• Journal of The Korean Association For Science Education
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• v.33 no.3
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• pp.650-663
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• 2013

Multidimensional scaling can be used to identify relationships among concepts, revealing the structure of the cognitive framework by measuring distances within perceptual maps. The current study sought to examine the relationships among concepts related to photosynthesis in 2,844 $3^{rd}-11^{th}$ grade science students. The questionnaire included items on 'location,' 'products,' 'reactants,' and 'environmental factors', presenting images related to each theme. Students provided responses corresponding to particular topics, and reported the extent to which the concept was related to the topic on a scale from 1 to 30. The survey results were as follows: first, students were not able to clearly distinguish between or understand the four main topics. Second, students organized their cognitive structures by closely associating related concepts after learning. Third, the presented concepts revealed a mixture of scientific and non-scientific concepts, suggesting that students needed to clearly distinguish the preconceptions through which they organized concepts, so that they are suitable for cognitive structures based on learning. Furthermore, non-scientific concepts within perceptions were consistently maintained throughout learning, affecting the proximity of scientific concepts.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1744-1759
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• 1992

A multidimensional simulation of turbulent flow and combustion with swirl in the cylinder of SI engine is implemented to clarify the effects of swirl. present simulation employs the ICED-ALE numerical technique, the skew-upwind difference scheme, a modified k_.epsilon. turbulence model, a combustion model of Arrhenius type and turbulence-mixing-control type. First, the calculations for swirling flow in an axisymmetric cylinder are carried out. The results are compared with the experimental data to validate the numerical analysis. Second, the calculations for intake, compression and combustion processes in an axisymmetric cylinder are performed. The effects of swirl on turbulent flow and combustion are examined through the parametric study of swirl number 0.0, 0.6, 1.2 and 2.4. As a result, it is numerically shown that the turbulent kinetic energy and the swirl velocity, which are produced during the intake process, affect the combustion process.

• The KIPS Transactions:PartB
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• v.19B no.3
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• pp.155-164
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• 2012

This study aims to identify the multidimensional variables and sub-variables and study their relative weight in music recommender systems when maximizing the rating function R. To undertake the task, a optimization formula and variables for a research model were derived from the review of prior works on recommender systems, which were then used to establish the research model for an empirical test. With the research model and the actual log data of real customers obtained from an on line music provider in Korea, multiple regression analysis was conducted to induce the optimal correlation of variables in the multidimensional model. The results showed that the correlation value against the rating function R for Items was highest, followed by Social Relations, Users and Contexts. Among sub-variables, popular music from Social Relations, genre, latest music and favourite artist from Items were high in the correlation with the rating function R. Meantime, the derived multidimensional recommender systems revealed that in a comparative analysis, it outperformed two dimensions(Users, Items) and three dimensions(Users, Items and Contexts, or Users, items and Social Relations) based recommender systems in terms of adjusted $R^2$ and the correlation of all variables against the values of the rating function R.

• The Korean Journal of Applied Statistics
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• v.31 no.4
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• pp.517-528
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• 2018

We provide R scripts to detect outliers in multivariate data and visualization. Detecting outliers is provided using three approaches 1) Robust Mahalanobis distance, 2) High Dimensional data, 3) density-based approach methods. We use the following techniques to visualize detected potential outliers 1) multidimensional scaling (MDS) and minimal spanning tree (MST) with k-means clustering, 2) MDS with fviz cluster, 3) principal component analysis (PCA) with fviz cluster. For real data sets, we use MLB pitching data including Ryu, Hyun-jin in 2013 and 2014. The developed R scripts can be downloaded at "http://www.knou.ac.kr/~sskim/ddpoutlier.html" (R scripts and also R package can be downloaded here).

• Journal of the Korean Society for Library and Information Science
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• v.41 no.2
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• pp.335-357
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• 2007

There has been many studies representing intellectual structures with multidimensional scaling(MDS) However MDS configuration is limited in representing local details and explicit structures. In this paper, we identified two components of MDS mapping approach; one is MDS algorithm and the other is preparation of data matrix. Various combinations of the two components of MDS mapping are compared through some measures of fit. It is revealed that the conventional approach composed of ALSCAL algorithm and Euclidean distance matrix calculated from Pearson's correlation matrix is the worst of the compared MDS mapping approaches. Otherwise the best approach to make MDS map is composed of PROXSCAL algorithm and z-scored Euclidean distance matrix calculated from Pearson's correlation matrix. These results suggest that we could obtain more detailed and explicit map of a knowledge domain through careful considerations on the process of MDS mapping.

• Korean Journal of Social Welfare Studies
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• no.36
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• pp.81-101
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• 2008

The purpose of this study is to analyze characteristics of welfare level for the persons with disabilities in Korean local governments. The study adopted multidimensional scaling and cluster analysis. Based on prior studies and comparative importance research, three indicators were extracted from the welfare circumstance index for the disabled. They are the ratio of the registered disabled population, the ratio of the disabled household in poor households, the ratio of dependence on public finance. Also, nine dimensions and twenty seven indicators were extracted from the welfare level index. The dimensions are as follows : Education, income & economic activities support, welfare services infra-structure, health & welfare service support, movement convenience & safety, rights protection, culture, leisure & information accessibility, welfare administration & budget for the disabled. The findings from the welfare circumstance index show that local governments are divided into three groups and all indicators are statistically significant. On the other hand, the findings from the welfare level index, show that local governments are divided into four groups and five indicators are statistically significant. Based on these findings, the study proposes improvement in the disabled welfare level, and balanced development of local governments.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.15-28
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• 2023

This study examined the affective representation and response consistency among individuals using affective videos, a naturalistic stimulus inducing emotional experiences most similar to those in daily life. In this study, multidimensional scaling was conducted to investigate whether the various affective representations induced through video stimuli are located in the core affect dimensions. A cross-participant classification analysis was also performed to verify whether the video stimuli are well classified. Additionally, the newly developed intersubject correlation analysis was conducted to assess the consistency of affective representations across participant responses. Multidimensional scaling revealed that the video stimuli are represented well in the valence dimension, partially supporting Russell (1980)'s core affect theory. The classification results showed that affective conditions were successfully classified across participant responses. Moreover, the intersubject correlation analysis showed that the consistency of affective representations to video stimuli differed with respect to the condition. This study suggests that the affective representations and consistency of individual responses to affective videos varied across different affective conditions.

• Science of Emotion and Sensibility
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• v.6 no.4
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• pp.33-40
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• 2003

This research was conducted to propose a sensibility model for web site design. At first, we collected 100 sensibility words related to web site design through analysis of journal and questionnaires and analysis of dictionary. 16 web sites were rated according to the degree of sensibility corresponding to each words, on the basis of the Semantic Differential(SD) method. The results of assessment were analyzed by means of the factor analysis and Multidimensional Scaling(MDS) method. From this relational analysis of sensibility words, the 18 representative words were abstracted as a result of the research included unique, unusual, rich, soft, cold, warm, vivid, simple, neat, dynamic, urban, light, somber, bright, dark, fresh, masculine, and hard. Also three sensibility dimensions bright-dark, soft-hard, simple-rich were found.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.797-807
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• 2013

The purpose of the study is to examine the effect of parents' raising attitudes, mental health on multidimensional perfectionism of university students. 312 university students in Daejeon and Seoul province were participated in the survey thru convenient sampling and conducted by correlation analysis and multiple regression. The results are as follows: First, the relations of parents' raising attitudes, mental health and multidimensional perfectionism are as follows: subordinate variabies of multidimensional perfectionism, self-oriented perfectionism and father-refusal, father-overprotection, mother-refusal, mother-overprotection, compulsiveness, depression, paranoia, psychosis; socially-imposed perfectionism and father-love, phobia, somatic were found significant. Secondly, multiple regression are as follows; the influencing variable on multidimensional perfectionism are mother-refusal, mother-overprotection, compulsiveness and paranoia, but another variables excepting these variabies were not relevant variabies.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.765-774
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• 2006

An association rule discovery, a technique to analyze the stored data in databases to discover potential information, has been a popular topic in stream data system. Most of the previous researches are concerned to single stream data. However, this approach may ignore in mining to multidimensional stream data. In this paper, we study the techniques discovering the association rules to multidimensional stream data. And we propose a AR-MS method reflecting the characteristics of stream data since make the summarization information by one data scan and discovering the association rules for significant rare data that appear infrequently in the database but are highly associated with specific event. Also, AR-MS method can discover the maximal frequent item of multidimensional stream data by using the summarization information. Through analysis and experiments, we show that AR-MS method is superior to other previous methods.