변압기용 방열기 특성을 고려한 온도 해석 연구

심현석(Hyun-Suk Shim),이승욱(Seung-Wook Lee),강한영(Han-Young Kang),최종웅(Jong-Ung Choi),박석원(Seok-Weon Park),이종호(Jong-Ho Lee) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.10

시력보정용안경의 온라인 판매를 위한 계획서의 문제점들에 대한 연구

심현석(Hyun-Suk Shim),서재명(Jae-Myung Seo),김상현(Sang Hyun Kim) 한국안광학회 2021 한국안광학회지 Vol.26 No.3

Purpose: We have studied the problems of the proposal to sell eyeglasses for vision correction online. Methods: We analyzed the contents of the plan submitted by the company, and identified and analyzed the problems through the current laws and overseas cases. Results: The contents of the plan to order, prepare and sell eyeglasses for vision correction online are not in line with reality, and they are violating the current law. In overseas cases where online sales are being implemented in advance, various problems such as the quality of glasses, the problem of eyeglass frames, and the optical problems of the dispensed glasses were confirmed. Recognizing that the system for vision correction glasses is different between Korea and foreign countries, and if the government wants to provide better services to people who need glasses for vision correction, expand the scope of korean optometrist work or support health insurance for vision correction glasses. It is necessary to think about policy measures to provide higher quality services to the public. Conclusions: The contents of the plan submitted by the company are very poor, inconsistent with reality, cause many problems and in violation of current laws, so these plan should not be implemented.

안경사의 사회적 역할과 지원방안에 대한 연구

심현석(Hyun-Suk Shim),심준범(Jun-Beom Shim),서재명(Jae-Myung Seo),김상현(Sang-Hyun Kim) 한국안광학회 2020 한국안광학회지 Vol.25 No.3

Purpose: In this study, we examined laws related to Korean optometrist and studied the contradictions between laws and solutions. Methods: We identified and examined laws directly and indirectly related to Korean optometrist. The contradictions in these laws and the social role of Korean optometrist were redefined, and the differences between the medical technician and Korean optometrist, and existing papers and reports related to Korean optometrist were reviewed. Results: The law on the support of the health care workforce has made it clear that Korean optometrist are health care workers, and as health and medical services personnel, Korean optometrist are currently working to improve eye health services. However, the interpretation of laws related to Korean optometrist is not clear. In other words, Korean optometrist do not need a doctors guidance, but they play the same role as medical technicians. They are not pharmacists, but they are dispensing, fitting, and selling sight correction ophthalmic devices on the doctors prescription. Korean optometrists are disadvantaged by the interpretation of the law that is not clear. To eliminate these disadvantages, a clear legal interpretation is needed, and the definition of Korean optometrist should include clear sentences related to refraction tests. Conclusions: It is time to clearly interpret the laws related to Korean optometrist who are playing a role as health care workers and to seek a support plan for Korean optometrist.

근거리 입체시와 사위 및 굴절이상의 상관관계

심현석(Hyun Suk Shim),김상현(Sang Hyun Kim),김영청(Young Cheong Kim) 한국안광학회 2015 한국안광학회지 Vol.20 No.1

Purpose: This study was investigated the relationship between the male and female of near stereoacuity and phoria, and was examined the correlations between near stereoacuity and phoria and refractive error. Methods: Adult 83 (male 36, female 47, mean age 21.09±1.74(19~29) years old) target was examined after full correction of refractive error. Near stereoacuity was measured by using Titmus-fly Stereotest(Stereo Optical Co., Inc., Chicago, IL, USA), and RANDOT Stereotest (Stereo Optical Co., Inc., Chicago, IL, USA), phoria was measured by using modified torrington method, at distance 40 cm. Results: In near stereoacuity, male was better good than female, and there was no difference between male and female (p>0.05). In near phoria, female was more higher than male, and there was a significant difference between male and female (p<0.05). Near stereoacuity by Titmus-fly test and Randot test result respectively was 262.17±562.43 sec (second of arc) 243.08±68.04 sec in esophoria, 148.42±269.54 sec, 107.40±263.74 sec in orthophoria, 113.94±152.46 sec, 79.70±136.83 sec in exophoria, there was a no difference between three phoria groups (p>0.05), and was a high correlation between phoria and near stereoacity(r=0.68). In addition, near stereoacuity in the refractive error respectively was 80.00± 571.43 sec, 68.75±36.82 sec in myopia, 133.57±224.15 sec, 93.14±214.95 sec in hyperopia, 511.20±855.00 sec, 511.4±855.60 sec, there was a significant difference between three phoria groups (p<0.05). when was classfiied near stersoacuity into degree of refractive error, near stersoacuity was best in emmetropia, and was reduced when refractive error was highest in high degree myopia, and hyperopia. Conclusions: Titmus-fly Stereotest and RANDOT Stereotest result, near stereoacuity of adults, when esophoria and high degree refractive error, was reduced, there was a relationship between near stereoacuity with phoria, and refractive error. In this both stereotests if was bad when near stereoacuity can expect a phoria and refractive error.

주시거리에 따른 우세안 방향의 변화 및 단안 편위량의 비교

심준범(Jun-Beom Shim),심현석(Hyun-Suk Shim) 한국안광학회 2020 한국안광학회지 Vol.25 No.1

Purpose: This study was conducted to determine the changes in the dominant eye and compare the single-eye inset amounts depending on the view distance. Methods: The direction changes in the dominant eye and single-eye inset amounts were measured as the view distance was changed to 200 cm, 50 cm, 40 cm, and 33 cm in the direction of the dominant eye in 64 adults with no underlying disease (mean age: 23.59 ± 3.73 years; 35 men, 29 women). Results: As a result, 59.5% of the right dominant eyes and 77.8% of the left dominant eyes showed varying direction changes in the dominant eye depending on the view distance (r = 0.583). Dominant eyes were found to show greater changes according to the viewing distance than those shown by non-dominant eyes. Differences in the single-eye inset amounts caused by changes in viewing distance showed a greater inset amount in the right direction than in the left direction at all viewing distances regardless of the direction of the dominant eye. Conclusions: Since the direction of the dominant eye may vary depending on the viewing distance and the single-eye inset amount differs, it is recommended to determine the direction of the dominant eye and single-eye inset amount after conducting a dominant eye test at the target distance to be corrected.

플립칩 접합용 초음파 혼의 CFD 열유동 해석

심현석,리광훈(Hyun suk Shim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

This paper introduce the CFD analysis for predicting the heat transfer at the Ultrasonic horn. Approximately Ultrasonic horn separates two part. One is preheating part and the other is cooling part. Temperature of preheating part rise up by 260℃ that make it possible to attach a chip to a semiconductor. Also there is a piezo material in the cooling part. When piezo work, it generates heat of 100℃. It can stand by 150℃. But the high temperature conducted from the preheating part has a bad affect on the piezo. These situation make it necessary cooling at piezo. Previously except of the piezo, all of them are composed of the SUS440c that has good thermal conductivity. This study shows way that not only cooling the piezo but also cutting off the conduction between preheating part and cooling part by using the Ti and Duralumin that have low thermal conductivity compare with the SUS440c. Conclusion of CFD analysis that the heat coming from the piezo can`t be transferred the horn cause of the Ti and Duralumin.

대비감도와 순간시지각과의 상관관계

김상현(Sang-Hyun Kim),심현석(Hyun-Suk Shim),서재명(Jae-Myoung Seo) 한국안광학회 2018 한국안광학회지 Vol.23 No.1

Purpose: The purpose od this study is to investigate the correlation of contrast sensitivity (CS) with transient visual recognition (TVR) and provide the baseline data of visual perception for motion. Methods: The CS and TVR with the variation of exposure duration were found targeting 39 adults. The CS measurement was conducted at 3 cpd with the exposure duration of 50 ms, 200 ms, 366 ms and 516 ms, while the TVR was found at 0.5 cpd with 10 ms and 20 ms. Results: The CS for men and women was 117.19±31.48 and 138.14±37.39 with 366ms, respectively. It showed that the CS for women was higher than the one for men (p<0.05). The TVR for all subjects showed 91.6±7.7 with 5 digits and 76.6±14.4 with 6 digits at 10 ms. At 20 ms with 5 digits it showed 94.7±6.2 with 5 digits. Consequently, it all had a significant difference for each other (p<0.05). There were positive correlations of CS at 50 ms with TVR at 10 ms with 5 digits (r = 0.361) and 6 digits (r = 0.312), at 20 ms with 5 digits (r = 0.35). Conclusions: There is a good correlation between CS and TVR. It is strongly recommended to take CS into account as well as TVR in future when it comes to evaluate the visual perception for motion.

자동굴절검사와 자각적 굴절검사의 비교분석 : 사진굴절검사기(VS100)를 중심으로

이경훈(Kyung-Hun Lee),심현석(Hyun-Suk Shim) 한국안광학회 2018 한국안광학회지 Vol.23 No.1

Purpose: This study was conducted for comparition the refractive error measured by auto-refraction and subjective refraction. Methods: 100 adults (200 eyes, mean age 22.04±3.14 years) included in this study. Refractive error was measured using by a Photorefractor (VS100), an open-view autorefractor (Nvision k-5001), and a closed autorefractor (ARK-1a). The measured values were converted into power vector components (M, J0, J45) and compared with subjective refraction. Results: The mean difference between subjective refraction and VS100 was M = -0.08±0.67 D, J0= -0.02±0.28 D, J45 = 0.01±0.23 D, and there was no significant difference in all components (p>0.05). The accuracy coefficients were M= 1.313, J0= 0.564, J45= 0.454. The mean difference between the subjective refraction and ARK-1a was M = 0.49±0.84 D, J0 = -0.05±0.19 D, J45 = 0.01±0.14 D, and there was a significant difference between the M and J0 components (p<0.05). However J45 components were not significantly different (p>0.05). The accuracy coefficients were M = 1.664, J0 = 0.372, J45 = 0.292. The mean difference between the subjective refraction and the Nvision K-5001 was M = 0.16±0.63 D, J0 = -0.09±0.30 D, J45 = 0.01±0.18 D, with a significant difference between M and J0 components (p<0.05), but there was no significant difference in J45 (p>0.05). The accuracy coefficients were M = 1.250, J0 = 0.603, J45 = 0.364. Conclusions: As a result of comparing the refractive error of the autorefractor, the refractive power of the photorefractor was measured in the positive direction, but this is considered to be less influenced by the accommodation, and the difference is considered to be small in term of clinical view. The sensitivity of VS100 was 87.7% and the specificity was 75.9%, which was useful for measuring refractive error and correlated with subjective refraction. Photorefractor can be used as a preliminary examinations for subjective refraction because they can open the binocular and measure the refraction error without a large mistake in a short time.

동적시력과 대비감도의 상관관계

심문식(Moon Sik Shim),강혜숙(Hye Sook Kang),김상현(Sang Hyun Kim),심현석(Hyun Suk Shim) 한국안광학회 2014 한국안광학회지 Vol.19 No.2

Purpose: The study was to analyze the correlation between kinetic visual acuity (KVA), visual acuity(static visual angle, SVA) and contrast sensitivity. Methods: Ninety-nine undergraduate students studying Ophthalmic Optics were fully corrected by the Topcon CV-3000 Phoropter. The contrast sensitivity was measured for the participants under the photopic condition (100 cd/m2) with Vector Vision CSV-1000E at 2.5 meter, while KVA was measured with KOWA AS-4A. The participants were classified into three groups L, M and H depending on the KVA (0.1~0.3, 0.31~0.6 and greater than 0.61, respectively) and were analyzed whether there was the correlation between the contrast sensitivity, visual acuity and refractive error. Results: The KVA was correlated with the contrast sensitivity for 3 cpd (r=0.26), for 6 cpd (r=0.48), for 12 cpd (r=0.38) and 18 cpd (r=0.47). Except for the low frequency of 3 cpd, they all were higher than the one of the SVA and the KVA (r = .0.37). The contrast sensitivity for 3, 6, 12 and 18 cpd was 59.41, 92.22, 38.41 and 14.39 in the group L, respectively. The contrast sensitivity in the group M was 66.03, 108.78, 53.51 and 19.20 and the one in the group H was 70.90, 146.10, 62.90 and 25.33 for 3, 6, 12 and 18 cpd, respectively. Conclusions: The correlation of the contrast sensitivity and the KVA was higher than the one of the contrast sensitivity and the SVA. It can be assumed that the contrast sensitivity will be high if the KVA is high, except for the case for low spatial frequency.

Changes in Macular Pigment Optical Density and Visual Acuity after Lutein Supplementation in Adults in Their 20s

Seong-Wook Lee(이성욱),Sun-Mi Choi(최선미),Hyun-Suk Shim(심현석) 한국안광학회 2020 한국안광학회지 Vol.25 No.2

Purpose: This study was conducted to determine whether lutein supplementation (including zeaxanthin) improves macular pigment optical density (MPOD) and visual acuity. Methods: One hundred and twenty adults in their 20s (60 subjects in the experimental group that received lutein, 60 subjects in the control group) who had no systemic diseases or specific eye diseases (macular pigment degeneration and cataract) were included and allocated to experimental and control groups. The experimental and control groups were administered with 20 ㎎ lutein (which naturally contains 1.5 ㎎ zeaxanthin) and soybean oil in pill form, respectively, once a day for 6 months. MPOD was measured with a Macular Pigment Screener II (MPS II ®) every month, while distance and near visual acuities, refractive error (S.E), and contrast sensitivity were measured before and after 6 months of the supplementation. Results: The MPOD in the control group did not improve after 6 months (baseline 0.64±0.10 to study end 0.63±0.13) in both eyes; the experimental group showed a statistically significant improvement from 0.62±0.11 before to 0.68±0.12 after the 6 months of supplementation (p=0.000, t=4.554). Subjects with high or low myopia in the experimental group also showed a statistically significant improvement in MPOD (right eye: high degree [p=0.029, t=2.435], low degree [p=0.000, t=4.160]; left eye: high degree [p=0.014, t=2.810], low degree [p=0.041, t=2.177]), while those with moderate myopia in the same group showed no significant change (right eye: p>0.05, t=0.569; left eye: p>0.05, t=0.535). The near visual acuities for both eyes in the experimental group significantly improved after the supplementation (p=0.001, t=3.419). Contrast sensitivity at most frequencies also improved for the right eye, left eye, and both eyes; there was no significant improvement in the right eye in the experimental group at high frequencies, and a decline was observed for all the frequencies in the right eye, left eye, and both eyes in the control group. Conclusions: Lutein supplementation for 6 months improves MPOD, myopia, near visual acuity, and contrast sensitivity at selected frequencies.