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On the Permutations Generated by Cyclic Shift
1 2 Journal of Integer Sequences, Vol. 14 (2011), 3 Article 11.3.2 47 6 23 11 On the Permutations Generated by Cyclic Shift St´ephane Legendre Team of Mathematical Eco-Evolution Ecole Normale Sup´erieure 75005 Paris France [email protected] Philippe Paclet Lyc´ee Chateaubriand 00161 Roma Italy [email protected] Abstract The set of permutations generated by cyclic shift is studied using a number system coding for these permutations. The system allows to find the rank of a permutation given how it has been generated, and to determine a permutation given its rank. It defines a code describing structural and symmetry properties of the set of permuta- tions ordered according to generation by cyclic shift. The code is associated with an Hamiltonian cycle in a regular weighted digraph. This Hamiltonian cycle is conjec- tured to be of minimal weight, leading to a combinatorial Gray code listing the set of permutations. 1 Introduction It is well known that any natural integer a can be written uniquely in the factorial number system n−1 a = ai i!, ai ∈ {0,...,i}, i=1 X 1 where the uniqueness of the representation comes from the identity n−1 i · i!= n! − 1. (1) i=1 X Charles-Ange Laisant showed in 1888 [2] that the factorial number system codes the permutations generated in lexicographic order. More precisely, when the set of permutations is ordered lexicographically, the rank of a permutation written in the factorial number system provides a code determining the permutation. The code specifies which interchanges of the symbols according to lexicographic order have to be performed to generate the permutation. -
4. Groups of Permutations 1
4. Groups of permutations 1 4. Groups of permutations Consider a set of n distinguishable objects, fB1;B2;B3;:::;Bng. These may be arranged in n! different ways, called permutations of the set. Permu- tations can also be thought of as transformations of a given ordering of the set into other orderings. A convenient notation for specifying a given permutation operation is 1 2 3 : : : n ! , a1 a2 a3 : : : an where the numbers fa1; a2; a3; : : : ; ang are the numbers f1; 2; 3; : : : ; ng in some order. This operation can be interpreted in two different ways, as follows. Interpretation 1: The object in position 1 in the initial ordering is moved to position a1, the object in position 2 to position a2,. , the object in position n to position an. In this interpretation, the numbers in the two rows of the permutation symbol refer to the positions of objects in the ordered set. Interpretation 2: The object labeled 1 is replaced by the object labeled a1, the object labeled 2 by the object labeled a2,. , the object labeled n by the object labeled an. In this interpretation, the numbers in the two rows of the permutation symbol refer to the labels of the objects in the ABCD ! set. The labels need not be numerical { for instance, DCAB is a well-defined permutation which changes BDCA, for example, into CBAD. Either of these interpretations is acceptable, but one interpretation must be used consistently in any application. The particular application may dictate which is the appropriate interpretation to use. Note that, in either interpre- tation, the order of the columns in the permutation symbol is irrelevant { the columns may be written in any order without affecting the result, provided each column is kept intact. -
Zero-One Laws
1 THE LOGIC IN COMPUTER SCIENCE COLUMN by 2 Yuri GUREVICH Electrical Engineering and Computer Science UniversityofMichigan, Ann Arb or, MI 48109-2122, USA [email protected] Zero-One Laws Quisani: I heard you talking on nite mo del theory the other day.Itisinteresting indeed that all those famous theorems ab out rst-order logic fail in the case when only nite structures are allowed. I can understand that for those, likeyou, educated in the tradition of mathematical logic it seems very imp ortantto ndoutwhichof the classical theorems can b e rescued. But nite structures are to o imp ortant all by themselves. There's got to b e deep nite mo del theory that has nothing to do with in nite structures. Author: \Nothing to do" sounds a little extremist to me. Sometimes in nite ob jects are go o d approximations of nite ob jects. Q: I do not understand this. Usually, nite ob jects approximate in nite ones. A: It may happ en that the in nite case is cleaner and easier to deal with. For example, a long nite sum may b e replaced with a simpler integral. Returning to your question, there is indeed meaningful, inherently nite, mo del theory. One exciting issue is zero- one laws. Consider, say, undirected graphs and let be a propertyofsuch graphs. For example, may b e connectivity. What fraction of n-vertex graphs have the prop erty ? It turns out that, for many natural prop erties , this fraction converges to 0 or 1asn grows to in nity. If the fraction converges to 1, the prop erty is called almost sure. -
Spatial Rules for Capturing Qualitatively Equivalent Configurations in Sketch Maps
Preprints of the Federated Conference on Computer Science and Information Systems pp. 13–20 Spatial Rules for Capturing Qualitatively Equivalent Configurations in Sketch maps Sahib Jan, Carl Schultz, Angela Schwering and Malumbo Chipofya Institute for Geoinformatics University of Münster, Germany Email: sahib.jan | schultzc | schwering | mchipofya|@uni-muenster.de Abstract—Sketch maps are an externalization of an indi- such as representations for the topological relations [6, 23], vidual’s mental images of an environment. The information orderings [1, 22, 25], directions [10, 24], relative position of represented in sketch maps is schematized, distorted, generalized, points [19, 20, 24] and others. and thus processing spatial information in sketch maps requires plausible representations based on human cognition. Typically In our previous studies [14, 15, 16, 27], we propose a only qualitative relations between spatial objects are preserved set of plausible representations and their coarse versions to in sketch maps, and therefore processing spatial information on qualitatively formalize key sketch aspects. We use several a qualitative level has been suggested. This study extends our qualifiers to extract qualitative constraints from geometric previous work on qualitative representations and alignment of representations of sketch and geo-referenced maps [13] in sketch maps. In this study, we define a set of spatial relations using the declarative spatial reasoning system CLP(QS) as an the form of Qualitative Constraint Networks (QCNs). QCNs approach to formalizing key spatial aspects that are preserved are complete graphs representing spatial objects and relations in sketch maps. Unlike geo-referenced maps, sketch maps do between them. However, in order to derive more cognitively not have a single, global reference frame. -
On the Normality of Numbers
ON THE NORMALITY OF NUMBERS Adrian Belshaw B. Sc., University of British Columbia, 1973 M. A., Princeton University, 1976 A THESIS SUBMITTED 'IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of Mathematics @ Adrian Belshaw 2005 SIMON FRASER UNIVERSITY Fall 2005 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. APPROVAL Name: Adrian Belshaw Degree: Master of Science Title of Thesis: On the Normality of Numbers Examining Committee: Dr. Ladislav Stacho Chair Dr. Peter Borwein Senior Supervisor Professor of Mathematics Simon Fraser University Dr. Stephen Choi Supervisor Assistant Professor of Mathematics Simon Fraser University Dr. Jason Bell Internal Examiner Assistant Professor of Mathematics Simon Fraser University Date Approved: December 5. 2005 SIMON FRASER ' u~~~snrllbrary DECLARATION OF PARTIAL COPYRIGHT LICENCE The author, whose copyright is declared on the title page of this work, has granted to Simon Fraser University the right to lend this thesis, project or extended essay to users of the Simon Fraser University Library, and to make partial or single copies only for such users or in response to a request from the library of any other university, or other educational institution, on its own behalf or for one of its users. The author has further granted permission to Simon Fraser University to keep or make a digital copy for use in its circulating collection, and, without changing the content, to translate the thesislproject or extended essays, if technically possible, to any medium or format for the purpose of preservation of the digital work. -
Diophantine Approximation and Transcendental Numbers
Diophantine Approximation and Transcendental Numbers Connor Goldstick June 6, 2017 Contents 1 Introduction 1 2 Continued Fractions 2 3 Rational Approximations 3 4 Transcendental Numbers 6 5 Irrationality Measure 7 6 The continued fraction for e 8 6.1 e's Irrationality measure . 10 7 Conclusion 11 A The Lambert Continued Fraction 11 1 Introduction Suppose we have an irrational number, α, that we want to approximate with a rational number, p=q. This question of approximating an irrational number is the primary concern of Diophantine approximation. In other words, we want jα−p=qj < . However, this method of trying to approximate α is boring, as it is possible to get an arbitrary amount of precision by making q large. To remedy this problem, it makes sense to vary with q. The problem we are really trying to solve is finding p and q such that p 1 1 jα − j < which is equivalent to jqα − pj < (1) q q2 q Solutions to this problem have applications in both number theory and in more applied fields. For example, in signal processing many of the quickest approximation algorithms are given by solutions to Diophantine approximation problems. Diophantine approximations also give many important results like the continued fraction expansion of e. One of the most interesting aspects of Diophantine approximations are its relationship with transcendental 1 numbers (a number that cannot be expressed of the root of a polynomial with rational coefficients). One of the key characteristics of a transcendental number is that it is easy to approximate with rational numbers. This paper is separated into two categories. -
Higher-Order Intersections in Low-Dimensional Topology
Higher-order intersections in SPECIAL FEATURE low-dimensional topology Jim Conanta, Rob Schneidermanb, and Peter Teichnerc,d,1 aDepartment of Mathematics, University of Tennessee, Knoxville, TN 37996-1300; bDepartment of Mathematics and Computer Science, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468; cDepartment of Mathematics, University of California, Berkeley, CA 94720-3840; and dMax Planck Institute for Mathematics, Vivatsgasse 7, 53111 Bonn, Germany Edited by Robion C. Kirby, University of California, Berkeley, CA, and approved February 24, 2011 (received for review December 22, 2010) We show how to measure the failure of the Whitney move in dimension 4 by constructing higher-order intersection invariants W of Whitney towers built from iterated Whitney disks on immersed surfaces in 4-manifolds. For Whitney towers on immersed disks in the 4-ball, we identify some of these new invariants with – previously known link invariants such as Milnor, Sato Levine, and Fig. 1. (Left) A canceling pair of transverse intersections between two local Arf invariants. We also define higher-order Sato–Levine and Arf sheets of surfaces in a 3-dimensional slice of 4-space. The horizontal sheet invariants and show that these invariants detect the obstructions appears entirely in the “present,” and the red sheet appears as an arc that to framing a twisted Whitney tower. Together with Milnor invar- is assumed to extend into the “past” and the “future.” (Center) A Whitney iants, these higher-order invariants are shown to classify the exis- disk W pairing the intersections. (Right) A Whitney move guided by W tence of (twisted) Whitney towers of increasing order in the 4-ball. -
Network Intrusion Detection with Xgboost and Deep Learning Algorithms: an Evaluation Study
2020 International Conference on Computational Science and Computational Intelligence (CSCI) Network Intrusion Detection with XGBoost and Deep Learning Algorithms: An Evaluation Study Amr Attia Miad Faezipour Abdelshakour Abuzneid Computer Science & Engineering Computer Science & Engineering Computer Science & Engineering University of Bridgeport, CT 06604, USA University of Bridgeport, CT 06604, USA University of Bridgeport, CT 06604, USA [email protected] [email protected] [email protected] Abstract— This paper introduces an effective Network Intrusion In the KitNET model introduced in [2], an unsupervised Detection Systems (NIDS) framework that deploys incremental technique is introduced for anomaly-based intrusion statistical damping features of the packets along with state-of- detection. Incremental statistical feature extraction of the the-art machine/deep learning algorithms to detect malicious packets is passed through ensembles of autoencoders with a patterns. A comprehensive evaluation study is conducted predefined threshold. The model calculates the Root Mean between eXtreme Gradient Boosting (XGBoost) and Artificial Neural Networks (ANN) where feature selection and/or feature Square (RMS) error to detect anomaly behavior. The higher dimensionality reduction techniques such as Principal the calculated RMS at the output, the higher probability of Component Analysis (PCA) and Linear Discriminant Analysis suspicious activity. (LDA) are also integrated into the models to decrease the system Supervised learning has achieved very decent results with complexity for achieving fast responses. Several experimental algorithms such as Random Forest, ZeroR, J48, AdaBoost, runs confirm how powerful machine/deep learning algorithms Logit Boost, and Multilayer Perceptron [3]. Machine/deep are for intrusion detection on known attacks when combined learning-based algorithms for NIDS have been extensively with the appropriate features extracted. -
Classification of 3-Manifolds with Certain Spines*1 )
TRANSACTIONS OF THE AMERICAN MATHEMATICAL SOCIETY Volume 205, 1975 CLASSIFICATIONOF 3-MANIFOLDSWITH CERTAIN SPINES*1 ) BY RICHARD S. STEVENS ABSTRACT. Given the group presentation <p= (a, b\ambn, apbq) With m, n, p, q & 0, we construct the corresponding 2-complex Ky. We prove the following theorems. THEOREM 7. Jf isa spine of a closed orientable 3-manifold if and only if (i) \m\ = \p\ = 1 or \n\ = \q\ = 1, or (") (m, p) = (n, q) = 1. Further, if (ii) holds but (i) does not, then the manifold is unique. THEOREM 10. If M is a closed orientable 3-manifold having K^ as a spine and \ = \mq — np\ then M is a lens space L\ % where (\,fc) = 1 except when X = 0 in which case M = S2 X S1. It is well known that every connected compact orientable 3-manifold with or without boundary has a spine that is a 2-complex with a single vertex. Such 2-complexes correspond very naturally to group presentations, the 1-cells corre- sponding to generators and the 2-cells corresponding to relators. In the case of a closed orientable 3-manifold, there are equally many 1-cells and 2-cells in the spine, i.e., equally many generators and relators in the corresponding presentation. Given a group presentation one is motivated to ask the following questions: (1) Is the corresponding 2-complex a spine of a compact orientable 3-manifold? (2) If there are equally many generators and relators, is the 2-complex a spine of a closed orientable 3-manifold? (3) Can we say what manifold(s) have the 2-complex as a spine? L. -
Algebras Assigned to Ternary Relations
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Repository of the Academy's Library Miskolc Mathematical Notes HU e-ISSN 1787-2413 Vol. 14 (2013), No 3, pp. 827-844 DOI: 10.18514/MMN.2013.507 Algebras assigned to ternary relations Ivan Chajda, Miroslav Kola°ík, and Helmut Länger Miskolc Mathematical Notes HU e-ISSN 1787-2413 Vol. 14 (2013), No. 3, pp. 827–844 ALGEBRAS ASSIGNED TO TERNARY RELATIONS IVAN CHAJDA, MIROSLAV KOLARˇ IK,´ AND HELMUT LANGER¨ Received 19 March, 2012 Abstract. We show that to every centred ternary relation T on a set A there can be assigned (in a non-unique way) a ternary operation t on A such that the identities satisfied by .A t/ reflect relational properties of T . We classify ternary operations assigned to centred ternaryI relations and we show how the concepts of relational subsystems and homomorphisms are connected with subalgebras and homomorphisms of the assigned algebra .A t/. We show that for ternary relations having a non-void median can be derived so-called median-likeI algebras .A t/ which I become median algebras if the median MT .a;b;c/ is a singleton for all a;b;c A. Finally, we introduce certain algebras assigned to cyclically ordered sets. 2 2010 Mathematics Subject Classification: 08A02; 08A05 Keywords: ternary relation, betweenness, cyclic order, assigned operation, centre, median In [2] and [3], the first and the third author showed that to certain relational systems A .A R/, where A ¿ and R is a binary relation on A, there can be assigned a certainD groupoidI G .A/¤ .A / which captures the properties of R. -
The Prime Number Theorem a PRIMES Exposition
The Prime Number Theorem A PRIMES Exposition Ishita Goluguri, Toyesh Jayaswal, Andrew Lee Mentor: Chengyang Shao TABLE OF CONTENTS 1 Introduction 2 Tools from Complex Analysis 3 Entire Functions 4 Hadamard Factorization Theorem 5 Riemann Zeta Function 6 Chebyshev Functions 7 Perron Formula 8 Prime Number Theorem © Ishita Goluguri, Toyesh Jayaswal, Andrew Lee, Mentor: Chengyang Shao 2 Introduction • Euclid (300 BC): There are infinitely many primes • Legendre (1808): for primes less than 1,000,000: x π(x) ' log x © Ishita Goluguri, Toyesh Jayaswal, Andrew Lee, Mentor: Chengyang Shao 3 Progress on the Distribution of Prime Numbers • Euler: The product formula 1 X 1 Y 1 ζ(s) := = ns 1 − p−s n=1 p so (heuristically) Y 1 = log 1 1 − p−1 p • Chebyshev (1848-1850): if the ratio of π(x) and x= log x has a limit, it must be 1 • Riemann (1859): On the Number of Primes Less Than a Given Magnitude, related π(x) to the zeros of ζ(s) using complex analysis • Hadamard, de la Vallée Poussin (1896): Proved independently the prime number theorem by showing ζ(s) has no zeros of the form 1 + it, hence the celebrated prime number theorem © Ishita Goluguri, Toyesh Jayaswal, Andrew Lee, Mentor: Chengyang Shao 4 Tools from Complex Analysis Theorem (Maximum Principle) Let Ω be a domain, and let f be holomorphic on Ω. (A) jf(z)j cannot attain its maximum inside Ω unless f is constant. (B) The real part of f cannot attain its maximum inside Ω unless f is a constant. Theorem (Jensen’s Inequality) Suppose f is holomorphic on the whole complex plane and f(0) = 1. -
Arxiv:1711.04390V1 [Math.LO]
A FAMILY OF DP-MINIMAL EXPANSIONS OF Z; ( +) MINH CHIEU TRAN, ERIK WALSBERG Abstract. We show that the cyclically ordered-abelian groups expanding (Z; +) contain a continuum-size family of dp-minimal structures such that no two members define the same subsets of Z. 1. Introduction In this paper, we are concerned with the following classification-type question: What are the dp-minimal expansions of Z; ? ( +) For a definition of dp-minimality, see [Sim15, Chapter 4]. The terms expansion and reduct here are as used in the sense of definability: If M1 and M2 are structures with underlying set M and every M1-definable set is also definable in M2, we say that M1 is a reduct of M2 and that M2 is an expansion of M1. Two structures are definably equivalent if each is a reduct of the other. A very remarkable common feature of the known dp-minimal expansions of Z; ( +) is their “rigidity”. In [CP16], it is shown that all proper stable expansions of Z; ( +) have infinite weight, hence infinite dp-rank, and so in particular are not dp-minimal. The expansion Z; , , well-known to be dp-minimal, does not have any proper ( + <) dp-minimal expansion [ADH+16, 6.6], or any proper expansion of finite dp-rank, or even any proper strong expansion [DG17, 2.20]. Moreover, any reduct Z; , ( + <) expanding Z; is definably equivalent to Z; or Z; , [Con16]. Recently, it ( +) ( +) ( + <) is shown in [Ad17, 1.2] that Z; , is dp-minimal for all primes p where be ( + ≺p) ≺p the partial order on Z given by declaring k l if and only if v k v l with ≺p p( ) < p( ) v the p-adic valuation on Z.