Miracle-dz/UniFAR-FTUs huggingface dataset:
The impact of flow regimes on asymmetry of orographic drag at moderate and low Rossby numbers

The change of flow regimes from “flow over” (non-blocked flow) to “flow around” (blockedflow) is generally identified by flow stagnation upstream of the mountain and increaseddeflection of flow around the edges of the mountain. Numerical calculations of simple flow pasta smooth mountain ridge presented here reveal another fundamental property of this changeof flow regimes. In the presence of the Coriolis force, the drag exerts a cyclonic couple on nonblockedflows, but an anticyclonic couple on blocked flows. The delaying effect of the Coriolisforce on the transition to the blocked flow regime is confirmed and the strength of the couplein blocked flows is also found to increase when the Rossby number U/f L decreases. A changein the flow regime from blocked to non-blocked flow when the Rossby number decreases givesa new high-drag regime at high non-dimensional mountain height (Nh/U) and increases substantiallythe temporal fluctuations of the drag. The sensitivity of the couple to the Rossby numberis confirmed in realistic simulations of blocked flow from PYREX. Data from Iceland definestwo regimes: at low Rossby number and high Nh/U, the drag on the right hand side is favoured, while at high Rossby numbers and low Nh/U the drag on the left side is larger.
Subspace methods for large inverse problems with multiple parameter classes

SUMMARY Most nonlinear inverse problems can be cast into the form of determining the minimum of a misfit functional of model parameters. This functional determines the misfit between observations and the corresponding theoretical predictions, subject to some regularization conditions on the form of the model. When there is only one type of parameter in the model, methods based on gradient techniques work well, especially when information on rate of change of gradients is included. In the case of problems depending on multiparameter classes, simple gradient methods mix parameters of different character and physical dimensionality. This may lead to rather poor convergence and strong dependence on the scaling of the different parameter types. These difficulties can be overcome by replacing a gradient step by a local minimization in a subspace spanned by a limited number of vectors in model space. The basis vectors for the subspace should be chosen in the directions determined by the variation of the misfit functional with respect to each of the parameter types, with supplementation if required by additional vectors representing the rate of change of the gradient partitions. The construction of the perturbation requires the inversion of a matrix with the dimensions of the subspace which is easily accomplished. Such a subspace scheme takes into account the different functional dependences on the various parameter types in a balanced way. The update to the current model does not depend on the scaling of the individual parameter classes. The subspace method is flexible and can be adapted to a wide range of choices of misfit criterion and modes of representation of the parameter classes. This style of iterative subspace procedure is well adapted to nonlinear problems with dependence on many parameters and can be successfully applied in a variety of problems, e.g. seismic reflection tomography, the simultaneous nonlinear determination of earthquake locations and velocity fields and in the inversion of full seismic waveforms.
Model reduction of behavioural systems

We consider model reduction of uncertain behavioural models. Machinery for gap-metric model reduction and multidimensional model reduction using linear matrix inequalities is extended to these behavioural models. The goal is a systematic method for reducing the complexity of uncertain components in hierarchically developed models which approximates the behavior of the full-order system. This paper focuses on component model reduction that preserves stability under interconnection. <<ETX>>
On the Levenberg–Yamaguchi formula for the Robin function

A reformulation of the Levenberg–Yamaguchi second variation formula for the Robin function is presented. Then a new moving frame proof to the reformulation is given. This generalizes the Levenberg–Yamaguchi second variation formula to the smooth variation of domains in almost complex manifolds.
Ulam-Zahorski problem on free interpolation by smooth functions

Let f be a function belonging to Cn[O, 1]. Is it possible to find a smoother function g E Cn+1 (or at least Cn+8 ) which has infinitely many points of contact of maximal order n with f (or at least arbitrarily many such points with fixed norm IIgIICn+e )? It turns out that for n = 0 and 1 the answer is positive, but if n > 2, it is negative. This gives a complete solution to the Ulam-Zahorski question on free interpolation on perfect sets.
A new spatiotemporal regularization method for estimating the cardiac transmembrane potential

In this study we propose a new spatiotemporal regularization algorithm for the inverse problem of electrocardiography. According to the bidomain theory the transmembrane potential is considered the primary source. Spatial and temporal constraints on this source are formulated with linear operators leading to a large-scale constrained quadratic optimization problem which is solved by an interior-point optimizer. The temporal constraint is formulated as a side-constraint and, consequently, no additional temporal regularization parameter is needed. The method would be capable of reconstructing ischemic and infarcted regions.
Constructive approximations for neural networks by sigmoidal functions

A constructive algorithm for uniformly approximating real continuous mappings by linear combinations of bounded sigmoidal functions is given. G. Cybenko (1989) has demonstrated the existence of uniform approximations to any continuous f provided that sigma is continuous; the proof is nonconstructive, relying on the Hahn-Branch theorem and the dual characterization of C(I/sup n/). Cybenko's result is extended to include any bounded sigmoidal (even nonmeasurable ones). The approximating functions are explicitly constructed. The number of terms in the linear combination is minimal for first-order terms. >
Ultrasonic investigation of the nonlinearity of fused silica for different hydroxyl-ion contents and homogeneities between 300 and 3°K

Abstract : The third-order elastic constants C111 of four types of fused silica were measured as a function of temperature between room temperature and 3 K. The room temperature values were determined absolutely by measuring the harmonic distortion of an initially sinusoidal ultrasonic wave propagating through the sample. Relative values were measured at lower temperatures. The results indicate that a relatively large OH content in fused silica gives rise to a relatively large value of C111 and that C111 is a weak function of temperature regardless of OH content. The relationship between the experimentally defined ultrasonic nonlinearity parameter beta = - ((13)C11 + C111)/3C11 and the Gruneisen parameter gamma also has been determined.
SAW delay lines for wirelessly requestable conventional sensors

Programmable reflectors of SAW ID-tags can be employed as passive transponders for conventional sensors of the capacitive, inductive and resistive type. The programmable reflector is a loadable split finger transducer, other fixed reflectors are used as reference bits. A noncoherent read out signal processing is sufficient, because the load of the programmable reflector influences both the phase and amplitude of the reflected wave. The principle is discussed, setup and results of some actual measurements are presented.
Police and thieves in the stadium: measuring the (multiple) effects of football matches on crime

Large sporting events affect criminal behaviour via three channels: fan concentration, self‐incapacitation and police displacement. I exploit information on football matches for London teams linked to detailed recorded crime data at the area level to estimate these effects empirically. I find that only property crime increases in the communities hosting matches but not violent offences. There is a negative away game attendance effect on crime which is due to voluntary incapacitation of potential offenders attending a match. Police displacement during home games increases property crime by 7 percentage points for every extra 10000 supporters in areas that are left underprotected.
Complete Tunneling of Light via Local Barrier Modes in A Composite Barrier with Metamaterials

We investigate the conditions of the complete tunneling of light across a composite barrier made of multiple layers involving metamaterials. It is shown that complete tunneling phenomena are related to the resonance transmission properties of local modes formed in barrier layers and that there are two distinctive kinds of local barrier modes involved in actual complete tunneling: the degenerate inner-barrier mode and the full barrier mode. Complete tunneling occurs via two successive mode couplings: from the incident plane wave to the plane wave in the transmission layer through the direct mediation of these two kinds of local barrier modes.
The predictability of deep convection in cloud‐resolving simulations over land

Cloud‐resolving models (CRMs) can be used to provide subgrid information for use in improving the representation of convection in large‐scale models. However, it is shown here that, for a 24‐hour simulation of convection over land, the total daily rainfall and instant rain rates can often be hard to predict. An ensemble of 2D CRM runs, which differ only in the initial white‐noise temperature perturbations added to the lowest 200 m, show a large spread of results. The size of the spread is shown to be dependent on the nature and strength of the forcing with the most significant differences between ensemble members when only a small number of convective cells exist in the domain. Further sensitivity experiments show that stronger forcing or increased domain size can reduce the spread of results due to an increased number of clouds. However, in all the simulations described in this paper, convection tended to organize into fewer but larger clouds during the day and, as this occurs, the ensemble members began to diverge even with a domain size of 1000 km. © Crown copyright, 2004.
Optimum design of switched reluctance motors using dynamic finite element analysis

Switched reluctance motors have the advantages of a high torque/weight ratio, as the large reluctance torque is made by the salient poles of both stator and rotor, and has high reliability. On the other hand, switched reluctance motors have the disadvantage of a large ripple torque, which is also made by the salient poles. Application to industrial fields have therefore been limited to special cases. For the optimum design of switched reluctance motors, this paper presents the methods and results of calculations carried out using dynamic finite element analysis. The methods are pole shape optimization, compensated current, etc. In the case of the calculated model, the motor ripple torque can be reduced to almost zero.
Testing Stationarity with Wavelet-Based Surrogates

AbstractTraditional methods of using surrogate data to test for linearity of time-series data can be extended into the time-frequency domain to test for stationarity. Surrogates are time series that are created directly from the original dataset through manipulation and seek to replicate important properties of the original dataset. By comparing the original signal to the surrogates, additional structure in the original dataset not explained by the replicated properties may be revealed. The surrogates used for the purpose of testing stationarity are stationarized versions of an original signal that have the same Fourier amplitudes, but have randomized phases. Wavelet analysis is used in this method to transform the signals into the time-frequency domain and wavelet scalograms are used to quantitatively compare the original signal to the stationarized surrogate signals. Methods introduced in previous research compare the local and global spectral features of the surrogate signals with the local and global .
Persistence of corners in free boundaries in Hele-Shaw flow

In this paper we investigate the movement of free boundaries in the two-dimensional Hele-Shaw problem. By means of the construction of special solutions of self-similar type we can describe the evolution of free boundary corners in terms of the angle at the corner. In particular, we prove that, in the injection case, while obtuse-angled corners move and smooth out instantaneously, acute-angled corners persist until a (finite) waiting time at which, at least for the special solutions, they suddenly jump into an obtuse angle, precisely the supplement of the original one. The critical values of the angle π and π/2 are also considered.
Three-dimensional conformal supergravity and Chern-Simons terms.

The supersymmetric extension of the gravitational Chern-Simons term in three-dimensional spacetime coincides with three-dimensional conformal supergravity. The action reads I = . gamma. /sub A/BR/sup B/. omega. /sup A/+(1/6)f/sub ABC/. omega. /sup C/ . omega. /sup B/. omega. /sup A/, with . gamma. /sub A/B the Killing supermetric and f/sub A/BC the structure constants of Osp(1/4). The constraints read R/sub munu//sup m/(P) = 0, R/sub munu//sup . cap alpha. /(Q) = 0, and R/sub munu/ /sup mn/(M) = 0. Even when auxiliary fields close the super-Poincare gauge algebra, I is invariant under local Poincare sypersymmetry and independent of auxiliary fields.
COMPENSATED COMPACTNESS FOR 2D CONSERVATION LAWS

We introduce a new framework for studying two-dimensional conservation laws by compensated compactness arguments. Our main result deals with 2D conserva- tion laws which are nonlinear in the sense that their velocity fields are a.e. not co-linear. We prove that if u e is a family of uniformly bounded approximate solutions of such equa- tions with H �1 -compact entropy production and with (a minimal amount of) uniform time regularity, then (a subsequence of) u e convergences strongly to a weak solution. We note that no translation invariance in space — and in particular, no spatial regularity of u(·,t) is required. Our new approach avoids the use of a large family of entropies; by a judicious choice of entropies, we show that only two entropy production bounds will suffice. We demonstrate these convergence results in the context of vanishing viscosity, kinetic BGK and finite volume approximations. Finally, the intimate connection between our 2D compensated compactness arguments and the notion of multi-dimensional non- linearity based on kinetic formulation is clarified.
On the Absolute Calibration of the Cepheid Distance Scale Using Hipparcos Parallaxes

The fundamental Hipparcos parallaxes (HIPP) of 219 Cepheids are used for the absolute calibration of the Galactic distance scale sampled by a modern Baade-Wesselink (BW) distance indicator, which reliably accounts for pulsation and thermal properties of Cepheid variable stars. Notably we map thermal properties into the Johnson-Cousins color (V-I). The BW realization is found to be much less affected than previously adopted optical luminosity laws by intrinsic scatter and systematic errors in representing individual Cepheid distances and thus is best suited for a calibration of the galactic distance scale using the fundamental Hipparcos parallaxes (HIPP). Comparisons between the actual Hipparcos calibration and three independent ground-based calibrations of the same BW distance scale show very close agreement at the 0.04 mag level, i.e., at the 1 σ level of the absolute accuracy claimed for BW realizations, although the Hipparcos calibration is affected by an uncertainty of ±0.10 mag due to propagation of parallax errors alone. Comparisons include the zero-age main-sequence calibration by Cepheids in clusters (Pleiades distance modulus at 5.57 mag), the calibration by pulsation parallaxes of Cepheids, and the calibration by updated model calculations of synthetic stellar spectra of Cepheids. Notably, the resulting galactic distance scale is found to be ~0.1 mag shorter than the value obtained in the original calibration of Feast & Catchpole. The implications of the actual calibration on the Cepheid-based distance to the Large Magellanic Cloud (LMC) and the extragalactic distance scale are briefly discussed. A true distance modulus of 18.59 ± 0.04 mag is presently achieved. Evidence from Hipparcos-based calibrations by different methods strongly supports the actual upward revision of 0.09 ± 0.04 mag for the LMC distance of 18.50 mag adopted in the Hubble Space Telescope Key Project program, corresponding to no more than a 5% decrease in the value of the Hubble constant.
On accuracy and efficiency of constrained reinitialization

The reinitialization, which is required to regularize the level set function, can be computationally expensive and hence is a determining factor for the overall efficiency of a level set method. However, it often has a significantly adverse impact on the accuracy of the level set solution. This short note is meant to shed light on the efficiency and accuracy issues of the reinitialization process. Using just one clearly defined level set propagation test case with an analytical solution the solutions obtained using a recently proposed efficient lower‐order constrained reinitialization (CR) scheme and standard low‐ and high‐order reinitialization schemes are juxtaposed to evidence the superiority of the novel CR formulation. It is shown that maintaining the location of the zero level set during the reinitialization is crucial for the accuracy and that the displacement caused by standard high‐order reinitialization schemes clearly outweighs the benefit of the high‐order smoothing of the level set function. Finally, results of a three‐dimensional problem are concisely reported to demonstrate the general applicability of the CR scheme. Copyright © 2009 John Wiley & Sons, Ltd.
Comments, conjectures, and conclusionsI. J. Good

Testing normality has attracted broad interest of both theoretical and applied statisticians for decades. Interest in this topic was accelerated by the Shapiro–Wilk W-test of normality (1965). The motivation of the original W-test was based on an analysis of variance view point, in which the slope estimator ŝ 1⁄4 ðm0V X Þ=ðm0V mÞ is the BLUE (Best Linear Unbiased Estimator) of the unknown standard deviation s of the normal distribution, where Xin is the ith order statistic of size n and m, V are the mean vector and covariance matrix of the order statistics of the standard normal distribution X 1⁄4 ðX1n; . ;XnnÞ respectively. The W test is constructed using ŝ normalized by s and some constants, where s 1⁄4 f Pn i1⁄41ðXin X Þ=ðn 1Þg. Note that s=C is another unbiased estimator of s, where C 1⁄4 ffiffiffi 2 p Gðn=2Þ=1⁄2 ffiffiffiffiffiffiffiffiffiffiffi n 1 p Gððn 1Þ=2Þ . The W statistic can be rewritten in weighted order statistics form as follows: W 1⁄4 ð Pn i1⁄41 aiXinÞ 2 Pn i1⁄41ðXi X Þ 2 ; ð1Þ
Magnetism in multilayer thin film rings

The magnetic and magnetoresistive behaviour of circular and elliptical thin film multilayer rings is discussed. Rings are particularly interesting because they can adopt several stable and metastable magnetic states characterized by different numbers of domain walls. Electrically contacted rings made of Co/Cu/NiFe or IrMn/Co/Cu/NiFe, with diameters of ∼0.5–5 µm and widths of ∼100 nm were fabricated by electron-beam lithography, sputtering and liftoff processing. We show that multilayer rings switch their magnetization by a qualitatively different mechanism compared with that of a single-layer ring; how the magnetization circulation direction around the ring can be controlled; how the rings can be electrically contacted to show large fractional field-induced changes in resistance and how these structures may be used in magnetic random access memories or magnetic logic devices.
Quantum Efficiency Measurement of Lamp Phosphors in Accordance with Radiometric Standards

To measure the quantum efficiencies of lamp phosphors, a JCSS (Japan Calibration Service System) traceable measurement method that uses a polychromator, with improved optical design to reduce stray light, and an integrating sphere has been developed. To verify the measurement accuracy of this method, a monochromator, which has a 0 - 45°incident optical system, was used. The BRDF (Bidirectional Reflectance Distribution Function) of the phosphor was measured by a goniophotometer. A comparison was made between these JCSS traceable measuring devices on the 260-400 nm wavelength characteristics of the internal quantum efficiency of the blue phosphor BAM (BaMgAl10O17:Eu2+) , which has excitation characteristics up to 400 nm. The results agreed within 4 % of the difference of the measured values. This is a good agreement considering that it was a composite measure and that the uncertainty of the spectral irradiance standard in the spectral region is lower than 3 %. It has also been established that the proposed method using a polychromator and an integrating sphere shows sufficient measurement accuracy.
Reduced-rank vector generalized linear models

Reduced-rank regression is a method with great potential for dimension reduction but has found few applications in applied statistics. To address this, reduced-rank regression is proposed for the class of vector generalized linear models (VGLMs), which is very large. The resulting class, which we call reduced-rank VGLMs (RR-VGLMs), enables the benefits of reduced-rank regression to be conveyed to a wide range of data types, including categorical data. RR-VGLMs are illustrated by focussing on models for categorical data, and especially the multinomial logit model. General algorithmic details are provided and software written by the first author is described. The reduced-rank multinomial logit model is illustrated with real data in two contexts: a regression analysis of workforce data and a classification problem.
Genesis and evolution of lubricant moguls

Presents studies on lubricant mogul formation when a slider flies over a disk surface. In the range of parameters used in this study, moguls form and reach a steady-state pattern within 100 revolutions. During this period, no significant net lubricant loss is observed in the track. The completion of the full mogul pattern is followed by an asymptotic lubricant loss from the track. The loss was not compensated by an increase in thickness outside the track. It is speculated that this lubricant loss from the disk is initiated when the peak thickness of the moguls exceeds the critical dewetting thickness, therefore allowing an energetically favored process. Theoretical modeling based on Van der Waal's interactions is presented.