Miracle-dz/UniFAR-FTUs huggingface dataset:
Numerical Simulation of Natural Convection Heat Transfer in Open Space between Two Horizontal Circular Planes.

空気中において無限水平面の一部を円形加熱面とし, その上方に狭い間隙を保って室温の垂直円柱を設置した場合の間隙内における自然対流熱伝達の数値解析を行った. 平板間隙距離およびレイリー数の組み合わせを種々変えてナビエ・ストークスの方程式およびエネルギー方程式の解析を行った結果は, 前に報告した平均熱伝達係数の測定値と良好に一致した. さらに, 等温線, 流線, および局所ヌッセルト数の計算結果から, 間隙内の対流状態にはレイリー数と間隙距離に応じて, 間隙外からの空気の流入による更新流れのみの単純な対流およびこれと間隙内部での渦流れの双方が存在する対流の2つがあること, ならびに平均熱伝達係数が各々の流れの強さと, それが熱伝達に関与する面積の比率から決定されることを明らかにした. 以上のことから, 前報で提出した熱伝達係数の相関式の妥当性について若干の考察を加えた.
Magnetocrystalline anisotropy in quenched and annealed Fe3Si

Magnetocrystalline anisotropy constant K 1 of Fe 1- x Si x (0.08≤ x ≤0.25) in both as-quenched and after-annealed samples was determined from torque measurements in 77∼300 K, in order to make clear the difference in K 1 between disorder and order phase (D0 3 type) of Fe 3 Si at x =0.25. The difference in K 1 between both the cases began to appear at x ≃0.17, and values of K 1 for x =0.25 were determined to be - 1.01× and 0.94×10 5 erg/cm 3 at 77 K in the as-quenched and the after-annealed, respectively. This difference in K 1 was apparently due to the one in the degree of order in D0 3 ; the former value was thought to be of nearly perfect disorder in long range and the latter of perfect order. In any case, it was concluded that K 1 of Fe 3 Si is negative in disorder and positive in order (D0 3 ).
On the Bartnik mass of outermost apparent horizons

In 1989 Bartnik introduced a notion of quasilocal mass in general relativity. The Hawking mass provides a lower bound for Bartnik's quasilocal mass on outermost apparent horizons by way of Penrose's conjecture on time symmetric slices, proven in 1997 by Huisken and Ilmanen and in full generality in 1999 by Bray. We compute Bartnik's mass for all non-degenerate outermost apparent horizons and show that it coincides with the Hawking mass. As a corollary we rederive a complete characterization of all non-degenerate outermost apparent horizons, we disprove a conjecture due to Gibbons in the spirit of Thorne's hoop conjecture, and construct a new large class of examples of horizons with arbitrarily negative integral curvature.
Censored Regression Quantiles

Using quantile regression to analyze survival times offers an valuable complement to traditional Cox proportional hazards modelling. Unfortunately, this approach has been hampered by the lack of a conditional quantile estimator for censored data that is directly analogous to the Kaplan–Meier estimator and applies under standard assumptions for censored regression models. Here a recursively reweighted estimator of the regression quantile process is developed as a direct generalization of the Kaplan–Meier estimator. Specifically, the asymptotic behavior is directly analogous to that of the Kaplan–Meier estimator, and computation is essentially equivalent to current simplex methods for the quantile process in the uncensored case. Some preliminary examples suggest the strong potential of these methods as a complement to the use of Cox models.
The Continuum-Armed Bandit Problem

In this paper we consider the multiarmed bandit problem where the arms are chosen from a subset of the real line and the mean rewards are assumed to be a continuous function of the arms. The problem with an infinite number of arms is much more difficult than the usual one with a finite number of arms because the built-in learning task is now infinite dimensional. We devise a kernel estimator-based learning scheme for the mean reward as a function of the arms. Using this learning scheme, we construct a class of certainty equivalence control with forcing schemes and derive asymptotic upper bounds on their learning loss. To the best of our knowledge, these bounds are the strongest rates yet available. Moreover, they are stronger than the $o(n)$ required for optimality with respect to the average-cost-per-unit-time criterion.
Elastic properties of bimesogenic liquid crystals

The second nematic phase found in some bimesogenic liquid crystals with an odd flexible spacer has aroused considerable interest due to many unusual properties exhibited by them. However, the reason for such molecules to exhibit transitions to the modulated phase is still unclear. Dozov [Europhys Lett. 2001;56:247] predicted that negative K 33 can lead to a modulated phase where the director has either splay-bend or twist-bend distribution. Though various theoretical studies have suggested that this scenario may be valid, no experimental evidence has so far been given. In order to study the influence of the elastic constants, we measured the splay and bend elastic constants in the ordinary nematic phase of a dimer material, CBC11CB, for temperatures down to 0.6°C above the Nx–Nu transition. Our results show that the bend constant is reduced by a factor of 2 compared with that closer to the I-Nu transition but is positive and the trend does not seem that K 33 will extrapolate to zero or fall below it for the temperature range investigated. Compared to K 11, K 33 is reduced by a factor of 3, close to the Nu–Nx transition temperature.
Fluid Model of a Sheath Formed in Front of an Electron Emitting Electrode Immersed in a Plasma with Two Electron Temperatures

The formation of a sheath in front of a negatively biased electrode (collector) that emits electrons is studied by a one‐dimensional fluid model. Electron and ion emission coefficients are introduced in the model. It is assumed that the electrode is immersed in a plasma that contains energetic electrons. The electron velocity distribution function is assumed to be a sum of two Maxwellian distributions with two different temperatures, while the ions and the emitted electrons are assumed to be monoenergetic. The condition for zero electric field at the collector is derived. Using this equation the dependence of electron and ion critical emission coefficients on various parameters ‐ like the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons ‐ is calculated for a floating collector. A modification of the Bohm criterion due to the presence of hot and emitted electrons is also given. The transition between space charge limited and temperature limited electron emission for a current‐carrying collector is also analyzed. The critical potential, where this transition occurs, is calculated as a function of several parameters like the Richardson emission current, the ratio between the hot and cool electron density, the ratio between hot and cool electron temperature and the initial velocity of secondary electrons. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Bayesian Analysis of MHD Waves in the Lower Atmosphere

Abstract Magneto-hydrodynamic wave modes propagating from the solar photosphere into the corona have the potential to be exploited as an observational tool in an analogous way to the use of acoustic waves in helio/terrestrial seismology. In regions of strong magnetic field photospheric p-modes are thought to undergo mode conversion to slow magneto-acoustic waves, and that these slow magnetoacoustic p-modes may be waveguided from the photosphere into the solar corona along the magnetic field. A Bayesian analysis technique is applied to observations which suggests four distinct p-modes may be resolved in the transition region.
Effects of image noise on contact edge roughness and critical dimension uniformity measurement in synthesized scanning electron microscope images

Abstract. We study the effects of noise in scanning electron microscope (SEM) images on the size and roughness of contact holes when they are measured using top-down SEM images. The applied methodology is based on the generation of synthesized top-down SEM images, including several model contact edges with controlled roughness, critical dimension (CD) uniformity, and noise. The sources of image noise can be the shot noise of SEM electron beams and microscope electronics. The results show that noise reduces CD and correlation length while it increases the rms value of contact edge roughness (CER). CD variation is increased with noise in images with smooth and identical contacts, whereas it remains almost unaltered in images including rough contacts with CD nonuniformity. Furthermore, we find that the application of a noise-smoothing filter before image analysis rectifies the values of CD (at small filter parameter) and of rms and correlation length (at larger filter parameters), whereas it leads to marginally larger deviations from the true values of CD variation. Quantitative assessment of the model predictions reveals that the noise-induced variations of CD and CER values are less important compared with those caused by process stochasticity and material inhomogeneities.
New Quasi-3D Hyperbolic Shear Deformation Theory for the Static and Free Vibration Analysis of Functionally Graded Plates

AbstractIn this paper, a new quasi-three-dimensional (3D) hyperbolic shear deformation theory for the bending and free vibration analysis of functionally graded plates is developed. By dividing the transverse displacement into bending, shear, and thickness stretching parts, the number of unknowns and governing equations of the present theory is reduced, and hence makes it simple to use. The present plate theory approach accounts for both transverse shear and normal deformations and satisfies the zero traction boundary conditions on the surfaces of the plate without using shear correction factor. Unlike any other theory, the number of unknown functions involved in displacement field is only five, as against six or more in the case of other shear and normal deformation theories. A comparison with the corresponding results is made to check the accuracy and efficiency of the present theory.
Enhanced cloud‐to‐ground lightning frequency in the vicinity of coal plants and highways in Northern Georgia, USA

Lightning amplification has been detected in areas with enhanced aerosol concentrations. Here the authors use cloud‐to‐ground (CG) lightning strike data across North Georgia to statistically model the lightning frequency as a function of distance from nearest coal plant and distance from nearest highway. Results show a threefold increase in lightning occurrence near coal plants and highways. Lightning enhancement near coal plants extends to distances exceeding 100 km; whereas, the lightning enhancement near highways is limited to a localized spike. The models explain not more than 11% of the spatial variability in flash frequency.
Equatorial Kelvin waves at 100 millibars

A marked oscillation with a periodicity slightly greater than a month occurred in the zonal wind at 100 mb over Gan (00°41′S, 73°09′E) through the months January to May 1966. Corresponding oscillations took place during this period over other equatorial stations round the globe, but on the whole the oscillations became weaker with increasing latitude. The meridional wind was not directly involved in the oscillations, which were manifestations of a wave which generally progressed eastward relative both to the earth and to the mean flow with, however, a somewhat irregular rate of progression. The wave had zonal global wave number 1. Although it also advanced southward over the eastern hemisphere, it was not far from being symmetrical (as opposed to antisymmetrical) about the Equator. It was largely confined to the region between 150 mb and 70 mb, but it generally propagated downwards, Over the eastern hemisphere the 100 mb temperature tended to lead the 100 mb zonal wind by about 1/4 cycle. At least over Gan the 100 mb height and the 100 mb zonal wind tended to be in phase. The effect as a whole was sufficiently like an equatorial Kelvin wave to be considered as such. especially over the eastern hemisphere. The wave was linked very indirectly to concurrent events at 100 mb at 40°N. Less marked equatorial Kelvin waves occurred at 100 mb in 1960, 1967 and 1969. The incidence of equatorial Kelvin waves at 100 mb did not appear to be closely related to the phase at 50 mb of the tropical quasi-biennial zonal wind oscillation.
Working correlation structure misspecification, estimation and covariate design: Implications for generalised estimating equations performance

The method of generalised estimating equations for regression modelling of clustered outcomes allows for specification of a working matrix that is intended to approximate the true correlation matrix of the observations. We investigate the asymptotic relative efficiency of the generalised estimating equation for the mean parameters when the correlation parameters are estimated by various methods. The asymptotic relative efficiency depends on three features of the analysis, namely (i) the discrepancy between the working correlation structure and the unobservable true correlation structure, (ii) the method by which the correlation parameters are estimated and (iii) the 'design', by which we refer to both the structures of the predictor matrices within clusters and distribution of cluster sizes. Analytical and numerical studies of realistic data-analysis scenarios show that choice of working covariance model has a substantial impact on regression estimator efficiency. Protection against avoidable loss of efficiency associated with covariance misspecification is obtained when a 'Gaussian estimation' pseudolikelihood procedure is used with an AR(1) structure.
Wake-up effects in Si-doped hafnium oxide ferroelectric thin films

Hafnium oxide based ferroelectric thin films have shown potential as a promising alternative material for non-volatile memory applications. This work reports the switching stability of a Si-doped HfO2 film under bipolar pulsed-field operation. High field cycling causes a “wake-up” in virgin “pinched” polarization hysteresis loops, demonstrated by an enhancement in remanent polarization and a shift of negative coercive voltage. The rate of wake-up is accelerated by either reducing the frequency or increasing the amplitude of the cycling field. We suggest de-pinning of domains due to reduction of the defect concentration at bottom electrode interface as origin of the wake-up.
Learning Physical Science through Astronomy Activities: A Comparison between Constructivist and Traditional Approaches in Grades 3-6.

We report on an evaluation of the effectiveness of Project ARIES, an astronomy-based physical science curriculum for upper elementary and middle school children. ARIES students use innovative, simple, and affordable apparatus to carry out a wide range of indoor and outdoor hands-on, discovery-based activities. Student journals and comprehensive teacher materials aid in making the science content accessible to students based on their shared experiences and observations. Approximately 750 Grades 3–6 students in ARIES (or treatment) classrooms are compared with approximately 650 Grades 4–6 students in control classrooms through a series of open-ended assessment measures, using a pretest and posttest format. A detailed analysis by item measures the gain in treatment and control groups. We identify concepts where the ARIES approach is more effective, where both are equally effective, and where neither results in much learning. (The ARIES approach was never less effective.) Although learning is in evidence for both control and treatment groups, overall, the ARIES students achieve roughly four times the gain of their control counterparts. In particular, ARIES students had much greater gains for the concepts that the control students found most difficult.
Spatial heterogeneity of resources versus lotka-volterra dynamics

Abstract The problem is motivated by a consideration of two phenotypes of a species in a strongly heterogenous spatial environment. The phenotypes vary in their diffusion rates and interspecific interactions. The aim is to investigate the relative strengths of the diffusion and reaction effects. The problem is thus of competing species type, but there are many questions which arise which are not covered by standard theory. We investigate, in particular, the stability of the equilibria and the existence of coexistence solutions with emphasis on cases where the spatial variation of the environment becomes large. We discuss briefly the implications of our results for the principle of competitive exclusions and for the question of the evolution of diffusion discussed in Dockery et al . ( J. Math. Biol. 37 (1998), 61–83).
Compressibility effects on the vortical flow over a 65° sweep delta wing

The aim of this study is to investigate numerically the compressibility effects on the vortical flow developing over the VFE-2 delta wing. This wing is equipped with a sharp leading-edge and a sweep angle equal to 65°. The angle of attack is set equal to 25.5°, and two different freestream Mach numbers are considered: M∞=0.4 and M∞=0.8. The simulations are based on a turbulent modeling coupling Delayed Detached Eddy Simulation and Zonal Detached Eddy Simulation approaches, allowing a faster decay of the eddy-viscosity in Large Eddy Simulation regions. Such a method allows a good agreement with available experimental data. These computations highlight a modification of the flow behavior with an increase in the freestream Mach number. Indeed, the leading-edge vortex moves toward the wing and its core is dilated. Moreover, it is demonstrated in this study that the leading-edge vortex interacts with shock wave at midchord. This interaction induces a decay of the Rossby number in the leading-edge region and th.
Energy and momentum dissipation through wave breaking

[1] Wave breaking plays an important role in air-sea interaction. Laboratory and field measurements suggest that the wave field dissipation can be significantly enhanced by wave breaking and acts as a source of energy for generating current and entraining air against the effect of buoyancy forces. In the present study, a breaking wave model is formulated by taking the acceleration threshold value of −g/2 as breaking criterion, and the statistics of breaking waves, such as breaking wave coverage per unit time, and the volume of breaking water per unit area of wave surface per unit time are estimated. Statistical models are also developed to assess energy and momentum dissipation through wave breaking. It is found that the energy and momentum dissipation rates decay as k−3 and k−2.5, respectively. The energy loss is mainly due to wave components at frequencies higher than the spectral peak frequency. Though energy loss due to wave components at frequencies lower than the spectral peak frequency is found, these wave components do not significantly lose energy after the breaking. The energy loss, when expressed as phase speed cb of breaking waves, is mainly in the range 0.20 cp < cb < 0.90 cp, where cp is the dominant wave phase speed, and the energy dissipation rate falls off rapidly toward shorter scales. This offers no support for the hypothesis of a “Kolmogorov cascade” in wind-generated waves analogous to that in turbulence, with energy input from the wind at large scales and dissipation from the waves at the smallest scales. It is also demonstrated that, compared with empirical formula results, our model of energy (or momentum) dissipation rate lies between those models that estimate by empirical formula the rate of energy (or momentum) loss from a breaker with proportional coefficients 0.0085 and 0.0007. In addition, the peak frequency of our model energy (or momentum) dissipation rate downshifts to the lower-frequency band as wind speed increases, whereas the peak of the empirical formula remains at the same frequency.
The correlation between dysfunctional intestinal flora and pathology feature of patients with pulmonary tuberculosis

Introduction Recent studies have provided insights into the important contribution of gut microbiota in the development of Pulmonary Tuberculosis (PTB). As a chronic consumptive infectious disease, PTB involves many pathological characteristics. At present, research on intestinal flora and clinical pathological Index of PTB is still rare. Methods We performed a cross-sectional study in 63 healthy controls (HCs) and 69 patients with untreated active PTB to assess the differences in their microbiota in feces via 16S rRNA gene sequencing. Results Significant alteration of microbial taxonomic and functional capacity was observed in PTB as compared to the HCs. The results showed that the alpha diversity indexes of the PTB patients were lower than the HCs (P<0.05). Beta diversity showed differences between the two groups (P<0.05). At the genus level, the relative abundance of Bacteroides, Parabacteroides and Veillonella increased, while Faecalibacterium, Bifidobacterium, Agathobacter and CAG-352 decreased significantly in the PTB group, when compared with the HCs. The six combined genera, including Lactobacillus, Faecalibacterium, Roseburia, Dorea, Monnoglobus and [Eubacterium]_ventriosum_group might be a set of diagnostic biomarkers for PTB (AUC=0.90). Besides, the predicted bacterial functional pathway had a significant difference between the two groups (P<0.05), which was mainly related to the nutrient metabolism pathway. Significant alterations in the biochemical index were associated with changes in the relative abundance of specific bacteria, the short chain fatty acid (SCFA)-producing bacteria enriched in HCs had a positively correlated with most of the biochemical indexes. Discussion Our study indicated that the gut microbiota in PTB patients was significantly different from HCs as characterized by the composition and metabolic pathway, which related to the change of biochemical indexes in the PTB group. It was hypothesized that the abovementioned changes in the gut microbiota could exert an impact on the clinical characteristics of PTB through the regulation of the nutrient utilization pathway of the host by way of the gut-lung axis.
Changes in microbubble dynamics near a boundary revealed by combined optical micromanipulation and high-speed imaging

The authors report optical observations of the change in the dynamics of one and the same ultrasound contrast agent microbubble due to the influence of interfaces and neighboring bubbles. The bubble is excited by a 2.25MHz ultrasound burst and its oscillations are recorded with an ultrahigh-speed camera at 15 million frames per second. The position of an individual bubble relative to a rigid wall or second bubble is precisely controlled using optical tweezers based on Laguerre-Gaussian laser beams [P. Prentice et al., Opt. Express 12, 593 (2004); V. Garbin et al., Jpn. J. Appl. Phys. 44, 5773 (2005)]. This allows for repeated experiments on the very same bubble and for a quantitative comparison of the effect of boundaries on bubble behavior.