• 조명전기설비학회논문지
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• 제20권9호
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• pp.78-83
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• 2006

A new measure, the distributed generation impact factor (DGIF), is used for evaluating the impact of newly introduced distributed generators on a networked distribution or a transmission system. Distribution systems are normally operated in a radial structure. But the introduction of distributed generation needs load flow calculation to analyze the networked system. In the developed framework, the potential share of every generation bus in each line flow of a networked system can be directly evaluated. The developed index does not require the solution of power flow equations to evaluate the effect of the distributed generation. The main advantage of the developed method lies in its capability of considering simultaneous outputs of multiple generation sites.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.43-48
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• 2022

Although the distribution system has been structured as complicated as a mesh in the past, the connection points for each line are always kept open, so that it is operated as a radial distribution system (RDS). For RDS, the line utilization rate is determined according to the maximum load on the line, and the utilization rate is usually kept low. In addition, when a fault occurs in the RDS, a power outage of about 3 to 5 minutes occurs until the fault section is separated, and the healthy section is transferred to another line. To improve the disadvantages of the RDS, research on the construction of a networked distribution system (NDS) that linking multiple lines is in progress. Compared to the RDS, the NDS has advantages such as increased facility utilization, load leveling, self-healing, increased capacity connected to distributed generator, and resolution of terminal voltage drop. However, when a fault occurs in the network distribution system, fault current can flow in from all connected lines, and the direction of fault current varies depending on the fault point, so a high-precision fault current direction determination method and high-speed communication are required. Therefore, in this paper, we propose an accurate fault current direction determination method by comparing the peak value polarity of the fault current in the event of a fault, and a communication-based protection coordination method using this method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.288-290
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• 2004

Networked Digital Recorder(NDR) Platform is a system that owns contents jointly between tv viewers connected by the broadcast broadband convergence network. NDR suggests a new content distribution chain model that users can receive broadcast contents, share contents and sends contents by convergence network. This paper looks at the system requirements, service model and the overall system architecture of NDR platform.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1757-1762
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• 2003

With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• Journal of Information Processing Systems
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• 제9권3호
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• pp.489-498
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• 2013

In this paper, we propose a common simulation model that can be reused for different performance evaluations of networked virtual environments. To this end, we analyzed the common features of NVEs, in which multiple regions compose a shared space, and where a user has his/her own interest area. Communication architecture can be client-server or peer-server models. In usual simulations, users move around the world while the number of users varies with the system. Our model provides various simulation parameters to customize the region configuration and user movement pattern. Furthermore, our model introduces a way to mimic a lot of users in a minimal experiment environment. The proposed model is integrated with our network framework, which supports various scalability approaches. We specifically applied our model to the interest management and load distribution schemes to evaluate communication overhead. With the proposed simulation model, a new simulation can be easily designed in a large-scale environment.

• 사물인터넷융복합논문지
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• 제9권1호
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• pp.125-129
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• 2023

최근 Internet of Things (IoT) 기반 Wireless Networked Control System (WNCS)에서 Sensor의 Status Update 및 Actuator로의 Actuation Update 분석을 위해 정보의 신선도를 측정하는 지표인 Age of Information (AoI)가 고려되고 있다. 또한 WNCS에 Edge Computing (EC)이 도입되면서 기존의 Cloud Computing 기반 아키텍처보다 낮은 AoI를 보장할 수 있다. 하지만 Controller가 관리하는 Sensor의 수가 증가하면서 Controller에 부하가 증가하여 AoI 요구사항을 만족시키지 못하는 문제점이 발생하게 되었다. 본 연구에서는 이러한 문제를 해결하기 위해 Actuator의 컴퓨팅 능력을 활용하여 Sensor의 Status Update를 해당 지역의 Actuator가 가용할 때 직접적으로 전송하여 Actuator가 직접 Actuation Update를 수행함으로써 AoI 요구사항을 만족시키고자 한다. 이를 위해 본 연구에서는 AoI 분석을 위한 분석 모델을 제시하였고 시뮬레이션을 통해 제안하는 방법이 기존 방법 대비 AoI를 줄일 수 있음을 보였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.404-411
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• 2004

With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with CPLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.243-249
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• 2003

With distribution industrial control system, the use of tow cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS(Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.15-19
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• 2022

The radial distribution systems (RDS) commonly used around the world has the following disadvantages. First, when the DL is operated on a radial system, the line utilization rate is usually kept low. Second, if a fault occurs in the radial DL, a power outage of 3 to 5 minutes is occurring depending on the operator's proficiency and fault situation until the fault section is separated and the normal section is replaced. To solve this problem, Various methods have been proposed at domestic and foreign to solve this problem, and in Korea, research is underway on the advanced system of operating multiple linked DL always. A system that is electrically linked always, and that is built to enable high-speed communication during the protection coordination is named networked distribution system (NDS). Because the load shares the DL, the line utilization rate can be improved, and even if the line faults, the normal section does not need to be cut off, so the normal section does not experience a power outage. However, since it is impossible to predict in which direction the fault current will flow when a failure occurs in the NDS, a communication-based protection coordination is used, but there is no backup protection coordination method in case of communication failure. Therefore, in this paper, we propose a protective cooperation method to apply as a backup method when communication fails in NDS. The new method is to change TCC by location of CB using voltage drop in case of fault.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.23.1-28
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• 1999

InterSpaceTM is an advanced networked virtual reality system that presents shared three-dimensional computer graphics (CG) worlds via the Internet where multiple users can enjoy synchronous communications with voice, video and text. Users can control their avatars as a surrogate interface. In InterSpace users can walk around and interact with other people and interact with contents. In this paper, we describe the function-distributed architecture used in InterSpace. The architecture enables flexible configuration of server functions and load distribution. It also allows users to select media and client PCs to switch servers dynamically.