• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.195-200
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• 2015

Purpose: This study was performed in order to figure out the influence of illumination on visual function. Methods: 40 adults (male 21, female 19) of average age $23.93{\pm}1.59$ years were participated in this study. The test chart surface illumination was adjusted to 5, 50, 200, 500 and 800 lx, and then amplitude of accommodation, near point of convergence, far and near distance phoria, far and near distance fusional vergence, relative accommodation, and accommodation lag were measured at each illumination condition. Results: As illumination intensity of test chart was reduced, amplitude of accommodation was significantly decreased (p<0.05), accommodation lag was also decreased, near point of convergence was receded, and horizontal phoria showed a tendency of esodeviation. In the case of negative fusional vergence, with reduction of illumination intensity, the break point and the recovery point were decreased but in the case of positive fusional vergence, the break point was increased. The negative and positive relative accommodation were significantly decreased (p<0.05) with reduction of illumination intensity. Conclusions: In clinical practice, visual functional test should be performed under condition of adequate illumination level through patient's living environment and job.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.9-19
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• 2020

With the recent development of various kinds of virtual reality devices, there has been an active research effort to increase the sense of reality by recognizing the physical behavior of users rather than by classical user input methods. Among such devices, the Leap Motion controller recognizes the user's hand gestures and can realistically trace the user's hand in a virtual reality environment. However, manipulating an object in virtual reality using a recognized user's hand often causes the hand to pass through the object, which should not occur in the real world. This study presents a way to build a visual feedback system for enhancing the user's sense of interaction between hands and objects in virtual reality. In virtual reality, the user's hands are examined precisely by using a ray tracing method to see if the virtual object collides with the user's hand, and when any collision occurs, visual feedback is given through the process of reconstructing the user's hand by moving the position of the end of the user's fingers that enter the object through sign distance field and reverse mechanics. This enables realistic interaction in virtual reality in real time.

• Korean Journal of Heritage: History & Science
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• v.50 no.1
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• pp.58-77
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• 2017

This study applied the index called Visual Perception Intensity (VPI) which quantitatively deals with landscape values and viewpoints to designate the cultural heritage areas in the Scenic Sites. The results of the study are as follows. First, a VPI selection index was presented for designating the cultural heritage areas in the Scenic Sites. The index was applied in consideration of the distance from the viewing point to the object and its incident angle. In addition, the process of the VPI analysis was implemented with GIS and the analysis algorithm was constructed. Second, the possibility of VPI was examined by comparing the simple frequency of the cumulative visibility with the results of the VPI. The VPI was analyzed to be more influenced by the incidence angle than the distance between the viewpoint and the object within a 4.74 km area. Third, a field survey was performed to investigate the effectiveness of the VPI classification. The survey was implemented based on the results of the investigation into the VPI to examine whether human visual perception was fully reflected. It was confirmed through the field survey that an area with high VPI was also an important area. Fourth, a plan for the cultural heritage area adjustment was constructed by applying the VPI to the areas already designated as Scenic Sites. As a result of classifying the VPI into three classes, it was found that the areas with the second class or higher were needed to be designated as cultural heritage areas and the areas with the third class as the Historical and Cultural Environments Preservation Area.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.147-154
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• 2022

This paper evaluated visual function and stereoacuity function after surgery for intermittent exotropia. Subjects of this study were 18 patients (male: n = 10, female: n = 8) mean aged 12.06±5.43 years diagnosed with intermittent exotropia who underwent strabismus surgery. Of these subjects, 72.2% of the subjects underwent strabismus surgery once and 27.8% had it twice. Visual function and stereoacuity function were tested for these subjects. For data analysis, frequency analysis, cross analysis, and correlation analysis were used, and statistical significance was set at p<.05. Regarding the deviation state after strabismus surgery, exodeviation accounted for the most(72.2%), followed by diplopia(50.0%) and suppression(33.3%) for distance sensory fusion. Regarding near sensory fusion, fusion(50.0%) accounted for the most, followed by diplopia(44.4%). After strabismus surgery, subjects with distance stereoacuity blindness were the most at 61.1% and there were no subjects with a normal range of 40-60 arcsec. Near stereoacuity blindness subjects accounted for 33.3% and subjects with 40-60 arcsec accounted for 1.1%. Even after surgery for intermittent exotropia, there were some areas that did not improve in deviation state, stereoacuity, or sensory fusion. Therefore, it is necessary to manage and control strabismus through non-surgical methods before and after surgery for intermittent exotropia.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.150-155
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• 2011

The aim of this study was investigated long distance export condition of paprika from Korea to Canada, and evaluated the effect of non-perforated breathable films on the storability of paprika during MA storage in the simulated long distance export condition. The long distance export condition of paprika from Korea to Canada was $7{\pm}1^{\circ}C$ and RH 90% during shipping for 20 days, and then the temperature of that was increased to $13^{\circ}C$ for 3 hours during transferring from refrigerated container to storage room in Canada, and decreased $3{\sim}4^{\circ}C$ for 3 days before distributing to local markets. The temperature and relative humidity of local markets was $16^{\circ}C$ and 60%, respectively. The packing material treatments were non-packing, as control, perforated film (6 mm diameter hole, $18holes/m^2$), and 3 kind of laser treated non-perforated films (oxygen transmission rate was 5,000, 20,000 and 100,000 $cc/m^2{\cdot}day{\cdot}atm$). Under the simulated long distance export condition; $7^{\circ}C$ and RH 90% for 15 days and then $20^{\circ}C$ and RH 55% for 7 days, the fresh weight loss of paprika was less than 1% in 3 kind of laser treated non-perforated film treatments but was more than 4% in control and perforated film treatment that showed severe deterioration of visual quality after 20 days of storage. The atmosphere of paprika packages was changed 5% oxygen and 15% carbon dioxide in 5,000 $cc/m^2{\cdot}day{\cdot}atm$ treatment, and 16% oxygen and 4~5% carbon dioxide in 20,000 $cc/m^2{\cdot}day{\cdot}atm$ treatment during room temperature storage after cold storage for 15 days. A carbon dioxide concentration of these 2 treatments was exceeded the optimal MA and CA condition. There was no significant difference in ethylene concentration among 3 kind of laser treated non-perforated film treatments. A paprika packed with 100,000 $cc/m^2{\cdot}day{\cdot}atm$ non-perforated film showed the highest visual quality under the simulated long distance export condition. However, the firmness and soluble solids did not show any significant difference among 3 kind of laser treated non-perforated film treatments. Therefore, we may suggest that 100,000 $cc/m^2{\cdot}day{\cdot}atm$ laser treated non-perforated film was the proper film for MAP of paprika under long distance export condition that was $7{\pm}1^{\circ}C$ and RH 90% for 15 days, and then $20^{\circ}C$ and RH 55% for 7 days.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.34-41
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• 2004

The purpose of this paper is to look at the characteristics of surface finishing which is one of the form accuracies and to obtain the fundamental technical data from the process of machining with diamond tool through experiment and theoretical analysis. The experiments were conducted with domestic made ultra-precision machine and MCD.PCD tool, with aluminum alloyed material and brass being used for the work pieces. The goal of the size accuracy was set to 100nm. The most suitable tool nose radius and machining conditions were selected, and the variations of the surface roughness were observed using SEM method while machining the distance of up to 500km. These data were evaluated and they examined the variation of the machined surfaces while cutting up to 500km of machining distance. At the same time, the state for the wear of diamond tool nose was analyzed and carefully examined through the newest measuring device. Additionally, the characteristics of ultra-precision machining technology were studied through visual analysis.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.137-143
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• 1998

The measurement of the inter outer canthal distance(IOCD), inter inner canthal distance(IICD), width palpebral fissure (WPF) and distribution of cataract, corneal abnormality and palpebral abnormality-were followed in III Korean in leprosy patient. The average dimension of IOCD was in male 89.9 mm and in female 88.4 mm, IICD were in male 36.9 mm and female 35.8 mm, and LPF was in male 52.9 mm, female 52.6 mm. The IOCD and LPF were decreased but IICD was not 29.7%, palpebral abnormality was 19.4% and corneal abnormality was 37.8%. These data were not changed by sex but increased by age. So the causes of visual impairment int the disease were corneal abnormalities that were the most common complications.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.3
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• pp.419-425
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• 2020

There are many accident risks in logging operation of forestry such as struck by felled trees and caught in, under, or between felled trees. These accidents are primarily occurred by not keeping a safe distance between workers. According to the forestry safety instruction, workers are not supposed to go into the safety zone which is a circle with a radius of more 2 times the height of felling tree. However, this rule does not keep because of poor safety consciousness, poor sight and extreme noise of logging operation machines. This problem causes many major accidents every year. To solve this problem, we made forestry safety helmets based on IoT technology. These helmets have functions to make a visual and an acoustic alarm signal when reach the distance between workers within 20 meters. We developed the algorithm to operate the helmet's functions and conducted tests to check the functions. As a result of tests, we assured the normal system operating conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.4
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• pp.365-371
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• 2009

A intelligent mobile hexapod robot with various types of sensors and wireless camera is introduced. We show this mobile robot can detect objects well by combining the results of active sensors and image processing algorithm. First, to detect objects, active sensors such as infrared rays sensors and supersonic waves sensors are employed together and calculates the distance in real time between the object and the robot using sensor's output. The difference between the measured value and calculated value is less than 5%. This paper suggests effective visual detecting system for moving objects with specified color and motion information. The proposed method includes the object extraction and definition process which uses color transformation and AWUPC computation to decide the existence of moving object. We add weighing values to each results from sensors and the camera. Final results are combined to only one value which represents the probability of an object in the limited distance. Sensor fusion technique improves the detection rate at least 7% higher than the technique using individual sensor.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.77-81
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• 2002

The purpose of this study is to examine quantitatively the relationship between visual image quality and degradation In spatial resolution for a gamma camera by the increase in distance from collimator. The relationship between the portion(p) of images identified the difference of image quality and the difference(${\Delta}FWHM$) in FWHM between paired images was showed in a sigmoid curve. Using Dendy's method, minimum level to be correctly identified the difference of Image duality on three out of four occasion(p=0.75) was corresponded to 0.4 mm in ${\Delta}FWHM$. Using fuzzy theory, the level to be identified the difference of image quality was examined under various conditions. The truth-value of fuzzy sets-degraded or slightly degraded and not-degraded in image quality between palled Images-was gained the peak at 0.5 mm of ${\Delta}FWHM$. It was founded that changes of $0.4{\sim}0.5\;mm$ in FWHM-corresponding about 2 cm distance from collimator could be sufficiently identified in the difference of image quality.