Miracle-dz/UniFAR-FTUs huggingface dataset:
Characterization of Droplets and Vapor Concentration Distributions in Split-Injection Diesel Sprays by Processing UV and Visible Images

Recent experimental studies have shown that with split injection strategy, the soot and NOx emissions from a diesel engine can be reduced significantly in comparison with a conventional non-split injection. To understand the mechanism of emissions reduction, it is essential to clarify the process of mixture formation in the diesel spray. For characterizing the droplets and vapor concentration distributions inside a fuel spray, a dual-wavelength laser absorption-scattering technique (LAS) was developed by using the 2nd harmonic (532nm) and the 4th harmonic (266nm) of an Nd: YAG laser and using dimethylnaphthalene as a test fuel. By applying the ultraviolet-visible LAS imaging technique, the distributions of droplets and vapor concentrations in the spray, which was injected into a high-temperature and high-pressure nitrogen ambient in a constant volume vessel by a common-rail diesel injection system, were measured and quantitatively analyzed. The effect of injection mass ratio of double-pulse injections on distributions of equivalence ratios of vapor and droplets in the sprays was examined.
Quasi-random classes of hypergraphs

We investigate the relations among a number of different graph properties for k-uniformhypergraphs, which are shared by random hypergraphs. Various graph properties form equivalence classes which in turn constitute a natural hierarchy. The analogues for binary functions on k-tuples and for hypergraphs with small density are also considered. Several classes are related to communication complexity and expander graphs.
Electric fields measured by ISEE‐1 within and near the neutral sheet during quiet and active times

A statistical survey of electric fields observed at 146 neutral sheet crossing events of the ISEE-1 satellite during 1980 has been made. The observations can be divided into two classes-quiet or turbulent-according to the magnitude of the standard deviation in the 3 second spin period sine wave least-squares fit to the electric field data. Events classified as turbulent are also turbulent in the magnetic field. During quiet crossings, the dawn-dusk component of the electric field, E/sub y/, is usually constant to < or =1/2 mV/m, with larger variations sometimes occurring over 2-10 minute time scales. During turbulent crossings, E, fluctuates rapidly with 3-second-average peak-to-peak amplitudes of 2-16 mV/m, and instantaneous field magnitudes up to approx.30 mV/m. Turbulent crossings correlate with high levels of ground magnetic activity as indicated by AE and ground magnetograms and with southward interplanetary magnetic field, while quiet crossings occur primarily during periods of low magnetic activity and northward or mixed interplanetary magnetic field.
On a Likely Shape of the Random Ferrers Diagram

We study the random partitions of a large integern, under the assumption that all such partitions are equally likely. We use Fristedt's conditioning device which connects the parts (summands) distribution to the one of ag-sequence, that is, a sequence of independent random variables, each distributed geometrically with a size-dependent parameter. Confirming a conjecture made by Arratia and Tavare, we prove that the joint distribution of counts of parts with size at mostsn? n1/2(at leastsn? n1/2, resp.) is close? in terms of the total variation distance? to the distribution of the firstsncomponents of theg-sequence (of theg-sequence minus the firstsn? 1 components, resp.). We supplement these results with the estimates for the middle-sized parts distribution, using the analytical tools revolving around the Hardy? Ramanujan formula for the partition function. Taken together, the estimates lead to an asymptotic description of the random Ferrers diagram, close to the one obtained earlier by Szalay and Turan. As an application, we simplify considerably and strengthen the Szalay? Turan formula for the likely degree of an irreducible representation of the symmetric groupSn. We show further that both the size of a random conjugacy class and the size of the centraliser for every element from the class are doubly exponentially distributed in the limit. We prove that a continuous time process that describes the random fluctuations of the diagram boundary from the deterministic approximation converges to a Gaussian (non-Markov) process with continuous sample path. Convergence is such that it implies weak convergence of every integral functional from a broad class. To demonstrate applicability of this general result, we prove that the eigenvalue distribution for the Diaconis? Shahshahani card-shuffling Markov chain is asymptotically Gaussian with zero mean, and variance of ordern? 3/2.
FRACTIONAL HEAT CONDUCTION EQUATION AND ASSOCIATED THERMAL STRESS

ABSTRACT A quasi-static uncoupled theory of thermoelasticity based on the heat conduction equation with a time-fractional derivative of order α is proposed. Because the heat conduction equation in the case 1≤α≤2 interpolates the parabolic equation (α = 1) and the wave equation (α = 2), the proposed theory interpolates a classical thermoelasticity and a thermoelasticity without energy dissipation introduced by Green and Naghdi. The Caputo fractional derivative is used. The stresses corresponding to the fundamental solutions of a Cauchy problem for the fractional heat conduction equation are found in one-dimensional and two-dimensional cases.
Interactive Open-Ended Learning for 3D Object Recognition

The thesis contributes in several important ways to the research area of 3D object category learning and recognition. To cope with the mentioned limitations, we look at human cognition, in particular at the fact that human beings learn to recognize object categories ceaselessly over time. This ability to refine knowledge from the set of accumulated experiences facilitates the adaptation to new environments. Inspired by this capability, we seek to create a cognitive object perception and perceptual learning architecture that can learn 3D object categories in an open-ended fashion. In this context, ``open-ended'' implies that the set of categories to be learned is not known in advance, and the training instances are extracted from actual experiences of a robot, and thus become gradually available, rather than being available since the beginning of the learning process. In particular, this architecture provides perception capabilities that will allow robots to incrementally learn object categories from the set of accumulated experiences and reason about how to perform complex tasks. This framework integrates detection, tracking, teaching, learning, and recognition of objects. An extensive set of systematic experiments, in multiple experimental settings, was carried out to thoroughly evaluate the described learning approaches. Experimental results show that the proposed system is able to interact with human users, learn new object categories over time, as well as perform complex tasks. The contributions presented in this thesis have been fully implemented and evaluated on different standard object and scene datasets and empirically evaluated on different robotic platforms.
High quality preconditioning of a general symmetric positive definite matrix based on its U

A new matrix decomposition of the form A D U T U C U T R C R T U is proposed and investigated, where U is an upper triangular matrix (an approximation to the exact Cholesky factor U0), and R is a strictly upper triangular error matrix (with small elements and the fill-in limited by that of U0). For an arbitrary symmetric positive matrix A such a decomposition always exists and can be efficiently constructed; however it is not unique, and is determined by the choice of an involved truncation rule. An analysis of both spectral and Kcondition numbers is given for the preconditioned matrix M D U T AU 1 and a comparison is made with the RIC preconditioning proposed by Ajiz and Jennings. A concept of approximation order of an incomplete factorization is introduced and it is shown that RIC is the first order method, whereas the proposed method is of second order. The idea underlying the proposed method is also applicable to the analysis of CGNE-type methods for general non-singular matrices and approximate LU factorizations of non-symmetric positive definite matrices. Practical use of the preconditioning techniques developed is discussed and illustrated by an extensive set of numerical examples. © 1998 John Wiley & Sons, Ltd.
A Comparison of Shear- and Buoyancy-Driven Planetary Boundary Layer Flows

Abstract Planetary boundary layer (PBL) flows are known to exhibit fundamental differences depending on the relative combination of wind shear and buoyancy forces. These differences are not unexpected in that shear instabilities occur locally, while buoyancy force sets up vigorous thermals, which result in nonlocal transport of heat and momentum. At the same time, these two forces can act together to modify the flow field. In this study, four large-eddy simulations (LESs) spanning the shear and buoyancy flow regimes were generated; two correspond to the extreme cases of shear and buoyancy-driven PBLs, while the other two represent intermediate PBLs where both forces are important. The extreme cases are used to highlight and quantify the basic differences between shear and convective PBLs in 1) flow structures, 2) overall statistics, and 3) turbulent kinetic energy (TKE) budget distributions. Results from the two intermediate LES cases are used to develop and verify a velocity scaling and a TKE budget mode.
Single-shot dual-polarization holography: measurement of the polarization state of a magnetic sample

In this paper a single-shot digital holographic set-up with two orthogonally polarized reference beams is proposed to achieve rapid acquisition of Magneto-Optical Kerr Effect images. Principles of the method and the background theory for dynamic state of polarization measurement by use of digital holography are presented. This system has no mechanically moving elements or active elements for polarization control and modulation. An object beam is combined with two reference beams at different off-axis angles and is guided to a detector. Then two complex fields (interference terms) representing two orthogonal polarizations are recorded in a single frame simultaneously. Thereafter the complex fields are numerically reconstructed and carrier frequency calibration is done to remove aberrations introduced in multiplexed digital holographic recordings. From the numerical values of amplitude and phase, a real time quantitative analysis of the polarization state is possible by use of Jones vectors. The technique is demonstrated on a magnetic sample that is a lithographically patterned magnetic microstructure consisting of thin permalloy parallel stripes.
On the mirror instability in the presence of electron temperature anisotropy

Computation of the mirror instability growth rate in an ion-electron bi-Maxwellian plasma is revisited, starting from the low-frequency kinetic theory. The role of the electron finite Larmor radius (FLR) effects on the instability quenching is shown to possibly be dominant, even near threshold where the smallest unstable scales significantly exceed the electron gyroscale. Validation of the results by comparison with predictions of the fully kinetic whamp software is also presented. The influence of the electron temperatures on the ion FLR effects very near threshold, where the electron kinetic effects are negligible, is also pointed out.
Compressibility effects on large structures in free shear flows

Space‐time correlations were used to study compressibility effects on large structures in mixing layers. Two high Reynolds number mixing layers with Mc=0.51 (case 1) and 0.86 (case 2) were studied. The results indicate that the structures in case 1 are similar to those in the subsonic case, but less organized. The structures in case 2 are highly three dimensional, with a good spatial but a poor temporal organization. The streamwise correlations showed a decay rate 4 to 5 times greater for case 2 relative to case 1. While the spanwise correlations for case 1 showed trends similar to incompressible mixing layers, the behavior of case 2 was very different. The pressure fluctuations in the fully developed region of case 2 displayed significant rms variation in the spanwise direction with a well‐defined pattern. Based on these measurements, the structures in case 2 seem to be of a horseshoe type, transversely spanning the mixing layer with the head in the low‐speed side and the legs inclined in both the x‐y an.
Quantum chemical contribution to electron neutrino mass determination

Theoretical data have been obtained needed to analyze the experimental measurements of the T2 β-decay energy distribution near the end point. The energies of the six lowest 1∑+ states of HeT+ have been computed for internuclear distances 1.0 ≦4 R ≦ 4.0 bohr. The wavefunctions have been used to calculate the transition probabilities to these states from the electronic ground state of T2. Distribution of the probabilities over the final vibrational and rotational states has been evaluated including rotationally predissociating resonances. Using the stabilization method the 1∑+ resonance states of HeT+ above the ionization limit have been investigated. Preliminary potential energy curves for several of these states have been determined for a wide range of internuclear distances.
BURNETT DESCRIPTION OF STRONG SHOCK WAVES

In 1992 Salomons and Mareschal [Phys. Rev. Lett. 69, 269 (1992)] gave evidence that the Burnett equations can provide an important improvement over the Navier-Stokes equations for shock waves at high Mach numbers. In this Letter we solve the Burnett equations and make a comparison with the results from molecular dynamics, the Navier-Stokes equations, and the theory advanced by Holian et al. [Phys. Rev. E 47, R24 (1993)]. A qualitative analysis of the Burnett equations is also done and some open problems are mentioned.
A Comparison Between the Direct and the Classical Numerical Methods for the Solution of Cauchy Type Singular Integral Equations

Cauchy type singular integral equations can be solved numerically either directly (through the use of an appropriate numerical integration rule and reduction to a system of linear equations) or after a previous reduction to an equivalent Fredholm integral equation of the second kind and application of the numerical technique to this equation. In this note it is proved in the special case when the Gauss-Chebyshev numerical integration rule is used that both methods are equivalent in the sense that they provide the same numerical results for the same number of abscissas used in numerical integrations.
Species identification and measurement of activity in odontocete species of Palmyra Atoll by acoustic monitoring

Acoustic monitoring has been used to study odontocete presence at Palmyra Atoll, a remote island in the Northern Line Islands chain. Long‐term recordings of high‐frequency, broadband acoustic data have become possible with recent technological advances. A High‐frequency Autonomous Recording Package (HARP) has been developed which samples at 200 kHz with a duty cycle of 1/4 for up to seven months. This instrument has recorded since October 2006 at Palmyra Atoll. Visual and acoustic surveys were conducted around Palmyra Atoll using a four‐element towed hydrophone array sampling real‐time at 200 kHz to obtain species‐specific acoustic data. These data are used as reference for automatic detection algorithms applied on the long‐term recordings. To date, acoustically and visually detected odontocetes include bottlenose dolphins (Tursiops truncatus), spinner dolphins (Stenella longirostris), melon‐headed whales (Peponocephala electra) and beaked whales of the genus Mesoplodon. The long‐term HARP data reveal aco.
Experimental Modeling of Gas–Solid Heat Transfer in a Pipe with Various Inclination Angles

Gas–solid flow in a pipe with different configurations (vertical, horizontal, and inclined positions) is studied experimentally. Air with temperature around 170°C and sand particles with mean diameter of 253 μm are used as gas and solid mediums, respectively. Effects of different parameters (pipe slope and solid particles feed rate) are studied on heat transfer rate between gas and solid particles. The Nusselt number decreases at lower solids feed rate in a dilute regime of the mixture; however, it increases at higher solids feed rates. Furthermore, results show that a higher Nusselt number takes place at the angles closer to 45 degrees.
Fundamental structures and asymptotic microlocalization in sheaves of generalized functions

The usual properties of generalized functions are described by means of two fundamental structures. With those structures we can construct in a general way a sheaf Aof differential algebras containing most of the special cases met in the literature. The sheaf properties of Aallow us to define a local and microlocal analysis which generalizes the classical one in the distribution theory.
On the Unimodality of High Convolutions

Abstract : It has been conjectured, for any discrete density function on the integers, that there exists an n sub o such that the n-fold convolution is unimodal for all n or = n sub o. A similar conjecture has been stated for continuous densities. We present several counterexamples to both of these conjectures. As a positive result, it is shown for a discrete density with a connected 3-point integer support that its n-fold convolution is fully unimodal for all sufficiently large n.
Dynamical Lifetimes of Objects Injected into Asteroid Belt Resonances

Numerical simulations of particles placed in orbital resonances in the main asteroid belt show that the typical dynamical lifetimes of objects that could become near-Earth asteroids or meteorites are only a few million years, with the majority destroyed by being transferred to Jupiter-crossing orbits or being driven into the sun. Particles that fortuitously migrate to the terrestrial planet region may be pushed to high-inclination orbits by resonances but are still dynamically eliminated on time scales of ∼10 million years. These shorter lifetimes may require a reassessment of our qualitative understanding about near-Earth asteroids and meteorite delivery.
Evidence for highly localized damage in internal tin and powder-in-tube Nb3Sn strands rolled before reaction obtained from coupled magneto-optical imaging and confocal laser scanning microscopy

Nb3Sn strands for high-current, high-field magnets must be cabled before reaction while the conductor is still composed of ductile components. Even though still in the ductile, deformable state, significant damage can occur in this step, which expresses itself by inhomogeneous A15 formation, Sn leakage or even worse effects during later reaction. In this study, we simulate cabling damage by rolling recent high performance powder-in-tube (PIT) and internal tin (IT) strands in controlled increments, applying standard Nb3Sn reaction heat treatments, and then examining the local changes using magneto-optical imaging (MOI), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). These combined characterizations allow any local damage to the filament architecture to be made clear. MOI directly reveals the local variation of superconductivity while CLSM is extremely sensitive in revealing Sn leakage beyond the diffusion barrier into the stabilizing Cu. These techniques reveal a markedly different response to deformation by the PIT and IT strands. The study demonstrates that these tools can provide a local, thorough, and detailed view of how strands degrade and thus complement more complex extracted strand studies.
Quelques problèmes combinatoires concernant les ordres totaux et les relations monomorphes

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Slow Motions of a Viscous Fluid around Two Spheres

Dean and O'Neill's solution referred to bi-spherical coordinates for the slow motion of a viscous fluid is extended to the general flow with plane symmetry around two spherical obstacles. In particular, the case of two spheres of equal diameter is discussed in detail. The result is first applied to the fluid motion caused by the spheres moving vertically to their line of centres. The drag and couple if the spheres are prevented to rotate, or the drag and angular velocity if they are free to rotate, experienced by each sphere are numerically evaluated and compared with values calculated from corresponding approximate formulae known before. The application is also attempted to the spheres in laminar shear flow.
Resolutivity of ideal boundary for nonlinear Dirichlet problems

We consider a quasi-linear second order elliptic di¨erential equation on a euclidean domain. After developing necessary potential theory for the equation which extends some part of the theories in the book by Heinonen±KilpelaÈinen±Martio, we show that the ideal boundary of the Royden type compacti®cation of the domain is resolutive with respect to the Dirichlet problem for the equation.
A compendium of publicly available Monte Carlo transport codes (including new tools) for the simulation of radiation imaging detectors

Simulations play a vital role in the understanding and analysis of existing and emerging medical imaging tech nologies. Over the last years, Monte Carlo simulations have become increasingly necessary tools for studying the fundamental limitations and for the design and optimization of medical imaging systems. We compare available open-source software packages from the Division of Imaging and Applied Mathematics at the FDA for modeling scintillator- and semiconductor-based radiation imaging detectors for applications in x-ray and nuclear imaging including MANTIS, hybridMANTIS, cartesianDETECT2, and ARTEMIS. We describe the significant features of these packages and discuss their advantages or disadvantages. We also introduce a graphical user interface which greatly facilitates the set up of simple experiments involving scintillator structures with columnar geometries.
The Influence of Near-Surface, High-Entropy Air in Hurricane Eyes on Maximum Hurricane Intensity

Abstract Using a time-dependent axisymmetric numerical model, the authors evaluate whether high-entropy air near the surface in hurricane eyes can substantially increase hurricanes’ maximum intensity. This local high-entropy anomaly is ultimately created by surface entropy fluxes in the eye. Therefore, simulations are conducted in which these surface fluxes are set to zero; results show that the high-entropy anomaly is eliminated, yet the axisymmetric tangential wind speed is only slightly weakened (by ∼4%, on average). These results contradict the hypothesis that transport of high-entropy air from the eye into the eyewall can significantly increase the maximum axisymmetric intensity of hurricanes. In fact, all simulations (with or without high-entropy anomalies) have an intensity that is 25–30 m s−1 higher than Emanuel’s theoretical maximum intensity. Further analysis demonstrates that less then 3% of the total surface-entropy input to the hurricane comes from the eye, and therefore the total magnitude o.