bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental validation of an advanced impedance pneumography for monitoring ventilation volume during programmed cycling exercise
Authors: Zhou Xing , Liu Qin , Bai Zixuan , Xue Shan , Kong Zhibin , Ma Yixin 
Published: May 2024

Abstract

Objective. Impedance pneumography (IP) has provided static assessments of subjects’ breathing patterns in previous studies. Evaluating the feasibility and limitation of ambulatory IP based respiratory monitoring needs further investigation on clinically relevant exercise designs. The aim of this study was to evaluate the capacity of an advanced IP in ambulatory respiratory monitoring, and its predictive value in independent ventilatory capacity quantification during cardiopulmonary exercise testing (CPET). Approach. 35 volunteers were examined with the same calibration methodology and CPET exercise protocol comprising phases of rest, unloaded, incremental load, maximum load, recovery and further-recovery. In 3 or 4 deep breaths of calibration stage, thoracic impedance and criterion spirometric volume were simultaneously recorded to produce phase-specific prior calibration coefficients (CCs). The IP measurement during exercise protocol was converted by prior CCs to volume estimation curve and thus calculate minute ventilation (VE) independent from the spirometry approach. Main results. Across all measurements, the relative error of IP-derived VE (VER) and flowrate-derived VE (VEf) was less than 13.8%. In Bland-Altman plots, the aggregate VE estimation bias was statistically insignificant for all 3 phases with pedaling exercise and the discrepancy between VER and VEf fell within the 95% limits of agreement (95% LoA) for 34 or all subjects in each of all CPET phases. Significance. This work reinforces the independent use of IP as an accurate and robust alternative to flowmeter for applications in cycle ergometry CPET, which could significantly encourage the clinical use of IP and improve the convenience and comfort of CPET.
Automatically detecting OSAHS patients based on transfer learning and model fusion
Authors: Ding Li , Peng Jianxin , Song Lijuan , Zhang Xiaowen 
Published: May 2024

Abstract

Objective. Snoring is the most typical symptom of obstructive sleep apnea hypopnea syndrome (OSAHS) that can be used to develop a non-invasive approach for automatically detecting OSAHS patients. Approach. In this work, a model based on transfer learning and model fusion was applied to classify simple snorers and OSAHS patients. Three kinds of basic models were constructed based on pretrained Visual Geometry Group-16 (VGG16), pretrained audio neural networks (PANN), and Mel-frequency cepstral coefficient (MFCC). The XGBoost was used to select features based on feature importance, the majority voting strategy was applied to fuse these basic models and leave-one-subject-out cross validation was used to evaluate the proposed model. Main results. The results show that the fused model embedded with top-5 VGG16 features, top-5 PANN features, and MFCC feature can correctly identify OSAHS patients (AHI > 5) with 100% accuracy. Significance. The proposed fused model provides a good classification performance with lower computational cost and higher robustness that makes detecting OSAHS patients at home possible.
Optimization of the on/off status configuration of control units in an active vibration isolation system—experiment
Authors: Wu Di , Zheng Shiruo , He Peitao , Zhang Zhiyi 
Published: May 2024

Abstract
Active vibration isolation (AVI) is an important measure to attenuate vibration transmission in underwater vehicles and multiple active control units are usually used to attenuate low frequency vibrations induced by power equipment. Under certain operation conditions, however, the pre-installed control units in an AVI system may be redundant. Hence, it is necessary to optimize the on/off status configuration of all the control units. An optimization approach is proposed for configuration optimization of control units and validated by experiments. The criterion of the proposed approach is derived from the vibration responses of the monitoring points. The involved optimization, formulated as a constrained 0–1 nonlinear programming problem, utilizes the on/off status of control units as the input variable and the number of active units as the constraint. Optimized configurations were obtained by solving the nonlinear programming problem and deployed to the experimental system. The test results have demonstrated that vibration of the monitoring points can be effectively suppressed by activating only a portion of control units, and the configurations corresponding to maximum vibration reduction vary with different excitations.
Experiment and simulation study on the functional fatigue of shape memory alloy beam actuators
Authors: Wang Xiaoyuan , Leng Jiaming , Rao Zhixiang , Yan Xiaojun 
Published: May 2024

Abstract
The functional fatigue behavior of shape memory alloy (SMA) beam actuators is gaining importance as their utilization in engineering applications becomes more widespread. However, research on the functional fatigue behavior of SMA beam actuators under bending conditions is not as extensive as that on SMA wires. In this paper, an experimental study and theoretical analysis of the functional fatigue behavior of SMA beam actuators were conducted. A measuring method for bending deflection and an automatic thermal cyclic test bench was designed. A series of functional fatigue tests were conducted on SMA beam actuators under different bias load conditions and the functional fatigue patterns were obtained. The material damage factor is defined and calculated through specimen tests. By incorporating the damage factor to modify the existing constitutive model, a model considering functional fatigue and tension-compression asymmetry is obtained. Finite element analysis (FEA) is performed based on this modified model to simulate the actuating performance of SMA beam actuators and to compute the deflection at different numbers of cycles. Additionally, a small parameter study on the actuator shape is conducted using FEA. By comparing the FEA results with functional fatigue experimental data, the effectiveness of the modified model is validated, demonstrating its capability to describe functional fatigue and predict actuator lifespan.
Parameters optimization of solar PV cell using genetic-iterative algorithm
Authors: Ben Said Y , Nouri L , Sakhi Z , Bennai M 
Published: May 2024

Abstract
Accurately determining optimal parameters from current-voltage (IV) data in solar photovoltaic (PV) models is crucial for effective system simulation and control. In this study, we propose a novel approach that combines genetic algorithm and iterative techniques maximizing their strengths, and exploiting the influence of each parameter on the IV curve to categorize them into groups. This adaptable method can adjust the interval of each parameter to different scenarios during optimization. We evaluated the method across various solar cell models including both the ‘SDM’ and ‘SDM-based PMM’, achieving notable accuracy and reliability compared to other advanced meta-heuristic algorithms. The results indicate a value of 7.3870e-5 for the SDM and 9.3365e-4 for the PMM (STM6-40/36). The proposed algorithm demonstrates notable accuracy and reliability, highlighting its usefulness in accurately determining parameters in solar PV models.
A two-symmetric electrode hydride supercapacitor developed from G-C3N4 decorated with poly-2-aminobenzenethiol
Authors: Ben Gouider Trabelsi Amira , Rabia Mohamed , Alkallas Fatemah H , Esayed Asma M 
Published: May 2024

Abstract
The incorporation of poly-2-aminobenzene thiol (P2ABT) onto 2D g-C3N4 sheets results in the formation of a P2ABT/g-C3N4 nanocomposite, exhibiting favorable morphological and electrical properties that position it as a promising candidate for a paste utilized in a two-symmetric electrode hydride supercapacitor. The decoration process involves the oxidation of 2-aminobenzene thiol with K2S2O8, leading to the polymer coating of the embedded 2D g-C3N4 materials, yielding a robust composite. Analysis via scanning electron microscopy (SEM) unveils the formation of 2D sheets of g-C3N4 with an average length, width, and thickness of 750 nm, 200 nm, and 15 nm, correspondingly. The composite establishes a sturdy network with a porous structure, indicative of the synergistic combination of the electrical characteristics of the polymer and g-C3N4. In the construction of the two-symmetric electrode supercapacitor, an impressive specific capacitance (CS) of 310 F g−1 is achieved at 0.2 A/g. The supercapacitor exhibits a promising energy density (E) of 26.8 W h kg−1 and maintains retention stability even after undergoing 1000 charge/discharge cycles. Notably, the retention rate remains high at 98% after 250 cycles and 96% after an extended cycling period of 1000 cycles. This exceptional performance positions the supercapacitor as a prospective candidate for applications in industrial settings and within batteries. Its advantages lie in its ease of fabrication, mass production capabilities, and cost-effective manufacturing techniques, opening new avenues for these materials in energy storage fields.
A non-invasive blood glucose detection using a slotted microstrip antenna sensor
Authors: Syamala Neeli , Kumar Bandi Kiran , Raju K Padma 
Published: May 2024

Abstract
A novel highly sensitive and compact slotted microstrip antenna sensor consisting of slots with defected ground structure is designed. The substrate used in the design of antenna is FR-4 of concise dimensions 30 × 30 × 1.6

mm

3

and the developed antenna resonates at 3 GHz. The human finger consisting of several layers namely bone, blood, fat and skin is modelled in the electromagnetic simulation (Computer Simulation Technology) environment resulting in finger phantom. The finger phantom is situated at different locations on proposed antenna for evaluating the concentrations of glucose from 0 to 1000 (mg/dL) and the corresponding shift in frequencies are estimated. For detection of glucose concentration in human blood, the obtained frequency shifts in the proposed work are used. In this proposed work, at the top side of proposed antenna, the finger phantom is situated, an uttermost shift in frequency of 48 MHz, sensitivity of 48 KHz/(mg/dL) and a least possible shift in frequency of 24 MHz, sensitivity of 24 KHz/(mg/dL) are obtained.
Temperature-switchable anti-reflective structure based on vanadium dioxide phase transition in the visible and near-infrared wavelength regions
Authors: Daliran Neda , Hassanzadeh Abdollah 
Published: May 2024

Abstract
Nowadays, the anti-reflective (AR) structures are essential in many applications like display screens, photovoltaic structures and light detection and ranging. Traditionally, the AR surfaces are almost multilayer (ML) structures to minimize the reflection value by producing the destructive interference of reflected light beams at the layers’ interfaces. In the new and advanced AR surfaces, nanostructures (NS) are proposed and used for minimizing the reflection. In this paper, we propose a temperature-switchable AR-ML-NS, based on vanadium dioxide (VO2) phase transition from semiconductor to metallic state around the critical temperature of 68 °C. Here, a pyramidal NS of VO2 is considered on top surface of a ML which minimizes the light reflection of the structure. While some AR structures may work in some restricted light wavelengths, here our proposed structure’s AR wavelength region can be tuned between the visible and near-infrared (NIR) region through the thermal phase transition of VO2. VO2 phase control leads to a temperature-switchable AR structure, which is of great importance for investigating different switchable AR structures.
Superior performance in double-diffused MOSFET by multi-trench gate structure: physical investigation and design
Authors: Shokouhi Shoormasti Ali , Abbasi Abdollah , Orouji Ali A 
Published: May 2024

Abstract
The Double-diffused Metal-Oxide-Semiconductor (D-MOSFET) is the first Power MOSFET structure to be widely used across an extensive range of power levels. This article describes a physical investigation and design of D-MOSFET construction with superior performance. We introduce a groundbreaking exploration into the design of trench gates within U-shaped double-diffused MOSFETs (UDMOSFETs), focusing on Baliga’s figure of merit (BFOM). The findings provide valuable insights for advancing power semiconductor devices, underscoring the importance of trench gate technology in optimizing device performance. The BFOM reaches its peak when the doping concentration of the drift region (NDrift) is 6 × 1016 cm−3 with an indication of almost 40% improvement in MTG-UDMOSFET (M = 4) compared to C-UDMOSFET. Furthermore, within the optimum values of NDrift, length of the drift region, and depth of trench gate, the on-resistance in MTG-UDMOSFET (M = 4) experiences a 46% reduction compared to the conventional structure.
Mechanism of formation and evolution of bound states in the continuum of split-hole all-dielectric metasurface under asymmetric displacement perturbation
Authors: Chen Ying , Zhao Guoting , Li Weiqiang , Cui Dongyan , Shi Moqing , Wang Qinghui 
Published: May 2024

Abstract
Bound states in the continuum (BICs) with ultra-high Q properties have attracted much attention for their perfect localization in the continuous spectral range coexisting with extended waves. In this study, breaking the traditional excitation form of structure breakage or excitation field asymmetry, a monolithic silicon nanodisk array with relative displacement generated by the complete splitting of square nanopores is proposed based on the unique electromagnetic properties of all-dielectric metamaterials. During the introduction of perturbations by asymmetric displacements of splitting holes, it is shown by numerical simulations that two BICs at different wavelengths can be realized. Combined with eigenmodes of group theory, the symmetric matching relationship between the symmetry-protected BICs and the free-space radiation during the evolution process is analytically demonstrated, and the formation mechanism and the evolution law of the BICs excited by this metasurface are deeply investigated. meanwhile, it also provides a theoretical basis for the polarization dependence of quasi-BICs excitation and the ultra-high Q factor expression of BICs. Furthermore, near-field distribution and multipole decomposition show that the field distribution and surface currents support the excitation of BIC-driven toroidal dipole and magnetic quadrupole dual modes. This study not only provides an effective reference for the stability of high-Q resonance wavelengths, but also solves the problem of the lack of universality in analyzing the resonance mechanism based on resonance phenomena, and provides solid theoretical support for the study of displacement-mediated BICs resonance excitation and evolution.
Influence of plasma on the optical appearance of spinning black hole in Kalb-Ramond gravity and its Existence around M87* and Sgr A*
Authors: Raza Muhammad Ali , Zubair M. , Maqsood Eiman 
Published: May 2024

Abstract
The visible universe is filled with different types of plasma media in the form of stars, nebulas and other forms of excited gases. These matter fields have a high influence on the gravity and are likely to be present around the black holes due to the immense gravitational attraction. Since a plasma medium affects the speed of light, therefore we investigated the null geodesics and various optical features around the rotating black hole in Kalb-Ramond gravity immersed in plasma medium. Various plasma distributions are considered to develop a comparative study for their influence on unstable null circular orbits, shadows and evaporation rate of the black hole in the presence of a plasma medium. Moreover, the shadow results are also compared with Event Horizon Telescope data for M78* and Sgr A* in order to estimate the parametric bounds for which the rotating black hole in Kalb-Ramond gravity is considered either M87* or Sgr A* under the different values of plasma parameters. From this analysis, we also found the distribution of plasma that has a significant impact on the above mentioned features and is most likely to be present around M87* and Sgr A*.
Simulation-based inference of deep fields: galaxy population model and redshift distributions
Authors: Moser Beatrice , Kacprzak Tomasz , Fischbacher Silvan , Refregier Alexandre , Grimm Dominic , Tortorelli Luca 
Published: May 2024

Abstract
Accurate redshift calibration is required to obtain unbiased cosmological information from
large-scale galaxy surveys. In a forward modelling approach, the redshift distribution n(z) of
a galaxy sample is measured using a parametric galaxy population model constrained by
observations. We use a model that captures the redshift evolution of the galaxy luminosity
functions, colours, and morphology, for red and blue samples. We constrain this model via
simulation-based inference, using factorized Approximate Bayesian Computation (ABC) at the image
level. We apply this framework to HSC deep field images, complemented with photometric redshifts
from COSMOS2020. The simulated telescope images include realistic observational and instrumental
effects. By applying the same processing and selection to real data and simulations, we obtain a
sample of n(z) distributions from the ABC posterior. The photometric properties of the simulated
galaxies are in good agreement with those from the real data, including magnitude, colour and
redshift joint distributions. We compare the posterior n(z) from our simulations to the
COSMOS2020 redshift distributions obtained via template fitting photometric data spanning the
wavelength range from UV to IR. We mitigate sample variance in COSMOS by applying a reweighting
technique. We thus obtain a good agreement between the simulated and observed redshift
distributions, with a difference in the mean at the 1σ level up to a magnitude
of 24 in the i band. We discuss how our forward model can be applied to current and future
surveys and be further extended. The ABC posterior and further material will be made publicly
available at https://cosmology.ethz.ch/research/software-lab/ufig.html.
Particle content of very inclined air showers for radio signal modeling
Authors: Guelfand Marion , Chiche Simon , Kotera Kumiko , Prunet Simon , Pierog Tanguy 
Published: May 2024

Abstract
The reconstruction of very inclined air showers is a new challenge for next-generation radio experiments such as the AugerPrime radio upgrade, BEACON, and GRAND, which focus on the detection of ultra high energy particles. To tackle this, we study the electromagnetic particle content of very inclined air showers, which has scarcely been studied so far. Using the simulation tools CORSIKA and CoREAS, and analytical modeling, we explore the energy range of the particles that contribute most to the radio emission, quantify their lateral extent, and estimate the atmospheric depth at which the radio emission is strongest. We find that the spatial distribution of the electromagnetic component in very inclined air showers has characteristic features that could lead to clear signatures in the radio signal, and hence impact the reconstruction strategies of next-generation radio-detection experiments.
Neutron stars in scalar torsion theories with non minimal coupling
Authors: Kehal Youcef , Nouicer Khireddine , Boumaza Hamza 
Published: May 2024

Abstract
We explore the existence and configurations of static and slowly rotating neutron stars (NSs) within a specific truncation of teleparallel scalar torsion theory. In this model, a scalar field ϕ is non-minimally coupled to the torsion scalar as ξTϕ
2, in the presence of the scalar potential V(ϕ) = -μ
2
ϕ
2/2 + λϕ
4/4. We establish the hydrostatic equilibrium equations for the static scenario and numerically solve them for both interior and exterior regions, employing appropriate boundary conditions near the center and at a distant location far away from the star's surface. Radial profiles of metric functions and the scalar field, alongside mass-radius diagrams, are plotted, utilizing four different realistic equations of state (EOS). Our results align closely with observational constraints from the GW170817 event, revealing a maximal mass of 2.37 M
⊙ achieved with the BSk21 EOS for a coupling parameter ξ = 0.25. Extending our analysis to encompass slow rotation, we establish the relationship between the star's moment of inertia and its mass. Furthermore, we explore future observations of NSs utilizing the redshift surface observable. Finally, we demonstrate the validity of the universality relation between the two forms of normalized moment of inertia within teleparallel scalar torsion theory with non minimal coupling.
Sound classification with time-frequency features in forest environment
Authors: Xu Sizhe , Chen Yang 
Published: May 2024

Abstract
The study of forest sound classification has drawn more attention recently due to its potential for illegal activities and natural disaster monitoring. Based on the forest sound classification dataset (FSC22), a dataset specific to possible sound existing in the forest, five classification methods are utilized to investigate the relationship between recognition accuracy and the number of sound acoustic features, as well as the number of target classes. The results confirmed that extreme random forest is the best method for forest sound classification, with an accuracy of around 70% when the target class number is above 20. Further, Mel-frequency cepstral coefficients are the critical feature for sound classification, while fuzzy labels in the dataset may reduce the success rate of recognition.
Sound absorption model of thin woven fabric with tortuosity effects by equivalent circuit method
Authors: Tang Xiaoning , Zhu Shubing 
Published: May 2024

Abstract
The fabric has been widely used as a noise-reduction material. This paper presents a revised equivalent circuit model to simulate the acoustical behavior of woven fabric with backing an air gap, with a special focus on including a tortuosity parameter. The simulated sound absorption of three fabrics with and without the tortuosity parameter was experimentally validated. The equivalent circuit model including the tortuosity parameter predicts the absorption curve better, particularly at the local minima in comparison to the existing models without the tortuosity effects. It is beneficial to the structural design of woven fabric with enhanced sound absorption.
Numerical study of the behavior of a near-wall bubble under the influence of an acoustic wave
Authors: Tian Lei , Zhang Yongxue 
Published: May 2024

Abstract
Acoustic cavitation has been applied to many ultrasonic fields, but its characteristics are not fully understood, especially near the wall. To analyze the dynamics of a near-wall acoustic bubble, an acoustic pressure wave boundary condition is developed in the OpenFOAM platform. We first conducted the model’s validation with an experiment to prove its accuracy. The bubble’s radius increases when the bubble is excited by the lower-pressure wave, and it decreases under the higher-pressure wave. When the bubble collapses, its pressure and temperature will reach the maximum value. In accordance with the non-dimensional distance, the dynamics of the acoustic-driven bubble are classified into three types, i.e., the liquid jet not touching the nearby wall, the liquid jet touching the wall, and no obvious liquid jet. The maximum value of pressure and temperature increases with the dimensionless distance decreasing if the dimensionless distance is small. However, there is no variation of these peak values with dimensionless distance if the dimensionless distance is large.