• Journal of Environmental Impact Assessment
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• v.15 no.3
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• pp.179-191
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• 2006

The authors argue that the current Government Information System for asthmatics appears to be non-user friendly due to lack of the cartographic representation for the text based statistical data. Acknowledging these constraints, an operational, user-friendly map for asthmatic prevalence has been generated by combining existing statistical data with the administrative Dong boundary map under GIS environment. The Geographical User Interface, in particular, were ideally suited to deriving the major distribution patterns that more asthmatic prevalence tends to be occurred on conventional commercial district and industrial complex. A visual map using spatial modelling technology were generated to show the fact that some degree of increasing or decreasing trends of asthmatic prevalence already exists in the experimental sites. It could be used as an evidence to restrict initiation of development activities causing negative influence to asthma such as road construction. The result of this study would play a crucial role in improving the quality of environmental health information service if it is operationally introduced into the Government since the highly user-friendly interface provides a completely new means for disseminating information for asthmatics in a visual and interactive manner to the general public.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.103-111
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• 2007

The purpose of this study is to categorize and analyze the body shape of obese Korean men that are needed for industrial design. Using the anthropometric data that were surveyed through the 5^th Size Korea project, this study was conducted in four steps mostly through the multivariate statistical analysis. In the first step, Broca, BMI, WHR indices are used to define obesity and select obese men from Korean adults and teens. After 34 human anthropometric variables are supposed to be related to obesity were extracted through an expect survey. In the second step, a factor analysis was executed for those human anthropometric variables. Through this analysis, we obtained the human body factors that are related to the representation of obesity. Then the third step, we used a cluster analysis from the result of the factor analysis. And ANOVA analysis was also conducted to obtain the critical obese human anthropometric variables. In the final step, we found the characteristics of the body types of obese men according to clusters and ages. The body types of obese men classified in the study are expected to be applied to product design for clothing, furniture, automobile packaging, etc.

• Journal of the Korean Statistical Society
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• v.33 no.1
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• pp.79-97
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• 2004

We propose a permutation approach to the classic Behrens-Fisher problem of comparing two means in the presence of unequal variances. It is motivated by the observation that a paired test is valid whether or not the variances are equal. Rather than using a single arbitrary pairing of the data, we average over all possible pairings. We do this in both a parametric and nonparametric setting. When the sample sizes are equal, the parametric version is equivalent to referral of the unpaired t-statistic to a t-table with half the usual degrees of freedom. The derivation provides an interesting representation of the unpaired t-statistic in terms of all possible pairwise t-statistics. The nonparametric version uses the same idea of considering all different pairings of data from the two groups, but applies it to a permutation test setting. Each pairing gives rise to a permutation distribution obtained by relabeling treatment and control within pairs. The totality of different mean differences across all possible pairings and relabelings forms the null distribution upon which the p-value is based. The conservatism of this procedure diminishes as the disparity in variances increases, disappearing completely when the ratio of the smaller to larger variance approaches 0. The nonparametric procedure behaves increasingly like a paired t-test as the sample sizes increase.

• Communications for Statistical Applications and Methods
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• v.24 no.6
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• pp.627-640
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• 2017

A common interest in gene expression data analysis is to identify genes that present significant changes in expression levels among biological experimental conditions. In this paper, we develop a Bayesian approach to make a gene-by-gene comparison in the case with a control and more than one treatment experimental condition. The proposed approach is within a Bayesian framework with a Dirichlet process prior. The comparison procedure is based on a model selection procedure developed using the discreteness of the Dirichlet process and its representation via Polya urn scheme. The posterior probabilities for models considered are calculated using a Gibbs sampling algorithm. A numerical simulation study is conducted to understand and compare the performance of the proposed method in relation to usual methods based on analysis of variance (ANOVA) followed by a Tukey test. The comparison among methods is made in terms of a true positive rate and false discovery rate. We find that proposed method outperforms the other methods based on ANOVA followed by a Tukey test. We also apply the methodologies to a publicly available data set on Plasmodium falciparum protein.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.1044-1049
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• 2000

Projection that can be used as a feature for image representation, includes much available informations such as approximated shape and location. But when we retrieve image using it, there are some disadvantage such as requiring much index data and making different length of projected vector for differenr image size. In order to overcome these problems, we propose a method of using block variance for the projected vector. We use block variance of the projection vector to localize the characteristics of image and to reduce the number of index data in database. Proposed algorithm can make use of statistical advantage through database including various size of images and be executed with fast response time in implementation.

• Science of Emotion and Sensibility
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• v.11 no.4
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• pp.501-510
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• 2008

The purpose of this study was to investigate whether the orientation of the head position across different categories affect reaction time and accuracy of object recognition. Fifty four right handed undergraduate students were participated in the experiment. Participants performed the word-picture matching tasks, which were different in terms of head direction of object (i.e., Left-headed or Right-headed) and object category (i.e., natural : animal or artificial : tool). Participants were asked to decide whether each picture matched the word which was followed by the picture. For accuracy, no statistically significant difference was found for both animal and tool pictures due to the ceiling effect. Interaction effect of category and orientation were statistically significant, whereas only the main effect of category was significant. In the animal condition, faster reaction times were observed for left to right than right to left presentation, while no statistical significant difference was found in the tool condition. The orientation of the object's canonical representation was different across different categories. The faster RT for the animal condition implies that the canonical representation for animal is left-headed. This could be due to the orientation of the face.

• Journal of Educational Research in Mathematics
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• v.13 no.4
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• pp.463-483
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• 2003

In the learning of mathematics, students experience the semiotic activities of representing and interpreting mathematical signs. We called these activities as the representing and interpreting of mathematical signs. On the foundation of Peirce's three elements of the sign, we analysed that students constructed the representamen to interpret the concept of correlation as for the object, "as one is taller, one's size of foot is larger" 4 middle school students who participated the gifted center in Seoul, arranged the statistical data, constructed their own representamen, and then learned the conventional signs as a result of the whole class discussion. In the process, students performed the detailed representing and interpreting of signs, depended on the templates of the known signs, and interpreted the process voluntarily. As the semiotic activities were taken place in this way, it was needed that mathematics teacher guided the representing and interpreting of mathematical signs so that the representation and the meaning of the sign were constructed each other, and that students endeavored to get the negotiation of the interpretants and the representamens, and to reach the conventional representing.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.4
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• pp.53-67
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• 1998

This article investigates the potentialities of using empirical variables and their associated statistical relationships in document representation and retrieval. To this end, a newly devised empirical fact retrieval system was evaluated in comparison to a simulated traditional retrieval system involving a set of predetermined empirical queries. Results indicate that the EFRS generally outperformed the TRS in terms of the precision, search effort, and measures of user satisfaction.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2923-2928
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• 2007

The study of model for velocity and turbulence within the urban canopy was carried out. To evaluate existing urban model we conducted wind tunnel experiment and large-eddy simulation (LES). Mean velocity profile and turbulence are measured within simple three different obstacle arrays. To obtain supplemental data and to verify morphological model large-eddy simulation was performed. Several methods have been used to achieve embodying the flow field in urban area. Recently, morphological method obtaining flow parameters from the statistical or physical representation of obstacle elements is a arising method. It was found that all morphological model, evaluated in this study, over predict the friction velocity, most sensitive one among the flow parameters. Velocity and turbulence in the urban canopy layer were improved by the correction using 'true' friction velocity.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.372-378
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• 2015

Background subtraction is the first processing stage in video surveillance. It is a general term for a process which aims to separate foreground objects from a background. The goal is to construct and maintain a statistical representation of the scene that the camera sees. The output of background subtraction will be an input to a higher-level process. Background subtraction under dynamic environment in the video sequences is one such complex task. It is an important research topic in image analysis and computer vision domains. This work deals background modeling based on modified adaptive Gaussian mixture model (GMM) with three temporal differencing (TTD) method in dynamic environment. The results of background subtraction on several sequences in various testing environments show that the proposed method is efficient and robust for the dynamic environment and achieves good accuracy.