• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2615-2621
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• 2010

The multi-band six-port phase correlator using metamaterial was designed and fabricated in this paper. The lumped metamaterial structure that can process the dual-band receiving signal was analyzed. Based on the analyzed results, the small-sized metamatrial six-port phase correlator for multi-band direct conversion method was proposed and fabricated. Also, the resistive power divider and $90^{\circ}$ hybrid coupler that comprises the six-port phase correlator were implemented based on the scattering parameters of metamatrial six-port phase correlator. The measured results of the proposed six-port phase correlator show the good agreement with simulation results. The performance of the six-port phase correlator shows the reflection loss below -20 dB in the dual-band. Also, the proposed six-port phase correlator got a good transmission characteristic within 1 dB gain difference and ${\pm}4.1^{\circ}$ phase imbalance, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1918-1924
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• 2011

This article proposes a POD system framework which creates templates by using the Web service environment with good accessibility, provides them so that users can easily edit them, and uses COM ports following Web standard capable of real-time printing with the same quality as edited files. The characteristic of framework proposed in this article is that it creates programs which users with basic skill in Internet use can learn and use relatively easily when compared with existing specialized editing programs and which allows users to print real-time such files as personally created by them in the same quality as on the screen, and thereby enhances accessibility thereof.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.53-59
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• 2011

In this paper, the implementation of a production control system has been studied in order to obtain Realtime Cost Calculation using an exact Machine Factor and Man Factor based on RFID reader data transferred through network. For the study, microprocessor built in the controller of production facilities is used and also RFID reader is built additionally. Control part, card reader used for check the beginning and ending working time of workers, and Machine Factor and Man Factor calculated are transferred to server via PLC transmission port, serial transmission port, or Ethernet transmission port. By using the system, the production cost or the production efficiency is calculated exactly. Therefore it is possible to improve production rate and cost reduction by the use of the proposed production control system.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.747-752
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• 2020

Special logistics, such as steel coils or steel plates, are being shipped and deployed depending on experienced personnel. Therefore, there is a great possibility of accidents due to immaturity by human error or lack of experience. There is a need to prevent the possibility of such an accident in advance, to apply security requirements required for special logistics, to ensure the stability of cargo, and to operate an management system to check the correct loading list. In addition, accurate shipping inspection is necessary to balance the ship. This paper analyzes the problems of shipping inspection currently being implemented and proposes a web-based port special logistics shipping inspection and balancing operation system to improve it.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.143-148
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• 2023

Currently, pilots and tugs perform the function of minimizing or eliminating property damage by preventing accidents on ships, ports, and human life by supporting docking/unloading and access and departure of ships. The piloting/tuging system is an essential function for the smooth functioning of the port, and it is the system that has the greatest influence on the cargo volume of the port. In this study, we developed an pilot and tugs information system analysis and operating system that can improve port operation efficiency, reduce the waiting time of ships, optimize the operation of ships, and allocate optimal pilots and tugs by utilizing the operation information of the tugbosts.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.769-774
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• 2010

The performance of underwater communication system is influenced on channel characteristic. Delay spread cause by reverberation and multi-path happen the ISI (Inter Symbol Interference) and reduces the communication performance. In this paper, we analyze the performance of acoustic communication experiment in underwater to use the OFDM (Orthogonal Frequency Division Multiplexing) technique for overcome the reverberation and multi-path. As a result, we acquired the BER of modulation techniques. The BER of 2kbps data rate is $1.22{\times}10^{-1}$ and BER of 4 kbps data rate is $2.47{\times}10^{-2}$.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.419-429
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• 2023

The pinnacle of rapidly changing and advancing maritime transportation technology is expected to be the Maritime Autonomous Surface Ship (MASS). The implementation of various services within the MASS is likely to be feasible through the ship-centric network known as the S2X communication system. However, existing communication systems face issues such as service traffic saturation and failure to meet demanded functionalities, necessitating the proactive introduction of additional communication technologies. In this study, the concept of S2X communication for the MASS was redefined, deriving required functionalities and ultimately selecting frequencies suitable for utilization. Candidate frequency groups suitable for the derived communication requirements were identified, and communication frequencies prioritized for the initial application were chosen through expert consensus. It is anticipated that through further research, including experimentation to validate these frequencies, they could be utilized in implementing services for autonomous ship navigation in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1531-1537
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• 2018

In maritime logistics, a large number of containers are transported to the destination through a port in the form of composite transportation such as ships, trucks, and railways. Logistics parties such as shipping companies and consignors prefer having the real-time information on the entry and exit of the logistics hubs of the freight. Particularly, a port is an important space that connects the maritime and inland areas. Hence, the interest about freight of the logistics party in port is high. This study describes tracking the location of freight by using GPS dynamically based on area type rather than point type. This presents dynamic information of location tracking when the freight enters, exits from, and passes through a certain port area. I suggest a real-time location of the container cargos tracking algorithm in port-entry, port-exit, and port inside using Active IP-RFID technology based on the location tracking algorithm of previous research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1632-1642
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• 2005

Is there my relationship between a port information system and a port type? This paper aims to define its relationship through a study on the port types of advanced countries and their information systems. In terms of port ownership and its governing body, the port type can be divided into 4 types: state-run, public corporation, local government-run, and private ownership. According to the port type, the major activities of ports are different. In the case of a state-run and local government-run port, they put emphasis on the function of administration, but a public corporation and private ownership stress the importance of customer services. The study results of the mutual relationship of a port type and an information system show that the state-run and local government-run ports have a good administration-oriented system, and public corporation and privatized ports have an excellent customer-oriented community system and e-business system. The differences in the information system by port type provide an important suggestion to the improvement of information system of Busan Port Authority. As Busan port has been transformed from a state-run type to a public corporation, a new port information system has to be followed. Accordingly, this study has suggested a three-stage development plan: The first is a mirroring stage of stabilizing the port management, the second is a cooperation stage of enhancing customer services through the establishment of a community system, and the third is an e-business stage of developing a profit system in order to create value added.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.246-255
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• 2023

Public conflicts in the port sector can cause additional social costs and delay the supply of port infrastructure, which can negatively affect local industries and national competitiveness. Although the importance of conflict management in the port sector is gradually increasing, there is still no systematic conflict management countermeasure. Therefore, in this study, the limitations of the current conflict management system in the port sector were considered, and a Delphi survey was conducted targeting experts and stakeholders in the port sector and conflict management. In addition, criteria for diagnosing conflicts in the port sector, causes of conflicts, proactive management measures, and ex post solutions were derived. The results of the Delphi survey analysis showed that the biggest causes of conflict were the absence of stakeholder opinion collection, consultation, and communication tools. Preliminary conflict management measures including a public deliberation process to collect local opinions and discuss development directions before deciding on specific issues, and ex post conflict resolution measures including investigation of causes of conflicts and objective personnel management in the process of preparing alternatives (e.g., securing reliability) were determined as the most important factors. In addition, based on the results obtained in this study, conflict management techniques for each phase of the port development project were presented. These findings are expected to be used as a useful reference material to reflect the port sector, which has not been included in the "Public Institution Conflict Management Manual (2016)" of the Office for Government Policy Coordination.