• Journal of Ocean Engineering and Technology
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• v.37 no.5
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• pp.181-189
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• 2023

The fuel consumption of marine diesel engines holds paramount importance in contemporary maritime transportation and shapes energy efficiency strategies of ocean-going vessels. Nonetheless, a noticeable gap in knowledge prevails concerning the influence of ship hull conditions and propeller roughness on fuel consumption. This study bridges this gap by utilizing artificial intelligence techniques in Matlab, particularly convolutional neural networks (CNNs) to comprehensively investigate these factors. We propose a time-series prediction model that was built on numerical simulations and aimed at forecasting ship hull and propeller conditions. The model's accuracy was validated through a meticulous comparison of predictions with actual ship-hull and propeller conditions. Furthermore, we executed a comparative analysis juxtaposing predictive outcomes with navigational environmental factors encompassing wind speed, wave height, and ship loading conditions by the fuzzy clustering method. This research's significance lies in its pivotal role as a foundation for fostering a more intricate understanding of energy consumption within the realm of maritime transport.

• Journal of Marine Bioscience and Biotechnology
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• v.9 no.2
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• pp.35-42
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• 2017

Hydrothermal liquefaction of lipid-extracted Tetraselmis sp. feedstock containing 80 wt.% water was conducted in a batch reactor at different temperatures (300, 325, and $350^{\circ}C$) and reaction times (5, 10, 20, 40, and 60 min). The biocrude yield, elemental composition and higher heating value obtained at various reaction conditions were used to predict the optimum conditions for maximizing energy recovery of biocrude with good quality. A maximum energy recovery of 67.6% was obtained at $325^{\circ}C$ and 40 min with a high energy density of 31.8 MJ/kg and lower contents of nitrogen and oxygen. Results showed that reaction conditions of $325^{\circ}C$, 40 min was most suitable for maximizing energy recovery while at the same time achieving improved quality of biocrude.

• Fashion & Textile Research Journal
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• v.14 no.6
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• pp.977-982
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• 2012

We investigated the characteristics of subjects in marine leisure activities and the wearing conditions of a rash guard through a consumer survey. The questionnaire examined the number of rash guards owned by different styles, wearing size, choice of rash guard compared with ordinary clothes, and the satisfaction in a rash guard (color, textile, size, quality, price, function, and design) using Likeret Scales. The subjects were 105 adult men and the data analysis utilized an SPSS 20.0 Package. The results were significant for wearing conditions correspondent with the marine leisure activities. More years of experience resulted in a higher number of rash guards owned. A higher level of participation in sport resulted in more different styles of rash guards. More years of experience resulted in an increase preference for tight rash guards. In the case of wearing L and XL size that selected the smaller rash guard over the ordinary clothes, it was evaluated at "satisfaction" level in color, textile, size, quality, function, design. In the case of wearing XS, S and M size that did the larger and same as ordinary, it was at "ordinary" level and bellow.

• Ocean Systems Engineering
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• v.1 no.1
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• pp.17-28
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• 2011

The purpose of this paper is to demonstrate the efficacy of modeling a surface effect ship's air-cushion flexible seal utilizing a two-dimensional beam under steady state conditions. This effort is the initial phase of developing a more complex three-dimensional model of the air-seal-water fluid-structure interaction. The beam model incorporates the seal flexural rigidity and mass with large deformations while assuming linear elastic material response. The hydrodynamic pressure is derived utilizing the OpenFOAM computational fluid dynamic (CFD) solver for a given set of steady-state flow condition. The pressure distribution derived by the CFD solver is compared with the pressure required to deform the seal beam model. The air pressure, flow conditions and seal geometry are obtained from experimental analysis. The experimental data was derived from large-scale experimental tests utilizing a test apparatus of a canonical surface effect ship's flexible seal in a towing tank over a variety of test conditions.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.15
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• pp.137-165
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• 2001

The study on the duration of risk in the marine insurance has been paid a great attention because the marine insurance has to provide several indemnity conditions including the one to be compensated the loss when the accident happens. The research examines as to how the duration of risk has been extended from the beginning period to now. The results show the duration of risk has been continually extended in terms of place and time by a dramatic change of environment related to the marine insurance including marine transportation, a variety of goods, development of marine communication, many different trading conditions, etc, and requirement of the assured. The validity of the duration of risk is effected when the ship leaves at the port and is terminated when the ship arrives at the final destination. It in the Lloyd's age has been started when the products was charged to the ship and terminated when the one was safely discharged to the destination. Recently, the duration of risk in England Marine Insurance attaches from the time the goods leave the warehouse or place of storage at the placed named for the commencement of the transit, continues during the ordinary course of transit and terminates on delivery to the consignees or other final warehouse or place of storage at the destination named. Further research on the extension of the duration of risk must be conducted according to the being large scale of the ship and goods.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.883-887
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• 2016

This study aims to evaluate the corrosion behavior of a newly developed high-strength steel in marine environments. Metals used in seawater are easily deteriorated because of the presence of corrosive species such as chloride ions in it. Seawater causes much higher corrosion than fresh water. Thus, the corrosion of steel in marine environment has been recognized as a crucial problem in designing structures which cannot be cathodically protected. In this study, the corrosion resistance of a newly developed high-strength steel was evaluated. Four different specimens were tested to confirm the corrosion resistance. The exposure corrosion test was carried out by exposing the specimens to different marine environments such as atmospheric, tidal, splash, and submerged zones for two years. The specimens taken out from each location were cleaned ultrasonically and chemically prior to the evaluation of their corrosion resistance by the weight loss method. Finally, the pitting depth of the specimens was also measured to evaluate their pitting corrosion. The conditions used for the corrosion test were similar to the environmental conditions. The corrosion test results revealed that the corrosion rate and pitting corrosion of the newly developed high-strength steel was lower than that of the other carbon steels.

• Journal of Environmental Science International
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• v.27 no.9
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• pp.797-802
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• 2018

Information about the density of fish eggs is important to understand the vertical distribution of eggs and survival in early stage, in particular change in egg density is one of major issue in fisheries. This paper describes a practical application of an experimental system for measurement of the fish egg density under laboratory conditions. The device can control the temperature range in each water column, and make different densities at each layer. The density of olive flounder (Paralichthys olivaceus) eggs have ranged from 1,018.49 to $1,020.93kg/m^3$ and were aggregated around the density of $1,020kg/m^3$. The results show that the device is applicable for measuring the fish egg density under laboratory conditions.

• Journal of Microbiology
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• v.45 no.3
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• pp.241-245
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• 2007

This study was conducted to determine the optimal conditions for introduction of exogenous DNA into Synechocystis sp. PCC 6803. Of the three transformation techniques studied, electroporation, ultrasonic transformation and natural transformation, natural transformation showed the highest efficiency. Additionally, this study demonstrated that the higher plasmid concentration and longer homologous recombining fragments resulted in a greater number of transformants. For successful transformation, the lowest concentration of plasmid was $0.02\;{\mu}g/ml$, and the shortest homologous recombining fragment was 0.2 kb. Use of Synechocystis sp. PCC 6803 in the logarithmic growth phase resulted in two-fold higher transformation rate than that of the same organism when cells in the latent phase or the plateau phase were used for transformation. Pretreatment of the host strain, Synechocystis sp. PCC 6803, with EDTA (2 mM) for two days prior to transformation increased the transformation efficiency by 23%. Additionally, incubation of the cells and DNA for 5 h under light conditions increased the transformation efficiency by two orders of magnitude. Moreover, recovery treatment of the cells before they were plated onto antibiotic medium also increased the transformation efficiency.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.34-40
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• 2015

The design, procurement and fabrication of FPSO project ordered by Inpex Browse, Ltd. have been currently carried out by DSME(Daewoo Shipbuilding Marine and Engineering Co.). The unit will be installed and operated in the Ichthys field offshore of North-Western Australia and there are the particular design requirements to do with performance on the environment loads corresponding to max. 10,000 years return period wave. Also, the operational life of FPSO has to be over 40 years. With this background, this paper introduces the structural design procedure of crane pedestal foundation operated in north-western Australia offshore. The design of crane pedestal foundation structure is basically based on international design code (i.e. API Spec. 2C), Classification society's rule and project specifications. The design load cases are mainly divided into the crane normal operating conditions and crane stowed conditions according to environment conditions of the offshore with 1-year, 5-year, 10-year, 200-year and 10,000-year return period wave. This design experience for crane pedestal foundation operated in north-western Australia offshore will be useful to do engineering of other offshore crane structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.111-112
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• 2015

There is high possibility of steel corrosion on the reinforced concrete exposed to marine environment by chloride ion penetration. And it show a big difference of concrete durability under conditions of splash zone, tidal zone, and immersion zone. Therefore, in this paper, half-cell potential and chloride ion penetration depth was measured to evaluate the durability of slag concrete by marine exposure experiment. As a result, SC70 specimen showed no steel corrosion, regardless of the marine exposed conditions. Also, a deterrent effect on chloride ion penetration by replacement of slag in tidal zone and immersion zone could be confirmed.