Green shipping oriented waste disposal optimization for cruise ships under stochastic context

The rapid development of the cruise industry has brought a series of marine environmental problems. In the process of cruise navigation, cruise operation and passengers on board will produce an uncertain amount of waste. Generally, the total amount of waste is far greater than its capacity. It is necessary to dispose of waste in multiple ports of the line, which requires a certain fee to be paid to the port. Therefore, this paper studied a waste disposal problem for cruise ships to decide which port to sign and how much waste should be discharged under the uncertain amount of produced waste. These decisions affect the operating costs of cruise companies, so it is necessary to calculate and analyze scientifically through some optimization models. Based on the theory of system engineering, this paper analyzed the background of the above-mentioned decision-making problems and proposed three models successively by using the theory and tools of mathematical programming. The models include a deterministic model, a stochastic programming model that applied to arbitrary probability distributions of emission parameters, and a three-stage robust optimization model that can cope with the uncertain parameter interval. Then, considering the above problems and the characteristics of the model, this paper designed a Tabu search (TS) and particle swarm optimization (PSO) algorithms to solve large-scale problems in stochastic and robust models, respectively. Extensive experiments in this paper validated the effectiveness and efficiency of the proposed models and algorithms. The decision-making method of cruise waste emissions proposed in this paper has certain application value and guiding significance for the development of the current global green shipping industry.