Miracle-dz/UniFAR-FTUs huggingface dataset:
Prediction and spectral profile estimation in multivariate calibration

Direct and indirect calibration have been compared with respect to both prediction and model interpretation. This included their ability to estimate the pure spectral profile of each known constituent in a mixture of different metal–ion complexes. In the examples, the predictions by indirect calibration, represented by the PLS and O‐PLS methods, were consistently better than those of direct calibration, exemplified by the CLS method. It was further demonstrated that indirect calibration is equally capable to direct calibration in estimating the pure spectral profiles, as long as the unknown systematic variation is properly handled. A linear transformation of the regression coefficient matrix, given by K = B(BTB)−1, is all that is needed. Note that this does not only apply to spectral data, but any situation where the Y‐variables can be assumed to additively contribute to the variation in the X matrix. Throughout the examples, the O‐PLS method was able to maintain good spectral profile estimates and predictions. This indicates that O‐PLS may be the approach for simultaneous good prediction and interpretation of complex multivariate systems. Copyright © 2004 John Wiley & Sons, Ltd.
Comment on ‘The smallest clock’

It has been suggested that Wigner's clock inequalities can be applied to biological systems. Pešić was the first to suggest this by applying these inequalities to the reproduction time of a mycoplasma (1993 Eur. J. Phys. 14 90). More recently, Goel applied Wigner's clock inequalities to the system formed by a Taq DNA polymerase reading a phage lambda DNA strand, concluding that the behaviour of polymerases is governed by quantum mechanical processes. By means of a counterexample, using a Pfu DNA polymerase, I show that current experimental evidence does not allow us to conclude that Wigner's inequalities govern the behaviour of polymerases. Furthermore, both works are based on an incorrect interpretation of the concept of position uncertainty.
The antimony-vacancy defect in p-type germanium

Ge-n+p mesa diodes have been produced in 2-Ωcm single crystals using a molecular-beam epitaxy (MBE) process to grow the Sb-doped epitaxial Ge n+-top layer. The diodes are characterized by a leakage current at room temperature of 8×10−4A∕cm2 at a reverse bias of 3 V. The diodes have been used to study irradiation-induced defects in p-type Ge, in particular Sb-related defects, where Sb stems from in-diffusion during the MBE growth. Two lines in the deep level transient spectroscopy (DLTS) spectra are related to the presence of Sb. One of these lines originates from the single-acceptor state of the SbV pair with an enthalpy of ionization of ΔHp=(0.309±0.007)eV, the other from a state with an enthalpy of ionization of ΔHp=(0.095±0.006)eV, which is concluded to be the single donor-charge state of the SbV pair.
The Spectral Element Method for the Shallow Water Equations on the Sphere

The spectral element method is implemented for the shallow water equations in spherical geometry and its performance is compared with other models. This is the first step in evaluating the suitability of spectral elements for climate modeling. The potential advantages and disadvantages of spectral elements over more conventional models used for climate studies are discussed. The method requires that the sphere be tiled with rectangles, for which we make use of the gnomonic projection to map the sphere onto the cube. To measure the performance of the method relative to other models, results are presented from a standard suite of shallow water test cases for the sphere. These results confirm the spectral accuracy of the method.
Linear Quadratic Differential Games with Mixed Leadership: The Open-Loop Solution

This paper is concerned with open-loop Stackelberg equilibria of two-player linear-quadratic differential games with mixed leadership. We prove that, under some appropriate assumptions on the coefficients, there exists a unique Stackelberg solution to such a differential game. Moreover, by means of the close interrelationship between the Riccati equations and the set of equations satisfied by the optimal open-loop control, we provide sufficient conditions to guarantee the existence and uniqueness of solutions to the associated Riccati equations with mixed-boundary conditions. As a result, the players' open-loop strategies can be represented in terms of the system state.
Oscillation Frequency and Amplitude Effects on the Wake of a Plunging Airfoil

The flow over a NACA 0012 airfoil, oscillated sinusoidally in plunge, is simulated numerically using a compressible two-dimensional Navier-Stokes solver at a Reynolds number of 2 ×10 4 . The wake of the airfoil is visualized using a numerical particle tracing method. Close agreement is obtained between numerically simulated wake structures and experimental wake visualizations in the literature, when the flow is assumed to be fully laminar. The wake structures, and the lift and thrust of the airfoil, are shown to be strongly dependent on both the Strouhal number and the reduced frequency k of the plunge oscillation at this Reynolds number. Leading-edge separation appears to dominate the generation of aerodynamic forces for reduced frequencies below approximately k = 4 but becomes secondary for higher frequencies. Wake structures appear to be controlled primarily by trailing-edge effects at all frequencies tested up to k=20. Aerodynamic force results obtained at this Reynolds number show marked differences from those predicted by potential flow analyses at low plunge frequency and high amplitude but are similar at high frequency and low amplitude, consistent with the effect of leading-edge separation.
Einstein oscillators that impede thermal transport

The Einstein model of a solid usually lacks a clear illustration in introductory solid-state physics courses because most solids are much better described by the Debye model. Filled antimony skutterudites, materials that have recently attracted much attention because of their potential for thermoelectric applications, provide a canonical illustration of the Einstein model. The filling atoms are loosely bound in the atomic cage formed by their neighbors, and hence their description as independent harmonic oscillators is adequate. Simple models for the heat capacity and thermal conductivity of a solid are introduced, with emphasis on the density of vibrational states. These models are used in conjunction with experimental results obtained from heat capacity and inelastic neutron scattering measurements to demonstrate the applicability of the concept of the Einstein oscillator to the filling guests in antimony skutterudites. The importance of these Einstein oscillators for impeding thermal transport is discussed and some simple problems involving the heat capacity, thermal conductivity, and inelastic neutron scattering are proposed.
Calculations and observations of proton precipitation in the dayside aurora

A simple procedure to evaluate the Balmer excitation rates of H(alpha ) and H(beta ) to produce the corresponding volume emission rates vs. height, using semi-empirical range relations of protons in air, is used. The calculations are carried out with identified ion-energy particle spectra of the dayside aurora obtained by low altitude satellites. It is found that the calculated emission intensities of H(alpha ) and H(beta ) are observable for ground-based optical detection. Measurements of the dayside aurora at Longyearbyen, Svalbard, are discussed in relation to these calculations. Furthermore, it is observed pulsed proton events on the dayside which have decreasing time between each event show increase in the emission intensity and a fluctuating behavior in the primary initial proton energy. Each pulsed proton event was associated with an enhancement in the green 5577 angstrom emission, and some corresponded to poleward-moving auroral forms.
UE Set Selection for RR Scheduling in Distributed Antenna Transmission with Reinforcement Learning

SUMMARY In this paper, user set selection in the allocation sequences of round-robin (RR) scheduling for distributed antenna transmission with block diagonalization (BD) pre-coding is proposed. In prior research, the initial phase selection of user equipment allocation sequences in RR scheduling has been investigated. The performance of the proposed RR scheduling is inferior to that of proportional fair (PF) scheduling under severe intra-cell interference. In this paper, the multi-input multi-output technology with BD pre-coding is applied. Furthermore, the user equipment(UE)setsintheallocationsequencesareeliminatedwithreinforcement learning. After the modiﬁcation of a RR allocation sequence, no estimated throughput calculation for UE set selection is required. Numerical results obtained through computer simulation show that the maximum selection, one of the criteria for initial phase selection, outperforms the weighted PF scheduling in a restricted realm in terms of the computational complexity, fairness, and throughput. key words: distributed antenna transmission, round-robin scheduling,
A Method for Retrieving Coarse-Resolution Leaf Area Index for Mixed Biomes Using a Mixed-Pixel Correction Factor

The leaf area index (LAI) is a key structural parameter of vegetation canopies. Accordingly, several moderate-resolution global LAI products have been produced and widely used in the field of remote sensing. However, the accuracy of the current moderate-resolution global LAI products cannot satisfy the requirements recommended by the LAI application communities, especially in heterogeneous areas composed of mixed land cover types. In this study, we propose a mixed-pixel correction (MPC) method to improve the accuracy of LAI retrievals over heterogeneous areas by considering the influence of heterogeneity caused by the mixture of different biome types with the help of high-resolution land cover maps. The DART-simulated LAI, the aggregated Landsat LAI, and the site-based high-resolution LAI reference maps are used to evaluate the performance of the MPC method. The results indicate that the MPC method can reduce the influences of spatial heterogeneity and biome misclassification to obtain the LAI with much better accuracy than the Moderate Resolution Imaging Spectroradiometer (MODIS) main algorithm, given that the high-resolution land cover map is accurate. The root mean square error (RMSE) (bias) decreases from 0.749 (0.486) to 0.414 (0.087), while the R2 increases from 0.084 to 0.524, and the proportion of pixels that fulfill the uncertainty requirement of the GCOS increases from 38.2% to 84.6% for the results of site-based high-resolution LAI reference maps. Spatially explicit information about vegetation fractional cover can further reduce uncertainties induced by variations in canopy density for the results of DART simulated data. The proposed method shows potential for improving global moderate-resolution LAI products.
Changes in Maternal Heart Rate and Autonomic Regulation following the Antenatal Administration of Corticosteroids: A Secondary Analysis

While the effect of antenatally administered corticosteroids on fetal heart rate (HR) and heart rate variability (HRV) is well established, little information is available on how these drugs affect maternal physiology. In this secondary analysis of a prospective, observational cohort study, we quantify how corticosteroids affect maternal HR and HRV, which serve as a proxy measure for autonomic regulation. Abdominal ECG measurements were recorded before and in the five days following the administration of betamethasone—a corticosteroid commonly used for fetal maturation—in 46 women with singleton pregnancies. Maternal HR and HRV were determined from these recordings and compared between these days. HRV was assessed with time- and frequency-domain features, as well as non-linear and complexity features. In the 24 h after betamethasone administration, maternal HR was significantly increased (p < 0.01) by approximately 10 beats per minute, while HRV features linked to parasympathetic activity and HR complexity were significantly decreased (p < 0.01 and p < 0.001, respectively). Within four days after the initial administration of betamethasone, HR decreases and HRV features increase again, indicating a diminishing effect of betamethasone a few days after administration. We conclude that betamethasone administration results in changes in maternal HR and HRV, despite the heterogeneity of the studied population. Therefore, its recent administration should be considered when evaluating these cardiovascular metrics.
KINETIC MONTE CARLO STUDIES OF H2 FORMATION ON GRAIN SURFACES OVER A WIDE TEMPERATURE RANGE

We have used the continuous-time random-walk Monte Carlo technique to study the formation of H2 from two hydrogen atoms on the surface of interstellar dust grains with both physisorption and chemisorption sites on olivine and carbonaceous material. In our standard approach, atoms must first enter the physisorption site before chemisorption can occur. We have considered hydrogen atom mobility due to both thermal hopping and quantum mechanical tunneling. The temperature range between 5 K and 825 K has been explored for different incoming H fluxes representative of interstellar environments with atomic hydrogen number density ranging between 0.1 cm−3 and 100 cm−3 and dust grain sizes ranging from 100 sites to 106 sites, the latter corresponding roughly to olivine grains of radius 0.2 μm. In addition, we have also considered rough surfaces with multiple binding sites. Tunneling is found to dominate the surface chemistry at low temperature, but as the temperature increases, the scenario changes. The inclusion of chemisorption sites can provide a meaningful efficiency for H2 production up to temperatures as high as 700 K depending upon the depth of the chemisorption well. We found that over virtually the entire temperature range studied, the use of rate equations overestimates the H2 formation rate to some extent. This overestimate is large at high temperatures, due to very low surface residence times. We have also considered models in which chemisorption sites are entered directly and diffusion proceeds only to other chemisorption sites.
Evaluation of Fillers for Magnesium Potassium Phosphate Cement (MKPC) for the Encapsulation of Low and Intermediate Level Metallic Radioactive Wastes

This study investigates the effect of coal fly ash (FA), wollastonite (WO), pumice (PM), and metakaolin (MK) as filler materials in the rheological, mechanical, chemical, and mineralogical properties of a magnesium potassium phosphate cement (MKPC), designed for the encapsulation of low and intermediate level radioactive wastes containing reactive metals. Workability, compression strength, dimensional stability, pH, chemical composition, and mineralogical properties were studied in different pastes and mortars of MKPC with a fixed molar ratio of MgO/KH2PO4 = 1. No new mineral phases were found with the addition of the fillers, denoting their low chemical impact on the MKPC system. Moreover, all formulations with a water/cement mass ratio of <0.65 presented compressive strengths higher than 30 MPa after 90 days, and pH values lower than 8.5, corresponding to the passivation zone of aluminum corrosion.
Full-Volume 3D Fluid Flow Reconstruction With Light Field PIV

Particle Imaging Velocimetry (PIV) is a classical method that estimates fluid flow by analyzing the motion of injected particles. To reconstruct and track the swirling particles is a difficult computer vision problem, as the particles are dense in the fluid volume and have similar appearances. Further, tracking a large number of particles is particularly challenging due to heavy occlusion. Here we present a low-cost PIV solution that uses compact lenslet-based light field cameras as imaging device. We develop novel optimization algorithms for dense particle 3D reconstruction and tracking. As a single light field camera has limited capacity in resolving depth (z-dimension measurement), the resolution of 3D reconstruction on the x-y plane is much higher than along the $z$z-axis. To compensate for the imbalanced resolution in 3D, we use two light field cameras positioned at an orthogonal angle to capture particle images. In this way, we can achieve high-resolution 3D particle reconstruction in the full fluid volume. For each time frame, we first estimate particle depths under a single viewpoint by exploiting the focal stack symmetry of light field. We then fuse the recovered 3D particles in two views by solving a linear assignment problem (LAP). Specifically, we propose an anisotropic point-to-ray distance as matching cost to handle the resolution mismatch. Finally, given a sequence of 3D particle reconstructions over time, we recover the full-volume 3D fluid flow with a physically-constrained optical flow, which enforces local motion rigidity and fluid incompressibility. We perform comprehensive experiments on synthetic and real data for ablation and evaluation. We show that our method recovers full-volume 3D fluid flows of various types. Two-view reconstruction results achieves higher accuracy than those with one view only.
Methodology and Implementation of Beam Steering Using C-Shaped Split Rings for Fabry–Perot Antennas

The design process of beam-steering partially reflective surface (PRS) made up of C-shaped split-ring resonators (CSRRs) is presented in this article. Through analyzing the transmission characteristics of CSRRs with variable opening angles and orientations, spatially abrupt phase and magnitude are introduced over PRS to reshape the wavefronts of linear polarization waves. Based on the designed two distributions and the two control methods, four arrangements of $5\times $ 5 CSRRs are fabricated to validate the design methodology of beam steering. Furthermore, two reconfigurable Fabry–Perot (FP) antennas are proposed based on liquid-metal and mechanically rotating reconfiguration. An agreement between simulated and measured results shows higher aperture efficiency and desirable radiation patterns while demonstrating excellent reconfiguration reliability. Besides, an eight-element phased array combined with liquid-metal PRS is fabricated and shows improved scanning performance and stable gain fluctuation.
Nucleation of AgInSbTe films employed in phase-change media

In phase-change technology small volumes of a chalcogenide material are switched between amorphous and crystalline states by local heating with a short laser or current pulses. AgInSbTe is an alloy frequently used in optical data storage, which could also be applied in electronic data storage. For those applications it is crucial to understand the reliability and reproducibility of the switching process. In this work the first crystallization of an AgInSbTe alloy has been studied on a microsecond time scale using a focused laser beam. The experiments show that nucleation is a process governed by statistics. A correlation between the success of a nucleation event with the probability of nucleation is established. By measuring the nucleation probability as a function of laser pulse duration, the incubation time is determined to 11μs. The results are compared to measurements of the growth velocity of this material. The analysis of the temperature dependence of the growth velocity explains why AgInSbTe shows .
Symblicit Calculation of Long-Run Averages for Concurrent Probabilistic Systems

Model checkers for concurrent probabilistic systems have become very popular within the last decade. The study of long-run average behavior has however received only scant attention in this area, at least from the implementation perspective. This paper studies the problem of how to efficiently realize an algorithm for computing optimal long-run average reward values for concurrent probabilistic systems. At its core is a variation of Howard and Veinott's algorithm for Markov decision processes, where symbolic and non-symbolic representations are intertwined in an effective manner: the state space is represented using binary decision diagrams, while the linear equation systems which have to be solved for the induced Markov chains to improve the current scheduler are solved using an explicit state representation. In order to keep the latter small, we apply a symbolic bisimulation minimization algorithm to the induced Markov chain. The scheduler improvement step itself is again performed on symbolic data structures. Practical evidence shows that the implementation is effective, and sometimes uses considerably less memory than a fully explicit implementation.
Optical waveguide sensor using evanescent wave excitation of fluorescent dye in sol-gel glass

The sol-gel process for low temperature fabrication of porous glass has been used to entrap chemically-sensitive dyes for optical sensor applications. Evanescent wave excitation was used to examine the behaviour of an unclad fibre which was dipcoated with a thin layer of porous cladding within which a pH-sensitive dye was entrapped. The performance of the pH sensor is reported and the potential of the technique for distributed and integrated optic sensing is discussed. < >
InGaN-Based Blue Light-Emitting Diodes Grown on Epitaxially Laterally Overgrown GaN Substrates

InGaN single-quantum-well-structure blue light-emitting diodes (LEDs) were grown on epitaxially laterally overgrown GaN (ELOG) and sapphire substrates. The emission spectra showed the similar blue shift with increasing forward currents for both LEDs. The output power of both LEDs was almost the same, as high as 6 mW at a current of 20 mA. The LED on sapphire had a considerable amount of leakage current in comparison with that on ELOG. These results indicate that the In composition fluctuation is not caused by dislocations, the dislocations do not act as nonradiative recombination centers in the InGaN, and the dislocations forms the leakage current pathway in InGaN.
Impulse Response Estimation with Binary Measurements: A Regularized FIR Model Approach

FIR (finite impulse response) model is widely used in tackling the problem of the impulse response estimation with quantized measurements. Its use is, however, limited, in the case when a high order FIR model is required to capture a slowly decaying impulse response. This is because the high variance for high order FIR models would override the low bias and thus lead to large MSE (mean square error). In this contribution, we apply the recently introduced regularized FIR model approach to the problem of the impulse response estimation with binary measurements. We show by Monte Carlo simulations that the proposed approach can yield both better accuracy and better robustness than a recently introduced FIR model based approach.
Ultrasonic measurement of elastic constants of anisotropic materials with laser source and laser receiver focused on the same interface

A noncontact laser–ultrasonic technique is described that allows determination of material properties of anisotropic platelike samples. The method requires access to only one side of the sample. Plane waves are synthesized by scanning the surface with a laser line source at judiciously chosen intervals. By doing so, the intricacies associated with the reflection of an acoustic ray off an interface of an anisotropic medium are avoided. The plane-wave reflections off the opposite free surface of the plate are simply governed by Snell's law. The identification of the stiffness-tensor components is based on the inversion of the phase velocities of these reflected plane waves. The procedure developed is presented and applied to both simulated and experimental signals. The method is easy to implement, and provides a means for noncontact measurement of elastic properties where there is limited access to test specimens.