Miracle-dz/UniFAR-FTUs huggingface dataset:
Linear models of acoustic waves in sunspot umbrae

The two-dimensional, linear hydrodynamics of quiet solar and umbral model atmospheres in a plane-parallel, adiabatic approximation are investigated. The 5.5-8.5 mHz oscillations observed in umbral chromospheres and transition regions are interpreted as acoustic waves propagating parallel, or nearly parallel, to the temperature gradient. These waves are not totally internally reflected by the steep temperature gradient and, thus, are not trapped. Partial reflections, however, are effective in modulating the transmission as a function of frequency. The resonant transmission mechanism of Zugzda, Locans, and Staude (1983) is found to produce a spectrum of resonances in the transmission of acoustic waves in any atmosphere with a temperature minimum. Since the observed umbral oscillations display power in only a narrow range of frequencies, characteristics of the umbral models, wave propagation, and observations that would tend to suppress the higher frequency resonances are examined.
Sample Size Reestimation for Clinical Trials With Censored Survival Data

A flexible design with updating of sample size in clinical trials is proposed for censored survival data. Patients enter trials serially and are subject to random loss to follow-up. The statistical inference is based on a weighted average of the linear rank statistics, where the weight function at each look depends on prior observed data. A stopping rule is devised to allow early termination and acceptance of the null hypothesis when the experimental treatment offers no advantage or is inferior to the control. The null hypothesis that two survival distributions are equal may be rejected only at the last step when the weight function is used up. The overall type I error rate is preserved. Independent increments for the sequential linear rank statistic is key to deriving asymptotic properties of the test statistic. Some extensive simulations have been carried out to compare the operating characteristics of the method under different scenarios, and for a comparison with the usual log-rank test with fixed sample design. The methodology is also illustrated with a colon cancer clinical trial.
Simulation of single and many particle gauge theories with ultracold atomic gases

The study of systems formed from ultracold atomic gases has emerged to become one of the most active research fields within the condensed matter landscape. These highly controllable macroscopic systems amalgamate ideas from many sub disciplines of physics, including the study of low temperatures, quantum optics and quantum information theory as well as the seemingly disparate field of high energy physics. The central concept of this thesis is gauge theories as applied to systems of bosonic atoms, which at temperatures close to absolute zero form Bose-Einstein condensates. To simulate the mathematical structure of a gauge theory, the geometric (Berry) phase formalism is adopted. This is in turn accomplished by considering the adiabatic following of the eigenstates of the light-matter coupling for an ensemble of atoms forming a Bose-Einstein condensate. These concepts are then applied to show how one can generate a spin-orbit coupling in a one-dimensional condensate, which additionally features a random mass term that allows us to study the physics of Anderson localization in an intriguing “quasi” relativistic regime. One of the features of light induced gauge potentials is that they are static; in the sense that there is no feedback between the light-matter interaction and the matter field. In the second part of this thesis it is demonstrated how such a feedback mechanism can be induced by the appropriate modification of the light-matter interaction. The consequences this has for the condensate are then described at the mean-field level, including the expected experimental signatures of the resulting ‘interacting’ gauge theory, in terms of the expansion of the condensate and also the structure of the solitons of this nonlinear system. Finally, this nonlinear model is applied to a double well system, from which the associated Bose-Hubbard model is derived and analysed; and the nonlinear Josephson problem studied.
Analytical Solutions to H∞ and H2 Optimization of Dynamic Vibration Absorbers Attached to Damped Linear Systems

H∞ and H 2 optimization problems of the Voigt type dynamic vibration absorber (DVA) are classical optimization problems, which have been already solved for a special case when the primary system has no damping. However, for the general case including a damped primary system, no one has solved these problems by algebraic approaches. Only the numerical solutions have been proposed until now. This paper presents the analytical solutions for the H∞and H 2 optimization of the DVA attached to the damped primary systems. In the H∞ optimization the DVA is designed such that the maximum amplitude magnification factor of the primary system is minimized; whereas in the H 2 optimization the DVA is designed such that the squared area under the response curve of the primary system is minimized. We found a series solution for the H∞ optimization and a closed-form algebraic solution for the H 2 optimization. The series solution is then compared with the numerical solution in order to check the accuracy in connection with the truncation error of the series. The exact solution presented in this paper is too complicated to handle by a hand-held calculator, so we proposed an approximate solution for the practical object.
Ferroelectric materials and devices in infrared detection and imaging

Abstract The use of ferroelectric materials for infrared detection and thermal imaging is an established technology. For example, small pyroelectric detector arrays form the basis of the infrared burglar and intruder alarm industry, and the pyroelectric vidicon camera tube has been successfully exploited for thermal imaging in a wide range of industrial and civil applications. Interest in the ferroelectric materials for infrared devices has continued to grow, based on the ambient temperature operation and the potential for low power and cheap detector technologies. In the recent programmes, the attention has turned to research on the new technologies needed to fabricate large hybrid arrays of ferroelectric detectors interfaced with silicon readout ICs. The key items in the hybrid device for the research programmes are firstly the ferroelectric material for the detector wafer, secondly the design of the silicon readout circuit and thirdly the solder bump, flip-chip technology used to fabricate the hybrid.
Adaptive Bayesian bandwidth selection in asymmetric kernel density estimation for nonnegative heavy-tailed data

In this paper, we consider an interesting problem on adaptive Birnbaum–Saunders-power-exponential (BS-PE) kernel density estimation for nonnegative heavy-tailed (HT) data. Treating the variable bandwidths , of adaptive BS-PE kernel as parameters, we then propose a conjugate prior and estimate the 's by using the popular quadratic and entropy loss functions. Explicit formulas are obtained for the posterior and Bayes estimators. Comparison simulations with global unbiased cross-validation bandwidth selection technique were conducted under four HT distributions. Finally, two applications based on HT real data are presented and analyzed.
Dynamic tuning of optical waveguides with electrowetting pumps and recirculating fluid channels

We have developed an approach for using electrowetting actuation in recirculating fluidic channels to achieve dynamic tuning of optical fiber structures. The electrically controlled and fully reversible motion of the fluids and lubricants in these channels alters the refractive index profile experienced by the optical waveguide modes of the fiber. When combined with in-fiber gratings and etched fibers, this fluidic system yields dynamically adjustable narrow and broadband fiber filters, respectively. The nonmechanical operation of these systems, their ability to support switching speeds on the order of milliseconds, and their excellent optical characteristics indicate a promising potential for electrowetting-actuated fluidic tuning in optical fiber devices and other photonic components.
Experimental study of thermal effects on the mechanical behaviour of a clay

The paper presents the results of an experimental study of thermal effects on the mechanical behaviour of a saturated clay. The study was performed on CM clay (Kaolin) using a temperature‐controlled triaxial apparatus. Applied temperatures were between 22 and 90°C. A comprehensive experimental program was carried out, including: (i) triaxial shear tests at ambient and high temperatures for different initial overconsolidation ratios; (ii) consolidation tests at ambient and high temperatures; and (iii) drained thermal heating for different initial overconsolidation ratios. The obtained results provide observations concerning a wide scope of the thermo‐mechanical behaviour of clays. Test results obtained at 90°C were compared with tests performed at ambient temperature. Based on these comparisons, thermal effects on a variety of features of behaviour are presented and discussed. Focus is made on: (i) induced thermal volume change during drained heating; (ii) experimental evidence of temperature influence on preconsolidation pressure and on compressibility index; (iii) thermal effects on shear strength and critical state; and (iv) thermal effects on elastic modulus. Thermal yielding is discussed and yield limit evolution with temperature is presented. The directions of the induced plastic strains are also discussed. Several remarks on the difference in the mechanical behaviour at ambient and high temperatures conclude the paper. Copyright © 2004 John Wiley & Sons, Ltd.
Hall and drift mobility of polar p-type semiconductors : I. Theory?

The contribution to the Hall and drift mobility from the polar scattering by optical modes of p-type semiconductors for low electric fields is investigated including the essential effect of light to heavy hole band mobility and the Hall coefficient factor substantially whereas it hardly influences the heavy hole mobility. Polar scattering by optical modes is considered only. The importance of these effects in any real situation depends on the relative strength of the other scattering processes and this is discussed in several particular cases in a forthcoming paper.
Electro-optics interaction imaging in active plasmonic devices

During surface plasmon polariton (SPP) excitation, the imaging of the interaction between the DC current and the Transverse Mode (TM) optical field is reported for the first time. Using an optical microscope, we have successfully captured images of electro-optic interaction during plasmonic demodulation phenomena. A significant response is observed when images of the transmitted light – which represents SPP excitation – become less bright in the presence of an electric field when the thin-film metal thickness is approximately equivalent to the skin depth of gold (30 nm). The synchronization achieved between the optical reflectance analysis and the SPP imaging shows that maximum interaction is achieved when the optical reflectance change, ΔR is 0.0530.
Algebraic multigrid methods for solving generalized eigenvalue problems

Three algebraic multigrid (AMG) methods for solving generalized eigenvalue problems are presented. The first method combines modern AMG techniques with a non‐linear multigrid approach and nested iteration strategy. The second method is a preconditioned inverse iteration with linear AMG preconditioner. The third method is an enhancement of the previous one, namely the locally optimal block preconditioned conjugate gradient. Efficiency and accuracy of solutions computed by these AMG eigensolvers are validated on standard benchmarks where part of the spectrum is known. In particular, the problem of isospectral drums is addressed. Copyright © 2005 John Wiley & Sons, Ltd.
Experimental Study on Flow and Heat Transfer in a 19.6-μm Microtube

The flow and the heat transfer characteristics in a quartz microtube with an inner diameter of 0.0196 mm are investigated experimentally. Measuring the pressure drop between the inlet and outlet of the microtube and the average temperature of the microtube wall heated by steam when the working fluid is distilled water, the corresponding friction factors and Nusselt number are obtained. The experimental results show the friction factors in the microtube exceed those of the Hagen–Poiseuille prediction due to the predominance of the effects of the electrical double layer and the entrance. Also, the experimental Nusselt number is less than the classical laminar at Reynolds number < 500 due to the effect of the variation of the thermophysical properties with the temperature.
Flow Control Applied to the Front Rounded Edge of a Bluff Body

An experimental study was performed on a 2D square prism with one rounded front edge with the purpose of reducing the aerodynamic drag by means of active flow control of boundary layer separation. Highly efficient suction and oscillatory blowing (SaOB) actuators were installed at the front curved edge, aimed to inhibit the separation phenomenon. The experimental results show significant decrease in the form-drag, narrowing of the wake and correspondingly an increase in the base pressure in the presence of the SaOB actuation. The mechanism of drag reduction is elimination of the separation from the front-cured edge of the model.
STATISTICS OF FLARING LOOPS OBSERVED BY THE NOBEYAMA RADIOHELIOGRAPH. III. ASYMMETRY OF TWO FOOTPOINT EMISSIONS

Two footpoint (FP) emissions are compared in a total of 24 events with loop-like structures imaged by the Nobeyama Radioheliograph (NoRH), which are divided into two groups: when the optically thin radio spectrum in the looptop is harder than those in the two FPs (group 1) and when it is softer than those in at least one FP (group 2). There are always correlative variations of the brightness temperatures and polarization degrees, the spectral indices, the column densities of nonthermal electrons, and magnetic field strengths in the two FPs. The maximum differences of these parameters in the two FPs may reach one or two orders of magnitude (except the polarization degree). The logarithm of the ratio of the magnetic field strengths in the two FPs is always anti-correlated with the logarithms of the ratios of the brightness temperatures in the two FPs, but correlated with the differences of the spectral indices in the two FPs. Only two anti-correlations exist in group 1, between the difference of the absolute polarization degrees in the two FPs and the logarithm of the ratio of the brightness temperatures in the two FPs and between the difference of the spectral indices in the two FPs and the logarithm of the ratio of the column densities of nonthermal electrons in the two FPs. Only two positive correlations appear in group 1, between the difference of the absolute polarization degrees in the two FPs and the relative ratio of magnetic field strengths in the two FPs and between the logarithm of the ratio of the column densities of nonthermal electrons in the two FPs and the logarithm of the ratio of the brightness temperatures in the two FPs. These four statistics in group 2 are just opposite to those in group 1, which may be directly explained by gyrosynchrotron theory. Moreover, the asymmetry of the two FP emissions in group 2 is more evident than that in group 1, which may be explained by two kinds of flare models, respectively, in the two groups of events, i.e., the energy release above a single loop (group 1) and in the coalescence of two flaring loops (group 2). The asymmetry of the two FP emissions cannot simply be explained by the mirroring effect, but it may strongly depend on the asymmetry of the initial pitch angles of nonthermal electrons in the two FPs. The normal or abnormal events are defined as whether a stronger emission corresponds to a stronger or weaker polarization in the two FPs, with a comparable proportion of the normal and abnormal events in the two groups.
Multi-scale physics mechanisms and spontaneous edge transport bifurcations in fusion plasmas

The magnitude of radial transport in magnetic confinement devices for controlled nuclear fusion suffers spontaneous bifurcations when specific system parameter values are exceeded. Here we show, for the first time, that the correlation length of the plasma potential becomes of the order of the machine size during the edge bifurcation itself, quite unlike the density fluctuations. The mechanism governing the development of this bifurcation, leading to the establishment of an edge transport barrier, is still one of the main scientific conundrums facing the magnetic fusion community after more than twenty years of intense research. The results presented here show the dominant role of long-range correlations when approaching the Low to High confinement edge transition in fusion plasmas. This is in line with the expectation that multi-scale interactions are a crucial ingredient of complex dynamics in many non-equilibrium systems.
Ground state properties of randomly-doped Kondo lattice model

We study the ground state properties of a Kondo lattice model with random configuration of f electrons, as a function of f-electron density nf. We show that the strength of on-site screening (averaged exchange energy per f electron) shows a rapid decrease at a certain value of nCOf. For nf > nCOf the correlation between f electrons gradually grows and the system is expected to change from local Fermi liquid to heavy Fermi liquid.
On hidden nodes for neural nets

Recent results indicate that the number of hidden nodes (H) in a feedforward neural net depend only on the number of input training patterns (T). There appear to be conjectures that H is on the order of T-1 and of log/sub 2/T. A proof is given that the maximum number of separable regions (M) in the input space is a function of both H and input space dimension (d). The authors also show that H=M -1 and H=log/sub 2/M are special cases of that formulation. M defines a lower bound on T, the number of input patterns that may be used for training. Application to some experiments are investigated. >
Electromagnetic mixing formulas and applications

A definitive treatment of the mathematical analysis of macroscopic dielectric and magnetic properties of geophysical, biological and other materials, including special reference to chiral and nonlinear material, the effects of structure and anistrophy are discussed in detail in this book, along with mixtures involving chiral and nonlinear materials, high-frequency scattering phenomena and dispersive properties.
Electromagnetic and microwave absorption properties of (Co2+–Si4+) substituted barium hexaferrites and its polymer composite

The electromagnetic (EM) and microwave absorption properties of (Co2+–Si4+) substituted barium hexaferrite compositions BaCox2+Fey+2Six+y4+Fe12−2x−2y+3O19 (x=0.9 and y=0.0, 0.05, and 0.2) and its polymer composites prepared from hexaferrite, polyaniline, and carbon powders dispersed in polyurethane matrix have been investigated at the microwave frequency range of the X band (8.2–12.4GHz). The hexaferrite compositions were synthesized by solid-state reaction technique, whereas polyaniline, by chemical route. The permeabilities of a ferrite are drastically reduced at higher gigahertz frequencies. The permittivities, however, can be enhanced by appropriate choice of composition and processing temperature. In the present ferrite composition, silicon content is taken in excess so as to convert some of the Fe3+ ions to Fe2+ ions. This conversion has been shown to enhance EM and absorption properties. Mossbauer spectroscopy on the samples establishes that addition of excess Si4+ converts some of the Fe3+ to Fe2+.
Rate/Mean Regression for Multiple‐Sequence Recurrent Event Data with Missing Event Category

Abstract. Censored recurrent event data frequently arise in biomedical studies. Often, the events are not homogenous, and may be categorized. We propose semiparametric regression methods for analysing multiple‐category recurrent event data and consider the setting where event times are always known, but the information used to categorize events may be missing. Application of existing methods after censoring events of unknown category (i.e. ‘complete‐case’ methods) produces consistent estimators only when event types are missing completely at random, an assumption which will frequently fail in practice. We propose methods, based on weighted estimating equations, which are applicable when event category missingness is missing at random. Parameter estimators are shown to be consistent and asymptotically normal. Finite sample properties are examined through simulations and the proposed methods are applied to an end‐stage renal disease data set obtained from a national organ failure registry.
Occluded human recognition for a leader following system using 3D range and image data in forest environment

This paper describes the occluded target recognition and tracking method for a leader-following system by fusing 3D range and image data acquired from 3D light detection and ranging (LIDAR) and a color camera installed on an autonomous vehicle in forest environment. During 3D data processing, the distance-based clustering method has an instinctive problem in close encounters. In the tracking phase, we divide an object tracking process into three phases based on occlusion scenario; before an occlusion (BO) phase, a partially or fully occlusion phase and after an occlusion (AO) phase. To improve the data association performance, we use camera's rich information to find correspondence among objects during above mentioned three phases of occlusion. In this paper, we solve a correspondence problem using the color features of human objects with the sum of squared distance (SSD) and the normalized cross correlation (NCC). The features are integrated with derived windows from Harris corner. The experimental results for a leader following on an autonomous vehicle are shown with LIDAR and camera for improving a data association problem in a multiple object tracking system.
Postscript: Contrasting Predictions for Preference Reversal.

In this post scrit, the authors discuss an article by Hotaling, Busemeyer, and Li (see record 2010-22285-008) which provided a valuable reply to the challenges the current authors raised for the decision field theory (DFT) account of preference reversal in multiattribute choice. They agree with Hotaling, Busemeyer, and Li's observation that with the addition of an internal stopping rule-where a decision is reached when the first choice unit reaches a response criterion-the model is more stable and less subject to violations of dominance. Indeed, in its present form, DFT captures most existing data on preference reversals, and its limitations (due to linearity) have the virtue of facilitating analytical calculations. It is therefore interesting to contrast DFT and alternative accounts of preference reversals (e.g., leaky competing accumulators [LCA; Usher & McClelland, 2004] or the context-dependent advantage model [Tversky & Simonson, 1993]). This note builds on the improved clarity of DFT mechanisms resulting from this exchange and highlights predictions that could distinguish between competing explanations and drive further experimental research. We also note common aspects of DFT and LCA and draw implications for theories of decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
On the effect of misspecifying the error density in a deconvolution problem

The author studies the effect of a misspecification of the error density on the mean integrated squared error (MISE) of the deconvolution estimator. He shows that the MISE converges to a certain functional which he defines. He also illustrates the fact that the limit can sometimes be infinite. Finally, he derives some guidelines for selecting the error density in order to ensure robustness properties of the procedure.