bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methodology of Index Analysis of the Information Society Development Level
Authors: Korepanov O. S. 
Published: July 2018

The purpose of the article is to analyze changes in methodological approaches to calculating the indexes of information and communication technologies development (ICT) proposed by the International Telecommunication Union (ITU). The article analyzes the process of development of ICT and the transformation of territories towards the formation of an information society, examines three main stages in evolution of the information society, which are in line with the structure of the ICT Development Index (IDI).
An international methodology for calculating the ICT development index is based on three sub-indexes: access to ICT, use of ICT and practical ICT skills developed by the ITU in 2010. The basic indices of aggregate sub-indexes, their nominal values and the methodology for calculating the ICT Development Index are presented in the annual reports of the ITU “Measuring the Information Society” 2009–2017. The article also analyzes the significance of the ICT development indexes and the corresponding sub-indexes for the countries of the world, which ranked among the top ten leaders by the corresponding rating.
A comparative analysis of the IDI values of Ukraine and Iceland, one of the leading countries by IDI-2016 level, is made; the corresponding diagram is constructed on the basis of the statistical indicators used for the calculation and the corresponding sub-indexes. The dynamics of changes of IDI basic statistical characteristics by region of the world in 2012-2017 is analyzed.
The changes to the IDI calculation methodology of 2018, proposed by the specialized international expert groups, are analyzed. The proposed changes relate to a set of metrics that should be additionally included in the IDI instead of a few excluded. The analysis of changes in methodological approaches to the calculation of IDI shows significant differences in the ICT development by geographical region of the world. There are also significant fluctuations in the experience of individual countries within each region.
Chi-square, Student and Fisher-Snedecor Statistical Distributions and Their Application
Authors: Motsnyi F. V. 
Published: July 2018

The Chi-square distribution is the distribution of the sum of squared standard normal deviates. The degree of freedom of the distribution is equal to the number of standard normal deviates being summed. For the first time this distribution was studied by astronomer F. Helmert in connection with Gaussian low of errors in 1876. Later K. Pearson named this function by Chi-square. Therefore Chi –square distribution bears a name of Pearson’s distribution.
The Student's t-distribution is any member of a family of continuous probability distributions that arises when estimating the mean of a normally distributed population in situations where the sample size is small and population standard deviation is unknown. It was developed by W. Gosset in 1908.
The Fisher–Snedecor distribution or F-distribution is the ratio of two-chi-squared variates. The F-distribution provides a basis for comparing the ratios of subsetsof these variances associated with different factors. The Fisher-distribution in the analysis of variance is connected with the name of R.Fisher (1924), although Fisher himself used quantity for the dispersion proportion.
The Chi-square, Student and Fisher – Snedecor statistical distributions are connected enough tight with normal one. Therefore these distributions are used very extensively in mathematical statistics for interpretation of empirical data. The paper continues ideas of the author’s works [15, 16] devoted to advanced based tools of mathematical statistics. The aim of the work is to generalize the well known theoretical and experimental results of statistical distributions of random values. The Chi-square, Student and Fisher – Snedecor distributions are analyzed from the only point of view. The application peculiarities are determined at the examination of the agree criteria of the empirical sample one with theoretical predictions of general population. The numerical characteristics of these distributions are considered. The theoretical and experimental results are generalized. It is emphasized for the corrected amplification of the Chi-square, Student and Fisher – Snedecor distributions it is necessary to have the reliable empirical and testing data with the normal distribution.
Small and Nearby NEOs Observed by NEOWISE During the First Three Years of Survey: Physical Properties
Authors: Masiero Joseph R. , Redwing E. , Mainzer A. K. , Bauer J. M. , Cutri R. M. , Grav T. , Kramer E. , Nugent C. R. , Sonnett S. , Wright E. L. 
Published: July 2018

Abstract
Automated asteroid detection routines set requirements on the number of detections, signal-to-noise ratio, and the linearity of the expected motion in order to balance completeness, reliability, and time delay after data acquisition when identifying moving object tracklets. However, when the full-frame data from a survey are archived, they can be searched later for asteroids that were below the initial detection thresholds. We have conducted such a search of the first three years of the reactivated Near-Earth Object Wide-field Infrared Survey Explorer data, looking for near-Earth objects discovered by ground-based surveys that have previously unreported thermal infrared data. Using these measurements, we can then perform thermal modeling to measure the diameters and albedos of these objects. We present new physical properties for 116 Near-Earth Objects found in this search.
The Dynamical Complexity of Surface Mass Shedding from a Top-shaped Asteroid Near the Critical Spin Limit
Authors: Yu Yang , Michel Patrick , Hirabayashi Masatoshi , Schwartz Stephen R. , Zhang Yun , Richardson Derek C. , Liu Xiaodong 
Published: July 2018

Abstract
The regolith transport near the surface of an asteroid is inherently sensitive to the local topography. In this paper, conditions of surface mass shedding and the subsequent evolution of the shedding material are studied for the primary of 65803 Didymos, serving as a representative for a large group of top-shaped asteroids that rotate near their critical spin limits. We considered the influences of an asymmetric shape and a non-spherical gravity, and demonstrate that these asymmetries play a significant role in the shedding process as well as in the subsequent orbital motion. The mass shedding conditions are given as a function of the geological coordinates, and show a clear-cut dependency on the local topographic features. We find that at different stages of the Yarkovsky–O’Keefe–Radzievskii–Paddack spin-up, the bulged areas exhibit a uniform superior advantage of enabling mass shedding over the depressed areas. “Dead zones” free from mass shedding are found around the polar sites. Numerical simulations show that the orbital motion of the shedding material experiences a drastic change as the spin rate is approaching the critical limit. The “mass leaking” effect is reinforced as the spin rate increases; the lower spin rates correspond to a higher capability of trapping the lofted particles in the vicinity of the asteroid, which statistically improves the probability of collisional growth in orbit. We also find that the topological transition of the equilibrium point can in practice lead to rapid clearance of the shedding material and transport of their orbits to larger distances from the surface.
The Volatile Composition of Comet C/2017 E4 (Lovejoy) before its Disruption, as Revealed by High-resolution Infrared Spectroscopy with iSHELL at the NASA/IRTF
Authors: Faggi S. , Villanueva G. L. , Mumma M. J. , Paganini L. 
Published: July 2018

Abstract
In 2017 April, we acquired comprehensive high-resolution spectra of newly discovered comet C/2017 E4 (Lovejoy) as it approached perihelion, and before its disintegration. We detected many cometary emission lines in the range (2.8–5.3) μm, in four customized instrument settings (L1-c, L3, Lp1-c, and M1) of iSHELL—the new near-IR high-resolution immersion echelle spectrograph at NASA/IRTF (Maunakea, Hawaii). We identified 12 molecular species: nine primary volatiles (H2O, HCN, NH3, CO, C2H2, C2H6, CH4, CH3OH, H2CO) and three product species (CN, NH2, OH). We detected 85 H2O emission lines from 12 water vibrational bands across L1-c and M1 settings. The many detected water emission lines enabled retrieval of accurate measures for ortho- and para-H2O independently, thereby reducing systematic uncertainty in the derived ortho–para ratio and nuclear spin temperature. Excitation analyses and emission profile analyses were performed for all species, and molecular abundance ratios relative to water are compared with values found for other Oort Cloud comets in our infrared database. Abundance ratios are consistent for most species, with the exception of underabundant methanol and overabundant ammonia in E4.
Electron and Proton Acceleration in Trans-relativistic Magnetic Reconnection: Dependence on Plasma Beta and Magnetization
Authors: Ball David , Sironi Lorenzo , Özel Feryal 
Published: July 2018

Abstract
Nonthermal electron acceleration via magnetic reconnection is thought to play an important role in powering the variable X-ray emission from radiatively inefficient accretion flows around black holes. The trans-relativistic regime of magnetic reconnection—where the magnetization σ, defined as the ratio of magnetic energy density to enthalpy density, is ∼1—is frequently encountered in such flows. By means of a large suite of two-dimensional particle-in-cell simulations, we investigate electron and proton acceleration in the trans-relativistic regime. We focus on the dependence of the electron energy spectrum on σ and the proton β (the ratio of proton thermal pressure to magnetic pressure). We find that the electron spectrum in the reconnection region is nonthermal and can be modeled as a power law. At low β, the slope, p, is independent of β and hardens with increasing σ as

p
≃
1.8
+
0.7

/

σ

. Electrons are primarily accelerated by the nonideal electric field at X-points, either in the initial current layer or in current sheets generated between merging magnetic islands. At higher values of β, the electron power law steepens, and the electron spectrum eventually approaches a Maxwellian distribution for all values of σ. At values of β near β
max ≈ 1/4σ, when both electrons and protons are relativistically hot prior to reconnection, the spectra of both species display an additional component at high energies, containing a few percent of particles. These particles are accelerated via a Fermi-like process by bouncing between the reconnection outflow and a stationary magnetic island
The Brightest Galaxies in the Dark Ages: Galaxies’ Dust Continuum Emission during the Reionization Era
Authors: Casey Caitlin M. , A. Zavala Jorge , Spilker Justin , da Cunha Elisabete , Hodge Jacqueline , Hung Chao-Ling , Staguhn Johannes , Finkelstein Steven L. , Drew Patrick 
Published: July 2018

Abstract
Though half of cosmic starlight is absorbed by dust and reradiated at long wavelengths (3 μm–3 mm), constraints on the infrared through the millimeter galaxy luminosity function (or the “IRLF”) are poor in comparison to the rest-frame ultraviolet and optical galaxy luminosity functions, particularly at z ≳ 2.5. Here, we present a backward evolution model for interpreting number counts, redshift distributions, and cross-band flux density correlations in the infrared and submillimeter sky, from 70 μm–2 mm, using a model for the IRLF out to the epoch of reionization. Mock submillimeter maps are generated by injecting sources according to the prescribed IRLF and flux densities drawn from model spectral energy distributions that mirror the distribution of SEDs observed in 0 < z < 5 dusty star-forming galaxies (DSFGs). We explore two extreme hypothetical case studies: a dust-poor early universe model, where DSFGs contribute negligibly (<10%) to the integrated star formation rate density at z > 4; and an alternate dust-rich early universe model, where DSFGs dominate ∼90% of z > 4 star formation. We find that current submm/mm data sets do not clearly rule out either of these extreme models. We suggest that future surveys at 2 mm will be crucial to measuring the IRLF beyond z ∼ 4. The model framework developed in this paper serves as a unique tool for the interpretation of multiwavelength IR/submm extragalactic data sets, and will enable more refined constraints on the IRLF than can be made from direct measurements of individual galaxies’ integrated dust emission.
Reproducing Type II White-light Solar Flare Observations with Electron and Proton Beam Simulations
Authors: Procházka Ondřej , Reid Aaron , Milligan Ryan O. , Simões Paulo J. A. , Allred Joel C. , Mathioudakis Mihalis 
Published: July 2018

Abstract
We investigate the cause of the suppressed Balmer series and the origin of the white-light continuum emission in the X1.0 class solar flare on 2014 June 11. We use radiative hydrodynamic simulations to model the response of the flaring atmosphere to both electron and proton beams, which are energetically constrained using Ramaty High Energy Solar Spectroscopic Imager and Fermi observations. A comparison of synthetic spectra with the observations allows us to narrow the range of beam fluxes and low energy cutoff that may be applicable to this event. We conclude that the electron and proton beams that can reproduce the observed spectral features are those that have relatively low fluxes and high values for the low energy cutoff. While electron beams shift the upper chromosphere and transition region to greater geometrical heights, proton beams with a similar flux leave these areas of the atmosphere relatively undisturbed. It is easier for proton beams to penetrate to the deeper layers and not deposit their energy in the upper chromosphere where the Balmer lines are formed. The relatively weak particle beams that are applicable to this flare do not cause a significant shift of the τ = 1 surface and the observed excess WL emission is optically thin.
NLTE Analysis of Copper Lines in Different Stellar Populations∗
Authors: Shi J. R. , Yan H. L. , Zhou Z. M. , Zhao G. 
Published: July 2018

Abstract
The copper abundances of 29 metal-poor stars are determined based on the high-resolution, high-signal-to-noise ratio spectra from the UVES spectrograph at the ESO VLT telescope. Our sample consists of the stars of the Galactic halo, thick- and thin-disk, with [Fe/H] ranging from ∼−3.2 to ∼0.0 dex. The non-local thermodynamic equilibrium (NLTE) effects of Cu i lines are investigated, and line formation calculations are presented for an atomic model of copper including 97 terms and 1089 line transitions. We adopted the recently calculated photoionization cross sections of Cu i, and investigated the hydrogen collision by comparing the theoretical and observed line profiles of our sample stars. The copper abundances are derived for both local thermodynamic equilibrium (LTE) and NLTE based on the spectrum synthesis methods. Our results show that the NLTE effects for Cu i lines are important for metal-poor stars, in particular for very metal-poor stars, and these effects depend on the metallicity. For very metal-poor stars, the NLTE abundance correction reaches as large as ∼+0.5 dex compared to standard LTE calculations. Our results indicate that [Cu/Fe] is under-abundant for metal-poor stars (∼−0.5 dex) when the NLTE effects are included.
The Globular Cluster Systems of Ultra-diffuse Galaxies in the Coma Cluster
Authors: Lim Sungsoon , Peng Eric W. , Côté Patrick , Sales Laura V. , Brok Mark den , Blakeslee John P. , Guhathakurta Puragra 
Published: July 2018

Abstract
Ultra-diffuse galaxies (UDGs) are unusual galaxies with low luminosities, similar to classical dwarf galaxies, but with sizes up to ∼5 larger than expected for their mass. Some UDGs have large populations of globular clusters (GCs), something unexpected in galaxies with such low stellar density and mass. We have carried out a comprehensive study of GCs in both UDGs and classical dwarf galaxies at comparable stellar masses using Hubble Space Telescope (HST) observations of the Coma cluster. We present new imaging for 33 Dragonfly UDGs with the largest effective radii (>2 kpc), and additionally include 15 UDGs and 54 classical dwarf galaxies from the HST/ACS Coma Treasury Survey and the literature. Out of a total of 48 UDGs, 27 have statistically significant GC systems, and 11 have candidate nuclear star clusters. The GC specific frequency (S

N
) varies dramatically, with the mean S

N
being higher for UDGs than for classical dwarfs. At constant stellar mass, galaxies with larger sizes (or lower surface brightnesses) have higher S

N
, with the trend being stronger at higher stellar mass. At lower stellar masses, UDGs tend to have higher S

N
when closer to the center of the cluster, i.e., in denser environments. The fraction of UDGs with a nuclear star cluster also depends on environment, varying from ∼40% in the cluster core, where it is slightly lower than the nucleation fraction of classical dwarfs, to ≲20% in the outskirts. Collectively, we observe an unmistakable diversity in the abundance of GCs, and this may point to multiple formation routes.
Rapid Flaring in the Galactic-plane Gamma-Ray Transient Fermi J0035+6131
Authors: Pandel Dirk , Kaaret Philip 
Published: July 2018

Abstract
We investigate the gamma-ray and X-ray emission from the transient gamma-ray source Fermi J0035+6131, which was discovered with the Fermi Large Area Telescope (LAT) near the Galactic plane at b = 1.°3, and we discuss potential multi-wavelength counterparts of the gamma-ray source. Our analysis of over 9 years of Fermi LAT data revealed two flaring events lasting 10–30 hr during which the gamma-ray flux increased by a factor of >300 compared to the long-term average. We also analyzed X-ray data obtained with XMM-Newton and Swift and identified several sources with a hard X-ray spectrum inside the Fermi LAT confidence region. The two brightest X-ray sources have known counterparts at other wavelengths and are associated with the compact radio source VCS4 J0035+6130 and the B1 IV:nn star HD 3191, respectively. VCS4 J0035+6130, which is also detected in the near infrared, is likely an active galaxy serendipitously located behind the Galactic disk and is the most compelling candidate for the counterpart of the gamma-ray source. HD 3191 appears to be part of an X-ray binary with a compact companion and is unlikely to be associated with Fermi J0035+6131.
UV Surface Environments and Atmospheres of Earth-like Planets Orbiting White Dwarfs
Authors: Kozakis Thea , Kaltenegger Lisa , Hoard D. W. 
Published: July 2018

Abstract
An Earth-like exoplanet orbiting a white dwarf (WD) would be exposed to different UV environments than Earth, influencing both its atmospheric photochemistry and UV surface environment. Through the use of a coupled 1D climate-photochemistry code, we model atmospheres of Earth-like planets in the habitable zone (HZ) of WDs for surface temperatures between 6000 and 4000 K, corresponding to about 7 billion years of WD evolution, and discuss the evolution of planetary models in the HZ during that evolution.
Deciphering the Activity and Quiescence of High-redshift Cluster Environments: ALMA Observations of Cl J1449+0856 at z = 2
Authors: Strazzullo V. , Coogan R. T. , Daddi E. , Sargent M. T. , Gobat R. , Valentino F. , Bethermin M. , Pannella M. , Dickinson M. , Renzini A. , Arimoto N. , Cimatti A. , Dannerbauer H. , Finoguenov A. , Liu D. , Onodera M. 
Published: July 2018

Abstract
We present Atacama Large Millimeter/submillimeter Array observations of the 870 μm continuum and CO(4–3) line emission in the core of the galaxy cluster Cl J1449+0856 at z = 2, a near-IR-selected, X-ray-detected system in the mass range of typical progenitors of today’s massive clusters. The 870 μm map reveals six F
870μm > 0.5 mJy sources spread over an area of 0.07 arcmin2, giving an overdensity of a factor of ∼10 (6) with respect to blank-field counts down to F
870μm > 1 mJy (>0.5 mJy). On the other hand, deep CO(4–3) follow-up confirms membership of three of these sources but suggests that the remaining three, including the brightest 870 μm sources in the field (F
870μm ≳ 2 mJy), are likely interlopers. The measurement of 870 μm continuum and CO(4–3) line fluxes at the positions of previously known cluster members provides a deep probe of dusty star formation occurring in the core of this high-redshift structure, adding up to a total star formation rate of ∼700 ± 100 M
⊙ yr−1 and yielding an integrated star formation rate density of ∼104
M
⊙ yr−1 Mpc−3, five orders of magnitude larger than in the field at the same epoch, due to the concentration of star-forming galaxies in the small volume of the dense cluster core. The combination of these observations with previously available Hubble Space Telescope imaging highlights the presence in this same volume of a population of galaxies with already suppressed star formation. This diverse composition of galaxy populations in Cl J1449+0856 is especially highlighted at the very cluster center, where a complex assembly of quiescent and star-forming sources is likely forming the future brightest cluster galaxy.
The Kinematics of Extended Lyα Emission in a Low-mass, Low-metallicity Galaxy at z = 2.3∗
Authors: Erb Dawn K. , Steidel Charles C. , Chen 陈 Yuguang 昱光 
Published: July 2018

Abstract

Ly
α

photons are resonantly scattered by neutral hydrogen, and may therefore trace both the spatial extent and the kinematics of the gas surrounding galaxies. We present new observations of the extended

Ly
α

halo of Q2343-BX418, a low-mass (

M

⋆

=
5
×

10

8

M

⊙

), low-metallicity (Z ≈ 0.25 Z
⊙) star-forming galaxy at z = 2.3. Using the Keck Cosmic Web Imager (KCWI), the blue-sensitive optical integral field spectrograph recently installed on the Keck II telescope, we detect

Ly
α

in emission to a radius of 23 kpc, and measure an exponential scale length of 6 kpc in the outer region of the extended halo. We study the double-peaked spectroscopic

Ly
α

profile in individual spectral pixels (“spaxels”) over a ∼25 × 30 kpc region, finding significant variations in the peak ratio and peak separation. The profile is dominated by the red peak in the central regions, while in the outskirts of the extended halo the red and blue peak strengths are roughly equal; these observations are consistent with a model in which the peak ratio is largely determined by the radial component of the outflow velocity. We find a gradient of 300

km

s

−
1

in the

Ly
α

peak separation across the extended halo, indicating variations in the column density, covering fraction, or velocity range of the gas. These new observations emphasize the need for realistic, spatially resolved models of

Ly
α

radiative transfer in the halos of galaxies.