• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.361-370
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• 2004

The purpose of this study was to evaluate the outcome and Factors that influence the quantity of Phoria in the low correction and perfect correction. Also the coincidence with the opticenter and the pupillary distance was a principal factor that influence the quantity of Phoria. Thereupon, this study is attributed to promote the perfect Phoria test. The subjects for this study were 120 persons(240 eye) in myopic refractive errors. ISP/WIN program was used for the data analysis. The collected data was analyzed by descriptive statistics and Spearman's correlation coefficient. The results of this study were as follows: 1. The prism pattern was difference between low correction and perfect correction in the Phoria test. The proportion of orthophoria was changed from 10.0% to 12.5%, exophoria was changed from 67.5% to 62.5%, and esophoria was changed from 22.0% to 32.5%, respectively. 2. The average of optical center distance and pupillary distance were 31.70mm and 31.49 mm, respectively. 3. Among the 120 myopic glasses wearers, the distance between optical centers was coincided with the pupillary distance in 37.5%, and discrepant in 62.5%. 4. For the patients who were coincided with the pupillary distance, the proportion of exophoria decreased 53.33%, esophoria increased 20.0%. 5. For the changing of the quantity of Phoria in the low correction, the degree of exophoria decreased 1.11 prism diopters in the perfect correction, esophoria increased 0.39 prism diopters.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.97-101
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• 2009

Purpose: To assess the refractive state of the westerners (male: 44, female: 62) in twenties who visited the A optical shop at Seoul. Methods: The visual acuity test was performed by the objective and subjective method. Results: The emmetropia and myoptia were 35 and 177 eyes (83.49%), respectively. About 26.76% of tested males was ametropia. Myopia compound and myopia simple astigmatism were found in 60.56% and 12.68% of tested males, respectively. However, about 43.40% of tested females was ametropia. Myopia compound and myopia simple astigmatism were 49.06% and 7.55% were found in tested females, respectively. As for the equivalent spheric power of myopic abnormal refractive eyes, the -0.5D < spheric equivalent ${\leq}$ -2.00D was 35.02% of tested westerners, the -2.00D < spheric equivalent ${\leq}$ -6.00D was 60.45% and anything over the -6.00D was 4.53%. The percentages of with-the-rule, against-the-rule and oblique astigmatism among people with astigmatism were 59.82%, 26.78% and 13.40%, respectively. The average of pupillary distance in male (63.5${\pm}$2.4 mm) was greater than that in female (59.7${\pm}$2.3 mm). Conclusions: Korean opticians were provided some useful information about making up a prescription for the westerners in twenties by this research.

• Journal of The Korean Ophthalmological Society
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• v.60 no.5
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• pp.470-473
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• 2019

Purpose: To investigate the relationship between dominant eye and refractive error in patients with myopic anisometropia. Methods: This study population consisted of myopes less than 15 years old who were followed up for anisometropia defined as interocular difference of spherical equivalent (SE) ≥1.0 diopter (D). All patients underwent the hole-in-the-card test at far and near to determine ocular dominance. The data were analyzed for statistical significance using Fisher's exact test. Results: A total of 102 eyes in 51 patients were analyzed. The mean age of the patients was 10.4 ± 1.4 years and 54.9% were male. The mean SE was -2.97 ± 1.95 D in the right eye and -3.02 ± 1.92 D in the left eye. The right eye was the dominant eye in 43.1% and 37.3% at distance and near, respectively. The agreement of dominancy between distant and near was 82.4%. The near dominant eyes showed statistically significant accordance with more myopic eyes (p = 0.009). On the other hand, there was no statistically significant relationship between more myopic eyes and distant dominant eyes (p = 0.09). Conclusions: The near dominant eye was more myopic eye in patients with myopic anisometropia. This was considered to be related with the lag of accommodation in dominant eye with near distance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.320-320
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• 2004

반도체용 노광장비나 검사장비, 초정밀 광학렌즈, 비구면 렌즈 가공 등의 핵심이 되는 것은 초정밀결정기술이다. 서브미크론의 정밀도를 갖는 장비는 한치의 오차도 허용치 야고 계획된 경로대로 정확하게 목표지점에 도달해야 초정밀 가공을 기대 할 수 있다 초정밀 공기정압 스테이지는 저마찰 특성과 높은 운동정밀도, 청정환경유지가 가능하여 반도체 노광장비에서 PDP 나 LCD검사장비, 초정밀가공 가공기 등 다양한 정밀장비에서 활용된다.(중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.646-655
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• 2002

장대 교량이 위치한 지반에서 지진에 의한 지반 운동은 교량의 길이 방향으로 공간적인 변화를 일으킨다. 지형 변화나 지반 매질의 물성 변화가 있는 비균질한 지반에서 지반 운동의 진폭과 주파수 성분은 변화하고 이 부지 효과(site effect)는 교량의 지진 응답에 지배적인 영향을 미치며 그 영향은 파전파 효과(wave passage effect)에 의한 지반 각 지점의 지진파 도달시간 차이나 비균질성이 큰 지반에서 파의 다중 반사, 굴절에 의한 영향보다 크다[1]. (중략)

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.25-28
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• 2011

본 논문은 광학 격자 필름과 평행 렌즈를 이용하여 무안경 3D 디스플레이 시스템을 구현한 연구이다. 기존 패럴랙스 배리어 시스템에서는 시점에 따라 크로스토크가 발생하는 영역과 역 입체시 영역을 갖게 되는데 이는 시청자가 정확한 3D영상을 볼 수 없도록 한다. 이를 평행 렌즈를 이용하여 좌, 우안에 해당하는 영상을 평행하게 이동시켜 설계된 격자 필름의 위치에 맺힐 수 있게 하고 격자 필름으로 빛을 굴절시켜 각 눈에 해당하는 영상만 볼 수 있는 영역을 갖게 하였다. 제안하는 방법을 이용해 크로스토크를 회피하여 보다 정확한 3D영상을 볼 수 있도록 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.120-128
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• 2017

The refraction phenomenon of radio waves should be considered to improve the detection accuracy of target altitudes for long-range surveillance radars, however, it is difficult to estimate accurate refractivity of atmosphere for every location. In this paper, we propose the atmosphere evaluation metric(AEM) to estimate atmospheric conditions at target locations using target altitudes obtained from primary surveillance radar(PSR) and secondary surveillance radar(SSR). To verify the suitability of the proposed metric, we observed atmospheric conditions and calculated estimation errors of target altitudes using measured data.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.133-138
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• 2009

Purpose: This study was designed to investigate the changes of vision and ocular functions induced by increase of blood alcohol level. Methods: Blood alcohol level, vision, refractive errors, near point convergence, heterophoria, and relative convergence were measured at 1 h, 4 h, and 24 h after acute alcohol ingestion of 0.7 g per kg body weight. Results: At 1 h after alcohol ingestion, myopization and ocular functions which measured near point convergence, positive and negative convergences, and degree of heterophoria remarkedly worked a changes accompanied with the maximum value of blood alcohol level. But at 24 h after that, all of ocular functions were recovered to degree of 90~99% compared with non-alcoholic normal conditions. Conclusions: As the increase of blood alcohol level is able to induce the significant changes of visual acuity and ocular functions, opticians have to understand thoroughly the patient's conditions by alcohol ingestion before refractive test and ocular examinations.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.115-119
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• 2001

To research the refractive error of the eyes on the 30's employees, 510 eyes were tested by the object and subject methods. The results were as follows. 1. Among the 510 eyes, myopia is 74.4%, hyperopia is 0.9% and emmetropia is 24.7%, respectively. 2. In test, the low myopia (-0.50Dt < Spherical Equivalent ${\leq}$ -2.00Dt) is 24.1%, the middle myopia(-2.00Dt < Spherical Equivalent ${\leq}$ -6.00Dt) is 51.4%, the high myopia(-6.00Dt < Spherical Equivalent) is 14.8% and the low hyperopia(+0.50Dt < Spherical Equivalent ${\leq}$ +2.00Dt) is 1.2%, respectively. 3. In test of astigmatism, the amount of astigmatism with-the rule is 58.5%, the amount of astigmatism against-the rule is 22.6% and the amount of astigmatism with oblique is 18.9%, respectively.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.95-100
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• 2006

To reveal subsurface structures of the Ulsan fault, seismic data were recorded along a 750-m long line near Nongso-Eup in Ulsan. P and S waves were generated simultaneously by impacting a 5 kg sledgehammer on a tilted plate. The data were received by 16 10-Hz 3-component geophones at 3 m intervals. Refracted P waves were inverted using the tomography method. Dip moveout and migration were applied to reflection data processed following a general sequence. Four layers were identified based on P-wave velocities and P- and S-wave stacked image. From top to bottom, the P-wave velocity of each layer ranges in $300{\sim}1100\;m/s$, $1100{\sim}1700\;m/s$, $1700{\sim}2700\;m/s$, and greater than 2700 m/s. The corresponding thickness of the top three layers averages 3.9 m, 5.9 m, 4.4 m, respectively. The S-wave stack section is effective to define subsurface structures shallower than 10 m.