• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.928-931
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• 1996

It is necessary to develop the simulator for the test of stability and torque before the walking experiment of biped robot, because a robot may be damaged in an actual experiment. This thesis deals with the development of three-dimensional simulator for improving efficiency and safety during development and experimentation. The simulator is composed of three parts-solving dynamics, rendering pictures and communicating with the robot. In the first part, the D-H parameter and parameter of links can be loaded from the file and edited in the program. The results are obtained by using the Newton-Euler method and are stored in the file. Through the above process, the proper length of link and driving force can be found by using simulator before designing the robot. The second part is organized so that the user can easily see a specific value or a portion he wants by setting viewing parameters interactively. A robot is also shown as a shaded rendering picture in this part. In the last part, the simulator sends each desired angle of joints to the robot controller and each real angle of joints is taken from the controller and passed to the second part. The safety of the experiment is improved by driving the robot after checking whether the robot can be actuatable or not and whether the ZMP is located within the sole of the foot or not for a specific gait. The state of the robot can be easily grasped by showing the shaded rendering picture which displays the position of the ZMP, the driving force and the shape of robot.

• 대한원격탐사학회지
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• 제25권6호
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• pp.487-499
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• 2009

Atmospheric correction of satellite measurements is a major step to estimate accurate surface reflectance of solar spectrum channels. In this study, Simplified Method for the Atmospheric Correction (SMAC) radiative transfer model used to retrieve surface reflectance from MODIS (MODerate resolution Imaging Spectrometer) top of atmosphere (TOA) reflectance. It is fast and simple atmospheric correction method, so it uses for work site operation in various satellite. This study attempts a test of accuracy of SMAC through a sensitivity test to detected error sources and to improve accuracy of surface reflectance using SMAC. The results of SMAC as compared with MODIS surface reflectance (MOD09) was represented that low accuracy ($R^2\;=\;0.6196$, Root Means Square Error (RMSE) = 0.00031, bias = - 0.0859). Thus sensitivity analysis of input parameters and coefficients was conducted to searching error sources. Among the input parameters, Aerosol Optical Depth (AOD) is the most influence input parameter. In order to modify AOD term in SMAC code, Stepwise multiple regression was performed with testing and remove variable in three stages with independent variables of AOD at 550nm, solar zenith angle, viewing zenith angle. Surface reflectance estimation by using Newly proposed AOD term in the study showed that improve accuracy ($R^2\;=\;0.827$, RMSE = 0.00672, bias = - 0.000762).

• 대한원격탐사학회지
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• 제21권6호
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• pp.445-456
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• 2005

지표변수는 지면 근처의 기후변화에 중요한 역할을 하기 때문에, 충분히 높은 정확성을 가진 값이 산출되어야 한다 하지만 지표 반사도는 강한 이방성(non-Lambertian) 특징을 가지고 있기 때문에, 위성 천저각으로부터 멀어질수록 태양-지점-위성과의 기하학적 영향을 더욱 강하게 받는 효과를 가져온다. 또한 지표 각 영향을 포함하고 있는 지표 반사도는 노이즈를 가지게 된다. 따라서 본 연구의 목적은 한반도 지역의 MODIS 반사도 자료(250m)를 이용하여 각 영향이 제거된 보다 정확한 반사도 값에 대한 데이터베이스를 제공하는 것이다. 본 연구에서는 매일 2회씩 제공하는 MODIS(Moderate Resolution Imaging Spoctroradiometer) 센서의 가시영역과 근적외영역의 반사도(250m)자료를 이용하였다. 먼저 구름화소를 제거하기 위해서 연속적인 물리과정을 통하여 각각의 구름 화소를 제거하였다. 그리고 지리보정은 MODIS 센서에서 제공하는 지리정보자료를 이용하여 2차 다항회귀식을 통한 최근접 내삽법을 사용하였다. 본 연구에서는 지표 이방성 효과를 보정하기 위해서 반 경험적 양방향성분포함수(BRDF) 모델을 사용하였다. 이 알고리즘은 위성으로부터 관측된 위성천정각, 태양천정각, 위성방위각, 태양방위각과 같은 각 성분을 이용하여 Kernel-deriven 모델의 역변환을 통하여 지표 반사도를 재생산한다. 먼저 우리는 BRDF 모델을 수행하기 위해 총 31일 모델 관측 실행기간을 고려하였다. 다음 단계로 각각의 화소 및 밴드에 대해서 BRDF 모델을 통하여 분리된 각 성분들을 변조함으로써 위성 직하점 반사도 정규화가 수행되었다. 모델을 이용하여 산출된 반사도 값은 실제 위성 반사도 값과 잘 일치하였고, RMSE(Root Mean Square Error)값은 전체적으로 약 0.01(최고값=0.03)이였다. 마지막으로, 우리는 한반도 지역에 대해서 2001년 동안 총 36개로 구성된 정규화 지표반사도 값의 데이터베이스를 구축하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.41-42
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• 2001

본 연구에서는 빠른 응답특성과 넓은 시야 각 특성을 갖는 Optically Compensated Bend Mode Liquid Crystal Displays(OCB LCDs)의 전기광학 특성을 계산하였다. 액정의 운동방정식을 시뮬레이션하여 얻은 분자배열 분포로부터 광학적 투과 특성을 계산하였으며, 누설광 차단과 수평 및 수직 방향의 넓은 시야각을 확보하기 위하여 보상필름으로써 Wide View Film을 적용하였다. 이러한 결과를 이축성 필름을 사용한 기존의 OCB LCDs와 비교함으로써 Wide View Film을 적용한 OCB LCDs의 시야의존 특성이 향상됨을 확인하였다.

• 복식문화연구
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• 제19권2호
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• pp.316-323
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• 2011

This research aim concerns questioning how we can generate environments suggestive of nature fused with built environments through textiles. Through literature reviews and experiments with available the 3D imaging techniques of Holography, Lenticular and other new technologies. We also have researched towards finding the most effective method for 3D imaging techniques for textile applications. The advantage of the combining technique is to create the possibility of seeing a number of different floating 3D illusory images, depending on the viewing angle. This objective is to produce intriguing textile patterns and images in which the objects and colours change as viewpoints change. Experimental work was carried out in collaboration with professional textile researchers, scientists, artists and designers conducting research in this field.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.895-898
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• 2004

We propose configurations for a transflective in-plane switching (IPS) cell using muti-domain structures. Usually, the cell configurations for a transflective liquid crystal(LC) cell have a complicated structure, because retardation change of transmissive part and reflective part are not same. The transflective LC cell should have two configurations for each part, such as a multi-cell gap structure. With the ion-beam alignment and the horizontal switching LC cell, a simple structure for a transflective LC cell is proposed. The configuration only adopts one cell gap structure, which may help the enhancement of a yield. Their original optical properties in conventional transmissive and reflective type IPS liquid crystal dispaly(LCD) are kept, it shows the wide-viewing angle and the good wavelength dispersion characteristics.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.415-418
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• 2004

The performance of dichroic sponge polymer dispersed liquid crystals (D-SPDLC) can be improved further by modifying the TFT diffusing reflector using a $TiO_2$ layer. A metal-like glare was suppressed, and a wider viewing angle than previously reported was achieved. The display showed above newspaper-standard reflectivity and contrast ratio.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1197-1199
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.288-288
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• 2009

We have studied polarity effects of dielectric anisotropy effects on electro-optical characteristics of a twisted nematic mode driven by fringe electric field, which has wide viewing angle characteristics. Our device is designed as normally black mode between parallel polarizers. The perfect polarization conversion of incident light, which passes through a polarizer, is achieved, when it passes through the twisted liquid crystal (LC) layer. If an electric field is applied, the LC molecules with a positive (or negative) dielectric anisotropy rotate parallel (or perpendicular) to the horizontal component of a fringe electric field as increasing transmittance. From the calculated results, enhanced transmittance of the fringe field-twisted nematic (FF-TN) mode with positive dielectric anisotropy of + 8.2 can be obtained.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.201-204
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• 2005

Recently, the generation of panoramic images and high quality mosaic images from video sequences has been attempted by a variety of investigations. Among a matter of investigation, in this paper, left and right stereo mosaic image generation utilizing airborne-video sequence images is focused upon. The stereo mosaic image is generated by creating left and right mosaic image which is generated by front and rear slit having different viewing angle in consecutive video frame images. The generation of stereo mosaic image proposed in this paper consists of several processes: camera parameter estimation for each video frame image, rectification, slicing, motion parallax elimination and image mosaicking. However it is necessary to check the feasibility on generating stereo mosaic image as explained processes. Therefore, in this paper, we performed the feasibility test on generating stereo mosaic image using video frame images. In doing so, anaglyphic image for stereo mosaic images is generated and tested for feasibility check.