• 수산해양기술연구
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• 제25권1호
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• pp.29-34
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• 1989

이상과 같은 제어계의 구성방법으로 제어계를 설계할 경우에는 오차신호에 대한 PI제어기와 플란트의 상태피이드백을 아울러 행하는 제어계로 됨을 알 수 있으며, 또한 응답 시뮬레이션 결과로부터 알 수 있듯이 본 연구에서 제안하는 방법으로 제어기를 구성할 경우 양호한 제어가 가능하다. Fig.3의 플로우챠트의 그림에서 점선으로 표시된 실시간제어실험의 프로그램은 구성은 되어 있으나 실제로 실험을 행하지 못한 아쉬움이 있으며, 다음 기회에 이 부분의 실험도 행하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1234-1235
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• 2011

A DC Power Distribution Systems(DC PDS) are widely used in telecommunication system, electric vehicle, aircraft, military system, etc. In the DC PDS, DC bus voltage instability may be occurred by the operation of multiple loads such as pulsed power load, motor drive system, and constant power loads. To damp the transients of the DC bus voltage, the Voltage Bus Conditioner(VBC) with the PI compensator is used. In this paper, the validity of the proposed VBC system is verified by PSIM simulation package.

• 약학회지
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• 제27권4호
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• pp.249-256
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• 1983

When the reaction rate constant k of phospholipase D on liposome was measured by the ANS fluorometry, k of phospholipase D on DMPC liposome which was made of L-$\alpha$-PI, cholesterol and L-$\alpha$-PS decreased than that of phospholipase D on DMPC liposome with cholesterol or with PI and cholesterol. Optimal $Ca^{2+}$ concentration, the most important factor on effect of phospholipase D, also decreased to 1mM, as compared with 10mM and 60mM respectively when cholesterol and PI were added, and cholesterol only was added. The change of cholesterol Mol% had a great influence on k value of phospholipase D. But in case of addition of L-$\alpha$-PS to cholesterol, the influence was relatively diminished.

• 유변학
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• 제11권2호
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• pp.67-72
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• 1999

본 연구에서는 가해지는 자기장에 따라 항복응력이 변하는 자기유변유체를 이용한 제동 장치를 개발하였다. 현재 선진국을 중심으로 활발히 연구되어지는 자기유변유체는, 유체에 가해지는 자기장의 변화에 따라 유체의 항복응력이 변하는데, 이러한 성질을 이용하여 제동력의 정확한 제어가 가능하다. 본 연구에서는 개발된 제동 장치를 이용하여, 외부에서 회전체에 가해지는 토크가 변동할 경우에 회전체의 회전 속력를 일정하게 유지시키는 기능을 구현하였다. 회전체의 회전속력을 측정하여, 비례-적분 피드백 제어를 사용하여 구현하였다. 우선, 실험과 시뮬레이션 결과의 비교를 통해 개발된 제동 장치의 매개변수값을 구하였고, 이 값들을 이용하여 비례-적분 피드백 제어 시뮬레이션 결과를 예측하였다. 또한 초기 각속력이 있는 자유낙하실험, 수동 크랭킹 실험들을 수행하여, 개발된 장치를 통하여 회전체의 회전속력을 일정하게 유지할 수 있음을 확인하였다. 이러한 속력 제한 기능은 개발된 제동 장치의 응용의 한 예로서, 회전체의 적절한 물리량을 측정한 후. 적절한 피드백 제어를 가하면, 얼마든지 원하는 다른 기능을 구현해 낼 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.209-212
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• 2001

Polyimide(PI) films have been considered as the interlayer dielectric materials due to low dielectric constant, low water absorption, high gap-fill and planarization capability. The PI mm Was etched with using inductively coupled plasma (ICP). The etching characteristics such as etch rate and selectivity were evaluated to gas mixing ratio. High etch rate was $8300{\AA}/min$ and vertical profile was approximately acquired $90^{\circ}$ at $CF_{4}/(CF_{4}+O_{2})$ of 0.2. The selectivies of polyimide to PR and $SiO_{2}$ were 1.2, 5.9, respectively. The etching profiles of PI films with an aluminum pattern were measured by a scanning electron microscope (SEM). The chemical states on the PI film surface were investigated by x-ray photoelectron spectroscopy (XPS). Radical densities of oxygen and fluorine in different gas mixing ratio of $O_{2}/CF_{4}$ were investigated by optical emission spectrometer (OES).

• 한국정밀공학회지
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• 제31권10호
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• pp.905-911
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• 2014

A Loss-in-Weight (LIW) feeder, a type of automated measuring device, is a continuous feeder used in many mass production industries. Due to its versatility, there have been constant demands of LIW feeders in food production supply lines as well as chemical and pharmaceutical industries. In this paper, the process of designing a LIW feeder system with better performance will be examined and compared with commercial products. This system is characterized by low pass Butterworth filter and feed forward PI control. The filter is for noise disposal caused by dynamic condition of a LIW feeder. The feed forward PI control, based on linearity feature of feeders, is adequate for stable driving of the system. At the end, a possible evaluation method of LIW system will be proposed to verify the specific achievement of this paper.

• Applied Biological Chemistry
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• 제39권2호
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• pp.140-146
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• 1996

Imidacloprid와 일련의 새로운 1-(6-chloro-3-pyridylmethy)-3-N-nitroimidazolidin-2-ylideneamine 유도체들을 합성하고 imidazolidine고리의 3-N-치환기(R) 변화에 따른 구조와 벼멸구(Nilaparvata lugens) 및 복숭아 혹 진딧물(Myzus persicae)에 대한 선택적인 살충활성 관계(SAR)를 검토한 바, 벼멸구에는 STERIMOL 파라미터인 B1상수$({\AA})$보다 소수성$({\pi})$, 그리고 복숭아 혹 진딧물에는 입체상수(Es)보다 극성 치환기상수$({\sigma}^{ast})$ 큰 변수로 작용하였다. 벼멸구의 경우에는 ${\pi}$상수의 적정값이 0.52이고 복숭아 혹 진딧물의 경우에는 $\sigma^{\ast}$상수의 적정값이 1.17로 이들 값에 가까운 값을 갖는 치환체일수록 큰 살충활성이 예상되었다. 두 경우, 모두 공통적으로 methyl 및 benzenesulfonyl-치환체(7 및 8)와 같은 센 전자끌게들은 살충활성에 기여하지 않았다. 그러나, 비치환(H)체(1)인 imidacloprid는 가장 큰 살충활성을 나타내었으며 H의 ${\pi}$상수와 ${\sigma}^{\ast}$상수가 이들 두 상수의 적정값에 미치지 못하지만, 양호한 살충활성을 나타낸 까닭은 2-N-nitro group의 산소원자와 3-imid group의 수소원자 사이에 형성된 분자내 회합(H-결합)에 기인함을 알았다. 그리고 pH 6.0 이하의 산성 수용액에서는 대단히 큰 잔류성을 나타내었으며 $45^{\circ}C$의 pH 7.0에서$(K_{obs};5{\times}10^8sec.^{-1})$ 반감기(t1/2)는 대략 6개월이었다.

• Journal of Power Electronics
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• 제4권3호
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• pp.169-179
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• 2004

This paper presents the steady-state analysis of the three-phase self-excited induction generator (SEIG). The three-phase SEIG with a squirrel cage rotor is driven by a variable-speed prime mover (VSPM) or a constant-speed prime mover (CSPM) such as a wind turbine or a micro gas turbine. Furthermore, a PI closed-loop feedback voltage regulation scheme of the three-phase SEIG driven by a VSPM on the basis of the static VAR compensator (SVC) is designed and evaluated for the stand-alone AC and DC power applications. The simulation and experimental results prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in terms of its fast responses and high performances

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.680-683
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• 1996

The dynamics of the vehicle system has highly nonlinear components such as an engine, a torque converter and variable road condition. This thesis proposes a Fuzzy Logic Algorithm that shows better control performance than Antiwindup PI in the highly nonlinear vehicle system. Traction Control System(TCS), which adjusts throttle valve opening by Fuzzy Logic Algorithm improves vehicle drivability, steerability and stability when vehicle is starting and cornering. When a throttle valve is opened at large degree, Fuzzy Logic Algorithm shows better performances like a small settling time and a small oscillation than Antiwindup PI in simulation. The decreased desired slip ratio improves steerability in the simulation when a vehicle is cornering. The Fuzzy Logic Algorithm has been tested by a 1/5-scale vehicle for tracking the constant desired velocity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.40.1-40.1
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• 2011

This paper presents a pitch controller which can hold output power constant at the rated value. Although wind turbine contains complicated nonlinearities, its behaviour within a certain operating range of a point can be approximated by that of a linear model. By doing so, we can apply rather simple and systematic linear control techniques such as PID and LQR(Linear Quadratic Regulator) to design a linear pitch controller. Because these linear controllers are valid only in a sufficiently small range around an operating point, linearized wind turbine model under the condition of varying wind speed needs a linear pitch controller can achieve the aims of tracking the rated rotor rotational speed. We propose an improved linear pitch controller taking each merit of LQR and PI controller under the condition of varying operating points in this paper.