• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.555-566
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• 2017

For multivariate datasets with large number of variables, classical dimensional reduction methods such as principal component analysis may not be effective for data visualization. The underlying reason is that the dimensionality of the space of variables is often larger than two or three, while the visualization to the human eye is most effective with two or three dimensions. This paper proposes a working procedure which first partitions the variables into several "latent" clusters, explores individual data subsets, and finally integrates findings. We use R pakacage "ClustOfVar" for partitioning variables around latent dimensions and the principal component biplot method to visualize within-cluster patterns. Additionally, we use the technique for embedding supplementary variables to figure out the relationships between within-cluster variables and outside variables.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.195-195
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• 2020

이 연구는 기후변화 위험에 노출되어 있는 북한에 대한 잠재증발산량의 미래 변화를 전망하였다. 이를 위해 IPCC AR5의 RCP 기후변화 시나리오로부터 모의된 미래 기온자료를 APCC (APEC Climate Center) Integrated Modeling (AIMS)를 사용하여 25개 관측 지점에 대해서 상세화하여, McGuinness-Borne 방법으로 잠재증발산량을 추정하였다. 6개의 성능 지표와 TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution)로 27개 GCMs 간의 과거 기후 재현성을 비교하여, 관측 지점 규모에서 적정 GCM을 선정하였다. 마지막으로 각 지점에서 선정된 대표 시나리오(representative climate change scenarios, RCCS)로 북한 지역의 잠재증발산량의 미래 변화를 3개의 구간(F1: 2011-2040; F2: 2041-2070; F3: 2071-2100)에서 all CCS(climate change scenario)와 비교하고, 미래 변화를 정량적으로 제시하였다. 그 결과 공간 해상도가 더 높은 GCM이 RCCS로 선정되었으며, 미래로 갈수록 잠재증발산량이 증가하리라 전망되었다. 또한, 여름철 잠재증발산량의 모델 간 변동성은 미래 구간에 따라 점진적으로 증가되었고, 연 평균 증발산량은 과거 기후대비 1.4배(F1), 2.0배(F2) 및 2.6배(F3) 증가하였다.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.119-120
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• 2011

본 연구는 중소기업의 글로벌 혁신역량에 관련 선행연구를 조사분석한 연구이다. 국내외 중소기업의 글로벌혁신역량에 관한 선행연구를 광범위하게 조사한 후 중소기업의 글로벌 혁신역량에 영향을 미치는 대표적인 잠재변수를 선정한다. 각 잠재변수별로 유의적으로 판명된 지표를 분석하여 기업내부역량 중 글로벌혁신역량에 중요한 요인인 CEO역량, 기술역량, 마케팅역량, 생산역량, 인적자원역량, 재무역량, 네트워크역량으로 재분류한다. 향후 잠재변수사이의 상관관계를 분석하여 상호교호작용효과를 배제한 잠재변수별 순효과(net effect)를 분석하고자 한다.

• Journal of the Korean Arthroscopy Society
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• v.5 no.2
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• pp.124-130
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• 2001

Purpose : To identify occult intra-articular pathologies in the acute ankle fracture using arthroscopy and to investigate the factors to predict its possibility of occult injuries that could be occurred. Materials and Methods : This prospective study included fifty patients who got operation for the ankle fractures. Ankle arthroscopy was performed to document the type and anatomical location of occult lesion. We investigated the correlation between incidence of occult injuries and specific fracture type. Results : Of fifty ankles, 37 ankles had occult lesion. Twenty five loose bodies including displaced fragments were found and various cartilage lesions were found in 31 ankles. Tibial avulsion fragment by anterior inferior tibiofibular ligament was occurred in 6 cases. There was no correlation between the incidence of occult lesion and various factors including age, sex, injury mechanism and fracture type(p>0.05). Conclusion : The ankle arthroscopy had an effective role for the detection and treatment of occult injuries and it was difficult to predict the occurrence or associated accurately in all of th ankle fractures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.404-414
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• 2020

This study aims to explore latent classes in terms of changing patterns in achievement motivation among the samples from elementary school to middle school students in multicultural families and to investigate factors to predict latent groups and their relationship with academic achievement. 1254 pairs of mother and child from the 1st to 6th years of Multicultural Adolescents Panel Study (MAPS) was utilized for the Latent Class Growth Analysis (LCGA), One-way ANOVA, Multinomial Logistic Regression. The results showed that there were four distinct subgroups within the samples in terms of achievement goal orientations (i.e. very-high changing group, average changing group, low stable group, very-low stable group) at all six time points, and students who reported high achievement motivation were likely to have higher academic achievement. Four groups were extracted based on parent's efficacy, students' self-esteem, and teacher's support. Suggestions and practical implications for understanding the types of subgroups for the achievement motivation of multicultural families were discussed.

• Korean Journal of Social Welfare Studies
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• v.40 no.3
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• pp.377-406
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• 2009

This study used laten class growth analysis to identify discrete developmental patterns of delinquent behaviors in adolescence. This present article also examined associations among these trajectories to determine how the development of delinquent behaviors relates to protective and risk factors, which include parental monitoring, attachment with parent, association with deviant peers, self-control, and negative stigma from others. Four-wave panel data from a Korea Youth Panel Study were used for the latent class growth model analysis. The sample consisted of 3,446 adolescents who were assessed at 4 measurement waves with approximately 1-year interval. Four trajectories of delinquent behaviors emerged: delinquency persistence, delinquency increaser, delinquency decreaser, normative group(almost no delinquent behaviors). Association with deviant peers had the most proximal strong influence on the probability of being in the delinquency increaser and delinquency persistence group compared, noed to the normative group. Parental monitoring, self-efficacy and negative stigma also differentiated the four delinquent behavior trajectories from one another after controllig for socio-demographic variables. The study suggested that there is a significant heterogeneity in the timing and change rate of delinquency progression. Adolescent delinquency prevention and intervention programs will need to consider this heterogeneity and enhance attention to protective and risk factors depending on the subpopulation.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.99-107
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• 2010

Analyzing mode choice among transportation demand estimate procedures is complicated and understanding characteristics of travelers is also difficult. Generally, it is well known that traveler choose mode considering psychometric factors and characteristic besides socio-demographic indicators. Accordingly, many researches has investigated on methodology that can be applied in mode choice to reflect psychometric factor or specific preference. Latent Class Analysis among various studies is recognized as the theoretically potential approach. This study focuses on class segmented using latent class cluster to analyze impact that included psychometric factors and characteristics on mode choice. It also provides evidence that mode choice model for each class and mode choice model not considering latent class are different. This study based on citizen's stated preference and revealed preference on a new transit on the Han river shows that latent class cluster analysis is the potential approach considering latent preference.

• Journal of the Korean Society for information Management
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• v.26 no.3
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• pp.451-462
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• 2009

The aim of this study is to apply latent semantic indexing(LSI) techniques for efficient automatic classification of opinionated documents. For the experiments, we collected 1,000 opinionated documents such as reviews and news, with 500 among them labelled as positive documents and the remaining 500 as negative. In this study, sets of content words and sentiment words were extracted using a POS tagger in order to identify the optimal feature set in opinion classification. Findings addressed that it was more effective to employ LSI techniques than using a term indexing method in sentiment classification. The best performance was achieved by a supervised LSI technique.

• KDI Journal of Economic Policy
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• v.29 no.1
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• pp.79-112
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• 2007

Opening domestic market to international trade may enhance not only actual competition but also potential competition from foreign competitors. It seems that the competition authority has focused mainly on the actual competition (measured by the current market share) and has paid less attention to the potential competition. In this regards, this paper investigated the relation between potential foreign competition and domestic market structure. Using dynamic panel regression model, we analyzed the dynamic response of import penetration to the changes of domestic market condition in Korea as a proxy for the degree of potential foreign competition. The empirical results suggests that potential foreign competition does exist in the Korean manufacturing sector and this tendency is more stronger when the market is more concentrated. Thus, in order to effectively implement competition policy, it is necessary to consider both actual and potential competition.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.23-34
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• 2015

This Study analyzed heavy snow properties according to the area that was based by winter weather properties and the damage data by the heavy snow among each local government of Chungcheongbuk-do. The result of analysis, Jecheon-si and Boeun-gun are represented the highest dangerous regions by potential degree of risk by average amount of snowfall for 35 years. But, the potential degree of risk by maximum amount of snowfall for 35 years is different with it. Cheongju-si and Youngdong-gun, Goesan-gun, Boeun-gun are represented the highest dangerous regions. Examining the frequency of regions with potential danger factors according to the characteristics of heavy snowfall, Boeun-gun and Jecheon-si, Goesan-gun, Youngdong-gun, Cheongju-si is derived the highest dangerous regions in Chungcheongbuk-do.