• Journal of Information Display
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• 제10권4호
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• pp.188-194
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• 2009

Conventional stereoscopic (3D) displays using binocular parallax generate unnatural conflicts between convergence and accommodation. These conflicts can affect the observer's ability to fuse binocular images and may cause visual fatigue. In this study, time series changes in visual fatigue and depth sensation when viewing stereoscopic images with changing parallax were examined. In particular, the physiological changes, including the subjective symptoms of visual fatigue, when viewing five parallax conditions, were examined. Then a comparative analysis of the 2D and 3D conditions was performed based on the visual function. To obtain data regarding the visual function, the time series changes in the spontaneous-blinking rate before and during the viewing of 3D images were measured. The time series change results suggest that 2D and 3D images cause significantly different types of visual fatigue over the range of binocular disparity.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.18-21
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• 1991

In this paper, the effect of background grey levels on the visual perception of target image displayed on CRT monitor has been investigated. The purpose of this study is to investigate the efficacy of CRT monitor as a display medium of image information especially in medical imaging field. Three sets of experiments have been performed in this study; the first was to measure the luminance response of CRT monitor and to find the best fitting equation, and the second was the psychophysical experiment measuring the threshold grey level difference between the target image and the background required for visual discrimination for various background grey levels, and the third was to develop a visual model that is predictable of the threshold grey level difference measured in the psychophysical experiment. The result of psycophysical experiment shows that the visual perception performance is significantly degraded in the range of grey levels lower than 50, which is turned out due to the low luminance change of CRT monitor in this range while human eye has been adapted to relatively bright ambient illumination.

• 한국안전학회지
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• 제27권2호
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• pp.117-126
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• 2012

Understanding driver's characteristic of visual activity is important process because driver depends on a visual signal more than 90% for getting outside information needed to drive, thus a series of driving, including perception, judgement, and activity, is completed. This study analyzes quantified driver's sight range in curved section where recognition of various information is critical due to biggest speed change among sections. Simulation is utilized for this study because of safety problem on field experiment and difficulties in using equipment. Building 6 roads that have different in curve radius by virtual driving map, experiment is carried out recruiting 30 people. Through analytical researches, it shows that drivers keep an eye on direction of driving, and driver's visual range is narrowed on left curve than right curve, and the more curve radius become small, the more drivers see in narrow angle.

• 한국실내디자인학회논문집
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• 제20권6호
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• pp.183-191
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• 2011

This study is to set up the appropriate range of observation time through contemplating the characteristics of observation time run for the information acquisition of space. The conclusions reached through this study are as the followings. First, this study could find out that even though the evaluation elements on the three types for image evaluation were the same, the information acquisitions were different as those types varied. On the other hand, the change of the average run-time by type for the information acquisition was found not to be big, in other words, even though the run-time was alike, the information acquisitions varied depending on the type. Second, he evaluation by language media showed the average value by element had the order of [shape>position>number>existence] and the range of their run-time was 94.6~102.9 seconds. The average rate of information acquisition shown at the visual media had the order of [composition>shape>material&color] and the range of run-time was 93.1~99.7 seconds. Third, the evaluation by language media showed that for male subjects the range of information acquisition rate was 39.1~91.4% and that of run-time 85.1~106.0 seconds and for female ones 46.0~94.6% and 96.3~112.3 seconds respectively. In case of the visual media, male subjects showed the range of information acquisition rate was 40.3-66.7% and the range of run-time 82.4~97.9 seconds and the female ones, 42.2~71.0% and 94.0~115.1 seconds respectively, through which we could see that at the evaluation by language media and visual media both the female's range of information acquisition and that of observation time were higher than the male's.

• 한국전문물리치료학회지
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• 제17권3호
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• pp.1-10
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• 2010

The purpose of this study was to measure intra-rater and inter-rater reliability and range of motion for measurement of passive shoulder internal rotation range of motion and to compare anterior glide distance of humeral head in three methods. Fifty healthy subjects and fifty patients with shoulder musculoskeletal pain were recruited for this study. The subjects' passive shoulder internal rotation range of motion was measured by visual estimation, manual stabilization, and pressure biofeedback unit methods. In two trials, measurements were performed on each subject by two examiners. Intraclass correlation coefficient (ICC(3,1)) was used to determine the reliability of each measurement. The intra-rater reliability of the three methods was excellent (ICC=.77~.93) in both groups. The inter-rater reliability of the visual estimation method was poor (ICC=.20, .29), the manual scapular stabilization method was poor and fair (ICC=.09, .50), and the pressure biofeedback unit method was excellent (ICC .86, .75) in the experimental and control groups. In the experimental group, the difference of examined range of motion by each examiner was significant in the visual estimation method and manual scapular stabilization method, but there was an insignificant difference between the groups is the pressure biofeedback unit method. This result suggests that the intra-rater and inter-rater reliability of a pressure biofeedback unit was better than the other methods. The difference in distance of the anterior glide of humeral head was insignificant among all the methods. The pressure biofeedback unit method was the most reliable method, so it is proposed to be a new and reliable method to measure internal rotation range of motion.

• 한국실내디자인학회논문집
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• 제22권5호
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• pp.152-161
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• 2013

This study is about the visual appreciation by sex with the analysis of time range of observing data which was got through observation experiment with the space of lobby in hospitals. The observation data of the subjects who observed the space include the frequency and time, through which the process of visual appreciation could be evaluated with the definition of the frequency and the time of observation. First, the fact that men had higher frequency of observation than women means the former had more movement than the latter, and another fact of their fewer times can be understood as the time of their staying was shorter. That is, even though the men had more movements of sight, they showed the feature of staying shorter. Second, the rate high and low of observation frequency and times made it possible for observation characteristics to be defined as 'intensive search' 'active search' 'fixed concentration' and 'search wandering.' The definition of understanding this process of visual appreciation can be available for a frame of effective analysis of observation characteristics according to the passage of time. Third, the intense search is the case of 'high frequency' having the feature of high visual appreciation owing to the active visual actions for acquiring information. Men were found to have more intense search which decreased gradually as time passed, while women showed the feature of many times of intense search. Fourth, it was found that with many observation data in a certain range of time the subjects had fixed concentration, where women were found to have repetitive fixed concentration along with the change of observation time while men were seen to have more observation tendency for fixed concentration. Fifth, at the cross tabulation of frequency and times, men had the feature of dispersed visual appreciation while women had more distinction between fixation and movement, which revealed that there is surely the difference between men and women in the process of visual appreciation.

• 한국항해항만학회지
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• 제32권5호
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• pp.327-332
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• 2008

본 논문에서는 국내 무역항 항로에 배치되는 등부표의 최적 배치에 대한 기준을 설정하기 위한 기초자료로서 항해자들을 대상으로 등부표의 시인거리와 배치에 대한 선호를 분석하였다. 무역항의 각 규모를 감안하여 항만별로 약 $30{\sim}150$부의 설문지를 배포하였고, 총 356부의 유효한 설문지가 분석에 사용되었다. 육안으로 청명한 날씨의 주간에 부표를 인지하는 거리는 $2{\sim}4$마일이 55.0%로 가장 많았다. 부표의 배치방식에서는 양측 부표방식의 선호가 62.1%로써 가장 높았다 또한 부표의 전후사이의 선호 간격은 평균 1.09마일이었다 쌍안경 없이 시인할 수 있는 부표의 기수는 2기가 40.6%로 가장 선호되었다.

• 한국안광학회지
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• 제20권3호
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• pp.355-362
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• 2015

목적: 확산적 흐림의 투과율이 시력과 대비감도에 미치는 영향에 대하여 알아보았다. 방법: 평균연령 $22.83{\pm}0.50$세의 대학생 30명(남 13명, 여 17명)을 대상으로 Optec$^{(R)}$ 6500으로 시력과 대비감도를 측정하였다. 확산적 흐림의 도구로 백내장 시뮬레이터용 확산필름을 사용하였고, 백내장의 진행 정도나 안개의 농도가 반영될 수 있도록 확산적 흐림의 투과율을 변화시키면서 측정하였다. 결과: 시력과 확산적 흐림의 투과율은 비례식 $VA(T)=1.84{\times}10^{-2}T-0.65$으로 맞춤되었다. 대비감도는 모든 공간주파수에서 감소하였는데, 고공간주파수 대역에서의 대비감도가 더 큰 영향을 받아 정상범위를 먼저 벗어났고 대비감도의 정점은 저공간주파수 방향으로 이동하였다. 대비감도함수들의 교차점으로부터 대비감도가 정상범위를 벗어나는 확산적 흐림의 투과율 및 정점공간주파수의 이동을 산출한 결과, 투과율이 약 78.70%이 되면 대비감도의 정점이 6 cpd에서 3 cpd로 이동하는 것으로, 그리고 약 69.71%이 되면 모든 공간주파수에서의 대비감도가 정상범위를 벗어나는 것으로 평가되었다. 결론: 확산적 흐림의 투과율의 감소는 시력의 저하와 더불어 대비감도의 감소, 정상범위의 이탈 및 정점대비감도 이동 등을 유발시켜 시각적 불편함을 일으킨다는 점에서 백내장이나 안개 운전 시에는 더 많은 주의가 요구된다.

• Journal of Korean Neurosurgical Society
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• 제61권1호
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• pp.60-65
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• 2018

Objective : Choroidal metastases (CMs) are the most common intraocular tumor. Management is mainly radiation therapy with goals of pain control and visual improvement. However, many radiation-related complications are reported. Since gamma knife radiosurgery (GKS) for CM was first reported in 1995, few cases have been reported. We report 7 cases of CMs treated with GKS. Methods : From April 2011 to November 2014, 7 patients with CM underwent GKS. Their median age at treatment was 64 years (range, 51-71 years). Four males and three females were treated. Lung cancer was the most common primary pathology, followed by renal cell carcinoma and stomach cancer. Four patients had multiple cerebral lesions and were treated simultaneously for choroidal lesions. The median marginal dose of 20 Gy (range, 15-25 Gy) was administered at the 50% isodose line. Results : Median follow-up period after GKS was 8 months (range, 2-38.3 months). Four patients expired due to underlying malignancy progression. Except for two patients who were not followed with magnetic resonance image after GKS, all patients showed size reduction in the treated lesions, but a new choroidal lesion appeared in one patient and one recurred. Six of seven patients reported subjectively improved visual symptoms. Visual acuity improved in 2 patients, and 2 were stable upon objective examination. One patient showed no improvement in visual acuity, but ocular pain was relieved; another patient showed improved vision and tumor remission, but visual deterioration recurred. Conclusion : GKS was shown to be safe and effective and should be considered for CM treatment.

• 대한물리의학회지
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• 제7권4호
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• pp.509-514
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• 2012

PURPOSE: This study aims to compare the effects of upper backbone joint mobilization and self-stretching exercise in the patients with chronic neck pain. METHODS: Thirty seven patients with chronic neck pain were divides into self stretching group(SSG, n=18) and mobilization group(MG, n=19). To assess the degree of neck pain, the visual analog scale (VAS) was utilized, and to measure the joint range of motion at the flexion-extension, it was compared and analyzed by using the cervical range of motion (CROM) device. RESULTS: The joint range of motion and visual analog scale of SSG and MG showed significant effects on both groups. In the comparison of groups, there was no significant difference, but it indicated effects on improving the pain and the range of joint motion in MG. CONCLUSION: According to the analysis, not only self-stretching exercise intervening for direct treatment but also upper backbone joint mobilization intervening for indirect treatment are effective to improve the pain and the range of motion.