Miracle-dz/UniFAR-FTUs huggingface dataset:
Isentropic Mass Exchange between the Tropics and Extratropics in the Stratosphere

Abstract The isentropic mass exchange between the Tropics and extratropics in the stratosphere is investigated with a semi-Lagrangian transport model for the periods from 1 June to 31 October 1992 and from 1 December 1992 to 30 April 1993 using winds from the U.K. Meteorological Office data assimilation system. Calculations with an idealized, initially zonally symmetric tracer show that in the middle and upper stratosphere the bulk of tropical air is transported into the midlatitudes of the winter hemisphere although there exist quasi-permeable barriers in the subtropics. The transport takes place in the form of planetary-scale “tongues” of material that are drawn poleward in association with the episodic amplification of planetary-scale waves in high latitudes of the winter hemisphere. Once air of tropical origin is transported to the midlatitudes it is irreversibly mixed with the midlatitude air in the “surf zone. ” Air of tropical origin can, however, hardly penetrate into the interior of the winter pol.
Injective morphisms of real algebraic varieties

1. A recent note of D. J. Newman [3] shows that for polynomial maps of the real plane into itself injectivity implies surjectivity. The present note combines two independently obtained corrections and generalizations of Newman's proof. We need some preliminaries. Take the complex numbers as universal domain and define a real algebraic set to be the set of real points of an algebraic set that is defined over the reals. A real algebraic set V is Zariski-dense in its Zariski closure V, which is an algebraic set defined over the reals, and V is the set of real points of V. Any algebraic subset of V meets V in a real algebraic subset. V is irreducible (in its Zariski topology), i.e. V is a real algebraic variety, if and only if V is irreducible (over the complex numbers), we define dim V =dim V, and we call PC V simple if P is a simple point of V; such points P exist, and there exist uniformizing parameters that are defined over the reals for 7 at such a point P, hence real local power series expansions, so that at each of its simple points V, in its ordinary topology, is locally a real analytic manifold of dimension dim V. For real algebraic sets V, W define a rational map f: V-*W to be the restriction to VX W of a rational map f: V--W that is defined over the reals; the rational map f: V-*W is a morphism if f is defined at each point of V. Supposing the morphism of real algebraic varieties f: V-*W to be such that f(V) is Zariski-dense in W, a simple point PE V may be found such that f(P) is simple on Wand df has the correct rank dim V-dim W at P, implying that, for the real analytic structure of V, W at P, f(P) respectively, f is locally a projection onto a direct factor; in particular, if f is finite-to-one, then dim V=dim W
New bilinearization, Bäcklund transformation and infinite conservation laws for the KdV6 equation with Bell polynomials

By using the Bell polynomials method and symbolic computation, we study the integrability of the KdV6 equation. We develop, in this work, new results regarding the integrability concept. We show that the newly developed bilinear representation and bilinear Bäcklund transformation are different from those reported in the literature. Moreover, we firstly present the infinite conservation laws, and the conserved densities and fluxes are given in explicit recursion formulas. Copyright © 2015 John Wiley & Sons, Ltd.
Parametric Instabilities Due to Lower-Hybrid Radio Frequency Heating of Tokamak Plasmas

The linear theory of parametric instabilities relevant to radiofrequency heating near the lower‐hybrid frequency of tokamak‐type plasmas is presented. The dispersion relations are analyzed numerically to all orders of the ion Larmor radius. The complete range of unstable spectra is obtained for 1<ω0/ωlh<5, for both deuterium and hydrogen plasmas. As the pump wave propagates from the edge of the plasma toward its interior, the transition from resonant decay to decay into quasi‐modes is demonstrated. The effects of inhomogeneities upon the threshold for parametric decay, such as density gradients, finite pump width, and magnetic shear, are obtained. The relevance of these results to recent tokamak experiments is discussed briefly.
Modulational interaction between drift waves and trapped ion convective cells: A paradigm for the self‐consistent interaction of large‐scale sheared flows with small‐scale fluctuations

The linear and nonlinear dynamics of modulational interaction between small‐scale drift waves and large‐scale trapped ion convective cells are investigated. This example is a paradigm of the more general problem of describing the self‐consistent interaction of small‐scale fluctuations with mean sheared flows. The growth rate of modulational instability is determined by spectral properties of drift waves and can exceed the linear growth rate of the trapped ion mode. An anisotropic spectrum of drift waves is always modulationally unstable. The spatial orientation of the convective cell pattern and structure (i.e., shear strength) is determined by drift wave spectrum anisotropy and propagation direction. In the presence of a sheared magnetic field, which pins small‐scale drift waves to mode rational surfaces, the modulational growth rate becomes intrinsically anisotropic, on account of the modified radial structure of drift waves.
Southern Extratropical Cyclone Behavior in ECMWF Analyses during the FROST Special Observing Periods

Abstract The data collected during the three special observing periods (SOPs) of the Antarctic First Regional Observing Study of the Troposphere project provide an excellent base upon which to study the behavior of cyclonic systems in winter, spring, and summer in the Southern Hemisphere. This paper provides a report on the behavior of these cyclonic systems during the three SOPs as revealed in the twice-daily ECMWF operational analyses. The study has been undertaken with an objective cyclone tracking algorithm applied to the digital analyses. The results revealed cyclone behavior generally in accord with long-term climatologies developed with this scheme. In the SOPs the authors observed many systems to be generated in the western part of the ocean basins and then to move east and, to a lesser extent, south. In the three periods they found a concentration of tracks just to the north of the Antarctic continent, being particularly noticeable in the Indian Ocean. At the same time, they found significant dif.
Propagation of a Gaussian beam in a nonhomogeneous plasma

The asymptotic theory of Choudhary and Felsen [IEEE Trans. Antennas Propag. AP‐21, 827 (1973)] on the propagation of scalar inhomogeneous waves in two‐dimensional isotropic media is extended to the case of three‐dimensional vector fields. The theory is applied to the propagation of Gaussian beams in nonhomogeneous media. The wave trajectory equations are then reformulated for anisotropic media and used for tracking a Gaussian beam in a tokamak plasma.
Geometric and subjective analysis of stereoscopic I3A cluster images

This paper presents a geometric and subjective analysis of stereoscopic versions of close range I3A clusters (Subject- Camera distances below 5 m). The geometry of the stereoscopic pipeline from the scene to the viewer's eyes is a very relevant issue in stereoscopic media. One important factor is the camera separation, because it can be used to control the perceived depth of stereoscopic images. The computational camera separations were compared to subjectively preferred camera separations. Participants evaluated the strength and naturalness of depth sensation and overall viewing experience from the still images with single-stimulus method. Results showed that participants were able to perceive the change of depth range even though the images were shown in random order without a reference depth scale. A mild depth sensation was preferred over strong depth sensations. The computational camera separation differed from the subjectively preferred camera separation when the depth range of the scene was narrow. This result indicates that scenes with narrow depth should not be imaged with a long camera separation just to fill the depth budget of the display.
Tensor Methods in Statistics

This book provides a systematic development of tensor methods in statistics, beginning with the study of multivariate moments and cumulants. The effect on moment arrays and on cumulant arrays of making linear or affine transformations of the variables is studied. Because of their importance in statistical theory, invariant functions of the cumulants are studied in some detail. This is followed by an examination of the effect of making a polynomial transformation of the original variables. The fundamental operation of summing over complementary set partitions is introduced at this stage. This operation shapes the notation and pervades much of the remainder of the book. The necessary lattice-theory is discussed and suitable tables of complementary set partitions are provided. Subsequent chapters deal with asymptotic approximations based on Edgeworth expansion and saddlepoint expansion. The saddlepoint expansion is introduced via the Legendre transformation of the cumulant generating function, also known as the conjugate function of the cumulant generating function. A recurring them is that, with suitably chosen notation, multivariate calculations are often simpler and more transparent than the corresponding univariate calculations. The final two chapters deal with likelihood ratio statistics, maximum likelihood estimation and the effect on inferences of conditioning on ancillary or approximately ancillary statistics. The Bartlett adjustment factor is derived in the general case and simplified for certain types of generalized linear models. Finally, Barndorff-Nielsen's formula for the conditional distribution of the maximum liklelihood estimator is derived and discussed. More than 200 Exercises are provided to illustrate the uses of tensor methodology.
The structure and stability of flame balls: a near-equidiffusional flame analysis

The structure and stability of flame balls is examined in the context of an asymptotic analysis in which $\theta \to \infty ,\, ( {{\text{1 - Le}}} ) = O( 1/\theta )$, where $\theta $ is the activation energy and Le the Lewis number. The heat-loss mechanism necessary for stable solutions is radiation from the burnt gas. For heat losses less than the quenching value there are two stationary solutions, but the one with the smaller radius is always unstable to one-dimensional disturbances. When ${\text{Le}} = 1$ the large solution is also unstable, but for ${\text{Le}} < {\text{Le}}_c < 1$, where ${\text{Le}}_c $ is a critical value, a portion of the large-solution branch is stable. Sufficiently large solutions are always unstable to three-dimensional disturbances, independent of Le. These results imply that flame balls can only be generated if Le is sufficiently small, and are consistent with previous results which suggest that the three-dimensional instability is not a Turing instability but is instead a c.
Impact of Traditional and Non-Traditional Lipid Parameters on Outcomes after Intravenous Thrombolysis in Acute Ischemic Stroke

Contradicting evidence exists regarding the role of lipids in outcomes following intravenous (IV) thrombolysis with tissue plasminogen activator (tPA). Restricted cubic spline curves and adjusted logistic regression were used to evaluate associations of low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratio with poor functional outcome, symptomatic intracranial hemorrhage (SICH) and 90-day mortality, among 1004 acute ischemic stroke (AIS) patients who received IV tPA in a comprehensive stroke center. Quartile (Q) 1, Q2 and Q3 of HDL-C were associated with increased odds of poor functional outcome (adjusted odds ratio (adjOR) 1.66, 95% CI 1.06–2.60, p = 0.028, adjOR 1.63, 95% CI 1.05–2.53, p = 0.027, adjOR 1.56, 95% CI 1.01–2.44, p = 0.048) compared to Q4. Q2 and Q4 of non-HDL-C were associated with increased odds of SICH (adjOR 4.28, 95% CI 1.36–18.90, p = 0.025, adjOR 5.17, 95% CI 1.64–22.81, p = 0.011) compared to Q3. Q1 and Q2 of LDL-C was associated with increased odds of mortality (adjOR 2.57, 95% CI 1.27–5.57, p = 0.011 and adjOR 2.28, 95% CI 1.10–5.02, p = 0.032) compared to Q3. In AIS patients who received IV tPA, low LDL-C was associated with increased odds of mortality while HDL-C may be protective against poor functional outcome.
Particle generation and thin film surface morphology in the tetraethylorthosilicate/oxygen plasma enhanced chemical vapor deposition process

Particle generation by gas-phase nucleation in the plasma enhanced chemical vapor deposition process and its effects on thin film surface morphology were studied experimentally for a conventional radio frequency plasma reactor using tetraethylorthosilicate (TEOS) vapor and oxygen gases. The particles suspended in the plasma space and deposited on the film were observed simultaneously by in situ laser light scattering methods and an ex situ scanning electron microscopic method. The generated particles were trapped in the plasma/sheath boundary under all four experimental conditions, in which TEOS concentrations were 0.5 and 5.0 vol % and reactor pressures were 66.7 and 533.3 Pa (0.5 and 4.0 Torr). The size and amount of particles and the film morphology were found to depend on the TEOS concentration and the reactor pressure. Under the conditions in which highly concentrated particles were generated in plasma, dome-like structures of 50–400 nm in diameter were observed on the thin film surface. The average .
Polarization property of terahertz wave emission from gammadion-type photoconductive antennas

We have investigated the polarization property of terahertz (THz) wave emission from gammadion-type photoconductive antennas (PCAs). It was experimentally shown that the polarization of emitted THz wave from the gammadion-type PCAs was elliptic. Finite difference time domain simulation reproduces the experimental observation fairly well. From simulation, we find out that the gammadion-type PCAs have two kinds of radiation; i.e., the radiation from the gap of the PCA and the radiation from the bends of electrode. These two kinds of radiation have different polarization and different time delay, which results in the observed elliptic polarization.
Multiple scattering of sound

Abstract We present a topical review which summarizes the main contributions to ‘multiple scattering of acoustic and elastic waves’ including the most recent advances. The review is divided into five main parts. In the first part, the effects of multiple scattering on ultrasonic propagation are illustrated on the basis of three experimental examples. In the second and third parts, we present the two possible descriptions for the propagation of an acoustic wave in a random medium. The first one is based on the study of the coherent wave, i.e. the wave amplitude averaged over disorder, whereas the second one deals with the propagation of the incoherent intensity, i.e. the intensity averaged over disorder. We especially insist on the microscopic basis for the phenomenological radiative transfer equation and show how it can be solved in the diffusion approximation. The theory is illustrated with experimental results obtained on a two-dimensional multiple-scattering prototype made of thousands of steel rods randomly distributed and immersed in water. In the fourth part, we present experimental evidence that the diffusion equation fails in describing all the aspects of the propagation of an acoustic wave in a random medium: e.g. the coherent backscattering effect recently observed for ultrasonic waves. We show that this effect arises as a consequence of reciprocity. Finally, in the fifth part, we discuss another property which is not taken into account in the radiative transfer theory: the reversibility of an acoustic wave propagating in a disordered medium.
HIGHER DIMENSIONAL UNIFICATION BY ISOMETRY

A unified theory based on a homogeneous fiber bundle Q(M,G/H) is discussed in detail. In spite of the fact that the theory retains the full G‐gauge invariance, the physical gauge group K is shown to be K=H*/(H∩H*), where H* is the centralizer of H in G. A principal fiber bundle P(M,G,H) is also constructed by introducing an additional left action H on P(M,G) that commutes with the right action G, and a unified theory based on P(M,G,H) is discussed. It is shown that the theory based on Q(M,G/H) is, in fact, the H projection of the Einstein–Hilbert action from P(M,G,H), with the identification Q(M,G/H)=P(M,G,H)/H.
Transitions in convection of a low Prandtl number fluid driven by a horizontal temperature gradient

Oversize materials (e.g., maps, drawings, charts) are re­ produced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. These are also available as one exposure on a standard 35mm slide or as a 17" x 23" black and white photographic p rin t for an additional charge.
Petrologic evidence for collisional heating of chondritic asteroids

Abstract The identification of the mechanism(s) responsible for heating asteroids is among the major problems in planetary science. Because of difficulties with models of electromagnetic induction and the decay of short-lived radionuclides, it is worthwhile to evaluate the evidence for collisional heating. Localized impact heating is responsible for forming shock veins, melt pockets, metal-sulfide mixtures, vugs, agglutinates and a wide variety of melt-rock clasts. New evidence for localized impact heating comes from the high proportion of relict type-6 material among impact-melt-bearing ordinary chondrites (OC). This relict material was probably metamorphosed by residual heat within large craters. Olivine aggregates composed of faceted crystals with 120° triple junctions occur within the melted regions of the Chico and Rose City OC melt rocks; the olivine aggregates formed from shocked, mosaicized olivine grains that underwent contact metamorphism. Large-scale collisional heating is supported by the correlation in OC between petrologic type and shock stage; no other heating mechanism can readily account for this correlation. The occurrence of impact-melt-rock clasts in OC that have been metamorphosed along with their whole rocks indicates that some impact events preceded or accompanied thermal metamorphism. Such impact events, occurring during or shortly after accretion, are probably responsible for substantially melting ∼0.5% of OC. These events most have heated a larger percentage of OC to subsolidus temperatures sufficient to have caused significant metamorphism. If collisional heating is viable, then OC parent asteroids must have been large; large OC asteroids in the main belt may include those of the S(IV) spectral subtype. Collisional heating is inconsistent with layered ("onion-shell") structures in OC asteroids (wherein the degree of metamorphism increases with depth), but the evidence for such structures is weak. It seems likely that collisional heating played an important role in metamorphosing chondritic asteroids.
An overview of some recent developments on the Invariant Subspace Problem

An overview of some recent developments on the Invariant Subspace Problem This paper presents an account of some recent approaches to the Invariant Subspace Problem. It contains a brief historical account of the problem, and some more detailed discussions of specific topics, namely, universal operators, the Bishop operators, and Read’s Banach space counter-example involving a finitely strictly singular operator.
Unstable Radiative-Dynamical Interactions. Part II: Expanded Theory

Abstract The basic theory of unstable radiative-dynamical interactions developed in a companion paid is extended to account for several complicating effects. Treating the effect of absorber perturbations on the shortwave radiative heating rate at all levels, rather than simply locally, is shown to either enhance or suppress the radiative-dynamical instability, depending on the perturbation vertical wavelength. Dissipative processes generally reduce or eliminate the instability, although in one case mechanical dissipation can actually enhance the instability. Vertical shear generally suppresses the instability for radiative-dynamical feedback rates greater than the adiabatic growth rate associated with baroclinic instability, and enhances the instability for feedback rates less than the adiabatic growth rate. The radiative-dynamical interaction generally increases the growth ate beyond that associated with baroclinic instability, but the growth rate never exceeds the sum of the feedback rate and the adiaba.
Acoustic flexural mode on a ridge of semi-infinite height

Several recent analyses of the flexural mode on a ridge of semi-infinite height (plate edge) contain results which are inconsistent and generally limited in range. We present accurate theoretical calculations, and a set of measurements which agree very well with them, and we compare our results with the earlier ones. We also give a simple model which yields other wave properties (such as the vertical decay rate), indicate and verify quantitatively the wave behaviour at high frequencies, and show the relation between this wave type and the usual flexural mode on a ridge of finite height.
Bayesian Modeling of Joint Regressions for the Mean and Covariance Matrix

An important problem in agronomy is the study of longitudinal data on the growth curve of the weight of cattle through time, possibly taking into account the effect of other explanatory variables such as treatments and time. In this paper, a Bayesian approach for analysing longitudinal data is proposed. It takes into account regression structures on the mean and the variance‐covariance matrix of normal observations. The approach is based on the modeling strategy suggested by Pourahmadi (1999, Biometrika 86, 667–690). After revising this methodology, we present the Bayesian approach used to fit the models, based on a generalization of the Metropolis‐Hastings algorithm of Cepeda and Gamerman (2000, Brazilian Journal of Probability and Statistics, 14, 207–221). The approach is used to the study of growth and development of a group of deaf children. The paper is concluded with a few proposed extensions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion-acoustic waves triggered by left-hand polarized finite-amplitude waves propagating in the beam direction

[1] Nonlinear ion-acoustic like waves triggered by large-amplitude circularly polarized waves propagating in the direction of a proton beam are studied. The properties are strongly dependent on the nature of the large-amplitude wave. Waves belonging to the Alfven branch of the dispersion relation require much larger amplitude values to excite the ion-acoustic waves than those belonging to the beam branch of the dispersion relation. The former can trigger only forward propagating waves and always above a wave number threshold, while the latter can destabilize forward as well as backward propagating waves with a zero wave number threshold. It is shown that in some cases the unstable frequency spectrum is very narrow, and damping rates are very small even under conditions where the linear theory predicts strong Landau damping. It is conjectured that these type of waves might be of common occurrence in the fast solar wind, preferably closer to the Sun. These results are consistent with observation of electrostatic ion-acoustic like emissions in the solar wind.