• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.706-707
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• 2016

본 연구에서는 가상증강현실과 미술의 연계로 가상현실의 세계에서 3D 펜과 같이 그림을 그릴 수 있는 시스템을 기획하고자 한다. 가상의 3D 펜과 HMD, Leap Motion 기기를 이용하여, VR공간의 가상 캔버스에 자신만의 그림 세계를 만들고, 실시간으로 여러 명의 사용자들과 연동하여 함께 그림을 그리고, 저장, 공유할 수 있도록 한다. 여럿이 가상현실 공간을 돌아다닐 수 있기 때문에 협동하여 작품을 만들 수 있는 교육용으로도 사용할 수 있다. 또한 입체적인 것을 설명할 때 중요한 부분을 공간페인팅을 함으로써 2D의 한계를 넘어설 수 있다. 이 시스템은 창의적으로 무언가를 그려내는 것을 3D로 표현하기 때문에 더욱 풍부한 작품이 나올 수 있고 창의력 향상에 도움이 될 것이다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.98-101
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• 2002

기존의 이동로봇 시스템은 완전한 자율주행이 주된 목표였으며 이때 영상정보는 단지 모니터링을 하는 보조적인 수단으로 사용되었다. 이에 따라 이동로봇의 자체 기능이 점차 고도화되는 방향으로 연구가 진행되었고, 제작비 또한 함께 상승하게 되었다. 그러나 구동만이 목적인 저렴한 이동로봇 시스템을 조작자가 원격 제어하는 것 또한 중요한 분야 중 하나이다. 이때 원격제어에 사용되는 신호로는 카메라에 의한 영상정보와 초음파 센서 등에 의한 거리정보를 주로 사용하게 된다. 그러나 영상정보는 3차원의 입체적 정보를 제공하는 데에는 부적절하기 때문에 초음파 센서를 이용한 거리정보가 매우 유용하게 된다. 본 논문에서는 초음파 센서의 정보를 이용한 원격제어용 힘 반향 조이스틱을 개발하였다. 힘 반향 알고리즘은 하나의 식으로 표현하기 곤란하므로 전문가 시스템의 구현이 매우 필요한 분야이다. 따라서 퍼지 논리를 사용하여 생성한 힘 반향 알고리즘을 이동로봇 원격제어에 사용함으로써 조작자가 이동로봇 주변환경을 쉽게 인식하여 이동로봇을 안전하게 주행할 수 있도록 하였다.

• Journal of Broadcast Engineering
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• v.18 no.3
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• pp.425-434
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• 2013

Observers usually experience visual fatigue when they watch contents displayed on 3D display. There has been various research on visual fatigue incurred in stereoscopic displays that use 3D glasses, but relatively less studies have been done in the area of autostereoscopic displays. i3D system refers to interactive 3D system that makes it possible for users to interact with contents using their hands. Current research measured visual fatigue that users experience from i3D under various visual environments. We examined the effects of viewing distance, disparities and visual orientation on visual fatigue in i3D. The results indicated that visual fatigue decreased with longer distance and smaller disparity. Visual fatigue increased with angle when 3D fusion was unstable. In addition, there was an interaction effect between angle and distance in which visual fatigue increased with distance under stable 3D fusion but there was no difference in visual fatigue as a function of distance when 3D fusion was unstable. These results would be importantly used to develop autostereoscopic displays that minimize visual fatigue.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.179-186
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• 2011

Purpose: This study aimed to compare and assess changes of visual functions in viewing an anaglyph 3D image. Methods: Visual functions were examined before and after viewing a 2D image and an anaglyph 3D image with red-green glasses on seventy college students (mean age = 22.29${\pm}$2.19 years). Visual function tests were carried out for von Graefe phoria test, accommodative amplitude test by (-) lens addition, negative relative accommodation (NRA) and positive relative accommodation (PRA) test, negative relative convergence (NRC) and positive relative convergence (PRC) test, accommodative facility, and vergence facility test. Results: Assessment of the visual functions indicated that near exophoria and accommodative amplitude were reduced after viewing a 3D image, and although there were small changes in relation to these findings, NRC and PRC showed tendencies to increase and decrease at near, respectively. There were no significant changes with NRA and PRA, and accommodative and vergence facility were shown to have improved. Conclusions: Changes of visual functions were more in the 3D image than the 2D image, especially at near than distance. Particularly, the improvement of accommodative and vergence facility could be related to an effect of subsequent accommodation and vergence shift to have stereopsis in the 3D image. These results indicate that an anaglyph 3D image may, to some extent, be the effect of vision training such as anaglyphs.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.1-11
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• 1998

One of the desired features for the realizations of high quality Information and Telecommunication services in future is "the Sensation of Reality". This will be achieved only with the visual communication based on the 3- dimensional (3-D) moving images. The main difficulties in realizing 3-D moving image communication are that there is no developed data transmission technology for the hugh amount of data involved in 3-D images and no established technologies for 3-D image recording and displaying in real time. The currently known stereoscopic imaging technologies can only present depth, no moving parallax, so they are not effective in creating the sensation of the reality without taking eye glasses. The more effective 3-D imaging technologies for achieving the sensation of reality are those based on the multiview 3-D images which provides the object image changes as the eyes move to different directions. In this paper, a multiview 3-D imaging system composed of 8 CCD cameras in a case, a RGB(Red, Green, Blue) beam projector, and a holographic screen is introduced. In this system, the 8 view images are recorded by the 8 CCD cameras and the images are transmitted to the beam projector in sequence by a signal converter. This signal converter converts each camera signal into 3 different color signals, i.e., RGB signals, combines each color signal from the 8 cameras into a serial signal train by multiplexing and drives the corresponding color channel of the beam projector to 480Hz frame rate. The beam projector projects images to the holographic screen through a LCD shutter. The LCD shutter consists of 8 LCD strips. The image of each LCD strip, created by the holographic screen, forms as sub-viewing zone. Since the ON period and sequence of the LCD strips are synchronized with those of the camera image sampling adn the beam projector image projection, the multiview 3-D moving images are viewed at the viewing zone.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.399-408
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• 1998

Purpose : This study was designed to demonstrate the potential therapeutic advantage of 3-dimensional (3-D) treatment planning over the conventional 2-dimensional (2-D) approach in patients with carcinoma of the nasopharynx. Materials and Methods : The two techniques were compared both qualitatively and quantitatively for the boost portion of the treatment (19.8 Gy of a total 70.2 Gy treatment schedule) in patient with T4. The comparisons between 2-D and 3-D plans were made using dose statistics, dose-volume histogram, tumor control probabilities, and normal tissue complication probabilities. Results : The 3-D treatment planning improved the dose homogeneity in the planning target volume. In addition, it caused the mean dose of the planning target volume to increase by 15.2$\%$ over 2-D planning. The mean dose to normal structures such as the temporal lobe, brain stem, parotid gland, and temporomandibular joint was reduced with the 3-D plan. The probability of tumor control was increased by 6$\%$ with 3-D treatment planning compared to the 2-D planning, while the probability of normal tissue complication was reduced. Conclusion : This study demonstrated the potential advantage of increasing the tumor control by using 3-D planning. but prospective studies are required to define the true clinical benefit.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.179-181
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• 1986

Computed tomography (CT) adds a new dimension in the study of body contour, organs, and tissues as well as various pathologic conditions. This modality provides a great degree of accuracy in radiation therapy Planning (RTP). However, CT images are usually taken on a small reduced format so that possible errors can be made during inputting the CT data into an automatic planner. Authors have designed a simple inexpensive magnifying device of CT images to obviate errors created by reduced image.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.41-52
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• 2002

Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.51-60
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• 2011

Purpose: This study was to investigate visual performance and subjective satisfaction with multifocal soft contact lenses at near works in university students. Methods: In a cross-over study design, 26 students (6 male, 20 female) who did not have any ocular disorder with at least 20/20(1.0) binocular vision were fitted with singlevision lenses (SofLens$^{TM}59$, Bausch + Lomb Co. USA) or multifocal lenses (SofLens Multifocal, Bausch + Lomb Co. USA). After 2 weeks, visual performance assessments included visual acuity, stereoacuity and contrast sensitivity function at distance and near. Near point of accommodation, accommodative facility, near point of convergence, vergence facility and near range of clear vision at near were examined. Students' satisfaction and preference were measured using survey questionaries. Results: Subjects maintained at least 20/20 binocular vision with multifocal and single-vision lenses at distance and near. There was no difference between multifocal and single-vision lenses in stereoacuity, contrast sensitivity function and vergence facility at far and near. The near point of accommodation, accommodative facility, near point of convergence and the near range of clear vision with multifocal lenses were better than single-vision lenses. On the survey questionaries, subjects reported that they preferred and satisfied with multifocal lenses with near works, and single-vision lenses with distance works. Conclusions: The majority of university students preferred multifocal to single vision lenses because multifocal lenses provided better visual performance at near works. This study suggests that multifocal lens is helpful for young adult in prolonged near works.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.757-758
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• 2010

At the time of medical treatment and surgical operation, halogen lamp and plasma lamp were mainly used as luminous source for lighting. These two luminous sources have drawbacks that the life of lamps are not long, various problems are brought about due to excessive heat generation and its volume is very big because of cooling device. Accordingly, in this research a ring light was developed so that a partial shadowless shooting for the patient's affected area at the medical treatment room and surgical operation room using high luminance LED for which attention is being paid as new lighting parts for medical purpose. LED which was applied to the development used high luminance three color LED for full color for which various color materialization and the adjustment of radiation intensity are possible and we can get white light in order to emphasize the delicate expression for generic tone of shooting object, strong highlight, simple shadow and three dimensional effect at the time of close-up shadowless shooting of the affected area.