• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.977-985
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• 2012

Performance optimization of a small engine intake port has been studied through computational and experimental approach. Port angle, flange area and port shape are very important design parameters affecting performance of an intake port. Especially, radius of curvature of intake port inner surface has major effect on the flow coefficient of an intake port. As increasing port angle and flange area, flow coefficient is increased because pressure distribution and pressure gradient in the intake port are improved. Even though computational results over-predict maximum 8% compared with experimental result, they describe the tendency of flow coefficient according to the design parameters. Optimized intake port shows about 4.5% improved flow performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.23-28
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• 2011

To secure basic data for intake port design, effects of a port masking on the part load performance were investigated in a 4 valve SI engine. For this purpose, 9 kinds of masking, which have different shapes and masking ratio, are applied to the engine intake system. The characteristics of the performance were estimated through mixture response test at various engine load and speed. The results show that NOx emission, one of indexes for stratification, increases considerably in spite of retarded spark timing due to the stratification which is caused by unequal flow distribution between the two intake ports. The mechanism of stratification by masking is different from axial stratification and the fuel entering through masked port plays a very important role in this stratification process. In conclusion, the port masking method could be easily applied to engine intake system and be very effective for inducing the stratified charging without the change of port design.

• Journal of Fisheries and Marine Sciences Education
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• v.19 no.3
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• pp.441-456
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• 2007

The purpose of this study was to obtain an objective conclusion of safety assessment and to suggest proper countermeasures for the fishing vessels' entering or leaving the port of Gamcheon, in where the pier No. 4 for the fishing vessels will be newly opened soon. 20 times of the manoeuvring simulation were performed respectively onto entering and leaving the port of Gamcheon with the various conditions in weather and current, and then each of result was carefully analyzed. In spite of some increasing demand of entering the port in future, the safety will not be largely worse if the suggestion will be taken.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1278-1288
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• 2019

A DC-DC Non-Isolated Three-Port Cuk-Cuk (NI-TPCC) converter for interfacing renewable energy sources (RESs) such as Fuel Cell (FC) and Photovoltaic (PV) energy with a DC load is presented in this paper. It features single-stage power conversion from both of the input ports to the load port. The proposed NI-TPCC converter is designed based on the classical Cuk converter. The operational modes and power flow are analyzed in the continuous conduction mode (CCM), and the relationships among the port voltages are derived. Continuous currents in all three ports with less ripple enhance the performance of a fuel cell and its operating life. Furthermore, the output inductor is shared with both of the input ports, which reduces the number of active and passive components. The effectiveness of the designed NI-TPCC converter has been validated through simulation and experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.623-629
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• 2020

This study examined the airflow field around a gun port on the flight condition of gunfire to verify the aircraft performance and safety effects and gun gas rate, path according to the options of diverter configuration. The gun port diverter not only effectively lowered the heat generated by gunfire but also effectively discharged the gun gas upwards. The path of gun gas can be changed according to its configuration. According to the optional configuration of the rear-gun-port diverter, the flow rate, path, and pressure of the gun gas were analyzed during gunfire. An analysis of the internal velocity distribution and the temperature change of the gun port revealed a rapid decrease in flow rate through the rear diverter according to the option configuration. The forward flow rate showed a similar tendency with little change. This ensures that the gun gas generated during gunfire has a sufficient flow distance from the aircraft surface, regardless of the rear gun port diverter's optional configuration. The flow stagnation of gun gas according to the option configuration of diverter had a great influence on the internal temperature rise of a gun port.

• Proceedings of the Korea Port Economic Association Conference
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• 2007.07a
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• pp.37-50
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• 2007

Taking advantage of geographical position of Korea located on the main route of world-wide service, Port Logistics Industry can be strategic industry which secures international competitiveness necessary for Korea to be hub of Northeast Asian's logistics. Along with the advent of super large container vessel, world ports environment changed from "milkway" type, which means vessel calls every port for service to "Hub & Spoke" type, which means vessel calls regional central port and feeder service for the rest ports. As environment changes, regional ports in Northeast Asia are competing each other tougher and tougher and introducing or developing port logistics information system based on state-of-the-art technology in order to adapt themselves to new environment, thus to be Hub port. Taking this situation into consideration, we want to define clearly the meaning and scope of port logistics IT and review the global trend of port logistics IT. Finally we want to find future development of port logistics IT which we have to achieve.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1626-1637
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• 2006

The pressure pulsation due to the gear geometry of the gerotor (generalized rotor) pump mainly occurs in an instant that the chamber of the gerotor enters the delivery port and leaves the suction one. Such a pressure pulsation may result in undesirable vibration and noise of pump components as well as cavitation in hydraulic system. Therefore, it is very important to examine the pressure characteristic of the gerotor pump at its design and analysis stages. In this paper, in order to reduce the pressure pulsation in the gerotor pump, the port plate with the relief grooves is designed by referring to as notch of vane pump and relief groove of piston pump. A series of the theoretical analyses on the pressure pulsation is performed in consideration of various design parameters of the port plate, including the installation positions of the port inlet/outlet and the groove width, and the operating conditions such as rotational velocity and delivery pressure.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.361-373
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• 2020

In Jeju, in order to efficiently manage and coexist fishing boats and passenger ships in narrow ports, it is necessary to establish reasonable policies. The survey was conducted on 99 fishing ports, from December 1 to 31, 2018. A site survey was conducted on 30 parties (15 in Jeju City and 15 in Seogwipo City) concerning with the use of fishing ports in Jeju to review the appropriate conditions for selecting fishing ports as control subjects. The survey determined size of pleasure craft mooring within fishing port (20%), size of fishing boat mooring (20%), and accessibility of fishing port (20%) under on-site survey factors as well as willingness to form a consultative group between fishing boat and pleasure craft users (20%). Upon the request of the survey, positive and negative opinions were collected on the establishment of a safety control center in the fish port. Based on the survey results, the factors mentioned above were applied to each and every fishing port within Jeju. The bottom five fishing ports in Jeju with the lowest total factor scores were identified and selected as control subjects for review and study. Of the five fishing ports selected as control subjects amidst the 99 fishing ports in Jeju, Dodu Fishing Port had the lowest score of 22% among the national fishing harbors. Among the local fishing ports, Hwabuk Fishing Port had the lowest score of 18%, followed by Sagae Fishing Port with a score of 22%. Hamdeok Fishing Port had the lowest score of 24% among the fishing port villages, whereas Ojo Fishing Port had the lowest score of 24% among the small fishing ports.

• Journal of Navigation and Port Research
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• v.42 no.5
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• pp.347-356
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• 2018

The presence of the Fourth Industrial Revolution is omniscient, led by full force emergence of technologies that make biological, physical, and digital worlds borderless. All industries which jump on the bandwagon, can observe convergence and merging of bushiness happening within, between and across industries. As the shipping and port logistics industry is said to be in eye of this storm, the purpose of this study is to investigate the shipping and port logistics industry's awareness regarding 4th IR, as well to identify necessary countermeasures in responding to progression of this trend. Analytic Hierarchy Process (AHP) methodology was then used to compare the importance of four phases of countermeasures, reviewed by experts in the field. Results showed that countermeasures should be first orchestrated to the 'Merging and Integration of Inter-industry', then followed by 'P reemptive Introduction of Advanced Technology', 'Expansion of Intra-industry Businesses', and eventually 'Automation, Unmanned Technology'. Last but not least, four phases of countermeasures which should be introduced and executed one phase after another, are outlined for the shipping and port logistics industry to boost its competitiveness in addressing this progressive trend.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.810-817
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• 2007

Every ports is making great efforts to get competitiveness. It is progressing for the research on port model of new concept that connect port-related business to be developed from base running simple cargo processing to universal port that has economical efficiency and competitiveness, This research shows development way of Busan port that connect ship-repair industry which is port-related business. Development way is especially handled link between port and ship-repair industry field activation of high value-added ship as LNG etc.