• 한국정보전자통신기술학회논문지
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• 제7권3호
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• pp.117-120
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• 2014

수문 제어의 주요기술은 두 개의 실린더가 하나의 수문을 동시에 10[m] 이상 들어 올리는 행정 동안 정밀하게 제어되도록 하여 동기 작동 시키는 것이다. 실린더에 공급되는 유량 및 압력이 일정하지 않으며, 실린더 피스톤의 비선형적인 마찰력에 의해 두 개의 실린더 위치 오차가 발생하게 되면 수문의 개폐 시 비틀림 현상을 야기 시켜서 수문의 마모를 발생시키고, 수문의 개폐작동 불능 현상을 마들기도 한다. 배수갑문용 유압실린더의 위치 및 동기 제어기를 설계하기 위하여 fuzzy PI 제어기를 이용하여 두 개의 실린더의 위치 및 동기 제어기를 설계하고, 시뮬레이션을 통해 효용성을 제시한다.

• 한국위성정보통신학회논문지
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• 제12권1호
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• pp.18-21
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• 2017

In this paper we present IoT compliant HD Digital Signage Controller design using Raspberry Pi. Nowadays, the digital signage system have gained increasing popularity and rapidly growing communications medium that offers a wide range of exciting ways with customers, enhance brand awareness, increase sales and margin uplift by replacing the traditional static signage system. This paper presents a cost-effective IoT based HD Digital Signage Controller (DSC) using R-Pi computer that can use various kinds of displays in order to make the system as efficient and affordable as possible to provide advertisement or other relevant information to people in public areas. The system is designed in such way the information about surrounding related place is taken through sensors and directly uploaded to the internet, and thus can be accessed anytime and displayed on screens by using Raspberry Pi that serves as controller in the system. The design and implementation of the system developed by using python programming language and its hardware consists of sensors, Arduino, Raspberry Pi 3 model B board and the displays. The main targets of this study are build a cost effective Digital Signage system as well as broadcasting information at display contents in public areas and control those digital signs.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.395-402
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• 2000

This paper presents the improvement for speed characteristics of a Brushless DC Motor (BLDCM), it was applied to digital PI control for this. The practical PID control has been widely used to velocity control of DC motors. In this paper, a digital PI controller is used in order to decrease the speed error in constant velocity control of BLDCM. A TMS320C31 DSP is used for the microprocessor of digital PI control. The method using the DSP carry out the real-time control. The DSP has the rapid calculation ability and sampling time used lms. Driving BLDCM used 50W, motor input DC 150V and rotation speed 3000rpm. When BLDCM is to approval for discretion velocity at the acceleration and deceleration driving with any load, it was a feasible for stabilization control. Therefore, the experimental results indicate the superiority and validity of the velocity control by digital PI control.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.343-346
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• 1998

The generation of pretilt angle in nematic liquid crystal (NLC) and electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique P-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about 2.5$^{\circ}$with P-polarized UV light irradiation of 20$^{\circ}$on PI-3 surface at 20 min.; However pretilt angle of about 0.5$^{\circ}$are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with P-polarized UV light irradiation of 20$^{\circ}$on PI-1 surface at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau$$\sub$d/ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• 한국응용곤충학회지
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• 제38권3호
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• pp.249-253
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• 1999

국내 콩씨스트선충의 race 분포를 규명하기 위해 전국 8개도 21개 지역으로부터 선충을 채집하여 검정한 결과, 4종류의 race가 발견되었은데, 그중 race 3(48%)이 가장 많았으며 race 5(24%), race 1(19%),race 6(9%) 순이었고 지역별 차이는 없었다. 국내포장에 서식하는 콩씨스트선충 집단중 약 33%는 저항성품종으로 알려진 Pickett를, 약 43%는 PI88788을 가해할 수 있는 virulence gene을 가지고 있었는데, Peking과 PI90763은 모든 씨스트선충 집단에 대해 저항성으로 나타났다. 국내 콩씨스트선충 저항성 품종 육성에는 Peking이나 PI90763을 교배모본으로 하여 race 5와 6에 대한 저항성 품종을 육성하는 것이 바람직할 것으로 보인다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.891-894
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• 2002

We studied characteristics of polyimide (PI) about Liquid Crystal on Silicon (LCOS) microdisplay. In order to compare two kinds of PI and choose one PI, we measured some items. First, we measured thermal imidization of SE-7492, SE-5291 (Nissan) PI using FT-IR. The results of thermal imidization are same 85%for SE-7492 and 86% for SE-5291. The second, we measured voltage-holding ratio (VHR) of LCOS imager using two kinds PI and one liquid crystal (LC) that is a mixture developed by Merck. The third, we measured contrast ratio (C/R) of LCOS imager using function generator from ov to 4V. The results of VHR and C/R are higher LCOS imager using SE-7492 than LCOS imager using SE-5291. And last we measured response time and the result is same two types LCOS Imagers. So, we choose PI of LCOS imager and concluded that LC is much better matched of PI using SE-7492.

• 한국진공학회지
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• 제1권1호
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• pp.139-144
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• 1992

Ionized Cluster Beam(ICB) 방법을 이용하여 Polyimide(PI) 박막을 증착시켰다. 증 착된 PI 박막의 결정성과 이미드화의 정도를 투과전자현미경(TEM)과 적외선 분광 스펙트럼 (FT-IR)을 이용하여 분석하였다. 최적의 조건에서 증착된 PI 박막은 이미드화가 최대로 증 가하였고 결정구조를 가짐을 관찰할 수 있었다. 이것은 다른 방법으로 제작된 PI 박막과 비 교할 때 훨씬 우수한 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.541-543
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• 1998

Generally, PI control is simple and easy to implement and gains of PI control are determined by specifying a dynamics of the servo driver system. However, the gain-tuning is so difficult that it is relied on an expert's effort. This paper presents a gain auto-tuning method for PI controllers based on a fuzzy inference mechanism. First, the proposed fuzzy inference system identifies a system moment of inertia and adjusts control gains by using the difference in speed responses between a real plant and a reference model. Second, this paper proposes an improved fuzzy PI controller. To reduce the speed overshoot, we adapt a control method that selects a proper PI gains with respect to the load inertia variation. To prove the validity of the proposed gain tuning algorithm and the feasibility of the servo drive, a high performance servo drive will be implemented by DSP(TMS320C31) and intelligent power module (IPM). The proposed controller is applied to the speed control of the 300W AC servo motor. Some simulations and experimental results show that the proposed fuzzy PI controller is more robust than the conventional PI controller against the load inertia variation.

• 조명전기설비학회논문지
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• 제21권6호
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• pp.33-39
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• 2007

본 논문은 부하에 대한 빠른 응답 특성을 보이는 새로운 SRM 구동 토폴로지를 제안하였다. PI 제어기 출력이 포화될 때 windup 현상이 나타나고 그 결과로 성능이 저하된다. 따라서 전동기의 가변속 제어 성능을 위해 가속 시에는 개선된 Anti-Windup PI 제어기만을 사용하고 감소 시에는 추가로 부하의 특성을 고려하여 braking 동작을 사용하였다. 시뮬레이션 및 실험 결과는 속도 성능면에서 제안된 방식이 종래의 다른 제어 방식에 비해 우수함을 보여 준다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.191-193
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• 2005

This paper presents Hybrid PI controller of IPMSM drive using fuzzy adaptive mechanism(FAM) control. To increase the robustness, fixed gam PI controller, Hybrid PI controller proposes a new method based self tuning PI controller. Hybrid PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.