• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.138-139
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• 2008

An iron-cored voltage transformer(VT) is usually used to obtain the standard low voltage signal for protection and measurement. Generally, the iron-cored transformers have errors due to the hysteresis characteristics of the iron-core. An error compensating algorithm for iron-cored instrument transformer can improve the accuracy of conventional voltage transformers. This paper describes the iron-cored electronic voltage transformer having the error compensating algorithm. The innovative product composes an iron-cored VT and an intelligent electronic device(IED) having the error compensating algorithm. The test results of the iron-cored electronic voltage transformers in Korea Electro-technology Research Institute(KERI) are presented.

• 한국전자통신학회논문지
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• 제11권11호
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• pp.1107-1112
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• 2016

본 연구는 한국전력 eIoT(: energy Internet of Thing) 플랫폼을 활용한 스마트오피스 기능이고, 망구성은 센싱 디바이스, 게이트웨이, 플랫폼, 그리고 서비스서버로 구성 한다. 핵심 기능들은 게이트웨이와 디바이스간 LoRa(: Long Range) 기술을 활용하여 프로토콜 데이터 전달하는 부분, 지능화된 애플리케이션 처리 부분 그리고 PS-LTE(: Public Safety-Long-Term Evolution) 시스템에 연동되는 공공 안전 데이터처리 부분이다. 그리고 스마트오피스에서 서비스될 수 있는 리소스트리가 제시되며, 이것은 애플리케이션 서버와 디바이스에서 공통적으로 사용된다.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.198-201
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• 2001

Recently the wireless-internet has been spreading extensively. People are spending a large part of their time gaining access to information using a mobile device. With the rapid growth of on-line Electronic Commerce, the use of mobile devices creates a new paradigm that provides users with location-independent real time service. Although this new paradigm does have some advantages, limited process speed, low bandwidth, the low battery capacity of mobile devices, and a high rate of wireless network errors causes many overhead expenses during service time with the server. In this paper, we suggest an autonomous service delivery system, which provides mobile agent capability to users that cannot maintain a connection. We have developed the system based on java mobile agent technology. Using this system, we can provide more effective service to users when the user is sending requirements for service through a mobile device that has limited resources. Furthermore we can manage the contact server dynamically when new services are added.

• 센서학회지
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• 제17권5호
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• pp.350-360
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• 2008

In every large hospital, nurses must perform simple repetitive tasks such as measuring body temperature. Such tedious work reduces nurses' motivation to provide quality medical care, which is an important element of the medical services provided by a hospital. If a device were available to measure body temperature, nurses could focus on the more important aspects of providing quality medical care to the patients. However, body temperature is generally measured from the throat, anus, tympanum or armpit, where it is difficult to affix a patch type device. In addition, general body temperature measuring points shows moving artifact error; therefore, it is not good point to continually measure the temperature. In this paper, a patch type skin temperature measuring system was developed. To appropriately measure the skin temperature, a thermal transducer was implemented with a thin (0.5 mm) temperature sensor. The system is small and thin ($H6.6{\sim}5.3{\times}L35{\times}W24\;mm$), and weighs only 5 g including a battery, case and circuit; therefore, it is small and light enough to function as a patch type device. Moreover, the system worked for 5 days. To investigate differences between the experimental and conventional thermometer, simple clinical experiments were performed with 17 volunteers, and the result showed some correlation between the implemented system and conventional thermometer (Correlation coefficient = 0.647, P<0.1).

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.459-465
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• 2022

This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.365-367
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• 2005

This paper proposes a hardware of IED for power transformer protection that is well constructed using DSP chip and MPU chip. The performance of the adaptive relaying algorithm, by real-time testing in a prototype of it, has been verified. And test results indicate the proposed relaying of the IED was proven to be faster and more reliable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.360-362
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• 2004

In this paper, as the preceding research for development of intelligent electronic device for digital based substation automation system, we tried to select the most suitable digital filter by comparison of frequency response characteristic, performance of wanted frequency component extraction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.513-514
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• 2015

스마트 그리드의 대두와 함께 원격 계측 및 제어를 위한 IED(Intelligent Electronic Device)의 역할이 커지면서 IED의 통신시스템에 대한 개발이 빠르게 이루어져 왔으나 비용 및, 개발용이성 등의 이유로 여전히 보안성이 낮은 통신프로토콜을 주로 사용되고 있다. 본 연구에서는 계측 및 제어를 위한 IED와 서버 간 ModBus 통신 보안성을 향상시키고자 VPN을 적용하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.122-127
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• 2005

This paper proposes a prototype IED hardware design and it's real-time experimental results. To evaluate performance of the IED, the study is well constructed power system model including power transformer utilizing the EMTP software and the testing is made through simulation of various cases. The relaying that is well constructed using DSP chip and RISC CPU etc. has been developed and the prototype IED has been verified through on-line testing by LabVIEW simulator. The results show that an advanced relaying based prototype IED never mis-operated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.507-508
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• 2007

IEC 61850은 변전소자동화시스템에 대한 국제 표준 규격이다. IEC 61850 파트 6은 통신관련 IED(Intelligent Electronic Device) 구성과 IED 파라미터, 통신 시스템 구성, 개폐소 구조 및 이들 간의 관계를 설명하는 파일 형식을 규정한다. 이 파일 형식의 주요 목적은 IED 능력 설명, 호환되는 방법으로 여러 제조사들의 IED 엔지니어링 도구와 시스템 엔지니어링 도구 간의 SA 시스템 설명을 교환하는 것이다. 본 논문에서는 XML을 이용한 IED Configurator TOOl 구현을 제시하였다.