• The Journal of Korean Association of Computer Education
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• v.7 no.3
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• pp.57-66
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• 2004

The purpose of this study is to determine the relationship among the hypermedia structure(hierarchical and network), learner's cognitive style(field-independent and field-dependent), and learning performance in the elementary school. 128 students(4th graders) having field-independent and field-dependent cognitive style were randomly allocated into hierarchical and network structures of hypermedia learning program. There was not significant interaction between hypermedia structure and cognitive style in learning performance. The students in the hierarchical hypermedia structure showed higher learning performance than ones in the network hypermedia structure. Field-independent students significantly got higher results than field-dependent ones. It is concluded that instructional designers should consider hypermedia structure, learner's cognitive style, and learning outcomes when they plan and design hypermedia learning program.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.123-139
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• 2015

The purpose of this study is to analyze the effect of the parent's socioeconomic status to the academic achievement, together with the mediation effect of the private education expenditure. The structural equation modeling (SEM) method is used with the survey of private education expenditures data collected by Statistics Korea in 2011. In SEM, the multi-group effect is also analyzed for gender, region and school level. The analysis results show that the high socioeconomic status of parent tends to increase the private education expenditures but does not affect the academic achievement, and there are the significant multi-group effect for gender, region, and school level.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.310-319
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• 2013

The genetic diversity and structure of eight populations of Coreanomecon hylomeconoides Nakai, an endemic Korean plant, were investigated using 50 ISSR loci from eight primers. The average percentage of polymorphic loci was 47.3%. The Shannon's index (SI=0.218) and gene diversity (h=0.142) were relatively lower than those of other long-lived perennials. The Sancheong (SI=0.233, h=0153), Gwangyang (SI=0.263, h=0.171), and Suncheon (SI=0.241, h=0.159) populations showed greater genetic diversity than the Namhae and Gwangju populations, which are on the edge of the distribution. Analysis of molecular variance (AMOVA) showed that 18% of the total variation could be attributed to differences among populations, and 82% to differences within populations, indicating moderate gene flow among adjacent populations. These results were supported by value of Nm (2.184). The UPGMA conducted using the genetic distance and Bayesian cluster analysis showed a remarkable geographic trend structured into east and west regions. Overall, the results indicate that the Sancheong and Gwangyang populations, which had a large population size and higher degree of genetic diversity, should be the focus of in situ conservation.

• Journal of Life Science
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• v.20 no.8
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• pp.1151-1158
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• 2010

The genetic diversity and population structures of fourteen Carex okamotoi (Cyperaceae) populations in Korea were determined using genetic variation at 25 allozyme loci. The Carex okamotoi species is native to Korea. It is endemic to three mountains (Mt. Taeback, Mt. Sobak, and Mt. Noreong) where it is found at 700~1,500 m above sea level. The percentage of polymorphic loci was 40.0%. Genetic diversity at the species level and at the population level was low ($H_{ES}$=0.106; $H_{EP}$=0.094), and the extent of the population divergence was relatively low ($G_{ST}$=0.082). Measurement of deviation from random mating ($F_{IS}$) within the 14 populations was 0.238. An indirect estimate of the number of migrants per generation was 2.78 (Nm=2.78). Analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. Mean genetic identity between populations was 0.986.

• Journal of Life Science
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• v.16 no.6
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• pp.898-903
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• 2006

The genetic diversity and population structure of fifteen Potentilla discolor Bunge populations in Korea were determined using genetic variations at 19 allozyme loci. Fourteen of the 19 loci (73.7%) showed detectable polymorphism. Genetic diversity at the species level and at the population level was high ($H_{ES}\;=\;0.215$, $H_{EP}\;=\;0.196$, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}\;=\;0.069)$. Total genetic diversity values $(H_T)$ varied between 0.0 and 0.656, giving an average overall polymorphic loci of 0.292. The interlocus variation of genetic diversity within populations $(H_S)$ was high (0.274). On a per locus basis, the proportion of total genetic variation due to differences among populations $(G_{ST})$ ranged from 0.010 for Pgm-2 to 0.261 for Pgd-2 with a mean of 0.069, indicating that about 6.9% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. discolor. The estimate of gene flow based on $G_{ST}$ was high among Korean populations of P. discolor (Nm = 3.36).

• Journal of Life Science
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• v.16 no.1
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• pp.64-70
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• 2006

Starch gel electrophoresis was used to estimate genetic diversity and population structure of Pyrola fauriena H. Andr. in Korea. The percentage of polymorphic loci within enzymes was $57.1\%$. The values of genetic diversity at the species level and at the population were higher than average values for herbaceous with similar life history traits (Hes : 0.149; Hep = 0.134, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}=0.082)$. $F_{IS}$, a measure of the deviation from random mating within the 12 populations, was 0.298. An indirect estimate of the number of migrants per, generation (Nm = 2.81) indicates that gene flow is moderate among Korean populations of the species. Analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. This indicates that some populations sampled may have been substructured largely due to rhizotamous spread and decrease of population sizes.

• Journal of the Korean Society for information Management
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• v.21 no.1
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• pp.93-117
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• 2004

This study is to develop a hierarchic clustering model fur document classification and browsing in OPAC systems. Two automatic indexing techniques (with and without controlled terms), two term weighting methods (based on term frequency and binary weight), five similarity coefficients (Dice, Jaccard, Pearson, Cosine, and Squared Euclidean). and three hierarchic clustering algorithms (Between Average Linkage, Within Average Linkage, and Complete Linkage method) were tested on the document collection of 175 books and theses on library and information science. The best document clusters resulted from the Between Average Linkage or Complete Linkage method with Jaccard or Dice coefficient on the automatic indexing with controlled terms in binary vector. The clusters from Between Average Linkage with Jaccard has more likely decimal classification structure.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.51-58
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• 2014

Genetic diversity and genetic structures were estimated in seven natural populations of Phellodendron amurense Rupr in South Korea using ISSR markers. The average of polymorphic loci per primer and the proportion of polymorphic loci per population were 4.5 and 78.8% respectively with total 27 polymorphic loci from 6 ISSR primers. The Shannon's diversity index(I) was 0.421 and the expected heterozygosity($H_e$) was 0.285, which was similar to the heterozygosity (hs =0.287) inferred by Bayesian method. In AMOVA, 7.6% of total genetic variation in the populations was resulted from the genetic difference among populations and the other 92.4% was resulted from the difference among individuals within populations. Genetic differentiation(${\theta}^{II}$) and inbreeding coefficient(f) for total population were estimated to be 0.066 and 0.479 by Bayesian method respectively. In Bayesian clustering analysis, seven populations were assigned into three groups. This result was similar to the results of genetic relationships by UPGMA and PCA. The first group included Hwachoen, Gapyeong, Bongpyeong and Yongpyeong population, and the second included two populations in Sancheong region. Muju population was discretely assigned into the third group in spite of the geographically short distance from the Sancheong region. There was no significant correlation between genetic relationship and geographic distribution among populations in Mantel's test. For conservation of the phellodendron trees, it would be effective to consider the findings resulted from this study with ecological traits and life histories of this species.

• Proceedings of the Korean Society for the Gifted Conference
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• 2003.05a
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• pp.91-108
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• 2003

본 연구의 목적은 다음과 같다. 첫째, 암묵적 방법에 의해 도출된 영재성과 명시적 이론간에 차이가 있는가\ulcorner 둘째, 과학 분야와 인문 분야에는 어떤 영재성 요인들이 있는가\ulcorner 셋째, 분야별로 영재성의 요인구조 어떤 차이가 있는가\ulcorner 연구의 방법은 세 단계로 이루어졌다. 연구의 첫 단계는 과학자, 학부모, 교사, 대학생을 대상으로 암묵적 이론 접근으로 영재 의미를 구명하였다. 연구의 두 번째 단계는 자연계 영재 집단 469명, 인문계 영재집단 285명에 대하여, 암묵적 이론 접근에 의해 밝혀진 영재의 특징들은 과학영재와 인문영재를 구분하는 준거가 되는지의 여부를 요인분석(factor analysis)을 통하여 검증하였다. 연구의 세 번째 단계는 검증된 자료를 가지고 인문계 영재 집단과 자연계 영재 집단 간의 영재성 요인 구조상의 차이를 검토하였다.

• Proceedings of the Korea Association of Information Systems Conference
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• 1998.10a
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• pp.64-71
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• 1998

정보시스템 분야에서 성공적인 정보시스템 개발을 위하여 사용자 참여, 몰입, 만족 과 관련된 많은 연구가 진행되었다. 초기의 연구에서는 사용자 참여와 몰입의 개념이 혼용 되었으나 현재는 구분되는 개념으로 사용되고 있다. 초기 연구에서 몰입과 만족에 관한 연 구가 있었으나 구분되는 개념으로 보았을 때 몰입보다는 참여와 만족에 관한 연구로 보아야 할 것이고, 그후 진행된 대부분의 연구가 사용자 참여와 만족간의 관계에 대한 것이었다. 이들 연구에서는 사용자의 참여 정도가 사용자 만족에 어떠한 영향을 미치는가를 분석하였 다. 그러나 이들의 연구는 일관성 있는 결과를 제시하지 못하였는데, 이와 같은 결과가 나 타난 데에는 다른 여인도 작용하였겠지만, 개발에 참여한 사용자의 주관적 심리 상태인 사 용자 몰입 정도의 차이가 결과의 불일치를 가져오는 요인으로 작용하였을 수 있다. 본 연구 에서는 사용자 참여와 몰입간의 관계를 분석하기 위하여, 시스템 개발에서 사용자와 개발자 간의 관계를 집단으로 간주하여, 집단의 구조적 측면과 집단의 행위적 측면에서 이들 관계 를 분석하였다. 이들 관계에 영향을 주는 조절변수로 구조적 측면에서는 공식화, 집권화 정 도를, 행위적 측면에서는 갈등의 정도, 집단 응집성, 의사소통 수준을 사용하였다.