Miracle-dz/UniFAR-FTUs huggingface dataset:
Tri-band four elements MIMO antenna system for WLAN and WiMAX application

A new L-shaped slot dipole for multiple-input–multiple-output (MIMO) antenna system with an L-shaped slit is presented for WLAN and WiMAX applications. The L-shaped slot provides two bands at 2.4 and 5.2 GHz, and the third frequency at 3.5 GHz is achieved by introducing the L-shaped slit. The MIMO antenna consists of four symmetrical antenna elements. Each element is fed through a 50- microstrip feed line-coupling electromagnetic field to the slot. A high isolation of 16 dB among the four antennas is achieved for an antenna spacing less than 0.05 . The MIMO structure gives high gain ( dB), low correlation ( ), and high radiation efficiency ( ) The results indicate that the proposed MIMO antenna can provide spatial or pattern diversity to increase data capacity of wireless communication systems.
On Regular Fréchet-Lie Groups, I; Some Differential Geometrical Expressions of Fourier-Integral Operators on a Riemannian Manifold

Preface In this series of papers, we are going to construct a theory of infinite dimensional Lie groups, which will be called “regular Fr\’echet-Lie groups” throughout this series. Roughly speaking a regular Frechet-Lie group is a Fr\’echet-Lie group (i.e., a Lie group modeled on a locally convex Fr\’echet space) on which product integrals can be defined. For instance, consider a continuous curve $A(t)$ in the space $M(n)$ of
Morphological and electron transport studies in ZnO dye-sensitized solar cells incorporating multi- and single-walled carbon nanotubes

Dye-sensitized solar cells (DSSCs) incorporating zinc oxide (ZnO) nanostructures and carbon nanotubes (CNTs) were fabricated using a chemical bath deposition method. The nanoflake structures captured by a field-emission scanning electron microscopy analysis traced the appearance of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) in the photoanode thin film. The photovoltaic performance of the photoanode was quantified by means of an electrochemical impedance spectroscopy (EIS) unit with GAMRY-Physical Electrochemistry. The ZnO–SWCNT-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (Jsc), open-circuit voltage (Voc) and fill factor (FF) of 1.31%, 15.31 mA cm−2, 0.224 V and 0.36, respectively. The EIS unit was also employed to quantify the charge transport resistance (Rct), transport resistance (Rt) and effective electron lifetime (τeff) of the DSSC. The impedance analysis of the ZnO–SWCNT-based DSSC also determined greater highly efficient electron transport due to long effective electron diffusion length than the film thickness of the photoanode.
Vertically grating-coupled ARROW structures for III--V integrated optics

We propose a new all-planar technology scheme for coupling active gain or absorbing regions to low-propagation-loss, large-mode passive regions using monolithic waveguides vertically directionally coupled with a grating in an antiresonant reflecting optical waveguide (ARROW) geometry. Basic aspects of the concept have been demonstrated by laser action in an InGaAsP/InP ARROW grown by hydride vapor phase epitaxy and optically pumped by a Nd:YAG laser. This is the first demonstration of interlayer vertical directional grating coupling in III-V waveguides.
A theoretical investigation of the electronic structure and some thermodynamic properties of β-PbF2

The electronic structure and some structural and thermodynamic properties of beta -PbF2 have been theoretically investigated by means of the periodic Hartree-Fock method within a core-pseudopotential framework, and using a 3-1G (split-valence) basis set for valence electrons. Band structure, projected densities of states (DOS) and Mulliken populations are discussed; the ionic character of beta -PbF2 is confirmed (net charge on fluorine, -0.80 electron). The calculated total DOS is compared with the available photo-emission spectrum. The unit-cell parameter, the energy of formation, the bulk modulus and its derivative with respect to pressure (related to the Gruneisen constant) are also studied. The results are in overall agreement with previous semi-empirical theoretical calculations and with experimental data.
Observations of spontaneous toroidal flow in the LHD

Spontaneous toroidal flows driven by radial electric fields and ion temperature gradients are studied in the Large Helical Device (LHD). The positive radial electric field drives spontaneous flow in the counter-direction at the plasma edge and in the co-direction near the magnetic axis. The difference in the direction of the spontaneous flow between the core and the edge is considered to be due to the difference in the ratio of the helical ripple to the toroidal ripple. It is clearly observed that the ion temperature gradient causes a spontaneous toroidal flow and is expected to be one of the dominant components of the toroidal flows in the high ion temperature discharges in the LHD.
Isothermal-isobaric ensemble simulations of melting in quantum solids

An isothermal-isobaric ensemble version of the Fourier path-integral Monte Carlo method is formulated and applied to study melting in quantum solids. Experimental molar volumes of solid ortho-${\mathrm{D}}_{2},$ para-${\mathrm{H}}_{2},$ and HD are shown to be reasonably well reproduced by simulations using a Lennard-Jones potential. The fcc and hcp solid structures of ortho-${\mathrm{D}}_{2}$ are compared at 14 K and 0.85 MPa. The large quantum effects in solid ${\mathrm{D}}_{2}$ are demonstrated by the fact that the quantum solid at 14 K and 0.85 MPa has an average kinetic energy per particle which is 3.2 times its classical value and a density which is 21% less than that for the corresponding classical solid. The 0.85 MPa isobar, starting with an fcc solid at 14 K, is mapped out between 14 and 30 K. Changes in the various structural and energetic quantities with temperature have been monitored as a function of temperature. The instantaneous normal-mode spectrum of the quantum system is followed as a function of temperature and shown to undergo significant changes on melting of the quantum solid. In particular, the Einstein frequency and the average participation ratio of the real branch is shown to decrease sharply on melting while the fraction of imaginary frequencies increases.
Numerical investigation of 2D convection with extremely large viscosity variations

Previous experimental studies of convection in fluids with temperature‐dependent viscosity reached viscosity contrasts of the order of 105. Although this value seems large, it still might not be large enough for understanding convection in the interiors of Earth and other planets whose viscosity is a much stronger function of temperature. The reason is that, according to theory, above 104–105 viscosity contrasts, convection must undergo a major transition—to stagnant lid convection. This is an asymptotic regime in which a stagnant lid is formed on the top of the layer and convection is driven by the intrinsic, rheological, temperature scale, rather than by the entire temperature drop in the layer. A finite element multigrid scheme appropriate for large viscosity variations is employed and convection with up to 1014 viscosity contrasts has been systematically investigated in a 2D square cell with free‐slip boundaries. We reached the asymptotic regime in the limit of large viscosity contrasts and obtained s.
Measurement‐based fuzzy interpolation of room impulse responses

Application of room impulse responses (RIRs) to acoustic evaluation and auralization often requires many measurements to get enough information about the hall, or to provide enough flexibility for virtual sound source placements in convolution reverberation. In this paper we propose a measurement‐based fuzzy modeling method to approximate the RIR function at an arbitrary location between available measured points, without a priori information on the hall geometry or wall reflection parameters. For the fuzzy model identification we define an accuracy indicator of the spatial density of the source positions and predict the required number of them in a selected hall. This indicator quantifies the relationship of the early reflections, determined for various measured positions. This paper also proposes a method that treats nonuniform spatial sampling of the measurement positions, and its implementation for 2D cases is shown. Nonuniform spatial sampling can be useful when RIRs at some source positions ‐‐ e.g. .
Analysis of low count time series data by poisson autoregression

Abstract. This study provides new methods of assessing the adequacy of the Poisson autoregressive time‐series model for count data. New expressions are given for the score function and the information matrix and these lead to the construction of new types of residuals for this model. However, these residuals often need to be supplemented by formal statistical procedures and an overall test of the model adequacy is given via the information matrix equality that holds for correctly specified models. The techniques are applied to a monthly count data set of claimants for wage loss benefit, in order to estimate the the expected duration of claimants in the system.
Analysis of Axially Polarized Piezoelectric Ceramic Rings

An axisymmetric analytical model is presented of axially polarized piezoelectric ceramic rings with radius a few times the wall-thickness and the length. The only assumptions made are that axial displacement and electric potential are functions of only the axial coordinate and that radial displacement is a function of only the radial coordinate. Then, exact solutions to the exact governing equations are determined. The boundary conditions on electric potential are satisfied exactly. The other boundary conditions are satisfied in an average sense. The input electrical admittance of stress-free rings with losses are computed and compared with that obtained using ATILA—a finite element program. Good agreement is obtained for the resonance and anti-resonance frequencies and the values of conductance and susceptance at the first resonances in the lower and upper branches.
Stueckelberg mechanism for antisymmetric tensor fields

It is shown how vector Stueckelberg fields can be introduced to ensure gauge invariance for mass terms for an antisymmetric tensor field. Scalar Stueckelberg fields allow one to have gauge invariance for these vector fields. Both the Abelian and non-Abelian cases are considered. Fully antisymmetric rank-three tensor fields and symmetric rank-two tensor fields are also discussed. PACS No.: 11.15-1
Representation of 3D heterogeneous cloud fields using copulas: Theory for water clouds

It is shown that a general representation of GCM column cloud fraction within probability density function (PDF)‐based statistical cloud parametrizations can be obtained using statistical functions called copulas that encapsulate the dependence structure of rank statistics in a multivariate system. Using this theory, a new Gaussian copula formulation of GCM cloud overlap is obtained. The copula approach provides complete flexibility in the choice of the marginal PDF of each layer's moisture and temperature, and, compared with earlier approaches, including the ‘generalized overlap’ approach, allows a far more general specification of the correlation between any pair of layers. It also allows easy addition of new layer variables, such as temperature, into the modelled grid‐column statistics. As a preliminary test of this formulation, its ability to statistically describe a cloud‐resolving model simulation of a complex multi‐layer case‐study, including both large‐scale and convective clouds, is examined. The Gaussian copula cloud fraction is found to be significantly less biased than other common cloud overlap methods for this case‐study. Estimates of several nonlinear quantities are also improved with the Gaussian copula model: the variance of condensed water path and the fluxes of solar and thermal radiation at atmospheric column boundaries. This first paper, though limited to the simpler case of water clouds, addresses subgrid‐scale variability in both moisture and temperature. This work is envisaged as a first step towards developing a generalized statistical framework for GCM cloud parametrization and for assimilating statistical information from high‐resolution satellite observations into GCMs and global analyses. Copyright © 2008 Royal Meteorological Society
Weighting by Inverse Variance or by Sample Size in Random-Effects Meta-Analysis

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each effect size, but in practice these weights have to be estimated, being affected by sampling error. When assuming a random-effects model, there are two alternative procedures for averaging independent effect sizes: Hunter and Schmidt’s estimator, which consists of weighting by sample size as an approximation to the optimal weights; and Hedges and Vevea’s estimator, which consists of weighting by an estimation of the inverse variance of each effect size. In this article, the bias and mean squared error of the two estimators were assessed via Monte Carlo simulation of meta-analyses with the standardized mean difference as the effect-size index. Hedges and Vevea’s estimator, although slightly biased, achieved the best performance in terms of the mean squared error. As the differences between the values of both estimators could be of practical relevance, Hedges and Vevea’s estimator should be selected rather than that of Hunter and Schmidt when the effect-size index is the standardized mean difference.
Investigation of aberrations of Kirkpatrick-Baez mirrors

The flux distributions in the focal plane of Kirkpatrick-Baez optics are investigated as the parameters of the focusing ellipse of the mirrors are changed from typical laboratory optics to synchrotron beam line optics. This work shows the effects of the most predominant focusing imperfections that arise from conditions that violate the original assumptions of Kirkpatrick-Baez systems, including orthogonality of the mirror surfaces and paraxial rays.
The effect of grooved surface on dielectric multipactor

The effect of periodic rectangular grooves on vacuum multipactor has been theoretically and experimentally investigated. Dynamic calculation is applied to research the electron trajectory and impact energy under groove surface. Two-dimensional electromagnetic particle-in-cell simulation is used to analyze and compare multipactor scenario, statistic energy, and secondary emission yield on the flat surface with that on the corrugated surface. It has been found by computational and simulative analysis that grooved surface can explicitly suppress multipactor in the developmental stage of multipactor. S-band high power microwave (HPM) dielectric breakdown experiment under vacuum, with microsecond pulse length was conducted. It was confirmed by experiment that periodic grooves perpendicular to the major electric field can effectively increase transmitted power.
Testing for a change in repeated measures data

Four nonparametric test statistics for the change-point problem with repeated measures data are proposed. In a Monte Carlo simulation study, critical values for the proposed test statistics are simulated and the performances of the proposed tests are compared with the performances of some competitive tests in terms of asymptotic behavior and power. We provide appropriate recommendations for different occurrences of the change-point and illustrate the testing methods using a set of real data.
Determining the Susceptibility of Cloud Albedo to Changes in Droplet Concentration with the Advanced Very High Resolution Radiometer

Abstract Combustion Processes that Produce greenhouse gases also increase cloud condensation nuclei (CCN) concentrations, which in turn increase cloud droplet concentrations and thereby cloud albedo. A calculation of cloud susceptibility, defined in this work as the increase in albedo resulting from the addition of one cloud droplet per cubic centimeter (as cloud liquid water content remains constant), is made through the satellite remote sensing of cloud droplet radius and optical thickness. The remote technique uses spectral channels of the Advanced Very High Resolution Radiometer (AVHRR) instrument on board NOAA polar-orbiting satellites. Radiative transfer calculations of reflectance and effective surface and cloud emissivities are made for applicable sun and satellite viewing angles, including azimuth, at various radii and optical thickness for each AVHRR channel. Emission in channel 3 (at 3.75 µm) is removed to give the reflected solar component. These calculations are used to infer the radius and o.
A practical direct current discharge helium absorption cell for laser frequency locking at 1083 nm

We report the construction of a low pressure (∼0.5 Torr) helium direct current discharge cell to lock a 1083 nm InGaAs diode laser to the 2 3S–2 3P transition in helium using saturated absorption spectroscopy. The direct current discharge cell has the advantage of being radio frequency noise free.
Aussie, Aussie, Aussie, Oi-Oi-Oi: Infants love an Australian accent

This study examines infant’s attention to dialect differences following Nazzi et al.’s [J. Mem. Lang. , 43, 1–19 (2000)] finding that American 5‐month‐olds can discriminate British‐ and American‐English. Using a serial preference task, 48 6‐month‐old Australian and American infants heard sentence sets spoken in Australian‐ and American‐English. Results showed that at 6 months, American infants listen longer to Australian than American sentences, but Australian infants show no preference. By 8 months, American infants also show no preference. The developmental lag suggests Australian infants have more exposure to the American dialect (e.g., television programs) than American infants to the Australian dialect. Thus, it is predicted, with less linguistic experience, Australian 3‐month‐olds will show a dialect preference comparable to American 6‐month‐olds. Data from 14 3‐month‐olds support this hypothesis; moreover, they also listen longer to Australian than American sentences. Together the results imply that.
Interlaboratory comparison of phase doppler measurements in a research simplex atomizer spray

Author(s): McDonnell, VG; Samuelsen, GS; Wang, MR; Hong, CH; Lai, WH | Abstract: Phase Doppler interferometry is providing detailed information about the structure of sprays. Such information is attractive to those developing numerical models that predict spray behavior. However, the inherent complexity of sprays and advanced diagnostics warrants the development of a reference point for measurements. Hence, a "standard" spray is evaluated in the current study which can be used to evaluate instrument and operator performance and, once sufficient data sets are generated, can provide a benchmark data set for modeling challenges. A comprehensive set of mean and variation in five sets of measurements is provided. In general, the results reveal reasonable reproducibility, especially in quantities which are dependent solely upon the number of drops (e.g., mean velocities). It is also shown that statistics derived from individual drop sizes reveal less variability than those derived from the entire spray population. Finally, it is observed that quantities whichdepend upon drop volume and/or sample volume area (e.g., Sauter mean diameter, volume flux) are subject to the greatest variability. © 1994, American Institute of Aeronautics and Astronautics, Inc., All rights reserved.
Techniques for characterizing waveguide gratings and grating-based devices

Waveguide gratings used in laser technology, optical sensing or optical communications have to serve different specific purposes and, hence, have to have specific optical properties which can be tailored to a large extent. Characterization methods are required not only to measure the actual effect of a Bragg grating or long period grating under consideration but also to unveil the cause, i.e. to determine its spatial structure. This paper reviews the present status of the respective experimental characterization techniques. The methods emphasized rely on phase sensitive reflectometry together with advanced inverse scattering evaluation algorithms.
Potential application of tip-enhanced Raman spectroscopy (TERS) in semiconductor manufacturing

Tip-enhanced Raman spectroscopy (TERS), with nanometer spatial resolution, has the capability to monitor chemical composition, strain, and activated dopants and is a promising metrology tool to aid the semiconductor R&D processes. This paper addresses the major challenges which limit the application of TERS from routine measurement: the lack of comparability, reproducibility, calibration, and standardization. To address these issues, we have developed a robust test structure and the ability to generate high-quality tips using a high volume manufacturing (HVM) approach. The qualifying data will be presented.
Solar large-scale emitting chains: Preliminary remarks on the cycle variability

Abstract Preliminary remarks on the solar cycle phase variability of the microwave and EUV large-scale chains are outlined briefly based on the Nobeyama Radioheliograph and SOHO/EIT data. The observed complication of the chains in the course of the cycle appears to reflect the corresponding complication of the global solar magnetosphere.
On the Exact Size of Tests of Treatment Effects in Multi‐Arm Clinical Trials

When testing treatment effects in multi‐arm clinical trials, the Bonferroni method or the method of Simes 1986) is used to adjust for the multiple comparisons. When control of the family‐wise error rate is required, these methods are combined with the close testing principle of Marcus et al. (1976). Under weak assumptions, the resulting p‐values all give rise to valid tests provided that the basic test used for each treatment is valid. However, standard tests can be far from valid, especially when the endpoint is binary and when sample sizes are unbalanced, as is common in multi‐arm clinical trials.
Low frequency hysteresis loops of superparamagnetic nanoparticles with uniaxial anisotropy

The low frequency hysteresis loops of superparamagnetic nanoparticles with uniaxial anisotropy are calculated as a function of the particle diameter, alternating magnetic field amplitude H0, frequency, and particle magnetic parameters both for oriented and nonoriented assemblies. The magnetic field frequency is assumed so high, f>50–100 kHz, that the mechanical rotation of a particle in surrounding medium is restricted. Thus, only the Neel–Brown magnetization relaxation process is taken into account. Pronounced dependence of the specific loss power on the particle diameter is found in the linear regime pertaining to small magnetic field amplitudes. For an oriented assembly of Co nanoparticles with optimal diameter D≈6 nm the specific power loss can be as high as 1600 W/g for typical values H0=200 Oe and f=500 kHz. It is three times less for the corresponding nonoriented assembly. Nevertheless, using of particles with low anisotropy field, i.e., particles of soft magnetic type, seems to be preferable for t.