Miracle-dz/UniFAR-FTUs huggingface dataset:
Inherent Numerical Discretization Dilemma Analysis of Euler Equations

Euler equations, derived in 1755, are among the most important equations for general fluid analysis. Although this fundamental governing set of equations looks simple at first glance for incompressible, inviscid fluid flow, it does lead to a crucial numerical discretization dilemma related to existence, uniqueness, stability and oscillation problems. Take gradual pipe expansion flow, for instance: in the process of deriving Euler equations, the seemingly innocent artificial equalization of crosswise and forward-biased streamwise pressure will give serious discretization error compared with use of the Bernoulli equation. Here, the wall pressures, P W = P + dP, disappear from the Euler equations but later bring about troublesome problems, and even violate the fundamental energy principle. Various numerical measures have been devised to overcome such problems, such as artificial viscosity and streamline upwinding, but these are awkward and have high risk of flow field contamination in an attempt to somehow manipulate some energy dissipation when dealing with incompressible fluid flow. In this research, for the sake of finding the real culprit, we re-scrutinize the original derivation of Euler equations and compare the discretized Euler equation with a factorized Bernoulli equation, in order to find the actual pathology that leads to these serious numerical discretization dilemmas with the Euler equations.
Seasonal hydrologic predictions of low‐flow conditions over eastern USA during the 2007 drought

A seasonal streamflow monitoring and forecasting component is implemented into the Drought Monitoring and Prediction System (Luo and Wood, 2007a ), which supplements the existing soil‐moisture‐based analysis framework by providing real‐time streamflow monitoring and forecasting up to 6 months lead time. Evaluations were conducted over four basins in eastern USA to understand the forecast skill of the system for the extensive hydrologic droughts in 2007. Consistent with the agricultural drought forecasts reported by Luo and Wood ( 2007a ), the streamflow subsystem can forecast low‐flow conditions for up to three months in advance, with Brier scores ranging from 0.10 to 0.49. Copyright © 2008 Royal Meteorological Society
Natural transformations of the composition of Weil and cotangent functors

We study geometrical properties of natural transformations TT ∗ → T ∗TA depending on a linear function defined on the Weil algebra A. We show that for many particular cases of A, all natural transformations TT ∗ → T ∗TA can be described in a uniform way by means of a simple geometrical construction.
Static and dynamic effects due to electrostriction in GaN/AlN

A one-dimensional model accounting for electrostriction, lattice mismatch, piezoelectricity, and strain is presented with special emphasis on GaN/AlN heterostructures recently examined extensively in the literature. It is shown that electrostriction, being a second-order effect in the strain–electric field relation, plays a significant, sometimes dominant, contribution subject to DC voltage conditions and externally imposed hydrostatic pressure or AC conditions. It is argued that electrostriction, examined in a three-dimensional model, may give important contributions to the total strain at DC conditions even in the absence of hydrostatic pressure. Model results are based on experimentally reported values for electrostriction coefficients in GaN.
Medical image registration using modified iterative closest points

The closest iterative point (ICP) algorithm is commonly used in medical image registration. However, due to its natural limitation, the processing time and registration accuracy need to be further advanced. In this paper, by computing the moments of the reference and floating images, the centroids are computed and thus the initial translation parameters are obtained. The rotation angles acquired respectively by the second‐order central moments, inertia matrix, Karhunen–Loeve transformation (K‐LT) and singular value decomposition (SVD) are referred to as the initial rotation parameters of the ICP algorithm for image registration. The edges of the reference and floating images are detected by Canny operator and then the binarization images involving the feature points are acquired. The experimental results show that this proposed method has a fairly simple implementation, a low computational load, a fast registration and good registration accuracy. It also can efficiently avoid trapping into the local optimum and is adapted for both mono‐modality and multi‐modality image registrations. Copyright © 2010 John Wiley & Sons, Ltd.
Reflection off a mirror

Electromagnetic radiation incident upon a perfect conductor induces a current density at the surface of the material. This surface current density is the solution of an integral equation, and it is shown that for a flat surface this equation has a very simple solution. The current density at a point of the surface is determined by the incident magnetic field at the same point. The surface current density generates an electromagnetic field, and the total radiation field is the sum of this field and the incident field. It is shown explicitly that inside the material the field of the current density cancels exactly the incident field. The reflected field can be expressed as an integral over the known surface current density, and is therefore determined by the incident magnetic field at the surface only. When the source of the incident field is known, the reflected field can be expressed in terms of a source function, which is determined by the current density of the source. It is shown that this approach leads to a simple way of constructing the mirror image of an arbitrary source, and we illustrate the concept by determining the mirror image of an electric quadrupole.
Improvement of barium strontium titanate solidly mounted resonator quality factor by reduction in electrode surface roughness

Two barium strontium titanate solidly mounted resonators with different bottom electrode surface roughnesses were fabricated and tested. The surface roughness of the bottom electrode was reduced by changing the deposition method of the SiO2 layer in the acoustic Bragg reflector in the solidly mounted resonator. The surface roughness was reduced from 2.81 nm RMS to 1.45 nm RMS. This reduction in the surface roughness contributed to a significant increase in the quality factor of the resonator. The quality factor for the device with a smooth platinum bottom electrode was 110 to 87 over a bias range of 5 to 40 V, and for the device with a rough platinum bottom electrode it was 1 to 31 over the same bias range. The effective electromechanical coupling coefficient was 4% at 40 V and 3.4% at 40 V for the smooth and rough platinum bottom electrodes, respectively.
Multiresolution shape representation without border shifting

The authors show how exact dilations can be used to obtain multiresolution skeletons and how a new multiresolution approach to shape representation can be achieved in terms of such skeletons. In addition to allowing the accurate reconstruction of multiresolution versions of the original binary shapes, the proposed approach is characterised by great simplicity and the important property that the shape borders are not shifted as the smoothing increases.
SAS for Mixed Models

titioners who run experiments and managers looking to maximize information gain per cost. The third chapter also presents ideas about the characteristics of a good response variable. This discussion is well linked to the “measure” phase of Six Sigma and encourages the experimenter to think about how the response is capturing key aspects of the process or product under study. However, the author neglects to mention the broad array of tools available for analyzing more qualitative response variables than those presented. Part II presents many of the standard designs including factorial and fractional factorial designs, and basic response surface designs including blocking, Latin squares, and nested designs. Finally, there is a chapter on evolutionary operation. Interspersed are illustrations of how to use Minitab to construct the designs, as well as templates for particular designs that are useful for recording data. It is interesting that the author chooses to provide both of these options, as it would seem increasingly unusual for practitioners to hand record results in this computer age. The author is careful to avoid statistical jargon in the development and presentation of the designs, which may be a bit disorienting for the seasoned statistician navigating with standard terminology. The conversational style of the book is likely to be appreciated by the practitioner, who will find a very readable, common-sense presentation on the basic design of experiments. Part III analyzes the different designs introduced in the previous section, with a good overview of the goals of standard inference, the differences between the effect of factors on the mean and variance of the responses, and analyses in Minitab. Throughout this section, there are a number of applied examples, and the author makes it easy to connect a selected design in Part II with the corresponding analysis in Part III. Part IV examines three case studies and shows the breadth of tools available for the design and analysis of experiments. Here, careful interpretation of the results are made. These case studies make good illustrations for an undergraduate or graduate level statistics course on design as they show the whole process of experimentation, from response identification, design selection, and implementation to analysis and interpretation. Part V, “Utilization of Empirical Equations,” looks at extensions of design and analysis of experiments with a focus on applying them to quality-related questions. Overall, the book provides a readable, problem-focused look at design of experiments where basic tools for studying the effect of factors on the mean and variance of the response are considered. The absence of statistical jargon will appeal to many practitioners. The scope of the book is limited to more basic designs, Taguchi’s signal-to-noise ratio approaches, and quantitative responses. For the topics that it considers, it is a good reference and connects quality issues to design of experiments effectively.
Modelling Tonal Attraction Between Adjacent Musical Elements

Abstract A context-independent model of tonal attraction is presented based on the formal musical property of interval cycles. An interval cycle is the minimum number of additive iterations of an interval that are required for the original pitch classes to be re-stated. Interval cycles are conjectured to give rise to an abstract grouping property, interval cycle proximity, which in turn is responsible for tonal attraction. The model was tested using a probe tone experiment requiring subjects to rate the probe for strength of attraction/resolution with respect to a preceding context chord. The results, displayed as ‘attraction profiles’, agreed with the predictions of the model, and showed that even diatonic chords, such as dominant sevenths, can be heard chromatically. The results are discussed in relation to examples of real music and previous research within the field.
Investigation of lower hybrid wave coupling and current drive experiments at different configurations in experimental advanced superconducting tokamak

Using a 2 MW 2.45 GHz lower hybrid wave (LHW) system installed in experimental advanced superconducting tokamak, we have systematically carried out LHW-plasma coupling and lower hybrid current drive experiments in both divertor (double null and lower single null) and limiter plasma configuration with plasma current (Ip) ∼ 250 kA and central line averaged density (ne) ∼ 1.0–1.3 × 1019 m−3 recently. Results show that the reflection coefficient (RC) first is flat up to some distance between plasma and LHW grill, and then increases with the distance. Studies indicate that with the same plasma parameters, the best coupling is obtained in the limiter case (with plasma leaning on the inner wall), followed by the lower single null, and the one with the worst coupling is the double null configuration, explained by different magnetic connection length. The RCs in the different poloidal rows show that they have different coupling characteristics, possibly due to local magnetic connection length. Current drive effici.
Overview of global data assimilation developments in numerical weather‐prediction centres

Recent data assimilation developments which have taken place at numerical weather‐prediction centres are briefly discussed, from the perspectives of both the importance of data and algorithmic developments. The increase in quality and quantity of satellite data is seen to play a major role in the improvement of forecast performance, particularly in the southern hemisphere. Further optimization of the use of observations is possible through the proper evaluation of data impact and the optimization of the amount of data to be assimilated. The generalized advent of four‐dimensional variational assimilation is presented, and trends in the specification of error statistics are described. Finally, a more interactive forecasting system including an adaptive component is a new challenge to bring additional improvement to the forecasting of high‐impact weather. Copyright © 2005 Royal Meteorological Society
Evaporative Power in the Tropical Forest of the Panama Canal Zone

Abstract The physical processes that affect evapotranspiration and the technique of measuring the drying influence of the air in the tropical forest of the Panama Canal Zone during the rainy season were examined. The time rate of evaporation from the surfaces of white spherical porcelain atmometers was the measurement used to determine the evapotranspiration power of this environment. Evaporation, temperature, vapor pressure deficit and relative humidity profiles are shown from the forest floor through 28.5 m to the top of the canopy. The mean hourly rate of evaporation at the top of the canopy is 4 times that near the forest floor but may vary from as little as 2.8 times to as much as 12 times the rate of evaporation near the forest floor. Mean hourly rates of evaporation at the top of the canopy and near the forest floor change dramatically from day to night. The average daytime rate near the surface was about 2.5 times the nighttime rate, while at the top of the canopy it was about 4 times the nighttim.
On Komar integrals in asymptotically anti‐de Sitter space‐times

Recently, boundary conditions governing the asymptotic behavior of the gravitational field in the presence of a negative cosmological constant have been introduced using Penrose’s conformal techniques. The subsequent analysis has led to expressions of conserved quantities (associated with asymptotic symmetries) involving asymptotic Weyl curvature. On the other hand, if the underlying space‐time is equipped with isometries, a generalization of the Komar integral which incorporates the cosmological constant is also available. Thus, in the presence of an isometry, one is faced with two apparently unrelated definitions. It is shown that these definitions agree. This coherence supports the choice of boundary conditions for asymptotically anti‐de Sitter space‐times and reinforces the definitions of conserved quantities.
Phase-wrapping ambiguity in along-track interferometry

In a previous SPIE paper we described several variations of along-track interferometry (ATI), which can be used for moving target detection and geo-location in clutter. ATI produces a phase map in range/Doppler coordinates by combining radar data from several receive channels separated fore-and-aft (along-track) on the sensor platform. In principle, the radial velocity of a moving target can be estimated from the ATI phase of the pixels in the target signature footprint. Once the radial velocity is known, the target azimuth follows directly. Unfortunately, the ATI phase is wrapped, i.e., it repeats in the interval [-π, π], and therefore the mapping from ATI phase to target azimuth is non-unique. In fact, depending on the radar system parameters, each detected target can map to several equally-likely azimuth values. In the present paper we discuss a signal processing method for resolving the phase wrapping ambiguity, in which the radar bandwidth is split into a high and low sub-band in software, and an ATI phase map is generated for each. By subtracting these two phase maps we can generate a coarse, but unambiguous, radial velocity estimate. This coarse estimate is then combined with the fine, but ambiguous estimate to pinpoint the target radial velocity, and therefore its azimuth. Since the coarse estimate is quite sensitive to noise, a rudimentary tracker is used to help smooth out the phase errors. The method is demonstrated on Gotcha 2006 Challenge data.
General closed-form expressions for acoustic waves in elastically anisotropic solids

By solving the Christoffel equations, general closed-form expressions are obtained for the phase and group velocities and displacement eigenvectors of arbitrarily directed acoustic waves in elastically anisotropic solids. The relationship of these general results to expressions that hold in symmetry directions is shown, and applications to phonon focusing and the determination of acoustic axes and extrema of the phase velocity are discussed. Methods for extracting the elastic constants and orientation of a crystal from measured sound velocities are outlined.
Direct laser writing of flexible graphene field emitters

We report on the simple fabrication of highly efficient solution-processable, flexible graphene-based field emission (FE) cathodes via direct laser writing of emitting pixels on reduced graphene oxide (rGO) films deposited onto rGO:poly(3-hexylthiophene) (P3HT) composite layers. Laser processing gives rise to a pronounced vertical alignment of rGO bundles perpendicular to the substrate, while at the same time sharp graphene edges are protruding out of the bundle. The laser-fabricated cathodes exhibit outstanding FE properties with a turn-on field of as low as ∼0.6 V/μm and a field enhancement factor of 8900, which are the best reported to date for rGO FE cathodes. At the same time, the cathodes exhibit stable operation under extensive and repetitive bending, a critical requirement for every flexible technology. The flexible and solution-processable, graphene-based, technology developed could be useful for diverse potential applications including field emission displays, biochemical sensors as well as sola.
A BAYESIAN HIERARCHICAL MODEL FOR POISSON RATE AND REPORTING‐PROBABILITY INFERENCE USING DOUBLE SAMPLING

We analyse a combination of errant count data subject to under‐reported counts and inerrant count data to estimate multiple Poisson rates and reporting probabilities of cervical cancer for four European countries. Our analysis uses a Bayesian hierarchical model. Using a simulation study, we demonstrate the efficacy of our new simultaneous inference method and compare the utility of our method with an empirical Bayes approach developed by Fader and Hardie (J. Appl. Statist., 2000).
MAGNETOHYDRODYNAMIC SIMULATION-DRIVEN KINEMATIC MEAN FIELD MODEL OF THE SOLAR CYCLE

We construct a series of kinematic axisymmetric mean-field dynamo models operating in the αΩ, α2Ω and α2 regimes, all using the full α-tensor extracted from a global magnetohydrodynamical simulation of solar convection producing large-scale magnetic fields undergoing solar-like cyclic polarity reversals. We also include an internal differential rotation profile produced in a purely hydrodynamical parent simulation of solar convection, and a simple meridional flow profile described by a single cell per meridional quadrant. An α2Ω mean-field model, presumably closest to the mode of dynamo action characterizing the MHD simulation, produces a spatiotemporal evolution of magnetic fields that share some striking similarities with the zonally-averaged toroidal component extracted from the simulation. Comparison with α2 and αΩ mean-field models operating in the same parameter regimes indicates that much of the complexity observed in the spatiotemporal evolution of the large-scale magnetic field in the simulation can be traced to the turbulent electromotive force. Oscillating α2 solutions are readily produced, and show some similarities with the observed solar cycle, including a deep-seated toroidal component concentrated at low latitudes and migrating equatorward in the course of the solar cycle. Various numerical experiments performed using the mean-field models reveal that turbulent pumping plays an important role in setting the global characteristics of the magnetic cycles.
Modeling, design, and analysis of interferometric cantilevers for time-resolved force measurements in tapping-mode atomic force microscopy

Cantilevers with interferometric high bandwidth force sensors can resolve nonlinear tip-sample interaction forces in tapping-mode atomic force microscopy. In this paper, we provide a detailed analysis of time-resolved force measurements using such cantilever. We first model the probe as a coupled spring-mass system and investigate its steady state dynamics under tapping-mode imaging conditions. Next, we analyze the optical response of the interferometric force sensor: Diffraction patterns as a function of tip displacement are obtained both analytically and by simulations. Finally, the frequency response of the force sensor is calculated, and the effects of the sensor geometry variations on the sensor mechanical response are analyzed.
Weighted discrepancies and maximum likelihood estimation for discrete distributions

The paper shows that many estimation methods, including ML, moments, even-points, empirical c.f. and minimum chi-square, can be regarded as scoring procedures using weighted sums of the discrepancies between observed and expected frequencies The nature of the weights is investigated for many classes of distributions; the study of approximations to the weights clarifies the relationships between estimation methods, and also leads to useful formulae for initial values for ML iteration.
Magnetocaloric effect from indirect measurements: Magnetization and heat capacity

Accurate values for the magnetocaloric effect can be obtained from both magnetization and heat-capacity data. A reliable estimate of the experimental errors in the calculated magnetocaloric effect can be made from the known experimental errors of the measured physical properties. Attempts in the past to simplify the basic thermodynamic relation to allow the calculation of the adiabatic temperature change from the heat capacity at constant field and the magnetic entropy change calculated from the magnetization data fail because the assumption that heat capacity is magnetic-field independent is erroneous. A suitable approach to carry out these calculations from the combined heat capacity and magnetization data is suggested.
Transient Tropical Diabatic Heating and the Seasonal-Mean Response to ENSO

AbstractBoreal winter simulations of the Community Atmospheric Model, version 4.0, were carried out using observed sea surface temperature (SST) fields from the three El Nino events of 1982/83, 1991/92, and 1997/98 [control (CTL) runs] and from observed climatology (CLIM run). In each case, 50 ensemble members were run (1 November–31 March). The diabatic heating Q at every grid point, level, and day of the CTL runs in the Indo-Pacific region was stored and used in four additional suites of experiments, each of which parallels the appropriate CTL suite. In each suite, Q generated by the model is replaced by a specified subset of Q at every time step, grid point, and level spanning the Indo-Pacific. The Q subsets consist of the seasonal ensemble-CTL-mean Q for each ensemble member (suite FIX), the seasonal-mean Q from the appropriate ensemble member of the CTL (suite EFIX), the seasonal mean plus low-frequency component of Q (suite ESUBFIX), and the daily means of Q (suite DAYFIX). The midlatitude ENSO anoma.