• Title/Summary/Keyword: visual distance

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Influence of Visual Feedback Training on the Balance and Walking in Stroke Patients

  • Lee, Kwan-Sub;Choe, Han-Seong;Lee, Jae-Hong
    • The Journal of Korean Physical Therapy
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    • v.27 no.6
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    • pp.407-412
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    • 2015
  • Purpose: This study aimed to evaluate changes in the balance ability of patients whose head positions were altered due to stroke. Subjects were divided into three groups to determine the effects of the training on dynamic balance and gait. Methods: Forty-two stroke patients were enrolled. The Visual Feedback Training (VFT) group performed four sets of exercises per training session using a Sensoneck device, while the Active Range of Motion (ART) group performed eight sets per training session after receiving education from an experienced therapist. The Visual Feedback with Active Range of Motion (VAT) group performed four sets of active range of motion and two sets of visual-feedback training per session using a Sensoneck device. The training sessions were conducted three days a week for eight weeks. Results: The comparison of changes in dynamic balance ability showed that a significant difference in the total distance of the body center was found in the VFT group (p<0.05) and Significant differences were found according to the training period (p<0.05). The comparison of the 10 m walk test showed that the main effect test, treatment period and interactions between group had statistically significant differences between the three groups (p<0.05). Conclusion: Head-adjustment training using visual feedback can improve the balance ability and gait of stroke patients. These results show that coordination training between the eyes and head with visual feedback exercises can be used as a treatment approach to affect postural control through various activities involving the central nervous system.

The Effects of Sports Vision Training on Baseball Player's Visual Performance and Baseball Records (스포츠비젼 트레이닝이 시기능 및 야구성적에 미치는 영향)

  • Lee, Min-A;Oh, Jae-Man;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.1
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    • pp.87-97
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    • 2010
  • Purpose: The purpose of this study is to investigate the effects of sports vision training on baseball player's visual performance and baseball records. Methods: All subjects were 21 males of high school baseball players, and they participated on eight weeks of sports vision training program. Pre- and post- test results were obtained for static and dynamic visual acuity, static and dynamic stereo acuity, distance and near phoria, fusional reserves, near point of convergence, contrast sensitivity, visual-reaction time. Results: Statical analysis indicated significant improvement in most of mentioned visual variables and baseball records (p<0.001). Conclusions: It can be concluded that the sports vision training program improves visual skills of baseball players, which could lead to improvement in the baseball records. Vison training will be a promotor for baseball player to enhance their performance if proper test instruments and training course is supplied.

Development of Processing System for Audio-vision System Based on Auditory Input (청각을 이용한 시각 재현 시스템의 개발)

  • Kim, Jung-Hun;Kim, Deok-Kyu;Won, Chul-Ho;Lee, Jong-Min;Lee, Hee-Jung;Lee, Na-Hee;Yoon, Su-Young
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.25-31
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    • 2012
  • The audio vision system was developed for visually impaired people and usability was verified. In this study ten normal volunteers were included in the subject group and their mean age was 28.8 years old. Male and female ratio was 7:3. The usability of audio vision system was verified by as follows. First, volunteers learned distance of obstacles and up-down discrimination. After learning of audio vision system, indoor and outdoor walking examination was performed. The test was scored by ability of up-down and lateral discrimination, distance recognition and walking without collision. Each parameter was scored by 1 to 5. The results were 93.5 +- SD(ranges, 86 to 100) of 100. In this study, we could convert visual information to auditory information by audio-vision system and verified possibility of applying to daily life for visually impaired people.

A Study on the Spatial Characteristics from the "The Holy Trinity" Fresco Painted by Masaccio (마사치오의 "삼위일체" 벽화에서 나타난 공간적인 특성에 관한 연구)

  • Kim, Seok-Man
    • Journal of architectural history
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    • v.22 no.6
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    • pp.7-22
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    • 2013
  • The purpose of this paper is to study on the spatial characteristics from the "The Holy Trinity" fresco painted by Masaccio in the early Renaissance paintings. The results of this study are as follows. 1. The elevation composition of the "The Holy Trinity" fresco is divided into the upper and lower structure through horizontal axis on horizontal line around vanishing point. The upper structure is composed of vertical axis formed through the disposition of the "Trinity" elements and horizontal axis on horizontal line. The lower structure is composed of the sarcophagus and skeleton in such inside and the altar supported through circular columns of left and right. 2. The section composition of the "The Holy Trinity" fresco is composed of the ceiling structure of cylindrical-shaped vault on upper part around basic square floor plan that is interior space and upper structure. The exterior space and lower structure is placed with sarcophagus in inner part that altar and step is projected as same height and width in the outside direction. 3. The basic floor composition of the "The Holy Trinity" fresco is planned by square shape around structural columns that is placed at corners as symmetry through transverse, longitudinal and diagonal axis. The whole floor composition planned through the altar and step that is in exterior space at front, the apse of round form at rear part and the structure of the middle story concept at interior. 4. The visual aspect of the "The Holy Trinity" fresco is composed of the stable balance in relation with distance and height because the interior and exterior space as well as the upper structure and lower structure is formed by regular proportion system. The elevation angle of visual range was planned to view in detail generally or partially the architectural composition system and element, characters through proper visual distance, center and position.

Modified Speeded Up Robust Features(SURF) for Performance Enhancement of Mobile Visual Search System (모바일 시각 검색 시스템의 성능 향상을 위하여 개선된 Speeded Up Robust Features(SURF) 알고리듬)

  • Seo, Jung-Jin;Yoona, Kyoung-Ro
    • Journal of Broadcast Engineering
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    • v.17 no.2
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    • pp.388-399
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    • 2012
  • In the paper, we propose enhanced feature extraction and matching methods for a mobile environment based on modified SURF. We propose three methods to reduce the computational complexity in a mobile environment. The first is to reduce the dimensions of the SURF descriptor. We compare the performance of existing 64-dimensional SURF with several other dimensional SURFs. The second is to improve the performance using the sign of the trace of the Hessian matrix. In other words, feature points are considered as matched if they have the same sign for the trace of the Hessian matrix, otherwise considered not matched. The last one is to find the best distance-ratio which is used to determine the matching points. We find the best distance-ratio through experiments, and it gives the relatively high accuracy. Finally, existing system which is based on normal SURF method is compared with our proposed system which is based on these three proposed methods. We present that our proposed system shows reduced response time while preserving reasonably good matching accuracy.

A Study on the Visual System of the Digital Periapical Images (디지털 치근단방사선영상에 관한 시각 특성 연구)

  • Choi Eun-Suk;Koh Kwang-Joon
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.1
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    • pp.261-274
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    • 1999
  • Objectives: The purpose of this study was to evaluate the optimal distance and angle of observers by modulation transfer functions(MTFs) and receiver operating characteristics(ROCs), Material and Methods: Digital periapical radiograms were taken from 43 patients who have dental diseases(19 patients : dental caries. 12 patients : periapical lesions, 12 patients : periodontal diseases). Segmental images(4×4cm) were evaluated by 4 MTFs and ROC analysis. Results: The optimal distance(magnification) using MTF by Mannos & Sakrison was 12.97. and those by Nill. Ngan and Rao were 8.39, 4.78. 5.84 respectively. The optimal distance obtained from 4 radiologists by ROC analysis was 32cm(Az value: 0.89). and it was 40cm(Az value: 0.78) from 4 non-radiologists. There were significant differences of Az values between 4 radiologists and 4 non-radiologists at 24. 32 and 40cm (P<0.05). No significant differences of optimal distances were observed using 4 MTFs among +20, +10, 0, -10, -20 degrees(P>0.05). The optimal angle obtained from 4 radiologists by ROC analysis was +20 degree(Az value: 0.91). and no significant differences of Az values were observed among +20, +10, 0, -10 and -20 degrees(P>0.05). The optimal angle obtained from 4 non-radiologists by ROC analysis was 0 degree(Az value : 0.81). and no significant differences of Az values were observed among +20, +10, 0, -10 and -20 degrees(P>0.05). And there was significant difference of Az value between 4 radiologists and 4 non-radiologists at +20 degree(P<0.05). but no significant differences of Az values were observed among +10, 0, -10 and -20 degrees(P>0.05).

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Implementation of Stereoscopic 3D Video Player System Having Less Visual Fatigue and Its Computational Complexity Analysis for Real-Time Processing (시청피로 저감형 S3D 영상 재생 시스템 구현 및 실시간 처리를 위한 알고리즘 연산량 분석)

  • Lee, Jaesung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.12
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    • pp.2865-2874
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    • 2013
  • Recently, most of movies top-ranked in the box office are screening in Stereoscopic 3D, and the world's leading electronics companies such as Samsung and LG are getting the hots for 3DTV sales. However, each person has different binocular disparity and different viewing distance, and thus he or she feels the severe visual fatigue and headaches if he or she is watching 3D content with the same binocular disparity, which is very different from things he or she feels in the real world. To solve this problem, this paper proposes and implement a 3D rendering system that correct the disparity of 3D content by reflecting binocular distance and viewing distance. Then, the computational complexity is analyzed. Optical-flow and Warping algorithms turn out to consume 732 seconds and 5.7 seconds per frame, respectively. Therefore, a dedicated chip-set for both blocks is strongly required for real-time HD 3D display.

Comparison and Analysis for the Effects of Functional Progressive Addition Lenses on Binocular Vision of University Students (기능성 누진가입도렌즈가 대학생들의 양안시기능에 미치는 영향 비교 분석)

  • Kim, Chang Jin;Kim, Hyun Jung;Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.1
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    • pp.105-116
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    • 2010
  • Purpose: To analyze and compare differences between single vision lenses and functional progressive addition lenses and improvement to binocular visual function wearing functional lenses for pre-presbyopes altered their single vision lenses to functional progressive addition lenses with low addition. Methods: Healthy 32 subjects aged 24.03${\pm}$1.87 (male 23, female 9) who were recruited from university students wore functional progressive addition lenses (EYE-T, Chemilens Co., Korea, ADD 0.750) for 2 months. Objective refraction, corrected visual acuity at distance and near, near point of convergence, near point of accommodation, accommodative facility, phoria at distance and near were measured. And subjective satisfaction was investigated by using a questionnaire designed to fatigue, comfort, discomfort, overall satisfaction and preference. Results: Functional progressive addition lenses were better than single vision lenses at near point of convergence and accommodation, accommodative facility. Exo phoria measured at distance with single vision and functional progressive addition lenses. Exo phoria measured at near with functional progressive addition lenses was higher than that with single vision lenses. As a survey, the satisfaction was increased in questions related near work. However, single vision lenses were preferred in distance test of overall satisfaction, easy 10 adapt, lime to adapt. A survey showed thai preference of functional progressive addition lenses were increased 75.00% to 81.26% for near work, 50.00% to 65.63% for visual fatigue, 47.75% to 50.00% for visual comfort and 31.25% to 46.88% for overall comfort. Conclusions: Comparing between single vision lenses and functional progressive addition lenses, binocular visual function related near work, subjective satisfaction and preference was improved after wearing functional progressive addition lenses. This study suggested that functional progressive addition lenses were useful for long time near work.

The Effects of 4-Week Serratus Anterior Strengthening Exercise Program on the Scapular Position and Pain of the Neck and Interscapular Region

  • Kim, Duck-Hwa;Kwon, Oh-Yun;Yi, Chung-Hwi;Jeon, Hye-Seon
    • Physical Therapy Korea
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    • v.14 no.4
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    • pp.58-65
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    • 2007
  • The purpose of this study was to investigate the effects of serratus anterior strengthening exercises on scapular position and Visual Analog Scale (VAS) pain measurements taken at the resting position in young adults with adducted scapular. The exercise program included stretching of the scapular retractor and strengthening of the serratus anterior muscle. We measured the distance from the midline of the thorax to the vertebral border of the scapular with a tape line (Superior Kibler), and the distance from the 7th cervical spinous process to the acromial angle with 3-dimension motion analysis system, to compare the resting scapular position before and after exercise. Fifteen subjects with adducted scapular were recruited to compare the resting scapular position and VAS. The distance from 7th cervical spine process to acromial angle of the scapular and VAS decreased significantly (p<.01) after exercise, while the distance from the midline of the thorax to vertebral border of the scapular increased (p<.05). The conclusion is that the serratus anterior exercise program altered the resting scapular position and decreased VAS.

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Weighted Distance De-interlacing Algorithm Based on EDI and NAL (EDI와 NAL 알고리듬을 기반으로 한 거리 가중치 비월주사 방식 알고리듬)

  • Lee, Se-Young;Ku, Su-Il;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.9C
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    • pp.704-711
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    • 2008
  • This paper proposes a new de-interlacing method which results in efficient visual improvement. In the proposed algorithm, the distance weight was considered and the previously developed the EDI (Edge Dependent Interpolation) algorithm and the NAL (New Adaptive Linear interpolation) algorithm were used as a basis. The do-interlacing method was divided into two main parts. First, the edge direction was found by using information of closer pixels. Then, missing pixels were interpolated along with the decided edge direction. In this paper, after predicting the edge through the EDI algorithm, missing pixels were interpolated by using the weighted distance based on the NAL algorithm. Experimental results indicate that the proposed algorithm be superior to the conventional algorithms in terms of the objective and subjective criteria.