Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimization of the multiple sampling and signal extraction in nondestructive exposures

Abstract. We derive the full covariance matrix equations for proper treatment of correlations in signal fitting procedures, extending the results from previous publications. The straight line fits performed with these matrices demonstrate that a significantly higher signal to noise is obtained when the fluence exceeds 1 e−/s/pixel, in particular in long (several hundreds of seconds) spectroscopic exposures. The improvement arising from the covariance matrix is particularly significant for the initial intercept of the fit at t=0, a quantity which provides a useful redundancy to cross check the signal quality. We demonstrate that the mode that maximizes the signal-to-noise ratio in all ranges of fluxes studied is the one that uses all the frames sampled during the exposure. While there is no restriction on the organization of frames within groups for fluences lower than 1 e−/s/pixel, the co-adding of frames should be avoided whenever the fluence exceeds this value.
From pockets to channels: Density-controlled diffusion in sodium silicates

Classical molecular dynamics is used to study the dynamics of sodium atoms in liquid Na2O-3SiO2 (NS3) as a function of system density. It is found that diffusion displays different regimes with increasing density at fixed temperature: a channel-connected network at ambient pressures which reduces to small pockets once the density is increased. The obtained features can be further characterized by the probability of Na hopping that shows a percolative behavior at around 2.25 g/cm3 at the lowest temperature of 1500 K, which correlates with a threshold in the coordination number of the silicon and oxygen atoms. These results highlight the fact that transport properties in simple silicates can be substantially modified under a limited density change.
A Robust Two Sample Procedure to Estimate a Shift Parameter

SYNOPTIC ABSTRACT This study estimates the shift parameter in the two-sample location problem. The proposed method combines the sample X and sample Y which is shifted with an arbitrary shift variable and a convolution technique is used to smooth out the empirical density function of the combined samples. The smoothed empirical density function is later used in the construction of a log likelihood function for the combined sample. The likelihood function is minimized with respect to an arbitrary shift variable to find an estimate of the true shift parameter. As shown in the study, the proposed estimator is asymptotically efficient and robust against contaminations and outliers. This result is supported by an example and by a simulation study.
Prediction of Acoustic Environments from Horizontal Rocket Firings

In recent years, advances in research and engineering have led to more powerful launch vehicles which yield acoustic environments potentially destructive to the vehicle or surrounding structures. Therefore, it has become increasingly important to be able to predict the acoustic environments created by these vehicles in order to avoid structural and/or component failure. The current industry standard technique for predicting launch-induced acoustic environments was developed by Eldred in the early 1970s. Recent work has shown Eldred’s technique to be inaccurate for current state-of-the-art launch vehicles. Due to the high cost of full-scale and even sub-scale rocket experiments, very little rocket noise data is available. Much of the work thought to be applicable to rocket noise has been done with heated jets. A model to predict the acoustic environment due to a launch vehicle in the far-field was created. This was done using five sets of horizontally fired rocket data, obtained between 2008 and 2012. Thro.
Two Micron All Sky Survey, Infrared Astronomical Satellite, and Midcourse Space Experiment Color Properties of Intrinsic and Extrinsic S Stars

We attempt to select new candidate intrinsic and extrinsic S stars in the General Catalogue of Galactic S Stars (GCGSS) by combining data from the Two Micron All Sky Survey, the Infrared Astronomical Satellite, and the Midcourse Space Experiment. Catalog entries are cross-identified, yielding 528 objects, out of which 29 are known extrinsic S stars and 31 are known intrinsic S stars. Their color-color diagrams, (H - [12])-(K - [12]) and (K - [12])-(J - [25]), are drawn and used to identify a new sample of 147 extrinsic and 256 intrinsic S star candidates, while the nature of 65 stars remains identified. We infer that about 38% ± 10% of the GCGSS objects are of extrinsic type. Moreover, we think that colors such as J - [25] can be used to split off the two categories of S stars, while single colors are not appropriate. The color-color diagrams, such as (H - [12])-(K - [12]) and (K - [12])-(J - [25]), are proven to be powerful tools for distinguishing the two kinds of S stars.
Observation of giant enhanced backscattering of light from weakly rough dielectric films on reflecting metal substrates

The enhanced backscattering of light from a randomly rough surface, which is manifested as a narrow peak in the retroreflection di- rection in the angular distribution of the intensity of the light that is scat- tered diffusely, has been extensively studied. Both theoretical and ex- perimental investigations have shown that the height of the peak is never more than twice the height of the background at the position of the peak. We report the observation of a giant enhanced backscattering of light from a randomly weak rough dielectric film on a reflecting metal sub- strate, in which the ratio of the height of the peak to the height of the background at its position is greater than 10. It is found that this giant enhanced backscattering peak is accompanied by concentric circular in- terference fringes, whose axis is normal to the mean scattering surface, with both the specular and backscattering peak on the same ring. A possible mechanism for the giant backscattering is suggested. © 1996 Society of Photo-Optical Instrumentation Engineers. Subject terms: enhanced backscattering; wave scattering; opposition effect; lo- calization; thin films; physical optics; lidar and remote sensing.
Inference in ARCH and GARCH models with heavy-tailed errors

ARCH and GARCH models directly address the dependency of conditional second moments, and have proved particularly valuable in modelling processes where a relatively large degree of fluctuation is present. These include financial time series, which can be particularly heavy tailed. However, little is known about properties of ARCH or GARCH models in the heavy–tailed setting, and no methods are available for approximating the distributions of parameter estimators there. In this paper we show that, for heavy–tailed errors, the asymptotic distributions of quasi–maximum likelihood parameter estimators in ARCH and GARCH models are nonnormal, and are particularly difficult to estimate directly using standard parametric methods. Standard bootstrap methods also fail to produce consistent estimators. To overcome these problems we develop percentile–t, subsample bootstrap approximations to estimator distributions. Studentizing is employed to approximate scale, and the subsample bootstrap is used to estimate shape. The good performance of this approach is demonstrated both theoretically and numerically.
Implicit finite element methods for two‐phase flow in oil reservoirs

SUMMARY The equations governing immiscible, incompressible, two-phase, porous media flow are discretized by generalized streamline diffusion Petrov-Galerkin methods in space and by implicit differences in time. Systems of non-linear algebraic equations are solved by Newton-Raphson iteration employing ILUpreconditioned conjugate-gradient-like methods to the non-symmetric matrix system in each iteration. The resulting solution methods are robust, enable complex grids with irregular nodal orderings and allow capillary effects. Several numerical formulations are tested and compared for one-, two- and three-dimensional flow cases, with emphasis on problems involving saturation shocks, heterogeneous media and curved boundaries. For reservoirs consisting of multiple rock types with differing capillary pressure properties, it is shown that traditional Bubnov-Galerkin methods give poor results and the new Petrov-Galerkin formulations are required. Investigations regarding the behaviour of several preconditioned conjugate-gradient-like methods in these type of problems are also reported.
Application of microwave reflectometry to the measurement of fast magnetosonic waves in the Tokamak Fusion Test Reactor

The application of microwave reflectometry to the study of fast magnetosonic waves in the Tokamak Fusion Test Reactor (TFTR) is investigated. Assuming the validity of geometric optics for reflectometer measurements, it is shown that linearity to the fast wave amplitude is restricted to very small density fluctuation levels (n/n<10−3). Beyond this level, both phase and amplitude ambiguities occur that makes interpretation difficult. Measurements of 30 MHz fast magnetosonic waves in the core of TFTR plasmas are presented.
Femtosecond pulse inscription of a selective mode filter in large mode area fibers

We present a selective mode filter inscribed with ultrashort pulses directly into a few mode large mode area (LMA) fiber. The mode filter consists of two refractive index modifications alongside the fiber core in the cladding. The refractive index modifications, which were of approximately the same order of magnitude as the refractive index difference between core and cladding have been inscribed by nonlinear absorption of femtosecond laser pulses (800 nm wavelength, 120 fs pulse duration). If light is guided in the core, it will interact with the inscribed modifications causing modes to be coupled out of the core. In order to characterize the mode filter, we used a femtosecond inscribed fiber Bragg grating (FBG), which acts as a wavelength and therefore mode selective element in the LMA fiber. Since each mode has different Bragg reflection wavelengths, an FBG in a multimode fiber will exhibit multiple Bragg reflection peaks. In our experiments, we first inscribed the FBG using the phase mask scanning technique. Then the mode filter was inscribed. The reflection spectrum of the FBG was measured in situ during the inscription process using a supercontinuum source. The reflectivities of the LP01 and LP11 modes show a dependency on the length of the mode filter. Two stages of the filter were obtained: one, in which the LP11 mode was reduced by 60% and one where the LP01 mode was reduced by 80%. The other mode respectively showed almost no losses. In conclusion, we could selectively filter either the fundamental or higher order modes.
The crevice model of bubble nucleation

The crevice model for heterogeneous nucleation of bubbles in water in response to a decreasing liquid pressure is studied. The model neglects gas‐diffusion effects and is therefore more suited for acoustic than for flow cavitation. It is argued that previous work has overlooked the essential requirement of unstable growth of the interface in the crevice. As a consequence, the available results are incorrect in some cases. Another feature of the model which is considered is the process by which the interface moves out of the crevice. It is concluded that, depending on circumstances, the conditions for this step may be more stringent than those for the initial expansion of the nucleus inside the crevice. Some numerical examples are given to illustrate the complex behavior of nuclei, depending of geometrical parameters, gas saturation, contact angles, and other quantities.
Two-Photon Ionization of Cesium and Sodium Vapors

The breakdown and the growth of plasma of cesium and sodium vapors by an intense laser beam are investigated. The minimum intensity which is observable by a double probe is found to be inversely proportional to the root of the neutral atom density for either vapor. This result confirms that the two-photon ionization is a dominant process in the stage of breakdown. Further increase of the intensity of laser beam leads to a steep rise of the plasma density proportional to the square of the intensity followed by a slow rise and then the second steep rise. The first steep rise is explained by the two-photon ionization process too. The electron temperatures are estimated to be about 10 4 °K under the condition of the present work, by the probe and optical methods.
Active noise control system using motional feedback loudspeaker

The active noise control system using motional feedback (MFB) loudspeaker is proposed which is effective in the low frequency range. Although FIR digital filter is used for usual control system, it is difficult to realize ideal MFB type active control system be causethe group delay in FIR filter affects the phase characteristics. In this paper, we realize the IIR filter using DSP with high speed A/D and D/A convertors to reduce the group delay. The positive insertion loss is obtained from 21 to 94Hz on the model experiment. However, the obtained insertion loss is lower than one obtained in nu mericalsimulation because of an oscillation about 300Hz.
STATISTICAL STUDY OF CHROMOSPHERIC ANEMONE JETS OBSERVED WITH HINODE/SOT

The Solar Optical Telescope on board Hinode has revealed numerous tiny jets in all regions of the chromosphere outside of sunspots. A typical chromospheric anemone jet has a cusp-shaped structure and bright footpoint, similar to the shape of an X-ray anemone jet observed previously with the Soft X-ray Telescope on board Yohkoh. The similarity in the shapes of chromospheric and X-ray anemone jets suggests that chromospheric anemone jets are produced as a result of the magnetic reconnection between a small bipole (perhaps a tiny emerging flux) and a pre-existing uniform magnetic field in the lower chromosphere. We examine various chromospheric anemone jets in the solar active region near the solar limb and study the typical features (e.g., length, width, lifetime, and velocity) of the chromospheric anemone jets. Statistical studies show that chromospheric anemone jets have: (1) a typical length ∼1.0–4.0 Mm, (2) a width ∼100–400 km, (3) a lifetime ∼100–500 s, and (4) a velocity ∼5–20 km s−1. The velocity of the chromospheric anemone jets is comparable to the local Alfvén speed in the lower solar chromosphere (∼10 km s−1). The histograms of chromospheric anemone jets near the limb and near the disk center show similar averages and shapes of distributions, suggesting that the characteristic behavior of chromospheric anemone jets is independent of whether they are observed on the disk or at the limb. The observed relationship between the velocity and length of chromospheric anemone jets shows that the jets do not follow ballistic motion but are more likely accelerated by some other mechanism. This is consistent with numerical simulations of chromospheric anemone jets.
Twisted quantum fields in a curved space–time

Non-trivial space–time topology leads to the possibility of twisted fields viewed as cross sections of non-product vector bundles. For globally hyperbolic space–times twisted real and complex scalar fields are especially interesting, and are in one-to-one correspondence with certain groups determined by the space–time topology. Twisted fields can be quantized and lead to results differing from the usual ones. For example, spontaneous symmetry breaking may be suppressed and regularized vacuum self-energies take on different values. Sets of twisted fields may be collected together into a type of super-multiplet whose size is determined by the space–time topology.
EQUILIBRIUM PATTERNS OF CHAIN CLUSTERS COMPOSED OF FERROMAGNETIC PARTICLES IN AN EXTERNAL MAGNETIC FIELD

We carry out Monte Carlo simulations of a ferromagnetic colloidal system, which is subjected to an external magnetic field, to investigate the structures formed by chain clusters. The control parameters are the ratio of the dipole moment energy to thermal energy, λ, and the ratio of the interactive energy between the dipole and the external magnetic field to thermal energy, ξ. We investigate the effect of the system height on the pattern formations for λ=18 and ξ=30, ∞. Note that the system becomes paramagnetic when ξ=∞. We find that as the system height increases, chains coagulate to form fat clusters and spatially ordered structures are created when ξ=30, whereas chains form thin meandering walls when ξ=∞.
Polariton-based band gap and generation of surface acoustic waves in acoustic superlattice lithium niobate

We report the presence of surface acoustic wave (SAW) band gap on acoustic superlattice (ASL) in a single-crystal lithium niobate structure. The band gap behavior is determined by calculating the SAW band structure and also by simulating the transmission of an acoustic wave through a finite length section of ASL using finite element analysis. The calculated band gap appears at a frequency twice the value expected from purely acoustic Bragg scattering. We have identified the band gap as originating from a polariton-based mechanism due to the coupling between the electromagnetic wave and the surface vibrations. We have examined the influence of the band gap on SAW generation with the ASL and have shown that the calculated frequency resonance of the SAW lies in the vicinity of the upper stop-band edges. This results in the localization of the SAW in the ASL. Experimental confirmation is achieved through direct measurement of the SAW displacement by laser vibrometry on an actual ASL SAW transducer. The localization of generated SAW to the ASL transducer is observed confirming the prediction of the existence of a band gap.
Set-valued measures

A set-valued measure is a u-additive set-function which takes on values in the nonempty subsets of a euclidean space. It is shown that a bounded and non-atomic set-valued measure has convex values. Also the existence of selectors (vector-valued measures) is investigated. The Radon-Nikodym derivative of a set-valued measure is a set-valued function. A general theorem on the existence of R. -N. derivatives is established. The techniques require investigations of measurable set-valued functions and their support functions.
Determination of the phonon dispersion of zinc blende (3C) silicon carbide by inelastic x-ray scattering

We present an experimental and theoretical investigation of the phonon dispersion relations in zinc blende (3C) SiC. The experimental data were obtained for the entire Brillouin zone by inelastic x-ray scattering (IXS) using a synchrotron radiation source. Eigenvector analysis is performed with the aid of state-of-the-art linear response first principles calculations based on density functional theory. The theoretical predictions reproduce the experimental phonon dispersion remarkably well. These results are compared with data obtained previously for the 〈111〉 direction by Raman spectroscopy using several SiC polytypes and the backfolding technique. IXS data for 4H modification along the c axis are also reported.
Formal Analysis of SPDM: Security Protocol and Data Model version 1.2

DMTF is a standards organization by major industry players in IT infrastructure including AMD, Alibaba, Broad-com, Cisco, Dell, Google, Huawei, IBM, Intel, Lenovo, and NVIDIA, which aims to enable interoperability, e.g., including cloud, virtualization, network, servers and storage. It is currently standardizing a security protocol called SPDM, which aims to secure communication over the wire and to enable device attestation, notably also explicitly catering for communicating hardware components. The SPDM protocol inherits requirements and design ideas from IETF’s TLS 1.3. However, its state machines and transcript handling are substantially different and more complex. While architecture, specification, and open-source libraries of the current versions of SPDM are publicly available, these include no significant security analysis of any kind. In this work we develop the first formal models of the three modes of the SPDM protocol version 1.2. 1, and formally analyze their main security properties.
Dynamics of a two-dimensional ribbon of shallow water on an f-plane

An analytical solution is derived for the motion of an infinitely long fluid ribbon of shallow water, with parabolic depth and linear velocity distribution. The solution is of intrinsic dynamical interest and also offers a “bench-mark” for testing numerical methods which handle the intersection of a free surface with a horizontal boundary. The development is expressed in terms of the translation and deformation of the hump. The former component is determined uniquely by the initial velocity at the symmetry axis and the externally imposed uniform pressure gradient. On the other hand, the deformation component depends on the initial shear and divergence, but is unaffected by a uniform external pressure force. Relative to its axis, the fluid ribbon alternately expands and contracts, with a pulsation frequency (≥ the inertial frequency f) that is a function of a Rossby, and a rotational Froude number, defined in terms of the initial velocity, and height field. DOI: 10.1034/j.1600-0870.1993. 00004.x
New results on stability of switched positive systems: an average dwell-time approach

This study is concerned with the problem of exponential stability for a class of switched positive linear systems consisting of both stable and unstable subsystems. The sufficient conditions of exponential stability are established in continuous-time and discrete-time domains. Based on the average dwell-time approach, new stability results for such kind of systems are first derived, which allows the ascent of the multiple linear copositive Lyapunov functions caused by unstable subsystems. Furthermore, when all subsystems are stable, the exponential stability condition for switched positive systems is presented. Finally, numerical examples are given to illustrate the effectiveness of the results.
Epitaxial growth of YBa2Cu3O7/CeO2/YSZ thin films on silicon-on-insulator substrates

A silicon-on-insulator (SOI) substrate is a compliant type of substrate because it is possible to grow a wide variety of materials on it with a small lattice mismatch and a small thermal expansion mismatch. It is quite promising in microelectronics applications, such as hybrid semiconductor/superconductor devices. In this paper, a SOI substrate has been used to grow a superconducting thin film. Using in situ pulsed laser deposition, epitaxial YBaCuO (>4000 A) thin films have been grown on SOI (100) substrates via a multiple buffer layer of CeO2 and yttrium-stabilized zirconium oxide (YSZ). X-ray diffraction analyses have shown that both the YBaCuO films and the multiple buffer layers are c-axis orientated. We have obtained YBa2Cu3O7/CeO2/YSZ multilayers with a critical temperature, Tc, of 88 K and a critical current density, Jc, of 2 × 106 A cm−2 at 77 K.