Miracle-dz/UniFAR-FTUs huggingface dataset:
Index assignment for predictive wideband LSF quantization

In this paper we summarize some results derived earlier for the mean-square channel distortion of an autoregressive moving average (ARMA) vector quantizer with a maximum entropy encoder when the channel is assumed binary symmetric and memoryless. We discuss the required assumptions and their practical consequences in index assignment of ARMA vector quantizers. The discussion relates also to channel optimization of these quantizers. Furthermore, we compare noisy channel performance of memoryless, moving average, and autoregressive two-stage vector quantizers in line spectrum frequency quantization applied to wideband speech coding.
CONSTRUCTION OF LIE SUPERALGEBRAS $D(2,1;\alpha)$,\$G(3)$ AND $F(4)$ FROM SOME TRIPLE SYSTEMS

Abstract We have constructed Lie superalgebras $D(2,1;\alpha)$, $G(3)$ and $F(4)$ from $U(-1,-1)$-balanced Freudenthal–Kantor triple systems in a natural way. AMS 2000 Mathematics subject classification: Primary 17A40; 17B60
A differential attenuation method for simultaneous estimation of SPECT activity and attenuation distributions

A penalized weighted least squares (PWLS) reconstruction algorithm is described which simultaneously estimates activity and attenuation distributions from emission sinogram data alone. This estimation technique is based on differential attenuation information and is applicable to any SPECT imaging isotope with emissions at two or more distinct energies, after compensating for Compton scatter. A rotation-based forward projector is used to efficiently model photon attenuation at multiple emission energies, as well as distance-dependent spatial resolution. The algorithm was tested using simulated scatter-free /sup 201/Tl projection data from a single-slice numerical cardiac phantom with a large cold myocardial defect. Poisson noise was added to the projection data to mimic clinically realistic count densities. The activity estimates resulting from the proposed method had fewer artifacts and were substantially more accurate than images reconstructed with filtered backprojection without compensation for attenuation. Several techniques were employed to reduce the time required for the iterative routine to converge and to improve the stability of the solution, including: (1) a preconditioning image variable transformation; (2) a coarse-to-fine grid initialization schedule; and (3) a convex hull image mask determined directly from the projection data. The combined effect of these techniques was a reduction in compute time by a factor of /spl sim/200.
Power-law X-ray and gamma-ray emission from relativistic thermal plasmas

A common characteristic of cosmic sources is power-law X-ray emission. Extragalactic sources of this type include compact components of active galactic nuclei (AGN). The present study is concerned with a theoretical model of such sources, taking into account the assumption that the power-law spectra are produced by repeated Compton scatterings of soft photons by relativistic thermal electrons. This is one of several possible physical mechanisms leading to the formation of a power-law spectrum. Attention is given to the Comptonization of soft photon sources, the rates of pair processes, the solution of the pair equilibrium equation, and the constraints on a soft photon source and an energy source. It is concluded that the compactness parameters L/R of most of the cosmic sources observed to date lie below the maximum luminosity curves considered.
Nano-oxide layers and PtMn-based specular spin valves and heads

Nano-oxide layers and relevant spin valves have been investigated. Morphology observation shows that the nano-oxide layers are adequate for current spin valves as thin, dense, and uniform specular reflection layers to enhance scattering of electrons at interfaces. Large enhancement of /spl Delta/R/R (/spl sim/16% with a /spl Delta/R/spl sim/3.7 /spl Omega//sq) has been achieved with the help of specular reflection. Both full film and read heads data demonstrated thermally stable magnetic performance. Addition of nano-oxide layers does not compromise head ESD robustness. Readers with nano-oxide layers show amplitude sensitivity of up to 10 mV//spl mu/m and are suitable for >50 Gb/in/sup 2/ recording applications.
An Analysis of Hurricane Opal's Forecast Track Errors Using Quasigeostrophic Potential Vorticity Inversion

Abstract Hurricane Opal’s landfall in October 1995 forms the basis of a serious hurricane forecast problem—the potential for hurricane conditions over land with insufficient warning time. Official National Hurricane Center (NHC, a division of the Tropical Prediction Center) forecasts predicted landfall and passage inland over the eastern United States at a later time than observed because of underestimation of the northward component of the steering flow by the National Centers for Environmental Prediction’s (NCEP) operational models and other hurricane track models. The goal of this paper is to isolate the cause of the poor forecast of meridional storm motion in NCEP’s early Eta Model by using quasigeostrophic potential vorticity (QGPV) inversion. QGPV inversion permits decomposition of the steering flow into contributions from different synoptic-scale features. The inversion procedure is applied to the Eta analysis and 48-h Eta forecast valid at 1200 UTC 5 October 1995. Analyses from the European Centre.
Determination of diffraction efficiency for a second-order corrugated waveguide

The diffraction from a second-order corrugated waveguide is analyzed to determine its efficiency as an element to redirect a guided wave. Using a rectangular grating, the efficiency is evaluated in an approximate closed form. The dependence upon grating thickness, waveguide thickness, and wavelength are investigated and the results indicate usefulness as a simulation tool for photonic integrated circuits.
Ellipsis of Arguments: Its Acquisition and Theoretical Implications

This dissertation investigates the acquisition of Argument Ellipsis (AE). In Chapter 2, I discuss two theoretical approaches to the cross-linguistic distribution/acquisition of AE, namely, the Scrambling Analysis (Oku 1998) and the Anti-agreement Analysis (Saito 2007), and show that neither can be maintained, based on the facts from cross-linguistic distribution of AE and learnability considerations. Then, I propose that the cross-linguistic distribution/acquisition of AE are best accounted for by the morphology of extended nominal projections such as case and number. More specifically, it is argued that only languages that exhibit non-fusional, agglutinating (case) morphology allow AE. This proposal correctly explains the facts that are problematic for the previous analyses. Chapter 3 takes up the question of whether agreement actually blocks AE. Although the data reported by Şener and Takahashi (2010) suggest that subject agreement in Turkish blocks AE, in conformity to the Anti-agreement Analysis, I point out that AE in subject position can be blocked by various as-yet-unknown factors, and it is necessary to look at object agreement languages to test whether agreement blocks AE. The data from Hindi and Basque indicate that object agreement does not necessarily block AE, which supports the morphology-based analysis of AE put forth in this dissertation. Chapter 4 investigates how Japanese-speaking children acquire AE. It has been observed in the literature that Japanese-speaking children acquire case-markers quite early (Matsuoka 1998). Given that, the analysis proposed in this dissertation predicts that Japanese-speaking children acquire AE very early, despite the fact that direct positive evidence indicating that Japanese allows AE is virtually
An efficient method to reduce the numerical dispersion in the ADI-FDTD

A new approach to reduce the numerical dispersion in the finite-difference time-domain (FDTD) method with alternating-direction implicit (ADI) is studied. By adding anisotropic parameters into the ADI-FDTD formulas, the error of the numerical phase velocity can be controlled, causing the numerical dispersion to decrease significantly. The numerical stability and dispersion relation are discussed in this paper. Numerical experiments are given to substantiate the proposed method.
Examination of Disk-Type Multidegree-of-Freedom Ultrasonic Motor

A multidegree-of-freedom (MDOF) ultrasonic motor using the multimode of a disk vibrator is realized. A spherical rotor can rotate around arbitrary axes. However, at the beginning of research on the MDOF ultrasonic motor, the MDOF ultrasonic motor did not have any mechanisms for supporting a spherical rotor. Since the preload was given by only the rotor's own weight, the friction between the rotor and the stator vibrator was very small, but the torque characteristics of the MDOF motor were insufficient for practical use. The purpose of this study is to improve the motor performance further. In this paper, some support and preload mechanisms using a support plate were examined for the improvement of the motor performance. In addition to these methods, a sandwich structure in which two stator vibrators hold a spherical rotor is proposed. This structure has both a rotor support mechanism and a preload mechanism, and high torque by the torque composition of two stator vibrators can be obtained.
Acoustic Study of Suspension Sedimentation

By means of an acoustic technique, we follow the time and space dependence of the concentration of a settling suspension composed of spherical glass beads in water. The concentration profile consists of two shock fronts, one at the top, one at the bottom of the sedimentation column. The velocity determination of these two fronts allows a precise analysis of how the settling velocity for suspension concentrations close to the packing vanishes.
ON THE COVERAGE PROBABILITY OF CONFIDENCE INTERVALS IN REGRESSION AFTER VARIABLE SELECTION

This paper considers a linear regression model with regression parameter vector β. The parameter of interest is θ= aTβ where a is specified. When, as a first step, a data‐based variable selection (e.g. minimum Akaike information criterion) is used to select a model, it is common statistical practice to then carry out inference about θ, using the same data, based on the (false) assumption that the selected model had been provided a priori. The paper considers a confidence interval for θ with nominal coverage 1 ‐ α constructed on this (false) assumption, and calls this the naive 1 ‐ α confidence interval. The minimum coverage probability of this confidence interval can be calculated for simple variable selection procedures involving only a single variable. However, the kinds of variable selection procedures used in practice are typically much more complicated. For the real‐life data presented in this paper, there are 20 variables each of which is to be either included or not, leading to 220 different models. The coverage probability at any given value of the parameters provides an upper bound on the minimum coverage probability of the naive confidence interval. This paper derives a new Monte Carlo simulation estimator of the coverage probability, which uses conditioning for variance reduction. For these real‐life data, the gain in efficiency of this Monte Carlo simulation due to conditioning ranged from 2 to 6. The paper also presents a simple one‐dimensional search strategy for parameter values at which the coverage probability is relatively small. For these real‐life data, this search leads to parameter values for which the coverage probability of the naive 0.95 confidence interval is 0.79 for variable selection using the Akaike information criterion and 0.70 for variable selection using Bayes information criterion, showing that these confidence intervals are completely inadequate.
Chemical composition of summertime aerosol in the Po Valley (Italy), northern Adriatic and Black Sea

The Aerosol Direct Radiative Impact Experiment was conducted over the Po Valley, the northern Adriatic and the Black Sea in summer 2004, with the aim of characterizing physical, chemical and optical properties of the ambient aerosols, and calculating its direct impact on the radiative balance of the region. The UK BAE‐146 FAAM aircraft sampled in situ, while surface lidar and AERONET measurements were also taken. Ammonium sulphate and organics were found to dominate sub‐micron aerosol composition when air‐mass trajectories showed easterly flow. Under westerly anticyclonic flow, venting and recirculation of Po Valley surface air resulted in vertical stratification over both the Po Valley and northern Adriatic. Large ammonium nitrate concentrations were found in this recirculating air due to the large NOx and ammonium sources in the Po Valley. This large amount of ammonium nitrate makes a significant contribution to the regional radiative budget. Not only is it the most significant component mass in the column when Po Valley air flows over the Adriatic Sea, but the scattering will increase substantially due to additional amounts of water on aerosol particles rich in ammonium nitrate which are found in moist air masses. Organic aerosol mass was dominated by secondary material in both easterly and westerly conditions, with a relative reduction in the number of di‐ and poly‐acidic functional groups in the nitrate‐rich westerly air masses. Black Sea aerosol composition was dominated by ammonium sulphate and organic aerosol. Copyright © 2007 Royal Meteorological Society
Impact of Precipitation on Aerosol Spectral Optical Depth and Retrieved Size Distributions: A Case Study

Abstract A case study is presented on the impact of two isolated, strong thundershowers during a prevailing dry, sunny season on the spectral optical depths and inferred columnar size characteristics of atmospheric aerosols at a tropical station. Results show a remarkable decrease in the aerosol optical depth and change in the spectral slope after the rain. The scavenging was found to be dependent on the particle size distribution; the larger, supermicron particles were found to be removed faster during the first shower itself, even though it was of only moderate intensity, resulting in about a 64% decrease in the columnar mass loading. In the second shower, which was stronger and more widespread than the former, more of the submicron particles in the optically active submicron size range were removed, but the reduction in mass loading was very small. The effective radius decreased continuously and so too did the columnar mass loading (total aerosol volume). The data are used to estimate the apparent colu.
Development of a DC brush motor with 50% weight and volume reduction using an Nd-Fe-B anisotropic bonded magnet

There is a need to reduce the weight and size of dc brush motors for automobile use. In the current study, sintered ferrite magnets were replaced by Nd-Fe-B anisotropic bonded magnets in an effort to reduce the size and weight of the motor. Finite-element analysis was carried out, and a four-pole anisotropic magnet was determined to be optimal. Based on these results, an actual 35-W brush motor for power automobile seats was test produced. A roughly 50% reduction of weight and volume was realized in this test-produced motor, which also maintained the same torque as the currently used ferrite motor.
Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region

We measure the internal attenuation of bulk crystals of chemical vapor deposition zinc selenide (CVD-ZnS), chemical vapor deposition zinc sulfide (CVD-ZnSe), Si, and GaAs in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with the smallest internal attenuation of att=0.01 to 0.03 cm−1 among the major candidates. The measured attenuation is roughly in proportion to −2, suggesting it is dominated by bulk scattering due to the polycrystalline grains rather than by absorption. The total transmittance in the immersion grating is estimated to be at least >80%, even for the spectral resolution of R=300,000. Two potential problems, the scattered light by the bulk material and the degradation of the spectral resolution due to the gradient illumination in the diffracted beam, are investigated and found to be negligible for usual astronomical applications. Since the remaining problem, the difficulty of cutting grooves on CVD-ZnS and CVD-ZnSe, has recently been overcome by the nanoprecision fly-cutting technique, ZnS and ZnSe immersion gratings for astronomy can be technically realized.
Feedback phenomena in a semiconductor laser induced by distant reflectors

Multiple pass resonances in the noise spectrum and low-frequency self-oscillations in asymmetric geometrical configurations are described. The double peaked structure of the external cavity resonance f/sub c/ (at c/2L), the 'subharmonic cascading' from f/sub c/, and the generation of subharmonics of a modulated injection current are detailed. The exact field intensity distribution in the passive external resonator is shown to command these phenomena which reveal intermingled spatial and dynamical effects. The different behaviors are related to the characteristic curves of the laser. The authors have found that when the external cavity laser operates in its unstable regime, a locking of the otherwise randomly distributed intensity drops can occur giving a narrow resonance in the noise spectrum. In addition, based on the authors' observations, adapted rate equations are built starting from the Lang and Kobayashi model. Results show an adequate match between theory and experiments for the detailed microwave spectra, multiple pass resonances of the external cavity, and low-frequency resonances. >
An artificial‐dissipation‐based fractional step scheme for upper‐convected Maxwell (UCM) fluid flow past a circular cylinder

The fully explicit characteristic‐based split (CBS) scheme is employed to solve viscoelastic flow problems. The upper‐convected Maxwell (UCM) model is employed in the present study. In addition to allowing equal‐order interpolations for pressure and velocity, the proposed method along with an appropriate artificial damping scheme is able to produce stable solutions for different Deborah numbers (De). The higher‐order time terms introduced by the simplified characteristic Galerkin approximation are sufficient to obtain stable solution at very low De, but an additional damping is essential to maintain positive definitiveness of the conformation tensor at higher De. We demonstrate the need for an additional damping by analysing the basic forward time central space scheme applied to the constitutive equations. A second‐order artificial damping is employed to counteract the negative dissipation introduced by the explicit time discretization. The example studied in this paper is the widely used and difficult problem of flow past a circular cylinder. The results presented show that the velocity and extra stresses converge easily to a steady state at lower De values. At higher De values, the convergence to steady state is slow due to the incremental way in which the artificial damping is added. Copyright © 2008 John Wiley & Sons, Ltd.
Radio frequency noise during reentry

In flight, measurements of the effective noise temperature of a reentry plasma are compared with computed data. The vehicle utilized for the experiment was the Trailblazer II. The measurements were made at a frequency of 2235 MHz and transmitted to the ground in real time by X -band telemetry. Noise temperatures in excess of 5000\deg K were recorded. The flight data also demonstrate the importance of antenna location and angle of attack in determining the performance of an RF system. Another result of the flight has been to point out the power of temperature measurements as a diagnostic tool for flow field studies.
A Preliminary Survey of Rear-Flank Descending Reflectivity Cores in Supercell Storms

This paper develops a definition of a supercell reflectivity feature called the descending reflectivity core (DRC). This is a reflectivity maximum pendant from the rear side of an echo overhang above a supercell weak-echo region. Examples of supercells with and without DRCs are presented from two days during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX), as well as one day with tornadic high-precipitation supercell storms in central Kansas. It was found that in all cases, tornado formation was preceded by the descent of a DRC. However, the sample reported herein is much too small to allow conclusions regarding the overall frequency of DRC occurrence in supercells, or the frequency with which DRCs precede tornado formation. Although further research needs to be done to establish climatological frequencies, the apparent relationship observed between DRCs and impending tornado formation in several supercells is important enough to warrant publication of preliminary findings.
Coupling of ̇ V E and ̇ VCO 2 kinetics: insights from multiple exercise transitions below the estimated lactate threshold

During a step-change in exercise power output (PO), ventilation ( ̇ V E ) increases with a similar time course to the rate of carbon dioxide delivery to the lungs ( ̇ VCO 2 ). To test the strength of this coupling, we compared ̇ V E and ̇ VCO 2 kinetics from ten independent exercise transitions performed within the moderate-intensity domain. Thirteen males completed 3–5 repetitions of ∆40 W step transitions initiated from 20, 40, 60, 80, 100, and 120 W on a cycle ergometer. Preceding the ∆40 W step transitions from 60, 80, 100, and 120 W was a 6 min bout of 20 W cycling from which the transitions of variable ∆PO were examined. Gas exchange ( ̇ VCO 2 and oxygen uptake, ̇ VO 2 ) and ̇ V E were measured by mass spectrometry and volume turbine. The kinetics of the responses were characterized by the time constant ( τ ) and amplitude (Δ ̇ V E /Δ ̇ VCO 2 ). Overall, ̇ VCO 2 kinetics were consistently slower than ̇ VO 2 kinetics (by ~ 45%) and τ ̇ VCO 2 rose progressively with increasing baseline PO and with heightened ∆PO from a common baseline. Compared to τ ̇ VCO 2 , τ ̇ V E was on average slightly greater (by ~ 4 s). Repeated-measures analysis of variance revealed that there was no interaction between τ ̇ VCO 2 and τ ̇ V E in either the variable baseline ( p = 0.49) and constant baseline ( p = 0.56) conditions indicating that each changed in unison. Additionally, for Δ ̇ V E /Δ ̇ VCO 2 , there was no effect of either variable baseline PO ( p = 0.05) or increasing ΔPO ( p = 0.16). These data provide further evidence that, within the moderate-intensity domain, both the temporal- and amplitude-based characteristics of V ̇ E kinetics are inextricably linked to those of ̇ VCO 2 .