• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.485-491
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• 2014

In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.

• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.375-381
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• 2013

In order to establish eLoran system it needs the betterment of a receiver and a transmitter, the add of data channel to loran pulse for loran system information and the differential Loran for compensating Loran-c signal. Precise ASF database map is essential if the Loran delivers the high absolute accuracy of navigation demanded at maritime harbor entrance. In this study we developed the ASF mapping method using predicted ASFs compensated by the measured ASFs for maritime in the harbor. Actual ASF is measured by the legacy Loran signal transmitted from Pohang station in the GRI 9930 chain. We measured absolute propagation delay between the Pohang transmitting station and the measurement points by comparing with the cesium clock for the calculation of the ASFs. Monteath model was used for the irregular terrain along the propagation path in the Yeongil Bay. We measured the actual ASFs at the 12 measurement points over the Yeongil Bay. In our ASF-mapping method we estimated that the each offsets between the predicted and the measured ASFs at the 12 spaced points in the Yeongil. We obtained the ASF map by adjusting the predicted ASF results to fit the measured ASFs over Yeungil bay.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.437-444
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• 2017

The concentration of the HNS Accident for each region was confirmed to prepare against an HNS Spill accident by using a Concentration Index which is used to assess industry concentration trend. This is to present the HNS Accident Concentration Index by combining HNS Accident Scale Concentration Index and an HNS Accident Frequency Concentration Index based on the data of marine spill accidents including the HNS accident. Based on the HNS Accident Concentration Index, Ulsan was identified as a top priority region for preparedness, Yeosu, Busan and Taean were identified as priority regions for preparedness, Gunsan, Mokpo, Wando, Incheon, Tongyeong, Pyeongtaek and Pohang were identified as necessary regions for preparedness, Donghae, Boryeong, Buan, Seogwipo, Sokcho, Jeju and Changwon, in which no marine spill accidents occurred, were identified as support regions for preparedness.

• Journal of Navigation and Port Research
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• v.39 no.6
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• pp.457-463
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• 2015

A gas turbine engine plays an important role as a prime mover that is used in the marine transportation field as well as the space/aviation and power plant fields. However, it has a complicated structure and there is a time delay element in the combustion process. Therefore, an elaborate mathematical model needs to be developed to control a gas turbine engine. In this study, a modeling technique for a gas generator, a PLA actuator, and a metering valve, which are major components of a gas turbine engine, is explained. In addition, sub-models are obtained at several operating points in a steady state based on the trial running data of a gas turbine engine, and a method for controlling the engine speed is proposed by designing an NPID controller for each sub-model. The proposed NPID controller uses three kinds of gains that are implemented with a nonlinear function. The parameters of the NPID controller are tuned using real-coded genetic algorithms in terms of minimizing the objective function. The validity of the proposed method is examined by applying to a gas turbine engine and by conducting a simulation.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.145-150
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• 2020

The ship motion of large LNG ships affects ships' safety. The purpose of this study was to estimate the transfer function of roll motion among the hull motion of 153,000 m3 class LNG vessels. The ship motion transfer function was modeled using a Linear Time-Invarient system with single input, single output, and transfer function. The transfer function of the ship motion was estimated by the system identification method using single ocean wave as input of the model, and using the roll motion of the LNG ship obtained through ANSYS as the output of the model. The usefulness of the experimental results was evaluated using the precision and estimation rate of the model for cases wherein the different transfer function dimensions. Results of the experiment showed a precision at 99% and 98%, with estimation rate at 78% and 50%. From these results, we found the proposed method of estimating the transfer function of ship motion in this study reasonable. In the future, data of ship motion in actual sea conditions will be acquired and it will be applied to make the construction of models with multiple inputs and multiple outputs for practical use.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.289-299
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• 2006

This paper aims to provide strategies to attract container cargoes for the Incheon port by analysing O/D of the container cargoes with the year-2004 export and import data from. The Korean customs service. O/D analysis was carried out with establishing optimal zones, which are defined as City, Gun, Gu(Korean administrative districts) to which the export-import service can be provided from a certain port with minimized freight(or transport) cost and stevedoring fee. For the Incheon port, 35 administrative districts including Seoul and Incheon in Kyunggi-Do and Kangwon-Do are recognized as the optimal zones, and approximately 25.50% of around 2.02-million-TEU per year of the cargoes from the woes are exported and imported through the pan. The strategies to attract container cargoes was suggested by comparing the Incheon port to supposed-competitive pons. The Busan portn(64.89%), Guangyang port(4.46%) and Pyeongtaeck port(3.35%) are supposed as the competitive pons which have a large proportion of handling the cargoes from the optimal zones. When comparing the Incheon port to these ports, The Incheon pan requires a distinctive cost strategy, providing incentives to attract shipping companies and cargoes, improving efficiency related to loading-unloading at the port, and reinforcing Feeder-Network and advertisements about cost-saving to the shippers(the owners of goods) in the national capital region. Consequently, the mentioned requirements are suggested as the strategies to attract cargoes for the Incheon port.

• Journal of Navigation and Port Research
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• v.45 no.4
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• pp.186-193
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• 2021

To enhance the competitiveness of the Busan Port in accordance with changes in global shipping and port industry trends, the Busan New Port is promoting step-by-step integration and developing a port resource-sharing platform. However, inefficient resource-sharing can cause unnecessary additional costs or impede port productivity, so accurate supply and demand matching of shared resources is required. In this study, the supply and demand of port resources were investigated for employees of Busan New Port and North Port, and port resources that could be ideally shared through IPA(Importance Performance Analysis) were analyzed. As a result of analyzing the equipment in the port, Yard Tractor, Reach Stacker, and Top Handler were the top considerations, and for facilities in the port, berths and aprons, empty container yards, and refrigerated container yards were the most important considerations. As for the data in the port, gate status, equipment specifications, and berth and apron conditions were the top considerations.

• Journal of Navigation and Port Research
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• v.45 no.6
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• pp.346-351
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• 2021

With the goal of eradicating overwork, overload, and speeding of general freight cars(cargo) by the Ministry of Land, Infrastructure and Transport, Infrastructure and Transport, the "The Fare of safe transportation for freight cars System" has been enforced since 2020. 'The Fare of safe transportation for freight cars' rate for each item is being applied and supplemented, but the 'The Cost of safe transportation for freight cars' of general freight cars (cargo) and steel items is under discussion. The purpose of this study was to estimate the willingness to pay( WTP) for cargo. A survey was conducted on shippers, transportation companies (arrangers, carriers), and cargo drivers (using direct questioning among contingent valuation method (CVM) and the Tobit Regression analysis was conducted, and the average and median values of freight rates were derived using the estimated results, and the willingness to pay by tonnage of freight cars was confirmed. It is expected that the results of this study can be used as a reference to the "The Fare of safe transportation for freight cars Committee" an organization for deliberation and resolution of the 'The Cost of safe transportation for freight cars'.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.406-414
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• 2018

The objective of this study was to analyze the effect of characteristics of maritime telemedicine (service quality, recognition or not of service, health counselling service experience or not) on seafarer's satisfaction, and also analyze the effect of seafarer's satisfaction on loyalty. This study's data was collected from the Research Report of Survey of telemedicine service subjects in 2017 conducted in the maritime telemedicine pilot project. However, only 103 seafarers who received maritime telemedicine (Tele-Monitering) services were analyzed statistically. The main results of this study were as follows. ⅰ) Better service quality led to higher levels of satisfaction, ii) High levels of seafarer's satisfaction led to high levels of loyalty, iii) Seafarers whose age is under 50 than 30 years old are less satisfied, ⅳ) In total boarding career, Seafarers with more than 5 years but less than 10 years were more satisfied than seafarers with less than 5 years, ⅴ) Seafarers with more than 10 years but less than 15 years were more satisfied than seafarers with less than 5 years, ⅵ) Seafarers with more than 15 years but less than 20 years were more satisfied than seafarers with less than 5 years, ⅶ) Also, Seafarers in excess of 20 years were more satisfied than seafarers with less than 5 years, In conclusion, ⅰ) Better service quality led to higher levels of satisfaction and loyalty. Accordingly, the improvement of service quality is not only an important factor in improving satisfaction and loyalty, but also plays an important role in forming a positive image of maritime telemedicine. ⅱ) Seafarers with younger age and lower overall total boarding career were more satisfied. It is believed that the seafarer who are willing to use telemedicine and who are willing to refer to others are young.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.437-445
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• 2018

IMO (International Maritime Organization) has been strengthening the regulations of ship emission gas such as sulfur oxides (SOX), nitrogen oxides (NOX) and carbon dioxides (CO2) to protect the marine environment. Especially, ECA (Emission Control Area) has been set and operated in the USA and US. As a countermeasure against these environmental regulations, the demand for environmentally, friendly and highly efficient vessels has led to a growing interest in technology related research with respect to electric propulsion systems capable of reducing exhaust gas. Container ships were excluded from the application coverage of the electric propulsion systems for reasons of operation at economical speed. However, in the future, the need for electric propulsion system is expected to rise, because it is easy to monitor and control so that it can be an applicate to smart ship which are represented by fourth industrial revolution technology. In this study, research was carried out to design a generator and battery capacity through the load analysis of the 6,800TEU container ship to apply the electric propulsion system of the container ship. A capacity design based on the load analysis has an advantage that the generator can be operated in a high efficiency section through the load distribution control using the battery.