6,457 research outputs found
Two Higgs doublet models for the LHC Higgs boson data at 7 and 8 TeV
Updated LHC data on the new 126 GeV boson during the 7 and 8 TeV runnings
strengthen the standard model Higgs boson interpretation further. Through the
global analysis, we investigate whether the new particle could be one
of the scalar particles in two Higgs doublet models. Four types (Type I, II, X
and Y) are comprehensively studied. Taking the recent analysis on the
spin-parity of the new boson, we consider two scenarios: the new boson is
either the light CP-even one () or the heavy CP-even one (). It is
found that both scenarios are consistent with the new data, not only in the
parameter regions near the decoupling limit but also in other regions far from
the decoupling limit. In addition, the current data are compatible with the
possibility that the light Higgs boson is hidden in the mass window of
90-100 GeV. The diphoton or channel can provide a probe of this
possibility by the enhanced signal rates.Comment: To appear in JHE
Fast Recognition of birds in offshore wind farms based on an improved deep learning model
The safety of wind turbines is a prerequisite for the stable operation of
offshore wind farms. However, bird damage poses a direct threat to the safe
operation of wind turbines and wind turbine blades. In addition, millions of
birds are killed by wind turbines every year. In order to protect the
ecological environment and maintain the safe operation of offshore wind
turbines, and to address the problem of the low detection capability of current
target detection algorithms in low-light environments such as at night, this
paper proposes a method to improve the network performance by integrating the
CBAM attention mechanism and the RetinexNet network into YOLOv5. First, the
training set images are fed into the YOLOv5 network with integrated CBAM
attention module for training, and the optimal weight model is stored. Then,
low-light images are enhanced and denoised using Decom-Net and Enhance-Net, and
the accuracy is tested on the optimal weight model. In addition, the k-means++
clustering algorithm is used to optimise the anchor box selection method, which
solves the problem of unstable initial centroids and achieves better clustering
results. Experimental results show that the accuracy of this model in bird
detection tasks can reach 87.40%, an increase of 21.25%. The model can detect
birds near wind turbines in real time and shows strong stability in night,
rainy and shaky conditions, proving that the model can ensure the safe and
stable operation of wind turbines
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Department of ChemistryAnalysis of rotational spectra provides information about molecular structure and the rotational spectrum can also be used as a molecular fingerprint for molecule identification. Microwave spectroscopy is currently the most powerful tool to measure rotational spectra. High-resolution microwave spectroscopy can reach single kHz resolution and can get single Hz accuracy. Rotational Raman spectroscopy is a complementary method to microwave spectroscopy with different selection rules. But past Raman spectroscopy had a limited resolution, reaching only 100???s of MHz resolution.
High-resolution mass-CRASY breaks this limitation with a new method for high-resolution measurements. Time-domain measurements produce high-resolution mass-correlated rotational Raman spectra, and we obtained a resolution below 1 MHz resolution and kHz accuracy. In addition to high-resolution spectra, our technique produces correlated spectroscopic data. With mass-correlated information, we can assign signals for multiple molecules in an impure sample without purification. Here, we use this capability to resolve isotopologue spectra from naturally heterogeneous samples.
Our technique is still a new spectroscopic tool, so we need to prove its reliability. In this thesis, I describe the characterization of numerous molecules which J characterized with high-resolution mass-CRASY during my thesis. The measured molecules are linear, symmetric tops, and asymmetric tops all of which are Raman active. I prove the reliability and accuracy of CRASY by comparison to literature data, where available. The development and application of this new high-resolution technique allowed to obtain precise spectroscopic information for a large range of molecules.ope
What Questions do People Ask on a Human Papillomavirus Website? A Comparative Analysis of Public and Private Questions
Objective: In 2004, we launched the question and answer (Q&A) section on a human papillomavirus (HPV) website (www.hpvkorea.org) that provides ample and regularly updated information about HPV. The purpose of this study is to collect data pertaining to questions posed on this website about HPV and its related diseases and analyze the type of questions and frequency before and after introduction of HPV vaccine in Korea. Using these results, we intend to determine the clinical and practical implications for doctors treating HPV and for HPV website providers
Molecular-Beam Spectroscopy with an Infinite Interferometer: Spectroscopic Resolution and Accuracy
An interferometer with effectively infinite maximum optical path difference
removes the dominant resolution limitation for interferometric spectroscopy. We
present mass-correlated rotational Raman spectra that represent the world's
highest resolution scanned interferometric data and discuss the current and
expected future limitations in achievable spectroscopic performance.Comment: 8 pages, 12 figures, 1 table, submitted to the Journal of the Korean
Physical Societ
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