• 대한전자공학회논문지
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• 제25권1호
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• pp.94-100
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• 1988

To improve the switching time of active optical bistable devices, we propose an active optical bistable device that consists of a diode laser, a transistor, and a photodetector. By implementing the proposed device we realize the optical bistable device with a 5 nanosecond switching time. This is the fastest switching time among the hybrid type optical bistable devices. It is also experimentally demonstrated that the proposed device may be used in an optical disc pick up.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.831-833
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• 2003

BLDC (Blush-Less Direct Current) motors are widely used for machine tools and ODD (Optic Disc Drive). Topology Optimization is applied to the rotor of a BLDC motor to improve in efficiency and save money. Density method and design sensitivity are derived. The result of topology optimization shows better performance.

• 대한안과학회지
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• 제59권11호
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• pp.1097-1102
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• 2018

목적: 클로르페나피르 음독 후 중추신경계 손상을 동반한 독성 시신경병증 1예를 보고하고자 한다. 증례요약: 44세 여자가 7일 전부터의 양안 시력저하를 주소로 내원하였다. 환자는 내원 2주 전 자살 목적으로 클로르페나피르 한 모금을 음독했고, 직후 근처 병원에서 위세척을 시행하였다. 초기 최대교정시력은 우안 안전수지 30 cm, 좌안 안전수동이었다. 양안 동공은 5.0 mm로 커져 있었고, 빛에 대한 반응은 느렸으며 좌안에는 상대구심동공운동장애가 관찰되었다. 안저검사에서 양안 시신경유두부종이 관찰되었고, 뇌자기공명영상에서 양안 시신경과 속섬유막, 뇌량, 중소뇌각, 뇌간 등 백질 신경로를 따라 양쪽에 대칭적인 고강도신호가 관찰되었다. 클로르페나피르 중독으로 인한 독성 시신경병증으로 진단 후, 고용량 스테로이드치료를 3일간 시행하였으나 양안 최대교정시력은 광각무로 악화되었다. 3개월 후, 안저검사에서 양안 시신경위축이 관찰되었고, 빛간섭단층촬영에서 망막신경섬유층 및 신경절세포-내망상세포층 두께가 감소하였다. 결론: 매우 적은 양이라도 클로르페나피르에 노출되면 적절한 치료에도 불구하고 잠복기를 거쳐 심각한 시신경손상이 발생할 수 있으므로 주의해야 하겠다.

• 한국수의병리학회지
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• 제7권1호
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• pp.17-21
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• 2003

From February to September in 1996, a lot of blind cattle were reported in Dangjin Area of Chungnam Province. Blindness were observed in the 143 calves of the 1,496 calves from 79 farms. Blind cattle were found only in the farms where green pasture was not fed. After administration of vitamin A as the type of feed additives and parenteral injection, the blindness cases were not occurred in those farms. Both pupils were totally dilated with the absence of pupillary light reflex in all blind cattle. In the ophthalmoscopic examination, the fundus revealed multi focal linear white mottling which was more severe in nontapetal fundus than tapetal fundus. Serum vitamin A concentration was as low as 4.1 ,$\mu\textrm{g}$/dl in the calves of the affected farms. Narrowing of optic foramen, retinal degeneration and optic disc atrophy were shown in pathological findings.

• 대한수의학회지
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• 제58권4호
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• pp.219-221
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• 2018

A 2-year-old intact female Bengal cat was presented with a 6-month history of visual impairment. The cat manifested bilateral negative menace responses and dazzle reflexes and sluggish pupillary light reflexes. Bilateral fundus changes included generalized tapetal hyperreflectivity, advanced retinal vascular attenuation, and increased pallor of the optic disc. A diagnosis of bilateral retinal degeneration was made. The clinical findings suggest that the investigated Bengal cat was most likely to have an inherited retinal degeneration. Further studies of the Bengal cat breed are needed to determine the prevalence of inherited retinal degeneration in this breed in Korea.

• Korean Journal of Ophthalmology
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• 제32권6호
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• pp.470-477
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• 2018

Purpose: To investigate the relationship between the progression of visual field (VF) loss and changes in lamina cribrosa depth (LCD) as determined by spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging in patients with primary open angle glaucoma (POAG). Methods: Data from 60 POAG patients (mean follow-up, $3.5{\pm}0.7$ years) were included in this retrospective study. The LCD was measured in the optic disc image using SD-OCT enhanced depth imaging scanning at each visit. Change in the LCD was considered to either 'increase' or 'decrease' when the differences between baseline and the latest two consecutive follow-up visits were greater than the corresponding reproducibility coefficient value ($23.08{\mu}m$, as determined in a preliminary reproducibility study). All participants were divided into three groups: increased LCD (ILCD), decreased LCD (DLCD), and no LCD change (NLCD). The Early Manifest Glaucoma Trial criteria were used to define VF deterioration. Kaplan-Meier survival analysis and Cox's proportional hazard models were performed to explore the relationship between VF progression and LCD change. Results: Of the 60 eyes examined, 35.0% (21 eyes), 28.3% (17 eyes), and 36.7% (22 eyes) were classified as the ILCD, DLCD, and NLCD groups, respectively. Kaplan-Meier survival analysis showed a greater cumulative probability of VF progression in the ILCD group than in the NLCD (p < 0.001) or DLCD groups (p = 0.018). Increased LCD was identified as the only risk factor for VF progression in the Cox proportional hazard models (hazard ratio, 1.008; 95% confidence interval, 1.000 to 1.015; p = 0.047). Conclusions: Increased LCD was associated with a greater possibility of VF progression. The quantitative measurement of LCD changes, determined by SD-OCT, is a potential biomarker for the prediction of VF deterioration in patients with POAG.

• 한국임상수의학회지
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• 제32권1호
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• pp.123-126
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• 2015

A 14-year-old, male Shih-tzu was presented with glaucoma in the left eye. Menace response was negative in the left eye. On ophthalmic examination, exotropia, buphthalmos, bulging of upper lateral globe and episcleral injection was detected in the left eye. Also, there was corneal edema, corneal pigmentation and hyphema in the left eye. The pupil was difficult to observe due to corneal lesions in the left eye. On ultrasonographic examination, an amorphous large mass protruding from the region of the optic disc into the vitreous was observed in the left eye. Enucleation was performed in the left eye. Histologically, the left intraocular mass was diagnosed as glioma. Immunohistochemically, the neoplastic cells were positive to glial fibrillary acidic protein.

• 대한수의학회지
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• 제41권1호
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• pp.113-121
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• 2001

Beagle is one of the most popular laboratory animal in a dog. We investigated the incidence of spontaneous ophthalmic disease in Beagles in order to make basic data for quality control of Beagles in Korea. We surveyed 389 beagles from 3 different farms. The average prevalence rate of ophthalmic diseases was 19.3%. The prevalence rate of cataracts was higher than any other ophthalmic diseases, 7.5% and then in order of corneal scar(2.1%), retinal hemorrhage(1.5%), post-inflammatory retinal change(1.5%), cherry eye(1.0%), distichiasis(0.8%), entropion(0.8%), hypoplastic optic disc(0.8%), conjunctivitis(0.5%), retinal dysplasia(0.5%), asteroid hyalosis(0.3%), congenital eye anomaly(0.3%), corneal lipidosis(0.3%), conjunctival hemorrhage(0.3%), lens capsule pigmentation(0.3%), persistent hyperplastic primary vitreous (0.3%), posterior synechia(0.3%), eyelid tumor(0.3%) and uveal cyst(0.3%) were diagnosed. There was a slight difference between male(24.8%) and female(17.4%) in prevalence rate of ophthalmic disease. The incidence of spontaneous ophthalmic disease was increased with age. These data would be useful for using Beagles as laboratory animals and standard reference for quality control of dogs.

• 한국정보기술학회논문지
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• 제17권5호
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• pp.77-82
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• 2019

당뇨망막증은 망막의 말초혈관에 순환장애가 일어나 발생하는 당뇨병의 합병증으로, 이를 진단하기 위하여 미세혈관류를 분할하였다. 기존 필터와 특징을 사용한 혈관분할은 두꺼운 혈관은 비교적 잘 분할을 하나, 미세한 혈관에 대해서는 정확도가 떨어진다는 단점이 있다. 그리하여 전처리로 노이즈 제거를 위한 필터, 영상 대비를 위한 히스토그램 평활화를 사용하였으며, 픽셀 단위 분할을 위해 딥러닝 기법을 이용하였다. 기존 방법의 정확도는 90% ~ 94%이며, 제안한 방법의 정확도는 95%이다. 결과 영상에서 시신경 유두 및 삼출몰 주변에서 분할 오류가 나타나는 문제점이 있으나, 이는 네트워크 깊이가 얕음에 의한 오류로 향후 네트워크 변경을 통해 정확도를 개선할 수 있다.

• 한국게임학회 논문지
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• 제12권1호
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• pp.103-111
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• 2012

1970년대의 게임은 소형카세트와 축음기 등의 하드웨어에 음악 등과 같은 아날로그 파형을 저장하여 사용하였다. 이러한 구성 요소들로 인해 내구성이 매우 떨어질 수 밖에 없었다. 비디오 게임에 음악을 사용하는 경우 보다 저렴한 방법은 컴퓨터 칩을 사용하여 아날로그 음형을 컴퓨터 코드로 변환해 스피커로 보낼 수 있는 전기 파형으로 변환하는 것이다. 게임 음향 효과도 이와 같은 방식으로 생성되었다. 기술적 한계가 점점 극복되어, 작곡가들에게는 더 많은 자유가 부여되었으며 광디스크 등에 의해 미리 녹음된 사운드 트랙이 출현하게 되었다. 오늘날의 게임 개발자는 게임음악을 제작하는 기술에 대해 여러 가지 시도를 하고 있다. 게임 음악 제작의 변화가 기술과 비즈니스 영향을 받아 발달하는 과정에 따른 연구를 고찰하였다.