Miracle-dz/UniFAR-FTUs huggingface dataset:
A P ] 2 7 M ay 2 01 4 THE BI-DIMENSIONAL EULER EQUATIONS IN YUDOVICH TYPE SPACE AND bmo-TYPE SPACE

The present paper is devoted to the study of the global solution existence and uniqueness of the bi-dimensional Euler equations in Yudovich type space and bmo-type space. We first show the global regularity of the bi-dimensional Euler equations in the Spanne space involving unbounded and non-decaying vorticity. Next, we establish the estimate with a logarithmic loss of regularity for the transport equation in bmo-type space by developing the classical analysis tool such as the John-Nirenberg inequality. Based on this, we further optimize the control estimates for the vorticity-stream formulation of the bi-dimensional Euler equations with a bi-Lipschitz vector field in bmo-type space, by combining an observation introduced in [25] and the so-called “quasi-conformal property” of the incompressible flow.
External flow computations using global boundary conditions

We numerically integrate the compressible Navier-Stokes equations by means of a finite volume technique on the domain exterior to an airfoil. The curvilinear grid we use for discretization of the Navier-Stokes equations is obviously finite, it covers only a certain bounded region around the airfoil, consequently, we need to set some artificial boundary conditions at the external boundary of this region. The artificial boundary conditions we use here are non-local in space. They are constructed specifically for the case of steady-state solution. In constructing the artificial boundary conditions, we linearize the Navier-Stokes equations around the far-field solution and apply the difference potentials method. The resulting global conditions are implemented together with a pseudotime multigrid iteration procedure for achieving the steady state. The main goal of this paper is to describe the numerical procedure itself, therefore, we primarily emphasize the computation of artificial boundary conditions and the combined usage of these artificial boundary conditions and the original algorithm for integrating the Navier-Stokes equations. The underlying theory that justifies the proposed numerical techniques will accordingly be addressed more briefly.
Microphysical and short‐wave radiative structure of stratocumulus clouds over the Southern Ocean: Summer results and seasonal differences

Six case‐studies are presented of stratocumulus clouds observed during the summer phase of the Southern Ocean Cloud EXperiment (SOCEX). The experiment was conceived to investigate the microphysical properties of clouds in the unpolluted background region over the Southern Ocean. The case‐studies show evidence of decoupled stratocumulus layers, i.e. situations where cumulus clouds were covered by a uniform sheet of stratocumulus cloud. Optical depths of the clouds ranged from 2 to 23. Cloud droplet concentrations varied from 50 to 180cm−3, and mostly decreased with altitude, indicating the importance of droplet coalescence in reducing the number of large cloud droplets. Drizzle was observed on four of the six flights.
Evolution of binaries in the field of light particles and the problem of two black holes

Numerical experiments in the framework of the elliptic restricted three-body problem have been applied to obtain the effects of dynamical friction on the evolution of a binary in the field of light particles. Rate coefficients are derived for the evolution of the energy and angular momentum of the heavy binary. The results are compared with an N-body simulation and also with recent theoretical estimates for the case of high-velocity particles. Good agreement is observed in all the comparisons. The angular momentum transfer rate allows us to estimate the evolution of the eccentricity of the binary
Performance of gain-guided surface emitting lasers with semiconductor distributed Bragg reflectors

The performance limitations of gain-guided vertical cavity surface emitting lasers (VCSELs) which use epitaxially grown semiconductor distributed Bragg reflectors (DBRs) are discussed. The light-current (L-I) characteristics and emission wavelength of such lasers are examined as a function of temperature and time under continuous wave (CW) and pulsed operation. The authors observed a sharp roll-over in the CW L-I characteristics which limits the maximum output power. The threshold current under CW operation is found to be lower than that obtained under pulsed conditions. Several microseconds long delay in lasing turn-on is also observed. It is shown quantitatively that these anomalies are a consequence of severe heating effects. It is shown that reduction of the series resistance and threshold current density can lead to significant improvements in the power performance of VCSELs. >
Is data the new oil? Diminishing returns to scale

A key advantage of online advertising over offline is that online advertising can, with sufficient data, be far more accurately targeted than traditional advertising. But how much data is enough? The empirical literature tends to suggest that there are indeed economies of scale in using data for market targeting, but that these benefits are subject to diminishing returns in a static perspective. Is there a plateau, and is it perhaps very large? It is clear that a certain amount of data is necessary to identify meaningful consumer segments and to offer targeted advertising space as part of an advertising campaign; however, a simple correlation between the volume of data gathered by an advertiser and the return on investment of an advertising campaign neglects the complexity of advertising effectiveness. We provide a general assessment of key elements of the literature on economies of scale in the use of data for online advertising, and then seek to link these to the general literature on market targeting in order to provide insights as to the factors that limit effectiveness in using big data for market targeting.
Structure of Perceptions of Service Quality in Libraries: A LibQUAL+(tm) Study

The 25-item LibQUAL+TM protocol has been developed over a series of large-scale studies originally grounded in careful qualitative work. This study for the first time invoked confirmatory factor analysis to evaluate LibQUAL+TM score integrity. Participants were 60,027 undergraduate students, graduate students, and faculty from 146 colleges and universities in the United States and Canada. The results suggest that the model implied by LibQUAL+TM scoring (a) is reasonable, (b) is invariant across independent samples, and (c) fits all 3 major subgroups of library users.
The finite volume method solution of the radiative transfer equation for photon transport in non-thermal gas discharges: application to the calculation of photoionization in streamer discharges

This paper presents the development of a direct accurate numerical method to solve the monochromatic radiative transfer equation (RTE) based on a finite volume method (FVM) and its application to the simulation of streamer propagation. The validity of the developed model is demonstrated by performing direct comparisons with results obtained using the classic integral model. Comparisons with approximate solutions of the RTE (Eddington and SP3 models) are also carried out. Specific validation comparisons are presented for an artificial source of radiation with a Gaussian shape. The reported results demonstrate that whatever the value of the absorption coefficient, the results obtained using the direct FVM are in excellent agreement with the reference integral model with a significantly reduced computation time. When the absorption coefficient is high enough, the Eddington and SP3 methods are as accurate and become faster than the FVM. However, when the absorption coefficient decreases, approximate methods become less accurate and more computationally expensive than the FVM. Then the direct finite volume and the SP3 models have been applied to the calculation of photoionization in a double-headed streamer at ground pressure. For high values of the absorption coefficient, positive and negative streamers calculated using the SP3 model and the FVM for the photoionization source term are in excellent agreement. As the value of the absorption coefficient decreases, discrepancies between the results obtained with the finite volume and the SP3 models increase, and these differences increase as the streamers advance. For low values of the absorption coefficient, the use of the SP3 model overestimates the electron density and underestimates the photoionization source term in both streamers in comparison with the FVM. As a consequence, for low values of the absorption coefficient, positive and negative streamers calculated using the SP3 model for the photoionization source term propagate more slowly than those calculated using the FVM.
Nonlinearities in block-type reduced-order vocal fold models with asymmetric tissue properties

Modeling the vocal fold structure as a reduced-order system is an attractive approach for exploring the dynamics of both normal and pathological phonation. This approach has been used ubiquitously in scientific speech investigations due to its relatively high order of accuracy and low computational cost. In addition, good agreement can also be found between model and clinical data. In the case of pathological speech complex vocal fold dynamics may exist, exhibiting phenomenon such as bifurcation, and chaos. The ability to capture these features in reduced-order vocal fold models is a much celebrated feature. However, the question has arisen whether these nonlinearities arise due to the physics, or if they are merely an artifact of the model and its sensitivity to initial and boundary conditions. We explore the sensitivity of commonly-employed reduced-order vocal fold models to both contact mechanics, and the geometric prescription of the vocal fold model. Nonlinearities arising from asymmetric vocal fold .
Droplet shape and reorientation fields in nematic droplet/polymer films

Abstract Polymer films containing droplets of nematic liquid crystal form an important class of new electro-optic light valves and displays. While previous work has shown that the nematic droplet size is an important factor in the electro-optic properties of these films, here we report that the droplet shape is equally important in determing the electro-optics of the film. Electron micrographs show that for films using polyvinyl alcohol as the polymeric binder the cavities formed by the polymer matrix are oblate in nature, and aligned with the minor axis perpendicular to the film plane. In oblate cavities the elastic-deformation free energy is minimized when the director field in the droplet is aligned along a major axis of the spheroid; the electric field performs work on the nematic in reorienting the nematic into a higher-energy state, equal to the elastic-free-energy difference between the two configurations. Calculations and experiment are used to estimate the elastic and electric field free-energy-d.
Mathematical and computational modelling within a music analysis framework: motivic topologies as a case study

This paper revisits a mathematical model of motivic analysis, together with its computational realization, from an interdisciplinary perspective, relating it to concepts and methods in the field of computational music analysis. Issues such as segmentation, motivic formation, knowledge representation, similarity and categorization, and interpretation of results are discussed. A further introspection on the approach, in the context of mathematics, computation, and music analysis as a large interdisciplinary field, reveals relations between the three: the mathematical model (motivic topologies), its computational counterpart (OM-Melos), and music analysis (Réti's and Nattiez’ methods). In doing so, we stress the importance of neutrality, objectivity, and scientific rigour in the modelling part while at the same time preserving the freedom of the music analyst in order to create musically interesting results.
Secondary instability in rotating-disk flow

Primary instability of the three-dimensional boundary layer on a rotating disk introduces periodic modulation of the mean flow in the form of stationary crossflow vortices. Here we study the stability of this modulated mean flow with respect to secondary disturbances. These secondary disturbances are found to have quite large growth rates compared to primary disturbances. Both fundamental and subharmonic resonance cases are considered and their corresponding results indicate that the growth rate and the frequency of the secondary instability are insensitive to the exact nature of the resonance condition. The threshold primary stationary crossflow vortex amplitude for secondary instability found in this three-dimensional incompressible boundary layer is significantly larger than that for a two-dimensional boundary layer which is subjected to Tollmien–Schlichting instability. The secondary instability results in a pair of travelling counter-rotating vortices, tilted up and oriented at an angle to the primary stationary crossflow vortices. The computed velocity signals and flow visualization, evaluated based on this secondary disturbance structure, are compared with experimental results.
Improved Delayed Detached Eddy Simulation modeling and far-field trailing-edge noise estimation of a sharp-edged symmetric strut

This paper presents results of a Computational Fluid Dynamic (CFD) study of a sharp-edged symmetric flat strut at Reynolds number 500,000 based on chord at zero degrees angle of attack, and the subsequent estimation of far-field noise generated at the trailing-edge. Flow field results obtained using Improved Delayed Detached Eddy Simulation (IDDES) modelling and Reynolds-Averaged Navier Stokes (RANS) modelling techniques are compared with empirical wind-tunnel data. The flow is observed to be physically complex in nature, exhibiting numerical solutions that are sensitive to the mesh grid and freestream turbulence intensity. Although originally developed for use specifically with RANS-generated flow data, the RANS-based Statistical Noise Model (RSNM) technique, which estimates far-field noise from mean turbulence data via an acoustic Green's function and a statistical turbulence correlation model, is used here to estimate far-field noise spectra from both RANS and IDDES flow data. Far-field noise is also e.
Classical Aspects of Energy Transfer in Molecular Systems

The decay time of the luminescence of a molecule S in front of a metal mirror depends markedly on its distance from the mirror. This phenomenon is quantitatively explained by considering the radiation field of this dipole, given by Hertz classical equation. This field arrives at the molecule, after being reflected at the mirror, with a retardation of the order of 10−15 sec. The decay time of the luminescence depends on the phase shift produced by this retardation, and thus on the ratio of the distance of the oscillator from the mirror, and the wavelength of the emitted light. By measuring the distance dependence of the decay time of the luminescence this retardation effect can be studied. In quantum‐mechanical terms the phenomenon can be described as being due to a stimulation or inhibition of the emission of the light quantum. In contrast to the known cases of stimulated emission, the stimulating field is the radiation field of the emitter quantum itself. The energy transfer from an excited molecule S to.
Percolation behaviour of permeable and of adhesive spheres

The pair-connectedness function and the average cluster size are determined for two different three-dimensional fluid systems using the Percus-Yevick (PY) approximation (1980). The permeable-sphere model of Blum and Stell (1980) provides a one-parameter bridge from the ideal gas (perfectly penetrable spheres) to the PY hard-sphere fluid. Two of such particles are considered to be 'bound' when their cores overlap. The percolation transition is located as a function of the interpenetrability of the particles, and is found to correspond to an average coordination number z=4. Baxter's adhesive-sphere model (1968) is also investigated in the PY approximation and it is found that at the percolation transition the average coordination number is 2. The boundary between percolating and non-percolating homogeneous thermodynamic states is determined.
Adaptive EAP Estimation of Ability in a Microcomputer Environment

Expected a posteriori (EAP) estimation of ability, based on numerical evaluation of the mean and variance of the posterior distribution, is shown to have unusually good properties for computerized adaptive testing. The calculations are not complex, precede noniteratively by simple summation of log likelihoods as items are added, and require only values of the response function obtainable from precalculated tables at a limited number of quadrature points. Simulation studies are reported showing the near equivalence of the posterior standard deviation and the standard error of measurement. When the adaptive testings terminate at a fixed posterior standard deviation criterion of . 90 or better, the regression of the EAP estimator on true ability is virtually linear with slope equal to the reliability, and the measurement error homogeneous, in the range ± 2.5 standard deviations.
A QUANTUM THEORY OF GRAVITY BASED ON A COMPOSITE MODEL OF LEPTONS AND QUARKS

A quantum theory of gravity, based upon a composite model of leptons and quarks, is presented. The model treats leptons and quarks as composites of three kinds of spin- particles (rishons) and/or their antiparticles. A strong color force, mediated by massless hypergluons, binds rishons and/or antirishons together to form colorless leptons or colored quarks, the fundamental particles of the Standard Model. The new model provides a qualitative understanding of the mass hierarchy of the three generations of leptons and quarks. An earlier conjecture that the residual interaction of the strong color force acting between any two colorless particles be identified with the corresponding gravitational interaction, is shown to lead approximately to Newton's law of gravitation.
Comparison of Support Vector Machines to Other Classifiers Using Gene Expression Data

ABSTRACT Support vector machines (SVMs) was shown to outperform Fisher's linear discriminant analysis and two classification trees (C4.5 and MOC1) in binary classification of microarray gene expression data (MGED) (Brown et al., 2000; Furey et al. 2000). However, multiclass classification is more commonly encountered in identifying tumor subtypes using MGED. Using MGED, Dudoit et al. (2002) showed that diagonal linear discriminant analysis (DLDA) outperformed other linear and quadratic discriminants, nearest neighbor, and classification trees with univariate splits. It is of interest, therefore, to compare performance of SVMs to DLDA and the latest two classification trees with linear splits, which performered better than trees with univariate splits, in multiclass classification of MGED. Furthermore, the performance of SVMs with different types of kernels were studied by three types of multiclass MGED. Finally, we investigate how irrelevant and correlated variables (features) influence the performance of the three classifiers. Some suggestions are made for multiclass classification of MGED.
Explanation of Instabilities Observed on a Fermi-Pasta-Ulam Lattice

Exponential instability of waves on the cubically nonlinear, one-dimensional lattice is considered. The lattice has been modeled by the modified Korteweg-de Vries (mKdV) equation. It is shown that some solutions of the mKdV equation are unstable, and that these mKdV instabilities correspond to the instabilities observed on the lattice. Such instabilities may be important in determining whether or not a system behaves stochastically.
COMPUTATIONS OF DROP DYNAMICS WITH THE IMMERSED BOUNDARY METHOD, PART 2: DROP IMPACT AND HEAT TRANSFER

In Part 2 of the two-part article, the impact dynamics of a liquid drop on a flat surface with heat transfer is numerically simulate d with the immersed boundary method. Computations with both static and dynamic contact angles are adopted to assess the importance and implications of the modeling aspect. Both water and ink droplets are considered, with direct experimental visualization and quantitative measurement employed to assess the computation. The effects of wettability, viscosity, surface tension, and impact velocity on the droplet spreading and recoiling behavior and wall heat transfer are assessed. It is found that the drop inertia directly influences the spread characteristics, the surface tension plays a major role in the recoil frequency, the drop viscosity damps out the drop spread and recoil, and the contact angle affects both the spreading and recoiling processes. Overall, the dynamic contact angle model attenuates the recoiling of the drop. The wall heat flux distribution is clearly affected by the drop dynamics. Larger spreading results in a wider area of heat exchange. High heat flux rates take place at the early stage of impingement and decays in time.
Extending a complete convex metric

A metric D is convex if for every two points x, z there is a third point y such that D{x, y) + D(y, z) = D{x, z). A generalized continuum is a connected, locally compact, separable metric space. It is shown that if M-i is a space with a complete convex metric Dx and Mi is a locally connected generalized con- tinuum whose intersection with Mx is nonempty and compact, there is a complete convex metric for M^\jM% that extends Dx. Using this result, four classes of locally connected generalized continua are characterized by the type of complete convex metric they admit.
Linear and Second-Order Nonlinear Optical Properties of Arrays of Noncentrosymmetric Gold Nanoparticles

The optical properties of nanoscopic arrays of metal particles are dominated by plasmon resonances and electromagnetic interaction between the particles. We use electron-beam lithography to prepare arrays of noncentrosymmetric gold particles and study their linear and second-order nonlinear optical properties. By varying the orientation of the particles in a fixed lattice, we observe shifts in the polarized linear extinction spectra. The second-harmonic generation efficiencies of the two types of samples differ by up to 60%. The results show that the properties of the samples are sensitive to the smallest details of their structure.
Mindfulness and self-compassion as predictors of humor styles in US and Russia

Mindfulness and self-compassion are increasingly coming into mainstream psychological research in the Western world as they correlate with and predict various aspects of mental health and positivity. However, little is known about their relationship to another construct that is also associated with well-being, that is, humor. The unique contribution of the present study is in exploring whether mindfulness and self-compassion would predict the use of adaptive and maladaptive humor styles and whether this prediction will be the same across cultures. 90 U.S. and 106 Russian college students responded to a survey consisting of three measures: Mindfulness Attention Awareness Scale (MAAS; Brown & Ryan, 2003), Self-Compassion Scale-Short Form (SCS-SF; Raes, Pommier, Neff, & Van Gucht, 2011), and Humor Styles Questionnaire (HSQ; Martin, Puhlik-Doris, Larsen, Gray, & Weir, 2003). Our findings suggest that mindfulness and self-compassion can serve as predictors of humor styles, that is, more mindful and self-compassionate participants tended to use more adaptive humor styles and less maladaptive styles. However, the contribution of these two variables to the vari