Miracle-dz/UniFAR-FTUs huggingface dataset:
A Semiparametric Two-Factor Term Structure Model

This article proposes a semiparametric two-factor term structure model based on a consol rate and the spread between a short rate and the consol rate. The diffusion functions in both the consol rate and spread processes are nonparametrically specified so that the model allows for maximal flexibility of diffusion functions in fitting into data. The drift function of the spread process is specified as a mean-reverting function, while the drift function of the consol rate process is left unrestricted. A nonparametric procedure is developed for estimating the diffusion functions. The asymptotic biases of the nonparametric estimators are quantified when the step of discretization is fixed, while the asymptotic distributions of the nonparametric estimators are derived when the step of discretization tends to zero. The pricing and hedging performances of the model are evaluated in a simulated economic environment. Results show that the model performs quite well in the simulated economy. Copyright 2006, Oxford University Press.
A detection of the evolutionary time scale of the DA white dwarf G117 - B15A with the Whole Earth Telescope

The time rate of change for the main pulsation period of the 13,000 K DA white dwarf G117 - B15A has been detected using the Whole Earth Telescope (WET). The observed rate of period change, P(dot) = (12.0 + or - 3.5) x 10 to the -15th s/s, is somewhat larger than the published theoretical calculations of the rate of period change due to cooling, based on carbon core white dwarf models. Other effects that could contribute to the observed rate of period change are discussed.
Deep levels and persistent photoconductivity in GaN thin films

Photocurrent decay in GaN thin films was studied in the time span from a few seconds to several days. The persistent photoconductivity (PPC) behavior was observed not only in Mg-doped p-type GaN films but also in undoped n-type GaN films. The photoconductivity spectra and the photocurrent response time were measured using a weak probe light at several times after the samples had been kept in the dark. During the relaxation, the photocurrent due to the subband-gap probe light decreased more than the photocurrent due to the UV probe light. It is suggested that metastable centers at 1.1, 1.40, and 2.04 eV above the valence band edge are responsible for the PPC behavior in Mg-doped GaN, and that Ga vacancy is the candidate for PPC effect in n-type GaN.
The dynamics and simulation of tropical cumulonimbus and squall lines

Techniques of theoretical analysis and numerical simulation are combined to produce a dynamical model of tropical cumulonimbus convection which features a close cooperation between the updraught and downdraught circulations. The cloud-scale dynamics determine the structure and transfer properties. Sub-cloud-scale transfer is unimportant. A steady-state dynamical model shows that the upshear or down-shear propagation speed, c, of a cumulonimbus cell relative to the mid-level flow is determined as a function of the convective available potential energy, CAPE, and weakly influenced by the windshear through a non-dimensional number, R, of the large-scale flow. This propagation speed is almost constant for a wide range of R, with c≃ 0.3CAPE, but only possible if R ≳ 2.8 (small shear). This contrasts with a previous result for another regime of convection, obtained by Moncrieff and Green (1972), if R ⩽ 1 (high shear). The transfer of momentum is distinctive and of large magnitude. The initiation and growth of the convective circulation represent an essentially nonlinear, finite-amplitude process, whose properties are closely related to the wind profile in the tropical atmosphere. The numerical simulations attain a quasi-steady state of a complex, three dimensional nature, basic features of which can be represented in terms of the steady-state analysis. Moreover, the outflow of the downdraught air is closely related to the attainment of a steady circulation and suggests a mechanism both for the maintenance and the eventual breakdown of the convective regime.
Vibronic properties of the F + absorption band in calcium oxide

The shape and first four moments of the F+ absorption band in CaO have been studied as a function of temperature between 4.2 K and 300 K. Analysis of these results shows that the properties of the band can be accounted for very well in terms of Jahn-Teller coupling of the excited 2T1u state of the F+ centre to both Eg and T2g vibrational modes, with weaker coupling to A1g modes. The shape of the band agrees remarkably well with the calculations of O'Brien (1969). Values for the Huang-Rhys factors of S=3.3 for the Eg and T2g modes and SA=1.6 for the A1g modes are derived from a model where all modes have the same effective frequency of h(cross) omega =264 cm-1. An attempt to allow different frequencies for the various modes is only partially successful, due to the lack of detailed information on the frequency spectra of the coupled modes. Nevertheless such an analysis does suggest that the vibrational sidebands observed at frequencies of about 205 cm-1 and 302 cm-1 may be associated with A1g and (Eg, T2g) modes respectively. Measurements of the intensity, position and halfwidth of the zero phonon line as a function of temperature cannot be interpreted adequately in terms of conventional theories, unless the frequency of the interacting modes is made much smaller than the value used for the broad band.
Auditory reaction time measurements and equal-latency curves in the California sea lion (Zalophus californianus) and bottlenose dolphin (Tursiops truncatus)

Subjective equal-loudness contours are used to create weighting functions for human noise-mitigation criteria. Comparable direct measurements of subjective loudness with animal subjects are, however, difficult to conduct. Using methods similar to those used in previous mammalian studies, this study estimated subjective loudness through the measurement of response time (RT) in an auditory signal-detection task. Measurements were conducted in a sound-attenuating hut with a California sea lion and under water in a quiet pool with a bottlenose dolphin. Tonal stimuli were presented at supra- and near-threshold sound pressure levels (SPLs) using a method of constants. Median RT increased with decreasing SPL for both species across all tested frequencies. A Pieron function, which models RT as a function of SPL, was fitted to the RT-SPL curves in a nonlinear fashion. Equal-latency curves were based on the Pieron functions at each frequency. Preliminary results for the sea lion suggest that the equal-latency curve.
Numerical models for the collapse and fragmentation of centrally condensed molecular cloud cores

A new hydrodynamical code is used to investigate the gravitational collapse and fragmentation of centrally condensed molecular cloud cores. The numerical scheme is second-order accurate and uses explicit finite difference methods to advance the fluid variables on a three-dimensional Cartesian grid. Two initial power-law density profiles are considered, ρ ∞ r -1 and ρ ∞ r -2 , as well as two initial density perturbations in the azimuthal coordinate θ, ρ i = ρ(1 + a cos 2θ) where a = 0.1 and 0.5
Electrical transient analysis for disseminated mineralization

We present a short analysis of the electric transient response when a steady current in a frequency dispersive medium is interrupted. The model is a homogeneous host rock medium with a loading of spheroidally shaped metal ore grains. The latter can have a polarizable interface with the adjacent electrolyte. It is shown that the rate of decay of the electric field is more rapid for the smaller particles. Also, there is an optimum particle size if the area under the decay curve is to be maximized.
Global dynamics of a mathematical model of competition in the chemostat: general response functions and differential death rates

A model of exploitative competition of n species in a chemostat for a single, essential, nonreproducing, growth-limiting resource is considered. S. B. Hsu [SIAM J. Appl. Math., 34 (1978), pp. 760–763] applies LaSalle’s extension theorem of Lyapunov stability theory to study the asymptotic behavior of solutions in the special case that the response functions are modeled by Michaelis–Menten dynamics. G. J. Butler and G. S. K. Wolkowicz [SIAM J. Appl. Math., 45 (1985), pp. 138–151], on the other hand, allow more general response functions (including monotone and nonmonotone functions), but their analysis requires the assumption that the death rates of all the species are negligible in comparison with the washout rate, and hence can be ignored. By means of Lyapunov stability theory, the global dynamics of the model for a large class of response functions are studied, including both monotone and nonmonotone functions (though it is not as general as the class studied by Butler and Wolkowicz) and the results in .
Helium abundance anomalies and radiative forces in stellar envelopes

Detailed radiative acceleration calculations have been made for helium in stellar envelopes with log g between 3.5 And 4.5 and effective temperatures between 10,000 and 25,000 K. The observed /sup 4/He underebundances are easily explained by diffusion. Similarly, the occurrence of /sup 3/He stars in a narrow effective temperature range can be explained by diffusion. As the effective temperature increases above 18,000 K, however, the radiative acceleration does not increase substantially in the envelope. Consequently, diffusion cannot lead to /sup 4/He-rich stellar envelopes. Whenever a stellar envelope is stable enough for helium diffusion to be important, helium is underabundant in the stellar envelope. The He II convection zone will then usually disappear. The /sup 4/He-rich star may still be explained by diffusion in the atmospheric layers.After absorption of a photon, an He I atom is left in an excited state. It is shown that the contribution of the lines of He I to the effective radiative acceleration depends strongly on the collisional excitation and ionization rates of the excited states of He I. These are calculated along with the other atomic processes that influence radiative acceleration. It is so shown how detailed an atomic model need be if one ismore » to obtain accurate radiative acceleration. « less
Secondary instability in forced wavelength Görtler vortices

From an experimental study on the onset of secondary instability in forced wavelength Gortler vortices, it is found that the breakdown process of the Gortler vortices is due to the development of varicose and sinuous mode instabilities. The development of the varicose mode is characterized by the formation of horseshoe vortices that evolve downstream to form mushroom-like structures. This phenomenon is then followed by meandering of the vortices as an indication of the onset of sinuous mode instability, prior to turbulence. The spectrum analysis applied to the fluctuating velocity component shows the occurrence of peak frequency of about 150Hz, which is attributed to the fundamental secondary instability mode with its wavelength comparable to the spanwise wavelength of the primary Gortler vortices, at the location where the mushroom-like structures are clearly depicted in the mean velocity contours on the y-z plane. This confirms that the secondary instability is of the varicose type at the onset that is .
Oscillatory yielding of a colloidal star glass

We investigate the response of a well-characterized colloidal star glass to large-amplitude oscillatory stress and strain fields. By combining these measurements with dynamic time sweeps we demonstrate the importance of probing both strain- and stress-induced nonlinear rheology of such complex fluids in order to elucidate the yielding and fluidization behavior. We also show that, due to the strong time dependence, it is essential to perform dynamic time sweeps at different strain and stress amplitudes, which result in different departures of the glass cage from its quiescent quasiequilibrium structure. This allows for steady-state responses to be reached and for nonlinear oscillatory responses to be treated properly while also suggesting that yielding is a gradual process. Further, we use a recently published framework for analyzing nonlinear responses to large-amplitude oscillatory shear [Rogers et al., J. Rheol. 55, 435 (2011)], based on the analysis of the whole stress waveforms as a sequence of physic.
Metallic contamination in silicon during plasma resist stripping: a deep level transient spectroscopy study

Deep level transient spectroscopy is shown to be an easy way to investigate the defects induced in the silicon substrate during photoresist plasma etching. In this study it has been possible to discriminate between the contamination induced by the reactor environment and the contamination due to the resist itself. In particular, it is demonstrated that residual chromium and iron atoms present in the resist are responsible for a contamination of the Si substrate.
Deformation mechanisms of face-centered-cubic metal nanowires with twin boundaries

This letter addresses the issue of deformation mechanisms and mechanical tensile behavior of the twinned metal nanowires using atomistic simulations. Free surfaces are always the preferential dislocation nucleation sites in the initial inelastic deformation stage, while with further plastic deformation, twin boundary interfaces will act as sources of dislocations with the assistance of the newly formed defects. The smaller the twin boundary spacing, the higher the yielding stresses of the twinned nanowires. Twin boundaries, which serve both as obstacles to dislocation motion and dislocation sources, can lead to hardening effects and contribute to the tensile ductility. This work illustrates that the mechanical properties of metal nanowires could be controlled by tailoring internal growth twin structures. (c) 2007 American Institute of Physics.
Diffusion kinetics of formation of holographic polymer-dispersed liquid crystal display materials

The underlying physical phenomena behind the increased reflection/diffraction efficiency of holographically formed polymer-dispersed liquid crystal gratings formed from blended oligomers are investigated. Using parameters determined by in situ diffraction measurements during grating formation, a phenomenological diffusion model shows that a composition modulation in the polymer network results in blended oligomer systems. Scanning electron microscope studies reveal polymer morphologies consistent with this hypothesis.
Periodic response of fluidic networks with passive deformable features

This paper outlines the scaling parameters governing the frequency response of fluidic networks with embedded deformable features, which are subjected to periodic excitation. These parameters describe the impact of deformable feature properties on the relative importance of potential energy, kinetic energy, and viscous dissipation. They are used to identify device characteristics that produce specific frequency responses, such as low-pass, high-pass, and bandpass filters that exploit (or avoid) the effects of fluid inertia. Simulations illustrate that passive deformable diodes have little effect on the frequency response of high-pass filters comprised of elastomer features.
Comparison of Normalization Methods for Defining Copy Number Variation Using Whole-genome SNP Genotyping Data

Abstract Precise and reliable identification of CNV is still im-portant to fully understand the effect of CNV on genetic diversity and background of complex diseases. SNP marker has been used frequently to detect CNVs, but the analysis of SNP chip data for identifying CNV has not been well established. We compared various nor-malization methods for CNV analysis and suggest opti-mal normalization procedure for reliable CNV call. Four normal Koreans and NA10851 HapMap male samples were genotyped using Affymetrix Genome-Wide Human SNP array 5.0. We evaluated the effect of median and quantile normalization to find the optimal normalization for CNV detection based on SNP array data. We also explored the effect of Robust Multichip Average (RMA) background correction for each normalization process. In total, the following 4 combinations of normalization were tried: 1) Median normalization without RMA back-ground correction, 2) Quantile normalization without RMA background correction, 3) Median normalization with RMA background correction, and 4) Quantile nor-malization with RMA background correction. CNV was called using SW-ARRAY algorithm. We applied 4 differ-ent combinations of normalization and compared the ef-fect using intensity ratio profile, box plot, and MA plot. When we applied median and quantile normalizations without RMA background correction, both methods showed similar normalization effect and the final CNV calls were also similar in terms of number and size. In both median and quantile normalizations, RMA back-ground correction resulted in widening the range of in-tensity ratio distribution, which may suggest that RMA background correction may help to detect more CNVs compared to no correction.Keywords: copy number variation, normalization, SNP, Robust Multiarray Average
Towards simulation of flapping wings using immersed boundary method

In this work the immersed boundary method is applied to simulate incompressible turbulent flows around stationary and moving objects. The goal is to demonstrate that the immersed boundary technique along with a large eddy simulation approach is capable of simulating the effect of the so‐called leading edge vortex (LEV), which can be found in flapping wing aerodynamics. A Lagrangian method is used to approximate the solutions in the freshly cleared cells that lay within solid objects at one time step and emerge into fluid domain at the next time step. Flow around a stationary cylinder at ReD = 20, 40, and 3900 (based on cylinder diameter D) is first studied to validate the immersed boundary solver based on the finite volume scheme using a staggered grid. Then, a harmonically oscillating cylinder at ReD = 10 000 is considered to test the solver after the Lagrangian method is implemented to interpolate the solution in the freshly cleared cells. Finally, this approach is used to study flows around a stationary flat‐plate at several angles of attack and fast pitching flat‐plate. The rapidly pitching plate creates a dynamic LEV that can be used to improve the efficiency of flapping wings of micro air vehicle and to determine the optimum flapping frequency. Copyright © 2012 John Wiley & Sons, Ltd.
Electrically Controlled Millimeter-Wave Focusing Properties of Liquid Crystal Lens

The liquid crystal (LC) lens is prepared using planoconvex-shaped metal substrates as electrically controlled quasi-optical millimeter-wave devices. The millimeter-wave focusing properties of the LC lens are calculated by the finite-difference time-domain (FDTD) method and measured at 94 GHz. The focusing effects of the LC lens and changes in the focusing properties induced by the applied voltage have been obtained. The measured focusing properties of the LC lens agree with those calculated by the FDTD method.
Epilayer transfer for integration of III-V photodetectors onto a silicon platform using Au-Sn and Pd-Ge bonding

A novel process to bond InP-based, substrate-removed, vertical Schottky photodetectors to a commercially available silicon read-out integrated circuit is demonstrated as a new technique for optoelectronic hybridization. High-quality In(Al)GaAs epilayers were bonded to silicon substrates and patterned to form a 320/spl times/256 focal plane array to demonstrate this technique. The epilayers were joined to the silicon through a metal-metal bond of either Au-Sn or Ge-Pd. Scanning electron and optical microscopy revealed that the Au-Sn formed a eutectic (melting) bond, whereas the Ge-Pd formed a solid-state bond. Samples bonded with Ge-Pd exhibited superior performance and were easier to process than the Au-Sn samples. Using this bonding technique, samples with a dark current density of 595 pA//spl mu/m/sup 2/ at -5 V and a peak responsivity of 0.21 A/W over /spl lambda/=0.8 to 1.5 /spl mu/m were obtained. Bonded devices survived severe thermal cycling between 77 K and 373 K. The process described is uncomplicated and does not require any specialized equipment beyond that of a standard photolithography tool.
Perceptual Difficulty and the Right‐Ear Advantage for Vowels

An experiment was designed to test the hypothesis that the right‐ear advantage for speech in dichotic listening is correlated directly with perceptual difficulty, whether due to an inherent property of the stimulus (such as the “encodedness” of consonants) or to other loading factors in the perceptual situation. Brief vowel excerpts were presented dichotically, and perceptual difficulty allowed to vary along three dimensions: duration of stimuli, S/N ratio, and phonetic discriminability among vowels. Significant right‐ear advantages were indeed found, although not entirely in accord with the original hypothesis. Results are discussed in terms of both the degree of perceptual difficulty and the speech‐processing mode of perception.
HOT MOLECULAR CORES IN INFRARED DARK CLOUDS

We present high angular resolution continuum images and molecular line spectra obtained at 345 GHz with the Submillimeter Array (SMA) toward two massive cores that lie within Infrared Dark Clouds (IRDCs): G034.43+00.24 MM1 and G024.33+00.11 MM1. Both of these cores contain bright, unresolved (<2″) objects that have previously been imaged in the millimeter/submillimeter continuum with the Institut de RadioAstronomie Millimétrique (IRAM) Plateau de Bure Interferometer and SMA and show complex molecular line chemistry. The new, higher angular resolution SMA continuum images reveal that both cores contain massive (8, 26 M☉), unresolved (0.″6; ∼3000 AU) continuum emission features and emission from many complex molecular transitions, which confirm that these are hot molecular cores, an early stage in the formation of a high-mass star. Because these hot cores are located within IRDCs, they may well represent the very earliest phases in the formation of high-mass protostars and, hence, their detailed study may reveal the initial conditions within high-mass star-forming cores, before they are shredded apart by stellar winds and radiation.
A survey for extra-H II region ionized gas structures in irregular galaxies

We have conducted a deep Hα imaging survey of 51 irregular and amorphous galaxies with the objective of searching for large ionized gas structures outside of normal H II regions. In this sample 12% of the galaxies contain at least one ionized supershell (radius≥3OO pc), 24% contain supergiant ionized filaments which are not obviously connected with a particular star forming region, and 27% contain one or more of these types of structures. For the most part, large ionized gas structures are found in galaxies that are engaging in intense star formation or that contain at least one unusually large concentration of massive stars. Thus, in most galaxies these structures are likely to have been produced by massive stars
Wave Vector Selection in the Instability of an Interface in a Magnetic or Electric Field

The free surface of a magnetic (dielectric) fluid becomes unstable for a large enough vertical magnetic (electric)-field threshold. The experimentally observed wave vector selection disagrees with the inviscid-fluid linear stability analysis whatever the geometric pattern is. Taking into account the effect of the fluid viscosity on the wave undulation of the interface, we show that the wave vector of maximum growth rate is independent of the external control parameter in agreement with the experiments in this instability of the Kelvin-Helmholtz type.