An algorithm for solving convex programs with an additional convex—concave constraint

An implementable decomposition method based on branch-and-bound techniques is proposed for finding a global optimal solution of certain convex programs with an additional convex—concave constrainth(x, y) 0. A nonadaptive simplicial and an adaptive bisection are used for the branching operation, which is performed iny-space only. The bounding operation is based on a relaxation of the convex—concave constrainth(x, y) 0. The algorithm can be applied efficiently for linear programs with an additional affine multiplicative constraint.This work was partially supported by Alexander-von-Humboldt Foundation.     

Global Optimization Algorithm for the Nonlinear Sum of Ratios Problem

This article presents a branch-and-bound algorithm for globally solving the nonlinear sum of ratios problem (P). The algorithm economizes the required computations by conducting the branch-and-bound search in ^p, rather than in ⁿ, where p is the number of ratios in the objective function of problem (P) and n is the number of decision variables in problem (P). To implement the algorithm, the main computations involve solving a sequence of convex programming problems for which standard algorithms are available.     

A Finite Branch-and-Bound Algorithm for Linear Multiplicative Programming

On the basis of Soland's rectangular branch-and-bound, we develop an algorithm for minimizing a product of p (2) affine functions over a polytope. To tighten the lower bound on the value of each subproblem, we install a second-stage bounding procedure, which requires O(p) additional time in each iteration but remarkably reduces the number of branching operations. Computational results indicate that the algorithm is practical if p is less than 15, both in finding an exact optimal solution and an approximate solution.     

Unified Treatment of Algebraic and Geometric Difference by a New Difference Scheme and its Continuity Properties

We introduce a new operation for the difference of two sets A and C of R ⁿ depending on a parameter . This new operation may yield as special cases the classical difference and the Minkowski difference, if the sets A and C are closed, convex sets, if int(C) is nonempty, and if A or C bounded. Continuity properties with respect to both the operands and the parameter of this operation are studied. Lipschitz properties of the Minkowski difference between two sets of a normed vector space are proved in the bounded case as well as in the unbounded case without condition on the dimension of the space.     

The Hewitt–Nachbin Completion in Topological Algebra. Some Effects of Homogeneity

A space X is called Moscow if the closure of any open set is the union of some family of G -subsets of X. It is established that if a topological ring K of non-measurable cardinality is a Moscow space, then the operations in K can be continuously extended to the Hewitt–Nachbin completion K of K turning K into a topological ring as well. A similar fact is established for linear topological spaces. If F is a topological field such that the cardinality of F is non-measurable and the space F is Moscow, then the space F is submetrizable and the space F is hereditarily Hewitt–Nachbin complete. In particular, F=F. We also show the effect of homogeneity of the Hewitt–Nachbin completion on the commutativity of the Hewitt–Nachbin completion with the product operation.     

Relationships between Donsker classes and Sobolev spaces

Summary Let H be a separable real Hubert space. Let X be a second countable topological space and (X, , P) be a probability space where is the Borel sets. Let T: H C _b (X) be linear and continuous. Then the image of the unit ball of H is a Donsker class. So, if k ^–1L ² then the unit ball of the Sobolev space is a Donsker class for any P. For most other k it is not a Donsker class for any P with a bounded density.     

Evolution inclusions governed by subdifferentials in reflexive Banach spaces

The existence, uniqueness and regularity of strong solutions for Cauchy problem and periodic problem are studied for the evolution equation: where is the so-called subdifferential operator from a real Banach space V into its dual V*. The study in the Hilbert space setting (V = V* = H: Hilbert space) is already developed in detail so far. However, the study here is done in the V–V* setting which is not yet fully pursued. Our method of proof relies on approximation arguments in a Hilbert space H. To assure this procedure, it is assumed that the embeddings are both dense and continuous.     

Solving a Class of Multiplicative Programs with 0–1 Knapsack Constraints

We develop a branch-and-bound algorithm to solve a nonlinear class of 0–1 knapsack problems. The objective function is a product of m2 affine functions, whose variables are mutually exclusive. The branching procedure in the proposed algorithm is the usual one, but the bounding procedure exploits the special structure of the problem and is implemented through two stages: the first stage is based on linear programming relaxation; the second stage is based on Lagrangian relaxation. Computational results indicate that the algorithm is promising.     

Double Complexes and Cohomological Hierarchy in a Space of Weakly Invariant Lagrangians of Mechanics

For a given configuration space M and a Lie algebra G acting on M, the space V _0.0 of weakly G-invariant Lagrangians, i.e., Lagrangians whose motion equations left-hand sides are G-invariant, is studied. The problem is reformulated in terms of the double complex of Lie algebra cochains with values in the complex of Lagrangians. Calculating the cohomology of this complex by the method of spectral sequences, we arrive at the hierarchy in the space V _0.0: The double filtration {V _s.}, s = 0, 1, 2, 3, 4, = 0, 1, and the homomorphisms on every space {V _s.} are constructed. These homomorphisms take values in the cohomologies of the algebra G and the configuration space M. Every space {V _s.} is the kernel of the corresponding homomorphism, while the space itself is defined by its physical properties.     

On vectorial inner product spaces

Let E be a real linear space. A vectorial inner product is a mapping from E×E into a real ordered vector space Y with the properties of a usual inner product. Here we consider Y to be a -regular Yosida space, that is a Dedekind complete Yosida space such that , where is the set of all hypermaximal bands in Y. In Theorem 2.1.1 we assert that any -regular Yosida space is Riesz isomorphic to the space B(A) of all bounded real-valued mappings on a certain set A. Next we prove Bessel Inequality and Parseval Identity for a vectorial inner product with range in the -regular and norm complete Yosida algebra .