Let G=(V,E) be a bi-connected graph with non-negative weights on its m edges. Let n be the number of vertices of G. With respect to any spanning tree T of G we have a fundamental cycle basis of G formed by the m-n+1 fundamental cycles, each one corresponding to one of the co-tree edges. The problem of determining one such basis minimising the sum of the length of its cycles (MinFCB) is known to...

To the Editor:—We read with interest the articles by Polley et al. and Benhamou et al. in which they simultaneously published the same study in terms of objective and design performed on different continents. Minimum local analgesic concentration results, including the potency ratios, were surprisingly different from expectations. In a similar study comparing bupivacaine and ropivacaine minimum...

The multi-processor total tardiness problem (MPTTP) is an -hard scheduling problem, in which the goal is to minimise the tardiness of a set of jobs that are processed on a number of processors. Exact algorithms like branch and bound have proven to be impractical for the MPTTP, leaving stochastic local search (SLS) algorithms as the main alternative to find high-quality schedules. Among the avai...

Minimum Vertex Cover (MinVC) is a well known NP-hard combinatorial optimization problem, and local search has been shown to be one of the most effective approaches to this problem. State-of-the-art MinVC local search algorithms employ edge weighting techniques and prefer to select vertices with higher weighted score. These algorithms are not robust and especially have poor performance on instan...

Editor—In their response 1 to my criticisms 2 of their paper 3 Sell and colleagues accept some of my points, and refute others. On most of the latter we will simply have to agree to differ, but, not surprisingly , I cannot accept their quoting my own review 4 in support of their belief that the solutions which they used were isobaric! Their quote from the article ('Given the normal variation [o...

The main goal of this paper is to prove some new results and extend some earlier ones about functions, which possess the so called local-global minimum property. In the last section, we show an application of these in the theory of calculus of variations.

This paper is devoted to study the combinatorial properties of Local Minimum Spanning Trees (LMSTs), a geometric structure that is attracting increasing research interest in the wireless sensor networks community. Namely, we study which topologies are allowed for a sensor network that uses, for supporting connectivity, a local minimum spanning tree approach. First, we refine the current definit...

Traditional portfolio optimization has been often criticized since it does not account for estimation risk. Theoretical considerations indicate that estimation risk is mainly driven by the parameter uncertainty regarding the expected asset returns rather than their variances and covariances. This is also demonstrated by several numerical studies. The global minimum variance portfolio has been a...

Finding overlay topologies for peer-to-peer networks on top of the Internet can be regarded as a network design problem, in which a graph with minimum communication costs is desired. An example of such a graph is a spanning tree connecting all nodes in the overlay. We present evolutionary algorithms incorporating local search for the minimum routing cost spanning tree problem in which the overa...