• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.147-152
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• 2016

Purpose: This study was designed to be used as the basic visual function data after analyzing and investigating the refractive errors variation between city and rural elementary school children. Methods: To compare with city and rural areas, 2501 elementary school children who lived in Mokpo, Yeongam, Muan, Hampyeong were participated. Objective refraction, Subjective refraction and binocular function examinations were measured. Results: Mean of refractive error of rural areas was -1.47 D in 2012 years, -1.52 D in 2013 years, and -1.40 D in 2014 years. However average of refractive error was -1.65 D in 2012 years, -1.76 D in 2013 years and -1.75 D in 2014 years who lives in city areas. Average myopia was showed higher who lives in rural areas elementary school children than city areas elementary school children. There were significant differences between rural areas and city areas elementary school children (p = 0.03), but there were no significant differences by averagre hyperopia (p = 0.32). Average myopia was showed the tendency of increase as the students get older by analysis compare with rural and city areas elementary school children. It also showed high prevalence of myopia who lives in city areas elementary school children compare with lives in rural areas elementary school children. Conclusions: It is the very important to performed regular visual acuity test and correction during the largest refractive change period and it is necessary to have experts in the visual acuity test.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.555-560
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• 2013

Purpose: The aims of this study were to investigate the stereoacuity and subjective symptoms of aniseikonia with prescription of the size lens. Methods: Participants were myopic anisometropia patients with the binocular refraction difference between 1.75 D~3.50 D. Inclusion criteria of participants were no ocular pathology, no amblyopia, more than 1.0 of corrected visual acuity. With fully corrected spectacles and a correction with the size lens, Awaya aniseikonia test and Randot Stereo test were conducted respectively. In addition, subjective symptoms were also examined using questionnaire. Results: As the anisometropia increased, the aniseikonia increased. Under the anisometropia with same refractive correction was different for each individual. The prescription of size lens caused less aniseikonia than the general prescription of glasses. In addition, prescription of the size lens improved stereoacuity and relieved the symptoms of asthenopia. Conclusions: The prescription of size lens that can correct aniseikonia with prescription of glasses can improve stereoacuity and reduced asthenopia.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1145-1156
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• 2002

A method to measure the speed and distance of moving object is proposed using the stereo vision system. One of the most important factors for measuring the speed and distance of moving object is the accuracy of object tracking. Accordingly, the background image algorithm is adopted to track the rapidly moving object and the local opening operator algorithm is used to remove the shadow and noise of object. The extraction efficiency of moving object is improved by using the adaptive threshold algorithm independent to variation of brightness. Since the left and right central points are compensated, the more exact speed and distance of object can be measured. Using the background image algorithm and local opening operator algorithm, the computational processes are reduced and it is possible to achieve the real-time processing of the speed and distance of moving object. The simulation results show that background image algorithm can track the moving object more rapidly than any other algorithm. The application of adaptive threshold algorithm improved the extraction efficiency of the target by reducing the candidate areas. Since the central point of the target is compensated by using the binocular parallax, the error of measurement for the speed and distance of moving object is reduced. The error rate of measurement for the distance from the stereo camera to moving object and for the speed of moving object are 2.68% and 3.32%, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.18-27
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• 2012

This paper proposes a management method for a coastal black pine forest landscape considering the parallax effect. For the study, 10 coastal black pine forests in Gangneung were investigated about the average width of the coastal forests, the average diameters, and the intervals of the pines. Categorizations were realized for the 3 types of scene(sea, field, mountain, residential area, commercial area), diameter(16cm, 22cm, 28cm) and interval(5m, 7m, 10m) to produce a total of 45 scenic simulations. An investigation was made on the scenic preferences using 45 simulation images with S.D, and Likert Scales. The results were as follows: According the comparison of scenic preferences, natural landscapes(sea, field, and mountain) ranked high among preferences, with fabricated landscapes(residential area, commercial area) ranked low. The highest scenic preferences were shown with the seascape and an interval of 7m between the trees. On the contrary, the interrelationship was very low between the visual quantity of the scenic's elements(green, sky, building, road etc.) and the scenic preferences. As the results of the factor analysis, the 3 sense factors of "Depth(78.0%)" "Diversity(l5.6%)" and "Spatiality(6.4%)" explained coastal scenic preferences. "Spatiality" showed significant differences at intervals of 5~7m, and 10m between trees. This shows coastal forest management based on the interval of 10m standard affecting scenic preference.

• Korean journal of applied entomology
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• v.4
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• pp.59-64
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• 1965

This study was planned to find out the effects of several food-plants on the pupal weight and the number of eggs in the ovary of the fall webworm, Hyphantria cunea $D_{RURY}$. The larvae were separately reared on different food-plants in the Petri dish. Four to six day old pupae were used for the study of the pupal weight. The number of eggs in the ovary was counted under the binocular dissecting microscope. The loaves of the food-plants were sampled on Juiy 16, and analyzed by Kjeldahl method for the determination of total nitrogen content. The results obtained in this study were as follows; (1) The pupal weights were highly different according to the species of plants and sexes. The greatest pupal weight found in the pupae reared on the mulberry and the least one in the pupae reared on the apple tree. The weight female pupae was greater than that of male pupae in every case. (2) The number of eggs in the ovary was positively correlated to the pupal weight. (3) The nitrogen content of the food-plants used in this experiment was varied with the species of the plants. However, the nitrogen content of the food-plants was not significantly correlated to the pupal weight and the number eggs in the ovary.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.325-331
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• 2015

Purpose: This study was to find the correlation between exophthalmetry and visual functions. Methods: Exophthalmetry and visual functions of 200 adults without ophthalmophathy and general disease were examined. Exophthalmetry were measured with Hertel's exophthalmometer. Visual functions (myopia, distance exophoria, near exophoria, near point of convergence, near point of accommodation) were measured for three times. Results: The exophthalmetry was $13.59{\pm}1.10mm$. Myopia, distance exophoria, near exophoria, near point convergence, and near point accommodation were measured as $-2.48{\pm}1.91D$, $3.51{\pm}1.78{\Delta}$, $5.73{\pm}2.44{\Delta}$, $9.63{\pm}2.82cm$, and $21.73{\pm}10.28cm$. With increasing exophthalmetry, the unaided visual acuity, myopia and astigmatism were decreased. On the other hand, distance exophoria, distance esophoria, near exophoria, near point of convergence and near point of accommodation were significantly increased, while exophthalmetry was increased. Conclusions: The relationship between visual functions and exophthalmetry were found to be statistically significant. It could be used as the clinical criteria for prescription of binocular inspections.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.369-375
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• 2015

Purpose: The current study was performed to estimate the changes in reading speed and blinking rate according to different background colors when reading paper book and further investigate their correlation. Methods: Twenty-nine adults (10 males, 19 females) who consented to the present study and had no ocular disease, ocular surgery history showing normal binocular vision were participated into the study. The subjects were asked to read the novels with black letter printed on white, red, green and blue background for 15 min, respectively. Then, the reading speed per page and blinking rate per page were measured during reading and analyzed according to background colors. Results: Reading speed per page according to the background color showed a tendency to accelerate in the white and green background as the reading time increased however, it was almost unchanged in the blue background and rather decelerated in the red background. On the other hand, the blinking rate per page tended to decrease in all background as the reading time was increased however, the smallest reduction was shown in the red background. There was a correlation that the reading speed increased as the blinking rate decreased in all backgrounds and the best correlation was shown in the green background. Conclusions: From the results, a correlation between the increasing reading speed and the reducing blinking rate while reading paper book with same demand on accommodation and convergence was confirmed however, the change in blinking rate and reading speed was varied depending on the main wavelength of light. It might mean that the working speed and visual fatigue can be varied depending on the difference of main wavelength when doing near work. Thus, it can be suggested that the adjustment of working environment and conditions should be made according to the kind of required perception.

• 한국해양학회지
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• v.5 no.1
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• pp.37-40
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• 1970

This work concerns age studies of the spanish mackerel by vertebrae. The spanish mackerel samples were obtained mainly from Yosoo and Inchon regions during July to December, 1969. A total of 292 fish was collected during the present study. Except the vertebrae, the incremental growth is found to be vague or complicated on the most bony parts in spanish mackerel. The spanish mackerel has 50 vertebrae, and the size of vertebra varies according to its position. After several studies, therefore, sample centrum was selected from the 23rd vertebra throughout the present study. Sample centrum was then stained with Alizarin Red S. and examined under binocular stereoscopic microscope illuminated by reflected light. The surface of the centrum shows many ring-marks running parallel to the edge. The ring-marks were counted and the measurements of centrum radius (R) and radii of the ring-marks (r$\_$i/) were made by eyepiece micrometer. From available data, the average of each ring-mark radius was found to be; r$\_$1/=2.05mm, r$\_$2/=3.11mm, r$\_$3/=4.05mm, r$\_$4/=4.89mm, r$\_$5/=5.70mm and r$\_$6/=6.47mm, respectively. The mean fork length at the time of ring-mark formation was calculated to be; l$\_$1/=297.6mm, l$\_$2/= 390.1mm, l$\_$3/=472.2mm, l$\_$4/=545.5mm, l$\_$5/=616.2mm, and l$\_$6/= 683.4mm, respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.329-335
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• 2006

The aim of this study was to evaluate the relation between Asthenopia of near lateral phoria and fusional reserve and also to provide fundamental clinical data. A total of 97 subjects, aged between 17 and 35 years old, who had no strabismus, an eye trouble or whole body disease, were examined nacked visual acuity, corrected visual acuity, corrected diopter, phoria, fusional reserve tests from October of 2005 to July of 2006. We excluded 8 subjects for the following reasons: if they had an amblyopia affecting binocular vision or inaccurate data. After these exclusions, 87 subjects remained. The results were as follow. According to interview results was that in near works, exophoria and esophoria with asthenopia was 59.6%, 64.7%, and 52.6% respectively. The subjects who have exophoria of $0-6{\Delta}$ in the range of normal state was 19.1%. The subjects who have exophoria of $7{\Delta}$ over in the range of abnormal state was 80.9%. The fusional reserve was in inverse proportion to phoria. The fusional reserve was twice over of phoria were 30.3%, and twice under were 69.7%. The asthenopia complain persons were 33.9% with the twice over fusional reserve of phoria. The asthenopia no complain persons were 66.1% with the twice under fusional reserve of phoria. In conclusion, our research has shown conclusively that there is a link between asthenopia of lateral phoria and fusional reserve and we also find that fusional reserve must be examined when we prescribe for a patient who has phoria.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.511-518
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• 2015

Purpose: The purpose of this study is to evaluate correlation between convergence insufficiency and concentration by evaluating attentiveness in children who have convergence insufficiency symptoms. Methods: The CISS survey and examination for the near point of convergence were conducted to 74 in children aged 12 to 13 years in order to divide them into a normal binocular vision (NBV) and a convergence insufficiency (CI) group. The attentiveness examination was used to all subjects to figure out their emotional problems, hyperactivity and impulsiveness problems, and managerial or functional problems with a 5-point scale. Correlation between convergence insufficiency-related symptoms included in CISS and attentiveness problems was analyzed. Results: there were 29 children (39.2%) in the CI group, the mean scores of CISS of the NBV and CI group were $5.91{\pm}3.69$ and $18.31{\pm}7.00$ each (p<0.001). On the survey of CISS symptoms, children in the CI group frequently expressed such symptoms as eye fatigue, loss of attentiveness, blurry vision, and forgetting the line they have been reading. In the attentiveness examination, the CI group ($74.83{\pm}9.83$) gained higher scores in problematic concentration than the NBV group ($46.80{\pm}11.30$). Convergence insufficiency had significantly positive correlation with total attentiveness (r=0.798). Conclusions: In elementary school students, it has been found that when perceived symptoms related with convergence insufficiency are more serious, problematic attentiveness gets serious, too.