Miracle-dz/UniFAR-FTUs huggingface dataset:
Green upconversion lasing and thermo-optical bistability in ZBNA microspheres

We demonstrate upconversion lasing and fluorescence from active microspheres fabricated from a novel fluorozirconate, Er3+-doped glass, ZBNA, when pumped around 978 nm through a tapered optical fibre. An ultralow, green lasing threshold of ~3 μW for 550 nm emissions is measured. This is one order of magnitude lower than that previously obtained for ZBLAN microspheres. Optical bistability effects observed within the microspheres indicate that this material is suitable for low-frequency, all-optical switching. The bistable mechanism is discussed and attributed to shifts of the resonances due to thermal expansion of the sphere, where the heat is generated by phonon transitions excited after optical pumping around 978 nm. We also report multiple bistability loops within the microspheres. In a separate experiment, the latching behaviour of the microspheres is illustrated.
Multispectral polarized scene projector (MPSP)

This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the short wave infrared (SWIR) regime, can be used for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. The MPSP system generates both static and video images (up to 200 Hz) with 512×512 spatial resolution with active spatial, spectral, and polarization modulation with controlled bandwidth. It projects input SWIR radiant intensity scenes from stored memory with user selectable wavelength (850-1650 nm) and bandwidth (12-100 nm), as well as polarization states (six different states) controllable on a pixel by pixel basis. The system consists of one spectrally tunable liquid crystal filter with variable bandpass, and multiple liquid crystal on silicon (LCoS) spatial light modulators (SLMs) for intensity control and polarization modulation. In addition to the spectro-polarimetric sensor test, the instrument also simulates polarized multispectral images of military scenes/targets for hardware-in-the loop (HIL) testing.
An Indirect Adaptive Fuzzy Control Scheme for a Class of Nonlinear Systems

This paper presents an indirect adaptive control scheme, for a class of nonlinear systems in controller canonical form. Owing to the universal approximation property of a Takagi–Sugeno (T–S) fuzzy model, controller design is simplified by utilizing the T–S fuzzy model representation of a nonlinear system. An adaptation mechanism ensures that the estimator model asymptotically follow the actual T–S fuzzy model and thus removes the need of any a priori identification of the T–S fuzzy model of the system. The overall controller gain is a convex combination of the local linear gains which vary adaptively to ensure the convergence of the tracking error. Preliminary simulation results indicate the potential of the proposed method.
Performance of new ceramic scintillators for gamma- and x-ray detection

Ceramic materials show significant promise for the production of reasonably priced, large-size scintillators. Ceramics have recently received a great deal of attention in the field of materials for laser applications, and the technology for fabricating high-optical-quality polycrystalline ceramics of cubic materials has been well developed. The formation of transparent ceramics of non-cubic materials is, however, much more difficult as a result of birefringence effects in differently oriented grains. Here, we will describe the performance of a few new ceramics developed for the detection of gamma- and x-ray radiation. Results are presented for ceramic analogs of three crystalline materials - cubic Lu2O3, and non-cubic LaBr3, and Lu2SiO5 or LSO (hexagonal, and monoclinic structures, respectively). The impact of various sintering, hot-pressing and post-formation annealing procedures on the light yield, transparency, and other parameters, will be discussed. The study of LaBr3:Ce shows that fairly translucent ceramics of rare-earth halides can be fabricated and they can reach relatively high light yield values. Despite the fact that no evidence for texturing has been found in our LSO:Ce ceramic microstructures, the material demonstrates a surprisingly high level of translucency or transparency. While the scintillation of LSO:Ce ceramic reaches a light yield level of about 86 % of that of a good LSO:Ce single crystal, its decay time is even faster, and the long term afterglow is lower than in LSO single crystals.
RADIAL DISTRIBUTION OF COMPRESSIVE WAVES IN THE SOLAR CORONA REVEALED BY AKATSUKI RADIO OCCULTATION OBSERVATIONS

Radial variations of the amplitude and the energy flux of compressive waves in the solar corona were explored for the first time using a spacecraft radio occultation technique. By applying wavelet analysis to the frequency time series taken at heliocentric distances of 1.5–20.5 RS (solar radii), quasi-periodic density disturbances were detected at almost all distances. The period ranges from 100 to 2000 s. The amplitude of the fractional density fluctuation increases with distance and reaches ∼30% around 5 RS, implying that nonlinearity of the wave field is potentially important. We further estimate the wave energy flux on the assumption that the observed periodical fluctuations are manifestations of acoustic waves. The energy flux increases with distance below ∼6 RS and seems to saturate above this height, suggesting that the acoustic waves do not propagate from the low corona but are generated in the extended corona, probably through nonlinear dissipation of Alfvén waves. The compressive waves should eventually dissipate through shock generation to heat the corona.
ESTIMATION OF BODY WEIGHT OF WHITE-TAILED DEER (ODOCOlLEUS VIRGlNlANUS) FROM BONE SIZE

-Lower leg bones of 210 modem white-tailed deer (Odocoileus vitginianus) from 8 localities in eastern North America were used to examine factors influencing the relationship between bone size and body size. Locality (island versus mainland), age, and sex were shown to affect bone size-body weight relationships. After accounting for the compounding factors, a set of unified regressions are presented that estimate adult live weight in the late autumn of white-tailed deer. However, since live weight is subjected to many diverse influences, the estimates should be used only as an ordinal guide to size.
Spaceguard-1: a space-based observatory for NEO physical characterization and discovery

We investigate a broad system design for a space-based observatory operating at mid-infrared and visible wavelengths to perform physical characterization and discovery of near-Earth objects (NEOs) in the inner solar system. Our goals require measurements that are much more efficiently done from space. The mission objectives are to obtain accurate diameters, albedos and multiband reflectance properties for the known NEOs, and to conduct a search for objects spending most or all their orbital period inside Earth's orbit. The purpose is to observe a large fraction of the existing population during a mission operational lifetime of two years. A rather modest sized telescope (70 cm primary mirror and Ritchey-Chretien optical configuration) is found to be adequate to meet the objectives.
Colour correction of stereo images using local correspondence

A method for enhancing the accuracy of colour correction in stereo images is proposed. The goal is to perform colour compensation at the corresponding points in a stereo image pair using local correspondence information. First, the relevant matching points for colour transfer are extracted using a modified stereo matching algorithm. Then, in order to account for illumination variations and occlusion areas, a new colour transfer method is applied through the weighted sum of the colour difference using local features. The performance of the proposed algorithm has been tested on the reference colour-modified Middlebury dataset.
Discrimination of short speech-like formant transitions

In a series of experiments frequency and duration discrimination thresholds of short, linear rising or falling, speech‐like transitions were determined by means of same/different paired comparison tasks. Difference limens of single formant transitions varying in frequency extent at a constant duration (experiment 1), decreased with increase of transition duration. They were, on average, 70, 63, and 57 Hz for 20, 30, and 50 ms, respectively. However, when transition duration varied at a constant frequency extent (experiment 2), difference limens were, on average, 2.7, 4.5, and 4.9 ms for standard transitions of 20, 30, and 50 ms, respectively. In both experiments, thresholds between rising and falling transitions, determined in two frequency regions, and between transitions with either higher or lower rates of frequency change than the standard transition, were comparable. The extent to which the first formant transition and the steady‐state interfere with discrimination of the second formant transition is.
Quantitative evaluation of spatial phase light modulator characteristics in Fresnel incoherent correlation holography

Fresnel incoherent correlation holography (FINCH) is one of the methods for recording holograms of 3D samples under incoherent illumination. The FINCH combines the theory of spatial self-coherence and the in-line phase-shift technology together to form a complex hologram. A spatial phase light modulator (SPLM) plays important roles as the dynamic diffraction optical element (DOE) and phase shifter. When the incoherent light generated from each object point of the 3D samples incidents to a SPLM, it can be split into two spatial self-coherent beams with different curvatures. The hologram caused by these two beams can then be captured by an image detector. Three holograms with different phase shift are recorded sequentially for eliminating the zero-order and twin image, and then a complex valued hologram is obtained by superposing the three holograms. In this paper, the modulation characteristics of SPLM and phase shift error in FINCH are investigated. Based on digital holography, phase modulation characteristics of SPLM are measured under coherent and narrow-bandwidth incoherent illumination respectively. Phase shift error due to quasi monochromatic light illumination is then analyzed in FINCH. The effect of phase shift error on the quality of reconstructed image is also investigated. It is demonstrated the FINCH setup has a smaller phase shift error by experiment.
RECURSIVE KINEMATICS AND DYNAMICS FOR PARALLEL STRUCTURED CLOSED-LOOP MULTIBODY SYSTEMS*

A kinematic formulation for the parallel structured closed-loop multibody mechanical systems, such as Stewart Platform and Hexapod machine tools, is presented in this paper, which is recursive in nature. This also leads to the minimum order representation of the dynamic equations of motion. The recursive algorithms are known for their efficiency when a system is large. They also provide many physical interpretations. On the other hand, the minimum order dynamic equations of motion are desired in control and simulation. For the latter a minimum set of dynamic equations of motion leads to a numerically stable integration algorithm that does not violate the kinematic constraints. Two recursive algorithms, one for the inverse and another for the forward dynamics, are proposed. The overall complexity of either problem is O(n) + n O(m), where n and m are the number of legs and the total number of rigid bodies in each leg, respectively. Hence the proposed formulation exploits the advantages of both minimum order representation and recursive algorithms, which earlier were available only for the open-loop systems such as serial manipulators. The method is illustrated with three examples: a one-degree-of-freedom (DOF) slider-crank mechanism, four-bar linkage, and a two-DOF five-bar planar parallel manipulator. *Communicated by J. McPhee.
Extremely metal-poor stars in dwarf galaxies

Abstract We present Keck/HIRES spectra of six metal-poor stars in two of the ultra-faint dwarf galaxies orbiting the Milky Way, Ursa Major II and Coma Berenices, and a Magellan/MIKE spectrum of a star in the classical dwarf spheroidal galaxy (dSph) Sculptor. Our data include the first high-resolution spectroscopic observations of extremely metal-poor stars ([Fe/H] < −3.0) not belonging to the Milky Way (MW) stellar halo field population. We obtain abundance measurements and upper limits for up to 26 elements between carbon and europium. The stars span a range of −3.8 < [Fe/H] < −2.3, with the ultra-faints having large spreads in Fe. A comparison with MW halo stars of similar metallicity reveals substantial agreement between the abundance patterns of the ultra-faint dwarf galaxies and Sculptor and the MW halo for the light, α and iron-peak elements (C to Zn). This agreement contrasts with the results of earlier studies of more metal-rich stars (−2.5 ≲[Fe/H]≲ −1.0) in more luminous dwarfs, which found significant abundance discrepancies with respect to the MW halo data. The abundances of neutron-capture elements (Sr to Eu) in all three galaxies are extremely low, consistent with the most metal-poor halo stars, but not with the typical halo abundance pattern at [Fe/H]≳ −3.0. Our results are broadly consistent with a galaxy formation model which predicts that massive dwarf galaxies are the source of the metal-rich component ([Fe/H]≳ −2.5) of the MW inner halo, but we propose that dwarf galaxies similar to the dSphs are the primary contributors to the metal-poor end of the metallicity distribution of the MW outer halo.
Measurement and simulation of partial discharge in oil impregnated pressboard with an electrical aging process

The continuous test on oil impregnated pressboard insulation with internal void defect was developed and the phase resolved partial discharge (PRPD) pattern of partial discharge (PD) signals during the electrical aging process was measured. Two different void structures which have different void volume were used in this experiment. It shows that the PD pattern could be classified into five stages and a great diversity in the first four stages is observed. The larger void volume leads to larger PD magnitude. The computer numerical simulation model which is based on a physical discharge process was used and the causes of PD pattern change were interpreted by comparison with computer numerical simulation results. The initial values and change tendency of gas pressure and surface conductivity were determined through experiment. The model parameters in different stages have been studied as well as the insight into the physical changes in the void during electrical aging. The results provide rules for the identification of the electrical aging stage through the partial discharge measurements.
Review: Quantum noise in gravitational-wave interferometers

We present an overview of quantum noise in gravitational-wave interferometers. Current gravitational-wave detectors are modified variants of a Michelson interferometer and the quantum noise limits are strongly influenced by the optical configuration of the interferometer. We describe recent developments in the treatment of quantum noise in the complex interferometers of present-day and future gravitational-wave detectors and explore prospects for beating the standard quantum limit by use of both injected and ponderomotive squeezing in future interferometers.
Dielectric Behavior in an Oriented β-PVDF Film and Chain Reorientation Upon Transverse Mechanical Deformation

Films of semicrystalline poly(vinylidene fluoride) (PVDF) in the g -phase have been studied by means of dielectric measurements and Fourier Transform Infrared Spectroscopy (FTIR). The main goal of the study was to compare the dielectric relaxations of f - and g -PVDF and to improve the understanding of the structural changes that occur in g -PVDF during a mechanical deformation process and their impact in the electromechanical properties of the polymer. A reorientation of the chains and a decrease in the degree of crystallinity with increasing deformation was observed.
High resolution modelling of valley cold pools

The Met Office Unified Model has been adapted to run with a 100 m horizontal grid length for a region of complex terrain whose valleys are too narrow to be represented in the operational forecast (1.5 km grid length) model. Forecasts of temperatures are compared with observations from the COLd air Pooling EXperiment. The model provides a realistic representation of valley cold pools which form during stable nights, although the predictions are shown to be sensitive to vertical resolution. Reducing the vertical grid spacing near the surface results in lower night‐time temperatures and larger, more realistic, valley–hill temperature contrasts.
Optimizing the efficiency of cross‐validation in linear discriminant analysis through selective use of the Sherman–Morrison– Woodbury inversion formula

Cross‐validation (CV) is a necessary stage in the development of multivariate discriminant models, but is potentially very time‐consuming. Significant time saving is possible by employing update formula to avoid unnecessary recalculations. We show that using the Sherman–Morrison–Woodbury (SMW) inversion formula can sometimes provide additional speed gains. The potential gain depends on the structure of the dataset and CV approach. We recommend comparing rival schemes before starting long computational tasks. Datasets and Matlab® m‐files are available at www.metabolomics‐nrp.org. uk/publications.html Copyright © 2008 John Wiley & Sons, Ltd.
Non‐equilibrium Green function implementation of boundary conditions for full band simulations of substrate‐nanowire structures

The density of states of a nanowire exhibits peaks at energies in which the individual transverse modes begin to propagate. Under ideal conditions these modes are eigenstates solely determined by the cross sectional size and shape of the nanowire. However, for realistic nanowires, which are grown on semiconductor substrates, the density of states of the subsrate‐nanowire structure is dependent on the distance from the nanowire endpoints. Near the substrate, the density of states is is nonzero far below the energy corresponding to the first eigenstate of the ideal nanowire. This initial increase in the density of states occurs at energies near the conduction and valence band edges of the semiconductor substrate on which the nanowire is grown. Away from the substrate, the density of states begins to acquire ideal nanowire characteristics. In the present work this effect is captured by imposing boundary conditions, with properties of bulk material, at the nanowire base. The calculations utilize a first neighbor sp3s*d5 orbital basis within the non‐equilibrium Green function formalism. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An analytic approach to a class of fractional differential‐difference equations of rational type via symbolic computation

Fractional derivatives are powerful tools in solving the problems of science and engineering. In this paper, an analytical algorithm for solving fractional differential‐difference equations in the sense of Jumarie's modified Riemann–Liouville derivative has been described and demonstrated. The algorithm has been tested against time‐fractional differential‐difference equations of rational type via symbolic computation. Three examples are given to elucidate the solution procedure. Our analyses lead to closed form exact solutions in terms of hyperbolic, trigonometric, and rational functions, which might be subject to some adequate physical interpretations in the future. Copyright © 2013 John Wiley & Sons, Ltd.
Analysis of short‐time speech transmission index algorithms

Various methods have been shown to compute the Speech Transmission Index (STI) using speech as a probe stimulus (Goldsworthy & Greenberg, J. Acoust. Soc. Am., 116, 3679‐3689, 2004). Frequency‐domain methods, while accurate at predicting the long‐term STI, cannot predict short‐term changes due to fluctuating backgrounds. Time‐domain methods also work well on long speech segments and have the added potential to be used for short‐time analysis. This study investigates the accuracy of two time‐domain STI methods: envelope regression (ER) and normalized correlation (NC), as functions of window length, in various acoustically degraded environments with multiple talkers and speaking styles. Short‐time STIs are compared with a short‐time Theoretical STI, derived from octave‐band signal‐to‐noise ratios and reverberation times. For windows as short as 0.3 s, the ER and NC Methods track the short‐time Theoretical STI and both the Theoretical and ER Methods converge to the long‐term result for windows greater than 4 .
Optical micromanipulation takes hold

Optical micro-manipulation has seen a resurgence of interest in recent years which has been due in part to new application areas and the use of tailored forms of light beams particularly using holographic optical tweezers technology. Optical landscapes using evanescent waves can hold large arrays of particles (~1000) and may be enhanced using surface plasmon interactions or a dielectric resonator. Dynamics in a static 2D landscape of a Bessel beam can lead to optically induced separation.
Instability and convection in fluid layers: A report on Euromech 106

The 106th Euromech Colloquium on instability and convection driven by body forces in fluid layers was held in Grenoble from 11 to 14 September 1978 with the first two authors acting as chairmen. There were sixty-five participants coming from fifteen different countries and having widely different backgrounds. Fifty-seven papers were presented during the four full days of the meeting and are discussed in this report with the purpose of giving an up-to-date view of current research in convection.
RATIO OF ELECTRONS TO POSITRONS IN THE PRIMARY COSMIC RADIATION

An experiment is reported in which the positron-electron ratio of primary cosmic radiation was measured as a function of energy to obtain information on the nature of the electron source. The instrument used in the balloon-flight measurememts consists of a permanent magnet (6000 gauss), a spark chamber telescope, and a tantalum plate spark chamber. The energy interval was 50 to 1000 Mev. The observed primary electrons are tentatively assigned as of galactic origin. (R.E.U.)
An m-estimation-based model selection criterion with a data-oriented penalty

In Wu and Zen (1999), a linear model selection procedure based on M-estimation is proposed, which includes many classical model selection criteria as its special cases, and it is shown that the selection procedure is strongly consistent for a variety of penalty functions. In this paper, we will investigate its small sample performances for some choices of fixed penalty functions. It can be seen that the performance varies with the choice of the penalty. Hence, a randomized penalty based on observed data is proposed, which preserves the consistency property and provides improved performance over a fixed choice of penalty functions.