• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.471-477
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• 2014

Purpose: We have analyzed the transmittance distribution of the ocular lens using local transmittance microscope to investigate the optical homogeneity of the lens. Methods: The transmittance of the laser which is focused on the surface of the ocular lens was measured by using the photo-detector and lock-in amplifier and analyzed. Multi-coated, uncoated, and progressive lenses were analyzed. Results: In the measurement of the progressive lens and a physical stimulated lens, local transmittance microscopy analysis showed a high degree of match with the measurement results through the optical microscope. In addition, the average value of the transmittance is reduced and the standard deviation was increased in the presence of optical defects. In unstimulated lens, there are a large impact on transmittance whether the anti-reflective coating is presence or absence in both the local transmittance microscopy and general transmittance analysis. Conclusions: The distribution of the transmittance measured by local transmission microscopy were changed when the various stimulus is applied to the lenses. These analyzes by local transmission microscopy can be utilized as a way to evaluate or determine the uniformity of the coating film or lens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.93-103
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• 2016

This study consisted of descriptive research to determine the prevalence of dry eye disease using the Ocular Surface Disease Index (OSDI) questionnaire targeting workers in hospitals to understand the differences between general and health related characteristics depending on whether people have dry eye disease, and to determine the influencing factors of the disease. The subjects were 502 (Male: 51, Female: 451) general hospital employees in G-city. The data were collected from October 1 to October 31, 2015. Logistic regression was used to analyze the data. The results showed that hospital workers' prevalence of dry eye disease was 76.1%. Factors influencing DED in this population included currently having or adjusting medication (OR: 4.73), among those who felt their eyes dry, those who visited clinics and received medical treatment (artificial tears) (OR: 2.37), those who felt eye dryness (OR: 2.23), and not eating regularly (OR: 0.55). Moreover, 54.0% of those who had dry eye disease reported serious conditions. Accordingly, education to manage the risk factors of the disease and improve lifestyle is needed to prevent and manage dry eye disease.

• Elastomers and Composites
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• v.30 no.3
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• pp.207-217
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• 1995

The reinforcement of Inorganic filler silica treated with LBR-MDI In SBR vulcanizates were Investigated. The inorganic filler silica treated with MDI on unmodified surface and that of silica treated by MDI was retreated with LBR. The charateristics of vulcanization, physical properties, surface properites and dynamic properties were investigated after mixing those silica with SBR and unmodified silica with SBR. Rheometric studies of the vulcanization showed that S-series has fast scorch $time(t_{10})$ and an optimum cure $time(t_{90})$ in the SBR compounds. And it was turned out that SBR vulcanizates compounded with LBR treated silica was better than any other componnds in hardness, tensile strenght, 100 300% modula and elongation. We could confirm that urea bonding is formed from IR spectrum. We concluded that L-series shows the best reinforcement effect in SBR vulcanizates.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.41-44
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• 1996

There are studied for filmness methods due to disadvantage of conventional X-ray system. Have high DQE, high SNR, amorphous selenium was investigated with image plate. In this point, characteristics of all amorphous selenium image plate was investigated to understand the relationship between the amount of the X-ray exposure and the superficial charge potential in this study. Specially, changes in charge at the surface of the amorphous selenium plate with respect to change of X-ray energy(KeV) was investigated. It was found that the surface charge potential at the amorphous selenium inclosed with respect to the increse in X-ray exposure and that the changed surface potential was a semilinearity in 12.5KeV - 22.5KeV range. Therefore, which suggests that these results call be applied to the development of X-ray image plate.

• 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 Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.471-476
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• 2015

Purpose: We have analyzed the transmittance distribution of various ocular lenses using local transmittance microscope to investigate the optical homogeneity of the lens. Methods: The local transmittance of the laser which is focused on the surface of the spectacle lens was measured by using the photo-detector, lock-in amplifier and motorized-stage. 25 multi-coated lenses with non-tinted of 5 groups and 45 multicoated lenses with tinted of 9 groups were analyzed as a sample respectively. Results: Average and deviation of local transmittance for nontinted lenses were measured almost uniformly with various refractive index and coating. However, deviation of transmittance of for tinted lenses was analyzed as about 3.7 times larger than that of non-tinted lenses. Inhomogeneity of local transmittance of for tinted lenses was also analyzed as about 3.1 times larger than that of non-tinted lenses. Conclusions: We could analyze that standard deviation of transmittance and inhomogeneity of local transmittance of for tinted lenses is larger than that of non-tinted lenses using the local transmittance microscope. These analysis using local transmittance microscope can be utilized as a way to evaluate lens performance and improve optical homogeneity.

• Journal of applied mathematics & informatics
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• v.32 no.5_6
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• pp.649-663
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• 2014

Presence of eyelid on anterior ocular surface and its thermal effects play significant role in maintaining eye temperature. In most of the literatures of thermal modeling in human eye, the eyelid is not considered as an eye component. In this paper, finite element model is developed to investigate the thermal effects of eyelid closure and opening in human eye. Based on different properties and parameter values reported in literatures, the bio-heat transfer process is simulated and compared with experimental results in steady and transient state cases. The sensitivity analysis using various ambient temperatures, evaporation rates, blood temperatures and lens thermal conductivities is carried out. The temperature values so obtained in open eye show a good agreement with past results. The closure of eyelid is found to increase/decrease the eye temperature significantly than its opening, when the parameter values are considered to be at extreme.

• Journal of Veterinary Clinics
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• v.35 no.6
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• pp.311-314
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• 2018

Squamous cell carcinoma (SCC) is a form of neoplasm that origins from the epithelial surface of many organs. Ocular occurrence in small animals is rare, especially in the central cornea without the involvement of limbus or conjunctiva. In the current case, a 10-year-old, spayed female Shih-Tzu was presented with a central corneal mass. Through an ophthalmic examination the sign of corneal scarring around the mass was found. Pink fleshy lesion that protruded outward was removed through superficial keratectomy. The mass with the size of $8.5{\times}6.5$ millimeter was histopathologically diagnosed as corneal SCC infiltrating not only the epithelium, but also the superficial corneal stroma with surrounding superficial lymphoplasmacytic and neutrophilic chronic keratitis. Also, the adjacent, non-affected corneal epithelium was markedly hyperplastic and keratinized; the adjacent stroma was moderately vascularized and fibrotic. The pulse-dose therapy using 1% topical 5-flourouracil were applied for five cycles. The tumor has not recurred through nine months of follow-up time.

• Korean Journal of Veterinary Service
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• v.22 no.2
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• pp.113-119
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• 1999

The most common cause of death is ostrich chick fading syndrome(OCFS), which is due to bacterial infection during artificial incubation and hatching. Six farmed ostrich chicks aged 3 and 10 days in Chonbuk province, were submitted to Chonbuk Livestock Development and Research Institute for necropsy, Clinically, birds showed hair loss, ocular exudate, lethargy, diarrhea, and subsequently died 3-5 days after onset of clinical signs. Grossly, umbilicus was enlarged. White-yellowish purulent nodules were scattered on the lung and the membrane of air-sac was thickened and had inflamed exudate on the surface in two chicks that died 3 days after hatching. In 10 days-old chick, intestine was shown rodding segmentally. Yolk sac was still retarded and its surface was partially hemorrahgic. The synovial fluid of the leg was yellowish. Microscopically, multifocal purulent exudates were scattered on the lung. Capillary microthrombi in the glomerulus were prominent and tubular epithelia were necrotic. Necrotic hepatocytes were scattered and intestine were congested. Microbiologically, Pseudomonas sp and/or E coli were isolated from air-sac, lung and/or liver. This case suggests that poor hygiene during artificial incubation, hatching or in the first week after hatching may cause high mortality of the ostrich chicks.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.265-274
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• 2016

Purpose: The aim of this study was to evaluate relationship between worker's ophthalmoxerosis symptom and IAQ (Indoor Air Quality) variation after planting indoor plants at newly-built office building. Methods: We selected a new office building located in Sejong-si and occupants who work in the Office for study. The indoor air pollutant was investigated according to applying indoor plants. The indoor air quality of the new building was evaluated by measuring volatile organic compounds (VOCs), aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). Results: There was VOCs' reduction effect according to placing indoor plants because the concentration of VOCs in newly-built government office (Sejong-si) was highly decreased when the indoor plants was placed at the office. The occupants' SBS (Sick Building Syndrome) symptoms score was gradually decreased in accordance with applying indoor plants. However, SBS symptoms score was increased when the office was not applied indoor plants. There was not statistical significance in workers' dry eye questionnaire results. Conclusions: There was reduction effect of indoor air pollutant in applied indoor plants office. Also, in case of questionnaire results of ophthalmoxerosis and SBS (Sick Building Syndrome) symptoms score were showed positive effect. This study is needed longer-term study because of complements of difference of individual sensitivity and there are some limitations due to field survey research.