Miracle-dz/UniFAR-FTUs huggingface dataset:
Opinion Dynamics Model with Appraisal Systems on Two-Layer Social Networks

This paper is concerned with the opinion dynamics and decision-making problems in the two-layer social networks. An opinion dynamics model with the cooperative appraisal systems and the antagonistic appraisal systems is proposed, and sufficient conditions are offered to guarantee the convergence of the opinions. Moreover, multidimensional opinion dynamics models are simultaneously established, and necessary and sufficient conditions guaranteeing the neutralization of opinion is provided in terms of the spectral radius of the matrix. By employing our proposed opinion dynamics model to reproduce the social phenomenon of the boomerang effect in social psychology. Finally, simulation analysis shows that the discrepancy of the opinion is smaller in the case of interdependent issues than that in the case of interdependent issues, and the convergence rate of the opinion is directly proportional to the level of depending on the neighbor behavior.
A CORRELATION BETWEEN CENTRAL SUPERMASSIVE BLACK HOLES AND THE GLOBULAR CLUSTER SYSTEMS OF EARLY-TYPE GALAXIES

Elliptical, lenticular, and early-type spiral galaxies show a remarkably tight power-law correlation between the mass M• of their central supermassive black hole (SMBH) and the number NGC of globular clusters (GCs): M• = m•/⋆ × N1.08±0.04GC with m•/⋆ = 1.7 × 105 M☉. Thus, to a good approximation the SMBH mass is the same as the total mass of the GCs. Based on a limited sample of 13 galaxies, this relation appears to be a better predictor of SMBH mass (rms scatter 0.2 dex) than the M•–σ relation between SMBH mass and velocity dispersion σ. The small scatter reflects the fact that galaxies with high GC specific frequency SN tend to harbor SMBHs that are more massive than expected from the M•–σ relation.
Nonmonotonic temperature dependent transport in graphene grown by chemical vapor deposition

Temperature-dependent resistivity of graphene grown by chemical vapor deposition (CVD) is investigated. We observe in low mobility CVD graphene device a strong insulating behavior at low temperatures and a metallic behavior at high temperatures manifesting a non-monotonic in the temperature dependent resistivity.This feature is strongly affected by carrier density modulation. To understand this anomalous temperature dependence, we introduce thermal activation of charge carriers in electron-hole puddles induced by randomly distributed charged impurities. Observed temperature evolution of resistivity is then understood from the competition among thermal activation of charge carriers, temperature-dependent screening and phonon scattering effects. Our results imply that the transport property of transferred CVD-grown graphene is strongly influenced by the details of the environment
Near-zone sizes and the rest-frame extreme ultraviolet spectral index of the highest redshift quasars

The discovery of quasars with redshifts higher than six has prompted a great deal of discussion in the literature regarding the role of quasars, both as sources of reionization, and as probes of the ionization state of the intergalactic medium (IGM). However the extreme ultraviolet (EUV) spectral index cannot be measured directly for high-redshift quasars owing to absorption at frequencies above the Lyman limit, and as a result, studies of the impact of quasars on the IGM during reionization must assume a spectral energy distribution in the EUV based on observations at low redshift, z ≲ 1. In this paper we use regions of high Lyα transmission (near-zones) around the highest redshift quasars to measure the quasar EUV spectral index at z ∼ 6. We jointly fit the available observations for variation of near-zone size with both redshift and luminosity, and propose that the observed relation provides evidence for an EUV spectral index that varies with absolute magnitude in the high-redshift quasar sample, becoming softer at higher luminosity. Using a large suite of detailed numerical simulations, we find that the typical value of spectral index for a luminous quasar (M 1450 = -27) at z ∼ 6 is constrained to be α = 1.3 +0.4 ―0.3 for a specific luminosity of the form L v ∝ v ―α . This value is sensitive to the background ionization rate at z ∼ 6, and we present an updated estimate of Γ = (0.18 +0.18 ―0.09 × 10 ―12 s ―1 as part of our analysis. We find the scatter in spectral index among individual quasars to be in the range Δα ∼ 0.75-1.25. These values are in agreement with direct observations at low redshift, and indicate that there has been no significant evolution in the EUV spectral index of quasars over 90 per cent of cosmic time.
Data-constrained reionization and its effects on cosmological parameters

We perform an analysis of the recent WMAP7 data considering physically motivated and viable reionization scenarios with the aim of assessing their effects on cosmological parameter determinations. The main novelties are: (i) the combination of CMB data with astrophysical results from quasar absorption line experiments; (ii) the joint variation of both the cosmological and astrophysical [governing the evolution of the free electron fraction x_e(z)] parameters. Including a realistic, data-constrained reionization history in the analysis induces appreciable changes in the cosmological parameter values deduced through a standard WMAP7 analysis. Particularly noteworthy are the variations in Omega_bh^2 = 0.02258^{+0.00057}_{-0.00056} (WMAP7) vs. Omega_bh^2$ = 0.02183\pm 0.00054 (WMAP7 + ASTRO), and the new constraints for the scalar spectral index, for which WMAP7 + ASTRO excludes the Harrison-Zel'dovich value n_s=1 at more than 3\sigma. Finally, the e.s. optical depth value is considerably decreased with respect to the standard WMAP7, i.e. \tau_{e}=0.080\pm 0.012. We conclude that the inclusion of astrophysical datasets, allowing to robustly constrain the reionization history, in the extraction procedure of cosmological parameters leads to relatively important differences in the final determination of their values.
SPECTRAL ENERGY DISTRIBUTIONS OF ACCRETING PROTOPLANETS

Planets are often invoked as the cause of inferred gaps or inner clearings in transition disks. These putative planets would interact with the remnant circumstellar disk, accreting gas and generating substantial luminosity. Here I explore the expected appearance of accreting protoplanets at a range of evolutionary states. I compare synthetic spectral energy distributions with the handful of claimed detections of substellar-mass companions in transition disks. While observed fluxes of candidate companions are generally compatible with accreting protoplanets, challenges remain in reconciling the extended structure inferred in observed objects with the compact emission expected from protoplanets or circumplanetary disks. I argue that a large fraction of transition disks should harbor bright protoplanets, and that more may be detected as larger telescopes open up additional parameter space.
Learning about stars from their colors

We pose the question of how much information on the atmospheric parameters of late-type stars can be retrieved purely from colors using standard photometric systems. We carried out numerical experiments using stellar fluxes from model atmospheres, injecting random noise before analyzing them. We examined the presence of degeneracies among atmospheric parameters, and evaluated how well the parameters are extracted depending on the number and wavelength span of the photometric filters available, from the UV GALEX to the mid-IR WISE passbands. We also considered spectrophotometry from the Gaia mission. We find that stellar effective temperatures can be determined accurately ($\sigma \sim$ 0.01 dex or about 150 K) when reddening is negligible or known, based merely on optical photometry, and the accuracy can be improved twofold by including IR data. On the other hand, stellar metallicities and surface gravities are fairly unconstrained from optical or IR photometryy. However, our ability to retrieve these parameters can improve significantly by adding UV photometry. When reddening is considered a free parameter, assuming it can be modeled perfectly, our experiments suggest that it can be disentangled from the rest of the parameters. This theoretical study indicates that combining broad-band photometry from the UV to the mid-IR allows atmospheric parameters and interstellar extinction to be determined with fair accuracy. The use of UV passbands helps substantially to derive metallicities and surface gravities, as well as to break the degeneracy between effective temperature and reddening. The Gaia BP/RP data can disentangle all the parameters, provided the stellar SEDs are modeled reasonably well.
Network Data Feature Selection in Detecting Network Intrusion using Supervised Machine Learning Techniques

Network attacks have become necessary in today’s time due to increased network traffic. To determine whether network traffic is normal or anomalous a supervised machine learning system is developed. A network intrusion detection system (IDS) is a must-have piece of a security system. This proposed study aims to discover new patterns automatically from substantial quantities of network data, reducing time manually compiling intrusion and normal behavior patterns. The best model in terms of detection success rate was discovered using a supervised learning algorithm and feature selection method. AdaBoost outperforms Neural Network, kNN, and Naive Bayes in supervised machine learning with feature selection in this study, with a detection accuracy of 100.00%, 99.30%, 91.60%, and 99.70%, respectively. The Network Intrusion Detection dataset is used to classify network intrusions to evaluate the study and it has also been used in past studies. On the other hand, the proposed model proved to be more effective than other studies in terms of intrusion detection. The proposed approach can be used in various fields, including finance, health, and transportation. Furthermore, additional parameter tuning could be added, and different feature selection techniques could be used to improve the performance of the classifiers.
Far-Ultraviolet Spectroscopic Explorer Observations of the Magellanic Bridge Gas toward Two Early-Type Stars: Molecules, Physical Conditions, and Relative Abundances

We discuss Far Ultraviolet Spectroscopic Explorer (FUSE) observations of two early-type stars, DI 1388 (l = 291.°3, b = -41.°1) and DGIK 975 (l = 287.°3, b = -36.°0), in the low-density and low-metallicity (Z ~ 0.08 Z☉) gas of the Magellanic Bridge (MB). The data have a spectral resolution of about 15,000, and signal-to-noise ratios range between 10 and 30 per resolution element in the spectra of DI 1388 and between 7 and 11 in the spectra of DGIK 975. DI 1388 is situated near the SMC, while DGIK 975 is closer to the LMC, allowing us to probe the MB gas in a widely different locations. Toward DI 1388, the FUSE observations show molecular hydrogen, O VI, and numerous other atomic or ionic transitions in absorption, implying the presence of multiple gas phases in a complex arrangement. The relative abundance (with respect to S II) pattern in the MB along the DI 1388 sight line is attributed to varying degrees of depletion onto dust similar to that of halo clouds. The N/O ratio is near solar, much higher than N/O in damped Lyα systems, implying subsequent stellar processing to explain the origin of nitrogen in the MB. The diffuse molecular cloud in this direction has a low column density and low molecular fraction [log N(H2) ≈ 15.43 dex; fH2 ~ 10-5 to 10-4], yet two excitation temperatures (T01 = 94 K and T23 = 341 K) are needed to fit the distribution of the different rotational levels. Although this is not typically seen in the Galaxy, we show that this is not uncommon in the Magellanic Clouds. H2 is observed in both the Magellanic Stream and the MB, yet massive stars form only in the MB, implying significantly different physical processes between them. In the MB some of the H2 could have been pulled out from the SMC via tidal interaction, but some also could have formed in situ in dense clouds where star formation might have taken place. Toward DGIK 975, the presence of neutral and weakly and highly ionized species suggests that this sight line has also several complex gas phases. The highly ionized species of O VI, C IV, and Si IV toward both stars have very broad features, indicating that multiple components of hot gas at different velocities are present. C IV/O VI varies within the MB, but C IV/Si IV is relatively constant for both sight lines. Several sources (a combination of turbulent mixing layer, conductive heating, and cooling flows) may be contributing to the production of the highly ionized gas in the MB. Finally, this study has confirmed previous results that the high-velocity cloud HVC 291.5-41.2+80 is mainly ionized, composed of weakly and highly ions. The high ion ratios are consistent with a radiatively cooling gas in a fountain flow model.
Long-term simulations of multi-dimensional core-collapse supernovae: Implications for neutron star kicks

Core-collapse supernovae (CCSNe) are the final stage of massive stars, marking the birth of neutron stars (NSs). The aspherical mass ejection drives a natal kick of the forming NS. In this work we study the properties of the NS kick based on our long-term hydrodynamics CCSN simulations. We perform two-dimensional (2D) simulations for ten progenitors from a 10.8 to 20$\, M_{\odot }$ star covering a wide range of the progenitor’s compactness parameter, and two three-dimensional (3D) simulations for an 11.2$\, M_{\odot }$ star. Our 2D models present a variety of explosion energies between ∼1.3 × 1050 erg and ∼1.2 × 1051 erg, and NS kick velocities between ∼100 km s−1 and ∼1500 km s−1. For the 2D exploding models, we find that the kick velocities tend to become higher with the progenitor’s compactness. This is because the high progenitor compactness results in high neutrino luminosity from the proto-neutron star (PNS), leading to more energetic explosions. Since high-compactness progenitors produce massive PNSs, we point out that the NS masses and the kick velocities can be correlated, which is moderately supported by observation. Comparing 2D and 3D models of the 11.2$\, M_{\odot }$ star, the diagnostic explosion energy in 3D is, as previously identified, higher than that in 2D, whereas the 3D model results in a smaller asymmetry in the ejecta distribution and a smaller kick velocity than in 2D. Our results confirm the importance of self-consistent CCSN modeling covering a long-term post-bounce evolution in 3D for a quantitative prediction of the NS kicks.
Radiation effects on the Gaia CCDs after 30 months at L2

Since the launch of ESA's Gaia satellite in December 2013, the 106 large-format scientific CCDs onboard have been operating at L2. Due to a combination of the high-precision measurement requirements of the mission and the predicted proton environment at L2, the effect of non-ionizing radiation damage on the detectors was early identified pre-launch as potentially imposing a major limitation on the scientific value of the data. In this paper we compare pre-flight radiation-induced Charge Transfer Inefficiency (CTI) predictions against in-flight measurements, focusing especially on charge injection diagnostics, as well as correlating these CTI diagnostic results with solar proton event data. We show that L2-directed solar activity has been relatively low since launch, and radiation damage (so far) is less than originally expected. Despite this, there are clear cases of correlation between earth-directed solar coronal mass ejection events and abrupt changes in CTI diagnostics over time. These sudden jumps are lying on top of a rather constant increase in CTI which we show is primarily due to the continuous bombardment of the devices by high-energy Galactic Cosmic Rays. We examine the possible reasons for the lower than expected levels of CTI as well as examining the effect of controlled payload heating events on the CTI diagnostics. Radiation-induced CTI in the CCD serial registers and effects of ionizing radiation are also correspondingly lower than expected, however these topics are not examined here in detail.
Superluminous supernova progenitors have a half-solar metallicity threshold

Host galaxy properties provide strong constraints on the stellar progenitors of superluminous supernovae. By comparing a sample of 19 low-redshift (z < 0.3) superluminous supernova hosts to galaxy populations in the local Universe, we show that sub-solar metallicities seem to be a requirement. All superluminous supernovae in hosts with high measured gas-phase metallicities are found to explode at large galactocentric radii, indicating that the metallicity at the explosion site is likely lower than the integrated host value. We found that superluminous supernova hosts do not always have star formation rates higher than typical star-forming galaxies of the same mass. However, we confirm that high absolute specific star formation rates are a feature of superluminous supernova host galaxies, but interpret this as simply a consequence of the anticorrelation between gas-phase metallicity and specific star formation rate and the requirement of on-going star formation to produce young, massive stars greater than ∼10–20 M⊙. Based on our sample, we propose an upper limit of ∼0.5Z ⊙ ∼0.5Z⊙ for forming superluminous supernova progenitors (assuming an N2 metallicity diagnostic and a solar oxygen abundance of 8.69). Finally, we show that if magnetar powering is the source of the extreme luminosity, then the required initial spins appear to be correlated with metallicity of the host galaxy. This correlation needs further work, but if it applies, it is a powerful link between the supernova parameters and nature of the progenitor population.
A SHORT GAMMA-RAY BURST “NO-HOST” PROBLEM? INVESTIGATING LARGE PROGENITOR OFFSETS FOR SHORT GRBs WITH OPTICAL AFTERGLOWS

We investigate the afterglow properties and large-scale environments of several short-duration gamma-ray bursts (GRBs) with subarcsecond optical afterglow positions but no bright coincident host galaxies. The purpose of this joint study is to robustly assess the possibility of significant offsets, a hallmark of the compact object binary merger model. Five such events exist in the current sample of 20 short bursts with optical afterglows, and we find that their optical, X-ray, and γ-ray emission are systematically fainter. These differences may be due to lower circumburst densities (by about an order of magnitude), to higher redshifts (by Δz ≈ 0.5–1), or to lower energies (by about a factor of 3), although in the standard GRB model the smaller γ-ray fluences cannot be explained by lower densities. To study the large-scale environments, we use deep optical observations to place limits on underlying hosts and to determine probabilities of chance coincidence for galaxies near each burst. In four of the five cases, the lowest probabilities of chance coincidence (P(<δR) ∼ 0.1) are associated with bright galaxies at separations of δR ∼ 10″, while somewhat higher probabilities of chance coincidence are associated with faint galaxies at separations of ∼2″. By measuring redshifts for the brighter galaxies in three cases (z = 0.111, 0.473, 0.403), we find physical offsets of ≈30–75 kpc, while for the faint hosts the assumption of z ≳ 1 leads to offsets of ∼15 kpc. Alternatively, the limits at the burst positions (≳26 mag) can be explained by typical short GRB host galaxies (L ≈ 0.1–1 L*) at z ≳ 2–3. Thus, two possibilities exist: (1) ∼1/4 of short GRBs explode ∼50 kpc or ∼15 kpc from the centers of z ∼ 0.3 or z ≳ 1 galaxies, respectively, and have fainter afterglows due to the resulting lower densities; or (2) ∼1/4 of short GRBs occur at z ≳ 2 and have fainter afterglows due to their higher redshifts. The high-redshift scenario leads to a bimodal redshift distribution, with peaks at z ∼ 0.5 and z ∼ 3. The large offset scenario leads to an offset distribution that is well matched by theoretical predictions of NS–NS/NS–BH binary kicks, or by a hybrid population with globular cluster NS–NS binaries at large offsets and primordial binaries at offsets of ≲10 kpc (indicative of negligible kicks). Deeper constraints on any coincident galaxies to ≳28 mag (using the Hubble Space Telescope) will allow us to better exclude the high-redshift scenario.
Boundedness of solutions of measure differential equations

Many types of hybrid systems can be modeled by measure differential equations, in which Zeno behavior is allowed. This paper investigates uniform boundedness and uniformly ultimate boundedness of nonlinear measure differential equations in Banach spaces. The sufficient criteria of uniform boundedness and uniformly ultimate boundedness of the system are obtained by using Lyapunov functions in the lack of Lipschitz continuity assumptions. Furthermore, an important condition in the existing boundedness results of the system in the literature is not necessary here. Thus less conservative criteria of the boundedness of measure differential equations than those in the literature are deduced. As special cases, we also provide the less conservative criteria of the boundedness of dynamic equations on time scales and impulsive differential equations than those in the literature.
A Comparative Study on the Perceived Attractiveness of Oriental and South Asian Faces

The computation of perceived attractiveness from facial images has long been a research topic. Many models have been developed to predict the attractiveness of the face from the individual models that have been used to describe the geometry of the face (symmetry, golden ratio and neoclassical canons, according to artists from the Middle Ages, and a combination of the three). An experiment was conducted based on Oriental and South Asian ethnic groups, represented by Chinese and Pakistani facial images. Visual assessments of perceived attractiveness were carried out using a 6-point categorical scale and the results were used to derive a new set of facial feature ratios that maximized the perceived attractiveness of the two ethnic groups. The results were also used to develop a new polynomial model of attractiveness, and to test four existing models. The new model performed the best for Oriental faces. The new model was also best for South Asian faces together with the combined model. Ethnic group differences did not have a significant impact on the perceived attractiveness of the two groups. A set of new facial ratios for the two ethnic groups was determined to maximise attractiveness.