Minimal Time Route for Wind-Assisted Ships

2014 ◽  
Vol 48 (3) ◽  
pp. 115-124 ◽  
Author(s):  
Li Yuankui ◽  
Zhang Yingjun ◽  
Zhu Feixiang

AbstractAs a result of a global call for energy-saving and emission-reduction strategies as well as an urgent need to reduce the shipping cost of transoceanic crossings, this paper proposes a route that minimizes the time for such crossings and provides technical support to efficiently utilize wind power based on existing research for wind-assisted ships. To begin, the ocean winds around the ship route were analyzed, and the different influences on traditional ships and wind-assisted ships were listed for various wind speeds and directions. The number of waypoints of a route was subsequently calculated, and a model of the optimal ship route was then built based on the fixed power output of the main marine engine. A solution algorithm based on simulated annealing was then presented to determine the optimal wind-assisted ship routes by minimizing the travel time. Finally, a 76,000-DWT wind-assisted cargo ship was designated as the experimental ship, and the optimization model and its algorithm were simulated to generate an optimized wind-assisted route. The simulation indicated that the speed of a ship equipped with wind propulsion increases, which significantly reduces the travel time and fuel costs over the optimized route, despite the increased distance of this route. Thus, the route optimization algorithm designed in this study can be applied to optimize the routes for wind-assisted ships and theoretically guide further studies of wind-assisted projects.

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Sen Zhang ◽  
Guangyuan Qin ◽  
Yifan Xie ◽  
Yuan Tian ◽  
Liyuan Shi ◽  
...  

Environmental pollution has become an important obstacle on the path of ecological civilization construction, and it is urgent to control environmental pollution. By establishing an evolutionary game model, this thesis focuses on analyzing how paper-making enterprises choose their own emission reduction strategies under the reward and punishment mechanism. It further analyzes how social welfare changes under the reward and punishment mechanism, and finally through simulation research, this thesis analyzes the evolutionary paths of paper-making enterprises’ pollution emission strategies under the reward and punishment mechanism. The results of the reward and punishment mechanism are as follows: under the static reward and punishment mechanism, the game system will repeatedly oscillate around a point. There is no stable equilibrium point at this time. However, under the dynamic reward and punishment mechanism, the game system will tend to a stable equilibrium point. The results of social welfare analysis show that high-intensity rewards will reduce the amount of pollution discharged by paper-making enterprises, thereby maximizing social welfare. On the contrary, when paper-making enterprises discharge a large amount of pollution, they will be subject to high-intensity penalties. When facing high-intensity punishments, paper-making enterprises will tend to not to discharge. So social welfare is also maximized. The simulation research results show that reasonable punishment strategies are more effective than reward ones. Based on this, the author proposes countermeasures, such as establishing a reasonable reward and punishment mechanism, reasonably determining the reward and punishment intensity for polluting enterprises. The emission reduction strategies of paper-making enterprises will be affected by the government’s reward and punishment mechanism. A deep study of its internal mechanism is not only of great significance for pollution control but also of great significance for the development of a green economy.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Erick P. Massami ◽  
Benitha M. Myamba

The Greenhouse Gas (GHG) emissions due to transport operations have drastically increased in recent years. The sea transport in particular contributes 2.7 to 3 percent of CO2, a major component of GHG emissions globally. Numerous measures have been undertaken locally and internationally to alleviate the sea transport share of Greenhouse Gases. However, most of these measures will be fruitful if ship investors (e.g., ship owners and operators) would fully employ the GHG emission reduction strategies. Due to the scarcity of the statistical data in this respect, this study therefore presents a rough set synthetic assessment (RSSA) model to GHG emission abatement strategies in the Tanzanian shipping sector. The results of the assessment reveal that the Tanzanian shipping companies engaged in Cabotage trade are aware of the abatement strategies and moderately apply them.


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