Miracle-dz/UniFAR-FTUs huggingface dataset:
Parametric study of an acoustic levitation system

The fields and forces along the axis of an acoustic levitation device were measured and characterized. The device consisted of a St. Clair generator and reflector arranged in a single‐axis configuration. A significant (i.e., factor of four) enhancement in the levitation forces was obtained by using concave surfaces for the driver and reflector. For bodies of various sizes and geometries, the acoustic levitation force is roughly proportional to body volume until the characteristic ’’diameter’’ reaches ∼λ/2(λ=wavelength). In addition, the behavior of materials when in the liquid state was studied. Liquid drops were found to deform and generally rupture when a characteristic size was reached. The characteristic radius appears to depend on material parameters and is from 0.2–0.5 cm for most materials on the ground.
VARIATIONS IN A UNIVERSAL DARK MATTER PROFILE FOR DWARF SPHEROIDALS

Using a newly developed modeling technique, we present orbit-based dynamical models of the Carina, Draco, Fornax, Sculptor, and Sextans dwarf spheroidal (dSph) galaxies. These models calculate the dark matter profiles non-parametrically without requiring any assumptions to be made about their profile shapes. By lifting this restriction, we discover a host of dark matter profiles in the dSphs that are different from the typical profiles suggested by both theorists and observers. However, when we scale these profiles appropriately and plot them on a common axis, they appear to follow an approximate r−1 power law with considerable scatter.
The frequency and formation mechanism of B2-B5 main-sequence binaries

Twenty coude spectra were obtained for each of the 74 B2-B5 IV or V stars, and the results of their radial velocities were combined with those of a previous study of 42 similar stars, to examine the frequency and the formation mechanism of these binaries. New improved orbital elements are listed for nine known double-lined and 26 single-lined spectroscopic binaries. It is found that, systems with periods of 0.01 yr to 100,000 yrs, have secondary frequencies that fit the Salpeter (1955) luminosity function (but not the van Rhijn function), indicating that these systems were formed primarily by capture. For systems with periods shorter than 0.01 yr, the separations of components are only a few stellar radii, suggesting that these systems have undergone mass transfer; their secondary masses have no direct information concerning the formation mechanism. 53 refs.
Asymptotic analysis of nonspecular effects for the reflection and the transmission of a Gaussian acoustic beam incident on a solid plate

Experimental studies on the reflection and transmission of bounded acoustic beams at a liquid–solid plate–liquid interface show that, for incidences at or near the Lamb angles, some effects occur which are similar to those reported at a liquid–solid interface for the Rayleigh incidence. Theoretical descriptions of this phenomenon have been proposed that are based upon asymptotic considerations for the reflected beam and numerical considerations for the reflected and the transmitted beams. These previous theories are extended in this work. The reflected and transmitted Gaussian beams are described through a short wave asymptotic analysis in regions which are not restricted to the interfaces. The nonspecular effects which appear in the transmitted field composition are different according to whether the Lamb mode under consideration is symmetric or antisymmetric. The particular case when two Lamb modes are simultaneously excited is also studied. If the two modes have a different nature, the nonspecular effe.
Solitary Waves on a Two-Layer Fluid

This paper deals with weakly nonlinear long gravity waves on a stably stratified two-layer fluid. By using the reductive perturbation method, it is found that the fast mode is always governed by a Korteweg-de Vries (K-dV) equation whose coefficients depend on the thickness ratio and the density ratio. On the other hand, the slow mode is also governed, in general, by another K-dV equation except near and at the critical thickness ratio. At the critical thickness ratio, however, the slow mode is shown to be governed by a modified K-dV equation with cubic nonlinearity and near the critical thickness ratio it is governed by an equation of a combined form of the K-dV and modified K-dV equation. Steady solitary wave solutions to these equations are investigated in detail. A special solution representing a dispersive bore or hydraulic jump is also found.
Reaction-diffusion applied to discrete distorted circles for industrial control

In this article, a new implementation of active curves algorithms is proposed. It is question of an active region algorithm based on stationary states of a nonlinear diffusion principle. Its originality is to obtain a set of geometric envelopes in one pass, with a correspondence between level threshold of the grayscale result and a regularity scale, close to the original shape. This set of geometric envelopes gives a multiscale representation, from a very regular approximation to a full detailed and roughest representation. This property is used in a new subpixel circle center estimator developed in the purpose of distorted contours. Results are very promising as precision is noticeably improved compared to a least mean squares estimator. This estimator is then pretty well adapted to limit distortions caused by industrial processes.
Detecting and removing outlier(s) in electromyographic gait-related patterns

In this paper, we propose a method for outlier detection and removal in electromyographic gait-related patterns (EMG-GRPs). The goal was to detect and remove EMG-GRPs that reduce the quality of gait data while preserving natural biological variations in EMG-GRPs. The proposed procedure consists of general statistical tests and is simple to use. The Friedman test with multiple comparisons was used to find particular EMG-GRPs that are extremely different from others. Next, outlying observations were calculated for each suspected stride waveform by applying the generalized extreme studentized deviate test. To complete the analysis, we applied different outlier criteria. The results suggest that an EMG-GRP is an outlier if it differs from at least 50% of the other stride waveforms and contains at least 20% of the outlying observations. The EMG signal remains a realistic representation of muscle activity and demonstrates step-by-step variability once the outliers, as defined here, are removed.
Relative risk analysis of dengue cases using convolution extended into spatio-temporal model

Dengue Hemmorage Fever (DHF) cases have become a serious problem every year in tropical countries such as Indonesia. Understanding the dynamic spread of the disease is essential in order to find an effective strategy in controlling its spread. In this study, a convolution (Poisson-lognormal) model that integrates both uncorrelated and correlated random effects was developed. A spatial–temporal convolution model to accomodate both spatial and temporal variations of the disease spread dynamics was considered. The model was applied to the DHF cases in the city of Kendari, Indonesia. DHF data for 10 districts during the period 2007–2010 were collected from the health services. The data of rainfall and population density were obtained from the local offices in Kendari. The numerical experiments indicated that both the rainfall and the population density played an important role in the increasing DHF cases in the city of Kendari. The result suggested that DHF cases mostly occured in January, the wet session with high rainfall, and in Kadia, the densest district in the city. As people in the city have high mobility while dengue mosquitoes tend to stay localized in their area, the best intervention is in January and in the district of Kadia.
Water Distribution Reliability: Analytical Methods

Probabilistic reliability measures for the performance of water distribution networks are developed and analytical methods for their computation explained. The paper begins with a review of reliability considerations and measures for water supply systems, making use of similar notions in other fields. It classifies reliability analyses according to the level of detail with which the water system is modeled, and then concentrates on methods relevant to networks. Two probabilistic measures, reachability and connectivity, are explored for use in water distribution systems. Two algorithms for their computation are presented, one for series-parallel networks and one for general networks. These measures are computed for two systems, each with ten nodes. Additionally, the probability that a given point receives sufficient supply is proposed for use as a reliability measure. An algorithm is presented for the calculation of this measure, which combines a capacitated network algorithm with a method to efficiently search through network configurations involving multiple link failures. This measure is calculated for the two sample systems.
Dissolution of metal nanoparticles in glass under a dc electric field

The theory of electric-field-assisted dissolution of metal nanoparticles embedded in glass is presented. We demonstrate that the major mechanism of dissolution is associated with the ejection of ions and electrons caused by the ultrahigh electric field, which is built in the vicinity of a nanoparticle when the external electric field is applied and thermal poling of glass takes place. Our estimations show that for a silver nanoparticle embedded in soda-lime glass, the local electric field strength can be as high as 0.5 V nm−1 and the nanoparticle dissolves in a few seconds. The developed theory reproduces well the experimental results on electric-field-assisted dissolution of silver nanoparticles in glass.
Study on Camera Pose Estimation

A common need in photogrammetry, robotics and computer vision is performing camera pose estimation. A comparative analysis is presented here for three classical and representative algorithms, including direct linear transform (DLT), EPNP and Cayley method, each of which computes the translation and rotation matrix using non-iterative method with six or more point correspondences. The comparison shows qualitative and quantitative experimental results to determine (1) the accuracy and robustness under the influence of different levels of noise, (2) the accuracy, robustness and efficiency for different sizes of point correspondences.
Robust estimation and outlier detection with correlation coefficients

Two graphical methods are proposed for identifying bivariate observations that may unduly influence the sample correlation coefficient. Secondly, robust estimators of correlation are developed and a Monte Carlo comparative study is made of these and other wellknown estimators. Also considered are methods for developing positive-definite estimates of correlation matrices and extensions of robustness to other problems such as regression are mentioned.
ADAPTIVE ESTIMATORS OF A MEAN MATRIX: TOTAL LEAST SQUARES VERSUS TOTAL SHRINKAGE

An unknown constant matrix M is observed with additive random error. The basic problem considered is to devise an estimator of M that trades off bias against variance so as to achieve relatively low quadratic risk. This paper develops an adaptive total least squares estimator and an adaptive total shrinkage estimator of M that minimize estimated risk over certain large classes of linear estimators. It is shown that the asymptotic risk of the adaptive total least squares estimator is the smallest attainable among reduced rank total least squares fits to the data matrix. The asymptotic risk of the adaptive total shrinkage estimator is shown to be smaller still. A close link is established between total shrinkage and the Efron–Morris estimator of M. In the asymptotics, the row dimension of M tends to infinity, and the column dimension stays fixed. The risks converge uniformly when the signal-to-noise ratio and the measurement error variance are both bounded. A second problem treated is estimation of M under the assumption that a linear relation holds among its columns. In this formulation of the errors-in-variables linear regression model, rank constrained adaptive total least squares asymptotically dominates the usual total least squares estimator of M, and rank constrained adaptive total shrinkage is better still.This research was supported in part by National Science Foundation Grant DMS 0404547.
Bayesian classification of Neolithic tools

The classification of Neolithic tools by using cluster analysis enables archaeologists to understand the function of the tools and the technological and cultural conditions of the societies that made them. In this paper, Bayesian classification is adopted to analyse data which raise the question whether the observed variability, e.g. the shape and dimensions of the tools, is related to their use. The data present technical difficulties for the practitioner, such as the presence of mixed mode data, missing data and errors in variables. These complications are overcome by employing a finite mixture model and Markov chain Monte Carlo methods. The analysis uses prior information which expresses the archaeologist's belief that there are two tool groups that are similar to contemporary adzes and axes. The resulting mixing densities provide evidence that the morphological dimensional variability among tools is related to the existence of these two tool groups.
Spectral and temporal response of liquid-crystal-on-silicon spatial light modulators

Spectral and temporal phase response of selected types of liquid-crystal-on-silicon spatial light modulators were studied using femtosecond pulses, determining specific transfer functions of the devices. The phase response resulting from programed gray level distributions was detected by analyzing the diffraction characteristics and by spectral phase interferometry for direct electric-field reconstruction. The results indicate the appearance of distinct parameter ranges that enable minimum spatiotemporal distortion. Weak oscillations in the spectral phase are explained by Gires–Tournois resonances [F. Gires and P. Tournois, Acad. Sci. Paris, C. R. 258, 6112 (1964)].
Design of PARSEC the VLT laser

For the successful operation of laser referenced adaptive optic systems very powerful lasers for the creation of sodium guide stars are necessary. Here we introduce the design of PARSEC, the cw sodium-line laser for the VLT, and present out first laboratory results on the performance of the system. So far we have achieved a stable output power of 12.8W in a single spatial mode and a single frequency.
Analysis of vortex core in steady turbulent flow

Profiles of velocity and pressure for the vortex core in turbulent flow were obtained by solving Reynolds equation for the circumferential component of the fluid momentum. The viscous core radius is defined as a function of viscosity coefficient, vortex intensity, and a Reynolds stress component. The obtained velocity profiles are in much better agreement with known experimental data than are the Rankin vortex profiles.
Modeling Loose Joints in Elastic Structures— Simulation Algorithm and Results

This is the third paper in a four companion paper sequence. In these papers, a hybrid parameter multiple body system (HPMBS) methodology is utilized to model the frictional contact/impact of a loose bolted joint between two sections of a cantilever beam undergoing planar slewing motion. In this preliminary model, a “rigid” joint is utilized, allowing the members of the joint to be rigid, each attached to an elastic beam section. Frictional contact/impact is modeled at four contact points. The contact constraints and momentum transfer are modeled with the idea of instantly applied nonholonomic constraints. In this paper, the contact and switching algorithms, the numerical solution scheme, and simulation results are presented. The theoretical model of the variable structure dynamic system, the momentum transfer equations and the experimental comparison are presented elsewhere. The motivation for this work is the need for accurate low order models of complicated nonlinear phenomena in structural systems.
Nonlinear shallow-water oscillations in a parabolic channel: exact solutions and trajectory analyses

A new exact solution of the nonlinear shallow-water equations is presented. The solution corresponds to divergent and non-divergent free oscillations in an infinite straight channel of parabolic cross-section on the rotating Earth. It provides a description of the one-dimensional subclass of shallow-water flows in paraboloidal basins considered by Ball (1964), Thacker (1981), Cushman-Roisin (1987) and others in which the velocity field varies linearly and the free-surface displacement varies quadratically with the spatial coordinates. In contrast to the previous exact solutions describing divergent oscillations in circular and elliptic paraboloidal basins, the oscillation frequency of the divergent oscillation in the parabolic channel is found to depend, in part, on the amplitudes of the relative vorticity and free-surface curvature. This result is consistent with Thacker's (1981) numerical finding that when the free surface in parabolic channel flow is curved, the oscillation frequency depends on the amplitude of the motion. Solutions for parcel trajectories are also presented. The exact solution provides a rare description of a class of nonlinear flows and is potentially valuable as a validation test for numerical shallow-water models in Eulerian and Lagrangian frameworks.
A nonlinear parametric model reduction method for efficient gear contact simulations

A novel nonlinear parametric model order reduction technique for the solution of contact problems in flexible multibody dynamics is presented. These problems are characterized by significant variations in the location and size of the contact area and typically require high‐dimensional finite element models having multiple inputs and outputs to be solved. The presented technique draws from the fields of nonlinear and parametric model reduction to construct a reduced‐order model whose dimensions are insensitive to the dimensions of the full‐order model. The solution of interest is approximated in a lower‐dimensional subspace spanned by a constant set of eigenvectors augmented with a parameter‐dependent set of global contact shapes. The latter represent deformation patterns of the interacting bodies obtained from a series of static contact analyses. The set of global contact shapes is parameterized with respect to the system configuration and therefore continuously varies in time. An energy‐consistent formulation is assured by explicitly taking into account the dynamic parameter variability in the derivation of the equations of motion. The performance of the novel technique is demonstrated by simulating a dynamic gear contact problem and comparing results against traditional model reduction techniques as well as commercial nonlinear finite element software. Copyright © 2014 John Wiley & Sons, Ltd.
Agglomerated multigrid on hybrid unstructured meshes for compressible flow

A review of the applicability of the agglomerated multigrid solution acceleration approach for the simulation of compressible flows is presented. The flow descriptions are wide ranging, spanning from inviscid to turbulent and from steady state to transient. The spatial discretization is performed by a node‐centred finite volume scheme, with explicit addition of fourth‐order artificial dissipation. The improved performance resulting from the introduction of unstructured hybrid meshes is illustrated. For time‐dependent flows involving moving geometries, a second order geometrically conservative scheme is applied, with multigrid accelerated implicit timestepping. Copyright © 2002 John Wiley & Sons, Ltd.
Computer Simulation of the Time Evolution of a Quenched Model Alloy in the Nucleation Region

The time evolution of the structure function and of the cluster (or grain) distribution following quenching in a model binary alloy with a small concentration of minority atoms is obtained from computer simulations. The structure function S-bar (k,t) obeys a simple scaling relation, S-bar (k,t) = K/sup -3/F (k/K) with K (t) proportional t/sup -a/, a approx. = 0.25, during the latter and larger part of the evolution. During the same period, the mean cluster size grows approximately linearly with time.
NCTM’s Principles and Standards for School Mathematics: Implications for Administrators

The National Council of Teachers of Mathematics (NCTM) unveiled Principles and Standards for School Mathematics in April 2000. An extension of three earlier publications, Principles and Standards is a resource for anyone who makes decisions affecting mathematics education for prekindergarten through grade 12. This article highlights key points and discusses the importance of school administrators in realizing the vision set forth in the document.
Electro-rheological effects of liquid crystalline polymer on one-sided pattern electrodes

In most industrial robots, serious problems of vibratory behavior are caused because of elasticity in the drive systems. An electro-rheological (ER) fluid is a substance that can change its apparent viscosity by the application of an electric field, and homogeneous ER fluids are effective in reducing vibration in robots. Conventional research into ER fluids is based on parallel electrodes with ER fluids between them. Since a high voltage is required for use of ER fluids with parallel electrodes, problems of cost, safety and wiring for practical applications are of concern. In this article, we propose one-sided pattern electrodes that solve some of the above problems. A one-sided pattern electrode is an electrode in a pattern arranged on only one of the two surfaces of a pair of electrodes, with an insulator arranged on the other surface. We developed two kinds of one-sided pattern electrodes: a concentric circle form and a radial form, experimentally verifying the manifestation of ER effects in a liquid c.
THERMAL NON-EQUILIBRIUM REVISITED: A HEATING MODEL FOR CORONAL LOOPS

The location and frequency of events that heat the million-degree corona are still a matter of debate. One potential heating scenario is that the energy release is effectively steady and highly localized at the footpoints of coronal structures. Such an energy deposition drives thermal non-equilibrium solutions in the hydrodynamic equations in longer loops. This heating scenario was considered and discarded by Klimchuk et al. on the basis of their one-dimensional simulations as incapable of reproducing observational characteristics of loops. In this paper, we use three-dimensional simulations to generate synthetic emission images, from which we select and analyze six loops. The main differences between our model and that of Klimchuk et al. concern (1) dimensionality, (2) resolution, (3) geometrical properties of the loops, (4) heating function, and (5) radiative function. We find evidence, in this small set of simulated loops, that the evolution of the light curves, the variation of temperature along the loops, the density profile, and the absence of small-scale structures are compatible with the characteristics of observed loops. We conclude that quasi-steady footpoint heating that drives thermal non-equilibrium solutions cannot yet be ruled out as a viable heating scenario for EUV loops.