• Title/Summary/Keyword: eye development

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Study on Retrodirective Cross-eye Structure using Linear Phased Array Antenna (선형 위상배열 안테나를 이용한 역지향성 크로스아이 구조에 관한 연구)

  • Kim, In-seon;Park, Jintae;Kim, Ghiback;Park, Beomjun;Jang, Yeonsoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.1
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    • pp.11-17
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    • 2020
  • This study proposes a novel structure for the cross-eye, one of the representative jamming techniques of monopulse sensors. The proposed jammer tranceivers are composed of multi-channels with phased array antenna. We named this structure PRCJ(Phased array Retrodicetive Cross-eye Jammer). In this structure, formulas for calculating cross-eye gain and distance error are derived. We compare the properties of PRCJ with two-element retrodiredtive cross-eye jammer(TRCJ). PRCJ can achieve higher J/S because this structure can steer the spatially combined jamming signal in the direction of the incident monopulse signal. Because of the multiple channels in the phased array, it also increases the degree of freedom of channel matching. Finally, We preform a statistical analysis of the cross-eye gain according to the amplitude and phase errors. From this results, It has been found that PRCJ can get higher cross-eye gain than TRCJ.

Deception Performance Analysis of Cross Eye Technique against Conical Scan Radar (크로스 아이 기법의 원추형 스캔 레이더 기만 성능 분석)

  • Jang, Yeonsoo;Park, Jintae;Cho, Jihaeng;Lee, Changhoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.5
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    • pp.583-590
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    • 2018
  • Cross eye technique was proposed as an angle deception jamming technique against monopulse radars. Tracking radars use monopulse or conical scan methods for angle estimation of a target. Thus, if we verify deception performance of cross eye technique against a conical scan radar, efficient jamming systems can be developed to disturb both monopulse radars and conical scan radars. In this paper, we propose a mathematical model for a conical scan radar and a cross eye system. Using the proposed model, angular deception performance of the cross eye technique against conical scan radar is analyzed.

Cross Eye Technique with Single Transceiver (단일 송수신기 구조의 크로스 아이 기법)

  • Jang, Yeonsoo;Lee, Changhoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.5
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    • pp.598-605
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    • 2016
  • One of the effective methods for angular deception against monopulse radar is a cross eye technique. The typical cross eye technique can cause significant angular errors to monopulse radar by using two transceivers which transmit the signals with opposite phases. However, typical cross eye systems have high complexity of implementation because two transceivers should be installed with enough distance on the platform. In this paper, we propose a new cross eye technique with single transceiver based on the multipath effect. Then, angular deception performance of the proposed technique is analyzed.

Molecular Characterization of the Ocular EST Clones from Olive Flounder, Paralichthys olivaceus

  • Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Choul-Ji;Min, Byung-Hwa;Ha, Su-Jin;Park, Jong-Won;Kim, Young-Ok;Kim, Jong-Hyun;Kim, Kyung-Kil;Kim, Woo-Jin;Myeong, Jeong-In
    • Development and Reproduction
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    • v.14 no.2
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    • pp.107-113
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    • 2010
  • The olive flounder (Paralichthys olivaceus) is one of the most widely cultured flatfish in Korea and Japan. During development, in a process known as metamorphosis, this fish reorients itself to lie on one side, the body flattens, and the eye migrates to the other side of the body. However, few studies have focused on molecule regulation mechanism of eye development in olive flounder. To reveal the molecular mechanism of eye development, we performed the studies on identification of genes expressed in the eye of olive flounder using EST and RT-PCR strategy. A total of 270 ESTs were sequenced, and 178 (65.9%) clones were identified as known genes and 92 (34.1%) as unknown genes. Among the 178 EST clones, 29 (16.3%) clones were representing 9 unique genes identified as homologous to the previously reported olive flounder ESTs, 131 (73.6%) clones representing 107 unique genes were identified as orthologs of known genes from other organisms. We also identified a kind of eye development associated proteins, indicating EST as a powerful method for identifying eye development-related genes of fish as well as identifying novel genes. Further functional studies on these genes will provide more information on molecule regulation mechanism of eye development in olive flounder.

Differential Expression Patterns of Crystallin Genes during Ocular Development of Olive Flounder (Paralichthys olivaceus)

  • Yang, Hyun;Lee, Young Mee;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul Ji;Park, Jong Won;Hwang, In Joon;Kim, Sung Yeon;Lee, Jeong Ho
    • Development and Reproduction
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    • v.16 no.4
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    • pp.301-307
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    • 2012
  • Olive flounder Paralichthys olivaceus is one of the most widely cultured fish species in Korea. Although olive flounder receive attention from aquaculture and fisheries and extensive research has been conducted eye morphological change in metamorphosis, but little information was known to molecular mechanism and gene expression of eye development- related genes during the early part of eye formation period. For the reason of eyesight is the most important sense in flounder larvae to search prey, the screening and identification of expressed genes in the eye will provide useful insight into the molecular regulation mechanism of eye development in olive flounder. Through the search of an olive flounder DNA database of expressed sequence tags (EST), we found a partial sequence that was similar to crystallin beta A1 and gamma S. Microscopic observation of retinal formation correspond with the time of expression of the crystallin beta A1 and gamma S gene in the developmental stage, these result suggesting that beta A1 and gamma S play a vital role in the remodeling of the retina during eye development. The expression of crystallin beta A1 and gamma S were obviously strong in eye at all tested developing stage, it is also hypothesized that crystallin acts as a molecular chaperone to prevent protein aggregation during maturation and aging in the eye.

Studies on the Early Development of the Mouse Embryo Transplanted in the Anterior Chamber of the Eye (眼前房내에 이식한 생쥐배의 초기발생에 관한 연구)

  • Cho, Wan Kyoo;Kim, Moon Kyoo
    • The Korean Journal of Zoology
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    • v.15 no.1
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    • pp.25-33
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    • 1972
  • Two-Cell mouse embryos were incubated in the anterior chamber of the rat eye, which has been known as the best place among other animals' for the mouse ovum maturation, in order to observe the capability of their early development. Within 120 hours after incubation, 71.0% of two-cell embryos have developed to the blastocysts in the male rat eye, while only 38.5% in the eye of the same mouse as donated two-cell embryos. Thus, the rat eye chamber provides more favourable environment to the embryos than the mouse itself. The results are consistent with those of the previous studies comparing the maturation of the mouse follicular oocytes in the mouse and the rat eye chamber. Although the aqueous humor which is filled in the anterior chamber of the eye is characterized by its specific properties, being of higher osmolarity, higher concentrations of ascorbic acid, pyruvate and lactate, but lower of proteins and lower temperature than those in blood or lymph serum, The embryos are able to under-take their cleavage as normal as in vivo or in vitro. Concerning with a number of studies in vitro on the development of the mouse embryos which are requiring a very limited condition, the fact that they are able to manage their further development under very different enviroment from our knowledges would provide us a moment to understand their behavior during the early development. The difference of the proportion of the developed blastocysts between in the mouse eye chamber and in the rat can possibly be resulted from the species specific difference in the physicochemical properties between their eye chambers. This assumption is based upon the findings by many investigators who chmpared the nature of the eye chamber of various animals. As a consequence, the rat eye chamber might consist of better properties for the embryonal growth than the mouse eye chamber. The mouse embryos cleaved with a delayed period. In normal development they complete almost the cleavage within 94 hours after fertilization. However, in the present studies, 81.1% of two-cell embryos developed to the blastocysts and the morula in 120 hours in the eye chamber, assumed to be about 154 hours after fertilization. Such delay in development would be caused mainly by the low temperature of the eye chamber. At present we can make two assumptions to explain the capability of the emtryonal development in the eye chambers. One is that the embryos would possess an ability to adapt themselves to the environment which provides unfavourable conditions. The other is that the embryos might remain for a certain duration in the eye chamber, which is filled with a new body fluid produced immediately after the loss of the aqueous humor and the fluid of which becomes similar to blood serum in component. The first assumption is highly reliable since the embryonal cells are mostly at the undifferentiated state and so they probably engage a simple metabolism during their early period. The second assumption is induced by the fact that the rabbit eye chamber produces a plasmoid humor which has mostly similar components to blood serum after loss of aqueous humor through cornea by puncturing. However, the plasmoid humor is substituted by the initial aqueous humor in eight hours. Even though this finding, production of the new fluid, could be applied to the rat eye, it is hardly reliabel that the plasmoid humor remains for such a long period as 120 hours. Consequently, the development of the embryos is more likely due to their adaptability to the new environment during their early developmental stages.

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Development of Low-Cost Vision-based Eye Tracking Algorithm for Information Augmented Interactive System

  • Park, Seo-Jeon;Kim, Byung-Gyu
    • Journal of Multimedia Information System
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    • v.7 no.1
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    • pp.11-16
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    • 2020
  • Deep Learning has become the most important technology in the field of artificial intelligence machine learning, with its high performance overwhelming existing methods in various applications. In this paper, an interactive window service based on object recognition technology is proposed. The main goal is to implement an object recognition technology using this deep learning technology to remove the existing eye tracking technology, which requires users to wear eye tracking devices themselves, and to implement an eye tracking technology that uses only usual cameras to track users' eye. We design an interactive system based on efficient eye detection and pupil tracking method that can verify the user's eye movement. To estimate the view-direction of user's eye, we initialize to make the reference (origin) coordinate. Then the view direction is estimated from the extracted eye pupils from the origin coordinate. Also, we propose a blink detection technique based on the eye apply ratio (EAR). With the extracted view direction and eye action, we provide some augmented information of interest without the existing complex and expensive eye-tracking systems with various service topics and situations. For verification, the user guiding service is implemented as a proto-type model with the school map to inform the location information of the desired location or building.

Product Analysis and Development of Amblyopia Eye Patch for Children

  • Lim, Hosun;Sung, Juyoung
    • Fashion, Industry and Education
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    • v.14 no.2
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    • pp.1-10
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    • 2016
  • In the present study, the materials, sizes, and designs of blind eye patch products of skin-adhesive type and glass-attachment type currently available in the market will be analyzed and ergonomically appropriate blind eye patches will be developed. Although these skin-adhesive type eye patches were easy to use, they had shortcomings such as skin troubles due to the adhesive used on the weak and sensitive skin of children and the fact that eyebrows are pulled out and the skin is irritated when the eye patches are detached after being attached. The non-adhesive type eye patches were blind patches to be worn by putting into glasses. These products were made using diverse materials such as neoprene, non-woven fabrics, and felt and showed differences in tactile impressions and irritation to the skin depending on material characteristics. In addition, most products were efficient in blocking light with three-dimensional oval designs comprising darts. In the present study, blind eye patches were designed to reduce skin troubles by using sweat-absorbing and quick-drying functional materials with soft tactile impressions. In addition, to increase the effect to block light and the degree of tight contact with the skin when the blind eye patches are worn compared to existing eye patch designs, the sides of the wings of the blind eye patches were widened, glass frame fixing plates were added, and the darts were made to be curved thereby making an ergonomic design reflecting the shape of the face. The non-adhesive type blind eye patches developed in the present study are considered to enhance the wearing sensation with the use of the material without skin irritation but with cushioning feelings and the ergonomic design reflecting the contour of the face.

A Study on the Design of Fish-Eye Optic for Automotive Stop Light (자동차용 제동등을 위한 FISH-EYE OPTIC 설계에 관한 연구)

  • 임지만;이정환;서명원
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.231-240
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    • 1999
  • The most important thing to be considered in designing stop lamps for automobiles is to satisfy the photometric requirement in various countries and achieve the equal image. To meet these requirements, parabolic reflector and fish-eye optics has been widely applied. The form of the embodied optic is most important in satisfying the photometric requirement and achieving the equal image because the impact of fish-eye optic is decisive. In this study, a series of researches has been performed to optimize of the fish-eye optic by analyzing beam pattern through the photometric simulation based on CATAI program. The optimized results have been shown to meet the various photometric requirements including non dazzling condition considering the following car. The methodology of this study is excepted to influence the development procedure of light system. The time and cost for the system development would be greatly saved by suing this simulaion technique.

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Methodology Development of Clothing Appearance by Eye Movement Analysis (안구운동 분석을 통한 의복의 시각적 평가의 객관화)

  • Park Hye-Jun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.6 s.154
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    • pp.992-1000
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    • 2006
  • The main purpose of this research is to develop the methodology of objective evaluation of clothing appearance by eye movement analysis. The visual clothing items used in this study were skirt, one-piece, pants and shirt with the style variation of silhouette and details. By observing eye movement during visual evaluation of clothing, we can achieve the basic fixation data of eye movement. Moreover, we developed the Matlab program to extract the fixation coordinate and number of eye fixation on each part of the clothing item. As results, there were differences in the duration of fixation time for each item and the fixation time was not different by styles within a clothing item. However, we could find differences in the fixation time within a style, in other words, we could select the important parts of the clothing by observing the fixation time in a certain clothing item. It is also noted that time required in visual information processing differs depending on the item, and there was a region which contain more information independent with styles in the same item. By developing the objective method of visual evaluation that correspond to human's visual information processing, the results are expected to be applied in the retrieval program in internet shopping mall or in the development of contents for advertisement of clothing.