Showing papers in "Bulletin of The London Mathematical Society in 1986"

THE TRAVELING SALESMAN PROBLEM A Guided Tour of Combinatorial Optimization

Abstract: Combinatorial OptimizationAdvanced Intelligent Computing Theories and ApplicationsOpt ArtHybrid Feedback ControlAdvances in Multi-Objective Nature Inspired ComputingThe Traveling Salesman ProblemIntelligent Computational Optimization in EngineeringThe Traveling SalesmanFundamental Problems in ComputingSpecial Cases of the Traveling Salesman ProblemThe Quadratic Assignment ProblemStochastic Local SearchGraphs, Networks and AlgorithmsThe Traveling Salesman Problem as a Constrained Shortest Path Problem : Theory and Computational ExperienceThe Traveling Salesman ProblemLocal Search in Combinatorial OptimizationAn Elementary Inequality for the Traveling Salesman ProblemGraphs & Digraphs, Fourth EditionIn Pursuit of the Traveling SalesmanCombinatorial OptimizationEvolutionary Algorithms for Solving Large Time Dependent Traveling Salesman ProblemsDecision Modeling and Behavior in Complex and Uncertain EnvironmentsWorst-Case Analysis of a New Heuristic for the Travelling Salesman ProblemGeneralized Network Design ProblemsOptimizing a 48-city Traveling Salesman ProblemSolution of the Traveling Salesman Problem by Dynamic Programming on the HypercubeSelfOrganizing Migrating AlgorithmCluster Analysis Algorithms for Data Reduction and Classification of ObjectsThe Traveling Salesman Problem and Its VariationsStatistical Inference Via Convex OptimizationCombinatorial OptimizationEstimation of Distribution AlgorithmsGraph TheoryThe Travelling Salesman ProblemAdvanced Manufacturing and Sustainable LogisticsFundamentals of Supply Chain TheoryMetaheuristics for LogisticsInteger Programming and Network ModelsThe Selective Traveling Salesman Problem and Extensions : an OverviewScala and Spark for Big Data Analytics

The Geometry of Two-Weight Codes

Abstract: On etudie les relations entre les codes [n,k] lineaires a deux poids, les ensembles (n,k,h 1 h 2 ) projectifs et certains graphes fortement reguliers

A multiplicity result for periodic solutions of forced nonlinear second order ordinary differential equations

Abstract: On considere l'equation differentielle de Lienard x″+f(x)x'+g(t,x)=s, ou s est un parametre reel, f et g sont des fonctions continues, et g est 2π-periodique en t. On etudie le nombre de solutions 2π-periodiques quand g satisfait lim |x|→+∞ g(t,x)=+∞, uniformement en t

Variants on the Law of the Iterated Logarithm

Abstract: On passe en revue des resultats numeriques recents lies a la loi classique du logarithme itere

Subgroups of small index in infinite symmetric groups

Abstract: Throughout this paper Q will denote an infinite set, S:= Sym(Q) and G is a subgroup of S. If n: = |Q|, the cardinal of Q, then |.S| = 2\". Working in ZFC, set theory with Axiom of Choice (AC), we shall be seeking the subgroups G with \\S: G\\ < 2\". If A £ Q then S^ (respectively G{A}) denotes the setwise stabiliser of A in S (respectively in G); 5(A) and G(A) denote pointwise stabilisers; we identify S(A) with Sym(fi —A). A subset £ of Q such that |Z| = |Q — 1 | = |O| is known as a moiety ofQ. Suppose now that |Q| = n = Ko. If there is a finite subset A of Q such that 5(A) ^ G then certainly \\S:G\\ ^ Xo. Our theme is a rather strong converse:

FUNCTIONAL INTEGRATION AND PARTIAL DIFFERENTIAL EQUATIONS (Annals of Mathematics Studies, 109)

Abstract: Functional Integration and Partial Differential Equations-Mark Iosifovich Freidlin 1985-08-21 \"This book discusses some aspects of the theory of partial differential equations from the viewpoint of probability theory. It is intended not only for specialists in partial differential equations or probability theory but also for specialists in asymptotic methods and in functional analysis. It is also of interest to physicists who use functional integrals in their research. The work contains results that have not previously appeared in book form, including research contributions of the author\"-Publisher description.

Actions of Commutative Hopf Algebras

Abstract: We show that actions of finite-dimensional semisimple commutative Hopf algebras H on //-module algebras A are essentially group-gradings. Moreover we show that the centralizer of H in the smash product A # H equals A\" ® H. Using these we invoke results about group graded algebras and results about centralizers of separable subalgebras to give connections between the ideal structure of A, A and A # H. Examples of the above occur naturally when one considers: (1) finite abelian groups G of automorphisms of an algebra A with | G |~ e A; (2) G-graded algebras, for finite groups G; (3) finite-dimensional restricted Lie algebras L, with semisimple restricted enveloping algebra u(L), acting as derivations on an algebra A.

Blocking sets in desarguesian projective planes

Abstract: Using theorems of Redei, and of Brouwer and Schrijver, and Jamison, it is proved that a non-trivial blocking set in a desarguesian projective plane of order q has at least q + v(2q) + 1 points, if q is at least 7, odd and not a square and q ¦ 27. Further one can show that non-trivial blocking sets in the desarguesian planes PG(2, 11) and PG(2, 13) have at least 18 resp. 21 points, and this is best possible. In addition a nice description of a blocking set of size qt + qt-1 in the desarguesian plane PG(2, qt) is given, where q is some prime power.

Hyponormal Composition Operators

Abstract: In [1] D. Harrington and R. Whitley examined several questions of seminormality for composition operators. In that article they raise the question of finding a measure theoretic characterization of hyponormality for composition operators. In this article we establish criteria for hyponormality for weighted composition operators. By restricting attention to the case of weight function equal to 1 we arrive at a measure theoretic characterization of composition operator hyponormality. Harrington and Whitley also showed that if the measure is finite then hyponormality follows if and only if the transformation is measure preserving; equivalently, if and only if the composition operator is an isometry. We show that there are hyponormal weighted composition operators on finite measure spaces which are not scalar multiples of isometries.