Miracle-dz/UniFAR-FTUs huggingface dataset:
ANALYSIS OF THE EXTREME-ULTRAVIOLET QUIET SOLAR SPECTRUM.

The solar EUV spectrum provides a suitable approach for the study of the solar atmosphere because the emission lines and continua are formed at temperatures ranging from about 10,000 K, representative of the low chromosphere, to temperatures in excess of 3 million degrees K, originating predominantly in active regions. The OSO-4 experiment obtained spectra originating from a region at the center of the quiet solar disk. The spectrum is used to derive the emission measures and the chemical abundances for a number of elements. A one-dimensional temperature and density model is constructed from this analysis.
Compressible bubbles in Stokes flow

The problem of a two-dimensional inviscid compressible bubble evolving in Stokes flow is considered. By generalizing the work of Tanveer & Vasconcelos (1995) it is shown that for certain classes of initial condition the quasi-steady free boundary problem for the bubble shape evolution is reducible to a finite set of coupled nonlinear ordinary differential equations, the form of which depends on the equation of state governing the relationship between the bubble pressure and its area. Recent numerical calculations by Pozrikidis (2001) using boundary integral methods are retrieved and extended. If the ambient pressures are small enough, it is shown that bubbles can expand significantly. It is also shown that a bubble evolving adiabatically is less likely to expand than an isothermal bubble.
The Evaluation of H 106 Continuous Sampling Plans under the Assumption of Worst Conditions

Abstract Dodge-type continuous sampling plans are used to screen mass produced items so that long run quality requirements will be met. The choice of a particular Dodge-type plan is often based on the plan's aoql, the long run proportion of defectives that remains in the output after inspection under the assumption that the production process is in a “state of statistical control. ” Another measure by which a plan can be evaluated is the uaoql, the long run proportion of defectives remaining under the assumption that the production process operates in the worst possible way relative to the plan. This paper presents five graphs that can be used to provide uaoql values for a large number of h 106 plans. The linear program used to calculate these graphs is also included.
Robust sequential detection of weak signals in undefined noise using acoustical arrays

In detection problems where the noise distribution may be unknown, employing nonlinear elements that precede the standard detector often significantly improves system performance in non‐Gaussian noise. However, in order to optimize the system to the noise conditions and, thereby, prevent degradation under Gaussian noise, the nonlinear elements should possess an inherent capability for adapting to the changing noise conditions. This paper presents a discrete formulation based on m‐interval partitioning for sequentially detecting weak signals in undefined noise. Partitioning requires knowledge of a small number of quantiles and related functions from the unknown noise distribution. The resultant detector is easily implemented and is adaptable to slowly changing noise conditions. Two examples are given that clearly show improved performance, over a wide class of noise distributions, for an array employing m‐interval partitioning compared with arrays employing linear correlators and sign detectors.
A multigoal heuristic for facilities design problems: MUGHAL

Abstract This paper deals with the minimization of an objective function which incorporates two conflicting criteria; cost minimization and closeness rating maximization, for facilities design problems. The objective function represents the difference of materials handling cost and the closeness rating with predefined weights assigned to both criteria. A heuristic approach is developed which takes an initial layout and improves it step by step using a pairwise exchange routine.
Continuity and convexity of projections and barycentric coordinates in convex polyhedra

If sQ, , sn are linearly independent points of real ^-dimensional Euclidean space R then each point x of their convex hull S has a (unique) representation x = Σ? =oM)< with \(%) ^ 0 (i = 0, , n) and Σ? =<Λ<(#) — 1> and the barycentric coordinates λ0, , Xn are continuous convex functions on S (cf. [3, p. 288]). We shall show in this paper that given any finite set 809 •• ,s f n of points of R n we can assign barycentric coordinates λ>o> , λTO to their convex hull S in such a way that each coordinate is continuous on S and that one prescribed coordinate (λ0 say) is convex on £ (Theorem 2); the author does not know whether it is always possible to make all the coordinates convex simultaneously (cf. Example 3). In proving Theorem 2 we shall use certain "projections" which we now define; these projections are in general distinct from those of [1, p. 614] and [2, p. 12], Given two distinct points s0 and s of R , let sos be the open half-line consisting of all points sQ + X(s — s0) with λ > 0; given a point s0 of R n and a closed subset S of R such that s0 $ S, let C(s0, S) be the "cone" formed by the union of all open half-lines sos with s in S; and given a point x in such a cone C(sQ, S), let π(x) be the (unique) point of sox Π S which is closest to s0. Then we shall call the function π the "projection of C(so,S) on S. " Our proof of Theorem 2 depends on the fact that if S is a convex polyhedron then π is continuous (Theorem 1). This result may appear to be obvious, but it is not immediately obvious how a formal proof should be given; moreover, as we shall show (Examples 1 and 2), the conclusion need not remain true for polyhedra S which are not convex or for convex sets S which are not polyhedra. The author is indebted to the referee for improvements to Lemma 3, Example 1, and Example 2, and for the remark at the end of § 1.
A Study of Nocturnal Surface Wind Speed Overprediction by the WRF-ARW Model in Southeastern Texas

AbstractThe overprediction of surface wind speed during nighttime by the Advanced Research core of the Weather Research and Forecasting (WRF-ARW) model was investigated for a period of the Second Texas Air Quality Study (28 May–3 July 2006). In coastal regions of southeastern Texas, the model had a significant increase of wind speed biases on the surface in the evening throughout the period, especially between 4 and 12 June. The synoptic pattern was a high pressure system centered over the Louisiana–Mississippi area that was subjected to a weak easterly–southeasterly flow in the lower troposphere. The weather conditions favorable for sea-breeze development brought a southerly–southwesterly onshore flow to the near-surface levels. In comparison with measurements, the downward sensible heat flux was overpredicted at night, which resulted in a warm bias in surface temperature. For the vertical wind profile on days with an evening wind bias, sea-breeze-driven nocturnal low-level jets (southerly–southwesterly).
Uppsala general catalogue of galaxies

A heavy duty pneumatic radial tire is disclosed. This tire has a tread pattern formed in a tread divided into zigzag circumferential ribs by at least two zigzag main grooves. The tread includes a stress-mitigating rib arranged at least near the top of the convex part of the circumferential rib and parallel to the edge line of the circumferential rib through substantially an isolation groove.
Experimental Verification of the Theoretical Relationship Between Size and Critical Supersaturation of Salt Nuclei

Abstract Polydisperse NACl and (NH4)2SO4 salt particles were passed through a Goetz centrifuge, which transmitted only those particles smaller than the cutoff size of the centrifuge. In one set of experiments the sample from the centrifuge was passed directly into the thermal gradient cloud chamber and the threshold supersaturation for activating nuclei was recorded. In the second set of experiments the output sample from the centrifuge was passed through a mobility analyzer which transmitted a nearly monodisperse aerosol of a known size to the thermal-gradient cloud chamber. In the first experiment the threshold supersaturation agreed well with the critical supersaturation predicted by theory for particles of radii equal to the cutoff size of the Goetz centrifuge. Likewise, the critical supersaturation found for the nearly monodisperse aerosols transmitted through the mobility analyzer agreed well with that predicted by theory.
Design of a wideband bandpass filter based on signal-interaction concepts

A novel wideband bandpass filter (BPF) based on signal-interaction concepts is presented in this paper. Two transmission paths with a wideband double-sided parallel-strip line 180° inverter and a 3λ/4 transmission line are employed to transmit signals from Port 1 to Port 2. By introducing two λ/4 shorted lines, the passband transmission performance of the BPF can be improved effectively. The experimental results demonstrate that the proposed BPF can achieve three transmission zeros and good harmonic suppression in the whole operating band ranging from 1.35 to 3.41 GHz, with 3-dB fractional bandwidth of 86%.
Effect of dropped plies on the strength of graphite-epoxy laminates

The reduction in the compressive and tensile strength of graphite-epox y laminates with thickness discontinuities due to dropped plies was studied by experiment and analysis. The specimens were fabricated with all the dropped plies lumped together in the center of a 16-ply quasi-isotropic layup, such that one surface was flat and the slope of the opposite surface changed abruptly at the dropped ply location to accommodate the thickness change. Even though the thick and thin sections are symmetrically laminated, there exists bending-extensioii coupling due to the geometric eccentricity of the middle planes of the thick and thin sections. Results from tests on 37 specimens are reported that differed in the configuration of the dropped plies only. The axial strength of a laminate with dropped plies is less than the strength of its thin section, and the compressive strength of a laminate with dropped plies is less than its tensile strength. The reduction in axial strength is directly related to the axial stiffness change between the thick and thin sections. To examine the mechanism of failure, the three-dimensional state of stress in the dropped ply region was evaluated by the finite element method. A tensile interlaminar criterion predicted the correct location of failure, but underestimated the failure load, and therefore is a conservative analysis procedure for design.
Influence of oxygen passivation on optical properties of PbSe thin films

A series of PbSe thin films grown on a (111)-oriented Si substrate by molecular beam epitaxy were passivated by high-purity oxygen at different annealing temperatures. The photoluminescence intensity increased by more than two orders of magnitude at 4. 5μm after annealing the samples in an O2 atmosphere at 350°C. X-ray photoelectron spectroscopy revealed that PbO and SeO2 were formed during the oxidation process of PbSe, thus confirming the formation of the surface passivation layer which resulted in the observed significant increase in PL intensity.
A finite element model for free surface flows on fixed meshes

In this paper, we present a finite element model for free surface flows on fixed meshes. The main novelty of the approach, compared with typical fixed mesh finite element models for such flows, is that we take advantage of the particularities of free surface flow, instead of considering it a particular case of two‐phase flow. The fact that a given free surface implies a known boundary condition on the interface, allows us to solve the Navier–Stokes equations on the fluid domain uncoupled from the solution on the rest of the finite element mesh. This, together with the use of enhanced integration allows us to model low Froude number flows accurately, something that is not possible with typical two‐phase flow models applied to free surface flow. Copyright © 2007 John Wiley & Sons, Ltd.
Relation between the Karhunen Loève and cosine transforms

The cosine transform is nowadays widely used in image data compression studies as a result of its observed near optimum performance with respect to variance redistribution andits property of reducing block edge effects which occur at extreme values of compression. The reason for its good performance for a widely used class of sources is now demonstrated theoretically by showing that it can be derived from the optimum (Karhunen-Loeve) transform in the limiting case when the adjacent data-element correlation tends to unity.
Determination of Optional Cutting Scores in Criterion - Referenced Measurement,

An empirical methodology is proposed for determining optimal cutting scores for short-fixed-length criterion-referenced tests. Classification of outcome probabilities and validity coefficient approaches are developed using validation samples of instructed and uninstructed students. The optimal cutting score is selected according to the estimated probabilities of correct and incorrect mastery-nonmastery decisions. These probabilities, along with the gains and losses associated with the decisions, are then incorporated into an index of utility for identifying the cutting score which maximizes test usefulness in specific individual and group decision situations. The practical value of using the test compared to an alternative is also examined in terms of incremental validity.
Norm methods and partial weighting in multicriterion optimization of structures

Methods for generating Pareto optimal solutions to a multicriterion optimization problem are considered. The norm methods based on the scalarization of the original multicriterion problem by using the l-norm are discussed in a unified form and a parametrization suitable for different interactive design systems is suggested. In addition, an alternative approach which, instead of scalarization, reduces the dimension of the multicriterion problem is proposed. This is called the partial weighting method and it can beinterpreted as a generalization of the traditional scalarization technique where the weighted sum of the criteria is used as the objective function. The first of these two approaches (norm method) is very flexible from a designer's point of view and it can be applied also in non-convex cases to the determination of the Pareto optimal set whereas the latter (partial weighting method) is especially suitable for problems where the number of criteria is large. Throughout the article several illustrative truss examples are presented to augment the scanty collection of multicriterion problems treated in the literature of optimum structural design.
Nonlinear State Estimation of Differential Algebraic Systems

Abstract Abstract Kalman filter and its variants have been used for state estimation of systems described by ordinary differential equation (ODE) models. Moving Horizon Estimation (MHE) has been a popular approach in chemical engineering community for the estimation of both ODE and differential algebraic equation (DAE) systems but is computationally demanding. There has been some work on applying Extended Kalman filter for state estimation of DAE systems with measurements as functions of only the differential states. This work describes the estimation of nonlinear DAE systems with measurements being a function of both the differential and algebraic states. An Unscented Kalman filter (UKF) formulation is also derived for semi-explicit index 1 DAE systems. The utility of these formulations are demonstrated through a case study.
Feedback control of a flow past a cylinder via transverse motion

The instability giving rise to the Karman vortex street in a flow past a circular cylinder is responsible for the occurrence of large amplitude oscillations in the lift. In this work, we seek to control the instability via active feedback control by means of transverse displacements of the solid structure. Our investigation is based on Foppl’s four-dimensional potential flow model of point vortices. A feedback controller capable of manipulating the flow in order to maintain zero lift at all times is derived analytically by using perturbation methods and asymptotic expansions. We then apply the controller to the viscous flow by direct numerical simulation of the flow based on the two-dimensional Navier–Stokes equations and show that our control algorithm is capable of keeping the lift close to zero in the impulsively started viscous flow and, therefore, controlling vortex shedding. Computations are carried out at the Reynolds numbers Re=100 and Re=200.
SOFT X-RAY SPECTRAL FITS OF GEMINGA WITH MODEL NEUTRON STAR ATMOSPHERES

The spectrum of the soft X-ray pulsar Geminga consists of two components, a softer one which can be interpreted as thermal-like radiation from the surface of the neutron star, and a harder one interpreted as radiation from a polar cap heated by relativistic particles. We have fitted the soft spectrum using a detailed magnetized hydrogen atmosphere model. The fitting parameters are the hydrogen column density, the effective temperature T(sub eff), the gravitational redshift z, and the distance to radius ratio, for different values of the magnetic field B. The best fits for this model are obtained when B less than or approximately 1 x 10(exp 12) G and z lies on the upper boundary of the explored range (z = 0.45). The values of T(sub eff) approximately = (2-3) x 10(exp 5) K are a factor of 2-3 times lower than the value of T(sub eff) obtained for blackbody fits with the same z. The lower T(sub eff) increases the compatibility with some proposed schemes for fast neutrino cooling of neutron stars (NSs) by the direct Urca process or by exotic matter, but conventional cooling cannot be excluded. The hydrogen atmosphere fits also imply a smaller distance to Geminga than that inferred from a blackbody fit. An accurate evaluation of the distance would require a better knowledge of the ROSAT Position Sensitive Proportional Counter (PSPC) response to the low-energy region of the incident spectrum. Our modeling of the soft component with a cooler magnetized atmosphere also implies that the hard-component fit requires a characteristic temperature which is higher (by a factor of approximately 2-3) and a surface area which is smaller (by a factor of 10(exp 3), compared to previous blackbody fits.
Breather solutions of the discrete nonlinear Schrödinger equations with unbounded potentials

In this paper I investigate the existence of nontrivial breather solutions of the discrete nonlinear Schrodinger equation with the unbounded potential at infinity. First I derive a discrete version of compact embedding theorem. Then combining the Nehari manifold approach and the compact embedding theorem, I show the existence of breather solutions without Palais–Smale condition. The results on the exponential decay of breather solutions are also provided in this paper.
QALE‐FEM for modelling 3D overturning waves

A further development of the QALE‐FEM (quasi‐arbitrary Lagrangian–Eulerian finite element method) based on a fully nonlinear potential theory is presented in this paper. This development enables the QALE‐FEM to deal with three‐dimensional (3D) overturning waves over complex seabeds, which have not been considered since the method was devised by the authors of this paper in their previous works (J. Comput. Phys. 2006; 212:52–72; J. Numer. Meth. Engng 2009; 78:713–756). In order to tackle challenges associated with 3D overturning waves, two new numerical techniques are suggested. They are the techniques for moving the mesh and for calculating the fluid velocity near overturning jets, respectively. The developed method is validated by comparing its numerical results with experimental data and results from other numerical methods available in the literature. Good agreement is achieved. The computational efficiency of this method is also investigated for this kind of wave, which shows that the QALE‐FEM can be many times faster than other methods based on the same theory. Furthermore, 3D overturning waves propagating over a non‐symmetrical seabed or multiple reefs are simulated using the method. Some of these results have not been found elsewhere to the best of our knowledge. Copyright © 2009 John Wiley & Sons, Ltd.
On the scaling of steady structured waves in heterogeneous materials

Large amplitude steady waves in materials have been observed to display certain scaling relationships between the strain rate and the stress amplitude. In many homogeneous materials, strain rate scales with stress to the fourth power. However, scaling of strain rate with stress to the first, second, and fourth power has been found for different classes of heterogeneous materials. We examine wave structures for three classes of heterogeneous materials through mesoscale simulations that resolve the scale of heterogeneity explicitly. We utilize these simulations to gain insight into the scaling phenomena observed and to identify the critical non-dimensional parameters for the phenomena. These parameters are then applied to the available experimental data for the three classes. The same set of non-dimensional groups is found to be appropriate for layered and particulate composite materials, while somewhat different groups are found for granular materials. Two different types of simulations lead to different conclusions on the need for the inclusion of strength in the non-dimensionalization for granular materials. The groups formed are found to collapse the experimental data quite well when the strength parameter is not included. Finally, a simple model for granular materials demonstrates that the crucial aspect of their behavior that controls the scaling of waves is the need for mass transfer to close voids in the material.
Rapid Cycling Synchrotrons and Accumulator Rings for High-Intensity Hadron Beams

Boosted by the needs in high-energy physics and nuclear physics and also multidisciplinary applications, high-intensity proton synchrotrons and accumulator rings have been developed quickly around the world over the last 30 years. New projects and plans are proposed with even higher beam power. The proton beam power has increased from less than 10 kW in the 1970s to about 1 MW level today, and the required beam power in the coming decade is a few MW. This article reviews the achievements in designing and constructing rapid cycling synchrotrons (RCSs) and accumulator rings (ARs) and the future development trends, principally on proton beams but also including heavy ion beams. It presents the evolution of RCS and AR machines, today's design philosophy, relevant accelerator physics, and also state-of-the-art accelerator technology.
Absorption of planar waves in a draining bathtub

We present an analysis of the absorption of acoustic waves by a black hole analogue in (2+1) dimensions generated by a fluid flow in a draining bathtub. We show that the low-frequency absorption length is equal to the acoustic hole circumference and that the high-frequency absorption length is 4 times the ergoregion radius. For intermediate values of the wave frequency, we compute the absorption length numerically and show that our results are in excellent agreement with the low- and high-frequency limits. We analyze the occurrence of superradiance, manifested as negative partial absorption lengths for corotating modes at low frequencies.