• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.364-364
• /
• 2010

In the electricity control field, a relay is the most widely used electrical switch. But it has problems about a material transfer phenomenon, contact bounce, and the mechanical life. These Problems cause the serious problem in a facility. So, we tried to solve these problems by applying MOSFET electronic switch and could find good improvement compared to conventional electrical switch.

• Journal of the military operations research society of Korea
• /
• v.23 no.2
• /
• pp.171-191
• /
• 1997

In this paper, we design and construct a high speed LAN(Local Area Network) using FDDI(Fiber Distributed Data Interface) and Frame Relay in order to support our multimedia communication services. A program of this communication network is divided into requirement analysis, design, establishment and test. First, we propose an optimal communication method that compares various network techniques in the requirement analysis phase. Second, we design the physical network configuration, secure method, and address in the LAN and WAN. Finally, we establish and test the communication devices and lines. Ultimately, we minimized mistakes and satisfied user requirements using this program. We constructed efficiently a high speed data communication network using FDDI and Frame Relay.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.7
• /
• pp.9-18
• /
• 1997

In this paper, we implemented the communication module in the Telephone Network Access Subsystem(TNAS) of the Advanced Communications Processing System(ACPS). We defined some kinds of communication tasks and related resources like several queues which are executed in real-time operating system, and implemented the procedures for processing the user information. Through traffic modeling and simulation, the performance of the Service Processing board Assembly(SPA) is evaluated in the aspets of system utilization and buffer size. The ACPS should accommodate various public networks such as public switch telephone network, packet switchen data network, frame realy netork, and ATM network. The communications module proposed in this paper could be used inthe interface beween the SPA and the High Speed Network Adaptor of other network interface subsystems.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.3
• /
• pp.284-290
• /
• 2000

The measurement of electric current using optical techniques provides a number of important practical advantages including effective isolation from high line potentials and freedom from the saturation effects observed in conventional current transformers. In this work the optical current sensor which uses thin YIG(Yittrium Ion Garnet) film as a Faraday element has been developed. We have characterized this optical current sensor and implemented it to the OOCR(Opto-electronic OverCurrent Realy) Performance of the OOCR shows the possibility of replacing the present overcurrent relays with OOCR.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.10
• /
• pp.593-601
• /
• 2003

Distance realy is tripped by the line impedance calculated at the relay point. Accordingly the accurate operation depends on the precise calculation of line impedance. Impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding resistance, and sheath voltage limiters(SVLs). There are also several grounding systems in cable systems. Therefore, if there is a fault in cable systems, these terms will severely be caused much error to calculation of impedance. Accordingly the proper compensation should be developed for the correct operation of the distance relay. This paper presents the distance calculating algorithm in combined transmission line with power cable using wavelet transform. In order to achieve such purpose, judgement method to discriminate the fault section in both sections was proposed using D1 coefficient summation in db4. And also, error compensation value was proposed for correct calculation of impedance in power cables section.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.1
• /
• pp.7-12
• /
• 2004

The role of protective relay with correct setting value is very important for the reliable operation of power : system. The setting process of a protective relay is difficult and requires hard work of calculations. Therefore, KEPCO as been using PROSET2000, a computer program system, in order to automate the setting process of protective relays in power transmission network since 2000. This system has a database and relay setting modules for each type of realy with coresponding Human and Computer Interaction(HCI). For the setting of a new type of relay, it require a new module, a HCI and a database table corresponding to the new relay. But it's update is not easy in case of new type of relay. This paper discussed the update method introducing a concept of Open Interface. It addressd a method to make a new HCI for new relay in view of object-oriented method using UML(Unified Modeling Language). Using the UML, we updated the PROSET2000. HCI screens for a new relay is generated automatically using the information of the new relay stored in the database. And, the database management module is upgraded to solve problems in manage and maintain the database in view of Open Interface.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.2
• /
• pp.172-178
• /
• 2008

If the fault occurs on the underground power cable systems, the fault current on the sheath has an influence on all sections of cable because it's returned through earth at the directly grounded point and operation point of SVL(Sheath Voltage Limiter) on each insulated joint box. Therefore, the earth resistance and the operation of SVL have an effect on the zero-sequence current, and then the impedance between relaying point and fault point is increased. That causes the overreach of distance relay. For these reasons, the distance relay algorithm for protecting an underground power cable systems hasn't been developed till now. In this paper, new distance relay algorithm is developed for protecting a underground power cable system using fuzzy inference system which is the one of ACI(Advanced Computational Intelligence) techniques. This algorithm is verified by EMTP simulation of real power cable system, and proves to effectively advance the errors

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.48 no.7
• /
• pp.847-854
• /
• 1999

The setting of protective relays, which is critical to the power system security and reliability, requires a huge volume of data processing and repetitive calculation. Since it has been performed by relay engineers manually, it is vulnerable to human errors, its computerization has been pursued, in which the efficient management of the data is the key to the success. The database for power system protection must accommodate not only the power system network data but also a variety of protective devices. Also its information should be able to be viewed and updated with easy by operators and by computer programs. This paper describes several existing database designs for power system protection, their advantages and disadvantages. Also this paper has identified the required function and designed the database for the KEPCO power system data structure for the benefit of the relay setting process, etc..

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.20 no.2
• /
• pp.91-108
• /
• 2024

The purpose of this study is to investigate factors influencing the prospects of living labs among Millennials and Generation Z and to provide policy suggestions. This study proposed a comprehensive framework to investigate the influence of citizen awareness, perceived definition, willingness to participate, the role of local government. and expected satisfaction. This study employed an online survey conducted by a well-known research organization. Factor and regression analysis were utilized for data analysus. The results of this study indicate that the effects of citizen awareness, willingness to participate, the role of local government, and expected satisfaction on the prospects for living labs were significant for Millennials, whereas the effects of perceived definition and expected satisfaction on the prospects for living labs were significant for Generation Z. This study suggests the importance of developing better policies to create prospective living labs for real-world environments. This includes preparing policies for the development of future-oriented living labs, establising innovative living labs for practical applications, and designining future-realy living labs to address real-world challenges.

• Korean Journal of Food Science and Technology
• /
• v.19 no.3
• /
• pp.200-205
• /
• 1987

A microcomputer-based on-line monitoring and controlling system was built and applied to the dehycration operation. Drying conditions-drying temperatures and air velocities-were successfully controlled by the control deveices incorporated on/off realy and thyristor, and with the high language program. Drying variables-temperature in drier and weight loss of radish slice were accurately measured and acquisited. The computer-based drying system effectively saved the man power required to measure and record data during the drying period and also made possible to conduct the process undisturbed for long period. The drying rate curves of radish at various drying conditions were obtained from automatic data analyzing program. And also the computer programmed control made possible to investigate the effect of air velocity change during the drying period. The dynamic change of air velocity of from one to another level could be performed and affected markedly the drying rate at first stages of drying, but no significant effect were found in falling rate period.