• Title/Summary/Keyword: Visual Methods

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Effects of Low Visual Acuity Simulations on Eye-Hand Coordination and Brainwaves in Healthy Adults

  • Woo, Hee-Soon;Song, Chiang-Soon
    • Physical Therapy Rehabilitation Science
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    • v.11 no.3
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    • pp.296-303
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    • 2022
  • Objective: In general, macular degeneration, cataracts and glaucoma generally cause visual injury in clinical settings. This study aimed to examine the effects of low visual acuity simulations on hand manual dexterity function and brainwaves in healthy young adults. Design: Cross-sectional study design Methods: This study was an observational, cross-sectional study. Seventy healthy young adults participated in this study. To evaluate the effects of low visual acuity simulations on hand function and brain waves, this study involved four different visual conditions including (1) normal vision, (2) simulated cataracts, (3) simulated glaucoma, and (4) simulated macular degeneration. The hand function was measured to use the Minnesota manual dexterity test (MMDT), and the brainwaves was also measured to use the electroencephalography. Results: In hand function, placing and turning performance on the MMDT in the normal visual condition was significantly different than that in the cataract and macular degeneration conditions (p<0.05), and the placing performance was significantly differred in the normal condition than that in the simulated glaucoma. However, turning was not significantly different in the normal condition than that in the simulated glaucoma. The alpha, beta, and gamma waves did not significantly differ among the four visual conditions (p>0.05). Conclusions: The results suggest that limited visual information negatively affects the ability to perform tasks requiring arm-hand dexterity and eye-hand coordination. However, the effectiveness of low visual acuity on the brainwaves should be further studied for rehabilitative evidence of visual impairment.

An Optimal Method to Improve the Visual Quality of Medical Images

  • Shin, Choong-ho;Jung, Chai-yeoung
    • Journal of Integrative Natural Science
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    • v.8 no.2
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    • pp.141-144
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    • 2015
  • As the visual quality of X-ray images is a critical reference for the accuracy of the clinical diagnosis, the methods to improve the quality of X-ray images have been investigated. Among many existing methods, using frequency domain filter is a very powerful method to improve the visual quality of images. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the subjected image. The medical X-ray images using the optimal high pass filter has shown improved edges. Further, the optimal high frequency emphasis filter has shown the improved contrast of flat areas by using the result image from the optimal high pass filter. Also the resulting images of the global contrast have improved by the histogram equalization. As a result, the proposed methods have shown enhanced contrast and edges of the images with noise canceling effect.

Posture Stabilization Control for Mobile Robot using Marker Recognition and Hybrid Visual Servoing (마커인식과 혼합 비주얼 서보잉 기법을 통한 이동로봇의 자세 안정화 제어)

  • Lee, Sung-Goo;Kwon, Ji-Wook;Hong, Suk-Kyo;Chwa, Dong-Kyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1577-1585
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    • 2011
  • This paper proposes a posture stabilization control algorithm for a wheeled mobile robot using hybrid visual servo control method with a position based and an image based visual servoing (PBVS and IBVS). To overcome chattering phenomena which were shown in the previous researches using a simple switching function based on a threshold, the proposed hybrid visual servo control law introduces the fusion function based on a blending function. Then, the chattering problem and rapid motion of the mobile robot can be eliminated. Also, we consider the nonlinearity of the wheeled mobile robot unlike the previous visual servo control laws using linear control methods to improve the performances of the visual servo control law. The proposed posture stabilization control law using hybrid visual servoing is verified by a theoretical analysis and simulation and experimental results.

Acupuncture Treatment of a Child with Astigmatism and Visual Impairment (난시와 시력장애를 동반한 소아에 대한 침치료 1례 보고)

  • Heo, Jin;Jeong, Ju-Hyun;Lee, Byung-Ryul;Yang, Gi-Young;Kim, Young-Il
    • Journal of Acupuncture Research
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    • v.25 no.5
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    • pp.191-195
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    • 2008
  • Objectives : To estimate clinical effect of acupuncture treatment for astigmatism and visual impairment. Methods : Acupuncture treatment was performed on a young child, diagnosed as astigmatism and visual impairment from 23th May 2008 through 23th July 2008. Visual acuity and astigmatism were measured before and after treatment. Results : Visual acuity and astigmatism were improved after acupuncture treatment. Conclusions : This case demonstrates that acupuncture treatment has clinical possibilities for improving astigmatism and visual impairment and future studies will be required.

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Visual Preference in Green Roof Sites (옥상 녹화지의 시각적 선호도)

  • Lee, Gwan-Gyu
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.5 s.118
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    • pp.32-38
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    • 2006
  • Roof greening in a city can contributes to not only providing network opportunities for dispersed greenspace patches but also bringing more greenspaces into a city. In addition, it can help to flooding and microclimate control in the city. Recently, a number of roof greening projects have been introduced, mainly to public buildings and schools. Roof peening need to offers both ecological functions and convenience and satisfaction for urban residents. This study aims to provide directions for improving ecological benefits and visual preference of roof greening. Twelve scene slides were adopted to measure people's visual preference. The survey results show that landscape images can be categorized into naturalness, visual diversity, uniqueness, and spatial flexibility. Physical scenes can be classified into type I mostly greened by plants, type II mixed between convenience facilities and plants, and type III constructed with pond. People show high preferences to type I and type II when visual diversity is high. The results of this study suggest to enhance the visual preference by considering visual diversity when applying the ecological design methods to improve naturalness for roof greening.

Muscle Activity Based on Real-time Visual Feedback Training Methods by Rehabilitative Ultrasound Image in Elderly and Relationship between Heckmatt Scale, Muscle Thickness and Tone : A Pilot Study

  • Shin, Janghoon;Lee, Wanhee
    • Physical Therapy Rehabilitation Science
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    • v.10 no.1
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    • pp.82-89
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    • 2021
  • Purpose: This study is to investigate the muscle activity based on real-time visual feedback training methods by rehabilitative ultrasound image in elderly and correlation between Heckmatt scale grade, muscle tone and thickness. Design: Cross-sectional study: Pilot study Methods: 6 elderly participated in the study with 2 conditions. Under the condition of rehabilitation ultrasound imaging equipment, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using visual feedback based on Rehabilitative Ultrasound Imaging 1.0 (RUSI 1.0). Under the condition of only ultrasound images, all subjects performed voluntary maximal muscle contraction of the quadriceps 3 times using ultrasound image-based visual feedback. The muscle thickness and tone of the quadriceps were measured and the grades were classified by Heckmatt scale and all variables were comparative analyzed. Results: Heckmatt scale grade showed a negative correlation with muscle thickness at relaxation (p<0.05), and a negative correlation with the difference value obtained by subtracting muscle thickness at relaxation from muscle thickness at contraction in ultrasound image condition (p<0.05). The muscle tone during relaxation showed a negative correlation with the muscle thickness during relaxation (p<0.05). Conclusion: In the case of voluntary maximum muscle contraction of the quadriceps muscle in the elderly, it can be seen that the muscle thickness is getting larger when the RUSI 1.0-based visual feedback is provided than with only ultrasound image provided. And the lower Heckmatt scale grade is, the thicker the muscle is, and the lower the muscle tone is.

Comparison of two different methods of detecting residual caries

  • Vural, Uzay Koc;Kutuk, Zeynep Bilge;Ergin, Esra;Cakir, Filiz Yalcin;Gurgan, Sevil
    • Restorative Dentistry and Endodontics
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    • v.42 no.1
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    • pp.48-53
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    • 2017
  • Objectives: The aim of this study was to investigate the ability of the fluorescence-aided caries excavation (FACE) device to detect residual caries by comparing conventional methods in vivo. Materials and Methods: A total of 301 females and 202 males with carious teeth participated in this study. The cavity preparations were done by grade 4 (Group 1, 154 teeth), grade 5 (Group 2, 176 teeth), and postgraduate (Group 3, 173 teeth) students. After caries excavation using a handpiece and hand instruments, the presence of residual caries was evaluated by 2 investigators who were previously calibrated for visual-tactile assessment with and without magnifying glasses and trained in the use of a FACE device. The tooth number, cavity type, and presence or absence of residual caries were recorded. The data were analyzed using the Chi-square test, the Fisher's Exact test, or the McNemar test as appropriate. Kappa statistics was used for calibration. In all tests, the level of significance was set at p = 0.05. Results: Almost half of the cavities prepared were Class II (Class I, 20.9%; Class II, 48.9%; Class III, 20.1%; Class IV, 3.4%; Class V, 6.8%). Higher numbers of cavities left with caries were observed in Groups 1 and 2 than in Group 3 for all examination methods. Significant differences were found between visual inspection with or without magnifying glasses and inspection with a FACE device for all groups (p < 0.001). More residual caries were detected through inspection with a FACE device (46.5%) than through either visual inspection (31.8%) or inspection with a magnifying glass (37.6%). Conclusions: Within the limitations of this study, the FACE device may be an effective method for the detection of residual caries.

Object Classification based on Weakly Supervised E2LSH and Saliency map Weighting

  • Zhao, Yongwei;Li, Bicheng;Liu, Xin;Ke, Shengcai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.1
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    • pp.364-380
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    • 2016
  • The most popular approach in object classification is based on the bag of visual-words model, which has several fundamental problems that restricting the performance of this method, such as low time efficiency, the synonym and polysemy of visual words, and the lack of spatial information between visual words. In view of this, an object classification based on weakly supervised E2LSH and saliency map weighting is proposed. Firstly, E2LSH (Exact Euclidean Locality Sensitive Hashing) is employed to generate a group of weakly randomized visual dictionary by clustering SIFT features of the training dataset, and the selecting process of hash functions is effectively supervised inspired by the random forest ideas to reduce the randomcity of E2LSH. Secondly, graph-based visual saliency (GBVS) algorithm is applied to detect the saliency map of different images and weight the visual words according to the saliency prior. Finally, saliency map weighted visual language model is carried out to accomplish object classification. Experimental results datasets of Pascal 2007 and Caltech-256 indicate that the distinguishability of objects is effectively improved and our method is superior to the state-of-the-art object classification methods.

Factors Associated with Poor Self-rated Health according to Visual Impairment Severity

  • Jeon, Eunyoung
    • Journal of Korean Public Health Nursing
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    • v.35 no.1
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    • pp.149-164
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    • 2021
  • Purpose: To identify the factors associated with poor self-rated health in individuals with acquired visual impairment through classification of such individuals into severe and mild visual impairment groups. Methods: This descriptive, cross-sectional, survey-based study analyzed data from 563 individuals with visual impairment due to acquired causes who had been recruited in the 2017 Korean National Survey on Persons with Disabilities. Results: Individuals with severe visual impairment reported poorer self-rated health. Mild depression (p=.003), and low smartphone use (p=.045) were associated with poorer self-rated health in those with severe visual impairment. The factors associated with poor self-rated health in those with mild visual impairment were comorbidities, low smartphone use (p=.006), needed health information (p=.020), unbalanced diet (p<.001), low weight (p=.024), and lack of health checkups (p=.001). Conclusion: Depression was found to be a predictor of poor self-rated health in individuals with severe visual impairment, which highlights the need for nursing and related healthcare intervention to lower depression in this specific population. Further, promoting social network building and providing health information using smartphones may serve to encourage appropriate health behavior in people with severe visual impairment who have reduced mobility and health literacy.

The Effects of Temporary Visual Block on the Foot Pressure and Foot Area of Chronic Stroke Patients (일시적인 시각차단이 만성 뇌졸중 환자의 지면 족저압 분포와 족부면적에 미치는 영향)

  • Jeong, Seong-Hwa;Koo, Hyun-Mo
    • PNF and Movement
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    • v.17 no.1
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    • pp.103-109
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    • 2019
  • Purpose: The purpose of this study was to investigate the effect of temporary visual block existence and nonexistence on the change in foot pressure and foot area in stroke patients. Methods: Sixty-one chronic stroke patients volunteered to participate in the study. Foot pressure and foot area were measured using the Biorescue system. The subject maintain a comfortable standing position on the pressure-measuring plate one meter away from the computer. The sequence of the visual variation data while standing on the measuring plate was collected randomly. The data were collected with three repetitions and used the five-second measuring values except the first second and the last second according to each visual condition. All data were analyzed using SPSS version 21.0. The significance level for the statistical inspection was set as 0.05. Results: The comparison between the visual existence and nonexistence status showed statistically significant effects on foot pressure and foot area. The visual nonexistence status showed more improvement in foot pressure symmetry and area than visual existence status. Conclusion: This study shows that the foot pressure and foot area for the chronic stroke patients changed according to the visual states. It is predicted that these data will be used in rehabilitation training programs and to present temporary changes in visual status for stroke patients.