• Title/Summary/Keyword: electrical explosion

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A case study of remote wireless monitoring system for stray current due to subway system (지하철 누설전류 무선 원격 감시시스템 적용 사례)

  • Bae, Jeong-Hyo;Ha, Yoon-Cheol
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.1817-1818
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    • 2006
  • In present, most of metallic structures (gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway in Seoul and Pusan.In this case, subway system make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential, amplitude of stray current, point of source of stray current and so on. In this paper, results of development about Wireless Remote Monitoring and Control System on Underground Pipeline in Stray Current Conditions are presented. And also field test data should be reporting.

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Robust Flight Control System Using Neural Networks: Dynamic Surface Design Approach (신경 회로망을 이용한 강인 비행 제어 시스템: 동적 표면 설계 접근)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.12
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    • pp.518-525
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    • 2006
  • This paper presents the adaptive robust control method for the flight control systems with model uncertainties. The proposed control system can be composed simply by a combination of the adaptive dynamic surface control (DSC) technique and the self recurrent wavelet neural network (SRWNN). The adaptive DSC technique provides us with the ability to overcome the 'explosion of complexity' problem of the backstepping controller. The SRWNNs are used to observe the arbitrary model uncertainties of flight systems, and all their weights are trained on-line. From the Lyapunov stability analysis, their adaptation laws are induced and the uniformly ultimately boundedness of all signals in a closed-loop adaptive system is proved. Finally, simulation results for a high performance aircraft (F-16) are utilized to validate the good tracking performance and robustness of the proposed control system.

Development of an Incentive Level Evaluation Technique of Direct Load Control using Sequential Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 직접부하제어의 적정 제어지원금 산정기법 재발)

  • 정윤원;박종배;신중린
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.2
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    • pp.121-128
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    • 2004
  • This paper presents a new approach for determining an accurate incentive levels of Direct Load Control (DLC) program using sequential Monte Carlo Simulation (MCS) techniques. The economic analysis of DLC resources needs to identify the hourly-by-hourly expected energy-not-served resulting from the random outage characteristics of generators as well as to reflect the availability and duration of DLC resources, which results the computational explosion. Therefore, the conventional methods are based on the scenario approaches to reduce the computation time as well as to avoid the complexity of economic studies. In this paper, we have developed a new technique based on the sequential MCS to evaluate the required expected load control amount in each hour and to decide the incentive level satisfying the economic constraints. In addition, the mathematical formulation for DLC programs' economic evaluations are developed. To show the efficiency and effectiveness of the suggested method, the numerical studies have been performed for the modified IEEE reliability test system.

Synthesis of Ni nanopowder by wire explosion in liquid media (액중 전기폭발법을 이용한 니켈 나노분말 제조)

  • Cho, Chu-Hyun;Jin, Yun-Sik;Ha, Yoon-Cheol;Lee, Kyung-Ja;Rhee, Chang-Kyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.61-61
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    • 2010
  • 니켈 니켈 와이어를 증류수 및 에탄올 등의 유기용매 중에서 펄스파워 기술을 이용하여 전기적으로 폭발 시켰다. 폭발에 의하여 생성된 입자들은 직경이 수 마이크로미터 에서 수 십 나노미터에 이르는 넓은 입도분포를 보였다. 본 연구에서는 원심분리기술을 이용하여 입자의 크기별로 분리 회수가 가능함을 증명하였다. 또한 유기용매 중에서 제조된 니켈분말에 탄소가 포함되어 있으며, 열처리를 통하여 제거가 가능함을 실험을 통하여 밝혔다.

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Characteristics of GRP tube using Composite Hollow Bushing by Filament Winding (Filament Winding에 의한 Composite Hollow Bushing용 GRP tube의 특성)

  • Cho, Han-Goo;Kang, Hyung-Kyung;Yoo, Dea-Hoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.378-379
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    • 2008
  • Recently, composite hollow bushings have been increasingly employed mainly from the various characteristics. Composite bushings are superior to porcelain bushings in several respects, including lighter weight, better anti-pollution and anti-explosion properties, and easer manufacturing. Filament wound GRP tubes which have various winding angle were manufactured by using a filament winding machine. This paper will show some design issues and winding condition for composite bushing. And, results show that the winding condition of composite GRP tubes can be used to improved their bending strength and pressure, For bending and pressure tested, tubes with the hybrid winding pattern show higher strength than those of unit winding pattern. Also, the influence of absorption was evaluated through such as measurement of the dye penetration test and water diffusion test, also aspects of surface state using scanning electron microscopy.

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A Study of CMOS Device Latch-up Model with Transient Radiation (과도방사선에 의한 CMOS 소자 Latch-up 모델 연구)

  • Jeong, Sang-Hun;Lee, Nam-Ho;Lee, Min-Su;Cho, Seong-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.3
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    • pp.422-426
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    • 2012
  • Transient radiation is emitted during a nuclear explosion. Transient radiation causes a fatal error in the CMOS circuit as a Upset and Latch-up. In this paper, transient radiation NMOS, PMOS, INVERTER SPICE model was proposed on the basisi of transient radiation effects analysis using TCAD(Technology Computer Aided Design). Photocurrent generated from the MOSFET internal PN junction was expressed to the current source and Latch-up phenomenon in the INVERTER was expressed to parasitic thyristor for the transient radiation SPICE model. For example, the proposed transient radiation SPICE model was applied to CMOS NAND circuit. SPICE simulated characteristics were similar to the TCAD simulation results. Simulation time was reduced to 120 times compared to TCAD simulation.

$H_2$ sensor for detecting hydrogen in DI water using Pd membrane (발전기 스테이터의 냉각코일에 pinhole 발생을 검지 할 수 있는 수소센서 개발)

  • Choi, Sie-Young
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.442-445
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    • 1999
  • In this work, to detect of hydrogen in DI water in the generator area of nuclear power plants was fabricated Pd/Pt gate MISFET sensor using Pd membrane. $H_2$ permeation through Pd accounts for external mass transfer, surface adsorption and desorption, transitions to and from the bulk metal, and diffusion within the metal. The identification of pinholes in the generator area of plant is an important safety consideration, as hydrogen build-up gives rise to explosion. For this type of application the sensor needs to be isolated in DI water, accordingly, a Pd membrane was used to separate the DI water. The hydrogen in the DI water was then absorbed on the Pd thin film and diffused into the oil through the thin film. The Pd/Pt gate MISFET sensor, encapsulated by oil, will thereby detect permeated hydrogen.

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Summarization and Evaluation; Where are we today?!

  • Shamsfard, Mehrnoush;Saffarian, Amir;Ghodratnama, Samaneh
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2007.11a
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    • pp.422-429
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    • 2007
  • The rapid growth of the online information services causes the problem of information explosion. Automatic text summarization techniques are essential for dealing with this problem. There are different approaches to text summarization and different systems have used one or a combination of them. Considering the wide variety of summarization techniques there should be an evaluation mechanism to assess the process of summarization. The evaluation of automatic summarization is important and challenging, since in general it is difficult to agree on an ideal summary of a text. Currently evaluating summaries is a laborious task that could not be done simply by human so automatic evaluation techniques are appearing to help this matter. In this paper, we will take a look at summarization approaches and examine summarizers' general architecture. The importance of evaluation methods is discussed and the need to find better automatic systems to evaluate summaries is studied.

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INTRODUCTION OF SPARK EROSION

  • Jeong, Chang-Mo
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.4
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    • pp.402-411
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    • 2000
  • The dental profession is currently experiencing a technology explosion. Processes are being replaced by modern, inexpensive, and precise techniques that can be used to solve complex restorative problems. Electrical discharge machining(EDM, known as spark erosion in Europe) is a nonconventional, industrial technique that has application in dentistry. EDM may be defined as a metal removal process using a series of sparks to erode material from a workpiece in a liquid medium under carefully controlled conditions. EDM is recently adopted in the dental laboratory to fabricate precision attachments, hybrid tele-scope crowns, Ti-ceramic crowns. EDM has also been used to achieve a passive precision metal-to-metal fit between the substructure bar and the removable superstructure and to correct the fit of implant retained restorations. In this article, a brief history and explanation of EDM is discussed and a description of the use of this process for fabricating attachments and crowns or for correcting the fit of cast restorations is presented.

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Application of IMCS MBC Logic for Thermal Power Plant (발전소 통합감시제어시스템의 MBC 개발 로직 실계통 적용)

  • Shin, Man-Su;Yoo, Kwang-Myeng;Byun, Seung-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.6
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    • pp.845-851
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    • 2013
  • Because the existing control system has been operating for about 20 years, it is necessary to upgrade the system for stable and efficient operation. But, there is a difficulty in maintenance by difference of manufacturer of each main control systems for boiler, turbine and generator. This developed IMCS(Integrated Monitoring and Control System) consists of more than 10,000 inputs and outputs for large scale thermal power plant. This paper consists of the development journey of IMCS MBC(mill and burner control) ; core binary protection & monitoring logic including prevention circuit of boiler explosion & implosion. In this project, the IMCS for boiler, turbine and generator was developed on basis of one communications platform. In this paper, the whole journey of development of IMCS MBC is dealt with designing software and hardware, coding application software, and validating software and hardware.