bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the optimization of the classification method of rolling bearing fault type and damage degree based on SFO–VMD
Authors: Jing Laixing , Bian Jun , He Xiangdong , Liu Yanqiu 
Published: September 2023

Abstract
Currently, rolling bearings operate in harsh environments, resulting in acquired signals with a low signal-to-noise ratio. In light of this, this paper proposes an improved variational modal decomposition(VMD) combined with refine composite multi-scale fuzzy entropy (RCMFE) and linear support vector machine (LSVM) for fault diagnosis. Firstly, the sailfish optimization (SFO) algorithm is employed to optimize the important parameter combinations in the VMD algorithm, using the envelope entropy as its objective function. The analysis includes both simulated and real measured signals with varying signal-to-noise ratios. The results demonstrate that, compared to traditional manual parameter setting and empirical modal decomposition methods, this approach effectively addresses the parameter setting issue of VMD in the signal decomposition process. Additionally, it successfully eliminates noise to extract the fault characteristic signal hidden within the original signal. Secondly, the RCMFE algorithm is introduced to overcome the problem of commonly used dimensioned and dimensionless indicators being influenced by load and speed when used as characteristic indicators. By analyzing the influence of load and speed on the RCMFE value, the results demonstrate its strong stability as a feature indicator, unaffected by these factors. For the intelligent classification of failure type and damage degree, LSVM is chosen as the classification method. Analysis results indicate that the distribution characteristics of RCMFE values align better with LSVM compared to the common radial basis function support vector machine, resulting in a significant improvement in diagnosis accuracy.
Accurate near-wall measurements in wall bounded flows with optical flow velocimetry via an explicit no-slip boundary condition
Authors: Jassal Gauresh Raj , Schmidt Bryan E 
Published: September 2023

Abstract
High fidelity near-wall velocity measurements in wall bounded fluid flows continue to pose a challenge and the resulting limitations on available experimental data cloud our understanding of the near-wall velocity behavior in turbulent boundary layers. One of the challenges is the spatial averaging and limited spatial resolution inherent to cross-correlation-based particle image velocimetry (PIV) methods. To circumvent this difficulty, we implement an explicit no-slip boundary condition in a wavelet-based optical flow velocimetry (wOFV) method. It is found that the no-slip boundary condition on the velocity field can be implemented in wOFV by transforming the constraint to the wavelet domain through a series of algebraic linear transformations, which are formulated in terms of the known wavelet filter matrices, and then satisfying the resulting constraint on the wavelet coefficients using constrained optimization for the optical flow functional minimization. The developed method is then used to study the classical problem of a turbulent channel flow using synthetic data from a direct numerical simulation (DNS) and experimental particle image data from a zero pressure gradient, high Reynolds number turbulent boundary layer. The results obtained by successfully implementing the no-slip boundary condition are compared to velocity measurements from wOFV without the no-slip condition and to a commercial PIV code, using the velocity from the DNS as ground truth. It is found that wOFV with the no-slip condition successfully resolves the near-wall profile with enhanced accuracy compared to the other velocimetry methods, as well as other derived quantities such as wall shear and turbulent intensity, without sacrificing accuracy away from the wall, leading to state of the art measurements in the

y
+

<
1

region of the turbulent boundary layer when applied to experimental particle images.
Intelligent prediction of rolling bearing remaining useful life based on probabilistic DeepAR-Transformer model
Authors: Deng Linfeng , Li Wei , Zhang Weiqiang 
Published: September 2023

Abstract
Remaining useful life (RUL) prediction for rolling bearings requires highly accurate and stable long-term prediction capabilities in equipment health management, which demands that the prediction model has strong data reasoning and regression performance. However, it is difficult to accurately capture long-term dependencies via traditional convolutional neural network because the information loss and insufficient analysis are unavoidable during the feature extraction process. An end-to-end time series forecasting method called D-former for RUL prediction of rolling bearings is proposed in this paper. The method mainly consists of DeepAR and a multi-layer encoder, so it is able to extract degradation features directly from the original signal. This method has the following salient features: (1) the designed multi-head attention mechanism can highlight important feature information and realize parallel computing, so the method is extremely suitable for processing long-term time series; (2) the important time feature information is rearranged through DeepAR, so the method has the excellent domain adaptability, and it can achieve accurate prediction of rolling bearing RUL under different working conditions. The verification experiment was implemented on the IEEE PHM 2012 dataset and the XJTU-SY bearing dataset. The experimental results show that the proposed D-former method is actually superior to the existing mainstream RUL prediction methods.
A PTV-based feature-point matching algorithm for binocular stereo photogrammetry
Authors: Han Yukun , Pan Chong , Cheng Zepeng , Xu Yang 
Published: September 2023

Abstract
The procedure of feature matching is one of the most important components in binocular or multi-ocular stereoscopic photogrammetry. In this paper, a feature-point matching algorithm based on the technique of particle tracking velocimetry is proposed for the scenario of measuring complex surface morphology by dense-point three-dimensional reconstruction. The core idea is to mix the epipolar-line constraint of line-of-sight (LOS) with the measure of a global similarity pairing and estimate the depth of each feature point in an iterative way. Experimental test is conducted to verify the algorithm performance by measuring the surface topology of a wave-like model. The result demonstrates that the feature-point matching algorithm is superior to traditional LOS method in terms of accuracy and robustness. Moreover, replacing the first module of coarse matching in the proposed algorithm by LOS will save the computational cost significantly without sacrificing the measurement accuracy.
MARGANVAC: metal artifact reduction method based on generative adversarial network with variable constraints
Authors: Li Guang , Ji Longyin , You Chenyu , Gao Shuai , Zhou Langrui , Bai Keshu , Luo Shouhua , Gu Ning 
Published: September 2023

Abstract

Objective. Metal artifact reduction (MAR) has been a key issue in CT imaging. Recently, MAR methods based on deep learning have achieved promising results. However, when deploying deep learning-based MAR in real-world clinical scenarios, two prominent challenges arise. One limitation is the lack of paired training data in real applications, which limits the practicality of supervised methods. Another limitation is that image-domain methods suitable for more application scenarios are inadequate in performance while end-to-end approaches with better performance are only applicable to fan-beam CT due to large memory consumption. Approach. We propose a novel image-domain MAR method based on the generative adversarial network with variable constraints (MARGANVAC) to improve MAR performance. The proposed variable constraint is a kind of time-varying cost function that can relax the fidelity constraint at the beginning and gradually strengthen the fidelity constraint as the training progresses. To better deploy our image-domain supervised method into practical scenarios, we develop a transfer method to mimic the real metal artifacts by first extracting the real metal traces and then adding them to artifact-free images to generate paired training data. Main results. The effectiveness of the proposed method is validated in simulated fan-beam experiments and real cone-beam experiments. All quantitative and qualitative results demonstrate that the proposed method achieves superior performance compared with the competing methods. Significance. The MARGANVAC model proposed in this paper is an image-domain model that can be conveniently applied to various scenarios such as fan beam and cone beam CT. At the same time, its performance is on par with the cutting-edge dual-domain MAR approaches. In addition, the metal artifact transfer method proposed in this paper can easily generate paired data with real artifact features, which can be better used for model training in real scenarios.
3D modeling of positive streamers in air with inhomogeneous density
Authors: Guo Baohong , Ebert Ute , Teunissen Jannis 
Published: September 2023

Abstract
We study the effect of an inhomogeneous gas density on positive streamer discharges in air using a 3D fluid model with stochastic photoionization, generalizing earlier work with a 2D axisymmetric model by Starikovskiy and Aleksandrov (2019 Plasma Sources Sci. Technol.
28 095022). We consider various types of planar and (hemi)spherical gas density gradients. Streamers propagate from a region of density

n

0

towards a region of higher or lower gas density

n

1

, where

n

0

corresponds to

300

K

and

1

b
a
r

. We observe that streamers can always propagate into a region with a lower gas density. When streamers enter a region with a higher gas density, branching can occur at the density gradient, with branches growing in a flower-like pattern over the gradient surface. Depending on the gas density ratio, the gradient width and other factors, narrow branches are able to propagate into the higher-density gas. In a planar geometry, we find that such propagation is possible up to a gas density slope of

3.5

n

0

/

m
m

, although this value depends on a number of conditions, such as the gradient angle. Surprisingly, a higher applied voltage makes it more difficult for streamers to penetrate into the high-density region, due to an increase of the primary streamer’s radius.
Measurements of the amplitude-dependent microwave surface resistance of an Au/Nb bilayer
Authors: Oseroff Thomas , Sun Zeming , Liepe Matthias U 
Published: September 2023

AbstractSurface properties are critical to the capabilities of superconducting microwave devices. The native oxide of niobium-based devices is thought to consist of a thin normal conducting layer. To improve understanding on the importance of this layer, an attempt was made to replace it with a more easily controlled gold film. A niobium sample host microwave cavity was used to measure the surface resistance in continuous wave operation at4.0GHzand5.2GHz. Sample conditions studied include temperatures ranging from1.6Kto4.2Kwith RF magnetic fields on the sample surface ranging from∼1mTto the maximum field before the superconducting properties were lost (quench field). The nominal film thickness of the gold layer was increased from0.1nmto2.0nmin five steps to study the impact of the normal layer thickness on surface resistance on a single niobium substrate. The0.1nmfilm was found to reduce the surface resistance of the sample and to enhance the quench field. With the exception of the final step from a1.5nmgold film to2.0nm, the magnitude of the surface resistance increased substantially with gold film thickness. The nature of the surface resistance field-dependence appeared to be roughly independent from the gold layer thickness. This initial study provides new perspectives and suggests avenues for optimizing and designing surfaces for resonant cavities in particle accelerators and quantum information applications.
LIF /LIB Spectroscopy of crude oil-saturated carbonate bedrock
Authors: Parvin Parviz , Dehghanpour Hamid Reza , Faani Mohamad Mahdi , Bavali Ali , Ahmadinouri Fatemeh , Ebrahimnasab Setareh 
Published: September 2023

Abstract
Here, laser-induced breakdown spectroscopy (LIBS) is employed to identify constituent elements distinguishing nitrogen, oxygen, sulfur (NSO), and heavy metals in crude oil-saturated carbonate bedrock. The analysis of the spectra for both the bare rock samples and the oil-saturated specimens revealed the presence of NSO and heavy metal species (Ni, V) as the characteristics of heavy compounds in crude oil. On the other hand, the laser induced fluorescence (LIF) spectra of the crude oil are obtained over various temperatures ranging 50 °C–150 °C. The light compounds demonstrate better temperature sensitivity than the heavy compounds, leading to the identification/discrimination of those compounds.
Inflationary potential as seen from different angles: model compatibility from multiple CMB missions
Authors: Giarè William , Pan Supriya , Di Valentino Eleonora , Yang Weiqiang , de Haro Jaume , Melchiorri Alessandro 
Published: September 2023

AbstractThe cosmic microwave background (CMB) temperature and polarization anisotropies, as observed by independent astronomical missions such as WMAP, Planck, and most recently the Atacama Cosmology Telescope and the South Pole Telescope have played a vital role in accurately constraining cosmological theories and models, establishing cosmic inflation as the most widely accepted theory for describing the physics of the early Universe. However, the absence of a definitive detection of B-mode polarization and the emerging discrepancies among different CMB experiments present a challenge in determining which inflationary models best explain the observed data. In this work, we further explore this difficulty and conduct a case study by analyzing four well-known inflationary potentials in light of the latest CMB temperature and polarization anisotropy measurements and lensing data released by the Planck satellite and the Atacama Cosmology Telescope. Additionally, we incorporate B-modes polarization data from the BICEP/Keck Collaboration, as well as Baryon Acoustic Oscillations and Redshift Space Distortions measurements from BOSS DR12 and eBOSS DR16. We show that the most typical models such as Starobinsky and α-attractors are in disagreement with the Atacama Cosmology Telescope small-scale CMB measurements, particularly when combined with B-modes polarization data. On the other hand, these potentials are in perfect agreement with the Planck measurements at larger angular scales. This dichotomy makes it challenging to identify a single model or a group of models that can be universally considered as the preferred choice based on all available CMB observations.
Yang-Mills Casimir wormholes in D = 2 + 1
Authors: Santos Alana C.L. , Muniz Célio R. , Maluf Roberto V. 
Published: September 2023

Abstract
This work presents new three-dimensional traversable wormhole solutions sourced by the Casimir density and pressures related to the quantum vacuum fluctuations in Yang-Mills (Y-M) theory. We begin by analyzing the noninteracting Y-M Casimir wormholes, initially considering an arbitrary state parameter ω and determine a simple constant wormhole shape function. Next, we introduce a new methodology for deforming the state parameter to find well-behaved redshift functions. The wormhole can be interpreted as a legitimate Casimir wormhole with an expected average state parameter of ω = 2. Then, we investigate the wormhole curvature properties, energy conditions, and stability. Furthermore, we discover a novel family of traversable wormhole solutions sourced by the quantum vacuum fluctuations of interacting Yang-Mills fields with a more complex shape function. Deforming the effective state parameter similarly, we obtain well-behaved redshift functions and traversable wormhole solutions. Finally, we examine the energy conditions and stability of solutions in the interacting scenario and compare to the noninteracting case.
35 W highly effective Ytterbium-Erbium-Thulium tandem all-fiber 1.947 µm laser system at 975 nm diode pumping
Authors: Kir’yanov A V , Sholokhov E M 
Published: September 2023

Abstract
We report on progress towards effective mid-IR lasing using a tandem Ytterbium-Erbium/Thulium all-fiber laser system at near-IR diode pumping. ∼35 W 1.947 µm continuous-wave output power at ∼120 W 975 nm pump power (29% overall efficiency) is reached.
On the origin of the DIII-D L-H power threshold isotope effect
Authors: Callahan K.J. , Schmitz L. , Carter T.A. , Belli E.A. , Chrystal C. , Haskey S.R. , Grierson B.A. , Thome K.E. , Smith S.P. , McKee G.R. , Staebler G.M. , Holland C. , Ashourvan A. , Yan Z. 
Published: September 2023

Abstract
The increased low to high confinement mode (L to H-mode) power threshold

P

L
H

in DIII-D low collisionality hydrogen plasmas (compared to deuterium) is shown to result from lower impurity (carbon) content, consistent with reduced (mass-dependent) physical and chemical sputtering of graphite. Trapped gyro-Landau fluid (TGLF) quasilinear calculations and local non-linear gyrokinetic CGYRO simulations confirm stabilization of ion temperature gradient (ITG) driven turbulence by increased carbon ion dilution as the most important isotope effect. In the plasma edge, electron non-adiabaticity is also predicted to contribute to the isotope dependence of thermal transport and

P

L
H

, however its effect is subdominant compared to changes from impurity isotopic behavior. This L-H power threshold reduction with increasing carbon content at low collisionality is in stark contrast to high collisionality results, where additional impurity content appears to increase the power necessary for H-mode access.
A 1.3V 12-bit 100-MHz Current-Steering DAC in 55nm Technology
Authors: Zhong S G , Chen Z J , Xu N , Sun X F , Yang S Y , Wang R Y , Li B , Lin X L 
Published: September 2023

Abstract
In this paper, a 12-bit 100MS/s digital-to-analog converter (DAC) is presented, where a segmented current steering technique is employed. A “4+8” segmented architecture is used compromising the advantages and disadvantages of binary-weighted and thermometer-coded DACs. Cascode current source and cascode switch is used to achieve high input impedance and to minimize output glitches for good linearity and dynamic performance. The simulation results show that SFDR is over 77 dB, and the ENOB is 11.6 bit at least. The DAC consumes 2.27 mW from a 1.3-V supply.
Uncertainty analysis method of internal drag measurement for flow-through model in high-speed wind tunnel
Authors: Du Yufeng , Wang Lulu , Xiong Neng , Lin Jun 
Published: September 2023

Abstract
For aircraft with complex air intake and exhaust systems, the flow-through model simulating the internal flow passage is generally used to reduce the interference of internal and external flow fields when carrying out high-speed wind tunnel tests. The drag generated by the internal flow passage needs to be accurately measured and deducted from the full-model aerodynamic force, so as to obtain the aerodynamic characteristics of the aircraft to be tested. However, the existing internal drag measurement methods do not evaluate the uncertainty of the measurement results, which leads to the failure to evaluate the reliability of the flow-through model high-speed wind tunnel test results. This paper introduces the device and measurement method of internal drag of flow-through model. Based on GUM uncertainty analysis method, the analysis method of internal drag measurement uncertainty is established through strict mathematical derivation, which provides technical support for the evaluation of internal drag measurement uncertainty.
High-precision digital time-amplitude analysis system for the neutron Time-Of-Flight spectrometer in HL-2M
Authors: Zhang W. , Wu T.Y. , Li Y.G. , Zhang Y.P. 
Published: September 2023

Abstract
Neutron time-of-flight (TOF) spectrometers are widely used
for neutron diagnostics in large-scale fusion facilities. However,
traditional amplitude and time analysis methods are limited in terms
of resolution, flexibility, and other factors. To overcome these
limitations, we propose the Digital Time-Amplitude Analysis (DTAA)
system, which combines the advantages of both methods by using a
high-performance FPGA for real-time time and amplitude analysis of
particle pulses. The DTAA system provides accurate timing and pulse
shape information, fast processing speed, and low implementation
cost. We have also developed a multi-mode data joint time-of-flight
correction algorithm and verified its performance through
simulation. The DTAA system passed laboratory and tokamak tests,
achieving a time measurement precision of 122 ps and accurately
measuring neutron counts in tokamak experiments. This work
represents a key step towards comprehensive high-performance
integrated particle pulse analysis.
Accelerating China’s power sector decarbonization can save lives: integrating public health goals into power sector planning decisions
Authors: Luo Qian , Garcia-Menendez Fernando , Lin Jiang , He Gang , Johnson Jeremiah X 
Published: September 2023

Abstract
China, the world’s largest greenhouse gas emitter in 2022, aims to achieve carbon neutrality by 2060. The power sector will play a major role in this decarbonization process due to its current reliance on coal. Prior studies have quantified air quality co-benefits from decarbonization or investigated pathways to eliminate greenhouse gas emissions from the power sector. However, few have jointly assessed the potential impacts of accelerating decarbonization on electric power systems and public health. Additionally, most analyses have treated air quality improvements as co-benefits of decarbonization, rather than a target during decarbonization. Here, we explore future energy technology pathways in China under accelerated decarbonization scenarios with a power system planning model that integrates carbon, pollutant, and health impacts. We integrate the health effects of power plant emissions into the power system decision-making process, quantifying the public health impacts of decarbonization under each scenario. We find that compared with a reference decarbonization pathway, a stricter cap (20% lower emissions than the reference pathway in each period) on carbon emissions would yield significant co-benefits to public health, leading to a 22% reduction in power sector health impacts. Although extra capital investment is required to achieve this low emission target, the value of climate and health benefits would exceed the additional costs, leading to $824 billion net benefits from 2021 to 2050. Another accelerated decarbonization pathway that achieves zero emissions five years earlier than the reference case would result in lower net benefits due to higher capital costs during earlier decarbonization periods. Treating air pollution impacts as a target in decarbonization can further mitigate both CO2 emissions and negative health effects. Alternative low-cost solutions also show that small variations in system costs can result in significantly different future energy portfolios, suggesting that diverse decarbonization pathways are viable.