The container relocation problem (CRP) is one of the most crucial issues for container terminals. In a single bay, containers belonging to multiple groups should be retrieved by an equipped yard crane in accordance with their retrieval priorities. An operation of the crane can either relocate a...

In this paper, we investigate a new variant of the vehicle routing problem (VRP), termed the multi-period vehicle routing problem with time windows and limited visiting quota (MVRPTW-LVQ), which requires that any customer can be served by at most a certain number of different vehicles over the...

In this paper, we conduct a study of the job-shop scheduling problem with reverse flows. This NP-hard problem is characterized by two flows of jobs that cover the same machines in opposite directions. The objective is to minimize the maximal completion time of the jobs (i.e., the makespan).

In this paper, we suggest a new multi-objective artificial bee colony (ABC) algorithm by introducing an elitism strategy. The algorithm uses a fixed-size archive that is maintained based on crowding-distance to store non-dominated solutions found during the search process. In the proposed...

We investigate a periodic-review inventory system for a single item with stochastic demand and random yield. Since the optimal policy for such a system is complicated, we study the class of stationary linear-inflation policies where orders are only placed if the inventory position is below a...

The Maximum Balanced Subgraph Problem (MBSP) is the problem of finding a subgraph of a signed graph that is balanced and maximizes the cardinality of its vertex set. This paper is the first one to discuss applications of the MBSP arising in three different research areas: the detection of...

Given a double round-robin tournament, the traveling umpire problem (TUP) consists of determining which games will be handled by each one of several umpire crews during the tournament. The objective is to minimize the total distance traveled by the umpires, while respecting constraints that...

The Traveling Umpire Problem (TUP) is a challenging combinatorial optimization problem based on scheduling umpires for Major League Baseball. The TUP aims at assigning umpire crews to the games of a fixed tournament, minimizing the travel distance of the umpires. The present paper introduces two...