Miracle-dz/UniFAR-FTUs huggingface dataset:
Recurrent plot analysis of discharge sequences in tracking test of polybutylene polymers

Polymers are required to use in radiation environments as insulation materials. However, they often suffer from tracking failure. There is an increasing demand to evaluate radiation effects on dielectric performance. This paper presents a recurrence plot (RP) approach to analyse surface discharge sequences of gamma-ray irradiated polymer materials based on tracking test. Studying the non-linear characteristics of discharge sequences can assist in understanding the underlying mechanism of the discharge process. Discharge sequences of the test are extended to m-dimensional phase space by using the phase space reconstructed method. As test samples, polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN) were irradiated to 100 kGy and then up to 1 MGy with a dosage rate of 10 kGy h−1 by using a 60Co gamma source. The tracking tests were carried out according to the test method described in IEC60112. It is found that the RPs can give visual recurrent patterns of discharge sequences for identification of the effects of gamma-ray radiation dosage on the resistance to tracking of the polymers. The detection of recurrent patterns together with comparative tracking index value results indicate that with the increase in the radiation dosage, the resistance to tracking of PBT decreases, but increases for PBN.
An experimental investigation of flow in an oscillating pipe

The hydrogen-bubble technique has been used to measure the velocities of pulsating water flow in a rigid circular pipe. Mean flows with Reynolds numbers between 1275 and 2900 were superimposed on an oscillating flow produced by moving the pipe axially with simple harmonic motion. While the velocities in the oscillating boundary layers on the pipe wall were found to be close to those predicted by laminar flow theory, at the higher Reynolds numbers the velocities near the centre of the pipe were lower than those predicted and more uniformly distributed. The intermittency of the periodic bursts of turbulent motion at the higher Reynolds numbers was measured. At each mean-flow Reynolds number the turbulent intermittency of the flow was found to be a function of a single parameter: the harmonicflow Reynolds number.
A comparison of alternative kanban control mechanisms. I. Background and structural results

The design of inventory control policies for serial systems is a topic currently being explored by a number of researchers. Our goal -in two papers - is to synthesize and extend some of these efforts. We consider, simultaneously, four sources of variability in production lines - processing time variability, machine breakdowns, rework and yield loss - and show some similarities and differences in their effects on the performance of the line. In this paper we introduce an enhanced model that accommodates raw material and demand uncertainity and demonstrate that many of the sample path results obtained previously can be extended. The main objectives of this paper are: (1) to demonstrate that Constant-Work-in-Process (CONWIP) and the traditional kanban control are just two extremes in a finite family of implementable pull controls; (2) to show that while machine breakdowns, rework and random processing times have a similar effect in terms of the optimal decisions, yield losses in the line may have to be manag.
Valuative Criteria for Families of Vector Bundles on Algebraic Varieties

The object of this paper is to derive separation and completeness properties for the families of vector bundles on a nonsingular projective variety X over a fixed algebraically closed field k. By a vector bundle on X we mean a torsion-free coherent sheaf on X. If Xis a curve, such a sheaf must be locally free; thus this definition corresponds with the usual notion of vector bundle. On higher dimensional varieties, it appears that the category of locally free sheaves is too restrictive; for example, in this category, bundles do not in general have complete flags, whereas in the category of torsion-free sheaves, complete flags always exist (Proposition 1). Let S be an algebraic scheme over k. We define a family of vector bundles on X over S to be a coherent sheaf E on X x S, flat over S, such that for each s e S the induced sheaf E. on P`'(s) is torsion-free. We consider two such families E and E' to be equivalent if there is an invertible sheaf L on S such that E _ E' ( p*(L). Starting from the concept of a family of vector bundles, we are led to define a contravariant functor 'F3@ from the category of algebraic schemes over k to the category of sets, in the following way: If S is an algebraic scheme, let '0B,(S) be the set of equivalence classes of families of vector bundles on X over S. Then if T > S is a morphism of algebraic schemes and E a family of vector bundles over S, (g x X)*(E) will be a family of vector bundles over T. It is natural to ask whether the functor F3SX is representable; that is, is there an algebraic scheme V and a family of vector bundles E over V such that Hom (S, V) -= B,(S) for all S? Such a V would be a natural parameter space for the bundles on X, and E would be a "universal family". It turns out that this is too much to expect. First of all, there are too many bundles to be parameterized by an algebraic scheme: we must break the functor up into separate parts corresponding to certain natural invariants, for example, the Hilbert polynomial. Next, we must throw away some
Exact boundary controllability for non‐autonomous quasilinear wave equations

In this paper, we first show that quite different from the autonomous case, the exact boundary controllability for non‐autonomous wave equations possesses various possibilities. Then we adopt a constructive method to establish the exact boundary controllability for one‐dimensional non‐autonomous quasilinear wave equations with various types of boundary conditions. Finally, we apply the results to multi‐dimensional quasilinear wave equation with rotation invariance. Copyright © 2007 John Wiley & Sons, Ltd.
Viscous decay of long internal solitary waves

A formula for the viscous decay of a long internal solitary wave, propagating into a quiescent fluid in a two‐layer model was derived. The result is analogous to Keulegan’s (1948) formula for the viscous decay of long surface waves. The requirement of quiescent fluid ahead of the wave is important, as indicated by a comparison with experiments.
A Revised Model of Photon Resulted by an Etherono-Quantonic Theory of Fields

By an etherono-quantonic theory of the author [1], which deduces that the magnetic field of a magnetic moment is generated by an etherono-quantonic vortex GM = GA GB of etherons and of quantons with mass mh = h/c2, giving the magnetic induction B, a revi.
An alternative approach to Sacker–Sell spectral theory

In this article, the Morse spectrum is introduced for linear systems of nonautonomous difference equations. In contrast to the well-known Sacker–Sell spectrum, the exponential growth rates are not characterized for the whole system but for a suitable decomposition, given by the finest Morse decomposition. The theory of nonautonomous Morse decompositions is reviewed, and it is shown that the Sacker–Sell spectrum coincides with the Morse spectrum if the system has bounded growth. The observations in this paper can thus be seen as an alternative approach to Sacker–Sell spectral theory.
The halo distribution of 2dF galaxies

We use the clustering results obtained by Madgwick et al. (2003) for a sample of96 791 galaxies from the 2dF Galaxy Redshift Survey with redshift 0.01 < z < 0.15 to study the distribution of late-type and early-type galaxies within dark matter haloes of different mass. Within the framework of our models, galaxies of both classes are found to be as spatially concentrated as the dark matter within haloes, even though, while the distribution of star-forming galaxies can also allow for some steeper profiles, this is ruled out drastically in the case of early-type galaxies. We also find evidence for morphological segregation, as late-type galaxies appear to be distributed within haloes of mass-scales corresponding to groups and clusters up to about two virial radii, whereas passive objects show a preference to reside closer to the halo centre. If we assume a broken power law of the form (N g a l )(m) = (m/m 0 ) α 1 for m c u t ≤ m < m 0 and (N g a l )(m) = (m/m 0 ) α 2 at higher masses to describe the dependence of the average number of galaxies within haloes on the halo mass, fits to the data show that star-forming galaxies start appearing in haloes of masses m c u t ≃ 10 1 1 M O . , much smaller than what is obtained for early-type galaxies (m c u t ≃ 10 1 2 . 6 M O .). In the high-mass regime m ≥ m 0 , (N g a l ) increases with halo mass more slowly (α 2 ≃ 0.7) in the case of late-type galaxies than for passive objects which present α 2 ≃ 1.1. The above results imply that late-type galaxies dominate the 2dF counts at all mass-scales. We stress that - at variance with previous statements - there is no degeneracy in the determination of the best functional forms for p(r) and (N g a l ), as they affect the behaviour of the galaxy-galaxy correlation function on different scales.
Vaccination Strategies in a Potential Use of the Vaccine against Bovine Tuberculosis in Infected Herds

Simple Summary Bovine tuberculosis is a chronic infectious disease caused by Mycobacterium bovis characterized by the formation of tubercles in any organ or tissue. This disease affects various animal species and humans; therefore, it represents a significant veterinary and public health problem. Bovine tuberculosis control is based on the tuberculin test and the disposal of reactor animals. In underdeveloped countries, this strategy has not been successful due to the lack of economic resources to compensate producers for their slaughtered animals. Recently, it has been suggested to incorporate the Bacillus Calmette–Guérin (BCG) vaccine to reduce the disease prevalence by reducing the number of animals with lesions, the number of lesions per animal and bacterial load. Several experiments have shown the efficacy of different vaccine formulas against bovine tuberculosis. In Mexico, there is a growing interest, both from producers and authorities, to integrate the vaccine into current control programs, especially in dairy cattle, where the prevalence of the disease is high, and overcrowding favors the dissemination. Abstract Bovine tuberculosis (bTB) is a disease of cattle that represents a risk to public health and causes severe economic losses to the livestock industry. Recently, one of the strategies recommended for reducing the prevalence of the disease in animals is the use of the BCG vaccine, alone or in combination with proteins. It has been shown that the vaccine elicits a strong immune response, downsizes the number of animals with visible lesions, and reduces the rate of infection as well as the bacillary count. This paper, based on scientific evidence, makes suggestions about some practical vaccination alternatives that can be used in infected herds to reduce bTB prevalence, considering BCG strains, vaccine doses, routes of application, and age of the animals. Our conclusion is that vaccination is a promising alternative to be included in current control programs in underdeveloped countries to reduce the disease burden.
Microwave scattering and the straining of wind‐generated waves

The modulation in backscattered power from wind-generated waves due to the presence of a 0.575-Hz plunger-generated wave has been measured in a wave tank as a function of air friction velocity and plunger wave amplitude. The measurements were made at 9.375 GHz, a depression angle of 45° and vertical polarization. The straining of the wind waves is treated by a first-order perturbation of the Boltzmann transport equation and the scattering is calculated from a simple application of composite surface scattering theory utilizing first-order Bragg scattering. The theory predicts a characteristic relaxation behavior for the wind-speed dependence of the components of the modulation amplitude in phase and out of phase with the horizontal component of orbital velocity of the plunger wave. This relaxation behavior is closely followed by the observed modulation amplitudes for air friction velocities less than about 40 cm sec−1, i.e., winds less than about 7 m sec−1.
Specifying Weights in Spatial Forecasting Models: The Results of Some Experiments

The application of space-time forecasting models requires the specification of a set of place-to-place weights. The existing literature contains several recommendations for this specification. By a series of Monte Carlo simulations, various weighting rules are compared in terms of estimation of model parameters and accuracy of forecasts. It is shown that specification of the weights is important, especially when sample sizes are small and the data autocorrelated. Generally, the effective area of the weight function is more important than its distance decay.
The Asymptotic Distribution of the Lower Part Eigenvalues for Elliptic Operators

1o Introduction. Let A be a positive homogeneous elliptic operator with constant coefficients defined on R. We consider the eigenvalue problem of the ollowing form (1.1) Au--pu--2u. Here p(x) is a positive function with lim_= p(x)-O. If p(x) does no approach to zero too rapidly at infinity, then the operator A--p has an infinite sequence of negative eigenvalues approaching o zero. We denote by n() ( 0) the number of eigenvalues less than --r of problem (1.1). In this note we study the asymptotic behavior of n(r) as -0. Theasymptotic behavioror the SchrSdinger operator witha non-smooth potential p(x) was studied in Brownell and Clark [3], and McLeod [4]. Only the theorem and a sketch of its proof are presented here and he details will be published elsewhere. 2. Main result. Let A(D)--Y. = a.D" be an elliptic operator with constant coefficients defined on R. We suppose that A()>_ 0 ad denote by K(1, a) (l 0, a 0) the set of unctions p(x) which satisfy the following conditions" ( ) p(x) is decomposed as p(x)--pl(x)+p2(x) (ii) p(x) is a positive smooth unction with lim,, Ix]p(x)-a; (iii) p(x) is a aonnegative unction with compact support; (iv) p(x) e L, where p--1 if m>_n and pn/m if mn. Theorem. Let A be an elliptic operator satisfying the above conditions and suppose that p(x) belongs to K(1, a) and that m. Then,
The role of threading dislocations and unintentionally incorporated impurities on the bulk electron conductivity of In-face InN

The origin of bulk electrons in In-face InN has been studied by considering the effects of both unintentionally incorporated impurities and threading dislocation densities on electron transport properties. The concentration of unintentionally incorporated oxygen and hydrogen scaled with the bulk electron concentration while threading dislocations had no discernable effect on the electron concentration. We conclude that unintentional impurities were the significant source of electrons and threading dislocations acted only as scattering centers limiting the electron mobility in as-grown InN films. Further, we present In-face InN growth techniques controlling the incorporation of oxygen and hydrogen and reducing threading dislocation densities.
Spectra of Random Self Adjoint Operators

This survey contains an exposition of the results obtained in the studying the spectra of certain classes of random operators. It consists of three chapters. In the introductory Chapter I we survey some of the pioneering papers (two, in particular), which have sufficient depth of content to suggest the natural problems to be considered in this field. In Chapter II we study the distribution of the eigenvalues for ensembles of random matrices, for instance, the sum of one-dimensional projection operators onto random vectors uniformly and independently distributed over the surface of the -dimensional unit sphere. We show that as , the eigenvalue distribution ceases to be random and can be determined as the solution of a certain functional equation. Chapter III deals with the Schrodinger equation with a random potential. We establish ergodic properties of certain random quantities, constructed from the eigenvalues and eigenfunctions of this equation, and we study the distribution of eigenvalues in the cases when the potential is a Gaussian random field and a homogeneous Markov process.
Stochastic estimation using a continuum of models

We investigate a recursive multiple model tracking approach similar to the Generalized Pseudo-Bayesian 1 (GPB1) (Bar-Shalom and Li, 1993) approach. However, we consider a continuum of models rather than the discrete set that is usually implemented in the GPBI method. By doing so better models are available to improve tracker performance and solve the symmetry problem inherent in most multiple model approaches.
On a wave equation with supercritical interior and boundary sources and damping terms

This article addresses nonlinear wave equations with supercritical interior and boundary sources, and subject to interior and boundary damping. The presence of a nonlinear boundary source alone is known to pose a significant difficulty since the linear Neumann problem for the wave equation is not, in general, well‐posed in the finite‐energy space H1(Ω) × L2(∂Ω) with boundary data in L2 due to the failure of the uniform Lopatinskii condition. Further challenges stem from the fact that both sources are non‐dissipative and are not locally Lipschitz operators from H1(Ω) into L2(Ω), or L2(∂Ω). With some restrictions on the parameters in the model and with careful analysis involving the Nehari Manifold, we obtain global existence of a unique weak solution, and establish exponential and algebraic uniform decay rates of the finite energy (depending on the behavior of the dissipation terms). Moreover, we prove a blow up result for weak solutions with nonnegative initial energy.
Robust Control of Formation Dynamics for Autonomous Underwater Vehicles in Horizontal Plane

This paper presents a novel robust controller design for formation control of autonomous underwater vehicles (AUVs). We consider a nonlinear three-degree-of-freedom dynamic model for the horizontal motion of each AUV. By using the Jacobi transform, the horizontal dynamics of AUVs are explicitly expressed as dynamics for formation shape and formation center, and are further decoupled by feedback control. We treat the coupling terms as perturbations to the decoupled system. An H-infinity state feedback controller is designed to achieve robust stability of the closed loop formation and translation dynamics. By incorporating an orientation controller, the formation shape under control converges and the formation center tracks a desired trajectory simultaneously. Simulation results demonstrate the effectiveness of the controllers.
Multilevel Modeling Using R

This book is from the “Statistics in the Social and Behavioral Sciences” series of Chapman and Hall/CRC, which has quite a broad scope. The book’s preface states its goals as follows: “The goal of this book is to provide [. ] a comprehensive resource for the conduct of multilevel modeling using the R software package. ” “Our goal is to provide you with a guidebook that will serve as the launching point for your own investigations into multilevel modeling”. The content suggests that the book is written for R novices with weak statistical background – nothing is taken for granted except for means, variances, correlations, and perhaps the normal distribution. For this audience, the “own investigations into multilevel modeling” are a real stretch. It will be discussed at the end of this review, which audiences might benefit from the book for which purposes.
Mapping of mechanical stresses in silicon substrates due to lead–tin solder bump reflow process via synchrotron x-ray topography and finite element modelling

White beam synchrotron x-ray topography (WBSXRT) is a non-destructive technique, which is capable of analysing the strain and/or dislocation distribution in single crystal materials. This paper discusses the application of WBSXRT to the analysis of strain fields due to the microelectronic packaging of integrated circuits. A ball grid array package containing an Intel® Pentium® III microprocessor was employed to investigate the spatial extent of strain fields imposed on the underlying silicon substrate due to the reflow process for lead–tin solder bumps. Large area and section back-reflection SXRT images were taken before and after the reflow process at 350°C in atmosphere. The effects of strain imposed by the overlying bump structures in these x-ray topographs have been observed principally via orientational contrast. This was also the situation after the reflow process due to severe stresses in the underlying silicon beneath the lead bumps. The estimated magnitudes of shear stress, |τxy|, imposed on the underlying silicon were calculated to be of the order of 100 MPa. A simulation of the orientational contrast at the edge of bump was performed based on the kinematical theory of x-ray diffraction (Rantamaki R et al 1999 J. Appl. Phys. 86 4298). The degree of lattice distortion is well fitted to the topographs of the post-reflow sample. The spatial strain in the underlying silicon was relieved dramatically after the lead bumps were removed from the wafer, which confirms that the solder bump formation is indeed a major source of strain in the underlying Si. Finite element modelling was performed in two-dimensional plane strain mode. The magnitudes and spatial distribution of the stresses after the reflow process are in good agreement with the SXRT results.
On the electromagnetic two-body problem

The paper contains a direct attack on the electromagnetic two-body problem, based on the hypotheses (i) that the bodies are particles, (ii) that the fields are given by the retarded potential, (iii) that the force on a particle is the Lorentz ponderomotive force (without a radiation term). A method of successive approximation leading to an exact solution is outlined. General expressions are found for the rates of change of invariant quantities Which are the constants of energy and angular momentum in the Kepler problem, and formulae are developed for the principal parts of these expressions in the case where the ratio of the masses of the two particles is small. This is applied in detail to the case where the orbit of the light particle is approximately circular. It is found that energy disappears from the motion, so that the orbital particle slowly spirals in, but the rate at which this occurs is much less than that given by the usual formula for radiation from an accelerated electron. Except in some final calculations, no assumption of small velocity is made, the sole basis of approximation being the smallness of the mass-ratio.