• Title, Summary, Keyword: 외형 보정

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Deformation of the Reference Korean Voxel Model and Its Effect on Dose Calculation (표준한국인 체적소 모델 HDRK-Man의 외형 보정 및 선량 산출에 미치는 영향 평가)

  • Jeong, Jong-Hwi;Cho, Sung-Koo;Cho, Kun-Woo;Kim, Chan-Hyeong
    • Journal of Radiation Protection and Research
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    • v.33 no.4
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    • pp.167-172
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    • 2008
  • Recently a high-quality voxel model of a Korean adult male was constructed at Hanyang University by using very high resolution serially-sectioned anatomical images of a cadaver, which was provided by the Korean Institute of Science and Technology Information (KISTI). Most existing voxel phantoms are developed based on an individual in the supine posture. This study converted the HDRK-Man voxel model into surface model and adjusted the flattened back of the HDRK-Man to a normal shape in the upright posture using 3D graphic softwares such as $3D-DOCTOR^{TM}$, $Rapidform^{(R)}$2006, $Rhinoceros^{(R)}$4.0, $MAYA^{(R)}$8.5. The effective doses of adjusted model were compared with those of unadjusted model for some standard irradiation geometries (i.e., AP, PA, LLAT, RLAT). In general, the differences were not very large and, among those, the largest difference was found for the PA radiation geometry, as expected. These methodologies can be used for the development of various deformed posture models of HDRK-Man in the later stage of this project.

In-Flight Calibration Method for Direction Finding of Communication Signals based on Aviation Systems (항공 시스템 기반의 통신신호 방향 탐지를 위한 비행 보정 기법)

  • Chang, Jaewon;Joo, Jeungmin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.30 no.4
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    • pp.290-299
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    • 2019
  • Direction-finding equipment with multiple antennas are used to estimate the direction of a signal emitted by a source; they can be used to rescue a victim or locate a specified source. During direction finding, reflection waves are present and signal distortion is observed depending on the external shape and material of a system that incorporates the direction-finding equipment and multiple antennas. Therefore, to accurately estimate the azimuth of the signal source and develop the direction-finding equipment, a calibration should be performed to reflect the influence of the antenna arrangement(layout) and system contour. In this paper, we describe an in-flight calibration method to develop direction-finding equipment to locate communication signals using an aviation system, and we analyze the direction-finding performance when applying phase calibration data obtained through the in-flight calibration.

FMSS를 이용한 사고분석 방법

  • Lee, Dong-Seop
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.74-76
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    • 2011
  • 다기능 선박조종시뮬레이터(Full-mission Shiphandling Simulator)를 이용한 사고분석 방법은 먼저 사고관련 정보기록을 수집하여 이에 맞는 항만/해역의 데이터베이스를 만들고 이를 바탕으로 사고 선박의 제원, 사진 및 기타정보를 토대로 일반적인 변수 값 기관 특성정보, Hydrodynamic 특성 변경과 선박의 외형에 따라 선박의 데이터베이스를 만들고, 시험운항을 통한 수치를 보정한다. 그리고 이 데이터베이스를 기초로 하여 시뮬레이션 시나리오를 만들어서 사고 당시를 재연하면서 그때, 그때의 상황의 자료를 수집하여 분석하게 된다.

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Coordinates Transformation and Correction Techniques of the Distorted Omni-directional Image (왜곡된 전 방향 영상에서의 좌표 변환 및 보정)

  • Cha, Sun-Hee;Park, Young-Min;Cha, Eui-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.816-819
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    • 2005
  • This paper proposes a coordinate correction technique using the transformation of 3D parabolic coordinate function and BP(Back Propagation) neural network in order to solve space distortion problem caused by using catadioptric camera. Although Catadioptric camera can obtain omni-directional image at all directions of 360 degrees, it makes an image distorted because of an external form of lens itself. Accordingly, To obtain transformed ideal distance coordinate information from distorted image on 3 dimensional space, we use coordinate transformation function that uses coordinates of a focus at mirror in the shape of parabolic plane and another one which projected into the shape of parabolic from input image. An error of this course is modified by BP neural network algorithm.

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A New Linear Explicit Camera Calibration Method (새로운 선형의 외형적 카메라 보정 기법)

  • Do, Yongtae
    • Journal of Sensor Science and Technology
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    • v.23 no.1
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    • pp.66-71
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    • 2014
  • Vision is the most important sensing capability for both men and sensory smart machines, such as intelligent robots. Sensed real 3D world and its 2D camera image can be related mathematically by a process called camera calibration. In this paper, we present a novel linear solution of camera calibration. Unlike most existing linear calibration methods, the proposed technique of this paper can identify camera parameters explicitly. Through the step-by-step procedure of the proposed method, the real physical elements of the perspective projection transformation matrix between 3D points and the corresponding 2D image points can be identified. This explicit solution will be useful for many practical 3D sensing applications including robotics. We verified the proposed method by using various cameras of different conditions.

Adaptive Model-based Multi-object Tracking Robust to Illumination Changes and Overlapping (조명변화와 곁침에 강건한 적응적 모델 기반 다중객체 추적)

  • Lee Kyoung-Mi;Lee Youn-Mi
    • Journal of KIISE:Software and Applications
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    • v.32 no.5
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    • pp.449-460
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    • 2005
  • This paper proposes a method to track persons robustly in illumination changes and partial occlusions in color video frames acquired from a fixed camera. To solve a problem of changing appearance by illumination change, a time-independent intrinsic image is used to remove noises in an frame and is adaptively updated frame-by-frame. We use a hierarchical human model including body color information in order to track persons in occlusion. The tracked human model is recorded into a persons' list for some duration after the corresponding person's exit and is recovered from the list after her reentering. The proposed method was experimented in several indoor and outdoor scenario. This demonstrated the potential effectiveness of an adaptive model-base method that corrected distorted person's color information by lighting changes, and succeeded tracking of persons which was overlapped in a frame.

An Analysis on System Failure Mechanism of Sectoral Innovation Systems (SIS) : The Case of Mobile Internet Industry in Korea (무선인터넷서비스 산업혁신시스템 실패 메커니즘의 분석)

  • Lee, Kyoung-Ae
    • Journal of Korea Technology Innovation Society
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    • v.11 no.1
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    • pp.46-71
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    • 2008
  • Although the volume of mobile internet services has increased continually over the years, the rapid diffusion has still fallen short of expected quality. This paper considers mobile internet service industry in Korea as a system failure due to structural problems and attempts to identify systemic imperfection mechanisms from the supply side. The problems of mobile internet industry in Korea are categorized into interaction failures, institutional failures and capabilities failures which contribute to system failure and at the same time, failure types are linked to each other. It is needed to improve policy and institutions in operation and develop new policy for contents providers to promote mobile internet industry. This research findings will contribute to policy making to promote mobile internet service industry and development of sectoral system for emerging industries.

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EXB 하전입자빔 에너지 필터의 광학 특성 II

  • Jo, Bok-Rae
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.270.2-270.2
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    • 2013
  • 직선운동하는 하전입자의 진행방향에 수직한 평면상에 서로 직교하는 전기장과 자기장을 걸어주면, 하전입자에는 전기장에 의한 힘 FE와 자기장과 속도 v에 의한 로렌츠력 $F_B=q(v{\times}B)$가 동시에 작용하게 된다. 이때 Wien 조건 FB=-FE를 만족하는 질량 mA과, 에너지 EA를 가지는 하전입자 A는 휘지 않고 직선운동을 계속하나, 하전입자 A와 다른 에너지 $E_B\;(=E_A+{\delta}E)$나 질량 $m_B\;(=m_A+{\delta}m)$을 가지는 하전입자는 휘게 되며, 그 휘는 정도는 ${\delta}E$${\delta}m$에 비례하게 된다. 이 현상을 이용하여 다양한 종류의 에너지 또는 질량 분석기가 독일, 미국, 일본 등의 분석기기 선진국에서 개발되어 왔고, 전자현미경의 이미지 필터로도 활용되고 있으며, 통상 EXB 필터 또는 발명자의 이름을 딴 Wien 필터로 불리어지고 있다. $E{\times}B$ 필터는 일반적인 하전입자빔 렌즈와 다른 광학특성을 가지며, 지난 발표에서는 $E{\times}B$ 필터의 기본 궤도 방정식 및 다양한 2차 기하 수차 방정식의 유도과정 및 결과를 보여주었다. 본 발표에서는 EXB 필터의 전후에 배치시켜, 초점거리 등의 조정을 수행할 4극자와, $E{\times}B$ 필터에서 발생하는 2차 수차의 보정을 수행할 6극자의 광학특성의 계산 결과를 보여준다. 4극자-6극자-EXB필터-6극자-4극자 조합의 기본 광학궤도 계산 결과는 빔 다이어그램으로 보여준다. 6극자에 의해 수차를 줄여서 향상되는 에너지 분해능 값은 수치적으로 추정한다. 실제 제작이 된 각 부품의 외형 및 사진을 보여주어 에너지 필터의 제작 진행 상황을 보고한다.

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Development of Absorption Coefficients Estimation Algorithms for the Water Components by Empirical Method around Korean Waters (경험적인 방법에 의한 한반도 주변 해역에서 성분별 흡광계수 산출 알고리즘 개발에 관한 연구)

  • Moon, Jeong-Eon;Ahn, Yu-Hwan;Ryu, Joo-Hyung;Choi, Joong-Ki
    • Proceedings of the KSRS Conference
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    • pp.280-285
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    • 2009
  • 1998년 8월부터 2005년 6월까지 한반도 주변 해역에서 현장관측한 해수의 고유 광특성(IOPs)과 외형적 광특성(AOPs) 자료들을 이용하여 원격반사도$(R_{rs}(\lambda))$와 성분별 흡광계수의 총 합 $(\alpha(\lambda)=\alpha_w(\lambda)+\alpha_{ph}(\lambda)+\alpha_{ss}(\lambda)+\alpha_{dom}(\lambda))$의 상관관계를 분석하고, $R_{rs}(\lambda)$ 밴드비를 이용하여 흡광계수 산출 알고리즘을 개발하였다. 파장에 따른 $R_{rs}(\lambda)$와 총합 $\alpha(\lambda)$의 상관관계는 반비례적인 관계를 보였고, 파장 443 nm일 때 상관도$(R^2)$는 0.717이다. $\alpha_{ph}(\lambda)$ 산출알고리즘은 엽록소의 흡광과 관련된 파장 490 nm와 부유물의 산란과 관련된 파장 555 nm의 $R_{rs}(\lambda)$ 밴드비의 함수 형태로 구성하였고, 파장 443 nm일 때 RMS 값은 0.223이다. $\alpha_{ss}(\lambda)$$\alpha_{dom}(\lambda)$ 산출 알고리즘은 용존유기물의 흡광과 관련된 파장 412 nm와 부유물의 산란과 관련된 파장 555 nm의 $R_{rs}(\lambda)$ 밴드비의 함수 형태로 구성하였고, 파장 412 nm일 때 RMS 값은 각각 0.324와 0.230이다. $\alpha_{ph}(\lambda),\;\alpha_{ss}(\lambda),\;\alpha_{dom}(\lambda)$ 산출 알고리즘들은 대체적으로 현장값보다 높게 추정하였고 스펙트럼들은 잘 재현해냈다. 추후 이에 대한 개선과 알고리즘의 검보정이 요구된다.

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3D Digital Restoration of Traditional Wooden Building Using Parametric Modeling (Parametric 모델링 방식을 이용한 전통목조건축물의 3D 디지털 복원)

  • Lee, Kang-Hoon;Cho, Sae-Hong
    • Journal of Korea Multimedia Society
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    • v.12 no.8
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    • pp.1164-1171
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    • 2009
  • This paper proposes an efficient implementation way of traditional wooden building using Parametric modeling method which uses the relations of numerical value ratio between building materials. Building structures and order of construction for Geunjungjeon of Kyuungbok Palace is digitally implemented proving the efficiency of the suggested proposal. Although the existing digital modeling methods for traditional wooden building emphasize the exterior modeling of the building, our modeling method constructed numerous wooden materials and arranged those pieces orderly so that people can see the interior structures of the building which usually is beyond one's vision. The suggested Parametric modeling method, Multi-Object Texture Mapping, Physical Camera Restoration, and GI Renderer for implementing Geunjungjeon of Kyuungbok Palace can be practically used for digital implementation for other traditional wooden buildings.

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