데오도라이트를 이용한 위성체 얼라인먼트 측정에 관한 연구

윤용식,이동주 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.6

A measurement of spacecraft alignment is an important process of spacecraft assembly, integration and test because it is necessary that a ground station controls the precise positions of on-orbit spacecraft by using the alignment data of attitude orbit control sensors(AOCS) on spacecraft. In addition, accuracy of spacecraft alignment requirement is about 0.1°- 0.7°. The spacecraft alignment is measured by autocollimation of theodolite. This paper describes the measurement principle and method of spacecraft alignment. The result shows that all of the AOCS on the spacecraft are aligned within the tolerance quired through the alignment measurement.

A New Method for Three-dimensional Measurement with Two Horizontally-aligned Omni-directional Cameras

Sheng-Fuu Lin,Jau-Chi Ke,Hsin-Yi Liu,Jiao-Rou Liao 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

In this paper, a new method for three-dimensional measurement with two horizontally-aligned omni-directional cameras is proposed. Some omni-camera stereo vision systems calculate three-dimensional information which always considers either azimuth angles or elevation angles causing inaccuracy easily. The proposed method takes into account both azimuth angles and elevation angles in order to reduce errors. Besides, the range of interest (ROI) is 3 to 8 meters around cameras in the system. The proposed method has better performance than the vertically- or horizontally-aligned in the 3D measurement.

단일벽 탄소나노튜브의 수평배향도 및 밀도 향상 합성

곽은혜(Eun-Hye Kwak),임호빈(Ho-Bin Im),정구환(Goo-Hwan Jeong) 한국표면공학회 2014 한국표면공학회지 Vol.47 No.6

We present a synthesis of single-walled carbon nanotubes(SWNTs) for enhancement of parallel-alignment and density using chemical vapor deposition with methane feed gas. As-purchased ST-cut quartz substrates were heat-treated and line-patterned by electron-beam lithography in order to grow SWNTs with parallel alignment. We investigated the effects of various synthesis parameters such as catalyst oxidation, reduction, and synthesis conditions in order to enhance both tube density and degree of parallel alignment. The condition of 1 A of Fe catalyst film, atmospheric oxidation at 750ºC for 10 min, reduction under 400 Torr for 5 min, and growth at 865ºC under 300 Torr yields 33 tubes/10μm, which is the highest tube density with parallel alignment. Based on the results of atomic force microscope and Raman spectroscopy, it was found that SWNTs have diameter range of 0.8-2.0 nm. We believe that the present work would contribute to the development of SWNTs-based flexible functional devices.

조명기구배치에 따른 조도향상과 에너지 절약

홍진웅,이종필 광운대학교 신기술연구소 1999 신기술연구소논문집 Vol.28 No.-

학교의 조명기구 안정기는 전자식 안정기 에너지 기자재 2등급 이상의 고효율 안정기로32[W]의 형광등 기구를 사용하고 있다. 그리고 교육환경을 위한 적절한 교실조도는 300[lx] ~ 600[lx]로 규정하고 있어, 현재 수업중인 학교교실 2개교를 선택하여 조도를 측정하였다. 최근에는 교실에 실제 등기구를 설치하지 않고 컴퓨터를 이용한 시뮬레이션 방법을 이용하여 조도를 계산하므로 경제성을 향상시키고, 계산의 오차도 크게 줄이는 방법 등이 제시되고 있다. 따라서 본 논문에서는 교실의 실측조도와 시뮬레이션 한 2,3차원의 조도분포에 따른 균제도 등을 비교 검토하였고, 또한 교육환경의 조도향상과 에너지의 절약을 위해 시뮬레이션을 시행한 결과 파라보릭 루바형 조명기구를 수직 배열한 것이 수평 배열한 것보다 균제도 25[%], 조명을 1[%] 개선되고, Raceway방식은 같은 조도의 다른 배열방식의 단위 면적 당소비전력이 15[%]의 절감효과를 얻었다. For the school's lighting system, Fluorescent lamps of 32[W] are used which is the electronic ballast of high-efficiency lamp graded second place among the energy equipments. To maximize the educational environment, the illuminance of classroom should be controlled between 300[1x]~ 600[Ix]. So we selected two classroom of a school to measure the illuminating level. Recently, in order to increase the efficiency and to decrease an error of calculation, the lighting fixtures have been arranged by using computer simulation. In this paper, their is a comparison between the measured illuminance and illuminance distribution due to the uniformity ratio of 2 or 3 dimensions by simulation. To increase the educational environment's illuminance and to maximize the efficiency of the electrical energy, using vertical alignment of parabolic-louver type lighting fixture is recommended. Since it will improve about 25[%]of uniformity ratio and about l[%]of co-efficient of utilization rather than horizontal alignment. Also, there is 15[%]decrease of power consumption per unit area by using Raceway type.

Enhanced Cold Wall CVD Reactor Growth of Horizontally Aligned Single-Walled Carbon Nanotubes

Wei Mu,곽은혜,Bingan Chen,Shirong Huang,Michael Edwards,Yifeng Fu,Kjell Jeppson,Kenneth Teo,정구환,Johan Liu 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.3

Synthesisof horizontally-aligned single-walled carbon nanotubes (HA-SWCNTs) bychemical vapor deposition (CVD) directly on quartz seems very promising for thefabrication of future nanoelectronic devices. In comparison to hot-wall CVD, synthesisof HA-SWCNTs in a cold-wall CVD chamber not only means shorter heating, coolingand growth periods, but also prevents contamination of the chamber. However, sincemost synthesis of HA-SWCNTs is performed in hot-wall reactors, adapting this wellestablishedprocess to a cold-wall chamber becomes extremely crucial. Here, in orderto transfer the CVD growth technology from a hot-wall to a cold-wall chamber, asystematic investigation has been conducted to determine the influence of processparameters on the HA-SWCNT’s growth. For two reasons, the cold-wall CVDchamber was upgraded with a top heater to complement the bottom substrate heater;the first reason to maintain a more uniform temperature profile during HA-SWCNTsgrowth, and the second reason to preheat the precursor gas flow before projecting itonto the catalyst. Our results show that the addition of a top heater had a significanteffect on the synthesis. Characterization of the CNTs shows that the average density ofHA-SWCNTs is around 1 - 2 tubes/μm with high growth quality as shown by Ramananalysis.

연속발사 충격에 강인한 SDINS 신속 초기정렬기법 설계

이형섭(Hyung-Sub Lee),한경준(Kyung-Jun Han),이상우(Sang-Woo Lee),유명종(Myeong-Jong Yu) 대한전기학회 2016 전기학회논문지 Vol.65 No.6

In this paper, a SDINS(Strapdown Inertial Navigation System) rapid initial alignment technique robust to the pyro-shock in multi-launch rocket system is proposed. The proposed method consists of three steps. Firth, transfer alignment is performed to estimate misalignment between MINS(Master INS) and SINS(Slave INS), and the estimated misalignment is written in the memory when transfer alignment is completed. Next, the pre-filtering process is performed to get rid of the acceleration error induced by launcher vibration. Finally, the horizontal alignment is performed to compensate misalignment variation caused by pyro-shock. We verified the performance of the proposed alignment method comparing with the conventional transfer alignment method. The simulation shows that the proposed initial alignment technique improves alignment performance.

GIS 프로그래밍을 이용한 도로중심선 평면선형 평가

김동기,최세휴 한국도로학회 2012 한국도로학회논문집 Vol.14 No.1

The horizontal alignment of road is deeply related with the stability of the road and traffic capacity. It is necessary to analyze horizontal alignment of road accurately for efficient maintenance of the road and relevance judgment about the standard. Recently the study on horizontal alignment of road using Lidar data and GPS was concluded, but they were many problem analyzing horizontal alignment radius of curvature in wide area. In this study, the tool which the radius of curvature can evaluate the suitability about“ Rules about the Road Structure & Facilities Standards”by using center lines of the road of the digital map tries to implement on GIS. The interface was designed and implemented which can automatically estimate the Road Centerline Horizontal Alignment by using ESRI ArcObjectTM.. 도로의 평면 선형은 도로의 안정성과 교통 용량과 관계가 깊다. 도로의 효율적인 유지 관리와 기준에 대한 적합성 평가를위해서는 도로의 평면 선형을 정확하게 분석하는 방법이 필요하다. 최근 Lidar자료나 GPS를 이용한 도로의 평면 선형 연구가진행되고 있으나 넓은 지역에서의 평면 선형 곡선 반경을 분석하기에는 여러 가지 문제점을 가지고 있다. 본 연구에서는 수치지형도의 도로중심선을 이용하여 곡선 반경이 도로 구조·시설기준에 적합한지 여부를 평가하는 도구를 GIS 상에서 구현하고자 한다. 또한 ESRI ArcObjectTM와 프로그래밍 언어인 비주얼 베이직(Visual Basic)을 사용해 도로의 평면선형을 자동적으로 산정할 수 있는 인터페이스를 설계·구현하였다.

평면곡선과 종단곡선이 겹친 복합선형 구간에서 교통사고 특성분석

박민수,장명순 한국도로학회 2012 한국도로학회논문집 Vol.14 No.1

This study has been conducted to characterize the relations between the accident rate and the overlap section elements where the horizontal alignment and vertical alignment are overlapped. The researches were performed on Horizontal curve sections of 4-lane highways with 100km/h of design speed and speed limit. Korea Highway Corporation's Geographic Figurative Information System was adopted for geometric organization and Highway Traffic Accident Statistics was used. The results reveal that sections made of a single slope without vertical curve has greater accident rate than those with vertical curve, and that sections with 1 vertical curve are higher in the accident rate than those with over 2 vertical curve. For the sections with 1 vertical curve, SAG sections are higher than CREST sections and for the previous straight section of horizontal curve are higher than curved ones. In particular, when the road surface is wet, the accident rate is closely related with SAG vertical curves or leftward horizontal curved sections. This study will have meanings that it proposes the importance of design of road alignment by taking consideration of 3D synthetic alignment conditions for improvement of the road safety. 본 연구는 평면선형과 종단선형이 겹친 복합선형 구간에서 복합선형요소와 교통사고와의 특성을 파악하기 위한 목적으로 진행되었다. 이를 위해 설계속도 및 제한속도가 100km/h인 4차로 고속도로 중 평면곡선부를 대상으로 연구를 진행하였다. 기하구조자료는 한국도로공사「지리도형정보시스템」자료를 이용하였고 교통사고자료는「고속도로 교통사고 통계」자료를 활용하였다. 분석결과, 종단곡선이 없는 경우가 종단곡선이 있는 경우보다 사고율이 높게 나타났으며, 종단곡선이 1개인 경우가 종단곡선이 2개 이상인 경우보다 사고율이 높게 나타났다. 종단곡선이 1개인 경우, 오목종단곡선(SAG) 구간이 볼록종단곡선(CREST) 구간보다 사고율이 높게 나타났으며, 평면곡선부 이전 선형이 직선부인 경우가 곡선부인 경우보다 사고율이 높게 나타났다. 특히 노면상태가 습기(강우)일 때에는 평면곡선내 오목종단곡선인 경우이거나 평면곡선방향이 좌향구간의 경우 교통사고와 관련성이 높음을 확인하였다. 본 연구에서는 도로의 안전성을 높이기 위해 3차원적인 복합선형 조건을 고려한 도로 선형설계의 중요성을 제시하였다는 점에서 의미가 있을 것이다.

GPS/INS 센서 자료를 이용한 도로 평면선형인식 알고리즘 개발

정은비,주신혜,오철,윤덕근,박재홍 한국도로학회 2011 한국도로학회논문집 Vol.13 No.2

도로기하구조정보는 도로의 안전성평가 및 도로의 유지관리를 위한 필수적인 요소이다. 본 연구에서는 GPS(Global Positioning System)/INS(Inertial Navigation System)센서가 탑재된 조사차량을 이용하여 기하구조정보를 수집하였으며, 수집된 차량의 자세정보 중 평면선형과 관련된 Roll, Heading 자료를 이용하여 직선, 원곡선, 완화곡선을 구분하는 알고리즘을 개발하였다. 본 연구에서는평면선형 인식 이전에 전처리 과정으로 이동평균법을 통하여 자료를 평활화함으로써 원시자료의 이상치를 제거하여 평면선형 인식의신뢰성을 제고하였다. 유전알고리즘(GA, Genetic Algorithm)을 이용하여 분류정확도(CCR, Correct Classification Rate)를 최대로하는 알고리즘 파라미터를 설정한 결과 100%의 분류정확도를 보였다. 설정된 파라미터를 이용하여 고속도로와 국도 주행자료를 이용하여 알고리즘을 평가한 결과 90.48%와 88.24%의 분류정확도를 보여, 제안된 평면선형인식 알고리즘은 현장에서 적용 시 높은신뢰도를 가지는 정보를 제공 가능한 것으로 분석되었다. 본 연구에서 개발한 평면선형인식 알고리즘은 조사차량에 GPS/INS센서의소프트웨어로 탑재되어 도로 및 교통기술자에게 도로기하구조정보를 보다 용이하게 수집하고 분석할 수 있는 환경을 제공하는데 기여할 것으로 기대된다. Geometric information is a key element for evaluating traffic safety and road maintenance. This study developed an algorithm to identify horizontal alignment using global positioning system(GPS) and inertial navigation system(INS) data. Roll and heading information extracted from GPS/INS were utilized to classify horizontal alignment into tangent, circular curve, and transition curve. The proposed algorithm consists of two components including smoothing for eliminating outlier and a heuristic classification algorithm. A genetic algorithm(GA) was adopted to calibrate parameters associated with the algorithm. Both freeway and rural highway data were used to evaluate the performance of the proposed algorithm. Promising results, which 90.48% and 88.24% of classification accuracy were obtainable for freeway and rural highway respectively, demonstrated the technical feasibility of the algorithm for the implementation.

Application of GPS Surveying for Extracting Highway's Horizontal Alignment

Seo, Jeong-Hoon,Roh, Tae-Ho,Lee, Jong-Chool Korean Society of Surveying 2002 Korean journal of geomatics Vol.2 No.1

Korea is a small country with relatively large mountainous areas and has many difficulties from planning to completing one road. Maintaining a completed road presents even more difficulties. presently, in estimating design elements, the result varies according to the engineer and there are many cases that question the reliability of the results. Therefore, in this study, the alignment of highway was sampled using by the centerline path, the design elements of horizontal alignment were reduced by applying the Least Squares Method, and the accuracy was analyzed. By this method, IP, IA, R, $\Delta$R and A-parameter were also determined. By observing relatively long straight sections, the approximate values could be estimated, and particularly, the considerably accurate value of A-parameter was determined. This study, using the Least Squares Method, aims to contribute to the development of the alignment examination in frequent traffic accident regions.