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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Applied Statistics
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Journal DOI :
The Korean Statistical Society
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Volume & Issues
Volume 21, Issue 6 - Dec 2008
Volume 21, Issue 5 - Oct 2008
Volume 21, Issue 4 - Aug 2008
Volume 21, Issue 3 - Jun 2008
Volume 21, Issue 2 - Apr 2008
Volume 21, Issue 1 - Feb 2008
Selecting the target year
Estimating Infection Distribution and Prevalence of Malaria in South Korea Using a Back-calculation Formula
Jang, Hyun-Gap ; Park, Jeong-Soo ; Jun, Mi-Jeong ; Rhee, Jeong-Ae ; Kim, Han-Me-Ury ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 901~910
DOI : 10.5351/KJAS.2008.21.6.901
Incidence of Plasmodium vivax malaria in South Korea have been reemerged from mid-1990 and infected around 1600 patients annually recent years. The authors calculated the distribution of malaria infection and prevalence in South Korea using incidence (2001-2006) and incubation period distributions by a back-calculation formula and the least squares estimation method. The estimated infection has a normal distribution with a mean 207 and a standard deviation 30.7 days. In addition, the authors found the estimated daily average prevalence is 628.8 patients.
Applications of Parallel Coordinate Plots for Visualizing Gene Expression Data
Park, Mi-Ra ; Kwak, Il-Youp ; Huh, Myung-Hoe ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 911~921
DOI : 10.5351/KJAS.2008.21.6.911
Visualization of the gene expression data on a low-dimensional graph is helpful in uncovering biological information contained in the data. In this study, we focus on two modified versions of the parallel coordinate plot. First one is the ePCP(enhanced parallel coordinate plot) which shows "near smooth" connecting curves between axes spaced proportionately to the proximity of re-ordered variables. Second one is APCP(Andrews' type parallel coordinate plot) which is obtained by rotating Andrews' plot that has a form of the parallel coordinate plot. Visualization procdures using ePCP and APCP are given for the lymphoma data case.
Generalized Linear Mixed Model for Multivariate Multilevel Binomial Data
Lim, Hwa-Kyung ; Song, Seuck-Heun ; Song, Ju-Won ; Cheon, Soo-Young ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 923~932
DOI : 10.5351/KJAS.2008.21.6.923
We are likely to face complex multivariate data which can be characterized by having a non-trivial correlation structure. For instance, omitted covariates may simultaneously affect more than one count in clustered data; hence, the modeling of the correlation structure is important for the efficiency of the estimator and the computation of correct standard errors, i.e., valid inference. A standard way to insert dependence among counts is to assume that they share some common unobservable variables. For this assumption, we fitted correlated random effect models considering multilevel model. Estimation was carried out by adopting the semiparametric approach through a finite mixture EM algorithm without parametric assumptions upon the random coefficients distribution.
Comparison of Trend Tests for Genetic Association on Censored Ages of Onset
Yoon, Hye-Kyoung ; Song, Hae-Hiang ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 933~945
DOI : 10.5351/KJAS.2008.21.6.933
The genetic association test on age of onset trait aims to detect the putative gene by means of linear rank tests for a significant trend of onset distributions with genotypes. However, due to the selective sampling of recruiting subjects with ages less than a pre-specified limit, the genotype groups are subject to substantially different censored distributions and thus this is one reason for the low efficiencies in the linear rank tests. In testing the equality of two survival distributions, log-rank statistic is preferred to the Wilcoxon statistic, when censored observations are nonignorable. Therefore, for more then two groups, we propose a generalized log-rank test for trend as a genetic association test. Monte Carlo studies are conducted to investigate the performances of the test statistics examined in this paper.
Non-Inferiority Test in a Two-Arm Trial and a Three-Arm Trial Including a Placebo
Lee, Ji-Sun ; Kim, Dong-Jae ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 947~957
DOI : 10.5351/KJAS.2008.21.6.947
Two-arm non-inferiority trials is often applied to parametric procedure suggested by Hauschke et al. (1999). Since this design does not allow a direct comparison of a new treatment group with placebo group, parametric procedure in a three-arm non-inferiority trial with a placebo group was suggested by Pigeot et al. (2003). But, procedures in these designs are necessary for distribution assumptions. Therefore we propose, in this paper, non parametric procedures employing Wilcoxon rank sum test in a two-arm design and linear contrast test suggested by Scheirer et al. (1976) in a three-arm design. The proposed nonparametric procedures and parametric procedures are compared by Monte Carlo simulation study.
A Discrete Feature Vector for Endpoint Detection of Speech with Hidden Markov Model
Lee, Jei-Ky ; Oh, Chang-Hyuck ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 959~967
DOI : 10.5351/KJAS.2008.21.6.959
The purpose of this paper is to suggest a discrete feature vector, robust in various levels of noisy environment and inexpensive in computation, for detection of speech segments and is to show such properties of the feature with real speech data. The suggested feature is one dimensional vector which represents slope of short term energies and is discretized into three values to reduce computational burden of computations in HMM. In experiments with speech data, the method with the suggested feature vector showed good performance even in noisy environments.
Comparison of Discriminant Analyses for Consumers' Taste Grade on Hanwoo
Kim, Jae-Hee ; Seo, Gu-Re-Oun-Den-Nim ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 969~980
DOI : 10.5351/KJAS.2008.21.6.969
This paper presents the comparison of four methods, linear, quadratic, canonical and non-parametric discriminant analyses to discriminate the consumers' taste grade with sensory variables, such as tenderness, juiciness, flavor, and overall acceptability based on Consumer Sensory Survey. The classification ability of each method is measured and compared by the resubstitution error rate.
Statistical Matching Techniques Using the Robust Regression Model
Jhun, Myoung-Shic ; Jung, Ji-Song ; Park, Hye-Jin ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 981~996
DOI : 10.5351/KJAS.2008.21.6.981
Statistical matching techniques whose aim is to achieve a complete data file from different sources. Since the statistical matching method proposed by Rubin (1986) assumes the multivariate normality for data, using this method to data which violates the assumption would involve some problems. This research proposed the statistical matching method using robust regression as an alternative to the linear regression. Furthermore, we carried out a simulation study to compare the performance of the robust regression model and the linear regression model for the statistical matching.
Performance Evaluation of Software Task Processing Based on Markovian Perfect Debugging Model
Lee, Chong-Hyung ; Jang, Kyu-Beam ; Park, Dong-Ho ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 997~1006
DOI : 10.5351/KJAS.2008.21.6.997
This paper proposes a new model by combining an infinite-server queueing model for multi-task processing software system with a perfect debugging model based on Markov process with two types of faults suggested by Lee et al. (2001). We apply this model for module and integration testing in the testing process. Also, we compute several measure, such as the expected number of tasks whose processes can be completed and the task completion probability are investigated under the proposed model.
Meta Analysis of Usability Experimental Research Using New Bi-Clustering Algorithm
Kim, Kyung-A ; Hwang, Won-Il ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1007~1014
DOI : 10.5351/KJAS.2008.21.6.1007
Usability evaluation(UE) experiments are conducted to provide UE practitioners with guidelines for better outcomes. In UE research, significant quantities of empirical results have been accumulated in the past decades. While those results have been anticipated to integrate for producing generalized guidelines, traditional meta-analysis has limitations to combine UE empirical results that often show considerable heterogeneity. In this study, a new data mining method called weighted bi-clustering(WBC) was proposed to partition heterogeneous studies into homogeneous subsets. We applied the WBC to UE empirical results and identified two homogeneous subsets, each of which can be meta-analyzed. In addition, interactions between experimental conditions and UE methods were hypothesized based on the resulting partition and some interactions were confirmed via statistical tests.
Method of Deciding Optimal Double Pairs
Cho, Dae-Hyeon ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1015~1026
DOI : 10.5351/KJAS.2008.21.6.1015
In this paper, we are interested in tennis games and the best of all matches that is fair to most of all participants. We introduce a loss function. And using our introduced loss function and round robin method, we get a best match that obtains the minimal loss according to the number of participants.
The Effect of Repetitive Dive on Physiological Reactions and Stress Hormone in No Decompression Limit
Kim, Jun-Mo ; Kim, Sung-Gil ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1027~1035
DOI : 10.5351/KJAS.2008.21.6.1027
This research is aimed to investigate the effect of repetitive dive on physiological reactions, change of stress hormones in no decompression limit of sport SCUBA dive, an emerging recreational activity recently. In order to compare physiological reactions prior to and after the initial dive and after repetitive dive at a certain depth of a place, eight adult male divers with more than forty dives, who reside in Busan and were certified, were selected. The research results obtained from the procedures described above are follows: First, for physiological reactions, heart rates, temperatures, and systolic blood pressures had significant difference among prior to and after the initial dive and after the repetitive dive, while diastolic blood pressures did not show remarkable difference as it increased before and after the first dive but decreased following the repetitive dive again. Second, for change of stress hormones, it was not significantly different prior to and after the initial dive and following the repetitive dive, as well as before and during the first dive and the repetitive dive.
Internet Traffic Forecasting Using Power Transformation Heteroscadastic Time Series Models
Ha, M.H. ; Kim, S. ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1037~1044
DOI : 10.5351/KJAS.2008.21.6.1037
In this paper, we show the performance of the power transformation GARCH(PGARCH) model to analyze the internet traffic data. The long memory property which is the typical characteristic of internet traffic data can be explained by the PGARCH model rather than the linear GARCH model. Small simulation and the analysis of the real internet traffic show the out-performance of the PARCH MODEL over the linear GARCH one.
Decrement Models Under Fractional Independence Assumption
Lee, Hang-Suck ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1045~1063
DOI : 10.5351/KJAS.2008.21.6.1045
This paper derives conversion formulas from yearly-based absolute rates of decrements to monthly-based rates of decrement due to cause j under FI (fractional age independence) assumption that is a generalization of UDD assumption. Next, it suggests conversion formulas from monthly-based absoluterates of decrements to monthly-based rates of decrement due to cause j under FI assumption. In addition, it calculates conversion formulas from yearly-based rates of decrement due to cause j to the corresponding monthly-based absolute rates of decrements under FI assumption. Some numerical examples are discussed.
Modified Kolmogorov-Smirnov Statistic for Credit Evaluation
Hong, C.S. ; Bang, G. ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1065~1075
DOI : 10.5351/KJAS.2008.21.6.1065
For the model validation of credit rating models, Kolmogorov-Smirnov(K-S) statistic has been widely used as a testing method of discriminatory power from the probabilities of default for default and non-default. For the credit rating works, K-S statistics are to test two identical distribution functions which are partitioned from a distribution. In this paper under the assumption that the distribution is known, modified K-S statistic which is formulated by using known distributions is proposed and compared K-S statistic.
A Case Study on the Information Capacity Assessment Index of local Residents Using Score Card
Jeong, Hyeong-Chul ; Cho, Young-Im ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1077~1091
DOI : 10.5351/KJAS.2008.21.6.1077
In this study, we consider to assess the information ability of individuals related to local information. Questionnaire surveys are frequently used for studies on the measuring of information index and such specified indexes of society development. However, if questionnaire papers measured individuals' abilities and such parts of quality, the subjective judgments of respondents cannot but be intervened. Therefore a method which will enable subjective points to be comparatively objectified is needed. In this study, when an attempt is being made to measure individuals' information capacity through questionnaire surveys as the process for calculating the standards of regional information levels. Cases have been looked at for times when, by using a scorecard, individuals' subjective survey result have been be changed to be comparatively objectified scores and such process. The logit model was used in the preparation of the scorecard. In this study, we have presented a clue which enables the comparative measurement about regional information gaps by using characteristics of regional population statistics.
Precipitation Analysis Based on Spatial Linear Regression Model
Jung, Ji-Young ; Jin, Seo-Hoon ; Park, Man-Sik ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1093~1107
DOI : 10.5351/KJAS.2008.21.6.1093
In this study, we considered linear regression model with various spatial dependency structures in order to make more reliable prediction of precipitation in South Korea. The prediction approaches are based on semi-variogram models fitted by least-squares estimation method and restricted maximum likelihood estimation method. We validated some candidate models from the two different estimation methods in terms of cross-validation and comparison between predicted values and observed values measured at different locations.
Comparison of Shape Variability in Principal Component Biplot with Missing Values
Shin, Sang-Min ; Choi, Yong-Seok ; Lee, Nae-Young ;
Korean Journal of Applied Statistics, volume 21, issue 6, 2008, Pages 1109~1116
DOI : 10.5351/KJAS.2008.21.6.1109
Biplots are the multivariate analogue of scatter plots. They are useful for giving a graphical description of the data matrix, for detecting patterns and for displaying results found by more formal methods of analysis. Nevertheless, when some values are missing in data matrix, most biplots are not directly applicable. In particular, we are interested in the shape variability of principal component biplot which is the most popular in biplots with missing values. For this, we estimate the missing data using the EM algorithm and mean imputation according to missing rates. Even though we estimate missing values of biplot of incomplete data, we have different shapes of biplots according to the imputation methods and missing rates. Therefore we propose a RMS(root mean square) for measuring and comparing the shape variability between the original biplots and the estimated biplots.