Miracle-dz/UniFAR-FTUs huggingface dataset:
Commissioning of an integral-field spectro-polarimeter for PMAS

During 2007, a new polarimetric observing mode was added to the existing integral-field spectrograph PMAS. Initially, this instrumental upgrade is aimed to measure the linear polarization states and to determine the three Stokes parameters I, Q and U. The PMAS instrument offers an integral-field of view of up to 256 square arcseconds, while the spectrograph covers a wavelength region from 340 to 900 nm. The paper presents the opto-mechanical design of the polarimetric unit, summarizes calibration and test results and describes the first data taken during commissioning at the Calar Alto observatory. Given the range of applications and the large parameter space (two spatial coordinates, one wavelength dimension, plus polarimetric information), the realization of the PMAS 2D-Spectro-Polarimeter provides a unique capability for night-time astrophysical observations, such as the study of scattering processes or magnetic fields for a range of astronomical targets.
Nonlinear modelling of marine vehicles in 6 degrees of freedom

In this paper a unified framework for vectorial parametrisation of inertia, Coriolis and centrifugal, and hydrodynamic added mass forces for marine vehicles in 6 degrees of freedom (DOF) is presented. Emphasises is placed on representing the 6 DOF nonlinear marine vehicle equations of motion in vector form satisfying certain matrix properties like symmetry, skew-symmetry and positive definiteness. For marine vehicles, this problem was first addresed by Fossen [1]. The proposed representations in this paper are based on extensions of this work. The main results are presented as two theorems. The first theorem is derived by applying Newton's equations whereas the second theorem reviews the main results of Sagatun and Fossen [6] where the Lagrangian formalism is applied.
Twisted Gaussian Schell-model beams. I. Symmetry structure and normal-mode spectrum

We present a comprehensive normal-mode decomposition analysis for the recently introduced [ J. Opt. Soc. Am. A10, 95 ( 1993)] class of twisted Gaussian Schell-model fields in partially coherent beam optics. The formal analogies to quantum mechanics in two dimensions are exploited. We also make effective use of a dynamical SU(2) symmetry of these fields to achieve the mode decomposition and to determine the spectrum. The twist phase is nonseparable in nature, rendering it nontrivially two dimensional. The consequences of this, resulting in the need to use Laguerre–Gaussian functions rather than products of Hermite–Gaussians, are carefully analyzed. An important identity involving these sets of special functions is established and is used in deriving the spectrum.
The mass of the Coma cluster

Mass estimate uncertainties for the Coma cluster in position and velocity data for the galaxies are examined under the assumption that mass and galaxy distribution are parallel, on the one hand, and on the other, that the form of the mass distribution is not constrained. While low mass models have all the mass in the cluster core, and require the galaxies to be on or near circular orbits, high mass models are noted to have weakly concentrated mass distributions and primarily radial orbits. It is concluded that galaxy data alone are unlikely to clearly distinguish between these possibilities.
Quantitative magnetization measurements on nanometer ferromagnetic cobalt wires using electron holography

The magnetic remanent states of 4-nm-diameter single-crystalline Co nanowires are characterized using off-axis electron holography. Measurements are obtained from isolated wires, as well as from bundles of wires and “multibranch” wires joined by 15-nm-diameter nodes of Co. The fraction of magnetically active moments in a single 4-nm-diameter wire is measured to be 1.01±0.19, indicating that, to within experimental error, the wire is fully magnetized throughout its diameter.
Evaluation of a cesium iodide photocathode assisted with MgO-coated multiwall carbon nanotubes

This paper reports the enhanced photocurrent and relative quantum efficiency of cesium iodide (CsI) films on magnesium oxide (MgO)-coated multiwall carbon nanotubes (MWCNTs) on a silica substrate, i.e., CsI/MgO/MWCNTs/Si, when illuminating with 147 nm photons under an external electric field. The incorporation of MWCNTs resulted in significant enhancement of the photocurrent by several orders of magnitude compared to that of a conventional CsI. An analysis of the photoelectron energy spectrum attributed the phenomena to the creation of a very high electric field through the MgO/CsI film with the subsequent generation of avalanche secondary electrons.
Photonic crystal fiber nanospectrometer

A silica-based steering wheel core photonic crystal fiber (SW-PCF) with a nano-featured spectrometer chemical agent detection configuration is presented. The spectrometer chip acquired from Nano-Optic DevicesTM can reduce the size of the spectrometer down to a coin. Results are provided for PCF structures filled with sample materials for spectroscopic identification. Portable and compact spectroscopic detectors with long interaction lengths (> few mm) specially outfitted for extreme environmental conditions are of interest to both military and civil institutions who wish to monitor air/water composition. The featured PCF spectrometer has the potential to measure optical absorption spectra in order to detect trace amounts of contaminants in gaseous or aqueous samples. The absorption spectrum of the SW-PCF detection system was measured as a function of the fiber interaction length and material volume. The SW-PCF measured spectra agreed with reference spectra. The SW-PCF has a core diameter of 3. 9μm, outer diameter of 132. 5μm. A nearly 5 cm length of the SW-PCF was coupled to the surface of a thin nanofeatured chip. The remaining end of the SW-PCF section is coupled to a laser light source centered at λ=635nm. The diffraction pattern produced by the nano-featured chip is captured by an objective lens and CCD camera for image analysis. The position of the intensity pattern extracted from the analyzed image indicates the spectral components of the absorption characteristics for the detected sample. This nano-featured spectrometer offers spectral resolution down to 0.1nm that makes it possible to detect substances with very detailed spectral features.
Vector quantizer design for memoryless noisy channels

To handle the effect of transmission errors on the performance of vector quantization (VQ) in source coding, a channel index assignment function is proposed that can be incorporated into a source/channel model of VQ. Using this model, conditions for the optimality of a vector quantizer for a given distortion measure are obtained which generalize the familiar centroid and nearest neighbor conditions. The optimal codevectors are linear combinations of those for the noiseless case, weighted by the a posteriori channel transition probabilities. The optimal encoder selects the codevector that minimizes a weighted sum of the distortion between the input and each codevector, where the weights are channel transition probabilities. A derivation of the conditions for a memoryless channel is given, and an iterative design algorithm is described where at each step the average distortion monotonically decreases. Each iteration consists of three steps which separately modify the encoder, decoder, and the channel index assignment. <<ETX>>
Relationships for modified generalized integral transforms, modified convolution products and first variations on function space

In this paper we define a modified generalized integral transform (MGIT) and a modified convolution product (MCP) for functionals on function space. We then introduce classes of functionals which are dense in L2(Ca, b[0, T]) and establish various relationships between the MGIT and the MCP involving the first variation. Note that all results in [Chang SJ, Chung HS, Skoug D. Integral transforms of functionals in L2(Ca, b[0, T]). J Fourier Anal Appl. 2009;15:441–462; Chang SJ, Chung HS, Skoug D. Some basic relationships among transforms, convolution products, first variations and inverse transforms. Central Eur J Math. 2013;11:538–551; Chang KS, Kim BS, Yoo I. Integral transform and convolution of analytic functionals on abstract Wiener space. Numer Funct Anal Optim. 2000;21:97–105; Im MK, Ji UC, Park YJ. Relations among the first variation, the convolutions and the generalized Fourier–Gauss transforms. Bull Korean Math Soc. 2011;48:291–302; Lee Y-J. Integral transforms of analytic functions on abstract Wiener spaces. J Funct Anal. 1982;47:153–164; Kim BS, Skoug D. Integral transforms of functionals in L2(C0[0, T]). Rocky Mountain J Math. 2003;33:1379–1393] and [Chung HS, Tuan VK. Generalized integral transforms and convolution products on function space. Integral Transforms Spec Funct. 2011;22:573–586] are then corollaries of the results and formulas established in this paper.
The Taylor-Proudman Balance and the Solar Rotational Data

For the Sun (and because of the presence of buoyancy), the implications of the Taylor-Proudman balance (TPB, a balance between the pressure, Coriolis, and buoyancy forces in the radial and latitudinal momentum equations) differ fundamentally from those of an incompressible fluid. The TPB now only determines the latitudinal variations of the solar entropy in terms of the rotation law and known functions of r. As a consequence of the TPB, the energy equation is in fact an equation for the angular velocity, Ω(r, θ)=Ω0(ω0(r)+ω2(r)P2(cos θ)), where P2(cos θ) is the second-order Legendre polynomial. In agreement with data from the Solar Oscillations Investigations project (SOI) Michelson Doppler Imager (MDI) on board SOHO, we assume that ω0(r) is constant with r, and solve the equation for ω2(r) with a simple, heuristic expression for the convective flux [if ω0(r) is constant, then ∂Ω/∂r vanishes for θc=54. °7, P2(cos θc)=0, in remarkable agreement with Kosovichev's results inferred from isocontours for Ω(r, θ)]. For values of the meridional motions that are not too large, solutions for ω2(r) exist that agree with these isocontours. These solutions are such that the latitudinal variation of the convective flux, arising from the latitudinal variations of the entropy, required by the TPB, are significantly reduced.
The three arcsine laws

where arg sups tXs := inf{s : s t, Xs = S(X)t}, S(X)t := sups tXs. If (Bt)t 0 is the usual Brownian motion, then, as is well known, the variables θ(B)1, γ(B)1, and g(B)1 have the same distribution density, f(x) = 1/(π √ x(1− x) ). These three assertions together are called the arcsine laws and are proved independently. The present note reveals why the distributions of these functionals of the Brownian motion are the same. The link that we find between the quantities θ and γ allows us to compute explicitly the joint distributionP(γ(X)t ∈ dx, L(X)t ∈ dy, Xt ∈ dz), where L(X)t is the local time at zero of the process X, and as X we take the Brownian motion with drift Xt = B μ t = Bt + μt and the Brownian bridges Xt = β u,x t = Bt + t u (x− Bu), t < u. Let us first consider the quantities θ(B)t and g(B)t. We shall prove that they have the same distribution without reference to its explicit form.
SERK2v2: A new second‐order stabilized explicit Runge‐Kutta method for stiff problems

Traditionally, explicit numerical algorithms have not been used with stiff ordinary differential equations (ODEs) due to their stability. Implicit schemes are usually very expensive when used to solve systems of ODEs with very large dimension. Stabilized Runge‐Kutta methods (also called Runge–Kutta–Chebyshev methods) were proposed to try to avoid these difficulties. The Runge–Kutta methods are explicit methods with extended stability domains, usually along the negative real axis. They can easily be applied to large problem classes with low memory demand, they do not require algebra routines or the solution of large and complicated systems of nonlinear equations, and they are especially suited for discretizations using the method of lines of two and three dimensional parabolic partial differential equations. In Martín‐Vaquero and Janssen [Comput Phys Commun 180 (2009), 1802–1810], we showed that previous codes based on stabilized Runge–Kutta algorithms have some difficulties in solving problems with very large eigenvalues and we derived a new code, SERK2, based on sixth‐order polynomials. Here, we develop a new method based on second‐order polynomials with up to 250 stages and good stability properties. These methods are efficient numerical integrators of very stiff ODEs. Numerical experiments with both smooth and nonsmooth data support the efficiency and accuracy of the new algorithms when compared to other well‐known second‐order methods such as RKC and ROCK2. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
LARGE-SCALE SIMULATIONS OF BUBBLE-INDUCED CONVECTION IN A LIQUID LAYER

The flow pattern induced by a swarm of bubbles rising in a liquid layer is studied numerically. The fluid motion is described by spatially filtered Navier-Stokes equations forced by the presence of the bubbles. When the volume fraction and the residence time of the bubbles increase, a Rayleigh-Taylor-type instability develops. After transient stages, the flow reaches an equilibrium state made of counterrotating cellular structures. The simulations suggest that no wavelength selection mechanism exists in the present situation, making a striking difference with thermal convection.
On the Influence of Irregular Frequencies in the Integral Equation Solutions of the Time-Dependent Free Surface Problems

So far it has been known little about the problem for a 2-D general shaped body on free surface which makes arbitrary motion in time from t=0, though the problem might have broad application in ship hydrodynamics.As in the counterpart problem in the frequency domain appeared in the “strip method” or the “slender ship theory”, the problem in the time domain may have many solving methods. Among them the integral equation method seems to be most powerful. However, in solving the problem by source distribution method, one peculiar phenomenon occurs, that is, the irregular frequency effect in the time dependent source. This peculiarity is analysed theoretically by investigating the counterpart problem in the frequency domain.A procedure to avoid this peculiarity is presented, which is inherited from the results of Sayer & Ursell4) and Ogilvie & Shin.5) And a few attempts to the problem, making use of the integral equation methods, are illustrated in theories and numerical calculations.
Coherent Forecasting in Binomial AR(p) Model

This article concerns the forecasting in binomial AR(p) models which is proposed by Wei (2009b) for time series of binomial counts. Our method extends to binomial AR(p) models a recent result by Jung and Tremayne (2006) for integer-valued autoregressive model of second order, INAR(2), with simple Poisson innovations. Forecasts are produced by conditional median which gives 'coherent' forecasts, and we estimate the forecast distributions of future values of binomial AR(p) models by means of a Monte Carlo method allowing for parameter uncertainty. Model parameters are estimated by the method of moments and estimated standard errors are calculated by means of block of block bootstrap. The method is fitted to log data set used in Wei (2009b).
Do estimates of an integral really improve as n increases

One way to estimate fJof(x) dx is to partition the interval [0, 1] into n sections of equal lengths and use their right-hand endpoints to form the sum En lf(i/n)(1/n). Call this estimate En. If f is continuous, then En approaches the integral as n approaches infinity. A beginning calculus student or the author of a calculus text might ask, "As n increases, does the estimate get steadily closer to the integral? " In other words, is the approach monotonic? A quick sketch can produce an example where E1 equals the integral but E2 does not. So the answer is no. However, if the derivative f' is nonnegative throughout the interval, then E1 ? E2 ? fJof(x) dx as another quick sketch will show. A similar conclusion holds if f' is nonpositive, in which case we have E1 < E2 < fJof(x) dx. In short, if f' does not change sign in the interval [0, 1], then E2 is at least as good an estimate as E1, and similarly for any positive integers p and q, Epq is at least as good as EP. Keeping the assumption that f' ? 0, we next ask, "Is E2 ? E3? " Once again, a diagram will show that the answer is no. And this automatically raises the next question: "For which general f with nonnegative first derivative, do we have E2 2 E3? " At this point I talked to numerical analysts and looked in numerical analysis texts, but found no mention of the problem. Only after I had shown that En ? En+i for all n did I find that several mathematicians had studied this and related problems as early as 1929. I will first describe my own experience with the problem and its generalization and then the various techniques that others had employed in their solutions. Some of the arguments are elementary and could be sketched in a few minutes in a calculus class.
A peculiar stellar complex in NGC 6946 or the blue compact galaxy in front of this galaxy

The origin of the peculiar stellar complex in the outskirts of the spiral galaxy NGC 6946 is discussed. The complex hosts a superstar cluster, two dozen smaller bright clusters and many high-luminosity stars 5–30 Myears old. In spite of this, no features in H I or CO are associated with the complex. The most simple explanation is that the complex is a foreground blue compact galaxy, a member of the NGC 6946 group. The arc of high light absorption along the complex rim could then be the result of the ram pressure of the intergalactic medium gas. The existing velocity data cannot prove or disprove this hypothesis.
Estimates of Radiative Divergence during Phase III of the GARP Atlantic Tropical Experiment: Part II. Analysis of Phase III Results

Abstract The GATE Phase III radiative divergence profiles generally show less upper tropospheric radiative divergence and more middle level divergence than previous cilimatological estimates suggest. These differences are due primarily to the extensive middle and upper tropospheric cloudiness in the GATE area, the large mean values of total precipitable water vapor (∼5.1 cm), and the inclusion in the present study of the effects of the water vapor pressure broadened continuum. Averages for the 6 h local time periods 0000–0600, 0600–1200, 120–1800 and 1800–2400 show all layers of the GATE Phase III B-scale atmosphere experience a net radiative loss of energy. However, actual radiative heating of some layers is evident near midday. For a convectively suppressed composite case all levels above 700 mb show heating for the 1000–1400 LST period. The total troposphere shows a net radiative gain for the same 6 h interval (0900–1500 LST). For the enhanced convection case absolute warming is generally confined to t.
An Approach for Assessing Publication Bias Prior to Performing a Meta-Analysis

A semi-parametric method is developed for assessing publication bias prior to performing a meta-analysis. Summary estimates for the individual studies in the meta-analysis are assumed to have known distributional form. Selective publication is modeled using a nonparametric weight function, defined on the two-sided p-value scale. The shape of the estimated weight function provides visual evidence of the presence of bias, if it exists, and observed trends may be tested using rank order statistics or likelihood ratio tests. The method is intended as an exploratory technique prior to embarking on a standard meta-analysis.
Building Empathetic Transformer-based Chatbot: Deepening and Widening the Chatting Topic

Human-machine interaction, particularly via dialogue system, was a popular research area in the past decade. One of the challenges for dialogue systems is to recognize feelings and topics in the multi-turn conversation partner and reply accordingly, which is a key communicative skill in human-human interaction. This project aims at recognizing and acknowl-edging the speakers’ feelings and topics in conversations, by leveraging the novel EmpatheticDialogues dataset proposed by Facebook AI Research. We mainly focus on incorporating topic information into the Transformer framework to generate more informative and interesting responses. Firstly, we implement the Topic-prepend model, which inserts the topic information at the beginning of dialogue sentences based on the pre-trained topic classiﬁer. Secondly, we implement the Topic-aware model which adopts the joint attention mechanism and biased generation probability. The topic words are obtained by a pre-trained LDA topic model. Finally, we conduct experiments to compare our models with several baselines by both automatic and human evaluation. The results indicate that our models yield better performance by deepening and widening the chatting topic.
Hydrogen content of amorphous silicon films deposited in a multipole plasma

Hydrogenated amorphous silicon (a‐Si:H) samples are prepared in highly controlled conditions in a multipole dc discharge. Hydrogen content of the film is systematically analyzed as a function of deposition parameters such as ion flow, ion bombardment energy Eion, and substrate temperature. Hydrogen atomic concentration and profile are measured by nuclear reaction analysis. The essential role of ion bombardment is emphasized. Increasing deposition temperature and/or decreasing Eion results in a large decrease of the hydrogen content. Hydrogen‐enriched surfaces are observed when Eion≲10 eV. It is shown that SinH+m bombardment during film growth produces a dense hydrogen‐rich material.
High-power All-Fiber components: the missing link for high-power fiber lasers

Fiber lasers have shown extraordinary progress in power level, reaching the kilowatt range. These results were achieved with large mode area fibers pumped with high power laser diodes coupled with bulk-optics. To enable the commercial development of these high power fiber lasers, we have demonstrated several All-Fiber components, which replace the bulk-optic interface in the present laser configurations. These components include multimode fused fiber bundle combiners with or without signal fiber feed-through, Bragg gratings and mode field adaptors. The multimode fibers are used to couple several fiber pigtailed pump diodes to a double-clad fiber. Such combiners may contain a signal fiber to provide an input or output for the core modes of the double-clad fiber. Mode field adaptors perform fundamental mode matching between different core fibers. Bragg gratings are used as reflectors for the laser cavity. These components exhibit low-loss and high power handling of 200 Watts has been demonstrated. They enable the design of true high power single-mode All-Fiber lasers that will be small, rugged and reliable.
Analysis of the influence of lane changing on traffic-flow dynamics based on the cellular automaton model

Many cellular automaton models (CA models) have been applied to analyze traffic flow. When analyzing multilane traffic flow, it is important how we define lane-changing rules. However, conventional models have used simple lane-changing rules that are dependent only on the distance from neighboring vehicles. We propose a new lane-changing rule considering velocity differences with neighboring vehicles; in addition, we embed the rules into a variant of the Nagel–Schreckenberg (NaSch) model, called the S-NFS model, by considering an open boundary condition. Using numerical simulations, we clarify the basic characteristics resulting from different assumptions with respect to lane changing.