• Title/Summary/Keyword: Visual fixation

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The Study of Visual Fatigue by Monitor Letter Contrast with an Eye Tracker (아이트래커를 이용한 모니터 글자 대비도에 따른 눈의 피로도 연구)

  • Kim, Ha-Rim;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.4
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    • pp.533-538
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    • 2014
  • Purpose: This study is to investigate correlation between eye fatigue and letter contrast according to letter contrast changes on monitor display. Methods: Reading speed test were carried out for 53 subjects (mean age: $22.68{\pm}1.85$ years) who have over Best-corrected visual acuity (BCVA) 1.0, and 45 subjects, who could read over 123 out of 163 letters among 53 subjects were selected. They were asked to read the letters which were composed of Black (contrast 100%), Dark gray (contrast 80%), Gray (contrast 80%), Light gray (contrast 30%) randomly. The change of their eye fatigue by letter contrast on monitor display was measured by monitoring their eyes with an eye-tracker while they were reading letters. Results: Event Duration (sec) was 33.635 for Black, 32.266 Dark gray, 33.936 for Gray, and 34.848 for Light gray. Average of Fixation Duration (sec) was 0.224 for Black, 0.218 for Dark gray, 0.239 for Gray and 0.243 for Light gray. Average of Pupil diameter (mm) was 41.133 mm for Black, 41.160 mm for Dark gray, 40.880 mm for Gray and 40.459 mm for Light gray. Frequency (blinks/sec) was 0.211 for Black, 0.206 for Dark gray, 0.221 for Gray, and 0.238 for Light gray. Conclusions: Event Duration and average of Fixation Duration were the shortest for Dark gray and the longest for Light gray. In average Pupil diameter was the biggest Dark gray and the smallest for Light gray. Blink Frequency (blinks/sec) was the lowest for Dark gray and the highest for Light gray. Visual fatigue by brightness of letters on monitor display was the least for Dark gray followed by Black, Gray and Light gray.

Operative Treatment of Displaced Proximal Humerus Fractures with the Angular Stable Locking Compression Plate (각안정 잠김 압박 금속판을 이용한 전위된 근위 상완골 골절에 대한 수술적 치료)

  • Kim, Dong-Wook;Kim, Chong-Kwan;Jung, Sung-Won;Kim, Hyeon-Soo
    • Clinics in Shoulder and Elbow
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    • v.14 no.1
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    • pp.27-34
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    • 2011
  • Purpose: We examined the clinical and radiological outcomes for displaced proximal humerus fractures that were treated with a PHILOS angular stable plate. Materials and Method: Forty four patients who underwent surgery between March 2007 and February 2010 were included in this study. All the cases were followed up for an average of 12 months. All the patients were examined and interviewed using the Visual Analog Scale (VAS) score, the Constant score and standardized X-rays to check the neck-shaft angle (NSA) and the presence of medial support. Results: The average Visual Analog Scale score was 2.8 points and the average Constant score was 70.5 points. The average neck shaft angle was $122.5^{\circ}$ and this was statistically significant between the good result group and the poor result group. There were 36 cases of the presence of medial support and 8 cases of the absence of medial support and the difference was statistically significant. Complications such as fixation failure happened in 12 cases. Conclusion: PHILOS angular stable plate fixation as an operative treatment for displaced proximal humerus fractures is a good and reliable treatment option.

Characteristics of the Process of Visual Attention during Spatial Depth Perception (공간의 깊이감 지각과정에 나타난 시각정보획득 특성)

  • Kim, Jong-Ha;Cho, Ji Young
    • Science of Emotion and Sensibility
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    • v.21 no.1
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    • pp.115-128
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    • 2018
  • Understanding the process of spatial perception plays a significant role in the design process as well as in the use of actual spaces. The perception of spatial depth can vary according to the space composition and design even there is no change in the actual size of the space. The properties of 3-dimensional space are its width, height, and depth; however, compared to the perception of spatial width and height, little research and theories exist on spatial depth perception. The reasons may be there less interest lies in the effect of spatial depth perception than that of spaciousness or height of space. This study is an investigation of the process of spatial depth perception using an eye-tracking device with stimuli developed through Computer Graphics. A total of 44 interior design major students participated in the eye tracking experiment; and they looked at three images comprised of an identical room with only changes in the rear wall condition. The results show that a significant difference in the fixation duration per stimulus exists. In addition, a significant difference exists on the fixation duration per stimulus according to the participants' answer of the deepest space. The result of this study can help identify factors for spatial depth perception, validate the assumption on it, and provide knowledge on how to acquire desirable spatial depth by utilizing the research result.

A Study of Legibility by Monitor Letter Color with an Eye Tracker (아이트래커를 이용한 모니터 글자 색상에 따른 가독성에 대한 연구)

  • Kim, Ha-Rim;Kim, Soo-Hyun;Shin, Dong-Min;Jeong, Hee-Young;Kim, Young-Gil;Kim, Tae-Hong;Seo, Jae-Myoung;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.2
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    • pp.279-284
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    • 2014
  • Purpose: This study will be a basic research providing data which can reduce eye strain using monitor and electric media by measuring legibility of text color on monitor. Methods: Total experimental subjects who don't have color anomaly and best corrected visual acuity was over 1.0 were 50 and their mean age was $22.83{\pm}1.47$. Reading speed test were carried out with 163 words and subjects who could read over 123 words were selected for legibility examination. Monitor background color was white and letter colors were black, blue, red, and yellow for the legibility examination. Results: In case of text color of black, blue, red, and yellow, Event duration(sec) was measured to 41.89, 42.89, 45.32, and 56.28, respevtively, and reading error (number) was measured to 1.94, 2.74, 3.36, and 5.14. Average of fixation duration(sec) was measured to 0.25, 0.26, 0.27, and 0.32. Conclusions: In this paper, event Duration, reading error and average of fixation duration which can measure the legibility was reduced in a sequence of black blue, red, and yellow.

Short-Term Results of Subpectoral Tenodesis of the Proximal Biceps Tendon Using by Interference Screw (간섭나사를 이용한 흉근하 상완 이두근 건 고정술의 단기 추시 결과)

  • Kim, Jeong-Woo;Kang, Hong-Je
    • Clinics in Shoulder and Elbow
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    • v.13 no.1
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    • pp.7-13
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    • 2010
  • Purpose: Our purpose was to retrospectively analyze clinical results of subpectoral tenodesis of the proximal biceps tendon using an interference screw. Materials and Methods: We reviewed 23 cases of patients receiving tenodesis of the proximal biceps tendon between January 2008 and January 2009 for whom we had follow-up data for at least 1 year. Twenty-three cases were operated on using subpectoral tenodesis; 16 of these cases had a rotator cuff tear. The results were judged using a visual analog scale (VAS), ASES, tenderness on the biceps groove, fixation failure and the degree of deformity (BAD). Results: VAS and ASES scores were significantly improved in all patients by the time of the final observation. There were no significant complications or fixation failures. The patients without a tear of the rotator cuff had a better result than patients with a tear of the rotator cuff, but the difference between the two groups was not significant (p>0.05). Conclusion: In patients with pathology of the long head of the biceps brachii, benefits of subpectoral interference screw tenodesis include pain relief, maintenance of functional biceps, muscle strength, and cosmesis. Subpectoral biceps tenodesis using interference screw fixation appears to be a promising, reproducible, reliable technique for addressing anterior shoulder pain related to pathology of the long head of the biceps brachii.

A study on the Estimation of Observation amount and the Analysis of observation characteristics depending on the change of observation degree In Housing Space (주거공간에 있어 주시정도 변화에 따른 주시특성의 분석과 추정에 관한 연구)

  • Ban, Young-Sun;Kim, Jong-Ha
    • Korean Institute of Interior Design Journal
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    • v.21 no.1
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    • pp.95-102
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    • 2012
  • This study analyzed the observation characteristics with the subject of observation data through defining the change of the observation degree as attention /conscious observation /visual understanding. Furthermore, by obtaining the formular with which to estimate the subjects' observation amount, this study suggests a potential method for easier analysis of observation characteristics. The conclusions from the study are as the followings. First, the observation frequency was being generated with wide deviation among subjects while there was a flow-on characteristics depending on the degree of observation. These characteristics enabled the study to obtain the formular with which to estimate the observation amount. Second, the study could establish the area frequency by grade from the entire observation data. The area I was at most 4% for the area frequency but accounted for 18.2% of the entire effective observation time, and the area II 16% and 38.7% respectively. Accordingly, only considering the observation area distribution of the area I or the areas I and II shows which position of the space the subjects were observing. Third, with the subject of the relatively higher observation time at at the subject's observation characteristics, as the observation phase was getting higher, the observation time decreased more. Forth, by obtaining the formular to estimate the observation amount for observation data according to the change of observation degree, the study could find the estimating observation characteristics of additional subjects. The formular shortens the analysis time and facilitates the analysis process.

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A Study on perceptive characteristics of space type through comparative evaluation on the image rotation of Interior Space (실내공간의 이미지 전회비교 평가를 통한 공간유형별 지각특성에 관한 연구)

  • Choi, Gae-Young;Kim, Jong-Ha;Lee, Sang-Keun
    • Korean Institute of Interior Design Journal
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    • v.19 no.6
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    • pp.179-187
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    • 2010
  • For the user-centered interior space design, a designer needs to carefully focus on the details from which the user must keenly observe or concentrate on the space and how to deliberately check the image of the space. Following this view, for the user-centered interior space design this study analyzes the way which the space is represented from the perspective of the image assessment. The results obtained from this study are summarized as follows: First, this study analyzed the characteristic of space image change in the form of cross-comparison between one space and a rotated space. With analyzing of an eye fixation by showing the space, the space images of "concentration-dispersion" and "strengthening-weaken "have an important role in the analysis of the perception of space. it confirmed that the method of space perception was changed by rotated the space. Second, With changing quantities of image and extraction of deviation from adjective in survey, it quantitatively graps that respondents of feel in space perception by changing the space and "concentration" and 'dispersion" for process of space choice. The results of the research can provide important basis to judge the changing of space perception by visual perception. Third, through the analysis of image change rate and deviation rate, the characteristics of image change with space change can be analyzed. The results derived from the study provide the evidence to support the image change by space rotating.

Clinical Application and Effects of Sodium Hyaluronate-Carboxymethylcellulose (Guardix®) in Surgery of Ankle Fractures (족관절 골절 수술에서의 유착방지제(Guardix®)의 효과 연구)

  • Kim, Gab Lae;Kwon, Hwan Jin
    • Journal of Korean Foot and Ankle Society
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    • v.21 no.4
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    • pp.151-155
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    • 2017
  • Purpose: Reducing tenderness or pain on the ankle joint and improving the range of motion are thought to be possible using hyaluronate-based anti-adhesive agents. On the other hand, there are more aspects to be studied regarding the incidence of complications, such as resting pain, tenderness, and stiffness, after surgery. Therefore, the aim of this study was to prove the effectiveness of the agents after ankle fracture surgery. Materials and Methods: Patients, who underwent open reduction and internal fixation surgery due to ankle joint fractures from June 2015 to May 2016, were studied prospectively. Thirty patients of them received a $Guardix^{(R)}$ injection during their surgeries and were included in the injection group. The other 30 patients were included in the control group. Postoperatively, tenderness on the scar, a delay in wound healing, and the active range of motion were evaluated at 2, 6, and 12 weeks after surgery. Results: A significant difference in tenderness on the scar was observed 2 weeks after surgery. On the other hand, there was no significant difference at 6 and 12 weeks after the surgery. The agent-using group showed a 6.7% delay in wound healing and a 93.3% nondelaying. In the non-using group, the delay was 63.3%, while non-delay was 36.7% (p<0.001). The group that underwent $Guardix^{(R)}$ usage showed an effective result in the visual analogue scale, which was statistically significant (p<0.001). The result at 6 and 12 weeks after surgery showed a significant difference. Conclusion: Improvement was observed in the patients who underwent a $Guardix^{(R)}$ injection, regarding the range of motion, visual analog scale, and healing of the wound postoperatively.

Spatial Structure Analysis of View Angle Correction reflecting Characteristics of Universal Observation (보편적 주시특성을 반영한 시야각 보정 공간구조 분석)

  • Kim, Suk-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6917-6924
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    • 2015
  • The universal nature of humans is formed by the view angle and the visibility range. However, the majority of theories on spatial structure analysis based on the visual perception do neither reflect the view angle nor consider only the flat view angle. Some theories that reflect them is a theory where the part included in the view angle and the part excluded in the view angle have been separated in a dichotomous way, excluding the universal characteristics of humans. This study applied an observing probability to a 3-D visibility analysis theory by conducting a eye-tracking experiment, empirically determining the limits of the field of view, and deriving the observing probability by view angle. In addition, it attempted to identify the probability by manufacturing an application of spacial, visual perception analysis and applying the concept of multiple frustum culling. For the characteristics of observation, the data were measured and collected regarding the walking course for 3 minutes for an optional space, aimed for 33 people as subjects. Subsequently, the data were prepared by analyzing the observation fixation frequency probability.

The Prevalence of Computer Software for Investigations of Eye Problems among Computer Users (컴퓨터 사용자의 눈 문제 조사를 위한 소프트웨어의 유용성)

  • Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.1
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    • pp.17-26
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    • 2006
  • Video display units (VDU) are interfaces between computers and human operators. This study was performed to have a good understanding of the potential causes of eye problems in 50 students to enable them to perform an accurate assessment of the patient's visual performance while looking at a computer screen. The TSS Optometric Toolkit for Computer Users provides a powerful set of tools to enable eye care practitioners to assess visual performance under conditions that closely simulate a computer user's normal working conditions. The program consists of seven tests: Near vision chart, Sample text display, Spreadsheet display, Fixation disparity, Duochrome, Number search, Randolt Ring search. The results of this study show that 55% of the subjects do not have computer-related eye problems. It is apparent from this data that approximately 25% of all computer-related eye problems are attributable to the display screen, the workstation or inappropriate workpractices. Of the remaining cases, 20% of them will require general purpose spectacles and spectacles specifically for work at the computer. This study suggests that computer program, The TSS Optometric Toolkit for Computer Users, is very useful for assessment of computer-related eye problems.

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