• Title/Summary/Keyword: Natural park

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Synthesis of 4-Aza-cholestane Derivatives Containing Nitrosoureido Function as Antitumor Activity

  • Kim, Jack C.;Park, Jin Il;Hur, Tae-Ho
    • Bulletin of the Korean Chemical Society
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    • v.14 no.2
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    • pp.176-178
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    • 1993
  • A series of 4-(2-chloroethyl)nitrosocarbamoyl- and 4-methyl nitrosocarbamoyl analogs of 4-Aza-$5{\alpha}$-cholestane (5a and 5b), 4-Aza-5-cholestene (6a and 6b) were synthesized and evaluated for their inhibitory activity against the Sarcoma 180 cell. The steroidal nitrosoureas, 5a, 5b, 6a and 6b displayed modest activity in vitro.

Stereocontrolled asymmetric synthesis of pancratistatin

  • Park, Je-Eun;Kim, Sang-Hee;Ko , Hyo-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.362.1-362.1
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    • 2002
  • Pancratistatin is a highly oxygenated phenanthridone alkaloid. exhibits a high level of in vitro and in vivo cancer cell growth in inhibitory activity. and antiviral activity. The asymmetric synthesis of this alkaloid has been. accomplished from the commercially available (R)-(+)-3-Butyn-2-ol. We utilized the Claisen rearrangment and metathesis to install stereogenic centers in the cyclohexene ring that has absolute chemistry. (omitted)

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Weak-lensing Mass Reconstruction of Galaxy Clusters with Convolutional Neural Network

  • Hong, Sungwook E.;Park, Sangnam;Jee, M. James;Bak, Dongsu;Cha, Sangjun
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.49.4-50
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    • 2020
  • We introduce a novel method for reconstructing the projected matter distributions of galaxy clusters with weak-lensing (WL) data based on convolutional neural network (CNN). We control the noise level of the galaxy shear catalog such that it mimics the typical properties of the existing Subaru/Suprime-Cam WL observations of galaxy clusters. We find that our mass reconstruction based on multi-layered CNN with architectures of alternating convolution and trans-convolution filters significantly outperforms the traditional mass reconstruction methods.

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Comparative Study on Monetary Estimates of Natural Environment and Cultural Relics in Gyeongju National Park (경주국립공원의 문화유적과 자연환경의 가치추정 비교연구)

  • Kang, Kee-Rae;Kim, Dong-Pil;Baek, Jae-Bong
    • Korean Journal of Environment and Ecology
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    • v.26 no.2
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    • pp.273-282
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    • 2012
  • This study has estimated Gyeongju National Park's natural environment and cultural relic value in the same way and then been performed to compare the size of the value. Representative method to measure environmental property is contingent valuation methods, CVM. The variables and estimated models adopted for the calculation were same and the respondents were asked by distinguishing between the amount which they would pay to preserve the natural environment and that which they were willing to pay to preserve the cultural relics. As the result, WTP(Willing to pay), the amount that they were willing to pay to preserve the natural environment of Gyeongju National Park was 17,838 won per person and that to preserve the cultural relics appeared to be 316,248 won per person. Based on this, it was estimated that the value of the natural environment with which Gyeongju National Park provided annual visitors was 47 billion won and that the annual value of the cultural relics was 845.7 billion. If the natural environment and the cultural relics value elements are united, it can be estimated that the natural environment and cultural relic value got at the time of people's first visit to Gyeongju National Park is 334,086 won and that the annual value is 893.4 billion won. In this study, the value of the cultural relics has been estimated 18 times higher than that of the natural environment. This reason was that visitors judged that a total of 66 cultural properties including 11 national treasures, 23 treasures, 13 historic places, one historic sites and scenic spot and 18 local cultural properties, etc. which were distributed in Gyeongju National Park were worth far more than the natural environment. Based on the result of this study, the operating management plan of Gyeongju National Park should include a differentiated operation strategy through consultation with relevant experts by taking into account characteristics of the physical components.

Cell Cycle-dependent Expression of Chitin Synthase Genes in Aspergillus nidulans

  • Park, Bum-Chan;Maeng, Pil-Jae;Park, Hee-Moon
    • Journal of Microbiology
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    • v.39 no.1
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    • pp.74-78
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    • 2001
  • The transcription of the chitin synthase genes (chss) was cell cycle-regulated in Aspergillus nidulans and the expression pattern was classified into two groups. Group one, containing chsA and chsC, showed decreasing transcription level upon entry into the S-phase and no further variation during the remainder of the cell cycle. However, group two, containing chsB, chsD, and csmA showed a sharp decrease of mRNA level upon entry into the G2-phase and an increase during the M-phase. Our results suggested that the chss, belonging to same group with the similar expression pattern during the cell cycle are functionally linked and that chsD may play a role in hyphal growth and development in A. nidulans.

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A General Coverage-Based NHPP SRGM Framework

  • Park, Joong-Yang;Lee, Gye-Min;Park, Jae-Heung
    • Communications for Statistical Applications and Methods
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    • v.15 no.6
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    • pp.875-881
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    • 2008
  • This paper first discusses the existing non-homogeneous Poisson process(NHPP) software reliability growth model(SRGM) frameworks with respect to capability of representing software reliability growth phenomenon. As an enhancement of representational capability a new general coverage-based NHPP SRGM framework is developed. Issues associated with application of the new framework are then considered.