Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantum Non-locality, Black Holes and Quantum Gravity

It is now generally taken for granted that quantum gravitational effects will appear at Planck scale and no earlier. However, there is no theory of “quantum gravity”. Since Planck scales will not be experimentally accessible in the foreseeable future, purely speculative theories have been proposed, whereby the desired effects could appear at scales before the Planck scale. There has been no experimental support for these theories. On the other hand, Penrose has forcefully argued that the tests of Bell’s inequalities demonstrate nonlocality of Nature at the quantum level that is incompatible with the usual picture of spacetime at meter and and even kilometer scales. He has also argued that the state vector reduction is due to the effect of quantum gravity. In this paper the onset of quantum gravity is probed by confronting the extreme quantum (a photon) by the extreme of a gravitational field (a black hole).
The use of an electron beam evaporation source for electron microscope sample preparation

Some disadvantages of thin film evaporation techniques currently employed in electron microscope specimen preparation are discussed. A simple electron beam system for the evaporation of carbon and a range of shadowing agents is described which largely overcomes the difficulties in control and reproducibility inherent in resistively heated sources. The source evaporates carbon and platinum in a stable manner at power inputs between 120 and 300 W. Lower melting point materials such as germanium and chromium are evaporated using less than 50 W. It has been found that no significant changes in the stripping or structural properties of the films are introduced by the electron beam evaporation technique.
The distribution of forces in a granular system under external stress is a spinglass problem

There is now ample experimental and computational evidence that a well-defined and reproducible state can be achieved in a granular system under a repeated disturbance, e.g., if subjected to disturbance of amplitude A and frequency ω, a volume V(A, ω) is found which will be returned to if the system is subjected to A′, ω′ and then to A, ω. A microcanonical ensemble defines the entropy from volume V, where V equals the volume function W, just as E equals H in conventional statistical physics. A canonical version exists via a compactivity ∂V/∂S. Granular systems also have a distribution of intergranular forces generated by external forces or gravity. This paper shows that the idea that the configurations are determined by the Gibbsian formula exp(−W(∂S/∂V)) can be extended to the distribution of forces with a microcanonical condition P(external) = ∑(forcemomentsingrains)/V via exp(−Π(∂S/∂P)). The canonical ensemble immediately gives the exponential distribution of intergranular forces, found experimentally. The distribution must depend on the configuration and any physical property will have a value averaged over configurations, i.e. will give rise to a spinglass problem.
Modification of the Recursive Sidelobe Minimization Technique for the Range-Doppler Algorithm of SAR Imaging

Recursive sidelobe minimization (RSM) is a very effective technique to reduce the sidelobes of a synthetic aperture radar (SAR) image in the presence of multiplicative noise. However, it has little effect on the range sidelobes when used in a linear SAR using range-doppler algorithm (RDA). Therefore, we modified the RSM technique to use with RDA and simulated the imaging of a simple point target in the presence of multiplicative noise. The results from the simulations and experiments with real linear SAR data show that the proposed modification of the RSM can reduce the sidelobes not only in the azimuth direction, but also in the range direction without causing additional blurring.
Sensitivity analysis to unsteady perturbations of complex flows: a discrete approach

A discrete framework for computing the global stability and sensitivity analysis to external perturbations for any set of partial differential equations is presented. In particular, a complex‐step approximation is used to achieve near analytical accuracy for the evaluation of the Jacobian matrix. Sensitivity maps for the sensitivity to base flow modifications and to a steady force are computed to identify regions of the flow field where an input could have a stabilising effect. Four test cases are presented: (1) an analytical test case to prove the theory of the discrete framework, (2) a lid‐driven cavity at low Reynolds case to show the improved accuracy in the calculation of the eigenvalues when using the complex‐step approximation, (3) the 2D flow past a circular cylinder at just below the critical Reynolds number used to validate the methodology, and finally, (4) the flow past an open cavity presented to give an example of the discrete method applied to a convectively unstable case. The latter three (2–4) of the aforementioned cases were solved with the 2D compressible Navier–Stokes equations using a Discontinuous Galerkin Spectral Element Method. Good agreement was obtained for the validation test case, (3), with appropriate results in the literature. Furthermore, it is shown that for the calculation of the direct and adjoint eigenmodes and their sensitivity maps to external perturbations, the use of complex variables is paramount for obtaining an accurate prediction. Copyright © 2014 John Wiley & Sons, Ltd.
On the Horizontal Branch and the Helium Content of 47 Tucanae

Theoretical sequences of horizontal branch models, constructed using a new algorithm for the treatment of semiconvection, are described. The adopted composition parameters were chosen to bracket the ranges in metallicity and helium abundance appropriate to the globular cluster NGC 104 (47 Tucanae). By fitting the theoretical models to recent CCD photometry of the cluster, it is found that, on standard assumptions, its initial helium content must have been close to 24 percent by mass. In addition, best fits show that models for Fe/H = -0.65 provide an excellent match to the horizontal branch, if (m - M)v of about 13.44, and thereby yield consistency over the entire color-magnitude diagram of the cluster. This result reinforces the present age determination of about 13.5 Gyr for 47 Tuc. 44 refs.
Linguistic and social typology: The Austronesian migrations and phoneme inventories

Abstract There is a challenging issue for linguistic typology which involves the relationships which might exist between societal type and aspects of linguistic structure. Linguistic-typological studies have provided us with insights into the range of structures available in human languages, but we do not yet have explanations for why, of all the possible structures available, particular languages select particular structures and not others. A legitimate sociolinguistic viewpoint would be that some social explanations may be available. The sociolinguistic factors suggested as being relevant are language contact versus isolation, and community size and network structure. This paper deals with this thesis from the point of view of Austronesian phonology, with particular reference to Polynesian phoneme inventories.
Parametrization of admissible controllers for generalized Rosenbrock systems

The problem of parametrizing feedback systems with prescribed properties for general linear systems in Rosenbrock representation is considered. With this, the results of stabilizing controller parametrization for state space systems can be extended to the general case where system regularity is not assumed. The stabilization theory is formulated axiomatically to permit its application to a wide variety of design problems and is extremely elementary in nature.
Principles of a permanent-magnet axial-field d.c. machine

The theory of a permanent-magnet d.c. machine that has an axial field and a disc-shaped armature is discussed. Consideration is given to the effect that the distribution of magnetic field inthe airgap will have on the generation of e.m. f. The machine parameters in the angular and radialdirections are related to this distribution, so that a pole shape may be chosen that maximises the output power.
Aeroassisted orbital maneuvering using Lyapunov optimal feedback control

For advanced space transportation systems, such as the National Aerospace Plane or the Orbital Transfer Vehicle, the use of aeroassisted orbital transfer from a high Earth orbit to a low Earth orbit will require an optimizing closed-loop feedback controller, not only to achieve significant fuel savings, but also to compensate for large, unpredictable fluctuations in atmospheric density. We present a Lyapunov optimal function minimizing feedback control algorithm incorporating a preferred direction of motion at each state of the system, opposite to the gradient of a specified "descent function. " Lyapunov optimal feedback control is compared to an approximate minimum-fuel calculus of variations open-loop optimal control algorithm based on the 1962 U.S. Standard Atmosphere. The performance of the two controllers is simulated against both the 1962 U.S. Standard Atmosphere and an atmosphere corresponding to the STS-6 Space Shuttle flight, which contains density fluctuations on the order of + 40% compared to the U.S. Standard Atmosphere. In the STS-6 atmosphere the calculus of variations open-loop controller fails to achieve optimal atmospheric exit conditions. In fact, it fails to exit the atmosphere. The Lyapunov optimal feedback controller is able to achieve not only atmospheric exit, despite the ± 40% density fluctuations in the STS-6 atmosphere, but also achieves essentially the optimal (minimum-fuel) exit conditions.
Quasars and active galactic nuclei in rich environments. I, Fields surrounding optically faint quasars

Images in Gunn r (6500 + or {minus} 450 A) and g (4960 + or {minus} 400 A) of fields around 63 optically faint quasars have been obtained for the purpose of determining the effect of galaxy cluster environment on the optical evolution of quasars. The sample includes both radio-loud and radio-quiet quasars with m above 17.5 and between 0.3 and 0.6. A catalog of positional offsets from the quasar, magnitudes, and classification (stars or galaxies) of the detected objects is presented. 18 refs.
Comments on the Use of Eigenfunctions to Measure Structural Properties of Geographic Networks

The use of eigenfunctions has been proposed to measure spatial structure in networks. So far, however, there has been a paucity of applications of the approach, particularly to cellular networks (mosaics). This study uses specially constructed cellular networks which possess very similar degree vectors but dissimilar arrangements of vertex degrees to test the effectiveness of the approach. The results of this test indicate that there are several considerable limitations inherent in the procedure.
Study of Liquid-Metal Based Heating Method for Temperature Gradient Focusing Purpose

Temperature gradient focusing (TGF) is a highly efficient focusing technique for the concentration and separation of charged analytes in microfluidic channels. The design of an appropriate temperature gradient is very important for the focusing efficiency. In this study, we proposed a new technique to generate the temperature gradient. This technique utilizes a microchannel filled with liquid-metal as an electrical heater in a microfluidic chip. By applying an electric current, the liquid-metal heater generates Joule heat, forming the temperature gradient in the microchannel. To optimize the temperature gradient and find out the optimal design for the TGF chip, numerical simulations on four typical designs were studied. The results showed that design 1 can provide a best focusing method, which has the largest temperature gradient. For this best design, the temperature is almost linearly distributed along the focusing microchannel. The numerical simulations were then validated both theoretically and experimentally. The following experiment and theoretical analysis on the best design also provide a useful guidance for designing and fabricating the liquid-metal based TGF microchip.
Quantization of two types of Multisymplectic manifolds

This thesis is concerned with quantization of two types of multisymplectic manifolds that have multisymplectic forms coming from a Kahler form. In chapter 2 we investigate how Berezin-Toeplitz quantization can be used to quantize them and we study their properties in the semiclassical limit. In the last chapter of this work, we obtain two additional results. The first concerns the deformation quantization of the (2n − 1)-plectic structure that we examine in chapter 2, we make the first step toward the definition of a star product on the Nambu-Poisson algebra (C∞(M), {. , . , . }). The second result concerns the algebraic properties of the generalized commutator.
Deinterlacing with reduced flickering

Deinterlacing is a process of converting interlaced video signals into progressive video signals. Traditionally, deinterlacing methods have been evaluated in terms of PSNR. On the other hand, some artifacts can severely degrade perceptual video quality, but may not produce large mean square errors. One of such artifacts is flickering. This flickering artifact occurs more frequently as the video size increases. For example, for HD TV signals, this flickering artifact is more frequently observed. In this paper, we propose a deinterlacing method which noticeably reduces this flickering artifact with slight loss in terms of PSNR.
Eccentric Extrasolar Planets: The Jumping Jupiter Model

Abstract Most extrasolar planets discovered to date are more massive than Jupiter, in surprisingly small orbits (semimajor axes less than 3 AU). Many of these have significant orbital eccentricities. Such orbits may be the product of dynamical interactions in multiplanet systems. We examine outcomes of such evolution in systems of three Jupiter-mass planets around a solar-mass star by integration of their orbits in three dimensions. Such systems are unstable for a broad range of initial conditions, with mutual perturbations leading to crossing orbits and close encounters. The time scale for instability to develop depends on the initial orbital spacing; some configurations become chaotic after delays exceeding 108 y. The most common outcome of gravitational scattering by close encounters is hyperbolic ejection of one planet. Of the two survivors, one is moved closer to the star and the other is left in a distant orbit; for systems with equal-mass planets, there is no correlation between initial and final orbital positions. Both survivors may have significant eccentricities, and the mutual inclination of their orbits can be large. The inner survivor's semimajor axis is usually about half that of the innermost starting orbit. Gravitational scattering alone cannot produce the observed excess of “hot Jupiters” in close circular orbits. However, those scattered planets with large eccentricities and small periastron distances may become circularized if tidal dissipation is effective. Most stars with a massive planet in an eccentric orbit should have at least one additional planet of comparable mass in a more distant orbit.
Discussion: The beauty of expectiles

It is a pleasure to see here a plea for asymmetric statistics. They have very much to offer, both for meaningful data analysis and for fascinating research. As far as I know, this is the first paper to combine GAMLSS, quantiles and expectiles. It will draw more attention to this subject. I congratulate the editors and Thomas Kneib on this initiative. The paper has the character of a review, so there is little in it to disagree with. I can only say that I am a little surprised to see that quite a large part of the paper discusses advanced models for expected values. I also believe that expectiles did not get enough space. My contribution tries to correct that. I will repeat some material, to make this paper self-contained. Recent results will be sketched, but also a number of suggestions for important further work, some of them without even a clue of how to proceed. In addition, I have some remarks on the proper citing of previous work. See the end of the discussion for that.
Single-photon Kerr nonlinearities do not help quantum computation

By embedding an atom capable of electromagnetically induced transparency inside an appropriate photonic-crystal microcavity it may become possible to realize an optical nonlinearity that can impart a {pi}-rad-peak phase shift in response to a single-photon excitation. Such a device, if it operated at high fidelity, would then complete a universal gate set for all-optical quantum computation. It is shown here that the causal, noninstantaneous behavior of any {chi}{sup (3)} nonlinearity is enough to preclude such a high-fidelity operation. In particular, when a single-photon-sensitive {chi}{sup (3)} nonlinearity has a response time that is much shorter than the duration of the quantum computer's single-photon pulses, essentially no overall phase shift is imparted to these pulses by cross-phase modulation. Conversely, when this nonlinearity has a response time that is much longer than this pulse duration a single-photon pulse can induce a {pi}-rad overall phase shift through cross-phase modulation, but the phase noise injected by the causal, noninstantaneous response function precludes this from being a high-fidelity operation.
Force‐Free Magnetic‐Field Solution in Toroidal Coordinates

A method is presented for the solution of the force‐free magnetic‐field boundary‐value problem in toroidal coordinates. An exact solution utilizing the Stokes' current function is given for the free space surrounding the toroid. The solution of the force‐free equations within the current‐carrying region of the toroid, however, requires the use of approximate methods. A suitable approximate method is developed which, also in accordance with physical considerations, exactly satisfies the requirement that the divergence of the current be zero. Galerkin's method is chosen for use in this approximation and use is made of the flexibility of this method to reduce the complexity of the approximation process. A sample calculation using this approximation method and the results of this calculation are described. This approximation method is found to give an accurate solution to the boundary‐value problem with a minimum of effort. An equation describing the forces still present on the surface of the toroid is develo.
A three-stage design of non-linear control systems with time-delay

A new approach to the sub-optimal control of non-linear time-delay systems is presented in this paper. It consists of three stages. In the first stage the original time-delay system state equation is expanded about its nominal functions. The resulting linear time-varying system with delay is then reduced to a linear non-delay non-homogeneous system whose optimal control is the same. The third stage is the application of the maximum principle to the transformed system leading to the desired sub-optimal control. The method is applied to a non-linear system.
Effects of tube persistence length on dynamics of mildly entangled polymers

Recent atomistic simulations of polyethylene melt afford a close look at the entanglement dynamics of a real polymer. We analyze these results in a new way, by defining the tube primitive path as the mean path of consecutive molecular dynamics trajectories. The result suggests that tube is semiflexible, the persistence length being about half the entanglement length. The time dependent tangent–tangent correlation function of tube primitive path is then used to test the standard molecular model of tube dynamics. It is found that the effect of the semiflexibility is important in the mildly entangled system we studied and that incorporating its effect into the standard tube model improves the theory drastically.
Local mechanical spectroscopy with nanometer-scale lateral resolution

A new technique has been developed to probe the viscoelastic and anelastic properties of submicron phases of inhomogeneous materials. The measurement gives information related to the internal friction and to the variations of the dynamic modulus of nanometer-sized volumes. It is then the nanoscale equivalent to mechanical spectroscopy, a well-known macroscopic technique for materials studies, also sometimes called dynamic mechanical (thermal) analysis. The technique is based on a scanning force microscope, using the principle of scanning local-acceleration microscopy (SLAM), and allows the sample temperature to be changed. It is called variable-temperature SLAM, abbreviated T-SLAM. According to a recent proposition to systematize names of scanning probe microscope based methods, this technique should be included in the family of “mechanothermal analysis with scanning microscopy. ” It is suited for studying defect dynamics in nanomaterials and composites by locating the dissipative mechanisms in submicron phases. The primary and secondary relaxations, as well as the viscoplasticity, were observed in bulk PVC. The wide range of phenomena demonstrate the versatility of the technique. A still unexplained increase of the stiffness with increasing temperature was observed just below the glass transition. All of these observations, although their interpretation in terms of physical events is still tentative, are in agreement with global studies. This technique also permits one to image the variations of the local elasticity or of the local damping at a fixed temperature. This enables the study of, for instance, the homogeneity of phase transitions in multiphased materials, or of the interface morphologies and properties. As an illustration, the homogeneity of the glass transition temperature of PVC in a 50/50 wt % PVC/PB polymer blend has been demonstrated. Due to the small size of the probed volume, T-SLAM gives information on the mechanical properties of the near-surface, which may differ from bulk properties.
Response analysis and experimental results of holography-based modal Zernike wavefront sensor

The crosstalk problem inherent in holography based modal wavefront sensing (HMWS) becomes more severe with increasing aberrations of the incident beam. In this paper, the cause of crosstalk is theoretically revealed and then demonstrated using simulations. For extending the use of HMWS in correcting atmospheric turbulence introduced aberration, the sensor response is statistically analyzed with random aberrations created in accordance with the atmosphere turbulence model. The system parameters are optimized considering the turbulence strength and calibrated response curves are further used to improve the sensor performance. The simulation and first preliminary experimental results are shown for validating the method.
Total ionizing dose effect of γ-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory

The total ionizing dose (TID) effect of gamma-ray (γ-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ∼5.2 Mrad (HfO2) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy γ-ray exposure.