• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.199-203
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• 2016

This study relates to the development of a program for calculating the roofed pechan prism design data. First, we set the roofed pechan prism design variables and derive the relational expressions between them. With this expressions, we could develope the program that outputs the numerical data for roofed pechan prism design when the face-length and the effective incident beam diameter are given. In fact, applying this program to the prism which is not the commercial size, we were able to calculate the design data very quickly, so that we can easily acquire the 3D structure of the actual roofed pechan prism. This means that we can quickly ensure the structural data of roofed pechan prism which is required for the product development and we are able to develop the new products related to the scope at a faster speed.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.299-305
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• 2017

This study relates to the development of a program for calculating the design data and estimating on the Abbe-$K{\ddot{o}}nig$ prism. First, we set the Abbe-$K{\ddot{o}}nig$ prism design variables and derive the relational expressions between them. With this expressions, we could develope the program that outputs the numerical data for the Abbe-$K{\ddot{o}}nig$ prism design and three evaluation data for the Abbe-$K{\ddot{o}}nig$ prism analysis when the face-length, the effective convergent incident angle of incident beam, and the refraction index of prism are given. In fact, applying this program to the prism which is not the commercial size, we were able to calculate the design data very quickly, and we could easily understand the optical structure of the designed Abbe-$K{\ddot{o}}nig$ prism by the three evaluation data. This means that we can quickly ensure the structural data of the Abbe-$K{\ddot{o}}nig$ prism which is required for the product development.

• Current Optics and Photonics
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• v.2 no.1
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• pp.59-68
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• 2018

Opto-acoustic systems provide structural and functional information regarding biological tissues. Conventional opto-acoustic systems typically employ continuous or pulsed lasers as transmission sources. Compared to lasers, light emitting diodes (LEDs) are cost-effective and relatively portable excitation sources but are non, coherent. Therefore, in this study, a relatively low cost lens - a type of Ramsden eyepiece - was specially designed to theoretically calculate the illumination and achieve a constant brightness across the pupil of an eye. In order to verify the capability of the developed light-emitting diode-acoustic (LEDA) systems, we carried out experiments on bovine and bigeye tuna eyeball samples, which are of similar size to the human eye, using low frequency (10 MHz) and high frequency (25 MHz) ultrasound transducers. High frequency ultrasound transducers are able to provide higher spatial resolution compared to low frequency ultrasound transducers at the expense of penetration depth. Using the 10 MHz and 25 MHz ultrasound transducers, acceptable echo signals (3.82, 3.94, and 5.84 mV at 10 MHz and 282, 1557, 2356 mV at 25 MHz) from depth greater than 3 cm and 6 cm from the anterior surface of the eye were obtained. We thereby confirmed that the LEDA system using a pulsed LED with the designed Ramsden eyepiece lens, used in conjunction with low and high frequency ultrasound transducers, has the potential to be a cost-effective alternative method, while providing adequate acoustic signals from bovine and bigeye tuna ocular areas.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.311-322
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• 2012

Objective: The effect of lead on blood pressure remains controversial in spite of the numerous studies which have been conducted in the recent years. The aim of this study was to evaluate the effects of exposure to lead on blood pressure among non-smokers. Methods: In this cross sectional study, 1416 male and female non-smokers were enrolled, aged 20 years or older, from the Korean National Health and Nutrition Examination Survey 2008. Blood pressure, blood lead levels (BLLs), height, weight, and cotinine level were measured for all subjects. Results: Geometric mean BLLs of the participants was 2.20 ${\mu}g$/dl. BLLs were higher in the older, male, and lower education groups than the younger, female and higher education groups. After adjusting for age, sex, education and BMI through multiple regression analysis, a significant positive association between systolic blood pressure (p = 0.0357), diastolic blood pressure (p = 0.0111) and BLLs. Also, among the normal BMI group (18.5 kg/$m^2$ < BMI < 25 kg/$m^2$), we also found a significant positive association between diastolic blood pressure and BLLs (p = 0.0370). Conclusion: The present study showed that blood lead serves as a good predictor of blood pressure changes and that there was a statistically significant association between blood lead and blood pressure, especially diastolic blood pressure.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.361-368
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• 2011

Purpose: This study is to analyze the curriculum satisfaction and to provide basic information for effective school management of Dept. of Health section. Methods: This survey, modified questionnaires based on Hee-Joo Moon's(2005), is accordance with undergraduate students and shows very high credibility upper than Cronbach's Alpha. 1,500 questionnaires are distributed(01. Oct. 2010~30. Oct. 2010) but only 1,213(80.8%) are returned and, except for 14 insincerely answered, 1,199(79.9%) are used. Results: The results of the study are following. The population characteristic of this survey is that 445(18.1%) are male, 739(61.9%) are female, 595(49.6%) are in health section, and 604(50.4%) are in none health section. 628(53%) chose getting jobs as their motivations for school choice and 727(60.8%) chose getting jobs and career guidance as theirs. The satisfaction of male students was higher than that of female students based on the comparative analysis of the curriculum satisfaction. The satisfaction of the students in none health section was higher than that of those in health section based on the comparative analysis of the curriculum satisfaction. This survey indicates that once the satisfaction with the major courses and career guidance increase, the overall satisfaction grows. Conclusion: The keys to improve the curriculum satisfaction including students' in department of dental technology are to provide and develop differentiated curriculums and support programs that meet students' expectations. In addition, the customized curriculums based on the level and aptitudes of female students are needed.

• Applied Microscopy
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• v.47 no.2
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• pp.70-74
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• 2017

In the case of genus Nothobranchius, Nothobranchiidae, the morphology of fertilized eggs and ultrastructures of fertilized egg envelopes have been reported in only two fishes. Therefore it is hard for sure to these morphological characteristics show genus specificity because of lower research samples. So, we studied the morphology of fertilized egg, and compared the ultrastructures of outer surface, micropyle, and section of fertilized egg envelopes under the light and electron microscopes from the other two species, Nothobranchius foerschi and Nothobranchius rachovii, Nothobranchiidae to find out whether these structures have the species specificity or not. Both fertilized eggs were spherical, demersal and adhesive, and have a large oil droplet. The adhesive whip-like structures were distributed on the outer surface of egg envelope, and a micropyle located on the animal pole. The fertilized egg envelope consisted of two distinct layers: an outer electron-dense layer with adhesive structures and an inner lamellae layer in both species. The external shapes of fertilized egg and ultrastuctures of outer surface, micropyle, and section of fertilized egg envelope have same structure including results before. Our data indicate that these morphological characteristics of fertilized egg and fertilized egg envelope show genus Nothobranchius specificity.

• Current Optics and Photonics
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• v.4 no.4
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• pp.286-292
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• 2020

Imaging through multicore fiber (MCF) is of great significance in the biomedical domain. Although several techniques have been developed to image an object from a signal passing through MCF, these methods are strongly dependent on the surroundings, such as vibration and the temperature fluctuation of the fiber's environment. In this paper, we apply a new, strong technique called deep learning to reconstruct the phase image through a MCF in which each core is multimode. To evaluate the network, we employ the binary cross-entropy as the loss function of a convolutional neural network (CNN) with improved U-net structure. The high-quality reconstruction of input objects upon spatial light modulation (SLM) can be realized from the speckle patterns of intensity that contain the information about the objects. Moreover, we study the effect of MCF length on image recovery. It is shown that the shorter the fiber, the better the imaging quality. Based on our findings, MCF may have applications in fields such as endoscopic imaging and optical communication.

• Current Optics and Photonics
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• v.7 no.6
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• pp.738-744
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• 2023

Graphene-based saturable absorbers (SAs) are widely used as laser mode-lockers at various laser oscillators. In particular, transmission-type graphene-SAs with ultrabroad spectral coverage are typically manufactured on transparent substrates with low nonlinearity to minimize the effects on the oscillators. Here, we developed two types of transmitting graphene SAs based on CaF₂ and ZnSe. Using the graphene-SA based on CaF₂, a passively mode-locked mid-infrared Cr:ZnS laser delivers relatively long 540 fs pulses with a maximum output power of up to 760 mW. In the negative net cavity dispersion regime, the pulse width was not reduced further by inhomogeneous group delay dispersion (GDD) compensation. In the same laser cavity, we replaced only the graphene-SA based on CaF₂ with the SA based on ZnSe. Due to the additional self-phase modulation effect induced by the ZnSe substrate with high nonlinearity, the stably mode-locked Cr:ZnS laser produced Fourier transform-limited ~130 fs near 2,340 nm. In the stable single-pulse operation regime, average output powers up to 635 mW at 234 MHz repetition rates were achieved. To our knowledge, this is the first attempt to achieve shorter pulse widths from a polycrystalline Cr:ZnS laser by utilizing the graphene deposited on the substrate with high nonlinearity.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.255-261
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• 2015

Purpose: purchasing status and understanding trends of Functional progressive addtions lenses buyers', Correlation analysis of the Binocular Function value to determine ADD then can be apply sales and prescriptions. Methods: Years 2011 to 2014, 298 patients who were prescribed functional progressive lenses were analysed based on the prescription data and SPSS (Ver. 20.0) was treated using the statistics. Results: Results: The average age of our customers are $27.66{\pm}11.55$ years, average addition power is $+0.73{\pm}0.36D$, customers are using take a prescription of ADD $+0.75{\pm}0.28D$ was the highest 44.33% to 132 people. Near point of convergence of 276 people (92.62%) was mostly less than 10 cm, and near point of accommodation of 134 people (44.97%) was also below 10 cm, within 11~15 cm were 122 people (40.94%). Most of people were within normal range in terms of Near point of convergence and near point of accommodation, near point of accommodation tend to be longer than Near point of convergence. As you can see this result shows most of customers need extra help in their near point of accommodation instead of they are leak at it. FCC (Fused cross cylinder) check Value and ADD (addition power) tests showed that the value of a strong correlation (p=0.00), NPC and NPA were also p=0.001, the correlation of the NPC and ADD is p=0.003, In addition, NPA and ADD also showed a significant correlations (p=0.005). Near Point of Accommodation, negative relative accommodation, and positive relative accommodation are all significantly correlated (p=0.00). The short distance-related variables of the ADD which are NPC, NPA, Age, also appeared to side correlate significantly with each other. Conclusion: Binocular function values of the subjects were highly correlated with each other so precise examination is required. when Age young people are working at short distance, low ADD values was prescribed for solving discomfort. So, in the case of early presbyopia, accommodative insufficiency, or people feel fatigue when they often working at near although their accommodation function is normal, when functional progressive lenses are prescribed, expectation of this should be exactly notified.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.241-247
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• 2012

Purpose: This study was conducted to assess the association of metabolic syndrome and its components with glaucoma. Methods: We investigated the associations of metabolic syndrome and its components (abdominal obesity, impaired fasting glucose, high blood pressure, and dyslipidemia) with glaucoma using data from 19,162 adults aged 40 or above among the Korean National Health and Nutrition Examination Survey III (2005), IV (2007-9), V (2010). The logistic regression analysis was used for assessing those associations after adjusting demographic, lifestyle, and social economic status and for assessing the association of metabolic medication intakes with glaucoma risks. Results: After adjusting for age and sex, the risk of glaucoma was significantly higher in the subjects with impaired fasting glucose(Odds Ratio (95% confidence interval): 1.78 (1.25, 2.53)) and metabolic syndrome (1.45 (1.01, 2.08)) than subjects without those. These associations increased when additional adjusting for smoking, alcohol use, regular physical activity, income, education status(impaired fasting glucose: 1.89 (1.29, 2.77), metabolic syndrome: 1.52 (1.03, 2.25)). Glaucoma prevalence was borderline significantly increased according to the number of metabolic abnormalities(age and sex adjusted p for trend = 0.055). Use of antihypertensive medication was significantly associated with the risk of glaucoma. Conclusions: Metabolic syndrome and impaired fasting glucose were significantly associated with the increased glaucoma risk. Use of antihypertensive medication was also significantly associated with the increased glaucoma risk.