• Convergence Security Journal
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• v.13 no.3
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• pp.85-90
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• 2013

To provide high-quality services, national public institutions and companies have provided information and materials over the internet network. However, a risk of malware infection between transmission and reception of data leads to exposure to various security threats. For this reason, national institutions have proceeded with projects for network separation since 2008, and data linkage has been made using network connection storage through network separation technologies, along with physical network separation. However, the network connection storage has caused waste of resources and problems with data management due to the presence of the same data in internal network storage and external network storage. In this regard, this study proposes a method to connect internal and external network data using NAS storage as a way to overcome the limitations of physical network separation, and attempts to verify the priority of items for the optimization of network separation by means of AHP techniques.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.111-120
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• 2005

A mobile ad-hoc network is an autonomous system of mobile nodes which are free to move around randomly and organize themselves arbitrarily, hence a routing protocol that handles the dynamic network topology changes is required for the network. In this paper we present a multi -Path on-demand routing protocol called R-DSR (Robust Dynamic Source Routing), an extension to the existing IETF protocol DSR. The proposed protocol has it that every pair of 2-hop away nodes on the single route is additionally connected via an alternative node. Throughout mathematical analysis we show the proposed protocol reveals higher message delivery rate than that of the Das's multi-path protocol, currently known as one of the most typical approaches related to DSR.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.319-321
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• 2005

한국천문연구원에서는 한국우주전파관측망(Korean VLBI Network; KVN)에서 사용할 관측 시스템 중에서 소규모 자료획득시스템(DAS) 구축을 위하여 기가비트 고속샘플러, PC-VSI 보드, 소프트웨어 상관기를 도입하였다. 고속샘플러는 기가비트급 ADS1000, PC-VSI 보드는 VSI-H(VLBI Standard Interface Hardware) 표준을 따른 PCI 버스를 채택하고 있어 일반 컴퓨터에 설치하여 동작되며, 이 규격을 갖춘 시스템과의 데이터 입출력이 가능하다. 소프트웨어 상관기는 일본 NILT와의 연구협력을 통하여 본 연구원에서도 사용할 수 있게 되었으며, FX와 XF 형 2가지를 모두 갖추고 있다. 하지만 현재 구현된 소프트웨어 상관기는 측지 VLBI 관측을 위해 설계되어 있어, 향후 KVN의 하드웨어 상관기와 함께 천문 VLBI 관측을 위한 3기선 분의 소프트웨어 상관기로 개량하려고 한다. 이상에서 소개한 시스템을 좁은 의미로 K5 시스템이라고도 한다. 본 논문에서는 PC-VSI 보드에 대해 간략히 소개하고, K5 시스템을 이용하여 관측한 결과를 빨리 관측자가 원하는 정보를 얻을 수 있는 소프트웨어 상관기의 구조에 대해서도 소개하고자 한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1776-1786
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• 2010

Intelligent distribution automation system have total monitoring and control capability. The system covers substation, distribution network, distributed generations and customers at HV system. Various intelligent distribution facilities installed at distribution systems have voltage sensor, current sensor, aging monitoring sensor. Intelligent Feeder Remote Terminal Unit (IFRTU) tied to intelligent distribution facilities process information from facilities and it checks information of fault, power quality and aging of distribution facilities. The information is transmitted to master station through communication line. The master station have remote monitoring system covers substation, distribution network, distributed generations and customers. It also have various application programs that maintain optimal network operation by using information from on-site devices.

• Journal of the military operations research society of Korea
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• v.36 no.2
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• pp.71-84
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• 2010

This work describes capabilities based acquisition process in the SoS(System of Systems) environment. It is written as qualitative paper based on a cognitive paradigm. Future battle space is formed with grids of the various sensors and the shooters. It has been also transformed into a SoS concept which accomplishes missions and their functions through network based battle management systems in a single theater. The SoS is a set or arrangement of systems that results when independent and useful systems are integrated into a larger system that delivers unique capabilities. Therefore the acquisition process is changing over from single system requirements to capabilities based acquisition of the SoS. In this point of view, this paper analyzes functionally JCIDS, DAS and CEP which are critical elements of the acquisition process. From results of this comprehensive analysis, perspectives on the application of capabilities based acquisition suitable for Korean acquisition environment are presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.681-684
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• 2006

A new packet extraction program is presented to extract communication packet between a server and clients. The extracted packet source is used to develope a special driver to access general clients to the server. The proposed scheme employs a relay server to take a specified packet among a large number of packets on the same network. The proposed method is tested in PMS (Plant Management System) sewer and ProDAS (Process Data Aquisition and Analysis System) in a combined cycle power plant. The developed scheme can be applied for extracting a specified communication packet between the general server and client.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1618-1623
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• 2019

In this paper, inductive couplers realizing broadband powerline communication (PLC) are fabricated using Fe-based nanocrystalline alloy and their performance is analyzed. As a result of the field tests using the distribution automation system (DAS), the couplers achieve comparatively excellent data communication in the principal frequency band of broadband PLC although there is a difference in communication rate depending on the presence or absence of a branch. In addition, it has been confirmed that the communication speed is maintained for a real-time transmission even in a high current environment although there is a difference in the transmission rate depending on the distance. Hence, it is considered that the inductive couplers can be used as a core device to realize the intelligent power network by exploiting them for the monitoring and remote controlling of the power plant equipments for the DAS located in the inaccessible areas.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1199-1208
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• 2013

In recent years, the development of application programs for distribution system analysis and control has been essential part for distribution management system (DMS). In this paper, we propose the common database for application programs of distribution management system. The proposed database model has several characteristics as followings. First, the proposed database model is designed for the common use of almost the whole distribution application software. The static equipment model and dynamic type tables are mixed and the parallel table structure is applied. Second, the linked list structure of database are used for the fast processing of applications. The database model includes the hierarchy and non-hierarchy distribution system structure. Third, the reduction method of distribution database is applied. For this, we present the network reduction rules. The basic concept of reduction rules are the electrical unification of successive line section which has not lateral branches and the removal of simple lateral branches which has no devices and other laterals. Proposed database model is tested for the Jeju system of Korea Electric Power Corporation (KEPCO). Through the test, we verified that the proposed database structure can be effectively used to accomplish the distribution system operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1463-1471
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.9-15
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• 2007

As the Internet grows and the mass multimedia data become popular, the storage system migrates from DAS, where the storage and the server are directly connected, to SAN and NAS. SAN connects the storages with a separate network, and NAS provides only file services, connects the storages with IP network. However, SAN and NAS can not fulfill the needs for companies if used separately, thus are asked to be integrated. In this research, we propose an efficient data sharing method which employees the concept of GMC, Croup Master Cache for the integrated environment of SAN and NAS. GMC is based on MCI, Metadata server and Cluster system Integration, but tries to solve the high expansion cost problem with MCI. We introduce the basic concept of GMC, compare the performance of GMC with that of MCI using computer simulation.