Journal of Marine Science and Technology最新文献

The impact of fuel consumption on merchant ships is categorized in both economic and environmental ways in terms of sustainable blue growth. Apart from the economic benefits of reducing fuel consumption, attention should be paid to related environmental concerns with ship fuels. As a result of global regulations and agreements concerning mitigating greenhouse gases on board, such as the International Maritime Organization and Paris Agreement, ships have to take a step to reduce fuel consumption to adopt these regulations. The present study aims to determine optimal speed diversity depending on ships' cargo amounts and wind-sea states to reduce fuel consumption. Within this context, one-year voyage data from two model sister Ro-Ro cargo ships were used, including daily ship speed, daily fuel consumption, ballast water consumption, total ship cargo consumption, sea state, and wind state. The genetic algorithm method was used to determine the optimal diversity rate. In conclusion, after speed optimization, optimum speed result values are calculated between 16.59 and 17.29 knots; thus, approximately 18% of exhaust gas emissions were also reduced.

Today's social infrastructure, e.g., transportation, medical services, energy supply and distribution, may become temporarily unable to provide functions due to the damage to buildings or excessive congestion resulting from threats, such as natural disasters, rising sea levels, pandemics. Maritime-based responses, typified by hospital ships, are drawing attention as a method to mitigate these effects. However, while designing emergency infrastructure, it is necessary to consider not only the value of these systems in emergencies but also during normal times. This study adopts the systems approach, a set of methods to conduct decision-making when complex stakeholders' relationships are involved. We focus on medical functions and propose a conceptual design for a flexible hospital ship with dynamic capability during emergencies as well as normal times. Specifically, we examine the optimal combination of ship type, size, navigation range during normal times, operations during emergencies, and contract approaches. Quantitative evaluation of utility during emergencies and economic efficiency are considered in tradeoff. In addition to the conventional cost-based study, we examined benefit-cost through ship sharing, in which ships are leased to the private sector as merchant vessels during normal times to generate revenue.

This study proposed a safety supervision tool to HRA-based monitoring of ship maintenance operations via a digital platform. It is conceptualized to assist safety supervisors in the best proactive measures along with maintenance works onboard ships. The tool refers the marine maintenance and operations human reliability analysis (MMOHRA) concept. Moreover, it facilitates the timely and consistently practice of MMOHRA. Indeed, it accurately identifies critical tasks and associate recovery acts. Fundamentally, a rule-based mechanism supported with relation matrix response to general task type selection, EPCs' assignment, and human error probability (HEP) calculation, respectively. Then, the system automatically calculates, visualizes and manages HEP values of operation steps. Consequently, this study digitalizes maritime HRA investigations particular to maintenance operations. The proposed tool, compliance with the relevant sections of updated inspection regimes such as SIRE 2.0 and DryBms, has very high utility to effectively control human element onboard. This study also enables a further research potential to conduct an extended human reliability database in ship fleet level.