• 제목/요약/키워드: small states

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삼국시대 원추형 수식에 대한 연구 (A Study on the Cone Shaped Pendants in the Period of the Three States)

  • 김문자
    • 복식문화연구
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    • 제10권5호
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    • pp.485-492
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    • 2002
  • The purpose of this study is to classify of the Cone shaped Pendants in old tombs of Three Kingdom States. These Cone shaped Pendants are made of bronze and coated with gold plate or Gold. Each Cone shaped Pendants consists of a Sehwhan(細環) type or Taewhan type, a median part in the form of a several joined small globe, or circular shape, and finally a cone-shared pendant. Cone shaped Pendants is 5 part(A-L A-b, B-1-a, B-1-b, B-2-b type) in according to the styles of the Sehwhan(細環) and Taewhan type and median ornament types. A-a, A-b, B-1-a, B-1-b type was general style that was found in most of the old tombs in Kokuryo, Pacjae, ancient Silla. B-2-b type was excavated from the only Kokuryo tombs.

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Dipole Moments of the OH, OH$^+$, and OH$^-$Valence States by ab initio Effective Valence Shell Hamiltonian Method

  • Sun, Ho-Sung
    • Bulletin of the Korean Chemical Society
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    • 제9권2호
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    • pp.101-105
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    • 1988
  • The ab initio effective valence shell Hamiltonian method, based on quasidegenerate many-body perturbation theory, is generalized to calculate molecular properties as well as the valence state energies which have previously been determined for atoms and small molecules. The procedure requires the evaluation of effective operator for each molecular property. Effective operators are perturbatively expanded in powers of correlation and contain contributions from excitations outside of the multireference valence space. To demonstrate the validity of this method, calculations for dipole moments of several low lying valence states of OH, $OH^+$, and $OH^-$ to first order in the correlations have been performed and compared with configuration interaction calculations.

Geometries and Energies of S$_N$2 Transition States$^\dag$

  • Lee, Ik-Choon;Kim, Chan-Kyung;Song, Chang-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제7권5호
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    • pp.391-395
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    • 1986
  • MNDO calculations were carried out to determine reactant complexes and transition states of the $S_N2$ reactions of $CH_3X\;+\;Y^-\;{\to}\;CH_3Y\;+\;X^-$ where X = F, Cl, CN and Y = CN, OH, F, Cl. The leaving group ability was found to vary inversely with the activation barrier, which in turn was mainly ascribable to the deformation energies accompanied with bond stretching of C-X bond and inversion of $CH_3$ group. The nucleophilicity was shown to be in the order $Cl^->F^->OH^->CN^-$ but the effect on the activation barrier was relatively small compared with that of the leaving group. The bond breaking and bond formation indices and energy decomposition analysis showed that the TS for the reaction of $CH_3$Cl occurs in the early stage of the reaction coordinate relative to that of $CH_3$F. It has been shown that the potential energy surface (PES) diagrams approach can only accommodate thermodynamic effects but fails to correlate intrinsic kinetic effects on the TS structure.

Theoretical Studies on the Photochemical Reactions of 5,7-Dimethoxycoumarin with Adenosine. The Electronic States of 5,7-Dimethoxycoumarin and their Photoadducts

  • Kim, Ja-Hong;Han, Goang-Lae;Song, Young-Chil;Sohn, Sung-Ho
    • Bulletin of the Korean Chemical Society
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    • 제10권3호
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    • pp.223-226
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    • 1989
  • The chemical reactivity of 5,7-dimethoxycoumarine with adenosine has been calculated by the frontier electron and PPP-Cl MO methods. Results suggest that the major reactivity of the 5,7-dimethoxycoumarin is highest at the carbon-4 (position 4), whereas the electrophilic reactivity is generally spread all over the 5,7-dimethoxycoumarin molecule. These results are consistent with the experimental photoaddition reaction products. The small change of bond orders on excitation does not give enough reactivity to triplet states or the efficient intersystem crossing from $T_1\;to\;S_0$ inhibits photoaddition of 5,7-dimethoxycoumarine to adenosine. Although the relative intensity of the singlet band appears to be considerably higher than the triplet band intensity, its integrated intensity, i.e. oscillator strength, is comparable to that of the 5,7-dimethoxycoumarin and adenosine bands.

$^1H$ NMR Estimation of Multi-Redox potentials of Cytochrome $c_3$ from Desulfovibrio vulgaris Hildenborough

  • 박장수;강신원;최성낙
    • Bulletin of the Korean Chemical Society
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    • 제16권4호
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    • pp.331-336
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    • 1995
  • The macroscopic and microscopic redox potentials of tetrahemoprotein, cytochrome c3 from Desulfovibrio vulgaris(Hildenborough) (DvH) were estimated from 1H NMR and differential pulse polarography(DPP). Five sets of NMR resonances were confirmed by a redox titration. They represent cytochrome c3 molecules in five macroscopic redox states. The electron transfer in cytochrome c3 involves four consecutive one-electron steps. The saturation transfer method was used to determine the chemical shifts of eight heme methyl resonances in five different oxidation states. Thirty two microscopic redox potentials were estimated. The results showed the presence of a strong positive interaction between a pair of particular hemes. Comparing the results with those of Desulfovibrio vulgaris Miyazaki F (DvMF), it was observed that the two proteins resemble each other in overall redox pattern, but there is small difference in the relative redox potentials of four hemes.

Polarization Ellipticity of Micro-photoluminescence in a Single GaAs/AlGaAs Quantum Ring

  • Kim, Minju;Jang, Juyeong;Lee, Seunghwan;Song, Jindong;Kyhm, Kwangseuk
    • Current Optics and Photonics
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    • 제5권1호
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    • pp.72-76
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    • 2021
  • The polarized micro-photoluminescence spectrum was analyzed to investigate the anisotropic localized states in a single GaAs quantum ring. An energy difference of ~0.1 meV was observed from the perpendicularly polarized spectrum measured by a pair of linear analyzers. Spectral dependence of the polarized emission was also characterized in terms of rotation and ellipticity angles using four Stokes parameters. While the rotation angle indicates the symmetric axis of an anisotropic quantum ring with a small variation (± 2°), the ellipticity angle varies from 7.4° down to -2.5°. We conclude that optical anisotropy and birefringence are induced by the crescent-like lateral shape of localized states.

A pooled Bayes test of independence using restricted pooling model for contingency tables from small areas

  • Jo, Aejeong;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • 제29권5호
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    • pp.547-559
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    • 2022
  • For a chi-squared test, which is a statistical method used to test the independence of a contingency table of two factors, the expected frequency of each cell must be greater than 5. The percentage of cells with an expected frequency below 5 must be less than 20% of all cells. However, there are many cases in which the regional expected frequency is below 5 in general small area studies. Even in large-scale surveys, it is difficult to forecast the expected frequency to be greater than 5 when there is small area estimation with subgroup analysis. Another statistical method to test independence is to use the Bayes factor, but since there is a high ratio of data dependency due to the nature of the Bayesian approach, the low expected frequency tends to decrease the precision of the test results. To overcome these limitations, we will borrow information from areas with similar characteristics and pool the data statistically to propose a pooled Bayes test of independence in target areas. Jo et al. (2021) suggested hierarchical Bayesian pooling models for small area estimation of categorical data, and we will introduce the pooled Bayes factors calculated by expanding their restricted pooling model. We applied the pooled Bayes factors using bone mineral density and body mass index data from the Third National Health and Nutrition Examination Survey conducted in the United States and compared them with chi-squared tests often used in tests of independence.

작은도서관 통계지표 개선에 관한 연구 (A Study to Improve the Statistical Indicators of Small Libraries)

  • 안인자;윤소영;차성종
    • 한국도서관정보학회지
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    • 제42권4호
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    • pp.375-393
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    • 2011
  • 작은도서관이 공공도서관의 영역에 포함되면서 작은도서관의 제도적 보완, 지원 정책틀 마련, 운영활성화를 위한 정책적 결정을 하여야 하는 시기에 이르렀다. 이러한 정책결정 도구로서 도서관통계가 충실하게 이루어지도록 작은도서관 통계지표를 개선할 필요가 있다. 현재의 작은도서관통계(문고)는 2008년 마련된 공공도서관 통계의 틀에 일부항목을 수정하여 국가도서관통계에서 활용하고 있다. 하지만 항목의 불합리성으로 91.3%의 무응답율과 수집된 데이터의 오류가 상당히 많다. 본 연구에서 개선을 위하여 작은도서관 현황조사 4종, 평가기준 7종을 분석하고, 이를 기초로 하여 2차에 걸친 자문회의, 경기도 지역의 3개 지자체 작은도서관 108개관의 현장조사 결과를 반영하여 개선된 통계지표를 제시하였다. 제시된 통계는 7개 영역 37개 항목이다.

소형위성의 개발현황 및 군사적 활용 방안 (Development Trends of Small Satellites and Military Applications)

  • 이상현;오재요;권기범;이길영;조태환
    • 한국항행학회논문지
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    • 제21권3호
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    • pp.213-219
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    • 2017
  • 대형 위성들은 수십억 달러가 넘는 개발 비용이 사용되고, 우주환경에서 운영하기까지 수십 년이 걸릴 수도 있다. 이에 비해 소형 위성은 상용 소프트웨어, 센서 등을 활용해서 비용을 절감할 수 있으며 개발 기간을 2년 이내로 단축시킬 수 있다. 본 논문에서는 이렇게 많은 이점을 가지고 있는 소형위성의 국내외 개발현황을 살펴보고, 소형위성을 군에서 활용하기 위한 몇 가지 방안을 제안한다. 먼저, 해외 개발현황으로 미국, 일본의 소형위성 개발현황을 소개하고, 국내 소형위성 개발현황을 소개한다. 군사적 활용방안은 크게 교육, 연구, 작전 분야로 분류하여 제안한다. 최근 소형위성은 상업 분야에서 빠르게 발전하고 있으며 향후 군에서도 중요한 역할을 할 것이다. 따라서 향후 스타워즈를 준비하고 있는 군에게 소형위성은 반드시 필요한 자산이며, 연구개발을 통해 지속적으로 발전시켜 나가야 한다.

가족기업 종사 이중역할 수행자의 가족자원관리 행동유형 분석: 한국과 미국간 비교연구 (Family Resource Management Pattern by Dual Role Manager of the Family Business in Korea and The United States)

  • 김지희
    • 가정과삶의질연구
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    • 제20권2호
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    • pp.43-56
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    • 2002
  • While there is universal agreement that the ecosystems approach to family resource management is the must influential currently, questions have arisen about the broad applicability of the Deacon & Firebaugh (1988) ecosystems framework. Engberg (1996) has characterized the dominant approach in family resource management as technical and argued that a technical approach substantially restricts feasible actions in much of the world and should not be used in ethical practice. The purpose of the present paper is to compare the family resource management patterns by dual role manager of business owning families in Korea and The United States. Such a comparison is an essential step in the assessment of the usefulness of the Deacon & Firebaugh framework, in particular, and the ecosystems framework, more generally. Korean respondents are 105 family and business managers interviewed in 2000 as part of a survey of owners of small to medium size family business enterprises in Seoul. U.S. respondents are 259 dual role managers in the National Family Business Survey (NFBS 1997). Chi squared statistics indicated country differences on each of the ten(goal setting, standard setting, demand clarification, resource assessment, action sequencing, actuating, checking, adjusting, demand responses, resource change)management practices. Mean responses on eight of the practices(goal setting, standard setting, action sequencing, actuating, checking, adjusting, demand responses, resource changes) were significantly different between two countries. U.S. total score means of family resource management were higher than Korea. Factor analysis of the management scale items yielded different patterns for Korea, and the United States. Korean dual role manager of family business were categorized into three different patterns as classic oriented manager, goal oriented manager, action oriented manager and U.S. were categorized into Process oriented manager and Production oriented manager. Both the number of managerial strategies and the types of strategies used varied in the two countries.