bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of quantum correlations on parameter estimation in a spin reservoir
Authors: Mirza Ali Raza , Al-Khalili Jim 
Published: September 2024

Abstract
We study the impact of quantum correlations existing within the system-environment thermal equilibrium state while estimating the parameters of the spin reservoir. By employing various physical situations of interest, we present results for the reservoir temperature and its coupling strength with the central two-level system. The central system (probe) interacts with the bunch of randomly oriented spin systems and attains a thermal equilibrium state. We consider a projective measurement which prepares the probe’s initial state, and then the global system (probe and reservoir) evolves unitarily. The reduced density operator encapsulates the information about the spin reservoir which can be extracted by doing measurements on the probe. The precision of such measurement is quantified by quantum Fisher information. We repeat this process if the probe-reservoir initial state is not correlated (product state). We compare the estimation results for both with and without the outturn of initial correlations. In the temperature estimation case, our results are promising as one can significantly improve the accuracy of the estimates by including the effect of initial correlations. A similar trend prevails in the case of coupling strength estimation especially at low temperatures.
Parallel Analogy Method for Measuring FRD of the FASOT-IFU
Authors: Chen Xudong , Yan Yunxiang , Yan Qi , Wang Anzhi , Sun Kangquan , Peng Zifu , Wang Jiabin , Wang Pengfei , Zhong Yue , Qu Zhongquan , Geng Tao , Sun Weimin 
Published: September 2024

Abstract
A fiber integral field unit (IFU) was chosen for the Fiber Array Solar Optical Telescope (FASOT) to obtain high-spectral-resolution polarization solar spectral images. This IFU features a dual-array-end design, complemented by a dozen slit ends. Each consists of 2 sub-slits corresponding to the dual array ends. In order to accurately and quickly measure the focal ratio degradation of 8064 fibers in FASOT-IFU, a parallel analogy method (PAM) for FASOT-IFU was proposed. This method primarily relies on characterizing the focal ratio based on the full-width at half-maximum (FWHM) of the fiber’s output spot, and the linear relationship between the output focal ratio of the spot and the FWHM. By precisely calculating the focal ratio of the positioning fiber in the FASOT-IFU and treating it as a reference, the output focal ratio of the working fiber can be obtained by comparing the FWHM of the working fiber spot and the positioning fiber spot at the same emission distance. The average value of the output focal ratio by PAM corresponding to the 4032 fibers from Array A of the IFU is 6.0 and the standard deviation is 0.6. The values corresponding to the Array B are 6.2 and 0.40, respectively. The mean value exceeds the contractually specified F/5.5, and the proportion of optical fibers with a focal ratio greater than 5.5 accounts for 88% of the total number of optical fibers, meeting the design requirements of the FASOT system.
Analysis and measurement of vibration characteristics of a hollowing defect based on a laser self-mixing interferometer
Authors: Chen 陈 Yu-Xin 煜昕 , Chen 陈 Jin-Bo 金波 , Cao 曹 Peng 鹏 , Zhao 赵 You-Guang 有光 , Wang 王 Jun 钧 , Teng 滕 Xu-Wei 旭玮 , Wang 王 Chi 驰 
Published: September 2024

Abstract
To solve the problems with the existing methods for detecting hollowing defects, such as inconvenient operation, low efficiency and intense subjectivity, and to improve the efficiency of the acoustic-optic fusion method for detecting hollowing defects, in this paper the vibration characteristics of hollowing defects are measured and analyzed using a laser self-mixing interferometer. The ceramic tile above the hollowing defect is equivalent to a thin circular plate with peripheral fixed support. According to Kirchhoff’s classical circular plate theory and the circular plate displacement function based on the improved Fourier series, a theoretical model of a circular plate is established. By solving the characteristic equation, the theoretical modal parameters of hollowing defects are obtained. Subsequently, an experimental system based on a laser self-mixing interferometer is built, and modal experiments are carried out using the hammering method. The experimental modal parameters are obtained with a professional modal analysis software. Through comparative analysis between the theoretical and experimental modal parameters, the error of the natural frequency results is found to be tiny and the mode shapes are consistent. These results provide theoretical guidance for a practical non-destructive acoustic-optic fusion method for detecting hollowing defects.
Micron-resolved quantum precision measurement of magnetic field at the Tesla level
Authors: An 安 Si-Han 思瀚 , Ge 葛 Shi-Yu 仕宇 , Lu 卢 Wen-Tao 文韬 , Chen 陈 Guo-Bin 国彬 , Xia 夏 Sheng-Kai 圣开 , Chen 陈 Ai-Qing 爱庆 , Wang 王 Cheng-Kun 成坤 , Yu 虞 Lin-Yan 林嫣 , Zhang 张 Zhi-Qiang 致强 , Wang 汪 Yang 洋 , Tang 唐 Gui-Jin 贵进 , Cheng 程 Hua-Fu 华富 , Du 杜 Guan-Xiang 关祥 
Published: September 2024

Abstract
We develop a quantum precision measurement method for magnetic field at the Tesla level by utilizing a fiber diamond magnetometer. Central to our system is a micron-sized fiber diamond probe positioned on the surface of a coplanar waveguide made of nonmagnetic materials. Calibrated with a nuclear magnetic resonance magnetometer, this probe demonstrates a broad magnetic field range from 10 mT to 1.5 T with a nonlinear error better than 0.0028% under a standard magnetic field generator and stability better than 0.0012% at a 1.5 T magnetic field. Finally, we demonstrate quantitative mapping of the vector magnetic field on the surface of a permanent magnet using the diamond magnetometer.
Calibration of an ionisation chamber for parent–progeny decay
Authors: Pommé S 
Published: September 2024

Abstract
For a single radionuclide being measured in an ionisation chamber, a calibration factor can be established that relates the ionisation current to the source activity. The same applies to a decay chain in secular equilibrium, for which the calibration factor comprises the ionisation current produced by the parent and progeny nuclei combined. The calibration of an ionisation chamber for non-equilibrated parent–progeny decay poses a problem because the activity ratio of the parent and progeny nuclei varies with time. This study examines cases in which the half-lives of the parent and only one of the progenies in the decay series are significantly long. Thus, two calibration factors are involved, which combine differently as a function of time. By means of nuclear dating of the material, the parent–progeny activity ratio can be determined, and the respective contributions to the ionisation current can be unambiguously distinguished. Once the ionisation chamber is calibrated, two measurements taken at different times are sufficient to determine the activity and age of the parent–progeny mixture. This study presents equations for calculating the calibration factors and propagating uncertainties, illustrated with a case study focusing on the 227Th/223Ra decay chain used in alpha-immunotherapy.
Error field predictability and consequences for ITER
Authors: Pharr M. , Logan N.C. , Paz-Soldan C. , Park J.K. , Hansen C. 
Published: September 2024

Abstract
ITER coil tolerances are re-evaluated using the modern understanding of coupling to least-stable plasma modes and an updated center-line-traced model of ITER’s coil windings. This reassessment finds the tolerances to be conservative through a statistical, linear study of n = 1 error fields (EFs) due to tilted, shifted misplacements and nominal windings of central solenoid and poloidal field coils within tolerance. We also show that a model-based correction scheme remains effective even when metrology quality is sub-optimal, and compare this to projected empirical correction schemes. We begin with an analysis of the necessity of error field correction (EFC) for daily operation in ITER using scalign laws for the EF penetration threshold. We then consider the predictability of EF dominant mode overlap across early planned ITER scenarios and, as measuring EFs in high power scenarios can pose risks to the device, the potential for extrapolation to the ITER Baseline Scenario (IBS). We find that carefully designing a scenario matching currents proportionally to those of the IBS is far more important than plasma shape or profiles in accurately measuring an optimal correction current set.
Uncertainty analysis of a non-contact image-based measurement system for tracking mandibular movements path
Authors: Truffarelli Tiberio , Valenti Chiara , Tribbiani Giulio , Pagano Stefano , Marsili Roberto , Rossi Gianluca 
Published: September 2024

Abstract
Tracking mandibular movements is essential for the production of personalized gnathologic and prosthetic devices. The market offers several solutions of optical systems aimed at tracking the jaw, instruments that, using a camera and specific markers, allow reconstructing free mandibular movements. The purpose of this study is to analyse the measurement uncertainty of one of these new systems through comparison with a reference technique on simple linear displacements.
Application of the tomographic BOS technique to a H2-air premixed flame
Authors: Iapaolo F. , Cozzi F. , Orlando M. 
Published: September 2024

Abstract
Background Oriented Schlieren (BOS) is a line of sight optical (LoS) technique used for visualizing and measuring density gradients in transparent media by exploiting the fluid density and refractive index relationship. This study applies BOS to a premixed axis-symmetric hydrogen flame, aiming to quantitatively estimate its density and temperature distributions using the ARAP (Arbitrary Ray Axisymmetric Projection) deconvolution algorithm. The BOS technique consists in acquiring images of a background with and without the flame; light rays passing through the flame are deflected due to the heterogeneous refractive index field. Cross-correlation algorithms are then employed to quantify these deflections. The ARAP transform is preferred to Abel-based methods because it models light rays as converging to a single point according to the pinhole camera model. Assuming constant composition, density gradients are evaluated, and considering ideal gas behaviour and constant pressure, the temperature distribution is estimated. The study explores the influence of parameters like regularization and integration steps for the ARAP transform. Consistency analysis involves evaluating temperature trends at various flame heights and comparing them with thermocouple measurements. Additionally, a preliminary estimation of tomographic BOS uncertainties is provided.
The Effect of Noisy Magnetic Fields on Electrons
Authors: David Castaño-Yepes Jorge , Loewe Marcelo , Muñoz Enrique , Cristóbal Rojas Juan , Zamora Renato 
Published: September 2024

Abstract
In this work, we study the behavior of an electron in the presence of a constant and uniform magnetic field, which is subjected to white noise fluctuations with an autocorrelation of magnitude Δ
B
. Starting from the Schwinger representation for a propagator in the presence of a constant magnetic field, we use the method of replicas to determine the effect of the magnetic noise on the shape of the renormalized quasi-particle parameters. Leading to an effective charge and an effective refraction index that depend not only on the energy scale, as usual, but also on the magnitude of the noise ΔB and the average field B.
Irreversibility and response functions in the turbulent energy cascade
Authors: Cocciaglia Niccolò , Cencini Massimo , Vulpiani Angelo 
Published: September 2024

Abstract
The statistical properties of turbulent flows are fundamentally different from those of systems at equilibrium due to the presence of an energy flux from the scales of injection to those where energy is dissipated by the viscous forces: a scenario dubbed “direct energy cascade”. Here, we aim at characterizing the non-equilibrium properties of turbulent cascades in a shell model of turbulence by studying an asymmetric time-correlation function and the relaxation behavior of an energy perturbation, measured at scales smaller or larger than the perturbed one. We shall contrast the behavior of these two observables in both non-equilibrium (forced and dissipated) and equilibrium (inviscid and unforced) cases. Finally, we shall show that equilibrium and non-equilibrium physics coexist in the same system, namely at scales larger and smaller, respectively, of the forcing scale.
Complexity Measures in the Tight-Binding Model
Authors: Atenas Boris , Curilef Sergio 
Published: September 2024

Abstract
The deformation of a wave packet is a significant topic in classical and quantum mechanics. Understanding this phenomenon is relevant in the study of various physical systems. In this work, we characterize the evolution of a highly localized wave packet in a tight-binding lattice. We investigate the behavior of the probability distribution associated with the wave packet and the accompanying complexity measures. We take information entropy, disequilibrium, disorder, and complexity measures to describe the localization-delocalization process from a highly localized initial pulse, showing the particles moving in a lattice. The main result is obtained from the entropy definition (Logarithmic and Linear) and the inverse of the participant ratio to describe the expected localization-delocalization process, evoking two definitions of Complexity: CLMC
and CSDL
.
Generalised Lyapunov stretching in a weakly chaotic open dynamical system
Authors: Brevitt Samuel , Klages Rainer 
Published: September 2024

Abstract
Chaotic dynamical systems may be characterised by a positive Lyapunov exponent, which measures the exponential rate of separation of nearby trajectories. However in a wide range of so-called weakly chaotic systems, the separation of nearby trajectories is sub-exponential, for example stretched exponential, in time; and therefore in such cases the Lyapunov exponent vanishes. When a hole is introduced in chaotic systems, the Lyapunov exponent on the system’s fractal repeller can be related to the generation of entropy and the escape rate from the system via the escape rate formalism, but no suitable generalisation exists to weakly chaotic systems. In this work we show that in a paradigmatic one-dimensional weakly chaotic iterated map, the Pomeau-Manneville map, the generation of generalised Lyapunov stretching is completely suppressed in the presence of a hole. These results are shown based on numerical evidence, and explained with a fully analytic stochastic model.
Entanglement in Bound States of Two Particles with a Localized Center-of-Mass Wave-Function
Authors: Nogales B. , Curilef S. , Plastino A.R. 
Published: September 2024

Abstract
We explore some entanglement-related features of systems consisting of two particles coupled through a central potential. We consider two types of systems, constituted by particles in one spatial dimension interacting through an attractive Dirac Delta potential, or through a harmonic quadratic potential. The degree of freedom corresponding to the system’s center of mass is either regarded as confined within a one dimensional box, or described by a localized Gaussian wave-packet. As a quantitative indicator of the degree of entanglement between the particles, we use the linear entropy of the one-particle marginal density matrix. In general, this quantity cannot be calculated analytically (except in some special cases related to the Harmonic interaction). Consequently, the linear entropy has to be evaluated numerically. Since the concomitant numerical problem consist in evaluating a multi-dimensional integral in four dimensions, the Monte Carlo integration method is an appropriate one for this task. We explore numerically how the system’s entanglement depends on the different interaction potentials, on the different types of confinement for the system’s center of mass, and on the associated parameters describing the size and geometry of the system.
Quantitative analysis of student learning progress in online curses during the COVID-19 Pandemic
Authors: Tabilo Felipe , Velazquez L. 
Published: September 2024

Abstract
The pandemic of COVID-19 forced the transition of education to online platforms. This shift allowed for a more in-depth study of the learning process of students, as it provided access to information about their activities and interactions with the course’s contents [1-3]. In this work, we apply quantitative methods to analyze the student learning progress of students for two first year courses of the B.Sc. degree in Physics (Universidad Católica del Norte). The data are collected from activity logs of digital platforms during Academic year 2021, which were employed to characterize the student learning habits along these processes (experience, selectivity and workflow). Statistical analysis is based on the distribution of the time spent on learning activities, such as the daily time distribution and the cumulative attention per online materials. The results show that the learning process of students in online courses is complex and adaptive. We report statistical patterns similar to those found in financial markets. These empirical results provide evidence about the importance of economic principles and methods in the understanding of the teaching-learning process.
Energy efficiency evaluation of wind turbines based on entropy weight method and stacked autoencoder
Authors: Ma Jinke , Lu Nana , Sun Qitao , Liang Hao 
Published: September 2024

Abstract
To solve the problems of complex operating conditions of wind turbines and difficult to measure and evaluate energy efficiency, a quantitative evaluation method of energy efficiency of wind turbines based on the entropy weight method (EWM) and stacked automatic encoder (SAE) was proposed. Firstly, based on the Supervisory Control And Data Acquisition (SCADA) data of wind turbines, key evaluation indicators are extracted through preprocessing and feature extraction of wind turbine data. The EWM is used to determine the weights, and deep learning is combined with SAE to comprehensively obtain the energy efficiency value of wind turbines. Subsequently, the quartile method was used to determine the discrimination threshold for inefficient units, and the effectiveness of this method on SCADA data of a 5.5MW offshore wind farm was verified through numerical examples. The results show that this method can evaluate the energy efficiency level of wind turbines in real time and achieve 100% accuracy in identifying inefficient units, providing a reference for the maintenance and technical improvement of wind turbine energy efficiency performance.
Electricity theft detection model based on the CEEMDAN-CNN-ViT
Authors: Yang Hang , Yang Runkai , Li Xiang , Zhou Wenyuan 
Published: September 2024

Abstract
Most of the traditional power theft detection methods construct the model directly on the basis of the original power sequences, and do not simultaneously consider the long-period dependencies in the long-time sequences and the local connectivity features between periods, which limits the deep excavation of the behavioral laws of power users. In order to further improve the accuracy of power theft detection, this paper proposes a high-precision power theft detection model that integrates local anomaly filtering, energy consumption decomposition, and multi-feature fusion strategies. First, local anomaly filtering is used to eliminate local anomalies in the normalized energy consumption data to avoid the misleading effect of short-term abnormal behavior on the model. Then, the energy consumption decomposition based on CEEMDAN selects specific frequency band data that can accurately characterize the pattern of power theft users to improve the accuracy of power theft detection. Next, the long-time periodic features in the two-dimensional data and the short-time local features in the one-dimensional sequences are integrated by multi-feature fusion to enhance the adaptability of the model. The results show that the proposed model can effectively improve the detection accuracy, detection completeness, F1 score, and accuracy compared with the existing methods.
Convolutional neural networks-based multi-sensor data fusion analysis for transmission lines
Authors: Ye Jiang , Chen Yonghua , Xia Yunfeng , Liang Qishuai , Xia Zhongchen , Yang Jie 
Published: September 2024

Abstract
With the development of the power system, accurate assessment and fault diagnosis of the health status of transmission lines have become increasingly important. However, the standard data fusion algorithms do not fully exploit the correlation and weight disparity among multiple sensors. This study proposes a technique for analyzing transmission lines using a convolutional neural network-based approach to address this issue. By fusing data collected from multiple sensors in different directions, it can more accurately capture key information about transmission lines and conduct comprehensive analysis to evaluate their health status.
Reliability assessment of grid-connected microgrid based on sequential Monte Carlo simulation method
Authors: Ban Yongshuang , Li Chunhua , Wang Benke , Zhao Zeming , Wang Zengxu 
Published: September 2024

Abstract
A reliability evaluation model for grid-connected microgrid (MG) on the basis of sequential Monte Carlo simulation (SMCS) method is put forward, and factors affecting the reliability of power distribution network containing distribution generation (DG) and MG in grid-connected paradigm are studied. According to the research results, the reliability of the power distribution system can be heightened effectively by microgrid connection; increasing DG capacity can improve system reliability, and DG with constant output has a better improvement effect. Meanwhile, properly increasing the capacity of the energy storage system (ESS) or reducing its failure rate can improve the probability of steady operation (POSO) of the microgrid, but the effect of the failure rate is small.
Frequency stability control of sending-end power grid with multiple resources
Authors: Ye Xi , Ouyang Xuetong , Chen Baorui , Wang Xi , Zhu Tong , Zhou Shichen , Zhong Zuhao 
Published: September 2024

Abstract
High shares of renewables and power electronics (“double-high”) have become the main development trends for future power systems. In this context, power systems will face the practical problem of insufficient inertia and frequency regulation capability. This paper investigates frequency stability enhancement of the sending-end power grid by incorporating regulation capabilities of multiple resources. Based on power flow and transient calculation data, an equivalent model of frequency response for a practical power grid is established and validated. The frequency response under different scenarios considering various disturbance and renewable output scenarios is conducted, taking into account the simultaneous participation of resources such as direct current frequency limit control, energy storage, and renewables of different scales in frequency regulation to improve frequency stability and mitigate the risk of renewables trippings. Simulation results indicate that incorporating the potential frequency regulation capabilities of multiple resources into “double-high” frequency control strategy plays an important role in improving transient frequency response, reducing the risk of renewable tripping, and enhancing frequency stability margins.