• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.89-99
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• 2002

Since 1996, the document exchange method by EDI has been introduced in port and logistics industries in Korea to enhance the declaration activities to the Pusan Port Authority and Customs. In spite of these efforts, users such as shipping companies, shipping agents, and freight forwarders have complained the inconvenience of using EDI systems. The major reasons can be summarized as follows: repetitional EDI transfer, too much transfer time, inconvenient EDI software, and problems on message receiving confirmation. Furthermore, EDI has been used only for transmitting messages. To solve these problems, this study has adopted the integration system by applying the concept of SCM to logistics system by XML/EDl. In the view of SCM, the existing EDI has some problems because its role is only to transmit the messages. This paper is to suggest how current EDI systems in Port and logistics sector has to be chanced by Introducing SCM. The integration system gives us such advantages as accuracy of cargo data, integration of processes among firms, and keeping the trace of cargo.

• 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 Korean Port Research
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• v.14 no.2
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• pp.133-142
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• 2000

In order to streamline the procedure of data transmission in port and logistics industries, MOMAF introduced EDI systems as the method of data transmission of 19 documents 5 years ago. While operating EDI system, MOMAF has found the inconvenience and the inefficiency of using EDI systems in the field of requesting fast response. This thesis focuses on finding the possible fields of on-line processing system. The result of the paper presents that if data transmission area such as 'application for pilot'is changed to on-line processing method, the processing cost and time will be reduced compared with EDI processing method.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.393-396
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• 2005

Due to the fast growing rate of the global container trade, every major port is under the pressure of meeting the projected capacity demand. As a result, alternative solutions have been sought for improving capacity and meeting the growing demand for container storage area and terminal capacity. Moreover, material handling process re-engineering is now a critical issue for logistics and supply chain managers of airline, shipping lines, terminal and warehousing enterprises around the world. Therefore, the purpose of this paper is to develop the 3D simulator for executing performance valuation of port transportation systems. The developed 3D simulator system is to measure the effectiveness of the proposed total system and compare it with existing practices. The performance analysis variables are also defined for these comparisons

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.293-294
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• 2022

In recent years, the maritime industry system including port facilities, VTS(Vessel traffic service) is rapidly evolving with the development of technology. The connection between systems has been greatly expanded, and many research cases using this connectivity have been reported. This paper deals with the structural design of the arrival/departure support system for an autonomous ship. The system requires navigation data from the autonomous ship and radar/AIS data from the port. In this paper, design result on how the arrival/departure support system interacts with the autonomous ship and port system are addressed.

• 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.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1433-1444
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• 2017

A family of non-isolated DC-DC three-port converters (TPCs) that allows for a more flexible power flow among a renewable energy source, an energy storage device and a current-reversible DC bus is introduced. Most of the reported non-isolated topologies in this area consider only a power consuming load. However, for applications such as hybrid-electric vehicle braking systems and DC microgrids, the load power generating capability should also be considered. The proposed three-port family consists of one unidirectional port and two bi-directional ports. Hence, they are well-suited for photovoltaic (PV)-battery-DC bus systems from the power flow viewpoint. Three-port converters are derived by combining different commonly known power converters in an integrated manner while considering the voltage polarity, voltage levels among the ports and the overall voltage conversion ratio. The derived converter topologies are able to allow for seven different modes of operation among the sources and load. A three-port converter which integrates a boost converter with a buck converter is used as a design example. Extensions of these topologies by combining the soft-switching technique with the proposed design example are also presented. Experiment results are given to verify the proposed three-port converter family and its analysis.

• Journal of Korean Port Research
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• v.12 no.1
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• pp.25-33
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• 1998

The evaluation of port competition could be applied to determining the selection of a calling port. A few fundemental attributes of port competition were adapted by the 'brain storming' method. The criteria used for evaluating a port's competitiveness were as follows: efficiency of port operations, competitive power of each port's industry, economic activity of the hinderland associated with each port and capability of globalization. The weight of each criterion was 30%, 40%, 20% & 10%, respectively. And the most important factors that were considered in choosing each of the above criteria were profitability, port information system, cargo volume & inducement of foreign capital. The results of this study seemed to suggest that factors which influence port competition varied according to port circumstances, such as computer and communication systems and access to the global trade within the World Trade Organization

• The Journal of Information Systems
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• v.10 no.2
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• pp.103-128
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• 2001

At present, the EDI systems are indispensable software in port logistics industry. Currently, a monopolistic VAN/EDI service provider operates the EDI services. The current EDI client software has the 2-tier fat client/server architecture. However, the current EDI software is lack of Web interface and causes lots of cost for maintenance. Therefore, a variety of implementation architecture has been being tried by using script, XML and distributed object-oriented technology. Web/EDI and XML/EDI are the new EDI systems, However, the EDI systems have some limitations such as speed. This study intends to compare the variety implementation architecture for the EDI systems in the users' perspective and explore the strong and weak points of each architecture. We compared the EDI systems based on our experience of more than 2-years of implementation project for the EDI systems of port logistics. We categorized the EDI systems as client application EDI, Web EDI using script, XML/EDI, and 3-tier distributed object-oriented EDI system. We compared them with criteria such as speed, program maintenance, easiness of implementation and usage, security, and load balancing and fail-over. Finally we discuss the direction of optimal EDI system architecture for the future.