Miracle-dz/UniFAR-FTUs huggingface dataset:
Size-, shape-, and position-controlled GaAs nano-whiskers

We have developed a technique for the synthesis of size-selected, GaAs, epitaxial nano-whiskers, grown on a crystalline substrate. As catalysts, we used size-selected gold aerosol particles, which enabled us to fully vary the surface coverage independently of the whisker diameter. The whiskers were rod shaped, with a uniform diameter between 10 and 50 nm, correlated to the size of the catalytic seed. Furthermore, by the use of nano-manipulation of the aerosol particles by means of atomic force microscopy, we can nucleate individual nano-whiskers in a controlled manner at specific positions on a substrate with accuracy on the nm level.
An extended fisher criterion for feature extraction ‐ Malina's method and its problems

In the discussion of the two-class feature extraction problem in pattern recognition, Malina [7] proposed recently a new criterion for overcoming the defects of Fisher's criterion. the discussion in this paper focuses on the effectiveness of Malina's criterion and at the same time points out the problem in his feature extraction method, indicating how to avoid the difficulties. First, no clear definition is made in Malina's method for the coordinate system in the feature space, and the coordinate system used is not optimal. Second, the eigenvalue problem must be solved including the solution of inverse matrix in order to determine the feature axis. For the first problem, this paper points out tha the coordinate axis di and dj in the coordinate system in Malina's method satisfies diTdj = 0, where is the sum of covariance matrices in the class. Then the optimal coordinate system from that viewpoint is given. For the second problem, the inverse matrix is eliminated by performing a certain transformation (A-1 transformation) to the coordinate system of the original pattern space. the validity of A-1 transformation is shown by the invariance of the distances among classes, and it is shown that the above optimal coordinate system under A-1 transformation is the optimal orthogonal coordinate system satisfying diTdj = 0, i j. Finally, Malina's criterion is extended to the multiclass case and the problems are discussed.
Asymptotic normality of the maximum-likelihood estimator for general hidden Markov models

Hidden Markov models (HMMs) have during the last decade become a widespread tool for modeling sequences of dependent random variables. Inference for such models is usually based on the maximum-likelihood estimator (MLE), and consistency of the MLE for general HMMs was recently proved by Leroux. In this paper we show that under mild conditions the MLE is also asymptotically normal and prove that the observed information matrix is a consistent estimator of the Fisher information.
Spectral Budget Analysis of the Short-Range Forecast Error of the NMC Medium-Range Forecast Model

Abstract The budget of the systematic component of the short-range forecast error in the National Meteorological Center's Medium-Range Forecast Model (NMC MRF) is examined. The budget is computed for the spectral coefficients and the variances of vorticity, divergence, virtual temperature, and specific humility at every time step during the 24-h model integration. Two months in winter and three months in summer, totaling 150 cases, were integrated with the budget diagnostics. The results of the budget of the spectral coefficients—that is, the budget of mean error—showed compensation among large terms except near the model boundary; therefore, it is difficult to point to a significant source of the systematic error in the free atmosphere. Near the model lower boundaries, dynamics cannot fully compensate physical forcing, and estimation of some physical processes responsible for the mean errors is possible. In contrast, the budget of the variance of the coefficients—that is, the energy budget—is more intere.
Correcting ocular aberrations with a high stroke deformable mirror

The capabilities of a novel deformable mirror to correct ocular aberrations are analyzed. The deformable mirror, (MIRAO52 Imagine Eyes) is incorporated within a complex retinal imaging system able to produce simultaneous en-face optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) images of the retina. The performances of the deformable mirror have been examined by evaluating the amount of aberrations which the deformable mirror is able to correct for, the improvement in the signal-to-noise ratio and transversal resolution in both OCT and SLO images obtained from an artificial eye. Pairs of C-scan images were obtained at a frame rate of 2 Hz, with and without wave-front correction. The correction of aberrations increased the signal-to-noise ratio in images obtained from artificial eyes by up to 6 dB in the OCT channel and up to 31 dB in the SLO channel. Also, we demonstrated the high capability of the MIRAO52 deformable mirror to correct for high amounts of wave-front aberrations.
Turbulence: Challenges for Theory and Experiment

Research in macroscopic classical physics, such as fluid dynamics or aspects of condensed matter physics, continues to confront baffling challenges that are by no means less demanding than those at the post‐Newtonian frontiers of physics that have been explored since the beginning of this century. This is so even though the basic equations of macroscopic classical physics are known—indeed, have been known for centuries in many cases. Chaos and nonlinear dynamics are examples of the topics that pose new challenges to our understanding of macroscopic classical systems. Turbulence, a phenomenon related to but distinct from chaos, and having strong roots in engineering, has been increasingly in the focus of physics research in recent years.
Three directions in research on auditory scene analysis

Research on auditory scene analysis (ASA) began with some simple laboratory phenomena such as streaming and illusory continuity. Subsequently, research has gone in three directions, downwards towards underlying mechanisms (by neurophysiologists), upwards towards system organization (by computer scientists), and sideways towards other species (by neurobiologists). Each direction has its challenges. The downward approach sometimes takes a phenomenon-oriented view of ASA, leading to simple explanations of a single ASA demonstration, such as streaming, with no obvious connection to any larger system. Research done by the upward approach usually takes the form of a computer program to achieve ASA in a working system, often neglecting known facts about human ASA, in favor of mathematically understood principles. The sideways approach often finds that non-human animals can respond to an important sound despite the presence of other interfering sounds. However, there is no reason to believe that a frog, a fish and a human accomplish this by means of the same mechanisms. So finding out how some animal does this, while interesting in its own right, may shed little light on how humans do it. I will describe some properties of the human ASA system that should be borne in mind when manufacturing explanations.Research on auditory scene analysis (ASA) began with some simple laboratory phenomena such as streaming and illusory continuity. Subsequently, research has gone in three directions, downwards towards underlying mechanisms (by neurophysiologists), upwards towards system organization (by computer scientists), and sideways towards other species (by neurobiologists). Each direction has its challenges. The downward approach sometimes takes a phenomenon-oriented view of ASA, leading to simple explanations of a single ASA demonstration, such as streaming, with no obvious connection to any larger system. Research done by the upward approach usually takes the form of a computer program to achieve ASA in a working system, often neglecting known facts about human ASA, in favor of mathematically understood principles. The sideways approach often finds that non-human animals can respond to an important sound despite the presence of other interfering sounds. However, there is no reason to believe that a frog, a fish an.
A new integral equation approach to the Neumann problem in acoustic scattering

We suggest a new approach of reduction of the Neumann problem in acoustic scattering to a uniquely solvable Fredholm integral equation of the second kind with weakly singular kernel. To derive this equation we placed an additional boundary with an appropriate boundary condition inside the scatterer. The solution of the problem is obtained in the form of a single layer potential on the whole boundary. The density in the potential satisfies a uniquely solvable Fredholm integral equation of the second kind and can be computed by standard codes. Copyright © 2001 John Wiley & Sons, Ltd.
Partitioning of turbulent flux reveals contrasting cooling potential for woody vegetation and grassland during heat waves

We compared the capacity of woody versus grassy vegetation covers to buffer high temperatures during heat waves by partitioning turbulent heat between latent (λE) and sensible (H) fluxes, and quantifying advection using the Priestley‐Taylor coefficient (α), for a16‐year old grassland and an adjoining 6‐year old plantation. We found that because λE dominated (>65%) the turbulent flux in the plantation and was at least twice as large as on the grassland (λE< 35% of the turbulent flux) during heat waves, the ambient temperature over the plantation was up to 5 °C lower in the afternoon, and averaged 1.2 °C lower for the whole day, compared with the grassland. Both vegetation covers emitted significant amounts of H when soil water availability was limited and also in winter when canopy cover was mostly inactive because of dormancy in the grassland and mutual shading in the plantation due to low solar angle. During the winter, advection of additional energy from surrounding vegetation suppressed λE and reduced α to <1.0 in both vegetation covers. Advection enhanced λE during periods of frequent rainfalls in summer, with mean α rising to 2.6 in the grassland and 3.4 in the plantation. Consistently low λE but high H made the grassland a source rather than a sink for advective energy, while the plantation was the opposite. The broadleaved evergreen woody vegetation consistently maintained a larger λE than the grassland in this mid‐latitude environment, contrary to the smaller λE observed over mostly coniferous forests at high (northern) latitudes (>35°). Annual evapotranspiration was 54% lower from the grassland (384 mm) than from the plantation (834 mm). Woody vegetation covers dominated by broadleaved species are therefore preferred for buffering extreme high temperatures during heat waves and recommended for rehabilitating degraded landscapes in urban areas. We also present functions for approximating α for soil water limited conditions.
STREAMLINE UPWIND SCHEME FOR THE SEGREGATED FORMULATION OF THE NAVIER-STOKES EQUATION

A finite-element method has been developed that combines the segregated velocity-pressure equal-order formulation of the Navier-Stokes equation originated from the SIMPLE algorithm and the streamline upwind Petrov-Galerkin weighted residual method. To verify the proposed finite-element method, driven cavity flow and backward-facing step flow have been considered. The present results are compared with existing experimental results using laser Doppler velocimetry and numerical results using the finite-difference method and the velocity-pressure integrated, mixed-order interpolation method. It has been shown that the present method gives accurate results with less memory and execution time than the conventional finite-element method.
The asymmetric distribution of satellite galaxy velocities

Companion galaxies tend to have redshifts that exceed that of their associated primary. We show that the latest sample of satellite galaxies (from Zaritsky et al.) corroborates this assertion. We examine whether selection biases and contamination by galaxies that are not physical satellites can create the observed velocity asymmetry. As shown by Valtonen and Byrd (1986) for previous samples, simple models of the selection process reproduce the sense of the asymmetry, but not its magnitude unless the samples are dominated by interlopers. We expand on this model by using numerical simulations that include a simple model of galaxy clustering, and demonstrate that clustering can increase the magnitude of the expected asymmetry for a particular level of contamination. Depending on input assumptions, these models imply 1 sigma lower limits on the contamination level in the Zaritsky et al. (1992) sample of between 8 and 20 percent. Using the results from the analysis of that sample and the models, we conclude that, for the type of satellite galaxy sample discussed, here, a moderate level of contamination (about 10 percent) is sufficient to account for the observed asymmetry.
Estimation and Modeling of Enceladus Plume Jet Density Using Cassini Flight Data

After an interplanetary cruise of almost seven years, the Cassini spacecraft arrived at Saturn on 30 June 2004. In 2005, Cassini completed three flybys of Enceladus, a small icy satellite of Saturn. Observations made during these flybys confirmed the existence of water vapor plumes in the south polar region of Enceladus. During an Enceladus flyby, plume jets imparted on the spacecraft resulted in small but visible attitude control errors. Using the known and unique transfer function between the disturbance torque and the attitude control error, the disturbance torque could be estimated. Furthermore, given good estimates of the spacecraft’s projected area, center of pressure location, and spacecraft velocity, the time history of the Enceladus plume density could be reconstructed. Next, the density due to each plume jet as a function of both the radial distance of the spacecraft from the plume source and the angular distance of the spacecraft from the axis of symmetry of the jet was modeled. By comparing th.
Topologically clustering: a method for discarding mismatches

Wide baseline stereo correspondence has become a challenging and attractive problem in computer vision and its related applications. Getting high correct ratio initial matches is a very important step of general wide baseline stereo correspondence algorithm. Ferrari et al. suggested a voting scheme called topological filter in [3] to discard mismatches from initial matches, but they didn't give theoretical analysis of their method. Furthermore, the parameter of their scheme was uncertain. In this paper, we improved Ferraris' method based on our theoretical analysis, and presented a novel scheme called topologically clustering to discard mismatches. The proposed method has been tested using many famous wide baseline image pairs and the experimental results showed that the developed method can efficiently extract high correct ratio matches from low correct ratio initial matches for wide baseline image pairs.
Prescribing scalar curvatures on the conformal classes of complete metrics with negative curvature

Let (M n , g) be a complete noncompact Riemannian manifold with the curvature bounded between two negative constants. Given a function K on M n , in terms of the behaviors of K at infinite, we give a fairly complete answer to when the K can be the scalar curvature function of a complete metric g 1 which is conformal to g
HIV spread and partnership reduction for different patterns of sexual behaviour ‐ a study with the microsimulation model STDSIM

We studied how sexual behaviour affects population HIV spread simulating stylized risk profiles: (1) prostitution, no short relationships (resembling settings in South‐East Asia); (2) prostitution, concurrent short relationships (resembling South‐America and urban sub‐Saharan Africa); (3) no prostitution, concurrent short relationships (resembling rural sub‐Saharan Africa); (4) prostitution, serial short relationships (a generic low‐risk setting). We explored the impact on HIV prevalence of prevention programs accomplishing postponement of sexual debut, reduction in partner change rate and in prostitution. We described the representation of sexual behaviour in the microsimulation model STDSIM, comparing it to non‐individual‐based models. The profiles generate markedly different time courses of HIV spread. Concentration of risk causes a rapid initial spread (Profiles 1 and 2), whereas the final prevalence depends more on the overall extent of risk behaviour in the general population (highest for Profiles 2 and 3). Effects of partnership reduction are strongly context dependent. Small decreases in numbers of partners reduce HIV spread considerably if they reflect decreases in the contacts of highest risk in that setting. In settings with risk behaviour dispersed over a large part of the population (Profiles 2 and 3), indirect effects can cause the impact on HIV to be disproportionately large compared to the magnitude of behaviour change.
Low‐dimensional I/O modeling of Distributed Parameter Systems

Many model reduction techniques take a semi‐discretization of the original PDE model as starting point and aim then at an accurate approximation of its input/output map. In this contribution, we discuss the direct discretization of the i/o map of the original infinite‐dimensional system. First, the input and output signals are discretized in space and time, second, the system dynamics are approximated in form of the underlying evolution operator, leading to an approximated i/o map with matrix representation. The discretization framework, corresponding error estimations, a SVD‐based system reduction method and a numerical application in an optimization problem are presented for the example of a linear time‐invariant heat equation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An evaluation of the Confidence Removal Goal approach for making remediation decisions at Superfund sites

The Confidence Removal Goal approach was developed by the Gradient Corporation for the cleanup decisions at the METCOA Superfund Site. The CRG approach is a statistical approach to meet site cleanup goals based on the arithmetic mean of the contaminant concentration distribution. The CRG approach involves computing a threshold value c* (called the CRG value) from observed sample values in cases where the data distribution is log‐normal and the UCL of the population mean calculated for the sample exceeds the Cleanup Goal (CUG). The cleanup would then consist of removing all soils from the site with observed concentrations higher than the CRG value c*. At the METCOA site, the cadmium (Cd) and nickel (Ni) concentrations passed the test of log‐normality, and the UCL of the means exceeded their respective CUG values. The CRG values were then computed for observed Cd and Ni concentrations. In both cases, the CRG values turned out to be much higher than the respective observed maximum concentration. Based on these CRG values, it would appear that no cleanup would be needed at the METCOA site. A Monte Carlo simulation experiment was conducted by two of the authors of this article to investigate the performance of the CRG approach. The simulation experiments showed that the CRG approach had a rather high percentage of false negatives, i.e. it recommended no cleanup a large number of times when the simulation was performed for contaminated site conditions. The present article investigates the performance of the CRG approach for normal, uniform and exponential distributions, in addition to the log‐normal distribution. The CRG approach gives reasonable results for all models considered in this article, except for the log‐normal model, suggesting the inadequacy of the log‐normal distribution for modeling skewed environmental data. Copyright © 2002 John Wiley & Sons, Ltd.
The ablation dominated polymethylmethacrylate arc

High current density ( approximately 104 A cm-2) AC arcs in long confining tubes have been investigated experimentally and theoretically. A uni-dimensional arc model based on simplifying assumptions has been presented. The main energy transfer mechanism is via radiation to the bore surface, resulting in the heating, ablation and ionisation of the (C5H8O2) which becomes the main plasma source. The ablation results in high measured pressures ( approximately 100 bars) in the tube central stagnation zone. It is shown that a two-zone arc develops, namely a hot core and a cooler sheath. Semi-empirical scaling formulae linking current density with field gradient, core temperature, sheath temperature and pressure have been derived. Effects of turbulence on the arc model are discussed.
Filter Bank Methods for Hyperbolic PDEs

We use biorthogonal filter banks to solve hyperbolic PDEs adaptively with a sparse multilevel representation of the solution. The methods described are of finite difference type, and the filter banks are used to give a sparse representation of signals and to transform between grids on different scales. We derive bounds for the error and number of coefficients in the sparse representation. These bounds also apply for filter banks that are not associated with any wavelets. We develop algorithms for fast differentiation and multiplication in detail. The strength of the method is shown in various test problems.
Latitude Migration of Sunspot Groups

Characteristics of latitude migration of sunspot groups in the northern and southern hemispheres are investigated by using the Royal Greenwich Observatory data set from the years 1874 through 1999. Latitude migration of sunspot groups is found to be represented by a binomial formula, which quantitatively describes the Spörer law. Latitude migration velocity of sunspot groups is largest at the beginning of a solar cycle, and as the solar cycle progresses, it decreases with time, with an average of about 1. °6 yr-1 during a solar cycle. Two different methods have been employed to confirm that latitude migration in both hemispheres is statistically the same.
Optimal allocation to maximize the power of two-sample tests for binary response

We study allocations that maximize the power of tests of equality of two treatments having binary outcomes. When a normal approximation applies, the asymptotic power is maximized by minimizing the variance, leading to a Neyman allocation that assigns observations in proportion to the standard deviations. This allocation, which in general requires knowledge of the parameters of the problem, is recommended in a large body of literature. Under contiguous alternatives the normal approximation indeed applies, and in this case the Neyman allocation reduces to a balanced design. However, when studying the power under a noncontiguous alternative, a large deviations approximation is needed, and the Neyman allocation is no longer asymptotically optimal. In the latter case, the optimal allocation depends on the parameters, but is rather close to a balanced design. Thus, a balanced design is a viable option for both contiguous and noncontiguous alternatives. Finite sample studies show that a balanced design is indeed generally quite close to being optimal for power maximization. This is good news as implementation of a balanced design does not require knowledge of the parameters. Copyright 2012, Oxford University Press.