• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.719-720
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• 2008

마우스나 키보드를 벗어나 직관적인 손을 이용하는 테이블 탑 디스플레이는 대부분 Touch 정보를 이용한다. 직접적인 터치에 손 형상 및 제스처를 이용할 수 있다면 보다 자유롭게 시스템을 컨트롤 할 수 있을 것이다. 본 논문에서는 테이블 탑 디스플레이에서의 손형상 인식을 기술한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.243-243
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• 2004

상용화된 주사식 전자현미경(SEM)을 기본 구조로 하는 가공 시스템을 구축하여 전자빔(Electron beam)을 이용한 초미세 패턴(Nano pattern) 등 형상의 직접 성형, 혹은 직접 묘화(Direct writing) 가공을 수행하기 위해서는 크게 분류하여 연속적으로 스캐닝되는 전자빔을 요구에 따라 적절하게 극히 짧은 시간 내에 개폐하는 빔 블랭커(Beam blanker)와 효율적으로 초미세 패턴 등의 형상을 설계ㆍ가공하기 위한 전용 S/W의 두 가지 요소가 반드시 적용되어야 한다.(중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.33-34
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• 2001

지금까지 이러한 선망 어구의 조업시 형상에 관해 많은 연구 결과들이 있다. 그러나 이들 대부분이 해상실험 또는 모형실험으로서 실험자체의 어려움과 번거러움 등으로 다양한 실험이 불가능하다. 이러한 실험의 단점을 보완할 수 있는 것이 시뮬레이션에 의한 연구이다. 하지만, 선망어구는 매우 대형의 어구 시스템이며 대부분 그물이라는 유연한 물체에 의해 구성되어있어 외력에 대해 그 형상이 비선형적이므로 그 형상과 운동을 정의하기가 어렵다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04a
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• pp.531-534
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• 1995

기계부품의 설계는 공차정보를 포함한다. 이러한 공차정보는 그것의 특성에 따라 실제 부품에 속한 형상이 놓여야 할 공차영역으로 표현되고, 필요하다면, 각 공차간의 관계 도 포함하여야 한다. 기하 공차는 데이팀을 기준 좌표계로 하여 형상, 자세 및 위치를 구 속하며 이러한 관계는 변환 행렬로 표현할수 있다. 특히 이들 변환 행렬의 미소한 변화 를 나타내는 미소 변환 행렬은 각 좌표계간의 공차의 전파를 용이하게 한다. 이러한 표 현방법은 형상 모델링 시스템이나 공차에 관련된 문제에 쉽게 적용할 수 있다.

• Annual Conference of KIPS
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• 2009.11a
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• pp.283-284
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• 2009

본 논문은 단일 카메라 환경에서 손 형상을 입력정보로 사용하여 손 영역만을 분할한 후 자기 조직화 특징 지도(SOFM: Self Organized Feature Map) 신경망 알고리즘을 이용하여 손 형상을 인식함으로서 수화인식을 위한 보다 안정적이며 강인한 인식 시스템을 구현하고자 한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.56-64
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• 2013

The wind resistant capacity of bridges with a span of less than 200m is typically evaluated by Wind Resistant Design Manual for Highway Bridges in Japan. Also, the first vertical frequency plays an important role in the evaluation of their aerodynamic performance. An unexpected vortex-induced vibration of Nielsen arch bridge with span of 183m designed by this manual has been measured by monitoring system during typhoon. The amplitude of vibrations was about 2 times than the allowable vibration displacement. This paper presents the feature of vortex-induced vibration of this Nielsen arch bridge based on measured wind velocity, wind direction, and responses at midspan of main girder. From the result of FFT, the $1^{st}$ mode shape of the bridge is antisymmetric and the $2^{nd}$ is symmetric. Also, the dominant vibration of the bridge is the $2^{nd}$ vertical mode. According to these results, the $2^{nd}$ vertical vibration mode of this Nielsen arch bridge is prior to the first for the estimation of wind resistance capacity.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.629-636
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• 2011

This paper describes the smart structural system that uses smart materials for real-time monitoring and active control of bolted joints in steel structures. The impedance-based structural health monitoring (SHM) techniques, which utilize the electro-mechanical coupling property of piezoelectric materials, was used to detect loose bolts in bolted joints. By monitoring the measured electrical impedance and comparing it with the measured baseline, a bolt loosening damage was detected. The damage was evaluated quantitatively using the damage metrics in conductance signature with respect to the healthy states. When loosening damage was detected in the bolted joint, the external heater actuated the shape memory alloy (SMA) washer. Then the heated SMA washer expanded axially and adjusted the bolt tension to restore the lost torque. An experiment was conducted by integrating the piezoelectric-material-based SHM function and the SMA-based active control function on a bolted joint, after which the performance of thesmart self-healing joint system was investigated.

• The Journal of the Acoustical Society of Korea
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• v.40 no.4
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• pp.347-358
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• 2021

The objective of this study is to optimize the shape of doubly curved surface where a conformal array is equipped. That surface is modeled with a double-ellipsoid solid controlled by four parameters. By analyzing the performance of the conformal array beams with the beam pattern synthesis, two design parameters are determined. Then, we define the weighted object function which is formulated as the sum of sharp indexes for directivity index, the elevation resolution, and the bearing resolution. The direct calculation on all grids is used to evaluate the weighted object function and seek the optimal value of two design parameters when the weightings are given. In the simulation, four kinds of weighting cases are respectively applied to evaluate the weighted object function. The optimal shapes of double-ellipsoid solid are shown in each case. Especially, when the uniform weightings are used, the double-ellipsoid solid with more smooth surface is obtained.

• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.34-41
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• 2023

This paper applies the icing effect and wing rock uncertainty to small unmanned aerial vehicles (UAVs), which have recently attracted attention. Attitude control simulations were performed using various control methods. First, the selected platform, the Skywalker X8 UAV with blended wing-body (BWB) configuration, was linearized for both its baseline form, and a form with applied icing effects. Subsequently, using MATLAB SimulinkⓇ, simulations were conducted for roll and pitch attitude control of the baseline configuration and the configuration with icing effects, employing disturbance observer-based PID control, model reference adaptive control, and model predictive control. Furthermore, the study introduced wing rock uncertainty simultaneously with icing effects on the configured model-a combination not previously explored in existing research-and conducted simulations. The performance of each control Method was compared and analyzed.

• Electric Engineers Magazine
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• v.263 no.7
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• pp.28-35
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• 2004

접지 시스템의 계획은 접지전극 형상의 설계와 계통접지 방식에 따른 접지 시스템으로 구성하여야 하고 접지 또는 금속체간에 전위차가 발생하지 않도록 Bonding, 기술을 충분히 고려하여야 한다.<중략>