Miracle-dz/UniFAR-FTUs huggingface dataset:
The investigation of a μGal-level cold atom gravimeter for field applications

Typical atomic gravimeters have a heavy magnetic shielding to avoid the quadratic Zeeman effect, and also a complicated active vibration isolation system to suppress the vibration noise. Both of them make it difficult to build a mobile and compact gravimeter. In this paper, we present the implementation of an atomic gravimeter aiming at field applications. Our gravimeter uses improved magnetic coils instead of the expensive mu-metal for magnetic shielding. The quadratic Zeeman shift is evaluated with high accuracy. Moreover, a portable platform of relatively small size is applied for vibration isolation. The total interrogation time is optimized to 120 ms and the repetition rate is 2.2 Hz. A sensitivity of 1.0 × 10−7 g Hz−1/2 and a resolution of 5.7 × 10−9 g within 1000 s integration time are reached. A continuous g measurement over 128 h is carried out. Moreover, a whole seismic wave of about 1 h that occurred in Pakistan on 28 September 2013 is recorded by our atomic gravimeter. The results coincide with that recorded by a traditional seismic detector very well.
Image registration and fusion of MMW and visual images for concealed object detection

This paper addresses the registration and the fusion techniques between passive millimeter wave (MMW) and visual images for concealed object detection. The passive MMW imaging system detects concealed objects such as metal and man-made objects as well as small liquid and gel containers. The registration and fusion processes are required to combine information from both of visual and MMW images. The registration process is composed of feature extraction and matching stages. The body areas in two images are adjusted to each other in scale, rotation, and location. The image fusion method is based on discrete wavelet transform and a fusion rule, which emphasizes the person's identity and the hidden object together. The experimental and simulation results show the proposed technique can detect a concealed object and fuse two different types of images in a fully automated way.
The design of improved smoothing operators for finite volume flow solvers on unstructured meshes

Spatial operators used in unstructured finite volume flow solvers are analysed for accuracy using Taylor series expansion and Fourier analysis. While approaching second‐order accuracy on very regular grids, operators in common use are shown to have errors resulting in accuracy of only first‐, zeroth‐ or even negative‐order on three‐dimensional tetrahedral meshes. A technique using least‐squares optimization is developed to design improved operators on arbitrary meshes. This is applied to the fourth‐order edge sum smoothing operator. The improved numerical dissipation leads to a much more accurate prediction of the Strouhal number for two‐dimensional flow around a cylinder and a reduction of a factor of three in the loss coefficient for inviscid flow over a three‐dimensional hump. Copyright © 2001 John Wiley & Sons, Ltd.
Deferred Shifting Schemes for Parallel QR Methods

Parallel implementation of the QR algorithm for solving the symmetric eigenvalue problem requires more than a straightforward transcription of sequential code to parallel code. Experimental adjustments include new shifting techniques and omission of the initial reducing to upper Hessenberg form. In this paper, the theory of the convergence of algorithms of decomposition type for the algebraic eigenvalue problem developed by Watkins and Elsner is generalized. The results are extended to deferred shifting schemes, which allow pipelining of iterations in parallel implementations, and analyzing the deterioration of the convergence rate. Furthermore, it is shown that eigenvalues need not be simple to obtain quadratic convergence for nondefective nonsymmetric matrices and cubic convergence for symmetric matrices.
Electrostatically Induced Polyelectrolyte Association of Rodlike Virus Particles

Calculations of the electrostatic osmotic pressure for a closely packed phase of laterally ordered rodlike fd or M13 virus particles at equilibrium with a bulk salt solution have been performed using grand canonical Monte Carlo simulations. With increasing concentration of divalent counterions, the pressure becomes attractive. The attraction is stronger for higher surface charge density (of fd virus as opposed to M13 virus) and smaller counterion radius. The calculations agree with the results from light scattering measurements, which sensitively detect the formation of laterally ordered virus aggregates.
A Tobit Ridge Regression Estimator

This article analyzes the effects of multicollienarity on the maximum likelihood (ML) estimator for the Tobit regression model. Furthermore, a ridge regression (RR) estimator is proposed since the mean squared error (MSE) of ML becomes inflated when the regressors are collinear. To investigate the performance of the traditional ML and the RR approaches we use Monte Carlo simulations where the MSE is used as performance criteria. The simulated results indicate that the RR approach should always be preferred to the ML estimation method.
Multiscale salient region detection and salient map generation for synthetic aperture radar image

Abstract Saliency, which refers to distinctive parts of an image that can immediately attract attention without prior information, is significantly meaningful in machine vision, image interpretation, and moreover in quickly extracting vehicle targets or man–made constructions in remote sensing image processing. Different from optical images, synthetic aperture radar (SAR) image has unique characters such as multiplicative speckle noise, local intensity variation, and no color information. However, it is still a challenging work for SAR images to detect salient region and to generate saliency map with the methods performed on optical images. To address this problem, this paper presents a stable salient region detection and salient map generation method for SAR image. We propose a new local complexity metric, which is insensitive to speckle noise and can effectively describe the local intensity variation of SAR image. In addition, via incorporating a stable distribution distance measure, the self-dissimilarity metric is redefined. Using these two components, we construct the saliency metric and generate the salient map. Experimental results demonstrate the accuracy, robustness, and stability of our method for SAR images.
A multiplexing fiber optic microsensor system for monitoring oxygen concentration in plants

The accurate and rapid measurement of physiological O2 transport is vital for understanding spatially and temporally dynamic metabolism and stress signalling in plant cells and tissues. Single channel luminescent O2- quenched optrodes have been available for use in laboratory and field experiments since the early 2000’s. However, to collect the large datasets needed to understand O2 transport in complex systems, many experiments require a multiple channel O2 sensor system. This research reports the development of a multiplexing fiber optic O2 microsensor system designed to conduct high temporal resolution experiments for field studies of plant physiology. The 10 channel system was demonstrated for measuring O2 concentration in developing soybean seeds (Glycine max L. Merr.) within a climate controlled greenhouse.
Real‐time forecasting of photosmog episodes: the Naples case study

In this paper we analysed the ozone time series data collected by the local monitoring network in the Naples urban area (southern Italy) during the spring/summer period of 1996. Our aim was to identify a reliable and effective model that could be used for the real‐time forecasting of photosmog episodes. We studied the applicability of seasonal autoregressive integrated moving average models with some exogenous variables (ARIMAX) to our case study. The choice of exogenous variables—temperature, [NO2]/[NO] ratio and wind speed—was based on physical reasoning. The forecasting performance of all models was evaluated with data not used in model development, by means of an array of statistical indices: the comparison between observed and forecast means and standard deviations; intercept and slope of a least squares regression of forecast variable on observed variable; mean absolute and root mean square errors; and 95% confidence limits of forecast variable. The assessment of all models was also based on their tendency to forecast critical episodes. It was found that the model using information from the temperature data set to predict peak ozone levels gives satisfactory results, about 70% of critical episodes being correctly predicted by the 24 h ahead forecast function. Copyright © 2001 John Wiley & Sons, Ltd.
Symbols for trace class Hankel operators with good estimates for norms

Peller [4, 5] has proved that a Hankel operator S on the Hardy space H2 is in the trace class if and only if with h analytic on the open unit disc Dand with its second derivative belonging to the Bergman space L1a. This theorem does not include an estimate for the trace class norm ∥S∥1, of the operator in terms of the symbol function. In fact it is clear that cannot give an estimate for since the first two terms in the coefficient sequence of the Hankel operator have been removed by differentiation.
Formaldehyde in the orion molecular flow: evidence for a gentle acceleration

High-velocity gas (50 km s/sup -1/) has been observed in six transitions of formaldehyde toward the Orion infrared clusters. The region of the clusters has been mapped in the higher frequency transitions. The low-velocity emission probably arises from an ensemble of dense (approx.10/sup 7/--10/sup 8/) clumps. A similar density is required to reproduce the observed excitation of the high-velocity emission. The abundance of formaldehyde in the high-velocity gas (X(H/sub 2/CO)approx.10/sup -9/) is similar to the abundance in the ambient cloud and about an order of magnitude higher than that in the ''hot core. '' Chemical reactions at the high temperatures expected from direct heating of the H/sub 2/CO by a passing shock should drastically lower its abundance. The survival of high-velocity formaldehyde requires acceleration of only modestly heated (i.e,<400 K) cloud material, perhaps in the form of clumps similar to those producing the low-velocity emission.
Moving horizon control of nonlinear systems with input saturation, disturbances and plant uncertainty

We present a moving horizon feedback system, based on constrained optimal control algorithms, for nonlinear plants with input saturation, disturbances and plant uncertainty. The system is a non-conventional sampled-data system: its sampling periods vary from sampling instant to sampling instant, and the control during the sampling time is not constant, but determined by the solution of an open loop optimal control problem. We show that the proposed moving horizon control system is robustly stable and is capable of attenuating L ∞ bounded disturbances
Does the optical angular momentum change smoothly in fractional-charged vortex beams?

We consider the oscillations of the orbital angular momentum in the vortex beams with fractional topological charges, taking into account the vortex influence, beam astigmatism, and the displacement of the center of gravity on the basis of the intensity momenta approach. We revealed also that base contribution gives the optical vortices and displacement of the center of gravity. In addition, we analyze the distribution of the current lines in the erf-G beams with the topological charge p=1/2, revealing that there are two types of the curves: (1) closed C-like lines and (2) the inner closed lines.
The probabilistic significance of the rate matrix in matrix-geometric invariant vectors

Many queueing models have embedded Markov chains, whose invariant probability vector is of a (modified) matrix-geometric form. The rate matrix R is shown to have the following probabilistic interpretation: The element Rvj is the expected number of visits to the state (i + 1, j), before the first return to the set i = {(i, 1), …,(i, m)}, in a chain starting in the state (i, v).
Minimization Techniques for Piecewise Differentiable Functions: The l_1 Solution to an Overdetermined Linear System

A new algorithm is presented for computing a vector x which satisfies a given m by $n(m > n \geqq 2)$ linear system in the sense that the $l_1 $ norm is minimized. That is, if A is a matrix having m columns $a_1 , \cdots ,a_m $ each of length n, and b is a vector with components $\beta _1 , \cdots ,\beta _m $, then x is selected so that \[\phi (x) = ||A^T x - b||_1 = \sum _{i = 1}^m {\left|a_i^T x - \beta _i \right|} \] is as small as possible. Such solutions are of interest for the “robust” fitting of a linear model to data.The function $\phi $ is directly minimized in a finite number of steps using techniques borrowed from Conn’s approach toward minimizing piecewise differentiable functions. In these techniques if x is any point and $A_\mathcal {Z} $ stands for the submatrix consisting of those columns $a_j$ from A for which the corresponding residuals $a_j^T x - \beta _j $ are zero, then the discontinuities in the gradient of $\phi $ at x are handled by making use of the projector onto the null space o.
Alternative Expression of the Electric Field in the Source Region without the Source Dayadic Term

An alternative expression is derived for the evaluation of the electric field in the source region. This expression caters for a finite size, instead of an infinitesimally small, principal volume and does not contain the source dyadic term. This expression provides a fast and accurate evaluation of the electric field inside an arbitrary shape finite size principal volume. Numerical calculations on using the new expression are provided.
Temperature dependence of the first-order Raman phonon line of diamond

Micro-Raman scattering from single-crystal diamond was performed over the temperature range 77\char21{}873 K. These measurements show that the Raman phonon frequency and the linewidth are temperature dependent, the linewidth and the frequency extrapolated to 0 K are $1.103\ifmmode\pm\else\textpm\fi{}0.03{\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and $1332.7\ifmmode\pm\else\textpm\fi{}0.2{\mathrm{cm}}^{\mathrm{\ensuremath{-}}1},$ respectively. A linear relationship was found to exist between the downshift of the Raman frequency and the linewidth. In contrast to other group IV semiconductors, we show that in diamond the dependence of the phonon linewidth on the temperature is well described by the simple Klemens model which assumes that the zone center phonons decay into two acoustical phonons of opposite momentum but belonging to the same acoustic branch.
Analysis of Split‐plot Designs with Mirror Image Pairs as Sub‐plots

In this article we present a procedure to analyze split‐plot experiments with mirror image pairs as sub‐plots when third‐ and higher‐order interactions can be assumed negligible. Although performing a design in a split‐plot manner induces correlation among observations, we show that with such designs the essential search for potentially active factors can be done in two steps using ordinary least squares. The suggested procedure is tested out on a real example and on two simulated screening examples; one with a split‐plot design based on a geometric design and one with a split‐plot design based on a non‐geometric Plackett and Burman design. The examples also illustrate the advantage of using non‐geometric designs where the effects are partially aliased instead of being fully aliased as in highly fractionated fractional factorials. Copyright © 2005 John Wiley & Sons, Ltd.
Generation of low-frequency electrostatic and electromagnetic waves as nonlinear consequences of beam–plasma interactions

Nonlinear evolution of the electron two-stream instability in a current-carrying plasma is examined by using a two-dimensional electromagnetic particle-in-cell simulation. Formation of electron phase-space holes is observed as an early nonlinear consequence of electron–beam–plasma interactions. Lower-hybrid waves, electrostatic, and electromagnetic whistler mode waves are also excited by different mechanisms during the ensuing nonlinear wave–particle interactions. It is shown by the present computer simulation with a large simulation domain and a long simulation time that these low-frequency waves can disturb the electrostatic equilibrium of electron phase-space holes, suggesting that the lifetime of electron phase-space holes sometimes becomes shorter in a current-carrying plasma.
Modified effective medium formulation for the thermal conductivity of nanocomposites

This letter introduces a modified effective medium formulation for composites where the characteristic length of the inclusion is on the order of or smaller than the phonon mean free path. The formulation takes into account the increased interface scattering in the different phases of the nanocomposite and the thermal boundary resistance between the phases. The interface density of inclusions is introduced and is found to be a primary factor in determining the thermal conductivity. The predictions are in good agreement with results from Monte Carlo simulations and solutions to the Boltzmann equation.
Radio Continuum Sources in Nearby and Bright E/S0 Galaxies: Sample Selection and Well-Studied Cases

Un echantillon de 216 galaxies E/S0 proches et optiquement brillantes ont ete tirees du survey des redshifts du Center of Astrophysics. Les proprietes optiques fondamentales de l'echantillon sont tabulees. Les donnees du continuum radio montrent que 12 galaxies sont des radiosources confirmees pour lesquelles des images VLA sont disponibles. Une synthese des proprietes radio de ces 12 sources revele que (1) toutes montrent des noyaux radio compacts et des structures sur des echelles du parsec; (2) des structures sur des echelles du kpc sont courantes et sont habituellement collimatees et a 2 cotes vis-a-vis du noyau compact; et (3) une emission a l'echelle galactique, lorsqu'elle est presente, apparait habituellement comme des lobes doubles externes nourris par des jets doubles
Spectral clustering with eigenvector selection based on ensemble ranking

Ng-Jordan-Weiss (NJW) method is one of the most widely used spectral clustering algorithms. For a clustering problem with K clusters, this method clusters data using the largest K eigenvectors of the normalized affinity matrix derived from the data set. However, the top K eigenvectors are not always the most important eigenvectors for clustering. In this paper, we propose an eigenvector selection method based on an ensemble of multiple eigenvector rankings (ESEER) for spectral clustering. In ESEER method, first multiple rankings of eigenvectors are obtained by using the entropy metric, which is used to measure the importance of each eigenvector, next the multiple eigenvector rankings are aggregated into a single consensus one, then the first K eigenvectors in the consensus ranking list are adopted as the selected eigenvectors. We have performed experiments on artificial data sets, standard data sets of UCI repository and handwritten digits from MNIST database. The experimental results show that ESEER method is more effective than NJW method in some cases.
Mapping and statistics of ferroelectric domain boundary angles and types

Ferroelectric domain orientations have been mapped using piezo-force microscopy, allowing the calculation and statistical analysis of interfacial polarization angles, the head-to-tail or head-to-head configuration, and any cross-coupling terms. Within 1 µm2 of an epitaxial (001)p-oriented BiFeO3 film, there are >40 µm of linear domain boundary based on over 500 interfaces. 71° domain walls dominate the interfacial polarization angles, with a 2:1 preference for uncharged head-to-tail versus charged head-to-head boundary types. This mapping technique offers a unique perspective on domain boundary distributions, important for ferroelectric and multiferroic applications where domain wall parameters are critical.
Renormalized perturbation series and the semiclassical limit of quantum mechanics

The accuracy of the renormalized perturbation series for anharmonic oscillators and other simple quantum‐mechanical models increases with the quantum number when the adjustable parameter is determined by a simple variational criterion. In the semiclassical limit of quantum mechanics such an expansion converges towards the result of the Jeffreys–Wentzel–Kramers–Brillouin method to all orders. The hypervirial and Hellmann–Feynman theorems facilitate the derivation of the semiclassical series from Rayleigh–Schrodinger perturbation theory.
Application of the smooth variable structure filter to a multi-target tracking problem

The most popular and well-studied estimation method is the Kalman filter (KF), which was introduced in the 1960s. It yields a statistically optimal solution for linear estimation problems. The smooth variable structure filter (SVSF) is a relatively new estimation strategy based on sliding mode theory, and has been shown to be robust to modeling uncertainties. The SVSF makes use of an existence subspace and of a smoothing boundary layer to keep the estimates bounded within a region of the true state trajectory. This article discusses the application of two estimation strategies (the KF and the SVSF) on a multi-target tracking problem.
Exact Relations Between Damage Spreading and Thermodynamical Properties

We investigate the damage or Hamming distance between two configurations of Ising spins. We find an exact relation between the difference of the two possible types of damage and the spin-spin correlation function, which is generally valid. For the specific case of ferromagnetic interactions, heat bath dynamics and same sequence of random numbers, this relation involves only one type of damage. The susceptibility and the magnetization can also be expressed in terms of the damage. Numerical determination of the damage for the 2d Ising model is not only an efficient way to calculate correlation functions but also gives access to spin fluctuations visualized as clusters of damaged sites which have a fractal dimension d−β/ν at Tc and whose size distribution is also related to static exponents.
Microfabricating bacteriorhodopsin films for imaging and computing

An array of electrode sandwiched bacteriorhodopsin (bR) pixels was microfabricated for the wide variety of electro‐optical applications that have been suggested for this unique biological molecule. The electro‐optical properties of a microfabricated bR pixel was measured to prove that the production process is nondestructive. This method allows the microfabrication of biological materials that cannot be treated by conventional microelectronics technologies.
Geometric phases of two- and three-level atomic systems related to group theory

The Hamiltonians of two- and three-level atomic systems interacting with nearly resonant electro-magnetic fields are described. The geometric phase related to the σ z operator of a two-level system is analysed and it is shown that this phase is well defined also for an open circuit. For a closed circuit this phase becomes equivalent to twice the Berry phase. For three-level atomic system the eigenenergies of the Hamiltonian are obtained by solving a cubic equation. Simplified forms for these eigenenergies and a condition for degeneracy are obtained. For non-degenerate three-level system geometric phases related to Cartan subalgebra are analysed under the adiabatic approximation and their relations with the three-level Berry phases are clarified. We show how to use the general theory of non-Abelian connections to the Hamiltonian of a three-level atomic system which includes a degeneracy.