• Journal of the Korean Data and Information Science Society
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• 제28권1호
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• pp.143-152
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• 2017

블럭내의 완전랜덤화 제약은 하나의 블럭이 여러 실험구로 분할되는 분할요인모형으로 해결할 수 있다. 본 연구는 $3{\times}3$ 분할요인모형에서 두 주요인 및 하나의 블럭이 모두 고정일 경우에는, 실제로 존재하는 효과크기가 작을수록 혹은 검정대상의 요인효과 크기보다 검정대상 이외의 효과들의 크기가 상대적으로 작을수록 주구요인효과 및 세구요인효과 검정을 위한 순위변환 통계량의 검정력은 기존의 모수적 통계량의 검정력보다 뛰어남을 알 수 있다. 또한 모집단 모형의 오차항이 지수분포 및 이중지수분포일 때 효과크기 및 효과구성유형에 상관없이 거의 모든 상황하에서 순위변환 통계량의 검정력이 모수적 통계량의 검정력보다 상대적으로 높은 우위를 보이며, 정규분포 및 균일분포하에서는 상당히 유사한 수준을 나타낸다. 한편 두 주요인은 고정이나 하나의 블럭이 랜덤일 경우에는, 두 주요인 및 블럭이 모두 고정일 경우보다 모수적 통계량 및 순위변환 통계량의 검정력은 각각 낮은 수준을 보인다. 특히 주구요인효과 검정보다 세구요인효과 검정을 위한 모수적 통계량 및 순위변환 통계량의 검정력이 다소 낮은 수준임을 보이지만, 순위변환 통계량의 검정력은 모수적 통계량의 검정력에 비하여 높은 상대적 검정력 우위를 나타낸다.

• 대한수학회지
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• 제38권6호
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• pp.1117-1123
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• 2001

A ring is a DICC ring if every chain of right ideals in-dexed by the integers stabilizes to the left or to the right or to both sides. A counterexample is given to an assertion of karamzadeh and Motamedi that a transfinite power of the Jacobson radical of a right DICC ring is zero. we determine the behavior of the transfinite powers of the Jacobson radical relative to a torsion theory and consequently can obtain their correct behavior in the classical setting.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.1930-1932
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• 1997

Instantaneous active/reactive powers are defined in three phase four wire systems. The definition can be generally applicable to any source conditions and load conditions including nonlinear circuits. The zero-sequence power resulted from the zero-sequence voltage and zero-sequence current between two sub-systems affects both to the instantaneous active and reactive powers. The zero-sequence current can be controlled by compensation of the reactive power without power storage elements.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.228-232
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• 1997

The relation between instantaneous active/reactive powers and currents is defined by voltage mapping matrix in three-phase four-wire systems. Control strategies for an active filter without energy storage components are proposed on the basis of mapping matrices. It can compensate for the zero-sequence current, irrespectively of whether or not a zero-sequence voltage exists in a three-phase four-wire system.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.639-647
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• 2002

Efforts to obtain more power for unit root tests have continued. Pantula at el.(1994) compared empirical powers of several unit root test statistics and addressed that the weighted symmetric estimator(WSE) and the unconditional maximum likelihood estimator(UMLE) are the best among them. One can easily see that the powers of these two statistics are almost the same. In this paper we explain a connection between WSE and UMLE and suggest a unit root test statistic which may explain the connection between them.

• Journal of the Korean Statistical Society
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• 제32권2호
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• pp.93-101
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• 2003

This paper deals with testing the equality of the coefficients of variation in two inverse Gaussian populations. The likelihood ratio, Lagrange-multiplier and Wald tests are presented. Monte-Carlo simulations are performed to compare the powers of these tests. In a simulation study, the likelihood ratio test appears to be consistently more powerful than the Lagrange-multiplier and Wald tests when sample size is small. The powers of all the tests tend to be similar when sample size increases.

• Journal of applied mathematics & informatics
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• 제8권2호
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• pp.669-682
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• 2001

In this paper a nonparametric test for the parallelism of k regression lines against ordered alternatives, when the independent variables are positive and all regression lines have a common intercept is proposed. The proposed test is based on a Jonckheere-type statistic applied to residuals. Under some conditions the proposed test statistic is asymptotically distribution-free. The small-sample powers of our test are compared with other tests by a Monte Carlo study. The simulation results show that the proposed test has significantly higher empirical powers than the other tests considered in this paper.

• 대한수학회보
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• 제57권5호
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• pp.1231-1240
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• 2020

The asymptotic behavior of graded Betti numbers of powers of homogeneous ideals in a polynomial ring over a field has recently been reviewed. We extend quasi-polynomial behavior of graded Betti numbers of powers of homogenous ideals to ℤ-graded algebra over Noetherian local ring. Furthermore our main result treats the Betti table of filtrations which is finite or integral over the Rees algebra.

• Communications for Statistical Applications and Methods
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• 제4권2호
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• pp.565-579
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• 1997

A robust test is proposed for the problem of testing the parallelism of several regression lines against ordered alternatives. The proposed test statistic is based on a linear combination of one-step pairwise GM-estimators. We compare the performance of the proposed test with that of the other tests through a Monte Carlo simulation. The results of the simulation study show that the proposed test has stable levels, good empirical powers in various circumstances, and particularly higher empirical powers under the presence of extreme outliers or leverage points.

• 대한수학회지
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• 제39권3호
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• pp.351-361
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• 2002

We extend the Holder-McCarthy inequality for a positive and an arbitrary operator, respectively. The powers of each inequality are given and the improved Reid's inequality by Halmos is generalized. We also give the bound of the Holder-McCarthy inequality by recursion.