Miracle-dz/UniFAR-FTUs huggingface dataset:
Nonlinear Sound during Granular Impact

How does force propagate into granular material during impact from a high speed intruder? This occurs routinely, for example, in industrial processes or when a meteorite or other object strikes the earth. Stress propagation in a granular material is controlled by the dependence of the inter-particle force, f , on particle deformation, δ. These quantities are typically nonlinearly related: f ∝ δα, with α > 1. This means that a macroscopic linear wave description is invalid[1, 2, 3, 4, 5] when dynamic stresses are large compared to the original confining pressure[6, 7]. In this case, the actual stress propagation speed, vf , is very sensitive to α[8, 9, 10, 6]. Here, we experimentally study how forces propagate following an impact, and we explain these observations in terms of the nonlinear grain-scale force relation. We use high-speed video of impacts into beds of photoelastic particles to determine vf and the spatial structure of the force response just after impact. We show that the spatial structure of the excited granular network and vf depend on a dimensionless parameter, M ′ = tcv0/d, where v0 is the intruder speed at impact, d is the particle diameter, and tc is the collision time for a pair of grains impacting at relative speed v0. By measuring the nonlinear force law for our particles, finding α ≈ 1.4, we explicitly calculate tc, and hence M ′, for each v0. When M ′ ≪ 1, forces propagate along linear, chain-like structures, and the measured vf satisfies vf ∝ d/tc ∝ vb(v0/vb) α−1 α+1 , where vb is the speed of sound in the bulk material from which the particles are made. For larger M ′, the force response has a two-dimensional character (i.e., not chain-like), and forces begin to propagate faster than vf ∝ d/tc. However, this relation is still satisfied if tc is replaced with an analogous time, which uses the force response of a strongly compressed packing of grains.
Three-Dimensional Flows in Complex Geometries with the Lattice Boltzmann Method

It is shown that the lattice Boltzmann equation (LBE) for a lattice gas provides a viable numerical method for the study of three-dimensional flows in complex geometries. Numerical results for low Reynolds number flows in a three-dimensional random medium are reported. The Darcy's law is recovered and a preliminary estimation of the permeability presented.
A proximal point method for the sum of maximal monotone operators

In this paper, we concentrate on the maximal inclusion problem of locating the zeros of the sum of maximal monotone operators in the framework of proximal point method. Such problems arise widely in several applied mathematical fields such as signal and image processing. We define two new maximal monotone operators and characterize the solutions of the considered problem via the zeros of the new operators. The maximal monotonicity and resolvent of both of the defined operators are proved and calculated, respectively. The traditional proximal point algorithm can be therefore applied to the considered maximal inclusion problem, and the convergence is ensured. Furthermore, by exploring the relationship between the proposed method and the generalized forward‐backward splitting algorithm, we point out that this algorithm is essentially the proximal point algorithm when the operator corresponding to the forward step is the zero operator. Copyright © 2013 John Wiley & Sons, Ltd.
Conceptual Framework Connecting Brand Communication and Customer Experience

Relationship among expectations, (dis)satisfaction and customer experience is analysed in the scientific literature, but academic discussions tend to reserve a view on customer experience mostly regarding the influence of these elements. To expand understanding of customer experience, analysis of a broader picture becomes significant. This study aims to propose a conceptual framework connecting brand communication and customer experience. As a result, the proposed conceptual framework outlines the relationship among brand communication, expectations, the emotional state experienced during the consumption, (dis)satisfaction and customer experience. The outcome also reveals the degree of control of these elements in the process of customer experience formation, highlights where brands can take action to influence customer experience
SOUND FIELDS FOR THE PRODUCTION OF VIRTUAL ACOUSTIC IMAGES

The intention of this brief report is to introduce a method for generating virtual images that makes use of a form of sound field whose spatial complexity is less than that produced by existing methods. The method can be implemented in practice extremely effectively and preliminary results suggest that it may have many practical benefits, including an increased robustness in respect to head movement and, of course, the ability to site both transducers used for reproduction within on compact cabinet
A measurement of hydrogen ion transport parameters in Tokamak discharges

By modulating the small gas feed required to maintain a steady-state Tokamak discharge a small density perturbation may be induced from whose propagation particle transport parameters may be adduced. Experiments in TEXT show that the phenomena may be adequately described by a simple model with constant diffusion plus inward convection except near the density limit. Diffusion coefficients and convective velocities has been determined for a broad range of hydrogen discharges and found to scale approximately as (nq)-1. The results are plausibly related to impurity transport parameters, thermal diffusivity, and particle confinement times. Diffusion coefficients for deuterium are systematically lower than for hydrogen.
Discovery of a probable galaxy with a redshift of 3.218

The discovery of a narrow emission line object, probably a galaxy, with a redshift of 3.218, is reported. The object is a companion to the quasar PKS 1614 + 051, which is at a redshift of 3.209. This is the most distant non-QSO, nongravitationally lensed object presently known by a large margin. Its properties are consistent with those expected of a high-redshift galaxy. This object has an age of only a few percent of the present age of the universe. The object was discovered with a novel technique, which promises to push studies of distant galaxies to redshifts as high as those of the most distant quasars known, and which may eventually lead to the discovery of primeval galaxies. This discovery opens the way for studies of galaxies beyond redshift three, which should prove invaluable for observational cosmology.
Splitting Matching Pursuit Method for Reconstructing Sparse Signal in Compressed Sensing

In this paper, a novel method named as splitting matching pursuit (SMP) is proposed to reconstruct -sparse signal in compressed sensing. The proposed method selects largest components of the correlation vector , which are divided into split sets with equal length . The searching area is thus expanded to incorporate more candidate components, which increases the probability of finding the true components at one iteration. The proposed method does not require the sparsity level to be known in prior. The Merging, Estimation and Pruning steps are carried out for each split set independently, which makes it especially suitable for parallel computation. The proposed SMP method is then extended to more practical condition, e.g. the direction of arrival (DOA) estimation problem in phased array radar system using compressed sensing. Numerical simulations show that the proposed method succeeds in identifying multiple targets in a sparse radar scene, outperforming other OMP-type methods. The proposed method also obtains more precise estimation of DOA angle using one snapshot compared with the traditional estimation methods such as Capon, APES (amplitude and phase estimation) and GLRT (generalized likelihood ratio test) based on hundreds of snapshots.
Removing impulsive noise for infrared image with difference images and adaptive filter

In order to overcome the disadvantage of traditional median filtering method in removing impulsive noise, according to the characteristics of impulsive noise image, a novel approach based on difference images and adaptive filter with multiple windows is proposed. Firstly, utilize the noise image to obtain three difference images, while the difference images are computing in three different directions which are level, vertical, diagonal (counterclockwise rotation of 45° from the horizontal direction), and then get the position of impulse noise points by detecting these three difference image with setting different threshold. Secondly, handle the detected impulse noise point using adaptive filter with multiple windows. Finally, Peak Signal-to-Noise Ratio is used to assess ability of this approach in removing noise. Experimental results indicate that when the, the effect of image restoration by this method can be increased by 8dB compared with median filter. Advantage in removing noise but preserving detail is obvious compared with conventional median filtering method.
Shear-induced segregation of a granular mixture under horizontal oscillation

We study the segregation process of a granular mixture of discs on an horizontally oscillating tray by realistic molecular dynamics simulations. As found in the experiments, we observe the initially disordered mixture to segregate via the formation of stripes perpendicular to the driving direction. The segregation process turns out to be the result of a dynamical instability very similar to the Kelvin–Helmholtz instability observed in fluid mechanics, and it is not due to the depletion potential, i.e., to the effective potential existing between two big particles in a bath of smaller ones, but rather to a dynamical process whose nature is discussed.
Perceptual Mapping Based on Idiosyncratic Sets of Attributes

The authors describe a compositional perceptual mapping procedure, unrestricted attribute-elicitation mapping (UAM), which allows consumers to describe and rate the brands in their own terminology and thus relaxes the restrictive assumptions of traditional compositional mapping techniques regarding the structure and interpretation of the set of attributes. They compare the performance of three estimation techniques for constructing a group space based on the idiosyncratic data, namely, INDSCAL, CANCOR, and generalized procrustes analysis (GPA). Their findings indicate that the three estimation techniques perform about equally well. UAM also is compared with traditional compositional mapping. They find that UAM is superior on fit of the solution, interpretability, and sample reliability. UAM probably holds an edge with respect to data collection. Traditional compositional mapping is superior on ease of data analysis. No major difference was found on predictive validity and structural reliability.
ASCA Observation of the Superluminal Jet Source GRO J1655–40 in the 1997 Outburst

We report on the results of an ASCA observation of the Galactic jet source GRO 51655-40 performed from 1997 February 25 to February 28 covering a full orbital period (2.62 d). The averaged 2-10 keV flux was about 1.1 Crab. An absorption line feature centered at 6.8 keV was detected both in the GIS and SIS spectra. We interpret this as a blend of two resonance-absorption K alpha lines from H-like and He-like iron ions. We can consistently explain both the ASCA spectra and the simultaneous RXTE/PCA spectrum by a combination of K-absorption lines and K-absorption edges of iron ions. The fact that the absorption line is stably present over the whole orbital phase implies that the distribution of the highly ionized plasma is not affected by the companion star, which is consistent with its presence around the black hole. A curve of growth analysis shows that the plasma contains velocity dispersion along the line-of-sight larger than 300 km/s attributed to bulk motions. It is probably a part of a geometrically thick accretion flow in turbulent motions with velocities of 500-1600 km/s at an estimated radius of sim 10(exp 10)/cm.
Improved goodness-of-fit tests

Two statistics for testing goodness of fit for small sample sizes are provided. The first statistic, S, can be used to test the fit to any completely specified continuous distribution function and is more powerful than the Kolmogorov-Smirnov statistic in the cases tested. The second statistic, S, tests the fit to an exponential distribution with mean unknown. It is more powerful than a Kolmogorov-Smirnov type statistic suggested by Lilliefors (1969) for the cases tested. Critical values for Sn and Sn are given for sample size n = 1(1) 20 (5) 30 and x = 0-20, 0415, 0-10, 0 05 and 0.01. The critical values and power analyses were obtained by Monte Carlo techniques. These new statistics are closely related to the Kolmogorov-Smirnov statistic and are computationally equivalent.
Gain Calculation of Undoped GaAs Injection Laser Taking Account of Electronic Intra-Band Relaxation

The intra-band relaxation of electrons is a basic factor to be considered for the characterization of injection lasers, especially in the investigation of modal behavior under lasing operation. This paper discusses the gain and refractive index in quantitative terms and considers the intra-band relaxation phenomenon in undoped GaAs lasers. The linear and third order gain coefficients are summarized in arithmetic equations by numerical calculation. Some characteristic parameters in the equations are also confirmed experimentally through measurements of the output spectral profile and laser threshold. The results give a more consistent interpretation of non-oscillating and oscillating states than previously-established theories, which do not take into account the intra-band relaxation.
Penetration of backscattered electrons in polystyrene for energies between 1 and 25 MeV

A study of the quantitative aspects of backscattering of electrons has been published recently by Klevenhagen et al. (ibid., vol.27, p.363-73, 1982). To assess the full effect that the backscatter electrons have on the dose distribution in the region close to the scatterer-tissue interface, it is necessary to know the penetration of these electrons in the medium. This aspect has been studied in the work reported.
Wild representation type and undecidability

It has been conjectured that if A is a finite-dimensional algebra of wild representation type then there is no decision procedure for the theory of A-modules. Here I show that the conjecture is correct modulo a conjecture concerning representability of algebras as endomorphism rings of finite-dimensional modules over A. This second conjecture has been vertified for some classes of algebras.
Assessing macro influence on Brazilian yield curve with affine models

Using affine term structure models with latent and observable factors, we study the interaction between macro variables and the Brazilian yield curve contained in a daily dataset. Two versions of the model are tested, one in continuous time and estimated using maximum likelihood with Chen–Scott inversion (1993), and the other in discrete time and estimated using Monte Carlo–Markov Chain (MCMC) with Kalman filter. The effect of the inclusion of macro factors and changes of specification on the goodness-of-fit and dynamics are analysed. We conclude that the interaction between the macro variables and the yield curve is an important element for understanding the dynamics. Also, the choice of specification alters the response of the identified shocks.
New aspects of the violin vibrato

Usually the vibrato played on a violin is considered as a frequency modulation caused by the rolling motion of the touching finger; typical values are about 4.5–8 Hz for the vibrato frequency and up to ±40% and even more for the width of the vibrato. But the high number of more or less sharp resonances of the violin leads to an amplitude modulation of the partials too. Because of the unharmonic positions of these resonances some overtones are modulated in phase and other ones in antiphase. At higher frequencies individual partials fluctuate over the peak of a resonance or through the gap between two resonances and show an amplitude modulation of twice the vibrato frequency. When lower partials fluctuate in the order of 6 dB, components about 5000 Hz may reach an amplitude modulation of 20 dB or in extreme cases up to 35 dB. Because of the directivity these values depend on the direction of sound radiation, too. It may be a criterion for the sound quality of a violin, whether there are such enormous fluctu.
Multilayer Perceptron and Evolutionary Algorithm for Handwritten Digit Recognition

Handwritten digit recognition is an active topic in academia and industry alike. In order to improve accuracy, a lot of good works have been done, especially using the multilayer perceptron (MLP) approach. However, Setting the network structure and tuning some hyper parameters are the most diﬃcult part of designing the network. On the other hand, an evolutionary algorithm (EA) is a stochastic search approach to deal with the optimization problem. In this paper, the evolutionary algorithm has been used to determine the structure of MLP, including setting activation functions,optimization algorithms,and number of layers and number of neurons in each layer. Our object is using EA to ﬁnd a optimal structure of MLP for the given task. We test the model on the Semeion Handwritten Digit Data Set, achieving 98.11% accuracy, which is 5% higher than MetaNet, one of the baseline models.
Specific characteristics of negative corona currents generated in short point-plane gap

The Trichel pulse is a typical kind of negative corona current observed in electronegative gases with a highly regular form. The characteristics of the Trichel pulse, such as the repetition frequency, the amplitude of each pulse, and the mean current, are dependent on different discharge conditions. Quite many scholars have studied the mean current and the current-voltage characteristic of Trichel pulses, yet the specific characteristics of the pulses have barely been investigated. In this paper, a series of experiments were carried out in a short point-to-plane discharge gap to investigate the detailed characteristics of Trichel pulses. After numerical fitting of the experiment results was performed, a new set of empirical formulas were derived to predict the specific characteristics of the negative corona current under different conditions. Different from existing literature, this paper uses as variables the average electric field intensity and the corona inception field intensity which is independent of the gap spacing in the empirical formulas. In the experiments, an inverse correlation between amplitude and repetition frequency of the pulses was observed. Based on the investigation of the remaining space charge in the discharge gap, this correlation is theoretically proved to be caused by the influence of space charges.
Approximating the Distribution of the Sample R 2 in Best Subset Regressions

This note presents research on the problem of determining the distribution of the usual sample R2 statistic in multiple regression studies where the variables to be included in the regression equation are the subset of k variables, from a set of m variables, which maximize the sample R2 value or satisfy some similar criterion. A Monte-Carlo approach was used to estimate certain percentile points of the distribution of R2 under the null hypothesis of independence between the dependent variable and the m independent variables. A function has been developed which appears to provide a good approximation to percentile points of the R2 distribution.
Prediction of Dynamic Stall Onset for Oscillatory Low-Speed Airfoils

This research presents some common features of oscillatory airfoils, and the method for indicating dynamic stall onset for the unsteady process. Under deep stall conditions, the stall-onset angle in oscillation is independent of the mean angle of the oscillatory motion, and by combining the reduced frequency and the amplitude of the oscillatory motion, the equivalent reduced pitch rate is an analog of this motion to the constant reduced pitch rate of the ramp-up motion. By correlating with the measured data, and with the ramp-up results, the equivalent reduced pitch rate can be defined as a representation for the oscillatory motion. Accordingly, the triple-parameter problem of an oscillation (mean angle, reduced frequency, and amplitude) degrades into the single-parameter problem (equivalent reduced pitch rate). Based on these foundations, an extension of the stall-onset criterion is then made for oscillatory airfoils: a method of extracting the stall-onset parameters directly from oscillatory test data, and an indication of stall onset for the oscillatory airfoils. The results from the new proposed method have shown the consistency with the data of Glasgow University and the public data.
Magnetization Measurements and 87Rb-NMR on Rb2M3S4(M=Ni and Pd) with the Kagome Lattice.

We report results of magnetization measurements and 87 Rb-NMR on Rb 2 Ni 3 S 4 and Rb 2 Pd 3 S 4 which have the Kagome lattice. The anomalous increase of the magnetization found in the former system at low temperatures with decreasing temperature is not intrinsic and possibly caused by magnetic parts induced by lattice imperfections within the lattice. The NMR spectra of these systems measured for aligned sheets are successfully assigned.
Optimal Detuning Combination of Hitless Wavelength Selective Switch using Quadruple Series Coupled Microring Resonator

This paper presents an analytic discussion of the optimal detuning combination of a hitless wavelength selective switch using individual thermo-optic tuning of a quadruple series coupled microring resonator. We found analytically that asymmetrically detuning the resonant wavelengths of two ring resonators closest to the input busline waveguide can reduce the extinction ratio and switching crosstalk compared with other combinations. The intuitive insight on the optimal combination to realize a low crosstalk OFF-state is derivable through a metaphor of the Vernier effect, i.e., it is equivalent to the optimal arrangement of series-coupled microring resonators with different ring radii to reduce the crosstalk. Large extinction ratio of 24.9 dB and small switching crosstalk of -28.6 dB were experimentally demonstrated.
Load Recovery in Components Based on Dynamic Strain Measurements

4 This paper presents a modeling approach for estimating time varying loads acting on a component from experimental strain measurements. The strain response of an elastic vibrating system is written as a linear superposition of strain modes. Since the strain modes, as well as the normal displacement modes, are intrinsic dynamic characteristics of a component, the dynamic loads exciting a component are estimated by measuring induced strain fields. The accuracy of the estimated loads depends on a number of factors, such as the placement locations and orientations of the gauges on the instrumented structure, as well as the number of retained modes from strain modal analysis. A solution procedure based on the construction of D-optimal designs is implemented to determine the optimum locations and orientations of strain gauges such that the variance in load estimates is minimized. A numerical as well as an experimental validation of the proposed approach through two example problems is also presented. [DOI: 10.1115/1.4024384]
Subnanosecond time response of large-area superconducting stripline detectors for keV molecular ions

A large-area (200×200 μm2) superconducting stripline detector based on a parallel configuration of superconducting Nb nanowires is presented. We show that the parallel configuration provides a smart way to control the physical nonequilibrium state induced by the molecular impacts, which allows realizing large sensitive area and subnanosecond response at the same time. The experiments were carried out with molecular ions radiation in a keV energy range. The observed rise time was below 400 ps and the relaxation time was 500 ps, the best in this class of superconducting molecular detectors.