• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.875-888
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• 2008

Mosaic plots, proposed by Hartigan and Kleiner (1981, 1984), are very useful in visualizing categorical data. In mosaic plot, multi-way classified cell frequencies are represented by rectangles with proportional area. The plot is easy to understand while preserving the information contained in the data. Plot's appearance, however, does change substantially depending on the order of variables and the orders of categories with variable put into the plot. In this study, we propose the algorithms for ordering variables and categories of the categorical data to be explored via mosaic plots. We demonstrate our methods to three well-known datasets: Titanic, Housing and PreSex.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.595-610
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• 2013

Testing of order-restricted alternative hypothesis in $2{\times}k$ contingency tables can be applied to various fields of medicine, sociology, and business administration. Most testing methods have been developed based on a large sample theory. In the case of a small sample size or unbalanced sample size, the Type I error rate of the testing method (based on a large sample theory) is very different from the target point of 5%. In this paper, the exact testing method is introduced in regards to the testing of an order-restricted alternative hypothesis in categorical data (particularly if a small sample size or extreme unbalanced data). Power and exact p-value are calculated, respectively.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.181-183
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• 2006

본 논문은 고차원의 범주형 데이터에 대한 군집화에 대해서 다룬다. 기존의 범주형 데이터 객체를 위한 유사성(상이성) 계측들의 기저에 깔려 있는 한계점은 수치형 데이터에서와 같은 순서화 (ordering)의 부재와 데이터의 고차원성과 희소성에 기인하는데, 이를 효과적으로 극복할 수 있는 기법이 투영 군집화이다. 본 논문에서는 고차원의 범주형 데이터를 효과적으로 처리할 수 있는 투영 군집화를 다루며 핵심 요소인 군집 차원의 정의와 군집 응집도를 제안한다.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1196-1210
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• 1997

Timestamp-Ordering Prltocol among trancaction scheduling alforithms can cause the priority teversion that a transaction with higher priority is processed after the teansaction the trancaction withe lower priority by assigning timestamp to transactions entering system and scheduling them based on the timestamp.To prevent this reversion,we suggest a data priority-based timestamp ordering prioity within the same timestamp group after grouping teansactions into constant time interval based on entering points.To evaluate the performance of this protocol,we compared the performance of this protocol with that of others after constructing the simulation environment with real time database system.We verified that the performance of proposed protocol is supweior to that of timestamp ordering protocol under the comdition of high load and high data conflicts.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.899-910
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• 2016

Asymptotic tests are often not suitable for the analysis of sparse ordered contingency tables as asymptotic p-values may either overestimate or underestimate the true pvalues. In this pater, we describe permutation procedures in which we compute exact or resampling p-values for a weighted specific-category agreement in ordered $k{\times}k$ contingency tables. We use the weighted specific-category kappa proposed by $Kv{\dot{a}}lseth$ to measure the extent to which two independent raters agree on the specific categories. We carried out comparison studies between exact p-values, resampling p-values and asymptotic p-values using $3{\times}3$ contingency data (real and artificial data sets) and $4{\times}4$ artificial contingency data.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.157-164
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• 2015

This paper describes subspace clustering of categorical data for convergence and integration. Because categorical data are not designed for dealing only with numerical data, The conventional evaluation measures are more likely to have the limitations due to the absence of ordering and high dimensional data and scarcity of frequency. Hence, conditional entropy measure is proposed to evaluate close approximation of cohesion among attributes within each cluster. We propose a new objective function that is used to reflect the optimistic clustering so that the within-cluster dispersion is minimized and the between-cluster separation is enhanced. We performed experiments on five real-world datasets, comparing the performance of our algorithms with four algorithms, using three evaluation metrics: accuracy, f-measure and adjusted Rand index. According to the experiments, the proposed algorithm outperforms the algorithms that were considered int the evaluation, regarding the considered metrics.

• The Korean Journal of Applied Statistics
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• v.33 no.1
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• pp.25-46
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• 2020

This paper presents ordinal probit semiparametric regression models using Bayesian Spectral Analysis Regression (BSAR) method. Ordinal probit regression is a way of modeling ordinal responses - usually more than two categories - by connecting the probability of falling into each category explained by a combination of available covariates using a probit (an inverse function of normal cumulative distribution function) link. The Bayesian probit model facilitates posterior sampling by bringing a latent variable following normal distribution, therefore, the responses are categorized by the cut-off points according to values of latent variables. In this paper, we extend the latent variable approach to a semiparametric model for the Bayesian ordinal probit regression with nonparametric functions using a spectral representation of Gaussian processes based BSAR method. The latent variable is decomposed into a parametric component and a nonparametric component with or without a shape constraint for modeling ordinal responses and predicting outcomes more flexibly. We illustrate the proposed methods with simulation studies in comparison with existing methods and real data analysis applied to a Korean National Health and Nutrition Examination Survey (KNHANES) 2016 for investigating nonparametric relationship between smoking behavior and coffee intake.

• Journal of KIISE:Software and Applications
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• v.37 no.7
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• pp.491-502
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• 2010

When human beings acquire and develop knowledge through education, their prior knowledge influences the next learning process. As this is a fact that should be considered in machine learning, we need to examine the effects of controlling the order of training sequence on machine learning. In this research, the role of the supervisor is extended to control the order of training samples, in addition to just instructing the target values for classification problems. The supervisor sequences the training examples categorized by SOM to the learning model which in this case is MLP. The proposed method is distinguished in that it selects the most instructive example from categories formed by SOM to assist the learning progress, while others use SOM only as a preprocessing method for training samples. The result shows that the method is effective in terms of the number of samples used and time taken in training.

• The Journal of Korean Philosophical History
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• no.50
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• pp.333-361
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• 2016

The purpose of this study is to delve into reinterpretation and categorization of normative meaning of tradition. The normative meaning of tradition which plays a key role of the action-guiding power is the main source of morality. According to ecological cultural approach to diachronic transition of traditional value, traditional value leads its dynamic life: its origin, acculturation, transformation, distortion of traditional value depending upon periodic social change. It is necessary for traditional value to be reinterpreted and categorized, with a view to contributing to attribute & competency of democratic citizen in future society. The normative meaning of traditional value applicable for Korea's future society can be reinterpreted from its origin revealed in the classic. The order of discussion in this paper runs as follows. Firstly, we will investigate into dynamic change of the traditional value on the basis of the ecological cultural perspective and seek the possibility of modern reinterpretation of loyalty & filial piety as representative traditional value. Finally, we will treat the categorization and its significance of traditional value in the frame of Korean value including both western value and Korean traditional value.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.38-43
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• 1998

서로 다른 개발 과정에 있거나, 이미 개발된 게임 공간에 새로운 시나라요의 스케치를 포함시키는 경우 시간(temporal)과 공간(spatial)의 개념적인 동기화가 요구된다. 본 논문에서는 게임 시나리오 스케치의 표현 공간에 대한 범주를 나누며, 게임 장면 순서의 시간 관계성과 동적 장면의 공간 개념과의 동기화에 관한 표현법률 확장하는 표현 모델에 대한 논의를 한다.