bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient robotic-assisted bolt-ball joint looseness monitoring approach using CBAM-enhanced lightweight ResNet
Authors: Li Li , Yuan Rui , Lv Yong , Xu Shijie , Hu Huangxing , Song Gangbing 
Published: October 2023

Abstract
Bolt-ball joints are widely used in space structures, and their looseness may lead to major safety accidents. The current bolt monitoring methods based on deep learning usually have high computational complexity, and it is difficult to guarantee its computational efficiency under practical scenario. To mitigate this problem, here in this paper, an efficient robotic-assisted bolt-ball joint looseness monitoring approach using convolutional block attention module (CBAM)-enhanced lightweight ResNet is proposed. Firstly, the robotic-assisted tapping method is applied to bolt-ball joints to generate audio signals, which are constructed into time-frequency maps by continuous wavelet transform. Secondly, the original ResNet is improved as a lightweight network, which successfully reduces model complexity, and employs time-frequency maps as input. Then, CBAM is introduced to capture global information and focus on the critical feature. Thus, the efficiency of feature extraction is significantly improved. Finally, by the overall optimized structure, a CBAM-enhanced lightweight ResNet model is established to monitor the bolt-ball joints looseness state accurately. Experimental results demonstrate the high efficiency while maintaining very lightweight structure of the proposed method, verifying the effectiveness and superiority of the robot-assisted approach using CBAM-enhanced lightweight ResNet over other methods.
The Josephson junction as a quantum engine
Authors: Alicki Robert , Horodecki Michał , Jenkins Alejandro , Łobejko Marcin , Suárez Gerardo 
Published: October 2023

Abstract
We treat the Cooper pairs in the superconducting electrodes of a Josephson junction (JJ) as an open system, coupled via Andreev scattering to external baths of electrons. The disequilibrium between the baths generates the direct-current bias applied to the JJ. In the weak-coupling limit we obtain a Markovian master equation that provides a simple dynamical description consistent with the main features of the JJ, including the form of the current–voltage characteristic, its hysteresis, and the appearance under periodic voltage driving of discrete Shapiro steps. For small dissipation, our model also exhibits a self-oscillation of the JJ’s electrical dipole with frequency

Ω
=
2
e
V

/

ℏ

around mean voltage V. This self-oscillation, associated with ‘hidden attractors’ of the nonlinear equations of motion, explains the observed production of monochromatic radiation with frequency Ω and its harmonics. We argue that this picture of the JJ as a quantum engine resolves open questions about the Josephson effect as an irreversible process and could open new perspectives in quantum thermodynamics and in the theory of dynamical systems.
Comparison of confidence regions for quantum state tomography
Authors: Almeida Jessica O de , Kleinmann Matthias , Sentís Gael 
Published: October 2023

Abstract
The quantum state associated to an unknown experimental preparation procedure can be determined by performing quantum state tomography. If the statistical uncertainty in the data dominates over other experimental errors, then a tomographic reconstruction procedure must express this uncertainty. A rigorous way to accomplish this is via statistical confidence regions (CRs) in state space. Naturally, the size of this region decreases when increasing the number of samples, but it also depends critically on the construction method of the region. We compare recent methods for constructing CRs as well as a reference method based on a Gaussian approximation. For the comparison, we propose an operational measure with the finding, that there is a significant difference between methods, but which method is preferable can depend on the details of the state preparation scenario.
Optimal resetting strategies for search processes in heterogeneous environments
Authors: García-Valladares Gregorio , Plata Carlos A , Prados Antonio , Manacorda Alessandro 
Published: October 2023

Abstract
In many physical situations, there appears the problem of reaching a single target that is spatially distributed. Here we analyse how stochastic resetting, also spatially distributed, can be used to improve the search process when the target location is quenched, i.e. it does not evolve in time. More specifically, we consider a model with minimal but sufficient ingredients that allows us to derive analytical results for the relevant physical quantities, such as the first passage time distribution. We focus on the minimisation of the mean first passage time (MFPT) and its fluctuations (standard deviation), which proves to be non-trivial. Our analysis shows that the no-disorder case is singular: for small disorder, the resetting rate distribution that minimises the MFPT leads to diverging fluctuations—which impinge on the practicality of this minimisation. Interestingly, this issue is healed by minimising the fluctuations: the associated resetting rate distribution gives first passage times that are very close to the optimal ones.
Anisotropic strange stars and its maximum mass in Finch-Skea geometry in dimensions D ≥ 4
Authors: Das B , Goswami K B , Saha A , Chattopadhyay P K 
Published: October 2023

Abstract
In this article, we have demonstrated a stellar model for compact stars in the presence of strange matter embedded in D ≥ 4 dimensional space-time defined by the Finch-Skea metric. To study the relevant physical properties of the interior matter, we consider the equation of state (henceforth
EOS)

p
=

1

3

(
ρ
−
4
B
)

as proposed in the MIT bag model, where B is termed the bag constant. The mass-radius relationship in four and higher dimensions is determined using the range of values of surface density through the relation ρ

s
= 4B, for which bulk strange matter may be a viable issue for compact objects. Here, we choose the range of B so that stable strange matter may exist relative to a neutron at zero external pressure. We note that a maximum value of the stellar radius exists when B is fixed at a given allowed value for which metric functions considered to be real here. This is the maximum allowed radius

(

b

max

)

in this model, which depends on the surface density of a strange star. In four dimensions, the compactness of a star is found to be greater than 0.33. In the case of higher dimensions (D > 4), we observed different values of compactness. Causality conditions are satisfied interior to the star up to the maximum allowed radius

(

b

max

)

, for which the metric function is real. The validity of the energy conditions, surface redshift and other parameters of the stellar configuration are studied, and new results are found. The stability of the model is also studied.
The spatial wavefunction of half-integer spins
Authors: van Veenendaal Michel 
Published: October 2023

Abstract
Within a nonrelativistic framework, spin is generally included as an intrinsic angular momentum. It is proposed here that consistent results can be obtained with a spatial wavefunction of an oriented complex exponential

e

∓
i

a

ˆ

φ

, where the bivector

i

a

ˆ

is written in terms of the pseudoscalar
i
= e

x

e

y

e

z
and the axis of rotation given by the unit vector

a

ˆ

, which is generally an (effective) magnetic field direction (this can also be written as

e

∓
i
σ
·

a

ˆ

φ

in terms of the Pauli vector
σ
). The wavefunction is a multivector and not a complex scalar. The signs in the exponential correspond to the two directions of rotation around the axis. The transformation properties of these wavefunctions are given by the Pauli spinors. Spin can be viewed as a zero-point rotation arising from the noncommutativity of the momentum and the vector potential.
Dynamics of the modified emden and pseudo-modified emden equations: position-dependent mass, invariance and exact solvability
Authors: Mustafa Omar 
Published: October 2023

Abstract
We consider the modified Emden equation (MEE) and introduce its most general solution, using the most general solution for the simple harmonic oscillator’s linear dynamical equation (i.e. the initial conditions shall be identified by the PDM-MEE problem at hand). We use a general nonlocal point transformation and show that modified Emden dynamical equation is transformed to describe position-dependent mass (PDM) classical particles. Two PDM-MEE-type classical particles are used as illustrative examples, and their exact solutions are reported. Under specific parametric considerations, the phase-space trajectories are reported for the MEE-type and for PDM-MEE-type classical particles.
Novel efficient and scalable design of full-adder in atomic silicon dangling bonds (ASDB) technology
Authors: Rasmi Hadi , Mosleh Mohammad , Jafari Navimipour Nima , Kheyrandish Mohammad 
Published: October 2023

Abstract
Atomic Silicon Dangling Bonds (ASDB) is an advanced emerging nanotechnology to replace CMOS technology; because it allows the designing of circuits with very high-speed and low-density. However, one of the most critical challenges in implementing circuits in ASDB nanotechnology is output stability and possible defects, such as DB omission, DB misalignment, and DB extra deposition, which can be overcome using a suitable designing pattern. Therefore, developing stable and robust structures is considered as one of essential topics in ASDB. This paper first proposes two novel and stable computing circuits, including a three-input majority voter (MV3) and three-input XOR (XOR3); based on triangular and rhombus patterns, respectively. Then, an efficient ASDB full-adder is designed using the suggested MV3 and XOR3 gates. Finally, two and four-bit ripple carry adders are developed using proposed full-adder. Simulation results indicate that the suggested MV3 and XOR3 are superior to previous designs, by more than 80%, 48%, and 9.5%, averagely; in terms of occupied area, energy, and occurrence, respectively. Moreover, the proposed gates are investigated against possible defects, and the results show high stability.
The gamma-ray burst arising from neutrino pair annihilation in the static and spherically symmetric black-hole-like wormholes
Authors: Shi Yuxuan , Cheng Hongbo 
Published: October 2023

Abstract
We look into the neutrino-antineutrino pair
(ν+ν̅ ⟶ e-
+e+
) annihilation in the
Damour-Solodukhin wormhole spacetime whose metric component
involves a shift in contrast to the similar black hole. The deep
analysis of the surface temperature of the accretion disk of
static, spherically symmetric black-hole-like wormholes from R.
Kh. Karimov et al. reveals that the accretion disks of the
wormholes are hotter than that of comparable black holes,
indicating that the wormholes accretion disk can release
neutrinos. Further we investigate the energy deposition rate from
the neutrino pair annihilation around the Damour-Solodukhin
wormhole thought as a mimicker of Schwarzschild black hole. By
comparison made between the black-hole-like wormhole and the
similar black hole, we demonstrate that the wormhole's accretion
disk drawing the annihilation can become a source of gamma-ray
burst although the more significant deviation from the similar
black hole reduces the emitted power slightly. The ratio of energy
deposition per unit time from the annihilation surrounding the
accretion disk of the Damour-Solodukhin wormhole over the emitting
power of black hole might alter noticeably depending on how
slightly the metrics of the wormhole differ from the black hole
spacetime.
Correcting the Contamination of Second-order Spectra: Improving Hα Measurements in Reverberation Mapping Campaigns
Authors: Xi Wen-Zhe , Lu Kai-Xing , Feng Hai-Cheng , Li Sha-Sha , Bai Jin-Ming , Zhou Rui-Lei , Liu Hong-Tao , Wang Jian-Guo 
Published: October 2023

Abstract
Long-term spectroscopic monitoring campaigns on active galactic nuclei (AGNs) provide a wealth of information about its interior structure and kinematics. However, a number of the observations suffer from the contamination of second-order spectra (SOS) which will introduce some undesirable uncertainties at the red side of the spectra. In this paper, we test the effect of SOS and propose a method to correct it in the time domain spectroscopic data using the simultaneously observed comparison stars. Based on the reverberation mapping (RM) data of NGC 5548 in 2019, one of the most intensively monitored AGNs by the Lijiang 2.4 m telescope, we find that the scientific object, comparison star, and spectrophotometric standard star can jointly introduce up to ∼30% SOS for Grism 14. This irregular but smooth SOS significantly affects the flux density and profile of the emission line, while having little effect on the light curve. After applying our method to each spectrum, we find that the SOS can be corrected effectively. The deviation between corrected and intrinsic spectra is ∼2%, and the impact of SOS on time lag is very minor. This method makes it possible to obtain the Hα RM measurements from archival data provided that the spectral shape of the AGN under investigation does not have a large change.
Observation and Analysis of VLF Nocturnal Multimode Interference Phenomenon based on Waveguide Mode Theory
Authors: Yang Sai , Niu You-Tian , Wang Zhe , Zhao Xiu-Kun , Li Bei , Ding Yu-Ling , Zhao Ge-Ge , Zhang An-Qi 
Published: October 2023

Abstract
Very low frequency (VLF) signals are propagated between the ground-ionosphere. Multimode interference will cause the phase to show oscillatory changes with distance while propagating at night, leading to abnormalities in the received VLF signal. This study uses the VLF signal received in Qingdao City, Shandong Province, from the Russian Alpha navigation system to explore the multimode interference problem of VLF signal propagation. The characteristics of the effect of multimode interference phenomena on the phase are analyzed according to the variation of the phase of the VLF signal. However, the phase of VLF signals will also be affected by the X-ray and energetic particles that are released during the eruption of solar flares, therefore the two phenomena are studied in this work. It is concluded that the X-ray will not affect the phase of VLF signals at night, but the energetic particles will affect the phase change, and the influence of energetic particles should be excluded in the study of multimode interference phenomena. Using VLF signals for navigation positioning in degraded or unavailable GPS conditions is of great practical significance for VLF navigation systems as it can avoid the influence of multimode interference and improve positioning accuracy.
Two is better? combining EEG and fMRI for BCI and neurofeedback: a systematic review
Authors: Fleury Mathis , Figueiredo Patrícia , Vourvopoulos Athanasios , Lécuyer Anatole 
Published: October 2023

Abstract
Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are two commonly used non-invasive techniques for measuring brain activity in neuroscience and brain–computer interfaces (BCI). Objective. In this review, we focus on the use of EEG and fMRI in neurofeedback (NF) and discuss the challenges of combining the two modalities to improve understanding of brain activity and achieve more effective clinical outcomes. Advanced technologies have been developed to simultaneously record EEG and fMRI signals to provide a better understanding of the relationship between the two modalities. However, the complexity of brain processes and the heterogeneous nature of EEG and fMRI present challenges in extracting useful information from the combined data. Approach. We will survey existing EEG–fMRI combinations and recent studies that exploit EEG–fMRI in NF, highlighting the experimental and technical challenges. Main results. We made a classification of the different combination of EEG-fMRI for NF, we provide a review of multimodal analysis methods for EEG–fMRI features. We also survey the current state of research on EEG-fMRI in the different existing NF paradigms. Finally, we also identify some of the remaining challenges in this field. Significance. By exploring EEG-fMRI combinations in NF, we are advancing our knowledge of brain function and its applications in clinical settings. As such, this review serves as a valuable resource for researchers, clinicians, and engineers working in the field of neural engineering and rehabilitation, highlighting the promising future of EEG-fMRI-based NF.
Exploration of non-resonant divertor features on the Compact Toroidal Hybrid
Authors: Garcia K.A. , Bader A. , Frerichs H. , Hartwell G.J. , Schmitt J.C. , Allen N. , Schmitz O. 
Published: October 2023

Abstract
Non-resonant divertors (NRDs) separate the confined plasma from the surrounding plasma facing components (PFCs). The resulting striking field line intersection pattern on these PFCs is insensitive to plasma equilibrium effects. However, a complex scrape-off layer (SOL), created by chaotic magnetic topology in the plasma edge, connects the core plasma to the PFCs through varying magnetic flux tubes. The Compact Toroidal Hybrid (CTH) serves as a test-bed to study this by scanning across its inductive current. Simulations observe a significant change of the chaotic edge structure and an effective distance between the confined plasma and the instrumented wall targets. The intersection pattern is observed to be a narrow helical band, which we claim is a resilient strike line pattern. However, signatures of finger-like structures, defined as heteroclinic tangles in chaotic domains, within the plasma edge connect the island chains to this resilient pattern. The dominant connection length field lines intersecting the targets are observed via heat flux modeling with EMC3-EIRENE. At low inductive current levels, the excursion of the field lines resembles a limited plasma wall scenario. At high currents, a private flux region is created in the area where the helical strike line pattern splits into two bands. These bands are divertor legs with distinct SOL parallel particle flow channels. The results demonstrate the NRD strike line pattern resiliency within CTH, but also show the underlying chaotic edge structure determining if the configuration is diverted or limited. This work supports future design efforts for a mechanical structure for the NRD.
Study of voltage reversal of stacked sediment microbial fuel cells
Authors: Liu Xiao , Zhao Zhiwei , Jiang Helong 
Published: October 2023

Abstract
Sediment microbial fuel cell (SMFC) is a renewable energy source with a wide range of raw materials. They have a simple structure, low cost, and broad application prospects in the field of self-power supply, attracting the attention of many researchers. However, the output current of SMFC is weak and the output voltage is low, which does not meet the power supply requirements of general electronic devices. Therefore, it is necessary to connect multiple SMFCs to obtain the required voltage and current. Series operation can increase the output voltage, while parallel operation can increase the output current. However, voltage reversal occurs in series operation, which can affect the output performance of the battery. In this work, voltage reversal was studied by two SMFCs respectively connected in series and in parallel after their output voltage stabilized. External load of the series and parallel batteries were connected to 330 ohms, 680 ohms, 1000 ohms, 2000 ohms, and 380K ohms, respectively. It was found that batteries with poor performance in series battery packs experienced voltage reversal, which occurred at 330 ohms, 680 ohms, and 1000 ohms. When the resistances became 2000 ohms and 380K ohms, parallel battery packs did not experience similar phenomena. The reason for voltage reversal was provided in this article. In addition, voltage reversal occurred in the stage of low resistances, which indicating that the greater the current, the greater the possibility of voltage reversal.
A study of bottom-contact organic thin-film transistors based on source/drain tunneling structure
Authors: Ye Kang , Di Yunsong , Gan Zhixing , Liu Cihui , Xing Fangjian , Zhang Peng 
Published: October 2023

Abstract
During recent years, OLED display has become one of the important products for consuming electronics and industrial domains. For AMOLED display, thin film transistor (TFT) is necessary for driving OLED devices. As the polysilicon and amorphous silicon TFTs have become mainstreams, organic thin film transistors (OTFTs) have also been proposed and shown their advantages in low-temperature process compatible with flexible substrates. However, OTFTs applicable to drive OLED generally adopt bottom-contact configuration. The performance of bottom-contact OTFTs are often inferior relative to top-contact OTFTs, due primarily to the high contact resistance of bottom-contact OTFTs. To overcome this disadvantage, the source/drain tunneling structure is proposed in this article. This tunneling structure can not only decorate the electrode/organic semiconductor interface to obtain a good metal-semiconductor contact, but also can form a MOS configuration at source/drain contact, so as to increase the carrier concentration at the contact to further reduce contact resistance. In this paper, a typical P-type high-mobility small molecule material of Pentacene is employed as the active layer of the OTFT, while CuO film, Polystyrene (PS) film is separately selected as the tunneling layer at source/drain contact. The diverse parameters, especially field effect mobility, were analyzed by analyzing electrical characteristics of the top-contact and bottom-contact OTFTs. In addition, the contact resistances were confirmed by line transfer method. The bottom-contact OTFTs incorporating tunneling layer own a maximum hole mobility of 0.143cm2/V·s.
This suggested that the source/drain tunneling structure can indeed improve the electrical characteristics of bottom-contact OTFT, and further improvement is necessitated to achieve the high performance comparable to top-contact device.
High-order Sliding Mode Tracking Differentiator with Neural Network based Adaptive Parameter Estimation
Authors: Wang Xueyi , Jin Shanhai 
Published: October 2023

Abstract
This paper presents a new high-order sliding mode tracking differentiator with backpropagation neural network based adaptive parameter estimation (SMF-BP) to obtain accurate filtering and differentiation estimates from signals that contain noise. It is improved based on the Levant’s high-order sliding mode tracking differentiator. First, SMF-BP incorporates a sigmoid function to reduce overshoot. Second, the BP neural network is introduced to adjust the parameters adaptively to balance response speed and filtering performance. Finally, the validity of SMF-BP has been demonstrated through numerical simulation examples.