bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D reconstruction and depth estimation method for local anomalies of rail surface based on multi-view stereo matching
Authors: Hu Pengyu , Zhong Qianwen , Zheng Shubin , Chen Xieqi , Peng Lele 
Published: October 2024

Abstract
Detecting rail surface anomalies has become crucial for ensuring the safety of train operations. However, manual detection methods are time-consuming and labor-intensive. Although traditional detection models based on one-dimensional signals or two-dimensional images can effectively identify the existence of defects, they are difficult to use to obtain local depth characteristic information, leading to difficulties in accurately assessing the extent of damage in abnormal regions. Rail track maintenance strategies are typically developed based on the detected different depth ranges of defects. To address this issue, this paper proposes a local depth estimation method based on the point cloud of the target rail surface reconstructed by PatchmatchNet. Firstly, according to the acquisition method of multi-view images and the sampling environment at the site, a practical data collection protocol is established for generating a multi-view dataset of rail surface. Next, dense point cloud of the target rail surface were reconstructed by PatchmatchNet. Subsequently, a method for estimating the local anomaly depth is developed based on the point cloud. The experimental results indicate that the proposed method achieves a maximum estimation error of only 10% within a depth range of 0.35 mm., when compared to depth measurements obtained using a structured light camera. Finally, this paper presents a more comprehensive three-dimensional representation of the local abnormal physical structure, surpassing traditional one-dimensional and two-dimensional forms. This enhanced representation offers richer information for the effective determination of whether the anomalies constitute defects and aids in distinguishing true defects from other surface irregularities. Such advancement significantly improves the precision of defect assessment and supports the development of highly precise repair strategies.
A novel performance prediction method for harmonic reducers based on the trend-enhanced Fisher’s discriminant ratio-Wiener process
Authors: Zhang Yixin , Xu Yang , Xie Guosheng , Sheng Xiaowei , Li Peibo 
Published: October 2024

Abstract
Harmonic reducers, as core components of industrial robots, play a critical role in maintaining robot health. Performance degradation assessment and remaining useful life (RUL) prediction are essential for ensuring the operational reliability of such robots. To address the multistage characteristics and stochastic uncertainties in the performance degradation of harmonic reducers, a performance prediction method based on Fisher’s discriminant ratio and Wiener process is proposed. Firstly, the health indicator construction is defined as an optimization problem based on Fisher’s discriminant ratio and trend monotonicity constraints. By leveraging the sum of the multiplication of frequency amplitudes and optimized weights, precise segmentation of the multistage degradation process over the entire lifecycle is achieved. Notably, the optimized weights can automatically identify the resonance frequency bands caused by damage. Subsequently, a nonlinear Wiener process model with a drift coefficient in the form of a power function is established. The probability density function expression for RUL is derived based on the concept of first hit time. Additionally, a logarithmic likelihood function for the unknown parameters in the degradation model is constructed. The experimental results indicate that the proposed method surpasses the other two Wiener process models in terms of root mean square error, mean absolute percentage error, and cumulative relative accuracy. This provides robust support for preventive maintenance decision-making for harmonic reducers.
Engineering Fano resonances in plasmonic metasurfaces for colorimetric sensing and structural colors
Authors: Kohandani Reza , Saini Simarjeet Singh 
Published: October 2024

Abstract
In this paper, we present the design and fabrication of a plasmonic metasurface based on titanium dioxide (TiO2) nanowire arrays integrated with plasmonic layers. The structure is engineered to produce Fano resonances within the visible spectrum, resulting from the coupling of localized surface plasmon resonances, lattice modes, and nanowire’s optical modes. Experimentally, we show that by tuning the geometrical features of the metasurface, such as the length, diameter, and period of the nanowires, a high-quality factor single peak can be achieved in the reflection spectra, resulting in vivid structural colors in bright field. To our knowledge, this is the first demonstration of such vivid colors with nanowire arrays in bright field reflections. When characterized by refractive index fluids around the refractive index of water, the plasmonic metasurface also showed great potential for biochemical colorimetric sensing. The best design demonstrated a bulk sensitivity of 183 nm/RIU with high Q resonance features and linear changes in color values using image processing.
Effect of SiCN thin film interlayer for ZnO-based RRAM
Authors: Ko Woon-San , Song Myeong-Ho , Byun Jun-Ho , Lee Do-Yeon , Kwon So-Yeon , Hyun Jong-Sin , Choi Dong-Hyeuk , Lee Ga-Won 
Published: October 2024

Abstract
This study investigates the effect of silicon carbon nitride (SiCN) as an interlayer for ZnO-based resistive random access memory (RRAM). SiCN was deposited using plasma-enhanced chemical vapor deposition with controlled carbon content, achieved by varying the partial pressure of tetramethylsilane (4MS). Our results indicate that increasing the carbon concentration enhances the endurance of RRAM devices but reduces the on/off ratio. Devices with SiCN exhibited lower operating voltages and more uniform resistive switching behavior. Oxygen migration from ZnO to SiCN is examined by x-ray diffraction and x-ray photoelectron spectroscopy analyses, promoting the formation of conductive filaments and lowering set voltages. Additionally, we examined the impact of top electrode oxidation on RRAM performance. The oxidation of the Ti top electrode was found to reduce endurance and increase low resistive state resistance, potentially leading to device failure through the formation of an insulating layer between the electrode and resistive switching material. The oxygen storage capability of SiCN was further confirmed through high-temperature stress tests, demonstrating its potential as an oxygen reservoir. Devices with a 20 nm SiCN interlayer showed significantly improved endurance, with over 500 switching cycles, compared to 62 cycles in those with a 5 nm SiCN layer. However, the thicker SiCN layer resulted in a notably lower on/off ratio due to reduced capacitance. These findings suggest that SiCN interlayers can effectively enhance the performance and endurance of ZnO-based RRAM devices by acting as an oxygen reservoir and mitigating the top electrode oxidation effect.
PET image reconstruction using weighted nuclear norm maximization and deep learning prior
Authors: Kuang Xiaodong , Li Bingxuan , Lyu Tianling , Xue Yitian , Huang Hailiang , Xie Qingguo , Zhu Wentao 
Published: October 2024

Abstract
The ill-posed Positron emission tomography (PET) reconstruction problem usually results in limited resolution and significant noise. Recently, deep neural networks have been incorporated into PET iterative reconstruction framework to improve the image quality. In this paper, we propose a new neural network-based iterative reconstruction method by using weighted nuclear norm (WNN) maximization, which aims to recover the image details in the reconstruction process. The novelty of our method is the application of WNN maximization rather than WNN minimization in PET image reconstruction. Meanwhile, a neural network is used to control the noise originated from WNN maximization. Our method is evaluated on simulated and clinical datasets. The simulation results show that the proposed approach outperforms state-of-the-art neural network-based iterative methods by achieving the best contrast/noise tradeoff with a remarkable contrast improvement on the lesion contrast recovery. The study on clinical datasets also demonstrates that our method can recover lesions of different sizes while suppressing noise in various low-dose PET image reconstruction tasks. Our code is available at
https://github.com/Kuangxd/PETReconstruction
.
The impact of catalyst structure and loading material on the dynamics of plasma propagation in dielectric barrier discharges
Authors: Zhang Lei-Yu , Zhang Quan-Zhi , Mujahid Zaka-ul-Islam , Neuroth Constantin , Berger Birk , Schulze Julian 
Published: October 2024

Abstract
Based on a two-dimensional particle-in-cell/Monte Carlo collision model, the spatiotemporal dynamics of streamers in dielectric barrier discharges are investigated. The influence of coating materials with high dielectric constant (similar to catalysts) on pellets embedded in the bottom electrode is evaluated through numerical analysis. Upon interaction with the streamers, the coating material is polarized, leading to significant changes in potential and electric field at various positions near its surface. This effect results in drastic changes in discharge behavior, even triggering the formation of new streamer branches at the edges of the coating. Electrons display diverse energy distributions at various spatial positions and times during the streamer evolution, potentially impacting catalytic reaction rates. The plasma’s penetration into pores of dielectric pellets is contingent upon the sizes of the pores, affecting the electron density, energy, and the velocity of surface streamers. The revealed mechanisms are advantageous for controlling discharge characteristics and optimizing plasma treatment applications.
Investigation of traps in halide vapor-phase epitaxy-grown β-Ga2O3 epilayers/n+-Ga2O3 using deep-level transient spectroscopy
Authors: Sheoran Hardhyan , Kaushik Janesh K , Kumar Vikram , Singh Rajendra 
Published: October 2024

Abstract
A detailed investigation of deep traps in halide vapor-phase epitaxy (HVPE)-grown β-Ga2O3 epilayers has been done by performing deep-level transient spectroscopy (DLTS) from 200 K to 500 K on Pt/β-Ga2O3 and Ni/β-Ga2O3 Schottky diodes. Similar results were obtained with a fill pulse width of 100 ms irrespective of the different Schottky metal contacts and epilayers. Two electron traps at E2 (E
C–E
T = 0.65 eV) and E3 (E
C–E
T = 0.68–0.70 eV) with effective capture cross-sections of 4.10 × 10−14 cm2 and 5.75 × 10−15 cm2 above 300 K were observed. Below 300 K, a deep trap with a negative DLTS signal peak was also observed at E1 (E
C–E
T = 0.34–0.35 eV) with a very low capture cross-section of 3.28 × 10−17 cm2. For a short pulse width of 100 μs, only two electron traps, E2 and E3, at energies of 0.72 eV and 0.73 eV were observed, and one order of higher corresponding effective capture cross-sections. All traps were found to be unaffected by the electric field during the field-dependent DLTS study. From the filling pulse width dependence DLTS study, a decrease in the capacitance transient amplitude with the increasing pulse width was observed opposite to the capture barrier kinetics of the traps and attributed to the emission of carriers during the capture process. Trap concentrations were found to be high at the interface using depth profiling DLTS. Based on the available literature, it is suggested that these traps are related to FeGa, Fe-related centers, and complexes with hydrogen or shallow donors, and might be affected or generated during metallization by the electron beam evaporator and chemical mechanical polishing.
A hierarchical multistage holistic model for acoustic emission source monitoring in composites
Authors: Sikdar Shirsendu , Gullapalli Anirudh , Kundu Abhishek 
Published: October 2024

Abstract
This paper introduces a multistage smart structural health monitoring (SHM) model for carbon-fibre composites, with a focus on multiple types of acoustic emission (AE) source localization and classification. The SHM model uses time–frequency data from various AE events (such as tool drops, impact, and artificial debonding) across different zones of a composite structure. The SHM strategy demonstrates a robust smart monitoring of composites with high accuracy. Further, a hypothesis testing has been carried out that supports the superiority of a 2-stage identification process, revealing statistically significant higher accuracy and confidence intervals across all zones and AE source types. This research establishes a novel framework for solving a hierarchical multistage holistic damage source identification problem, offering robustness in identifying various damage scenarios and quantifying associated prediction uncertainties.
Mechanical properties and damage mechanism of SMAHC laminates
Authors: Ke Jun , Hu Yan , Chen Lan , Wu Zhenyu 
Published: October 2024

Abstract
The combination of smart materials and composite materials to achieve lightweight and intelligent structures has been an important research direction in recent years. In this paper, a three-dimensional woven hybrid shape memory alloy (SMA actuator) is modularly implanted into a composite laminate to prepare a SMA hybrid composite (SMAHC) laminate. The orthogonal test was designed with the three variables of SMA actuator modular implantation position, SMA pre-strain and SMA number. According to the orthogonal test results and finite element results, the influence of the three variables on the stiffness before heating, the stiffness change rate after heating and the strength of SMAHC laminates was studied. According to the test index, the influence of the three variables on the results was further evaluated. The results show that the implantation position has the greatest influence on the mechanical properties of SMAHC laminates, followed by SMA pre-strain, and the number of SMA has the least influence. The location and form of damage of SMAHC laminates are further summarized, and the bending damage mechanism of SMAHC laminates is analyzed.
Stochastic matrix multiplier using superconductor single-flux-quantum circuit
Authors: Yamanashi Yuki , Okumura Hijiri , Yoshikawa Nobuyuki 
Published: October 2024

Abstract
A superconducting single-flux-quantum (SFQ) circuit is suitable for stochastic computation that represents information in terms of the probability of ‘1’s in a finite-bit-length number train, due to its high-speed operation. In this paper, we demonstrate a matrix multiplier based on the SFQ logic circuits and superconductive random number generators (SRNGs). The stochastic multiplier required for the matrix product calculation is implemented using an AND gate. The stochastic adder is implemented by a multiplexer where the random number train generated by the SRNG is utilized as a control signal. We implemented

2
×
2

matrix multiplier targeting a frequency of 50 GHz, using the 10 kA cm−2 Nb 4-layer superconductor circuit fabrication process. Numerical calculation results show that the designed stochastic matrix multiplier can multiply with a computational error of 1.12% when the input stochastic numbers are 1000-bit number trains. In the measurements, the input stochastic numbers were also generated by SRNGs, and the operation of the test circuit was verified. We experimentally demonstrated the correct operation of the matrix multiplier, and the obtained calculation errors agreed with theoretical values. To the best of our knowledge, this is the first demonstration of stochastic arithmetic operation using SFQ circuits.
Effect of different metallic doping elements on the physical properties of iron oxide thin films
Authors: Aboud Ahmed A , Matar Zinab S , Mohaseb Mona 
Published: October 2024

Abstract
This study investigates the physical properties of pure and Co, Cr, Mn, and Ni-doped Fe2O3 thin films fabricated using spray pyrolysis techniques on glass substrates. The primary aim is to understand how doping influences the structural, optical, and dielectric properties of Fe2O3 thin films. The deposition parameters were kept constant for all samples, with a fixed dopant concentration of 3 weight percent (wt%). X-ray diffraction (XRD) analysis revealed a single diffraction peak indexed as (104), decreasing in crystallite size from 17.27 nm for the pure film to approximately 11.5 nm for all doped films. Field emission scanning electron microscopy (FE-SEM) images displayed non-homogeneous grain formation, characterized by an average grain size larger than the crystallite size, indicating agglomeration. The optical band gap value shifted from 2.54 eV for the pure film to higher values upon doping with various elements, signifying direct allowed transitions. Changes in refractive index dispersion with wavelength were observed based on the dopant type. The application of the Spitzer-Fan model revealed an increase in high-frequency dielectric constant upon doping compared to the pure film, varying across different dopants. Photoluminescence (PL) spectra recorded under excitation at 340 nm exhibited multiple emission peaks within the spectral range of 399 to 600 nm.
Angle-insensitive all-optical diodes in a large range of incidence by photonic heterostructure containing hyperbolic metamaterials
Authors: Qin Haoyuan , Li Junyang , Chen Hong , Ren Haoxin , Lu Guang , Du Guiqiang 
Published: October 2024

Abstract
We theoretically and systematically investigate angle-insensitive all-optical diodes using photonic heterostructures composed of different one-dimensional photonic crystals containing hyperbolic metamaterials. Hyperbolic metamaterials comprise metals with high nonlinear coefficients and transparent dielectrics. The results indicate that the photonic heterostructure shows angle insensitivity in transmittance, transmission contrast, and the critical intensity of the threshold over a large range of incidence, achieving a high transmission contrast of approximately 0.93 between forward and backward incident light. This angle insensitivity originates from the phase-variation compensation effect in a basic unit composed of hyperbolic metamaterials and transparent dielectric materials under TM polarization. These results provide important reference values for future experiments.
Effects of wall heating on wall pressure fluctuations and flow noise in a low-Reynolds-number turbulent channel flow with temperature-dependent viscosity
Authors: Liu Wenbo , Qiang Xuecai , Shang Dejiang , Qin Qikai , Liu Lihui , Liu Yongwei 
Published: October 2024

Abstract
Wall pressure fluctuations and flow noise substantially degrade sonar detection performance and the acoustic stealth performance of underwater vehicles. This paper numerically investigates the effects of wall heating on wall pressure fluctuations in turbulent channel flow of water with temperature-dependent viscosity, exploring a novel method for controlling wall pressure fluctuations and flow noise in underwater vehicles. Large-eddy simulation (LES) is employed for the numerical calculation of the flow field, while a hybrid method combining LES with Lighthills acoustic analogy is employed to predict flow noise. The numerical results show that when the temperature difference between the wall and the incoming flow is 30 K and 50 K, the peak root-mean-square pressure fluctuations decrease by 6.76% and 8.91%, respectively. Wall heating stabilizes the pressure field near the wall, with the spectral levels of wall pressure fluctuations showing average decreases of approximately 1 dB and 2 dB. Wall heating weakens the energy-containing structures of wall pressure fluctuations and increases the overall convection velocity by 1.22% and 3.81%, respectively. Flow structure analysis reveals that the weakening of energy-containing structures results from the suppression of the vortex structures in the near-wall region. In the wall heating cases, peak turbulent kinetic energy decreases by 12.6% and 15.8%, respectively. Moreover, the sound pressure level of flow noise decreases with increasing wall temperature, with the maximum noise reduction exceeding 3 dB. Previous studies have not yet explored the effects of viscosity reduction caused by wall heating on wall pressure fluctuations and flow noise. This study demonstrates that wall heating is a promising method for reducing wall pressure fluctuations and flow noise.
Elevating NIR photonic integration with tantalum-niobium pentoxide
Authors: Afsary Noor , Uddin Md Nasir , Islam Shariful , Alam Md Koushik , Ali Md Ashraf , Hoque Karimul , Rasel Md Omar Faruk 
Published: October 2024

Abstract
In this study, we present a novel material platform based on tantalum-niobium pentoxide (TaNbO5) for integrated photonics applications. TaNbO5 demonstrates exceptional attributes suitable for both linear and nonlinear optics across a wide range of near-infrared wavelengths. Our analysis of the TaNbO5 unit cell revealed crucial lattice parameters and a direct band gap value of 2.268 eV. At a wavelength of 1550 nm, TaNbO5 exhibits a refractive index of 2.22, an extinction coefficient of 5.24 × 10−4, and other optical properties. We determine a 0.8 μm cut-off core width for single-mode TaNbO5 waveguides, which achieve efficiencies exceeding 99% for single-mode configurations and 98% for multimode structures. When coupled with conventional waveguides, TaNbO5 waveguides demonstrate excellent transmission characteristics. Notably, at a wavelength of 1.55 μm, the single-mode waveguide exhibits minimal excess loss. These findings highlight the significant potential of TaNbO5 waveguides for various near-infrared applications, emphasizing their versatility and promising performance.
Spectral Performance of the Follow-up X-Ray Telescope on Board the EP Satellite
Authors: Zhao Xiaofan , Xu Jingjing , Cui Weiwei , Meidinger Norbert , Keil Isabell , Wang Yusa , Wang Hao , Zhao Zijian , Hou Dongjie , Zhu Yuxuan , Luo Laidan , Han Dawei , Yang Yanji , Wang Juan , Ma Jia , Yang Xiongtao , Huo Jia , Li Wei , Zhang Ziliang , Chen Yong 
Published: October 2024

Abstract
The Follow-up X-ray Telescope (FXT) is one of the two main scientific instruments on board the Einstein Probe astronomical satellite, which was launched in 2024 January. FXT focuses on the energy range of 0.3–10 keV and mainly conducts follow-up observations of transients and burst sources. It consists of two units of completely independent optical system and detector system (FXT-A and FXT-B). The focal plane detector adopts PNCCD provided by Max Planck Institute for Extraterrestrial Physics. FXT was designed to have three operating modes with different integration times and readout schemes, namely full-frame mode, partial-window mode and timing mode. We conducted a detailed calibration for PNCCD at the Institute of High Energy Physics before launch. Our results demonstrate that both FXT-A and FXT-B exhibit excellent spectral performance. The energy resolution (Full Width at Half Maximum) of FXT-A and FXT-B are both better than 85 eV at 1.487 keV. We determined a mean equivalent noise charge around 2.8 e− for FXT-A and FXT-B in three operating modes at −90°C ± 0.5°C, except for a few noisy pixels in full-frame mode. In addition, we measured the relation of charge transfer inefficiency as function of photon energy and confirmed the ability to detect photons in the energy range of 0.3–10 keV. These calibration results have been ingested into the initial version of calibration database and applied to the analysis of scientific data acquired by FXT.