Miracle-dz/UniFAR-FTUs huggingface dataset:
Vortex shedding from spheres

Vortex shedding from spheres has been studied in the Reynolds number range 400 < Re < 5 × 106. At low Reynolds numbers, i.e. up to Re = 3 × 103, the values of the Strouhal number as a function of Reynolds number measured by Möller (1938) have been confirmed using water flow. The lower critical Reynolds number, first reported by Cometta (1957), was found to be Re = 6 × 103. Here a discontinuity in the relationship between the Strouhal and Reynolds numbers is obvious. From Re = 6 × 103 to Re = 3 × 105 strong periodic fluctuations in the wake flow were observed. Beyond the upper critical Reynolds number (Re = 3.7 × 105) periodic vortex shedding could not be detected by the present measurement techniques. The hot-wire measurements indicate that the signals recorded simultaneously at different positions on the 75° circle (normal to the flow) show a phase shift. Thus it appears that the vortex separation point rotates around the sphere. An attempt is made to interpret this experimental evidence.
Long-Range Forecast Trajectories of Volcanic Ash from Redoubt Ash from Redoubt Volcano Eruptions

The Redoubt Volcano in Alaska began a series of eruptions on 14 December 1989. Volcanic ash was often reported to reach heights where, as it moved with the upper-level flow, it could affect aircraft operations thousands of km from the eruption. In an agreement between the National Oceanic and Atmospheric Administration (NOAA) and the Federal Aviation Administration, the NOAA Air Resources Laboratory (ARL) was assigned responsibility for providing long-range forecast trajectories of volcanic ash during a volcanic hazards alert. An ARL immediate-response program was implemented for the Redoubt Volcano eruptions. The response products, in the form of tables, maps, and written messages are discussed. An evaluation of the forecast trajectories is included. The evaluation is based on after-the-fact trajectories from analyzed wind fields and on actual ash cloud sightings. For 90% of the cases verified at 300 mb, the average forecast error was less than 25% of the downwind distance from the eruption (this often i.
Random shearing by zonal flows and transport reduction

The physics of random shearing by zonal flows and the consequent reduction of scalar field transport are studied. In contrast to mean shear flows, zonal flows have a finite autocorrelation time and can exhibit complex spatial structure. A random zonal flow with a finite correlation time τZF decorrelates two nearby fluid elements less efficiently than a mean shear flow does. The decorrelation time is τD=(τη/τZFΩrms2)1/2 (τη is the turbulent scattering time, and Ωrms is the rms shear), leading to larger scalar field amplitude with a slightly different scaling (∝τD/Ωrms), as compared to the case of coherent shearing. In the strong shear limit, the flux scales as ∝Ωrms−1.
Perturbation analysis of acoustic wave scattering at rough solid-solid interfaces

We apply a boundary perturbation approach to model the scattering of acoustic waves at rough solid-solid interfaces. This method incorporates mode conversion and allows straightforward separation of specular and diffuse components, the relative fractions of which play an important role in determining thermal boundary resistance and the performance of acoustic phonon devices. The effect of acoustic impedance mismatch on the distribution of scattered waves is investigated, as well as the coupling to interface modes.
Large-scale stochastic hereditary systems under Markovian structural perturbations. Part III. Qualitative analysis

In this final part of the work, the convergence and stability analysis of large-scale stochastic hereditary systems under random structural perturbations is investigated. This is achieved through the development and the utilization of comparison theorems in the context of vector Lyapunov-like functions and decomposition-aggregation method. The byproduct of the investigation suggests that the qualitative properties of decoupled stochastic hereditary subsystems under random structural perturbations are preserved, as long as the self-inhibitory effects of subsystems are larger than cross-interaction effects of the subsystems. Again, it is shown that these properties are affected by hereditary and random structural perturbations effects. It is further shown that the mathematical conditions are algebraically simple, and are robust to the parametric changes. Moreover, the work generates a concept of block quasimonotone nondecreasing property that is useful for the investigation of hierarchic systems. These results are further extended to the integrodifferential equations of Fredholm type.
Second-harmonic performance of a-axis-oriented ZnO nanolayers on sapphire substrates

We report on the nonlinear optical performance of sub-μm ZnO films grown by metal organic aerosol deposition on r-plane sapphire substrates. These films display scale-like nanocrystalline structures. Layers of different crystallite sizes and shapes are studied. Both, x-ray diffractometry and the characteristic angular and polarization dependence of the second harmonic generation, indicate a strongly uniform a-axis orientation of the crystallites. Using 35-fs Ti:sapphire laser pulses, we demonstrate much higher conversion efficiencies for ZnO layers than previously reported. The robust performance at normal incidence makes this device suitable for advanced pulse characterization techniques.
Parameter identification in nonlocal nonlinear evolution equations

We develop an approximation framework for identifying parameters in a general class of nonautonomous, nonlocal and nonlinear evolution equations. After establishing existence and uniqueness of solutions, we present a convergence theory for Galerkin approximations to inverse problems involving these equations. Our approach relies on the theory of maximal monotone operators in Banach spaces. An application to a nonautonomous nonlinear integral equation arising in heat flow is also discussed.
Some unsolved challenges in the computer simulation of condensed matter systems

Statistical mechanics of solids and fluids attempts to explain macroscopic properties of matter in terms of effective interaction potentials between atoms or molecules. In recent decades, the most widely used tools for this task have become the computer-simulation methods, such as Monte Carlo sampling or molecular dynamics. Although these methods are astonishingly successful, some severe difficulties still hinder the application of these methods to several of the most interesting problems in condensed-matter physics (such as the physics of the glass transition, the modelling of the dynamics of flexible macromolecules in dense polymer melts, the study of microscopic models for the mechanism of high-temperature superconductivity, etc). After a brief explanation of the physics one wishes to describe, the difficulties that one encounters with such a computational physics approach are outlined, and finally speculations on whether and how these challenges might be solved are mentioned.
SL2(C)-CHARACTER VARIETY OF A HYPERBOLIC LINK AND REGULATOR

In this paper, we study the SL2(C) character variety of a hyperbolic link in S 3 . We analyze a special smooth projective variety Y h arising from some 1-dimensional irreducible slices on the character variety. We prove that a natural symbol obtained from these 1-dimensional slices is a torsion in K2(C(Y h )). By using the regulator map from K2 to the corresponding Deligne cohomology, we get some variation formulae on some Zariski open subset of Y h . From this we give some discussions on a possible parametrized volume conjecture for both hyperbolic links and knots.
Emergency transshipment in decentralized dealer networks: When to send and accept transshipment requests

While there has been significant previous literature on inventory transshipment, most research has focused on the dealers' demand filling decision (when to fill transshipment requests from other dealers), ignoring the requesting decision (when to send transshipment requests to other dealers). In this paper we develop optimal inventory transshipment policies that incorporate both types of decisions. We consider a decentralized system in which the dealers are independent of the manufacturer and of each other. We first study a network consisting of a very large number of dealers. We prove that the optimal inventory and transshipment decisions for an individual dealer are controlled by threshold rationing and requesting levels. Then, in order to study the impact of transshipment among independent dealers in a smaller dealer network, we consider a decentralized two‐dealer network and use a game theoretic approach to characterize the equilibrium inventory strategies of the individual dealers. An extensive numerical study highlights the impact of the requesting decision on the dealers' equilibrium behavior in a decentralized setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
The noncompact binary X-ray source 4U 2129+47

The 5.2 hr X-ray binary 4U 2129+47 was observed for a full orbital cycle using the imaging proportional counter detector and the monitor proportional counter detector aboard the Einstein Observatory, as well as a 0.9 m reflector for 5 hrs continuous optical photometry. The X-ray and optical light curves, the X-ray spectrum, and the times of optical and X-ray minimum were determined. The shape of the 5.2 hr X-ray light curve is independent of energy. A partial X-ray eclipse occurred which was centered on the time of optical minimum and which lasted 20 percent of the orbital period. During this interval the X-ray intensity varied smoothly by a factor of three, and the light curve was symmetric relative to the time of minimum. These findings argue that the X-ray emitting region is extended and highly ionized. A model is presented in which an accretion disk corona scatters radiation from a central accreting neutron star.
A cooled UHF receiving system for radio astronomy

The 250 ft (76 m) Lovell radio telescope at Jodrell Bank has been a familiar feature on the Cheshire landscape for nearly forty years and throughout this time it has been a scientific instrument of tremendous value in radio astronomy research. This includes spectral line observations (allowing scientists to investigate the chemistry of the Universe), mapping of distant objects (up to the edge of the observable Universe) as part of the MERLIN network, and observation of pulsars, rapidly rotating neutron stars which emit sharp beams of radiation much like stellar `lighthouses'. Receiver sensitivity is of paramount importance in this work, as the `signals' of interest are weak in the extreme. In order to achieve the best possible sensitivity engineers at Jodrell Bank are using closed-cycle helium refrigerators to cool receivers to around 15 K. Hitherto such cooling techniques have been restricted to receivers operating at L-band and above. Pressure from astronomers, particularly those searching for pulsars, for greater sensitivity has led to the development of a dual frequency UHF cooled receiver front-end covering the radio astronomy bands nominally at 408 MHz and 610 MHz.
On-line range images registration with GPGPU

This paper concerns implementation of algorithms in the two important aspects of modern 3D data processing: data registration and segmentation. Solution proposed for the first topic is based on the 3D space decomposition, while the latter on image processing and local neighbourhood search. Data processing is implemented by using NVIDIA compute unified device architecture (NIVIDIA CUDA) parallel computation. The result of the segmentation is a coloured map where different colours correspond to different objects, such as walls, floor and stairs. The research is related to the problem of collecting 3D data with a RGB-D camera mounted on a rotated head, to be used in mobile robot applications. Performance of the data registration algorithm is aimed for on-line processing. The iterative closest point (ICP) approach is chosen as a registration method. Computations are based on the parallel fast nearest neighbour search. This procedure decomposes 3D space into cubic buckets and, therefore, the time of the matching is deterministic. First technique of the data segmentation uses accele-rometers integrated with a RGB-D sensor to obtain rotation compensation and image processing method for defining pre-requisites of the known categories. The second technique uses the adapted nearest neighbour search procedure for obtaining normal vectors for each range point.
Reconstruction of two-dimensional buried objects by a differential evolution method

The application of a global optimization procedure to the detection of buried inhomogeneities is studied in the present paper. The electromagnetic inverse problem is recast as a global optimization problem and iteratively solved by a differential evolution method. The approach is applied to two-dimensional configurations. The paper provides the mathematical formulation of the method together with a discussion on the application of the stochastic optimization procedure. Finally, the results of some numerical simulations are reported.
Refinable function vectors

Refinable function vectors are usually given in the form of an infinite product of their refinement (matrix) masks in the frequency domain and approximated by a cascade algorithm in both time and frequency domains. We provide necessary and sufficient conditions for the convergence of the cascade algorithm. We also give necessary and sufficient conditions for the stability and orthonormality of refinable function vectors in terms of their refinement matrix masks. Regularity of function vectors gives smoothness orders in the time domain and decay rates at infinity in the frequency domain. Regularity criteria are established in terms of the vanishing moment order of the matrix mask.
Magneto‐optic current sensing with birefringent fibers

To measure currents on high‐voltage lines, the Faraday rotation is used in a single‐mode optical fiber encircling the conductor. Disturbing linear birefringence is suppressed by twisting the fiber. With ∼10 m of fiber, coiled with a 3‐cm radius, we obtain 0.25 mrad/A polarization rotation, permitting measurement of currents of 0.2–2000 A.
Imaging deep and clear in thick inhomogeneous samples

Acquisition of images deep inside large samples is one of the most demanded improvements that current biology applications ask for. Absorption, scattering and optical aberrations are the main difficulties encountered in these types of samples. Adaptive optics has been imported form astronomy to deal with the optical aberrations induced by the sample. Nonlinear microscopy and SPIM have been proposed as interesting options to image deep into a sample. Particularly, light-sheet microscopy, due to its low photo bleaching properties, opens new opportunities to obtain information for example in long time lapses for large 3D imaging. In this work, we perform an overview of the application of adaptive optics to the fluorescence microscopy in linear and non-linear modalities. Then we will focus in the light-sheet microscopy architecture of two orthogonal optical paths which implies new requirements in terms of optical correction. We will see the different issues that appear in light-sheet microscopy particularly when imaging large and non-flat samples. Finally, we will study the problem of the isoplanetic patches.
Random variate generation for the digamma and trigamma distributions

We derive uniformly fast random variate generators for Sibuya's digamma and trigamma families. Some of these generators are based upon the close resemblance between these distributions and selected generalized hypergeometric distributions. The generators can also be used for the discrete stable distribution, the Yule distribution, Mizutani's distribution and the Waring distribution.
The effect of bubbles on the wall drag in a turbulent channel flow

The effect of a few relatively large bubbles injected near the walls on the wall drag in the “minimum turbulent channel” is examined by direct numerical simulations. A front-tracking/finite-volume method is used to fully resolve all flow scales including the bubbles and the flow around them. The Reynolds number, using the friction velocity and the channel half-height, is 135 and the bubbles are 54 wall units in diameter. The results show that deformable bubbles can lead to significant reduction of the wall drag by suppression of streamwise vorticity. Less deformable bubbles, on the other hand, are slowed down by the viscous sublayer and lead to a large increase in drag.
False activation of the cardiac catheterization laboratory: The price to pay for shorter treatment delay

Introduction In patients with acute ST elevation myocardial ischemia (STEMI), national efforts have focused on reducing door-to-balloon (D2B) times for primary percutaneous coronary intervention (PCI). This emphasis on time-to-treatment may increase the rate of inappropriate cardiac catheterization laboratory (CCL) activations and unnecessary healthcare utilization. To achieve lower D2B times, community hospitals and EMS systems have enabled emergency medical technicians (EMTs) and emergency department (ED) physicians to activate the CCLs without immediately consulting a cardiologist. Objective The purpose of this study is to determine the rate and main causes of inappropriate activation of the CCL which will aid in finding solutions to reduce this occurrence. Method This is a retrospective study, based on an electronic medical system review of all inappropriate CCL activation who presented to Providence Hospital and Medical Centers (PHMC) in Michigan, from January 2015 to July 2016. Results The CCL was activated 375 times for suspected STEMI. The false STEMI activation was identified in 47 patients which represents 12.5% of total CCL activation. The vast majority of this false activation was due to non-diagnostic electrocardiogram (ECG) that did not meet the STEMI criteria. Conclusion The subjective interpretation of the ECG by EMTs and ED physicians tend to show a wide variability, which may lead to higher-than-anticipated false activation rates of up to 36% in one study. Some studies had reported that up to 72% of inappropriate activations were caused by ECG misinterpretations. These false activations have ramifications that lead to both clinical and financial costs.
Dirac-Fock One-Centre Calculations Part 8. The 1Σ States of ScH, YH, LaH, AcH, TmH, LuH and LrH

Dirac-Fock one-centre expansion calculations are reported for the title molecules. The calculated bond lengths of YH, LaH and LuH are about 5% above experiment. The calculated force constants for YH and LuH are in excellent agreement with experiment. The lanthanoid contraction from LaH to LuH is calculated to be 21 pm (exp. 19) and the corresponding actinoid contraction of bond lengths from AcH to LrH 33 pm. The effective radius of Lr is only 3 pm larger than that of Lu but Ac is 15 pm larger than La. Very small relativistic effects on bond lengths and strengths are found. Trends in orbital energies and hybridizations across the Periodic Table are discussed, including an SCF lanthanoid expansion of the 5d shell from La to Lu. The 4d orbital energy of Y is anomalously high. This trend is termed primogenic repulsion' by the 3d shell.
Measurement of three-dimensional displacement fields and shape using electronic speckle photography

A stereoscopic electronic speckle photography system is presented that detects 3-D displacement fields or object shape with subpixel accuracy. The system is all electronic, and data are stored, results are presented, and calculations are performed in a PC computer. The expected standard deviation of measurements of small deformations are about 0.001% of the object size for in-plane measurements and about 0.006% of the object size for the out-of-plane component, when white light speckles are used.
On semiparametric transformation cure models

A general class of semiparametric transformation cure models is studied for the analysis of survival data with long-term survivors. It combines a logistic regression for the probability of event occurrence with the class of transformation models for the time of occurrence. Included as special cases are the proportional hazards cure model (Farewell, 1982s Kuk & Chen, 1992s Sy & Taylor, 2000s Peng & Dear, 2000) and the proportional odds cure model. Generalised estimating equations are proposed for parameter estimation. It is shown that the resulting estimators are asymptotically normal, with variance-covariance matrix that has a closed form and can be consistently estimated by the usual plug-in method. Simulation studies show that the proposed approach is appropriate for practical use. An application to data from a breast cancer study is given to illustrate the methodology. Copyright Biometrika Trust 2004, Oxford University Press.
Effects of Temperature on the Emulsification in Surfactant-Water-Oil Systems

The effect of temperature on the emulsification has been investigated by discontinuous molecular dynamic simulation. When a large oil drop is put in water, on one hand the mixing entropy makes it divide into small oil drops; on the other hand the interactions among particles drives the small oil drops fowards aggregation. The evolution of the mean size of oil drops obeys the exponential delay law. There exist an active temperature, at which, the addition of surfactants has obvious effect on the emulsification. The surfactants with low HLB value (e.g. H1T3) make the dispersity of emulsion decrease, and the surfactants with high HLB value (e.g. H2T2 and H3T1) make a contribution to increase the dispersity of emulsion.
Nonvolatile resistive switching memory utilizing gold nanocrystals embedded in zirconium oxide

Resistive switching characteristics of ZrO2 films containing gold nanocrystals (nc-Au) are investigated for nonvolatile memory applications. The sandwiched top electrode/ZrO2 (with nc-Au embedded)/n+ Si structure exhibits two stable resistance states (high-resistance state and low-resistance state). By applying proper voltage bias, resistive switching from one state to the other state can be achieved. This resistive switching behavior is reproducible and the ratio between the high and low resistances can be as high as two orders. The intentionally introduced nc-Au in ZrO2 films can improve the device yield greatly. ZrO2 films with gold nanocrystals embedded are promising to be used in the nonvolatile resistive switching memory devices.
Ray optics model and numerical computations for the radiation pressure micromotor

In this letter, the spinning of a micron sized radiation pressure motor is analyzed using geometrical optics to model for interactions of a highly focused laser beam with the medium discontinuities. The motor’s direction of rotation and dependence on focused beam parameters, predicted from the computations, are in agreement with previously published experimental results. The motor can be made to rotate in the clockwise or counterclockwise direction by changing the ambient medium only.
Microstructural origins of localization in InGaN quantum wells

The startling success of GaN-based light emitting diodes despite the high density of dislocations found in typical heteroepitaxial material has been attributed to localization of carriers at non-uniformities in the quantum wells (QWs) which form the active region of such devices. Here, we review the different possible structures within the QWs which could act as localization sites, at length scales ranging from the atomic to the tens of nanometre range. In some QWs several localization mechanisms could be operational, but the challenge remains to optimize the QWs' structure to achieve improved quantum efficiencies, particularly at high excitation powers.