Quantitative χn analysis of HREM images with applications to planar defects

Author(s):  
H. Zhang ◽  
L. D. Marks

A number of different methods have been suggested in the literature for using HREM in a quantitative fashion, including R factors and cross-correlation analyses. The problem with many of these is that it is difficult to realistically gauge the errors involved when they are applied to real systems. For instance, R-factors defined by:(1)(where n=1 or 2 and Ic is the calculated image, Ie the experimental data) assume a signal independent error. Furthermore, the absolute value of R is strongly dependent upon background levels which is misleading.

2015 ◽  
Vol 36 (4) ◽  
pp. 1037-1066 ◽  
Author(s):  
IDRIS ASSANI ◽  
DAVID DUNCAN ◽  
RYO MOORE

In this paper we extend Bourgain’s double recurrence result to the Wiener–Wintner averages. Let $(X,{\mathcal{F}},{\it\mu},T)$ be a standard ergodic system. We will show that for any $f_{1},f_{2}\in L^{\infty }(X)$, the double recurrence Wiener–Wintner average $$\begin{eqnarray}\frac{1}{N}\mathop{\sum }_{n=1}^{N}f_{1}(T^{an}x)f_{2}(T^{bn}x)e^{2{\it\pi}int}\end{eqnarray}$$ converges off a single null set of $X$ independent of $t$ as $N\rightarrow \infty$. Furthermore, we will show a uniform Wiener–Wintner double recurrence result: if either $f_{1}$ or $f_{2}$ belongs to the orthogonal complement of the Conze–Lesigne factor, then there exists a set of full measure such that the supremum on $t$ of the absolute value of the averages above converges to $0$.


2012 ◽  
Vol 85 (2) ◽  
pp. 202-216 ◽  
Author(s):  
BARBARA PRZEBIERACZ

AbstractWe investigate the Pexider-type functional equation where f, g, h are real functions defined on an abelian group G. We solve this equation under the assumptions G=ℝ and f is continuous.


1993 ◽  
Vol 113 (3) ◽  
pp. 473-478
Author(s):  
F. E. A. Johnson

We introduce a rational-valued invariant which is capable of distinguishing between the commensurability classes of certain discrete groups, namely, the fundamental groups of smooth closed orientable aspherical manifolds of dimensional 4k(k ≥ 1) whose Euler characteristic χ(Λ) is non-zero. The invariant in question is the quotientwhere Sign (Λ) is the absolute value of the signature of the intersection formand [Λ] is a generator of H4k(Λ; ℝ).


1931 ◽  
Vol 4 (4) ◽  
pp. 507-513 ◽  
Author(s):  
Kyoichi Hada ◽  
Koichi Fukaya ◽  
Takeji Nakajima

Abstract 1. The heat of vulcanization of the system: pure rubber-sulfur is determinated. 2. The absolute value of the experimental data is in doubt, however, since the results were widely different from those of Blake. 3. The experimental results are discussed. 4. The results of Blake are discussed. 5. The difference from the results of Blake is attributed to the difference in the content of resinous substances in the sample.


2012 ◽  
Vol 85 (2) ◽  
pp. 191-201 ◽  
Author(s):  
BARBARA PRZEBIERACZ

AbstractWe investigate the Pexider-type functional equation where f,g,h are real functions defined on an abelian group G.


2015 ◽  
Vol 25 (3) ◽  
pp. 484-485 ◽  
Author(s):  
TIM AUSTIN

In my recent paper [1] there is a mistake in the proof of Corollary 3. The first line of the displayed equation in that proof asserts that \[\int_G|\langle u,\pi^g v\rangle_V|^2\,\rm{d} g = \int_G\langle u\otimes u,(\pi^g\otimes \pi^g)(v\otimes v)\rangle_{V\otimes V}\, \rm{d} g.\] However, since the paper uses complex-valued representations, the integrand on the right here may not retain the absolute value of that on the left. Without this equality, the proof of Corollary 3 can no longer be reduced to an application of Lemma 2. However, it can be proved directly from Schur Orthogonality along very similar lines to the proof of Lemma 2.


1957 ◽  
Vol 3 (2) ◽  
pp. 102-104 ◽  
Author(s):  
P. Erdös

Letbe the rath cyclotomic polynomial, and denote by An the absolute value of the largest coefficient of Fn(x).Schur proved thatand Emma Lehmer [5] showed that An>cn1/3 for infinitely many n; in fact she proved that n can be chosen as the product of three distinct primes. I proved [3] that there exists a positive constant q such that, for infinitely many nand Bateman [1] proved very simply that, for every ∈>0 and all n>no(∈),


1962 ◽  
Vol 14 ◽  
pp. 511-518 ◽  
Author(s):  
A. G. Kislyakov

The aim of this communication is to present the results of an experimental research on the intensity of the radio emission of the Moon at 4 mm and to describe the method followed in observations and reductions. It was established that the radio brightness of the Moon,Tl, varies during the lunation according to the law:Tl= 230° + 73° cos (Ω0t-24°)K. The accuracy in measuring the absolute value of Moon's radio temperature is about ± 10%. The comparison between the phase dependence of the radio emission of the Moon at 4 mm and the data from observations of the radio temperature of the lunar disk on other wave lengths demonstrated that the homogeneous model of Moon's surface is in good agreement with the experimental data.


1986 ◽  
Vol 99 (2) ◽  
pp. 189-193 ◽  
Author(s):  
R. W. K. Odoni

In [3, 4] we showed how the use of a random-walk analogue can be made to yield non-trivial information about the behaviour of certain trigonometric sums in one variable. Our aim here is to show how our method can be adapted to yield similar results for a broad class of trigonometric sums in several variables. Letbe a polynomial in v independent variables with integral coefficients. We choose integers n ≥ 0, d ≥ 1 and p ≥ 2 with p prime, and assume that f(x) has total degree ≤ d + 1. We shall consider the problem of obtaining non-trivial upper bounds for the absolute value of sums of the typewhere P = {1, 2, …, p} and f is non-constant.


Author(s):  
F. T. Farmer ◽  
John Ashworth Ratcliffe ◽  
Edward Victor Appleton

In most of the investigation which have been made on wireless waves reflected from the ionosphere the experiments have been so designed as to provide information concerning the ionization density at different levels. The experimental data sought in such cases are usually critical penetration frequencies and equivalent heights of reflection. If, however, the amplitude of the downcoming waves is also observed, and the total absorption measured, it is possible to obtain information about the frequency of collision between electrons and molecules at different heights in the ionosphere. The measurements described in the present paper have been made so as to provide the latter type of information, and in particular to give evidence concerning the location of that part of the ionosphere which is of importance in producing absorption. For this purpose it is necessary to measure the absolute value of the absorption suffered by the wave, so that results on different wave-lengths may be compared. The methods which we have employed in making these measurements are described in § 2 and the results are discussed in § 4. The theoretical results which are used in § 4 are reviewed shortly in § 3. Most of the measurements discussed in this paper have been made on wave-lengths less than 200 m; a few measurements made with longer waves are discussed in § 6.


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