• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2625-2632
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• 2009

Recently, a speed control method of induction motor by vector control theory is applied to highly efficient industrial field. The speed sensors attached to motor are used for detection of rotating speed. In the case using speed sensor, the installation of cable for minimization of electric noise, weaken maintenance, increase of price are demerit. Therefore the study of speed sensorless vector control theory performed activity. The design of sensorless vector controller for induction motor using tabu search is studied. The proposed sensorless vector control for Induction Motor is composed of two parts. The first part is for optimizing the speed estimation with initial PI parameters. The second part is for optimizing the speed control with initial PI parameters using tabu search. Proposed tabu search is improved by neighbor solution creation using Triangular random distribution. In order to show the usefulness of the proposed method, we apply the proposed controller to the sensorless speed control of an actual AC induction Motor System. The performance of this approach is verified through simulation and the experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.08a
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• pp.128-132
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• 2008

본 논문에서는 현재 자가용 차량 번호판으로 사용되고 있는 4종류의 번호판인, 구형 녹색 번호판 두 종류와 유럽식 신형 흰색 번호판 두 종류에 대해 개별 코드를 효과적으로 추출하기 위한 개선된 퍼지 이진화 방법을 제안한다. 차량 영상에서 수직 에지와 반복 이진화 기법, 그리고 Grassfire 알고리즘을 적용하여 번호판의 후보 영역을 추출하고, 번호판의 형태학적 특징을 이용해 잡음을 제거한 후, 최종 번호판 영역을 추출한다 추출된 번호판 영역에서 개선된 퍼지 이진화 기법을 적용하여 개별 코드를 추출한다. 본 논문에서 제안하는 개선된 퍼지 이진화 방법은 추출한 번호판 영역을 그레이 레벨로 변환한 후에 번호판의 명도를 2구간으로 나누고 각각의 구간에 퍼지 소속 함수를 적용하여 번호판 영역을 이진화한 후, 퍼지 소속 함수에 의해 이진화 된 2개의 번호판 영역 중에서 가장 최적화된 번호판 영역을 선택하여 개별 코드를 추출한다. 본 논문에서 제안한 기법을 4종류의 번호판이 부착된 327장(구형녹색 50장, 신형녹색 157장, 짧은 흰색 60장, 긴 흰색 60장)을 대상으로 실험한 결과, 번호판 영역 추출은 327장의 영상중 97%가 추출되었고 개별 코드 추출은 번호판 영역이 추출된 324장의 영상에서 97%가 추출된 결과를 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.497-502
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• 2014

In this paper, a design method for a broadband planar dipole antenna for terrestrial digital television (DTV) reception is studied. The dipole is modified to half bow-tie type for size reduction. The balun between feeding microstrip line and coplanar strip (CPS) line is implemented with a rectangular patch inserted along the center of the CPS line. The proposed antenna is the structure of dual resonances, one is due to the dipole and the other is due to the CPS line attached by the balun. The effects of various geometrical parameters on the antenna performance are examined, and the antenna is designed for terrestrial DTV band (470-806 MHz). The prototype antenna is fabricated on an FR4 substrate with a size of $95mm{\times}178mm$, and tested experimentally to verify the results of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.418-422
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• 2005

The degradation of IPA according to coating conditions was examined by $TiO_{2}$/p-25-coated aluminium metal plate. Inorganic(KR-400), inorganic$\cdot$ organic hybrid(TMOS) and organic(A-9540) resins were used as binder $TiO_{2}$ coated surface of aluminum metal plate was clear with all binders, and the adhesion of binders was good except inorganic binder. The activity for IPA degradation appeared to range in order A-9540>TMOS>KR-400. The optimum activity was obtained when the ratio of TMOS and P-25 was 1.6:10, and when the ratio of A-9540 and P-25 was 1.0:6.0, respectly.

• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.465-472
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• 2005

In this paper, we propose the method of manipulating the gaze direction of 3D FPS game's character by using eye gaze detection from the successive images captured by USB camera, which is attached beneath HMB. The proposed method is composed of 3 parts. At first, we detect user's pupil center by real-time image processing algorithm from the successive input images. In the second part of calibration, when the user gaze on the monitor plane, the geometric relationship between the gazing position of monitor and the detected position of pupil center is determined. In the last part, the final gaze position on the HMD monitor is tracked and the 3D view in game is controlled by the gaze position based on the calibration information. Experimental results show that our method can be used for the handicapped game player who cannot use his(or her) hand. Also, it can Increase the interest and the immersion by synchronizing the gaze direction of game player and the view direction of game character.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1770-1772
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• 2003

본 연구는 국내에서 최초로 제안되고 적용가능성이 입증되어 설계, 제작된 Probe-type Pockets sensor(HY-Pockets Sensor)를 GIS등의 고전압 장비들에 응용한 레이저 부분방전 진단 시스템 개발을 목표로 하고 있다. 이러한 목적으로, 170kV 급 실 규모 GIS내부의 전류 도체에 다양한 곡률 반경의 침 전극을 부착시켜 부분 방전에 기인된 불평등 전계를 형성시켜 개발된 센서의 실규모 적용 가능성을 고찰하였다. 본 레이저 계측 시스템은 He-Ne laser, single multi-mode optical fiber, $2{\times}2$ 50/50 laser to single mode fiber coupler, probe-type Pockets sensor, photo detector 등으로 구성하여 레이저의 진행을 유도하고, 신호의 특성을 분석하였다. probe-type Pockets sensor로부터 의 출력 신호는 photo detector를 통해 전기적 신호로 변환되어 digital oscilloscope에 의해 측정되고, 또한 PC를 통해 데이터의 저장과 통계적, 분석적 처리 과정을 수행하게 된다. 본 연구의 결과로서 부분방전원에서 생성된 방전 신호에 대한 거리에 따른 센서 감도 결정, 그에 대한 센서 감도의 보정 향상, 전계의 세기의 변화에 따른 센서의 선형성 등이 도출되었고, 이러한 실험결과를 통해 실 GIS(170kv급) 내부에서 발생하는 부분방전의 검출에 본 레이저 부분방전 진단 시스템의 적용 가능성이 제시 되었다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.395-404
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• 2019

In the case of fire, surface treatment agents used in external insulation finishing methods are substances that are vulnerable to fire due to thin finishes and the combustion of polymers. In this study, it was expected that the performance of surface preparation mortars could be improved by using expandable graphite with excellent thermal performance. Experimental results showed that the mechanical properties of surf ace preparation mortar were improved by using the fly ash and silica fume. Surface treatment materials using expanded graphite have a characteristic of expanding when a fire occurs. It has been shown that heat-swellable surface treatment materials can reduce the penetration of heat sources into the surface of synthetic insulation.

• KSBB Journal
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• v.15 no.1
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• pp.27-34
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• 2000

A marine bacterium having a high oil-degrading activity was isolated form the oil-polluted southern sea of Korea, and was identified as Pseudomonas aeruginosa and was named Pseudomonas aeruginosa BYK-2. The optimal tmeperatur, culture time, pH and NaCl concentration for biosurfactant production and cell growth showed $25^{\circ}C$, 48h, 7.0 and 0%(w/v), respectively. After cultivation at $25^{\circ}C$, 180 rpm in 250 mL erlenmeyer flask for 7days, 1%(w/v) arabian light crude oil and bunker C oil which are considered to be hardly degradable compounds were degraded 92.1%(w/w) and 76%(w/w) respectively. And then, cell adherence was measured on various carbon sources. The cell adherence indicated over 80% on hydrocarbons(arabian light crude oil, kuwait curde oil, bunker C oil, n-paraffine, n-hexadecane, n-tetradecane) as carbon sources. Lecithin among fatty acids(oleic acid, olive oil, lecithin) showed highest cell adherence of 91.5%. The cell adherence of sugars(arabinose, trehalose, dextrose, galactose, lactose, fructose, maltose, sorbitol, sucrose) observed to be less than 70% except for arabinose, galactose, sorbitol and sucrose.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.1
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• pp.29-38
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• 2018

In order to evaluate the performance of the floating wave power, which is an axisymmetric oscillating water column type, linearized free surface boundary condition considering the influence of PTO (power takeoff) was derived and a finite element numerical model was established. Numerical experiments were carried out by varying cylinder length, skirt length, and depth of water, which are design parameters that can change the resonance of water column in cylinder and heave resonance of the float, which is considered to affect the power generation efficiency. Finally, the basic data necessary for the optimum design of the power generation system were obtained. As a result, the efficiency of the power generation system is dominated by the heave motion resonance of the float rather than the water column resonance in the cylinder, and the resonance condition for the heave motion can be changed efficiently by attaching the skirt to the outside of the buoy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.1-11
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• 2016

The information about the deformations of high-aspect-ratio wings is needed for the real-time monitoring of structural responses. Wing deformation in flight can be predicted by using relationship between the curvatures and the strains on the wing skin. It is also necessary to consider geometric nonlinearity when the large deformation of wing is occurred. The strain distribution on fixed-end is complex in the chordwise direction because of the geometric shape of fixed-wings on fuselages. Hence, the wing displacement can be diversely predicted by the location of the strain sensing lines in the chordwise direction. We conducted a study about prediction method of displacements regardless of the chordwise strain sensing locations. To correct spanwise strains, the ratio of spanwise strain to chordwise strain, Poisson's ratio, and the ratio of the plate strain to the beam strain were used. The predicted displacements using the strain correction were consistent with those calculated by the FEA and verified through the bending testing.