Miracle-dz/UniFAR-FTUs huggingface dataset:
Compensation for the Demagnetizing Field in Remanence Measurements of Perpendicular Magnetic Recording Films

Remanence measurements are very useful for estimating the characteristics of intergranular magnetic interactions in recording layers. However, it is necessary to compensate for the demagnetizing field in remanence measurements of perpendicular magnetic recording films. In this study, a new method of compensating for the demagnetizing field is proposed and an effective reverse field Heff is used to evaluate the dc demagnetization measurements, isothermal remanent magnetization measurements, and ΔM for perpendicular magnetic recording films.
Maximum entropy regularization strategies for inferring aerosol vertical distribution from light scattering measurements

A methodology is presented for obtaining information on aerosol vertical structure, a key variable in studies of aerosol climate forcing and atmospheric correction of satellite ocean-color imagery. The methodology employs ground-based angular measurements of atmospheric radiance, total or polarized, in the oxygen A-band centered on 763 nm. The radiance measured at different zenith angles is sensitive to different atmospheric layers, and the measurements can be inverted to retrieve the vertical profile of aerosol concentration. To solve the inverse problem, in which small errors in the data may yield large errors in the reconstructed profile, an iterative regularization scheme, robust to noise and perturbing effects (e.g., due to multiple scattering and non-null surface reflectance), is developed. Maximum entropy regularized solutions are introduced. The methodology is tested on atmospheric radiance data simulated for typical aerosol profiles and aerosol types. The retrieved aerosol profiles agree with the prescribed ones, indicating that the inversion scheme is efficient in achieving a proper balance between goodness-of-fit to the data and stability of the solution. The methodology has the potential to extend and complement surface observations of aerosol vertical structure made by lidar networks. This perspective is significant, since current information on aerosol vertical structure is insufficient to constrain and verify key assumptions in global aerosol models. The complementary information would contribute, via assimilation, to improving predictions of aerosol radiative forcing and to reducing uncertainties in model simulations of climate change. In addition, the methodology would help to evaluate the retrievals of aerosol vertical structure from space-borne lidars, and would be useful to check the atmospheric correction of satellite ocean-color imagery and develop improved correction algorithms in the presence of absorbing aerosols.
Iterative Procedures for Missing Values in Experiments

Healy and Westmacott (1956) gave an iterative missing value procedure in which a simple correction is subtracted from each estimated missing value at each iteration. Experience has however shown that it is advantageous to replace the simple correction by a multiple m of it, m > 1. The multiplier m = n/E, where n is the number of units and E the number of error degrees of freedom in the absence of missing values, gives an exact solution in one step for most factorial analyses with one missing value; for other analyses, also, convergence is faster with m = n/E than with m = 1. The algebra of the general iterative procedure is given. Criteria for convergence are discussed.
Looking at bulk-heterojunction organic photovoltaics from two viewpoints: morphology development and charge transfer

In this paper, a combined experimental and theoretical study was performed on the P3HT:PCBM system used in organic photovoltaics. Fast-scanning differential chip calorimetry, an advanced thermal analysis technique, was used to simulate the thermal annealing used in the production of P3HT:PCBM solar cells to increase the degree of crystallinity, and thus efficiency. The main advantage of this technique for stuying the thermal annealing are the very high rates of heating and cooling that can be used, up to 106 K.s-1, permitting one to avoid crystallization during cooling. In parallel with the experimental study, the charge transfer between donor (P3HT) and acceptor (PCBM) at the interface is studied using density functional theory. The charge separation between donor and acceptor present for the ground state of the combined system, diminished when the first triplet was investigated. This was explained by the formation of a bridge state, formed after population by the LUMO with one electron. Such a molecular orbital can facilitate charge transfer.
Primal-Dual TV Reconstruction in Refractive Deflectometry

CONCLUSIONS • CP method allows us to solve (1) even with the presence ofW. •W modifies the impact of the noise. • LS method degrades rapidly when increasing noise level as the diagonal operator W increases its impact on low frequencies. • As Fourier Transform of Radon Projections are provided in radial coordinates, further development must be done to find its correspondence in Cartesian coordinates. REFERENCES
Approximate entropy as a nonlinear feature parameter for fault diagnosis in rotating machinery

Feature extraction is always a crucial step for fault diagnosis in rotating machinery. When faults occur, rotating machinery always manifests nonlinear dynamic behavior. It is necessary to extract the nonlinear features hidden in the vibration signal for more accurate diagnosis. Approximate entropy (ApEn) is the nonlinear parameter identification method for measuring the irregularity of the stochastic signal or the stochastic process. In this paper, ApEn is used as a nonlinear feature parameter to measure the irregularity of the vibration signals for fault diagnosis in rotating machinery. Four typical faults are considered, which are imbalance, misalignment, shaft rubbing and oil whirl. To improve the distinguishability of the ApEn values of the different faults, the empirical mode decomposition (EMD) method is used to remove the basic frequency component from the signals of the various faults. The experimental study results demonstrate that EMD can separate the basic frequency component from the original signals satisfactorily. After removing the basic frequency component, the distinguishability of the ApEn values of the residual signals is improved greatly. The proposed strategy for the ApEn calculation of the various faults is proved effective. In addition, the simulation study is presented to investigate some characteristics of ApEn, which will benefit better application of ApEn in the field of fault diagnosis.
Extracting geometric primitives

Abstract Extracting geometric primitives is an important task in model-based computer vision. The Hough transform is the most common method of extracting geometric primitives. Recently, methods derived from the field of robust statistics have been used for this purpose. We show that extracting a single geometric primitive is equivalent to finding the optimum value of a cost function which has potentially many local minima. Besides providing a unifying way of understanding different primitive extraction algorithms, this model also shows that for efficient extraction the true global minimum must be found with as few evaluations of the cost function as possible. In order to extract a single geometric primitive we choose a number of minimal subsets randomly from the geometric data. The cost function is evaluated for each of these, and the primitive defined by the subset with the best value of the cost function is extracted from the geometric data. To extract multiple primitives, this process is repeated on the geometric data that do not belong to the primitive. The resulting extraction algorithm can be used with a wide variety of geometric primitives and geometric data. It is easily parallelized, and we describe some possible implementations on a variety of parallel architectures. We make a detailed comparison with the Hough transform and show that it has a number of advantages over this classic technique.
A Dispersion-Corrected Finite Element Model for Simulation of Distant Tsunamis

A dispersion-corrected finite element model is developed to simulate the propagation of distant tsunamis over a slowly varying topography. A linear Boussinesq wave equation is solved to consider the dispersion effect of tsunami waves by employing a linear triangular mesh and an explicit time integration scheme. The numerical dispersion associated with the explicit scheme is minimized by adjusting both the mesh size and the dispersion-correction parameter. In order to test the present model, numerical simulations for the propagation of an initial Gaussian hump over various constant depths are conducted, and the numerical results are compared with analytical solutions of the linear Boussinesq equations. The present model is also tested for the propagation of tsunamis over a submerged circular shoal and the numerical results are compared with the numerical solutions obtained using another Boussinesq model. The present model is shown to be efficient and considerably accurate.
Dynamical Collapse in W51 Massive Cores: CS (3-2) and CH3CN Observations

We present interferometric observations of the W51 region at 2 mm with the Nobeyama Millimeter Array. The 320 MHz band centered at 147 GHz covers transitions of the CS (3-2), CH3CN (8-7), H35α, CH3OCH3 (7-6) and (6-6), and HCOOCH3 (12-11), as well as the 2 mm continuum. Toward two dense cores, W51e2 and W51e8, spectroscopic signatures of cloud collapse are present in all the molecular lines observed. Line asymmetries increase systematically toward transitions of larger optical depths, consistent with expected signatures of a centrally condensed infalling cloud. Furthermore, the disparity between the blueshifted and the redshifted emission of the CS line is enhanced when the line is synthesized at higher angular resolution. Given that the continuum source is embedded in the core, we are able to locate the emitting gas of the blueshifted emission on the rear side and the gas of the redshifted emission on the front side of the central star. The new observations confirm our infall interpretations regarding the e2 and e8 cores based on the NH3 data. The compact CH3CN emission allows us to identify velocity gradients in the e2 and e8 cores. The gradient in the e2 core is consistent with the spin-up motions proposed by Zhang & Ho in 1997. CH3CN emission reveals hot components in the W51e2, W51e8, and W51-North:dust cores. The rotational temperature in each core is greater than 100 K. In W51-North, we detected a dust peak coincident with the peak of the dense molecular core. There is no 3.6 cm continuum detected at a level of less than 1 mJy. Although H2O and OH masers in the neighborhood indicate outflow activities, high-velocity gas is not apparent in the CS (3-2). This source may represent an extremely early evolutionary stage: the phase of massive protostars.
Revisiting Vacillations in Shallow-Water Models of the Stratosphere Using Potential-Vorticity-Based Numerical Algorithms

AbstractPolar vortex vacillations are investigated using long-term simulations of potential-vorticity (PV)-based shallow-water (SW) models for the stratosphere. In the models examined, mechanical forcing is applied through a time-independent topography mimicking tropospheric excitation of the stratosphere. Thermal forcing is applied through a linear relaxation of the mass field to a time-independent equilibrium state mimicking the radiative relaxation taking place in the stratosphere. The SW equations in the PV, velocity divergence, and acceleration divergence representation are solved for a range of resolutions using the “diabatic contour-advective semi-Lagrangian” (DCASL) algorithm and a standard pure semi-Lagrangian (SL) algorithm. Using very different numerical algorithms enables the determination of the degree of numerical sensitivity and the properties of the vacillations with much greater accuracy than in previous related studies.The focus here is on the Lagrangian or material evolution of the pola.
The spectral extension property and extension of multiplicative linear functionals

Let Wv be a commutative Banach algebra. Denote the spectral radius of an element a in v by p, (a). An extension of v is a Banach algebra -7 such that v is algebraically, but not necessarily continuously, embedded in w . We view v as a subalgebra of g . If g is an extension of v then Sp_ (a)U{O} C Sp, (a)U{O} and thus p_ (a) < p,, (a), Va E v . Let us say that v has the spectral extension property if p_ (a) = p-, (a) for all a E v and all extensions g of X , that sV has the strong spectral extension property if Sp. (a) U {O} = SpQ,(a) U {O} for all a E v and all extensions g of W , and that _v has the multiplicative Hahn-Banach property if every multiplicative linear functional X on v has a multiplicative linear extension to every commutative extension ' of v . We give characterizations of these properties for semisimple commutative Banach algebras.
Alternative to colour feature classification using colour contrast ocurrence matrix

Texture discrimination was the second more important task studied after colour perception and characterization. Nevertheless, colour texture assessment and characterization was few studied and no vector processing was proposed to assess this important visual information. In this work we show the construction of a new vector that integrates fully the information of texture and color. This vector is based on Julesz psico-physics conjectures and the Haralick cooccurrence matrix. A colour texture image in the CIEL*a* b* colour space is characterizing in a 3D matrix, from which it is possible to visually some variations in chromaticity. The performance of this vector had evaluated in tasks of classification in front of other developments that mix the texture and colour information. The colour contrast occurrence matrix (C2O) has the best classification rates in three of the four image database evaluated as OUTEX, VISTEX, STEX and ALOT. C2O texture classification was evaluated in front of co-occurrence matrix (GLMC), run-length matrix (RLM) and local binary patterns (LBP) approaches.
Tailored light fields: nondiffracting and self-similar beams for optical structuring and organization

Microscopic structuring and organization of matter utilizing optically induced forces has a high potential to enable novel material properties and photonic features. We briefly review two promising classes of light fields that combine a high degree of order with exciting propagation properties, and demonstrate applications in optical micromanipulation and the creation of refractive index gratings in photorefractive materials. While the class of nondiffracting beams allows for axially extended optical potential landscapes and corresponding structuring of the refractive index, the class of selfsimilar beams offers continuous diffraction during propagation that can be exploited for two- and three-dimensional optical organization. We demonstrate how the transverse organization of the structured light fields can be transferred to corresponding structuring of bulk material and colloidal systems.
Preimpact characterization of Comet P/Shoemaker-Levy 9

Abstract At McDonald Observatory, we have undertaken a major program of observations of Comet P/Shoemaker-Levy 9 in order to characterize the dynamics and physical make-up of the fragments prior to their disappearance in July 1994 when they collide with Jupiter. Observations have included astrometry, photometry, and spectroscopy. Our astrometric observations have been important for deriving accurate orbits for the individual fragments. With the photometry, we have derived (B-V) and (V-R) colors for a number of fragments. We show that they are slightly redder than the Sun in (B-V) and similar to the Sun in (V-R); they may show differences in colors for the individual fragments. We detected no gas with our spectroscopic observations and have derived sensitive upper limits on the quantity of gas. Our observations are consistent with the parent being a comet, as classified, but cannot rule out certain types of asteroids as progenitors.
SMALL GEOPOSITIONING ERROR FROM LARGE SETS OF IMAGERY

The geolocation error resulting from least-squares Multi-Image Geopositioning (MIG) with n images is shown theoretically and empirically to decrease as 1 / √ n , using a synthetically augmented set of 1000 overlapping Worldview-1 images. A novel heuristic approach called ‘Hourglassing’ is introduced, which requires no understanding of apriori covariance, but implicitly infers uncertainty from the distribution of the ray bundle itself. Hourglassing geolocation and error estimation is compared to MIG using the 1000-image testbed.
Gamma-ray bursts from stellar mass accretion disks around black holes

A cosmological model for gamma-ray bursts is explored in which the radiation is produced as a broadly beamed pair fireball along the rotation axis of an accreting black hole. The black hole may be a consequence of neutron star merger or neutron star-black hole merger, but for long complex bursts, it is more likely to come from the collapse of a single Wolf-Rayet star endowed with rotation ('failed' Type Ib supernova). The disk is geometrically thick and typically has a mass inside 100 km of several tenths of a solar mass. In the failed supernova case, the disk is fed for a longer period of time by the collapsing star. At its inner edge the disk is thick to its own neutrino emission and evolves on a viscous time scale of several seconds. In a region roughly 30 km across, interior to the accretion disk and along its axis of rotation, a pair fireball is generated by neutrino annihilation and electron-neutrino scattering which deposit approximately 10 exp 50 ergs/s.
Phascope: Fine-Grained, Fast, Flexible Motion Profiling based on Phase Offset in Acoustic OFDM Signal

Acoustic Doppler shift estimation is a cost-effective way to implement Human-Computer Interaction applications across existing smart devices such as smart phones and smart spekaers. However, due to the inherent uncertainty principle in the traditional time-frequency analysis, it remains challenging to profile motions accurately and timely. In this paper, phase offset in acoustic OFDM signal is leveraged for developing Phascope, a fine-grained, fast and flexible motion profiling scheme. We evaluate Phascope using simulation and experiment on COTS devices. Sub-millisecond response time is achieved for Phascope in our experiment. Besides, with optimal subcarrier selection and SNR of 30 dB over all subcarriers, Phascope can estimate motion speed of 0.1 m/s with 6.75% root-mean-square error (RMSE) compared to optimized FFT method.
Influence of Penning effects on high-pressure discharge in the plasma display panel

The influence of the Penning effects on the high-pressure discharge in a neon–xenon mixed gas was investigated in connection with applications to the plasma display panel. A theoretical model of the breakdown voltage in a mixed gas is developed, based on the Townsend criteria. The breakdown temperature Tb and voltage Vb are obtained in terms of the gas mixture ratio. As an example, electrical breakdown properties in neon gas mixed with xenon are investigated. It is shown that the electron breakdown temperature Tb decreases monotonically as the xenon mole fraction χ increases. The Penning effects modify the electron temperature significantly, particularly in the range of a small mole fraction. A preliminary experiment using the plasma display panel is carried out to verify some of the theoretical models. The Paschen curves of the breakdown voltage are experimentally obtained in terms of the pressure parameter (pd) and the xenon mole fraction. It is shown that the breakdown voltage is reduced significantly .
Global particle-in-cell simulations of fast-particle effects on shear Alfvén waves

This paper reports self-consistent global linear gyrokinetic particle-in-cell simulations of shear Alfven waves destabilized by fast particles in tokamak geometry. Resonant excitation of toroidal Alfven eigenmodes by fast particles and their transition to energetic particle modes (when the fast-particle drive is large enough) has been observed in the simulations.
Study of the structural evolution within polystyrene and polystyrene-gold composite colloidal crystals by atomic force microscopy and scanning electron microscopy

The simultaneous presence of hexagonal and quadratic arrangements of polystyrene microspheres in the top layers of polystyrene and gold-polystyrene composite colloidal crystals has been evidenced by both atomic force microscopy and scanning electron microscopy. It is thought that the formation of layers with the two different packing modes is in agreement with the phase transformations found in systems with confined geometries. The results of this study are relevant to the fabrication of high quality photonic crystals.
Modelling the oxidation of 15 VOCs to track yields of hydrogen

A box model simulating tropospheric conditions was used to trace the oxidation pathways of 15 volatile organic compounds (VOCs). Yields of hydrogen were calculated over the duration of the model simulation and conversion factors to hydrogen were determined for individual VOCs at various simulated levels of NOx. These were used to produce global budget estimates. Oxidation of non‐methane VOCs (NMVOCs) formed 20.1 Tg H2/year, while the overall VOC oxidation accounted for 45.3 Tg H2/year. To maintain the oxidation balance within global chemical transport models which do not include a detailed suite of NMVOC it may be vital to include this hydrogen source from NMVOC oxidation. Copyright © 2010 Royal Meteorological Society
Calibration of optical cantilever deflection readers

Because of its ultrahigh sensitivity, the optical lever detection method similar to that used in the atomic force microscope (AFM) has been widely employed as a standard technique for measuring microcantilever deflection. Along with the increasing interest in using the microcantilever as a sensing platform, there is also a requirement for a reliable calibration technique. Many researchers have used the concept of optical lever detection to construct microcantilever deflection readout instruments for chemical, physical, and biological detection. However, without an AFM piezo z scanner, it is very difficult to precisely calibrate these instruments. Here, we present a step-by-step method to conveniently calibrate an instrument using commercially available piezoresistive cantilevers. The experimental results closely match the theoretical calculation. Following this procedure, one can easily calibrate any optical cantilever deflection detection system with high reproducibility, precision, and reliability. A de.
The Index of a Pair of Projections

We discuss pairs of self-adjoint projections with P − Q ∈ J_(2n + 1), the trace ideal, and prove that for m ≥ n, tr(P − Q)^(2m + 1) = tr(P − Q)^(2n + 1) = dim(Ker Q ∩ Ran P) − dim(Ker P ∩ Ran Q) is an integer. We also prove that there exists a unitary V interchanging P and Q if and only if this integer is 0.
Broadband planar Luneburg lens based on complementary metamaterials

A two-dimensional broadband low-loss Luneburg lens has been designed based on the complementary metamaterials. The complementary I-shaped unit has been chosen as the basic cell due to its high resonant frequency, whose effective constitutive parameters are nearly constants at low frequencies. Numerical simulations are performed to determine the relationship between the unit geometry and the refraction index. The experimental sample has been fabricated and tested in a two-dimensional near-field microwave scanning apparatus, where the experiment and simulation results agree very well. Good focusing ability has been shown from the measured field distributions of the designed planar Luneburg lens.