Miracle-dz/UniFAR-FTUs huggingface dataset:
The Influence of the Shear-Induced Pressure Gradient on Thunderstorm Motion

Abstract In the present investigation we propose a simple theory to explain how a veering environmental wind shear vector can cause an initially symmetric updraft to grow preferentially to the right of the shear vector and acquire cyclonic rotation. The explanation offered is based on linear theory which predicts that interaction of the mean shear with the updraft produces favorable vertical pressure gradients along its right flank. To asses the validity of linear theory for large-amplitude updrafts, the three-dimensional, shallow, anelastic equations are numerically integrated using a simple parameterization for latent heating within a cloud and the linear and nonlinear forcing terms are separately analyzed. These results suggest that although the nonlinear effects strongly promote splitting of the updraft, the linear forcing remains the dominant factor in preferentially enhancing updraft growth on the right flank. We believe this differential forcing is a major contributor to the observed predominance o.
Multi-objective optimization design of bridge piers with hybrid heuristic algorithms

This paper describes one approach to the design of reinforced concrete (RC) bridge piers, using a three-hybrid multi-objective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs), namely MOSAMO1, MOSAMO2 and MOSAMO3. The procedure is applied to three objective functions: the economic cost, the reinforcing steel congestion and the embedded CO2 emissions. Additional results for a random walk and a descent local search multi-objective algorithm are presented. The evaluation of solutions follows the Spanish Code for structural concrete. The methodology was applied to a typical bridge pier of 23.97 m in height. This example involved 110 design variables. Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts. Further, the proposed procedure will help structural engineers to enhance their bridge pier designs.
Experimental analysis of statistical characteristics of a very shallow underwater acoustic channel

Underwater acoustic channel is characterized as a time‐varying and multipath environment. Not only each propagation path changes randomly but also the scattered waves from the surface and bottom deteriorate signal transmission resulting in fading channels and poor communication performance. In order to design communication algorithms and determine modem parameters the characteristics of random ocean channel must be analyzed in advance. In this paper we investigate the statistical channel properties with experimental data gathered in a very shallow water near the southern coast of South Korea using band‐limited signals with center frequencies of 20‐40 kHz. The impulse responses at several distances up to 4km are estimated and their statistical characteristics in the complex domain are analyzed. We found that the statistical properties are highly dependent on the channel impulse response and the carrier frequency.
Elementary particles in a curved space

The Fierz-Pauli program is carried out for spin-2 fields in-de Sitter space. A spin-s field is associated with an irreducible representation D(E0, s) of the universal covering group of SO(3, 2), with extremal weight (L0 5, L1 2) → (E0, s). (L0 5 is the time translation operator.) The particular cases D(s+1, s) (s=1, 2,.) are characterized by invariance of the field equations under a gauge group and is for this and other reasons called ‘the massless case’. The Fierz-Pauli program is carried out for s=2, E0>3; it fails in the special case E0=3 only. The limit, as E0 → 3, of the Fierz-Pauli field equation agrees with the linearized form of Einstein's gravitational field equation, with cosmological constant λ=-3ρ. Here ρ is the curvature constant of de Sitter space and the linearization referred to is defined relative to the de Sitter metric.
Arbitrage Theory with State-Price Deflators

The aim of this article is to develop some mathematical results for the existence of asset price bubbles, which is consistent with the martingale analysis of financial markets. More specifically, this article studies the relation between the divergence of the sum of dividend-price ratios and the absence of bubbles. The framework used describes a contemporary model of a securities market built in an environment with both uncertainty and a countable number of trading dates. The market allows trading of a finite number of corporate securities. In this context, no arbitrage condition is characterized by the existence of a state-price deflator across an infinite time horizon.
On cosmological constraints from statistics of X-ray clusters

We here studied the temperature and luminosity functions of X-ray clusters and obtained cosmological constraints from the statistics and the evolution of X-ray clusters for various cosmological models. The statistical analysis for the temperature function and the luminosity function for X-ray clusters, according to the hierarchical clustering scenario-the CDM model, for example-suggests that the density parameter Ω 0 ≃1.0 and the baryon fraction f b ≃0.15 with h=0.5 or f b ≃0.05 with h=1.0. The analysis for the temperature function shows us also that the bias parameter b≃1.5 and that the index for the power spectrum n≃-1.5, with the suggestion that secondary effects occur like that of the substructure or larger variance of the density perturbation in a large scale ≥8 h -1 Mpc
Second-harmonic generation from electrically poled SiO 2 glasses: effects of OH concentration, defects, and poling conditions

To clarify the origin of second-harmonic generation (SHG) from electrically polarized SiO2 glasses, we have investigated the influence of the OH concentration and structural defects in the SiO2 glasses and that of the poling conditions on the intensity of SHG. The SHG intensity was increased with increased OH concentration, and the most intense SHG was observed from the solgel-derived SiO2 glasses containing 2500 parts in 106 OH. On the other hand, the intensity of SHG was not clearly related to the specific defects observable by electron spin resonance and vacuum-ultraviolet absorption spectra. With respect to the poling conditions, the intensity of SHG was the largest when the glasses were poled by 3 kV at 200 °C for 4 h, and χ33(2) was evaluated as 0.37 pm/V, which was ∼8% of χ22(2) for LiNbO3.
Radio emission from chemically peculiar stars

In five VLA observing runs the initial survey of radio emission from magnetic Bp-Ap stars by Drake et al. is extended to include a total of 16 sources detected at 6 cm out of 61 observed, giving a detection rate of 26 percent. Of these stars, three are also detected at 2 cm, four at 3.6 cm, and five at 20 cm. The 11 new stars detected as radio sources have spectral types B5-A0 and are He-weak and Si-strong. No classical (SrCrEu-type) Ap stars have yet been detected. The 16 detected sources show a wide range of radio luminosities with the early-B He-S stars on average 20 times more radio luminous than the late-B He-W stars and 1000 times more luminous than Theta Aurigae. Multifrequency observations indicate flat spectra in all cases. Four stars have a detectable degree of circular polarization at one or more frequencies. It is argued that the radio-emitting CP (chemically peculiar) stars form a distinct class of radio stars that differs from both the hot star wind sources and the active late-type stars. The observed properties of radio emission from these stars may be understood in terms of optically thick gyrosynchrotron emission from a nonthermal distribution of electrons produced in a current sheet far from the star. In this model the electrons travel along magnetic fields to smaller radii and higher magnetic latitudes where they mirror and radiate microwave radiation.
On Numerical Types of Algebraic Curves on Rational Surfaces

The purpose of this paper is to study numerical properties of algebraic curves on rational surfaces. Here by curves and surfaces we mean projective irreducible varieties of dimension 1 and 2, respectively, which are defined over the field of complex numbers. We shall study pairs $(S, D)$ of projective non-singular rational surfaces $S$ and curves $D$ on $S$ . First, we recall some basic notions and results conceming birational geometry of pairs. Let $\Sigma_{b}$ denote a $P^{1}$ -bundle over $P^{1}$ that has a minimal section $\Delta_{\infty}$ with $\Delta_{\infty}^{2}=-b\leq 0$ . Furthermore, let $C$ be a curve on $\Sigma_{b}$ . The Picard group of $\Sigma_{b}$ is generated by the section
Composition of psychrotrophic microflora of water and biofilter filler in recirculation aquaculture system on trout farm

The advancement of RAS technology and advantages over flow-through systems has led to increasing of Recirculating Aquaculture Systems (RAS) use. All the key biological mechanisms involved in RAS need to be better understood, especially those determining the development of bacterial populations and their interactions with fish. This study presents new knowledge on compositions of psychrotrophic bacteria community in various parts of RAS for rainbow trout growing, which constitute essential tools for system management. Pseudomonas, Alcaligenes, Acinetobacter, Aeromonas, Enterobacteriaceae, and also a small number of gram-positive bacteria and cocci were identified as dominant taxa of psychrotrophic bacteria in RAS biotopes. Microorganisms of the genera Pseudomonas, Alcaligenes, Acinetobacter and Aeromonas are the autochthonous microflora which forms an active microbial fiofilm on biofilter filler.
Sound of carbon nanotube assemblies

Strong thermo- and photoacoustic responses have been detected for aligned arrays of multiwalled carbon nanotube (MWNT) forests and solid drawn MWNT sheets. When heated using alternating current or a near-IR laser modulated in 100–20000Hz range, the nanotube assemblies generated loud, audible sound, with higher sound pressure being detected from the MWNT sheets. An evaluation of nonlinear distortions of the thermoacoustic signal revealed a highly peculiar behavior of the third and fourth harmonics produced from forests grown on silicon wafers. The peculiarities were especially pronounced for short forests and can be associated with the heat transfer from the MWNT layer to the substrate. For both types of nanotube assemblies, the acoustic signal’s amplitude varied with frequency approximately by the power low fp. The power factor p was found to be unexpectedly high for short forests probably due to heat loss to the substrate. The observed peculiarities can be used for the characterization of the prepared MW.
Hyperspectral image fusion by the similarity measure-based variational method

Hyperspectral remote sensing is widely used in many fields suchas agriculture, military detection, mineral exploration, and so on. Hyperspectral data has very high spectral resolution, but much lower spatial resolution than the data obtained by other types of sensors. The low spatial resolution restrains its wide applications. On the contrary, we easily obtain images with high spatial resolution but insufficient spectral resolution (like panchromatic images). Naturally, people expect to obtain images that have high spatial and spectral resolution at the same time by the hyperspectral image fusion. In this paper, a similarity measure-based variational method is proposed to achieve the fusion process. The main idea is to transform the image fusion problem to an optimization problem based on the variational model. We first establish a fusion model that constrains the spatial and spectral information of the original data at the same time, then use the split bregman iteration to obtain the final fused data. Also, we analyze the convergence of the method. The experiments on the synthetic and real data show that the fusion method preserves the information of the original images efficiently, especially on the spectral information.
A Direct Interpolation Method for Irregular Sampling

Abstract In this paper, band-limited functions are reconstructed from their values taken at a sequence of irregularly spaced sample points. We use a modified Lagrange formula, which is attributed to Boas and Bernstein. The formula used in this paper differs from the classical Boas–Bernstein formula in the following way. Instead of using infinite canonical products with respect to the whole sequence of sample points, we use canonical products with respect to sequences of sample points which are irregularly spaced only on finite intervals. Estimates for the truncation error of this reconstruction method are given.
THE DESIGN OF SYSTEMS TO CONTROL ACTIVELY PERIODIC SOUND TRANSMISSION INTO ENCLOSED SPACES, PART I: ANALYTICAL MODELS

Abstract The physical arrangement of an active noise control system (control sources and error sensors) limits the maximum levels of sound attenuation which can be achieved under ideal conditions. This paper presents a theoretical framework suitable for aiding in the design of feedforward active systems to control sound transmission into coupled enclosures. The analytical models are formulated by using modal coupling theory, and as such can be readily applied to a variety of sound transmission problems. A variety of error criteria are used as the basis of model formulation such as minimization of acoustic potential energy in the enclosure, minimization of acoustic pressure amplitude at a discrete location, and minimization of structural kinetic energy. In the companion paper (part II [1]) these models are used to illustrate physical control mechanisms and the effect of design variables on system performance.
Combinatorial Approach to the N‐Representability of P‐Density Matrices

This paper considers the determination of N‐representability (for diagonal elements) of p‐density matrices restricted to certain finite‐dimensional subspaces of l2 of the configuration space of N identical antisymmetric particles. In particular, an arbitrary set of N + p spin orbitals is selected and one considers the (N+pp)‐dimensional subspace generated by all possible Slater determinants of the spin orbitals being considered. Applying a combinatorial approach to the problem, a necessary and sufficient set of conditions is determined; previous work has dealt only with necessary conditions, except in the 1‐matrix case. The paper concludes by presenting a probabilistic interpretation of these conditions which seems of particular interest for the 2‐matrix case. The conditions presented here in combination with the Pauli principle give a probabilistic view of the expected occupation of p‐tuples of spin orbitals in terms of the expected occupations of lower‐order‐tuples of spin orbitals.
A water wave analog of the Casimir effect

Two rigid plates are vertically suspended by thread such that they are parallel to and opposite each other. The plates are partially submerged in a dish of liquid that is attached to the top of a vertical shake table. When the shake table is driven with noise in a frequency band, random surface waves are parametrically excited, and the plates move toward each other. The reason for this attraction is that the waves carry momentum, and the wave motion between the plates is visibly reduced. The behavior is analogous to the Casimir effect, in which two conducting uncharged parallel plates attract each other due to the zero-point spectrum of electromagnetic radiation. The water wave analog can be readily demonstrated and offers a visual demonstration of a Casimir-type effect. Measurements of the force agree with the water wave theory even at large wave amplitudes, where the theory is expected to break down. The water wave analog applies to side-by-side ships in a rough sea and is distinct from the significant .
Dense Molecular Clouds in the Galactic Center Region. II. Statistical Properties of the Galactic Center Molecular Clouds

We present statistical properties of molecular clouds based on the Galactic center region survey in CS J = 1-0 with the 45 m radio telescope of the Nobeyama Radio Observatory. We identified 159 molecular cloud clumps from the survey data. We found that the velocity widths of the Galactic center molecular clumps are about 5 times larger than those of the Galactic disk molecular clouds with the same radius. We estimated the virial theorem masses and the LTE masses of the identified clumps. The virial-theorem masses are 1 order of magnitude larger than the LTE masses. We obtain the mass and size spectra for the Galactic center molecular clumps. The mass spectrum is dN/dM ∝ M-1.6±0.1 (M ≳ 1.0 × 104 M☉). The spectral index was approximately equal to the values obtained in the Galactic disk regions, although the statistical relations, such as the line width-size relation, for the Galactic center clouds are much different from those for the disk clouds. The size spectrum is dN/dR ∝ R-4.0±0.4 (R ≳ 3.3 pc). The spectral index is consistent with those for the disk clouds.
Performance analysis of a GI / D ‑ MSP ∕ 1 ∕∞ queueing system under different service phase initiations

The main objective of this paper is to derive some analytic results concerning GI / D - MSP ∕ 1 ∕∞ queueing model in which customers arrive according to a discrete-time renewal process. We assume that the service process is correlated and its configuration is designed through discrete-time Markovian service process under different service phase initiations to start a busy period. The system-length distributions at various time epochs have been obtained by employing the matrix-geometric approach. An explicit closed form expression for the waiting-time distribution in the queue measured in slots has also been derived. Computational experiences with a variety of numerical results are discussed to show the effect of system parameters on the performance measures. This queueing model has potential applications in the domain of computer networks, telecommunication systems, and wireless local communication networks for evaluating the various system performances. An application of this type of queueing model in the domain of network coding in wireless communications is also discussed. This provides relevant information to the system analysts, researchers, and industry people who are interested to investigate congestion problems using queueing theory.
Preparation and characteristics of Nb/Al‐oxide‐Nb tunnel junctions

Preparation and characteristics of refractory Nb/Al‐oxide‐Nb Josephson tunnel junctions with critical current densities jc from ∼103 to ∼4×104 A/cm2 were studied with respect to junction quality, uniformity, reproducibility and jc control. The key steps leading to improved junction parameters are emphasized and compared with previously used procedures. The results include jmaxc/jminc of 1.2, on a 1‐in. chip, Vm up to 56 mV in junctions with jc∼103 A/cm2, and Vm up to 24 mV with jc∼6×103 A/cm2. Good run‐to‐run reproducibility and control of jc are also demonstrated. In particular, jc is shown to increase by a factor of ∼40 when the oxygen pressure during the in‐situ oxidation of the Al overlayer is reduced from 1 to 0.01 Torr.
Carbon isotopic ratios in giant stars in the globular clusters M4 and M22

The abundances of C-12 and C-13 have been determined for seven stars in the globular cluster M4 and five stars in M22. The analysis utilizes low-resolution IR spectra, obtained with the KPNO-FTS, of the first-overtone vibration-rotation (V-R) bands of CO near a wavelength of 2.3 microns. This resolution is sufficient to resolve the individual V-R bands of C-12O and C-13O. Spectrum synthesis was used to derive individual carbon-12 and -13 abundances. This method of using low-resoluion spectra to obtain abundances was tested by deriving C-isotopic abundances in ten G and K giants that have been studied at high resolution by previous investigators: good agreement is found between the low- and high-resolution analyses. The globular cluster giants, in general, exhibit very low C-12/C-13 ratios, with most having C-12/C-13 of less than 10. Results suggest that those low-mass, low-metallicity giants have undergone extensive mixing of CN-processed material into their atmospheres. These results are compared to previous analyses of both metal-poor field giants and globular cluster giants, and discussed in terms of deep mixing in these stars. 40 refs.
A stochastic approximation algorithm for maximum‐likelihood estimation with incomplete data

We propose a new stochastic approximation (SA) algorithm for maximum‐likelihood estimation (MLE) in the incomplete‐data setting. This algorithm is most useful for problems when the EM algorithm is not possible due to an intractable E‐step or M‐step. Compared to other algorithm that have been proposed for intractable EM problems, such as the MCEM algorithm of Wei and Tanner (1990), our proposed algorithm appears more generally applicable and efficient. The approach we adopt is inspired by the Robbins‐Monro (1951) stochastic approximation procedure, and we show that the proposed algorithm can be used to solve some of the long‐standing problems in computing an MLE with incomplete data. We prove that in general O(n) simulation steps are required in computing the MLE with the SA algorithm and O(n log n) simulation steps are required in computing the MLE using the MCEM and/or the MCNR algorithm, where n is the sample size of the observations. Examples include computing the MLE in the nonlinear error‐in‐variable model and nonlinear regression model with random effects.
The characterization of pure and niobium-doped crystals of strontium titanate using Hall, electrical conductivity, and optical absorption data

A description is given of the heat treatment, under controlled conditions, of crystals of strontium titanate, both pure and niobium-doped, and of the effect of this treatment on the defect states in this material. Our analysis is based on evaluation of the results of electrical conductivity and Hall effect measurements, and those of optical absorption.
TRANSFER PRINCIPLES FOR INTEGRABILITY AND BOUNDEDNESS CONDITIONS FOR MOTIVIC EXPONENTIAL FUNCTIONS

We prove new transfer principles for motivic exponential functions. Where the first such transfer principle of (R. Cluckers, F. Loeser, Constructible exponential functions, motivic Fourier transform and transfer principle, Ann. Math., 171, 1011-1065 (2010)) treats equal- ities between integrals, the new transfer principles allow one to change the characteristic of the local field when studying integrability and bound- edness conditions. All these transfer principles have applications in the Langlands program. Further we have a theme of results, connecting loci of integrability and loci of boundednes with zero loci and giving new integration results in various settings.
3D Nonlinear Viscoelastic-Viscoplastic Model for Ramming Paste Used in a Hall-Héroult Cell

AbstractRamming paste is a carbonaceous porous material used in Hall-Heroult cells. It is baked in place under varying loads. To model the cell mechanical behavior during its lifespan, it was necessary to develop a constitutive law that included ramming paste creep behavior. A three-dimensional (3D) nonlinear viscoelastic-viscoplastic constitutive law was devised and developed to model the primary and secondary creep stages of baked paste. The model consisted of two parts (i.e., viscoelastic and viscoplastic). Each creep mechanism was based on the existence of a dissipative potential for the hydrostatic and deviatoric parts. Analytical solutions were presented for linear creep behavior. For the nonlinear case, the deviatoric part of the viscoelastic behavior could be obtained numerically, and all other parts analytically. Finally, model parameters were identified for paste baked and tested at different temperatures. A pattern search algorithm was used to optimize the model parameters. A comparison of the .