bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spread of parking difficulty in urban environments: A parking network perspective
Authors: Zhang Kangshuai , Cui Yunduan , Liu Qi , Shu Hongfeng , Peng Lei 
Published: June 2024

AbstractSpread of parking difficulty can be regarded as a special cascading failure process of urban parking systems. A comprehensive understanding of this process can be greatly helpful to build a more robust parking system. Parking network, a specified complex network, is proposed to model, simulate, and analyse the failure process of urban parking systems in this paper. This model is applied to the analysis of parking systems in an abstract city grid and the downtown area of Luohu, Shenzhen. The results demonstrate that the parking network can capture subtle variations among various parking cruising behaviours or strategies from a network perspective. To enhance the utility of the parking network, an auxiliary indicator named “Parking Difficulty Index” is introduced to help assess the failure degree of urban parking system, estimate the optimal timing for parking guidance intervention, and evaluate the effectiveness of various guidance strategies in mitigating parking difficulties.
Compact fully metallic multi‐mode waveguide antenna for cellular communications
Authors: Mokhtarani Ali , Ghattan Kashani Zahra , Navarro‐Cía Miguel 
Published: June 2024

AbstractThe needed isolation between elements for high‐performance beam steering array antennas is a challenging task especially when the distance between the antenna elements is reduced. To tackle this problem, the authors report a multi‐port multi‐mode single‐antenna with beam steering capability (±7 deg) suitable for cellular communications. The multi‐port multi‐mode characteristic of the proposed antenna enables size reduction and better taper efficiency than antenna arrays operating in the 3.3–3.7 GHz cellular band. The reported antenna exploits four Transverse Electric modes to modify the half‐power beamwidth of the radiation from 20° to 41° as required in cellular communication.
Magnetic braking below the cataclysmic variable period gap and the observed dearth of period bouncers
Authors: Sarkar Arnab , Rodriguez Antonio C. , Ginzburg Sivan , Yungelson Lev , Tout Christopher A. 
Published: June 2024

Context. Period bouncers are cataclysmic variables (CVs) that have evolved past their orbital period minimum. The strong disagreement between theory and observations of the relative fraction of period bouncers is a severe shortcoming in the understanding of CV evolution.
Aims. We test the implications of the hypothesis that magnetic braking (MB), which is suggested to be an additional angular momentum loss (AML) mechanism for CVs below the period gap (Porb ≲ 120 min), weakens around their period minimum.
Methods. We computed the evolution of CV donors below the period gap using the MESA code, assuming that the evolution of the system is driven by AML due to gravitational wave radiation (GWR) and MB. We parametrised the MB strength as AMLMB = κAMLGWR. We computed two qualitatively different sets of models, one in which κ is a constant and another in which κ depends on stellar parameters in such a way that the value of κ decreases as the CV approaches the period minimum (Porb ≈ 80 min), beyond which κ ≈ 0.
Results. We find that two crucial effects drive the latter set of models. (1) A decrease in κ as CVs approach the period minimum stalls their evolution so that they spend a long time in the observed period minimum spike (80 ≲ Porb/min ≲ 86). Here, they become difficult to distinguish from pre-bounce systems in the spike. (2) A strong decrease in the mass-transfer rate makes them virtually undetectable as they evolve further. So, the CV stalls around the period minimum and then “disappears”. This reduces the number of detectable bouncers. Physical processes, such as dynamo action, white dwarf magnetism, and dead zones, may cause such a weakening of MB at short orbital periods.
Conclusions. The weakening MB formalism provides a possible solution to the problem of the dearth of detectable period bouncers in CV observational surveys.
The backreaction of stellar wobbling on accretion discs of massive protostars
Authors: Meyer D. M.-A. , Vorobyov E. 
Published: June 2024

Context. In recent years, it has been demonstrated that massive stars see their infant circumstellar medium shaped into a large irradiated, gravitationally unstable accretion disc during their early formation phase. Such discs constitute the gas reservoir from which nascent high-mass stars gain a substantial fraction of their mass by episodic accretion of dense gaseous circumstellar clumps, simultaneously undergoing accretion-driven bursts and producing close-orbit spectroscopic companions of the young high-mass stellar object.
Aims. We aim to evaluate the effects of stellar motion caused by the disc non-axisymmetric gravitational field on the disc evolution and its spatial morphology. In particular, we analyse the disc’s propensity to gravitational instability and fragmentation and the disc’s appearance in synthetic millimetre band images pertinent to the ALMA facility.
Methods. We employed three-dimensional radiationhydrodynamical simulations of the surroundings of a young massive star in the non-inertial spherical coordinate system, adopting the highest spatial resolution to date and including the indirect star-disc gravitational potential caused by the asymmetries in the circumstellar disc. The resulting disc configurations were post-processed with the radiation transfer tool RADMC-3D and CASA software to obtain synthetic images of the disc.
Results. We confirm that the early evolution of the accretion disc is notably different when stellar wobbling is taken into account. The redistribution of angular momentum in the system makes the disc smaller and rounder, reduces the number of circumstellar gaseous clumps formed via disc gravitational fragmentation, and prevents the ejection of gaseous clumps from the disc. The synthetic predictive images at millimetre wavelengths of the accretion disc that includes stellar wobbling are in better agreement with the observations of the surroundings of massive young stellar objects, namely AFGL 4176 mml, G17.64+0.16, and G353.273, than our simulations of numerical hydrodynamics that omit this physical mechanism.
Conclusions. Our work confirms that stellar wobbling is an essential ingredient to account for in numerical simulations of accretion discs of massive protostars.
Past activity of Sgr A⋆ is unlikely to affect the local cosmic-ray spectrum up to the TeV regime
Authors: Fournier M. , Fensch J. , Commerçon B. 
Published: June 2024

Context The presence of kiloparsec-sized bubble structures on both sides of the Galactic plane suggests active phases of Sgr A⋆, the central supermassive black hole of the Milky Way in the last 1–6 Myr. We investigated the contribution of such events to the cosmic-ray (CR) flux measured in the solar neighborhood with numerical simulations.
Aims. We evaluate whether the population of high-energy charged particles emitted by the Galactic center could be sufficient to significantly impact the CR flux measured in the solar neighborhood.
Methods. We present a set of 3D magnetohydrodynamical simulations following the anisotropic propagation of CRs in a Milky Way-like Galaxy. We followed independent populations of CRs through time. We followed CRs originating from two different source types, namely supernovae and the Galactic center. To assess the evolution of the CR flux spectrum properties, we split these populations into two independent energy groups of 100 GeV and 10 TeV.
Results. We find that the anisotropic nature of CR diffusion dramatically affects the amount of CR energy received in the solar neighborhood. The typical timescale required to observe measurable changes in the CR spectrum slope is of the order 10 Myr, largely surpassing estimated ages of the Fermi bubbles in the active galactic nuclei (AGN) jet-driven scenario.
Conclusions. We conclude that a CR outburst from the Galactic center in the last few million years is unlikely have produced any observable feature in the local CR spectrum in the TeV regime within times consistent with current estimates of the age of the Fermi bubbles.
Pfannenplatzierung bei Daumensattelgelenksprothesen: Die Rolle des
Führungsdrahts
Authors: Daeschler Simeon C. , Sommer Jan , Tu Thomas Jing Zhi , Jaeger Sebastian , Knappe Kevin , Harhaus Leila , Panzram Benjamin 
Published: June 2024

Zusammenfassung
Hintergrund Die zunehmende Anwendung von Daumensattelgelenksprothesen bei
fortgeschrittener Rhizarthrose reflektiert den Erfolg der jüngsten
Prothesengenerationen durch ihre verbesserten funktionellen Ergebnisse und
geringeren Komplikationsraten. Eine präzise Ausrichtung der Prothesenpfanne
parallel zur proximalen Gelenkoberfläche des Trapeziums ist hierbei für die
Stabilität und Vermeidung von Luxationen essenziell. Dies stellt gerade für den
unerfahrenen „Beginner“ dieser Technik erfahrungsgemäß das größte Problem dar.
Trotz adäquater Positionierung des Führungsdrahtes können Fehlplatzierungen der
Pfanne auftreten, die eine intraoperativen Revision notwendig machen.
Material und Methoden Diese Studie untersucht die Abweichungen der
Pfannen- und Führungsdrahtpositionierung bei
Daumensattelgelenksprothesenimplantationen durch unerfahrene und erfahrene
Operateure mittels radiologischer Analyse an 65 Prothesen.
Ergebnisse Sowohl unerfahrene als auch erfahrene Operateure erreichten
eine präzise Führungsdrahtpositionierung mit mittleren Abweichungen von<2,2°.
Unerfahrene zeigten signifikant größere Pfannenabweichungen im dorsopalmaren und
lateralen Strahlengang (7,6±6,1° und 7,3±5,9°) im Vergleich zu erfahrenen
Operateuren (3,6±2,7° und 3,6±2,5°; p=0,012, p=0,017). Die Abweichung der Pfanne
zeigte bei unerfahrenen Operateuren eine jeweils entgegengesetzte
Richtungstendenz zum Führungsdraht (p<0,0038).
Schlussfolgerung Die Ergebnisse verdeutlichen die aktuellen
Herausforderungen bei der Pfannenpositionierung abhängig vom Erfahrungsgrad des
Chirurgen und hinterfragen die Zuverlässigkeit des aktuellen
Führungsdrahtsystems bei Prothesenimplantationen.
Analyzing single-action bias in dynamic climate change environments: insights from feedback and probability
Authors: Choudhary Gitanshu , Dutt Varun 
Published: June 2024

Abstract“Single action bias” (SAB) characterizes individuals’ inclination to undertake only one preventive measure against climate change, disregarding potentially more effective alternatives. This bias poses a significant obstacle to comprehensive responses to climate change. While dynamic climate simulators have been developed to raise awareness of climate change and encourage pro-environmental behaviors, the prevalence of SAB within these tools remains unexplored. This study introduces the “Single Action Bias-Interactive Climate Change Simulator” (SAB-ICCS) to investigate SAB’s manifestation in dynamic scenarios. Utilizing the framework of the Interactive Climate Change Simulator (ICCS), known for its efficacy in fostering pro-environmental actions, the SAB-ICCS explores how feedback, probability, and their interplay influence SAB prevalence during climate mitigation and adaptation decision-making. A total of 160 participants were randomly assigned to four conditions in the SAB-ICCS, varying feedback presence and climate change probability. Participants engaged in climate mitigation and adaptation actions, simulating the repercussions of climate change through investment choices in climate mitigation and adaptation (consisting of three insurance plans). The study’s dependent variables were the participants’ actions towards climate mitigation and adaptation. Results revealed a substantial prevalence of single action proportion (42%) compared to other action proportions. Furthermore, the total monetary investment was significantly higher when taking optimal actions than when exhibiting SAB. Moreover, a higher probability of climate change resulted in a higher prevalence of SAB (49%) than a lower probability (35%). Interestingly, feedback availability did not significantly impact SAB prevalence. Though both feedback and the probability of climate change influenced how participants exhibited SAB, and the absolute monetary investment was also significantly affected. This research enhances our comprehension of SAB within educational climate simulations, which is vital for informing climate education and policymaking. It offers insights for policymakers and educators to develop interventions addressing SAB, enhancing climate action strategies by understanding probability and feedback influences.
High-Resolution Recognition of Orbital Angular Momentum Modes in Asymmetric Bessel Beams Assisted by Deep Learning
Authors: Xu 徐 Pengfei 鹏飞 , Tong 童 Xin 鑫 , Zeng 曾 Zishuai 子帅 , Liu 刘 Shuxi 书悉 , Zhao 赵 Daomu 道木 
Published: June 2024

Abstract
Fractional orbital angular momentum (OAM) vortex beams present a promising way to increase the data throughput in optical communication systems. Nevertheless, high-precision recognition of fractional OAM with different propagation distances remains a significant challenge. We develop a convolutional neural network (CNN) method to realize high-resolution recognition of OAM modalities, leveraging asymmetric Bessel beams imbued with fractional OAM. Experimental results prove that our method achieves a recognition accuracy exceeding 94.3% for OAM modes, with an interval of 0.05, and maintains a high recognition accuracy above 92% across varying propagation distances. The findings of our research will be poised to significantly contribute to the deployment of fractional OAM beams within the domain of optical communications.
Do black holes remember what they are made of?
Authors: Bandyopadhyay Harshraj , Radice David , Prakash Aviral , Dhani Arnab , Logoteta Domenico , Perego Albino , Kashyap Rahul 
Published: June 2024

Abstract
We study the ringdown signal of black holes formed in prompt-collapse binary neutron star mergers. We analyze data from 47 numerical relativity simulations. We show that the

(
ℓ
=
2
,
m
=
2
)

and

(
ℓ
=
2
,
m
=
1
)

multipoles of the gravitational wave signal are well fitted by decaying damped exponentials, as predicted by black-hole perturbation theory. We show that the ratio of the amplitude in the two modes depends on the progenitor binary mass ratio q and reduced tidal parameter

Λ
~

. Unfortunately, the numerical uncertainty in our data is too large to fully quantify this dependency. If confirmed, these results will enable novel tests of general relativity in the presence of matter with next-generation gravitational-wave observatories.
Superspace worldline formalism approach to quantum gravity: dimensional reduction and holography
Authors: Roux J-B 
Published: June 2024

Abstract
Using the ADM formalism, we demonstrate that the Hamiltonian formulation of Quantum Gravity is exactly in the form of a worldline formalism in the superspace. We then show that the Keldysh partition function reduces to the partition function of Euclidean 3D gravity. After discussing the meaning of the time parameter, we show that in the gauge fields formalism, our Keldysh partition function reduces to a generating functional of a 2D conformal field theory. This functional exhibits a minimal time-lapse proportional to the square root of the cosmological constant. From the viewpoint of the Chern–Simons/Liouville correspondence, we calculate the exchange of virtual gravitons between two massive probes from the cosmological boundary.
Application and prospect of 2D materials in photodetectors
Authors: Liu Xiangzhi , Yang Xiaozhan , Tang Qian , Lv Yue , Zhang Gang , Feng Wenlin 
Published: June 2024

Abstract
With the continuous development of modern information technology, higher requirements are put forward for photoelectric detection technology. Two-dimensional (2D) materials have excellent optical, electrical and mechanical properties, and easy to process and integrate, which is expected to make up for the shortcomings of traditional devices. 2D materials, which cover material systems ranging from metals, semiconductors to insulators, are one of the main material choices for new photodetectors. In recent years, great progress has been made in the preparation of 2D photoelectricity device applications. In this paper, the latest research progress of 2D materials photodetectors is summarized, including the unique physical and chemical properties of 2D materials and the key parameters of photodetector. The research progress of photodetectors based on graphene, black phosphorus and transition metal dichalcogenides is highlighted. Finally, we give an outlook on the challenges of realizing high-performance photodetectors.
Quantifying the thermal effect and methyl radical production in nanosecond repetitively pulsed glow discharges applied to a methane-air flame
Authors: M Alkhalifa Ammar , Di Sabatino Francesco , A Steinmetz Scott , Pfaff Sebastian , Huang Erxiong , H Frank Jonathan , J Kliewer Christopher , A Lacoste Deanna 
Published: June 2024

Abstract
In this work, we investigated non-equilibrium plasma produced by nanosecond repetitively pulsed glow discharges applied across a lean premixed methane-air flame. The flame is stationary, axisymmetric, and laminar. The discharges are applied on the symmetry axis crossing the reactant gases, flame front, and product gases, allowing phase-locked averaged measurements and comparisons with axisymmetric numerical simulations. The thermal effect and methyl radical production are quantified in the discharge in the reactant gas region. One-dimensional, two-beam, hybrid, femtosecond-picosecond, coherent anti-Stokes Raman scattering is used to acquire spatial and temporal profiles of temperature and oxygen-to-nitrogen concentration ratio. Photo-fragmentation laser-induced fluorescence is used to acquire quantitative two-dimensional profiles of methyl radicals in the discharge providing the first quantitative imaging of methyl produced ahead of a flame by plasma-induced methane dissociation. The spatial profiles of temperature and oxygen-to-nitrogen concentration ratio are in steady state, indicating that individual discharges have an insignificant heating effect. Upper and lower bounds of the produced mole fraction of methyl radicals in the plasma are obtained due to uncertainties in the collisional quenching rates of excited state methylidyne radicals in the plasma. The discharges produce a maximum of 600–1100 ppm of methyl radicals upstream of the flame front within 25 ns. This amount is similar to the predicted methyl mole fraction for the flame without plasma and thus represents a significant chemical perturbation to the reactants upstream of the flame front. The produced methyl follows an exponential decay in the first microsecond after the discharge with a decay constant of 8 µs close to the flame, and 0.8 µs further from the flame. The decay then deviates from the exponential curve and the methyl persists for tens of microseconds. The results suggest that for the tested configuration, the thermal effect of individual discharges through fast gas heating is negligible, while active chemical species are produced in large quantities in the reactant gases, upstream of the flame front.
Lagrangian particle tracking in the atmospheric surface layer
Authors: Conlin Nicholas , Even Hannah , Wei Nathaniel J , Balantrapu N Agastya , Hultmark Marcus 
Published: June 2024

Abstract
Field measurements in the atmospheric surface layer (ASL) are key to understanding turbulent exchanges in the atmosphere, such as fluxes of mass, water vapor, and momentum. However, current field measurement techniques are limited to single-point time series or large-scale flow field scans. Extending image-based laboratory measurement techniques to field-relevant scales is a promising route to more detailed atmospheric flow measurements, but this requires significant increases in the attainable measurement volume while keeping the spatiotemporal resolution high. Here, we present an adaptable particle tracking system using helium-filled soap bubbles, mirrorless cameras, and high-power LEDs enabling volumetric ASL field measurements. We conduct analyses pertinent to image-based field measurement systems and develop general guidelines for their design. We validate the particle tracking system in a field experiment. Single-point Eulerian velocity statistics are presented and compared to data from concurrently operated sonic anemometers. Lagrangian displacement statistics are also presented with a comparison to Taylor’s theory of dispersion. The system improves the state-of-the-art in field measurements in the lower atmosphere and enables unprecedented insights into flow in the ASL.
Research on internal leakage detection of the ball valves based on stacking ensemble learning
Authors: Shi Mingjiang , Deng Liyuan , Yang Bohan , Qin Liansheng , Gu Li 
Published: June 2024

Abstract
Natural gas is an important clean energy source that is mainly transported through pipelines. The ball valve is a crucial piece of control equipment for the pipeline transportation system for natural gas, and the failure of internal leakage of the ball valve will seriously affect the natural gas transmission and increase the risk of sudden safety accidents. In response to the problems of the limitations of a single machine learning model in the traditional ball valve internal leakage rate prediction methods and failure to qualitatively analyze unilateral and bilateral internal leakage recognition of ball valve, a study of ball valve internal leakage detection based on Stacking ensemble learning is proposed. A total of 15 time and frequency domain feature parameters were obtained by feature extraction of 125 and 96 sets of raw acoustic emission signals from the ball valve; the parameters of a single machine learning model were adjusted by Bayesian optimization grid search. An internal leakage rate prediction model and an internal leakage recognition model are constructed, and the proposed model is compared and analyzed with a single model through a field ball valve internal leakage test. The results indicate that the Stacking ensemble learning model outperforms each single machine learning model in terms of SMAPE (17.2583), RMSE (1.1009), and MAE (0.9375) for internal leakage rate prediction. The Stacking ensemble learning model outperformed the single machine learning model in terms of accuracy (1.0000), recall (1.0000), precision (1.0000), FAR(0), and F1-score (1.0000) for internal leakage recognition. Stacking ensemble learning significantly enhances the model’s ability to detect internal ball valve leaks.