In many engineering optimization problems, objective function evaluations can be extremely computationally expensive. The effective global optimization (EGO) is a widely used approach for expensive optimization. Balance between global exploration and local exploitation is a very important issue...

Optimisation algorithms with good anytime behaviour try to return as high-quality solutions as possible independently of the computation time allowed. Designing algorithms with good anytime behaviour is a difficult task, because performance is often evaluated subjectively, by plotting the...

In this paper we examine computational complexity issues and develop algorithms for a class of "shoreline" single-vehicle routing and scheduling problems with release time constraints. Problems in this class are interesting for both practical and theoretical reasons. From a practical...

Learning curves can arise out of routing problems, or out of sequencing problems, or a combination of both. In this paper, learning curves arising out of routing problems are investigated by means of numerical simulations, whereas some properties of the learning curves arising out of sequencing...

Column generation is involved in the current most efficient approaches to routing problems. Set partitioning formulations model routing problems by considering all possible routes and selecting a subset that visits all customers. These formulations often produce tight lower bounds and require...

Traveling salesman problems with revenues form a generalization of traveling salesman problems.Here, next to travel costs an explicit revenue is generated by visiting a city.We analyze routing problems with revenues, where a predetermined route on all cities determines the tours along...

Using local search method, this paper provides a polynomial time approximation scheme for the minimum vertex cover problem on <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$$d$$</EquationSource> <EquationSource Format="MATHML"> <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mi>d</mi> </math> </EquationSource> </InlineEquation>-dimensional ball graphs where <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$$d \ge 3$$</EquationSource> <EquationSource Format="MATHML"> <math xmlns:xlink="http://www.w3.org/1999/xlink"> <mrow> <mi>d</mi> <mo>≥</mo> <mn>3</mn> </mrow> </math> </EquationSource> </InlineEquation>. The key to the proof is a new separator theorem for ball graphs in higher dimensional space....</equationsource></equationsource></inlineequation></equationsource></equationsource></inlineequation>

In this paper, a multi-period logistics network redesign problem arising in the context of strategic supply chain planning is studied. Several aspects of practical relevance are captured, namely, multiple echelons with different types of facilities, product flows between facilities in the same...

The n-queens problem is a classical combinatorial optimization problem which has been proved to be NP-hard. The goal is to place n non-attacking queens on an n×n chessboard. In this paper, two single-solution-based (Local Search (LS) and Tuned Simulated Annealing (SA)) and two population-based...