Miracle-dz/UniFAR-FTUs huggingface dataset:
Saturation of the Rod Mechanism of the Retina at High Levels of Stimulation

By means of the two-colour threshold method the threshold response of the rod or dark-adapting visual mechanism can be followed to relatively high field intensities. From the results obtained here by this method it is concluded that at a field intensity of about 100 scotopic trolands the sensitivity of the rod mechanism to stimulus differences begins to fall off rapidly and that at about 2000 to 5000 scotopic trolands (corresponding approximately to daylight luminances of 120 to 300 cd/m2) the rod mechanism becomes saturated and is no longer capable of responding to an increase of stimulus. D'apres les resultats obtenus par cette methode, on conclut que, pour une intensite du champ d'environ 100 trolands scotopiques, la sensibilite des bâtonnets aux variations d'excitation commence a baisser rapidement et que, pour 2 000 a 5 000 trolands scotopiques (correspondant approximativement a des luminances de 120 a 300 cd/m2 en lumiere du jour) les bâtonnets se saturent et ne peuvent plus repondre a une augmentat.
Giant sharp converse magnetoelectric effect from the combination of a piezoelectric transformer with a piezoelectric/magnetostrictive laminated composite

Giant sharp converse magnetoelectric (CME) coefficient of 11.9G∕V is obtained in a heterostructure formed by combining a Rosen-type 0.7Pb(Mg1∕3Nb2∕3)O3–0.3PbTiO3 (PMN-PT) piezoelectric single-crystal transformer with a CME laminated composite of a length-magnetized Tb0.3Dy0. 7Fe1.92 (Terfenol-D) magnetostrictive alloy plate sandwiched between two thickness-polarized, electroparallel-connected PMN-PT piezoelectric single-crystal plates. The observed giant sharp CME is found to originate from the step-up voltage-gain effect in the transformer and the resonance CME effect in the laminated composite. This heterostructure has promising applications in electrically controlled magnetic memory devices.
Dynamical properties of compact groups of galaxies

Radial velocities are presented for 457 galaxies in the 100 Hickson compact groups. More than 84 percent of the galaxies measured have velocities within 1000 km/s of the median velocity in the group. Ninety-two groups have at least three accordant members, and 69 groups have at least four. The radial velocities of these groups range from 1380 to 42,731 km/s with a median of 8889 km/s, corresponding to a median distance of 89/h Mpc. The apparent space density of these systems ranges from 300 to as much as 10 exp 8 sq h/sq Mpc, which exceeds the densities in the centers of rich clusters. The median projected separation between galaxies is 39/h kpc, comparable to the sizes of the galaxies themselves. A significant correlation is found between crossing time and the fraction of gas-rich galaxies in the groups, and a weak anticorrelation is found between crossing time and the luminosity contrast of the first-ranked galaxy.
Small grains and IRAS colors

The paper studies how infrared colors of dust emission from the interstellar medium vary with the energy density of the radiation field on the basis of IRAS observation of the California Nebula. The data suggest that color variations result from a combinatin of equilibrium emission from large grains, and nonequilibrium emission from small grains, with destruction of the small grains emitting at 12 microns at high energy density; it is estimated that 80 percent of these small particles are destroyed for an energy density in ultraviolet photons larger than 50 times that of the average interstellar radiation field in the solar neighborhood. In a color-color diagram, I(v)(60 microns)/I(v)(100 microns) versus I(v)(12 microns)/I(v)(25 microns), the California Nebula measurements at various distances to the ionizing star Zeta Per follow a sequence similar to that of galaxies. This result shows that the position of a galaxy along this sequence is a measure of the intensity of the radiation field in the regions responsible for the infrared emission. 25 references.
On the real parts of zeros of exponential polynomials

In the study of linear differential systems with a single time lag we are led to the study of the nature of the zeros of the characteristic exponential polynomial, which are in general infinite in number. In questions of stability the primary problem is determining the nature of the real parts of these zeros, stability only occurring if the real parts are all negative. The most notable achievement in this line is that of Pontrjagin [2] which states that if the exponential polynomial lacks a principal term (see Bellman and Cooke [l, p. 440]), it has an infinite number of zeros with arbitrarily large positive real parts. What happens when there is a principal term has until now not been discussed. This paper proposes to fulfill that need. In many applications it is possible to vary the coefficients slightly, and, in so doing, alter the zeros slightly. With only a finite number of zeros with positive real parts it may be possible to alter the coefficients in such a way as to achieve stability. If an infinite number of zeros with arbitrarily large positive real parts occurs, any hope of stabilizing the system vanishes. We will consider a linear differential system with time lag r having as its characteristic equation (1) F(z) = z + as»+ • • • Kee~(z + hz~ + . • • ) = = 0
Evidence for Shock Precursors in Tycho’s Supernova Remnant

We report optical spectroscopy and imaging of Tycho's supernova remnant (SNR) which suggest that two different precursors are associated with the blast wave. In long-slit spectra of the eastern rim, we find diffuse Hα emission extending ≳1' ahead of Knot g, a bright nonradiative shock propagating at velocity ~2000 km s-1. In addition to the hydrogen lines, the diffuse spectrum also exhibits [S II] λλ6716, 6731; [N II] λ6583; and weak [O III] λ5007 emission. Narrowband imagery of Tycho's SNR shows that the diffuse emission extends ahead of most of the Balmer-dominated optical filaments and drops sharply in the remnant interior, suggesting that the diffuse gas is overrun by the supernova shock. The line ratios of the diffuse gas are compared with predictions from a simple He II λ304 photoionization precursor model. The models predict that the radiative transfer of He II λ304 photons in the precursor produces spatially distinct ionization layers of H0, He0-He+, N0-N++, O0-O++, and S+-S+3 ahead of the shock. The models suggest that the diffuse emission arises from collisional excitation in mostly neutral gas which has been heated to a temperature ~12,000 K. In high-resolution echelle spectra of Knot g, we find that the narrow Hα component is broadened to 44 ± 4 km s-1, suggesting that the upstream gas may be further heated before it crosses the shock, perhaps by a fast neutral or cosmic-ray precursor. High-resolution spectroscopy of the Hα line in both the diffuse region and Knot g will be required to definitively establish the existence of a second precursor.
Image processing for higher definition television (Invited Paper)

The paper discusses the application of digital image-processing techniques to broadcast television with the goal of picture quality improvement. After defining picture quality targets and levels of system compatibility, a review of techniques is presented. These fall into the categories of achieving a wider picture format, improving vertical and horizontal resolution, and improving accurate color reproduction. Specific algorithms for vertical resolution improvement by display scan conversion and horizontal resolution improvement by three-dimensional signal processing are described. Many other approaches are also summarized and referenced, with a particular emphasis on European work.
LOG CANONICAL THRESHOLDS OF SMOOTH FANO THREEFOLDS

The complex singularity exponent is a local invariant of a holomorphic function determined by the integrability of fractional powers of the function. The log canonical thresholds of effective -divisors on normal algebraic varieties are algebraic counterparts of complex singularity exponents. For a Fano variety, these invariants have global analogues. In the former case, it is the so-called -invariant of Tian; in the latter case, it is the global log canonical threshold of the Fano variety, which is the infimum of log canonical thresholds of all effective -divisors numerically equivalent to the anticanonical divisor. An appendix to this paper contains a proof that the global log canonical threshold of a smooth Fano variety coincides with its -invariant of Tian. The purpose of the paper is to compute the global log canonical thresholds of smooth Fano threefolds (altogether, there are 105 deformation families of such threefolds). The global log canonical thresholds are computed for every smooth threefold in 64 deformation families, and the global log canonical thresholds are computed for a general threefold in 20 deformation families. Some bounds for the global log canonical thresholds are computed for 14 deformation families. Appendix A is due to J.-P. Demailly.
Cross-over Trials in Clinical Research

tween different measurements and to study relationships of the response (outcome) variable with other variables when the response variable is continuous, dichotomous, or categorical. Methods and discussions are also provided for the situations where experimental studies or missing data are involved. Each chapter contains examples, accompanied by computer outputs and their interpretation. Basically, the examples use the same longitudinal dataset, which consists of an outcome variable measured six times and four continuous or dichotomous, time-dependent or time-independent predictor variables. The author has made an effort to avoid heavy mathematical notation and formulas in presenting the statistical methods. Instead, many tables, diagrams, and plots are used for illustration. At the beginning, after a brief introduction to the subject as well as the standard statistical tools, the author covers some basic issues of longitudinal studies, such as different study designs and problems that commonly arise in longitudinal studies.This may well prepare the readers for the remainder of the book. The overview of the use of longitudinal data analysis with a few major statistical software packages (e.g., SAS, S–PLUS, STAT, SPSS) may be quite helpful. Overall, the book is well written, and the material is rich and carefully organized. The book might have been more naturally organized if the brief review on sample-size calculations had been presented in Chapter 2 (“Study Design”) instead of as a separate chapter at the end. This is not a textbook, and the author does not intend it to serve as such. Rather, the book is a welcome reference manual or practical guide for practitioners of statistical methods in (but not limited to) epidemiological and clinical studies. The book’s main value is in its rather comprehensive presentation of a collection of longitudinal data analyses arising from different research questions. In this sense, the book is unique. Some practitioners of statistics may have struggled to learn longitudinal data analysis by reading manuals of software packages. This book is potentially of great benefit to them.
Hausdorff dimension of Markov invariant sets

One of the old questions about exceptional minimal sets of codimension-one $C^{2}$-foliations of compact manifolds reads (compare [La]): Is the Lebesgue measure $|\mathscr{M}|$ of any exceptional minimal set ,St equal to $0$ ? The answer in general is still unknown. The class of Markov minimal sets was introduced by John Cantwell and Lawrence Conlon [CC] in the context of this question. Among the other results, they proved that $|\mathscr{M}|=0$ if $\mathscr{M}$ is a Markov exceptional minimal set. The same result in the particular case of a Markov exceptional minimal set with holonomy generated by two maps defined on a common interval was obtained in [Mat]. In $[LaW]$ , while studying relations between different invariants describing the dynamics of foliations, the authors observed that the question about the Hausdorff dimension $\dim_{H}$ of exceptional minimal sets is also of some interest. Since the inequality
A laboratory model for the general ocean cicrulation

A laboratory model for the study of a barotropic general ocean circulation has been constructed following the strict geometrical constraints of the B-plane approximation. Fluid is confined by plastic blocks to the volume defined by the intersection of two spherical surfaces, of common centre and slightly different radii with a circular cylinder whose axis intersects the centre of the spheres. The entire system is rotated and an interior circulation is provided by relative rotation of one of the bounding blocks. Uniform density of the rigidly enclosed fluid ensures the irrelevance of laboratory gravity and the absence of centrifugal effects on the flow. Fluid flow is observed with an electrochemical technique. Lines of coloured fluid which move with the local velocity are produced and photographed; velocities are inferred to 5% accuracy. Rossby numbers from 1.3 x 10-4 to 7.7 and Ekman numbers from 3.1 x 10-4 to 3.1 x 10-2 have been achieved. The apparatus can be oriented at an arbitrary mean latitude. The phenomena characteristic of linear subtropical gyres have been observed: a meridional Sverdrup flow, its associated zonal flow and a western boundary current. The existence, structure, and parameter dependencies of these features are in good agreement with the predictions of a general linear boundary layer analysis which has been developed for a thin barotropic ocean. The Sverdrup vorticity balance and the width and structure of the bottom frictional western boundary current have been established within the experimental uncertainties. In the nonlinear regime the position of the centre of the gyre has been measured as it migrates north-westward; a poleward eastern boundary current appears. These results agree with theoretical estimates for the onset of nonlinear behaviour. A long period time dependent flow is observed for high Rossby number. Quantitative studies have been made on an equatorial undercurrent which moves in a direction opposite to the surface forcing velocity. For low Rossby numbers this flow reverses with change in direction of the forcing velocity. In the nonlinear regime, the westward flowing undercurrent developed a streakiness and disappeared; whereas the eastward flowing current remained defined and measurable.
Waveguide propagation of ambient sound in the ocean-surface bubble layer

Measurements of the ambient sound generated by breaking waves over the range 40–20 000 Hz reveal well‐defined spectral peaks, the frequency of which may remain generally consistent from one breaking event to the next, but which can change significantly over the course of a storm, or from one storm to another. A theory is proposed, based on the concept of trapping of a portion of the sound in the waveguide formed by the ocean‐surface bubble layer. Simultaneous measurements of the bubble population and size distribution as a function of depth and time were obtained with a multifrequency inverted echo sounder, allowing calculation of the resulting (dispersive) sound‐speed anomaly profile. Theoretical predictions of the spectral peaks, which are associated with modal cutoff frequencies, are in good agreement with the observations. It is suggested that this result might have application to the remote determination of ocean‐surface bubble fields relevant to the study of wave breaking, turbulence, and the air–se.
Numerical solution of an evolution equation with a positive-type memory term

Abstract We study the numerical solution of an initial-boundary value problem for a Volterra type integro-differential equation, in which the integral operator is a convolution product of a positive-definite kernel and an elliptic partial-differential operator. The equation is discretised in space by the Galerkin finite-element method and in time by finite differences in combination with various quadrature rules which preserve the positive character of the memory term. Special attention is paid to the case of a weakly singular kernel. Error estimates are derived and numerical experiments reported.
Production of LaCaMnO_3 Composite by Ball Milling

La0.67Ca0. 33MnO3 perovskite-type manganite was synthesized by high-energy ball milling raw oxides of La2O3 (purity 99.9%), CaCO3 (purity > 99%), and MnO (purity > 99%). The ratio of ball and powder weight was 10:1 and the rotating speed was set to 500 rpm. X-ray analysis indicated that La0.67Ca0. 33MnO3 single phase was formed completely when milling time is up to 4 h. The peak intensity of perovskite structure decreased and a hump-like peak appeared with further milling time. When the milling time is longer than 40 h, the perovskite structure disappeared and the amorphous phase was formed completely. Scanning electron microscopy picture of 24 h milled sample showed that the particle size generally varies in a broad range from nanometer scale to a few μm. The magnetic measurements showed that ball milling samples have an inhomogeneous magnetic state and exhibit spin-glass like behavior. The signi cantly small magnetic entropy change and a remarkably broad temperature interval in entropy change were attributed to high degree of structural and magnetic disorder and broadening of magnetic transition.
Thermomigration in Pb-free SnAg solder joint under alternating current stressing

Lead-free solders have been adopted by the microelectronics industry. However, their thermomigration behaviors are unclear. Thermomigration in eutectic SnAg3.5 solder joints was investigated using an alternating current (ac) of 0.57 A at 100 °C. The ac eliminates the electromigration effect and creates a thermal gradient of 2829 °C/cm, facilitating the study of thermomigration. Arrays of tiny markers fabricated by a focused ion beam are employed to measure the thermomigration rate. It is found that Sn atoms migrated toward the hot end. The thermomigration flux and molar heat of transport are measured to be 5.0×1012 atoms/cm2 and 1.36 kJ/mole, respectively.
RANDOM OPPORTUNITIES FOR REDUCED COST REPLENISHMENTS

In this paper we consider the situation where the typical assumptions underlying the EOQ model are appropriate for an item, in particular a reasonably level demand rate exists. However, opportunities for special replenishments at a reduced unit cost occur at random. The following type of 3-parameter policy is considered. When a non-special (regular) replenishment is made, an order-up-to-level, S1;, is used. When a special opportunity arises we only take advantage of it if the current inventory is low enough (L2 or lower) and we order enough to raise the inventory level to S1. This situation was modelled earlier in the literature, but the solution procedure suggested involved a 3-dimensional search on the three control parameters, S1,, L2, and S2. We develop an approximate solution method which is much easier to use and which performs excellently on a wide range of examples. The performance of an even more simple method, based on always taking advantage of a special opportunity to replenish at reduced unit.
A Simulation Study of Multiple Comparisons with the Average under Heteroscedasticity

Abstract In many experimental situations, the average treatment performance within its own group is used as a benchmark to be compared with each individual treatment. Multiple comparison procedures with the average (MCA) are thus proposed. A simulation comparison study of the traditional MCA, the single-stage MCA and the two-stage MCA for normal distribution under heteroscedasticity is investigated by the Monte-Carlo techniques in this paper. It was found that the two-stage MCA has shorter confidence length than the single-stage MCA for most cases and it is also more robust for non-normal distributions. Therefore, the two-stage MCA is recommended. But when the additional samples at the second stage could be costly, the data-analysis oriented single-stage MCA can be used. A biometrical example to illustrate the single-stage MCA and the two-stage MCA with equal confidence length is also given in this article.
Spatial periodicity of spatially evolving turbulent flow caused by inflow boundary condition

Space-time evolution of a flow in a semi-infinite circular pipe {x⩾0,y2+z2⩽R2} is investigated via direct numerical simulations. The unsteady turbulent inflow velocity u∣x=0 is extracted from a streamwise-periodic auxiliary simulation. It is shown that at t≫0 spatially evolving flow does not depend on initial state u∣t=0. It takes the form of spatially periodic flow of the auxiliary simulation with superimposed spatially growing perturbation. The amplitude of the perturbation increases exponentially with distance from the inlet. The growth rate is estimated for the considered Reynolds number. The obtained results suggest that the memory of the inflow boundary condition in spatial simulations is evident for a significant distance from the inlet. In the considered case an almost periodic flow is established (with less than 1% relative deviation from the periodicity) over a distance as large as 70 pipe radii.
Classification of 4-Dimensional Generalized Symmetric Planes

A generalized Symmetrie plane is a stable plane with a compatible structure of a generalized Symmetrie space in the sense of differential geometry. This paper gives a complete classification of all 4-dimensional generalized Symmetrie planes. It is shown that a 4dimensional Symmetrie plane is isomorphic to an affine translation plane, to a Symmetrie or hermitian subplane of P2 C, or to the exceptional plane ΕΛ that is defined in this paper. The exceptional plane Em has symmetries exactly of order 3. It cannot be embedded into P2 C and has no 2-symmetric structure. Furthermore, the point space of ΕΛ is isomorphic to the affine Symmetrie space of type III of order 3. 1980 Mathematics Subject Classification (1985 Revision): 51H10, 53C35, 22E60.
Optical processes in quantum dots and wires

Quantum wires and dots are unique condensed matter systems where electron and hole localization can be achieved by lateral confinement down to quasi 0-dimensions. Here we review how these nanostructures are realized and their optical properties, mainly from an experimental point of view. We discuss changes in the energy and momentum mechanisms as the lateral dimensions are reduced, such as the so-called photon bottleneck, using the example of GaAs-GaAlAs quantum dots and wires. Examples of strain-relief by deep etching in both nominally lattice-matched and strained materials are given. The emission of hot luminescence or resonant Raman scattering from dots and wires is shown to be a fingerprint of exciton localization. Manu-body effects are shown to be important in nanostructures such as GaAs- GaAlAs and Si-SiGe dots and wires. The emergence of ultrathin submonolayer quantum wells has provided further insights into the role of exciton localization in nanostructures, and we discuss here the case of submonolayers of in-As embedded in a GaAs matrix. Considerations for devices are discussed along with future trends in the field.