54,953 research outputs found
J/psi (psi') production at the Tevatron and LHC at O(\alpha_s^4v^4) in nonrelativistic QCD
We present a complete evaluation for \jpsi(\psip) prompt production at the
Tevatron and LHC at next-to-leading order in nonrelativistic QCD, including
color-singlet, color-octet, and higher charmonia feeddown contributions. The
short-distance coefficients of \pj at next-to-leading order are found to be
larger than leading order by more than an order of magnitude but with a minus
sign at high transverse momentum . Two new linear combinations of
color-octet matrix elements are obtained from the CDF data, and used to predict
\jpsi production at the LHC, which agrees with the CMS data. The possibility
of \sa dominance and the \jpsi polarization puzzle are also discussed.Comment: Version published in PRL, 4 pages, 4 figure
Concept Validation for Selective Heating and Press Hardening of Automotive Safety Components with Tailored Properties
© (2014) Trans Tech Publications, Switzerland.A new strategy termed selective heating and press hardening, for hot stamping of boron steel parts with tailored properties is proposed in this paper. Feasibility studies were carried out through a specially designed experimental programme. The main aim was to validate the strategy and demonstrate its potential for structural optimisation. In the work, a lab-scale demonstrator part was designed, and relevant manufacturing and property-assessment processes were defined. A heating technique and selective-heating rigs were designed to enable certain microstructural distributions in blanks to be obtained. A hot stamping tool set was designed for forming and quenching the parts. Demonstrator parts of full martensite phase, full initial phase, and differentially graded microstructures have been formed with high dimensional quality. Hardness testing and three point bending tests were conducted to assess the microstructure distribution and load bearing performance of the as-formed parts, respectively. The feasibility of the concept has been validated by the testing results
A Complete Year of User Retrieval Sessions in a Social Sciences Academic Search Engine
In this paper, we present an open data set extracted from the transaction log
of the social sciences academic search engine sowiport. The data set includes a
filtered set of 484,449 retrieval sessions which have been carried out by
sowiport users in the period from April 2014 to April 2015. We propose a
description of interactions performed by the academic search engine users that
can be used in different applications such as result ranking improvement, user
modeling, query reformulation analysis, search pattern recognition.Comment: 6 pages, 2 figures, accepted short paper at the 21st International
Conference on Theory and Practice of Digital Libraries (TPDL 2017
Fermion masses in the economical 3-3-1 model
We show that, in frameworks of the economical 3-3-1 model, all fermions get
masses. At the tree level, one up-quark and two down-quarks are massless, but
the one-loop corrections give all quarks the consistent masses. This conclusion
is in contradiction to the previous analysis in which, the third scalar triplet
has been introduced. This result is based on the key properties of the model:
First, there are three quite different scales of vacuum expectation values:
\om \sim {\cal O}(1) \mathrm{TeV}, v \approx 246 \mathrm{GeV} and . Second, there exist two types of Yukawa couplings
with different strengths: the lepton-number conserving couplings 's and the
lepton-number violating ones 's satisfying the condition in which the second
are much smaller than the first ones: .
With the acceptable set of parameters, numerical evaluation shows that in
this model, masses of the exotic quarks also have different scales, namely, the
exotic quark () gains mass GeV, while the
D_\al exotic quarks (q_{D_\al} = -1/3) have masses in the TeV scale:
m_{D_\al} \in 10 \div 80 TeV.Comment: 20 pages, 8 figure
Task-Projected Hyperdimensional Computing for Multi-Task Learning
Brain-inspired Hyperdimensional (HD) computing is an emerging technique for
cognitive tasks in the field of low-power design. As a fast-learning and
energy-efficient computational paradigm, HD computing has shown great success
in many real-world applications. However, an HD model incrementally trained on
multiple tasks suffers from the negative impacts of catastrophic forgetting.
The model forgets the knowledge learned from previous tasks and only focuses on
the current one. To the best of our knowledge, no study has been conducted to
investigate the feasibility of applying multi-task learning to HD computing. In
this paper, we propose Task-Projected Hyperdimensional Computing (TP-HDC) to
make the HD model simultaneously support multiple tasks by exploiting the
redundant dimensionality in the hyperspace. To mitigate the interferences
between different tasks, we project each task into a separate subspace for
learning. Compared with the baseline method, our approach efficiently utilizes
the unused capacity in the hyperspace and shows a 12.8% improvement in averaged
accuracy with negligible memory overhead.Comment: To be published in 16th International Conference on Artificial
Intelligence Applications and Innovation
Development and Validation of a Spontaneous Smile Assay
IMPORTANCE Smiling can be a voluntary or involuntarymovement. Facial reanimation procedures differ in their ability to restore a spontaneous smile, and an assay designed to evoke and evaluate a spontaneous smile is not available. OBJECTIVE To develop and validate an assay to assess the spontaneous smile of patients with facial paralysis. DESIGN, SETTING, AND PARTICIPANTS Thiswas an exploratory cohort study. A series of short video clips were administered to laypersons via an online survey service from January 1, 2014, to March 31, 2014. Respondents rated how funny each video was on a visual analog scale from 0 to 100. The 4 funniest videos were selected to generate a 11/2-minute spontaneous smile assay. The assay was then administered from July 1, 2014, to December 31, 2014, to 2 different study groups: the first was composed of 100 healthy individuals (control group) and the second was composed of 30 patients with facial paralysis.We analyzed the capability of this assay to provoke at least 1 spontaneous smile and calculated smile excursion in both groups. Statistical analysis was performed using analysis of variance. INTERVENTION Spontaneous smile assay administered to both healthy and diseased groups. MAIN OUTCOMES AND MEASURES Ability of the assay to elicit smiles, as defined by an oral commissure excursion greater than 3 mm, as well as difference in commissure excursion. RESULTS Ninety-five (95.0%) participants in the control group and 29 (96.7%) patients with facial paralysis experienced at least 1 oral commissure excursion that appeared to be a spontaneous smile while viewing the assay. Mean oral commissure excursion with spontaneous smile was 9.08mm(95%CI, 2.77-15.39) in controls, 6.72mm(95%CI, 3.13-10.31) on the healthy side in patients with flaccid facial paralysis (P=.004 vs controls), and 9.64mm(95%CI, 3.52-15.76) on the healthy side in patients with nonflaccid facial paralysis (P=.74). Among patients with flaccid facial paralysis, a statistically significant difference was found between smile excursion of the affected and the unaffected sides (P = .03). There was no statistically significant difference in the measurement between sides for the control group (P = .67). CONCLUSIONS AND RELEVANCE Although humor is a challenging construct to universalize, our assay was able to elicit a smile in almost all individuals in the group with facial paralysis and the control group. The spontaneous smile assay will facilitate future research on the ability of facial reanimation procedures and other interventions to restore a spontaneous smile
Resolution requirements for numerical simulations of transition
The resolution requirements for direct numerical simulations of transition to turbulence are investigated. A reliable resolution criterion is determined from the results of several detailed simulations of channel and boundary-layer transition
radiative decays to light quark jets and color octet mechanism
We study radiative decays of to light quark jets in
nonrelativistic QCD by taking both the color singlet and color octet
operators into consideration. The cut for quark jet energy and cut for the
angle between two quark jets are introduced. The sensitivity to the soft and
collinear singularities in the loop integrals are greatly reduced by these
cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about
, the branching ratio for is found to be
from color singlet contributions. The color octet
contributions could be much larger than that of color singlet, depending on the
estimate of the color octet matrix elements. This process may provide a new
test for the color octet mechanism in nonrelativistic QCD.Comment: journal version; a few references adde
Human Observer and Automatic Assessment of Movement Related Self-Efficacy in Chronic Pain: from Exercise to Functional Activity
Clinicians tailor intervention in chronic pain rehabilitation to movement related self-efficacy (MRSE). This motivates us to investigate automatic MRSE estimation in this context towards the development of technology that is able to provide appropriate support in the absence of a clinician. We first explored clinical observer estimation, which showed that body movement behaviours, rather than facial expressions or engagement behaviours, were more pertinent to MRSE estimation during physical activity instances. Based on our findings, we built a system that estimates MRSE from bodily expressions and bodily muscle activity captured using wearable sensors. Our results (F1 scores of 0.95 and 0.78 in two physical exercise types) provide evidence of the feasibility of automatic MRSE estimation to support chronic pain physical rehabilitation. We further explored automatic estimation of MRSE with a reduced set of low-cost sensors to investigate the possibility of embedding such capabilities in ubiquitous wearable devices to support functional activity. Our evaluation for both exercise and functional activity resulted in F1 score of 0.79. This result suggests the possibility of (and calls for more studies on) MRSE estimation during everyday functioning in ubiquitous settings. We provide a discussion of the implication of our findings for relevant areas
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