• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.93-96
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• 2008

This study was performed for merge characteristic of Hybrid Rocket with multi-port. PE(Poly Ethylene) is fuel with 4 and 5 port grain and GOX(Gas Oxygen) is oxidizer. This study according to number of ports The multi-port grain merge with other grains during a combustion, then Hybrid Rocket performance is changed by change of a combustion area.

• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.199-214
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• 2022

A relative important analysis was conducted to determine what factors are required for port selection in Mokpo New Port and what needs to be addressed first in order to expand automobile and steel cargo handling. The port selection factors of Mokpo New Port were classified into 4 major and 13 intermediate categories, and AHP analysis was used. As a result, items such as 'port facilities', 'accessibility to international ports', 'port facility usage fees', and 'connectivity with neighboring cities/ports' were evaluated as important. The respondent groups were divided into shipowner and shipper, port operator and stevedore, and public official, and an analysis of variance (ANOVA) was conducted to verify if there was a difference in perception between the groups. As a result, shipowner and shipper, port operator and stevedore were similar, but there was a difference from public official group. Shipowner and shipper, port operator and stevedore with similar response characteristics were classified into the 'port practitioner' group, and public official were classified into the 'port policy maker' group, and the difference in perception between the group was tested. Therefore, there were differences in some major category items, and even in the intermediate category items such as 'possession of adjacent hinterland industrial complex', 'cargo equipment', '24-hour port operation', 'inland transportation cost', 'accessibility to international ports', 'marketing and incentives' with statistical. In other words, the 'port practitioner' group evaluated items that can increase cargo creation and handling productivity as important whereas the 'port policy maker' group considers port development and policies such as port infrastructure, connectivity with other ports, and incentive support items are more important.

• Journal of Navigation and Port Research
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• v.32 no.4
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• pp.287-294
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• 2008

Recently, amount of cargoes from main ports in Northeast Asia have rapidly increased and as well surplus port development in same region corresponded with the boom in external trade that resulted from successful export-oriented economics strategy by China, Japan and South Korea. To cope with this business circumstances, a certain form of port alliance is desperately needed to provide a suitable service to customer and establish their countervailing power against the shipping alliance. Nevertheless, Incheon seaport has not made a definite port alliance system with main ports in Northern China yet. Thus, the purpose of this study is to identify the key success factors to form a port alliance through examining previous studies. We have benchmarked previous studies which are related to main ports in global region and the questionnaire on customers of ports. By studying this, we are able to suggest a few strategies for forming successful port alliance to enhance Incheon port's capabilities in the long term plan. As a policy proposal, this study suggests Incheon port and main ports in Northern China should construct a logistics infrastructure through mutual investment and provide an incentive system when the ocean carrier makes port call to both ports.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.137-154
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• 2011

This study is to contribute to create favorable conditions for developing the new port in a timely and as well helps to propose role and establish status of incheon port in the future by reviewing port facility capacity of Incheon Newport, applied trigger rule reasonably. By applying trigger rule with annual growth rate(11.4%) between 2001 to 2009 rules it will be 18 berths reducing 2 years for completion date than annual growth rate(9.4%) forecasted by Ministry of Land, Transport and Maritime Affairs. This paper first suggests the tri-ports policies including Incheon new port, Busan port and Gwang-Yang port and creating favorable conditions for the early completion and lastly attracting high valued-added transshipment cargo for developing incheon new port in a timely.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.4
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• pp.406-414
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• 2004

In Gerotor pump, the pressure pulsations which occur due to the pump geometry result in vibration and noise of pump elements as well as cavitation in hydraulic system when the chambers of gerotor enter the delivery port and leave the suction port. Therefore it is important to study on the pressure pulsations before design and analysis of characteristics in Gerotor pump. In this paper, to reduce the unnecessary pressure pulsations, the port plate of Gerotor pump is designed based on the notch of the vane pumps and the relief grove of the piston pumps. The theoretical analysis of the pressure pulsations is performed in consideration of design parameters of the port plate which include each port positions and groove width and operating conditions which include rotational velocity and delivery pressure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.91-96
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• 2008

In this paper, a monopulse fled for three mode $2{\times}2$ array feed horn antenna was designed. Gain of single feed was 8.25dB. Increasing property of gain and rectangular waveguide and reflection of free space is decreased because it has structure extending to electric plane at connected part from transformation to free space. When fled port1 and port2 is placed vertically and thickness of aperture hem is reduced, isolation is satisfied with property of lower -25dB. Also, at higher frequency, it is confirmed that isolation is improved. Combination of electric field occurs less influence because port1 and port3 is placed horizontally and distribution of electric field is connected to parallel. However, because of combination of electric field, it is more improved from 2dB to 6dB than isolation of port1 and port2. Direct combination occult less effect at port1 and port4 than effect of port2 and port3, it is lower -35dB.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.1-10
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• 2022

Looking at the cargo trend of Gwangyang port (GWP) during past decade, petrochemical items grew by 26% and steel item grew by 12%, but container cargo just grew by 4%. Thus, Yeosu-Gwangyang Port Authority (YGPA) sets the port development initiative targeting at industrial core port considering GWP's strength as multi function port and industrial port and GWP's weakness as lower container cargo growth trend. The purpose of this study is proposing the projects about the GWP's industrial core port development. The results of the study is as follows. As a prerequisite for development as an industrial core port, it was suggested to form a consensus on the modification or change of the port performance index of univariate port cargo volume. The following three tasks were presented for GWP to develop as an industrial core port. It can be said that it is most necessary to derive, manage, and monitor GWP industrial core performance indicators. Next, it is necessary to conduct a survey on the satisfaction of industrial support in ports. Finally, it is necessary to measure the added value of the port area of GWP hinterland.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.59-72
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• 1998

This experimental study was carried out to investigate the characteristics of the in-cylinder eccentricity swirl flow generated by a 4 valve cylinder head with a tangential and a helical intake port. the measurements of the in-cylinder velocity field have been made by a two-channel LDA system. The mean flow coefficient(Cf(meam)), swirl ratio(Rs) and mass flowrate with valve eccentricity ratios and an intake port partition between the two intake ports were measured in the steady flow test fig using the ISM(impulse swirl meter). The experimental results indicated that the mass flowrate through the tangential intake port was 19% and 7.7% more than that of the helical intake port in case of with and without intake port partition respectively. There was a tendency to be a single rotation flow in swirl flow fields formed by a 4 valve cylinder head because of the interaction between the two intake ports. As the intake port partition was not set between flow coefficient(Cf(mean)) was 7.35%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.68-70
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• 2015

The four-port coupler circuit consists of input port, isolation port and two output ports. When it inserts a signal at the input port and the isolation port, the magnitude and phase of the output signal at two output ports are decided by the magnitude and phase of the input signal. This paper analyzes the output signal characteristic of two output ports due to the input signal magnitude and phase of two input ports using the typical 4-port coupler circuit, Branchline hybrid coupler and Ring-hybrid coupler. And, it studies about new way to use branchline hybrid coupler and ring-hybrid coupler on the basis of the this information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1458-1470
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• 2018

In this letter, a new dual-port Multiple-Input Multiple-Output (MIMO) antenna is introduced which has two independent signal feeding ports in a single antenna element to achieve smaller antenna volumes for the 5G mobile applications. The dual-port structure is implemented by adding a cross coupled semi-loop (CCSL) antenna as the secondary radiator to the ground short of inverted-F antenna (IFA). It is found that the port to port isolation is not deteriorated when an IFA and CCSL is combined to form a dual-port structure. The isolation property of the proposed antenna is compared with a polarization diversity based dual-port antenna proposed in the literature [9]. The operating frequency range is 3.3-4.0 GHz which is suitable for places where $4{\times}4$ MIMO systems are supposed to be deployed such as in China, EU, Korea and Japan at the band ${\times}$ (3.3 - 3.8GHz. The measured 6-dB impedance bandwidths of the proposed antennas are larger than 700 MHz with isolation between the feeding ports higher than 18 dB [1-2]. The simulation and measurement results show that the proposed antenna concept is a very promising alternative for 5G mobile applications.