• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.9-25
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• 1977

As a successive work of the variation studies of natural Pinus densiflora stands, some characteristics of individual trees of the three natural populations selected from the Kwang-won Province, the middle-east part of Korean peninsula, as shown in the location map, were investigated. And the statiscal differences between individuals within population, and between populations were analysed. Twenty trees from each population were selected for this study purpose. Doing this, those trees lagged in growth, usually showing poorer form, were eliminated. The results obtained are summarized as follows: 1. Though the average population ages had the ranage between 50 and 63, the growth of height or diameter was similar. Population No.9 is, however, considered to have better tree forms at glance. Population No.8 showed the heighest value not only in the clear-stem-length ratio. 0.53 but also in the crown-index 0.91. The higher value can be result from those trees having long lateral branches and relatively short crown height, meaning undesirable crown shape. In regard to the fine branchedness and the acuteness of branching angle, the population No.9. is considered to be a better one, whereas there was almost no difference in crown height among populations. 2. Checking the frequency distributions of the ratio of the clear-stem-height to the total height and the crown-indices, some difference between populations are considered. These might be attributed to the previous way of stand mangement which alters the density. 3. In the serration density, the average number of 54 per 1cm needle length, the significant differences exist between individual trees within population but not between populations. A few trees which extremly high serration density were observed. As in serration, so tendencies were in the number of stomata row and resin duct. 4. The population 8 had the resin duct index value of 0.074 as the highest which was twice or triple of the other ones. 5. The patterns of increasing process of the average 10-year-ring-segment were not similar till the 30 years of age, but beyond this, the tendency lines were aggregated. 6. Regading the average summer wood ratio, no diffrence between populations, but in the ranges, i.e. 23 to 30 in population No.8. and 16 to 36 in population No.9., with regad to the specific gravity of wood, there were hardly observed any difference between populations even in the ranges values. As the increase of tree ages, the increase of specific gravity was followed but the increasing patterns were not similar between populations. 7. No significant differences between populations in the average tracheid length and the range were detected. However, the length was increased according to the age increase. The increasing pattern was same between populations.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.156-164
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• 2005

The aim of this study was to analyze the isokinetic strength of ankle, lumbar and shoulder in fin swimmers. For this study, 7 male fin swimmers and 7 men general swimmers were selected. Isokinetic strength of ankle, lumbar and shoulder were measured by Biodex System 3,000. Statistical techniques for data analysis were a descriptive statistics and t-test. The results of this study were as following; The first, significant difference between two groups in right and left plantar flexion of ankle at $30^{\circ}/sec\;and\;180^{\circ}/sec$. But no significant difference was found between right and left in two groups. The second, significant difference between two groups in right dorsiflexion of ankle at $30^{\circ}/sec$. The third, significant difference between two groups in extension of lumbar at $60^{\circ}/sec$. The fourth, significant difference between two groups in right flexing of shoulder at $60^{\circ}/sec$ and $180^{\circ}/sec$. As result of this conclusion, the isokinetic strength of ankle and lumbar in fin swimming group showed significantly higher than non-fin swimming group.

• KDI Journal of Economic Policy
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• v.34 no.2
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• pp.1-15
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• 2012

We develop an identity choice model within the context of a stereotyping-cum-signaling framework. The model allows us to explore implications of the fact that, when individuals can choose identity, then the distribution of abilities within distinct identity groups becomes endogenous. This is significant because, when identity is exogenous and if the ability distributions within groups are the same, then inequality of group reputations in equilibrium can only arise if there is a positive feedback between group reputation and individual human capital investment activities (Arrow, 1973; Coate and Loury, 1993). Here we show that when group membership is endogenous then the logic of individuals' identity choices leads there to be a positive selection of higher ability individuals into the group with a better reputation. This happens because those for whom human-capital-investment is less costly are also those who stand to gain more from joining the favored group. As a result, ability distributions within distinct groups can endogenously diverge, reinforcing incentive-feedbacks. We develop the theoretical framework that can examine the positive selection and the endogenous group formation. The model implies that inequality deriving from stereotyping of endogenously constructed social groups is at least as great as the inequality that can emerge between exogenously given groups.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.565-578
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• 2006

Repeated measurement data between two group is often used in the field of medicine study. In this paper, we suggest a method for comparison of the trend between two groups based on repeated measurement data. First, we estimate regression coefficient of linear regression model from each subject and generate samples using the regression coefficient estimated previous. And then, we test the difference between two groups by unpaired t-test, Wilcoxon rank sum test and placement test using generated samples. Monte Carlo Simulation is adapted to examine the power and experimental significance levels of several methods in various combinations.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.177-183
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• 2021

This empirical study aims to find the factors to affect purchasing dairy products between the expert group and consumer group and also find the difference between the groups and the reasons, using AHP. Based on the results of the previous studies, four main factors were selected and they are products, marketing, quality, and social factors. Then, we surveyed the groups of consumers and experts, conducted AHP analysis, and compared the gaps between the groups. The factor of marketing, especially the sub-factor of brand, was found out the most biggest difference, followed by the sub-factor of hygiene in the factor of quality. The results of this study can contribute to the dairy industry to see the difference between the expert and consumer groups' choices.

• The Korean Journal of Zoology
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• v.34 no.4
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• pp.571-584
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• 1991

잉어과(Gyprinidae)의 Zocco속 어류 4종과 Candidia속 어류 1종에 대한 종간 유연관계와 종분화 연대측정 및 이들의 지질학적 분포경로를 밝히기 위하여 한국, 일본 및 대만에서 채집된 개체를 대상으로 전기영동법에 의한 유전자 분석을 하였다. 각 종의 지역별(한국, 일본, 대만) 집단간 유전적 유연관계를 분석한 결과 평균 유전적 근연치는 90% 이상이었다. Z. temmincki의 경우 일본집 단들은 한국의 A-type 집단과는 유연관계가 가까왔으나 한국의 B-type과는 유전적 차이가 현저하러다. Z. PlaD여5의 경우 한국집단과 일본집단사이의 유연관계는 S = 0.852였고, 한국집단과 대만집단 사이는 5 = 0.672, 일본집단과 대만집단 사이는 S = 0.751로서 지리적으로 현저한 차이를 업였다. Z. pochycephalus 3개 집단간의 유전적 근인치는 S = 0.963이었고 Candidia borbota 2개 집단간은 S = 0.946이었다. 종간의 유전적 근연환계를 비교한 결과 Candidia borbota와 Z. temmincki사이는 S = 0.608, Z. pluDpus와 1. pachycephalus사이는 S = 0.612였으나, Z. temmincki와 Z. platypus사이는 S = 0.441, Z. temmincki 와 Z. pochycepholus 사이는 S = 0.350이었고, Z. plotpus와 Condfda barbata사이는 S = 0.328로서 이들 사이에는 현저한 유전적 차이가 있었다. 각 종간의 롱분화 연대를 추산한 결과 이들은 약 480만년 전인 Pliocene 초기에 공통 조상종에서 분화하여 Z. temmincki, Candidia borbato group과 Z. plotypus, Z. pochycepholus group으로 분리되었고 약 260만년 전인 Pliocene 후기에 Z. temminc소와 Candidia borbota로 분화되었다고 추산되며 약 80만년 전인 Pleistocene시기에 남 temmincki B-type에서 h-type이 분화되었다짙 여겨진다. 한편 또 다른 한 단opP은 약 230만년 전인 열iocene후기에 대만 지역의 Z. plotypas에서 Z. pochvcepholus가 분화된 후 현재에 이르렀다고 추정된다. Z. platypus는 약150만년 이전인 초기 Pleistocene시기에 대만지역에서 한국 및 일본집단으로 분리되었다고 보며 이들 한국집단과 일본집단은 약 50만년 전 Pleistocene의 Middle기에 고황하 수계를 거쳐 현재의 분포 상황에 이르렀다고 여겨진다. 한편 대. temmin체과의 B-type에서 저온 적응으로 분화되었다고 추측되는 A-type은 약 20만년 전인 Pleistocene의 Riss기에 역시 고황하 수계를 통하여 한국과 일본으로 분포하여 현재에 이르렀다고 사료된다.

• Korean Journal of Culture and Social Issue
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• v.19 no.4
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• pp.529-552
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• 2013

This study examines how individual attitudes towards government and society are affected by political conservatism and liberalism. With survey data from 533 adults(M=249, F=284) who live in Seoul and surrounding areas, we examine the general attitudes towards society, expectation on general government and differences in attitudes towards the Roh Moo-hyun Gov't and the Lee Myung-bak Gov't between liberals and conservatives. Results show that liberals and conservatives vary by age and residence, whereas attitudes towards the general government and society are not. By contrast, liberals and conservatives are distinctly different evaluating governments with specific political tendency. Liberals are more positive to the Roh Moo-hyun Gov't than conservatives whereas the evaluation appears conversely on the Lee Myung-bak Gov't. These differences of attitudes are more distinctive when dividing liberals and conservatives by subjective judgement and political party preference than conceptual measurement of political ideology. These findings suggest that political conservatism and liberalism is the factor that has powerfully affected individual attitudes in the specific political context rather than a consistent ideological framework in Korean society.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.436-443
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• 2010

The purpose of this study is to investigate whether there are differences in three attitudes-attitudes toward English learning, attitudes toward American, and attitudes toward American culture between Korean and Chinese university students learning Korean in Korea. The subjects are 211 students, who are 101 Korean and 110 Chinese. Gardner(1985)'s AMTB questionnaire was administered to measure the learners' attitudes. And the collected data were analyzed by t-test to examine the differences between two groups. The results of this study showed that there were statistically very significant differences in attitudes toward English learning and there were significant differences in attitudes toward American between two groups. But there were no differences statistically in attitudes toward American culture between two groups. To make better learning environment for English learners, the differences in other affective variables between two groups need to be studied.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.73-82
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• 1998

본 연구의 목적은 일주일간 조사된 개인통행행태를 고려한 각 특성별 통행발생예측 방법을 제시하는데 있다. 이를 위하여 일주일간 통행빈도수의 차이를 고려한 집단간 차이를 검정하고, 그 원인을 분석하여 이에 따른 특성별 개인 통행발생예측 모형을 정립하였다. 전체 표본의 각 특성별 개인 내부 변이성을 분석해 본 결과 기간의 차이에 따른 개인 통행행태의 변화는 직업별, 나이별, 성별, 차량소유 유무, 주택소유 형태, 통행목적, 통행수단, 가구원수에 따라 집단간 차이를 보여주었다. 이러한 변수를 이용한 통행발생 예측모형의 분석결과 개인소득이 높을수록, 주책을 자가로 소유한 경우, 자동차를 소유한 경우, 학생일수록, 유직일수록 개인 통행발생량이 많은 것으로 분석되었다. 반면, 아니는 연령대가 높아질수록 통행수가 적어졌다.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.193-202
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• 2020

This study was intended to present the magnitude of privacy infringement concerns and their relationship to consumer innovation (functional innovation, hedonistic innovation, social innovation, cognitive innovation), to identify differences among groups and to suggest implications for marketing strategies for the spread of new products. The implications of this study are as follows. First, functional innovation has shown that differences exist between groups. Analysts say that sensitive groups are buying products that can simplify their work immediately after release despite concerns over privacy violations. Second, hedonistic innovation has shown that differences exist between groups. These findings suggest that sensitive groups prefer novel products, products that give excitement and excitement about products, and products that give new enjoyment and fun that they have never known before. Third, social innovation has been shown that there is no difference between groups. These analyses show that the self-esteem of using products that others have never experienced before, and the curiosity that anyone envies, are purchased or used first. Finally, cognitive innovation showed that differences existed between groups. These analyses show that new products are purchased when they meet the functions, design, and innovation that consumers want.