Miracle-dz/UniFAR-FTUs huggingface dataset:
Coupled Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation for Outlet Guide Vane and Prediffuser Flows

The objective of the present study was the development/testing of a novel hybrid Reynolds-averaged Navier–Stokes/large-eddy simulation methodology for predicting the flow at the compressor/combustor interface of a gas turbine engine. The coupling between the flow through the outlet guide vanes and the downstream combustor prediffuser represents the first key component of this interface. Important flow characteristics include three-dimensional turbulent outlet guide-vane wakes, end-wall boundary layers, and both favorable and adverse pressure gradient effects. There is a risk of flow separation if diffuser length and area ratio are not appropriately chosen; alternatively, a significant opportunity exists to reduce system flow losses if this risk is managed properly. Outlet guide-vane/prediffuser flow thus represents a significant modeling challenge. In the present approach to Reynolds-averaged Navier–Stokes/large-eddy simulation computational fluid dynamics, the Reynolds-averaged Navier–Stokes solver is ap.
Renormalization group theory of earthquakes

Abstract. We study theoretically the physical origin of the proposed discrete scale invariance of earthquake processes, at the origin of the universal log-periodic corrections to scaling, recently discovered in regional seismic activity (Sornette and Sammis (1995)). The discrete scaling symmetries which may be present at smaller scales are shown to be robust on a global scale with respect to disorder. Furthermore, a single complex exponent is sufficient in practice to capture the essential properties of the leading correction to scaling, whose real part may be renormalized by disorder, and thus be specific to the system. We then propose a new mechanism for discrete scale invariance, based on the interplay between dynamics and disorder. The existence of non-linear corrections to the renormalization group flow implies that an earthquake is not an isolated "critical point", but is accompanied by an embedded set of "critical points", its foreshocks and any subsequent shocks for which it may be a foreshock.
Formation of Planetary-Mass Objects by Protostellar Collapse and Fragmentation

Searches for very low mass objects in young star clusters have uncovered evidence for free-floating objects with inferred masses possibly as low as 5-15 Jupiter masses (MJup), similar to the masses of several extrasolar planets. We show here that the process that forms single and multiple protostars, namely, collapse and fragmentation of molecular clouds, might be able to produce self-gravitating objects with initial masses less than ~1 MJup, provided that magnetic field tension effects are important and can be represented approximately by diluting the gravitational field. If such fragments can be ejected from an unstable quadruple protostar system, prior to gaining significantly more mass, protostellar collapse might then be able to explain the formation of free-floating objects with masses below 13 MJup. These objects might then be best termed "sub-brown dwarf stars. "
Dynamical diagnostics for the glass transition in soft-sphere alloys

The structural slowing down in a binary alloy of soft spheres near the fluid-glass transition has been investigated by extensive molecular dynamics simulations. An attempt is made to characterise the transition on the basis of r- and k-space representations of the incoherent and coherent parts of the density autocorrelation functions. A careful analysis of the Van Hove functions allows the authors to put forward two novel diagnostics of the underlying 'ideal' glass transition, which yield the same value of the critical glass transition temperature. The latter appears to be independent of the mass ratio of the two species in the mixture. The damping of the longitudinal sound mode at the longest accessible wavelength appears to be surprisingly independent of temperature, while the damping of the corresponding transverse sound mode decreases significantly as the temperature is lowered.
Exactly solvable model of a wormhole supported by phantom energy

We have found a simple exact solution of spherically symmetrical Einstein equations describing a wormhole for an inhomogeneous distribution of the phantom energy. The equation of state is linear but highly anisotropic: while the radial pressure is negative, the transversal one is positive. At infinity the spacetime is not asymptotically flat and possesses on each side of the bridge a regular cosmological Killing horizon with an infinite area, impenetrable for any particles. This horizon does not arise if the wormhole region is glued to the Schwarzschild region. In doing so, the wormhole can enclose an arbitrary amount of the phantom energy. The configuration under discussion has a limit in which the phantom energy turns into the string dust, the areal radius tends to the constant. In this limit, the strong gravitational mass defect is realized in that the gravitational active mass is finite and constant while the proper mass integrated over the total manifold is infinite.
Numerical Methods for Estimation and Inference in Bayesian VAR-models

In Bayesian analysis of vector autoregressive models, and especially in forecasting applications, the Minnesota prior of Litterman is frequently used. In many cases other prior distributions provided better forecasts and are preferable from a theoretical standpoint. Several of these priors require numerical methods in order to evaluate the posterior distribution. Different ways of implementing Monte Carlo integration are considered. It is found that Gibbs sampling performs as well as, or better, then importance sampling and that the Gibbs sampling algorithms are less adversely affected by model size. We also report on the forecasting performance of the different prior distributions
The summation of the ordinary and renormalized perturbation series for the ground state energy of the quartic, sextic, and octic anharmonic oscillators using nonlinear sequence transformations

The strongly divergent Rayleigh–Schrodinger perturbation expansion for the ground state energy of the quartic, sextic, and octic anharmonic oscillator and a corresponding renormalized perturbation expansion [F. Vinette and J. Cižek, J. Math. Phys. 32, 3392 (1991)] are summed by Pade approximants, by Levin’s sequence transformation [D. Levin, Int. J. Comput. Math. B 3, 371 (1973)], and by a closely related sequence transformation which was suggested recently [E. J. Weniger, Comput. Phys. Rep. 10, 189 (1989)]. It is shown that the renormalized perturbation expansion can be summed much more easily than the original perturbation expansion from which it was derived, and that Levin’s sequence transformation diverges and is not able to sum the perturbation expansions. The Pade summation of the renormalized perturbation expansions gives relatively good results in the quartic and sextic case. In the case of the octic anharmonic oscillator, even the renormalized perturbation expansion is not Pade summable. The best.
A RESTRAINED CONDITION NUMBER LEAST SQUARES TECHNIQUE WITH ITS APPLICATIONS TO AVOIDING RANK DEFICIENCY

An algorithm for the constrained least squares problem is proposed in which the upper bound of the condition number of a parameter matrix is predetermined. In the algorithm, the parameter matrix to be obtained is reparameterized using its singular value decomposition, and the loss function is minimized alternately over the singular vector matrices and the singular values with condition number constraint. It was demonstrated that the algorithm recovered full rank matrices in simulated reverse component analysis, in which the matrices were estimated from their reduced rank counterparts. The proposed algorithm is useful for avoiding degenerate solutions in which parameter matrices become rank de(cid:12)cient, which is illustrated in its application to generalized oblique Procrustes rotation and three-mode Parafac component analysis.
Parallel-based calibration method for line-structured light vision sensor

Abstract. Determining the relative ubiety between the camera and the structured light plane projector is a classical problem in the measurement of line-structured light vision sensors. A geometrical calibration method based on the theory of vanishing points and vanishing lines is proposed. In this method, a planar target with several parallel lines is used. By moving the target to at least two different positions randomly, we can obtain the normal vector of the structured light plane under the camera coordinate system; as the distance of each two adjacent parallel lines has been known exactly, the parameter D of the structured light plane is determined; therefore, the function of the structured light plane can be confirmed. Experimental results show that the accuracy of the proposed calibration method can reach 0.09 mm within the view field of about 200×200 mm. Moreover, the target used in our calibration method can be easily produced precisely, and the calibration method is efficient and convenient as its simple calculation and easy operation, especially for onsite calibration.
A Minicomputer in a Senior Modern Physics Laboratory

A minicomputer was recently introduced in a senior modern physics laboratory. Operating in a conversational mode, it has been an excellent way both of teaching students computing and of encouraging them to use a computer routinely. The choice of computer languages is discussed, and the advantages and possible disadvantages of a minicomputer are listed.
Distinguishing bipartite states by local operations and classical communication

We present a general method for distinguishing bipartite states by local operations and classical communication. It unifies several available methods together. This method is applicable for arbitrary bipartite states, i.e., it works not only for entangled states but also for separable states. We also study the local distinguishability for maximally entangled states which are in an arbitrary basis.
A contribution to the contractibility problem for overlapping controllers

Abstract In this work, a contribution to the contractibility of decentralized control laws, in the context of the Inclusion Principle, is offered. By means of this principle, an overlapping system can be expanded to another bigger one where the subsystems are considered as disjoint. Under a control criterion, local controllers are designed for each subsystem. After this expansion-design process, the decentralized control laws need to be contracted and implemented in the original system. However, the contractibility conditions are not satisfied by arbitrary local gain matrices. In this paper, an explicit structure for the local gain matrices ensuring contractibility is presented; moreover, the possibility of using different control criteria in accordance with these structures is discussed.
Sustainment of elongated field reversed configurations with localized rotating magnetic field current drive

The effects of rotating magnetic field (RMF) antenna length on the sustainment of RMF driven field reversed configurations (FRC) have been investigated in the Translation, Confinement, and Sustainment (TCS) facility. FRCs could be sustained with axial lengths well beyond the RMF antenna, presumably due to induced axial flow. The FRC length, ls, in TCS was weakly dependent on the antenna length, la, with ls∼2la being achieved for the shortest antenna employed. Reducing antenna length led to more stable operation, with the FRCs less prone to rotational instabilities. Shorter antenna lengths also resulted in increases in the plasma temperature. At larger ratios of ls/la the RMF had to supply a greater torque per unit length, and it did this by increasing its penetration into the FRC, brought about automatically by a slight decrease in plasma density. Optimal overall current drive efficiency occurred at values of la/2rs of about 1.3, where rs is the separatrix radius, and values of ls/la of about 1.5. In cont.
A Novel Approach for RCS Reduction Using a Combination of Artificial Magnetic Conductors

A thin Artiflcial Magnetic Conductor (AMC) structure for Radar Cross-Section (RCS) reduction applications is presented. The manufactured prototype, which combines two unit-cell metallization sizes, presenting two resonant frequencies, shows broad AMC operation bandwidth, polarization angle independency, and its angular margin when operating under oblique incidence is also tested. It is shown that signiflcant RCS reduction can be achieved with the proposed AMCs combination even if a 180 - phaseshift between re∞ected waves is not met. Two designs are considered: the already mentioned design combining AMCs with overlapped frequency bands and the second one combining Perfect Electric Conductor (PEC) and AMC surfaces. A comparison between these two designs regarding RCS reduction, supported by measurements in an anechoic chamber, is presented.
Nanoscale ferroelectric tunnel junctions based on ultrathin BaTiO3 film and Ag nanoelectrodes

In this work, Ag nanoisland electrodes (nanoelectrodes) have been deposited on top of ultrathin ferroelectric BaTiO3 (BTO) films to form a nanoscale metal-ferroelectric-metal tunnel junction by integrating growth techniques of nanocluster beam source and laser-molecular beam epitaxy. The ultrathin BTO films (∼3 nm thick) exhibit both apparent ferroelectric polarization reversal and ferroelectric tunneling related resistive switching behaviors. The introducing of Ag nanoislands (∼20 nm in diameter) as top electrode substantially enhances the tunneling current and alters the symmetry of I-V hysteresis curves. The enhanced tunneling current is likely due to the reduction in tunneling barrier height and an increase in effective tunneling area by Ag nano-electrodes, while the improved symmetric in I-V curve may be attributed to the variation of electrode-oxide contact geometry.
Improved multi-objective ant colony optimization algorithm and its application in complex reasoning

The problem of fault reasoning has aroused great concern in scientific and engineering fields. However, fault investigation and reasoning of complex system is not a simple reasoning decision-making problem. It has become a typical multi-constraint and multi-objective reticulate optimization decision-making problem under many influencing factors and constraints. So far, little research has been carried out in this field. This paper transforms the fault reasoning problem of complex system into a paths-searching problem starting from known symptoms to fault causes. Three optimization objectives are considered simultaneously: maximum probability of average fault, maximum average importance, and minimum average complexity of test. Under the constraints of both known symptoms and the causal relationship among different components, a multi-objective optimization mathematical model is set up, taking minimizing cost of fault reasoning as the target function. Since the problem is non-deterministic polynomial-hard(NP-hard), a modified multi-objective ant colony algorithm is proposed, in which a reachability matrix is set up to constrain the feasible search nodes of the ants and a new pseudo-random-proportional rule and a pheromone adjustment mechinism are constructed to balance conflicts between the optimization objectives. At last, a Pareto optimal set is acquired. Evaluation functions based on validity and tendency of reasoning paths are defined to optimize noninferior set, through which the final fault causes can be identified according to decision-making demands, thus realize fault reasoning of the multi-constraint and multi-objective complex system. Reasoning results demonstrate that the improved multi-objective ant colony optimization(IMACO) can realize reasoning and locating fault positions precisely by solving the multi-objective fault diagnosis model, which provides a new method to solve the problem of multi-constraint and multi-objective fault diagnosis and reasoning of complex system.
The dynamics of luminous galaxies in isothermal halos

is a good es assuming that the galaxies are spherical, n0n—rotating and have a constant velocity butions by fitting the line-of-sight velocity dispersion profiles of 37 elliptical galaxies We examine the dynamics of luminous galaxies in singular isothermal mass distri ABSTRACT using spherical, non-rotating dynamical models. We can control for the effects of ellipticity OCR Output the elliptical galaxies with axisymmetric models, an isothermal halo using the observed photometric and velocity dispersion profiles. We study matter dispersion. study the dynamics of ellipticals in central dispersion to luminosity in an
Active Control of Low Frequency Buzz-Saw Tones; Theory and Experiment

This paper discusses some theoretical and experimental issues related to the active control of buzz-saw tones radiated from an aircraft engine inlet at takeoff. Buzz-saw tones occur when the rotor tip speed becomes supersonic. It arises due to the formation of shocks at the blade tips, which then propagate non-linearly along the engine duct. Buzz-saw noise comprises a series of tones harmonically related to the shaft rotation frequency (Engine Orders). Moreover, it has been shown that the noise at each Engine Order comprises just one single spinning mode. Whilst there has been considerable work aimed at assessing the feasibility of active control for reducing the tones due to rotor – stator interaction, buzz-saw noise has been overlooked. This is surprising given the low frequencies at which Buzz-Saw noise occurs, and its simple modal content, which both suggest that buzz-saw noise is particularly suited to active control. This paper describes various control strategies for reducing buzz-saw noise. The paper concludes with the results of a laboratory experiment aimed at demonstrated experimentally the effectiveness with which a single spinning mode, characteristic of an EO = 3 buzz-saw tone, can be controlled. Reductions in excess of 14dB are reported at some frequencies.
Multiple Comparisons and Type III Errors

Abstract In multiple comparison procedures often the ordering of populations is of more interest than the testing of hypotheses. In such a situation it is important to control the probability of a Type III error (introduced by Harter 1957 to indicate that one population is concluded to be better than another when actually it is worse). The studentized differences between means may be used to give ordering conclusions on all pairs of populations under consideration. Although this may be done by setting up confidence intervals using Tukey's honest significant difference, a more efficient method (when the confidence intervals themselves are not of interest) is suggested here, and tables are provided for its implementation.
Development of line-shaped optical system for YAG2ω laser annealing used in the manufacture of low-temperature poly-Si TFT

We have developed a new optical system that transforms the circle profile beam generated with near Gaussian intensity distribution by the YAG2ω laser (second harmonics of a Q-switched Nd:YAG laser) into a line-profile beam. This transformed bean has uniform distribution to within 5% in the longitudinal direction, and is about 100 mm long and 40 micron wide. For homogenization in the longitudinal direction, we employ a waveguide plate homogenizer. The laser beam is divided by waveguide plates, and the divided beams are overlapped on the surface of the works. We successfully reduced interference fringes by increasing the fixed optical pass difference beyond the inherent time and coherent length for every divided pair of adjacent beams under a controlled space coherent length. In the width direction, the laser beam is focused up to the limited M2 value.
Mechanical behavior of MoS2 nanotubes under compression, tension, and torsion from molecular dynamics simulations

The mechanical behavior of different types of single-walled and double-walled MoS2 nanotubes when subjected to external compressive, tensile, and torsional loading is investigated using classical molecular dynamics simulations. The forces on the atoms are determined using a reactive empirical bond-order potential parameterized for Mo-S systems. The simulations report on the elastic properties of the different MoS2 nanotube systems as well as the interrelationships between the buckling behavior and the structural parameters of the nanotubes, such as length, diameter, chirality, and number of walls. The simulations predict that the most important factor influencing mechanical response is the number of walls present and, to a lesser extent, the diameters of the nanotubes, with the other structural parameters predicted to have little effect on the results over the range investigated. These findings are consistent with reported density functional theory calculations and experimental data for WS2 and MoS2 nanot.
Different processes underlie the detection of second-order motion at low and high temporal frequencies

The aim of this project was to determine whether first- and second-order motion stimuli are detected by the same mechanism. We began by measuring the temporal contrast sensitivity function (CSF) for the directional discrimination of 0.3 c deg-1 drifting spatial beat patterns and luminance modulated gratings. The CSF for beat patterns was bimodal, with sensitivity maximal near 1–2 Hz and 10–12 Hz. In contrast, the CSF for luminance gratings had a single peak near 10 Hz. Separate adaptation experiments were then done using all permutations of beat patterns and luminance gratings as the test and adaptation stimuli. In general, sensitivity to a test pattern of fixed temporal frequency (2, 4, 8 or 16 Hz) was measured both before and after adaptation to patterns whose temporal frequency varied over a wide range. The rationale for these experiments was that if first- and second-order stimuli are processed by the same mechanisms, the adaptation tuning curves should all be similar. Our results show that this is the case at high temporal frequencies (> 4 Hz), but not at low temporal frequencies. The post-adaptation sensitivity functions for test patterns with temporal frequencies of 8 Hz and 16 Hz were bandpass, with maximal adaptation near 12 Hz, and showed evidence of beat-specific adaptation; for 2 Hz test patterns the sensitivity functions were lowpass, adaptation declining above 20 Hz, but there was no beat-specific adaptation. The shape of the CSFS and the results of the adaptation experiments show that separate processes mediate the detection of drifting beat patterns at low and high temporal frequencies. The results are consistent with the hypothesis that fast second-order motion is detected by Fourier-type mechanisms, preceded by a nonlinearity, and slow second-order motion is detected by a process involving a comparison of local luminance features.
The most massive pulsating white dwarf stars

Abstract Massive pulsating white dwarf stars are extremely rare, because of their small size and because they are the final product of high-mass stars, which are less common. Because of their intrinsic smaller size, they are fainter than the normal size white dwarf stars. The motivation to look for this type of stars is to be able to study in detail their internal structure and also derive generic properties for the sub-class of variables, the massive ZZ Ceti stars. Our goal is to investigate whether the internal structures of these stars differ from the lower-mass ones, which in turn could have been resultant from the previous evolutionary stages. In this paper, we present the ensemble seismological analysis of the known massive pulsating white dwarf stars. Some of these pulsating stars might have substantial crystallized cores, which would allow us to probe solid physics in extreme conditions.