• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.451-457
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• 2020

Diverse sensors are equipped on P-3C Maritime Patrol Aircraft for RoKN to detect and monitor tactical targets. Tactical targets are maintained/shared by tactical computer stations which consist of a clustering network in the aircraft and displayed in various ways on TSDs(Tactical Situation Displays) for mission operators to perform their specified missions. Korea peninsula is widely covered with the sea areas and neighboured with several countries; which makes huge number of ships and aircraft deployment around the place. Due to an increase in number of sensors and enhancement of their sensitivities; we were aware of the necessity of TSD improvements to provide huge number of tactical targets and to display them efficiently. In this paper, we propose a solution for the improvements by using previous backup data and re-usage of the data, then we verify the proposal through implementation and evaluation results.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.347-357
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• 2019

The usefulness of processing and analysis systems of GIS-based agricultural climate data is affected by the reliability and availability of computing infrastructures such as cloud, on-premises, and hybrid. Cloud technology has grown in popularity. However, various reference cases accumulated over the years of operational experiences point out important features that make on-premises technology compatible with cloud technology. Both cloud and on-premises technologies have their advantages and disadvantages in terms of operational time and cost, reliability, and security depending on cases of applications. In this study, we have described characteristics of four general computing platforms including cloud, on-premises with hardware-level virtualization, on-premises with operating system-level virtualization and hybrid environments, and compared them in terms of advantages and disadvantages when a huge amount of GIS-based agricultural climate data were stored and processed to provide public services of agro-meteorological and climate information at high spatial and temporal resolutions. It was found that migrating high-resolution agricultural climate data to public cloud would not be reasonable due to high cost for storing a large amount data that may be of no use in the future. Therefore, we recommended hybrid systems that the on-premises and the cloud environments are combined for data storage and backup systems that incur a major cost, and data analysis, processing and presentation that need operational flexibility, respectively.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.9-16
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• 2022

In this paper, we propose a plan to design and utilize the RDBS(Record Block Data file management System) so that data can be recovered when data files in the Combat Management System are mismatched. The CMS(Combat Management System) manages the same files in multiple IPN(Infomation Processing Node) repositories to support multiplexing. However, mismatches in data files can occur due to equipment maintenance or user immaturity. The existing CMS does not manage the history of changes in data files, and when a mismatch occurs, data file were synchronized based on the latest date. But, It is difficult to say that files with the latest date have the highest reliability, and once the file synchronization has progressed, it cannot be recovered with pre-synchronization data. To solve this problem, data was stored and synchronized in units of record blocks using RDBS proposed in this paper, and the Rsync algorithm was used to reduce the overhead of file synchronization due to units of record blocks. SW applied with RDBS was tested for performance in a simulated environment, and it was confirmed that it could be applied to CMS through normal operation confirmation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.165-176
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• 2009

The process of berthing/deberthing operations for entering/leaving vessels in Busan northern harbor was analyzed and evaluated by using an integrated VTS(vessel traffic service) system installed in the ship training center of Pukyong National University, Busan, Korea. The integrated VTS system used in this study was consisted of ARPA radar, ECDIS(electronic chart display and information system), backup(recording) system, CCTV(closed-circuit television) camera system, gyro-compass, differential GPS receiver, anemometer, AIS(automatic identification system), VHF(very high frequency) communication system, etc. The network of these systems was designed to communicate with each other automatically and to exchange the critical information about the course, speed, position and intended routes of other traffic vessels in the navigational channel and Busan northern harbor. To evaluate quantitatively the overall dynamic situation such as maneuvering motions for target vessel and its tugboats while in transit to and from the berth structure inside a harbor, all traffic information in Busan northern harbor was automatically acquired, displayed, evaluated and recorded. The results obtained in this study suggest that the real-time tracking information of traffic vessels acquired by using an integrated VTS system can be used as a useful reference data in evaluating and analyzing exactly the dynamic situation such as the collision between ship and berth structure, in the process of berthing/deberthing operations for entering/leaving vessels in the confined waters and harbor.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.12-20
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• 2017

A maritime DGPS in Korea offers pseudo-range correction information and monitors integrity of correction data by using multiple GNSS receivers. The maritime DGPS reference station and integrity monitor service sets alarm threshold value about integrity monitoring parameters for preventing service interruption status. However there is no way to avoid system interruption according to malfunction of backup systems and outside factors. Therefore, in this paper, warning threshold values were proposed for maritime DGPS operator can be counteract in advance. And Markov analysis method was carried out for selection of these warning threshold values.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.41-51
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• 1996

KITSAT-1 and 2 are microsatellites weighting 50kg and all the on-board data are processed by the on-board computer system. Hence, these on-board computers require to be highly reliable and be designed with tight power consumption, mass and size constraints. On-board computer(OBC) systems for KITSAT-1 and 2 are also designed with a simple flexible hardware for reliability and software takes more responsibility than hardware. KITSAT-1 and 2 on-board computer system consist of OBC 186 as the primary OBC and OBC80 as its backup. OBC186 runs spacecraft operating system (SCOS) which has real-time multi-tasking capability. Since their launch, OBC186 and OBC80 have been operating successfully until today. In this paper, we describe the development of OBC186 hardware and software and analyze its in-orbit operation performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.77-85
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• 2018

Renewable energy has been increasingly used and widely acclaimed as one of the solutions to rampant environmental problems. Among numerous kinds of renewable sources, the penetration rate of the PV system is relatively higher than that of others due to ease of installation. However, one disadvantage of the PV system is its dependence on weather condition. The PV system is especially critical when it is used for standalone systems because it cannot operate when the power generated from a PV module is not enough. Therefore, PV systems are often used with an energy storage system, such as batteries, to store backup energy when the weather condition is insufficient to supply power to the system. Blackout time can be reduced by increasing the size of the energy storage system, but it is a trade-off with system cost. In this work, optimal sizing of a standalone PV system is proposed to supply power to the system without blackout. The sizing of PV modules and batteries is performed by a simulation based on actual irradiation data collected during the past five years. The Life cycle costing of each system is evaluated to determine an optimal set of PV modules and batteries among several different combinations. The standalone PV system designed by the proposed method can supply power to the system with no interruption as long as the weather condition is similar to those of the past five years.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.984-987
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• 2013

In concept, such as the backup of wired network and disaster prevention network of water treatment measurement and control system, reliability and security of high level of sending and receiving data between the nodes must be ensured in Ad-hoc network construction. Rather than apply the common communication protocols of Ad-hoc network construction during the FA network of closed water treatment facility with the facility of a certain scale is concentrated contrast, and high characteristics of the water treatment system infrastructure, public facilities We have developed a specific protocol another that applies the OTP of communication frame of process control commands and H-ARQ with ZRP by applying the flexibility to time constraints such as precision industrial plants to ensure the safety and property of facility operation.

• Journal of Korean Society of Archives and Records Management
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• v.14 no.2
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• pp.117-128
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• 2014

Social Network Service (SNS) has gained great popularity. Recently, facebook has been used most active. Most of government ministries of Republic of Korea operates facebook. In the case of facebook, it takes advantages of possibilities to inform the direction of policy to aggregate opinions of people for issues. Information gained from facebook has a very important value to be reflected in the policy or to understand public opinions. Long-term storage for this information should be considered. In the case of overseas, tools for long-term storage of documentary facebook have recently been developed. However, it does not save all the data in facebook and ignores the principles for long-term storage. These tools are limited to a simple backup. Therefore, this study aims to investigate how to reproduce, store and collect facebook page records of the government ministries.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.3
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• pp.217-227
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• 1989

A process control graphic system is proposed as an efficient tool for monitoring the operation of power plant. It uses the multi-processor structure with 60 Kbyte shared memory as an implemental type of the distributed computer system, so that it is flexible, functionally extensible, and applicable to real-time process. The shared memory is used as a real-time database handling the process values and operator's commands. The database files, generated by the user-interactive graphic editor developed for the system or text editor, have the characteristics of simplicity and user-friendliness. The process control graphic system, that can monitor the operation of boiler and function as a backup controller in case of failure in boiler controller, is applied to Ulsan power plant. As a result, it displays the operating data of the boiler process without error by 14 pages of color graphic image according to the operation menu, and additionally functions well as a fault-tolerant control system.