• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.181-190
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• 2008

In this paper, we suggest a new 4-port receiver instead of 6-port schematic for the demodulation of BPSK. The designed receiver is implemented by a ring-hybrid balun, two power detectors, and a comparator For the validity of the proposed receiver, we demonstrate a BPSK modulator/demodulator at 2.45 GHz. The measured data shows that the proposed 4-port receiver can successfully demodulate a data rate of 1 Mbps.

• Journal of Multimedia Information System
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• v.5 no.4
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• pp.265-272
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• 2018

Busan is Korea's No. 1 trading port, and the logistics industry plays an important role in the regional industry as a whole. In Busan, various efforts are being made to revitalize the port logistics industry, but it is necessary to develop various policies and related technologies linked with the 4th industry. In this study, we propose a smart refrigeration logistics center, which is required for the activation of Busan New Port and the new port of Pusan New Port, which is connected with the 4th industry. I would like to present the operation direction of the center.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1105-1110
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• 2007

This paper describes an equivalent circuit modeling of 4-port connector system. A coupled transmission line was designed and fabricated, mimicking a 4-port connector system, and then S-parameters were measured using 4 port VNA (Vector Network Analyzer). The S-parameters from measurement and from Full-wave simulator coincided quite nice. By using these S parameters, an equivalent circuit parameters for a 4-port system was obtained. The time domain response from the equivalent circuit model matched to the signals, which was measured using TDR(Time Domain Reflectometry) meter. We were also convinced that there should be enough bandwidth to get a meaningful time domain result from Fourier inverse transformation of the S parameters. In addition, we applied the conversion algorithm to the 4-port connector system, which calculates the S-parameters of a 4 port system using the data from a 2-port VNA with the other ports open. Comparison of the two data, one from measurement and the other one from the conversion algorithm, was made in this manuscript.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.52-56
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• 2009

The design method of a four-port stripline circulator with a single ferrite disk is proposed using Green's function method. The four-port circulator gives the flexibility of the design of the communication system. Two cascaded three-port circulators has been used as a four-port circulator. However, if a four-port circulator with a single ferrite disk replace the present four-port circulator, then it will give less weight and volume and so has the advantage in satellite application.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.157-169
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• 1997

The effects of intake port eccentricity on the characteristics of in-cylinder swirl ratio in a 4-valve diesel engine having the two intake ports; one is a helical intake port and the other is a tangential intake port were investigated by using the ISM(impulse swirl meter) in steady flow test rig. Swirl ratio($R_s$) and mean flow coefficient($C_{f(mean)}$) with valve eccentricity ratio($N_y$) and axial distance(Z/B) were measured. As the results from this experiment, the characteristics of in-cylinder swirl ratio formed by a 4-valve cylinder head were largely affected by intake port eccentricity. There is a difference in the mass flowrate through the two intake ports, and the mass flowrate through the tangential intake port is 19% more than that of the helical intake port. Therefore, we could know that the effects of the mass flowrate ratio through each intake port besides intake port shape should be conidered.

• Journal of Navigation and Port Research
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• v.33 no.4
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• pp.263-270
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• 2009

Busan North port is facing crisis due to the opening of the New port. The North Port and NewPort are competing for a limited volume of cargoes and this competition is leading after all to price competition, lowering cargo work fee that may result in the failure of both This paper proposed the balanced development plans, which are the strategies of business tie-up and activation between the North Port and NewPort by introducing the strategy of "co-opetition" and the analysis for the success factor of co-opetition: to solve this operational problems on Busan port. It is found out that activation strategy is more successful co-opetition strategy than business tie-up strategy. The execution for the two co-opetition strategies will lead Busan Port to the balanced development as well as the enhanced competitiveness and will leap Busan port into global hub port as well.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.449-455
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• 2022

Objectives: In order to provide basic data for future researchers, this study aims to explore future tasks after reviewing the changes in port safety management due to the enforcement of the Special Act on Port Safety. Methods: The provisions of the Special Act on Port Safety were analyzed and the latest literature related to port safety management was reviewed. Results: There are two major changes that have stemmed from the Special Act on Port Safety: 1. The scope of application for port participants has been expanded, safety education has been made compulsory, and safety management plans have been established and implemented for each business site. 2. The government is operating a port safety consultative body for each port and has hired one port safety inspector for each of the eleven local maritime and fisheries offices across the country. Future tasks include elaboration of port safety accident statistics, strengthening shipping companies' responsibility for stevedore safety, the unification of contracts, and government interest and support for port safety facilities. Conclusions: The primary feature of the Special Act on Port Safety is the emphasis on autonomous safety management by participants in port transportation. In addition, the enactment of the special law has allowed the Ministry of Maritime Affairs and Fisheries to actively intervene in port loading and unloading safety.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.276-281
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• 1989

Comparison 3-port servo system with 4-port is made to obtain optimal design for heavy and unidirectional hydraulic system, It is concluded that 3-port servo system it more adequate than 4-port for the heavy load system which is usually operated at lower frequencies. High performance electro-hydraulic position controller is designed using 3-port servo valve. It includes dynamic pressure feedback as a inner loop and position feedback as a outer loop.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.353-358
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• 2017

This study aims to propose an assessment tool of port service quality (PSQ) in the context of container transport logistics (CTLs), by taking the perspectives from port users. The CTLs defined in this study are the relevant activities of serving the physical flows of a container box from a point of origin via a container port to a point of destination. To address the ports' role in collaboration between its channel members in CTLs, the PSQ measures for all port user groups (i.e. common PSQ measures) are selected based on the relevant CTLs activities involved by port, and its users within terminal/port area as well as throughout the CTLs chain. An importance-performance analysis (IPA) is applied as a diagnostic tool to analyse the status quo of Busan Port in CTLs contexts, by comparing the importance and performance (IP ) scores against each individual CTLs criterion. The findings from the IPA reveal that port managers and policy makers at the Busan Port should concentrate on six PSQ measures (i.e. SR1, SR4, ITS1, VAS1, VAS4, ICI3) to enhance PSQ in CTLs. However, four measures (i.e. ITS2, ITS3, ITS4, VAS2) are identified as a possible overkill, indicating an area of inefficiency where a remedial action of the cost-cutting decision is necessary. On the other hand, the Busan port shows an outstanding performance on four measures such as SR2, SR3, ICI1 and ICI2. The measures are not only important but also high performance. The study findings provide managerial guidance to port managers in Busan Port, in view of searching for managerial and operational strategies for sustainable port growth.

• International Commerce and Information Review
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• v.4 no.2
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• pp.279-301
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• 2002

Lately, one of the most representative phases on business world is the diffusion of internet business. This change has been making new port business model called 'e-Port' in maritime transport. The focus of this article is to suggest some strategies on the implementation of e-Port in Korea. To research and analyze the e-Port realities, we first reviewed the previous study on Internet Marketing and e-Business. Six strategies that are critical on e-Port model were classified: (1) contents, (2) community, (3) commerce, (4) connection, (5) communication, (6) customization. Secondly, we chose and evaluated website of eight ports: Hongkong, Singapore, Antwerp, Hamburg, as successful e-port models. And then, we investigated actual conditions of e-Port in Pusan, Inchon, K wangwang, and Gusan. And then we try to find effective plan on the operation of e-Port.