ShantanuT01/DACTYL-Pretraining huggingface dataset:
Neural style transfer (NST) can create impressive artworks by transferring reference style to content image. Current image-to-image NST methods are short of fine-grained controls, which are often demanded by artistic editing. To mitigate this limitation, we propose a drawing-like interactive style transfer (IST) method, by which users can interactively create a harmonious-style image. Our IST method can serve as a brush, dip style from anywhere, and then paint to any region of the target content image. To determine the action scope, we formulate a fluid simulation algorithm, which takes styles as pigments around the position of brush interaction, and diffusion in style or content images according to the similarity maps. Our IST method expands the creative dimension of NST. By dipping and painting, even employing one style image can produce thousands of eye-catching works. The demo video is available in supplementary files or in http://mmcheng.net/ist.
We address a possibility of the flare process initiation and further maintenance of its energy release due to a transformation of sunspot longitudinal waves into transverse magnetic loop oscillations with initiation of reconnection. This leads to heating maintaining after the energy release peak and formation of a flat stage on the X-ray profile. We applied the time-distance plots and pixel wavelet filtration (PWF) methods to obtain spatio-temporal distribution of wave power variations in SDO/AIA data. To find magnetic waveguides, we used magnetic field extrapolation of SDO/HMI magnetograms. The propagation velocity of wave fronts was measured from their spatial locations at specific times. In correlation curves of the 17 GHz (NoRH) radio emission we found a monotonous energy amplification of 3-min waves in the sunspot umbra before the 2012 June 7 flare. This dynamics agrees with an increase in the wave-train length in coronal loops (SDO/AIA, 171 {\AA}) reaching the maximum 30 minutes prior to the flare onset. A peculiarity of this flare time profile in soft X-rays (RHESSI, 3-25 keV) is maintaining the constant level of the flare emission for 10 minutes after the short impulse phase, which indicates at the energy release continuation. Throughout this time, we found 30-sec period transverse oscillations of the flare loop in the radio-frequency range (NoRH, 17 GHz). This periodicity is apparently related to the transformation of propagating longitudinal 3-min waves from the sunspot into the loop transverse oscillations. The magnetic field extrapolation showed the existence of the magnetic waveguide (loop) connecting the sunspot with the energy release region. A flare loop heating can be caused by the interaction (reconnections) of this transversally oscillating waveguide with the underlying twisted loops.
Excited-state relaxations in molecules are responsible for a red shift of the absorption peak with respect to the emission peak (Franck-Condon shift). The magnitude of this shift in semiconductor quantum dots is still unknown. Here we report first-principle calculations of excited-state relaxations in small (diameter < 2.2 nm) Si nanocrystals, showing that the Franck-Condon shift is surprisingly large (~60 meV for a 2.2 nm-diameter nanocrystal). The physical mechanism of the excited-state relaxations changes abruptly around 1 nanoeter in size, providing a clear demarcation between ``molecules'' and ``nanocrystals''.
A classical and a relativistic law of motion for an advancing shell are deduced applying the thin layer approximation. A new parameter connected with the quantity of absorbed matter in the expansion is introduced; this allows of matching theory and observation.
Visual Question Answering (VQA) has attracted a lot of attention in both Computer Vision and Natural Language Processing communities, not least because it offers insight into the relationships between two important sources of information. Current datasets, and the models built upon them, have focused on questions which are answerable by direct analysis of the question and image alone. The set of such questions that require no external information to answer is interesting, but very limited. It excludes questions which require common sense, or basic factual knowledge to answer, for example. Here we introduce FVQA, a VQA dataset which requires, and supports, much deeper reasoning. FVQA only contains questions which require external information to answer.   We thus extend a conventional visual question answering dataset, which contains image-question-answerg triplets, through additional image-question-answer-supporting fact tuples. The supporting fact is represented as a structural triplet, such as <Cat,CapableOf,ClimbingTrees>.   We evaluate several baseline models on the FVQA dataset, and describe a novel model which is capable of reasoning about an image on the basis of supporting facts.
I describe the disk mass-rotation velocity relation which underpins the familiar luminosity-linewidth relation. Continuity of this relation favors nearly maximal stellar mass-to-light ratios. This contradicts the low mass-to-light ratios implied by the lack of surface brightness dependence in the same relation.
Upper bounds for neutral as well as charged Higgs boson masses in a two-doublet model are obtained on the basis of tree unitarity conditions \`a la Lee, Quigg and Thacker. A wide variety of scattering processes are considered so extensively that our bounds are more restrictive than those obtained previously for neutral Higgs bosons and are also of a new kind for charged Higgs boson. It is argued that at least one of the Higgs bosons should be lighter than 580 ${\rm GeV}/c^{2}$.
Fluid dynamical models preceded the first heavy ion accelerator experiments, and led to the main trend of this research since then. In recent years fluid dynamical processes became a dominant direction of research in high energy heavy ion reactions. The Quark-gluon Plasma formed in these reactions has low viscosity, which leads to significant fluctuations and turbulent instabilities. One has to study and separate these two effects, but this is not done yet in a systematic way. Here we present a few selected points of the early developments, the most interesting collective flow instabilities, their origins, their possible ways of detection and separation form random fluctuations arising from different origins, among these the most studied is the randomness of the initial configuration in the transverse plane.
Within time-dependent density functional theory, combined with the Korringa-Kohn-Rostoker Green functions, we devise a real space method to investigate spin dynamics. Our scheme enables one to deduce the Coulomb potential which assures a proper Goldstone mode is present. We illustrate with application to 3$d$ adatoms and dimers on Cu(100).
Autonomous driving vehicles and robotic systems rely on accurate perception of their surroundings. Scene understanding is one of the crucial components of perception modules. Among all available sensors, LiDARs are one of the essential sensing modalities of autonomous driving systems due to their active sensing nature with high resolution of sensor readings. Accurate and fast semantic segmentation methods are needed to fully utilize LiDAR sensors for scene understanding. In this paper, we present Lite-HDSeg, a novel real-time convolutional neural network for semantic segmentation of full $3$D LiDAR point clouds. Lite-HDSeg can achieve the best accuracy vs. computational complexity trade-off in SemanticKitti benchmark and is designed on the basis of a new encoder-decoder architecture with light-weight harmonic dense convolutions as its core. Moreover, we introduce ICM, an improved global contextual module to capture multi-scale contextual features, and MCSPN, a multi-class Spatial Propagation Network to further refine the semantic boundaries. Our experimental results show that the proposed method outperforms state-of-the-art semantic segmentation approaches which can run real-time, thus is suitable for robotic and autonomous driving applications.
Assuming only a hierarchical structure of the heavy Majorana neutrino masses and of the neutrino Dirac mass matrix m_D of the see-saw mechanism, we find that in order to produce the observed baryon asymmetry of the Universe via leptogenesis, the scale of m_D should be given by the up-quark masses. Lepton flavor violating decays \mu \to e + \gamma, \tau \to \mu + \gamma and \tau \to e + \gamma are considered and a characteristic relation between their decay rates is predicted. The effective Majorana mass in neutrinoless double beta decay depends on the CP violating phase controlling the leptogenesis if one of the heavy Majorana neutrinos is much heavier than the other two. Successful leptogenesis requires a rather mild mass hierarchy between the latter. The compatibility of this hierarchical see-saw model with the low energy neutrino mixing phenomenology requires that the mixing angle limited by the CHOOZ and Palo Verde experiments should be relatively large, \sin^2\theta_3 \gtap 0.01. The CP violation effects in neutrino oscillations can be observable. In general, there is no direct connection between the latter and the CP violation in leptogenesis. If the CP violating phases of the see-saw model satisfy certain relations, the baryon asymmetry of the Universe and the rephasing invariant J_{CP} which determines the magnitude of the CP violation effects in neutrino oscillations, depend on the same CP violating phase and their signs are correlated.
The total cross section for electron-positron annihilation into hadrons is calculated in the region just below the B meson threshold. QCD corrections up to third order, quark mass effects, initial state radiation, the running of alpha_QED and the tails of the Upsilon resonances are included in the prediction. For given alpha_s the prediction is accurate to 0.5 percent. An experimental measurement with the corresponding precision would allow to determine alpha_s with high accuracy at intermediate energies.
We present results from {\it XMM-Newton/RGS} observations of prominent knots in the southest portion of Tycho's supernova remnant, known to be the remnant of a Type Ia SN in 1572 C.E. By dispersing the photons from these knots out of the remnant with very little emission in front of or behind them, we obtained the nearly uncontaminated spectra of the knots. In the southernmost knot, the RGS successfully resolved numerous emission lines from Si, Ne, O He$\alpha$ and Ly$\alpha$, and Fe L-shell. This is the first clear detection of O lines in Tycho's SNR. Line broadening was measured to be $\sim 3$ eV for the O He$\alpha$ and $\sim 4.5$ eV for Fe L lines. If we attribute the broadening to pure thermal Doppler effects, then we obtain kT$_{O}$ and kT$_{Fe}$ to be $\sim 400$ keV and 1.5 MeV, respectively. These temperatures can be explained by heating in a reverse shock with a shock velocity of $\sim 3500$ km s$^{-1}$. The abundances obtained from fitting the RGS and MOS data together imply substantially elevated amounts of these materials, confirming previous studies that the knots are heated by a reverse shock, and thus contain ejecta material from the supernova. We are unable to find a Type Ia explosion model that reproduces these abundances, but this is likely the result of this knot being too small to extrapolate to the entire remnant.
These are expanded notes of the mini-courses on Pila's work that Yuri Bilu gave in Basel in April 2011, Yaroslavl in August 2011 and Chennai in February 2012. The topics covered include the Bombieri-Pila theorem, its extensions and applications to some prominent conjectures (Manin-Mumford, Andr\'e-Oort).
In this article we review the ideas in Tsai (2018) toward proving the one-point, lower-tail large deviation principle for the Kardar--Parisi--Zhang equation.
We are concerned with random walks on $\mathbb{Z}^d$, $d\geq 3$, in an i.i.d. random environment with transition probabilities $\epsilon$-close to those of simple random walk. We assume that the environment is balanced in one fixed coordinate direction, and invariant under reflection in the coordinate hyperplanes. The invariance condition was used in Baur and Bolthausen (2014) as a weaker replacement of isotropy to study exit distributions. We obtain precise results on mean sojourn times in large balls and prove a quenched invariance principle, showing that for almost all environments, the random walk converges under diffusive rescaling to a Brownian motion with a deterministic (diagonal) diffusion matrix. We also give a concrete description of the diffusion matrix. Our work extends the results of Lawler (1982), where it is assumed that the environment is balanced in all coordinate directions.
Large-scale distributions of hot-gas temperature and Fe abundance in the Perseus cluster have been studied with multi-pointing observations by the GIS instrument on ASCA. Within a radius of 20' from the cluster center, the energy spectra requires two temperature components, in which the cool component indicates kT ~ 2 keV and the hot-component temperature shows a significant decline from about 8 keV to 6 keV toward the center. In the outer region of the cluster, the temperature shows a fluctuation with an amplitude of about 2 keV and suggest that a western region at ~16' from the cluster center is relatively hotter. As for the Fe abundance, a significant decline with radius is detected from 0.44 solar at the center to ~0.1 solar at a 50' offset region. If observed Fe-K line intensity within 4' from the center is suppressed by a factor of 2 due to the resonance scattering effect, the corrected Fe mass density follows the galaxy distribution. Finally, our results do not support the large-scale velocity gradients previously reported from the same GIS data.
The joint distribution of the maximum loss and the maximum gain is obtained for a spectrally negative Levy process until the passage time of a given level. Their marginal distributions up to an independent exponential time are also provided. The existing formulas for Brownian motion with drift are recovered using the particular scale functions.Keywords Maximum drawdown Maximum drawup Spectrally negative Reflected process Fluctuation theory
Using the Glauber theory, we calculate reaction cross sections for the deformed halo nucleus $^{31}$Ne. To this end, we assume that the $^{31}$Ne nucleus takes the $^{30}$Ne + $n$ structure. In order to take into account the rotational excitation of the core nucleus $^{30}$Ne, we employ the particle-rotor model (PRM). We compare the results to those in the adiabatic limit of PRM, that is, the Nilsson model, and show that the Nilsson model works reasonably well for the reaction cross sections of $^{31}$Ne. We also investigate the dependence of the reaction cross sections on the ground state properties of $^{31}$Ne, such as the deformation parameter and the p-wave component in the ground state wave function.
We characterize the statistical properties of a large number of agents on two major online auction sites. The measurements indicate that the total number of bids placed in a single category and the number of distinct auctions frequented by a given agent follow power-law distributions, implying that a few agents are responsible for a significant fraction of the total bidding activity on the online market. We find that these agents exert an un-proportional influence on the final price of the auctioned items. This domination of online auctions by an unusually active minority may be a generic feature of all online mercantile processes.
Using the new framework of graph separations developed recently by Diestel and Oum, we show that there is a natural witness to large branch-width which can be defined in a similar way to a bramble. We also apply our methods to a more recent object of study in the area, a common generalization of tangles and blocks, called profiles.
We present a photometric study of two new double-mode Cepheids, pulsating in the first and second overtones modes: V470 Cas and GSC 2901-00089. For the search of the double-mode variability, we used all available observations from the ROTSE-I/NSVS and SuperWASP online public archives. Our multicolour CCD observations in the B, V and R bands in Johnson's system confirm the double periodicity of these variables. We study period variations of the two stars; variations of the first overtone periods were reliably detected. In addition, we consider the Petersen diagram for the Galactic 1O/2O Cepheids.
We present a new method for simulating Markovian jump processes with time-dependent transitions rates, which avoids the transformation of random numbers by inverting time integrals over the rates. It relies on constructing a sequence of random time points from a homogeneous Poisson process, where the system under investigation attempts to change its state with certain probabilities. With respect to the underlying master equation the method corresponds to an exact formal solution in terms of a Dyson series. Different algorithms can be derived from the method and their power is demonstrated for a set of interacting two-level systems that are periodically driven by an external field.
Transits of single atoms through higher-order Hermite-Gaussian transverse modes of a high-finesse optical cavity are observed. Compared to the fundamental Gaussian mode, the use of higher-order modes increases the information on the atomic position. The experiment is a first experimental step towards the realisation of an atomic kaleidoscope.
In this paper, the work function of graphene doped by different metal adatoms and at different concentrations is investigated. Density functional theory is used to maximize the reduction of the work function. In general, the work function drops significantly before reaching saturation. For example in the case of Cs doping, the work function saturates at 2.05 eV with a modest 8 % doping. The adsorption of different concentrations on metal adatoms on graphene is also studied. Our calculations show that the adatoms prefer to relax at hollow sites. The transfer of electron from metallic dopants to the graphene for all the studied systems shifts the Fermi energy levels above the Dirac-point and the doped graphenes become metallic. The value of Fermi energy shifts depends on the type of metallic dopants and its concentrations. A detail analysis of the electronic structure in terms of band structure and density of states, absorption energy, and charge transfer for each adatom-graphene system is presented.
Magnetism in two-dimensional materials is not only of fundamental scientific interest but also a promising candidate for numerous applications. However, studies so far, especially the experimental ones, have been mostly limited to the magnetism arising from defects, vacancies, edges or chemical dopants which are all extrinsic effects. Here, we report on the observation of intrinsic antiferromagnetic ordering in the two-dimensional limit. By monitoring the Raman peaks that arise from zone folding due to antiferromagnetic ordering at the transition temperature, we demonstrate that FePS3 exhibits an Ising-type antiferromagnetic ordering down to the monolayer limit, in good agreement with the Onsager solution for two-dimensional order-disorder transition. The transition temperature remains almost independent of the thickness from bulk to the monolayer limit with TN ~118 K, indicating that the weak interlayer interaction has little effect on the antiferromagnetic ordering.
Thermoelectric measurements have the potential to uncover the density of states of low-dimensional materials. Here, we present the anomalous thermoelectric behaviour of mono-layer graphene-nanowire (NW) heterostructures, showing large oscillations as a function of doping concentration. Our devices consist of InAs NW and graphene vertical heterostructures, which are electrically isolated by thin ($\sim$ 10nm) hexagonal boron nitride (hBN) layers. In contrast to conventional thermoelectric measurements, where a heater is placed on one side of a sample, we use the InAs NW (diameter $\sim 50$ nm) as a local heater placed in the middle of the graphene channel. We measure the thermoelectric voltage induced in graphene due to Joule heating in the NW as a function of temperature (1.5K - 50K) and carrier concentration. The thermoelectric voltage in bilayer graphene (BLG)- NW heterostructures shows sign change around the Dirac point, as predicted by Mott's formula. In contrast, the thermoelectric voltage measured across monolayer graphene (MLG)-NW heterostructures shows anomalous large-amplitude oscillations around the Dirac point, not seen in the Mott response derived from the electrical conductivity measured on the same device. The anomalous oscillations are a signature of the modified density of states in MLG by the electrostatic potential of the NW, which is much weaker in the NW-BLG devices. Thermal calculations of the heterostructure stack show that the temperature gradient is dominant in the graphene region underneath the NW, and thus sensitive to the modified density of states resulting in anomalous oscillations in the thermoelectric voltage. Furthermore, with the application of a magnetic field, we detect modifications in the density of states due to the formation of Landau levels in both MLG and BLG.
Galaxy redshift surveys are subject to incompleteness and inhomogeneous sampling due to the various constraints inherent to spectroscopic observations. This can introduce systematic errors on the summary statistics of interest, which need to be mitigated in cosmological analysis to achieve high accuracy. Standard practices involve applying weighting schemes based on completeness estimates across the survey footprint, possibly supplemented with additional weighting schemes accounting for density-dependent effects. In this work, we concentrate on pure angular systematics and describe an alternative approach consisting in analysing the galaxy two-point correlation function where angular modes are nulled. By construction, this procedure removes all possible known and unknown sources of angular observational systematics, but also part of the cosmological signal.We use a modified Landy-Szalay estimator for the two-point correlation function that relies on an additional random catalogue where angular positions are randomly drawn from the galaxy catalogue, and provide an analytical model to describe this modified statistic. We test the model by performing an analysis of the full anisotropic clustering in mock catalogues of luminous red and emission-line galaxies at 0.43 < z < 1.1. We find that the model fully accounts for the modified correlation function in redshift space, without introducing new nuisance parameters. The derived cosmological parameters from the analysis of baryon acoustic oscillations and redshift-space distortions display slightly larger statistical uncertainties, mostly for the growth rate of structure parameter fs8 that exhibits a 50% statistical error increase, but free from angular systematic error.