625 research outputs found
Nucleon gravitational form factors from instantons: forces between quark and gluon subsystems
Using the instanton picture of the QCD vacuum we compute the nucleon form factor of the quark part of the energy momentum tensor (EMT). This
form factor describes the non-conservation of the quark part of EMT and
contributes to the quark pressure distribution inside the nucleon. Also it can
be interpreted in terms of forces between quark and gluon subsystems inside the
nucleon.
We show that this form factor is parametrically small in the instanton
packing fraction. Numerically we obtain for the nucleon EMT a small value of
at the low normalisation point of GeV. This smallness implies interesting physics picture - the forces
between quark and gluon mechanical subsystems are smaller than the forces
inside each subsystem. The forces from side of gluon subsystem squeeze the
quark subsystem - they are compression forces. Additionally, the smallness of
might justify Teryaev's equipartition conjecture. We estimate
that the contribution of to the pressure distribution inside the
nucleon is in the range of 1 -20 % relative to the contribution of the quark
-term.Comment: 8 pages, published versio
Trap-Based Pest Counting: Multiscale and Deformable Attention CenterNet Integrating Internal LR and HR Joint Feature Learning
Pest counting, which predicts the number of pests in the early stage, is very
important because it enables rapid pest control, reduces damage to crops, and
improves productivity. In recent years, light traps have been increasingly used
to lure and photograph pests for pest counting. However, pest images have a
wide range of variability in pest appearance owing to severe occlusion, wide
pose variation, and even scale variation. This makes pest counting more
challenging. To address these issues, this study proposes a new pest counting
model referred to as multiscale and deformable attention CenterNet
(Mada-CenterNet) for internal low-resolution (LR) and high-resolution (HR)
joint feature learning. Compared with the conventional CenterNet, the proposed
Mada-CenterNet adopts a multiscale heatmap generation approach in a two-step
fashion to predict LR and HR heatmaps adaptively learned to scale variations,
that is, changes in the number of pests. In addition, to overcome the pose and
occlusion problems, a new between-hourglass skip connection based on deformable
and multiscale attention is designed to ensure internal LR and HR joint feature
learning and incorporate geometric deformation, thereby resulting in an
improved pest counting accuracy. Through experiments, the proposed
Mada-CenterNet is verified to generate the HR heatmap more accurately and
improve pest counting accuracy owing to multiscale heatmap generation, joint
internal feature learning, and deformable and multiscale attention. In
addition, the proposed model is confirmed to be effective in overcoming severe
occlusions and variations in pose and scale. The experimental results show that
the proposed model outperforms state-of-the-art crowd counting and object
detection models
Isovector helicity quark quasi-distributions inside a large Nc nucleon
In this letter, we report the results for the isovector polarized quark
quasi-distribution functions in the large
, calculated within the chiral quark-soliton model. It is shown that the
polarized quark quasi-distributions present good convergence to the light-cone
PDFs in the limit of the nucleon boost momentum (or the
velocity ), compared to the case of the unpolarized isosinglet
distributions
A Study on the impact of FDI on economic growth in ASEAN
Thesis(Master) --KDI School:Master of Development Policy,2015This paper examines the impact of foreign direct investment (FDI) on economic growth of the Association of Southeast Asian Nations (ASEAN) countries, using the panel data of ASEAN 8 countries over the period of 2000-2012. Employing various social factors and macroeconomic indicators as independent variables for fixed effect model and random effect model, we find evidence for the positive impact of FDI on economic growth of the region in both estimations.masterpublishedSu Hyeon SON
- …