The SuperDARN radars map high-latitude ionospheric plasma drift velocities by measuring the Doppler frequency shift of HF signals scattered by decameter electron density irregularities. In many cases the ionospheric returns are contaminated by strong scatter from the ground or sea surface. In this paper we develop and test a two-component fitting algorithm to separate ionospheric and surface sc...

In this work, a new scatter search-based approach is studied for the NP-Hard satisfiability problems, in particular for its optimization version namely max-SAT. The paper describes a scatter search algorithm enhanced with a tabu search component combined with a uniform crossover operator. The latter is used to identify promising search regions while tabu search performs an intensified search of...

In this paper, we first formalize the problem to be solved, i.e., the Scatter Problem (SP). We then show that SP cannot be deterministically solved. Next, we propose a randomized algorithm for this problem. The proposed solution is trivially self-stabilizing. We then show how to design a self-stabilizing version of any deterministic solution for the Pattern Formation and the Gathering problems....

Time-dependent prize-collecting arc routing problems (TD-PARPs) generalise the regular (PARPs). PARPs have arcs associated with collectable prizes along travelling costs. TD-PARPs allow travel times to vary at horizon so that real-life uncertain factors such as traffic and weather conditions can be taken into account. A TD-PARP is find a route maximises profit i.e. total collected minus two fac...

This paper presents a novel hybrid ant colony optimization approach called SS_ACO algorithm to solve the vehicle routing problem. The main feature of the hybrid algorithm is to hybridize the solution construction mechanism of the ant colony optimization (ACO) with scatter search (SS). In our hybrid algorithm, we use ACO algorithm and greedy heuristic to generate the initial solutions which are ...