas âbadâ firms will have low-ability workers unlikely to receive much training
Credit bureaus between risk-management, creditworthiness assessment and prudential supervision
"This text may be downloaded for personal research purposes only. Any additional reproduction for other purposes, whether in hard copy or electronically, requires the consent of the author. If cited or quoted, reference should be made to the full name of the author, the title, the working paper or other series, the year, and the publisher."This paper discusses the role and operations of consumer Credit Bureaus in the European Union in the context of the economic theories, policies and law within which they work. Across Europe there is no common practice of sharing the credit data of consumers which can be used for several purposes. Mostly, they are used by the lending industry as a practice of creditworthiness assessment or as a risk-management tool to underwrite borrowing decisions or price risk. However, the type, breath, and depth of information differ greatly from country to country. In some Member States, consumer data are part of a broader information centralisation system for the prudential supervision of banks and the financial system as a whole. Despite EU rules on credit to consumers for the creation of the internal market, the underlying consumer data infrastructure remains fragmented at national level, failing to achieve univocal, common, or defined policy objectives under a harmonised legal framework. Likewise, the establishment of the Banking Union and the prudential supervision of the Euro area demand standardisation and convergence of the data used to measure debt levels, arrears, and delinquencies. The many functions and usages of credit data suggest that the policy goals to be achieved should inform the legal and institutional framework of Credit Bureaus, as well as the design and use of the databases. This is also because fundamental rights and consumer protection concerns arise from the sharing of credit data and their expanding use
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