• Title/Summary/Keyword: Natural reproduction

검색결과 412건 처리시간 0.022초

3D TV by electro-holography -- Fast hologram calculation by networking --

  • Koki-SATO;Kunihiko-TAKANO;Takeshi-KOYAMA
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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    • pp.63-66
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    • 1998
  • Recently, a study of Virtual-Reality becomes active. Expectation to 3-D reproduction technology rises with it. Electro-holography using Spatial-light-modulator attracts attention, because natural 3-D animated image is provided. It is important to execute hologram calculation at high speed to realize the real time electro-holography. In other words, a higher-speed computer and a study of calculation algorithm becomes an important subject. This time, we realized to fast calculation of Fresnel-Hologram by networking technology.

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Research for 3D-TV by Electro-holography

  • Koki-SATO
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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    • pp.219-226
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    • 1999
  • Recently a study of Virtual-Reality becomes active. Expectation to 3-D reproduction technology rises with it. Electro-holography using Spatial light modulator (SLM) attracts attention, because natural 3-D animated image is provided. In this paper recent development of 3D-TV by Electro-holography is reported. We consider the conditions to holographic TV such as input, transmission and display systems. Also we consider about fast hologram calculation because It is important to execute hologram calculation at high speed to realize the real time electro-holography. Then we consider the possibility of real time holography.

Recycling of $CO_2$-Silicate Bonded Sand

  • Kwon, Hyuk-Moo;Lee, Seoung-Won
    • Resources Recycling
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    • 제5권1호
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    • pp.9-13
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    • 1996
  • Once-used $CO_2$-silicate bonded sand from domestic foundry is mostly discarded in a reclaimed land because of its bad collapsibility and reproduction properties. So this causes serious environmental problem. We can get 82% recovery of silica from used sand by scrubbing reclamation process in this research. When we repeat the reclamation-recycling of the foundry sand, artificial silica sand is broken down below 2-cycles, but natural silica sand does not destroyed when used repeatedly more than 10-cycles and have a good property of recycling with little change of its size.

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A Study on Categorization and Reproduction of Content Based on Natural Language Processing (자연어처리 기반 콘텐츠 범주화 및 재생산에 대한 연구)

  • Choi, Junsik;Lee, Seoyoung;Lim, Inho;Kim, Youngjong
    • Proceedings of the Korea Information Processing Society Conference
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    • 한국정보처리학회 2019년도 춘계학술발표대회
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    • pp.311-313
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    • 2019
  • 다양한 요약 프로그램이 존재하지만 입력되는 정보의 형태가 텍스트에 한정되어있다. Sumalyze는 그러한 한계점을 보완한 파이썬 언어 기반 라이브러리다. 다양한 형식의 데이터를 입력받으며 컨텐츠의 종류에 맞는 요약과 범주화를 제공한다. 또한, 컨텐츠의 핵심파악을 돕기 위해 요약에 대한 분석을 제공한다.

A NEW CLASS OF INTERPOLATORY HERMITE SUBDIVISION SCHEMES REPRODUCING POLYNOMIALS

  • Jeong, Byeongseon
    • East Asian mathematical journal
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    • 제38권3호
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    • pp.365-377
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    • 2022
  • In this paper, we present a new class of interpolatory Hermite subdivision schemes of order 2 reproducing polynomials. Each member in this class, denoted by Hn for n ≥ 1, preserves polynomials of degree up to 4n + 1 admitting the approximation order of 4n + 2. Furthermore, it has free parameters which provide flexibility in designing curves/surfaces. H1, the simplest and the most attractive scheme in this class, achieves C4 smoothness with the parameters in certain ranges, and its performance is demonstrated with numerical examples.

The Effect of Jazf1 Overexpression in Zebrafish Cardiac Development

  • Shin, Mi-Jung;Yuh, Hyung-Soo;Seo, Byoung-Boo;Park, Hum-Dai;Yoon, Du-Hak;Ryoo, Zae-Young
    • Reproductive and Developmental Biology
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    • 제35권4호
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    • pp.457-461
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    • 2011
  • JAZF1 (Juxtaposed with Another Zinc Finger gene 1) transcription factor are Zn-finger proteins that bind to the nuclear orphan receptor TAK/TR4 (Nakajima et al., 2004). The nuclear orphan receptor TAK1/TR4 functions as a positive as well as a negative regulator of transcription. It was recently reported that congenital cardiovascular malformations are significantly more frequent in Neurofibromatosis 1 (NF1) patients with microdeletion syndrome than in those with classical NF1. JAZF1 was expressed in adult heart of patients with microdeletion syndrome. JAZF1 is highly conserved among various species include zebrafish. We hypothesized that the expression of zebrafish Jazf1 may lead to severe forms of congenital heart disease that allow the survival of newborns and adults. In this study, we created Jazf1 transgenic zebrafish which over-express zebrafish Jazf1 cDNA under control of the CMV promoter. Our results suggested that Jazf1 expression may play an important role in zebrafish cardiac development.

Ganglioside GT1b Mediates Neuronal Differentiation of Mouse Embryonic Stem Cells

  • Lee, So-Dam;Jin, Jung-Woo;Choi, Jin;Choo, Young-Kug
    • Development and Reproduction
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    • 제13권3호
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    • pp.155-161
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    • 2009
  • It has been reported that ganglioside GT1b is expressed during neuronal cell differentiation from undifferentiated mouse embryonic stem cells (mESCs), which suggests that ganglioside GT1b has a direct effect on neuronal cell differentiation. Therefore, this study was conducted to evaluate the effect of exogenous addition of ganglioside GT1b to an in vitro model of neuronal cell differentiation from undifferentiated mESCs. The results revealed that a significant increase in the expression of ganglioside GT1b occurred during neuronal differentiation of undifferentiated mESCs. Next, we evaluated the effect of retinoic acid (RA) on GT1b-treated undifferentiated mESCs, which was found to lead to increased neuronal differentiation. Taken together, the results of this study suggest that ganglioside GT1b plays a crucial role in neuronal differentiation of mESCs.

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In Vitro Maturation of Round Spermatids Using Porcine Oviduct Epithelial Cell Monolayer Condition Medium

  • Jabed Md. Anower;Kamal Tania;Lee Seung-Min;Kim Byung Ki
    • Reproductive and Developmental Biology
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    • 제29권4호
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    • pp.241-245
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    • 2005
  • Porcine oviduct epithelial cells (POEC) are widely used in co-culture experiments to improve early embryonic development, in vitro fertilization in embryo transfer programs for domestic animals and in vitro maturation of immature germ cells. POEC were mechanically isolated and cultured in tissue culture medium 199. Cells grew continuously, and confluent monolayers were formed after 7 days. After forming confluent monolayer of epithelial cells, supernatant was collected as the condition medium for maturing round spermatids in vitro. Round spermatids were also separated mechanically and cultured in the POEC condition medium. In this study we observed that $20\%$ of round spermatid cultured were matured into elongating spermatid after 24 h, and about $10\%$ of round spermatid cultured showed complete elongation (elongated spermatid) within $24\~48$ h of in vitro culture. No further development was observed within $50\~72$ h and transformed cells lost their viability after 72 h. These preliminary findings suggest that the condition medium from POEC may be possible to overcome the round spermatid block by improving the milieu of culture system.

Exploration of Mycobiota in Cypripedium japonicum, an Endangered Species

  • Cho, Gyeongjun;Gang, Geun-Hye;Jung, Hee-Young;Kwak, Youn-Sig
    • Mycobiology
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    • 제50권2호
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    • pp.142-149
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    • 2022
  • Orchids live with mycorrhizal fungi in mutualism. This symbiotic relationship plays an essential role in the overall life cycle of orchids from germination, growth, settlement, and reproduction. Among the 1000 species of the orchid, the Korean lady's slipper, Cypripedium japonicum, is known as an endangered species. Currently, only five natural habitats of the Korean lady's slipper remain in South Korea, and the population of Korean lady's slipper in their natural habitat is not increasing. To prevent extinction, this study was designed to understand the fungal community interacting in the rhizosphere of the Korean lady's slipper living in the native and artificial habitats. In-depth analyses were performed to discover the vital mycorrhizal fungi contributing to habitat expansion and cultivation of the endangered orchid species. Our results suggested that Lycoperdon nigrescens contributed most to the increase in natural habitats and Russula violeipes as a characteristic of successful cultivation. And the fungi that helped L. nigrescens and R. violeipes to fit into the rhizosphere community in Korean lady's slipper native place were Paraboeremia selaginellae and Metarhizium anisopliae, respectively. The findings will contribute to restoring and maintaining the endangered orchid population in natural habitats.

Ruvbl1 is Essential for Ciliary Beating during Xenopus laevis Embryogenesis

  • Chan Young Kim;Hyun-Kyung Lee;Hongchan Lee;Hyun-Shik Lee
    • Development and Reproduction
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    • 제27권3호
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    • pp.159-165
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    • 2023
  • The Ruvb-like AAA ATPase1 (Ruvbl1; also known as Pontin) is an evolutionary conserved protein belonging to the adenosine triphosphates associated with diverse cellular activities (AAA+) superfamily of ATPases. Ruvbl1 is a component of various protein supercomplexes and is involved in a variety of cellular activities, including chromatin remodeling, DNA damage repair, and mitotic spindle assembly however, the developmental significance of this protein is unknown and needs detailed investigation. We investigated the developmental significance of Ruvbl1 in multiciliated cells of the Xenopus laevis epidermis since ruvbl1 is expressed in the multiciliated cells and pronephros during X. laevis embryogenesis. The knockdown of ruvbl1 significantly impaired cilia-driven fluid flow and basal body polarity in the X. laevis epidermis compared to control embryos, but did not affect cilia morphology. Our results suggest that Ruvbl1 plays a significant role in embryonic development by regulating ciliary beating; however, further investigation is needed to determine the mechanisms involved.