• 미생물학회지
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• 제27권3호
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• pp.265-271
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• 1989

서해안의 대표적 내만인 천수만 해역에서 4계절간 분리한 세균들을 대상으로 수리학적 분류를 설시하였다. 총 48가지의 형태학적, 생리적, 생화학적 실험 결과 분리된 계절에 따라 온도에 대한 서로 다른 적응 양상을 보여 주었으며, 전체적으로 다양한 환경변화에 높은 생존 능력을 보여주였다. 각 세균을 동정한 결과 Enterobacteriaceae, Aeromonas Pseudomonas와 Vibrio 등이 우점종으로 나타났으며, 계절별로는 봄 가을에 Aeromonas가, 여름 및 겨울에는 각각 Pseudom monas 와 Enterobacteriaceae가 제l우점종임이 발견되었다 Cluster analysis 결과 젠체 세규 군집은 75%의 유사도 수1 에서 총 29개의 phenetic group으로 나뉘어졌으며 각 group별로 계절적 구분이 뚜렷하였다. 전체적으로 계절에 놔른 서로 다른 생리적 특성과 종 구성이 전반적인 생태계에의 다양성과 안정성을 높여주는 것으로 나타났다.

• 농촌계획
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• 제20권2호
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• pp.115-126
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• 2014

The purpose of this study is to segment foreign tourists who are visiting rural tourism village based on importance attributes of rural experiences tourism. From the literature review, rural experience tourism and its' importance attributes were discussed and these are, peculiar cultural experience, rural experience tourism price, food, natural scenery, accessibility, accommodation and convenient facility. On-site survey was conducted to collect the data from 8 rural tourism villages and a total of 258 useful samples were collected and analyzed. Frequent, cluster analysis, MDA, and MANOVA were performed to produce the results. The cluster analysis showed that three clusters solution was appropriate and named as moderated satisfaction group, high satisfaction group, and highly satisfaction group. The results of MANOVA showed that there were differences among the groups in terms of satisfaction and loyalty of rural experiences tourism. Theoretical and practical implications were discussed in the conclusion section.

• International Journal of Aeronautical and Space Sciences
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• 제4권2호
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• pp.1-8
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• 2003

Satellite formation flying is the placing micro-satellites with the same mission into nearby orbits to form a cluster. Clohessy-Wiltshire equations are used to describe the relative motion and control strategies between satellites within a cluster, which are known as Hill's equations. Even though Hill's equations are powerful in determining initial conditions for the satellite formation flying, they can not accurately express the relative motion under J2 perturbation. Some methods have been developed for the determination of initial conditions to avoid limits of Hill's equation. This paper gives a new method of determining initial conditions using mean elements. For this research mean elements were transformed to osculating elements using Brouwer's theory and the orbit was propaeated with the consideration of J2-J8 to get a relative position. The results show that satellites within a cluster are maintained in the desired boundary for long period and the method is effective on a fuel saving for satellite formation flying.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.307-309
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• 2007

SVDD의 scale prob1em을 해결하기 위하여, 학습 데이터를 sub-groupings하여 group 단위로 SVDD를 통해 학습함으로써 학습 시간을 줄이는, K-means clustering을 이용한 SVDD 방범(KMSVDD)이 제안되었다. 하지만 KMSVDD는 K-means clustering 알고리즘의 본질상 최적의 K값을 정하기 힘들다는 문제와, 동일한 데이터를 학습할지라도 clustered group이 램덤하게 형성되기 때문에 매번 학습의 결과가 달라지는 문제점이 있었다. 또한 데이터의 분포 상태와 관계없이 무조건 타원(dlliptic) 형태의 K개의 cluster로 나누기 때문에 각각의 나눠진 cluster들은 데이터 분포에 대한 특징을 나타내기 힘들게 된다. 이러한 문제점을 해결하기 위하여 본 논문에서는 데이터 분포에서 mode를 먼저 찾은 후 이 mode를 기준으로 clustering하는 Mean Shift clustering 방법을 이용한 SVDD를 제안하고자 한다. 제안된 알고리즘은 KMSVDD와 비교해 데이터 학습 속도에서는 큰 차이가 없으면서도 데이터의 분포 상태를 고려한 형태로 clustering 한 sub-group을 학습하므로 학습의 정확도가 일정하게 되며, 각각의 cluster는 데이터 분표의 특징을 포함하는 효과가 있다. 또한 Mean Shift Kernel의 bandwidth의 결정은 K-Means의 K와는 달리 어느 정도 여유를 갖고 결정되어도 학습 결과에는 차이가 없다. 다양한 데이터들을 이용한 모의실험을 통하여 위의 내용들을 검증하도록 한다.

• 미생물학회지
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• 제43권2호
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• pp.137-141
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• 2007

Streptomyces 5균주 간의 유사도를 혈청학적 방법으로 측정하였다. 항원으로는 충분히 생장한 균체의 외피를 Tween 20으로 용출시킨 용액을 사용하였고 항체는 토끼를 면역시켜 얻었다. 면역확산과 ELISA 결과 항원-항체 반응의 정도가 균주간의 분류학적 유사성과 비례적으로 반영되지 않았다. 즉 군집 A에 속하는 균주들 사이의 항원-항체 반응이 낮게 측정된 반면에 군집 F의 Streptomyces Iavendulae와 군집 A의 Streptomyces viridochromogenes가 특이적으로 비교적 높게 나타났다.

• 동아시아식생활학회지
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• 제22권6호
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• pp.895-902
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• 2012

This study was conducted to understand the Ramyun's selection attributes of Korean adults and examine differences in demographic characteristics and meal intake behavior among three groups of samples divided based on the Ramyun's selection attributes. Self-administered questionnaires were completed by 702 adults, and data were subjected to frequency analysis, chi-square analysis, factor analysis, reliability tests, cluster analysis, and discriminant analysis using SPSS. The results of the study were as follows. The Ramyun's selection attributes for Korean adults investigated were food quality (four variables), price (three variables), and company reliability (four variables). Cluster analysis resulted in the subjects being divided into three groups according to their Ramyun's selection attributes, a high-selection group, mid-selection group, and low-selection group. Three groups of samples classified by Ramyun's selection attributes differed based on demographic characteristics (gender and education level) and meal intake behavior (meal numbers, reason for meal, meal time, and meal size).

• Elastomers and Composites
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• 제48권3호
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• pp.225-231
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• 2013

본 연구에서는 carboxylated SBR latex와 zinc oxide가 SBS 복합재의 내마모성과 debris 특성 개선에 미치는 영향을 관찰하였다. 실리카를 첨가한 SBS 복합재는 실리카 입자간의 수소 결합에 의한 강한 filler-filler interaction으로 인한 낮은 분산성 때문에 기계적 강도, NBS 내마모성, debris 특성이 전체적으로 감소하는 것으로 나타났다. carboxylated SBR latex를 첨가한 SBS 복합재는 carboxyl group과 실리카의 silanol group간의 결합을 통하여 filler-filler interaction이 감소하고 실리카의 분산성이 증가하기 때문에 기계적 강도, NBS 내마모성, debris 특성이 향상되는 것을 확인 하였다. carboxylated SBR latex와 zinc oxide를 동시에 첨가한 경우, carboxyl group에 의한 실리카의 분산성 향상과 더불어 zinc ion과 carboxyl group간의 ion cluster 형성을 통하여 물성이 크게 증가하였다. Zinc ion과 carboxyl group간의 ion cluster 형성은 $1550{\sim}1650cm^{-1}$의 zinc carboxylate group stretch 피크의 FT-IR 분석 결과로 확인하였다. carboxylated SBR latex와 zinc oxide를 첨가한(SC-4) 복합재의 경우, 인장강도 $156kgf/cm^2$, 신장율 936%, 인열강도 59.4kgf/cm의 우수한 기계적 강도를 나타내었으며, NBS 내마모성은 338%로 가장 우수한 특성을 나타내었다. 또한, 표면 마찰 시에 debris 발생 역시 크게 감소하며, 표면 마찰 저항의 증가로 파도 형태의 마모 특성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.48-54
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• 2012

The $[Fe_4S_4]^{2+}$ clusters with 2-, 3-, and 4-pyridinemethanethiolate (S2-Pic, S3-Pic, and S4-Pic, respectively) terminal ligands have been synthesized from the ligand substitution reaction of the $(^nBu_4N)_2[Fe_4S_4Cl_4]$ (I) cluster. The new $(^nBu_4N)_2[Fe_4S_4(SR)_4]$ (R = 2-Pic; II, 3-Pic; III, 4-Pic; IV) clusters were characterized by FTIR and UV-Vis spectroscopy. Cluster II was crystallized in the monoclinic space group C2/c with a = 24.530 (5) $\AA$, b = 24.636(4) $\AA$, c = 21.762(4) $\AA$, ${\beta}=103.253(3)^{\circ}$, and Z = 8. The X-ray structure of II showed two unique 2:2 site-differentiated $[Fe_4S_4]^{2+}$ clusters due to the bidentate-mode coordination by 2-pyridinemethanethiolate ligands. Cluster III was crystallized in the same monoclinic space group C2/c with a = 26.0740(18) $\AA$, b = 23.3195(16) $\AA$, c = 22.3720(15) $\AA$, ${\beta}=100.467(2)^{\circ}$, and Z = 8. The 3-pyridinemethanethiolate ligand of III was coordinated to the $[Fe_4S_4]^{2+}$ core as a terminal mode. Cluster IV with 4-pyridinemethanethiolate ligands was found to have a similar structure to the cluster III. Fully reversible $[Fe_4S_4]^{2+}/[Fe_4S_4]^+$ redox waves were observed from all three clusters by cyclic voltammetry measurement. The electrochemical potentials for the $[Fe_4S_4]^{2+}/[Fe_4S_4]^+$ transition decreased in the order of II, III and IV, and the reduction potential changes by the ligands were explained based on the structural differences among the complexes. The complex III was reacted with sulfonium salt of $[PhMeSCH_2-p-C_6H_4CN](BF_4)$ in MeCN to test possible radical-involving reaction as a functional model of the [$Fe_4S_4$]-SAM (S-adenosylmethionine) cofactor. However, the isolated reaction products of 3-pyridinemethanethiolate-p-cyanobenzylsulfide and thioanisole suggested that the reaction followed an ionic mechanism and the products formed from the terminal ligand attack to the sulfonium.

• 천문학회보
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• 제41권2호
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• pp.30.3-31
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• 2016

The M81 Group is the nearest among the known groups of galaxies. HI maps show that all main galaxies of this group are interacting, indicating that this group is in the active phase of formation. On the other hand, wide field imaging shows that globular cluster candidates are found not only in the member galaxies but also between the galaxies in this group. In this study we present preliminary results based on MMT/Hectospec spectroscopy of the globular cluster candidates in this group. We find that the intragroup globular clusters have mostly low metallicity, while the globular clusters in M81 have mostly high metallicity. We will discuss the implication of this result and the kinematics of the globular clusters in relation with the formation history of the M81 Group.

• 한국의류학회지
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• 제27권6호
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• pp.601-611
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• 2003

The main objective of this study was to investigate the relationship between benefits segmentation and knitwear purchasing behavior of college female students. A questionnaire was developed to measure benefits segmentation, knit wear purchasing behavior. The questionnaire was administered to 505 college female students in Chonbuk and Chonnam. The data was analyzed using percentage, frequency, mean, factor analysis, cluster analysis and ANOVA, Duncan multiple range test. The results of the study were as follows: The college female students were classified into four subdivisions by the cluster analysis: recreation pursuit group, fashion pursuit group, individuality pursuit group, self-improvement pursuit group on the basis of pursuit benefit factors. The knitwear purchasing motives of consumers were significantly different according to pursuit benefit subdivision. The individuality pursuit group was the highest user of mass media fashion information sources. The fashion pursuit group used purchasing experience and advice of others less than other groups. Consumers' evaluation criteria of knitwear products were significantly different depending on pursuit benefit subdivision in design and coordination, goods traits, practicality, individual expression, and external criterion. The other groups used purchasing experience and advice of others more than the fashion pursuit group.