Load scheduling for multiple quay cranes in port container terminals
This paper proposes a method to schedule loading operations when multiple yard cranes are operating in the same block. The loading scheduling methods in this paper are based on a genetic algorithm and a simulated annealing method, which consider interferences between adjacent yard cranes. It attempts to minimize the make-span of the yard crane operation. We consider the container handling time, the yard crane travel time, and the waiting time of each yard crane, when evaluating the makespan of the loading operation by yard cranes. An encoding method considering the special properties of the optimal solution of the problem is suggested. Numerical experiment was conducted to compare performances of the algorithms suggested in this study.
[Show abstract] [Hide abstract] ABSTRACT: Container handling problems at container terminals are considered as NP-hard combinatorial optimization problems. In this paper, we propose an optimization methodology for solving container handling problems using genetic algorithm. The proposed methodology is applied on a real case study data of container terminal at Port-said Port in Egypt. The computational results show the effectiveness of the proposed methodology for container terminal where 56% reduction in ship service time (loading/unloading) in port is achieved.
- "It attempts to minimize the make-span of the yard crane operation. They are considered that the container handling time, the yard crane travel time, and the waiting time of each yard crane, when evaluating the make span of the loading operation by yard cranes . Guo et. "
[Show abstract] [Hide abstract] ABSTRACT: In traditional approaches, the objective of yard crane (YC) dispatching is usually to minimize makespan of YC operations or to minimize vehicle waiting time. However, one of the most important objectives of terminal operation management is to minimize total weighted vessel turnaround time. We prove that minimizing the maximum tardiness of vehicle jobs from one vessel will minimize the vessel’s turnaround time. Therefore minimizing the total weighted maximum tardiness of all YCs’ jobs will minimize the total weighted vessel turnaround time. We propose algorithm MTWMT to minimize total weighted maximum job tardiness. We compare the performance of our algorithm with the optimal algorithms RBA* and MMS-RBA* from earlier studies. RBA* minimizes total vehicle waiting time while MMS-RBA* minimizes makespan. Experimental results confirm that MTWMT is most effective in reducing total weighted vessel turnaround time.
- "Deciding the job sequence for a YC which we refer to as the YC dispatching problem is investigated in this paper. In many works presented in the past, the objective is to minimize the total (average ) vehicle waiting time (Ng and Mak, 2005a and 2005b; Kumar and Omkar, 2008; Guo et al., 2011); or to minimize the makespan (Jung and Kim, 2006; Lee et al., 2007), that is, the total time taken to finish a set of jobs by the YC. Minimizing vehicle waiting times helps vehicles to return to the QCs as soon as possible after they arrive at the yard blocks. "
[Show abstract] [Hide abstract] ABSTRACT: This paper presents a simulation-based analysis of a multiple-round timber combinatorial auction in the timber industry. Currently, most timber auctions are single unit auctions (i.e., each forest stand is sold separately). However, other types of auctions could be applied in order to take advantage of the various needs of the bidders with respect to species, volumes and quality. This study aims to analyze the use of combinatorial auction to this specific context using a simulation approach. Various number of auctions per year, periodicity, lot size, and number of bidders are considered as parameters to setup the different market configurations. The outcomes of both combinatorial auction and single unit auction are compared with respect to different setup configurations. In particular, this analysis shows that combinatorial auction can bring more profit for both seller and buyer when the market is less competitive.
- "Combinatorial auctions are also useful for scheduling problems of loading cranes in maritime terminals (i.e. Brewer, 1999; De Vries and Vohra, 2003; Cramton et al., 2006; Jung and Kim, 2006). Multiple-round auctions are a series of any type of auctions that are announced sequentially. "