bluuebunny/crossref_metadata_2025_split huggingface dataset:
REDUCING THE DIMENSION OF DATA IN MULTICHANNEL SPATIAL-TEMPORAL INFORMATION PROCESSING SYSTEMS
Authors: Шарамет А.В. 
Published: March 2023

раскрыты основные особенности применения метода главных компонент для снижения размерности обрабатываемой информации. Особенностью данного метода является четырехэтапная обработка данных, что позволяет его реализовать на базе многопоточных вычислительных платформ. Показано, что на первом этапе осуществляется центрирование данных, на втором - осуществляется поиск главного направления с последующим поиском его максимума на третьем этапе и отысканием остальных векторов на четвертом. Данные этапы могут выполняться параллельно и обособленно. В качестве объекта исследования рассматривалась фазированная антенная решетка в составе обзорной радиолокационной станции. Необходимость снижения размерности вызвана тем, что в результате обзора воздушного пространства о каждом воздушном объекте в самом упрощенном случае формируется информация о его азимуте, дальности и высоте. Особенностью решаемой задачи является то, что такая информация об одном и том же объекте формируется в нескольких информационных каналах. По результатам пространственно-временной обработки она вся отображается на плоскости в реальном масштабе времени. Обработка экспериментально полученных данных позволила сформулировать ограничения на применение метода главных компонент для решения данной задачи. Отмечено, что представленные результаты позволяют рассматривать данный метод в качестве основы нового направления развития систем распознавания воздушных объектов
the article reveals the main features of the application of the principal component method to reduce the dimensionality of the processed information. A feature of this method is four-stage data processing, which allows it to be implemented on the basis of multithreaded computing platforms. It is shown that data centering is carried out at the first stage, the main direction is searched at the second stage, followed by the search for its maximum at the third stage and the search for the remaining vectors at the fourth. These steps can be performed in parallel and separately. The phased array antenna as part of the survey radar station was considered as the object of the study. The need to reduce the dimension is caused by the fact that as a result of an overview of the airspace, information about its azimuth, range and altitude is formed about each aerial object in the most simplified case. The peculiarity of the problem being solved is that such information about the same object is generated in several information channels. According to the results of space-time processing, it is all displayed on the plane in real time. Processing of the experimentally obtained data allowed us to formulate restrictions on the use of the principal component method for solving this problem. It is noted that the presented results allow us to consider this method as the basis of a new direction of development of air object recognition systems
Bleach-Associated Uveitis: A Case Report
Authors: Markov Gueorgui , Yani Zdravkov  , Alexander Oscar  
Published: March 2023

Introduction: Chemical ocular injuries represent ophthalmologic emergencies with potentially blinding complications. Burns with alkalis tend to be more serious due to deeper tissue penetration as a result of colliquative necrosis. Uveitis is usually observed in higher grades of burns with significant alterations in the anterior segment of the eye. This study aimed to report a case of late-onset unilateral uveitis following a mild alkali burns with sodium hypochlorite (bleach).
Case presentation: A 64-year-old Caucasian woman reported that 3 weeks ago, she had an accident with bleach coming in contact with both eyes. At that time, she had emergency ocular irrigation with saline to both eyes, and she had also used artificial tears for about a week. Besides bilateral conjunctival hyperaemia and punctate corneal epithelial erosions, no other complications had been noted. Her symptoms had subsided in several days. Upon presentation to the clinic, reduced best-corrected visual acuity was observed in both eyes to 20/30, which was attributed to age-related cataracts, normal intraocular pressure, normal conjunctiva in both eyes, the clear cornea in the right eye (OD) and several white, round, middle-sized granulomatous keratic precipitates in the left eye (OS), without epithelial and stromal alterations. The anterior chamber of OS demonstrated a 0.5+ cellular reaction. The remaining ocular status was normal.
Conclusion: Based on the history of chemical ocular injury, the lack of systemic diseases and the mild form of ocular inflammation, no additional diagnostic tests were offered. The patient was started on topical dexamethasone phosphate for 1 month with an initial dose of one drop four times daily, which led to remission.
The Implementation of Outdoor Learning Strategy Focusing on Outdoor Project to Enhance Students' Ability in Writing Descriptive Text
Authors: Piala Ratna Andina , Miolo Sartin T , Mohammad Titien Fatmawaty 
Published: March 2023

ABSTRACT
Writing is the process of expressing and developing ideas in written form. Students face some difficulties in writing descriptive text, to solve this problem the researcher tried to enhance students writing ability in descriptive text by using Outdoor Learning Strategy. Outdoor learning strategy is a strategy that use natural or environment as a place to learn and it purpose to help students can understand the material. Therefore, this study aimed to know the students improvement after got treatment of outdoor learning strategy. This research used a descriptive quantitative method, with pre – experimental design with the type one group pre – test post – test design. Population of this study is all students of class X IPA SMA Negeri 1 Suwawa and sample of this research were the students class X IPA 3. The data were collected by doing test and scoring with rubric. This research were analyzing by using t test. The result of this research shows that the mean score of pre – test is 6.84 and post – test is 14.4. Moreover, the result of hypothesis verification, it is found that T count = 74.8 at the level of significance (a = 0.05) and degree of freedom (df) = 25 – 1= 24. Then, it is found that T table= 2.064. It can be concluded that Outdoor Learning strategy can enhance students ability in writing descriptive text, because based on the criteria above shows that t count is more than t table 74.8 ≥ 2.064. Thus, it can be concluded that Outdoor Learning strategy can enhance students’ ability in writing descriptive text.
Keywords: writing, descriptive text, outdoor learning strategy
Ground-based Optical Transmission Spectroscopy of the Nearby Terrestrial Exoplanet LTT 1445Ab
Authors: Diamond-Lowe Hannah , Mendonça João M. , Charbonneau David , Buchhave Lars A. 
Published: March 2023

Abstract
Nearby M-dwarf systems currently offer the most favorable opportunities for spectroscopic investigations of terrestrial exoplanet atmospheres. The LTT 1445 system is a hierarchical triple of M dwarfs with two known planets orbiting the primary star, LTT 1445A. We observe four transits of the terrestrial world LTT 1445Ab (R = 1.3 R
⊕, M = 2.9 M
⊕) at low resolution with Magellan II/LDSS3C. We use the combined flux of the LTT 1445BC pair as a comparison star, marking the first time that an M dwarf is used to remove telluric variability from time-series observations of another M dwarf. We find Hα in emission from both LTT 1445B and C, as well as a flare in one of the data sets from LTT 1445C. These contaminated data are removed from the analysis. We construct a broadband transit light curve of LTT 1445Ab from 620 to 1020 nm. Binned to 3 minute time bins, we achieve an rms of 49 ppm for the combined broadband light curve. We construct a transmission spectrum with 20 spectrophotometric bins each spanning 20 nm and compare it to models of clear, 1× solar composition atmospheres. We rule out this atmospheric case with a surface pressure of 10 bars to 3.2σ confidence, and with a surface pressure of 1 bar to 3.1σ confidence. Upcoming secondary eclipse observations of LTT 1445Ab with the James Webb Space Telescope will further probe the cases of a high-mean-molecular-weight atmosphere, a hazy or cloudy atmosphere, or no atmosphere at all on this terrestrial world.
Applying the Metallicity-dependent Binary Fraction to Double White Dwarf Formation: Implications for LISA
Authors: Thiele Sarah , Breivik Katelyn , Sanderson Robyn E. , Luger Rodrigo 
Published: March 2023

Abstract
Short-period double white dwarf (DWD) binaries will be the most prolific source of gravitational waves (GWs) for the Laser Interferometer Space Antenna (LISA). DWDs with GW frequencies below ∼1 mHz will be the dominant contributor to a stochastic foreground caused by overlapping GW signals. Population modeling of Galactic DWDs typically assumes a binary fraction of 50% and a log-uniform zero-age main sequence (ZAMS) orbital period distribution. However, recent observations have shown that the binary fraction of close, solar-type stars exhibits a strong anticorrelation with metallicity that modulates the ZAMS orbital period distribution below 104 days. In this study, we perform the first simulation of the Galactic DWD population observable by LISA that incorporates an empirically derived metallicity-dependent binary fraction, using the binary population synthesis suite COSMIC and a metallicity-dependent star formation history. We compare two models: one that assumes a metallicity-dependent binary fraction, and one with a binary fraction of 50%. We repeat our analysis for three different assumptions for Roche-lobe overflow interactions. We find that while metallicity impacts the evolution and intrinsic properties of our simulated DWD progenitor binaries, the LISA-resolvable populations of the two models remain roughly indistinguishable. However, the size of the total Galactic DWD population orbiting in the LISA frequency band is reduced by more than half when accounting for a metallicity-dependent binary fraction for two of our four variations, which also lowers the effective foreground. The LISA population remains unchanged in number for two variations, highlighting the sensitivity of the population to binary evolution prescriptions.
SOFIA Observations of 30 Doradus. II. Magnetic Fields and Large-scale Gas Kinematics
Authors: Tram Le Ngoc , Bonne Lars , Hu Yue , Lopez-Rodriguez Enrique , Guerra Jordan A. , Lesaffre Pierre , Gusdorf Antoine , Hoang Thiem , Lee Min-Young , Lazarian Alex , Andersson B-G , Coudé Simon , Soam Archana , Vacca William D. , Lee Hyeseung , Gordon Michael 
Published: March 2023

Abstract
The heart of the Large Magellanic Cloud, 30 Doradus, is a complex region with a clear core-halo structure. Feedback from the stellar cluster R136 has been shown to be the main source of energy creating multiple parsec-scale expanding-shells in the outer region, and carving a nebula core in the proximity of the ionization source. We present the morphology and strength of the magnetic fields (B-fields) of 30 Doradus inferred from the far-infrared polarimetric observations by SOFIA/HAWC+ at 89, 154, and 214 μm. The B-field morphology is complex, showing bending structures around R136. In addition, we use high spectral and angular resolution [C ii] observations from SOFIA/GREAT and CO(2-1) from APEX. The kinematic structure of the region correlates with the B-field morphology and shows evidence of multiple expanding-shells. Our B-field strength maps, estimated using the Davis–Chandrasekhar–Fermi method and structure-function, show variations across the cloud within a maximum of 600, 450, and 350 μG at 89, 154, and 214 μm, respectively. We estimated that the majority of the 30 Doradus clouds are subcritical and sub-Alfvénic. The probability distribution function of the gas density shows that the turbulence is mainly compressively driven, while the plasma beta parameter indicates supersonic turbulence. We show that the B-field is sufficient to hold the cloud structure integrity under feedback from R136. We suggest that supersonic compressive turbulence enables the local gravitational collapse and triggers a new generation of stars to form. The velocity gradient technique using [C ii] and CO(2-1) is likely to confirm these suggestions.
Addressing Systematics in the Traceback Age of the β Pictoris Moving Group
Authors: Couture Dominic , Gagné Jonathan , Doyon René 
Published: March 2023

Abstract
We characterize the impact of several sources of systematic errors on the computation of the traceback age of the β Pictoris moving group (βPMG). We find that uncorrected gravitational redshift and convective blueshift bias absolute radial velocity measurements by ∼0.6 km s−1, which leads to erroneously younger traceback ages by ∼2 Myr. Random errors on parallax, proper motion, and radial velocity measurements lead to an additional bias of ∼0.6 Myr on traceback ages. Contamination of astrometric and kinematic data by kinematic outliers and unresolved multiple systems in the full input sample of 76 members and candidates of βPMG also erroneously lowers traceback ages by ∼3 Myr. We apply our new numerical traceback analysis tool to a core sample of 25 carefully vetted members of βPMG using Gaia Data Release 3 data products and other kinematic surveys. Our method yields a corrected age of 20.4 ± 2.5 Myr, bridging the gap between kinematic ages (11–19 Myr) and other age-dating methods, such as isochrones and lithium depletion boundary (20–26 Myr). We explore several association size metrics that can track the spatial extent of βPMG over time, and we determine that minimizing the variance along the heliocentric curvilinear coordinate

ξ

′

(i.e., toward the Galactic Center) offers the least random and systematic errors, due to the wider UVW space velocity dispersion of members of βPMG along the U-axis, which tends to maximize the spatial growth of the association along the

ξ

′

-axis over time.
Three-dimensional Global Simulations of Type-II Planet–Disk Interaction with a Magnetized Disk Wind. I. Magnetic Flux Concentration and Gap Properties
Authors: Aoyama Yuhiko , Bai Xue-Ning 
Published: March 2023

Abstract
Giant planets embedded in protoplanetary disks (PPDs) can create annulus density gaps around their orbits in the type-II regime, potentially responsible for the ubiquity of annular substructures observed in PPDs. Although a substantial amount of works studying type-II planetary migration and gap properties have been published, they have almost exclusively all been conducted under the viscous accretion disk framework. However, recent studies have established magnetized disk winds as the primary mechanism driving disk accretion and evolution, which can coexist with turbulence from the magnetorotational instability (MRI) in the outer PPDs. We conduct a series of 3D global nonideal magnetohydrodynamic (MHD) simulations of type-II planet–disk interactions applicable to the outer PPDs. Our simulations properly resolve the MRI turbulence and accommodate the MHD disk wind. We found that the planet triggers the poloidal magnetic flux concentration around its orbit. The concentrated magnetic flux strongly enhances angular momentum removal in the gap, which is along the inclined poloidal field through a strong outflow emanating from the disk surface outward to the planet gap. The resulting planet-induced gap shape is more similar to an inviscid disk, while being much deeper, which can be understood from a simple inhomogeneous wind torque prescription. The corotation region is characterized by a fast trans-sonic accretion flow that is asymmetric in azimuth about the planet and lacking the horseshoe turns, and the meridional flow is weakened. The torque acting on the planet generally drives inward migration, though the migration rate can be affected by the presence of neighboring gaps through stochastic, planet-free magnetic flux concentration.
Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog
Authors: Rodriguez Antonio C. , Kulkarni Shrinivas R. , Prince Thomas A. , Szkody Paula , Burdge Kevin B. , Caiazzo Ilaria , van Roestel Jan , Vanderbosch Zachary P. , El-Badry Kareem , Bellm Eric C. , Gänsicke Boris T. , Graham Matthew J. , Mahabal Ashish A. , Masci Frank J. , Mróz Przemek , Riddle Reed , Rusholme Ben 
Published: March 2023

Abstract
Magnetic cataclysmic variables (CVs) are luminous Galactic X-ray sources, which have been difficult to find in purely optical surveys due to their lack of outburst behavior. The eROSITA telescope on board the Spektr-RG mission is conducting an all-sky X-ray survey and recently released the public eROSITA Final Equatorial Depth Survey (eFEDS) catalog. We crossmatched the eFEDS catalog with photometry from the Zwicky Transient Facility and discovered two new magnetic CVs. We obtained high-cadence optical photometry and phase-resolved spectroscopy for each magnetic CV candidate and found them both to be polars. Among the newly discovered magnetic CVs is eFEDS J085037.2+044359/ZTFJ0850+0443, an eclipsing polar with orbital period P
orb = 1.72 hr and WD mass M
WD = 0.81 ± 0.08M
⊙. We suggest that eFEDS J085037.2+044359/ZTFJ0850+0443 is a low magnetic field strength polar, with B
WD ≲ 10 MG. We also discovered a non-eclipsing polar, eFEDS J092614.1+010558/ZTFJ0926+0105, with orbital period P
orb = 1.47 hr and magnetic field strength B
WD = 36–42 MG.
Formulating the r-mode Problem for Slowly Rotating Neutron Stars
Authors: Andersson Nils , Gittins Fabian 
Published: March 2023

Abstract
We revisit the problem of inertial r-modes in stratified stars, drawing on a more precise description of the composition stratification in a mature neutron star. The results highlight issues with the traditional approach to the problem, leading us to rethink the computational strategy for the r-modes of nonbarotropic neutron stars. We outline two strategies for dealing with the problem. For moderate to slowly rotating neutron stars the only viable alternative may be to approach the problem numerically from the outset, while a meaningful slow-rotation calculation can be carried out for the fastest known spinning stars (which may be close to being driven unstable by the emission of gravitational waves). We demonstrate that the latter approach leads to a problem close, but not identical, to that for barotropic inertial modes. We also suggest that these reformulations of the problem likely resolve the long-standing problem of singular behavior associated with a corotation point in rotating relativistic neutron stars. This issue needs to be resolved in order to guide future gravitational-wave searches.
Introducing TIGRESS-NCR. I. Coregulation of the Multiphase Interstellar Medium and Star Formation Rates
Authors: Kim Chang-Goo , Kim Jeong-Gyu , Gong Munan , Ostriker Eve C. 
Published: March 2023

Abstract
Massive, young stars are the main source of energy that maintains multiphase structure and turbulence in the interstellar medium (ISM), and without this “feedback” the star formation rate (SFR) would be much higher than is observed. Rapid energy loss in the ISM and efficient energy recovery by stellar feedback lead to coregulation of SFRs and the ISM state. Realistic approaches to this problem should solve for the dynamical evolution of the ISM, including star formation and the input of feedback energy self-consistently and accurately. Here, we present the TIGRESS-NCR numerical framework, in which UV radiation, supernovae, cooling and heating processes, and gravitational collapse are modeled explicitly. We use an adaptive ray-tracing method for UV radiation transfer from star clusters represented by sink particles, accounting for attenuation by dust and gas. We solve photon-driven chemical equations to determine the abundances of hydrogen (time dependent) and carbon/oxygen-bearing species (steady state), which then set cooling and heating rates self-consistently. Applying these methods, we present high-resolution magnetohydrodynamics simulations of differentially rotating local galactic disks representing typical conditions of nearby star-forming galaxies. We analyze ISM properties and phase distributions and show good agreement with existing multiwavelength galactic observations. We measure midplane pressure components (turbulent, thermal, and magnetic) and the weight, demonstrating that vertical dynamical equilibrium holds. We quantify the ratios of pressure components to the SFR surface density, which we call the feedback yields. The TIGRESS-NCR framework will allow for a wide range of parameter exploration, including in low-metallicity systems.
Revisiting the Parameter Space of Binary Neutron Star Merger Event GW170817
Authors: McDowell Austin , MacFadyen Andrew 
Published: March 2023

Abstract
Since the gravitational wave event GW170817 and gamma-ray burst GW170817A, there have been numerous studies constraining the burst properties through analysis of the afterglow light curves. Most agree that the burst was viewed off-axis with a ratio of the observer angle to the jet angle (θ
obs/θ

j
) between 4 and 6. We use a parameterized model and broadband synchrotron data up to ∼800 days post-merger to constrain parameters of the burst. To reproduce the hydrodynamics of a gamma-ray burst outflow, we use a two-parameter “boosted fireball” model. The structure of a boosted fireball is determined by the specific internal energy, η
0, and the bulk Lorentz factor, γ

B
( ∼ 1/θ

j
), with shapes varying smoothly from a quasi-spherical outflow for low values of γ

B
to a highly collimated jet for high values. We run simulations with γ

B
in the range 1–20 and η
0 in the range 2–15. To calculate light curves, we use a synchrotron radiation model characterized by F
peak, ν

m
, and ν

c
, and calculate millions of spectra at different times and θ
obs values using the boxfit radiation code. We can tabulate the spectral parameter values from our spectra and rapidly generate arbitrary light curves for comparison to data in MCMC analysis. We find that our model prefers a gamma-ray burst with jet energy E

j
∼ 1050 erg and with an observer angle of

θ

obs

=

0.65

−
0.14

+
0.13

radians and ratio to the jet opening angle of (θ
obs/θ

j
) =

5.4

−
0.38

+
0.53

.
Bright-mode Emission from PSR B0823+26 Using the Five-hundred-meter Aperture Spherical Radio Telescope
Authors: Chen J. L. , Wen Z. G. , Duan X. F. , He D. L. , Wang N. , Lyu C. B. , Wang H. G. , Li D. , Yuan J. P. , Han W. , Wang Z. , Yuen R. , Yan W. M. , Xiang B. B. , Dang S. J. , Wang H. , Niu J. R. , Wang J. P. , Ergesh T. , Cui S. R. , Zhang Y. J. 
Published: March 2023

Abstract
Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we have recorded over 1.2 × 104 single pulses from PSR B0823+26 (J0826+2637) at 1.25 GHz with 500 MHz bandwidth. These high-sensitivity observations detected with FAST are unprecedented. We investigated potentially interesting emission features by analyzing the polarimetric individual pulses during the bright state. The average pulse profile has a weak postcursor component and a wide interpulse along with a narrow main pulse. The pulse energy distribution of the main pulse shows the presence of triple emission modes. When the emission ceases in the main pulse component, low-level emission in the interpulse component is detected, whereas the absence of any emission in the postcursor component is shown. In the postcursor emission region, bright pulses are detected in 422 rotations with the relative pulse energy described by a power-law distribution with index of −2.52 ± 0.09, while the peak flux density ratio appears to follow a logarithmic normal distribution. The intervals between bright pulses can be described with a Poisson process with the occurrence rate estimated to be one bright pulse every 14 s. The fluctuation spectral analysis reveals the existence of a form of periodic amplitude modulation unrelated to subpulse drifting in both the main pulse and interpulse components. Furthermore, the modulation patterns in the main pulse and interpulse are found to be locked in pulse longitude, signifying some information transfer between the two magnetic polar regions.