Miracle-dz/UniFAR-FTUs huggingface dataset:
Trapped Surface Wave and Lateral Wave in the Presence of a Four-Layered Region

In this paper, propagation model considers the region as a perfect conductor, covered by the two layer dielectrics, and air above. Propagation of the electromagnetic field in the presence of a fourlayered region is examined in detail when a vertical electric dipole and observation point are located in the air. Similar to the threelayered case, analytical results are found for the electromagnetic field, which includes four wave modes: a direct wave, an ideal reflected wave, trapped surface waves, and lateral waves. The wave number of the trapped surface wave, which is contributed by the sums of residues of the poles, is between the wave numbers k0 in the air and k2 in the lower dielectric layer. The lateral wave is evaluated by the integrations along the branch cut. Analysis and computations shows that the trapped surface wave play a major role in communication at large distance when both the source point and observation point are on or close to the boundary between the air and the upper dielectric layer.
Oscillation and Asymptotic Behavior of Second Order Difference Equations With Nonlinear Neutral Terms

In this paper, we derive sufficient conditions for the oscillation of all / bounded solutions of ac lass of second order nonlinear difference equations with a nonlin- ear neutral term. Existence criterion is also derived for the eventually positive and asymptotically stable solution of this equation. Examples are provided to illustrate the results.
Comparing pivotal and REML-based confidence intervals for heritability

Heritability quantifies the extent to which a physical characteristic is passed from one generation to the next. From a statistical perspective, heritability is the proportion of the phenotypic variance attributable to (additive) genetic effects and is equal to a function of variance components in linear mixed models. Relying on normal distribution assumptions, one can compute exact confidence intervals for heritability using a pivotal quantity procedure. Alternatively, large-sample properties of the restricted maximum likelihood (REML) estimator can be used to construct asymptotic confidence intervals for heritability. Exact and asymptotic intervals are compared loineye muscle area measurements and balanced one-way random effects models having groups of correlated responses. In some cases the two interval methods yield vastly different results and the REML-based confidence interval does not maintain the nomiral coverate value even for seemingly large sample sizes. For finite sample size applications, the validity of the REML-based procedure depends on the correlation structure of the data.
Delay-dependent stability analysis for neural networks with additive time-varying delay components

This article studies the problem of stability analysis for neural networks (NNs) with two additive time-varying delay components. By taking both the independence and the variation of the two delay components into consideration, a more general Lyapunov functional is defined. By estimating the upper bound of the derivative of the Lyapunov functional more tightly, a less conservative delay-dependent stability criterion is established in terms of linear matrix inequalities. To reduce the computational complexity, a method for eliminating slack variables is provided, and then a simplified stability criterion is obtained. Some numerical examples are given to illustrate the effectiveness of the proposed method and the significant improvement over the existing results.
MEASUREMENT AND MODELLING OF LINEAR SYSTEMS IN THE PRESENCE OF NON-LINEAR DISTORTIONS

In [3] the measurement and modelling of linear systems in the presence of non-linear distortions has been studied for a special class of periodic excitation signals. This paper extends the theory of [3] to more general classes of (periodic) excitation signals. Also, enhanced properties of the best linear approximation and the stochastic non-linear distortions are obtained. The theory is illustrated on a simulation and a real measurement example.
Magnetic Properties for Magnetic Quantum Dot Arrays: Fast Fourier Transformation and Micromagnetism Study

Based on the Monte-Carlo simulation and fast Fourier transformation-micro-magnetism (FFTM) method, magnetic properties with different parameters for the 4×4 Magnetic Quantum Dot Arrays (QDA) were studied. The calculating processes show that the same calculated results can be obtained by both methods above. But the FFTM method can save much time in obtaining results, which suggest that the method be employed to study more complex systems. The calculated results indicate that there exists obvious difference in the magnetic hysteresis loops with different temperatures, which can be well explained by considering the relationship between the easy-magnetization axis and the organization anisotropy of the QDA system. Furthermore, saturation field (Hs) increases with the dipolar interaction increasing, which is attributed to the competition between dipolar energy (ED) and Zeeman energy (EZ). The calculated results can fit the experimental results very well. Besides, it is found that the dipolar interaction constant D has a great influence on magnetic properties.
Predictability of Extratropical Cyclones: The Influence of Initial Condition and Model Uncertainties

Errors in numerical weather forecasts can be attributed to two causes: deficiencies in the modeling system and inaccurate initial conditions. Understanding of the characteristics of the growth of forecast spread related to model uncertainty is less developed than that for initial condition uncertainty. In this research, the authors aim to construct a theoretical basis for describing such forecast error growth resulting from model uncertainty using mostly an empirical modeling approach. Primitive equation models with different vertical discretization and different horizontal resolutions are used to investigate the impacts of model uncertainties on the predictability of extratropical cyclones. Three sets of initial perturbations related to an upper-level trigger, with slightly different amplitudes, are designed for representing the situation when the initial condition uncertainty leads to significant forecast error growth. Forecast error growth is here estimated by following the properties of a developing cyclone in the simulations. Generally, there are three phases for forecast error growth in the experiments with initial condition and model uncertainties. For the experiments with the structured initial condition uncertainties, the errors grow rapidly at the earlier transient stage, with the growth rate well above the fastest growing normal mode. Afterward the error grows exponentially at approximately the same growth rate as the cyclone, followed by a saturation period, when the growth rate starts to decline. For the experiments with the model uncertainties, the forecast errors are initially zero and increase as time to a power of , which is between 0.5 and 3 depending on the strength of the cyclone at the time the simulation is initiated. After a certain time interval, the exponential growth phase and saturation period start as in the initial error experiments. Starting an integration with a stronger initial cyclone, the forecast error associated with the model uncertainty takes a shorter time to reach the exponential growth period and the forecast error grows more rapidly initially with a smaller value of . Also, when the initial cyclone is strong enough, then the exponential growth phase may only last for a very short time.
Fine-Pitch Copper Wiring Formed with Super-Inkjet and Oxygen Pump

We have successfully printed wires of 5 µm line widths and spaces in copper nanoparticle ink with a super-inkjet printer. The wires show resistivity as low as 8.1 µΩ·cm after sintering at 250 °C in an extremely low oxygen atmosphere generated by an oxygen pump. To our knowledge, this is the first report of micron-scale copper wiring formed by a direct printing method without any masks or templates.
Em Fields Inside a Prolate Spheroid Due To a Thin Circular Loop: a Higher-Order Perturbation Approach - Abstract

This paper presents an alternative analysis of obtaining radiated electromagnetic (EM) fields in a dielectric prolate spheroid using the perturbation technique. A circular loop antenna is used as a radiator on the top of the spheroid. The spheroid is approximated by the first a few terms of the Taylor series expansion (higher-order approximation), and coefficients for transmission and scattered EM fields are found using the perturbation method where the coefficients are also expanded into Taylor series and determined by matching the boundary conditions on the spheroidal dielectric surface. After the approximated coefficients and EM fields are obtained, validity of the approach is discussed and limitations are also addressed.
Observer design and detection for nonlinear descriptor systems

A nonlinear observer is considered for a class of continuous nonlinear descriptor systems subject to unknown inputs and faults. This class is partly characterized by globally Lipschitz nonlinearities, and a member system may be singular and possibly non-causal. The observer structure chosen makes it useful for both state estimation for feedback controls and residual generation for fault detection. Results on the existence of solutions are given and some useful bounds are derived which are important in the observer design, which is based on a transformed system and on the solution of a Riccati equation. The existence, convergence properties and robustness of the observer are investigated by the use of a quadratic Lyapunov function. Conditions are given for a bound to hold on the norm of the transfer function relating the residual error to the disturbance (linear case). A design algorithm is given and applied to the estimation of the states of a flexible joint robot.
TESTS FOR VARYING-COEFFICIENT PARTS ON VARYING-COEFFICIENT SINGLE-INDEX MODEL

To study the relationship between the levels of chemical pol- lutants and the number of daily total hospital admissions for respiratory diseases and to find the eect of temperature/relative humidity on the admission number, Wong et al. (17) introduced the varying-coecient single-index model (VCSIM). As pointed out, it is a popular multivari- ate nonparametric fitting technique. However, the tests of the model have not been very well developed. In this paper, based on the estima- tors obtained by the local linear technique, the average method and the one-step back-fitting technique in the VCSIM, the generalized likelihood ratio (GLR) tests for varying-coecient parts on the VCSIM are estab- lished. Under the null hypotheses the new proposed GLR tests follow the ´ 2 -distribution asymptotically with scale constant and degree of freedom independent of the nuisance parameters, known as Wilks phenomenon. Simulations are conducted to evaluate the test procedure empirically. A real example is used to illustrate the performance of the testing approach.
Optical cavity effects in InGaN/GaN quantum-well-heterostructure flip-chip light-emitting diodes

Optical cavity effects have a significant influence on the extraction efficiency of InGaN/GaN quantum-well-heterostructure flip-chip light-emitting diodes (FCLEDs). Light emitted from the quantum well (QW) self-interferes due to reflection from a closely placed reflective metallic mirror. These interference patterns couple into the escape cone and cause significant changes in the extraction efficiency as the distance between the QW and the metallic mirror varies. In addition, the radiative lifetime of the QW also changes as a function of the distance between the QW and the mirror surface. Experimental results from packaged FCLEDs, supported by optical modeling, show that a QW placed at a neighboring position corresponding to a minimum in overall light extraction. Furthermore, the optical model and experimental data are used to estimate the absolute internal quantum efficiency.
Temperature and thickness dependent permittivity of (Ba,Sr)TiO3 thin films

The temperature and thickness dependence of permittivity of (Ba,Sr)TiO3 has been investigated. The films were deposited by liquid-source metalorganic chemical vapor deposition onto Pt/SiO2/Si, with thicknesses ranging from 15 to 580 nm. The dielectric response was measured from 100 to 520 K. As film thickness decreased, the maximum dielectric constant decreased, the temperature at which the maximum dielectric constant occurred decreased, and the peak in the dielectric constant became more diffuse. A model incorporating a thickness independent interior and a nonferroelectric surface cannot account for these thickness dependencies. To appropriately model these observations a physical model containing thickness and temperature dependent interior and surface components is necessary.
The Sample Selection Model from a Method of Moments Perspective

It is shown how the usual two-step estimator for the standard sample selection model can be seen as a method of moments estimator. Standard GMM theory can be brought to bear on this model, greatly simplifying the derivation of the asymptotic properties of this model. Using this setup, the asymptotic variance is derived in detail and a consistent estimator of it is obtained that is guaranteed to be positive definite, in contrast with the estimator given in the literature. It is demonstrated how the MM approach easily accommodates variations on the estimator, like the two-step IV estimator that handles endogenous regressors, and a two-step GLS estimator. Furthermore, it is shown that from the MM formulation, it is straightforward to derive various specification tests, in particular tests for selection bias, equivalence with the censored regression model, normality, homoskedasticity, and exogeneity.
The standing hydraulic jump: theory, computations and comparisons with experiments

In this theoretical and computational study of the flow of a liquid layer, under the influence of surface tension and gravity most notably, the nonlinear equations governing an interaction between viscous effects and the effects of surface tension, gravity and streamline curvature for the limit of large Reynolds numbers are derived. The aim is to make a comparison between the predictions of this theory and the experiments of Craik et al. on the axisymmetric hydraulic jump. Such a jump is commonly encountered in the everyday context of the initial filling of a kitchen sink, for example, and it is found in the present work that initially all the effects listed above can play a primary role in practice in the local jump phenomenon. As a first step here, the flow of the layer over a small obstacle is considered. It is seen that as surface tension becomes increasingly significant the upstream influence becomes more wave-like. Second, calculations and analysis of the nonlinear free interaction are presented and show wave-like behaviour upstream, followed downstream by a depth profile not unlike that in the typical hydraulic jump. The effects of gravity dominate those of surface tension downstream. Finally, comparisons are made with the experiments and show fair quantitative agreement, supporting the present proposition that these hydraulic jumps are caused by boundary-layer separation due to a viscous–inviscid interaction forced by downstream boundary conditions on, in this case, a fully developed, high-Froude-number liquid layer.
Conjugate Mixed Convection With Surface Radiation From a Vertical Plate With a Discrete Heat Source

The results of a numerical study of the problem of two-dimensional, steady, incompressible, conjugate, laminar, mixed convection with surface radiation from a vertical plate with a flush-mounted discrete heat source are reported. The governing equations, written in vorticity-stream function form, are solved using a finite-volume based finite difference method. A hybrid grid system has been employed for discretization of the computational domain. The effects of (i) the magnitude and location of the heat source, (ii) the material and surface properties of the plate, and (iii) the free-stream velocity on both heat transfer and fluid flow have been studied. Based on a large set of (more than 550) numerical data, correlations have been developed for maximum and average non-dimensional plate temperatures and mean friction coefficient. A method for evaluating the forced convection mean friction coefficient component, which may be used in estimating the power input required for maintaining the flow, has been proposed
Stochastic simulation and first‐order multiple scatter solutions for acoustic propagation through oceanic internal waves

The existing theory of acoustic propagation through an oceanic internal wave field with a Garrett and Munk spectrum is modified and, by numerical computation, is shown to be consistent. The fractional sound speed computation is rederived to satisfy the Garrett and Munk spectrum and used to compute a stochastic simulation of the internal wave sound speed fluctuation field. The Garrett and Munk spectrum in (ω, j) space has been normalized by 4π, and the acoustic scattering is redefined to accommodate scattering from the internal wave phase fronts as in an acoustic phase grating. These modifications are then used to compute the coherent acoustic intensity by two methods: a first‐order multiple scatter approximation and a stochastic simulation. Also, the Rytov approximation is shown to be equivalent to the first‐order multiple scatter approximation in the form of the stochastic parabolic equation method in the unsaturated region. The computational results show agreement in the weak scattering region using typ.
Thermodynamics of Newman-Unti-Tamburino charged spaces

We discuss and compare at length the results of two methods used recently to describe the thermodynamics of Taub-Newman-Unti-Tamburino (NUT) solutions in a de Sitter background. In the first approach ($\mathbb{C}$ approach), one deals with an analytically continued version of the metric while in the second approach ($\mathbb{R}$ approach), the discussion is carried out using the unmodified metric with Lorentzian signature. No analytic continuation is performed on the coordinates and/or the parameters that appear in the metric. We find that the results of both these approaches are completely equivalent modulo analytic continuation and we provide the exact prescription that relates the results in both methods. The extension of these results to the AdS/flat cases aims to give a physical interpretation of the thermodynamics of NUT-charged spacetimes in the Lorentzian sector. We also briefly discuss the higher-dimensional spaces and note that, analogous with the absence of hyperbolic NUTs in AdS backgrounds, there are no spherical Taub-NUT-dS solutions.
Global error estimates for exponential splitting

Global errors of principal exponential splitting formulae, i.e., first-order splitting, Strang's splitting and parallel splitting, are investigated. It is found that the commutativity of the underlying matrices in the exponents plays an important role in the analysis. It is shown that the global error estimates behave as polynomials in the splitting steps when the steps are small and decay exponentially when the splitting steps are chosen to be large. They are much more reliable than those derived from the traditional local truncation error analysis when relatively large splitting steps are adopted. This corresponds, for example, to solving partial differential equations using relatively large Courant numbers
Correlation of X-ray burst properties with source state in the 'atoll' source 4U/MXB 1636-53

A series of Exosat observations of the atoll source 4U/MXB 1636 - 53 shows that duration and temperature of the X-ray bursts strongly correlate with the X-ray spectral and fast variability characteristics of the persistent emission of the source. This implies that spectral shape, fast variability, and burst duration and temperature all correlate well with accretion rate M. This provides a strong argument that in the atoll sources, source-state is determined by M, just as in the Z sources. These observations also show that the persistent X-ray intensity can vary independently from the other mentioned characteristics. Therefore, intensity is probably not a good measure for the accretion rate. 16 refs.
On the Resistance to the Rotation of a Disc Immersed in a Fluid

The motion of a fluid due to the rotation of an immersed plane disc about an axis perpendicular to itself is turbulent if ωa 2/ν is greater than about 105, where ω is the angular velocity of the disc, a its radius, and ν the kinematic viscosity of the fluid. The torque opposing the rotation, due to the surface friction of the fluid, was calculated originally by Kármán, both when the motion of the fluid is steady and when it is turbulent.
Broad Emission Lines From the Mass-Loss Envelopes of Giant Stars in Active Galactic Nuclei

The source of emission lines with broad range of critical densities emitted from AGNs is investigated. The envelope structure and optical line emissivity of a typical red giant mass-loss envelope is calculated, the emission line profiles are computed for power-law distributions of stars and are compared with the observed line profiles, and the constraints on the orbital motions and stellar distributions, provided by the stellar collision rate, are discussed. The results obtained suggest that the emission lines of active galaxies arise from self-replenishing giant star envelopes during a brief phase (less than 1,000,000 yr) of stellar evolution. 33 references.
Existence of invisible nonscattering objects and nonradiating sources

The radiation that is due to the scattering of an incoming light wave from an object or that is generated by a source distribution is considered. It is assumed that the field propagation can be described by the equation of radiative transport or, in the P1 approximation, by the diffusion equation. It is shown by explicit examples that there is a class of object (source) distributions that generate scattered (radiation) fields that are identically zero outside these distributions. The existence of these invisible object and source distributions leads to serious complications for the inverse, i.e., the reconstruction, problem.
Gravitational microlensing - The effect of random motion of individual stars in the lensing galaxy

We investigate the influence of random motion of individual stars in the lensing galaxy on the light curve of a gravitationally lensed background quasar. We compare this with the effects of the transverse motion of the galaxy. We find that three-dimensional random motion of stars with a velocity dispersion sigma in each dimension is more effective in producing 'peaks' in a microlensed light curve by a factor a about 1.3 than motion of the galaxy with a transverse velocity v(t) = sigma. This effectiveness parameter a seems to depend only weakly on the surface mass density. With an assumed transverse velocity of v(t) = 600 km/s of the galaxy lensing the QSO 2237+0305 and a measured velocity dispersion of sigma = 215 km/s, the expected rate of maxima in the light curves calculated for bulk motion alone has to be increased by about 10 percent due to the random motion of stars. As a consequence, the average time interval Delta t between two high-magnification events is smaller than the time interval Delta(t) bulk, calculated for bulk motion alone, Delta t about 0.9 Delta(t) bulk.