• Title/Summary/Keyword: space plane

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Photogrammetry 기법을 활용한 MSC 설치면의 정밀 측정

  • Woo, Sung-Hyun;Kim, Hong-Bae;Moon, Sang-Mu;Im, Jong-Min
    • Aerospace Engineering and Technology
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    • v.3 no.1
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    • pp.126-133
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    • 2004
  • Photogrammetry, as its name implies, is a 3-dimensional coordinate measuring technique that uses photographs as the fundamental medium for metrology. In the last few years the accuracy of photogrammetry has increased dramatically thanks to the rapid advance of digital camera manufacturing technique. This paper discusses photogrammetric measurement of the interface surface of MSC(Multi-Spectral Camera), which is a main payload of KOMPSAT-2. Total 24 paper targets on the objective surfaces and two scale bars calibrated with high accuracy were used for measurement, and multiple images were taken from 11 different camera angles by using a spacecraft rotation dolly. As a result of analysis, 3D coordinates of each targeted point were obtained and the flatness value based on the selected reference plane was calculated and compared with the pre-determined requirement. The technique acquired by this study is expected to be used for the 3D precise measurement of ultra-light weight and inflatable space structures such as a satellite antenna and a solar array.

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Fast Axis Estimation from 3D Axially-Symmetric Object's Fragment (3차원 회전축 대칭 물체 조각의 축 추정 방법)

  • Li, Liang;Han, Dong-Jin;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.6
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    • pp.748-754
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    • 2010
  • To reduce the computational cost required for assembling vessel fragments using surface geometry, this paper proposes a fast axis estimation method. Using circular constraint of pottery and local planar patch assumption, it finds the axis of the symmetry. First, the circular constraint on each cylinder is used. A circular symmetric pot can be thought of unions of many cylinders with different radii. It selects one arbitrary point on the pot fragment surface and searches a path where a circumference exists on that point. The variance of curvature will be calculated along the path and the path with the minimum variance will be selected. The symmetric axis will pass through the center of that circle. Second, the planar patch assumption and profile curve is used. The surface of fragment is divided into small patches and each patch is assumed as plane. The surface normal of each patch will intersects the axis in 3D space since each planar patch faces the center of the pot. A histogram method and minimization of the profile curve error are utilized to find the probability distribution of the axis location. Experimental results demonstrate the improvement in speed and robustness of the algorithms.

A Study on the Transformation in Design Process of Ronchamp Chapel (롱샹 성당의 설계 변형 과정 연구)

  • Lee, Jeong-Kyu
    • Journal of architectural history
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    • v.8 no.1 s.18
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    • pp.81-94
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    • 1999
  • This Study aims at searching the meanings in the creative process of Ronchamp chapel by analyzing the drawings of the site, plan, section and elevation in chronological order. The origins of his architectural creation are identifying with the site(memories of Acropolis), analogies of crab shell, air plane wing and hydraulic dams. The architect informed himself about the site ,the tradition of pilgrimage associated with the place, and its devotion to the Holy Virgin; he looked into the rituals of the Catholic religion, spoke with ecclesiastics; he studied and annotated a monograph devoted to the site of Ronchamp. Also ,the plan required that it be possible to collect rainwater, since such was rare on the hill. In the first design phase, overall conception of building was carried out in the sketches and drawings from June 1950 to November 1950. The second phase in the elaboration of the project was from January 1951(at which time preliminary project was presented to the Commission of Holy Art) to April 1953. The modifications made were in response to opinions expressed by the patrons. The building moved to east and gargoyle moved to west, then, the elevations of north and west were changed. He designed the artificial land and bell tower from the first phase even after the beginning of construction ,he wanted them to be built .But they were not constructed, so the outer space for rituals of religion had no tension. I concluded that Le Corbusier had gifted ability and efforts to create spontaneous birth(after incubation) of the whole work, and the execution of drawings itself. He devoted himself to accomplish the project in spite of the change in situation or by clients.

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Gesture based Input Device: An All Inertial Approach

  • Chang Wook;Bang Won-Chul;Choi Eun-Seok;Yang Jing;Cho Sung-Jung;Cho Joon-Kee;Oh Jong-Koo;Kim Dong-Yoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.3
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    • pp.230-245
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    • 2005
  • In this paper, we develop a gesture-based input device equipped with accelerometers and gyroscopes. The sensors measure the inertial measurements, i.e., accelerations and angular velocities produced by the movement of the system when a user is inputting gestures on a plane surface or in a 3D space. The gyroscope measurements are integrated to give orientation of the device and consequently used to compensate the accelerations. The compensated accelerations are doubly integrated to yield the position of the device. With this approach, a user's gesture input trajectories can be recovered without any external sensors. Three versions of motion tracking algorithms are provided to cope with wide spectrum of applications. Then, a Bayesian network based recognition system processes the recovered trajectories to identify the gesture class. Experimental results convincingly show the feasibility and effectiveness of the proposed gesture input device. In order to show practical use of the proposed input method, we implemented a prototype system, which is a gesture-based remote controller (Magic Wand).

A Study on Attitude Estimation of UAV Using Image Processing (영상 처리를 이용한 UAV의 자세 추정에 관한 연구)

  • Paul, Quiroz;Hyeon, Ju-Ha;Moon, Yong-Ho;Ha, Seok-Wun
    • Journal of Convergence for Information Technology
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    • v.7 no.5
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    • pp.137-148
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    • 2017
  • Recently, researchers are actively addressed to utilize Unmanned Aerial Vehicles(UAV) for military and industry applications. One of these applications is to trace the preceding flight when it is necessary to track the route of the suspicious reconnaissance aircraft in secret, and it is necessary to estimate the attitude of the target flight such as Roll, Yaw, and Pitch angles in each instant. In this paper, we propose a method for estimating in real time the attitude of a target aircraft using the video information that is provide by an external camera of a following aircraft. Various image processing methods such as color space division, template matching, and statistical methods such as linear regression were applied to detect and estimate key points and Euler angles. As a result of comparing the X-plane flight data with the estimated flight data through the simulation experiment, it is shown that the proposed method can be an effective method to estimate the flight attitude information of the previous flight.

New bimaxillary orthognathic surgery planning and model surgery based on the concept of six degrees of freedom

  • Jeon, Jaeho;Kim, Yongdeok;Kim, Jongryoul;Kang, Heejea;Ji, Hyunjin;Son, Woosung
    • The korean journal of orthodontics
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    • v.43 no.1
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    • pp.42-52
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    • 2013
  • The aim of this paper was to propose a new method of bimaxillary orthognathic surgery planning and model surgery based on the concept of 6 degrees of freedom (DOF). A 22-year-old man with Class III malocclusion was referred to our clinic with complaints of facial deformity and chewing difficulty. To correct a prognathic mandible, facial asymmetry, flat occlusal plane angle, labioversion of the maxillary central incisors, and concavity of the facial profile, bimaxillary orthognathic surgery was planned. After preoperative orthodontic treatment, surgical planning based on the concept of 6 DOF was performed on a surgical treatment objective drawing, and a Jeon's model surgery chart (JMSC) was prepared. Model surgery was performed with Jeon's orthognathic surgery simulator (JOSS) using the JMSC, and an interim wafer was fabricated. Le Fort I osteotomy, bilateral sagittal split ramus osteotomy, and malar augmentation were performed. The patient received lateral cephalometric and posteroanterior cephalometric analysis in postretention for 1 year. The follow-up results were determined to be satisfactory, and skeletal relapse did not occur after 1.5 years of surgery. When maxillary and mandibular models are considered as rigid bodies, and their state of motion is described in a quantitative manner based on 6 DOF, sharing of exact information on locational movement in 3-dimensional space is possible. The use of JMSC and JOSS will actualize accurate communication and performance of model surgery among clinicians based on objective measurements.

Single-Crystal Structure of |Li50Na25|[Si117Al75O384]-FAU

  • Kim, Hu Sik;Suh, Jeong Min;Kang, Jum Soon;Lim, Woo Taik
    • Journal of the Korean Chemical Society
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    • v.57 no.1
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    • pp.12-19
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    • 2013
  • The single-crystal structure of fully dehydrated partially $Li^+$-exchanged zeolite Y, ${\mid}Li_{50}Na_{25}{\mid}[Si_{117}Al_{75}O_{384}]$-FAU, was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $Fd\bar{3}m$ at 100(1) K. Ion exchange was accomplished by flowing stream of 0.1 M aqueous $LiNO_3$ for 2 days at 293 K, followed by vacuum dehydration at 623 K and $1{\times}10^{-6}$ Torr for 2 days. The structure was refined using all intensities to the final error indices (using only the 801 reflections with ($F_o$ > $4{\sigma}(F_o)$) $R_1/R_2=0.043/0.140$. The 50 $Li^+$ ions per unit cell are found at three different crystallographic sites. The 19 $Li^+$ ions occupy at site I' in the sodalite cavity: the $Li^+$ ions are recessed 0.30 ${\AA}$ into the sodalite cavity from their 3-oxygens plane (Li-O = 1.926(5) ${\AA}$ and $O-Li-O=117.7(3)^{\circ}$). The 20 $Li^+$ ions are found at site II in the supercage, being recessed 0.23 ${\AA}$ into the supercage (Li-O = 2.038(5) ${\AA}$ and $O-Li-O=118.7(3)^{\circ}$). Site III' positions are occupied by 11 $Li^+$ ions: these $Li^+$ ions bind strongly to one oxygen atom (Li-O = 2.00(8) ${\AA}$). About 25 $Na^+$ ions per unit cell are found at four different crystallographic sites: 4 $Na^+$ ions are at site I, 5 at site I', 12 at site II, and the remaining 4 at site III'.

Preparation and Structure of $[Cu(L)]I_2\cdot2H_2O(L: 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,$0^{1.18},0^{7.12}$]docosane) ($[Cu(L)]I_2\cdot2H_2O(L: 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,$0^{1.18},0^{7.12}$docosane) 착물의 합성 및 구조)

  • Choe, Gi-Yeong;Kim, Dong-Un;Seo, Il-Hwan
    • Korean Journal of Crystallography
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    • v.9 no.1
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    • pp.1-5
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    • 1998
  • The complex[Cu(L)I2, 2H2O(1) (L:3,14-Dimethyl-2,6,13,17-tetraazatricyclo [14,4,01.18, 07.12]docosane) has been prepared and structurally characterized. The complex (1) crystallizes in the triclinic system, space group P1, a=8.400(1)Å, b=8.986(3) Å, c=9.156(1) Å, α=82.42(1)˚, β=73.61(1)˚ λ=81.04(2)˚, Z=1, R for 1926 observed reflections of [F0>40(F0)], measured at 288K, was 0.042. The tetracoordination around Cu atom of complex(1) is square plane and the average bond distance of Cu-N is 2.029 (11) Å. Both six-membered chelate rings adopts a chair conformation and the five-membered ring are gauche with the sec-NH centers having the RRSS configuration.

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The Slewing Mirror Telescope of the Ultra Fast Flash Observatory Pathfinder

  • Jeong, Soomin;Choi, Ji Nyeong;Jung, Aera;Kim, Min Bin;Kim, Sug-Whan;Kim, Ye Won;Kim, Jieun;Lee, Jik;Lim, Heuijin;Na, Go Woon;Nam, Jiwoo;Park, Il Hung;Ripa, Jakub.;Suh, Jung Eun
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.208.2-208.2
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    • 2012
  • The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. The first realization of UFFO is the 20kg UFFO-Pathfinder (UFFO-P) to be launched on board the Russian Lomonosov satellite in 2013 by the Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will rotate to bring the GRB into the SMT's field of view instead of slewing the entire spacecraft. SMT can image the UV/Optical counterpart with about 4-arcsec accuracy. However it will provide a important understanding of the GRB mechanism by measuring the sub-minute optical photons from GRBs. SMT can respond to the trigger over $35^{\circ}{\times}35^{\circ}$ wide field of view within 1 sec by using Slewing Mirror Stage (SMS). SMT has 10-cm Ritchey-Chretien telescope and $256{\times}256$ pixilated Intensified Charge-Coupled Device (ICCD) on focal plane. In this paper, we discuss the overall design of UFFO-P SMT instrument and payloads development status.

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The Crystal and Molecular Structure of Salicylaldehyde-4-morpholinothiosemicarbazone (Salicylaldehyde-4-morpholinothiosemicarbazone의 결정 및 분자구조)

  • C. H. Koo;H. S. Kim;C. T. Ahn
    • Journal of the Korean Chemical Society
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    • v.21 no.1
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    • pp.3-15
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    • 1977
  • Crystals of salicylaldehyde-4-morpholinothiosemicarbazone, $C_{12}H_{15}O_2N_3S$, are orthorhombic with space group Pna21. Unit-cell dimensions are a = 11.85(5), b = 15.45(5) c = 7.18(3)${\AA}$ with z = 4. Three-dimensional intensity data were collected from the multiple-film equi-inclination Weissenberg photographs taken with $CuK{\alpha}$ radiation. The intensities were estimated visually. The structure was solved by Patterson and Fourier methods and refined by the block-diagonal least-squares methods until the final R value becomes 0.11 for the 1064 observed independent reflections. The morpholine ring has a chair form. The rest atoms of salicylaldehyde-4-morpholinothiosemicarbazone molecule excluding morpholine ring and sulfur atom approximately lie on a plane. The hydroxyl group of the salicylaldehyde and the nitrogen atom of the thiosemicarbazone form an intramolecular hydrogen bond, $O-H{\cdot}{\cdot}{\cdot}N$, of 2.67${\AA}$. The short intermolecular distances all appear to be normal van der Waals contacts.

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