We introduce an NP-complete special case of the Weighted Set Cover problem and show its fixed-parameter tractability with respect to the maximum subset size, a parameter that appears to be small in relevant applications. More precisely, in this practically relevant variant we require that the given collection C of subsets of a some base set S should be “tree-like.” That is, the subsets in C can...

This paper introduces a modification on the movement force vector of the Birbil and Fang’s electromagnetism-like algorithm [1] for solving global optimization problems with bounded variables. The proposed movement vector combines the total force exerted on each point of the population, at the current iteration, with the rate of change in the force vector of a previous iteration. Several widely ...

A soft-decision decoder for an error-correcting block code of Hamming distance d is said to achieve boundeddistance (BD) decoding if its error-correction radius is equal to that of a complete Euclidean distance decoder. The Chase decoding algorithms are reliability-based algorithms achieving BD decoding. The least complex version of the original Chase algorithms (“Chase-3”) uses about d/2 trial...

The Dandelion-like codes are eight bijections between labeled trees and strings of node labels. The literature contains optimal sequential algorithms for these bijections, but no parallel algorithms have been reported. In this paper the first parallel encoding and decoding algorithms for Dandelion-like codes are presented. Namely, a unique encoding algorithm and a unique decoding algorithm, whi...

In this paper we consider four versions of Kovarik’s iterative orthogonalization algorithm, for approximating the minimal norm solution of symmetric least squares problems. Although the theoretical convergence rate of these algorithms is at least linear, in practical applications we observed that a too large number of iterations can dramatically deteriorate the already obtained approximation. I...

This paper discusses the question how ES/EP-like algorithms perform the evolutionary search in real-valued N-dimensional parameter spaces. It will be shown that the sometimes invoked model of a perturbed gradient search does not seem to give an appropriate picture of the search process. Instead, the search behavior is described as the antagonism of exploitation and exploration, where exploitati...

In this paper we consider the problem of computing market equilibria in the Fisher setting for utility models such as spending constraint and perfect, price-discrimination. These models were inspired from modern e-commerce settings and attempt to bridge the gap between the computationally hard but realistic separable, piecewise-linear and concave utility model and, the tractable but less releva...

The success of many machine learning and pattern recognition methods relies heavily upon the identification of an appropriate distance metric on the input data. It is often beneficial to learn such a metric from the input training data, instead of using a default one such as the Euclidean distance. In this work, we propose a boosting-based technique, termed BOOSTMETRIC, for learning a quadratic...

One of the most commonly known algorithm to perform neural Principal Component Analysis of real-valued random signals is the Kung-Diamantaras’ Adaptive Principal component EXtractor (APEX) for a laterally-connected neural architecture. In this paper we present a new approach to obtain an APEX-like PCA procedure as a special case of a more general class of learning rules, by means of an optimiza...