5,887 research outputs found
Discrete Charge Dielectric Model of Electrostatic Energy
Studies on nanoscale materials merit careful development of an electrostatics
model concerning discrete point charges within dielectrics. The discrete charge
dielectric model treats three unique interaction types derived from an external
source: Coulomb repulsion among point charges, direct polarization between
point charges and their associated surface charge elements, and indirect
polarization between point charges and surface charge elements formed by other
point charges. The model yields the potential energy, U(N), stored in a general
point charge system differing from conventional integral formulations,
and , in a manner
significant to the treatment of few electron systems.Comment: 1 figure, 2 parts, ep
Assessing the Influencing Factors on the Accuracy of Underage Facial Age Estimation
Swift response to the detection of endangered minors is an ongoing concern
for law enforcement. Many child-focused investigations hinge on digital
evidence discovery and analysis. Automated age estimation techniques are needed
to aid in these investigations to expedite this evidence discovery process, and
decrease investigator exposure to traumatic material. Automated techniques also
show promise in decreasing the overflowing backlog of evidence obtained from
increasing numbers of devices and online services. A lack of sufficient
training data combined with natural human variance has been long hindering
accurate automated age estimation -- especially for underage subjects. This
paper presented a comprehensive evaluation of the performance of two cloud age
estimation services (Amazon Web Service's Rekognition service and Microsoft
Azure's Face API) against a dataset of over 21,800 underage subjects. The
objective of this work is to evaluate the influence that certain human
biometric factors, facial expressions, and image quality (i.e. blur, noise,
exposure and resolution) have on the outcome of automated age estimation
services. A thorough evaluation allows us to identify the most influential
factors to be overcome in future age estimation systems
Axion gauge symmetries and generalized Chern-Simons terms in N=1 supersymmetric theories
We compute the form of the Lagrangian of N=1 supersymmetric theories with
gauged axion symmetries. It turns out that there appear generalized
Chern-Simons terms that were not considered in previous superspace formulations
of general N=1 theories. Such gaugings appear in supergravities arising from
flux compactifications of superstrings, as well as from Scherk-Schwarz
generalized dimensional reduction in M-theory. We also present the dual
superspace formulation where axion chiral multiplets are dualized into linear
multiplets.Comment: References added and few misprints correcte
The ICC Compression Questionnaire: A Comprehensive Tool to Evaluate Compression Materials or Devices Applied in Subjects with Lymphedema or Chronic Venous Disease
Background: Compression therapy is an important part of the treatment of patients with lymphedema or chronic venous disease. However, there is no validated questionnaire evaluating the effect of compression and its acceptance by the patient. Therefore, the aims of this study were to construct a questionnaire evaluating the effect of compression and its acceptance by the patient, that is, the Dutch ICC Compression Questionnaire (ICC-CQ), to investigate its reliability and validity, and to translate it into English.
Methods and Results: Eleven experts in applying compression and 51 Dutch patients with experience of using compression were involved in the construction process. One part of the ICC-CQ has to be completed by the patient and evaluates seven domains. The other part has to be completed by the health care provider and comprises three domains. Reliability and validity of the final version was investigated in a new group of 79 Dutch-speaking patients with lymphedema or chronic venous disease, wearing compression garments (N = 52) or bandages (N = 27). Except for one domain, the Intraclass Correlation Coefficients for test-rest/interrater reliability ranged from 0.55 to 0.93. Cronbach's alpha for internal consistency ranged from 0.71 to 0.97. Eighty-nine percent of the patients fully understood the questionnaire indicating good face validity, and 87% found it complete indicating good content validity. Construct validity was considered good since 10 out of 11 hypotheses were accepted.
Conclusion: The ICC-CQ is the first reliable and valid questionnaire evaluating different kinds of compression and the experience by patients with lymphedema or chronic venous disease
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Online homework is not significantly associated with course enjoyment
The purpose of this research was to discover if using online homework contributes to an overall higher enjoyment of the Introductory Psychology class, given that other factors are held constant. Students who used the online homework PsychPortlal for the Introductory Psychology 202 class would rate the “overall enjoyment of the psychology 202 class” higher than those students who didn’t used PsychPortal as a practice tool for the class
Constraining the Radii of Neutron Stars with Terrestrial Nuclear Laboratory Data
Neutron star radii are primarily determined by the pressure of isospin
asymmetric matter which is proportional to the slope of the nuclear symmetry
energy. Available terrestrial laboratory data on the isospin diffusion in
heavy-ion reactions at intermediate energies constrain the slope of the
symmetry energy. Using this constraint, we show that the radius (radiation
radius) of a 1.4 solar mass neutron star is between 11.5 (14.4) and 13.6 (16.3)
km.Comment: 11 pages, 3 figures; version to be published in Phys. Lett.
Optical Gravitational Lensing Experiment. OGLE-1999-BUL-19: The First Multi-Peak Parallax Event
We describe a highly unusual microlensing event, OGLE-1999-BUL-19, which
exhibits multiple peaks in its light curve. The Einstein radius crossing time
for this event is approximately one year, which is unusually long. We show that
the motion of the Earth induces these multiple peaks in the light curve, since
the relative transverse velocity of the lens projected into the observer plane
is very small (v = 12.5 km/s). This is the lowest velocity so far published and
we believe that this is the first multiple-peak parallax event ever observed.
We also believe that this event may be exhibiting slight binary-source
signatures in addition to these parallax-induced multiple peaks. With
spectroscopic observations it is possible to test this `parallax plus
binary-source' hypothesis and (if this hypothesis turns out to be correct) to
simultaneously fit both models and obtain a measurement of the lens mass.
Furthermore, spectroscopic observations could also supply information regarding
the lens properties, possibly providing another avenue for determining the lens
mass. We found that most of the I-band blending is probably caused by light
from the lens or a binary companion to the source. However, in the V-band,
there appears to be a second blended source 0.35" away from the lensed source.
HST observations will be very useful for understanding the nature of the
blends. We also suggest that a radial velocity survey of all parallax events
will be very useful for further constraining the lensing kinematics and
understanding the origins of these events and the excess of long events toward
the bulge.Comment: 36 pages, 7 figures. Accepted for publication in MNRA
The dimension of the space of R-places of certain rational function fields
We prove that the space of -places of the field
of rational functions of two variables with coefficients in a totally
Archimedean field has covering and integral dimensions \dim
M(K(x,y))=\dim_\IZ M(K(x,y))=2 and the cohomological dimension for any Abelian 2-divisible coefficient group .Comment: 8 page
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