Miracle-dz/UniFAR-FTUs huggingface dataset:
How Does the Eye Warm? Part II: Sensitivity to Vertical Wind Shear and a Trajectory Analysis

AbstractIn Part II of this study, idealized simulations of tropical cyclones are used to investigate the influence of vertical wind shear on the structure of warming and descent in the eye; results are compared with the no-shear simulation that was analyzed in Part I. During intensification of a tropical cyclone in a quiescent environment, time-averaged eye descent is maximized at 12–13-km height. Warming is not generally maximized at these levels, however, because the static stability is at a minimum. Consequently, the perturbation temperature is maximized at midlevels. Each of the above results remains valid for sheared tropical cyclones, and therefore shear does not systematically alter the height of the warm core.An analysis of over 90 000 parcel trajectories yields further insight into the mechanisms of eye warming and addresses several outstanding questions regarding the character of eye descent. The rate at which parcels are stirred from the eye into the eyewall is a strong function of intensity. W.
Path integration over compact and noncompact rotation groups

Applications of group theoretical methods in the path integral formalism of nonrelativistic quantum theory are considered. Analysis of the symmetry of the Lagrangian leads to the expansion of the short time propagator in matrix elements of unitary irreducible representations of the symmetry group. Identification of the coordinates with the group parameters transforms the path integral to integrals over the group manifold. The integration is performed using the orthogonality of the representations. Compact and noncompact rotation groups are considered, where the corresponding path integral is embedded in Euclidean and pseudo‐Euclidean spaces, respectively. The unit sphere and unit hyperboloid may either be viewed as the group manifold itself or at least as a group quotient. In the first case Fourier analysis leads to an expansion in group characters. In the second case an expansion in zonal spherical functions is obtained. As examples the groups SO(n), SU(2), SO(n−1,1), and SU(1,1) are explicitly discussed.
Scaling of relative viscosity of emulsions

A scaling analysis of the relative viscosity of two-phase liquid-liquid emulsions is presented. According to the analysis, the relative viscosity of two oil-in-water emulsions at the same oil concentration and particle Reynolds number is the same, even if the emulsions differ greatly in droplet size. Experimental results are presented to confirm the validity of the proposed scaling relations.
Role of interface roughness and alloy disorder in photoluminescence in quantum‐well structures

A formalism to study the effect of alloy disorder and interface roughness on the linewidths of excitonic emission spectra in quantum‐well structures is developed. The study includes the cases where the alloy forms (a) the barrier region, (b) the well region, and (c) both the barrier and well regions of the quantum‐well structures, and demonstrates the importance of alloy quality in all three cases. The relative importance of the effects of alloy disorder and interface roughness on the excitonic linewidths is discussed. As an illustration, the formalism is applied to AlGaAs/GaAs, InP/InGaAs, and InAlAs/InGaAs quantum‐well structures and the results compared with the available experimental data.
Effect of viscosity on droplet-droplet collision outcome: Experimental study and numerical comparison

The influence of viscosity on droplet-droplet collision behavior at ambient conditions was studied experimentally and numerically. N-decane, monoethyleneglycol (MEG), diethyleneglycol (DEG), and triethyleneglycol were used as liquid phase providing viscosities in the range from 0.9to48mPas. Collision Weber numbers ranged approximately from 10 to 420. A direct numerical simulation code, based on the volume-of-fluid concept, was used for the simulations. Experimentally, observations of two droplet streams using a modified stroboscopic technique (aliasing method) were used to investigate the whole range of impact parameters during one experimental run. The experimental method has previously been verified for the water/air system [C. Gotaas et al., Phys. Fluids 19, 102105 (2007)]. In the present work, it was tested and validated for the n-decane/air system. Measured data agree well with those published in the literature. Well-defined regions of stretching separation and coalescence were identified, while refl.
Stability of mixed-convection flow in a tall vertical channel under non-boussinesq conditions

We have examined the linear stability of the fully developed mixed-convection flow in a differentially heated tall vertical channel under non-Boussinesq conditions. The Three-dimensional analysis of the stability problem was reduced to an equivalent two-dimensional one by the use of Squire's transformation. The resulting eigenvalue problem was solved using an integral Chebyshev pseudo-spectral method. Although Squire's theorem cannot be proved analytically, two-dimensional disturbances are found to be the most unstable in all cases. The influence of the non-Boussinesq effects on the stability was studied. We have investigated the dependence of the critical Grashof and Reynolds numbers on the temperature difference. The results show that four different modes of instability are possible, two of which are new and due entirely to non-Boussinesq effects.
Out-of-Plane Bending of Beam-Wall Joints Based on Elastic Medium Thick Plate Theory

The out-of-plane response of beam-wall joints is studied in the present paper. The governing equations of shear walls obtained by using the orthotropic elastic medium thick plate theory are solved. Additionally, different reinforcing ratios for shear walls in different directions are considered. It is also found that reinforced shear walls can be simplified as isotropic walls no matter whether the reinforcing ratio in both directions is the same or not for most engineering structures. In view of this, the out-of-plane response of beam-wall joints is investigated based on the isotropic medium thick plate theory and the effects of geometrical parameters of the joints on the responses of the shear walls are discussed in detail. For further simplification, the equivalent frame model is introduced and a very simple formula to determine the equivalent width is suggested for practical applications.
Noncircular elliptic discs as numerical ranges of nilpotent operators

We show that (1) if A is a nonzero quasinilpotent operator with ran A n closed for some n ≥ 1, then its numerical range W(A) contains 0 in its interior and has a differentiable boundary, and (2) a noncircular elliptic disc can be the numerical range of a nilpotent operator with nilpotency 3 on an infinite-dimensional separable space. (1) is a generalization of the known result for nonzero nilpotent operators, and (2) is in contrast to the finite-dimensional case, where the only elliptic discs which are the numerical ranges of nilpotent finite matrices are the circular ones centred at the origin.
VIRTUAL KNOT PRESENTATION OF RIBBON TORUS-KNOTS

Any ribbon torus-knot in 4-space is naturally associated with a virtual knot. We investigate a relationship between ribbon torus-knots and virtual knots from this viewpoint. We also give a new example of a non-classical virtual knots which can not be detected by the group and the Z-polynomial.
Velocity‐free attitude stabilization with inertial vector measurements

This paper deals with the attitude stabilization problem of a rigid body, where neither the angular velocity nor the attitude is used in the feedback; only body‐referenced vector measurements are needed. The proposed control scheme is based on an angular velocity observer‐like system relying solely on vector measurements. The proposed controller ensures almost global asymptotic stability and provides some interesting performance properties through an appropriate tuning of the control gains. The performance and effectiveness of the proposed control scheme are illustrated via simulation results where the control gains are adjusted using a nonlinear optimization. Copyright © 2015 John Wiley & Sons, Ltd.
Skill importance in women’s soccer

Abstract Soccer analytics often follow one of two approaches: 1) regression models on number of shots taken or goals scored to predict match winners, or 2) spatial and/or temporal analysis of plays for evaluation of strategy. We propose a new model to evaluate skill importance in soccer. Play by play data were collected on 22 NCAA Division I Women’s Soccer matches with a new skill notation system. Using a Bayesian approach, we model play sequences as discrete absorbing Markov chains. Using posterior distributions, we estimate the probability of 35 distinct offensive skills leading to a shot during a single possession.
The Transitional Pre-Main-Sequence Object DI Tauri: Evidence for a Substellar Companion and Rapid Disk Evolution

We report mid-IR observations of two young stars found in the Taurus dark cloud, spatially resolving for the first time their 10 μm emission. The weak-emission T Tauri star DI Tau, tentatively identified by Skrutskie et al. on the basis of 12 μm IRAS data as an object in the process of dissipating its circumstellar disk, is found to have no infrared excess at a wavelength of 10 μm. The nearby classical T Tauri star DH Tau exhibits excess emission at 10 μm consistent with predictions based on circumstellar disk models. While both objects appear to have the same stellar mass, age, and rotation rate, they differ in two fundamental respects: DH Tau is a single star with an active accretion disk, and DI Tau is a binary system lacking such a disk. The companion to DI Tau has a very low luminosity and is located at a projected distance of ~20 AU from the primary. Assuming the system to be coeval, we derive a mass below the hydrogen burning limit for the companion. We speculate that the formation of a substellar mass companion has led to the rapid evolution of the circumstellar disk that may have surrounded DI Tau.
An Introduction to Stochastic Processes in Physics

Contents: Preface and Acknowledgments Chapter 1: Random Variables Chapter 2: Expected Values Chapter 3: Random Steps Chapter 4: Continuous Random Variables Chapter 5: Normal Variable Theorems Chapter 6: Einstein's Brownian Motion Chapter 7: Ornstein-Uhlenbeck Processes Chapter 8: Langevin's Brownian Motion Chapter 9: Other Physical Processes Chapter 10: Fluctuations without Dissipation Appendix A: "On the Theory of Brownian Motion," by Paul Langevin, translated by Anthony Gythiel Appendix B: Kinetic Equations Answers to Problems References Index
A Super-Algebraically Convergent, Windowing-Based Approach to the Evaluation of Scattering from Periodic Rough Surfaces

We introduce a new second-kind integral equation method to solve direct rough surface scattering problems in two dimensions. This approach is based, in part, upon the bounded obstacle scattering method that was originally presented in Bruno et al. [2004] and is discussed in an appendix of this thesis. We restrict our attention to problems in which time-harmonic acoustic or electromagnetic plane waves scatter from rough surfaces that are perfectly reflecting, periodic and at least twice continuously differentiable; both sound-soft and sound-hard type acoustic scattering cases---correspondingly, transverse-electric and transverse-magnetic electromagnetic scattering cases---are treated. Key elements of our algorithm include the use of infinitely continuously differentiable windowing functions that comprise partitions of unity, analytical representations of the integral equation’s solution (taking into account either the absence or presence of multiple scattering) and spectral quadrature formulas. Together, they provide an efficient alternative to the use of the periodic Green’s function found in the kernel of most solvers’ integral operators, and they strongly mitigate the rapidly increasing computational complexity that is typically borne as the frequency of the incident field increases. After providing a complete description of our solver and illustrating its usefulness through some preliminary examples, we rigorously prove its convergence. In particular, the super-algebraic convergence of the method is established for problems with infinitely continuously differentiable scattering surfaces. We additionally show that accuracies within prescribed tolerances are achieved with fixed computational cost as the frequency increases without bound for cases in which no multiple reflections occur. We present extensive numerical data demonstrating the convergence, accuracy and efficiency of our computational approach for a wide range of scattering configurations (sinusoidal, multi-scale and simulated ocean surfaces are considered). These results include favorable comparisons with other leading integral equation methods as well as the non-convergent Kirchhoff approximation. They also contain analyses of sets of cases in which the major physical parameters associated with these problems (i.e., surface height, wavenumber and incidence angle) are systematically varied. As a result of these tests, we conclude that the proposed algorithm is highly competitive and robust: it significantly outperforms other leading numerical methods in many cases of scientific and practical relevance, and it facilitates rapid analyses of a wide variety of scattering configurations.
Assessing Dimensionality of Noncompensatory Multidimensional Item Response Theory With Complex Structures

The purpose of this study was to investigate the effect of complex structure on dimensionality assessment in noncompensatory multidimensional item response models using dimensionality assessment procedures based on DETECT (dimensionality evaluation to enumerate contributing traits) and NOHARM (normal ogive harmonic analysis robust method). Five methods were evaluated: two DETECT-based methods—exploratory and cross-validated—and three NOHARM-based methods: root mean square residual (RMSR), χ G / D 2 , and approximate likelihood ratio (ALR). The results suggested that the studied methods had varying degree of success in correctly counting the number of dimensions and in meaningfully labeling sets of items as dimension-like. In two-dimensional, shorter tests, χ G / D 2 and ALR largely outperformed RMSR- and DETECT-based methods in conditions with small and medium sample sizes, across all levels of complexity and correlations. Lengthening of the test in two-dimensional conditions led to most notably improved accuracy in determining the correct number of dimensions for NOHARM-based RMSR, whereas for the remaining methods, increase in the number of items had differential effect. DETECT-based methods, on the other hand, had more success in labeling sets of items as dimension-like in conditions with two dimensions, irrespective of the test length, suggesting the items that ought to be together were more often grouped together. Performance of the methods was further evaluated in conditions with larger dimensionality (i.e., 3) and conditions with the increased number of items (i.e., longer tests).
On the suboptimal design of regulators using time-multiplied performance index

The suboptimal design of linear regulators with time-multiplied quadratic performance index, using constant state feedback gains is considered. The necessary conditions to be satisfied by the suboptimal control law are derived in a simpler way using the Hamiltonian approach. An example is given to illustrate more clearly the effect of time-multiplied performance index on the transient response.
Robust Estimation of Mixture Complexity

In many applications, it is important to find the mixture with fewest number of components, known as the mixture complexity, that provides a satisfactory fit to the data. This article focuses on developing an estimator of mixture complexity that is consistent when the form of component densities are unknown but are postulated to be members of some parametric family and is simultaneously robust against model misspecification. We treat the estimation of mixture complexity as a model selection problem and construct an estimator of mixture complexity as a byproduct of minimizing a Hellinger information criterion. This estimator is shown to be consistent for any parametric family of mixtures. When the model is correctly specified, Monte Carlo simulations for a wide variety of normal mixtures show that our estimator is very competitive with several others in the literature in correctly identifying the true mixture complexity. The basic construction, being firmly rooted in the minimum Hellinger distance approach, enables our estimator to naturally inherit the property of robustness, which is examined, through simulations, under symmetric departures from postulated component normality. In terms of correctly identifying the mixture complexity under model misspecification, our estimator performs much better than an estimator based on the Kullback–Leibler distance due to James, Priebe, and Marchette. An example concerning hypertension is revisited to further illustrate the performance of our estimator.
Evaluating the Calibration of Multi-Step-Ahead Density Forecasts Using Raw Moments

The evaluation of multi-step-ahead density forecasts is complicated by the serial correlation of the corresponding probability integral transforms. In the literature, three testing approaches can be found that take this problem into account. However, these approaches rely on data-dependent critical values, ignore important information and, therefore lack power, or suffer from size distortions even asymptotically. This article proposes a new testing approach based on raw moments. It is extremely easy to implement, uses standard critical values, can include all moments regarded as important, and has correct asymptotic size. It is found to have good size and power properties in finite samples if it is based on the (standardized) probability integral transforms.
Neutron resonance spectroscopy for the characterization of materials and objects

The resonance structure in neutron induced reaction cross sections can be used to determine the elemental compositions of materials or objects. The occurrence of resonances is the basis of neutron resonance capture analysis (NRCA) and neutron resonance transmission analysis (NRTA). NRCA and NRTA are fully non-destructive methods to determine the bulk elemental composition without the need of any sample preparation and resulting in a negligible residual activity. They have been applied to determine the elemental composition of archaeological objects and to characterize reference materials used for cross section measurements. For imaging applications a position sensitive neutron detector has been developed within the ANCIENT CHARM project. The detector is based on a 10 × 10 array of 6Li-glass scintillators mounted on a pitch of 2.5 mm, resulting in a 25 × 25 mm2 active area. The detector has been tested at the time-of-flight facility GELINA and used at the ISIS spallation source to study cultural heritage objects.
Determining soil hydraulic functions from evaporation experiments by a parameter estimation Approach: Experimental verifications and numerical studies

A parameter estimation method is developed for the determination of unsaturated soil hydraulic properties from evaporation experiments under laboratory conditions. Variables used in the inversion procedure are soil water pressure heads at various positions and total soil weights, both measured as a function of time during the experiment. Unknown parameters of different analytical expressions used to describe the soil hydraulic properties are estimated by coupling a finite difference solution of the Richards equation with a nonlinear optimization problem. This problem is formulated by minimizing the deviations between the numerical solution of the transient flow process and the real system response measured during the experiment. Minimization of the objective function is performed using a version of the Levenberg‐Marquardt's method; the procedure also provides information about the uncertainty in parameter estimates. The performance of the selected parametric relationships is evaluated, and the applicability and accuracy of the proposed inverse method are shown by comparing estimated water retention and hydraulic conductivity functions with experimental results obtained via the instantaneous profile method. Parameter sensitivity analyses and stability of the inverse solutions are discussed with reference to the originally designed evaporation experiment and to an evaporation method that is developed with a view to reducing experimental efforts. Further insights into the properties of existence and uniqueness of inverse solutions are gained by examining contour plots of the objective functions under varying experimental conditions. The results confirm the reliability and flexibility of the proposed method and suggest that the evaporation flux imposed at the upper soil surface may determine the well posedness of the optimization problem.
Electrical charge transport and energy conversion with fluid flow during electrohydrodynamic conduction pumping

The electrohydrodynamic (EHD) conduction pumping takes advantage of the electrical Coulomb force exerted on dielectric liquid by externally applied electric field(s). The conduction term here represents a mechanism for electric current flow in which charged carriers are produced not by injection from electrodes or induction from electric fields, but by dissociation of neutral electrolytic species within the dielectric liquid. The EHD conduction pumping can be applied to drive both isothermal liquid and two-phase fluids without the degradation of the working fluid electric properties. Such nonmechanical and low-power-consumption pumping mechanism can be utilized for active flow generation/control under both terrestrial and microgravity conditions. So far, the majority of conducted studies has been focused mainly on the experimental realization of the EHD conduction pumping phenomenon and the computational fluid dynamics simulation verification. More fundamental studies, such as theoretical analysis with convection terms included, generalized nondimensional modeling, and pumping efficiency prediction, are required for a complete understanding of this new EHD pumping phenomenon. An asymptotic nondimensional theoretical model for the EHD conduction pumping has been presented in this paper, with the fluid convection taken into account. The theoretical analysis provided here reveals the effects of flow convection on the EHD conduction pumping and the associated energy transport/conversion during the pumping process. Based on the asymptotic model, the pumping efficiency of the EHD conduction pumping is analytically derived and compared with the experimental data. Such results help clarify the capabilities and limitations corresponding to the nature of the EHD conduction pumping.The electrohydrodynamic (EHD) conduction pumping takes advantage of the electrical Coulomb force exerted on dielectric liquid by externally applied electric field(s). The conduction term here represents a mechanism for electric current flow in which charged carriers are produced not by injection from electrodes or induction from electric fields, but by dissociation of neutral electrolytic species within the dielectric liquid. The EHD conduction pumping can be applied to drive both isothermal liquid and two-phase fluids without the degradation of the working fluid electric properties. Such nonmechanical and low-power-consumption pumping mechanism can be utilized for active flow generation/control under both terrestrial and microgravity conditions. So far, the majority of conducted studies has been focused mainly on the experimental realization of the EHD conduction pumping phenomenon and the computational fluid dynamics simulation verification. More fundamental studies, such as theoretical analysis with co.