Miracle-dz/UniFAR-FTUs huggingface dataset:
A Two-Season Impact Study of Satellite and In Situ Data in the NCEP Global Data Assimilation System

Abstract Observing system experiments are used to quantify the contributions to the forecast made by conventional in situ and remotely sensed satellite data. The impact of each data type is assessed by comparing the analyses and forecasts based on an observing system using all data types. The analysis and forecast model used for these observing system experiments is the National Centers for Environmental Prediction (NCEP) Global Data Assimilation/Forecast System (GDAS/GFS). The case studies chosen consist of 45-day periods during January–February 2003 and August–September 2003. During these periods, a T254–64 layer version of NCEP’s Global Spectral Model was used. The control run utilizes NCEP’s operational database and consists of all data types routinely assimilated in the GDAS. The two experimental runs have either all the conventional in situ data denied (NoCon) or all the remotely sensed satellite data denied (NoSat). Differences between the control and experimental runs are accumulated over the 45-d.
Emission properties of different cathodes at E⩽105 V/cm

We present results of the investigation of different types of cathodes operating in an electron diode powered by a high-voltage generator (300 kV, 250 ns, 84 Ω, ⩽5 Hz). The cathodes which have the same emitting area of 100 cm2 are made of metal–ceramic, carbon fibers, carbon fabric, velvet, or corduroy. We also tested carbon fibers and carbon fabric cathodes coated by CsI. It was shown that for all types of cathodes the electron emission occurs from the plasma which is formed as a result of a flashover of separate emitting centers. The amount of the emitting centers and the time delay in the electron emission were found to depend strongly on the accelerating electric field growth rate. Experimental data concerning the uniformity of the light emission from the cathode surface and divergence of the generated electron beams are presented. Data related to the general parameters of the diode, namely its impedance, power, and energy are given as well. For all the cathodes investigated the observed diode impedan.
Functional Principal Component Analysis of Density Families With Categorical and Continuous Data on Canadian Entrant Manufacturing Firms

This article investigates the evolution of firm distributions for entrant manufacturing firms in Canada using functional principal components analysis. This methodology describes the dynamics of firms by examining production variables, size, and labor productivity, and a financial variable, leverage (debt-to-asset ratio). We adapt the canonical functional principal components analysis to allow for the inclusion of qualitative information in the form of discrete variables, industry, and region, to capture market structure differences, which is shown to change the dynamics of firm size and labor productivity distributions only. We also perform various tests with the null hypothesis that the distributions are equal across time. When accounting for industry and regional categories, there is a substantial fall in the number of rejections of the null hypothesis of equality for size and labor productivity, which is not the case for leverage. These results show the importance of including qualitative information to account for potential heterogeneity when applying functional principal component analysis to firm-level data. Finally, the methodology finds a correlation between the evolution of variable distributions and macroeconomic factors. This article has supplementary material online.
Holomorphic correspondences mating Chebyshev-like maps with Hecke groups

We prove structure theorems for holomorphic correspondences realizing matings between pinched polynomial-like maps with connected Julia sets and Hecke groups (Fuchsian representations of free products C2 * Cn of cyclic groups of orders 2 and n). We show that such matings are generated by two-to-two subcorrespondences if and only if the maps are Chebyshev-like. We describe the dynamical behaviour of these matings in detail in the case n = 4 and we present a conjectured combinatorial description of the connectedness locus in parameter space in this case.
Quasipositive plumbing (constructions of quasipositive knots and links, V)

A Seifert surface S ⊂ S 3 = ∂D 4 is a ﬁber surface if a push-oﬀ S → S 3 \ S induces a homotopy equivalence; roughly, S is quasipositive if pushing Int S into Int D 4 ⊂ C 2 produces a piece of complex plane curve. A Murasugi sum (or plumbing ) is a way to ﬁt together two Seifert surfaces to build a new one. Gabai proved that a Murasugi sum is a ﬁber surface iﬀ both its summands are; we prove the analogue for quasipositive Seifert surfaces. The slice (or Murasugi ) genus g s ( L ) of a link L ⊂ S 3 is the least genus of a smooth surface S ⊂ D 4 bounded by L . By the local Thom Conjecture, g s ( ∂S ) = g ( S ) if S ⊂ S 3 is quasipositive; we derive a lower bound for g s ( ∂S ) for any Seifert surface S , in terms of quasipositive subsurfaces of S .
Phase retrieval method for biological samples with absorption

Interferometric microscopy is an important technique to obtain the phase distribution of cells and tissues. However, in practice, the absorption effect of the biological samples and non-uniformities in the beam could induce errors in solving phase distributions by traditional methods. In this paper, an improved phase retrieval method is introduced to quantitatively calculate the phase distribution of absorbing samples. The proposed method could acquire more accurate phase distributions and optical transmitted sample images physically. Comparing with conventional phase retrieval methods, the proposed method has higher accuracy and calculation efficiency.
The statistics of peaks of Gaussian random fields

A set of new mathematical results on the theory of Gaussian random fields is presented, and the application of such calculations in cosmology to treat questions of structure formation from small-amplitude initial density fluctuations is addressed. The point process equation is discussed, giving the general formula for the average number density of peaks. The problem of the proper conditional probability constraints appropriate to maxima are examined using a one-dimensional illustration. The average density of maxima of a general three-dimensional Gaussian field is calculated as a function of heights of the maxima, and the average density of 'upcrossing' points on density contour surfaces is computed. The number density of peaks subject to the constraint that the large-scale density field be fixed is determined and used to discuss the segregation of high peaks from the underlying mass distribution. The machinery to calculate n-point peak-peak correlation functions is determined, as are the shapes of the profiles about maxima.
The far ultraviolet (1200–1900 Å) spectrum of Jupiter obtained with a rocket‐borne multichannel spectrometer

New far ultraviolet spectra of Jupiter with a significant improvement in sensitivity and spectral resolution have been obtained from a sounding rocket by using a 10-channel spectrometer behind a pointing telescope. The major results obtained from these spectra are (1) a new measurement of the Jovian H I λ 1216-A brightness (a comparison with other measurements indicates that the Ly α emission is likely to be variable), (2) the measurement of the wavelength-dependent albedo for Rayleigh scattered solar radiation from ∼1550 to 1875 A with ∼25-A resolution making it possible to set new upper limits on the abundances of some of the minor constituents in the upper Jovian atmosphere, and (3) a demonstration that weak emissions between ∼1250 and ∼1500 A and near 1600 A are probably the Lyman bands of H2 excited by low-energy electrons.
Light trapping properties of pyramidally textured surfaces

The light trapping properties of textured optical sheets have become of recent interest in photovoltaic energy conversion since light trapping allows a significant reduction in the thickness of active solar cell material. Previous analyses have concentrated on sheets with randomly textured (Lambertian) surfaces. The texturing of crystalline silicon substrates with anisotropic etches to give surfaces covered by square based pyramids defined by intersecting (111) crystallographic planes is a widely used technique for reflection control in silicon solar cells. This paper analyzes the light trapping properties of substrates with such pyramidally textured surfaces. Important differences are found from the case of Lambertian surfaces with practical consequences for the design of high efficiency silicon solar cells.
A numerical continuous model for the hydrodynamics of fluid particle systems

SUMMARY In order to understand the hydrodynamic interactions that can appear in a fluid particle motion, an original method based on the equations governing the motion of two immiscible fluids has been developed. These momentum equations are solved for both the fluid and solid phases. The solid phase is assumed to be a fluid phase with physical properties, such as its behaviour can be assimilated to that of pseudo-rigid particles. The only unknowns are the velocity and the pressure defined in both phases. The unsteady two-dimensional momentum equations are solved by using a staggered finite volume formulation and a projection method. The transport of each particle is solved by using a second-order explicit scheme. The physical model and the numerical method are presented, and the method is validated through experimental measurements and numerical results concerning the flow around a circular cylinder. Good agreement is observed in most cases. The method is then applied to study the trajectory of one settling particle initially off-centred between two parallel walls and the corresponding wake effects. Different particle trajectories related to particulate Reynolds numbers are presented and commented. A two-body interaction problem is investigated too. This method allows the simulation of the transport of particles in a dilute suspension in reasonable time. One of the important features of this method is the computational cost that scales linearly with the number of particles. Copyright © 1999 John Wiley & Sons, Ltd.
Optimally conclusive discrimination of nonorthogonal entangled states by local operations and classical communications

We consider one copy of a quantum system prepared with equal prior probability in one of two nonorthogonal entangled states of multipartite distributed among separated parties. We demonstrate that these two states can be optimally distinguished in the sense of conclusive discrimination by local operations and classical communications alone. This proves strictly the conjecture that Virmani et al. confirmed numerically and analytically. Generally the optimal protocol requires local POVM operations which are explicitly constructed. The result manifests that distinguishable information is obtained only and completely at the last operation and all prior operations give no information about that state.
Circular lines of circular polarization in three dimensions, and their transverse-field counterparts

A superficially paradoxical phenomenon is associated with curved c lines, on which the polarization of a three-dimensional optical field in space is purely circular. If the c line has fixed index (signed half-integer winding number), its two intersections with an observation plane, each with the same index, coalesce and annihilate when the c line is tangent to the plane, seeming to contradict the conservation of index. But there is no paradox: for the associated C line (distinct from the c line) on which the field transverse to the observation plane is circularly polarized, the two intersections have opposite indices, so their total index is zero, which is conserved during the annihilation. The different geometries of the c and C lines are studied in detail for model fields where the c line is a circle.
Estimates of effective aerodynamic roughness length over mountainous areas of the Tibetan Plateau

Wind profile data were measured by a wind profiler at QOMS (The Qomolangma Station for Atmospheric Environmental Observation and Research, Chinese Academy of Sciences) and, in separate experiments, GPS radiosondes were used at Shiquanhe Station and Litang Station on the Tibetan Plateau (TP). All three stations are located in the most rugged areas of the TP. QOMS is surrounded by the Himalaya, Shiquanhe Station by the Transhimalaya and Litang station is near the Hengduan Mountains. Using observational wind profile data, effective aerodynamic roughness length z0meff and zero‐plane displacement height d0 are determined using the neutral logarithmic wind profile law. The results show that the values of z0meff derived from the wind profiles can be considerably larger than the small‐scale aerodynamic roughness lengths of the land surface around the three stations. Subsequently, several parametrization schemes which use land surface characteristics to estimate z0meff and d0, such as roughness obstacle height and density, were assessed. The result indicates that of all the methods available, that proposed by Grant and Mason, where the drag coefficient D = 0.5, gives the best estimate of z0meff . The interim European Centre for Medium‐range Weather Forecasts (ECMWF) Re‐Analysis (ERA‐Interim) dataset underestimates effective aerodynamic roughness length in mountainous areas of the TP due to its use of a smaller drag coefficient of D = 0.4. For estimating d0, the method of Kutzbach performs well when the density of roughness obstacles (λ) is low, whereas the method of Raupach et al. gives a more reliable estimate when λ is high. Although this analysis has some limitations, it can feasibly account for form drag being exerted by an unresolved topography in the mountainous areas of the TP.
On the Enumeration of Rooted Non-Separable Planar Maps

It has been shown elsewhere (1, 4) that the number of rooted non-separable planar maps with n edges is In the present paper we improve upon this result by finding the number fi,j of rooted non-separable planar maps with i + 1 vertices and j + 1 faces. We use the definitions of (1). Among the non-separable planar maps only the loop-map and the link-map have i = 0 or j = 0. We therefore confine our attention to the case in which i and j are both positive.
On the Excitation and Propagation of Zonal Winds in an Atmosphere with Newtonian Cooling.

Abstract A system of equations, including Newtonian cooling and valid away from the equator, is derived for atmospheric zonal winds and the associated zonal temperature and meridional circulation fields. A time scaling is introduced to distinguish three regimes of motion. For short time scales a variation of the usual nondissipative forced symmetric vortex problem is recovered. For intermediate time scales, a “diffusive model” is defined, while for long time scales a “steady state” model is defined. Two examples of the solution of the diffusive equation are given. From the first example we infer that our model is capable of explaining many of the observed features of the downward progression of the stratospheric biennial oscillation. Momentum is carried downward by Coriolis torques resulting from propagating meridional cells. The solutions of our second example describe transient zonal winds which resemble those observed to propagate downward from the stratopause in Meteorological Rocket Network data time.
Reflection-type Optical Waveguide Index Profiling Technique

We report a new configuration of a reflection-type confocal scanning optical microscope system for measuring the refractive index profile of an optical waveguide. Several improvements on the earlier design are proposed; a light emitting diode (LED) at 650 nm wavelength instead of a laser diode (LD) or He-Ne laser is used as a light source for better index precision, and a simple longitudinal linear scanning and curve fitting techniques are adapted instead of a servo control for maintaining an optical confocal arrangement. We have obtained spatial resolution of 700 nm and an index precision of $2\times10^{-4}$ . To verify the system's capability, the refractive index profiles of a conventional multimode fiber and a home-made four-mode fiber were examined with our proposed measurement method.
On the effects of horizontal resolution and diffusion in a two-layer general circulation model with a zonally symmetric forcing

The general circulation of a two-layer spectral model with a simple symmetrical forcing is determined from long-term integrations. It is found that the zonal as well as the meridional mean flow is clearly influenced by the horizontal resolution of the model. Related to that, it is also found that the meridional eddy transport of momentum is increased significantly by an increase of the horizontal resolution. As a main result of the present study, it is demonstrated, that the response of the model to an increase of the horizontal resolution can also be obtained to a considerable extent by using a suitable, strongly scale-dependent, linear diffusion in the model. Considering especially the spectral distribution of kinetic energy, it is found that an increase of the horizontal resolution as well as the use of a selective horizontal diffusion on the smaller scales results in a significant increase of the eddy kinetic energy on the large scales connected with an enhancement of the baroclinicity of the zonal mean flow. As to be expected, the effect of increasing horizontal resolution or the scale selective diffusion is also to decrease the kinetic energy on the smaller scales, with the result that the energy spectrum is approaching a – 3-power law for a wider range of wavenumbers. DOI: 10.1034/j.1600-0870.1990. t01-4-00003.x
Two-dimensional random walk and critical behavior of double-strand DNA

The phase behavior in a double-strand homopolynucleotide is considered. The relative distance between the corresponding monomers of two polymer chains is modeled by the two-dimensional random walk on the square lattice. Returns of the random walk to the origin describe the formation of base pairs between the complementary units. We obtain a completely denatured state below the finite temperature Tc. It was shown that Tc is the point of the infinite-order phase transition. The specific behavior of the order parameter, free energy and correlation functions has been addressed.
Spatial–temporal model for wind speed in Lithuania

In this paper, we propose a spatial–temporal model for the wind speed (WS). We first estimate the model at the single spatial meteorological station independently on spatial correlations. The temporal model contains seasonality, a higher-order autoregressive component and a variance describing the remaining heteroskedesticity in residuals. We then model spatial dependencies by a Gaussian random field. The model is estimated on daily WS records from 18 meteorological stations in Lithuania. The validation procedure based on out-of-sample observations shows that the proposed model is reliable and can be used for various practical applications.
Using the simultaneous generalized Schur decomposition as a Candecomp/Parafac algorithm for ill‐conditioned data

The Candecomp/Parafac (CP)method decomposes a three‐way array into a prespecified number R of outer product arrays, by minimizing the sum‐of‐squares of the residual array. The practical use of CP is sometimes complicated by the occurrence of so‐called ‘degenerate’ sequences of solutions, in which several outer product arrays become highly correlated in all three modes and some elements of the outer product arrays become very large in magnitude. It is known that for I× J× 2 arrays, fitting a simultaneous generalized Schur decomposition (SGSD) avoids the problems of ‘degeneracy’ due to the non‐existence of an optimal CP solution. In this paper, we consider the application of the SGSD method also for other array formats, when the array has a best fitting CP decomposition with ill‐conditioned component matrices, in particular such that it resembles the pattern of a ‘degeneracy’. For these cases, we compare the performance of two SGSD algorithms and the alternating least squares (ALS) CP algorithm in a series of numerical experiments. Copyright © 2009 John Wiley & Sons, Ltd.
Left-right asymmetries in elastic and inelastic scattering of polarized electrons from argon, krypton and xenon atoms

Polarized electrons were scattered from unpolarized argon, krypton and xenon atoms with scattering angles ranging from 30 degrees to 125 degrees . For xenon elastic left-right asymmetries were measured at energies ranging from 1.5 to 10 eV. Inelastic scattering asymmetries were observed for argon, krypton and xenon at energies between 10 and 40 eV. For inelastic scattering from argon and krypton it could be shown that exchange, in conjunction with the spin-orbit coupling within the target atom, is the dominant mechanism for scattering asymmetries. For the heavy xenon, on the other hand, this simple mechanism is not sufficient to describe the observed spin effects. A comparison with theoretical data shows good agreement for elastic scattering from xenon, whereas, in the case of inelastic scattering, the theoretical predictions are rather unsatisfactory.
Grain-size effects in exchange-biased FeMn∕NiFe bilayers

FeMn∕NiFe exchange-biased films have been deposited on Si substrates and the average grain size in the antiferromagnet systematically varied from 54to70A. Vibrating-sample magnetometer measurements at room temperature show that the exchange field increases by a factor of about 3 with increasing grain size. Changes in the coercivity were much smaller. We believe the grain-size effects are due to thermal activation phenomena. Training effects give rise to a greater reduction in the exchange field for the system with the smallest grains. The absence of a significant change in the coercivity implies that it is primarily controlled by interfacial effects.
The morphology and dark matter distribution of the Coma cluster of galaxies from X-ray observations

The analysis of a spectral image of the Coma cluster obtained with a coded mask telescope flown as part of the Spacelab 2 mission is presented. The main cluster emission is elongated east-west and extends to a radius of at least 50 arcmin, while an additional region of X-ray emission is detected ∼50 arcmin to the south-west of the cluster centre. The energy range of the instrument and its imaging capabilities allow the temperature and density of the intracluster gas to be determined as a function of radius, and thus allow the total cluster mass profile to be determined
Experimental Study of Supersonic Inlet Buzz

An experimental study of supersonic inlet buzz is presented. This study was carried out on a mixed compression rectangular inlet model; tests were done at Mach numbers ranging from 1.8 to 3, with and without bleed. Inlet flows were analyzed thanks to Schlieren videos and signal processing of unsteady pressure recordings. Two kinds of buzz were observed: "little buzz," which is thought to correspond to an acoustic resonance phenomenon excited by the presence of a shear layer under the cowl lip (Ferri criterion), and "big buzz," which seems to be triggered by a boundary layer separation on the compression ramps (Dailey criterion). In some cases, little buzz could be virtually suppressed by the introduction of a bleed. The frequency of big buzz is shown to be already present in the flow before the onset of large-amplitude oscillations, which suggests that the underlying mechanism of big buzz, probably linked to acoustics, already exists before buzz starts.