• 한국콘텐츠학회논문지
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• 제16권7호
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• pp.451-456
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• 2016

방사선방호목적의 두부용 수학적 모의 피폭체를 제작하여 두부 CT촬영 시 시각기관(눈, 각막, 수정체)의 흡수선량을 분석하였다. 이후 안구차폐에 따른 방사선량 감소효과를 분석하였다. 그 결과 안구의 흡수선량은 에너지가 증가 할수록 높은 선량을 나타냈으며, 선량이 높은 장기는 두부를 제외하고 눈(eye), 각막(cornea), 수정체(lens) 순으로 평가되었다. 또한 눈의 경우 차폐체 전 후 선량 감소율을 약 38%에서 55%까지, 각막은 약 35%에서 52%를, 끝으로 수정체는 전면만 차폐한 경우 약 51%를 전면과 측면을 동시에 차폐한 경우 약 67%의 감소율을 나타냈다.

• Journal of Photoscience
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• 제9권2호
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• pp.249-251
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• 2002

The avian pineal as well as the retina has been known to contain several types of photoreceptors with different visual pigments such as rhodopsin, iodopsin and the pineal specific opsin, pinopsin. These organs are also known to have circadian clock to regulate melatonin production. Exposure of animals to light causes a decline of the melatonin level and the phase shifts of melatonin rhythms in the pineal and retina. Therefore, the circadian clock system of these organs seem to consist of three elements, i.e., light input, oscillator and melatonin output systems. In birds, it was suggested that rhodopsin might be involved in the entrainment of pineal melatonin rhythms from the action spectrum experiment for controlling NAT activity rhythms. However, there are much more pinopsin-immunoreactive (Pino-IR) cells than rhodopsin (Rho-IR) and iodopsin (Iodo-IR) cells in the avian pineal. We found that Pino-IR cells appeared earlier embryonic stages than Rho-IR and Iodo-IR cells. So, we tried to identify the visual pigments involved in the circadian melatonin rhythms in the pineal and retina. Organ cultured pineals were exposed to monochromatic light to find out which opsin participates in regulation of melatonin rhythms. The action spectra showed a peak at 475nm, suggesting that pinopsin is the major photopigment to regulate melatonin production in birds.

• 전기전자학회논문지
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• 제14권4호
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• pp.291-296
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• 2010

본 논문에서는 카메라 등에 의한 영상정보에서 주행로의 환경에 의한 주행체의 전후 및 좌우로 기울어지는 자세 변화를 감지하는 방법을 제시한다. 주행체의 자세가 어떤 방향으로 기울게 되면 그에 따라 영상정보의 피사체 위치가 상하 또는 좌우로 기울어져 변화한다. 이는 사람이 평형기관 외에 시각에 의하여 자세 변화를 감지하고 그에 따라 반응하는 것과 같은 원리이다. 본 논문에서 제시한 방법은 카메라를 통하여 얻은 영상에서 영상정보뿐 아니라 부수적으로 자세변화 감지동작도 수행할 수 있음을 제시하였고 그 내용을 실험을 통하여 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.661-664
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• 2002

A control of the body posture and movement is maintained by the vestibular system, vision, and proprioceptors. Afferent signals from those receptors are transmitted to the vestibular nuclear complex, and the efferent signals from the vestibular nuclear complex control the eye movement. The postural disturbance caused by loss of the vestibular function results in nausea, vomiting, vertigo and loss of craving for life. The purpose of this study is to develop a off-vertical rotatory system for evaluating the function of semicircular canals and otolith organs, selectively, and visual stimulation system for stimulation with horizontal, vertical and 3D patterns. The Off-vertical axis rotator which stimulates semicircular canals and otolith organs selectively is composed of a comportable chair, a DC servo-motor with reducer and a tilting table controlled by PMSM. And a double feedback loop system containing a velocity feedback loop and a position feedback loop is applied to the servo controlled rotatory chair system. Horizontal, vertical, and 3D patterns of the visual stimulation for applying head mounted display are developed. And wireless portable systems for optokinetic stimulation and recording system of the eye movement is also constructed. The Gain, phase, and symmetry is obtained from analysis of the eye movement induced by vestibular and visual stimulation. Detailed data were described.

• 대한인간공학회지
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• 제30권1호
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• pp.195-202
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• 2011

Objective: The aim of this study is to investigate and review the previous researches about objective measuring fatigue caused by visual stimuli. Also, we analyze possibility of alternative visual fatigue measurement methods using facial expression recognition and gesture recognition. Background: In most previous researches, visual fatigue is commonly measured by survey or interview based subjective method. However, the subjective evaluation methods can be affected by individual feeling's variation or other kinds of stimuli. To solve these problems, signal and image processing based visual fatigue measurement methods have been widely researched. Method: To analyze the signal and image processing based methods, we categorized previous works into three groups such as bio-signal, brainwave, and eye image based methods. Also, the possibility of adopting facial expression or gesture recognition to measure visual fatigue is analyzed. Results: Bio-signal and brainwave based methods have problems because they can be degraded by not only visual stimuli but also the other kinds of external stimuli caused by other sense organs. In eye image based methods, using only single feature such as blink frequency or pupil size also has problem because the single feature can be easily degraded by other kinds of emotions. Conclusion: Multi-modal measurement method is required by fusing several features which are extracted from the bio-signal and image. Also, alternative method using facial expression or gesture recognition can be considered. Application: The objective visual fatigue measurement method can be applied into the fields of quantitative and comparative measurement of visual fatigue of next generation display devices in terms of human factor.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1492-1496
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• 1992

Takayasu`s arteritis is a nonspecific inflammatory vascular disease of unknown origin. It most often cuases stenosis of the aorta or its branch arteries with ischemic changes in the organs supplied, but the vessels inside these organs are not directly involved. From 1983 to 1991, we performed operation on 6 patients with Takayasu`s arteritis. There were 6 female patients ranging in age from 17 years to 36 years. Symptoms included headache, dizzness, visual disturbance, and motor weakness or pain of arm. In 5 cases, bypass graft arised from ascening aorta[ventral aorta] were done, and in one, stenotic segments of left subclavian and vertebral arteries were resected an graft interposition done. Follow-up has been 62.4$\pm$34.8 months[ranging from 11 to 113 months], results of each patient were exellent, except one postoperative death.

• 한국콘텐츠학회논문지
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• 제8권6호
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• pp.121-129
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• 2008

소리를 이용한 정보의 표현 방법은 무형의 특징을 가진 매체를 이용하여 어떠한 방법을 통하여 구체적인 형태를 이끌어 내는가에 대한 문제에서 시작된다. 이 과정에서 소리를 매개체로 이용하여 구성되는 오디오-비쥬얼 시스템은 청각적 소재를 이용한 시각적 표현이라는 방법적 측면에서 감각 기관의 연계에 대한 역할을 맡고 있는 부분에서 청각의 시각화라는 비 구체적 감각에 대한 구체화라는 변형의 의미를 갖는다. 오디오-비쥬얼 시스템 형태를 통한 작품을 표현하는데 있어 기존에 사용되던 프로그래밍을 통한 비규칙적 프로시쥬얼(Procedure)적 동적(動的) 이미지 또는 비동적(非動的) 이미지를 사용한 표현 방법에서 시각적 출력 방법의 제한으로 인한 표현 방법의 제한이 생겨날 수 있는 부분에 있어 동적 이미지를 이용한 오디오-비쥬얼 시스템을 통하여 소리를 매체로 한 다양한 표현 결과물을 이끌어낼 수 있다. 본 논문에서는 동적 이미지를 사용한 오디오-비쥬얼 시스템을 통해 다양한 청각적 소재의 시각화 방법 및 소리를 이용한 애니메이션 표현법의 새로운 대안을 제시한다.

• 한국산업정보학회논문지
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• 제4권4호
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• pp.94-99
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• 1999

가상 현실 기술은 사용자가 현실과 유사한 방법으로 정보를 공유할 수 있는 방법이다. 가상 현실기술은 인간의 오감을 이용한 사실적인 환경을 제공하고 인터넷 환경에서 사용자는 가상 현실 공간을 공유할 수 있는 장점을 가지고 있다. 이러한 가상 공간을 이용하여 갤러리를 모의 구현하고 갤러리 정보영역에 미술작품의 내용을 음성 데이터베이스로 구성한다. 외부의 사용자는 대리인(avatar)을 통하여 가상현실갤러리에서 미술작품을 감상할 수 있다. 본 논문은 감상자가 미술작품에 근접했을 경우 감상의 질을 높히기 위하여 해상도를 높히고, 큐레이터(curator)를 도입하여 미술작품 감상시 작품의 정보를 음성과 문자 메시지를 출력함으로서 상호 작용성을 높혀 사용자에게 현장감을 증대할 수 있다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (B)
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• pp.109-111
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• 2002

Visual organs play an important role in human information recognition processes. If they are expressed in a way of digital information, it makes much bigger amount of visual information among any other information. For that reason, MPEG-2 has been taken use of to represent information compressing technology in multi-media. Although the imported data would basically contain noises, when original video images are encoded into MPET-2. Accordingly, we propose soft- $\alpha$ filter to improve image quality of digital image received from the actual image and to reduce noises from them. We also propose a method combining vertical/horizontal filter and soft- $\alpha$ filter on MPEG-2 video image. We can get two kinds of effects from the advantages of this kind of combination. Firstly, it will reduce processing time ducting horizontal and vetical filtering process. It will cover time for soft- $\alpha$ filter. Secondly, it will simplify the colors in horizontal and vertical filter. Therefore we can get clearer quality without noises from soft- $\alpha$ filter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.377-380
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• 2001

The vestibular system located in the inner ear controls reflex body posture and movement. It has the semicircular canals sensing an angular acceleration and the otolith organs sensing a linear acceleration. With this organic signal, medical doctor decide if a person has disease or not. To obtain this data, a precision stimular system is considered. Robust control is needed to obtain eye signals induced by off-vertical axis rotation because of an unbalanced load produced by tilting the axis of the system upto 30 degrees. In this study, off-vertical axis rotatory system with visual stimulation system are developed. This system is consisted of head mounted display for generating horizontal, vertical, and three dimensional stimulus patterns. Furthermore wireless recording system using RF modem is considered for noiseless data transmission.