• Title/Summary/Keyword: oscillatory

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Phenomenological Model Based Fault Diagnosis of Dynamic Plants (현상적 모델에 기초한 플랜트시스템 고장감지기법)

  • Kim, Jae-Hwa;Chang, Tae-Gyu
    • Proceedings of the KIEE Conference
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    • 1997.07b
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    • pp.456-458
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    • 1997
  • 본 논문에서는 플랜트의 계측신호들에 나타나는 현상적인 특징파형들을 감지하여 플랜트의 고장을 진단하는 기법을 제시하고, 플랜트의 고장시 나타나는 여러 특징 파형들의 전형인 oscillatory 파형을 감지하는 알고리즘을 prediction filtering 기법을 적용하여 얻는 과정을 기술하였다. 또한 이의 구체적 적용 예로 500MW급 화력발전소의 보일러 제어 시스템을 대상으로 여러 고장상황에 대한 고장감지 알고리즘을 설계하였고 제시한 기법의 유용성을 보이기 위한 시뮬레이션 적용 결과를 보였다.

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High conservative nonlinear vibration equations by means of energy balance method

  • Bayat, Mahmoud;Pakar, Iman;Bayat, Mahdi
    • Earthquakes and Structures
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    • v.11 no.1
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    • pp.129-140
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    • 2016
  • This paper presents He's Energy Balance Method (EBM) for solving nonlinear oscillatory differential equations. Three strong nonlinear cases have been studied analytically. Analytical results of the EBM are compared with numerical solutions using Runge-Kutta's algorithm. The effects of different important parameters on the nonlinear response of the systems are studied. The results show the presented method is potentially to solve high nonlinear vibration equations.

A Study on Unsteady Flow measurement using Laser Doppler Velocimeter in Curved Duct (곡관에서 laser유속계를 이용한 비정상유동 계측에 대한 연구)

  • 조병기
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.4
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    • pp.81-89
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    • 1996
  • In the present study, the unsteady in a square-selctional 180.deg. curved duct are experimentally investigated. The experimental study using air in a square-sectional 180.deg. curved duct is carried out to measure axial velocity distributions with data acquisition and processing system. In this system, Rotating Machinery Resolver(RMR) and PHASE Software are used to obtain the results of unsteady flows. In conclusion, the exact measurement of unsteady flow using LDV system depends upon uniformity of metreials, duct thickness, and scattered particles.

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The stabilization of a missile actuator using fuzzy controller (퍼지제어에 의한 미사일 조종날개용 구동모터의 안정화에 관한 연구)

  • Kim, Sang-Woo;Kwon, Yong-Soo
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.18-21
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    • 1998
  • A stabilization scheme of a missile actuator using fuzzy controller is proposed. A variable-reluctance stepping motor adopted as a actuator is critically restricted useful operation since pronounced oscillatory behaviour at a certain input frequencies. The previous stabilization scheme. which employs frequency modulation, of the clock-pulse source using derived from the modulation envelope of the total intake current is modified using fuzzy control. The proposed scheme has apparent advantage, particularly in size, mass and flexibility.

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Dynamic Characteristic of Moving Coil Type LOA with Consideration of Driving Method (구동 방식을 고려한 가동코일형 LOA의 동특성)

  • Jang, S.M.;Kweon, C.;Jeong, S.S.;Sung, S.Y.;Lee, S.L.;Kim, B.S.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.681-683
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    • 2000
  • This paper presents to find suitable driving voltage source for moving-coil-type linear oscillatory actuator(LOA). Thus, we construct control system and proposed three type driving voltage source. This scheme demonstrated experiments. Then, we find suitable driving voltage source for LOA.

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Prediction of Harbour Resonance by the Finite Difference Approach

  • Lee, Jung-Lyul;Park, Chan-Sung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.124-129
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    • 1998
  • When the strong wind or long wave energy is transferred into the water body of a harbour, the harbour exhibits oscillatory resonant motions which often cause significant damage to moored ships and navigation hazards. Therefore, a number of theoretical and numerical investigations of such resonant oscillations have been carried out but most of them were limited to harbours connected with open sea of constant depth. (omitted)

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The Effect of Ni Atoms Inserted in Ag Spacer on the Magnetic Property of Ni/Ag(Ni at %)/Ni Trilayered Films

  • Lee, S.J.
    • Journal of Magnetics
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    • v.4 no.4
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    • pp.128-130
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    • 1999
  • We have measured the magnetization of Ni/Ag(Ni at %)/Ni (50$\AA$/30 $\AA$/50 $\AA$) trilayered films including Ni atoms inserted in non-magnetic Ag spacer. The magnetization as a function of applied field at 5 K and as a function of temperature at 100 Oe were investigated respectively using SQUID magnetometer. In these measurements peaks of magnetization at some critical temperatures were observed in all the samples. The antiferromagnetic coupling energy between neighboring Ni layers showed oscillatory behaviors according to the amounts of the Ni atoms inserted in Ag spacer. Loose spin model suggested by slonczews야 was used to explain such results.

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An Asymmetrical Half-Bridge Dc-to-Dc Converter Employing Charge Control (전하 제어를 적용한 비대칭 하프 브리지 직류-직류 컨버터)

  • Lim, Won-Seok;Choi, Byung-Cho
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1184-1186
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    • 2003
  • In this paper, a charge controlled asymmetrical half-bridge (ASHB) dc-to-dc converter is presented. For ASHB do-to-dc converter, the peak current-mode control was found to be problematic primarily due to the oscillatory behavior of the current feedback signal. To resolve this problem, a charge control method is applied to the ASHB do-to-dc converter. A 50W prototype ASHB dc-to-dc converter was built, and successfully tested.

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Monitoring System of Moving Coil Type LOA (가동코일형 LOA의 모니터링 시스템)

  • Jang, S.M.;Jeong, S.S.;Lee, S.H.;Kweon, C.;Chang, K.W.
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.284-286
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    • 2000
  • This paper presents the results of monitoring for measuring characteristics of Linear Oscillatory Actuator we used LabVIEW software. The results is divided into two parts, thats is part for electrical quantity calculation, mechanical quantify calculation detecting part.

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