• 수산경영론집
• /
• 제36권3호
• /
• pp.89-117
• /
• 2005

Currently, the tax - exempted vessel fuel is provided for commercial fishing in order to increase the competitive power of fishery production thorough the National Federation of Fisheries Cooperatives. The National Federation of Fisheries Cooperatives should predict the exact amount of fuel consumption for fishing every year to request the fuel from the government. Unfortunately, there is no sophisticated model to predict the tax - exempted vessel fuel consumption. In 2003, the consumption of the tax- exempted vessel fuel was only $25.1\%$ of the estimation amount by the National Federation of Fisheries Cooperatives. This causes an inefficiency in the petroleum management. Moreover, we need some data such as the annual average fishing hours, fishing days and fishing behavior to adopt a new policy regarding fishing. Up to now, the data have been obtained by survey with response in the fishery field. In the most case, we have a small number of data because we spend so much time and money consuming for collecting fishing data. As a result, the level of confidence of the data is associated with the sample size and normally low. In order to achieve more accurate data, we need to develope an efficient method for collecting fishing data. In this research, we proposed a new method to predict the tax- exempted vessel fuel consumption more exactly. The prediction results from the proposed method has been compared with the results from the current method. According to the results in this research, the method proposed here produced much better accuracy than the current method. In addition, we also proposed in the paper for collecting fishing data of the annual average fishing hours using the tax - exempted vessel fuel consumption and the gasoline consumption of vessel engine. The fishing data obtained by using the method proposed in this research could be much more efficient and accurate because it doesn't need to estimate from survey sample data.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2000년도 제 25회 정기총회 및 추계학술발표회
• /
• pp.101-110
• /
• 2000

• Journal of Advanced Research in Ocean Engineering
• /
• 제1권2호
• /
• pp.94-105
• /
• 2015

In this study, a thruster allocation method of a deep-sea working vessel was proposed with the aims of producing the demanded generalized forces and moment for dynamic positioning while at the same time minimizing total power. For this, an optimization problem for thrust allocation was mathematically formulated with design variables, objective function, and constraints. The genetic algorithms (GA) was used to solve the formulated problem. The proposed method was applied to an example of finding optimal thrust allocation of the deep-sea working vessel having 5 thrusters. The result showed that the method could be used to determine better strategy for thruster allocation of the vessel as compared to existing study.

• 한국항해항만학회지
• /
• 제34권9호
• /
• pp.693-698
• /
• 2010

In port and its approach channel, traffic accidents such as collision, aground, minor collision have reached about 77% of total marine casualty in the area. In this paper, an attempt to enhance the safe navigation was proposed by offering marine traffic supporting system which helps VTS operator assist vessel effectively with the quantitative assessment on difficulty of each vessel. The system collects navigation data from onboard AIS, assesses the data in assessment mode to analyze the navigation difficulties of each vessel and displays the degree of danger of each vessel on the ECDIS in real-time to decide the intervention time or order of priority for VTS operator. The effectiveness of the system was verified by the VTS operators in Korea.

• 한국항해항만학회지
• /
• 제38권6호
• /
• pp.561-565
• /
• 2014

This paper is mainly concerned with the interaction effects between two vessels and sidewall with a mound. Experimental study on hydrodynamic forces between ship and sidewall with a mound was already shown in the previous paper, measured by varying the distances between ship and sidewall. The ship maneuvering simulation was conducted to find out the minimum safe distance between vessels, which is needed to avoid sea accident in confined waters. From the inspection of this investigation, it indicates the following result. When and if one vessel passes the other vessel through the proximity of sidewall with a mound, the spacing between two vessels is needed for the velocity ratio of 1.2, compared to the case of 1.5. Also, for the case of ship-size estimation, the ship maneuvering motion is more affected by interaction effects for the overtaken small vessel, compared to the overtaking large vessel.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1995년도 VTS and IBS 95 The Korean Institute of Navigation 1995년도
• /
• pp.73-88
• /
• 1995

I. Introduction II. State of vessel-source marine pollution 1. Pollution by tanker accidents 2. Pollution by tanker operations 3. Pollution by chemicals 4. Pollution by garbage and sewage III. Regulatory regime for ship safety and vessel-source 1. Regime for ship safety 2. Regime for vessel-source marine pollution prevention IV. Cause analysis of Contemporary vessel-source marine pollution. 1. Diversity of interested parties of shipping 2. Fierce international competition of shipping 3. Wide variagions in ship safety indicators by natons 4. Limitation of enforcing oil spill activities 5. Limitation of international countermeasures V. Summary conclusions and suggestions Note and References

• Nuclear Engineering and Technology
• /
• 제52권1호
• /
• pp.185-191
• /
• 2020

Plant-specific analyses of an advanced reactor have been performed to assure the structural integrity of the reactor pressure vessel during transient conditions, which are expected to initiate pressurized thermal shock (PTS) events. The vessel failure probabilities from the probabilistic fracture mechanics analyses are combined with the transient frequencies to generate the through-wall cracking frequencies, which are compared to the acceptance criterion. Several sensitivity analyses are performed, focusing on the orientations and sizes of cracks, the copper content, and a flaw distribution model. The results show that the integrity of the reactor vessel is expected to be maintained for long-term operation beyond the design lifetime from the PTS perspective using the design data of the advanced reactor. Moreover, a fluence level exceeding 9×10¹⁹ n/㎠ is found to be acceptable, generating a sufficient margin beyond the design lifetime.

• 한국수소및신에너지학회논문집
• /
• 제35권3호
• /
• pp.280-289
• /
• 2024

In this study, a cryogenic vessel was constructed to maintain and control the safe pressure of liquid hydrogen boil-off gas (BOG), and the numerical analysis was conducted on the development of computational fluid dynamics model inside the high-pressure vessel. An evaluation system was constructed using cryogenic inner and outer containers, pre-cooler, upper flange, and internal high-pressure container. We attempted to analyze the performance of the safety valve by injecting relatively high temperature hydrogen gas to generate BOG gas and quickly control the pressure of the high-pressure vessel up to 10 bar. As a results, the liquid volume fraction decreased with a rapid evaporation, and the pressure distribution increased monotonically inside a high pressure vessel. Additionally, it was found that the time to reach 10 bar was greatly affected by the filling rate of liquid hydrogen.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2951-2954
• /
• 2007

Tumor hemodynamics in vascular state is numerically simulated using pressure node solution. The tumor angiogenesis pattern in our previous study is used for the geometry of vessel networks. For tumor angiogenesis, the equation that governed angiogenesis comprises a tumor angiogenesis factor (TAF) conservation equation in time and space, which is solved numerically using the Galerkin finite element method. A stochastic process model is used to simulate vessel formation and vessel. In this study, we use a two-dimensional model with planar vessel structure. Hemodynamics in vessel is assumed as incompressible steady flow with Newtonian fluid properties. In parent vessel, arterial pressure is assigned as a boundary condition whereas a constant terminal pressure is specified in tumor inside. Kirchhoff's law is applied to each pressure node to simulate the pressure distribution in vessel networks. Transient pressure distribution along with angiogenesis pattern is presented to investigate the effect of tumor growth in tumor hemodynamics.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
• /
• pp.33-36
• /
• 2005

In this research, for the smart health monitoring of the hydrogen storage high pressure composite vessel, the feasibility study of an embedded fiber Bragg grating(FBG) sensor is carried out. To verify strain measurement in various temperature environment which is needed for the hydrogen pressure vessel, tensile test of a composite specimen with both an embedded FBG sensor and a strain gauge is made in low temperature. Before we try a real-size hydrogen storage pressure vessel, a small & cheap composite pressure vessel having the same structure is fabricated with embedded FBG sensors and tested. In the case of an aluminum liner inside the vessel, survivability of FBG sensors at the interface is lower than the other areas.