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# Collision and avalanche effect in families of pseudorandom binary sequences

Author: Viktória Tóth

## Abstract

Recently a constructive theory of pseudorandomness of binary sequences has been developed and many constructions for binary sequences with strong pseudorandom properties have been given. In the applications one usually needs large families of binary sequences of this type. In this paper we adapt the notions of collision and avalanche effect to study these pseudorandom properties of families of binary sequences. We test two of the most important constructions for these pseudorandom properties, and it turns out that one of the two constructions is ideal from this point of view as well, while the other construction does not possess these pseudorandom properties.

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# The study of collision and avalanche effect in a family of pseudorandom binary sequences

Author: Viktória Tóth

## Abstract

In an earlier paper we studied collisions and avalanche effect in two of the most important constructions given for large families of binary sequences possessing strong pseudorandom properties. It turned out that one of the two constructions (which is based on the use of the Legendre symbol) is ideal from this point of view, while the other construction (which is based on the size of the modulo p residue of f(n) for some polynomial f(x) ∈

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\mathbb{F}_p$$ \end{document}
[x]) is not satisfactory since there are “many” collisions in it. Here it is shown that this weakness of the second construction can be corrected: one can take a subfamily of the given family which is just slightly smaller and collision free.

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# Extension of the notion of collision and avalanche effect to sequences of k symbols

Author: Viktória Tóth

## Abstract

In recent papers [14], [15] I studied collision and avalanche effect in families of finite pseudorandom binary sequences. Motivated by applications, Mauduit and Sárközy in [13] generalized and extended this theory from the binary case to k-ary sequences, i.e., to k symbols. They constructed a large family of k-ary sequences with strong pseudorandom properties. In this paper our goal is to extend the study of the pseudorandom properties mentioned above to k-ary sequences. The aim of this paper is twofold. First we will extend the definitions of collision and avalanche effect to k-ary sequences, and then we will study these related properties in a large family of pseudorandom k-ary sequences with “small” pseudorandom measures.

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# Petrogenetic and tectonic aspects of collisional granitoids from the Sanandaj-Sirjan Belt of Iran

Authors: Robab Hajialioghli and Mohssen Moazzen

F. Mouthereau 2005 Convergence history across Zagros (Iran): Constraints from collisional and earlier deformation International Journal of Earth Sciences

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# First report of a malignant collision skin tumour with malignant melanoma and anaplastic sarcoma components in a dog

Authors: Csaba Jakab and Gyula Balka

Cantor, A. S., Moschos, S. and Jukic, D. M. (2010): A principal case of multiple lymphoid collision tumors involving both B-cell chronic lymphocytic leukemia and metastatic malignant melanoma. Dermatol. Online J

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# Collisional processes in muon catalyzed fusion as studied by the classical collision theory

Authors: Kwang-Pill Lee, Kil-Oung Choi, Sun-Tae Hwang, Y. Yamada and Sh. Ohno

## Abstract

Collisional processes involving a negative muon in the deuterium and tritium system were studied using the classical binary encounter theory. The time needed for slowing down of a 10 keV muon was found to be of the order of 10–8s to 10–12s, depending on the density of the system. The Sticking Probabilities for the d-t and d-d fusions were obtained to be 0.48% and 10.2%, respectively. The usefulness of the classical model for understanding fundamental processes in muon catalyzed fusion is suggested.

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# Calculation of cross sections for positron-Ar collisions

Authors: K. Tókési and Á. Kövér

## Abstract

The three-body classical trajectory Monte-Carlo (CTMC) method is used to investigate positron-argon atom collisions. The total ionization cross sections are presented along with singly and doubly differential cross sections. The existence of the cusp-like peak in the triply differential electron and positron spectra at positron impact is predicted.

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# Collision cell chemistry for the analysis of radioisotopes by inductively coupled plasma mass spectrometry

Authors: V. Epov, V. Taylor, D. Lariviere, R. Evans and R. Cornett

## Abstract

The application of reaction and collisional chemistry with inductively coupled plasma mass spectrometry for the measurement of 90Sr, 135Cs, 137Cs, 210Pb, and 226Ra were investigated. Improvement in sensitivity of all the aforementioned radioisotopes was found by optimization of the collision cell parameters. It was demonstrated that the measurements of radiocesium and radiostrontium require different collision cell parameters if they are measured in the presence or absence of Ba and Zr. The detection limits were improved by a factor of 100, 33, 22, 500, and 50 for 90Sr, 135Cs, 137Cs, 210Pb, and 226Ra, respectively.

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# Direct determination of 226Ra in environmental matrices using collision cell inductively coupled plasma mass-spectrometry

Authors: V. Epov, D. Lariviere, R. Evans, C. Li and R. Cornett

## Abstract

Direct determination of 226Ra in complex environmental matrices (biological and uranium ore samples) by collision-cell inductively coupled plasma mass-spectrometry was investigated. Possible polyatomic interferences were studied and their effects on 226Ra measurements were determined. The instrumental conditions for optimal signal-to-noise ratio for 226Ra were found. Concentrations of 226Ra in certified reference samples were measured using both external calibration and standard addition approaches. The best precision was obtained by applying standard additions. The absolute detection limit for 226Ra was 1 fg with optimal gas flow rates for the collision cell of 7 ml.min-1 for helium and 4 ml.min-1 for hydrogen.

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# Atomic collision induced projectile excitation—Its application to identification of heavy ion fusion products

Authors: W. Faust, P. Armbruster, S. Hofmann, G. Münzenberg, H. Ewald and K. Güttner

## Abstract

Collision induced X-rays are shown to be a useful tool to determine atomic numbers and yields of heavy ion fusion products. In the reaction56Fe(132Xe; xn, yp) the elements Hg, Au, and Pt are produced as primary fusion products. A resolving power Z/ΔZ of 72±7 has been obtained. Improvements and restrictions of the method are discussed.

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