50,942 research outputs found
Does the h-index have predictive power?
Bibliometric measures of individual scientific achievement are of particular
interest if they can be used to predict future achievement. Here we report
results of an empirical study of the predictive power of the h-index compared
to other indicators. Our findings indicate that the h-index is better than
other indicators considered (total citation count, citations per paper, and
total paper count) in predicting future scientific achievement. We discuss
reasons for the superiority of the h-index.Comment: Sect. V added on combining h and N_c, with new Fig. 11. Other minor
changes. To be published in PNA
Device for measuring the contour of a surface
Light from a source is imaged by a lens onto a surface so that the energy from the source is concentrated into a spot. As the spot across the surface is scanned, the surface moves relative to the point of perfect focus. When the surface moves away from perfect focus the spot increases in size, while the total energy in the spot remains virtually constant. The lens then reimages the light reflected by the surface onto two detectors through two different sized apertures. The light energy going to the two detectors is separated by a beam splitter. This second path of the light energy through the lens further defocuses the spot, but as a result of the different sizes of the apertures in each light detector path, the amount of defocus for each is different. The ratio of the outputs of the two detectors which are indicative of the contour of the surface is obtained by a divider
A Non-Parametric Learning Approach to Identify Online Human Trafficking
Human trafficking is among the most challenging law enforcement problems
which demands persistent fight against from all over the globe. In this study,
we leverage readily available data from the website "Backpage"-- used for
classified advertisement-- to discern potential patterns of human trafficking
activities which manifest online and identify most likely trafficking related
advertisements. Due to the lack of ground truth, we rely on two human analysts
--one human trafficking victim survivor and one from law enforcement, for
hand-labeling the small portion of the crawled data. We then present a
semi-supervised learning approach that is trained on the available labeled and
unlabeled data and evaluated on unseen data with further verification of
experts.Comment: Accepted in IEEE Intelligence and Security Informatics 2016
Conference (ISI 2016
Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures
Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong blade–vortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor
Spectrometer integrated with a facsimile camera
This invention integrates a spectrometer capability with the basic imagery function of facsimile cameras without significantly increasing mechanical or optical complexity, or interfering with the imaging function. The invention consists of a group of photodetectors arranged in a linear array in the focal plane of the facsimile camera with a separate narrow band interference filter centered over each photodetector. The interference filter photodetector array is on a line in the focal plane of the facsimile camera along the direction of image motion due to the rotation of the facsimile camera's vertical mirror. As the image of the picture element of interest travels down the interference filter photodetector array, the photodetector outputs are synchronously selected and sampled to provide spectral information on the single picture element
Electronic structure induced reconstruction and magnetic ordering at the LaAlOSrTiO interface
Using local density approximation (LDA) calculations we predict
GdFeO-like rotation of TiO octahedra at the -type interface between
LaAlO and SrTiO. The narrowing of the Ti bandwidth which results
means that for very modest values of , LDA calculations predict charge
and spin ordering at the interface. Recent experimental evidence for magnetic
interface ordering may be understood in terms of the close proximity of an
antiferromagnetic insulating ground state to a ferromagnetic metallic excited
state
Non-collinear Magnetoelectronics
The electron transport properties of hybrid ferromagnetic|normal metal
structures such as multilayers and spin valves depend on the relative
orientation of the magnetization direction of the ferromagnetic elements.
Whereas the contrast in the resistance for parallel and antiparallel
magnetizations, the so-called Giant Magnetoresistance, is relatively well
understood for quite some time, a coherent picture for non-collinear
magnetoelectronic circuits and devices has evolved only recently. We review
here such a theory for electron charge and spin transport with general
magnetization directions that is based on the semiclassical concept of a vector
spin accumulation. In conjunction with first-principles calculations of
scattering matrices many phenomena, e.g. the current-induced spin-transfer
torque, can be understood and predicted quantitatively for different material
combinations.Comment: 163 pages, to be published in Physics Report
Arkansas Small-Grain Cultivar Performance Tests 2004-2005
Small-grain cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for smallgrain producers
- …