bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arm-locking frequency noise suppression for astrodynamical middle-frequency interferometric gravitational wave observatory
Authors: Nian Jun , Ni Wei-Tou 
Published: August 2024

Abstract
For space gravitational wave detection, arm locking is a proposal useful in decreasing the frequency noise of the laser sources for current developing space missions Laser Interferometer Space Antenna (LISA) and Taiji/TianQin. In this paper, we study the application of arm locking to the Astrodynamical Middle-frequency Interferometric Gravitational wave Observatory (AMIGO) to decrease the frequency noise of laser sources. For AMIGO, the arm-locking technique can suppress the laser frequency noise by three orders of magnitude. The advantage of this is to make the auxiliary noise assignment for AMIGO easier and more relaxed. For the first-generation time-delay interferometry (TDI) configuration, the laser frequency noise contribution is already below the core noise contribution. For the simple Michelson TDI configuration (X0), the arm locking makes the acceleration-thrust scheme, the delay-line scheme, or the combined scheme easier to implement. Within a relatively short period of less than a day (compared to less than twenty days for LISA/Taiji), the Doppler frequency pulling can be efficiently reduced to within ±0.001 Hz and does not affect the mission duty cycle much.
Simulation study on electrical tree propagation under electrical and mechanical stresses
Authors: Liang Hucheng , Du Boxue 
Published: August 2024

Abstract
Epoxy insulators in gas-insulated power apparatus are subjected to the combined effects of electrical and mechanical loads. In this work, a simulation model is built based on the energy theory to explore the electrical tree growth of epoxy resin under tensile and compressive stresses. With increasing AC voltage, the electrical tree growth is promoted, exhibiting a morphology with more branches. Tensile stress accelerates the electrical tree growth, while proper compressive stress has the opposite effect. However, when the compressive stress exceeds a certain value, electrical tree growth is promoted again. When the mechanical stress is vertical to the needle electrode, these effects primarily impact the length of the trees. Conversely, in parallel cases, mechanical stress mainly affects the width of the electrical trees. Filler doping play the role of obstacles as well as enhancing the electric field concentration, the electrical tree growth is firstly inhibited and then promoted as the doping content increases. The electrical tree morphologies of simulation and experiment are in good consistency, proving the reasonability of the simulation model.
Gear fault diagnosis using spectral Gini index and segmented energy spectrum
Authors: Tong Shuiguang , Fu Zilong , Tong Zheming , Cong Feiyun 
Published: August 2024

Abstract
Fault diagnosis of gears is crucial for maintaining the stable operation of a gearbox within a mechanical system. Traditional envelope demodulation methods depend on the distribution of sidebands around a central frequency. However, due to various interferences such as amplitude modulation, frequency modulation and assembly errors, the sidebands do not always distribute regularly. To circumvent dependence on sidebands distribution, a novel method, based on spectral Gini index (SGI) and segmented energy spectrum, is proposed to extract fault features from the perspective of energy variation in a specific frequency band to achieve fault diagnosis. Considering the operational characteristics of gears, the vibration signal is segmented into a series of short-time vectors according to the meshing frequency, to calculate the frequency response during each gear engagement. The SGI is employed as a new method to determine the optimal frequency band. An energy sequence is obtained by calculating the energy values of the segmented vectors within the optimal frequency band. Subsequently, the spectrum of the energy sequence is computed to identify the fault characteristic frequency. For comparison, methods based on band-pass filtering and envelope demodulation are also conducted and discussed. The effectiveness of the proposed method is validated through numerical and experimental studies.
Prediction of remaining life of bearings based on integral correction and global attention mechanism
Authors: Sun Xianbin , Kong Liya , Yin Gang , Zheng Xin 
Published: August 2024

Abstract
Rolling bearing failure is an important cause of equipment failure, and its remaining service life prediction is a key research direction to detect the health status and service life of machinery. However, the feature indicators extracted based on expert knowledge cannot better characterize the trend of bearing degradation in the early and middle term, and the neural network has poor prediction effect for longer sequences. To address the above problems, a method is proposed to predict the remaining life of rolling bearings based on integral transformation and global attention mechanism. Firstly, the time domain feature indicators of vibration signals are integrally corrected and transformed into integral corrected indicators to solve the problem of inconspicuous information of bearing degradation in the front and middle term; then, a long and short time memory neural network based on global attention mechanism is built to deeply explore the mapping relationship between the integral feature indicators of long sequences and the remaining life of bearings, which gives full play to the advantage of global attention on weight optimization allocation; finally, a linear regression function is used to construct health indicators and achieve the prediction of the remaining life of rolling bearings. Experiments were conducted on the bearing data of PRONOSTIA and compared with other methods, and the results showed that the method has better accuracy and prediction precision than other methods.
ZPW-2000A track circuit anomaly detection based on dual-channel decision fusion
Authors: Lin Junting , Niu Pengyuan , Li Qian , Wang Bohan 
Published: August 2024

Abstract
This paper proposes an anomaly detection method for the ZPW-2000 A track circuit that analyzes massive monitoring data to reflect the circuit’s operational status in real time. The study utilizes two independent parallel channels for anomaly detection: Extended Isolated Forest (EIF) and Variable Auto-Encoder (VAE), each employing a distinct detection mechanism. In order to enhance the training effect, the VAE model’s training dataset is initially refined through the EIF model for data purification. Anomaly detection outputs from the dual channels are mapped to a two-dimensional space, and using Kernel Density Estimation for effective decision fusion. The dual-channel decision fusion model exhibits exceptional performance, achieving a detection accuracy of 98.78%, a precision rate of 97.62%, a recall of 96.48%, and an F1 score of 97.05%, significantly surpassing the performance of the standalone EIF or VAE methods. This technique substantially enhances the accuracy and robustness of anomaly detection. It introduces a fresh perspective and approach to anomaly detection in track circuit.
A model fusion optimization strategy for lithium mill equipment state prediction
Authors: Xiao Yanjun , Ning Fuan , Yin Shanshan , Wan Feng 
Published: August 2024

Abstract
Improving the ability and accuracy of intelligent state prediction of large and complex equipment is one of the important directions of current intelligent operation and maintenance technology research. Due to the influence of insufficient analysis of equipment degradation characteristics, single function of traditional prediction model, and difficulty in determining the optimal parameters of the model make the prediction effect poor. In this paper, a state prediction model fusion optimization strategy is proposed for lithium mill equipment as an example. Based on the process flow and vibration mechanism, the inherent vibration characteristics of the roller bearing system are analyzed, and the degradation characteristics of the roller bearing under resonance conditions are explored from the finite element equivalent model, so as to determine the equipment operation stage and the starting point of degradation. The state prediction task is divided into degradation phase and residual life prediction phase, and Time-Convolutional Denoising Autoencoder (TCDAE) and two-layer Sparse Auto Encoder (SAE) are designed for data feature enhancement and degradation feature fusion and dimensionality reduction. Construct BO-BiGRU state prediction model to mine the feature information hidden in the whole time series of data points and adjust the model parameters adaptively using Bayesian Optimization method. The novelty of this study is to analyze the degradation characteristics of key components, correct the theoretical degradation starting point by using the degradation trend formula, and establish a unified framework from monitoring data to condition prediction. Compared with the original model constructed by the above algorithm, the fusion model proposed in this paper has significantly improved performance. The data analysis shows that the prediction accuracy after model fusion is substantially improved, and the accuracy after TCDAE feature enhancement is improved by about 10.2%, the accuracy after two-layer SAE model fusion and dimensionality reduction improved by about 9.8%, and the state accuracy after BO-BiGRU model improved by about 11.6%. The crux to the research depends on the construction of a state prediction model, which is based on the analysis of the bearing degradation process and the effective integration of algorithms. Predictive maintenance of critical components also improves product quality.
Frequency selective illumination for high aperture coherence scanning interferometry
Authors: Künne Marco , Stelter Andre , Pahl Tobias , Lehmann Peter 
Published: August 2024

Abstract
Coherence scanning interferometry is a widely used optical topography measurement technique, which can achieve axial resolutions in the sub-nanometer regime. Nevertheless, in the lateral dimension it is inherently diffraction limited and multiple problems arise when approaching this limit. Especially for challenging surface topographies like steep slopes or small grating periods measurement artifacts start to cause massive deviations in the 3D reconstruction of the surface due to the increased influence of noise on increasingly weak signals. In this study we present an illumination approach for Linnik-type CSI, which highlights oblique incident angles of the illuminating light cone in high numerical aperture (0.95) systems. It is demonstrated, that this approach can significantly improve the signal-to-noise ratio for measurements at steep surface slopes and therefore increase the subsequent surface reconstruction.
Infrared routing and switching with tunable spectral bandwidth using arrays of metallic nanoantennas
Authors: Sadeghi Seyed M , Knox Harrison , Roberts Dustin T , Gutha Rithvik R , Sharp Christina , Hatef Ali 
Published: August 2024

Abstract
We study infrared routing and switching with tunable spectral bandwidth using in-plane scattering of light by flat Au nanoantenna arrays. The base dimensions of these nanoantennas are approximately 250 by 850 nm, while their heights vary from 20 to 150 nm. Our results show that, with the increase in height, the arrays become more efficient scatterers while their spectra broaden within the 1–1.6 µm range. Our findings demonstrate that such processes strongly depend on the incident light polarization. For a given polarization, the incident light is efficiently scattered in only two opposite directions along the plane of the arrays, with insignificant transmission. Switching such a polarization by 90∘, however, suppresses this process, allowing the light to mostly pass through the arrays with minimal scattering. These unique characteristics suggest a tunable beam splitter application in the 1–1.6 µm range and even longer wavelengths.
Thermal energy and electro-osmotic for biomimetic artificial olfactory cilia in tri-hybrid nanofluids: entropy-defying approaches
Authors: Fatima Nahid , Saidani Taoufik , Ijaz Nouman , Saleem Najma , Zeeshan Ahmad 
Published: August 2024

Abstract
Biomimetic artificial olfactory cilia have demonstrated potential in identifying specific volatile organic compounds linked to various diseases, including certain cancers, metabolic disorders, and respiratory conditions. These sensors may facilitate non-invasive disease diagnosis and monitoring. Cilia Motility is the coordinated movement of cilia, which are hair-like projections present on the surface of particular cells in different species. Cilia serve an important part in several biological functions, including motility, fluid movement, and sensory reception. Cilia motility is a complicated process that requires the coordinated interaction of structural components and molecular pathways. Cilia are made up of a highly structured structure known as the axoneme, which is made up of microtubules grouped in a unique pattern. The axoneme is made up of nine outer doublet microtubules and a core pair of singlet microtubules. This arrangement offers structural support and serves as a scaffold for the proteins involved in ciliary movement. Our latest endeavors investigate these Multiphysics phenomena in ciliary beating flows that are inspired by biology, utilizing copper, gold, and titania nanoparticles. We examine their functions in biological systems such as peristaltic transport computationally. Our models give precise two- and three-dimensional velocity, temperature, and concentration solutions by integrating transverse magnetohydrodynamics with laser heating. Furthermore, at the channel wall expressions, the skin friction coefficient, Sherwood number, Nusselt number and optimization of entropy generation are acquired and analyzed. Important properties of the velocity and scalar profiles are revealed by a thorough analysis of dimensionless parameters. The simplified examination provides more insight into the trapping patterns that result from the complex interaction between nanofluid rheology and optics. These findings greatly contribute to our knowledge and improvement of nanofluidic transport technologies in a variety of fields supporting industry, sustainability, and medicine. Our combined computational and experimental methodology clarifies the complex dynamics in these systems and provides design guidance for the engineering of improved fluidic devices that make use of multifunctional nanomaterial interfaces and peristaltic motion.
Implementation of matrix compression in the coupling of JOREK to realistic 3D conducting wall structures
Authors: Cipolletta F , Schwarz N , Hoelzl M , Ventre S , Isernia N , Rubinacci G , Soba A , Mantsinen M J ,   the JOREK Team
Published: August 2024

Abstract
JOREK is an advanced non-linear simulation code for studying MHD instabilities in magnetically confined fusion plasmas and their control and/or mitigation. A free-boundary and resistive wall extension was introduced via coupling to the STARWALL and CARIDDI codes, both able to provide dense response matrices describing the electromagnetic interactions between plasma and conducting structures. For detailed CAD representations of the conducting structures and high resolutions for the plasma region, memory and computing time limitations restrict the possibility of simulating the ITER tokamak. In the present work, the Singular Value Decomposition provided by routines from the ScaLAPACK library has been successfully applied to compress some of the dense response matrices and thus optimize memory usage. This is demonstrated for simulations of Tearing Mode and Vertical Displacement Event instabilities. An outlook to future applications on large production cases and further extensions of the method are discussed.
Dynamics of Airyprime beams with higher-order spectral phase modulation in the fractional Schrödinger equation
Authors: Zhao Shoukui , Li Juncen , Li Tianqi , Huang Xianwei , Bai Yanfeng , Fu Xiquan 
Published: August 2024

Abstract
In this paper, the effects of spectral phase modulation on propagation characteristics of Airyprime beams modeled by fractional Schrödinger equation are studied, and the propagation dynamics of Airyprime beams are analyzed. It is found that the second and third-order spectral phase modulation significantly affect the beams dynamics. For the second-order spectral phase modulation, an increase in the Lévy index leads to a forward shift of the peak position, and the peak intensity increases for the positive spectral modulation coefficient, while the opposite tendency of the peak intensity is found for the negative spectral modulation coefficient. In addition, the appearance of multiple peaks depends on the positive modulation coefficient. For the third-order spectral phase modulation, the peak intensity increases under the larger spectral phase modulation coefficient with the backward shift of the maximum peak position, and an increase of the Lévy index results in the forward shift of the focusing position. The results show potential applications of Airyprime beams in various fields such as optical controlling and manipulation.
Lie symmetries, exact solutions and conservation laws of time fractional Boussinesq–Burgers system in ocean waves
Authors: Yu Jicheng , Feng Yuqiang 
Published: August 2024

Abstract
In this paper, the Lie symmetry analysis method is applied to the time-fractional Boussinesq–Burgers system which is used to describe shallow water waves near an ocean coast or in a lake. We obtain all the Lie symmetries admitted by the system and use them to reduce the fractional partial differential equations with a Riemann–Liouville fractional derivative to some fractional ordinary differential equations with an Erdélyi–Kober fractional derivative, thereby getting some exact solutions of the reduced equations. For power series solutions, we prove their convergence and show the dynamic analysis of their truncated graphs. In addition, the new conservation theorem and the generalization of Noether operators are developed to construct the conservation laws for the equations studied.
Neural networks for estimation of divertor conditions in DIII-D using C III imaging
Authors: Boyer M.D. , Scotti F. , Gajaraj V. 
Published: August 2024

Abstract
Deep learning approaches have been applied to images of C III emission in the lower divertor of DIII-D to develop models for estimating the level of detachment and magnetic configuration (X-point location and strike point radial location). The poloidal distance from the target to the C III emission front is used to represent the level of detachment. The models perform well on a test dataset not used in training, achieving F
1 scores as high as 0.99 for detachment state classification and root mean squared error (RMSE) as low as 2 cm for front location regression. Predictions for shots with intermittent reattachment are studied, with class activation mapping used to aid in interpretation of the model predictions. Based on the success of these models, a third model was trained to predict the X-point location and strike point radial position from C III images. Though the dataset covers only a small range of possible magnetic configurations, the model shows promising results, achieving RMSE around 1 cm for the test data.
Use of differential plasma rotation to prevent disruptive tearing mode onset from 3-wave coupling
Authors: Richner N.J. , Bardóczi L. , Callen J.D. , La Haye R.J. , Logan N.C. , Strait E.J. 
Published: August 2024

Abstract
Plasma differential rotation is found to be capable of preventing disruptive neoclassical tearing modes (NTMs) seeded by nonlinear three-wave coupling. As tearing modes degrade confinement and can lead to disruptions, stabilization strategies are crucial to the successful operation of future devices. In ITER-relevant scenarios on DIII-D, rotationally coupled

m

/

n

= 1/1 and 3/2 modes have been observed to drive 2/1 islands through three-wave coupling. The frequency of the driven 2/1 mode is set by matching conditions and the frequencies of the driving modes. When the driven mode frequency matches the local plasma rotation frequency, e.g. at low differential rotation, the driven 2/1 island can grow into a disruptive NTM. Using neutral beam torque as an actuator to scan the differential rotation, these experiments demonstrate that a sufficiently large frequency mismatch prevents destabilization of disruptive 2/1 NTMs by three-wave coupling. This work indicates that differential rotation can be used as an actuator to prevent NTMs seeded by three-wave coupling.
Visual simulation of UAV mission planning schemes
Authors: Xie Wei , Tian Ye , Chang Qi , Zhang Dong , Zheng Wenquan 
Published: August 2024

Abstract
To effectively assess the rationality of trajectory planning for small unmanned aerial vehicles (UAVs) executing search missions in complex terrain areas, we suggest using the STK (System Tool Kit) software to evaluate the reconnaissance effectiveness of UAVs. Firstly, the STK software is employed to calculate and analyze the coverage characteristics of UAV sensors in the target area. Secondly, the connectivity of UAV-to-GPS satellite communication links is evaluated. Lastly, the effectiveness of communication links such as UAV-to-ground control stations is examined. Simulation results indicate that STK enables multi-angle analysis and assessment of route planning effectiveness. The computed results are accurate, the display is intuitive, and the operation is simple and fast, making it suitable for evaluating and analyzing the rationality of UAV search and rescue route planning schemes in complex terrain conditions. This, in turn, provides reliable and effective data support for optimizing UAV route planning.
Research on the design laws of stealth structures for typical components of aircraft leading edges
Authors: Xia Liang , Lan Xuhui , Chen Jinsong , Chen Xin , Wang Ran , Wu Jiaxun 
Published: August 2024

Abstract
Considering the design of stealth structures for typical components of aircraft leading edges, this article selects typical aircraft’s leading edge structures. Firstly, the stealth mechanism of the aircraft’s leading edge structure is analyzed. Then, by adjusting the height, length, and angle of the leading edge structure item by item, the relationship between RCS value changes and the stealth performance of typical components of the leading edge is studied from the perspective of metal electromagnetic characteristics. Finally, the design rules of stealth structures for typical components of aircraft leading edges are summarized, providing support for the design of aircraft stealth structures.
Mechanism analysis and improvement methods of NTF defects in use for civil aircraft
Authors: Zhou Qin , Huang Caolin , Zou Zhaoliang 
Published: August 2024

Abstract
The NTF defects in use are raised, including NTF telegraphing, waving, shrinking, bubbling, etc. NTF installation and materials are illustrated, and the mechanism of NTF defects in use is analyzed and clarified, which noted that floor surface, floor deformation, peripheral squeezing, and seat tracks are related to NTF defects in use. Based on mechanism analysis and practical situations, the improvement methods are proposed and verified to be effective.