• Journal of the Korean Statistical Society
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• v.9 no.1
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• pp.39-60
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• 1980

In the last paper, we have discussed the cannonical representatin of a dynamic linear model, on which some aggregation schemes were devised. The relationships of those aggregation schemes with dynamic properties were investigated. This paper tries to analyse she control strategy for the aggregated linear dynamic model and to investigate the dynamic properties of disaggregative model controlled by aggregated model. For the logical consistency with the last paper, all the sections and all the equations are numbered in a sequence.

• Korean Journal of Hydrosciences
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• v.2
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• pp.69-84
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• 1991

US NWS/NETWORK is applied for the analysis of the flood of July 11-15, 1981 through the Goan-Indogyo reach of the Han River. For the flood hydrography synthesis of the lateral inflows from the major tributaries into the main reach the Cleak method is employed. NETWORK coupled with the Clark method of hydrography synthesis simulated with a fair accuracy the oberved flood hydrograph at the downstream boundary of the routing reach. The dffect of SCS runoff curve number for fributary flood synthesis is evaluated. The characteristics of the station variations and time variations of the flood discharges in the reach is also analyzed.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.749-754
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• 1999

The cost is known to be proportional to the size of sample. We consider a cost function of the form Cost=c1np+c2npmq where c1, c2 p, and q are all positive constants. This cost function is to be used in finding an optimal allocation in two-stage cluster sampling. The optimal allocations of n and m gives the properties of uniqueness under some conditions and of monotonicity with p>0 when q=1.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.967-976
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• 1999

In this paper we study the Hellinger distance based goodness-of-fit tests that are analogs of likelihood ratio tests. The minimum Hellinger distance estimator (MHDE) in normal models provides an excellent robust alternative to the usual maximum likelihood estimator. Our simulation results show that the Hellinger deviance test (Simpson 1989) based goodness-of-fit test is robust when data contain outliers. The proposed hellinger deviance test(Simpson 1989) is a more direcct method for obtaining robust inferences than an automated outlier screen method used before the likelihood ratio test data analysis.

• Communications for Statistical Applications and Methods
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• v.3 no.2
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• pp.283-290
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• 1996

For finite discrete distributions with prescribed moments, there is a well-known upper bound on the index of the support. In this paper, we are interested in the smoothest density with prescribed moments among the class of smooth functions. We define an index of continuous distribution through the support and derive an upper bound on the index of the smoothest density. Some examples are given, some of which achieve the upper bound.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.755-760
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• 1999

In multivariate stratified sampling surveys it is general to use a few stratification variables which are highly correlated with the important variables at design stage. But there might be some secondary study variables which are not so highly correlated with those stratification variables. In that case it is not efficient to use the same type of estimator due to the secondary variables as the one base on the important variables. A post-stratified estimation is proposed to increase the efficiency of the estimator with existence of secondary variables. The proposed method is illustrated with a set of fishery household population survey data.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.893-900
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• 1999

We use statistical tests which are useful for two-sample problem for detecting edges in gray-level images. An edge is detected by examining changes in gray-level value between adjacent pixel neighborhoods. Some experimental results show that nonparametric detectors such as Mann-Whitney test median test and Kolmogorov-Smirnov test perform effectively in both noisy and noise-free images while parametric T test is sensitive to noise.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.977-994
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• 1999

Five equating methos for elective subjects of College Scholastic Ability Test were analyzed under a common-items nonequivalent groups design using a real data set of 110 thousand examinees. Five methods were (a)two-stage linear equating (b) two-stage equi-percentile equating (c) Tucker equating (d) Frequency estimation equating and (e)Braun-Holland equating. The results indicated that Frequency estimation equating fits well and two-stage linear equating produces most different equating results from the Frequency estimation equating.

• Communications for Statistical Applications and Methods
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• v.3 no.2
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• pp.21-28
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• 1996

Collinearities contained in MEM cause the same problems as they do in traditional regression model, so the detection of collinearities is a crucial topic in MEM. One diagnostic was introduced by Carrillo-Gamboa and Gunst, but their method did not work in some cases. Two alternative collinearity diagnostics that provide reasonable measure of collinearities are proposed. Simulation study is performed to compare the small-sample properties of the proposed collinearity diagnostics.

• Journal of the Korean Statistical Society
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• v.3 no.1
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• pp.31-57
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• 1974

The economic behavior of individuals' selection of particular kye and positions in a kye is based upon choice criteria. The selection of a kye or a position in a kye is not the same as an investor's portfolio selection. A kye member combines in varying degrees the characteristics of both a borrower and a lender of funds. In the following sections we shall first propose choice criteria for borrowers and lenders of funds, then we will try to test various hypotheses derived from the choice criteria by empirical data.