bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circular lattice benzene-core PCFs with flat near-zero dispersion for low-power broad-spectrum supercontinuum generation
Authors: Le Tran Bao Tran , Van Lanh Chu 
Published: March 2024

Abstract
A circular photonic crystal fiber infiltrated with benzene with different air-hole diameters is proposed as a new supercontinuum light source. Optical properties related to dispersion, effective mode area, nonlinear coefficient, and attenuation of the fundamental mode are investigated numerically. Two optimized structures are selected and verified against supercontinuum generation (SCG) in detail. The first structure (#F1) possesses all-normal dispersion, while the second (#F2) has a zero-dispersion wavelength. The possibility of coherent, octave-spanning SCG is proved by a 40 fs pulse, 1.064 μm wavelength, and 0.45 kW of power in-coupled into the core of #F1. Otherwise, injecting a 90 fs duration, 1.5 μm wavelength, and 0.555 kW peak power pump pulse into #F2 generates a broad SC spanning 0.76–4.23 μm. With the advantages of flat near-zero dispersion, high nonlinearity, low attenuation, and low input power used for SCG, the proposed fibers may lead to new low-cost all-fiber optical systems.
Renewed diffraction formula using reciprocity
Authors: Xia Yingjie , Feng Xuping 
Published: March 2024

Abstract
We present a new diffraction formula derived from the reciprocal theorem. This formula utilizes secondary waves generated from the unobstructed region of a plane near the diffraction object, with the plane’s normal vector aligned along the source-receiver axis. Importantly, our approach successfully mitigates the mathematical inconsistencies inherent in Kirchhoff’s diffraction formula and eliminates the inclination factor, resulting in a highly effective solution. This method is beneficial for scenarios involving irregularly shaped objects.
Solving the fractional Fornberg-Whitham equation within Caputo framework using the optimal auxiliary function method
Authors: Iqbal Naveed , Hussain Shah , Nazim Tufail Muhammad , Mohammed Wael W 
Published: March 2024

Abstract
In this work, we solve the fractional-order Fornberg-Whitham (FW) problem in the context of the Caputo operator by using the Optimal Auxiliary Function Method. Tables and figures showing full numerical findings indicate the correctness and efficacy of this strategy. The results provide insights into the solution behavior of the FW equation and demonstrate the applicability of the Optimal Auxiliary Function Method. By giving insight on the behavior of the FW equation in a fractional context, this research advances the use of fractional calculus techniques in the solution of complicated differential equations.
Criterion for ultra-fast bubble walls: the impact of hydrodynamic obstruction
Authors: Ai Wen-Yuan , Nagels Xander , Vanvlasselaer Miguel 
Published: March 2024

AbstractThe Bödeker-Moore thermal friction [1] is usually used to determine whether or not a bubble wall can run away. However, the friction on the wall is not necessarily a monotonous function of the wall velocity and could have a maximum before it reaches the Bödeker-Moore limit. In this paper, we compare the maximal hydrodynamic obstruction, a frictional force that exists in local thermal equilibrium, and the Bödeker-Moore thermal friction. We study the former in a fully analytical way, clarifying its physical origin and providing a simple expression for its corresponding critical phase transition strength above which the driving force cannot be balanced out by the maximal hydrodynamic obstruction. We find that for large parameter space, the maximal hydrodynamic obstruction is larger than the Bödeker-Moore thermal friction, indicating that the conventional criterion for the runaway behavior of the bubble wall may have to be modified. We also explain how to apply efficiently the modified criterion to particle physics models and discuss possible limitations of the analysis carried out in this paper.
An experimental and theoretical study on Dy3+-doped ZBLAN fiber laser, core-pumped at 1.1 μm
Authors: Jung Junha , Lee Kyungtaek , Kim Jeehwan , Kim Ingwon , Lee Ju Han 
Published: March 2024

Abstract
An experimental and theoretical investigation into a core-pumped Dy3+-doped ZBLAN fiber laser with 1.1 μm pumping was conducted to figure out a configuration for better slope efficiency. First, the laser was experimentally constructed with a simple Fabry–Pérot cavity incorporating AlF3 no-core fiber endcaps. The maximum output power of 607 mW was obtained readily with a slope efficiency of 25%. Next, a 5-energy level model was adopted for a numerical simulation to figure out the optimum output mirror reflectivity for the particular experimental laser setup in terms of slope efficiency. The best slope efficiency of 30% was shown to be obtainable with an output mirror of a 22% reflection.
Asymmetric nucleation processes in spontaneous mode switch of active matter
Authors: Yang 杨 Bing 冰 , Wang 王 Yanting 延颋 
Published: March 2024

Abstract
Flocking and vortical are two typical motion modes in active matter. Although it is known that the two modes can spontaneously switch between each other in a finite-size system, the switching dynamics remain elusive. In this work, by computer simulation of a two-dimensional Vicsek-like system with 1000 particles, we find from the perspective of the classical nucleation theory that the forward and backward switching dynamics are asymmetric: going from flocking to vortical is a one-step nucleation process, while the opposite is a two-step nucleation process, with the system staying in a metastable state before reaching the final flocking state.
Weak Merging Scenario of CLASH Cluster A209
Authors: Feng Wen-Cheng , Yu Heng , Zhao Hai-Hui , Hou Xiao-Lan , Jia Shu-Mei , Li Cheng-Kui , Cheng Yu-Lin , Tozzi Paolo , Sun Ming , Chen Yong 
Published: March 2024

Abstract
We study the structural and dynamical properties of A209 based on Chandra and XMM-Newton observations. We obtain detailed temperature, pressure, and entropy maps with the contour binning method, and find a hot region in the NW direction. The X-ray brightness residual map and corresponding temperature profiles reveal a possible shock front in the NW direction and a cold front feature in the SE direction. Combined with the galaxy luminosity density map we propose a weak merger scenario. A young sub-cluster passing from the SE to NW direction could explain the optical subpeak, the intracluster medium temperature map, the X-ray surface brightness excess, and the X-ray peak offset together.
Influence of spatio-temporal filtering on hand kinematics estimation from high-density EMG signals
*
Authors: Sîmpetru Raul C , Cnejevici Vlad , Farina Dario , Del Vecchio Alessandro 
Published: March 2024

Abstract

Objective. Surface electromyography (sEMG) is a non-invasive technique that records the electrical signals generated by muscles through electrodes placed on the skin. sEMG is the state-of-the-art method used to control active upper limb prostheses because of the association between its amplitude and the neural drive sent from the spinal cord to muscles. However, accurately estimating the kinematics of a freely moving human hand using sEMG from extrinsic hand muscles remains a challenge. Deep learning has been recently successfully applied to this problem by mapping raw sEMG signals into kinematics. Nonetheless, the optimal number of EMG signals and the type of pre-processing that would maximize performance have not been investigated yet. Approach. Here, we analyze the impact of these factors on the accuracy in kinematics estimates. For this purpose, we processed monopolar sEMG signals that were originally recorded from 320 electrodes over the forearm muscles of 13 subjects. We used a previously published deep learning method that can map the kinematics of the human hand with real-time resolution. Main results. While myocontrol algorithms essentially use the temporal envelope of the EMG signal as the only EMG feature, we show that our approach requires the full bandwidth of the signal in the temporal domain for accurate estimates. Spatial filtering however, had a smaller impact and low-order spatial filters may be suitable. Moreover, reducing the number of channels by ablation resulted in large performance losses. The highest accuracy was reached with the highest number of available sensors (n = 320). Importantly and unexpected, our results suggest that increasing the number of channels above those used in this study may further enhance the accuracy in predicting the kinematics of the human hand. Significance. We conclude that full bandwidth high-density EMG systems of hundreds of electrodes are needed for accurate kinematic estimates of the human hand.
Effect of toroidal rotation on impurity transport in tokamak improved confinement
Authors: Mochinaga Shota , Kasuya Naohiro , Fukuyama Atsushi , Yagi Masatoshi 
Published: March 2024

Abstract
The centrifugal force effects from toroidal rotation in improved confinement plasmas are analyzed on high-Z impurities in tokamaks. Tungsten (W) transport simulations are performed using the impurity transport code developed in the integrated code TASK. The geometric factors PA
and PB
are introduced into the neoclassical transport coefficients to include the effects of the toroidal rotation, which come from poloidal asymmetry in the high-Z impurity profiles. Inward neoclassical particle pinch driven by the main ion density gradient is enhanced by the poloidal asymmetry to be the dominant mechanism for W accumulation in the plasma central region. Simulations with experimental plasma profiles show good agreement with the experimental results and first-principle simulation results in the H-mode. In the hybrid mode and advanced mode, the impurity accumulation is enhanced in the internal transport barrier (ITB) regions. The condition to suppress impurity accumulation is investigated by calculating dependencies on the toroidal rotation velocity and ITB position. The neoclassical transport is sufficiently small with the prospected ITER condition of the Mach number of main ions Mi
∼ 0.1. The impurity transport inside the ITB is strongly influenced by competition between the density peaking effect and the temperature screening effect, and the present simulations show suppression of the impurity accumulation with the outer ITB position to improve the plasma performance, due to the relatively larger temperature gradient of the main ion.
The influence of landfast ice on the navigation in the Arctic Northeast Passage
Authors: Liu Minjun , Zhao Jiechen , Zhao Jixiang , Gnatiuk Natalia , Shalina Elena , Chen Xuejing , Shao Zhiyuan , Xiao Jing , Chen Ziyi , Zhang Sihan , Zhao Dinglong , Mu Fangru 
Published: March 2024

Abstract
Landfast ice is one of the most important factors that affect the navigation safety of Arctic Northeast and Northwest Passages but usually is treated as drift ice in previous studies. This study focused on the situation of landfast ice in four key traits of the Arctic Northeast Passage from 2007 to 2021 and calculated the navigational windows for different ice-class vessels in the influence of landfast ice. The results show that the extent of landfast ice in these straits generally reaches its maximum from March to June, and decreases to a minimum or even disappears in July and August. The proportion of landfast ice extent in the four straits is quite different, such as Bering Strait (1.3%), De Long Strait (3.6%), Dmitry Laptev and Sannikov Strait (DLS Strait) (53.5%), and Vilkitsky Strait (27.8%). The average navigational windows range from 27 weeks (Bering Strait) to 8 weeks (Vilkitsky Strait) per year, and the Bering Strait showed the smallest increase trend (0.20 weeks per year), while the Vilkitsky Strait experienced the largest increase trend (0.62 weeks per year). The increasing navigational windows in the key straits are beneficial for future commercial and scientific expeditions of polar vessels in the Northeast Passage.
Sea ice drift vector extraction based on feature matching using CS-1 Images
Authors: Yang Y L , Xie T 
Published: March 2024

Abstract
The study emphasizes the crucial role of sea ice drift in Arctic climate research and the protection of human activities. Employing C-SAR/01 (CS-1) imagery as the primary data source, the study assesses the effectiveness of the ORB feature matching algorithm for extracting Arctic Sea ice drift vectors. Additionally, it investigates the spatial distribution variations in the drift vectors extracted from the HH and HV polarization channels. The accuracy of the extracted drift vectors is validated using manually extracted sea ice drift data. Experimental results reveal a significant disparity in the number of drift vectors extracted from CS-1 HV polarization images compared to HH polarization images. The sea ice drift vectors extracted using the Oriented fast and Roasted Bried (ORB) operator demonstrate an average velocity error of less than 0.27 cm/s (0.31 km/d) and an average direction error of less than 5.66° in HV polarization images.
An Elevation Editing Method for Water Bodies in InSAR derived DSM
Authors: Yuan Yibo , Hu Jun , Gui Rong 
Published: March 2024

Abstract
In the InSAR-DSM, which is the Digital Surface Model (DSM) acquired through Interferometric Synthetic Aperture Radar (InSAR), the presence of significant noise, voids, and elevation anomalies in water bodies is pervasive. These disparities arise from factors such as diminished backscattering due to electromagnetic wave absorption by water, surface-based specular reflection, and the impact of temporal decorrelation. To tackle this challenge, an automated elevation editing method for water bodies based on InSAR-DSM is introduced. Water bodies are automatically categorized as oceans, lakes, or rivers based on their morphological characteristics and location criteria. Distinct algorithms are subsequently deployed for elevation editing within each category. Results demonstrate that after editing water body elevations, all missing values within the original InSAR-DSM for water bodies are effectively addressed. Elevation anomalous pixels within water bodies are reduced by 68.5%, and the elevation standard deviation, which reflects elevation variability in water bodies, is decreased by 47.31%. This process effectively rectifies water body elevations within InSAR-DSM.
Extracting shallow water depth from the fusion of multi-temporal ICESat-2 data and multi-spectral imageries
Authors: Zhang Yunsheng , Zuo Longjiao , Zhao Yan , Zhao Le , Liu Yixuan 
Published: March 2024

Abstract
With the development of satellite remote sensing and laser altimetry data, the fusion of laser altimetry data and multi-spectral images for shallow water depth inversion has become an economically convenient way. However, there are few methods that take into account the temporal dimension of data to integrate the results of water depth inversion in multiple temporal phases. In response to this issue, this article proposed a shallow water depth inversion method that integrates multi-source and multi-temporal remote sensing data. This method utilized the random forest (RF) algorithm to estimate the water depth values at different time, taking into account the contextual information of Sentinel-2 imagery and using the overall least squares as the theoretical model to fuse the multi-temporal water depth inversion results. This article took the Yongle Islands in the South China Sea as the research area and conducted the shallow water inversion experiments using ICESat-2 (Ice, Cloud and Land Elevation Satellite 2) data from 5 temporal phases and one Sentinel-2 imagery. The results show that the mean value of RMSE (root mean square error) and R2 (determination coefficient) of the proposed method using single temporal imagery was 1.53m and 0.7610, which outperformed the inversion accuracy of traditional methods that ignore image context information. The RMSE and R2 of the multi-temporal fusion model was 1.15m and 0.8622, which was 0.08m and 0.0199m higher than existing median filtering fusion method.
Interpolation of China’s Nearshore Sea Surface Temperature Based on Information Diffusion with Small Sample Sizes
Authors: Wang Min , Shi Minghang , Xu Yongqi , Cao Xiaomeng , Gu Wenjie 
Published: March 2024

Abstract
Addressing the issue of data sparsity and gaps caused by missing values, this study employs an information diffusion approach to effectively spread information from sparse sample points to monitoring locations. By thoroughly extracting insights from a limited dataset, it achieves more precise interpolation outcomes. To validate the superiority of the information diffusion interpolation technique under conditions of sparse samples, we utilize sea surface temperature (SST) data from the offshore waters of China as a case study. We compare three interpolation methods: Kriging, Gaussian information diffusion, and asymmetric information diffusion. The calculations and comparisons of interpolation results are conducted across varying sample sizes. The findings indicate that in situations with relatively sparse samples, asymmetric information diffusion yields the most favorable results, with Kriging and Gaussian diffusion exhibiting comparable performance. In cases of extremely sparse samples, asymmetric information diffusion yields the lowest interpolation error, followed by Gaussian diffusion, while Kriging performs the least effectively. Thus, when confronted with sample sparsity, the application of the information diffusion interpolation method can yield notably improved results.
Targeted observation for the climatology temperature in the Kuroshio region based on the CNOP approach
Authors: Liu Jingyi , Guo Wuhong , Cui Baolong 
Published: March 2024

Abstract
To reduce the cost of ocean observations and improve prediction accuracy of the Kuroshio region temperature, this study investigates the related targeted observation by using the conditional nonlinear optimal perturbation (CNOP) approach. Results show that the scheme of vertical-integrated energy is more suitable for the identification of sensitive area in the related targeted observation. By conducting a set of observation system simulation experiments (OSSEs), we discovered that the sensitive areas identified by the CNOP exert substantial influence on temperature predictions within the target area. The dynamic diagnosis further indicated that the pressure gradient and Coriolis force in the momentum equations greatly contribute the development of the prediction biases. These findings implied that the implement of CNOP-based targeted observation represents a cost-effective strategy for enhancing temperature predictions in the Kuroshio region.
A Global Coupled Atmosphere-Wave Model System Based on C-Coupler2. Part II: Preliminary Results
Authors: Peng Wei , Li Xiang , Hao Sai , Liu Xiaoyan 
Published: March 2024

Abstract
A global coupled atmosphere-wave model system (MPAS-NWW3) that consists of MPAS-A (Model for Prediction Across Scales-Atmosphere) and NWW3 (the Third Generation Wave Model, WAVEWATHCH III) with C-Coupler2 (the Community Coupler2) is demonstrated with a focus on the atmospheric results in global and the specific marine area in the year 2020. Results from the two-way coupled MPAS-NWW3 model and standalone MPAS-A are compared with reanalysis products. The coupled model performs better in terms of high wind speeds and long valid hours. This indicates that the coupled model has an obvious inhibitory effect on surface wind in areas with strong winds.
Analysis of Acoustic Elements in Northwest Pacific Ocean Based on Operational MODAS Data and Its Response to Kuroshio Seasonal Variation
Authors: Li Yang , Wu Xiangyu , Chen Zhiqiang , Wang Dakui , Wang Xidong , Kuang Xiaodi 
Published: March 2024

Abstract
This study utilized operational MODAS (Modular Ocean Data Assimilation System) data to analyze the seasonal variation of acoustic elements of Northwest Pacific Ocean (NWPO). Combining the seasonal variation of the Kuroshio, it further investigated the impact of the Kuroshio seasonal variation on acoustic properties. The results indicate that the distribution of acoustic elements have significant seasonal variation, with a strong correlation between sonic layer depth and mixed layer depth. The acoustic thermocline depth and thermocline depth show significant correlations in the whole area in winter and spring, while in the rest two seasons, it only occurs in low latitude, the southern part of South China Sea (SCS), and also the Kuroshio area.
Memory of HF radar surface-current assimilation on different forecasting variables of ocean circulation models
Authors: Wu Lunyu , Ning Jinjin , Jiao Yang 
Published: March 2024

Abstract
In this study, using nudging method, the current data from a pair of HF radar along Jiangsu coast was assimilated to unstructured grid models based on FVCOM. Several experiments were conducted to examine the effect of radar data on surface velocity, elevation and sea surface salinity forecast. The results show that the gain of assimilation on surface velocity and elevation forecasts disappeared fast within a few hours, while salinity forecasts can be influenced for more than 10 days. This fast diminishing of the gain of data assimilation on current and elevation can be attributed to the fast wave propagation from elsewhere to the radar coverage area.
Research on underwater unmanned platform route planning based on marine environment constraints
Authors: Guo Zilong , Hong Mei , Zhang Yongchui , Shi Jian , Zhang Yunxiang , Wang Hongrui , Qian Longxia 
Published: March 2024

Abstract
Since the development of unmanned systems, autonomous underwater unmanned platforms have become an important facility for countries to explore the ocean field which play an important role in both military and civilian. In this paper, the route planning of underwater unmanned platform is carried out from three constraints: the risk that affects the operational effectiveness of the unmanned underwater platform, the navigation resistance and the navigation path length. The simulation results show that the model can deal with three constraints reasonably and plan a suitable route.
Risk assessment of ice-class-based navigation in Arctic: a case study in the Vilkitsky Strait
Authors: Chen Xuejing , Zhao Jiechen , Zhao Yiding , Liu Xueqin , Ma Linwei , Liu Minjun , Shao Zhiyuan , Xiao Jing , Chen Ziyi , Zhang Sihan , Zhao Dinglong , Mu Fangru 
Published: March 2024

Abstract
Over the past four decades, the decrease in Arctic sea ice has driven significant growth in vessel traffic through the Arctic passages. A precise and quantitative sea ice risk assessment would be the cornerstone of route planning for Arctic ships. Taking the chokepoint of Arctic Northeast Passage, the Vilkitsky Strait, as an example, the temporal and spatial characteristics of ice conditions in the strait were analyzed based on simulated ice thickness and observed sea ice concentration data from 2012 to 2021. Additionally, navigation risk in the strait was assessed based on the Polar Operational Limit Assessment Risk Indexing System (POLARIS). The results showed that the strait experienced 100% sea ice coverage from December to May, peaking in thickness of nearly 2 m in May, receding starting in June, and presenting ice-free passages by August and September. A significant interannual variability is evident in the timing of sea ice melting and freezing. Moreover, the average navigability of the strait was 365 days for vessels with an ice class of PC3, 72 days for PC6 and fewer than 64 days for those below B1. Remarkably, in 2013, 2014, and 2021, vessels below PC5 had less than 30 navigable days in the strait.