• Title/Summary/Keyword: 운동시차

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Geocentric parallax measurements of Near-Earth Asteroid using Baselines with domestic small-size observatories (국내 소형천문대 기선을 이용한 근접 소행성 지심시차 측정)

  • Jeong, Eui Oan;Sohn, Jungjoo
    • Journal of the Korean earth science society
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    • v.37 no.7
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    • pp.398-407
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    • 2016
  • We cooperated with four domestic educational astronomical observatories to construct a baseline and perform simultaneous observations to determine the geocentric parallax, distance, and motion of 1036 Ganymed, an Amor asteroid near the Earth. Observations were made on the day when simultaneous observations were possible from September to November 2011. Measured distances of 1036 Ganymed were 0.394 AU on Sept. 26, 0.365 AU on Oct. 11, and 0.340 AU on Oct. 25, respectively, which were within the error range as compared with the measured distances proposed by the US Jet Propulsion Laboratory. The 1036 Ganymed showed a tilting motion during the observation period, and the tangential angular velocities were measured at $0.037-0.052^{{\prime {\prime}}\;sec^{-1}$. Through this study, it was shown that the simultaneous observations among educational astronomical observations can obtain distance measurements with an error range of about 5% for asteroids near 0.4 AU. And it expected to be used as a research & education program emphasizing collaborative observation activities based on a network between observatories.

Enhancement of Pruning Order Determining for Immersive Video Test Model (이머시브 비디오 테스트 모델에서의 프루닝 기법의 개선)

  • Shin, Hong-Chang;Yun, Junyoung;Lee, Gwangsoon;Eum, Homin;Seo, Jungil
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2020.07a
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    • pp.305-307
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    • 2020
  • 이머시브 비디오 서비스를 위해 MPEG-I Visual 그룹에서는 3DoF+ 기술과 관련하여 MIV(Metadata for Immersive video)의 표준화를 진행하고 있으며, 이를 위해 다시점 영상 및 전방위 장면을 촬영한 ERP 규격의 영상들이 주어진 경우에 운동시차를 제공할 수 있는 영상 합성 레퍼런스 소프트웨어인 TMIV SW를 제공한다. TMIV는 기본적으로 송신부인 인코더와 수신부인 디코더로 구성이 되어있으며, 인코더에서 가장 중요한 기능은 다수의 입력 시점영상 간의 중복된 데이터를 찾아내서 제거하는 프루닝 과정이다. 프루닝 방법에 따라 데이터 전송량과 디코더에서의 합성 품질이 달라지기 때문에 인코더에서 핵심이라고 할 수 있다. 본 논문은 인코더의 프루닝의 효율을 높이기 위해 전체 흐름도에서 프루닝 순서 변경 과정을 추가하고 그 과정에서 시점 영상간 중첩 영역을 계산하여 이를 토대로 프루닝 순서를 결정하는 방법을 제안하였고 이를 통해 데이터 압축률이 향상됨을 확인할 수 있었고, 또한 수신부에서 영상 합성의 품질이 달라짐을 확인할 수 있었다.

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Stereoscopic Image Conversion Algorithm using Object Segmentation and Motion Parallax (객체 분할과 운동 시차를 이용한 입체 영상 변환 알고리즘)

  • Jung, Jae-Sung;Cho, Hwa-Hyun;Yoon, Jong-Ho;Choi, Myung-Ryul
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1129-1132
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    • 2005
  • In this paper, we proposed real-time stereoscopic image conversion algorithm using object segmentation and motion parallax. The proposed algorithm separates objects using luminance of image, extracts moving object among objects of the image using motion parallax and generates depth map. Parallax process is done based on the depth map. The proposed method has been evaluated using visual test and APD(Absolute Parallx Difference) for comparing the stereoscopic image of the proposed method with that of MTD. The proposed method offers realistic stereoscopic conversion effect regardless of the direction and velocity of the 2-D image.

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HEVC Tile Grouping for Viewport-dependent 3DoF+ Streaming (사용자 시점 기반 3DoF+ 스트리밍을 위한 타일 그룹 분할 방법)

  • Lee, Soonbin;Jeong, Jong-Beom;Kim, Sungbin;Ryu, Eun-Seok
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2019.11a
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    • pp.256-258
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    • 2019
  • 최근 MPEG-Immersive 표준화 그룹에서는 여러 위치에 존재하는 다수의 360 영상을 취득하고 처리하여 사용자에게 제한적인 화면 전환 이동에 따른 운동 시차(motion parallex)를 제공하는 3 degrees of freedom plus (3DoF+) 기술에 관한 표준화가 진행되고 있다. 이러한 3DoF+ 표준화 기술에서의 압축은 기존의 HEVC 코덱을 사용하나, 현재 존재하는 360 영상 사용자 시점 기반 스트리밍 기법을 3DoF+ 스트리밍에 적용하기 위해서는 기존의 360 영상과 다르게 영상 서로 간의 참조과정으로 인한 의존성으로 문제가 존재한다. 본 논문에서는 해당 문제점을 서술하고, MCTS(Motion-Constrained Tile Set)를 사용하여 보다 적은 디코더와 사용자 시점에 맞게 효율적으로 영상을 전송할 수 있는 MCTS 기반 타일 그룹 분할 방법을 제안한다.

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소형무인항공기용 영상 이동표적표시(MTI) 기법과 동향

  • Yun, Seung-Gyu;Gang, Seung-Eun;Go, Sang-Ho
    • ICROS
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    • v.20 no.4
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    • pp.37-43
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    • 2014
  • 소형 무인항공기가 발달함에 따라 영상센서의 활용이 증가하였다. 특히 발전된 컴퓨팅 파워와 소형화된 영상센서의 발달로 무겁고 값비싼 레이더 장비의 기술을 영상센서로 구현하는 연구가 활발히 진행 중이다. 영상 이동표적표시(Moving Target Indication MTI) 기법은 이런 시대의 흐름에 따라 발달된 기술이며 현재 미군의 소형무인항공기 RQ-11 Raven에 상용화 되었다. 본 논문에서는 소형 무인항공기용 영상 MTI 기법의 원리를 설명하고 영상 MTI에서 주로 사용하는 카메라 운동 보 정 기법인 매개변수/비매개변수 방식의 영상정합의 접근법을 위주로 설명하였다. 또한 소형 무인항공기용 영상감시시스템 구현에서 가장 큰 문제점인 시차/항공기 진동 보정에 대한 진행 중인 연구논문도 소개하였다.

Holographic tabletop display using time multiplexing (시간 다중화 방식의 홀로그래픽 테이블탑 디스플레이)

  • Heo, Daerak;Lim, Sungjin;Jeon, Hosung;Hahn, Joonku
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • fall
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    • pp.49-50
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    • 2021
  • 본 논문에서는 홀로그래픽 영상을 시간 다중화 방식으로 구현한 360 도 홀로그래픽 테이블탑 디스플레이에 대해서 설명한다. 공간 다중화 방식의 경우 필요한 광학 소자의 수와 정렬 난이도를 시간 다중화 방식을 이용하여 해결하고, 홀로그래픽 영상을 재생하기 위하여 푸리에 변환 광학 소자를 추가하여 부드러운 운동 시차를 갖는 형태로 구현한다. 설계된 홀로그래픽 테이블탑 디스플레이는 풀-컬러 영상을 재생하기 위해서 총 3 개의 고속 구동이 가능한 DMD(Digital micromirror device)를 정렬하는 라이트 엔진 구조를 갖고 있다.

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Recent Tectonism in the Korean Peninsula and Sea Floor Spreading (한반도(韓半島)의 신기(新期) 지형운동(地穀運動)에 관(關)하여)

  • Park, Byong Kwon;Kim, Suh Woon
    • Economic and Environmental Geology
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    • v.4 no.1
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    • pp.39-43
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    • 1971
  • The Korean Peninsula is located between the tectonically stable Asian Continent and the tectonically active Japanese islands. The east coast of Korea shows evidence of uplift whereas the west coast shows evidence of submergence. However, radiocarbon dates indicate that the rate of submergence of the west coast of Korea is slower than the tectonically stable east coast of North America. Therefore, both east and west coasts of Korea might have been uplifted during the last post-glacial period. This uplift may result the spreading line of the from compressional strain produced along East Sea of Korea (Japan Sea) and/or the conversion hinge line of the Pacific mantle convection current plunging beneath the Asian continent. This downturn is supposed to be located in the Japan Trench. High heat flow near the east coast of Korea produces the differential strain. This strain accelerates the compressional strain of the peninsula. The Sea Floor Spreading Theory can explain the tectonism of the Korean Peninsula in Recent time. Baek-Doo Mt. and Han-Ra Mt., dormant volcanoes, may be an evidence of westward movement of the Korean Peninsula.

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Comparison of the Effects of Abdominal Massage and Lower Extremity Exercise using Survival Analysis in Rehabilitation Patients of Brain Injury (생존분석을 이용한 복부마사지와 하지관절운동의 뇌병변 재활환자 배변완화시기 효과 비교)

  • Young-Ji, Kim;Dong-Soon, Shin;Sung-Lim, Kim;Kyu-Ock, Park;Na-Ryeong, Do
    • Journal of Industrial Convergence
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    • v.21 no.2
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    • pp.25-32
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    • 2023
  • Constipation is the most common digestive disorder, and it occurs frequently in the early stages and affects the prognosis on rehabilitation stage in the patients with brain injury. The purpose of this study is to evaluate the bowel habits of brain-injured patients undergoing enteral nutrition immediately after admission to rehabilitation and transmission, and to investigate the effects of abdominal massage and lower extremity exercise. The study design is a quasi-experimental study to investigate the effect of a bowel care intervention (abdominal massage and lower extremity exercise) applicable to patients with brain lesions. As a result of the study, the number of bowel movements was significantly higher in the intervention group (p=.030), and the use of suppositories in the control group was statistically significantly higher than that in the intervention group (p=.004). The time of constipation relief was 1.73 days for the experimental group and 4.61 days for the control group, indicating that there was a difference in the time of constipation relief between the two groups (p<.001). Abdominal massage and lower extremity exercise were effective as nursing interventions to relieve constipation and prevent constipation in patients with brain injury from the early stage of rehabilitation.

The Effects of Weight Reduction Programme for Obese Primary School Students on Serum Lipid Level (초등학교 비만아동을 위한 비만관리프로그램이 혈중지질농도 변화에 미치는 효과)

  • Jung, Mi-Hee;Han, Sang-Sook;Lim, So-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8437-8446
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    • 2015
  • This study was designed to examine the effects of weight reduction programme(WRP) for obese primary school students on serum lipid level. This research used non-equivalent control group non-synchronized design that was conducted on two groups comprising 5th and 6th graders: an experimental group that received 12-week long WRP that combines diet, exercise and behavior modification therapy and the control group that did only rope-jumping. The collected data were analysed using ${\chi}^2$-test, t-test, ANOVA, Pairwise Comparsons by SPSS 18.0 Programme. It was proven that the WRP of this study was effective in lowering the total cholesterol(F=4.21, p=.049) and triglyceride(F=4.25, p=.049). WRP may be used as a basis for further studies that may be conducted after intervening the motivation level of the study subjects.

A Quadtree-based Disparity Estimation for 3D Intermediate View Synthesis (3차원 중간영상의 합성을 위한 쿼드트리기반 변이추정 방법)

  • 성준호;이성주;김성식;하태현;김재석
    • Journal of Broadcast Engineering
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    • v.9 no.3
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    • pp.257-273
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    • 2004
  • In stereoscopic or multi-view three dimensional display systems, the synthesis of intermediate sequences is inevitably needed to assure look-around capability and continuous motion parallax so that it could enhance comfortable 3D perception. The quadtree-based disparity estimation is one of the most remarkable methods for synthesis of Intermediate sequences due to the simplicity of its algorithm and hardware implementation. In this paper, we propose two ideas in order to reduce the annoying flicker at the object boundaries of synthesized intermediate sequences by quadtree-based disparity estimation. First, new split-scheme provides more consistent auadtree-splitting during the disparity estimation. Secondly, adaptive temporal smoothing using correlation between present frame and previous one relieves error of disparity estimation. Two proposed Ideas are tested by using several stereoscopic sequences, and the annoying flickering is remarkably reduced by them.