• Journal of the Korean Magnetics Society
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• v.26 no.5
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• pp.154-158
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• 2016

A CRDM (Control Rod Drive Mechanism) is an electromagnetic device which drives a control rod assembly linearly to regulate the reactivity of a nuclear core. An RPIS (Rod Position Indication System) is used as a position indicator for a control rod assembly of a CRDM of SMART, and an RPIS consists of permanent magnets and reed switches. SMART is designed for the maximum coolant temperature of $350^{\circ}C$, and the permanent magnets are installed inside of the reactor. The reed switches and electrical circuit are installed outside of the reactor on the other hand. Test coil for a reed switch is test equipment for quality verification of a reed switch, and a test coil consists of a coil and core. In this study, magnetic property of test coil and permanent magnet on a reed switch is compared by using finite element electromagnetic simulation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.1-9
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• 2012

Reinforced concrete buildings will be deteriorated as passed time or effect of an earthquake, etc in main elements. In order to manage such cracks, time and efforts, expense, etc, are required. So micro lead switch sensors are embedding or bonding in flexible specimens, and these are smart elements for diagnostic crack damages by external force such as physical load, dynamic load, etc in this study. The monitoring to crack damages are studied using radio frequency system. If load is received on the center of flexible specimens, embedded and bonded lead switch sensors will be destroyed, and these become to send signals of damages at radio frequency system connected with lead switch sensors. This study is fundamental research of the diagnostic system for architectural elements using radio frequency.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.850-853
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• 2011

The position indicator for cryogenic valves used in space launch vehicle should have high reliability and accuracy. Because the valves operate in cryogenic environment, the position indicator has to measure the valve status independently of the environmental factor, such as moisture and external contamination. We have developed the position indicator using a permanent magnet and reed switches to satisfy these requirements. We analyzed the characteristics of a permanent magnet and reed switches, then selected the appropriate components for cryogenic temperature. The shape and position of components were also considered to measure the open/close information of valve accurately Finally, the position indicator was applied to the valve prototype model, and verified the feasibility of design parameters.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.97.1-97
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.109.1-109
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.103-103
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• 2002

• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.79-87
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• 2012

In this study, static displacement sensors using lead switches are bonded on concrete beams and RC beams, and monitoring systems to crack damages are studied using radio frequency. If load is received on the center of flexible specimens, bonded static displacement sensors will be destroyed, and these become to send signals of damages at radio frequency system connected with static displacement sensors. Study of these functional building elements will be protected from external factors by unusual weather, earthquake, etc, in RC buildings and structures.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.593-596
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• 2008

The reed switch position transmitter (RSPT) is used as a position indicator for the control rod in commercial nuclear power plants made by ABB-CE. But this position indicator has some problems when directly adopting it to the integral reactor. The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. Therefore the resolution of the position indicator for the integral reactor should be achieved to sense the position of the control rod more precisely than that of the RSPT of the ABB-CE. This paper adopts seismic resistance reed switches to the position indicator in order to reduce the damages or impacts during the handling of the position indicator and earthquake.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.4 s.316
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• pp.42-47
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• 2007

To reduce the chattering errors of reed switch sensors in the automatic remote measurement of water meter a reed switch sensor was analyzed and improved. The operation of reed switch sensors can be described as a mechanical contact switch by approximation of permanent magnet piece to generate an electrical pulse. The reed switch sensors are used mostly in measurement application to detect the rotational or translational displacement. To apply for water flow measurement devices, the reed switch sensors should keep high reliability. They are applied for the electronic digital type of water flow meters. The reed switch sensor is just mounted simply on the conventional mechanical type flow meter. A small magnet is attached on a pointer of the water meter counter rotor. Inside the reed sensor two steel leaf springs make mechanical contact and apart repeatedly as rotation of flow meter counter. The counting electrical contact pulses can be converted as the water flow amount. The MCU sends the digital flow rate data to the server using the wireless communication network. But the digital data is occurred difference or won by chattering noise. The reed switch sensor contains chattering error by it self at the force equivalent position. The vibrations such as passing vehicle near to the switch sensor installed location causes chattering. In order to reduce chattering error, most system uses just software methods, for example using filter algorithm and also statistical calibration methods. The chattering errors were reduced by changing leaf spring structure using mechanical characteristics.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1745-1746
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• 2008

수도 원격검침을 위한 수도미터의 측정방법이 리드스위치, MR 센서방식, 엔코더방식, Cyble 방식등 다양하게 제시되고 있다. 그러나, 홀효과를 이용한 반도체 소자로 제공되는 Hall IC방식의 경우 많은 장점이 있으나 수도 원격검침분야에 적용된 사례가 전무하여 본 연구를 통하여 Hall IC방식이 원격검침용 수도미터에 적용하여 효과적 사용이 가능한지 적용성을 분석코자 한다.