Miracle-dz/UniFAR-FTUs huggingface dataset:
Explosive Cyclogenesis and Large-Scale Circulation Changes: Implications for Atmospheric Blocking

Abstract Large-scale circulation changes attending explosive surface cyclogenesis are quantitatively examined in two cases selected from recent winter seasons. Both cases feature a rapidly deepening surface cyclone over the western Atlantic Ocean, but changes in the 500 mb geopotential height field near the cyclone differ in each case. One event, during January 1977, is characterized by the retrogression of an anticyclonic vortex (blocking high) in the 500 mb height field downstream of the surface cyclone. The second case, in February 1978, is distinguished by the formation of a 500 mb cyclonic vortex (cutoff low) upstream of the surface cyclone, but no downstream anticyclonic vortex is observed. The retrogression of the January 1977 block over the Atlantic Ocean coincides with the migration of a 500 mb synoptic-scale perturbation (associated with the surface cyclone) from a planetary- scale trough over North America toward a planetary-scale ridge over Europe. In the February 1978 case, the blocking cyclo.
Detached-Eddy Simulation

Detached-eddy simulation (DES) was first proposed in 1997 and first used in 1999, so its full history can be surveyed. A DES community has formed, with adepts and critics, as well as new branches. The initial motivation of high–Reynolds number, massively separated flows remains, for which DES is convincingly more capable presently than either unsteady Reynolds-averaged Navier-Stokes (RANS) or large-eddy simulation (LES). This review discusses compelling examples, noting the visual and quantitative success of DES. Its principal weakness is its response to ambiguous grids, in which the wall-parallel grid spacing is of the order of the boundary-layer thickness. In some situations, DES on a given grid is then less accurate than RANS on the same grid or DES on a coarser grid. Partial remedies have been found, yet dealing with thickening boundary layers and shallow separation bubbles is a central challenge. The nonmonotonic response of DES to grid refinement is disturbing to most observers, as is the absence of.
Necessary Conditions for Optimality of Cauchy Problems for Parabolic Partial Differential Systems

Recently Zolezzi, [4] presented a necessary condition for optimality for the problem of optimal control of systems governed by parabolic partial differential equations with a first boundary condition. In this paper, we have developed (Theorem 4.3 and Corollary 4.5) a similar necessary condition for Cauchy problems (unbounded domains) that arise naturally in the optimal control problems of stochastic Ito differential systems with fixed terminal time. For the proof of our results we use several theorems of Aronson [1] which have been slightly modified to suit our requirements.
Application of probabilistic and dictionary-based relaxation techniques to a statistical method of edge detection

Two relaxation schemes, a probabilistic and a dictionary-based one, applied to edge detection in images are described. The problem of local edge detection is defined by using a statistical approach. The solution, in terms of statistical decision theory, leads to a multiple, composite, overlapping testing problem that involves configurations of sets of four pixels (quadriplets). The relaxation schemes are also developed using the quadriplets as labeling objects. The initial probabilities for the label set of each object are obtained from the conditional risks given by the local statistical tests. The interaction neighborhood adopted for the two methods is the 4- neighborhood. The iterative label probability updating is performed using a classical heuristic procedure in the two schemes. Tests using noisy synthetic and real images are presented. An experimental analysis of convergence to a consistent and non-ambiguous labeling and speed of convergence is performed for the two schemes and the results are compared. A change in the dictionary according to a modification in the definition of consistency is proposed and the resulting scheme is tested and compared with the two other ones.
A fast first-order continuation total variation algorithm for image denoising

This paper describes a new denoising algorithm which named Continuation total-variation denoising (CTVD) algorithm. The algorithm is based on the novel Nesterov’s first-order method, most notably Nesterov’s smoothing technique, tailored to the image processing application. The algorithm also introduces a fixed point continuation technique to increase the convergence rate, and in particular when to deal with high dynamic range signals and largescale problems.
On the Construction of Free Random Variables

Abstract We investigate some ways to obtain free families of random variables from an initial free family in a tracial noncommutative probability space. The random variables in this initial free family are multiplied on the left and the right by certain operators from an algebra free from the entire family. Aspects of freeness related to this algebra are also considered.
A streamlined derivation of the Black-Scholes option pricing formula

Abstract This article presents a simplified derivation of the Black-Scholes formula for option valuation via the interplay of three essential tools. The pedagogical discussion utilises only elementary integration techniques, basic facts from normal distribution theory and concept of indicator function and is therefore accessible to any junior undergraduate pursuing a degree in financial mathematics, actuarial science, economics and business. Illustrating the use of these mathematical techniques adds rigour to student’s critical thinking and brings a perspective that finance studies is an interdisciplinary area.
Encounters between degenerate stars and extrasolar comet clouds

Under the assumption that the presence of comet clouds around otherwise normal stars is a common occurrence in the Galaxy, the observational consequences of random penetration encounters between the general Galactic population of degenerate stars and these comet clouds is considered. The only case considered is where the compact stars is a single star. For this scenario, encounters involving neutron stars (NSs) result in impact rates 1000-10,000 times slower than in the model of Tremaine and Zytkow (1986). The rate for white dwarfs (WDs) is larger than the one for NSs by a factor of about 30 times the ratio of the degenerate star number densities. The mean impact rate is significantly increased if the number of comets in a cloud is nearly independent of the mass of the central star. It is concluded that some of the observed gamma-ray bursts may be caused by accretion of comets onto NSs and that this scenario, but with a WD as the accretor, probably contributes to the optical flash background rate. 38 refs.
A Comparison of Log-Linear and Regression Models for Systems of Dichotomous Variables

The relative abilities of dummy variable regression and log-linear models to locate significant relationships in systems of dichotomous variables are compared. On logical grounds log-linear models are superior to regression since the data more readily meet the assumptions of the former. Two illustrative examples suggest that the methods converge in their findings when the range in proportions of the dependent dichotomy is between . 25 and. 75, but may differ on which effects are significant when proportions are more extreme. Substantive differences under the two methods are likely to be small, however.
Piezoelectric droplet ejector for ink-jet printing of fluids and solid particles

In this article, we present a technique for the deposition of inks, organic polymers, and solid particles, using a fluid ejector. The ejector design is based on a flextensional transducer that excites axisymmetric resonant modes in a clamped circular plate. It is constructed by bonding a thin piezoelectric annular disk to a thin edge clamped circular plate. Liquids or solid particles are placed behind one face of the plate which has a small orifice (50–200 μm diameter) at its center. By applying an ac signal across the piezoelectric element, continuous or drop-on-demand ejection of photoresist (Shipley Microposit S1400-21, S1400-27, S1805, and S1813), oil-based ink, water, or talcum powder [Mg3Si4O10(OH)2] has been achieved. Successful deposition of a photoresist has been accomplished without spinning, and thus without waste. A boundary integral method was used to numerically simulate drop formation from the vibrating orifice. Simulations have been used to optimize ejection performance.
Adaptive wavelet threshold for image denoising

Threshold selection is the critical issue in image denoising via wavelet shrinkage. Many powerful approaches have been investigated, but few have been to make the threshold values adaptive to the changing statistics of images and meanwhile maintain the efficiency of the algorithm. In this work an efficient adaptive algorithm to capture the dependency of inter-scale wavelet coefficients is proposed. Experiments show that higher peak signal-to-noise ratio can be obtained as compared to other threshold-denoising algorithms.
On Scattering of Waves by an Elliptic Cylinder and by a Semielliptic Protuberance on a Ground Plane

The Mathieu function series solution for the scattering of a plane wave by a perfectly conducting elliptic cylinder is used to derive explicit long-wavelength approximations (k = 2π/λ∼0) for arbitrary polarization, for arbitrary angles of incidence and observation, and for arbitrary eccentricity. We obtain closed-form approximations for the scattering coefficients of the elliptic modes which yield series correct to order k6 on expansion; similarly, for the far-field scattering amplitudes. The corresponding series for the scattered intensity and total scattering cross section are given to order h5 for E parallel to a generator, and to order k7 for E perpendicular. Analogous results are also obtained for the semielliptic protuberance on a ground plane. For this case the series for the intensities and cross sections for both polarizations are correct to order k7. Numerical results obtained from series approximations, from closed forms, and from tables of functions, are given.
On the motion of gas bubbles in homogeneous isotropic turbulence

This paper is concerned with the motion of small gas bubbles, equivalent diameter about 1.0 mm, in isotropic turbulent flows. Data on the mean velocity of rise and the dispersion of the bubbles have been obtained numerically by simulating the turbulence as a sum of Fourier modes with random phases and amplitudes determined by the Kraichnan and the von Kármán–Pao energy-spectrum functions, and by calculating the bubble trajectories from a reasonably well-established equation of motion. The data cover the range β[les ]1, where β is the ratio between the turbulence intensity and the velocity of rise of the bubbles in still fluid. An approximate analysis based on the assumption that β is small yields results that compare favourably with the numerical data, and clarifies the important role played by the lift forces exerted by the fluid.
NEW LARGE SAMPLE AND BOOTSTRAP METHODS ON SHAPE SPACES IN HIGH LEVEL ANALYSIS OF NATURAL IMAGES

This paper, dedicated to the 80th birthday of Professor C. R. Rao, deals with asymptotic distributions of Fréchet sample means and Fréchet total sample variance that are used in particular for data on projective shape spaces or on 3D shape spaces. One considers the intrinsic means associated with Riemannian metrics that are locally flat in a geodesically convex neighborhood around the support of a probability measure on a shape space or on a projective shape space. Such methods are needed to derive tests concerning variability of planar projective shapes in natural images or large sample and bootstrap confidence intervals for 3D mean shape coordinates of an ordered set of landmarks from laser images.
SUPER SYMMETRY IN STRONG AND WEAK INTERACTIONS

For strong interaction two new fermion mass units 105.32 MeV and 11450 MeV are assumed. Existence of "Integral charge quark bosons", "Integral charge effective quark fermions", "Integral charge (effective) quark fermi-gluons" and "Integral charge quark boso-gluons" are assumed and their masses are estimated. It is noticed that, characteristic nuclear charged fermion is Xs · 105.32 = 938.8 MeV and corresponding charged boson is Xs(105.32/x) = 415.0 where Xs = 8.914 is the inverse of the strong coupling constant and x = 2.26234 is a new number by using which "super symmetry" can be seen in "strong and weak" interactions. 11450 MeV fermion and its boson of mass = 11450/x = 5060 MeV plays a crucial role in "sub quark physics" and "weak interaction". 938.8 MeV strong fermion seems to be the proton. 415 MeV strong boson seems to be the mother of the presently believed 493,496 and 547 MeV etc, strange mesons. With 11450 MeV fermion "effective quark-fermi-gluons" and with 5060 MeV boson "quark boso-gluon masses" are estimated. "Effective quark fermi-gluons" plays a crucial role in ground state charged baryons mass generation. Light quark bosons couple with these charged baryons to form doublets and triplets. "Quark boso-gluons" plays a crucial role in ground state neutral and charged mesons mass generation. Fine and super-fine rotational levels can be given by [I or (I/2)] power(1/4) and [I or (I/2)] power(1/12) respectively. Here, I = n(n+1) and n = 1, 2, 3, ….
Particle simulation study of collisionless driven reconnection in a sheared magnetic field

Nonlinear development of collisionless driven reconnection and the consequent energy conversion process between the field and particles in a sheared magnetic field are investigated by means of a two-and-one-half-dimensional particle simulation. Magnetic reconnection takes place in two steps irrespective of a longitudinal magnetic field, but the growth rate of the reconnection field varies in proportion to the E×B drift velocity at an input boundary. It is clearly observed that the triggering mechanism of collisionless driven reconnection for the fast growing phase changes from an electron meandering dominance in a weak longitudinal field to an electron inertia dominance in a strong field. The electron acceleration and heating take place in the reconnection area under the influence of reconnection electric field, while the electron energy is converted to the ion energy through the action of an electrostatic (ambipolar) field excited by magnetic compression in the downstream. It is also found that, in the p.
Finite quantum electrodynamics: a field theory using an indefinite metric

A finite relativistic field theory of quantum electrodynamics is formulated; the theory involves as an essential element the use of an indefinite metric to remove the divergences. Two auxiliary fermion fields with anticommutation relations of opposite sign from the normal fermion field (electron) are coupled with the electron to the electromagnetic field in such a manner that any matrix element, calculated by a perturbation expansion, is finite. Although the new Lagrangian is not explicitly gauge invariant, the electromagnetic field is quantized by a method that yields a propagator in the true Landau gauge, and it is shown that this is sufficient to insure that the physical vector particles are zero-mass transverse quanta (i.e., photons). The physical electron mass and the fine-structure constant are put into the theory, leaving only the masses of the two auxiliary fields as parameters. The effects of mass and charge renormalization are calculated (the former using a technique involving a Taylor expansion in the mass), and are required to be small so that there is no explicit contradiction to the validity of the perturbation expansion. The anomalous magnetic moment of the electron and the differential and total cross sections for Compton scattering are calculated and compared with experiment. A range of the auxiliary mass parameters is found for which the predictions agree with experiment and for which the expansion criteria are satisfied. Thus, a finite quantum electrodynamics is accomplished.
Smooth full field reconstruction of velocity and its gradients from noisy scattered velocimetry data in a cross-slot flow

We present a method combining generalized Tikhonov regularization with a finite element approximation for reconstructing smooth velocity and velocity gradient fields from spatially scattered and noisy velocity data in a two-dimensional complex flow domain. Synthetic velocity data for a cross-slot geometry are generated using the Oldroyd-B solution, subsequently perturbed by random noise. Performances of diverse finite element continuity-regularization criterion combinations are tested against noise-free data, while the optimum regularization parameter is determined using generalized cross-validation. The best performance is achieved for the velocity field and its gradients simultaneously by C2 continuous Hermite finite elements and minimization of a norm of the velocity’s third derivative. The standard regularization criterion based on the second derivative is shown to lead to systematic distortions in boundary regions, allowing therefore a lower reduction in the statistical error. Furthermore, optical fi.
Application of computational fluid dynamic modelling to improve flow and grit transport in Terrence J. O'Brien Water Reclamation Plant, Chicago, Illinois

ABSTRACT The Terrence J. O'Brien Water Reclamation Plant (WRP) serves a population of around 1.3 million people and service area of 368.8 km2 in Chicago, IL. Metropolitan Water Reclamation District of Greater Chicago, the agency responsible for the maintenance and operation of the WRP, observed non-uniform distribution of grit deposition between the six grit tanks. Single- and multiphase flow simulations were used to investigate the non-uniform grit distribution and to evaluate potential solution alternatives to ensure the plant operates at an optimal capacity. The simulations revealed the formation of secondary currents due to a bend in the approach conduit; this explained the preferential sediment conveyance along the left side of the conduit and higher deposition at the southernmost grit tanks. Baffles at the centre of the approach conduit and a constriction wall along the left side were recommended for breaking the secondary currents and uniform distribution of the grits.
SCENARIO FOR THE ONSET OF SPACE-TIME CHAOS

The onset of space-time chaos is studied on the basis of a Galilean invariant model that exhibits the essential characteristics of the phenomenon. By keeping the linear part of the model extremely simple, one has better than usual control of the classes of available stationary solutions. These stationary solutions include not only spatially periodic but also a large set of spatially chaotic solutions that can be characterized by words of a symbolic language. The main proposition of this paper is that space-time chaos in Galilean invariant models can be understood in a qualitative fashion as an orbit in the space of functions that visits words in this language in a random fashion. The appearance of topological defects and other ``signatures'' of space-time chaos are a natural consequence of this dynamics. Finally, we construct a simple demonstration of this scenario.
Efficient constructions of frameproof codes

If C is a code of length n over a p-ary alphabet, then x is called a descendant of the codewords a, b,. e if x/sub i//spl isin/{a/sub i/, h/sub i/,. , e/sub i/} for i=1. , 1 n. The authors study codes with the following property: the descendant of any coalition of codewords of a given maximal size does not belong to C.
Variations in Surface Air Temperatures: Part 1. Northern Hemisphere, 1881–1980

Abstract We have produced, using objective techniques, a long-term series of average Northern Hemisphere temperatures based on monthly mean station data gridded on a 5° latitude by 10° longitude grid. Difficulties in the estimation of this parameter are discussed, deficiencies in the currently available data base and possible effects on the estimated average are described, and monthly mean data are presented. Long-term trends and extremes are identified in the annual and seasonal data. All seasons show similar long-term trends, but there are noticeable differences on time scales of 10 years and less. For example, for winter temperature, the early 20th century warming peaked during the 1940's whereas the maximum in the other seasons was in the previous decade. Both the magnitude of the long-term trends and the year-to-year variability has been greatest in winter. There is evidence that the long-term cooling that characterized the 1940's, 1950's and 1960's has ended. Warming began in the mid to late 1960's .
Objective Sensitivity Analysis of Biological Oscillatory Systems

Abstract Oscillations are crucial for biological functions regulated by complex networks of interacting components. Model-based analysis will help to understand the oscillation mechanisms and predict system behaviour. Features such as period, amplitude, and phase are normally used to characterise oscillations. The corresponding objective sensitivity analysis is not trivial since the raw state sensitivity of limit cycle oscillators is unbounded as time tends to infinity. By introducing the concept of basal state sensitivity, a new phase sensitivity measure is presented based on the cumulative phase directly derived from the raw state sensitivity. In this context, all the objective sensitivities on amplitude, period, and phase can be related to the raw state sensitivity. The algorithm is developed based on intuitive measures of objective sensitivities that can be efficiently calculated. The results are illustrated by the application to a circadian rhythm model.
On a Theorem of Ono and Skinner

Abstract In a recent paper, Ono and Skinner [1998, Ann. of Math. 147 , 453–470] show that if a half integral weight eigenform g ( z ) is good , then g ( z ) has infinitely many coefficients prime to l, for all but finitely many primes l. Their paper ends with the conjecture that all half-integral weight eigenforms (with the exception of certain theta functions) are, in fact, good. We give a brief and elementary proof of the “good” conjecture.
Method of electric powertrain matching for battery-powered electric cars

The current match method of electric powertrain still makes use of longitudinal dynamics, which can’t realize maximum capacity for on-board energy storage unit and can’t reach lowest equivalent fuel consumption as well. Another match method focuses on improving available space considering reasonable layout of vehicle to enlarge rated energy capacity for on-board energy storage unit, which can keep the longitudinal dynamics performance almost unchanged but can’t reach lowest fuel consumption. Considering the characteristics of driving motor, method of electric powertrain matching utilizing conventional longitudinal dynamics for driving system and cut-and-try method for energy storage system is proposed for passenger cars converted from traditional ones. Through combining the utilization of vehicle space which contributes to the on-board energy amount, vehicle longitudinal performance requirements, vehicle equivalent fuel consumption level, passive safety requirements and maximum driving range requirement together, a comprehensive optimal match method of electric powertrain for battery-powered electric vehicle is raised. In simulation, the vehicle model and match method is built in Matlab/simulink, and the Environmental Protection Agency (EPA) Urban Dynamometer Driving Schedule (UDDS) is chosen as a test condition. The simulation results show that 2.62% of regenerative energy and 2% of energy storage efficiency are increased relative to the traditional method. The research conclusions provide theoretical and practical solutions for electric powertrain matching for modern battery-powered electric vehicles especially for those converted from traditional ones, and further enhance dynamics of electric vehicles.