Miracle-dz/UniFAR-FTUs huggingface dataset:
The influence of feature detection on working memory in complex auditory fields

Research reveals that feature detectors may enhance listener performance in auditory detection tasks involving frequency modulation (FM) [Cusack and Carlyon, J. Exp. Psychol. 29, 713-725 (2003)]. The influence of these detectors on discrimination of auditory information is mostly unknown. This study investigated the impact of FM on listener performance in auditory, delayed-comparison tasks for conditions that differed in the number of background stimuli within two perceptual windows separated by various retention intervals. The background stimuli within both windows were either all modulated sinusoids or pure-tones for a given trial. An additional stimulus was presented in each window that could differ in its modulation state (FM or unmodulated sinusoid) across the two windows. The temporal placement and frequencies of all stimuli within the first window were assigned randomly for a given trial and the second window followed these parameters. Listeners were to determine whether the two windows were the sa.
Hydrodynamic stability of selfgravitating streaming magnetized fluid cylinder

The magnetohydrodynamic stability criterion of self-gravitating streaming fluid cylinder under the combined effect of capillary, inertia, pressure gradient and electromagnetic forces has been derived. The results are discussed analytically and some data are verified numerically for different parameters of the problem. The magnetic field is stabilizing, but the streaming is destabilizing while the self-gravitating and capillary forces are stabilizing or destabilizing according to restrictions. The stable and unstable domains are identified and moreover the influences of the magnetic field and capillary forces on the self-gravitating instability of the model have been examined. The including of the electromagnetic force together with both the capillary and self-gravitating forces improve the instability of the model. However, the self-gravitating instability will never be suppressed whatever are the effects of the capillary and MHD forces stabilizing effects.
Vibrational relaxation of the 2 A g − excited state in all- trans -β-carotene obtained by femtosecond time-resolved Raman spectroscopy

Relaxation kinetics in all-trans-\ensuremath{\beta}-carotene has been investigated by recently developed femtosecond Raman spectroscopy. We observed the stimulated Raman signal of the ${2A}_{g}^{\ensuremath{-}}$ excited state which is converted from the photogenerated ${1B}_{u}^{+}$ state. The vibrational relaxation in the ${2A}_{g}^{\ensuremath{-}}$ state takes place within 0.6 ps until the $l=1$ vibrational level, but the relaxation from the $l=1$ level to the $l=0$ level is slower than 10 ps. The unusual kinetics is explained in terms of the ${1B}_{u}^{\ensuremath{-}}$ state which exists between the $l=1$ and $l=2$ levels of the ${2A}_{g}^{\ensuremath{-}}$ state.
Exact solutions for steady two-dimensional flow of a stratified fluid

Three classes of exact solutions for steady two-dimensional flows of a stratified fluid are found. The flows which correspond to these solutions have arbitrary amplitude (however defined). Two of the three classes of solutions have close bearings on the lee-wave problem in meteorology. It is also shown that the amplitudes of the lee-wave components (if there is more than one component) depend not on the details of the shape of the barrier, but only on certain simple integral properties of the function for the singularity distribution generating the barrier.
An exact solution for progressive capillary waves of arbitrary amplitude

An exact solution is found in a fairly simple form for two-dimensional progressive waves of arbitrary amplitude on a fluid of unlimited depth, when only surface tension and not gravity is taken into account as the restoring force. The calculated wave forms are exhibited graphically for various amplitudes, and the relation between wave velocity and amplitude is plotted. The wave of greatest height occurs when the vertical distance between trough and crest is 0·730 wavelengths (compared with 0·142 for gravity waves). Higher waves are prevented from appearing by the enclosing of air bubbles in the troughs.
Urdu character recognition using fourier descriptors for optical networks

This work deals with the problem of recognition of Urdu characters using Fourier descriptors for optical networks. In particular, the scope of this work has been to develop a robust Urdu characters pattern classification, representation, and recognition system, which can classify patterns even if they are deformed by transformations like rotation, scaling, and translation or any combination of these, in the presence of noise. Fourier descriptors are used to uniquely describe, classify, and recognize Urdu characters within one sub-class, that provide a remarkably simple way to draw definite conclusions from vague, ambiguous, noisy or imprecise information. Although current information transmission media i.e. cable, Ethernet etc. may still be used for communications but we proposed new technology i.e. WDM (Wavelength Division Multiplexing) due to its high speed and low loss transmission. Finally experimental results are presented to show the power and robustness of the proposed technique for Urdu character recognition.
Femtosecond nonlinear optical properties of lead-germanium oxide amorphous films

The nonlinear (NL) response of lead-germanium oxide amorphous films was investigated using a Ti:saphire laser delivering pulses of ≈150fs at 800nm. The Kerr shutter technique was employed to reveal the time response of the nonlinearity that is smaller than 150fs. The sign and magnitude of the nonlinearity were obtained using a novel technique called thermally managed eclipse Z scan which allows the simultaneous characterization of cumulative and noncumulative NL effects. The NL refractive index of electronic origin, n2≈2×10−17m2∕W, and the NL absorption coefficient, α2≈3×103cm∕GW, were determined.
Decrease of nonlinearity and linewidth narrowing in spin-transfer oscillators under the external field applied near the hard axis

Angular dependence of power spectra is measured for tunnel-type spin-transfer oscillators by changing the direction of the external field in the plane. The oscillation frequency shows the red shift with increasing the current in the case that the field directions are away from the hard axis of the free layer. The frequency shift changes from red to blue at a specific direction near the hard axis, where the linewidth is much reduced. These results are explained by taking into account the nonlinearity arising from the in-plane anisotropy as well as that arising from the demagnetizing effect.
The dispersion relation for a nonlinear random gravity wave field

The dispersion relation for a random gravity wave field is derived using the complete system of nonlinear equations. It is found that the generally accepted dispersion relation is only a first-order approximation to the mean value. The correction to this approximation is expressed in terms of the energy spectral function of the wave field. The non-zero mean deviation is proportional to the ratio of the mean Eulerian velocity at the surface and the local phase velocity. In addition to the mean deviation, there is a random scatter. The root-mean-square value of this scatter is proportional to the ratio of the root-mean-square surface velocity and the local phase velocity. As for the phase velocity, the nonzero mean deviation is equal to the mean Eulerian velocity while the root-mean-square scatter is equal to the root-mean-square surface velocity. Special cases are considered and a comparison with experimental data is also discussed.
Consensus analysis via integral quadratic constraints

This note proposes a unified approach to analyse linear time-invariant consensus problems via the use of integral quadratic constraints (IQCs) without recourse to loop transformations, which may cloud the inherent structural properties of the multi-agent networked systems. The main technical hindrance to using IQCs lies in the presence of the marginally stable integral action in consensus setups. It is shown that by working with conditions defined on modified signal spaces of interests and exploiting the graph structure underlying the connections between the dynamic systems, IQC methods can be applied directly to consensus analysis. A decentralised and scalable condition for consensus is proposed in this setting, which generalises some of the existing results in the literature. (Less)
Site dependence of wind‐dominated ambient noise in shallow water

A survey of ambient noise data taken under wind‐dominated conditions in shallow water shows substantial differences in spectrum level (often greater than 10 dB) under the same windspeed and sea‐state conditions. This area‐dependent effect, which is evident even in long‐term averaged data, is caused by differences in ocean bottom properties, water depth, and sound‐speed profile. A shallow‐water, wind‐noise model is used to remove propagation effects from selected data sets that cover a broad range of bottom types, water depths, and sound‐speed profiles. These reduced data exhibit less variability, and it is concluded that the model is capable of predicting the effect of the shallow‐water environment on the spectrum level of wind‐dominated ambient noise. The results also suggest that commonly used universal ambient noise curves that do not take into account environmental differences are inferior to the model predictions in shallow water.
Thin-Film Encapsulation of Thin-Cathode Organic Light-Emitting Devices

We have developed a novel thin-film encapsulation method for thin-cathode organic light-emitting devices (OLEDs) by introducing organic (not polymer)/inorganic multiple thin films to protect devices, which is shown to slow down the permeation rate of moisture and oxygen. From the stability test of devices, the projected lifetime of thin-cathode OLEDs with thin-film encapsulation was similar to that of thin-cathode OLEDs with glass lid encapsulation.
Effect of surface on defect creation by self-ion bombardment of Si(001)

We have studied defect formation and defect distributions in silicon under low-energy (25\char21{}800 eV) self-bombardment of the $2\ifmmode\times\else\texttimes\fi{}1$ terminated Si(001) surface. We applied the classical molecular dynamics technique and collected statistically significant averages to be able to detect defect production trends in the energy dependence. The number of defects created in implantations was found to be a superlinear function of energy at low energies $(l400\mathrm{eV})$ and larger than the defect production in the bulk up to about 1 keV. We have also examined the depth dependence of close-to-surface damage and explored the energy and time dependence of the defect creation mechanisms and the sensitivity of the results to the choice of the model potential.
Increasing the Efficiency of Ideal Solar Cells by Photon Induced Transitions at Intermediate Levels

Recent attempts have been made to increase the efficiency of solar cells by introducing an impurity level in the semiconductor band gap. We present an analysis of such a structure under ideal conditions. We prove that its efficiency can exceed not only the Shockley and Queisser efficiency for ideal solar cells but also that for ideal two-terminal tandem cells which use two semiconductors, as well as that predicted for ideal cells with quantum efficiency above one but less than two. {copyright} {ital 1997} {ital The American Physical Society}
Dimension and Character Formulas for Lie Supergroups

A character formula is derived for Lie supergroups. The basic technique is that of symmetrization and antisymmetrization associated with Young tableaux generalized to supergroups. We rewrite the characters of the ordinary Lie groups U(N), O(N), and Sp(2N) in terms of traces in the fundamental representation. It is then shown that by simply replacing traces with supertraces the characters of certain representations for U(N/M) and OSP(N/2M) are obtained. Dimension formulas are derived by calculating the characters of a special diagonal supergroup element with (+1) and (−1) eigenvalues. Formulas for the eigenvalues of the quadratic Casimir operators are given. As applications, the decomposition of a representation into representations of subgroups is discussed. Examples are given for the Lie supergroup SU(6/4) which has physical applications as a dynamical supersymmetry in nuclei.
Nonadiabatic transitions induced by a time‐dependent Hamiltonian in the semiclassical/adiabatic limit: The two‐state case

We show rigorously, within the two‐state approximation, that in the semiclassical limit h/→0 a nonadiabatic transition induced by an analytic time‐dependent Hamiltonian is localized to the vicinity of a complex crossing of the two adiabatic potential curves, with transition amplitude independent of the nonadiabatic coupling and given by a simple formula of A. M.Dykhne.
Shooting method for vortex solutions of a complex-valued Ginzburg–Landau equation

In this paper, we study all the stationary solutions of the form u(r)einθ to the complex-valued Ginzburg–Landau equation on the complex plane: here (r, θ) are the polar coordinates, and n is any real number. In particular, we show that there exists a unique solution which approaches to a nonzero constant as r → ∞.
Lévy flights: Exact results and asymptotics beyond all orders

A comprehensive study of the symmetric Levy stable probability density function is presented. This is performed for orders both less than 2, and greater than 2. The latter class of functions are traditionally neglected because of a failure to satisfy non-negativity. The complete asymptotic expansions of the symmetric Levy stable densities of order greater than 2 are constructed, and shown to exhibit intricate series of transcendentally small terms—asymptotics beyond all orders. It is demonstrated that the symmetric Levy stable densities of any arbitrary rational order can be written in terms of generalized hypergeometric functions, and a number of new special cases are given representations in terms of special functions. A link is shown between the symmetric Levy stable density of order 4, and Pearcey’s integral, which is used widely in problems of optical diffraction and wave propagation. This suggests the existence of applications for the symmetric Levy stable densities of order greater than 2, despite their failure to define a probability density function.
Survey analysis of chorus intensity at Saturn

In order to conduct theoretical studies or modeling of pitch angle scattering of electrons by whistler mode chorus emission at Saturn, a knowledge of chorus occurrence and magnetic intensity levels, PB, as well as the distribution of PB relative to frequency and spatial parameters is essential. In this paper an extensive survey of whistler mode magnetic intensity levels at Saturn is carried out, and Gaussian fits of PB are performed. We fit the spectrum of wave magnetic intensity between the lower hybrid frequency and fceq/2 and for frequencies in the interval fceq/2 < f < 0.9 fceq, where fceq is the cyclotron frequency mapped to the equator. Saturn chorus is observed over most local times, but is dominant on the nightside in the range of 4.5 < L <7.5, with minimum power at the equator and peak power in the range of 5° < λ < 10°. Saturn wave magnetic intensity averaged in frequency bins peaks in the range of 10−5 < PB < 10−4 nT2 for 0.4 < β < 0.5 (β = f/fceq). Gaussian fits of PB with frequency and latitude are obtained for lower band chorus. Plasma injection regions are occasionally encountered with significant chorus power levels. Upper band chorus is seen almost exclusively within plasma injection regions, and the number of events is very limited, but when present, the average levels of PB can be higher than the lower band chorus. The overall magnetic intensity contribution of the upper band, however, is insignificant relative to the lower band.
Learning sparse wavelet codes for natural images

We show how a wavelet basis may be adapted to best represent natural images in terms of sparse coefficients. The wavelet basis, which may be either complete or overcomplete, is specified by a small number of spatial functions which are repeated across space and combined in a recursive fashion so as to be self-similar across scale. These functions are adapted to minimize the estimated code length under a model that assumes images are composed as a linear superposition of sparse, independent components. When adapted to natural images, the wavelet bases become selective to different spatial orientations, and they achieve a superior degree of sparsity on natural images as compared with traditional wavelet bases.
The design of ultrasonic lead magnesium niobate-lead titanate (PMN-PT) composite transducers for power and signal delivery to implanted hearing aids

We present a system for efficiently powering implanted hearing aids by transmitting an ultrasonic signal across the skin. The use of ultrasound as method for power and signal transfer is known for embedded systems in industrial applications and has more recently been investigated for use with other medical implants. In our application, ultrasonic transducers are investigated as they offer substantially reduced size relative to traditional magnetic induction coil power delivery. The developed transducers use lead magnesium niobate-lead titanate (PMN-PT) piezoelectric material in a 1–3 composite formulation. PMN-PT offers an electromechanical coupling factor (kt, an indicator of maximum efficiency) that is up to 60% greater than traditional piezoceramics, while the use of composite transducers removes geometric constraints that can limit the achieved efficiency. The fabrication methods for the transducers are detailed. Experimental results are presented to show the composite transducers achieve a kt of 0.86 (out of 1.00), and a power transmission efficiency that is improved by 38% relative to a similar non-composite transducers. It is also demonstrated that these transducers offer sufficient bandwidth for amplitude or frequency modulation schemes to transmit data signals along the power carrier beam.
Element-by-Element Implicit Algorithms for Heat Conduction

A new type of element-by-element implicit algorithm is proposed for heat conduction analysis. The algorithm is shown to be unconditionally stable, but does not involve a global coefficient matrix. Consequently, there are considerable operation count advantages over typical implicit schemes. Numerical test examples indicate the good behavior of the method. It is believed that the new approach will enable large heat conduction calculations to be performed much more economically than heretofore and is suggestive of related developments in other areas of engineering and the physical sciences.
Reliable Dissipative Control for a Class of Uncertain Singular Markovian Jump Systems via Hybrid Impulsive Control

In this paper, the problem of robust normalization and reliable dissipative control is investigated for a class of uncertain singular Markovian jump systems with actuator failures. The uncertainties exhibit in both system matrices and transition rate matrix of the Markovian chain. A new impulsive and proportional–derivative control strategy is presented. The gain matrices of the impulsive control part can be obtained together with the design approach. Moreover, the dissipative control results obtained in this paper include the results of H‐infinity and passive control as special cases. Finally, two numerical examples are provided to illustrate the effectiveness and applicability of the proposed methods.
Observations of interstellar neon in the helium focusing cone

[1] Extended pickup ion distributions in the heliosphere have been found to originate either from interstellar neutral gas or from the so-called inner source. Because of the motion of the Sun through the interstellar medium, interstellar neutral gas flows through the inner heliosphere and for some of the species is focused on the downwind side by the gravitation of the Sun. This gravitational focusing cone, which is absent for inner source ions, has been identified for He with UV backscattering and pickup ion observations and is used to diagnose the interstellar parameters. Using the large geometric factor of the Plasma and Suprathermal Ion Composition instrument on the Solar Terrestrial Relations Observatory mission, we have studied heavy pickup ions in the mass-per-charge range 12–20 during 2007 and 2008. We have clearly identified C+, N+, O+, the H2O+ group, and Ne+ among the heavy pickup ions. Out of these, Ne+ shows clear enhancements during two consecutive focusing cone passages, as evidenced by concurrent He+ enhancements during these periods, whereas all the other species are evenly distributed. This is the first observation of the interstellar focusing cone for Ne, whose survival probability as neutrals is only slightly lower than that of He and substantially higher than for other elements.
Representations involved in short‐term versus long‐term word learning by preschool children with and without phonological disorders

This study explores whether sublexical (i.e., individual sound) and/or lexical (i.e., whole‐word) representations contribute to word learning and whether these contributions change across short‐term versus long‐term learning. Sublexical representations were indexed by phonotactic probability, the likelihood of occurrence of a sound sequence, whereas lexical representations were indexed by neighborhood density, the number of similar sounding words. Thirty‐four preschool children participated in a short‐term word learning task that exposed them to nonwords varying in phonotactic probability and neighborhood density and tested learning of these nonwords. Long‐term learning was assessed through comprehension and production of real words varying in phonotactic probability and neighborhood density. Results showed that phonotactic probability and neighborhood density equally influenced short‐term word learning. In contrast, long‐term word learning was affected primarily by neighborhood density. Thus, both sublex.
A fast spin images matching method for 3D object recognition

Spin image has been applied to 3D object recognition system successfully because of its advantages of rotation, translation and view invariant. However, this method is very time consuming, owning to its high-dimensional characteristics and its complicated matching procedure. To reduce the recognition time, in this paper we propose a coarse-to-fine matching strategy for spin images. There are two steps to follow. Firstly, a low dimensional feature is introduced for a given point. The feature contain two components, its first component is the perpendicular distance from the centroid of the given point’s neighbor region to the tangential plane of the given point, its second component is the maximum distance between the projection point of the centroid on the tangential plane and projection points of the neighbor region on the tangential plane. Secondly when comparing a point from a target with a point from a model, their low features are matched first, only if they satisfy the low feature constrains, can they be selected as a candidate point pair and their spin images are further matched by similarity measurement. When all the target points and all the model points finish above matching process, those candidate point pairs with high spin image similarity are selected as corresponding point pairs, and the target can be recognized as the model with the most amount of corresponding point pairs. Experiment based on Stanford 3D models is conducted, and the comparison of experiment results of our method with the standard spin image shows that the propose method is more efficient while still maintain the standard spin image’s advantages.