Miracle-dz/UniFAR-FTUs huggingface dataset:
Apodization of the incident light beam by an optimized quasi-Gaussian profile shifted along an aperture of the acousto-optical cell with appreciable acoustic losses

It is well known that an appropriate apodization of the light beam within acousto-optical data processing makes it possible to increase the potential dynamic range of a system up to 40 dB and more. Customary, the Gaussian apodization is used when a light beam incidents on a rectangular uniform operative aperture of acousto-optical cell. However, modern acousto-optics exploits often rather high-frequency radio-wave signals in a view of increasing the frequency bandwidth by itself or/and growing the time-bandwidth product inherent in a cell. Anyway, similar acoustooptical cells operate with such frequencies that acoustic losses become already pronounced, so that the effect of these losses along an aperture of a cell has to be taken into account. Typically, acceptable level of the acoustic losses accounts about 3 − 6 dB per cell’s aperture. By this it means that the expected no-uniformity of distributing the acoustic energy is now not negligible. To obtain really optimized profile of the incident light beam apodization the expected influence of acoustic losses ought to be analyzed and estimated. In connection with aforementioned no-uniformity or asymmetry, one can propose exploiting a quasi-Gaussian profile of the incident light beam reasonably shifted relative to the center of an aperture of the acousto-optical cell with appreciable acoustic losses.
Simple integral screenprinting process for selective emitter polycrystalline silicon solar cells

This letter describes a new simple fabrication process, developed recently for ‘‘blue response’’ improvement in low‐cost polycrystalline silicon solar cells. A selective emitter is created by heavily doping the emitter, followed by a wet etching‐back of the cell area between the fingers. An improvement up to 17 mV in Voc, 1.5 mA/cm2 in Jsc, and 1% (absolute value) in η is obtained. Effective phosphorus gettering, self‐alignment, and application in a low‐cost full screenprinting technology are the main advantages of the proposed process.
Dust cooling of hot gas.

The cooling rates of a hot gas by ion-grain collisions are shown to be significant at temperatures above 1 million K. The importance of this cooling mechanism in certain phases of supernova explosions is noted. High-temperature modifications of this cooling mechanism in astronomical sources are discussed. A cooling curve is plotted for collisionally ionized gas containing cosmic abundances of heavy elements and graphite grains.
Modeling and Robust Analysis of a Liquid Rocket Engine

Stability and dynamic performance of liquid-propellant rocket engines (LPRE) are two of the fundamental issues in the enginevehicle integration process. This analysis requires the construction of a detailed model, trying to capture the most realistic phenomena involved, which generally include several sources of uncertainties. In this paper, a methodology for robust modeling and stability analysis is presented. Firstly, the linear models of the LPRE components are obtained by modeling the various physical processes, at a nominal regime of operation. Afterwards, the Laplace transform is applied to derive a block diagram representation of the linear LPRE. The stability study and dynamic analysis are carried out taking in account the uncertainties in parameters of the plant. The robust stability is assured via the Generalized Kharitonov's Theorem; and the robust frequency and step responses are obtained with the use of specialized MATLAB toolboxes. The robust performance of the system in the time domain is obtained in terms of the response to step function input, while taking into account the plant uncertainties, also known as robust step response. A practical application is illustrated by analyzing a simple pressurefed LPRE system. Copyright © 2000 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. INTRODUCTION During the engine-vehicle integration phase, the knowledge of the engine dynamics can avoid serious instability problems, caused by the dynamic coupling of the propellant feed system, the rocket engine, and the vehicle structure. The dynamic analysis helps to characterize many aspects of the engine system operation. It requires the construction of a mathematical model to describe approximately the most important phenomena of the actual system. The engine itself contains several sources of intense pressure fluctuations due to turbulent flow in feed lines, fluttering of pump wheel blades, vibrations of control valves, and unsteady motion in the combustion chamber and gas generator. The coupling of these oscillations with the natural frequencies of the system structure represents often a source of instability, sometimes observed with catastrophic consequences. In general, solving the dynamic equations is not a simple task, since the more realistic models are time-variant, non-linear and of high order, and include uncertainties used to represent imprecise physical parameters or unknown operating conditions. Even for linear time-invariant models, this problem can become quite difficult to solve when the parameters deviate from the nominal values in a known rated regime. Traditional numerical methods of analysis are not suited for these uncertain models since they require a great amount of computational effort. Besides, the direct approach of solving the coupled differential
Non‐Parametric Ecological Regression and Spatial Variation

Ecological studies aim to analyse the variation of disease risk in relation to exposure variables that are measured at an area unit level. In practice it is rarely possible to use the exposure variables themselves, either because the corresponding data are not available or because the causes of the disease are not fully understood. It is therefore quite common to use crude proxies of the real exposure to the disease in question. These proxies are rarely able to explain the disease variation and hence additional area level random effects are introduced to account for the residual variation. In this paper we investigate the possibility to model the effect of ecological covariates non‐parametrically, with and without additional random effects for the residual spatial variation. We illustrate the issues arising through analyses of simulated and real data on larynx cancer mortality in Germany, during the years of 1986 to 1990, where we use the corresponding lung cancer rates as a proxy for smoking consumption.
Ab initio study of optical properties of shock compressed silica and lithium fluoride

The equation of state and optical properties of shocked compressed silica and LiF are investigated using quantum molecular dynamics in a wide range of pressures and temperatures along the principal Hugoniot. For silica, the increase in reflectivity occurs at about 100 Gpa and saturates around 40%. For LiF, a pressure of 600 GPa is needed to observe a significant reflectivity, but no saturation is observed. Our results are in close agreement with the experimental measurements (Hicks D G, Celliers P M, Collins G W, Eggert J H and Moon S J 2003 Phys. Rev. Lett. 91 035502) and a simple fit of the optical index of LiF versus compression is provided.
Quantum correlations in information theory

The project concerned the study of quantum correlations (QC) in compound systems, i.e. statistical correlations more general than entanglement which are predicted by quantum mechanics but not described in any classical scenario. I aimed to understand the technical and operational properties of the measures of QC, their interplay with entanglement quantifiers and the experimental accessibility. In the first part of my research path, after having acquired the conceptual and technical rudiments of the project, I provided solutions for some computational issues: I developed analytical and numerical algorithms for calculating bipartite QC in finite dimensional systems. Then, I tackled the problem of the experimental detection of QC. There is no Hermitian operator associated with entanglement measures, nor with QC ones. However, the information encoded in a density matrix is redundant to quantify them, thus the full knowledge of the state is not required to accomplish the task. I reported the first protocol to measure the QC of an unknown state by means of a limited number of measurements, without performing the tomography of the state. My proposal has been implemented experimentally in a NMR (Nuclear Magnetic Resonance) setting. In the final stage of the project, I explored the foundational and operational merits of QC. I showed that the QC shared by two subsystems yield a genuinely quantum kind of uncertainty on single local observables. The result is a promising evidence of the potential exploitability of separable (unentangled) states for quantum metrology in noisy conditions.
Optimization of spectral sensitivities with Gaussian distribution functions for a color image acquisition device in the presence of noise

The acquisition of the colorimetric information about an object using a color image acquisition device is important at an early stage in a color management system. The accuracy of the colorimetric values estimated by the device responses depends not only on the spectral sensitivities of a set of sensors but also on the noise present in the devices. We address the optimization of a set of spectral sensitivities with Gaussian distribution functions based on a colorimetric evaluation model. It is demonstrated that the design of optimal sensors is contingent on finding the right balance between the human visual subspace and the subspace that maximizes the singular values of a matrix SLVΛ 1/2 to increase the robustness to noise, where S , L , V , and Λ represent a sensor matrix, a diagonal matrix for an illuminant, a basis matrix, and a diagonal matrix with eigenvalues of an autocorrelation matrix of reflectance spectra, respectively.
Non-LTE analysis of the Ofpe/WN9 star HDE 269227 (R84)

The paper presents the results of a spectral analysis of the Ofpe/WN9 star HD 269227 (R84), which assumes a spherically expanding atmosphere to find solutions for equations of radiative transfer. The spectra of hydrogen and helium were predicted with a non-LTE model. Six stellar parameters were determined for R84. The shape of the velocity law is empirically found, since it can be probed from the terminal velocity of the wind. The six stellar parameters are further employed in a hydrodynamic model where stellar wind is assumed to be directed by radiation pressure, duplicating the mass-loss rate and the terminal wind velocity. The velocity laws found by computation and analysis are found to agree, supporting the theory of radiation-driven stellar wind. R84 is surmised to be a post-red supergiant which lost half of its initial mass, possibly during the red-supergiant phase. This mass loss is also suggested by its spectroscopic similarity to S Doradus. 104 refs.
Three-dimensional broadband and high-directivity lens antenna made of metamaterials

We present the theoretical modeling and prototype demonstration of a three-dimensional broadband, low-loss, dual-polarization, and high-directivity lens antenna using gradient index (GRIN) metamaterials, which is composed of multi-layer microstrip square-ring arrays. The elements of metamaterials, closed square-ring units of variable sizes, are distributed on the planar substrate to satisfy the radial gradient index function and the axial impedance matching layer configuration of the lens. The gradient-index metamaterials are designed to transform the spherical wave-front into the planar wave-front and to minimize the reflection loss. A prototype lens antenna, which consists of a metal conical horn and the gradient-index lens, are simulated, constructed, and measured. The resemblance of simulation and measurement results shows that the prototype lens antenna maintains low return loss and high directivity on the whole X-band (from 8 GHz to 12 GHz). Compared to the traditional horn antenna, the metamaterial.
Stellar clusters in dwarf galaxies

We present new observations in the K s (2.2 μ m) and L' (3.7 μ m) infrared bands of a sample of blue dwarf galaxies with the larger aim of studying the population of massive stellar clusters, the occurrence of dust-embedded stellar clusters, and their properties. All K s images show a rich population of clusters, but only a small fraction of them is bright in L' . Most L' sources have radio counterparts. We derived the luminosity function in K s for the galaxies IC 4661 and NGC 5408, finding both to be consistent with those of similar galaxies. We also compared the number of clusters and their luminosities with the star-formation rate of the host galaxies and found no compelling evidence of correlation. We conclude that young clusters and embedded clusters are a common feature of blue dwarf galaxies and possibly of galaxies in general, we suggest that their occurrence is due to purely statistical effects rather than a phenomenon related to specific physical conditions. In this sense we expect these objects to be abundant at high red-shift.
The On-Orbit Performance of WFPC2

The second Wide Field and Planetary Camera (WFPC2) was successfully installed in the Hubble Space Telescope during the STS-61 servicing mission in 1993 December. The primary objective of this new camera is to provide diffraction-limited photometric imaging over a wide field and a spectral range from 0.12 to l.0 µm. Here we provide an overview of the characteristics of the new instrument and offer our perspectives based on the first 6 months of operations on-orbit.
Groups of Permutation Polynomials over Finite Fields

LetFbe a finite field. We apply a result of Thierry Berger (1996,Designs Codes Cryptography,7, 215? 221) to determine the structure of all groups of permutations onFgenerated by the permutations induced by the linear polynomials and any power map which induces a permutation onF. This generalizes a result of Leonard Carlitz (1953,Proc. Amer. Math. Soc.,4, 538).
Start-up performance of different proportional-integral-anti-wind-up regulators

Abstract It has been found that proportional-integral-anti-wind-up regulators may produce unacceptable sluggish start-up in a large class of industrial plants, such as DC drives and temperature- or pressure-control systems. In this paper the effect is clarified, better-suited regulator structures are discussed in both continuous and discrete forms, and stability test are outlined.
Operational entanglement detection based on (cid:2) -moments

We introduce (cid:2) -moments with respect to any positive map (cid:2) . We show that these (cid:2) -moments can effectively characterize the entanglement of unknown quantum states without theirs prior reconstructions. Based on (cid:2) -moments necessary and sufﬁcient separability criteria, as well as necessary optimized criteria are presented, which include the ones in Yu et al. (Phys Rev Lett 127:060504, 2021) as special cases. Detailed example is given to show that our criteria can detect bound entanglement that cannot be identiﬁedbypositivepartialtransposecriterion,withtheexplicitmeasurementoperatorstoexperimentallymeasurethecorresponding (cid:2) -moments.
Comparison of Redshift-known Gamma-Ray Bursts with the Main Groups of Bright BATSE Events

The small reference sample of six BATSE gamma-ray bursts with known redshifts from optical afterglows is compared with a comparison group of the 218 brightest BATSE bursts. These two groups are shown to be consistent both with respect to the distributions of the spectral peak parameter in the observer's frame and also with respect to the distributions of the frame-independent cosmological invariant parameter (CIP). Using the known values of the redshifts (z) for the reference sample, the rest-frame distribution of spectral parameters is built. The deredshifted distribution of the spectral parameters of the reference sample is compared with distribution of these parameters for the comparison group after deredshifting by the factor 1/(1 + z), with z a free parameter. Requiring consistency between these two distributions produces a collective estimation of the best fitting redshifts for the comparison group z = 1.8-3.6. These values can be considered as the average cosmological redshift of the sources of the brightest BATSE bursts. The most probable value of the peak energy of the spectrum in the rest frame is 920 keV.
Fiber feed for the SDSS spectrograph

A 640 fiber feed for a pair of moderate resolution spectrographs is being constructed for the sloan digital sky survey. The spectrograph slits, optical fibers and plug-plates are mounted together in removable cartridges. The cartridges protect the optical fibers and provide quick-change interfaces to the telescope and the spectrographs. Ten cartridges will be made to allow plugging to occur during the day. The fibers are constructed in harnesses of 20. These are mass-terminated in v- groove blocks at the spectrograph slit. At the input end the fibers are terminated in simple ferrules and manually plugged into aluminum plug-plates. The plug-plates are deformed to match the best focal surface of the telescope, and the holes are drilled to be parallel to the principal ray after bending. We describe a simple technique for drilling accurate holes.
The binary system MWC 349.

The ionized zone surrounding MWC 349 has been resolved using the VLA. On the basis of a radio continuum map, it is concluded that there is a physical interaction between the two stellar components of MWC 349, and that the system is therefore a binary. The B component can be classified as a B0 III star, yielding a distance of about 1.2 kpc for the binary. The low ratio of infrared to short-wavelength luminosity in the A component suggests a circumstellar dusty region of special geometry. It is proposed that an appreciable dust and gas disk surrounds the star, modifying the symmetry of its H II region, and yielding the low infrared luminosity and perhaps its extra circumstellar extinction.
Texture features for image classification and retrieval

In this paper, we present an approach to texture-based image retrieval using image similarity on the basis of the matching of selected texture features. Image texture features are generated via gray level co-occurrence matrix, run-length matrix, and image histogram. Since they are computed over gray levels, color images of the database are first converted to 256 gray levels. For each image of the database, a set of texture features is extracted. They are derived from a modified form of the gray level co-occurrence matrix over several angles and distances, from a modified form of the run-length matrix over several angles, and from the image histogram. A sequential forward search is performed on all these features to reduce the dimensionality of the feature space. A supervised classifier is then applied to this reduced feature space in order to classify images into well separated classes. For measuring the similarity between two images a distance between two texture feature vectors is calculated. First experiments with multiple queries in a large image database give good results in terms of both speed and classification rate.
MIXED-DISCRETE FUZZY PROGRAMMING FOR NONLINEAR ENGINEERING OPTIMIZATION

Abstract Engineering optimization often contains a mix of continuous, integer and discrete types of design variables. The design domain and constraints frequently are fuzzy and cannot be defined precisely. This paper proposes an algorithm of mathematical programming in which the A-formulation of fuzzy optimization combines the modified branch-and-bound with max-partial derivative branching techniques for solving mixed discrete fuzzy optimization problems. The construction of a membership function of a design goal is extremely important in order to obtain the true optimum. The paper proposes a strategy to construct and select the preferred objective membership function. Optimal designs of a reinforced concrete beam and a pressure vessel illustrate this strategy. The numerical results and the feasibility of the proposed methodology are presented and discussed.
An sl 2 -type tensor category for the Virasoro algebra at central charge 25 and applications

Let O 25 be the vertex algebraic braided tensor category of ﬁnite-length modules for the Virasoro Lie algebra at central charge 25 whose composition factors are the irreducible quotients of reducible Verma modules. We show that O 25 is rigid and that its simple objects generate a semisimple tensor subcategory that is braided tensor equivalent to an abelian 3-cocycle twist of the category of ﬁnite-dimensional sl 2 -modules. We also show that this sl 2 - type subcategory is braid-reversed tensor equivalent to a similar category for the Virasoro algebra at central charge 1. As an application, we construct a simple conformal vertex algebra which contains the Virasoro vertex operator algebra of central charge 25 as a PSL 2 ( C ) - orbifold. We also use our results to study Arakawa’s chiral universal centralizer algebra of SL 2 at level − 1, showing that it has a symmetric tensor category of representations equivalent toRep PSL 2 ( C ) . ThisalgebraisanextensionofthetensorproductofVirasorovertexoperator algebras of central charges 1 and 25, analogous to the modiﬁed regular representations of the Virasoro algebra constructed earlier for generic central charges by I. Frenkel–Styrkas and I. Frenkel–M. Zhu.
Mode testing in difficult cases

Usually, when testing the null hypothesis that a distribution has one mode against the alternative that it has two, the null hypothesis is interpreted as entailing that the density of the sampling distribution has a unique point of zero slope, which is a local maximum. In this paper we argue that a more appropriate null hypothesis is that the density has two points of zero slope, of which one is a local maximum and the other is a shoulder. We show that when a test for a mode-with-shoulder is properly calibrated, so that it has asymptotically correct level, it is generally conservative when applied to the case of a mode without a shoulder. We suggest methods for calibrating both the bandwidth and dip-excess mass tests in the setting of a mode with a shoulder. We also provide evidence in support of the converse: a test calibrated for a single mode without a shoulder tends to be anticonservative when applied to a mode with a shoulder. The calibration method involves resampling from a template density with exactly one mode and one shoulder. It exploits the following asymptotic factorization property for both the sample and resample forms of the test statistic: all dependence of these quantities on the sampling distribution cancels asymptotically from their ratio. In contrast to other approaches, the method has very good adaptivity properties.