Miracle-dz/UniFAR-FTUs huggingface dataset:
Raman microprobe study on temperature distribution during cw laser heating of silicon on sapphire

For the first time Raman microprobe experiments have been made to measure the space‐resolved temperature distribution induced in silicon‐on‐sapphire by a stationary elliptical Gaussian laser beam. The algorithm [J. Appl. Phys. 57, 965 (1985)] for solving the nonlinear heat equation in a two‐layer structure has been also extended to include the temperature dependence of laser power absorbed besides the temperature dependencies of thermal conductivity and diffusivity. The problems involved in applying the numerical calculations to the experimental situation are discussed. The numerical calculations of temperature distributions based on the present algorithm are found to give a good agreement with the present Raman microprobe results.
Minimizing the total weighted delivery time in container transportation scheduling

We consider the problem of transporting containers from one port to another using a fleet of ships. Each ship has a capacity constraint that limits the total number of containers it can carry; each ship calls on a specific set of ports that is referred to as its route and each ship follows a fixed route with a fixed departure time at each port. Each container has a release date, that is, the date when it becomes available for shipping at its origination port; it cannot be loaded onto a ship before its release date. Also, each container has an importance factor referred to as its weight. The delivery time of a container is defined as the time when the container is delivered by a ship at its destination port. We consider the problem of minimizing the total weighted delivery times over all containers. We consider three scenarios with regard to the routes of the ships, namely, (i) identical routes, (ii) nested routes, and (iii) arbitrary routes. We determine the computational complexity of the problems and provide heuristics with their worst‐case analyses. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
Randomness of low‐order models of two‐dimensional inviscid dynamics

A statistical analysis is performed of various low‐order truncations of the two‐dimensional inviscid Navier–Stokes equations. The behavior of the time‐averaged enstrophy and time‐correlation function of each Fourier mode is analyzed and compared to the behavior expected in a random dynamical system. Empirical evidence is presented for the randomness of all isotropically truncated models for which the wavenumber cutoff is large enough to insure that every mode is involved in nontrivial interactions. This evidence is contrasted with the apparent nonrandomness found in other special truncations. The results strengthen the evidence for the validity of statistical descriptions of two‐dimensional turbulence.
STRONG DYNAMICAL LOCALIZATION FOR THE ALMOST MATHIEU MODEL

In this note we prove Strong Dynamical Localization for the almost Mathieu operator Hθ,λ,ω=-Δ+ λcos(2π(θ + xω)) for all λ>2 and Diophantine frequencies ω. This improves the previous known result [22, 13] which established Dynamical Localization for a.e. θ and for λ≥15.
Transport properties of heterogeneous materials. Combining computerised X-ray micro-tomography and direct numerical simulations

Feasibility of a method for finding flow permeability of porous materials, based on combining computerised X-ray micro-tomography and numerical simulations, is assessed. The permeability is found by solving fluid flow through the complex 3D pore structures obtained by tomography for actual material samples. We estimate overall accuracy of the method and compare numerical and experimental results. Factors contributing to uncertainty of the method include numerical error arising from the finite resolution of tomographic images and the rather small sample size available with the present tomographic techniques. The total uncertainty of computed values of permeability is, however, not essentially larger than that of experimental results. We conclude that the method provides a feasible alternative for finding fluid flow properties of the kind of materials studied. It can be used to estimate all components of permeability tensor and is useful in cases where direct measurements are not achievable. Analogous methods can be applied to other modes of transport, such as diffusion and heat conduction.
Bulk-wave polarization fields in transversely isotropic elastic media

The bulk–wave polarization field of a transversely isotropic elastic material has three branches, each rotationally symmetric about the axis of transverse isotropy. The branches are not uniquely defined, however, by the propagation condition for plane bulk waves since the polarization of each wave is determined only to within a factor of −1. Two ground rules are adopted: discontinuities in the branches are restricted to the acoustic axes, along which two or all three of the plane bulk waves have equal speeds; and, in a specified ordering, the three polarizations are taken to form a right–handed orthonormal set. The topological character of the branches depends on the combinations c11−c44, c33−c44, c13c44 of the five distinct elastic moduli of the material. In the regular case in which each combination is non-zero, the ground rules permit an unambiguous specification of the branches, but when c11=c44 non‐uniqueness results from the presence of discontinuities in the basal plane. Polarization fields are constructed for all transversely isotropic elastic materials with positive definite strain energy and the results are related to an elastodynamic classification of these materials which is similarly exhaustive.
Algorithm of sub-pixel image registration based on Harris corner and SIFT descriptor

Since multi-cameras images involve much differences in spatial characteristics and spectral characteristics, so it is full of difficulties in the image registration. According to the different characteristics of the multi-cameras images, this paper proposed a new algorithm of sub-pixel image registration based on Harris corner and Scale Invariant Features Transform (SIFT) descriptor. The algorithm consists of three procedures: feature detection, pixel-level registration and sub-pixel-level registration. Firstly, the Harris algorithm was selected to extract the feature corners and determine the main direction of the Harris corners. Secondly, the SIFT descriptor was chose to describe the key points. Then, feature points acquired on matching by the two-way nearest neighbor algorithm. Finally, in the sub-pixel-level registration process, we carry out interpolation in the neighborhood of the pixel-level matching points. Then the pixel-level registration is taken once again. The experimental results show that, the proposed algorithm is accurate, efficient, and retains the rotational invariance of the SIFT descriptor. What’s more, processing speed is significantly increased.
The X-Ray Structure of the VELA X Region Observed from UHURU

BS>The X-ray source 2U 0832-45 in the Vela X region is centered on the pulsar PSR 0833--45 and is less than 1° . 2 in extent. Weak X-ray emission is seen from two other localized regions within the radio complex, but the diffuse emission of the Vela X-ray nebula seen below 2 keV is not detected in the Uhuru energy range. We consider it likely that the X-ray source at the pulsar is being excited by the rotational energy loss of the pulsar.
A theoretical model of multi-agent quantum computing

The best design for practical quantum computing is one that emulates the multi-agent quantum logic function of natural biological systems. Such systems are theorized to be based upon a quantum gate formed by a nucleic acid Szilard engine (NASE) that converts Shannon entropy of encountered molecules into useful work of nucleic acid geometric reconfiguration. This theoretical mechanism is logically and thermodynamically reversible in this special case because it is literally constructed out of the (nucleic acid) information necessary for its function, thereby allowing the nucleic acid Szilard engine to function reversibly because, since the information by which it functions exists on both sides of the theoretical mechanism simultaneously, there would be no build-up of information within the theoretical mechanism, and therefore no irreversible thermodynamic energy cost would be necessary to erase information inside the mechanism. This symmetry breaking Szilard engine function is associated with emission and/or absorption of entangled photons that can provide quantum synchronization of other nucleic acid segments within and between cells. In this manner nucleic acids can be considered as a natural model of topological quantum computing in which the nonabelian interaction of genes can be represented within quantum knot/braid theory as anyon crosses determined by entropic loss or gain that leads to changes in nucleic acid covalent bond angles. This naturally occurring biological form of topological quantum computing can serve as a model for workable man-made multi-agent quantum computing systems.
Improvement bi-block zero tree coding for video data compression

This paper presents a multispectral image compression method based on vector quantization technique that uses fuzzy c-means (FCM) algorithm to generate the codebook. There are two ways to form the vector set from the input image: the intraband vector forming where each vector was formed by dividing the input image into blocks, and the interband vector forming where each vector was formed by the gray values of all bands representing a pixel. In this research, a modified version of FCM was used to reduce the computational time. The experimental results comparing the effect of both vector forming methods are given.
One-photon pair annihilation in magnetized relativistic plasmas

In supersonic magnetic fields, electron-positron pairs may annihilate into single photons producing spectral features above 1 MeV. The paper calculates the exact one-photon annihilation rate in the general case where pairs may annihilate from excited Landau states, extending the previous studies which were restricted to pairs in the ground state. Asymptotic expressions for annihilation spectra and rates in the limit of large pair quantum numbers are also derived. It is found that the rate of annihilation from excited states can exceed the rate from the ground state by orders of magnitude in fields less than about 2 x 10 to the 12th G. This allows one-photon annihilation to be competitive with the two-photon process at typical neutron star field strengths. Annihilation spectra from a Maxwellian pair plasma at transrelativistic temperatures show fine structure near threshold on a scale (h/2pi)omega sub B as the result of contributions from individual pair states, which blend into a smooth continuum at higher energies. 19 references.
Effects of contact space charge on the performance of quantum intersubband photodetectors

Highly non-uniform electric field exists in the active region of quantum intersubband devices, primarily due to the presence of PN junctions forming between heavily doped contact regions and non-intentionally doped barriers. Using a combination of experiments and theoretical simulations, we investigate the effect of this non-uniform internal electric field on the photodetector operation. Three quantum dots-in-a-well (DWELL) photodetectors have been fabricated with top spacer, bottom spacer, and no spacer around the active region, respectively, to demonstrate the effect of the non-uniform field. Drift-diffusion based calculations of the electric field provide further insight into the device operation.
On the best quadratic approximation of nonlinear systems

We present a new approach to the approximation of the input-output map of a nonlinear system which transforms stochastic signals. The proposed approach is based on the best approximation technique with a specific second degree operator acting on the observed input signal. We show that the obtained approximant minimizes the mean squared error between a desired output signal and the output signal of the approximating system. The strict justification of the proposed approach is provided including theorems on the error representation associated with the approximation process. Three broad extensions of the method are outlined. The simulations demonstrate the efficiency of the proposed technique with am example of its application to image processing.
Photonic crystal fiber pump combiner for high-peak power all-fiber thulium lasers

We report on the performance of a prototype pump combiner for use with thulium-doped photonic crystal fiber (PCF). This platform is attractive for “all-fiber” high energy and high peak power laser sources at 2 μm. We will report on the performance of this integrated amplifier in comparison to free space amplification in Tm:PCF. In particular, we carefully look for spectral/temporal modulation resulting from multimode interference between fundamental and higher order transverse modes in the amplifier to evaluate this for ultrashort chirped pulse amplification. The slope efficiency for the all-fiber amplifier is 22.1 %, indicating the need for further improvement. However, an M2 < 1.07 demonstrates excellent beam quality, as well as amplified polarization extinction ratios of ~25 dB.
Upper Limit for J/psi ---> gamma Axion

The authors have searched with the crystal ball detector for axionlike particles in radiative J/psi decays. An upper limit on the branching ratio B(J/psi.--> gamma.+a)<1.4 x 10/sup -5/ (90% C.L.) is obtained. This result holds for long-lived, noninteracting pseudoscalar or vector particles of mass less than 1 GeV. Thus, this experiment also places stringent limits on the existence of other possible light bosons such as those arising in supersymmetric theories.
BINARY CENTRAL STARS OF PLANETARY NEBULAE DISCOVERED THROUGH PHOTOMETRIC VARIABILITY. II. MODELING THE CENTRAL STARS OF NGC 6026 AND NGC 6337

Close-binary central stars of planetary nebulae (CSPNe) provide an opportunity to explore the evolution of PNe, their shaping, and the evolution of binary systems undergoing a common-envelope phase. Here, we present the results of time-resolved photometry of the binary central stars (CSs) of the PNe NGC 6026 and NGC 6337 as well as time-resolved spectroscopy of the CS of NGC 6026. The results of a period analysis give an orbital period of 0.528086(4) days for NGC 6026 and a photometric period of 0.1734742(5) days for NGC 6337. In the case of NGC 6337, it appears that the photometric period reflects the orbital period and that the variability is the result of the irradiated hemisphere of a cool companion. The inclination of the thin PN ring is nearly face-on. Our modeled inclination range for the close central binary includes nearly face-on alignments and provides evidence for a direct binary-nebular shaping connection. For NGC 6026, however, the radial-velocity curve shows that the orbital period is twice the photometric period. In this case, the photometric variability is due to an ellipsoidal effect in which the CS nearly fills its Roche lobe and the companion is most likely a hot white dwarf. NGC 6026 then is the third PN with a confirmed central binary where the companion is compact. Based on the data and modeling using a Wilson–Devinney code, we discuss the physical parameters of the two systems and how they relate to the known sample of close-binary CSs, which comprise 15%–20% of all PNe.
A Note on Local Influence Based on Normal Curvature

Object functions other than the likelihood displacement, such as a parameter estimate or a test statistic, can also be used in local influence analysis. The normal curvatures of these object functions have been studied in situations where the slopes were non‐zero. In these situations, we show that the normal curvature is not scale invariant and thus ambiguous conclusions will be drawn. Comments on the application of the general normal curvature formula are presented.
On the reflection coefficient which exceeds unity

The acoustic reflection coefficient at a lossy liquid–lossless solid interface is shown to be greater than unity near Rayleigh critical angle. This result does not violate the principle of energy conservation. A ray model is presented to explain the underlying physical phenomenon. The peak value of the reflection coefficient is predicted by an approximate expression.
Adaptive subspace detection of extended target in white Gaussian noise using sinc basis

For the high resolution radar (HRR), the problem of detecting the extended target is considered in this paper. Based on a single observation, a new two-step detection based on sparse representation (TSDSR) method is proposed to detect the extended target in the presence of Gaussian noise with unknown covariance. In the new method, the Sinc dictionary is introduced to sparsely represent the high resolution range profile (HRRP). Meanwhile, adaptive subspace pursuit (ASP) is presented to recover the HRRP embedded in the Gaussian noise and estimate the noise covariance matrix. Based on the Sinc dictionary and the estimated noise covariance matrix, one step subspace detector (OSSD) for the first-order Gaussian (FOG) model without secondary data is adopted to realise the extended target detection. Finally, the proposed TSDSR method is applied to raw HRR data. Experimental results demonstrate that HRRPs of different targets can be sparsely represented very well with the Sinc dictionary. Moreover, the new method can estimate the noise power with tiny errors and have a good detection performance.
Historical ocean subsurface temperature analysis with error estimates

Abstract An objective analysis of monthly ocean subsurface temperatures from 1950 to 1998 is carried out. The analysis scheme and the results with estimated analysis errors are presented. The analysis domain is global with a horizontal grid of 1° × 1° and 14 vertical levels in the upper 500 m. Subsurface temperature observations used in the objective analysis are archived by the National Ocean Data Center of the National Oceanic and Atmospheric Administration, together with those collected through the global telecommunication system and domestic communication lines in Japan. All the observations are preprocessed by quality control and data selection procedures developed in this study. Together with these observations, three-dimensional fields of the upper-ocean temperature are optimally estimated using a variational technique. To ensure smooth and continuous vertical temperature profiles, a constraint term is introduced to the cost function that is minimized in the analysis. In addition, the analysis sche.
Formation of Aluminum Schottky Contact on Plasma-Treated Cadmium Telluride Surface

We have studied the effect of plasma treatment on the rectification property and performance of the CdTe radiation detector with the Al Schottky electrode. The Te-rich layer on the CdTe surface etched with Br-methanol caused the degradation of the rectification property of the Al/CdTe Schottky contact. To remove the Te-rich layer, plasma treatment was carried out. The plasma treatment did not roughen the CdTe surface, and it removed the Te-rich layer. In terms of current–voltage characteristics of the Al/CdTe Schottky contact, the leakage current of the samples with plasma treatment was lower than that of the samples without plasma treatment. Moreover, in terms of detector performance, the samples with plasma treatment showed a higher energy resolution than those without plasma treatment. We achieved a high energy resolution of 1.6 keV FWHM at 59.5 keV using the plasma-treated Al/CdTe/Pt detector, which is comparable to the value obtained using a conventional Schottky-type In/CdTe/Pt detector.
Phonon-assisted tunneling in reverse biased Schottky diodes

Reverse current–temperature (IΓ/T) characteristics of Al–GaAs Schottky diodes with oxidized interfaces are measured in the temperature region of 250–400 K at various reverse bias voltage in order to elucidate a mechanism of carrier transport through the barrier. The IΓ/T dependencies are explained on the basis of phonon-assisted electrons tunneling from interface states to the semiconductor model. The barrier height, evaluated from the IΓ/T characteristics (activation energy) which depends on the applied voltage and temperature, is discussed. It is shown that these dependencies are due to the above-mentioned carrier transport through the Schottky barrier mechanism. The important of the phonon-assisted tunneling process on the current transport in the diodes is emphasized.
Dihomology III. A Generalization of the Poincaré Duality for Manifolds

which is a topological invariant of the space X, but not an invariant of homotopy type. The E term is the Cech cohomology of X with coefficients in the sheaf £ of local singular homology of X, and the ETM term is related to the ordinary global singular homology of X. The sequence therefore relates the local and global structures of the space. If X is a closed orientable w-manifold, then the local homology sheaf reduces to the simple sheaf of integers, and the spectral sequence collapses to the familiar isomorphism of Poincare, H^Hn_Q. If X is a polyhedron, there is a simple way of defining E, and its dual $, using a triangulation. In order to obtain the spectral sequences as quickly as possible we give this simplicial method in §2, and summarize the properties of the sequences in Theorem 1. In §3 we generalize E,£ to arbitrary topological spaces, using a combination of singular homology and Cech cohomology, and verify that the simplicial sequences are in fact topological invariants. The functorial qualities of E,$ are also discussed. Since both E and $ involve both homology and cohomology, they are not functors on the category of topological spaces but we prove in Theorem 2 that if we generalize them further they are functors on a category of maps, the sequences of a space being those associated with the identity map. The last section is concerned with the geometrical interpretation of E and $, and, in particular, of the filtrations induced on the homology and cohomology groups. It appears that the filtration of a homology or cohomology class has something to do with the dimension of that part of the space in which it is 'situated', and we prove two theorems which are feelers in this direction. Theorem 3 connects the homology filtration with cap products, while Theorem 4 concerns the filtration of a cohomology
Weighted D-filtering

A new type of filter which has the most desirable properties of an image smoothing filter is proposed. These properties are (1) robust smoothing efficiency, (2) edge preservation, and (3) thin-line detail preservation. The new filter, called the weighted D filter, computes its output as the median of weighted averages, instead of plain averages as used in the Hodges-Lehman D filter, of symmetrically placed order statistics. Experiments in which one particular weighting scheme is considered in detail are discussed. The experimental and comparison results verify the useful properties of the proposed filter. >
Thermodynamics and an Introduction to Thermostatistics

GENERAL PRINCIPLES OF CLASSICAL THERMODYNAMICS. The Problem and the Postulates. The Conditions of Equilibrium. Some Formal Relationships, and Sample Systems. Reversible Processes and the Maximum Work Theorem. Alternative Formulations and Legendre Transformations. The Extremum Principle in the Legendre Transformed Representations. Maxwell Relations. Stability of Thermodynamic Systems. First--Order Phase Transitions. Critical Phenomena. The Nernst Postulate. Summary of Principles for General Systems. Properties of Materials. Irreversible Thermodynamics. STATISTICAL MECHANICS. Statistical Mechanics in the Entropy Representation: The Microanonical Formalism. The Canonical Formalism Statistical Mechanics in Helmholtz Representation. Entropy and Disorder Generalized Canonical Formulations. Quantum Fluids. Fluctuations. Variational Properties, Perturbation Expansions, and Mean Field Theory. FOUNDATIONS. Postlude: Symmetry and the Conceptual Foundations of Thermostatistics. Appendices. General References. Index.