Miracle-dz/UniFAR-FTUs huggingface dataset:
Application of a Monotonic Upstream-biased Transport Scheme to Three-Dimensional Constituent Transport Calculations

The application of van Leer's scheme, a monotonic, upstream-biased differencing scheme, to three-dimensional constituent transport calculations is shown. The major disadvantage of the scheme is shown to be a self-limiting diffusion. A major advantage of the scheme is shown to be its ability to maintain constituent correlations. The scheme is adapted for a spherical coordinate system with a hybrid sigma-pressure coordinate in the vertical. Special consideration is given to cross-polar flow. The vertical wind calculation is shown to be extremely sensitive to the method of calculating the divergence. This sensitivity implies that a vertical wind formulation consistent with the transport scheme is essential for accurate transport calculations. The computational savings of the time-splitting method used to solve this equation are shown. Finally, the capabilities of this scheme are illustrated by an ozone transport and chemistry model simulation.
Superprism effect in bidimensional rectangular photonic crystals

In this letter, we show that photonic crystals with geometries of lower symmetry, such as the rectangular geometry, are uniquely suited for applications involving the superprism effect. The extra degree of freedom provided by the anisotropy of the unit cell allows more freedom in searching for suitable iso-frequency curves. Also, the appearance of multiple orders of diffraction allows more than one incident plane wave to couple to the same Bloch mode. This extra degree of freedom is decisive when trying to optimize the transmission. We illustrate these ideas on a particular rectangular configuration which ensures a strong angular superprism effect, a well collimated transmitted beam, and power transmissions of up to 80%.
Pulsar statistics: the birthrate and initial spin periods of radio pulsars

We investigate the birthrate and initial spin periods of radio pulsars using the recently revised pulsar distance scale of Cordes et al. Our technique is based upon the model-free approach originally suggested by Phinney & Blandford, which makes no assumptions about pulsar luminosity as a function of period, the beaming fraction, or field decay in radio pulsars. It eliminates the large statistical errors inherent in previous methods by restricting the sample to pulsars with luminosities greater than some minimum value. We verify the validity of our approach, and shortcomings of previous methods, by using Monte Carlo simulations on synthetic populations of pulsars which take into account random errors in the pulsar distance scale
Unveiling the kinematics of the disk and the ionized stellar wind of the massive star MWC349A through RRL masers

Abstract The kinematics of photoevaporating disks and their associated ionized outflows around massive stars are fundamental to understand how these stars are formed and they evolve in their early phases of their evolution. To date, the important advances have been provided by studying the UC-HII region of MWC349A thanks to their strong maser emission at Hydrogen radio-recombination lines (RRLs). This B[e] star is one of the best prototypes of massive star with an ionized outflow expanding at nearly constant velocity. A 3D radiative transfer model applied to the H30α line has allowed to constrain the disk kinematics, which seems to follow pure Keplerian rotation in its outer parts. The model has also allowed us to constraints the launching radius of the outflow. Our results are supported by the agreement of our model predictions with the observations for other observed RRLs. Recent high-frequency observations of RRL masers with the Herschel Space Telescope (HIFI) show that the kinematics of the disk inner regions is not well understood. Modeling of these lines will constrain the formation of the ionized winds.
Representation Theorems for Interacting Moran Models, Interacting Fisher-Wrighter Diffusions and Applications

We consider spatially interacting Moran models and their diffusion limit which are interacting Fisher-Wright diffusions. The Moran model is a spatial population model with individuals of different type located on sites given by elements of an Abelian group. The dynamics of the system consists of independent migration of individuals between the sites and a resampling mechanism at each site, i.e., pairs of individuals are replaced by new pairs where each newcomer takes the type of a randomly chosen individual from the parent pair. Interacting Fisher-Wright diffusions collect the relative frequency of a subset of types evaluated for the separate sites in the limit of infinitely many individuals per site. One is interested in the type configuration as well as the time-space evolution of genealogies, encoded in the so-called historical process. The first goal of the paper is the analytical characterization of the historical processes for both models as solutions of well-posed martingale problems and the development of a corresponding duality theory. For that purpose, we link both the historical Fisher-Wright diffusions and the historical Moran models by the so-called look-down process. That is, for any fixed time, a collection of historical Moran models with increasing particle intensity and a particle representation for the limiting historical interacting Fisher-Wright diffusions are provided on one and the same probability space. This leads to a strong form of duality between spatially interacting Moran models, interacting Fisher-Wright diffusions on the one hand and coalescing random walks on the other hand, which extends the classical weak form of moment duality for interacting Fisher-Wright diffusions. Our second goal is to show that this representation can be used to obtain new results on the long-time behavior, in particular (i) on the structure of the equilibria, and of the equilibrium historical processes, and (ii) on the behavior of our models on large but finite site space in comparison with our models on infinite site space. Here the so-called finite system scheme is established for spatially interacting Moran models which implies via the look-down representation also the already known results for interacting Fisher-Wright diffusions. Furthermore suitable versions of the finite system scheme on the level of historical processes are newly developed and verified. In the long run the provided look-down representation is intended to answer questions about finer path properties of interacting Fisher-Wright diffusions.
Sliding Mode Controllers Design through Bifurcation Analysis

Abstract Basic concepts for designing sliding mode controllers (SMC) are reviewed from the point of view of Filippov vector fields and new conceptual tools are developed. The possibility of reducing the n -dimensional sliding dynamics to that of certain topologically equivalent (n − 1)-dimensional standard vector field is shown. The need of a sliding dynamics bifurcation analysis, as much global as possible, in order to determine the structural stability of closed loop control systems is emphasized. The usefulness of the approach is shown by revisiting a well known application in power electronics, as is the boost converter, obtaining sound design criteria.
First principles study of oxygen vacancy states in monoclinic ZrO2: Interpretation of conduction characteristics

We perform first-principles calculation of monoclinic ZrO2 with oxygen vacancies by using a hybrid functional method to obtain band gap and corresponding energy levels of vacancy states with different charges or coordination numbers. The result agrees well with experimentally measured value. Based on the calculations, explanation for the conduction characteristics which is dependent on applied electric field in monoclinic ZrO2 volume is given.
On The Performance Of Maximum-Likelihood Reconstructions In Positron Emission Tomography

The conventional reconstruction techniques in positron emission tomography are based on deterministic principles, i.e., the stochastic nature of the measurements is completely ignored. This approach is quite acceptable in situations where the number of detector counts is sufficiently high. In practice, however, there are limitations to both the amount of activity administered to the patient, and the acquisition time, which usually results in a relatively low number of counts. It is known that the statistical fluctuations of these measurements can give rise to severe reconstruction artefacts. Stochastic methods are preferable in this context, as they use the information contained in the measurements more efficiently. In this paper, we present a modified version of Rockmore and Macovski's maximum-likelihood formula (for Poission measurement statistics), which takes into account the attenuation of the subject. Our implementation, based on an iterative algorithm, produces excellent images with low noise content and virtually no artefacts. Furthermore, the resolution comes close to the theoretical limit imposed by the sampling distance. A suboptimal version of the algorithm is also presented. Comparisons are made between the error performance of both algorithms and that of the filtered backprojection method. In order to make a fair comparison, we include two curves (corresponding to different convolution filters) for the conventional method. The absence of artefacts and lower noise, especially in low intensity areas of the images, are distinct advantages for diagnostic purposes. Alternatively, acceptable recon-structions can be obtained with shorter acquisition times or lower radionuclide doses for the patient.
Measuring the dispersion of a surface layer by breaking waves using planar laser induced fluorescence

Surface films can be found all over the world, from the algae blooms of the Mediterranean to oil or sewage pollution near harbours and cities. In this paper the experimental method of planar laser induced fluorescence is used to measure how breaking waves disperse these films. The method for preparing and extracting quantitative results from laboratory experiments is presented with sample results for depth, area and fractal dimension from mild spilling breakers. Two cases are examined, a single isolated breaker and an identical breaking wave occurring 32 s after an initial breaker has disturbed the film.
Quantum Chaos on Graphs

We quantize graphs (networks) which consist of a finite number of bonds and nodes. We show that their spectral statistics is well reproduced by random matrix theory. We also define a classical phase space for the graph, where the dynamics is mixing and the periodic orbits (loops on the graph) proliferate exponentially. An exact trace formula for the quantum spectrum is developed and used to investigate the origin of the connection between random matrix theory and the underlying chaotic classical dynamics. Being an exact theory, and due to its relative simplicity, it offers new insights into this problem which is at the forefront of the research in quantum chaos and related fields. [S0031-9007(97)04707-8]
The electrostatic problem of two conducting spheres

In continuation of his previous paper on the spherical condenser † the author discusses the capacities, the mutual actions and the field in the neighbourhood of two electrified spherical conductors. After a brief introductory statement of this historical problem an attempt is made to solve it by elementary theory. The magnitudes of the errors introduced by this method are pointed out. Accurate formulae are then obtained by the method described in the preceding paper. These formulae enable the capacity coefficients to be computed in all cases to any required degree of accuracy without difficulty. A few simplified formulae which will be useful in practice are also given. The discussion of the mutual actions between the spheres shows that when their potentials or charges are of like sign the force between them may be attractive or repulsive, depending on the ratio of the potentials or the charges. In this case there are always two ratios of the charges and of the potentials which make the mutual force zero. Methods of computing the forces in other cases are given. Simple formulae are found for calculating the potential gradients at the points on the spheres where the line joining their centres cuts their surfaces. This tells us whether the charge on the spheres is all positive or all negative or partly positive and partly negative. In the Appendix a few more accurate but more elaborate formulae are given.
Experimental advanced superconducting tokamak ohmic discharge simulation by the tokamak simulation code

The tokamak simulation code (TSC) has been used to model several ohmic discharges in the experimental advanced superconducting tokamak (EAST) experiments. Good agreement between the simulation and experiment has been obtained in the plasma current and shape evolution, as well as electron temperature, surface voltage and volt–second consumption. With the verified TSC transport models, an ohmic discharge has been predicted. The poloidal field current trajectories, plasma current and shape evolution follow the designed traces in the experiment.
Using the Box-Cox t distribution in GAMLSS to model skewness and kurtosis

The Box-Cox t (BCT) distribution is presented as a model for a dependent variable Y exhibiting both skewness and leptokurtosis. The distribution is defined by a power transformation Y v having a shifted and scaled (truncated) t distribution with degrees of freedom parameter τ. The distribution has four parameters and is denoted by BCT(μ, σ,ν, τ). The parameters μ, σ,ν and τ may be interpreted as relating to location (median), scale (centile-based coefficient of variation), skewness (power transformation to symmetry) and kurtosis (degrees of freedom), respectively. The generalized additive model for location, scale and shape (GAMLSS) is extended to allow each of the parameters of the distribution to be modelled as linear and/or non-linear parametric and/or smooth non-parametric functions of explanatory variables. A Fisher scoring algorithm is used to fit the model by maximizing a (penalized) likelihood. The first and expected second and cross derivatives of the likelihood with respect to μ, σ,ν and τ, required for the algorithm, are provided. The use of the BCT distribution is illustrated by two data applications.
Loop-erased random walk, uniform spanning forests and bi-Laplacian Gaussian field in the critical dimension

For $N=n(\log n)^{\frac{1}{4}}$, on the ball in $\mathbb{Z}^{4}$ with radius $N$ we construct a $\pm 1$ spin model coupled with the wired spanning forests. We show that as $n\rightarrow \infty $ the spin field has bi-Laplacian Gaussian field on $\mathbb{R}^{4}$ as its scaling limit. The precise fluctuation magnitude of the field is $\sqrt{3\log N}$. In order to prove such results, we show that the escape probability of the loop-erased random walk (LERW) renormalized by $(\log n)^{\frac{1}{3}}$ converges almost surely and in $L^{p}$ for all $p>0$. This improves the known mean field picture of 4D LERW. As an application, we provide a construction of the bi-infinite LERW, thus solving a question of Benjamini-Lyons-Peres-Schramm in the case of $\mathbb{Z}^{4}$.
Numerical and Experimental Study of the $Q$ Factor of High- $Q$ Micropillar Cavities

Micropillar cavities are potential candidates for high-efficiency single-photon sources and are testbeds for cavity quantum electrodynamics experiments. In both applications a high quality (Q) factor is desired. It was recently shown that the Q of high-Q semiconductor micropillar cavities exhibit pronounced quasi-periodic variations in the regime from 1 to 4 μm, and a detailed understanding of the variational behavior of the Q is required. Here, we study the origin of these variations using a multi-mode Fabry-Perot model appropriate for this regime. We analyze in detail contributions to the effective reflectivity of the fundamental mode arising from coupling to scattering channels involving higher-order cavity modes and propagating Bloch modes in the distributed Bragg reflectors (DBRs). We show how these weak contributions lead to strong variations of the Q factor, and we relate the average periodicity of these variations to the thickness of the DBRs and the derivative of the effective indices of the guided Bloch modes. We also examine the influence of various geometrical parameters, including the number of DBR layers pairs, the amplitude of the corrugation of the pillar sidewalls and the number of etched layer pairs in the bottom DBR on the Q versus diameter relation. Comparisons are made between extensive numerical simulations and experimental measurements, and a good qualitative agreement is found.
Positions and proper motions of pulsars

Accurate radio positions have been determined for 40 pulsars using the VLA. 19 of these pulsars were observed at three epochs, 1984.98, 1986.39 and 1989.08, from which proper motions have been obtained with an accuracy better than 0.01 arcsec per year for the stronger pulsars. Absolute positions have a precision of a few tenths of an arcsecond or better and, after correcting for known proper motions, are in excellent agreement with positions derived from pulsar timing observations. Proper motions have also been determined for 21 pulsars from a comparison of the VLA positions with previously published positions
Classification of Posture Reconstruction with Univariate Time Series Data Type

The existing classification methods are mostly designed to solve problems with multivariate time series data types although in general there is also univariate time series data attributes that are often encountered in the application of classification problems. This research raises the problem with univariate time series data type in posture reconstruction data classification. We propose a classification technique such as k-nearest neighbor for classification of univariate time series data type. We first collect the data of posture reconstruction. from k-NN method we determine that the number of k is 5 and doing the similarity measurement by using Euclidean Distance. We rank the results based on the number of k and the similarity measurement to get the final result. Based on the experiment of this research, the accuracy that we get from k-NN is 0.995 with the balance precision and recall. Therefore, classification method particularly k-NN can be used to solve the univariate time series problem in posture reconstruction.
Approximate and Analytic Solutions for Deformation of Finite Porous Filters

The deformation, using linear poroelasticity, of a two-dimensional box of porous material due to fluid flow from a line source is considered as a model of certain filtration processes. Analytical solutions for the steady-state displacement, pressure, and fluid velocity are derived when the side walls of the filter have zero solid stress. A numerical solution for the case where the porous material adheres to the side walls is also found. It will be shown, however, that simpler approximate solutions can be derived which predict the majority of the deformation behavior of the filter.
Introduction of new coordinates to the Schottky space - The general case -

In the previous paper [4], we introduced new coordinates to the Schottky space with respect to a standard system of loops $\Sigma$ , and we defined the augmented Schottky space. As we shall explain in \S 1, a standard system of loops is a special case of a basic system of loops. In this paper, in \S 2, we will introduce new coordinates to the Schottky space in the general case, namely, in the case where $\Sigma$ is a basic system of loops. In \S 3, by using these coordinates, we will define the augmented Schottky space in the general case. We will discuss, in \S 4, relations between the augmented Schottky space and compact Riemann surfaces with or without nodes. This paper was written while the author stayed at the State University of New York at Stony Brook. He wishes to express his deepest gratitude to Professors I. Kra, B. Maskit and P. Matelski for many suggestions and giving him the opportunity to devote himself to this work.
Excitation and propagation of electromagnetic waves in nonuniform density ducts

With the use of a full wave formulation, a study is made of radiation and propagation of electromagnetic waves in nonuniform cylindrical ducts excited by given azimuthally symmetric sources. For an infinitely long duct, the eigenfunction set involving both localized and non-localized waves is obtained for arbitrary values of driving frequency, external magnetic-field strength, plasma density, and its variation transverse to the duct axis. Using this set, the radiation characteristics of an annular current immersed in the duct are found for the whistler range. The subsequent propagation of excited waves is then analyzed in a duct whose parameters vary slowly along the external magnetic field. The applications of the results obtained are discussed.
The Free Vibration Of Circularly Cylindrical Shell And Plate Systems

Abstract A Rayleigh-Ritz approach, previously shown to apply to the free vibration of beam systems and rectangular plate systems, is applied to the free vibrational problem of systems comprised of circularly cylindrical, thin shells and thin annular or circular plates. The approach utilizes the concept of artificial springs which permit the convenient joining together of the components of each system and simplifies the selection of the trial functions for the Rayleigh-Ritz solution; in this work, orthogonal polynomials are used. Several example systems are treated: a cylindrical shell with a circular plate at each end (described in the literature as a drum or a hermetic can), a double cylindrical shell with an annular plate at each end, and a similar system in which the inner cylinder is extended. The approach is shown to yield rapidly convergent and accurate results.
Spaced‐antenna analysis in the frequency domain

Data from spaced-antenna experiments are normally analysed by correlation techniques in the time domain, but several authors have recently pointed out that an equivalent analysis can be carried out in the frequency domain. To explore any possible advantages of such a procedure, we assume Gaussian forms for the correlation functions so that their Fourier transforms can be evaluated analytically. The power spectrum is shown to be a convolution of two terms, one of which represents “beam broadening” due to the mean wind, and the other represents the broadening due to turbulent motions. The cross spectrum has a phase which is a linear function of frequency, the slope of which is related to the “apparent velocity” of correlation analysis. If this same cross-spectral phase is interpreted by the method of Doppler interferometry, the velocity obtained is also the apparent velocity. The Gaussian model is extended to include the effects of vertical velocity and of scatter which is centered off zenith. A computational scheme is presented in which an analysis equivalent to conventional “full correlation analysis” is carried out entirely in the frequency domain. The method is illustrated using data from Adelaide.