• Title/Summary/Keyword: 초점렌즈

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A Study on The Comic Presentation Through Three-Dimensional Shot (입체적인 쇼트를 통한 코믹연출연구)

  • Hwang, Kil-Nam;Kim, Jae-Woong
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.91-99
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    • 2008
  • When making a comic film, the comic presentation that uses stress and exaggeration is the important subject among other things. In this study we tried to investigate the comic effect using the movement of three-dimensional shot. To conduct this study, we extracted the shot manufactured through the Flow Motion of a 3D Production Program Virtual Camera and a High Speed Motion Picture Camera. The shot manufactured applying this manufacturing skill and using three-dimensional production method for the video contents efficiently made was classified into several scenes. The focus of this study is to search for the factor that makes the atmosphere of a story comic through three-dimensional production shot. According to the shot analysis, three-dimensional production method plays a role in developing more stories on space and time by visualizing stories in three dimensions, which makes the most use of the movement of camera, lens and the utilization of focus. In addition, in the presentation where many comic and exaggerated factors are provided, we used the technology that stresses a scene using the size of a shot and the lasting time and presented the method that exaggerates space using a 3D Production Program Virtual Camera and a High Speed Motion Picture Camera. By reviewing the qualitative improvement and the efficient method on making comic films through the possibility that the atmosphere of this three-dimensional shot can apply to the effect for comic presentation, we tried to approach the comic presentation.

Optical Design of a Subminiature Catadioptric Omnidirectional Optical System with an LED Illumination System for a Capsule Endoscope (LED 조명계를 결합한 캡슐내시경용 초소형 반사굴절식 전방위 광학계의 설계)

  • Moon, Tae Sung;Jo, Jae Heung
    • Korean Journal of Optics and Photonics
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    • v.32 no.2
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    • pp.68-78
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    • 2021
  • A subminiature catadioptric omnidirectional optical system (SCOOS) with 2 mirrors, 6 plastic aspherical lenses, and an illumination system of 6 light emitting diodes, to observe the 360° panoramic image of the inner intestine, is optically designed and evaluated for a capsule endoscope. The total length, overall length, half field of view (HFOV), and F-number of the SCOOS are 14.3 mm, 8.93 mm, 51°~120°, and 3.5, respectively. The optical system has a complementary metal-oxide-semiconductor sensor with 0.1 megapixels, and an illumination system of 6 light-emitting diodes (LEDs) with 0.25 lm to illuminate on the 360° side view of the intestine along the optical axis. As a result, the spatial frequency at the modulation transfer function (MTF) of 0.3, the depth of focus, and the cumulative probability of tolerance at the Nyquist frequency of 44 lp/mm and MTF of 0.3 of the optimized optical system are obtained as 130 lp/mm, -0.097 mm to +0.076 mm, and 90.5%, respectively. Additionally, the simulated illuminance of the LED illumination system at the inner surface of the intestine within HFOV, at a distance of 15.0 mm from the optical axis, is from a minimum of 315 lx to a maximum of 725 lx, which is a sufficient illumination and visibility.

Comparison of the Accuracy of Stereo Camera Calibration According to the Types of Checkerboards (체커보드의 유형에 따른 스테레오 카메라 캘리브레이션의 정확도 비교)

  • Kim, Eui Myoung;Kwon, Sang Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.6
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    • pp.511-519
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    • 2020
  • For camera calibration, a checkerboard is generally used to determine the principal point, focal length, and lens distortions. The checkerboard has a planar and three-dimensional shape, and camera calibration parameters are affected by the size of the checkerboard, the placement of the target, and the number of target points. In this study, the accuracies of the types of checkerboards were compared using checkpoints for stereo camera calibration, and the purpose of this study was to propose the best performance checkerboard. The checkerboard with large flat shape showed comparatively high accuracy through comparison with the check points. However, due to the size of the checkerboard, it was inconvenient to move and rotate, and there was a disadvantage in that it was difficult to shoot so that the target points could all appear in the stereo camera. The checkerboard, which was manufactured in a small size in a flat shape, was easy to move and rotate but had the lowest three-dimensional accuracy. The checkerboard with targets with height values had the hassle of having to determine the three-dimensional coordinates of the target points by using observation equipment for camera calibration, but it was small in size, convenient to move and rotate, and showed the highest three-dimensional accuracy.

The characteristics of lesson design prepared by pre-service teachers according to the structural changes of lesson design template (수업 설계안 구조 변화에 따른 예비교사들의 수업 설계 특징 분석)

  • Lee, Seon Young;Han, Sunyoung
    • The Mathematical Education
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    • v.60 no.1
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    • pp.77-110
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    • 2021
  • In this study, a student participation-centered class based on student mathematical thinking as a the meaningful subject was called a student thinking-based math class. And as a way to support these classes, I paid attention to lesson design. For student thinking-based mathematics classes, it is necessary not only to anticipate student thinking and teacher feedback, but also to plan in advance how to properly arrange and connect expected student responses. The student thinking-based lesson design template proposed in this study is a modified three-step(introduction, main topic, summary) lesson design template. The reason for revising the existing design template is that it has limitation that it cannot focus on mathematical thinking. Using the conceptual framework of student thinking-based mathematics lesson as a lens, the difference between the three-step lesson design prepared by pre-service teachers and the students' thinking-based lesson design prepared by the same pre-service teachers was analyzed. As a result of planning lessons using the student thinking-based lesson design, more attention was paid to the cognitive and social engagement of students. In addition, emphasis was placed in the role of teachers as formative facilitator. This study is of significant in that it recognizes the importance of classes focusing on students' mathematical thinking and provides tools to plan math classes based on students' thinking.

A study on lighting angle for improvement of 360 degree video quality in metaverse (메타버스에서 360° 영상 품질향상을 위한 조명기 투사각연구)

  • Kim, Joon Ho;An, Kyong Sok;Choi, Seong Jhin
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.1
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    • pp.499-505
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    • 2022
  • Recently, the metaverse has been receiving a lot of attention. Metaverse means a virtual space, and various events can be held in this space. In particular, 360-degree video, a format optimized for the metaverse space, is attracting attention. A 360-degree video image is created by stitching images taken with multiple cameras or lenses in all 360-degree directions. When shooting a 360-degree video, a variety of shooting equipment, including a shooting staff to take a picture of a subject in front of the camera, is displayed on the video. Therefore, when shooting a 360-degree video, you have to hide everything except the subject around the camera. There are several problems with this shooting method. Among them, lighting is the biggest problem. This is because it is very difficult to install a fixture that focuses on the subject from behind the camera as in conventional image shooting. This study is an experimental study to find the optimal angle for 360-degree images by adjusting the angle of indoor lighting. We propose a method to record 360-degree video without installing additional lighting. Based on the results of this study, it is expected that experiments will be conducted through more various shooting angles in the future, and furthermore, it is expected that it will be helpful when using 360-degree images in the metaverse space.

Trends and Refractive Status of Cataract Surgery - An Optometry Clinic-Based Survey in Chungbuk (백내장 수술 경향과 굴절상태 - 충북 지역의 안경원 중심으로 조사)

  • Kim, Hyeong-Su;Son, Jeong-Sik;Yu, Dong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.143-148
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    • 2013
  • Purpose: The aim of this study was to investigate the distribution of age and gender, types of intraocular lens (IOL), and refractive errors in subjects who had cataract surgery. Methods: 2,217 subjects who had cataract surgery were surveyed at an optometry clinic in Chungbuk from 2010 to 2012. Information about IOL was obtained from case history, reflective and retroillumination images IOL by auto refracto-keratometer. Refractive errors were determined by objective and subjective refraction. Results: The mean age of the subjects was $71.74{\pm}10.62$ years. The number of cataract surgeries increased from 524 persons in 2010 to 888 persons in 2012. Of the subjects surveyed, 52 persons (2.3%) were under the 40 years of age, 144 persons (6.5%) were in 50s, 404 persons (18.2%) were in 60s, 1,132 persons (51.1%) were in 70s, 485 persons (21.9%) were in above 80s. Cataract surgery was significantly prevalent in more female (1,338 persons, 60.4%) than in male (879 persons, 39.6%). Types of IOL were 2,141 persons (96.6%) for monofocal lens, special IOLs such as multifocal, accommodative and toric lens were 76 persons (3.4%). The distribution of refractive errors after cataract operation were 1,588 eyes (38.5%) for simple myopic astigmatism, 327 eyes (7.9%) for simple hyperopic astigmatism, 601 eyes (14.6%) for mixed astigmatism, 1,240 eyes (30.0%) for myopia, 136 eyes (3.3%) for hyperopia, and 234 eyes (5.7%) for emmetropia. The uncorrected and best corrected visual acuity of the subjects were $0.55{\pm}0.25$ and $0.80{\pm}0.23$, respectively. Conclusions: The prevalence of cataract surgery increased with age until 70s years of age, it was more prevalent in men than women over 60s, and frequency of special types of IOL were low. Most cataract surgeries left residual refractive errors. Therefore even after cataract surgery it may need spectacles for better vision at either distance or near.