Miracle-dz/UniFAR-FTUs huggingface dataset:
The velocity and vorticity vector fields of a turbulent boundary layer. Part 2. Statistical properties

Many of the statistical properties of both the velocity and the vorticity fields of a nominally zero-pressure-gradient turbulent boundary layer at Rδ = 27650 (Rθ = 2685) have been simultaneously measured. The measurements were made with a small nine-sensor hot-wire probe which can resolve the turbulence to within about six Kolmogorov microscales just above the sublayer. The statistical properties of the velocity vector field compare very well with other laboratory measurements and with direct numerical simulations when Reynolds-number dependence is taken into account. The statistical properties of the vorticity field are also in generally good agreement with the few other measurements and with the direct numerical simulations available for comparison. Near the wall, r.m.s. measurements show that the fluctuating spanwise vorticity is the dominant component, but in the outer part of the boundary layer all the component r.m.s. values are nearly equal. R.m.s. measurements of the nine individual velocity gradients show that the gradients normal to the wall of all three velocity components are the largest, with peaks occurring near the wall as expected. Gradients in the streamwise direction are everywhere small. One-dimensional spectra of the vorticity components show the expected shift of the maximum energy to higher wavenumbers compared to spectra of the velocity components at the same location in the flow. The budget of the transport equation for total enstrophy indicates that the viscous dissipation rate is primarily balanced by the viscous diffusion rate in the buffer layer and by the rotation and stretching rate in the logarithmic layer.
Robust rotation-invariant texture classification: wavelet, Gabor filter and GMRF based schemes

Three novel feature extraction schemes for texture classification are proposed. The schemes employ the wavelet transform, a circularly symmetric Gabor filter or a Gaussian Markov random field with a circular neighbour set to achieve rotation-invariant texture classification. The schemes are shown to give a high level of classification accuracy compared to most existing schemes, using both fewer features (four) and a smaller area of analysis (16/spl times/16). Furthermore, unlike most existing schemes, the proposed schemes are shown to be rotation invariant demonstrate a high level of robustness noise. The performances of the three schemes are compared, indicating that the wavelet-based approach is the most accurate, exhibits the best noise performance and has the lowest computational complexity.
Short-cavity InGaAsP injection lasers: Dependence of mode spectra and single-longitudinal-mode power on cavity length

Simple expressions are given to describe the lower and upper limits of the single-mode (single-frequency) power as a function of the cavity length for InGaAsP injection lasers. It has been found that the lower limit of the single-mode power is proportional to the cavity length, while the upper limit is inversely proportional to the cavity length. Thus, a short-cavity laser provides a favorable geometry for obtaining single mode output over a wide range of power levels and currents above threshold. The mode stability versus temperature is also improved by a short-cavity design. The theoretical results agree with our recent experiments on very-short-cavity ( 50-75 \mu m) stripe-geometry InGaAsP lasers, which have shown consistent single-mode output over wide current ranges.
Numerical solution of problems in incompressible fluid flow: treatment of the température-velocity coupling

The cost of obtaining solutions to fluid flows depends strongly on how well the solution procedure treats the interequation couplings. For natural convection flows, treatment of the temperature-velocity coupling is often of the utmost importance. The first purpose of the present paper is to report the conditions under which the temperature-velocity coupling is important in natural convection flows, and the improvement in convergence rate that may be achieved by implicitly accounting for this coupling within the discrete equations of motion. It is shown that the strength of the coupling depends on the Prandtl number, and that substantial acceleration of the convergence rate can be achieved by appropriate treatment of the coupling. To translate improved convergence rate into computational savings requires that an efficient method be found for solution of the coupled linear set of equations. The second purpose of the paper is to present such a method, and to report the computation effort required to obtain s.
NOTES AND CORRESPONDENCE A Cautionary Note on the Use of the Kolmogorov-Smirnov Test for Normality

The Kolmogorov–Smirnov goodness-of-fit test is used in many applications for testing normality in climate research. This note shows that the test usually leads to systematic and drastic errors. When the mean and the standard deviation are estimated, it is much too conservative in the sense that its p values are strongly biased upward. One may think that this is a small sample problem, but it is not. There is a correction of the Kolmogorov–Smirnov test by Lilliefors, which is in fact sometimes confused with the original Kolmogorov–Smirnov test. Both the Jarque–Bera and the Shapiro–Wilk tests for normality are good alternatives to the Kolmogorov–Smirnov test. A power comparison of eight different tests has been undertaken, favoring the Jarque–Bera and the Shapiro–Wilk tests. The Jarque–Bera and the Kolmogorov– Smirnov tests are also applied to a monthly mean dataset of geopotential height at 500 hPa. The two tests give very different results and illustrate the danger of using the Kolmogorov–Smirnov test.
Theta dichotomy and doubling epsilon factors for Sp͠n(F)

In this work, we aim to prove the theta dichotomy conjecture for dual pairs of type ( Sp(W ),O(V )) with dim(V ) odd. The crux of the proof relies on the analysis of the reducibility of a certain degenerate principal series representation of the group Sp(W � ) having double the rank of Sp(W ). This analysis is carried out by way of a normalized standard intertwining operator which is also used to define an epsilon factor coming from the doubling integral construction of Piatetski-Shapiro and Rallis. In this paper, we also illustrate the connection between the doubling epsilon factor and the theta dichotomy conjecture.
A Reappraisal of Misspecified Econometric Models

This paper is the text of the 1994 Tjalling Koopmans Lecture of the Cowles Foundation. The aim of this lecture was to survey the roles of misspecified models in econometrics. Through 10 stories we show how the misspecifipation problems can be dealt with and how misspecified models can play a positive role in inference processes.
Symmetries of generalized Klein-Gordon (including sine-Gordon) equations in three or more dimensions

Much recent attention has been devoted to those nonlinear partial differential equations admitting higher-order conservation laws (e.g. [2] and references therein) or equivalently admitting higher-order symmetries. In particular the sine-Gordon equation possesses such symmetries [5, 7] where is the two-dimensional d'Alembertian operator. The question posed and solved here is whether such behaviour is possible in higher dimensions. We therefore consider the ‘Generalized Klein–Gordon’ (GKG) equation in N dimensions where and N ≥ 3.
Third-Order Translog Utility Functions

This article examines the advantages of estimating a third-order rather than a second-order translog utility function in a theoretical and empirical context. It is demonstrated that the rigor of tests for appropriate functional form is increased by increasing the order of approximation. An empirical example demonstrates that a second-order approximation can lead to inconsistent parameter estimates, whereas the third-order translog allows for better modeling of the preference structure and more consistent estimates for policy decisions.
Dislocation Models of Crystal Grain Boundaries

The energies and motions of grain boundaries between two crystallites are investigated theoretically using the dislocation model of grain boundaries. Quantitative predictions made for simple boundaries for cases in which the plane of the boundary contains the axis of relative rotation of the grains appear to agree with available experimental data. The quantitative expression for energy per unit area for small angles is approximately $[\frac{\mathrm{Ga}}{4\ensuremath{\pi}(1\ensuremath{-}\ensuremath{\sigma})}]\ensuremath{\theta}[A\ensuremath{-}\mathrm{ln}\ensuremath{\theta}]$ where $G$ is the rigidity modulus, $a$ the lattice constant, $\ensuremath{\sigma}$ Poisson's ratio, $\ensuremath{\theta}$ the relative rotation and $A$ approximately 0.23. Grain boundaries of the form considered may permit intercrystalline slip and may act as stress raisers for the generation of dislocations.
Global uniform asymptotic stability of cascade time-varying nonlinear systems: case study

Concerns the global stabilization of a class of cascaded nonlinear systems. If driven subsystem (1) has a globally stable equilibrium point at x=0 when y/spl equiv/0, then the problem reduces to design an output feedback control law for the driving subsystem (2) without destabilizing (1). Previous stability results are reviewed, and the author considers a wider class of time-varying nonlinear cascaded systems and shows that the system is globally uniformly asymptotically stable (GUAS) if the zero dynamics of the first subsystem is GUAS and if the second subsystem is globally uniformly exponentially stable. The basic tools used for stability analysis are classical techniques of Lyapunov direct method.
Optimal growth of the Batchelor vortex viscous modes

We present calculations of optimal linear growth in the Batchelor (or q) vortex. The level of transient growth is used to quantify the effect of the viscous centre modes found at large Reynolds number and large swirl. The viscous modes compete with inviscid-type transients, which are seen to provide faster growth at short times. Following a smooth transition, the viscous modes emerge as dominant in a different regime at later times. A comparison is drawn with two-dimensional shear flows, such as boundary layers, in which weak instability modes (Tollmien–Schlichting waves) also compete with inviscid transients (streamwise streaks). We find the competition to be more evenly balanced in the Batchelor vortex, because the inviscid transients are damped faster in a swirling jet than a two-dimensional shear flow, so that despite their weak growth rates the viscous modes may be relevant in some situations.
Strongly Real Elements in the Linear Groups PSLn(q)

We investigated which elements in some projective special linear and unitary groups are strongly real. In particular we showed every real element in PSL2(q) strongly real. We write a full table for real classes which are not strongly real in the unitary groups as well as a table for the non real classes in the unitary groups.
Clitics as Nonbranching Elements and the Linear Correspondence Axiom

Recent work on South Slavic cliticization standardly assumes that clitic ordering in Bulgarian and Macedonian is derived through rightward head adjunction, which is inconsistent with Kayne's (1994) Linear Correspondence Axiom (LCA). In this squib I show that this potentially very serious problem for the LCA can be resolved if we adopt a particular approach to the structural representation of clitics, which is meant to hold crosslinguistically: namely, that clitics are syntactically defined as nonbranching elements (i.e. ambiguous X°/XPs), as suggested in Chomsky (1995). To the extend that it is successful, the analysis presented here will provide evidence for the clitics-as-nonbranching-elements hypothesis
Magnetoelectric Properties of CoFe O -BaTiO Core-Shell Structure Composite

The CoFe O -BaTiO core-shell structure composite has been successfully synthesized by wet chemical method. X-ray characterization showed that the composite consisted of two single phases: CoFe O and BaTiO . The saturation magnetization of the CoFe O component in composite was found to be similar to those of the bulk sample. It was observed that the longitudinal and transverse magnetoelectric coefficients of the core-shell structure are 18 times higher than those of the mixed structure.
An alternative method for the estimation of the magnetic moment of non-spherical magnetotactic bacteria

A new approach to the determination of the magnetic moment of non-spherical magnetotactic bacteria is described. This is achieved by studying the reaction of non-motile bacteria to applied homogenous magnetic fields. The magnetic moment is calculated from the 'flip time' of a magnetotactic bacterium as its dipole realigns itself when the polarity of the applied magnetic field is reversed. The results are compared with measurements obtained from three other techniques.
STATIONARITY OF THE SOLUTION OF Xt= AtXt‐1+εt AND ANALYSIS OF NON‐GAUSSIAN DEPENDENT RANDOM VARIABLES

We give general and concrete conditions in terms of the coefficient (stochastic) process {At} so that the (doubly) stochastic difference equation Xt= AtXt-1+et has a second-order strictly stationary solution. It turns out that by choosing {At} and the “innovation” process {et} properly, a host of stationary processes with non-Gaussian marginals and long-range dependence can be generated using this difference equation. Examples of such nowGaussian marginals include exponential, mixed exponential, gamma, geometric, etc. When {At} is a binary time series, the conditional least-squares estimator of the parameters of this model is the same as those of the parameters of a Galton-Watson branching process with immigration.
Averaging regularity results for PDEs under transversality assumptions

Let u = u(x,y) and f = f(x,y) be two functions related by a PDE P(x,y,Dx,Dy)u = f; the regularity of the y-average ∫ u(x,·)dy as a function of x is investigated knowing that of u and f. Our method consists in reducing P to a microlocal normal form under a natural transversality assumption. The 2-microlocal regularity of u is also determined knowing that of f. These results are then applied to a homogenization problem. This article generalizes the results of [16] and [12] on velocity averaging and homogenization for kinetic equations.
Robust adaptive numerical compensation for friction and force ripple in permanent-magnet linear motors

This paper describes a robust adaptive compensation method for friction and force ripple present in the dynamics of permanent-magnet linear motors. The method is used in ultraprecise positioning applications. The compensation algorithm consists of a PID component and an adaptive component for estimating friction and force ripple. The adaptive component is continuously refined on the basis of just prevailing input and output signals. Computer simulations and real-time experimental results verify the effectiveness of the proposed scheme for high-precision motion trajectory tracking.
Bilinear modelling of batch processes. Part II: a comparison of PLS soft‐sensors

The on‐line monitoring of batch processes based on principal component analysis (PCA) has been widely studied. Nonetheless, researchers have not paid so much attention to the on‐line application of partial least squares (PLS). In this paper, the influence of several issues in the predictive power of a PLS model for the on‐line estimation of key variables in a batch process is studied. Some of the conclusions can help to better understand the capabilities of the proposals presented for on‐line PCA‐based monitoring. Issues like the convenience of batch‐wise or variable‐wise unfolding, the method for the imputation of future measurements and the use of several sub‐models are addressed. This is the first time that the adaptive hierarchical (or multi‐block) approach is extended to the PLS modelling. Also, the formulation of the so‐called trimmed scores regression (TSR), a powerful imputation method defined for PCA, is extended for its application with PLS modelling. Data from two processes, one simulated and one real, are used to illustrate the results. Copyright © 2008 John Wiley & Sons, Ltd.
On best‐fit corotated frames for 3D continuum finite elements

We discuss a strategy to construct corotated frames for three‐dimensional continuum finite elements by minimizing deformations within the frame. We find that irrespective of the type of element and the number of nodes, using a quaternion parametrization of rotations, this minimization is naturally stated as computing the smallest eigenvalue of a 4 × 4 matrix. The simplicity of this smallest eigenvalue plays a crucial role when linearizing the kinematics. Ensuant quaternion algebra, although lengthy, results in remarkably simple formulas for projections that arise in the linearized kinematics. The exact stiffness matrix does not require computation of the second derivative of the rotation function and is also given by a simple formula. As a result, the implementation of this corotational formulation becomes particularly straightforward. Furthermore, in contrast to other results in the literature, the stiffness matrix for elements with translational DOFs is symmetric. For illustration, this corotational formulation is applied to a solid‐shell finite element, and numerical results are presented. Copyright © 2014 John Wiley & Sons, Ltd.
Asymptotic Analysis for a Class of Infinite Systems of First-Order PDE: Nonlinear Parabolic PDE in the Singular Limit

Abstract We study the asymptotic behavior of solutions of the Cauchy problem for a functional partial differential equation with a small parameter as the parameter tends to zero. We establish a convergence theorem in which the limit problem is identified with the Cauchy problem for a nonlinear parabolic partial differential equation. We also present comparison and existence results for the Cauchy problem for the functional partial differential equation and the limit problem.
Complete spacelike hypersurfaces with constant scalar curvature and sectional curvatures ≥ 1 in De Sitter space

Hypersurfaces with constant scalar curvature and two different principal curvatures isometrically immersed in an ( 1) n + -dimensional space form M’ (C) of constant curvature c and especially in ( ) n S c + have been extensively investigated within the last four decades. In the present work, we study complete spacelike hypersurfaces with constant scalar curvature and have sectional curvatures ( ) 1 K π ≥ in de Sitter space 6 1 (1) S and find a result on the type number of such a hypersurface.
Local structure in magnetostrictive melt-spunFe80Ga20alloys

We perform a detailed investigation of the local atomic structure in highly magnetostrictive $\ensuremath{\alpha}\text{-FeGa}$ melt-spun ribbons. By using extended x-ray absorption fine structure (EXAFS) analysis at the Fe and $\text{Ga}\text{ }K$ edges coupled to x-ray diffraction (XRD) and to ab initio full multiple scattering calculations of the x-ray absorption near edge structure (XANES), we test for the presence of different local defect structures proposed in literature as being responsible for the large magnetostriction in these alloys. XRD shows that the ribbons crystallize in the A2 phase. Invisible by XRD, the presence of small Ga clusters is excluded by both EXAFS and XANES since no first shell Ga-Ga bonds are detected. However, EXAFS analysis of the second coordination shell around Ga clearly provides evidence for the presence of one highly strained $(+4%)$ Ga-Ga pair and five Ga-Fe pairs, among the six crystallographically equivalent $⟨001⟩$ atomic pairs. This conclusion supports recent total energy calculations that assign the large magnetostriction in these alloys to the strain caused by the rotation of the magnetization in the vicinity of such defects.
A T5 spin–lattice relaxation rate for non-Kramers ions

It is shown theoretically that, for non-Kramers paramagnetic ions, the second-order Raman phonon process gives a spin–lattice relaxation rate varying as T5 at low temperatures. This new relaxation rate for non-Kramers ions is similar to the one discussed by Orbach and Blume for multilevel Kramers ions. An unusual feature of the second-order Raman process as applied to non-Kramers doublets is that terms in the spin–lattice interaction which are diagonal in the spin states enter in an essential way. The conditions under which the T5 relaxation process dominates other relaxation processes are discussed.
GRAVITATIONAL TIDES IN THE OUTER PLANETS. II. INTERIOR CALCULATIONS AND ESTIMATION OF THE TIDAL DISSIPATION FACTOR

The theory of excitation of tidal oscillations in a fluid planetary body is formulated, and separable equa­ tions are derived that extend the results of the classical theory of tides to the nonhydrostatic interiors of planets. The theory is applied to the example of the gravitational tidal response of Jupiter to forcing by lo. The tidal response is found to crucially depend on the static stability in the interior of the planet, the response of the planet being as much as two to three orders of magnitude greater than the response with a neutral interior. The tidal dissipation factor Q is calculated for Jupiter and found to agree with the values required by the astronomical arguments only if the interior has finite (though small static stability. We are led to the conclusion that the interior of Jupiter must have regions which are stably stratified. Subject headings: planets and satellites: individual (Jupiter) Jupiter has a rotational period of 9.92 hr and a radius approximately 10 times greater than Earth's and 10 times smaller than the Sun's. The main constituents of the plant, hydrogen (90% by mass) and helium (10%), do not solidify, and because of the low density the mass of the planet is only 318 times greater than Earth's. The planet is primarily made up of a highly compressed but relatively cold liquid, with an inte­ rior core at probably 0.1 of the planetary radius. The visible atmospheric envelope is approximately at a pressure of 1 bar and a temperature of 150 K, while the pressure at the core is approximately 40 Mbar at a temperature of nearly 20,000 K (Stevenson 1978). Observations on the thermal emission revealed the existence of an interior heat source which accounts for around 35°/o of the 14 W m- 2 emitted to space. While much progress has been made in our understanding of the general structure of the planet (cf. Stevenson 1978), most of the meteorologically relevant information is limited to the region above the visible clouds of the planet. The data for the meteorology of the planet is still scant, making the theories for the observed cloud level circulations speculative (Ingersoll
Convergence analysis of the recursive least M-estimate adaptive filtering algorithm for impulse noise suppression

We present the convergence analysis of the recursive least M-estimate (RLM) adaptive filter algorithm, which was recently proposed for robust adaptive filtering in the impulse noise environment. The mean and mean squares behaviors of the RLM algorithm, based on the modified Huber M-estimate function (MHF), in the contaminated Gaussian (CG) noise model are analyzed. Close-form expressions are derived. The simulation and theoretical results agree very well with each other and suggest that the RLM algorithm is more robust than the RLS algorithm under the CG noise model.