Miracle-dz/UniFAR-FTUs huggingface dataset:
Fluctuating Pressure Environment of a Drag Reduction Spike

Wind-tunnel measurements have been made of the fluctuating pressure environment in a region of spikeinduced flow separation. Extremely large pressure fluctuations (30% of freest ream dynamic, pressure) were measured on the sides of the spike base at transonic speeds which are related to the nonaxisymmetric, vortical nature of the separated flow at a>0. Even higher (42% of freestream dynamic pressure) pressure fluctuations were observed on the windward side of the nose cap at supersonic speeds and a>7 deg. This is the result of an intermittent shock-shock interaction. The method of Coe et al. of normalizing the spectral data with the local separated flow height was moderately successful in collapsing the data into a manageable number of characteristic spectra. However, the spectra for the spike-induced separation at supersonic speeds agreed better with the results of Speaker and Ailman for two-dimensional step-induced separation than they did with the threedimensional ramp-induced separation of Coe et al. Spectral peaks were observed which corresponded to Roberts' critical subsonic wake flapping frequency.
Elastic Dynamic Effects on the Trajectory of a Flexible Launch Vehicle

This paper explains the full process of calculating the trajectory and vibration characteristics of a spinning flexible launch vehicle. The rigid and elastic coupled equations of motion are derived using the Lagrangian approach. The transfer matrix method of linear multibody system dynamics is used to evaluate the vehicle’s natural frequencies and bending mode shapes, which vary with time in the boosting phase of flight. The vehicle is idealized as a nonuniform beam with variable mass and stiffness distributions with thrust and mass depleting effects accounted for. The aerodynamic loads on the vehicle are obtained through the slender-body aerodynamic derivatives method based on quasi-steady theory. Because of thrust effect in the boosting phase, the vehicle experiences larger deformations than at burnout. Different mode orders and zero structural damping are applied respectively, which leads to the conclusion that the flexible vehicle’s vibration is basically a function of the fundamental mode, and struct.
Retrieval of Raindrop Size Distribution from Simulated Dual-Frequency Radar Measurements

Abstract Observations of raindrop size distributions (DSDs) have validated the use of three-parameter distribution functions in representing the observed spectra. However, dual-frequency radar measurements are limited to retrieving two independent parameters of the DSD, thus requiring a constraint on a three-parameter distribution. In this study, disdrometer observations from a variety of climate regions are employed to develop constraints on the gamma distribution that are optimized for dual-frequency radar rainfall retrievals. These observations are composited by reflectivity, and then gamma parameters are fit to the composites. The results show considerable variability in shape parameter between regions and within a region at different reflectivities. Most notable is that oceanic regions exhibit maxima in shape parameter at 13.6-GHz reflectivities between 40 and 50 dBZ, in contrast to continental regions. The shape parameter and slope parameter of all composite DSDs are poorly correlated. Thus, constra.
Dynamic Micromagnetic Simulations of Susceptibility Spectra in Thin Films With Nonuniform Magnetization

The high-frequency response of magnetic systems to a weak rf magnetic field can be characterized by the dynamic susceptibility tensor. The calculation of this quantity requires a precise knowledge of the magnetization configuration inside the sample. The aim of this paper is to demonstrate the ability of dynamic micromagnetic simulations for investigating the high-frequency susceptibility spectra of thin films with nonuni- form magnetization distributions. As an illustrative example, the case of ferromagnetic films supporting a weak-stripe-domain structure is addressed. The zero-field susceptibility spectra over the frequency range 0.1 - 40 GHz are computed using a two-di- mensional dynamic micromagnetic model. These spectra exhibit multiple resonances whose number and resonance frequencies depend on the equilibrium spin configuration and on the rf exciting field orientation. A modal analysis permits us to correlate these magnetic excitations with spin regions of the stripe domain structure. The influence of the uniaxial perpendicular anisotropy, the film thickness and an in-plane static magnetic field applied along the stripe direction on the main features of spectra (number of resonances, resonance frequencies, intensities, and linewidths) is then investigated. Finally, these theoretical results are discussed in light of available experimental data.
Numerical Study of the Structure and Thermodynamics of Colloidal Suspensions by Variational Method

In this paper, we present the results of calculation of the structure and thermodynamics properties of the dispersions colloidal solution ended using the variational method with the scaling process. We assume that the interaction potential between colloids is of Yukawa or Sogami types. The former is purely repulsive, while the second, it involves, in addition to a repulsive part, a Van der Waals attractive tail. We compute the structure factor and thermodynamics properties, using, first, the variational method with the rescaling technique, and second, the integral equation one with the hybridized mean spherical approximation. We first compare the results relative to these theories, and with those obtained within Monte Carlo simulation. We show that results from integral equation method with a Sogami potential and those of simulation are in good quantitative agreement. Finally, our theoretical results are compared to those of experiment by Tata and coworkers. We find that integral equation theory with Sogami potential agrees well with experiment.
On the Finite amplitude thermal instability of a rapidly rotating fluid sphere

Abstract The onset of instability for a self-gravitating, internally heated, fluid sphere of radius, r∗0, at large Taylor number, [Ttilde] (a measure of the rotation rate), is investigated. The pioneering work of Roberts (1968) and Busse (1970) has shown that at the onset of instability convection is concentrated in a layer of thickness, r∗0[Ttilde]−1/9, which forms a cylindrical surface, coaxial with the diameter parallel to the angular velocity. Inside this layer, Rossby waves of short length scale, r∗0 [Ttilde]− 1/6, propagate eastwards. For Rayleigh numbers, [Rtilde]∗, close to the critical value, [Rtilde]∗ c , determined by Busse (1970), a linear equation governing the evolution of the waves on the long length scale, r∗0[Ttilde]−1/9, and a long lime scale is derived. , When [Rtilde]∗ is greater than [Rtilde]∗c some disturbances applied at time t∗ = 0 initially grow exponentially. Nevertheless the equation has the remarkable property that, as t∗ → ∞, all solutions decay exponentially irrespective of th.
MEMORY PARAMETER ESTIMATION IN THE PRESENCE OF LEVEL SHIFTS AND DETERMINISTIC TRENDS

We propose estimators of the memory parameter of a time series that are robust to a wide variety of random level shift processes, deterministic level shifts, and deterministic time trends. The estimators are simple trimmed versions of the popular log-periodogram regression estimator that employ certain sample-size-dependent and, in some cases, data-dependent trimmings that discard low-frequency components. We also show that a previously developed trimmed local Whittle estimator is robust to the same forms of data contamination. Regardless of whether the underlying long- or short-memory process is contaminated by level shifts or deterministic trends, the estimators are consistent and asymptotically normal with the same limiting variance as their standard untrimmed counterparts. Simulations show that the trimmed estimators perform their intended purpose quite well, substantially decreasing both finite-sample bias and root mean-squared error in the presence of these contaminating components. Furthermore, we assess the trade-offs involved with their use when such components are not present but the underlying process exhibits strong short-memory dynamics or is contaminated by noise. To balance the potential finite-sample biases involved in estimating the memory parameter, we recommend a particular adaptive version of the trimmed log-periodogram estimator that performs well in a wide variety of circumstances. We apply the estimators to stock market volatility data to find that various time series typically thought to be long-memory processes actually appear to be short- or very weak long-memory processes contaminated by level shifts or deterministic trends.
Curvature properties of the slowness surface of the system of crystal acoustics for cubic crystals

In this paper we study geometric properties of the slowness surface of the system of crystal acoustics for cubic crystals. In particul ar we shall study curvature properties of the surface and the behaviour of the surface near singular points. The main result is that in the generic nearly isotropic case ther e are no planes which are tangent to the surface along entire curves. This is in contra st with what happens for the slowness surface of the system of crystal optics for bi-a xial crystals. Geometric information of the type we shall obtain is needed to understand the long-time behaviour of global solutions of the system of crystal acoustics.
Turbulent compressible convection in a deep atmosphere. III - Tests on the validity and limitation of the numerical approach

The effects of various approximations on the results of three-dimensional computation of turbulent compressible convection are examined and related to the phenomenon of bubble breaking in stellar convection. The problem of viscosity and the numerical issue of efficiency versus accuracy in such computations are discussed, and a model is formulated and tested with regard to turbulent viscosity and accuracy. Results on the convergence to a statistically stationary state, the effects of time accuracy on the statistics, the effects of the adjustable constant parameter c(mu), and the effects of aspect ratio, horizontal grid size, and vertical grid distribution are discussed. A preliminary look at the three-dimensional flow structure is given.
Hierarchical hybrid control systems: a lattice theoretic formulation

The notion of dynamical consistency is extended to hybrid systems so as to define the set of dynamically consistent hybrid partition machines associated with a continuous system S. Following the formulation of the notions of between-block and in-block controllable hybrid partition machines, the lattice HIBC(S) of hybrid in-block controllable partition machines is defined and investigated. Based on these constructions, the definition and properties of hierarchical-hybrid control systems are presented together with an example.
Estimation of Shelter Temperatures from Operational Satellite Sounder Data

Abstract As a first step in the development of a technique for estimating daily maximum and minimum shelter temperatures for agricultural monitoring, this study made use of operational satellite sounder data to estimate shelter temperature. Linear regression methods were used with a ground-truth data set of surface observations matched against data from operationally derived soundings. Regression estimates based solely on temperature predictors from the satellite soundings yielded residual standard deviations of 1.6–2.6 K for the NOAA-6 and NOAA-7 clear and partly cloudy retrievals. Regressions for cloudy conditions based only on the microwave retrievals had errors ranging from 2.9–4.0 K. Shelter temperatures estimated by regression have errors somewhat smaller than those reported for the lower levels of the atmospheric soundings. This suggests that satellite temperature soundings near the surface are more accurate than previous studies indicate.
ACTION OF A GROTHENDIECK–TEICHMÜLLER GROUP ON TORSION ELEMENTS OF FULL TEICHMÜLLER MODULAR GROUPS OF GENUS ONE

In this paper we define a new version of Grothendieck–Teichmuller group defined by three generalized equations coming from finite-order diffeomorphisms, and we prove that it is isomorphic to the known version IΓ of the Grothendieck–Teichmuller defined in [H. Nakamura and L. Schneps, On a subgroup of the Grothendieck–Teichmuller group acting on the tower of profinite Teichmuller modular groups, Invent. Math.141 (2000) 503–560]. We show that acts on the full mapping class groups for 2g - 2 + n > 0. We then prove that the conjugacy classes of prime-order torsion of are exactly the discrete prime-order ones of . Using this we prove that acts on prime-order torsion elements of in a particular way called λ-conjugacy, analogous to the Galois action on inertia.
The fractional parts of an additive form

Heilbronn (6) proved that for every ε ≥ 0 and N ≥ 1 and every real θ there is an integer x such that , where C(ε) depends only on ε and ∥α∥ is the difference between α and the nearest integer, taken positively. Danicic(1) obtained an analogous result for the fractional parts of nkθ, the proof of this is more readily accessible in Davenport(4). Danicic(2) also obtained an estimate for the fractional parts of a real quadratic form in n variables, and in order to extend this result to forms of higher degree it is desirable to first obtain results for additive forms.
A Godunov‐type fractional semi‐implicit method based on staggered grid for dam‐break modeling

A semi‐implicit finite volume model based upon staggered grid is presented for solving shallow water equation. The model employs a time‐splitting scheme that uses a predictor–corrector method for the advection term. The fluxes are calculated based on a Riemann solver in the prediction step and a downwind scheme in the correction step. A simple TVD scheme is employed for shock capturing purposes in which the Minmond limiter is used for flux functions. As a consequence of using staggered grid, an ADI method is adopted for solving the discretized equations for 2‐D problems. Several 1‐D and 2‐D flows have been modeled with satisfactory results when compared with analytical and experimental test cases. The model is also capable of simulating supercritical as well as subcritical flow. Copyright © 2010 John Wiley & Sons, Ltd.
SUPPORTS OF INFINITELY DIVISIBLE DISTRIBUTIONS.

Abstract : There has been a considerable amount of recent interest in the problem of characterizing absolutely continuous infinitely divisible distributions by their Levy-Khintechine representation, and in the singular case, characterizing the dimension of the support. It is easy to give examples of infinitely divisible distributions of 0-dimensional support whose convolution is absolutely continuous. This work shows that the dimension of the marginals of a process of independ ent stationary increments can do anything consistent with dimension increasing on convolution and the marginals possibly becoming absolutely continuous. (Author)
Heat flux induced by gravity waves

A derivation is given of the heat flux induced by large amplitude gravity waves; the case where nonlinear or turbulent damping exceeds molecular damping. This case is typical of the middle atmosphere. The derivation is based on a simple algorithm for converting the linear dispersion relation for gravity waves into a nonlinear one, and generalizes a recent derivation by Walterscheid. The derived heat deposition flux is shown to cause local cooling where the waves are close to saturation, but could cause heating where the waves are far from saturation. It is then proven that the heat flux is related to the diffusivity and to the wave momentum deposition flux by simple expressions. Hence, knowledge of one transport coefficient is practically equivalent to knowledge of the other two. The derivation is limited to waves that have some randomicity.
Observation of preplanetary disks around MWC 349 and LKH-alpha 101

Infrared spectra of three highly reddened emission-line objects (MWC 349, MWC 297, and LKH-alpha 101) have been obtained from both aircraft and ground-based observatories. These spectra show bright emission lines which are consistent with recombination in an H II region. Additional optical data for MWC 349 yield a model which consists of a central O6.5 star with circumstellar disk seen face-on, a surrounding H II region, and circumstellar dust. The parameters of the disk are discussed in terms of the viscous dissipation model of Lynden-Bell and Pringle (1974). The observations are in excellent agreement with the predictions of the model and represent the first substantial case for a newly formed star with a preplanetary disk.
ON FIXED POINTS OF GENERALIZED SET-VALUED CONTRACTIONS

Abstract Using a variational method introduced in [D. Azé and J.-N. Corvellec, ‘A variational method in fixed point results with inwardness conditions’, Proc. Amer. Math. Soc.134(12) (2006), 3577–3583], deriving directly from the Ekeland principle, we give a general result on the existence of a fixed point for a very general class of multifunctions, generalizing the recent results of [Y. Feng and S. Liu, ‘Fixed point theorems for multi-valued contractive mappings and multi-valued Caristi type mappings’, J. Math. Anal. Appl.317(1) (2006), 103–112; D. Klim and D. Wardowski, ‘Fixed point theorems for set-valued contractions in complete metric spaces’, J. Math. Anal. Appl.334(1) (2007), 132–139]. Moreover, we give a sharp estimate for the distance to the fixed-points set.
A Straightforward Approach to Markov Chain Monte Carlo Methods for Item Response Models

This paper demonstrates Markov chain Monte Carlo (MCMC) techniques that are particularly well-suited to complex models with item response theory (IRT) assumptions. MCMC may be thought of as a successor to the standard practice of first calibrating the items using E-M methods and then taking the item parameters to be known and fixed at their calibrated values when proceeding with inference regarding the latent trait, in contrast to this two-stage E-M approach, MCMC methods treat item and subject parameters at the same time; this allows us to incorporate standard errors of item estimates into trait inferences, and vice versa. We develop a MCMC methodology, based on Metropolis-Hastings sampling, that can be routinely implemented to fit novel IRT models, and we compare the algorithmic features of the Metropolis- Hastings approach to other approaches based on Gibbs sampling. For concreteness we illustrate the methodology using the familiar two-parameter logistic (2PL) IRT model; more complex models are treated in a subsequent paper (Patz & Junker, in press).
Longtime behavior of the coupled traveling wave model for semiconductor lasers

The coupled traveling wave model is a popular tool for investigating longitudinal dynamical eects in semiconductor lasers, for example, sensitivity to delayed optical feedback. This model consists of a hyperbolic linear system of partial dieren tial equations with one spatial dimension, which is nonlinearly coupled with a slow subsystem of ordinary dieren tial equations. We rst prove the basic statements about the existence of solutions of the initial-boundary-value problem and their smooth dependence on initial values and parameters. Hence, the model constitutes a smooth innite-dimension al dynamical system. Then we exploit this fact and the particular slow-fast structure of the system to construct a low-dimensional attracting invariant manifold for certain parameter constellations. The o w on this invariant manifold is described by a system of ordinary dieren tial equations that is accessible to classical bifurcation theory and numerical tools like such as AUTO.
Red giants in open clusters ? IX. NGC 2324, 2818, 3960 and 6259

We present accurate radial velocities and photoelectric UBV photometry for 73 and 57 red-giant candidates, respectively, in the intermediate-age open clusters NGC 2324, 2818, 3960 and 6259. These data conrm the membership of 47 stars, 12 of which (26%) are spectroscopic binaries; three preliminary orbits have been determined in NGC 3960. From Washington photometry of 8 red giant members, the metallicity of NGC 6259 is found to be (Fe/H) = 0:06 0:08. At the age of these clusters, most of the red giants are observed in the core- helium (clump) burning phase, the general morphology of which is well reproduced by theoretical models with convective overshooting. However, a number of bona de cluster giant members are found signicantly to the red of the isochrones tting the rest of the CMD of these and a few other clusters. Some of these stars are binaries, but others seem to be single. In either case, their red colours and/or low luminosities remain unexplained by current stellar evolution theory.
Dynamic saturation of optical transitions in high-power molecular lasers

An analysis is made of the saturation of optical transitions in high-power molecular lasers under conditions of transient excitation of the active medium and simultaneous departure from equilibrium in the translational, rotational, and vibrational degrees of freedom of the emitting molecules. The dependence of the saturation intensity on typical time parameters of a system is obtained in two limiting cases of homogeneous and inhomogeneous broadening of spectral lines and estimates are obtained of the saturation intensity for several specific laser systems (electric-discharge CO2 laser and pulsed as well as cw chemical HF lasers).
Neural mechanisms underlying sensory feedback control of speech

The DIVA model predicts that perturbation of speech will result in activation of sensory error cells that encode the mismatch between the expected and realized sensory consequences of speech production. Cells coding auditory and somatosensory errors are hypothesized to lie in posterior superior temporal gyrus and supramarginal gyrus, respectively. Activation of these error cells drives compensatory articulator movements, marked by increased activation of ventral motor cortex. To test these hypotheses, blood oxygen level dependent responses during normal and perturbed feedback conditions were assessed in two fMRI experiments. In one experiment, transient, unexpected auditory perturbations were induced by shifting F1 upward or downward; in another, a small balloon was inflated during speech production to induce a somatosensory perturbation. Increased bilateral activation in higher‐order sensory cortices in response to the feedback perturbation was consistent with model predictions. Increased activation of f.
Pressure loss equations for laminar and turbulent non-newtonian pipe flow

The equations that define Newtonian pipe flow are well established and used routinely by engineers and scientists throughout the world. The same cannot be said for non-Newtonian flows, which have a higher degree of complexity. This paper presents a coherent set of equations for the laminar and turbulent flow of Herschel-Bulkley fluids. These equations are consistent with those used for Newtonian fluids and previous work on the behavior of generalized non-Newtonian fluids. A numerical model for non-Newtonian flows is discussed and has been compared with experimental measurements from different sources. This model has been used to run a series of simulations to find the coefficients required for a new turbulent friction factor correlation. A new Reynolds number has been defined that represents the conditions in turbulent flows more realistically than the existing Metzner-Reed Reynolds number.