• 한국항공우주학회지
• /
• 제33권10호
• /
• pp.98-103
• /
• 2005

해상도 2.5m 급 지구관측 카메라인 MAC(Medium-sized Aperture Camera)의 비행모델이 정렬 및 조립되었다. 본 논문에서는 지상에서 측정한 MAC의 시스템 MTF 성능, MTF를 이용한 초점면부의 정렬 등에 대해 논의한다. 칼날주사방식을 이용하여 MAC의 시스템 MTF를 측정하였고, 이를 위해 회절한계 성능의 구경 450 mm 급의 카세그레인 시준기를 만들어 사용하였다. 시스템 MTF를 이용하여 CCD 검출기 초평면부의 최적의 초점에 정렬하였다.

• 한국초전도저온공학회:학술대회논문집
• /
• 한국초전도저온공학회 2003년도 추계학술대회 논문집
• /
• pp.55-58
• /
• 2003

We fabricated the textured Ni substrate and evaluated the effects of processing variables on microstructural evolution and texture transformation. Ni-rods as an initial specimen were prepared by two different methods, i.e., powder metallurgy(P/M) and plasma arc melting(PAM) The texture of the substrate was characterized by pole-figure and surface condition was evaluated by atomic force microscopy. It was observed that the texture of substrate made by P/M did not significantly varied with annealing temperature of 800~120$0^{\circ}C$ and the full-width at half-maximums (FWHM) of both in-plane and out-of-plane were 9$^{\circ}$~10$^{\circ}$. On the other hand, the texture of substrate made by PAM was more dependent on the annealing temperature and the FWHMs of in-plane texture was 9$^{\circ}$~13$^{\circ}$ at the temperature range. In addition, twin texture, (221)＜221＞, was formed as the temperature increased further. The grain size of substrate made by P/M was smaller than that made by PAM and this difference was correlated to the microstructure of initial specimens.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 추계학술대회
• /
• pp.227-229
• /
• 2016

무인 항공기는 공중을 비행한다는 특성에 따라 추락할 경우 항공기뿐만 아니라 인명 및 재산피해를 동반할 가능성이 발생한다는 점에서 어떠한 환경에서도 정확한 제어가 가능한 하드웨어의 높은 신뢰성이 요구된다. 현재 무인 항공기 제어의 핵심은 비행 간 여러 외부 환경 변화 속에서도 기체의 중심을 잡아 불안정한 비행 및 추락을 방지하는 것이다. 본 연구는 무인항공기의 안정적인 비행을 돕는 하나의 관성 측정 장치를 이용한 기체의 중심을 잡는 기존 방식을 보완하여, 한 방향으로 장착되는 관성 측정장치를 역방향으로 장착하여, 두 개의 관성 측정 장치의 무인 항공기 기체가 가지는 가속도 3축, 자이로 3축에 대한 총 여섯 가지 센서 값을 이중으로 처리하는 시스템을 설계하여 무인 항공기의 주추락 원인 중 하나인 관성 측정 장치의 고장이나 전달되는 값의 오류로 인한 추락을 미연에 방지한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제36권5호
• /
• pp.375-379
• /
• 2010

Introduction: In the management of dentofacial deformities, variable movement of the maxilla can be made possible by a Le Fort I osteotomy. Posterior impaction of the maxilla necessary for rotation of the maxillomandibular complex enhances the functions and esthetic results. In cases of posterior impaction of the maxilla, an increase in the figure of the occlusal plane angle and incisor inclination can occur. This study reports the relationship between the amount of posterior impaction and the change in the occlusal plane angle and incisor inclination in a Le Fort I osteotomy by preoperative and postoperative lateral cephalograms. Materials and Methods: Twenty patients who had undergone orthognathic surgery in Dong-A University Medical Center participated in this study. Lateral cephalometrics, within 3 weeks prior to surgery and 3 days after surgery, were used for analysis. Pre and postoperative measurements of the occlusal plane angle and incisal inclination based on the Frankfort horizontal (FH) plane were performed. X and Y were defined as the amount of vertical change in the upper incisor tip and the amount of vertical change in the upper first molar mesial cup tip through the operation. The amount of final posterior maxillary impaction was determined by subtracting Y from X, which is the difference in vertical height. According to the amount of posterior maxillary impaction, the change in the occlusal plane angle and incisal inclination was measured. Results: The average posterior maxillary impaction was 2.91 mm and the average change in the occlusal plane angle and incisal inclination was $6.54^{\circ}$after surgery. As a result, each mm of posterior maxillary impaction changed the occlusal plane angle and incisal inclination by $2.25^{\circ}$. Statistically, there was high significance. Two cases were observed: one with the same amount of posterior maxillary impaction performed on both the right and left showing $2.20^{\circ}$, and the other with a different amount of posterior maxillary impaction performed showing $2.35^{\circ}$. In this case, there was no significance difference between the two cases. Conclusion: Each mm of posterior maxillary impaction changes the occlusal plane angle and incisal inclination by an average of $2.25^{\circ}$. In posterior maxillary impaction, there was no significant difference in the amount of change in the occlusal plane angle and incisal inclination regardless of whether there was an equal amount of posterior maxillary impaction on both sides. This study is expected to help in the presurgical orthodontic preparation and presurgical treatment planning.

• 복식문화연구
• /
• 제1권2호
• /
• pp.131-144
• /
• 1993

Even though it has been to research on the variance of clothing pressure and on its effect of human body, it has not been available to evaluate the clothing pressure as an objective standard ta for the determination of an extra quantity of bodice' basic pattern. In this paper the basic pattern(the close adherence original shape) is determined by a drawing of plane figure after detaching an unweaving clothing from the inside of the gypsum, and the extra quantity is figured by a extension quantity when is formatted with 0.5, 1.0, 1.5 cm extra quantity longitudinal-cross section figures. With our experimental method, review the variance of clothing pressure according to difference of the extra quantity which was figured with subjects wearing experimental clothing including the extra quantity. The difference of the extra quantity was able to calculate with data form the subjects when anatomical position and five movements, then compare with subjects wearing non-extra quantity experimental clothing. The results of experiment as the follows : 1. There is only few body portions with the significant variance according to the increasing of he extra quantity at he body portion and the sleeve portion. 2. The clothing pressure of the sleeve portion was higher than the clothing pressure of the body portion. The difference of clothing pressure according to the variance of the extra quantity at the sleeve portion is more significant than the body portion. 3. Consider several important pressure points which wil be the No. 1 at the front of body portion. No. 17, 18 at the back of body portion and No. 21 at the sleeve portion. 4. It is important to have plane figure of gypsum when format an basis pattern.

• 한국전자파학회논문지
• /
• 제20권9호
• /
• pp.961-966
• /
• 2009

본 논문에서는 메타 구조 Broadside Coupled 나선형 공진기(BC-DSRs)를 이용하여 전압 제어 발진기의 위상 잡음 특성을 줄이기 위한 새로운 구조를 제안하였다. 이러한 특성 실현을 위하여 연속된 나선형 구조를 신호면과 그라운드 면에 각각 적용하였다. 일반적인 전압 제어 발진기와 비교하였을 때, 본 논문에서 제안한 VCO는 더 큰 결합 계수를 가지며, 이로 인하여 얻을 수 있는 더 높은 Q값을 통하여 전압 제어 발진기의 위상 잡음을 줄일 수 있다. 1.8 V의 공급 전력을 갖는 전압 제어 발진기는 주파수 조절 범위, $5.749{\sim}5.853\;GHz$에서 $-121{\sim}-117.16\;dBc$/Hz @ 100 kHz의 위상 잡음 특성을 갖는다. 또한 전압 제어 발진기의 Figure Of Merit(FOM)은 동일한 주파수 조절 범위에서 $-198.45{\sim}-194.77\;dBc$/Hz @ 100 kHz의 특성을 보였다.

• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제20권2호
• /
• pp.163-175
• /
• 2017

본 연구는 평면 도형의 도형 분류하기 과제를 제시할 때 길이와 각의 표기 여부가 도형의 개념 이해에 어떤 영향을 주는지 알아보는데 목적이 있다. 이를 위해, 초등학교 4학년 학생 33명을 대상으로 분류하기 과제 해결 과정을 Eye-tracker를 통해 녹화하고 정답률과 Gaze Duration을 중심으로 분석하였다. 그 결과, 이등변삼각형과 정삼각형의 분류하기에서는 길이를 제시하였을 때 정답률이 증가하고 Gaze Duration은 감소하였다. 예각삼각형과 둔각삼각형 과제에서도 직각을 표기했을 때 정답률이 증가하고 Gaze Duration이 감소하였다. 이러한 결과로 볼 때, 평면도형을 분류하는 과제를 제시할 때는 길이와 각을 표기하여 학생들이 어림하여 도형을 분류하기 보다는 도형의 개념 이해를 바탕으로 분류하는 것을 측정하는 데 초점을 두어야 할 것이다.

• Progress in Superconductivity
• /
• 제6권2호
• /
• pp.133-137
• /
• 2005

We fabricated the Au/Ni template for YBCO coated conductors and evaluated texture formation and the microstructural evolution. The cube textured Ni substrate was fabricated by rolling and recrystallization annealing, and subsequently Au layer formed on the substrate by electroless-plating method. The texture was evaluated by pole-figure with x-ray goniometer with orientation distribution function (ODF) analysis. The surface roughness and grain boundary morphology of template were characterized by atomic force microscopy (AFM) We observed that Au layer deposited epitaxially on Ni substrate and formed a strong cube texture when plating time was optimized. The full-width at half-maximum (FWHM) was $8.4^{\circ}$ for out-of-plane and $9.98^{\circ}$ for in-plane texture for plating time of 30 min. Microstructural observation showed that the Au layer was homogeneous and dense without formation of crack/microcrack. In addition, we observed that root-mean-square (RMS) and depth of grain boundary were 14.6 nm and 160 $\AA$ for the Au layer, respectively, while those were 27.0 nm and 800 $\AA$ for the Ni substrate, indicating that the electoless-plated Au layer had relatively smooth surface and effectively mollified grain groove.

• 한국초등수학교육학회지
• /
• 제15권1호
• /
• pp.141-159
• /
• 2011

본 연구에서 초등학교 6학년 학생들이 도형의 높이 개념을 이해하는 데 어떠한 특징을 보이는지 알아보기 위하여 초등학교 6학년 학생들이 평면도형(삼각형, 평행사변형, 사다리꼴), 입체도형(원뿔, 원기둥, 각기둥, 각뿔)의 높이 개념 이해에서 어떠한 특징을 보이는지를 알아보았다. 그 결과로 학생들은 평면도형의 높이 측정에서 밑변이 수형하지 않은 도형에서 어려움을 나타냈고, 일상의 높이 경험과 연관되는 오류를 보이고, 높이 개념을 언어적으로 표현하는 데에 어려움을 느끼고 있음을 알 수 있었다.

• 한국군사과학기술학회지
• /
• 제15권1호
• /
• pp.93-100
• /
• 2012

In this paper, the deterministic optimal design for the tail plane made of composite materials is conducted under the deterministic loading condition and compared with that of the metallic materials. Next, the reliability analysis with five random variables such as loading and material properties of unidirectional prepreg is conducted to examine the probability of failure for the deterministic optimal design results. The MATLAB programing is used for reliability analysis combined with FEA S/W(COMSOL) for structural analysis. The laminated composite is assumed to the equivalent orthotropic material using classical laminated plate theory. The response surface methodology and importance sampling technique are adopted to reduce computational cost with satisfying the accuracy in reliability analysis. As a result, structural weight of composite materials is lighter than that of metals in deterministic optimal design. However, the probability of failure for the deterministic optimal design of the tail plane structures is too high to be neglected. The sensitivity of each variable is also estimated using probabilistic sensitivity analysis to figure out which variables are sensitive to failure. The computational cost is considerably reduced when response surface methodology and importance sampling technique are used. The study of the computationally inexpensive method for reliability-based design optimization will be necessary in further work.