Miracle-dz/UniFAR-FTUs huggingface dataset:
Oscillatory thermocapillary convection in open cylindrical annuli. Part 2. Simulations

Oscillatory thermocapillary convection in open cylindrical annuli heated from the outer wall is investigated numerically. Results at fixed inner/outer radius ratio of 0.5, aspect ratios ($Ar$) of 1, 2.5, 3.33, and 8, zero Biot number, and a Prandtl number of 6.84 are obtained and compared with experiments (Part 1 of this paper). Convection is steady and axisymmetric at sufficiently low values of the Reynolds number (${\it Re}$). Transition to oscillatory states occurs at critical values of $Re$ which depend on $Ar$. With $Ar\,{=}\, 1$, 2.5 and 3.33, we observe 5, 9 and 12 azimuthal wavetrains, respectively, travelling clockwise at the free surface near the critical $Re$. With $Ar \,{=}\, 8$, there are 20 standing waves near the critical $Re$. Experimental results in Part 1 support this finding. A multi-roll structure appears beyond the critical $Re$ in shallow liquid layers with $Ar \,{=}\, 3.33$ and 8. The critical $Re$ and frequency are in qualitative but not in quantitative agreement with the experimental ones. Either heat loss from the free surface or heating from the surroundings to the free surface stabilizes the flow, and the critical $Re$ increases with increasing Biot number while the critical period goes down. The numerical results agree better with the experimental ones if the free surface is assumed to be heated as shown in Part 1. We have also computed supercritical time-dependent states and find that while the non-dimensional frequency increases with increasing $Re$ near the critical region, it approaches an asymptote at supercritical $Re$.
Computational Dispersion Properties of Horizontal Staggered Grids for Atmospheric and Ocean Models

Abstract The computational dispersion properties of horizontally and time-horizontally staggered grids using corresponding centered-difference schemes for approximation of the Adjustment, or gravity wave equation, are analyzed in terms of their group velocity characteristics. Results are obtained for atmospheric and oceanic models, the latter being characterized by a much smaller Rossby radius of deformation. Three best time-horizontally staggered grids have practically the same advantageous computational dispersion properties as the Arakawa C grid for both atmospheric and oceanic models—namely, the time-staggered D (or Eliassen) and time-staggered C (only with a semi-implicit scheme) grids—and to a certain extent the Lilly grid. Both, the Arakawa B and the time-staggered A grids for atmospheric and oceanic models, along with the Arakawa E and the time-staggered E grids only for atmospheric models (although having worse dispersion properties) also may be used as additional practical options. For all grids.
Halo common proper motion stars - Subdwarf distance scale, halo binary fraction, and UBVRI colors

Common proper motion stars identified by Luyten (1979, 1980) were selected according to reduced proper motion and photometric criteria to produce a list of candidate halo objects. UBVRI photometry was obtained to identify genuine halo parts. About 20 percent of the stars with (Fe/H) less than -1.0 were found to have random errors not less than several x 0.1 mag in distance modulus, in addition to the photometric errors, thought to be due to the existence of close binary companions to some of the common proper motion stars. The implications of these errors for kinematic studies of field Population II stars are considered. Systematic errors of order 16 percent were also detected in distances derived from the U-B,B-V deblanketing technique. It is suggested that Population II field stars did not originate in globular clusters which subsequently disintegrated but formed in less dense environments. Several K subdwarfs were found with very high UV excesses, comparable with those predicted by some synthetic colors.
Natural sums and abelianizing

This form is chosen [6] because A\ί A—> Ax A is an epimorphism —>-», so that there is at most one mapping > making the diagram commutative; / and g are called summable if this mapping exists, and then their sum is the composed mapping A -^ A x A —> B. This partially defined addition, called the natural sum, turns out to be the same as Fitting's [2] pointwise multiplication of homomorphisms with commuting values; it has been used in extensive investigations of direct decompositions by Euros [9] and Livsic [10, 11, 12]. Of course a dual diagram applies in categories which have naturally distinguished monomorphisms A V A >—> A x A. In many categories there is a naturally distinguished mapping AvA-+AxA which is neither epimorphic nor monomorphic. This is the situation in the category of homotopy types of topological spaces with base point, and the theory of homotopy operations, despite some analogies, apparently requires the apparatus currently in use there [1] which is not related to Mac Lane's fundamental diagram. However, Mac Lane's approach
Random walks and boundaries of CAT(0) cubical complexes

We show under weak hypotheses that the pushforward $\{Z_no\}$ of a random-walk to a CAT(0) cube complex converges to a point on the boundary. We introduce the notion of squeezing points, which allows us to consider the convergence in either the Roller boundary or the visual boundary, with the appropriate hypotheses. This study allows us to show that any nonelementary action necessarily contains regular elements, that is, elements that act as rank-1 hyperbolic isometries in each irreducible factor of the essential core.
Escobar type theorems for elliptic fully nonlinear degenerate equations

abstract:In this paper we prove non-existence and classification results for elliptic fully nonlinear elliptic degenerate conformal equations on certain subdomains of the sphere with prescribed constant mean curvature along its boundary. We also consider non-degenerate equations. Such subdomains are geodesic balls in ${\Bbb S}^m$, punctured balls and annular domains.Our results extend those of Escobar when $m\geq 3$, and Hang-Wang and Jim\'{e}nez when $m=2$.
Building Algebra Testlets: A Comparison of Hierarchical and Linear Structures.

Earlier (Wainer & Lewis, 1990), we reported the initial development of a testlet-based algebra test. In this account, we provide the details of this excursion into the use of testlets. A pretest of two 15–item algebra tests was carried out in which examinees' performance on a 4-item subset of each test (a 4–item testlet) was used to predict performance on the entire test. Two models for constructing the testlets were considered: hierarchical (adaptive) and linear (fixed format). These models are compared with each other. It was found on cross–validation that, although an adaptive testlet is superior to a fixed format testlet, this superiority is modest, whereas the potential cost of that superiority is considerable. It was concluded that in circumstances similar to those we report a fixed format testlet that uses the best items in a pool can do almost as well as the optimal adaptive testlet of equal length from that same pool.
Polynomial Values in Subfields and Affine Subspaces of Finite Fields

For an integer $r$, a prime power $q$, and a polynomial $f$ over a finite field ${\mathbb F}_{q^r}$ of $q^r$ elements, we obtain an upper bound on the frequency of elements in an orbit generated by iterations of $f$ which fall in a proper subfield of ${\mathbb F}_{q^r}$. We also obtain similar results for elements in affine subspaces of ${\mathbb F}_{q^r}$, considered as a linear space over ${\mathbb F}_q$.
Solvability of generalized div-curl system and Friedrichs inequalities.

In this article, we consider the solvability of two generalized div-curl systems. They are referred to as the equations of magnetostatics and electro- , resp. Necessary compatibility conditions on the data for the existence of solutions are fully described, and existence of $W^{m, p}$-solutions is proved. Moreover, we give some description for the null spaces. As a corollary, we give the estimates of gradient via generalized ${\rm div}$ and ${\rm curl}$ in $L^p$-framework, which can be considered as Friedrichs inequalities. Furthermore, two decompositions of Sobolev spaces are given.
Endoscopic diagnosis and treatment of ulcerative colitis‐associated neoplasia

Shiro Oka, Toshio Uraoka, Kenji Watanabe, Keisuke Hata, Keisuke Kawasaki, Kenichi Mizuno, Masashi Misawa, Naoki Hosoe, Tomohiko Moriyama and Hiroshi Kawachi Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Department of Gastroenterology and Hepatology, Gunma University Graduate School of Medicine, Maebashi, Department of Intestinal Inflammation Research, Hyogo College of Medicine, Nishinomiya, Department of Surgical Oncology, The University of Tokyo, Center for Diagnostic and Therapeutic Endoscopy, School of Medicine, Keio University, Department of Pathology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Iwate Medical University, Morioka, Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, and Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
Speckle tracking echocardiography in cats with preclinical hypertrophic cardiomyopathy

Abstract Background Cats with hypertrophic cardiomyopathy (HCM) have decreased left ventricular (LV) longitudinal deformation detected by mitral annular plane systolic excursion (MAPSE) and speckle tracking echocardiography. People with preclinical HCM have decreased systolic LV longitudinal and radial strain (S) and strain rate (SR), with preserved circumferential S and SR. Hypothesis/Objectives Cats with preclinical HCM have decreased systolic LV deformation compared to normal cats. Animals Seventy‐three client‐owned cats with (n = 37) and without (n = 36) preclinical HCM. Methods Retrospective echocardiographic study. Left and right ventricular longitudinal S and SR, LV radial and circumferential S and SR were calculated by STE. Left ventricular mass was also calculated. Correlation between STE variables and LV hypertrophy was determined and receiver‐operating characteristic (ROC) curves were plotted for prediction of HCM. Results Cats with HCM had smaller absolute longitudinal S (−14.8 ± 3.3% vs −19.7 ± 2.7%, P < .001), longitudinal SR (−2.36 ± 0.62 vs −2.95 ± 0.68 second−1, P < .001), radial S (46.2 ± 21.3% vs 66.7 ± 17.6%, P < .001), and radial SR (5.60 ± 2.08 vs 6.67 ± 1.8 second−1, P < .001) compared to healthy controls. No difference was observed for circumferential S and SR. Cats with HCM had greater LV mass (13.2 ± 3.7 g vs 8.6 ± 2.7 g, P < .001). The ROC with the greatest area under the curve (AUC) for the identification of HCM (0.974) was plotted from a logistic regression equation combining LV mass, MAPSE at the free wall, and LV internal diameter in diastole (LVIDd). Conclusions and clinical importance Cats with preclinical HCM have decreased long axis and radial deformation. Decreased longitudinal deformation and decreased LVIDd are factors that would support a diagnosis of HCM.
On Convergence of the Feynman Path Integral Formulated Through Broken Line Paths

We study the convergence of the Feynman path integral formulated through broken line paths in nonrelativistic quantum mechanics. The rigorous proof of its convergence had been given little except for special cases for a long time. In the preceding paper the author showed for a class of potentials that this path integral converges and gives the probability amplitude, i.e. the solution of the Schrodinger equation. In the present paper we generalize this result, showing the boundedness theorem on the weighted Sobolev spaces for some integral operators and joining this boundedness theorem to the method in the preceding paper. We note that the result obtained is gauge invariant.
Loss increase in silicone-coated fibres with heat treatment

Loss-increase characteristics for four kinds of silicone-coated optical fibres with heat treatment have been investigated OH ion absorption loss increase occurs by heat treatment above 250°C, and becomes marked in heat treatment at 500°C for GeO2-doped silica fibres. The others did not exhibit any loss increase at 1.39 μm due to OH ions. It was found, from the experiments, that the loss-increase characteristics in heat treatment depend strongly on the glass system in the fibre core.
Shear strength in principal plane of wood

In this study, the writers used Tsai and Wu's tensor polynomial theory to rederive a formula originally derived by Cowin for shear strength variation in a plane of material symmetry of orthotropic materials. Experimental work was then performed (based on a method by Arcan, Hashin, and Voloshin) on Sitka spruce specimens to verify the formula. The theory and experiment agreed closely. When the angle between shear force and grain on the longitudinal‐tangential plane increased from 0‐30° shear strength decreased more than 43%. Engineers should take this relationship into account when designing wood structural members.
The hyperbolic Yang–Mills equation
in the caloric gauge : local well-posedness and control of energy-dispersed
solutions

This is the second part in a four-paper sequence, which establishes the Threshold Conjecture and the Soliton Bubbling vs.~Scattering Dichotomy for the hyperbolic Yang--Mills equation in the $(4+1)$-dimensional space-time. This paper provides the key gauge-dependent analysis of the hyperbolic Yang--Mills equation. We consider topologically trivial solutions in the caloric gauge, which was defined in the first paper arXiv:1709.08599 using the Yang--Mills heat flow. In this gauge, we establish a strong form of local well-posedness, where the time of existence is bounded from below by the energy concentration scale. Moreover, we show that regularity and dispersive behavior of the solution persists as long as energy dispersion is small. We also observe that fixed-time regularity (but not dispersive) properties in the caloric gauge may be transferred to the temporal gauge without any loss, proving as a consequence small data global well-posedness in the temporal gauge. The results in this paper are used in the subsequent papers arXiv:1709.08604, arXiv:1709.08606 to prove the sharp Threshold Theorem in caloric gauge in the trivial topological class, and the dichotomy theorem in arbitrary topological classes.
Flocking coordination using active leader and local information

In this paper coordination of a group of agents by a coordinator agent, called the leader‐agent (LA), is discussed. Agents have identical finite sensing radii and access only the local information. Inter‐agent interactions bring them together as a multi‐agent network system. In a recently proposed flocking algorithm using a virtual leader, it is proved that if a fraction of agents are informed then the center of mass of the multi‐agent system tracks the virtual leader. The minimum number of the fraction is always greater than one. In this paper the only informed agent is the LA. Interaction functions are defined to make the model of the multi‐agent system suitable for the design of the coordination control algorithm. The leader‐agent accesses its local data and actively plans its motions through a nonlinear control method. It is proven in this paper that the multi‐agent system tracks the virtual leader and a locally defined point near the LA converges to the position of the virtual leader. It is also shown that in this case, center of mass of the multi‐agent system follows the virtual leader but with a finite distance. We have also discussed positive effects of the LA on network connectivity. Finally illustrative examples are added as well. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
The non-stationary hysteresis phenomenon in shock wave reflections

Abstract The non-stationary transition from Mach to regular reflection followed by a reverse transition from regular to Mach reflection is investigated experimentally. A new experimental setup in which an incident shock wave reflects from a cylindrical concave surface followed by a cylindrical convex surface of the same radius is introduced. Unlike other studies that indicate problems in identifying the triple point, an in-house image processing program, which enables automatic detection of the triple point, is developed and presented. The experiments are performed in air having a specific heats ratio 1.4 at three different incident-shock-wave Mach numbers: 1.2, 1.3 and 1.4. The data are extracted from high-resolution schlieren images obtained by means of a fully automatically operated shock-tube system. Each experiment produces a single image. However, the high accuracy and repeatability of the control system together with the fast opening valve enables us to monitor the dynamic evolution of the shock reflections. Consequently, high-resolution results both in space and time are obtained. The credibility of the present analysis is demonstrated by comparing the first transition from Mach to regular reflection ( $\mathrm{MR} \rightarrow \mathrm{RR} $ ) with previous single cylindrical concave surface experiments. It is found that the second transition, back to Mach reflection ( $\mathrm{RR} \rightarrow \mathrm{MR} $ ), occurs earlier than one would expect when the shock reflects from a single cylindrical convex surface. Furthermore, the hysteresis is observed at incident-shock-wave Mach numbers smaller than those at which the dual-solution domain starts, which is the minimal value for obtaining hysteresis in steady and pseudo-steady flows. The existence of a non-stationary hysteresis phenomenon, which is different from the steady-state hysteresis phenomenon, is discovered.
Design of high-density electron spin-polarized test masses

We present a method of designing test masses with a high density of electron spins for use in mechanical experiments searching for weak spin interactions. Nested arrangements of rare-earth permanent magnets are shown to achieve spin densities of order 1024spins kg−1 together with stray magnetic fields at negligible levels. A full magnetostatic analysis of the proposed designs is presented, the mechanical feasibility is analyzed and the related manufacturing issues are addressed.
Itô vs Stratonovich in the presence of absorbing states

It is widely assumed that there exists a simple transformation from the Ito interpretation to the Stratonovich one and back for any stochastic differential equation of applied interest. While this transformation exists under suitable conditions, and transforms one interpretation into another at the price of modifying the drift of the equation, it cannot be considered universal. We show that a class of stochastic differential equations, characterized by the presence of absorbing states and of interest in applications, does not admit such a transformation. In particular, formally applying this transformation may lead to the disappearance of some absorbing states. In turn, this modifies the long-time, and even the intermediate-time, behavior of the solutions. The number of solutions can also be modified by the unjustified application of the mentioned transformation, as well as by a change in the interpretation of the noise. We discuss how these facts affect the classical debate on the Ito vs Stratonovich dilemma.
Exploring the Full Stellar Population of the Upper Scorpius OB Association

We investigate the stellar population and star formation history of the Upper Scorpius OB association, the most nearby region of recent massive star formation, over the full stellar mass range from 0.1 to 20 M⊙. The first part of this paper describes an extension of our large spectroscopic survey (Preibisch et al., published in 2001) for low-mass pre–main-sequence (PMS) stars in Upper Scorpius. Using the multiobject spectrograph 2dF at the Anglo-Australian Telescope, we obtained spectra of 469 stars with magnitudes R = 12.5–18.0 in a 6 deg2 area. Among these, we find 68 new PMS stars, nearly all of them M-type stars, by their strong lithium absorption lines. The total area covered by our 2dF survey is now 9 deg2 and contains 166 new PMS stars. Combining these results with our earlier investigation (Preibisch & Zinnecker) yields a sample of 250 PMS stars in the mass range ∼0.1 to ∼2 M⊙. The location of these stars in the HR diagram suggests a mean age of 5 Myr without a significant age spread. In the second part of this paper, we also consider the population of 114 high-mass members identified in detailed Hipparcos studies. We construct a combined HR diagram for the 364 high- and low-mass members and find that the whole stellar population is very well characterized by a very narrow age distribution around 5 Myr. We estimate individual masses for all members and construct an empirical mass function covering the mass range from 0.1 up to 20 M⊙. A power-law fit to the mass function gives a slope of α ∼ -2.6 above ∼2 M⊙ and a much flatter slope (α ∼ -0.9) below ∼0.6 M⊙. The initial mass function of Upper Sco is not identical, but within the errors consistent with recent determinations of the field initial mass function. There is certainly no deficit of low-mass stars in the Upper Sco OB association, but rather a small excess of low-mass stars. Our results on the stellar age distribution confirm earlier indications that the star formation process in Upper Sco was triggered and support previous conjectures that the triggering event was a supernova shock wave originating from the nearby Upper Centaurus–Lupus association.
Modular representation theory in type A via Soergel bimodules

In this paper we express certain multiplicities in modular representation-theoretic categories of type A in terms of affine p-Kazhdan-Lusztig polynomials. The representation-theoretic categories we deal with include the categories of rational representations of GL(n), representations of the quantum group for gl(n), and representations of (degenerate) cyclotomic Hecke and Schur algebras, where the base field is an algebraically closed field of arbitrary prime characteristic. In order to approach this problem we define Soergel-theoretic versions of parabolic categories O in characteristic p. We show that these categories have many common features with the classical parabolic categories O; for example, they are highest weight. We produce a homomorphism from a (finite or affine) type A 2-Kac-Moody category to the diagrammatic version of the category of singular Soergel bimodules (again, of finite or affine type A). This leads to a categorical Kac-Moody action on the Soergel-theoretic categories O. Then we relate the representation-theoretic categories to Soergel-theoretic ones by proving a uniqueness result for highest weight categorical actions on Fock spaces.
Increase in surface albedo caused by agricultural plastic film

The area of agricultural greenhouses and cropland covered by plastic film has increased in China over the past three decades. Construction of large‐area plastic greenhouse potentially changes the physical and radiative properties of the surface and its albedo, thereby potentially affecting the surface energy budget and climate change. This study aims to investigate the effect of the plastic‐film cover on surface albedo based on computations with a simplified model and several field observation experiments. The results showed that surface albedo increased by ∼23.5 and ∼33.9% on clear and overcast days, respectively, if grassland was covered by plastic film. Surface albedo of bare soil covered by plastic film increased by ∼16.6% under clear sky conditions. A larger increase in surface albedo was derived for surface types with smaller surface albedo. Model calculations were in good agreement with field observations.