Miracle-dz/UniFAR-FTUs huggingface dataset:
A note on wavelet-based method for damage detection

The applicability of Gabor wavelet transform of time history data in detecting a thin damage in beam is examined. For the case where the damage position is completely unknown, the use of two load positions is suggested. Cases considered are the position of the sensors relative to the damage and load positions, the height of the damage, the severity of the damage, and the effect of boundary conditions. The results show that the method is suitable for detecting localized damage and relatively robust in terms of sensor position, damage height, and degree of damage.
Topologies in generalized Orlicz sequence spaces

In 1994 S. D. Parashar and B. Choudhary defined certain paranorms in some Orlicz sequence spaces of Maddox type. Their ideas are applied later by many authors for topologization of various generalized Orlicz sequence spaces. We determine alternative F-seminorms in such spaces by using the standard arguments of modular spaces theory and a result about the topologization of sequence spaces defined by modulus functions.
Texture recognition of SAR image based on surfacelet transform

In order to take full use of SAR image dark areas information, texture recognition method of SAR image based on Surfacelet transform is proposed. Firstly, SAR image in test samples is decomposed into brightness SAR image and reflection SAR image based on Retinex model; secondly, the decomposed SAR image carries through Surfacelet transform, in order to reduce computational complexity and shorten the follow-up recognition time, the decomposed SAR image is processed two dimension three level scale Surfacelet transform, and the first level is 8 directions, the others are 8,2 directions respectively, after image Surfacelet transform, the sparsity of the distribution coefficient is even more evident, especially high-frequency sub-band; thirdly, coefficient matrixes of high-frequency sub-band reduce dimension processing by using the singular value decomposition theory of matrix; fourthly, the final eigenvector are composed of character of energy of coefficient matrix in low-frequency sub-band and first and second-order moment of coefficient matrix in intermediate frequency sub-band and eigenvector by reducing dimension in high-frequency subband; at last, use BP neural network to train with supervised and recognize of samples. The method takes full use of SAR image dark areas information, and the simulation results show that the method the recognition rate is better than other methods.
Patterns of time propagation on the grid of potential curves

Time-propagation patterns are studied for a network formed by two bands of equidistant rectilinear parallel diabatic potential curves that cross each other. In the case of weak coupling between the bands the propagation proceeds mostly via a diabatic path. In the case of strong coupling a different regime of antidiabatic propagation is revealed. For the intermediate case of coupling strength the propagation is basically described by an overlay of diabatic and antidiabatic patterns; interestingly, the adiabatic propagation is never operative. The present dynamic quantum model is compared with those models that assume a reduction of the problem to a succession of pairwise transitions between the states.
A direct calculation of the tunnelling current. III. Effect of localized impurity states in the barrier

For Pt. II see ibid., vol.4, 2598 (1971). The effect of an impurity level located in the barrier of a metal-insulator-metal tunnelling junction is investigated with the help of a new formalism. In agreement with Hurault's results (1971) it is found that a sharp resonance peak appears in the d2I/dV2 characteristic, when the impurity state energy crosses either electrode Fermi level. The width of this resonance peak is proportional to the width of the virtual bound state arising from the interaction of the two electrode continuum with the impurity state. It is stressed that the resonance effect cannot be interpreted as the opening of a new tunnelling channel. The dependence of the effect on the location of the impurity state is briefly studied.
A 2×2 Matrix Algebra for Electromagnetic Wave Propagation in Stratified Biaxial Media

Summary We present a new 2×2 matrix algebra for electromagnetic wave propagation in stratified biaxial media. Our method is based on Maxwell's equations and the continuity of the tangential components of the electric and magnetic field vectors and gives an exact complete solution. No restrictions are necessary for the orientations of the axes of the dielectric tensors of the stratified medium and the properties of the incident plane wave. A complete and systematic methodology is provided for calculating all wave parameters and all properties of the reflected and transmitted waves in terms of 2×2 Fresnel reflection and transmission matrices.
BOUNDARY CONTROL OF A CHANNEL: PRACTICAL AND NUMERICAL STUDIES

Abstract The problem of stability of the non-linear Saint-Venant equations stated by two conservation laws perturbed by non-homogeneous terms is presented. Under some assumptions on those non-homogeneous functions, previous results on the stability of two conservation laws are developed using the Riemann coordinates approach. This stability result applied to the regulation of the water flow and level of the shallow water equations is validated by simulations and experimentations on a real river data and a micro-channel respectively.
Spectral Analysis of Rossi X-Ray Timing Explorer Observations of A3667

X-ray emission from the cluster of galaxies A3667 was measured by the Proportional Counter Array and High-Energy X-Ray Timing Experiment experiments on board the Rossi X-Ray Timing Explorer (RXTE) satellite during the period 2001 December-2002 July. Analysis of the ~141 ks RXTE observation and lower energy ASCA Gas Imaging Spectrometer data yields only marginal evidence for a secondary power-law emission component in the spectrum. The 90% confidence upper limit on nonthermal emission in the 15-35 keV band is determined to be 2.6 × 10-12 ergs cm-2 s-1. When combined with the measured radio flux and spectral index of the dominant region of extended radio emission, this upper limit implies a lower limit of ~0.4 μG on the mean, volume-averaged, intracluster magnetic field in A3667.
Finite element estimation of induction motor parameters for sensorless applications

Purpose – To purpose of this paper is to introduce a procedure to compute the d‐ and q‐axis parameters of the induction motor.Design/methodology/approach – A finite element procedure, based on the d‐ and q‐axis model of the induction motor is adopted.Findings – Such a procedure is well suited to analyse IM with anisotropic rotor, where an intentionally created saliency is introduced in the rotor bar geometry, so as to detect the IM rotor position without sensor.Originality/value – The proposed procedure allows one to evaluate the sensorless control capability of the IM. It will be useful for both analysis of the IM performance and design of the machine itself.
On a dusty-gas shock tube

Analytical and numerical methods were used to investigate the flow induced by a shock wave in a shock-tube channel containing air laden with suspended small solid particles. Exact results are given for the frozen and equilibrium shock-wave properties as a function of diaphragm-pressure ratio and shock-wave Mach numbers. The driver contained air at high pressure. A modified random-choice method together with an operator-splitting technique show clearly both the decay of a discontinuous frozen shock wave and a contact discontinuity, and the formation of a stationary shock structure and an effective contact front of finite thickness. The effects of particle diameter, particle-number density and diaphragm- pressure ratio on the transitional behaviour of the flow are investigated in detail. The alteration of the flow properties owing to the presence of particles is discussed thoroughly and compared with classical shock-tube flows.
The Marshall-Olkin Fréchet Distribution

We introduce a new distribution, namely Marshall–Olkin Fréchet distribution. The probability density and hazard rate functions are derived and their shape properties are considered. Expressions for the nth moments are given. Various results with respect to quantiles, Rényi entropy and order statistics are obtained. The unknown parameters of the new distribution are estimated using the maximum likelihood estimation method adopting three different iterative procedures. The model is applied on a real data set on survival times. [Supplementary materials are available for this article. Go to the publisher's online edition of Communications in Statistics—Theory and Methods for the following free supplemental resource: A file that will allow the random variables from MOF distribution to be generated. ]
Geometric formulation of mechanical systems with one-sided constraints

A geometric formulation of analytical mechanics of systems with holonomic and holonomic one-sided constraints is proposed. This is an extension of work by Tulczyjew (1986) in which non-holonomic constraints were also considered, but not the one-sided case. The introduction of Lagrange multipliers to give explicit equations of motion was not considered by Tulczyjew either. This allows the authors to study problems of motion of particles hitting moving walls. They verify that the conditions of collision are satisfied.
Design and fabrication of efficient collimation and focusing optics for mid-IR quantum cascade lasers

Quantum cascade lasers (QCL) are a new class of solid-state lasers capable of delivering mid-infrared (mid-IR) radiation wavelengths from 3.5 μm to 25 μm. QCLs are finding extensive use in chemical sensing applications due to the abundance of absorption features in the molecular fingerprint region spanned by these sources. They are also being exploited in the field of electro-optical infrared countermeasures. QCL devices exhibit an elliptical emission profile that is highly divergent in the fast axis of the laser waveguide. The far-field profile of the QCL emission, 62° and 32° ± 2° for the fast and slow axes, respectively, places stringent demands on the design of efficient collimation lenses. Because of the current lack of commercially available mid-IR optical components, QCL users must design and fabricate custom micro-optics to efficiently collect, collimate, and focus the QCL emission. In this paper, we report the design, fabrication, and characterization of germanium aspheric collimating and focusing optics designed for mid-IR Fabry-Perot QCLs with an emission wavelength of 8.77 μm. Custom aspheric collimating and focusing lenses with a numerical aperture (NA) of 0.85 and 0.20, respectively, were designed and fabricated using single-point diamond turning. Measurements of the transmitted wavefront error at mid-IR wavelengths showed diffraction-limited performance with Strehl ratios >0.94 and >0.99 for the collimation and focusing lenses, respectively. A beam propagation figure of merit (M2) of 1.8 and 1.2 was measured for the fast and slow axes, respectively, of a Fabry-Perot QCL using a confocal optical system comprised of these lenses.
Sampling design for classifying contaminant level using annealing search algorithms

A stochastic method for sampling spatially distributed contaminant level is presented. The purpose of sampling is to partition the contaminated region into zones of high and low pollutant concentration levels. In particular, given an initial set of observations of a contaminant within a site, it is desired to find a set of additional sampling locations in a way that takes into consideration the spatial variability characteristics of the site and optimizes certain objective functions emerging from the physical, regulatory and monetary considerations of the specific site cleanup process. Since the interest is in classifying the domain into zones above and below a pollutant threshold level, a natural criterion is the cost of misclassification. The resulting objective function is the expected value of a spatial loss function associated with sampling. Stochastic expectation involves the joint probability distribution of the pollutant level and its estimate, where the latter is calculated by means of spatial estimation techniques. Actual computation requires the discretization of the contaminated domain. As a consequence, any reasonably sized problem results in combinatorics precluding an exhaustive search. The use of an annealing algorithm, although suboptimal, can find a good set of future sampling locations quickly and efficiently. In order to obtain insight about the parameters and the computational requirements of the method, an example is discussed in detail. The implementation of spatial sampling design in practice will provide the model inputs necessary for waste site remediation, groundwater management, and environmental decision making.
Noise Spectra and Directivity for a Scale-Model Landing Gear

An extensive experimental study has been conducted to acquire detailed noise spectra and directivity data for a high-fidelity, 6.3%-scale, Boeing 777 main landing gear. The measurements were conducted in the NASA Langley Quiet Flow Facility using a 41-microphone directional array system positioned at a range of polar and azimuthal observer angles with respect to the model. DAMAS (Deconvolution Approach for the Mapping of Acoustic Sources) array processing as well as straightforward individual microphone processing were employed to compile unique flyover and sideline directivity databases for a range of freestream Mach numbers (0.11 – 0.17) covering typical approach conditions. Comprehensive corrections were applied to the test data to account for shear layer ray path and amplitude variations. This allowed proper beamforming at different measurement orientations, as well as directivity presentation in free-field emission coordinates. Four different configurations of the landing gear were tested: a baseline configuration with and without an attached side door, and a noise reduction concept “toboggan” truck fairing with and without side door. Spectral analyses demonstrated that individual microphones could establish model spectra. This finding permitted the determination of unique, spatially-detailed directivity contours of spectral band levels over a hemispherical surface. Spectral scaling for the baseline model confirmed that the acoustic intensity scaled with the expected sixth-power of the Mach number. A comparison of spectra and directivity between the baseline gear and the gear with an attached toboggan indicated that the toboggan fairing may be of some value in reducing gear noise over particular frequency ranges. Finally, spectrum results were scaled quantitatively to data obtained from flyover tests of a full-scale 777 aircraft. The comparison showed good agreement in frequency and level, suggesting the general applicability of the model-scale noise results.
Numerical simulation of tropical cumulus clouds and their interaction with the subcloud layer

Abstract A two-dimensional numerical model suitable for simulating an ensemble of cumulus clouds has been developed. It differs from similar models in its greater emphasis on turbulent processes in the boundary layer and in clouds. In the model, cloud-scale dynamics are coupled with a third-moment turbulence closure. A turbulence-scale condensation scheme is used to parameterize the cloud water mixing ratio. We studied the response of tropical cumulus clouds to imposed large-scale vertical advection by doing two simulations: one with upward large-scale vertical velocity (the “disturbed” case) and one without any (the “undisturbed” case) but otherwise identical. Deep cumulus clouds formed in the disturbed case, while only shallow clouds formed in the undisturbed case. Time-averaged and horizontally averaged heat and moisture budgets from the simulations show that the subcloud layer (SCL) in the disturbed case was strongly affected by cumulus circulations and rain evaporation. Both cumulus updrafts and down.
New classes of conversed quantities associated with non-Noether symmetries

A result of Hojman and Harleston (1981) has been used to extend the known relationship between conserved quantities and non-Noether symmetries. It is shown that N constants of the motion may be derived from each non-Noether symmetry of an N-dimensional Lagrangian system; this applies whether the symmetry is continuous or discrete. In addition, the properties of the Cartan form are utilised to to give a new proof of the Hojman-Harleston theorem.
Notes on Estimation of the General Odds Ratio and the General Risk Difference for Paired‐Sample Data

Under the matched‐pair design, this paper discusses estimation of the general odds ratio ORG for ordinal exposure in case‐control studies and the general risk difference RDG for ordinal outcomes in cross‐sectional or cohort studies. To illustrate the practical usefulness of interval estimators of ORG and RDG developed here, this paper uses the data from a case‐control study investigating the effect of the number of beverages drunk at “burning hot” temperature on the risk of possessing esophageal cancer, and the data from a cross‐sectional study comparing the grade distributions of unaided distance vision between two eyes. Finally, this paper notes that using the commonly‐used statistics related to odds ratio for dichotomous data by collapsing the ordinal exposure into two categories: the exposure versus the non‐exposure, tends to be less efficient than using the statistics related to ORG proposed herein.
An Improved Shift-and-Ratio Effective Channel Length Extraction Method for Metal Oxide Silicon Transistors with Halo/Pocket Implants

The original shift-and-ratio method tends to significantly over-estimate the effective channel length Leff of metal–oxide–silicon (MOS) transistors with halo/pocket implants because the carrier mobility of the short transistor tends to be smaller than that of the long transistor. A modification of the original method has been tested on both n-channel metal–oxide–silicon (NMOS) and p-channel metal–oxide–silicon (PMOS) transistors fabricated by state-of-the-art complementary metal–oxide–silicon (CMOS) technology. The values of Leff generated by this method are more reasonable than the original shift-and-ratio method with much less computation time involved. The theoretical basis of our method is that the carrier mobility of the short transistor is approximately equal to that of the long transistor when the gate voltage is close to the threshold voltage for state-of-the-art MOS transistors with <2 nm gate oxide.
Temperature dependence of polarization and charge dynamics on the BaTiO3(100) surface by scanning probe microscopy

Variable-temperature atomic force microscopy, piezoresponse force microscopy (PFM), and scanning surface potential microscopy were combined to determine the temperature response of polarization and screening charge on BaTiO3(100) surfaces. The ferroelectric-domain induced surface corrugations and piezoelectric response decrease with temperature and disappear at the Curie temperature. The temperature dependence of the PFM contrast is explained within the framework of the Ginzburg–Devonshire theory with the effect of a dielectric tip-surface gap taken into account. The temperature dependence of the surface potential contrast is ascribed to the interplay between the release of the screening charges with temperature and their slow relaxation. The results indicate that surface potential polarity is reversed relative to that expected from polarization orientation on BaTiO3 in ambient.
Numerical modeling of hole interband tunneling in wurtzite GaN and SiC

The time evolution of Bloch electrons (holes) moving in a constant electric field has been studied for GaN and 2H-SiC using a numerical model based on realistic band structures. The large band gap of GaN and the SiC polytypes provide much larger critical fields than in conventional semiconductors, which allows device operation at very high electric fields. At sufficiently high electric fields the carriers may change band during drift due to tunneling. GaN has a direct band gap, while the hexagonal SiC polytypes have indirect band gaps. In spite of this difference the valence band structure is very similar due to the wurtzite symmetry. In this work the GaN and the 2H-SiC polytype are considered as wurtzite prototype semiconductors in order to study valence band to band tunneling in wurtzite semiconductors for electric fields directed along the c axis. A large valence band to band tunneling probability was found for both materials at electric fields above 400 kV/cm. This shows the importance of considering .
Near-Infrared Spectra of Icy Outer Solar System Surfaces: Remote Determination of H2O Ice Temperatures

We present new 1.20 to 2.35 μm spectra of satellites of Jupiter, Saturn, and Uranus, and the rings of Saturn, obtained in 1995 and 1998 at Lowell Observatory. For most of the target objects, our data provide considerable improvement in spectral resolution and signal-to-noise over previously published data. Absorption bands with shapes characteristic of low-temperature, hexagonal crystalline H2O ice dominate the spectra of most of our targets in this wavelength range. We make use of newly published temperature-dependent wavelengths and relative strengths of H2O absorption bands to infer ice temperatures from our spectra. These ice temperatures are distinct from temperatures determined from thermal emission measurements or simulations of radiative balances. Unlike those methods, which average over all terrains including ice-free regions, our temperature-sensing method is only sensitive to the ice component. Our method offers a new constraint which, combined with other observations, can lead to better understanding of thermal properties and textures of remote, icy surfaces. Ice temperatures are generally lower than thermal emission brightness temperatures, indicative of the effects of thermal inertia and segregation between ice and warmer, darker materials. We also present the results of experiments to investigate possible changes of water ice temperature over time, including observations of Titania at two epochs, and of Ganymede and saturnian ring particles following emergence from the eclipse shadows of their primary planets. Finally, we discuss limitations of our temperature measurement method which can result from the presence of H2O in phases other than hexagonal ice-Ih, such as amorphous ice, hydrated mineral phases, or radiation-damaged crystalline ice. Our spectra of Europa and Enceladus exhibit peculiar spectral features which may result from effects such as these.
Discovering New V-Type Asteroids in the Vicinity of 4 Vesta

We present results on the identification of two new V-type asteroids, 809 Lundia and 956 Elisa. These asteroids are located in the neighborhood of Asteroid 4 Vesta, but they do not belong to Vesta's dynamical family. Their spectra in the visible wavelength are consistent with the spectra of the Vesta family members (Vestoids) and of other V-type objects in the nearby region too. The possible existence of two spectroscopic groups of V-type asteroids in the Vesta region is discussed.
Attosecond physics in photoemission from a metal nanotip

Nanometre-scale metal tips irradiated by femtosecond laser pulses represent ultrafast electron sources. The combination of the laser pulse and the tip offers the possibility of extending attosecond science from atomic or molecular gases to surfaces of solid nanoemitters. We first review this emerging research field focusing on electron rescattering at sharp metal tips. In particular, we investigate the carrier–envelope phase effects that reveal attosecond emission dynamics. Furthermore, we present detailed theory models that support this interpretation.