• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.41-47
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• 2007

The structure of ER valve is simple that its designing and manufacturing are easy. The flow rate and pressure of ER fluids flowing in the ER valve are controlled only by electric field. In this study a three port ER valve is designed and manufactured. Then, the flow rate and pressure dorp of ER fluids flowing in the ER valve are measured. The system proposed controls flow rate and pressure fast. So, this system can be easily substituted for the existing hydaulic and pneumaitc control system.

• Journal of Korea Port Economic Association
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• v.22 no.1
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• pp.175-198
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• 2006

This paper presents a network capacity model that can be used as an analytical tool for strategic planning and resource allocation for multimodal transportation systems. In the context of freight transportation, the multimodal network capacity problem (MNCP) is formulated as a mathematical model of nonlinear bi-level optimization problem. Given network configuration and freight demand for multiple origin-destination pairs, the MNCP model is designed to determine the maximum flow that the network can accommodate. To solve the MNCP, a heuristic solution algorithm is developed on the basis of a linear approximation method. A hypothetical exercise shows that the MNCP model and solution algorithm can be successfully implemented and applied to not only estimate the capacity of multimodal network, but also to identify the capacity gaps over all individual facilities in the network, including intermodal facilities. Transportation agencies and planners would benefit from the MNCP model in identifying investment priorities and thus developing sustainable transportation systems in a manner that considers all feasible modes as well as low-cost capacity improvements.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.270-271
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• 2014

In spite of the methodology of evacuation process on vessels should be different comparing to the architecture on land, some have simulated the evacuations onboard ship with simulation tools which is developed only for the architecture. On this study, a vessel-oriented simulation tool is used to analyze the possibility of evacuation for a passenger ship. ${\cdots}$(중략)${\cdots}$ As a result of the simulation analysis, it is clear that the initial responding time and start-to-move time are so important, ${\cdots}$(중략)${\cdots}$.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.72-78
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• 1996

Based on experimental analysis, the characteristics of pulsating pressure wave propagation is clarified by testing of 4-stroke gasoline engine. The pulsating pressure wave in exhaust system is generated gyulsating gas flow due the working of exhaust valve. The pulsating pressure wave is closely concerned to the loss of engine power according to back pressure and exhaust noise. It is difficult to exactly calculate pulsating pressure wave nonlinear effect. Therefore, in the first step for solving these problems, this paper contains experimental model and analysis method which are applied two-port network analysis. Also, it shows coherence function, frequency response function. back pressure, and gradient of temperature in exhaust system.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.81-88
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• 2008

Flow characteristics have one of the effects in the process of engine. The numerical analysis makes it possible to predict the flow fields. This paper presents characteristics of steady flow according to variation of valve lift in a gasoline engine. The numerical computations have been made to observe the pressure distribution in accordance with the variable valve lift. Characteristics of tumble flow and swirl flow according to the variable valve has also been investigated. We could find that tumble ratio and swirl ratio is different between with/without PDA valve. The steady flow test was simulated through three-dimensional analysis on intake port design for comparing with experimental data and confirming the feasibility of applying analytic method. As a result, this study shows the possibility of the usage of numerical simulation to predict the flow characteristics for gasoline engine.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.243-252
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• 1999

Recently several research groups using CORMIX, approved by EPA, have been working on the hydrodynamic mixing processes due to the ocean discharges. It provides a useful tool for analyzing near field mixing characteristics through the outfall system. This paper applies CORMIX 1 & 2 to the Pusan Jungang Effluent Outfall System, which is planned to be in the Gamchun harbour and will be completed in 2011. This model output shows the trajectoral variation of dilution and concentration for three cases of outfall system. Dilution differences have been simulated and found the highest dilution condition under the different displacement of outfall system. On the basis of these outputs it will be proposed the optimum outfall system type and location. This approach might contribute on protecting the serious water quality problem due to the ocean discharge.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.19-33
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• 1999

This paper is concerned with developing a standard costing model based on the case study of PECT and GCT and analysing their profitability in order to improve operation efficiency and design business strategy. In doing so, the model can be a useful tool to analyze current calculation system of lease charge at the two terminals and to judge whether the level of lease charge currently applied to them is justifiable for their profitability. This paper also deals with break-even analysis of container terminal operating companies on the basis of the model and forecast of their profitability. On the top of that, it tries to look into the arguments and to suggest proposals for improving their profitability.

• Journal of Navigation and Port Research
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• v.31 no.2
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• pp.121-126
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• 2007

Evaluation of collision risk plays a key role in developing the expert system of navigation and collision avoidance. This paper presents a new collision risk model formula that is one modification model on the basis of one approach to the evaluation of collision risk using sech function produced in earlier studies. And as a tool of the evaluation field of ship collision, this paper applied the new model in appraising the collision risk and represented how to decide the safe range of own ship's action. Moreover this paper also analyzed theoretically how to determine the coefficients as described in the new modification model, and suggested the appropriate values as applicable.

• Journal of Navigation and Port Research
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• v.32 no.2
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• pp.115-120
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• 2008

This paper deals with effect of wind forces and moment acting on the training ship SAE NURI. The results of drift angle and counter rudder angle due to wind effect are calculated by using the static equilibrium method especially with nonlinear mathematical expression, and then the critical wind velocity is found out. The given results can be applied directly to T/S SAE NURI in handling under the wind condition and used for merchant ships as a referential tool.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.265-266
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• 2022

전통적으로 선박교통관제서비스는 정보제공(INS), 항행지원(NAS), 교통관리(TOS)로 구분되어 왔으나, 최근 IMO 결의서 A.1158의 개정을 통해 선박교통관제서비스의 목적을 선박 항해에 안전하지 않은 상황을 선제적으로 모니터링하고 통제하는 것으로 규정하고 있다. 이를 위해 기존의 VTS 서비스 용어들을 모두 삭제하였으며, IALA에서도 관제사의 의사결정도구에 대한 개정을 논의하고 있는 상황이다. 이에 본 논문에서는 빅데이터 기반의 관제사 의사결정도구를 제안하였으며, 적용 가능성을 검토하였다. 제안하는 방법은 관제사의 주관적인 판단과 단순한 규칙에 의존하던 기존의 관제 방법과는 달리 데이터를 기반으로 하는 객관적인 관제 기준을 제시할 수 있으며, 이러한 방법이 실제 관제 현장에 적용되어 해양사고를 방지하고, 항만의 운영 효율을 향상시킬 수 있기를 기대한다.