Miracle-dz/UniFAR-FTUs huggingface dataset:
Free-surface boundary conditions for elastic staggered-grid modeling schemes

I present an accurate, stable, and simple implementation of the elastic free surface for staggered‐grid modeling schemes. The method is based on the presumption that the elastic Hooke's tensor on the free surface can be taken as similar to a transversely isotropic medium. The anisotropic elastic properties are then analyzed. The final scheme is isotropic, but with modified elastic properties on the free surface. The proposed scheme shows good agreement with an analytical solution.It is shown that the Rayleigh wave can not be properly resolved at two gridpoints per shortest wavelength if the shortest wavelength is calculated as the Rayleigh‐wave velocity over the maximum frequency. The Rayleigh wave is exponentially damped away from the free surface and requires denser sampling than purely propagating waves.
Intermixing in heteroepitaxial islands: fast, self-consistent calculation of the concentration profile minimizing the elastic energy

We present a novel computational method for finding the concentration profile which minimizes the elastic energy stored in heteroepitaxial islands. Based on a suitable combination of continuum elasticity theory and configurational Monte Carlo, we show that such profiles can be readily found by a simple, yet fully self-consistent, iterative procedure. We apply the method to SiGe/Si islands, considering realistic three-dimensional shapes (pyramids, domes and barns), finding strongly non-uniform distributions of Si and Ge atoms, in qualitative agreement with several experiments. Moreover, our simulated selective-etching profiles display, in some cases, a remarkable resemblance to the experimental ones, opening intriguing questions on the interplay between kinetic, entropic and elastic effects.
Effects of sampling rate on automated fatigue recognition in surface EMG signals

Abstract This study investigated the effects different sampling rates may produce on the quality of muscle fatigue detection algorithms. sEMG signals were obtained from isometric contractions of the arm. Subsampled signals resulting in technically relevant sampling rates were computationally deduced from the original recordings. The spectral based fatigue recognition methods mean and median frequency as well as spectral moment ratio were included in this investigation, as well as the sample and the fuzzy approximate entropy. The resulting fatigue indices were evaluated with respect to noise and separability of different load levels. We concluded that the spectral moment ratio provides the best results in fatigue detection over a wide range of sampling rates.
A general conversion model of China rainfall rate distributions with different integration times

Rainfall data with 1 minute integration time is required in the prediction of rain attenuation for the given time percentage. But most of the data available have longer integration time, such as 10 min, 30 min, 60 min, etc. Therefore the conversion model for rainfall rate is needed. In this paper, several conversion models with different integration times are firstly introduced and analyzed on the basis of the measured data in several locations in China.Then, a general conversion model suitable for China rainfall rate distributions is presented by employing the parameter fit technique.The simulated results show that the model is available in different rain zone with a good accuracy.
Analysis of Pixel-level Remote Sensing Image Fusion Methods

Different remote sensing images have their own virtues and limits;and image fusion is designed for completely using their virtues to compose new images.Three methods-PCA,Brovey and wavelet transform are used to fuse the SPOT multispectral data and the panchromatic data on the pixel-level.The wavelet transform used the Mallat's algorithm and biorthogonal wavelet function,the virtue of the latter is that the function will not distort the image when the reverse wavelet transform is performed.The fusion results are evaluated both qualitatively and quantitatively in the aspects of spectral and spatial quality;the results show that the best method of the three is wavelet transform.The wavelet transform method makes the fusion image preserve both the spatial quality of the pan image and spectral quality of the multispectral image,while the other two methods make the fusion images to distort the spectral quality of the multispectral image.At the same time,the influences of different wavelet functions used in the Mallat's algorithm on the related fusion image are compared.Different wavelet functions result in differences in reserving the spectral and spatial quality of the fusion image.If we use the biorthogonal wavelet transform to fuse image,we can select the proper wavelet basis function for the practical demand(the compromise between high spatial detail and high spectral quality preserve).
Estimating the Collision Rate of Inertial Particles in a Turbulent Flow: Limitations of the "Ghost Collision" Approximation

Most studies of collisions in turbulent flows are based on the "ghost collision" approximation, whereby one follows a number of particles, and simply counts the number of times the distance between two particles becomes less than the sum of their radii; particles are kept in the flow after they collided. We discuss here the limitations of this approximation, and demonstrate, using a simple model flow, that it leads to overestimates of the real collision rate by as much as ∼ 30% at small Stokes numbers.
Statistics of the Global Tropopause Pressure

Abstract Statistics of the global tropopause pressure are evaluated for the period between 1979 and 1993. The analysis is based on gridded data as provided by the ECMWF reanalysis project. The thermal and dynamical definitions of the tropopause are applied in order to derive the surface separating the troposphere from the stratosphere. The dynamical tropopause is evaluated for threshhold values of potential vorticity of ±1.6, ±2.5, and ±3.5 potential vorticity units. Positive (negative) values are applied for the Northern (Southern) Hemisphere. The thermal tropopause is determined using the lapse-rate criteria. Frequency distributions of the tropopause pressure are shown above continental, ocean, polar, midlatitude, and tropical areas. Trends in the tropopause pressure are evaluated and compared with observed trends in total ozone.
Ground Characterization of the Scanner for Radiation Budget (ScaRaB) Flight Model 1

Abstract The Scanner for Radiation Budget (ScaRaB) is a satellite-based radiometer for measurements of the planetary radiation budget. It was launched in January 1994 on a Russian METEOR-3 platform and provided excellent data from February 1994 to March 1995. The radiometer is briefly described. Onboard calibration is performed by tungsten filament lamps and blackbody simulators. The onboard sources were characterized on ground, as well as the spectral response function of the instrument and the linearity of the channels. The ground measurements are described and the results are presented. The error in the blackbody calibration is estimated to 0.4% and to less than 1.5% for the various lamp sources. The lamp sources showed significant drifts during ground testing that could be corrected.
Supercritical Flow Interaction within the Cape Blanco–Cape Mendocino Orographic Complex

Abstract Supercritical flow interaction occurring in the marine boundary layer between closely spaced coastal capes is investigated with a mesoscale numerical prediction model. As an extension of previous work, the U.S. Navy’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) is used to perform idealized model simulations with marine layers of varying upstream Froude number to elucidate the different flow responses for a single convex bend. The impact upon the supercritical flow of introducing a series of closely spaced coastal bends is then investigated. The expansion fan is significantly reduced in magnitude and size by the formation of a compression wave at a blocking, concave bend approximately 150 km downstream. Building upon the idealized marine layer response, real-data forecasts are then examined for several time periods of supercritical flow interaction between Cape Blanco, Oregon, and Cape Mendocino, California. Observations from the Coastal Waves 1996 (CW96) field program were colle.
A RECURSIVE METHOD FOR DISCRETELY MONITORED GEOMETRIC ASIAN OPTION PRICES

We aim to compute discretely monitored geometric Asian option prices under the Heston model. This method involves explicit formula for multivariate generalized Fourier transform of volatility process and their integrals over different time intervals using a recursive method. As numerical results, we illustrate efficiency and accuracy of our method. In addition, we simulate scenarios which show evidently practical importance of our work.
Predicting kWh/kWp performance for amorphous silicon thin film modules

The BP Solar factory in Toano, VA is producing tandem amorphous silicon PV modules called Millennia. With this product commercially available it is important to be able to predict the performance and energy production obtainable from these modules anywhere in the world. The formulas developed to predict crystalline silicon module kWh/kWp performance do not work because for tandem junction a-Si: (1) the temperature coefficients, particularly the one for peak power, are functions of temperature and irradiance. Therefore a single coefficient cannot be used to calculate expected power under different operating conditions; and (2) the output power depends on the history of the module. During operation the module is continually undergoing light induced degradation and thermal annealing.
Parameters of lossy cavity resonators calculated by the finite element method

The calculation of the resonance frequency and quality factor of closed or aperture coupled cavity resonators with volume and wall losses by an edge finite element method is discussed. An efficient solver is developed to solve the complex nonlinear eigenvalue problem. The effect of the roughness of the walls on the quality factor is taken approximately into account.
Compact integrated diversity antenna for wireless communications

We introduce a compact integrated antenna that has two feed ports with more than 20 dB isolation between them. The significance of the design is that it can be utilized in compact wireless communication handsets to provide diversity signals or act as a duplexer allowing the receive and transmit signals to be well isolated. The antenna design is based on merging two patch antennas together in combination with capacitive loading so that a compact design can be obtained. Justification for the design is provided by considering the mutual coupling using the reaction principle and finite-dimensional time-domain (FDTD) simulations. Experimental results are also presented for a design that operates in the 2100-2200 MHz band for possible application in forthcoming third-generation wireless systems. Results include radiation patterns, S-parameters, and signal correlations between ports so that the diversity performance and isolation characteristics of the antenna can be demonstrated. These show that in typical wireless environments envelope cross correlations of less than 0.1 between the ports are obtained.
Optimal flow control using a POD-based reduced-order model

ABSTRACT The flow control constitutes a challenging research topic with numerous applications in aeronautics, aerodynamics, fluid mechanics, civil engineering, and so on. Due to the use of iterative algorithms, it is costly in both CPU time and memory requirements. In this paper, an optimal control strategy with reduced-order model built with proper orthogonal decomposition approach is proposed. The methodology is developed to control an anisothermal flow in a lid-driven cavity with one control parameter and then extended to at two control parameters. The control is realized in quasi-real time, which opens the way to promising practical applications.
Nonresonant optogalvanic laser-induced signals in prebreakdown gas discharges. I. Simplified model for time dependence of metastable atom density changes

Electrical responses of low-biased noble gases irradiated by medium-intensity, nonresonant, short laser pulses can be described by a limited number of internal processes. Simplified rate equations for the main processes are solved analytically. It is assumed that (1) a four-level model describes the gas energy states and (2) metastable levels (the most populated excited levels) are the principal source for free-electron concentration change. The solution in the form of a series of time-varying exponentials represents the behavior of the metastable atom density perturbed by laser pulse illumination. Although this polynomial type of representation of discharge behavior is typically assumed empirically, here it is derived analytically, and coefficients in such polynomials are related to actual quantum processes within the discharge and initial laser-induced perturbation. >
Dichotomous choice models and dummy variables

Summary. In an article recently published in this journal, Oksanen demonstrated that the coefficients of observation-specific dummy variables are not estimable in dichotomous logit models. This paper extends Oksanen's result in two ways. First, it is shown that observation-specific dummy variables cannot be estimated in a large class of dichotomous choice models, which include probit as well as logit models. Second, it is shown that the dummy variable need not be observation-specific. The dummy variable can describe a group with more than one member as long as each member of the group makes the same choice. Oksanen's result is thus a special case in which the dichotomous choice model is the logit model, and the observation-specific dummy variable represents a group with one member. In an article recently published in this journal, Oksanen (1986) explores the use of observation-specific dummy variables in linear probability and logit models. An observation-specific dummy variable takes on the value 1 for one observation and 0 for all others. Oksanen demonstrates that, while the coefficients of observation-specific dummy variables can be estimated in linear probability models, the coefficients are undefined and cannot be estimated in logit models. The purpose of this paper is to extend Oksanen's result in two ways. The first is to demonstrate that the coefficients of observation-specific dummy variables cannot be estimated for an entire class of dichotomous choice models which includes logit models as a special case. Second, it is shown that the coefficients of more generally defined dummy variables cannot be estimated in dichotomous choice models. Oksanen's result that coefficients of observation-specific dummy variables cannot be estimated is extended to a large class of dichotomous choice models. The class includes all dichot6mous choice models in which the probability of choice can be expressed as the integral of a continuous density function, f(t), that is positive for all t. This stipulation can also be stated in terms of the cumulative distribution function F. No finite numbers a and b can exist such that F(a) = 0 and F(b)= 1. This class includes probit models as well as logit models.
On pricing European options under HCIR model: A comparative study

This paper concerns the numerical solution of the three-dimensional Heston- Cox- Ingersoll- Ross (HCIR) partial differential equation for the fair values of European- style financial options. Adomian decomposition method and Homotopy perturbation method are two powerful methods which consider an approximate solution of the HCIR stochastic differential equation which is reformed to PDE form. Also, the theoretical analysis of these methods shows two methods are equivalent in solving nonlinear equations.
Online sketch recognition for mixed point and irregular military symbols

Most of current research on online sketched military symbols recognition concerns only one type of symbols,point symbols or irregular symbols,using different methods to recognize separately. But in practical applications the two types of symbols are mixed. It becomes a major issue to find a way to recognize a type-unknown military symbol. A minimum spanning tree( MST) covering model-based mixed recognition method was proposed. In the training phase,two MST-based covering models were built for point and irregular symbols respectively. And then a two-class support vector machine( SVM) classifier was trained. In the recognition phase,the coarse type identification was accomplished by using the geometrical and structural information firstly. Then the confidence estimations were calculated and integrated to identify the type of the unknown symbol. Different types of symbols were classified by two existing modules. The algorithm was tested on 113 classes of point symbols and 36 classes of irregular symbols. The accuracy rate of symbol type identification was 94. 7%,and the final recognition rate was 91. 6% in real time.
Philosophical Logic: An Introduction to Advanced Topics

1. Introduction / Sentences / Truth and Falsity / Defense and Refutation / Inference, Form and Implication / Formally Valid Inference / Conjunctions / Inference with Conjunctions / Negation / Inference with Negation / Truth-Functionality and Negation / Grouping / 2. Sentential Logic / Simple Sentences / Sentences / Derivations: A First Look / A Note on Sets / Lines / Derivations Again / Theorems / Truth Sets / Soundness / Completeness / Extensions of SL / Conditionalization / Model Sets / Syntax and Semantics / 3. Quantificational Logic / Singular Terms / Predicates / Some Symbolic Conventions / Some / The Language QL / Derivations / Truth Sets / All / Further Extensions of QL / Model Sets / Identity / Model Sets for QL / 4. Sentential Modal Logic / Non-Truth-Functional Sentential Operators / Sentential Modal Operators / Derivations / S5, S4, T, and B / Possible Worlds / At a World and In a World / Model Sets and Model Systems / Deontic Logic and Model Sets / 5. Quantification and Modality / Some Derivations / Model Sets and Systems / An Alternative / 6. Set Theory / The Axiom of Extensionality / Axioms of Separation / Pairing Axiom and Rule U / The Restriction on the A2 Axiom / The Null Set / An Interpretation / More Axioms / General Intersection Operation / Order and Relations / Functions / Sizes of Sets / The Power Set Axiom / A Basic Theorem / 7. Incompleteness / The Language of Arithmetic / Three Key Concepts / Three Key Theorems / The Core Argument / Concluding Observations / 8. An Introduction to Term Logic / Syllogistic / The Limits of Syllogistic / Term Functor Logic / Singular Terms and Identity in TFL / Relationals in TFL / The Logic of Sentences in TFL / Rules of Inference for Derivations in TFL / Derivation in TFL / The Bridge to TFL / 9. Modal Term Logic / Modal Operators on Terms / Modal Operators on Sentences / Rules of Derivation for Modal TFL / Modal Inference in TFL / Rules, Axioms and Principles / List of Symbols / Glossary / Index.
Computing optimal (s, S) policies in inventory models with continuous demands

Special algorithms have been developed to compute an optimal (s, S) policy for an inventory model with discrete demand and under standard assumptions (stationary data, a well-behaved one-period cost function, full backlogging and the average cost criterion). We present here an iterative algorithm for continuous demand distributions which avoids any form of prior discretization. The method can be viewed as a modified form of policy iteration applied to a Markov decision process with continuous state space. For phase-type distributions, the calculations can be done in closed form.
Improved DGS parameter extraction method for the polarization purity of circularly polarized microstrip antenna

An improved method of parameter extraction of the most popular dumbbell shaped defected ground structure (DGS) is developed, which removes the drawbacks of the earlier approaches of parameter extraction methods. The proposed method is validated considering a circularly polarized (CP) microstrip antenna integrated with dumbbell shaped DGS for application of suppression of cross polarization. A set of fabricated laboratory prototypes, with and without DGS, is experimentally studied. The results show that the integration of DGS with antenna provides polarization purity of about 10 dB compared to the same patch without DGS at bore‐sight of the patch and enhances the return loss bandwidth about 40%. Good agreement among theory, simulated results, and the experimental results qualifies the proposed method as an effective tool for parameter extraction of the DGS. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2016.
DES Simulation of Flow Field of Propeller Tip Vortex

Based on the Detached Eddy Simulation model,the tip vortex flow field of the propeller in the wake is investigated.A structure grid is generated for the current computational domain.To reduce the discrete error caused by the grid,the mesh refinement is applied to the area of tip vortex core in the numerical simulation.In order to do research on the tip vortex,‘Q-Criterion' is used to define the structure of vortex.The calculated results show that the numerical method can exactly predict the velocity distribution,vortex core location and vortex structures in tip vortex formation and evolution.
Multiple View Motion Tracking of Gridded Surfaces using Topological Structure

AbstractThis paper describes a novel algorithm for interframe motion tracking of gridded surfaces across close range video sequences. The topological approach exploits the regular grid structure, simplifying feature extraction requirements, and reducing dimensionality of the projective tracking problem from eight to two. Multiple view grid asymmetry is implemented using loosely defined tracking fiducials that do not need to be explicitly detected or measured. Results from an experimental setup validate the accuracy and robustness of the algorithm. Timing results demonstrate throughput greater than the 15 frames per second camera data acquisition rate.
Functional Nanowires

Nanotechnology offers the promise of enabling revolutionary advances in diverse areas ranging from electronics, optoelectronics, and energy to healthcare. Underpinning the realization of such advances are the nanoscale ma te rials and corresponding nanodevices central to these application areas. Semiconductor nanowires and nanobelts are emerging as one of the most powerful and diverse classes of functional nanoma terials that are having an impact on science and technology. In this issue of MRS Bulletin , several leaders in this vibrant field of research present brief reviews that highlight key aspects of the underlying materials science of nanowires, basic device functions achievable with these materials, and developing applications in electronics and at the interface with biology. This article introduces the controlled synthesis, patterned and designed self-assembly, and unique applications of nanowires in nanoelectronics, nano-optoelectronics, nanosensors, nanobiotechnology, and energy harvesting.