• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.5
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• pp.36-44
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• 1993

In this paper, a simple design method is represented for a contiguous-band waveguide manifold diplexer which employs a half-wavelength line at the input port of the singly terminated bandpass filterand has resonant-slot coupled E-plane T-junctions. This design method is based on the fact that the input impedance characteristics of the singly terminated bandpass filter are approximately unchanged when a resonant slot and a half-wavelength line at the input port of the filter are employed. This design method is also applicable to the design of the multiplexer. A contiguous-band waveguide manifold diplexer using the post coupled cavity filters is designed, constructed, and tested. The computed and experimental results show the validity of the theory.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.337-344
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• 2017

In the offshore crane system, the requirements on the operating safety are extremely high due to many external factors. Rope extension is one of the factors producing vertical vibration of load. In this study, the load is carried by the motor-winch actuator control and the rope is modeled as a mass-damper-spring system. To control the load position and suppress the vertical vibration of the load, a control system based on input-output linearization method is proposed. By the simulation and experiment results with pilot crane model, the effectiveness of proposed control method is evaluated and verified.

• Journal of Korea Port Economic Association
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• v.17 no.1
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• pp.53-72
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• 2001

This study focuses on analyzing the economic effects and probes the necessity of establishing a customs free zone at the Port of Busan. It first considers the economic effects of establishing a customs free zone at the Port of Busan, then suggests policy prescriptions for introducing and operating the free zone system and improving the logistics functions of the Port. The timeline of this study is focused on 2007, when all of Busan Port will operate as a customs free zone and the first stage of the New Busan Port and distribution parks will be built and opened for operation. The regression analysis, which was conducted using the inter-industry relations table(input-output table data), provided a quantitative prediction on the effects of making Busan Port into a customs free zone. Regarding the impact of a free zone system on the domestic and regional economy, this research found that the impact of a customs free zone on domestic industries and the regional economy once the customs free zone is established throughout all of Busan Port would be highly positive. The positive economic effects on the domestic and Busan regional economy might be further strengthened if the value-added logistics function of Busan Port could be supplemented by effective linking to the hinterlands.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.331-336
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• 2004

In order to strengthen the competitiveness of port against calling for the huge vessel and reducing the shipping service time, the productivity of container terminal must be improved. This productivity variously results according to the kinds of productivity evaluation model, input elements like yard, equipment, employee, facility, etc,. But, it is discussed that the productivity is measured by partial productivity evaluation model or general input elements. Therefore, we measured for the productivity of the container terminal using the Developed the data Envelopment Analysis (DEA), which is developed in order to evaluate the relative efficiency of decision making units - it's difficult to clear cause and effect between input and output. We measured the whole productivity of container terminal in Busan according to decision of the correct input elements. And we investigated the change of the productivity measurement result according to input elements, presents more accurate productivity evaluation model in container terminal.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.117-120
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• 1999

Input queueing is useful for high bandwidth switches and routers because of lower complexity and fewer circuits than output queueing. The input queueing switch, however, suffers HOL-Blocking, which limits the throughput to 58%. To get around this low throughput, we propose a simple scheduling algorithm called Synchronous Input Port (SIP). This method synchronize packets and switching without blocking, which is shown to have better performance over the established algorithms

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.8
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• pp.1188-1195
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• 2022

The 6-port phase correlator consists of one in-phase power divider and three 3-dB 90-degree phase difference power dividers, and is mainly used in a demodulation circuit that determines the phase of an input signal. This paper proposes the wideband 6-port phase correlator that consists of an in-phase power divider using a wideband 2:1 impedance transformer with three 37.5-Ω coaxial cables, and a 3-dB 90-degree phase difference power divide using Wireline. The proposed wideband phase correlator fabricated at a center frequency of 1000MHz has the value of the input reflection coefficient(S₁₁ and S₂₂) -14dB or less in the frequency range of 640~1270MHz. Also, the signal transmission characteristic(S_i1), from the in-phase power divider input port to four output ports, has the amplitude of -6.5±0.6dB and the phase error of within ±3.4°, and the signal transmission characteristic(S_i2), from the 90 degree phase difference power divider input port to four output ports, has the amplitude of -6.1±0.6dB and the phase error of within ±6.2°.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1293-1302
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• 2018

Multiport power converters have recently become popular to researchers and engineers. However, more improvements are required in terms of their soft-switching operation, bidirectional operation, and integration. In this study, a bidirectional three-port three-switch DC-DC converter is proposed. The converter contains a low-current ripple port and ripple-free current port. Through the integrated structure, utilization of a coupled inductor, and a new switching strategy, the aforementioned specifications are achieved. A modified switching strategy is also utilized in the converter, which has resulted in the bidirectional operation of the converter between ports. Finally, a comprehensive analysis is presented, and the converter characteristics are validated by experimental results.

• IE interfaces
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• v.11 no.1
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• pp.97-103
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• 1998

In these days many people have studied on the berthing problem. The operation rules differ from port so port and the problem is highly dependent on the environment of port. The purpose of this study is to develop a decision support system decision makers of the berthing problem for Inchon Port. The system is developed with graphic user interface(GUI) using user-interactive approach and some general and specific rules for Inchon Prot are considered. The system is composed of the following four parts ; the input/output part, the automatic berthing part by the system using rules, the manual berthing part by user, and the part for modifying results or handling exceptional events. The system is designed to assign ship to berths by matching the characteristics with environmental and operational constraints of Inchon Port. We expect that this system can provide decision makers with an efficient and fast way to berthing and can reduce wastes of time, space, and manpower in port operations.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.163-170
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• 2008

Auxiliary port which had been known to be used to reduce the expansion loss of a refrigeration system was applied to a R134a reciprocating compressor in a household refrigerator cycle with an intention of improving the compressor performance. Effects of the auxiliary port on the compressor performance was investigated by a computer simulation program. When a simple hole was made on the side wall of the cylinder as an auxiliary port and surrounding gas inside the compressor shell was assumed to be drawn into the cylinder through the hole, maximum COP improvement of 1.66% was obtained. With auxiliary port equipped with a plate type of check valve, maximum COP was raised to be 1.99%. COP improvement was more distinctive with decreasing the discharge pressure; COP improvement was 5% with discharge pressure of 7 bar.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.637-644
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• 2008

Auxiliary port which had been known to be used to reduce the expansion loss of a refrigeration system was applied to a R134a reciprocating compressor in a household refrigerator cycle with an intention of improving the compressor performance. Effects of the auxiliary port on the compressor performance was investigated by a computer simulation program. When a simple hole was made on the side wall of the cylinder as an auxiliary port and surrounding gas inside the compressor shell was assumed to be drawn into the cylinder through the hole, maximum COP improvement of 1.66% was obtained. With auxiliary port equipped with a plate type of check valve, maximum COP was raised to be 1.99%. COP improvement was more distinctive with decreasing the discharge pressure; COP improvement was 5% with discharge pressure of 7 bar.