Miracle-dz/UniFAR-FTUs huggingface dataset:
On a ogawa–type integral with application to the fractional brownian motion

We construct a deterministic Ogawa–type integral with respect to a continuous function that, in particular, can be a trajectory of the Fractional Brownian motion. This integral is related with the Stratonovich integral and with the integrals introduced by Ciesielski et altri and Zähle. We give a sufficient condition for the integrability of a function in this sense, that does not imply its continuity. Under this sufficient condition, we obtain a Besov regularity property of the indefinite integral. We also study the stochastic Ogawa integral for stochastic processes when integrate with respect to the Fractional Brownian motion of Hurst parameter H ∈ (1/2, 1)
The Ionization Fraction in Dense Cloud Cores

The degree of ionization, x(e) = n(e)/n(H2), and the cosmic-ray ionization rate, ζ, in 24 cloud cores have been determined by comparing observational data from Butner et al. on the abundance ratios RD = [DCO+]/[HCO+] and RH = [HCO+]/[CO] with a simple analytical chemical model and with a detailed "pseudo-time-dependent" chemical model. The results are dependent on the depletion of elemental carbon and oxygen from their cosmic abundances, especially for cores with a low degree of ionization. We determine the depletion of C and O from the measured HC3N/CO abundance ratios using model results. We find that the range of fractional ionization in the dark cores extends from ~10-6 to ~10-8, with inferred cosmic ray ionization rates in the range of 10-16-10-18 s-1. This corresponds to ambipolar diffusion timescales of between 3 × 107 and 3 × 105 yr, with a median value of 5 × 106 yr. The ratio of ambipolar diffusion to the free-fall timescales varies between 3 and 200, with a median value of 50. We find, rather surprisingly, no clear segregation in the ambipolar diffusion timescales between cores with embedded stars and those without. An interesting by-product of our results is the conclusion that the cyanopolyyne-rich core in TMC-1 is atypical in its abundance distribution and may be unusually young.
Frequency conversion of picosecond radiation in ultraviolet (338-366 nm) and vacuum ultraviolet (113.5-117.0 nm) ranges

The results of nonlinear optical conversion of picosecond radiation continuously tuneable in the ultraviolet (UV) and vacuum ultraviolet (VUV) ranges are presented. Sum frequency generation of the second harmonic of Nd:glass laser radiation and of parametric waves in the UV range (338-366 nm) was investigated. UV pulses (7 ps) with an energy of 3 mJ were attained in this range. The maximal sum frequency conversion efficiency in UV range was 0.12 (for λ = 349 nm). Third-harmonic generation (THG) in gas mixtures tuneable in the 113.5-117.0 nm range was studied. THG efficiencies of 3×10-5 and 8×10-4 and the range of VUV frequency tuning of 2600 cm-1 were achieved for pure Xe and gas mixtures respectively.
Simulation of hypersonic flows on unstructured grids

The paper describes a solver for the compressible inviscid flow equations which is based on a flux vector splitting strategy able to deal with chemical reaction effects. The methodology here adopted is based on a modification of the Flux Vector Splitting technique due to van Leer.11 The scheme operates on completely unstructured grids and has been coupled with an adaptive remeshing procedure to compute high speed flows. Solutions for two-dimensional problems for non-reactive and reactive air in thermodynamic equilibrium are presented.
Rare Event Simulation of Small Noise Diffusions

An important sampling method for certain rare event problems involving small noise diffusions is proposed. Standard Monte Carlo schemes for these problems behave exponentially poorly in the small noise limit. Previous work in rare event simulation has focused on developing estimators with optimal exponential variance decay rates. This criterion still allows for exponential growth of the statistical relative error. We show that an estimator related to a deterministic control problem not only has an optimal variance decay rate but can have vanishingly small relative statistical error in the small noise limit. The sampling method based on this estimator can be seen as the limit of the zero variance importance sampling scheme, which uses the solution of the second‐order partial differential equation (PDE) associated with the diffusion. In the scheme proposed here this PDE is replaced by a Hamilton‐Jacobi equation whose solution is computed pointwise on the fly from its variational formulation, an operation that remains practical even in high‐dimensional problems. We test the scheme on several simple illustrative examples as well as a stochastic PDE, the noisy Allen‐Cahn equation. © 2012 Wiley Periodicals, Inc.
Linear Results on the Barrier Effects of Mesoscale Mountains.

Abstract We examine the factors determining whether a mountain acts as a strong barrier to an impinging flow. A primary concern is the extent to which the barrier effect is reduced when smoothed orography is used in a numerical model. These questions are addressed within the model of linear, rotating, stratified flow over topography first studied by Queney. The ground level Green's functions for this model are derived and their near- and far-field asymptotic behavior is discussed. Using the asymptotic results, the upstream deceleration is estimated as a function of Ro=U/fL and hm=Nhm/U, where U is the far upstream speed of the cross-mountain flow, f the Coriolis parameter, L the mountain width, N the Brunt-Vaisala frequency, and hm is the maximum mountain height. Effects of terrain shape are also considered. The Green's functions are evaluated numerically and used to calculate the response to a family of mountain profiles; a comparison with asymptotic results shows the latter to be very useful. It is conc.
Physics‐based preconditioners for flow in fractured porous media

Discrete fracture models are an attractive alternative to upscaled models for flow in fractured media, as they provide a more accurate representation of the flow characteristics. A major challenge in discrete fracture simulation is to overcome the large computational cost associated with resolving the individual fractures in large‐scale simulations. In this work, two characteristics of the fractured porous media are utilized to construct efficient preconditioners for the discretized flow equations. First, the preconditioners are tailored to the fracture geometry and presumed flow properties so that the dominant features are well represented there. This assures good scalability of the preconditioners in terms of problem size and permeability contrast. For fracture dominated problems, numerical examples show that such geometric preconditioners are comparable or preferable when compared to state‐of‐the‐art algebraic multigrid preconditioners. The robustness of the physics‐based preconditioner for less favorable fracture conditions is further demonstrated by a systematic degradation of the fracture hierarchy. Second, the preconditioners are physics preserving in the sense that conservative fluxes can be computed even for an inexact pressure solutions. This facilitates a scheme where accuracy in the linear solver can be traded for efficiency by terminating the iterative solvers based on error estimates, and without sacrificing basic physical modeling principles. With the combination of these two properties a novel preconditioner is obtained which bridges the gap between multiscale approximations and iterative linear solvers.
Dust Devil–Like Vortices in an Urban Area Detected by a 3D Scanning Doppler Lidar

Abstract Atmospheric boundary layer (ABL) observations were conducted in an urban area (Sapporo, Japan) from April 2005 to July 2007 using a three-dimensional scanning coherent Doppler lidar. During this period, 50 dust devil–like vortices were detected in the area; they occurred during the daytime and were located at vertices or in the branches of convective cells (“fishnet” patterns of wind field). The diameters of the vortex cores ranged from 30 to 120 m, and maximum vorticity ranged from 0.15 to 0.26 s−1. More than 60% of the vortices were cyclonic; the rest were anticyclonic. The tangential velocity component of the strongest vortex varied from −5.4 to +1.4 m s−1, and the signal-to-noise ratio was weak in the core. Temporal changes were observed in the three-dimensional structures of two vortices from 1330 to 1354 (Japan standard time) 14 April 2005, and the temporal evolution of the stronger vortex was studied. The vortex initially formed along a low-level convergence line in a fishnet and developed.
High-efficiency silver-halide sensitized gelatin holograms with low absorption and scatter

Abstract We report for the first time the results of a comparative performance study of silver-halide sensitized gelatin (SHSG) holograms recorded in the familiar Agfa 8E75 HD plates and the new BB-640 plates manufactured by Holographic Recording Technologies. High diffraction efficiency (∼ 90%) and low absorption and scatter (∼5.4%) are the distinguishing features of the BB-640 plates, given the fact that both kinds of plates have been prepared and processed under identical conditions. Thus, in summary, our investigation reveals that high quality SHSG holograms could obtained using the new BB-640 plates.
Consistent Specification Testing via Nonparametric Series Regression

This paper proposes two consistent one-sided specification tests for parametric regression models, one based on the sample covariance between the residual from the parametric model and the discrepancy between the parametric and nonparametric fitted values; the other based on the difference in sums of squared residuals between the parametric and nonparametric models. The authors estimate the nonparametric model by series regression. The new test statistics converge in distribution to a unit normal under correct specification and grow to infinity faster than the parametric rate [square root of] n under misspecification, while avoiding weighting, sample splitting, and nonnested testing procedures used elsewhere. Copyright 1995 by The Econometric Society.
Integrated Methods for Household Greywater Treatment: Modified Biofiltration and Phytoremediation

Most countries around the world have experienced water scarcity in recent decades as fresh water consumption has increased. However, untreated wastewater is routinely discharged into the environment, particularly in developing countries, where it causes widespread environmental and public health problems. The majority of wastewater treatment method publications are heavily focused on high-income country applications and, in most cases, cannot be transferred to low and middle-income countries. An experimental study was conducted to evaluate the performance efficiency of pilot-scale physicochemical and biological treatment methods for the treatment of household greywater in Jimma, Ethiopia. During the experiment, grab samples of greywater were taken from the combined treatment system's influent and effluent every 7 days for 5 weeks and analyzed within 24–48 hours. Temperature, DO, EC, turbidity, TDS, and pH were measured on-site, while BOD, COD, TSS, TP, TN PO4−3-P, NO3-N, NH4-N, Cl−, and FC were determined in the laboratory. During the five-week pilot-scale combined treatment system monitoring period, the combined experimental and control system's mean percentage reduction efficiencies were as follows: turbidity (97.2%, 92%), TSS (99.2%, 97.2%), BOD5 (94%, 57.4%), COD (91.6%, 54.7%), chloride (61%, 35%), TN (68.24, 42.7%), TP (71.6%, 38.7%), and FC (90%, 71.1%), respectively. Similarly, the combined experimental and control systems reduced PO4−3-P (12.5 ± 3 mg/L), NO3-N (4.5 ± 3 mg/L), and NH4-N (10.19 ± 2.6 mg/L) to PO4−3-P (3.5 ± 2.6 mg/L, 7.5 ± 1.6 mg/L), NO3-N (0.8 ± 0.5, 3.6 ± 2.3 mg/L), and NH4-N (7 ± 2.9 mg/L, 15.9 ± 3.9 mg/L), respectively. From the biofiltration and horizontal subsurface flow constructed wetland combined systems, the experimental combined technology emerged as the best performing greywater treatment system, exhibiting remarkably higher pollutant removal efficiencies. In conclusion, the combined biofiltration and horizontal subsurface flow constructed wetland treatment system can be the technology of choice in low-income countries, particularly those with tropical climates.
Discrete-TimeH∞ Integral Control Via LMIs Applied to a Furuta Pendulum

The Furuta pendulum represents a challenging problem in the control area due to its nonlinear dynamics and unstable equilibrium point. Besides those issues, the implementation of control techniques in Furuta pendulum prototypes also needs to deal with possible uncertainties in parameter values, noises, and non-modeled dynamics, which can lead the controlled system to instability. The H∞ control tends to be an interesting approach for this type of application since this technique is able to mitigate the effect of the disturbances that can act on the controlled system and has been successfully applied in systems with uncertainties. In this paper, we present anH∞ control strategy applied to a Furuta pendulum system that uses, in addition to the state feedback, an integrator in the feedback loop. The controller was designed, simulated, and put into practice in a real prototype. The controller was implemented via a digital computer; then analog/digital and digital/analog converters were presented in the control loop to interface the continuous signal of the plant with the discrete nature of the controller. This fact was considered in the control design by representing the system dynamics in discrete time. Since not all variables required for state feedback are physically measured in the prototype used, a state observer was employed in the control loop in order to estimate the state variables. In addition, the adopted design procedure that used LMIs established a maximum value for the H∞ norm of the closed-loop system, as well as limited the norm of the state feedback gain and ensured an adequate decay rate. Thus, it was possible to guarantee the suitable performance of the controlled system. The same integral control structure was also used with a feedback gain designed through the pole placement technique, and its results were used for performance comparison. The outcomes, both from simulations and from the real equipment, show the efficiency of the applied control regarding disturbance rejection and that the adopted design procedure is adequate for controlling physical systems.
Superconvergence analysis for nonlinear parabolic equation with E Q rot1 nonconforming ﬁnite element

E Q rot1 nonconforming ﬁnite element method (FEM) applied to a class of nonlinear parabolic equation is discussed. First, by use of two typical characters of this element (one is that the associated FE interpolation operator is identical to its traditional Ritz projection operator; the other is that the consistency error is of order O ( h 2 ) , one order higher than the interpolation error, when the exact solution of the problems belongs to H 3 (cid:2)) ), the supercloseness of order O ( h 2 ) in broken H 1 -norm for semi-discrete scheme is obtained without the boundedness of numerical solution in L ∞ -norm through splitting the numerical solution into several parts. Moreover, we get the desired result with requirement of u , u t ∈ H 3 (cid:2)) only. Secondly, a linearized Crank–Nicolson fully discrete scheme is proposed and the superclose property of order O ( h 2 + τ 2 ) is derived by constructing a suitable auxiliary problem. Finally, a numerical example is carried out to conﬁrm our theoretical analysis. Here, h is the subdivision parameter and τ is the time step.
Robust H ∞ control for singular time-delay systems with saturating actuators via static output feedback

The problem of H ∞ robust exponential stability and static output feedback stabilization of uncertain singular time-delay systems with saturating actuators are investigated. First, the delay-dependent condition is given to guarantee that the singular time-delay systems are not only exponential admissible, but also satisﬁes H ∞ performance γ . Moreover, the estimation of stability region and the design method of H ∞ static output feedback controller are given by solving a convex optimization problem. Some simulation examples are provided to demonstrate the merit of the proposed design methods.
Application of the Homotopy–Pad ´ e technique in the prediction of optimal convergence-control parameter

A major issue in the convergence of an obtained series solution via the homotopy analysismethodistheproperchoiceoftheso-calledconvergence-controlparameter c 0 . Inthis paper a new approach based on Homotopy–Pad ´ e technique in the prediction of the proper convergence-control parameter values c 0 is proposed. This approach seeks to predict an optimal value of convergence-control parameter c 0 to get a faster convergent series solution. The numerical results demonstrate the validity, efﬁciency, and performance of the proposed approach.
Integrability conditions for a determination of collective submanifolds

SummaryWe have recently proposed a method of determining collective submanifolds,i.e. integrability conditions of a time-dependent Hartree-Bogoliubov (TDHB) equation, from the group-theoretical standpoints. On the other hand, as shown by Marumoriet al., the «invariance principle of the Schrödinger equation» and the canonicity condition lead us necessarily to the equation of the collective motion expressed in the canonical form. Our method may be also expected to give a criterion how we extract the collective submanifolds effectively out of a full TDHB manifold under the use of the canonical equation. If it is established, we may investigate the range of the validity of the theory of the so-called «maximally decoupled» collective motions in the TDHB case.RiassuntoAbbiamo proposto recentemente un metodo di determinare sottovarietà collettive, cioè condizioni di integrabilità di un’equazione di Hartree-Bogoliubov dipendente dal tempo (TDHB), dal punto di vista del gruppo teorico. D’altra parte, come mostrato daMuramoriet al., il «principio d’invarianza dell’equazione di Schrödinger» e la condizione di canonicità ci portano necessariamente all’equazione di moto collettivo espressa in forma canonica. Si può anche prevedere che il nostro metodo dia un criterio per estrarre efficacemente la sottovarietà collettive da una sottovarietà piena TDHB usando la regione canonica. Se è stabilito, si può studiare l’intervallo di validità dei cosiddetti moti collettivi maggiormente disaccoppiati nel caso TDHB. РезюмеМы недавно предложили метод определения коллективных подмножеств, т. е. условий интегрируемости зависящего от времени уравнения Хартри-Боголюбова, с точки зрения теории групп. С другой стороны, как показано Марумори и др. , «принцип инвариантности уравнения Шредингера» и условие каноничности приводят к уравнению для коллективного движения, выраженному в канонической форме. Ожидается, что метод может также датя критерий, как зффективно извлечя коллективные подмножества из множества зависящего от времени уравнения Хартри-Боголюбова, используя каноническое уравнение. Мы можем исследовать область справедливости теории так называемых «максимально не связанных» коллективных движений в случае зависящего от времени уравнения Хартри-Боголюбова.
Optimal Regularity for One-Dimensional Porous Medium Flow

We give a new proof of the Lipschitz continuity with respect to t of the pressure in a one dimensional porous medium flow. As is shown by the Barenblatt solution, this is the optimal t-regularity for the pressure. Our proof is based on the existence and properties of a certain selfsimilar solution.
Semiclassical Particles with Arbitrary Spin in the Riemann-Cartan Spacetime

By means of the Fock-Papapetrou method and the WKB method, the equations of world line and spin precession are derived for elementary particles with arbitrary spin s moving in the Riemann­ Cartan spacetime. It is shown that the world line is the geodesics of the metric, and that the spin precession due to torsion depends on the spin s. In particular, the intrinsic. spin vector is not Fermi-Walker transported along the world line relative either to the nonsymmetric connection or to the ordinary symmetric connection.
Speech synthesis by linear interpolation of spectral parameters between dyad boundaries

A recent study [Olive and Spickenagel, J. Acoust. Soc. Am. 59, 993-996 (1976)] has shown that area parameters derived from linear prediction analysis can be linearly interpolated between dyad boundaries with very little distortion in the resultant synthesized speech. The success of area parameter interpolation raises a question: can other acoustic parameters, such as the power spectrum of the speech waveform, be similarly interpolated? The spectrum is of special interest because speech can be synthesized in real time from spectral parameters on a programmable digital filter. To study this question a speech analysis-synthesis system using spectral parameters (samples of power spectra at different frequencies) was simulated. These parameters were determined from the speech signal at every dyad boundary, and interpolated for intermediate values. Dyad boundaries (representing the limits of transition regions between phonemes) were determined manually. Informal listening tests comparing synthetic speech with and without linear interpolation showed slight degradation in the interpolated speech. This degradation is significantly reduced by using an additional point within the dyad boundaries for interpolation.
The ν1 + ν3 bands of 16O18O16O and 16O16O18O

Abstract Using 0.003 cm −1 resolution Fourier transform spectra of 18 O-enriched ozone around 4.8 μm, the first high-resolution analysis of the ν 1 + ν 3 bands of (OOO)-O-16-O-18-O-16 and (OOO)-O-16-O-16-O-18 has been performed. The experimental rotational energy levels were reproduced satisfactorily with the aid of a Hamiltonian model taking fully into account the vibration-rotation interactions. Indeed, it did not prove possible to fit properly the (101) levels without including in the Hamiltonian model both the Coriolis interactions coupling the levels of (101) with those of (002) and (200) and the Darling-Dennison interaction coupling the levels of (002) with those of (200). In this way reliable vibrational energies and rotational and coupling constants were deduced with the following band-centers: ν 0 (ν 1 + ν 3 ) = 2049.3694 cm −1 for 16 O 18 O 16 O, and ν 0 (ν 1 + ν 3 ) = 2090.3406 cm −1 for 16 O 16 O 18 O.
An Affine SIFT Matching Algorithm Based on Local Patch Shape Estimation

In this paper we present an affine SIFT matching method to achieve reliable correspondence points in stereo matching with large viewpoint changes. We extended the affine invariant of the conventional SIFT approach by estimating the shape of the local patch around the interest point. Since we can obtain the scale information by SIFT detector, a second moment matrix (SMM) descriptor was employed to describe the shape. Furthermore, by comparing the shapes of the potential matches, we can normalize the template of SIFT descriptor and obtain the initial affine transformation. At last, we applied the iterative based method to achieve a fine registration with the estimated initial transformation parameters. The experiment results show that the proposed method is more robust to viewpoint changes and the accuracy of registration is better than feature based methods.