AN IMAGE ANALYSIS OF MULTIPLE‐LAYER RESISTIVITY PROBLEMS

Geophysics ◽  
1959 ◽  
Vol 24 (3) ◽  
pp. 485-509 ◽  
Author(s):  
Irwin Roman

The Kelvin method of images is expressible by a transflection at a boundary. The original source is augmented by a supplement and a complement. The supplement contributes to the potential on the same side of the boundary as the source, but it lies at the optical image position of the source in the boundary. The complement lies at the position of the source but contributes to the potential on the opposite side of the boundary. For two or more boundaries, there are two exterior regions and one or more interior regions. For a source in the top layer, a primary sequence starts with a downward transflection and a secondary sequence with an upward transflection. To each primary sequence of transflections there corresponds a secondary sequence with an upward transflection at the upper boundary ahead of it. The exterior images are not transflected again. Successive transflections occur at adjacent boundaries, suggesting a link of two transflections. To a sequence of links, called a chain, there corresponds an associated sequence, obtained by dropping the last transflection. Exterior images follow from interior, associated from chain, and secondary from primary. Thus, only primary, interior, chain images need to be traced. Each potential is the sum of terms of the form m/r where m is the strength of a specific image, r is the distance of that image from the test point, and the sum includes all images contributing to that potential. The addition of each boundary introduces images and potentials that must be added to those existing prior to the introduction, but it does not otherwise alter them. For the three‐boundary problem, the separate image strengths are determined by simple multiplication after a kernel polynomial is calculated. The latter is a finite polynomial in the reflection‐factor at the middle boundary and can be tabulated. For the images of a specific potential and depth group, the strengths satisfy a recursion formula that serves as a check on direct evaluations.

1948 ◽  
Vol 44 (3) ◽  
pp. 342-344 ◽  
Author(s):  
P. A. P. Moran

A rubber molecule containing n + 1 carbon atoms may be represented by a chain of n links of equal length such that successive links are at a fixed angle to each other but are otherwise at random. The statistical distribution of the length of the molecule, that is, the distance between the first and last carbon atoms, has been considered by various authors (Treloar (1) gives references). In particular, if the first atom is kept fixed at the origin of a system of coordinates and the chain is otherwise at random, it has been conjectured that the distribution of the (n + 1)th atom will tend, as n increases, towards a three-dimensional normal distribution of the formwhere σ depends on n. Thus r2 (= x2 + y2 + z2) will be approximately distributed as σ2χ2 with three degrees of freedom.


1995 ◽  
Vol 27 (3) ◽  
pp. 652-691 ◽  
Author(s):  
Harry Kesten

We consider positive matrices Q, indexed by {1,2, …}. Assume that there exists a constant 1 L < ∞ and sequences u1< u2< · ·· and d1d2< · ·· such that Q(i, j) = 0 whenever i < ur < ur + L < j or i > dr + L > dr > j for some r. If Q satisfies some additional uniform irreducibility and aperiodicity assumptions, then for s > 0, Q has at most one positive s-harmonic function and at most one s-invariant measure µ. We use this result to show that if Q is also substochastic, then it has the strong ratio limit property, that is for a suitable R and some R–1-harmonic function f and R–1-invariant measure µ. Under additional conditions µ can be taken as a probability measure on {1,2, …} and exists. An example shows that this limit may fail to exist if Q does not satisfy the restrictions imposed above, even though Q may have a minimal normalized quasi-stationary distribution (i.e. a probability measure µ for which R–1µ = µQ).The results have an immediate interpretation for Markov chains on {0,1,2, …} with 0 as an absorbing state. They give ratio limit theorems for such a chain, conditioned on not yet being absorbed at 0 by time n.


1970 ◽  
Vol 7 (01) ◽  
pp. 89-98
Author(s):  
John Lamperti

In the first part of this paper, we will consider a class of Markov chains on the non-negative integers which resemble the Galton-Watson branching process, but with one major difference. If there are k individuals in the nth “generation”, and are independent random variables representing their respective numbers of offspring, then the (n + 1)th generation will contain max individuals rather than as in the branching case. Equivalently, the transition matrices Pij of the chains we will study are to be of the form where F(.) is the probability distribution function of a non-negative, integervalued random variable. The right-hand side of (1) is thus the probability that the maximum of i independent random variables distributed by F has the value j. Such a chain will be called a “maximal branching process”.


1955 ◽  
Vol 75 ◽  
pp. 1-6
Author(s):  
J. K. Anderson
Keyword(s):  
The Body ◽  
A Chain ◽  

The vase here described was recently presented to the Otago Museum in commemoration of the distinguished services of Dr. H. D. Skinner, for many years Director of the Museum. It was formerly on the Rome market. It is restored from fragments, and missing pieces of the neck, mouth, and shoulder have been replaced by plaster. The joints and plaster restorations have been carefully painted over, and there has been a good deal of repainting where the glaze was worn. On the mouth, neck, and shoulder the restorations, though extensive, merely fill gaps in a well-defined pattern, and can therefore be passed over without a detailed description. The repainting of the figures on the body of the vase will be described at greater length below. The clay is a fine, clear red, rather lighter than the usual colour of Attic. The principal dimensions of the vase are as follows (measurements in metres):The body is ovoid, with high, flat shoulders. It is separated from the wide flaring foot by a low, raised ridge. A similar ridge separates the shoulder from the neck, which is cylindrical with slightly concave sides. The lip flares widely. The side handles are small and slope slightly upward; they are attached just above the widest part of the vase and below the sharpest curve of the shoulder. The vertical handle is divided by three deep, vertical grooves. The inside of the mouth and the upper surface of the foot are ornamented with rounded tongues of black glaze. These were painted alternately red and white, but the paint, which was applied on top of the black glaze, is now much worn. On the lower part of the body are short black rays; above these is a rather wider zone with a chain of five-petalled lotuses linked to five-leaved palmettes.


1940 ◽  
Vol 5 (4) ◽  
pp. 150-151 ◽  
Author(s):  
James Dugundji

The object of this note is to show that there is no finite characteristic matrix for any one of Lewis and Langford's systems.Theorem I. There is no finite characteristic matrix for any one of the systems S1–S5.Proof. Let M be a matrix with less than n elements for which all the provable formulas in S1, or S2, or S3, or S4, or S5, are satisfied. Let Fn represent the formulawhere ∑ stands for a ∨-chain, and the pi, are variables in any one of the calculi. Using M, there is always at least one summand in Fn where pi and pk have the same value. Therefore, Fn can always be written in the form (a = a)∨ B, and thus will give, for any B, a “designated” value, since the formula (p = p) ∨ q is provable in any one of the systems S1–S5.Give to any one of the systems S1–S5, the following matrix, due to Henle:1. Elements: all possible classes formed from the integers 1, 2, 3, …, n.2. “Designated” element: the class {1, 2, 3, …,n}.3. Boole-Schröder algebra on the elements.4. ◊N = N (N the null class)◊A = {1, 2, …, n} (A any non-null class).5


2016 ◽  
Vol 81 (1) ◽  
pp. 237-263 ◽  
Author(s):  
NATASHA DOBRINEN

AbstractThe generic ultrafilter${\cal G}_2 $forced by${\cal P}\left( {\omega \times \omega } \right)/\left( {{\rm{Fin}} \otimes {\rm{Fin}}} \right)$was recently proved to be neither maximum nor minimum in the Tukey order of ultrafilters ([1]), but it was left open where exactly in the Tukey order it lies. We prove${\cal G}_2 $that is in fact Tukey minimal over its projected Ramsey ultrafilter. Furthermore, we prove that for each${\cal G}_2 $, the collection of all nonprincipal ultrafilters Tukey reducible to the generic ultrafilter${\cal G}_k $forced by${\cal P}\left( {\omega ^k } \right)/{\rm{Fin}}^{ \otimes k} $forms a chain of lengthk. Essential to the proof is the extraction of a dense subsetεkfrom (Fin⊗k)+which we prove to be a topological Ramsey space. The spacesεk,k≥ 2, form a hierarchy of high dimensional Ellentuck spaces. New Ramsey-classification theorems for equivalence relations on fronts on εkare proved, extending the Pudlák–Rödl Theorem for fronts on the Ellentuck space, which are applied to find the Tukey and Rudin–Keisler structures below${\cal G}_k $.


1970 ◽  
Vol 7 (1) ◽  
pp. 89-98 ◽  
Author(s):  
John Lamperti

In the first part of this paper, we will consider a class of Markov chains on the non-negative integers which resemble the Galton-Watson branching process, but with one major difference. If there are k individuals in the nth “generation”, and are independent random variables representing their respective numbers of offspring, then the (n + 1)th generation will contain max individuals rather than as in the branching case. Equivalently, the transition matrices Pij of the chains we will study are to be of the form where F(.) is the probability distribution function of a non-negative, integervalued random variable. The right-hand side of (1) is thus the probability that the maximum of i independent random variables distributed by F has the value j. Such a chain will be called a “maximal branching process”.


Author(s):  
Rahul Shukla ◽  
Richard Billings ◽  
Anurag Bakhshi ◽  
John Schulze ◽  
Atchyuth Gorti ◽  
...  

Abstract In general, scan shift failures are difficult to debug. Usually we use the compressed-mode chain test or scan capture-based chain diagnosis to ascertain the small chain segment or the position of the sequential element in the chain that is the cause of the failure. This method of diagnosis works well when the failures are static and limited to a chain segment, but fails to give results when the failure is caused by intra chain or inter chain segment interactions. This paper presents a scenario in which the root cause of the chain failures was due to interaction between chains. We call it the “invisible flaky chain defect” because -- although we were able to replicate failure at a test point (voltage-frequency) on the Shmoo -- the failing cycles changed from run to run.


1978 ◽  
Vol 15 (02) ◽  
pp. 321-339 ◽  
Author(s):  
Gérard Letac

Nelson [9], [10] has computed the generating function of return probabilities to the initial state for a particular Markov chain on permutations of three objects. The formula obtained is The present paper studies three distinct Markov chains generalizing the Nelson chain: the so-called three-coloured chain, with some birth-and-death processes on ℤ as a particular case, a chain on a graph close to the graph of the edges of a cube, and the daisy library. Two other themes piece together these chains: the notion of coloured chain and the technique of computation by additive processes.


Author(s):  
Yu-Liang Liu

With the commutation relations of the spin operators, we first write out the equations of motion of the spin susceptibility and related correlation functions that have a hierarchical structure, then under the “soft cut-off” approximation, we give a set of equations of motion of spin susceptibilities for a spin [Formula: see text] antiferromagnetic Heisenberg model that is independent of whether or not the system has a long-range order in the low energy/temperature limit. Applying for a chain, a square lattice and a honeycomb lattice, respectively, we obtain the upper and the lowest boundaries of the low-lying excitations by solving this set of equations. For a chain, the upper and the lowest boundaries of the low-lying excitations are the same as that of the exact ones obtained by the Bethe ansatz, where the elementary excitations are the spinon pairs. For a square lattice, the spin wave excitation (magnons) resides in the region close to the lowest boundary of the low-lying excitations, and the multispinon excitations take place in the high-energy region close to the upper boundary of the low-lying excitations. For a honeycomb lattice, we have one kind of “mode” of the low-lying excitation. The present results obey the Lieb–Schultz–Mattis theorem, and they are also consistent with recent neutron scattering observations and numerical simulations for a square lattice.


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