• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.67-71
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• 2016

Two Korean Rhodeus bittering fishes are known as having a unique reproduction system that the female deposits its egg inside freshwater mussels. Among them, R. ocellatus and R. uyekii show an ecological difference in feeding items and micro-habitat. Through a light microscope, the visual cells of the retina in the two species were investigated to get information between vision and environment related with habitat. The two fishes' eyes are spherical and R. ocellatus has relatively larger eyes. For the two species, the visual cells of the retina consisted of long single cones, short single cones, unequal double cones and rods. In the cones, all show a row mosaic pattern. Although the two species have a different micro-habitat in the wild, the component of the visual cells was very similar to each other.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.218-223
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• 2017

Using both light and scanning electron microscopies, it was investigated on the visual cells as well as the eyes of Macropodus ocellatus (Pisces, Osphronemidae). This species had a circular lens and yellowish cornea. The eyes had $3.5{\pm}0.2mm$ which is $31.1{\pm}3.0%$ in a percentage of eye diameter relative to head length. The retina ($158.2{\pm}10.6{\mu}m$) was built of several layers, including the visual cell layer which consists of three types of cells: single cons ($27.8{\pm}1.6{\mu}m$) and equal double cone ($33.9{\pm}3.7{\mu}m$), and large rods ($57.3{\pm}1.3{\mu}m$). The visual cell layer then was classified into the correct pattern. All visual cells were clearly distinguished from two parts (inner and outer segments). The elongated rod cells were extend to the bottom of the retinal pigment epithelium. In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles. The M. ocellatus single and double cones appearance form a flower-petal arrangement, which is a regular mosaic pattern that contains quadrilateral units by four double cones surrounding a single cone.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.257-262
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• 2015

The visual cells in the retina of Iksookimia longicorpa (Pisces, Cobitidae) were investigated by light and scanning electron microscopes. The retina ($216.42{\pm}13.36{\mu}m$) has several layers, and the visual cell layer consists of unequal double cones and large rods. In a double cone, two members are unequal such that one cone is longer than the other (long element $26.42{\pm}1.7{\mu}m$, short element $16.82{\pm}1.1{\mu}m$). The cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. The visual cells observed have an outer segment (hematophilic), inner segment (eosinophilic). In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles (calyceal processes) of membrane discs surrounded by double membranes.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.243-247
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• 1998

전자현미경 영상인 유방암 조직세포의 암 분포 정도를 알기 위해, 조직세포중 암이 퍼진 부분과 그렇지 않은 부분에 대해 정량적 분석과 세포수에 의한 분석을 비교하여 보았다. 유방암 조직세포의 면역조직화함염색에서 암이 있는 세포핵은 갈색으로 나타났고, 그렇지 않은 세포는 푸른색으로 나타났다. 이것은 환자를 진단하고 예지하는데 있어서 중요한 요인으로 작용하지만 지금까지는 의사의 주관적인 생각이 다분히 포함된 판단에 의존할 수 밖에 없었다. 의료영상이미지의 시각적 표현을 위해 RGB칼라를 HLS칼라로 변환하여 사용하였으며, 이것은 시각적으로 좀 더 쉽게 갈색세포핵과 푸픈색 세포핵을 구분하게 해 주었다. 두 세포핵을 분리하기 위해 히스트그램의 임계치와 Box classification의 두 알고리즘의 사용하여 추출하였다. 그리고 추출한 세포핵들에 대해 각각 정량적인 분석과 세포수에 의한 분석을 하였다. 이러한 실험은 시각적 병리정밀검사에 좋은 보조도구로 사용될 수 있을 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.393-397
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• 2007

최근 시각 장애인을 위한 인공망막 모델 구현에 관한 연구 중 시피질 자극기 기술은 시각 자극 전달의 중간 단계를 생략하고 직접 뇌세포를 자극하는 것이다. 본 논문에서는 망막에서 시각 피질로 시각정보를 전달할 때 발생하는 시각 피질의 특성, 즉 방향성에 대한 반응 특성을 특징 데이터로 구성하여 인식함으로써 인간 시각 정보 처리와 유사한 영상 추출 및 인식 모델을 제안한다. 제안된 방법은 영상의 특징을 추출 한 후 Delta-bar-delta 기반 오류 역전파 알고리즘을 적용하여 영상의 특징들을 인식한다. 제시된 방법의 성능을 분석하기 위하여 다양한 숫자 패턴들을 대상으로 실험한 결과, 제안된 망막 세포로부터 전달된 정보를 방향성에 대한 민감성을 고려하여 영상의 특성을 추출하여 인식하는 모델이 기존의 영상 추출 및 인식 모델보다 인식률에 있어서는 별 차이가 없지만 다양한 실험에서 확인할 수 있듯이 인간 시각과 같이 인식 성능이 민감하지 않는 것을 알 수 있었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.6
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• pp.477-482
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• 2020

The human visual cortex has the characteristic that reacts sensitively to stimuli with special directional or temporal frequency changes while it is insensitive to selective stimuli of spatial phases. In this paper we implemented the model of complex cell using an image estimation iterative algorithm by Gabor wavelet transform. The performance of implemented model evaluated the consistency between the physiological experimental results in related papers. The implemented model is limited in the complete model of the receptive field in the retina where simple cells and complex cells are distributed together. But the implemented model express the reaction of the complex cells from the point of view of the detection of corners and edges.

• Applied Microscopy
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• v.32 no.1
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• pp.17-30
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• 2002

The retinae of Todarodes pacificus and Octopus minor are divided into four layers that are an outer segment, a rod base region, an inner segment, and a plexiform layer, respectively. The retina of Octopus minor is about $20{\mu}m$ thicker ($400{\sim}420{\mu}m$) than that of Todarodes pacificus ($385{\sim}400{\mu}m$). A retina is composed of visual cells and supporting cells. The microvilli of length $0.6{\sim}0.7{\mu}m$ are packed densely on top of the supporting cells of Octopus minor while they are not found in Todarodes pacificus. The visual cells and supporting cells have pigment granules that exclude light. In case of Todarodes pacificus, the pigment granules of the visual cell are larger ($2.0{\times}0.5{\mu}m$) than those of the supporting cell ($1.0{\times}0.3{\mu}m$). But, the sizes of both cells are similar in Octopus minor. In the upper portion of a visual cell, microvilli shaped like a comb are forming a rhabdome (diameter, 60 nm) of a hexagonal structure. The rhabdome consists of 4 rhabdomere and the total area of a rhabdom of Octopus minor is larger than that of Todarodes pacificus. The synaptosome constructing a plexiform layer in Todarodes pacificus are divided into two types, each of which possess electron dense-core vesicles and electron lucent vesicles, respectively. Octopus minor also has two types of synaptosomes but each type comprises a mixture of electron dense vesicles and electron lucent vesicles, and electron lucent vesicles only, respectively, which is different from the case of Todarodes pacificus.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.199-206
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• 2010

Stem-cell therapy has the potential to improve vision in patients with untreatable retinal disease. Various types of cell source including fetal, embryonic and adult stem cells, intrinsic and extrinsic factors for differentiation into retinal progenitors and transplantation mode were discussed in this review. Experimental approaches have successfully induced photoreceptor precursor cells and retinal pigment epithelium. Stem-cell-based therapy is a promising treatment to restore vision in patients with retinal disease, in spite of the challenges.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.19-23
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• 2003

Neurons in the mammalian visual cortex can be dassified into the two main categories of simple cells and complex cells based on their response properties. Here, we find the complex features corresponding to the response of complex cells by applying the unsupervised independent component analysis network to input images. This result will be helpful to elucidate the information processing mechanism of neurons in primary visual cortex.

• Journal of Life Science
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• v.23 no.6
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• pp.804-811
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• 2013

Melanopsin is an opsin-like photopigment found in the small proportion of photosensitive ganglion cells of the retina. It is involved in the regulation of the synchronization of the circadian cycle as well as in the control of pupillary light reflex. The purpose of the present study is to investigate whether melanopsin is also expressed in the other areas of the central visual system outside the retina. We have studied the distribution and morphology of neurons containing melanopsin in the mouse visual cortex with antibody immunocytochemistry. Melanopsin immunoreactivity was mostly present in neuronal soma, but not in nuclei. We found that melanopsin was present in a large subset of neurons within the adult mouse visual cortex with the highest density in layer II/III. In layer I of the visual cortex, melanopsin-immunoreactive (IR) neurons were rarely encountered. In the mouse visual cortex, the majority of the melanopsin-IR neurons consisted of round/oval cells, but was varied in morphology. Vertical fusiform and pyramidal cells were also rarely labeled with the anti-melanopsin antibody. The labeled cells did not show any distinctive distributional pattern. Some melanopsin-IR neurons in mouse visual cortex co-localized with nitricoxide synthase, calbindin and parvalbumin. Our data indicate that melanopsin is located in specific neurons and surprisingly widespread in visual cortex. This finding raises the need of the functional study of melanopsin in central visual areas outside the retina.