• Title/Summary/Keyword: structural determination

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Structural determination of triterpenic acids in Prunellae Spica by fast atom bombardment tandem mass spectrometry (하고초의 생리활성 성분 Triterpenic Acids의 FAB-MS를 이용한 구조 규명)

  • Ahn, Young Min;Lee, Kang Ro;Hong, Jongki
    • Analytical Science and Technology
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    • v.21 no.4
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    • pp.245-258
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    • 2008
  • Five triterpenic acids as marker compounds were extracted and isolated from Prunellae Spica by column chromatography and reversed-phase high-performance liquid chromatography (HPLC), and their purity was determinated by HPLC (purity ${\geq}90%$). Molecular weight and elemental compositions of the five marker compounds were determined by fast atom bombardment high-resolution mass spectrometry (FAB-HRMS). The structural determination of the five marker compounds was carried out fast atom bombardment collision-induced dissociation tandem mass spectrometry (FAB-CID-MS/MS). The collision-induced dissociation (CID) of protonated molecules $[M+H]^+$ and deprotonated molecules $[M-H]^-$ produced diverse product ions due mainly to retro Diels-Alder reaction (RDA), dehydration and decarboxylation. Moreover, the CID-MS/MS spectra of the $[M-H]^-$ ions were observed charge-remote fragmentation (CRF) patterns. On the basis of interpretation of CID-MS/MS spectra, structural elucidation of triterpenic acids isolated from Prunellae Spica was clearly performed.

Antitumor Substances from Higher Plants in Asian Region

  • Itokawa, Hideji;Takeya, Koichi
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 1996.09a
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    • pp.10-11
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    • 1996
  • In this review, we summarize the isolation, structural determination, antitumor activity of substances from higher plants which were collected in Asian region.

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Antitumor Substances from Higher Plants in Asian Region

  • Hideji Itokawa;Koichi Takeya
    • Korean Journal of Plant Resources
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    • v.8 no.3
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    • pp.341-364
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    • 1995
  • In this review, we summarize the isolation, structural determination, antitumor activity of substances from higher plants which were collected in Asian region.

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Probabilistic evaluation of separation distance between two adjacent structures

  • Naeej, Mojtaba;Amiri, Javad Vaseghi;Jalali, Sayyed Ghasem
    • Structural Engineering and Mechanics
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    • v.67 no.5
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    • pp.427-437
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    • 2018
  • Structural pounding is commonly observed phenomenon during major ground motion, which can cause both structural and architectural damages. To reduce the amount of damage from pounding, the best and effective way is to increase the separation distance. Generally, existing design procedures for determining the separation distance between adjacent buildings subjected to structural pounding are based on approximations of the buildings' peak relative displacement. These procedures are based on unknown safety levels. The aim of this research is to estimate probabilistic separation distance between adjacent structures by considering the variability in the system and uncertainties in the earthquakes characteristics through comprehensive numerical simulations. A large number of models were generated using a robust Monte-Carlo simulation. In total, 6.54 million time-history analyses were performed over the adopted models using an ensemble of 25 ground motions as seismic input within OpenSees software. The results show that a gap size of 50%, 70% and 100% of the considered design code for the structural periods in the range of 0.1-0.5 s, leads to have the probability of pounding about 41.5%, 18% and 5.8%, respectively. Finally, based on the results, two equations are developed for probabilistic determination of needed structural separation distance.

The Effects of Individual Character and Environmental Character of Adults with Intellectual Disability on Self-Determination - Focusing on Mediating Effect of Opportunity - (성인 지적장애인의 개별적 특성과 환경적 특성이 자기결정에 미치는 영향 - 기회제공의 매개효과를 중심으로 -)

  • Lee, Boksil
    • Korean Journal of Social Welfare
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    • v.65 no.2
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    • pp.5-28
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    • 2013
  • This study was to examine the effects of individual and environmental character among adults with intellectual disabilities on self-determination and to address issue of self determination in practical terms. This study was analyzed by the Structural Equations Models with 219 individuals with intellectual disabilities in residential home in the Metropolitan area, the Yeongnam area, the Honam area. The results showed that individual factors such as adaptive behavior and provider-user relationship recognition, and environmental factors such as institution size and institution location were directly affected to the self-determination of them. The opportunity was a full mediating effect in this process. In conclusion, this study stated how importance of the consumerism. Also it was suggested that some practical strategies to improve their self-determination in changing residential environment and support methods of the service in way to emphasis their opportunities.

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The Structural Relationship between Parental Career and Care Support for Multicultural Youth and Teacher Relations, Career Preparation and Career Determination

  • Lee, Hyoung-Ha
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.5
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    • pp.199-208
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    • 2020
  • The purpose of this study is to analyze the influence of career support and teacher relations of parents in order to determine the career determination of multicultural youths, and to confirm the influence of career preparation between parental career and care support and teacher relations. To this end, data from 2017 (the 7th year) was used among the data from the Multicultural Youth Panel Survey (MAPS). According to the analysis results, first, career support, teacher relations, and career preparation of multicultural youth parents have a positive impact on career determination. Second, the importance of the relative influence of career preparation, which is an internal context factor, was also confirmed in the process of determining the career path of multicultural youths. Third, it was analyzed that the higher the career and childcare support of multicultural youth parents, the more positive the teacher relationship, the higher the career determination. Career preparation was confirmed to play a role in mediating career support and teacher relations among multicultural youth parents in determining career paths. Based on the results of this analysis, practical alternatives were proposed to enhance the career determination of multicultural youths.

The Effects of Metaverse Related Self-determination on Intention to Continuous Use Through Intrinsic Motivation: Moderating Effect of Member Trust (메타버스 관련 자기결정성이 내적 동기를 통해 지속적 이용 의도에 미치는 영향: 구성원 신뢰의 조절 효과)

  • Hwang, Inho
    • The Journal of Society for e-Business Studies
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    • v.27 no.2
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    • pp.79-103
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    • 2022
  • COVID-19 is forcing people to minimize face-to-face networking activities between members of society, and they are increasing their use of online platforms. In particular, interest in the metaverse, a virtual community with enhanced realism, is growing. Specifically, this study suggests a mechanism to improve the intention to continuous use of metaverse users by using the self-determination theory, and confirms that trust between metaverse members moderates the relationship between self-determination and intrinsic motivation. We obtained 353 samples through a questionnaire targeting those who have used metaverse and verified the hypothesis through structural equation modeling. As a result of the analysis, individual self-determination of the metaverse formed intrinsic motivation such as identification and enjoyment, which affected the intention to continue use, and the trust of metaverse members partially moderated the relationship between self-determination and motivation. The result contributes to the sustainability of the metaverse platform by suggesting an approach to users and the environment to improve the intention of continuous use of metaverse.

Practical Determination Method of Initial Cable Forces in Cable-Stayed Bridges (사장교 시스템의 실용적인 초기형상 결정법)

  • Song, Yo-Han;Kim, Moon-Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.1
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    • pp.87-95
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    • 2011
  • A rational method for determination of initial cable forces in cable-stayed bridges without complicated nonlinear analysis is presented. Initial shape analysis for cable-stayed bridges should be able to find optimizated initial cable forces and unstrained length that minimize deflection and vending moments of the deck and pylon. A presented method utilizing the idea of force equilibrium organizes initial shape analysis for each types of cable-stayed bridges. The results of that analysis were compared to several existing methods for 2D numerical examples. And for 3D actual bridges, the improved TCUD method was performed to demonstrate the accuracy of this study.