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Research on the site selection and path layout of the logistics distribution center of marine ships based on a mathematical model

Tong Haolin

Archives of Transport

2022

Vol. 63, iss. 3

23--34

For logistics enterprises, site selection and path layout are related to the cost and efficiency of distribution, which is a very critical issue and has an important impact on the development of enterprises. Compared with land logistics, the cost of marine ship logistics is higher due to the high cost of ships, so the research on the location and path layout of its distribution centers is also particularly important. This paper established a two-layer model under the assumption that unit transpor-tation costs and administration expenses are known for the site selection and path layout problems of marine ship logistics distribution centers. Corresponding constraint conditions were set. The upper layer was the optimization model of the site selection problem of the distribution center, and the objective function was to minimize operating and construction costs and was solved using the quantum particle swarm optimization (QPSO) algorithm. The lower layer was the optimization model of the distribution path layout, and the objective function was to minimize the logistics distribution cost and was solved using the ant colony optimization (ACO) algorithm. The model was verified through an example analysis. It was assumed that there were three ships, five candidate distribution centers, and ten customer points. The model was solved in MATLAB software. The results of the example analysis showed that compared with K-means, genetic algorithm (GA), and particle swarm optimization (PSO)-ACO algorithms, the QPSO-ACO algorithm had the shortest running time, about 60 s, which saved about 50% compared to the K-means algorithm. The optimal cost of the QPSO-ACO algorithm was 293,400 yuan, which was significantly lower than the K-means, GA, and PSO-ACO algorithms (459,600 yuan, 398,300 yuan, and 357,700 yuan). In this example, the site obtained by the QPSO-ACO algorithm was distribution center 2, and the obtained path distribution was 1-7-5-4, 2-6-3, and 10-8-9. The results verify the effectiveness of the QPSO-ACO algorithm in solving the problem of site selection and path layout. The QPSO-ACO algorithm can be applied in the actual marine ship logistics.

Logistyka recyklingu morskich jednostek pływających w świetle uwarunkowań prawnych i kosztów środowiskowo-społecznych

Pawlak M.

Prace Wydziału Nawigacyjnego Akademii Morskiej w Gdyni

2015

Z. 30

139--150

Azjatyckie stocznie złomowe, niezapewniające bezpiecznych procesów pracy przy demontażu statków morskich oraz nieposiadające odpowiednich urządzeń i środków do przeciwdziałania i zwalczania dużych rozlewów substancji chemicznych i ścieków zawierających substancje niebezpieczne, stanowią zagrożenie dla zdrowia i życia ludzkiego oraz środowiska morskiego, zwłaszcza w rejonie demontażu. Logistyka recyklingu jednostek wycofanych z eksploatacji musi przebiegać w sposób bezpieczny dla ludzi i środowiska. Ewolucja przepisów prawnych, rozwój procedur i technologii w tym zakresie wymuszają globalne zmiany, stanowiące wyzwanie przede wszystkich dla zakładów zajmujących się demontażem tych jednostek, co pozwala mieć nadzieję na znaczną poprawę bezpieczeństwa procesów pracy i zmniejszenie zagrożenia dla środowiska naturalnego.

Asian dismantling shipyards do not ensure safe working conditions during ship demolition processes, nor are equipped in adequate facilities and measures to prevent and combat spills of chemicals and wastes containing hazardous substances. Therefore they pose a threat to human life and health and to the marine environment, particularly in the area of ships dismantling. Logistics of recycling of end-of-life marine vessels must cover processes safe for humans and the environment. The evolution of legislation, development of procedures and technologies in the field of concern, force global changes that are the challenge especially for dismantling shipyards, which hopefully will lead to significant improvement in safety of work processes and will reduce the risk of the environment pollution.