bluuebunny/crossref_metadata_2025_split huggingface dataset:
Challenging interferometric imaging: Machine learning-based source localization from uv-plane observations
Authors: Taran O. , Bait O. , Dessauges-Zavadsky M. , Holotyak T. , Schaerer D. , Voloshynovskiy S. 
Published: May 2023

Context. Rising interest in radio astronomy and upcoming projects in the field is expected to produce petabytes of data per day, questioning the applicability of traditional radio astronomy data analysis approaches under the new large-scale conditions. This requires new, intelligent, fast, and efficient methods that potentially involve less input from the domain expert.
Aims. In our work, we examine, for the first time, the possibility of fast and efficient source localization directly from the uv-observations, omitting the recovering of the dirty or clean images.
Methods. We propose a deep neural network-based framework that takes as its input a low-dimensional vector of sampled uv-data and outputs source positions on the sky. We investigated a representation of the complex-valued input uv-data via the real and imaginary and the magnitude and phase components. We provided a comparison of the efficiency of the proposed framework with the traditional source localization pipeline based on the state-of-the-art Python Blob Detection and Source Finder (PyBDSF) method. The investigation was performed on a data set of 9164 sky models simulated using the Common Astronomy Software Applications (CASA) tool for the Atacama Large Millimeter Array (ALMA) Cycle 5.3 antenna configuration.
Results. We investigated two scenarios: (i) noise-free as an ideal case and (ii) sky simulations including noise representative of typical extra-galactic millimeter observations. In the noise-free case, the proposed localization framework demonstrates the same high performance as the state-of-the-art PyBDSF method. For noisy data, however, our new method demonstrates significantly better performance, achieving a completeness level that is three times higher for sources with uniform signal-to-noise ratios (S/N) between 1 and 10, and a high increase in completeness in the low S/N regime. Furthermore, the execution time of the proposed framework is significantly reduced (by factors ~30) as compared to traditional methods that include image reconstructions from the uv-plane and subsequent source detections.
Conclusions. The proposed framework for obtaining fast and efficient source localization directly from uv-plane observations shows very encouraging results, which could open new horizons for interferometric imaging with existing and future facilities.
Unterschiedlicher Verlauf von Immunreaktionen und Endothelzellverlust nach perforierender Low-Risk-Keratoplastik und Descemet Membrane Endothelial Keratoplasty bei Fuchs-Endotheldystrophie
Authors: Jablonski Laura Katharina , Zemova Elena , Daas Loay , Munteanu Cristian , Seitz Berthold 
Published: May 2023

Zusammenfassung
Hintergrund Ziel der vorliegenden Studie ist es, die Häufigkeit von Immunreaktionen und den Endothelzellverlust nach perforierender Keratoplastik (PKP) vs. Descemet Membrane Endothelial Keratoplasty (DMEK) bei Patienten mit Fuchs-Endotheldystrophie (FED) gegenüberzustellen.
Patienten und Methoden In der vorliegenden retrospektiven Studie wurden insgesamt 962 Operationen (OPs; 225 Excimer-Laser-PKP und 727 DMEK) von 700 Patienten, die zwischen dem 28.06.2007 und dem 27.08.2020 in der Universitäts-Augenklinik des Saarlandes durchgeführt wurden, statistisch ausgewertet. Zum einen wurde die Prävalenz und der zeitliche Verlauf der aufgetretenen Immunreaktionen mittels Kaplan-Meier-Verfahren sowie die Auswirkungen der Immunreaktionen auf die Endothelzellen und die Hornhautdicke analysiert. Zum anderen wurden Endothelzelldichte, Pleomorphismus und Polymegalismus der Endothelzellen für die Zeitpunkte U1 = präoperativ, U2 = 6 Wochen postoperativ, U3 = 6 – 9 Monate postoperativ, U4 = 1 – 2 Jahre postoperativ und U5 = 5 Jahre postoperativ ausgewertet. Weiter erfolgte dazu jeweils eine statistische Testung auf Unterschiede zwischen den beiden OP-Arten sowie im longitudinalen Verlauf.
Ergebnisse Insgesamt traten im beobachteten Zeitraum 54 Immunreaktionen auf, wobei die Wahrscheinlichkeit für eine solche bei der PKP mit 8,9% signifikant größer war als in der DMEK-Gruppe mit 4,5% (p = 0,011). Der Vergleich der beiden Kaplan-Meier-Kurven ergab im Log-Rank-Test ebenfalls einen signifikanten Unterschied zwischen den beiden OP-Techniken (p = 0,012). Der Endothelzellverlust durch die Immunreaktion war nur bei der PKP signifikant (p = 0,003). Auf alle OPs bezogen sank die Endothelzelldichte bei beiden OP-Techniken signifikant mit der Zeit (jeweils p < 0,0001), bei der DMEK stärker als bei der PKP (p < 0,0001). Außerdem war die Zelldichte bei der PKP insgesamt signifikant höher als bei der DMEK (p < 0,0001). Der Polymegalismus sank nur bei der DMEK-Gruppe signifikant (p < 0,0001). Der Pleomorphismus war im Durchschnitt bei der DMEK signifikant höher als bei der PKP (p < 0,0001).
Schlussfolgerung Die Prognose der DMEK bei Patienten mit FED scheint nach Immunreaktionen günstiger zu sein als die der PKP, da nicht nur seltener Immunreaktionen auftraten, sondern diese auch milder verliefen. Die Endothelzelldichte war allerdings in der PKP-Gruppe während des gesamten Follow-ups signifikant höher.
Test-retest reliability of suppression head impulse paradigm (SHIMP) in healthy individuals
Authors: Nagarajan Aishwarya , Ghimire Shashish , Elizabeth Varsha Sam , Sinha Sujeet Kumar 
Published: May 2023

Objective:
The Video Head Impulse Test (vHIT) is an efficient tool to assess VOR. vHIT has been widely used to detect the presence of peripheral vestibular impairment. vHIT uses two paradigms: HIMP (Head Impulse Paradigm) and SHIMP (Suppression Head Impulse Paradigm). The current study aimed to determine the test-retest reliability of the Suppression Head Impulse Paradigm (SHIMP) in normal individuals.

Method:
Twenty-eight healthy young individuals aged 18–30 years with normal hearing sensitivity and normal middle ear function participated in the study. The participants also had no signs and symptoms or history of vestibular problems. The SHIMP paradigm was performed twice (sessions I and II) with an inter-session interval of twodays.

Results:
Paired sample t-test showed no significant difference in VOR gain and asymmetry values between sessions I and II. Cronbach’s alpha also showed a good test-retest reliability for VOR gain and asymmetry values. Kappa Coefficient showed good reliability for the presence of anticompensatory saccades.

Conclusion:
VOR Gain functions and the presence of anti-compensatory saccades are highly reliable parameters when tested with SHIMP. Thus, any deviance in the gain parameters indicates a vestibular impairment rather than variability in the SHIMP test paradigm.
A possible interpretation of Λ baryon spectrum with pentaquark components
Authors: Xu Kai , Kaewsnod Attaphon , Zhao Zheng , Htun Thiri Yadanar , Limphirat Ayut , Yan Yupeng 
Published: May 2023

Abstract
The Λ baryon spectrum is studied within the SU(3) flavor symmetry in a constituent quark model. We found that it is rather difficult to accommodate some negative-parity Λ resonances as single q
2
s (q = u, d quarks) states in the conventional three-quark picture. The ground

q

3

s

q

¯

pentaquark mass spectrum is evaluated and a possible interpretation is proposed in the work: the observed Λ(1405)1/2−, Λ(1670)1/2− and Λ(1800)1/2− are three-state mixtures of two p-wave q
2
s states and one ground

q

3

s

q

¯

pentaquark state, so are the Λ(1520)3/2−, Λ(1690)3/2− and Λ(2050)3/2− resonances. Both Λ(1405)1/2− and Λ(1520)3/2− contain considerable

q

3

s

q

¯

pentaquark components.
Synchronous fault feature extraction for rolling bearings in a generalized demodulation framework
Authors: Liu Kangning , Shi Juanjuan , Shen Changqing , Huang Weiguo , Zhu Zhongkui 
Published: May 2023

Abstract
Generalized demodulation (GD) has the potential to process non-stationary vibration signals since it can demodulate a signal with a curved time–frequency (TF) ridge into a signal, with a TF ridge parallel to a time axis with an improved time-frequency representation (TFR) energy concentration level. However, current GD methods require iteration operations and cannot simultaneously deal with vibrations from multiple components of rolling bearings. This paper proposes a method based on the GD framework, which can simultaneously demodulate multiple components of interest using the Hadamard product between matrices. A synchronous extractor is also constructed to post-process TFRs of generalized demodulated signals to further improve the TF aggregation. Unlike the conventional synchronous extraction transform, the synchronous extractor in this paper can be directly applied to TF ridges parallel to the time axis without the estimation of instantaneous frequencies (IFs). Then, the post-processed TF ridges are backward demodulated to restore the actual IF. The proposed synchronous fault feature extraction method in the GD framework also allows for the signal reconstruction. Both simulated and experimental signals are applied to validate the effectiveness of the proposed method for rolling bearing fault diagnosis.
Third-order nonlinear Hall effect in two-dimensional Dirac systems
Authors: Gao Yang , Zhang Zhi-Qiang , Ding Kai-He 
Published: May 2023

Abstract
We theoretically investigate the third-order nonlinear Hall effect by employing the quantum kinetic equation and present an analytic formula for the third-order harmonic conductivity, where the intraband and the mixed inter-band contributions caused by the external electric field as well as the multiphoton process dressed Berry curvature are unveiled. These results are applied in a two-dimensional Dirac system. We find that the third-order harmonic conductivity exhibits a crossover from the negative to positive value due to the intraband transition of the electrons in the low-frequency region, whereas a kink or dip structure due to the multiphoton process between the conduction and valence bands in the high-frequency region. In experiment, these features can be identified by detecting the transverse current. Our work deepens the understanding of the multiphoton process in the nonlinear transport of topological materials and enlightens a possible way to its characterization in experiments.
Prospects for constraining interacting dark energy models from gravitational wave and gamma ray burst joint observation
Authors: Hou Wan-Ting , Qi Jing-Zhao , Han Tao , Zhang Jing-Fei , Cao Shuo , Zhang Xin 
Published: May 2023

Abstract
With the measurement of the electromagnetic (EM) counterpart, a gravitational wave (GW) event could be treated as a standard siren. As a novel cosmological probe, GW standard sirens will bring significant implications for cosmology. In this paper, by considering the coincident detections of GW and associated γ ray burst (GRB), we find that only about 400 GW bright standard sirens from binary neutron star mergers could be detected in a 10-year observation of the Einstein Telescope and the THESEUS satellite mission. Based on this mock sample, we investigate the implications of GW standard sirens on the interaction between dark energy and dark matter. In our analysis, four viable interacting dark energy (IDE) models, with interaction forms Q = 3βHρ
de and Q = Q = 3βHρ
c, are considered. Compared with the traditional EM observational data such as CMB, BAO, and SN Ia, the combination of both GW and EM observations could effectively break the degeneracies between different cosmological parameters and provide more stringent cosmological fits. We find that the GW data could play a more important role for determining the interaction in the models with Q = 3βHρ
c, compared with the models with Q = 3βHρ
de. We also show that constraining IDE models with mock GW data based on different fiducial H
0 values yield different results, indicating that accurate determination of H
0 is significant for exploring the interaction between dark energy and dark matter.
Processing composite materials with lasers
Authors: Teirumnieka Ē , Pīgožnis K , Blumberga D , Teirumnieks E , Lazov L 
Published: May 2023

Abstract
Composite materials, consisting of fibers and binders of natural and artificial origin, are increasingly used in various fields of industry. Processing of the obtained materials into finished forms is often difficult and expensive. Treatment of composite materials, such as milling, cutting, or grinding, is currently dominant.
At present, lasers are increasingly used in production processes. It should be noted that modern industrial production is unthinkable without the use of laser equipment. However, when using lasers, initial adjustment of their laser parameters is required for optimal material processing. When considering different lasers and materials to be processed, the setting parameters are different and the obtained processing quality is varied.
In the research, samples of composite materials have been made, consisting of epoxy resin as a binder and hemp, flax, and carbon fibers as reinforcing materials. The obtained composite materials have been studied with fiber laser for their processing quality.
Polarization properties of two-dimensional polarization holographic gratings inscribed in azopolymer thin films
Authors: Mateev G , Nedelchev L , Nazarova D , Nikolova L , Ivanov B , Strijkova V , Stoykova E 
Published: May 2023

Abstract
Azopolymers are efficient photoanisotropic materials and for this reason are commonly used for inscription of polarization-selective diffraction gratings by polarization holography. More often however, the characteristics of one-dimensional (1D) gratings are studied. Here, we present real time diffraction efficiency kinetics and polarization properties of two-dimensional (2D) polarization holographic gratings, each of them obtained by overlapping two perpendicular 1D gratings. The gratings are consecutively inscribed using as recording medium the azopolymer poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt], or PAZO. To record the gratings, He-Cd laser (λ = 442 nm) was used with left and right circular polarizations (LCP and RCP) of the recording beams. Our results show that the volume polarization grating has lower influence on the polarization properties of the 2D grating than the surface relief scalar grating.
Case study of biomass-burning aerosol events over Sofia, Bulgaria, based on AERONET sun photometer data
Authors: Evgenieva Ts , Gurdev L , Toncheva E , Dreischuh T 
Published: May 2023

Abstract
In the present work, the peculiarities were analyzed of aerosol events over Sofia, Bulgaria, characterized by a daily-mean aerosol optical depth (AOD) exceeding 0.3 and Ångström exponent (AE) above unity. Such aerosol situations arise most frequently in summer and early autumn, and sometimes in late autumn and winter. The analysis was based on AERONET sun photometer data and showed that the corresponding aerosol ensembles consisted mainly of fine-fraction biomass-burning (BB) smoke particles due to summer wildfires or domestic heating in winter, with a high sphericity factor (SF) that reached unity and a low linear particle depolarization ratio (LDR) of the order of thousandths. In the cases of aged BB smoke particles, the values of AE decrease without essential changes in SF and LDR. The presence or the periodic appearance of desert dust and/or marine aerosols during the day will also lead to a lower AE, accompanied however by a decreasing SF and an increasing LDR.
Optical properties of 3D printed orthodontic retainers
Authors: Uzunov T , Yordanova-Ignatova T , Grozdanova-Uzunova R , Stoyanova N , Stoev Y , Apostolov N , Taneva I , Bogdanov V 
Published: May 2023

Abstract
The orthodontic retainers, used after orthodontic treatment are mainly produced by thermoforming. Studies and knowledge regarding directly printed orthodontic retainers and their optical properties are limited. The optical properties were tested using a source of monochromatic light and a spectrometer, which measures the intensity of the light passing through the specimens at different wavelengths. The best optical properties are seen with thermoformed specimens, whereas with 3D printed specimens polishing diminished the intensity of light passing through. The transparency of thermoformed materials is superior to that of 3D printed ones. Polishing the materials reduced their optical properties. Despite the fact that less light is transmitted through the 3D printed specimens, the materials offer clinically acceptable and satisfying optical properties.
Nonparaxial solitons in air
Authors: Dakova A , Kasapeteva Z , Dakova D , Kovachev L 
Published: May 2023

Abstract
In the present work the soliton regime of propagation in air of ultra-short long-wavelength infrared laser pulses is investigated. The dispersion of atmospheric air in mid-infrared and long-wavelength infrared shows anomalous group velocity dispersion regions for wavelengths in the ranges of 3.5 to 4.2μm and 9.3 to 13.5μm. In these spectral regions the atmospheric air is transparent. From other hand, the nonparaxiality leads to waveguiding regime of propagation for femtosecond pulses with shape of light disks (the transverse size is much bigger than the longitudinal one). It allows reducing this 3D + 1 task to 1D + 1 problem in the same manner as in optical fibers. The combination between anomalous group velocity dispersion and atmospheric nonlinearity is a base for the observation of optical solitons in the air transparency regions for the indicated wavelengths. The main equation in our research is the 1D + 1 nonlinear nonparaxial amplitude equation, written in Galilean and Laboratory coordinate systems. New analytical solution in the form of bright soliton is found. The critical power, needed for the observation of these solitons is of two orders of magnitudes less than the critical one for self-focusing. That is why there are no conditions for ionization of the media.
Effect of carbon content on resistance to cavitation erosion of Cr-C coatings deposited by Arc PVD method
Authors: Safonov V , Zykova A , Steller J , Tolmachova G , Donkov N 
Published: May 2023

AbstractThe aim of the study is a comparative analysis of effect of the carbon content in the range from 2 to 25 at.% on the resistance to cavitation erosion of Cr-C coated samples by means of the rotating disk method. The effect of carbon concentration in the range from 2 to 25 at % on the structure, properties and cavitation resistance of Cr-C vacuum-arc coatings deposited in argon with toluene at a pressure of 0.08 to 0.23 Pa on 12Cr18Ni10Ti stainless steel samples has been studied. It has been established that the application of coatings leads to a decrease in the rate of cavitation erosion of steel from 4 to 6 times. Chromium coatings with a two-phase structure containing carbide Cp7C3show maximum durability.
Low temperature electrical transport in thin carbon films deposited on SiO2/Si substrates by pulsed laser deposition
Authors: Valcheva E , Kirilov K , Dikovska A , Milenov T 
Published: May 2023

Abstract
In this paper electrical transport studies are performed on thin carbon films deposited on SiO2/Si substrates by pulsed laser deposition (PLD) applying laser ablation of micro-crystalline graphite target. Experiments were carried out on 320 - 420 nm thick SiO2 on Si substrates as well as on hydrogenated diamond-like carbon (DLC) films deposited on SiO2/Si. Structural studies by means of XPS, SEM and Raman spectroscopy revealed that the films can be characterized as nano-sized carbon phases possessing different phase composition (i.e. the ratio sp3/sp2 hybridized carbon, etc.). The electrical conductivity/resistivity of the films was measured in the temperature range 10 K < T < 300 K. Four-contact Van der Pauw method as well as two contact schemes have been applied. Some films have low room temperature resistivity in the range ρ = (0.1–1.5)×10-3 Ω.·m and consist predominantly of sp2 hybridized carbon with Raman spectra, which resemble that of nano-sized graphene depending on the deposition conditions and substrates used. The thinnest only 0.5 nm layer deposited directly on SiO2 exhibits relatively low specific resistance (~10-3 Ω. m), which can be taken as an indication of good deposition conditions of graphene-like layers. The current flow mechanism was explored at temperatures from 300 K down to 10K. The temperature dependence reveals non-metallic behavior - the conductivity decreases at decreasing temperature as opposed to typical metal behaviour. A model of variable range hopping (VRH) mechanism is applied to explain the low temperature conductivity drawn from transport in nanocrystalline disordered systems.
Surface structuring of β-TCP and transition to α-TCP induced by femtosecond laser processing
Authors: Aceti D M , Filipov E , Sotelo L , Fontanot T , Christiansen S , Lasgorceix M , Leriche A , Buchvarov I , Daskalova A 
Published: May 2023

Abstract
Tricalcium phosphate (Ca3(PO4)2, TCP), is one of the most studied and used as material for bioresorbable implants. The β phase has a slower dissolution dynamic and ensures mechanical support for a longer time in biological environment, while a faster release of ions characterize the α phase that trigger a stronger biological response. In this work a femtosecond laser system was used to process β-TCP pellets surface. The femtosecond laser processing results in surface morphology modification, by turning the flat mirror polished surface into a rough and opaque one. The morphological and phisycochemical characteristics of material surface were studied by means of SEM, AFM, Raman, XRD and contact angle measurement. The processed surface showed the formation of micro and nano roughness alongside, furthermore a partial phase transformation from β-TCP to α-TCP was detected. A significant improvement in surface wettability for three different liquids (i.e.water, ethylene glycol and diiodo-methane) is reported. This implies an increase in surface free energy as well. The combination of α and β phase, together with the increased roughness obtained by laser processing, could positively affect the cell adhesion and metabolic activity.
Decomposition of Carbon Emission Influencing Factors and Peak Prediction in Ningxia Region
Authors: Yan Zhenhua , Li Yongliang , Luo Hairong , Zhang Shuang , Zhu Dongge 
Published: May 2023

Abstract
To meet the demand for carbon emission prediction, it is necessary to master the measurement criteria and influencing factors of carbon emission and improve the accuracy of prediction results in the form of a combined application of multiple algorithmic models. This paper proposes a carbon emission impact factor decomposition model based on LMDI and a carbon emission prediction model based on the EEMD-BSO-GPR model. The study of carbon emission forecasting within the study region allows the study of the stage in which carbon emissions are located, the relationship between emissions and influencing factors such as industrial structure, affluence, energy structure, technology level, degree of openness to the outside world, and population size. The combined forecasting model can also meet the demand for carbon emission forecasting in the region with higher forecasting accuracy.
Functional Positioning and Configuration of Wind Energy Storage in the Power System
Authors: Du Yiyue 
Published: May 2023

Abstract
Wind power as a renewable energy source has both strong fluctuations in output power affecting the power balance in real-time operation of the system. In power systems with high wind power penetration, energy storage devices are used to dissipate wind energy and achieve optimal allocation of resources for generating units and storage devices to meet economic requirements. In this paper, we mainly use horizontal planning and vertical planning to calculate the total cost of power generation and the optimal wind power access to optimize the output quota of each unit.