Miracle-dz/UniFAR-FTUs huggingface dataset:
A Determination of the Solar Photospheric Boron Abundance

We present a reanalysis of the B I λ2496. 771 line in the solar photosphere using up-to-date line lists, new atomic data, and employing LTE spectrum synthesis. Adopting the two most recent values for the photoionization cross section for Mg I 3p 3Po (the dominant continuous opacity source in this spectral region), along with two different types of model atmospheres, we find a mean photospheric boron abundance of log ϵ(B)=2.70, with estimated statistical uncertainties of -0.12 and 0.21 dex. For all cases investigated, we find tolerable spectrum synthesis fits to the nearby Fe I line at 2496.533 Å, which has a well-determined laboratory gf-value. With the adopted Mg I cross sections we find much better agreement between the predicted model and observed continuum intensities at the solar limb, which is in contrast to results from earlier studies. In addition, as a check on the boron abundance derived from the ultraviolet B I line we analyze the weak, excited B I transition at 16244.670 Å. This line is marginally detected and the derived value of log ϵ(B)=2.55±0.2 is not in disagreement with the UV abundance, but is significantly larger than previous upper-limit estimates from infrared spectra. The results obtained for the photospheric boron abundance are within the errors identical to the accepted meteoritic value of 2.78±0.05: we find no measurable boron depletion in the solar photosphere.
Highly singular quintic curves

The origin of this paper lies in a study of the unfolding space of the stratum N16 of singularity theory, and the question, at which points of the stratum the versal deformation space ceases to be topologically trivial over the stratum. This question turns out to be closely related to the study of how a plane section (= binary quintic) of a quintic curve varies as we deform the curve, either rigidly (under GL3) or equisingularly.
Ergodicity and mixing in four-mode spectral models of two-dimensional turbulence

A system of equations derived by truncating a Fourier representation of the two-dimensional Euler equations which uses four frequencies is investigated. The system has been used by Lorenz, for example, to model atmospheric flow. Also, truncated Fourier representations have been used in many analytic and numerical investigations of turbulence. Since the investigations take a statistical mechanics approach, an important question is whether the truncated systems are ergodic or mixing. The following results have been obtained. If the four frequencies of the truncation form a rectangle, then the system has six constants of motion and these define four disjoint tori. On each torus the solutions of the system are either ergodic with respect to a unique invariant measure or they are all periodic. But, the solutions are never mixing. A computer program has been written which gives a representation of the system’s trajectory as it moves on one of the four tori.
FINITE ELEMENT METHODS BASED ON GENERALIZED EXPO-RATIONAL B-SPLINES WITH HARMONIC POLYNOMIAL COEFFICIENTS

We present an upgrade of a recent work [7] where the performance of several novel Partition of Unity Methods (PUM) [2] were examined on non-degenerate triangulations for solving linear elliptic partial differential equations. The current study focuses on changing the local polynomials as functional coefficients in the Partition of Unity Methods (PUM) from Taylor expanding polynomials to harmonic polynomials. We provide numerical results to illustrate the behavior of the PUM when switching from local Taylor polynomials to local harmonic polynomials. These results support the conclusion that on sufficiently refined meshes harmonic polynomials tend to outperform Taylor polynomials. AMS Subject Classification: 65N30, 65N38, 31A05
Friction, Stability and the Design of Robotic Fingers

For practical reasons, compliant materials are often used on the gripping surfaces of robotic hands. Such materials are not well described by the Coulomb friction law or by simple point-contact or line-contact kinematics. In this paper, a shearing model is used to describe the contact friction. Models ofpointed, curved, flat, soft, and soft-curved fingertips are then developed and compared in terms of their contribu tion to the stiffness and stability of a simple grasp. There is a spectrum of contact conditions defined by the fingertip radius and contact area relative to the object size. This spectrum provides insights for designing and controlling robotic fingers.
THE X-RAY EMISSION OF A-TYPE STARS

From X-ray images in the ROSAT public archives, we determine soft X-ray fluxes, or flux upper limits, for 74 A-type stars, which have been observed during deep integrations with the PSPC. Nine supposedly single, late A stars (0.20 < B-V < 0.35) are found to coincide with X-ray sources. The X-ray luminosities we infer for these stars range from levels comparable to the Active Sun, at log Lx ~27.6, to much brighter emission levels similar to those observed for active late-type binary systems, near log Lx ~30.1. Another 10 sources are identified with early A stars (0.0 < B-V < 0.2). Five of these are confirmed double stars, the rest are ostensibly single. The maximum luminosity we detect in the early A stars, log Lx = 30.1, is 3.5 orders of magnitude brighter than the X-ray upper limits for the nondetected stars. Additional study, including radial velocity monitoring and/or optical interferometry, will be needed to determine whether the putatively single X-ray emitting stars are in fact single, or whether their emission is produced entirely or in part by unknown or unresolved binary companions. The level of X-ray emission associated with chemically normal, single A stars thus far appears to be uncorrelated with any obvious stellar property, including the rotation rate, which is known to greatly influence the dynamo activity and the X-ray emission levels of lower mass stars.
Ion cyclotron emission due to fast Alfvén-wave radiative instabilities in tokamaks induced by newly born fusion products

The velocity distribution functions of newly born (t=0) charged fusion products (protons in DD and alpha particles in DT plasmas) of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v∥ such that v⊥≈v∥ ≈Vj, where ½Mj V2j =Ej, the directed birth energy of the charged fusion-product species j of mass Mj. As the time t progresses, these distribution functions will evolve into a Gaussian in velocity (i.e. a drifting Maxwellian type), with thermal spreads given by the perpendicular and parallel temperatures T⊥j(t) =T∥j(t), with Tj(t) increasing as t increases and finally reaching an isotropic saturation value of formula here Here Td is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j=protons and alpha particles respectively, and τj≈¼τsj is the thermalization time of the fusion product species j in the background deuterium plasma, with τsj the slowing-down time. For times t of the order of τj, the distributions can be approximated by a Gaussian in the total energy (i.e. a Brysk type). Then, for times t[ges ]τsj, the velocity distributions of the fusion products will relax towards their appropriate slowing-down distributions. Here we shall examine the radiative stability of all these (i.e. a monoenergetic ring, a Gaussian in velocity, a Gaussian in energy, and the slowing-down) distributions.
Formation Control Protocols for Nonlinear Dynamical Systems Via Hybrid Stabilization of Sets

In this paper, we develop a hybrid control framework for addressing multiagent formation control protocols for general nonlinear dynamical systems using hybrid stabilization of sets. The proposed framework develops a novel class of fixed-order, energy-based hybrid controllers as a means for achieving cooperative control formations, which can include flocking, cyclic pursuit, rendezvous, and consensus control of multiagent systems. These dynamic controllers combine a logical switching architecture with the continuous system dynamics to guarantee that a system generalized energy function whose zero level set characterizes a specified system formation is strictly decreasing across switchings. The proposed approach addresses general nonlinear dynamical systems and is not limited to systems involving single and double integrator dynamics for consensus and formation control or unicycle models for cyclic pursuit. Finally, several numerical examples involving flocking, rendezvous, consensus, and circular formation protocols for standard system formation models are provided to demonstrate the efficacy of the proposed approach. [DOI: 10.1115/1.4027501]
Nonlinear systems and higher-order statistics

The author illustrates various ways higher order statistics are used in the analysis of various nonlinear models. The Navier-Stokes equation is used to illustrate the nonlinear interaction of different wave numbers in a homogeneous velocity field. A hybrid method is used to illustrate the estimation of bispectral density function of a continuous-time stationary process sampled by a random point process. A set of specific nonlinear models is used to demonstrate the use of higher order statistics to discriminate among competing models. <<ETX>>
Generation of entanglement via adiabatic passage

We propose several robust schemes to prepare entangled states among spatially separated $\ensuremath{\Lambda}$-type atoms via stimulated Raman adiabatic passage and fractional stimulated Raman adiabatic passage techniques. The atomic spontaneous radiation, the cavity decay, and the fiber loss are efficiently suppressed by engineering adiabatic passage and controlling appropriately atom-field couplings. The schemes can be extended to generate the $n$-cavity mode $W$ state.
Design and implementation of the tapered resistive sheets to control edge scattering

Closed-form expressions for equivalent surface resistance of the tapered resistive sheets realized by geometric variation based on frequency selective surfaces concepts are presented in this paper. These expressions can be used efficiently to calculate the equivalent surface resistive of tapered resistive sheets with variable periodic structures of said geometries. These equivalent surface resistances of tapered resistive sheets calculated from these expressions are compared to and closely agree with results obtained from a numerical simulation of the actual tapered resistive meta-surfaces. Finally, we propose the tapered resistive sheets based on these expressions to control edge scattering, and excellent agreement with these results from the actual tapered resistive sheets loading can be obtained.
Coupled electro-mechanical response of an electroactive polymer cantilever structure and its application in energy harvesting

Ionic polymer-metal composites (IPMC), piezoelectric polymer composites and nematic elastomer composites are materials, which exhibit characteristics of both sensors and actuators. Large deformation and curvature are observed in these systems when electric potential is applied. Effects of geometric non-linearity due to the chargeinduced motion in these materials are poorly understood. In this paper, a coupled model for understanding the behavior of an ionic polymer beam undergoing large deformation and large curvature is presented. Maxwell's equations and charge transport equations are considered which couple the distribution of the ion concentration and the pressure gradient along length of a cantilever beam with interdigital electrodes. A nonlinear constitutive model is derived accounting for the visco-elasto-plastic behavior of these polymers and based on the hypothesis that the presence of electrical charge stretches/contracts bonds, which give rise to electrical field dependent softening/hardening. Polymer chain orientation in statistical sense plays a role on such softening or hardening. Elementary beam kinematics with large curvature is considered. A model for understanding the deformation due to electrostatic repulsion between asymmetrical charge distributions across the cross-sections is presented. Experimental evidence that Silver(Ag) nanoparticle coated IPMCs can be used for energy harvesting is reported. An IPMC strip is vibrated in different environments and the electric power against a resistive load is measured. The electrical power generated was observed to vary with the environment with maximum power being generated when the strip is in wet state. IPMC based energy harvesting systems have potential applications in tidal wave energy harvesting, residual environmental energy harvesting to power MEMS and NEMS devices.
ON THE ASYMPTOTIC DISTRIBUTION OF BARTLETT'S Up‐STATISTIC

Abstract. In this paper the asymptotic behaviour of Bartlett's Up-statistic for a goodness-of-fit test for stationary processes, is considered. The asymptotic distribution of the test process is given under the assumption that a central limit theorem for the empirical spectral distribution function holds. It is shown that the Up-statistic tends to the supremum of a tied down Brownian motion. By a counterexample we refute the conjecture that this distribution is in general of the Kolmogorov-Smirnov type. The validity of the central limit theorem for the spectral distribution function is then discussed. Finally a goodness-of-fit test for ARMA-processes based on the estimated innovation sequence is given, and it is shown that this test statistic is asymptotically Kolmogorov-Smirnov distributed.
When the analogy breaks down: modelling the atom on the solar system

Analogy is one of the most potent tools in the teacher's repertoire, and has been recognized as a common feature of science teaching. It is also accepted, however, that teaching effectively using analogy requires careful planning. It is important to emphasize the limitations of the analogies used in explaining scientific ideas. This article also highlights another potential difficulty: when the analogue is not as familiar to learners as the teacher may assume.
CCD Image Geometrical Distortion Correct and Large Touch Screen

There are geometric distortions in all the images produced by the CCD camera lens, and the distortions are all nonlinear. Coordinate conversion is an effective method for geometric correction. The calculations will boost as the higher degrees of the polynomial. It is impossible to apply directly in real time correction system. This article introduces a correction according to divided areas through linear polynomial on the base of higher degree polynomial coordinate conversions. In the method the image is divided into uneven loop like areas at first. In each area you can take a linear polynomial approximating higher degree polynomial. Because CCD camera lens distortions are radial distortions, high precision can be acquired through the linear polynomial on the base of higher degree polynomial. In the same time the calculations can be decreased and meet the needs of real-time correction. Apply this method on large touch screen, it can correct the distortion effectively and is useful in engineering.
Helioseismological test of a new model for stellar convection

We compare the predictions of two solar models with the observed p-mode eigenfrequencies. The two models use the same input microphysics (nuclear reaction rates, opacity, and equation of a state) and the same numerical evolutionary code, but differ in the treatment of turbulent convection. The first model employs the standard mixing-length theory of convection (MLT), while the second model employs a new model of turbulent convection (CM) whose primary goal was that of accounting for the whole spectrum of turbulent eddies so as to avoid the MLT approximation that such a wide spectrum be represented by a single, large eddy. The main result of this paper is that the p-mode eigenfrequencies calculated with the CM model show an overall improvement with respect to those calculated with the standard MLT model.
Complexity Reduction Algorithm for Quantized EGT Codebook Searching in Multiple Antenna Systems

Reduced complexity codebook searching for Quantized Equal Gain Transmission(QEGT) is proposed over MIMO-OFDM systems. QEGT codebook is divided into M groups of Q index members. Each group has a representative index. At the 1st stage only the representative indices are searched then the best index is selected. At the 2nd stage the optimum index is determined only among the group of the selected representative index. This strategy reduces the overall index search algorithm comparing to the conventional methods. Monte-Carlo simulation shows that the searching complexity is reduced, but the link-level performance is still almost the same as the conventional methods when the number of transmission antennas are 3 to 7.
Star Formation in Galaxies between Redshifts of 0.7 and 1.8

We present an analysis of the star formation rate in galaxies with redshifts in the range 0.7 < z < 1.8 using Near Infrared Camera and Multi-Object Spectrograph (NICMOS) grism spectral observations. We detect 163 galaxies in an area of ∼4.4 arcmin2, 37 of which show possible Hα emission. We extend the observed Hα luminosity function (LF) in this redshift range to luminosities a factor of 2 fainter than earlier work and are consistent in the region of overlap. Using the Hα LF, we estimate a star formation rate (SFR) density in this redshift range of 0.166 M⊙ yr-1 Mpc-3 (H0 = 75 km s-1 Mpc-1), consistent with other estimates based on emission lines and supporting the order-of-magnitude increase in SFR density between z = 0 and z = 1. Our measurement of SFR density is a factor of ≈2–3 greater than that estimated from UV data, comparable to the factor observed locally, implying little evolution in the relative extinctions between UV and Hα out to z ≈ 1.3.
High-resolution differential phase contrast imaging using a magnifying projection geometry with a microfocus x-ray source

Differential x-ray phase contrast imaging using a grating interferometer was combined with a magnifying cone beam geometry using a conventional microfocus x-ray tube. This brings the advantages of a magnifying cone beam setup, namely, a high spatial resolution in the micron range and the possibility of using an efficient, low resolution detector, into differential phase contrast imaging. The authors present methodical investigations which show how the primary measurement signal depends on the magnification factor. As an illustration of the potential of this quantitative imaging technique, a high-resolution x-ray phase contrast tomography of an insect is presented.
MEMORY AND BISTABILITY IN A ONE-DIMENSIONAL LOOP OF MODEL CARDIAC CELLS

Unidirectional propagation has been studied in a one-dimensional loop of model cardiac cells represented as a homogeneous and isotropic cable. Membrane ionic currents were represented by a modified Beeler-Reuter model. The time constants of the gate variables of the slow inward current acting during the plateau of the action potential were divided by a parameter K ≥1. In the space-clamped model, increasing K shortens the action potential duration, changes the shape of the restitution curve and adds a slow memory component to the dynamics. In a paced regime, it promotes bistability in which period-1 and period-2 patterns coexist over an interval of pacing frequencies. In the loop, bistability is created between periodic and aperiodic modes of sustained reentry for an interval of loop length. The bistability of the space-clamped and loop model are both related to the form of the restitution curve.
Relationship between convection over Central America and the intensity of the jet stream bearing on the 1999 December European storms

During 26–28 December 1999, two very powerful and devastating extratropical cyclones hit Western Europe. These two storms were associated with an upper‐level zonal jet, remarkable in its intensity and its large extension over the Atlantic Ocean. In this study, we focus on the relationship between the exceptional features of this jet stream and some heavy precipitation that occurred over Central America during mid‐December. A Rossby‐wave train excited by strong convective activity over this area is likely to play a key role in this teleconnection. To assess this tropical–extratropical interaction, several numerical experiments have been performed with the French global model ARPEGE. Firstly, the effects of convection have been neutralized within a domain localized over Central America. Then, to combine the model with observations, a new strategy has been devised. Within a selected window, the parametrized latent heat release has been deduced from Tropical Rainfall Measuring Mission (TRMM) precipitation data, translated in terms of a potential vorticity (hereafter PV) source and incorporated into the model using PV inversion. These simulations show, in particular, that the convective activity over Central America triggers a wave train that moves poleward and eastward with the group velocity, finally to strengthen the North Atlantic jet stream, leading to windstorms Lothar and Martin. Copyright © 2011 Royal Meteorological Society
A decomposition scheme for acoustic obstacle scattering in a multilayered medium

We consider the acoustic wave scattering by an impenetrable obstacle embedded in a multilayered background medium, which is modelled by a linear system constituted by the Helmholtz equations with different wave numbers and the transmission conditions across the interfaces. The aim of this article is to construct an efficient computing scheme for the scattered waves for this complex scattering process, with a rigorous mathematical analysis. First, we construct a set of functions by a series of coupled transmission problems, which are proven to be well-defined. Then, the solution to our complex scattering in each layer is decomposed as the summation in terms of these functions, which are essentially the contributions from two interfaces enclosing this layer. These contributions physically correspond to the scattered fields for simple scattering problems, which do not involve the multiple scattering and are coupled via the boundary conditions. Finally, we propose an iteration scheme to compute the wave field in each layer decoupling the multiple scattering effects, with the advantage that only the solvers for the well-known transmission problems and an obstacle scattering problem in a homogeneous background medium are applied. The convergence property of this iteration scheme is proven.
Modeling of precedence‐effect behavior in single neurons and in human listeners

Many of the physiological observations of Yin (reported in this session) are consistent with the precedence effect observed in human psychophysical data. In an attempt to understand the mechanisms involved in the generation of these observations, models for the observed neural interactions are being investigated. Since precedence‐effect phenomena are fundamentally related to transient parts of stimuli, the models of these phenomena incorporate descriptions of responses to transient stimuli. In contrast to models for the observed binaural interaction in the medial superior olive (MSO) for sinusoidal stimuli, models for responses to click stimuli in the inferior colliculus (IC) must include inhibitory effects. These effects are long‐lasting (tens of milliseconds) and asymmetric, consistent with earlier data from the IC with binaural clicks [L. H. Carney and T. C. T. Yin, J. Neurophys. 62, 144–161 (1989)]. The location of this inhibitory interaction is not clear since physiological measurements in lower leve.