bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dedicated convolutional neural network for noise reduction in ultra-high-resolution photon-counting detector computed tomography
Authors: Huber Nathan R , Ferrero Andrea , Rajendran Kishore , Baffour Francis , Glazebrook Katrina N , Diehn Felix E , Inoue Akitoshi , Fletcher Joel G , Yu Lifeng , Leng Shuai , McCollough Cynthia H 
Published: August 2022

Abstract

Objective. To develop a convolutional neural network (CNN) noise reduction technique for ultra-high-resolution photon-counting detector computed tomography (UHR-PCD-CT) that can be efficiently implemented using only clinically available reconstructed images. The developed technique was demonstrated for skeletal survey, lung screening, and head angiography (CTA). Approach. There were 39 participants enrolled in this study, each received a UHR-PCD and an energy integrating detector (EID) CT scan. The developed CNN noise reduction technique uses image-based noise insertion and UHR-PCD-CT images to train a U-Net via supervised learning. For each application, 13 patient scans were reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) and allocated into training, validation, and testing datasets (9:1:3). The subtraction of FBP and IR images resulted in approximately noise-only images. The 5-slice average of IR produced a thick reference image. The CNN training input consisted of thick reference images with reinsertion of spatially decoupled noise-only images. The training target consisted of the corresponding thick reference images without noise insertion. Performance was evaluated based on difference images, line profiles, noise measurements, nonlinear perturbation assessment, and radiologist visual assessment. UHR-PCD-CT images were compared with EID images (clinical standard). Main results. Up to 89% noise reduction was achieved using the proposed CNN. Nonlinear perturbation assessment indicated reasonable retention of 1 mm radius and 1000 HU contrast signals (>80% for skeletal survey and head CTA, >50% for lung screening). A contour plot indicated reduced retention for small-radius and low contrast perturbations. Radiologists preferred CNN over IR for UHR-PCD-CT noise reduction. Additionally, UHR-PCD-CT with CNN was preferred over standard resolution EID-CT images. Significance. CT images reconstructed with very sharp kernels and/or thin sections suffer from increased image noise. Deep learning noise reduction can be used to offset noise level and increase utility of UHR-PCD-CT images.
Comprehensive analysis of optoelectronic performance of ultraviolet phototransistors based on AlGaN/GaN heterostructure
Authors: Chen Dingbo , Chen Yu-Chang , Zeng Guang , Li Yu-Chun , Li Xiao-Xi , Peng Bo-Fang , Lu Hong-Liang 
Published: August 2022

Abstract
Optoelectronic performance of ultraviolet phototransistors (UVPTs) based on AlGaN/GaN high-electron-mobility transistor (HEMT) configuration is comprehensively studied under different illumination wavelengths, light power densities, gate biases, and drain voltages. A special photoresponse mechanism combining photovoltaic effect and photoconductive effect is proposed to explain the variation of detection performance with the optical and electrical conditions. By comparing the photoreponse characteristics under typical illumination wavelengths of 310 and 360 nm, the optoelectronic properties of the HEMT-based UVPTs are deeply revealed and summarized. This work can provide suggestions and guidelines for designing of AlGaN/GaN-based UVPTs in III–V integrated photonic systems.
Electrical-performance and reliability improvement of flexible low-temperature polycrystalline silicon thin-film transistors via post-annealing process
Authors: Im Hwarim , Ahn Jeong Hyun , Kim Won-Young , Ha Tae Eun , Jo Eun Kyung , Oh Yunjung , Cha Myoung Geun , Choi Sanggun , Lim Jun Hyung , Kim Yong-Sang 
Published: August 2022

Abstract
We investigated the improvement methods of the electrical characteristics and reliability of flexible low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) by optimizing the annealing process. We investigated the effect of annealing on the device properties via electrical measurement and density-of-state (DOS) analysis. The annealing temperature should be reduced for flexible LTPS TFTs compared to rigid devices because the range of the thermal stability of flexible substrate is narrower than that of the glass substrate. As the activation annealing temperature (T
a) decreased, the threshold voltage and field-effect mobility (μ
FE) decreased, and the subthreshold swing (SS) increased. When the post-annealing temperature (T
pa) decreased, μ
FE increased, and the changes in the other parameters were negligible. The DOS decreased with an increase in T
a and a reduction in T
pa. These results originated from ineffective dopant activation and defect curing due to the lower T
a and the enhanced hydrogen defect passivation at the lower T
pa. Therefore, flexible LTPS TFTs with reduced T
a values exhibited similar μ
FE values and lower SS values when the post-annealing process was omitted. Furthermore, removing the post-annealing process improved the reliability of the flexible LTPS TFTs with reduced T
a values under electrical stress. According to a hot-carrier instability analysis, defect passivation by hydrogen was more stable than defect curing with a higher T
a. Consequently, although T
a was low for flexible LTPS TFTs, the electrical performance and reliability could be improved by optimizing the post-annealing process.
Experimental and numerical studies on SMA-viscoelastic hybrid self-centering braces
Authors: Ping Yiwei , Fang Cheng , Shi Fei , Wu Honglei , Yam Michael C H , Chen Yiyi 
Published: August 2022

Abstract
This study presents a novel hybrid self-centering solution, namely, shape memory alloy (SMA)-viscoelastic hybrid brace (SVHB), to enhance structural seismic resilience and meanwhile, to overcome some shortcomings of existing self-centering braces. The study commences with a detailed introduction of the working principle of the SVHB, followed by a series of tests on individual SMA cables and viscoelastic dampers (VEDs). After gaining a basic understanding of the behavior of the critical components, a comprehensive experimental study on SVHB specimens considering different design parameters and loading conditions is carried out. Numerical models are subsequently developed and validated, followed by a parametric study providing a more in-depth insight into the influence of varying brace parameters. The individual SMA cables show stable flag-shaped hysteretic curves, with a fracture strain of around 15%. The individual VED displays typical parallelogram-shaped hysteretic responses, with a slight hardening effect at large shear strain. The SVHB specimen shows anticipated axial deformation mode with almost zero residual deformation upon unloading. The hysteretic response of the SVHB is the summation of that of the SMA cables and VEDs working in parallel. The average initial stiffness of the SVHB specimen is 87.4 kN mm−1, and the equivalent viscous damping ratio is up to 14.4%. Following the experimental study, a multiple spring-based modelling strategy is proposed which can accurately capture the complex nonlinear behavior of the SVHB. The influences of various parameters, such as rate sensitivity of VED and proportion of critical components, on the behavior of SVHBs are finally revealed.
In-vitro and in-vivo studies of 4D printed shape memory scaffolds with bioactive fillers and coating for enhanced bone tissue regeneration
Authors: Zhou Wanmei , Dong Xueming , He Yang , Zheng Wei , Leng Jinsong 
Published: August 2022

Abstract
Bone tissue engineering is considered one of the pivotal treatments for bone defects in patients. However, the conventional strategies for repairing irregular and complex bone defects are highly unsatisfactory, and appropriate repairing of bone defects remains a challenge. In recent years, smart scaffolds integrated with multiple functions have emerged as promising alternatives for the treatment of various bone defects. In this study, 4D printed shape memory polymer (SMP) scaffolds containing bioactive fillers (hydroxyapatite and alendronate) and collagen–dexamethasone (Col–Dex) coating were fabricated, and their microstructures, porosity, mechanical properties, and biological functions were thoroughly investigated. The SMP scaffolds manufactured in this study could be programmed into temporary shapes of small sizes and then recovered to working sizes and shapes under an alternating magnetic field to fill bone defects. In addition, the biological studies including cytotoxicity tests, osteogenesis-related gene expressions, fluorescence staining imaging, and animal experiments demonstrated the effective biological activities and osteogenic effects of the 4D printed SMP scaffolds, with potential applications in bone tissue regeneration. In other words, the prepared 4D printed scaffolds with bioactive fillers and the Col–Dex coating will provide an efficient approach for personalized bone tissue repair as well as enhanced bone tissue regeneration.
The effect of facet lines on critical current density and trapped field in bulk RE–Ba–Cu–O single grains
Authors: Shi Y , Mousavi T , Dennis A R , Ainslie M D , Speller S C , Grovenor C R H , Durrell J H , Cardwell D A 
Published: August 2022

Abstract
Bulk, single grain RE–Ba–Cu–O (where RE = rare earth or yttrium) [(RE)BCO] high temperature superconductors could potentially be used to generate stable magnetic fields for magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR). In these applications, however, the homogeneity of the magnetic field is of critical importance. As a result, the spatial distribution of critical current density, J
c, within the bulk single grain and the effects of the magnetisation process, which are primary drivers of the uniformity of the achievable trapped magnetic field, are fundamental to assessing the performance of these technologically important materials. This paper reports the systematic measurement of the distribution of J
c–B at 77 K over a vertical cross-section of a single grain along a facet line and through the seed crystal [(110)-F] at 20 positions within a 20 mm diameter Gd–Ba–Cu–O sample in an attempt to understand and assess the distribution of J
c along this microstructural feature. A comparison of the data within the whole vertical plane across the seed measured along the a or b direction within the [(100)-a] plane shows that J
c–B at 77 K at the facet line is more than 10% higher for applied fields between 0.2 T and 2.5 T. The effect of the J
c–B relationship of the facet line on the overall trapped field measured in an individual bulk sample was investigated by measuring the magnitudes of trapped fields and their contour maps for sections cut from four single grain samples of GdBCO–Ag at different sizes and shapes parallel to the ab-plane from the top to the bottom of the bulk sample. Based on the results reported here, we demonstrate a method to achieve more uniform trapped fields through an optimal arrangement of an assembly of sections of individual GdBCO single grains.
Improvement on Faraday rotation measurement affected by the stray lights on the HL-2A tokamak
Authors: Wang Z H , Li Y G , Li Y , Wang H X , Yi J , Wen R N , Shi Z B 
Published: August 2022

Abstract
Formic-acid (HCOOH, λ = 432.5 μm) laser
P
olarimeter-
I
nterferomet
er
(
PIer
) has been developed on the HL-2A tokamak, which provides 4 channels of line-integrated electron densities and 4 channels of Faraday rotation angles, respectively. Affected by the stray lights arising from the reflection of the probe waves in the optical system, the measurement of Faraday rotation angles was drastically contaminated during the HL-2A experiments, showing an obvious oscillation modulation during the electron density ramp-up/down. This paper introduces an effective correction approach used to improve the accuracy of Faraday rotation measurement on the HL-2A tokamak. Based on the method, the deviation term originating from the stray lights can be effectively subtracted from the contaminated Faraday rotation measurement. The preliminary result indicates that the interference amplitude on Faraday rotation angle is reduced by about 80%, and the corrected data is consistent with the experimental measurement by using the optical isolator that consists of a λ/4 wave-plate and polarizer under the similar discharges.
Color image encryption algorithm based on 3D spiral transform and radial diffusion
Authors: Zhang Xiaoqiang , Yang Xiaochang 
Published: August 2022

Abstract
While digital image information is convenient to transmit in Internet, there is a great risk of information leakage in practice. To satisfy the demands for image content security and real-time communication, we propose a color image encryption algorithm based on a three-dimensional (3D) spiral transform and radial diffusion. Firstly, a 3D spiral transform is designed by combining the R, G and B channels of the color image with the traditional spiral transform; secondly, after the randomly selecting the spiral starting point by the chaotic sequence, the plained image is scrambled by the 3D spiral transform; thirdly, after randomly selecting the method of radial diffusion by the chaotic sequence, the scrambled image is radially diffused by chaotic sequences to obtain the cipher image. Simulation results and theoretical analyses show that the proposed algorithm not only has an excellent encryption effect, but also has the strong security to resist common attacks. Thus, the proposed algorithm can be suitable for the color image transmission under the network platform with the high-security requirement.
Moving boundary problems for a canonical member of the WKI inverse scattering scheme: conjugation of a reciprocal and Möbius transformation
Authors: Rogers Colin 
Published: August 2022

Abstract
Reciprocal links between certain solitonic systems and their hierarchies are well-established. Moreover, the AKNS and WKI inverse scattering schemes are known to be connected by a composition of gauge and reciprocal transformations. Here, a reciprocal transformation allied with a Möbius-type mapping is applied to a class of Stefan-type problems for the solitonic Dym equation to generate a novel exact parametric solution to a class of moving boundary problems for a canonical member of the WKI system.
Nonparametric Bayesian inference for meta-stable conformational dynamics
Authors: Köhs Lukas , Kukovetz Kerri , Rauh Oliver , Koeppl Heinz 
Published: August 2022

Abstract
Analyses of structural dynamics of biomolecules hold great promise to deepen the understanding of and ability to construct complex molecular systems. To this end, both experimental and computational means are available, such as fluorescence quenching experiments or molecular dynamics simulations, respectively. We argue that while seemingly disparate, both fields of study have to deal with the same type of data about the same underlying phenomenon of conformational switching. Two central challenges typically arise in both contexts: (i) the amount of obtained data is large, and (ii) it is often unknown how many distinct molecular states underlie these data. In this study, we build on the established idea of Markov state modeling and propose a generative, Bayesian nonparametric hidden Markov state model that addresses these challenges. Utilizing hierarchical Dirichlet processes, we treat different meta-stable molecule conformations as distinct Markov states, the number of which we then do not have to set a priori. In contrast to existing approaches to both experimental as well as simulation data that are based on the same idea, we leverage a mean-field variational inference approach, enabling scalable inference on large amounts of data. Furthermore, we specify the model also for the important case of angular data, which however proves to be computationally intractable. Addressing this issue, we propose a computationally tractable approximation to the angular model. We demonstrate the method on synthetic ground truth data and apply it to known benchmark problems as well as electrophysiological experimental data from a conformation-switching ion channel to highlight its practical utility.
Pattern Recognition Using SVM for the Classification of the Size and Distance of Trans-Neptunian Objects Detected by Serendipitous Stellar Occultations
Authors: Hernández-Valencia B. , Castro-Chacón J. H. , Reyes-Ruiz M. , Lehner M. J. , Guerrero C. A. , Silva J. S. , Hernández-Águila J. B. , Alvarez-Santana F. I. , Sánchez E. , Nuñez J. M. , Calvario-Velásquez L. T. , Figueroa Liliana , Huang C.-K. , Wang Shiang-Yu , Alcock C. , Chen W.-P. , Granados Contreras Agueda Paula , Geary J. C. , Cook K. H. , Kavelaars J. J. , Norton T. , Szentgyorgyi A. , Yen W.-L. , Zhang Z.-W. , Olague G. 
Published: August 2022

Abstract
We present a new pipeline based on the Support Vector Machine algorithm to confirm the detection and perform classification of small solar system objects by serendipitous stellar occultations. This pipeline is designed to analyze light curves and to identify the occultation events and the classification of the occulting bodies according to their size, typically from a fraction to a few kilometers, and their distance from the Sun, typically a few tens of astronomical units. The input light curves for this pipeline were obtained from the event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We explore parameters affecting occultation light curves such as spectral type, apparent magnitude and finite angular size of the occulted star, angle from opposition, and readout cadence for the observations; also we assumed a Poisson noise distribution as expected from the TAOS II project. We find that occultation events, especially by trans-Neptunian objects with diameters ≥2 km are detected with 99.99%, 99.53%, and 86% efficiency for stars with a visual apparent magnitude of 12, 14, and 16, respectively at 0.05 s of exposure time. In terms of size and distance classification the overall accuracy is 94%. However, for smaller objects the confirmation and classification depends mostly upon the signal-to-noise ratio.
Realization of phase dependent optical bistability in a quantum dot molecule via three-wave mixing
Authors: Wang Donghui 
Published: August 2022

Abstract
In this paper, we have proposed a new model based on the electron tunneling effect for controlling the optical bistability (OB) and optical multistability (OM) in a defect slab structure with a quantum dot molecule (QDM). Due to the presence of the electron tunneling effect, an additional weak signal beam can be generated in the system which makes the medium becomes phase dependent. We have studied the refractive index properties of the QDM via optical susceptibility of the propagated probe light. We have discussed the relative phase effect on negative refractive index (NRI) of the QDM nanostructure due to presence of electron tunneling. Then, by using the transfer matrix method, we have studied the transmission coefficient for NRI of the QDM nanostructure. Then, we have investigated the properties of transmitted light versus incident light for realizing the OB and OM. We have considered the relative phase effect on OB and OM properties of the transmitted beam and find that the switching between them is possible when electron tunneling is present in the quantum dot. Moreover, the optical thickness of the defect layer is also investigated on OB and OM in resonance and non-resonance conditions.
Shadow thermodynamics of non-linear charged Anti-de Sitter black holes*
Authors: Du Yun-Zhi , Li Huai-Fan , Zhou Xiang-Nan , Guo Wei-Qi , Zhao Ren 
Published: August 2022

Abstract
It is well known that when vacuum polarization emerges in quantum electrodynamics, the non-linear interaction between electromagnetic fields should be considered. Moreover, the corresponding field of non-linear electrodynamics can have important effects on black hole physics. In this work, we focus on the relationship between an observable quantity, that is, the shadow radius, and the first-order phase transition of non-linear charged AdS black holes in the framework of Einstein-power-Yang-Mills gravity. The results show that, under a certain condition, there exists a first-order phase transition from the viewpoint of both the shadow radius and horizon radius, which depend on temperature (or pressure). From the viewpoint of the shadow radius, the phase transition temperature is higher than that from the viewpoint of the horizon radius under the same condition. This may be due to the non-linear Yang Mills charge and the gravitational effect. This indicates that the shadow radius can be regarded as a probe to reveal the thermodynamic phase transition information of black holes. The thermal profiles of coexistent large and small black hole phases when the system is undergoing the phase transition are presented for two different values of the non-linear Yang Mills charge parameter:

. Furthermore, the effects of the non-linear Yang Mills charge parameter on the shadow radius and thermal profile are investigated.
Time-resolved terahertz spectroscopy for probing the effects of low-temperature annealing on CsPbBr3 evaporated thin-films
Authors: Gatto Lorenzo , Treglia Antonella , Crippa Gabriele , Devetta Michele , Folpini Giulia , Petrozza Annamaria , Stagira Salvatore , Vozzi Caterina , Cinquanta Eugenio 
Published: August 2022

Abstract
The fine-tuning of the growth conditions and post-deposition treatments is of fundamental importance to improve the efficiency of photovoltaic devices based on all-inorganic metal halide perovskites like CsPbBr3. In this work, we used time-resolved terahertz spectroscopy (TRTS) in combination with optical characterization techniques, x-ray diffraction (XRD), and scanning electron microscopy, to probe the different properties induced by a low-temperature (180 °C) annealing treatment on evaporated CsPbBr3 thin-films. We observed a faster build-up and relaxation dynamics in the annealed sample, accompanied by a remarkable decrease of the photoluminescence intensity and minor changes in the photoconductivity and XRD measurements as compared to the as-deposited sample. We estimated for both the samples a mobility of

μ
=

1.7
±
0.5

×

10
2

cm2 V−1 s−1. Our results suggest that the lattice reorganization induced by low-temperature annealing of evaporated CsPbBr3 could lead to a different charge carrier-phonon coupling and to an increased contribution of non-radiative recombination channels. We found that TRTS can be effectively used to follow the changes induced by post-deposition thermal annealing of CsPbBr3.
Micromasers as quantum batteries
Authors: Shaghaghi Vahid , Singh Varinder , Benenti Giuliano , Rosa Dario 
Published: August 2022

Abstract
We show that a micromaser is an excellent model of quantum battery. A highly excited, pure, and effectively steady state of the cavity mode, charged by coherent qubits, can be achieved, also in the ultrastrong coupling regime of field-matter interaction. Stability of these appealing features against loss of coherence of the qubits and the effect of counter-rotating terms in the interaction Hamiltonian are also discussed.