• Title/Summary/Keyword: stable operation

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Weld Quality of MCFC Separators With Large Active Area (MCFC용 대면적 분리판의 용접부 품질에 관한 고찰)

  • Kim, K.C.;Jun, J.H.;Kim, S.G.;Kuk, S.T.;Lim, H.C.;Jung, B.S.
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.135-138
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    • 2009
  • Quality evaluation of laser welded MCFC separator panels with large active area was performed. Lap joint was applied to produce stable air-tight seam weld by employing Nd:YAG laser. Results showed that surface contamination played a key role to form weld defects at the joint interface. However, there was no evidence that weld width at the lap joint changed after the stack operation time of 2,890h. Test results also revealed that the reinforcement values which were measured on the weld line after long time operation, were stable.

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Design of High-Speed Dynamic CMOS PLA (고속 다이나믹 CMOS PLA의 설계)

  • 김윤홍;임인칠
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.28B no.11
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    • pp.859-865
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    • 1991
  • The paper proposes a design of high-speed dynamic CMOS PLA (Programmable Logic Array) which performs stable circuit operation. The race problem which nay occur in a NOR-NOR implementation of PLA is free in the proposed dynamic CMOS PLA by delaying time between the clocks to the AND- and to the OR-planes. The delay element has the same structure as the product line of the longest delay in the AND p`ane. Therefore it is unnecessary to design the delay element or to calculate correct delay time. The correct delay generated by the delay element makes the dynamic CMOS PLA to perform correct and stable circuit operation. Theproposed dynamic CMOS PLA has few variation of switching delay with the increasing number of inputs or outputs in PLA. It is verified by SPICE circuit simulation that the proposed dynamic CMOS PLA has the better performance over existing dynamic CMOS PLA's.

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Assessment of Optimal Constitution Rate of Windturbine and Photovoltaic Sources for Stable Operation of Microgird (마이크로그리드의 안정적 운영을 위한 풍력 및 태양광 발전원 최적 구성 비율 산정 방안 연구)

  • Lee, Su-Mi;Chun, Yeong-Han
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.2
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    • pp.272-276
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    • 2010
  • Renewable energy sources are considered to be environment-friendly alternatives those are increasingly introduced in the power systems. Microgrid is one of the systems in which renewable sources have a main role as a energy suppliers. Decision of constitution rates of renewable energy sources is very important for the economical and stable operation of microgird systems. In this paper, we present a method to assess an optimal constitution rate of renewable sources especially of windturbine and photovoltaic systems.

Modeling and Controller Design of an Automotive HID Lamp Ballast (자동차 헤드라이트용 고압 방전등 안정기 시스템의 모델링 및 제어기 설계)

  • Lee, In-Gyu;Choe, Seong-Jin;Lee, Gyu-Chan;Jo, Bo-Hyeong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.8
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    • pp.545-550
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    • 2000
  • This paper presents design and analysis of an HID lamp ballast for a fast turn on characteristics and stable operation. It produces a high open circuit voltage for the ignition and it is controlled to supply effectively the power required to shorten the warm-up period after the breakdown. The lamp modeling by empirical data is presented. It is very effective in the designing of the control loop in the steady-state operating region. A stable operation of the lamp power regulation in the steady state is achieved, which is crucial for the long life time and constant light output. Stability analysis of the system is performed and the results are verified through various simulation results and the hardware experiments.

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Co-combustion of Bituminous Coal with Anthracite in a Down-firing, 200 MW Boiler

  • Park, Ho Young;Baek, Se Hyun;Kim, Young Joo;Kim, Tae Hyung;Kim, Hyun Hee;Lim, Hyun Soo;Park, Yoon Hwa
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.93-97
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    • 2015
  • The combustion tests for Korean anthracite-bituminous coal blend were carried out in the 200 MW utility boiler. The burning characteristics of the blend were studied with a thermogravimetric analyzer (TGA). From the observation of TGA burning profiles, it was found that the presence of bituminous coal in the blend appeared to enhance the reactivity of anthracite in the higher temperature region, indicating certain interactions between the two coals. The plant test showed the boiler operation was reasonably stable with somewhat poor combustion efficiency, and some modification of the combustion environment in the furnace is necessitate for the further stable plant operation.

A Study on feasibility for runway development -IIAC 4th runway construction case study- (인천국제공항 제4활주로 건설 타당성 연구)

  • Choi, Dong Yeop;Sin, Jung Ha;Chang, Chan Hyeok;Park, Sung Do
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.27 no.2
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    • pp.37-46
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    • 2019
  • Although This study is to produce various considerations for the proper time and feasibility of new runway with Incheon international airport $4^{th}$ runway development case. In order to validate the feasibility of runway development, it is main considerations to be increased airport capacity for accommodating increase air traffic demand, secure stable airport operation without degrading service level, cope with emergency situation and maintain competitive among competitive airports which are developing new runway. Conclusionally, to develop new runwlay at the proper time for sustainable and stable airport operation without stop is the best way of maintaining competitiveness among foreign competitive airports.

Glucose Diffusion Limiting Membrane Based on Polyethyleneimine (PEI) Hydrogel for the Stabilization of Glucose Sensor

  • Kim, Suk-Joon;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.12 no.2
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    • pp.225-229
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    • 2021
  • Commercially available continuous glucose sensors require the operation stability for more than two weeks. Typically, the sensor comprises a sensing layer and an over-coating layer for the stable operation inside the body. In the sensing layer, enzymes and mediators are cross-linked together for the effective sensing of the glucose. The over-coating layer limits the flux of glucose and works as a biocompatible layer to the body fluids. Here, we report the simple preparation of the flux-limiting layer by the condensation of polyethyleneimine (PEI), tri-epoxide linker, and trimethylolpropane triglycidyl ether (PTGE). The sensor is constructed by a layer-by-layer drop-coating of the sensing layer containing glucose dehydrogenase and the PEI-derived blocking layer. It is stable for more than 14 days, which is enough for the sensor in the continuous monitor glucose monitoring (CGM) system.

Study on the Public Food Waste Recycling Facility Operation (II) - Focusing on Improvement Plan - (음식물류폐기물 공공 자원화시설 운영에 관한 연구 (II) - 개선방안을 중심으로 -)

  • Hong, Yong-Pyo;Kim, Ung-Yong;Shin, Hyun-Gon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.24 no.1
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    • pp.51-57
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    • 2016
  • This study is conducted to find out the problems of the public food waste recycling facility operation and its improvement. In order to save the national budget by analyzing plans to expand including operation rate for the food waste recycling facility, the alternative ways are suggested. The result can be as follows: Policy switch is required not only to save budget and stable disposal of food waste but also to promote resource recycling rather than expanding public facilities. In order to change the policy for stable and eco-friendly disposal of food waste, it is necessary to adopt semipublic system that prevent the decline of the rate of operation of private resource recycling facility. Furthermore, it is required to prepare both qualified technologies of public resource recycling and the ways of profitability secure.

A Study on Standby Power and Reduced Power Consumption Control System for High-efficiency Module (대기전력 및 소비전력 절감을 위한 고효율 모듈제어 시스템에 관한 연구)

  • Lee, Myung-Hwan;Park, Yung-Teak;Chung, Hun-Suk;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.5
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    • pp.334-339
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    • 2012
  • A study on electrical and electronic equipment will occur in the atmosphere, which is essential to cut the power to prevent the waste of power by power measurement technology development and to develop the technology to do this operation is the main core of standby power to detect and block it and return the configured for software and hardware, while the actual construction to ensure stability through field testing and debugging of problems improved accordingly, as well as ease of installation and so it could be done while the test. In addition, in terms of basic hardware switching of standby power when blocking, reducing stress and ensure stable operation and circuit design, power off and back to ensure stable operation even when a protection circuit is applied.