Miracle-dz/UniFAR-FTUs huggingface dataset:
The Integrated Effect of Condensation in Numerical Simulations of Extratropical Cyclogenesis

Abstract By combining traditional sensitivity studies with techniques that focus on the conservation and invertibility properties of Ertel's potential vorticity (PV), we illustrate the effect of latent heating on the structure and evolution of three simulated extratropical cyclones. The cases include one continental cyclone development (15 December 1987), which we examine extensively, and two cyclones over the western Atlantic Ocean (6 January 1983 and 5 January 1985) of somewhat greater intensity, which are diagnosed to assess the generality of our findings for the continental case. Each storm featured a weaker cyclonic low-level circulation when latent heating was removed from the simulation, but the magnitude of the effect varied greatly. In all cases, the difference in intensity was attributed to velocities associated with a positive, condensation-produced PV anomaly above the warm front. The amplification of the surface thermal perturbations was not strongly altered in even the case most affected by .
Towards the Erdős-Gallai Cycle Decomposition Conjecture

In the 1960’s, Erdős and Gallai conjectured that the edges of any n-vertex graph can be decomposed into O(n) cycles and edges. We improve upon the previous best bound of O(n loglogn) cycles and edges due to Conlon, Fox and Sudakov, by showing an n-vertex graph can always be decomposed into O(n log⋆ n) cycles and edges, where log⋆n is the iterated logarithm function. Our arguments make use and further develop the theory of robust sublinear expander graphs.
The partition function modulo prime powers

Let (cid:2) ≥ 5 be prime, let m ≥ 1 be an integer, and let p ( n ) denote the partition function. Folsom, Kent, and Ono recently proved that there exists a positive integer b (cid:2) ( m ) of size roughly m 2 such that the module formed from the Z /(cid:2) m Z -span of generating functions for p (cid:2) (cid:2) b n +124 (cid:3) with odd b ≥ b (cid:2) ( m ) has ﬁnite rank. The same result holds with “odd” b replaced by “even” b . Furthermore, they proved an upper bound on the ranks of these modules. This upper bound is independent of m ; it is (cid:4) (cid:2) +1224 (cid:5) . In this paper, we prove, with a mild condition on (cid:2) , that b (cid:2) ( m ) ≤ 2 m − 1. Our bound is sharp in all computed cases with (cid:2) ≥ 29. To deduce it, we prove structure theorems for the relevant Z /(cid:2) m Z -modules of modular forms. This work sheds further light on a question of Mazur posed to Folsom, Kent, and Ono.
Detection of interstellar nitrogen sulfide

We report the detection and positive identification of interstellar NS. We observed emission toward Sgr B2 from the J=5/2$Yields$3/2 $sup 2$Pi$sub 1$/ $sub 2$ c-state (115.16 GHz) and d-state (115.6 GHz) transitions of $sup 14$N$sup 32$S. The NS column density is approx.10$sup 14$ cm$sup -2$ derived from statistical equilibrium calculations. We have compared the NS results with other sulfur-containing molecules. (AIP)
STABLE BUNDLES WITH $ c_1 = 0$ ON RATIONAL SURFACES

For an arbitrary rational surface the author proves the existence of a nonempty component of the moduli variety of rank bundles with and in which the -stable bundles constitute a nonempty open subset for any ample . Moreover, any birational isomorphism of surfaces gives rise to a birational isomorphism . Bibliography: 9 titles.
Coherent source imaging and dynamic support tracking for inverse scattering using compressive MUSIC

The goal of this paper is to develop novel algorithms for inverse scattering problems such as EEG/MEG, microwave imaging, and/or diffuse optical tomograpahy, and etc. One of the main contributions of this paper is a class of novel non-iterative exact nonlinear inverse scattering theory for coherent source imaging and moving targets. Specifically, the new algorithms guarantee the exact recovery under a very relaxed constraint on the number of source and receivers, under which the conventional methods fail. Such breakthrough was possible thanks to the recent theory of compressive MUSIC and its extension using support correction criterion, where partial support are estimated using the conventional compressed sensing approaches, then the remaining supports are estimated using a novel generalized MUSIC criterion. Numerical results using coherent sources in EEG/MEG and dynamic targets confirm that the new algorithms outperform the conventional ones.
The importance of Grüneisen parameters in developing interatomic potentials

We show that three representative interatomic potential functions for Si fail to describe properly the Gruneisen parameters γn, although one model is able to give a satisfactory account of the thermal expansion coefficient, α, by virtue of a fortuitous cancellation of errors in γn for the acoustic and optic modes. This suggests that in developing robust interatomic potentials intended to predict the thermomechanical behavior of crystals, the database used in parameter adjustment should include the fundamental quantities, γn, rather than the composite quantity α.
A 4-color theorem for toroidal graphs

It is well known that any graph imbedded in the torus has chromatic number at most seven, and that seven is attained by the graph K7. In this note we show that any toroidal graph containing no triangles has chromatic number at most four, and produce an example attaining this upper bound. The results are then extended for arbitrary girth.
OBSERVING WATER-SURFACE TEMPERATURES AT SEA1

Abstract SYNOPSIS This paper is largely a summary of water-surface temperature comparisons by the author on a winter-time West Indies cruise of The R. M. S. Empress of Britain. An attempt was made to determine the accuracy of observational methods under a great variety of conditions, including the most trying ones likely to be experienced. Temperatures obtained nearly simultaneously (1) from a low deck with a 2 or 4 quart tin bucket by quick dips forward of the ship's main outtakes and (2) aft in the propellor wash, and (3) in the discharge from faucets attached to the condenser intake pumps, were consistent always within 0.25° F. , and differed, on the average, but 0.1°F. Reliable results are evidently procurable from the stern, where “surface” observations may, perhaps, most accurately and readily be made in cold windy weather. A record from the condenser intake pipe appears truly representative of the surface temperatures under virtually all conditions. The condenser intake temperature recorded by engin.
Destruction of islands of stability

We describe the changes and the destruction of islands of stability in four dynamical systems: (a) the standard map, (b) a Hamiltonian with a cubic nonlinearity, (c) a Hamiltonian with a quartic nonlinearity and (d) the Sitnikov problem. As the perturbation increases the size of the island increases and then decreases abruptly. This decrease is due to the joining of an outer and an inner chaotic domain. The island disappears after a direct (supercritical) or an inverse (subcritical) bifurcation of its central periodic orbit C. In the first case, when C becomes unstable, a chaotic domain is formed near C. This domain is initially separated from the outer `chaotic sea' by KAM curves. But as the perturbation increases the inner chaotic domain grows outwards, while the outer `chaotic sea' progresses inwards. The last KAM curve is destroyed by forming a cantorus and the two chaotic domains join. But even then the escape of orbits through the cantorus takes a long time (stickiness effect). In the inverse bifurcation case the island around the central orbit is limited by two equal period unstable orbits. As the perturbation changes these two orbits approach and join the central orbit, that becomes unstable. Then the island disappears but no cantori are formed. In this case the stickiness is due to the delay of deviation of an orbit from the unstable periodic orbit when its eigenvalue is not much larger than 1.
Stabilization of Linear Systems by Noise

It is proved that the biggest Lyapunov number $\lambda _{\max } $ of the system $\dot x = (A + F(t))x$, where A is a fixed $d \times d$ matrix and $F(t)$ is a zero mean strictly stationary matrix-valued stochastic process, satisfies ${1 / d}$ trace $A \leqq \lambda _{\max } $. On the other hand, for each $\varepsilon > 0$ there is a process $F(t)$ for which $\lambda _{\max } \leqq {1 / d}$ trace $A + \varepsilon $. In particular, the system $\dot x = Ax$ can be stabilized by zero mean stationary parameter noise if and only if trace $A < 0$. The stabilization can be accomplished by a one-dimensional noise source. The results carry over to the case where A is a stationary process. They are also true for $F(t) = $ white noise.
A new horizon for hexagonal boron nitride film

Growth of hexagonal boron nitride (hBN), an isomorph of graphene/graphite, has been highlighted due to its highly insulating and transparent properties, in parallel with highly-conducting graphene counterpart, which could be useful for numerous applications. Nevertheless, difficulty arises from the absence of robust synthesis methods that provide large-area and high-quality hBN with controlled number of layers. In this article, we review the recent development for the synthesis of hBN with various approaches including liquid-metal, ultra-high-vacuum chemical vapor deposition (UHVCVD), and low-pressure CVD (LPCVD) methods. Its fundamental physical and chemical properties and its potential applications are further discussed. We expect that our comprehensive overview of the synthesis method of hBN will provide a route to find an ultimate method of synthesizing large-area and high-quality hBN with controlled number of layers.
Novel locomotion via biological inspiration

Animal behavioral, physiological and neurobiological studies are providing a wealth of inspirational data for robot design and control. Several very different biologically inspired mobile robots will be reviewed. A robot called DIGbot is being developed that moves independent of the direction of gravity using Distributed Inward Gripping (DIG) as a rapid and robust attachment mechanism observed in climbing animals. DIGbot is an 18 degree of freedom hexapod with onboard power and control systems. Passive compliance in its feet, which is inspired by the flexible tarsus of the cockroach, increases the robustness of the adhesion strategy and enables DIGbot to execute large steps and stationary turns while walking on mesh screens. A Whegs™ robot, inspired by insect locomotion principles, is being developed that can be rapidly reconfigured between tracks and wheel-legs and carry GeoSystems Zipper Mast. The mechanisms that cause it to passively change its gait on irregular terrain have been integrated into its hubs for a compact and modular design. The robot is designed to move smoothly on moderately rugged terrain using its tracks and run on irregular terrain and stairs using its wheel-legs. We are also developing soft bodied robots that use peristalsis, the same method of locomotion earthworms use. We present a technique of using a braided mesh exterior to produce fluid waves of motion along the body of the robot that increase the robot's speed relative to previous designs. The concept is highly scalable, for endoscopes to water, oil or gas line inspection.
Complexification of Lambda Length as Parameter for SL(2, C) Representation Space of Punctured Surface Groups

A coordinate‐system called λ‐lengths is constructed for an SL(2, C) representation space of punctured surface groups. These λ‐lengths can be considered as complexification of R. C. Penner's λ‐lengths for decorated Teichmüller spaces of punctured surfaces. Via the coordinates the mapping class group acts on the representation space as a group of rational transformations. This fact is applied to find hyperbolic 3‐manifolds which fibre over the circle.
Bifurcation and convergence of particle swarm optimization dynamics embedded into upper and lower bound

In this paper, we propose two types of dynamics of Particle Swarm Optimization (PSO) embedded into upper and lower bounds, which have more powerful abilities of searching the global optimal solution on their bounded constraints. The new type of dynamics called "nonlinear operator model" and "nonlinear variable transformation model" are inertial models, which are introduced by discretizing the convolution integral form on continuous time. After certifying stability and/or instability including chaos of dynamics by the bifurcation diagrams, the infuences of model parameters settings on the global search are investigated to achieve better performance than the orthodox PSO dynamics in copmutational simulations for a few benchmark objective functions.
Surface enhanced Raman scattering and localized surface plasmon resonance of nanoscale ultrathin films prepared by atomic layer deposition

An approach was proposed to characterize nanoscale ultrathin films using surface enhanced Raman scattering (SERS). Raman spectroscopy of the TiO2 film as thin as ∼2 nm, which was prepared by atomic layer deposition, was obtained by depositing a nanostructured Au layer on the film surface. Red-shift in the extinction spectrum of the nanostructured Au layer was observed with increasing TiO2 film thickness, ascribed to the increase in effective refractive index of the substrate slab and coupled plasmon resonance. This SERS technique can be applied to investigate a variety of solid-state ultrathin films in nanosclae materials and devices in future studies.
Tropical Circulations Associated with Southwest Monsoon Onset and Westerly Surges over the South China Sea

Abstract The earliest onset of the Asian summer monsoon occurs in early to middle May over the South China Sea. This onset is signified by the development of low-level westerlies and leads to heavy convective rainfall over southern China (pre-Mei-Yu). In June, low-level westerly surges over the northern South China Sea are associated with the Mei-Yu rainfall system in the Yangtze region and southern Japan. In this work, the ECMWF data for 1981–86 are used to study the tropical circulations associated with the development of low-level westerlies during both events. Composites of horizontal wind, geopotential height, moisture, and vertical velocity during six May onsets and nine June surges, respectively, indicate that both events occur with the approach of a midlatitude trough–front system. The possible triggering of the South China Sea summer monsoon onset by the midlatitude system may explain why the South China Sea onset occurs prior to other regions of the Asian monsoon. During boreal spring, this is t.
High power coupled ridge waveguide semiconductor laser arrays

Using index‐guided ridge waveguide structures, we have obtained single‐lobe far‐field pattern from coupled multiple‐stripe semiconductor laser arrays. A stable far‐field pattern has been observed up to 250‐mW peak pulsed power. This desired performance of a semiconductor laser array is achieved by intentional pumping of a laser array at coupling regions, which is possible in ridge waveguide structures.
Clumped X-ray emission around radio galaxies in Abell clusters

We have made a comparison of the X-ray and radio morphologies for a sample of 41 rich cluster fields using Einstein Observatory Imaging Proportional Counter (IPC) and Very Large Array (VLA) 20 cm images. Surprisingly, we find that 75% of the radio galaxies have a statistically significant X-ray peak or subclump within 5 min of the radio galaxy position. The X-ray luminosity and the generally extended nature of the X-ray subclumps suggest that these subclumps are overdense regions emitting free-free radiation, although there is also evidence for Active Galactic Nuclei (AGN) X-ray emission coming from some of the more compact, high surface brightness X-ray peaks. Some interesting correlations with radio morphology were also discovered. For clusters which contain wide-angle-tailed radio sources associated with centrally dominant galaxies, there are significant elongations or clumps in the central X-ray emission which are unusual for this type of cluster. We suggest that cluster radio galaxies are pointers to particular clusters or regions within clusters that have recently undergone mergers between cluster subsystems.
Thermal lensing effects in small oxide confined vertical-cavity surface-emitting lasers

The thickness and position of an oxide layer inside a vertical-cavity surface-emitting laser structure have been optimized for minimum optical scattering loss. In the resulting structure, the index guiding provided by the oxide aperture is very small. Consequently, for an oxide aperture radius <2 μm, the optical mode is only weakly confined. In devices using such small apertures, the formation of a thermal lens has a strong influence on optical guiding. The thermal lens leads to lower threshold currents and increased differential efficiency with continuous wave as compared to pulsed injection operation in devices with small apertures.
Influence of grain size on the transformation temperature of C49 TiSi2 to C54 TiSi2

Titanium disilicide exists in two possible crystallographic structures: the C49 (ZrSi2) structure and the C54 structure. At low annealing temperatures (400–650 °C), the C49 TiSi2 phase is formed. It transforms to the C54 phase at annealing temperatures between 650–800 °C. The transformation temperature (Ttr), however, appears to be influenced by the microstructure of the C49 phase. This is concluded from the observed difference in Ttr for TiSi2 thin films with varying average grain sizes.
Numerical solution of Space Shuttle Orbiter flow field

The supersonic, viscous laminar flow around the Space Shuttle Orbiter forebody has been computed with a parabolized Navier-Stokes code using a generalized coordinate transformation. The initial solution for the nose part of the Orbiter geometry was obtained with a three-dimensional time-dependent Navier-Stokes solver. It was necessary to employ a wind axis oriented coordinate system to obtain the initial solution with the time-dependent code. The generalized PNS technique used in this study allows the solution to be marched from the given initial data surface to any desired surface downstream. A grid point clustering scheme was employed to accurately describe the body shape by clustering points at the wing tip and at the wing body juncture. The computed heat transfer coefficients, pressure coefficients, and shock shapes are compared with the available experimental data for 0 degrees and 30 degrees angle of attack.
A model for tidally driven eccentric instabilities in fluid disks

Observations and simulations of superhump phenomena in close binary star systems and observations and previous studies of eccentric planetary rings, such as the rings of Uranus, indicate that eccentric instabilities occur in disks and rings. The eccentric stability of a fluid disk or ring in the presence of the tidal field of a comparison object which is in circular orbit is investigated. The disk can have pressure, viscosity, and self-gravity.
Culture-MERIS: an ESA weekly service for agriculture

The European Space Agency (ESA) has initiated a free and open service providing weekly surface reflectance composites for Europe and Africa. The project is named Culture-MERIS and targets land activities for agriculture and food security user communities. The Culture-MERIS demonstration products are based on data from Envisat's Medium Resolution Imaging Spectrometer (MERIS) in full resolution (FR) (300 m), with improved geolocation and atmospheric correction, and are updated every Wednesday, providing information for the full previous week.
Exact method for the simulation of Coulombic systems by spherically truncated, pairwise r−1 summation

Based on a recent result showing that the net Coulomb potential in condensed ionic systems is rather short ranged, an exact and physically transparent method permitting the evaluation of the Coulomb potential by direct summation over the r−1 Coulomb pair potential is presented. The key observation is that the problems encountered in determining the Coulomb energy by pairwise, spherically truncated r−1 summation are a direct consequence of the fact that the system summed over is practically never neutral. A simple method is developed that achieves charge neutralization wherever the r−1 pair potential is truncated. This enables the extraction of the Coulomb energy, forces, and stresses from a spherically truncated, usually charged environment in a manner that is independent of the grouping of the pair terms. The close connection of our approach with the Ewald method is demonstrated and exploited, providing an efficient method for the simulation of even highly disordered ionic systems by direct, pairwise r−1.
Entrainment into Mixed Layers. Part II: A New Closure

Abstract A new entrainment closure for convectively mixed boundary layers, particularly those topped by stratocumulus clouds, is developed and calibrated against results of large eddy simulations carried out by C. -H. Moeng. The closure differs principally in two ways from those developed by J. W. Deardorff, S. Nicholls, and others. The prediction of interface buoyancy flux from its vertical integral is modified by a height-weighting term. This accounts for the greater entrainment produced by buoyancy flux near the cloud top as compared to that generated by surface heating. The relationship between buoyancy flux at the top of a cloud layer and entrainment is reconsidered. Entrainment increases with the “wetness” of the cloud top, which is evidently a function of cloud-top liquid water content and the cloud-top jumps in potential temperature and total water content. This result is related to findings by S. Nicholls and J. D. Turton, though using a somewhat different approach and with different interpretatio.
Computerized Tomography with Unknown Sources

We give a reconstruction method for the attenuation coefficient in a 2D cross section of a 3D object from tomographic data which does not require knowledge of the positions or the intensity of the sources, and the sources may even be inside the object. Such a situation arises in emission computerized tomography. The method is based on consistency conditions in the range of the relevant integral transforms. The paper contains a detailed description of the algorithm and numerical results for computer generated data.
Estimating the state of a noisy continuous time Markov chain when dynamic sampling is feasible

A continuous time Markov chain is observed with Gaussian white noise added to it. To the well-known problem of continuously estimating the current state of the chain, we introduce the additional option of continuously varying the sampling rates, as long as some restriction (or cost) on the average sampling rate is satisfied. The optimal solution to this "dynamic sampling" problem is presented and analyzed in closed form for the two-state symmetric case. It is shown that the resulting dynamic sampling procedure has a much lower asymptotic average error rate compared to the one obtained when sampling at a constant rate. Alternatively, the dynamic sampling procedure can provide the same error rate using a much lower average sampling rate. The relative efficiency of the dynamic sampling procedure may in fact tend to infinity in some extreme cases.
Singular value decomposition for approximate block matching in image coding

The minimum Euclidean distance matching of a 2-D image block can be reorganised, via singular value decomposition, into a set of computations with the block's singular vectors. The first two or three pairs of singular vectors are usually sufficient to achieve a good approximation, calculated with fewer operations than Euclidean matching. Full search motion estimation can be speeded up by at least a factor of 2, with minimal loss of accuracy.