Global routing in VLSI (very large scale integration) design is one of the most challenging discrete optimization problems in computational theory and practice. In this paper, we present a polynomial time algorithm for the global routing problem based on an integer programming formulation. The algorithm features a theoretical approximation bound while ensuring all the routing demands are concur...

The onboarding phase of Free-to-Play mobile games, covering the first few minutes of play, typically sees a substantial retention rate among the players. It is therefore crucial to the success of these games that the onboarding phase promotes engagement to the widest degree possible. In this paper a set of heuristics for the design of onboarding phases in Free-to-Play mobile games is presented....

The problem of setting Open Shortest Path First (OSPF) weights on links such that congestion can be avoided is proved to be NP-hard. Many iterative heuristics have been applied to solve the OSPF weight setting (OSPFWS) problem. As the size of any combinatorial optimization problem increases, it becomes more difficult to find an optimum solution using sequential algorithms. In this paper, we inv...

Real-time communication where the timely delivery of the data transfer requests needs to be guaranteed is essential for several applications. This work formally introduces the Real-Time Unsplittable Data Dissemination Problem (RTU/DDP), which is a generalization of the unsplittable flow problem. RTU/DDP problem is proved to be NP-hard. Therefore, heuristic approaches are required to acquire goo...

In this paper we investigate the use of two evolutionary based heuristic to the bin packing problem. The intractability of this problem is a motivation for the pursuit of heuristics that produce approximate solutions. Unlike other evolutionary based heuristics used with optimization problems, ours do not use domain-speciic knowledge and has no specialized genetic operators. It uses a straightfo...

We describe a new hyper-heuristic method NELLI-GP for solving job-shop scheduling problems (JSSP) that evolves an ensemble of heuristics. The ensemble adopts a divide-and-conquer approach in which each heuristic solves a unique subset of the instance set considered. NELLI-GP extends an existing ensemble method called NELLI by introducing a novel heuristic generator that evolves heuristics compo...

We show how, by a constructive process we can generate arbitrarily large instances of the Traveling Salesman Problem (TSP) using standard fractals such as those of Peano, Koch or Sierpinski. We show that optimal solutions for these TSPs can be known a priori and thus they provide us with new non-trivial TSP instances ooering the possibility of testing heuristics well beyond the scope of testbed...

In a non-guillotinable rectangular strip packing problem (RF-SPP), the best orthogonal placement of given rectangular pieces on a strip of stock sheet having fixed width and infinite height are searched. The aim is to minimize the height of the strip while including all the pieces in appropriate orientations. In this study, a novel bidirectional best-fit heuristic (BBF) is introduced for solvin...

Based on recent research about coordinating concurrent hierarchical plans (CHiPs), we introduce a sound and complete hierarchical planner that can better reason about precomputed conditions (summary information) of abstract plans to potentially make better re nement decisions than previous approaches. A reasonable criticism of this technique is that the summary information can grow exponentiall...

We propose simple heuristics for the assembly line worker assignment and balancing problem. This problem typically occurs in assembly lines in sheltered work centers for the disabled. Different from the classical simple assembly line balancing problem, the task execution times vary according to the assigned worker. We develop a constructive heuristic framework based on task and worker priority ...