Miracle-dz/UniFAR-FTUs huggingface dataset:
PARITY AND PROJECTION FROM VIRTUAL KNOTS TO CLASSICAL KNOTS

We construct various functorial maps (projections) from virtual knots to classical knots. These maps are defined on diagrams of virtual knots; in terms of Gauss diagram each of them can be represented as a deletion of some chords. The construction relies upon the notion of parity. As corollaries, we prove that the minimal classical crossing number for classical knots. Such projections can be useful for lifting invariants from classical knots to virtual knots. Different maps satisfy different properties.
STABILITY IN QUEUES WITH IMPATIENT CUSTOMERS

This paper deals with GI/G/1 queueing systems with impatient customers that have individual deadlines until their beginning of service. The impatience law depends on the number of waiting customers and on the elapsed service time of the customer in service. An exhaustive analysis of the asymptotic behavior of the model, combining ideas of stochastic dominance of well–known processes and some properties of models with finite capacity, is provided. We prove that the model is ergodic, null recurrent or transient if the corresponding traffic parameter in a simple associated model is respectively lower than, equal to, or greater than one.
Thermal stability of NiMn spin valve heads

The thermal stability of NiMn-based spin valves was studied both at the coupon level and in full read/write heads. In the coupons, the blocking temperature distribution showed no component below 150/spl deg/C. As a result, the exchange field at elevated temperature was found to increase with time (because of improved chemical ordering of the NiMn layer), and irreversible losses in the /spl Delta/R/R response were observed only above 250/spl deg/C (because of layer interdiffusion). If a 10% drop in /spl Delta/R/R amplitude is used as a criterion to calculate time to failure, the NiMn heads should have several hundred years of lifetime at 150/spl deg/C operating temperature. Full read/write heads showed linear response with read-back amplitudes above 2 mV//spl mu/m at 6-mA operating current. In contrast to most other giant magnetoresistance heads, the output of the head remains the same after heating with a high bias current and degrades only with the shorting of the stripe. All these properties make NiMn superior to other antiferromagnets for spin valve head applications.
M-ESTIMATION FOR A SPATIAL UNILATERAL AUTOREGRESSIVE MODEL WITH INFINITE VARIANCE INNOVATIONS

We study the limiting behavior of the M-estimators of parameters for a spatial unilateral autoregressive model with independent and identically distributed innovations in the domain of attraction of a stable law with index α ∈ (0, 2]. Both stationary and unit root models and some extensions are considered. It is also shown that self-normalized M-estimators are asymptotically normal. A numerical example and a simulation study are also given.
Hole tone generation from highly choked jets

The hole tone generated from the passage of underexpanded jets through a circular hole in a rigid plate and the secondary sound wave emission associated with the strong hole tone generation were investigated experimentally. Flow visualization shows that when the jet passes through a hole whose diameter is less than the nozzle diameter and interacts with the plate around the hole, two immediately succeeding strong hole tones having partially plane and spherical wave fronts are radiated in the upstream direction of the plate. A particular flow condition, where the pressure ratio R=3.90, the nozzle‐to‐plate distance h/d=2.40, and the hole diameter D/d=1.00, was investigated in detail. In addition to the radiation of two succeeding strong hole tones in the upstream direction, four strong secondary sound waves are radiated downstream of the plate during one cycle of the hole tone generation. Flow visualization confirmed that the six sound waves found for this flow condition are generated by two different gener.
Elastic wave velocities of silica glass at high temperatures and high pressures

The elastic compressional (P) and shear (S) wave velocities of silica glass at simultaneous high pressures and high temperatures were measured using a combination of ultrasonic interferometry, in situ synchrotron x-ray diffraction, and radiographic techniques in a large-volume Kawai-type multianvil apparatus. We found no first-order amorphous-amorphous transformation throughout the pressure and temperature conditions between 2 and 5 GPa and up to 1173 K, contrary to previous studies suggested by piston cylinder experiments or molecular dynamics simulations. For each of the 650 and 800 K isothermal runs, the P and S wave velocities initially decreased with increasing pressure, reaching minimum values at around 3–4 GPa, followed by increases with pressure up to 6.1 GPa; on successive decompression to ambient pressure, both velocities changed irreversibly due to permanent densification, and no minima were observed in both velocities. We also found that, in a second compression-decompression cycle at 800 K, t.
On the number of substitutions with cycle lengths from a given set

Let Λ be a set of natural numbers, Sn (Λ) be the set of all the substitutions of degree η which have cycles with lengths from the set Λ only, αη(Λ) = |Sn(A)|/n! , where |5η(Λ)| is the cardinality of the set 5η(Λ). We study the asymptotic behaviour of αη(Λ) as η — » oo for various values of density of the set Λ. Let Λ be a set of natural numbers, 5η(Λ) be the set of all the substitutions of degree η which have cycles with lengths from the set Λ only, αη(Λ) = |5η(Λ)|/η! , where | oo for various values of density 7 of the set Λ. Hereafter 7 = lim*. ,«, ΝΔ(Χ)/Χ, where N^(x) = Σλ6Λ,λ<*1· Until recently, a number of results concerning this topic is obtained [1-7]. Before we formulate the assertions proved here, let us remind a definition [8]. Definition L A positive function L(x) is slowfy varying at infinity, if it is measurable on the semi-axis [Λ, oo), A > 0, and for any fixed XQ > 0 the equality *->«> L(x) holds. We denote the set of all the slowly varying at infinity functions by £. The following results are obtained in the present paper. Theorem 1. For any sequence Λ the inequality α«(Λ) holds. Corollary 1. If 7 is the density of the set Λ, then the inequality *M Σ ι] n Ιλ
Modelling the extreme ultraviolet emission during the low state of Hercules X-1

Hercules X-1 was observed for extended periods during its low state by the Extreme Ultraviolet Explorer (EUVE). These observations yield low-state light curves in the extreme ultraviolet (EUV) which are compared with a composite model here. The model includes reflection of soft X-rays off the companion HZ Her, including the shadowing of HZ Her by the accretion disc, and emission from the accretion disc surface. Four different geometries for the accretion disc were adopted, all derived from the RXTE All-Sky Monitor (ASM) 35-day light-curve modelling. Three were thin disc models for different system inclinations, i, and the fourth was a disc with a thick inner ring for i= 85°. With the HZ Her reflection model, with no free parameters except normalization, and a simple model for the disc emission, the models fit the data well. The disc emission accounts for about half of the EUV flux, depending on which accretion disc geometry is used. The disc geometry that best fits the EUV light curves is the disc with a thick inner ring, which is the same model that gives the best fit to the RXTE/ASM light curve.
Transient electromagnetic response of a three-dimensional body in a layered earth

The three‐dimensional (3-D) electromagnetic scattering problem is first formulated in the frequency domain in terms of an electric field volume integral equation. Three‐dimensional responses are then Fourier transformed with sine and cosine digital filters or with the decay spectrum. The digital filter technique is applied to a sparsely sampled frequency sounding, which is replaced by a cubic spline interpolating function prior to convolution with the digital filters. Typically, 20 to 40 frequencies at five to eight points per decade are required for an accurate solution. A calculated transient is usually in error after it has decayed more than six orders in magnitude from early to late time. The decay spectrum usually requires ten frequencies for a satisfactory solution. However, the solution using the decay spectrum appears to be less accurate than the solution using the digital filters, particularly after early times. Checks on the 3-D solution include reciprocity and convergence checks in the frequenc.
On approximate isometries

In a previous paper, a problem of mathematical "stability" for the case of the linear functional equation was studied. I t was shown that if a transformation f(x) of a vector space E\ into a Banach space £2 satisfies the inequality \\f(x+y)—f(x)—f(y)\\<e for some e > 0 and all x and y in £1, then there exists an additive transformation <j>(x) of £1 into E2 such that ||/(*) 0 ( a ) | | <e . In the present paper we consider a stability problem for isometries. By an e-isometry of one metric space E into another E' is meant a transformation T{x) which changes distances by at most e, where e is some positive number; that is, \p(x, y)—p(T(x)1 T(y))\ < e for all x and y in E. Given an e-isometry T(x), our object is to establish the existence of a true isometry U(x) which approximates T(x) ; more precisely, to establish the existence of a constant k > 0 depending only on the metric spaces E and E' such that p(T(x), U(x))<ke for all x in E. In this paper this result will be proved for the case in which £ = £ ' , where E is n-dimensional Euclidean space or Hubert space (not necessarily separable). The case in which E is the space C of continuous functions will be treated in another paper. The above problem of €-isometries is related to the problem of constructing space models for sets in which distances between points are given only with a certain degree of exactness (measurements are possible only with a certain degree of precision). The question of the uniqueness of the idealized model corresponding to the given measurements and the extrapolation from the measurements to the model could be looked upon as a problem in determining a strict isometry from an approximate isometry. In the case of certain simple metric spaces, for example the surface of the Euclidean sphere, this question can be answered in the affirmative, but it may be more difficult for other bounded manifolds. A simple but interesting example showing a case where the answer is negative has been worked out by R. Swain.
OCT in the field of laryngology: further perspectives

Early detection of cancerous lesions of the larynx may be the best method of improving patient quality of life and survival rates. New in-vivo technologies may be of great clinical relevance in improving the accuracy of sampling during microlaryngeal surgery. Optical coherence tomography (OCT) is an optical imaging technique that clearly identifies basement membrane violation caused by laryngeal cancer. With a microscope-based spectral domain OCT (SD-OCT) we reached in vivo a fairly accurate assessment of benign and dysplastic laryngeal lesions. Recent improvements in OCT technology have led to the development of high-speed OCT systems displaying millions of pixels per second. These systems allow non-contact real-time imaging of large sections of laryngeal tissue. Polarization contrast OCT (PS-OCT) may provide additional information about the lamina propria of the true vocal cord because of the birefringence of connective tissue. We present microscope-based high-speed SD-OCT images with and without polarization contrast and 3D volumes of selected laryngeal pathologies in order to demonstrate our current concepts for the intended intraoperative application. High-speed SD-OCT and polarization contrast can also be complemented by our recently developed rigid confocal endoscopic system to obtain cellular and sub-cellular information about the tissue. Further perspectives will be presented.
Observation of P donors on the Si(111) surface by scanning tunneling microscopy

We report on the individual observation of substitutional P donors on the reconstructed Si (111) 2 × 1 surface by means of scanning tunneling microscopy and tunneling spectroscopy. Depending on the scanning voltage, the dopants give rise to different features superimposed on the background lattice. This is explained by the influence of the charged P atom on the electronic surface-states resulting in a local band shift. The spatial arrangement of the donors obeys a statistical distribution, excluding significant clustering even at a P concentration of 6 × 1019 cm−3 which is far above the metal-insulator transition.
Stability analysis for discrete‐time fuzzy system by utilizing homogeneous polynomial matrix function

The purpose of this paper is to investigate the stability of nonlinear systems represented by a Takagi‐Sugeno discrete‐time fuzzy model. The homogeneous polynomial matrix function (HPMF) is developed to obtain new stabilization conditions. Applying the HPMF to the non‐parallel distributed compensation (non‐PDC) law and non‐quadratic Lyapunov function, some new stabilization conditions are obtained by the following two means: (a) utilizing the popular idea of introducing additional variables for some fixed degree of the HPMF; and (b) increasing the degree of the HPMF. It is shown that the conditions obtained with approach (a) are less conservative than some sufficient stability conditions available in the literature to date. It is also shown that as the degree of HPMF increases the conditions obtained under (b) become less conservative. An example is provided to illustrate how the proposed approaches compare with other techniques available in the literature. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
The formation of helium white dwarfs in close binary systems – II

We present a set of calculations of the evolution of low-mass, solar composition stars in close binary systems together with a canonical 1.4-M⊙, neutron star (NS). We restrict the initial mass and period values to those that give rise to the formation of ultracompact systems or low-mass helium white dwarf (He WD) stars. Specifically, we computed the evolution of 40 systems for which the initial masses of the normal (donor) stars were of 1.00, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00 and 3.50 M⊙, while the range of initial periods covered in this work was from 0.5 to 12 d. Calculations were performed employing the binary hydro code developed by the present authors, which handles the mass transfer rate in a fully implicit way together with state-of-the-art physical ingredients and diffusion processes. In this work we have assumed the standard scheme for the orbital evolution of the binary, considering the usual processes that produce angular momentum losses: mass loss from the system, magnetic braking and gravitational radiation. In the main part of this work we assume that the NS is able to retain only half of the matter coming from the donor star. The range of final masses has been from 0.01961 to 0.34351 M⊙ and periods from 39 min to 187 d. 26 out of the 40 considered systems give rise to the formation of a He WD as a compact remnant. In performing a comparison of our results with observations, we have employed three WD–NS systems, which are among the best known ones. These are PSR J0437−4715, PSR J1012+5307 and PSR B1855+09. In order to obtain good agreement between models and observations we have had to assume that the NS is able to retain only ≈10 per cent of the material released by the donor star. Otherwise, for the cases of PSR J0437−4715 and PSR B1855+09 we would be in conflict with the observed NS masses. For these two objects we have been able to fit WD and NS masses, the orbital period and also the time-scale for cooling of the WD with the evolution of one binary system. For the case of PSR J1012+5307, the problem is more delicate because the object has a mass near the threshold for the occurrence of thermonuclear flashes and the initial period is close to bifurcation point.
Speech perception, production, and intelligibility improvements in vowel‐pair contrasts among adults who receive cochlear implants

This study investigates relations among speech perception, speech production, and intelligibility in postlingually deaf adults who receive cochlear implants (CI). Measures were made for seven vowel pairs that neighbor in acoustic space from eight postlingually deafened adults, pre‐ and postimplant. Improvements in a speaker’s production, perception, and intelligibility of a given vowel contrast tended to occur together. Subjects who produced vowel pairs with reduced contrast in the preimplant condition (measured by separation in the acoustic vowel space) and who showed improvement in their perception of these contrasts postimplant (measured with a phoneme identification test) were found to have improved production contrasts post‐CI. These enhanced production contrasts were associated with enhanced intelligibility, as measured from responses of a group of normal‐hearing listeners. The results support the hypothesis that the implant user’s improving speech perception contributes, at least in part, to that s.
Status characteristics and expectation states theory: A priori model parameters and test*

We present a method of obtaining a priori values for the parameters of the mathematical model of the theory of status characteristics and expectation states. The combining function postulated by the model and the path counting rules for graph structures determine the form of the function f(i) which gives the strength of a path as a function of its length. Furthermore, substantive assumptions about the shape of the function f(i) lead to numerical values for the coefficients in the function, so that all parameters are determined. We demonstrate that these parameters fit the available data as well as the empirical parameters do. We also demonstrate that the mathematical model of the theory of status characteristics and expectation states fits quite well the data from twelve experiments conducted since its formulation.
Turbulent convection within rapidly rotating superadiabatic fluids with horizontal temperature gradients

Abstract A model is developed for small scale thermally driven turbulent convection in rapidly rotating systems. The Boussinesq equations of adiabatic and inviscid flow are perturbed about a basic state which is superadiabatic and which contains a horizontal temperature gradient balanced by a geostrophic wind. The growth rates and length scales of the most unstable modes are determined. It is found that these modes are either zonally or latitudinally symmetric, depending on the latitude and the horizontal temperature gradient. The transports of heat and momentum by the modes are computed. The linear amplitudes are assumed to be limited by shear instability. The model predicts a latitude dependent eddy diffusivity. The applicability of the model to astrophysical and planetary bodies is briefly discussed.
Decomposition of Global Ocean Currents Using a Simple Iterative Method

Abstract The common representation of two-dimensional nondivergent oceanic currents or fluxes by a streamfunction is extended to the divergent global case using the Helmholtz decomposition of the flow into rotational (nondivergent) and divergent (irrotational) components, represented by stream- and potential functions, respectively. An appropriate discretization of the problem, in either horizontal or vertical planes, is described. While a standard numerical solver of the Poisson equation for the streamfunction in the spherical, horizontal problem does not constrain the rotational flow to the ocean, a simple iterative procedure is used to do this. This involves modifying the coastal vorticity at each step by resetting the flow over land to zero. The scheme is easily programmed and efficiently determines the streamfunction for realistic flows. The potential can then be determined simply. The decomposition of the time-mean volume fluxes simulated by the Commonwealth Scientific and Industrial Research Organi.
Optical and Electrical Characteristics of Organic Light-Emitting Diodes with Two-Dimensional Photonic Crystals in Organic/Electrode Layers

Efficient light extraction is a critical issue for improving the overall efficiency of organic light-emitting diodes (OLEDs). Improvements in OLED efficiency are studied via the introduction of photonic crystal (PC) layers, which are expected to enable versatile control of photons. We fabricate two-dimensional PC structures in organic and electrode layers, in which most light is confined, to extract the light in the waveguide mode. Improvements in OLED efficiency of 20 and 130% are observed in spectrally integrated intensity and the peak intensity of forward-propagating light, respectively, in comparison with samples without PCs. As the thickness of the organic layer is partially reduced, lower operating voltages are found not to degrade light-extraction efficiency. We can expect further improvement in the overall OLED efficiency by optimizing PC structure.
Space and Time Variations in Turbulence during the Manhattan Midtown 2005 Field Experiment

Abstract The Manhattan Midtown-2005 field experiment (MID05) collected turbulence observations at 12 street-level sites (at 3-m height) and at 5 rooftop sites (at 220-m average height). The MID05 observations of 30-min averaged standard deviations of wind speed components and temperature and of sensible heat and momentum flux are found to be consistent with the authors’ previously reported averaged observations in similar tall-building surroundings in the Oklahoma City Joint Urban 2003 (JU2003) and Manhattan Madison Square Garden 2005 (MSG05) field experiments. The main focus of this paper, though, is on the magnitudes of the space and time variations of the 30-min averaged turbulence values. Wind tunnel experiments and computational fluid dynamics model outputs would suggest large variations, but the full-scale urban observations show that the standard deviations of the space and time variations are usually less than 50% of the averages. Some individual observations are tabulated and the minimum and maxi.
IMPORTANCE OF USING A REDUCED CONTRAST COUPLING MEDIUM IN 2D MICROWAVE BREAST IMAGING

Microwave imaging of the breast presents unique opportunities for tumor detection when compared with imaging of other anatomical sites. Because of the low permittivity of the breast relative to malignant tumors which are generally believed to be closer to that of biological saline due to rapid metabolism of the cancerous cells and associated angiogenesis, the contrast between normal and malignant breast tissue is considerably higher than that for other anatomical sites. However, the very same low permittivity of the breast presents significant challenges in terms of imaging. A lossy, permittivity—compatible liquid coupling medium is generally needed for medical microwave imaging, with saline being the most convenient for many sites—electrically because of its low contrast with the predominantly high water-content of the body, and economically because of its low cost and suitability for human contact. For breast imaging, a much lower permittivity liquid is required which must be environmentally safe and low in cost. We have been studying organic compounds and the degree to which their electrical properties can be controlled by dilution with varying fractions of saline. Initial 2D simulation and phantom experiments with reduced permittivity coupling mixtures have demonstrated significant improvements where previous limitations had been identified, including: (a) reduction of 3D wave propagation image artifacts, (b) reduction of the effective imaging slice thickness, (c) improvement in property characterization for large, low permittivity scatterers, and (d) enhancement of inclusion detection and artifact reduction. Results illustrating these improvements are presented here including a set of actual patient images and represent important milestones for clinical system development.