• East Asian mathematical journal
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• 제34권5호
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• pp.643-649
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• 2018

Let M be a connected n-dimensional submanifold of a Euclidean space $E^{n+k}$ equipped with the induced metric and ${\Delta}$ its Laplacian. If the position vector x of M is decomposed as a sum of three vectors $x=x_1+x_2+x_0$ where two vectors $x_1$ and $x_2$ are non-constant eigenvectors of the Laplacian, i.e., ${\Delta}x_i={\lambda}_ix_i$, i = 1, 2 (${\lambda}_i{\in}R$) and $x_0$ is a constant vector, then, M is called a 2-type submanifold. In this paper we proved that a connected 2-type hypersurface M in $E^{n+1}$ whose postion vector x satisfies ${\langle}{\Delta}x,x-x_0{\rangle}=c$ for a constant c, where ${\langle}$, ${\rangle}$ is the usual inner product in $E^{n+1}$, is of null 2-type and has constant mean curvature and scalar curvature.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5037-5042
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• 2012

Background: Tobacco contains agents which generate various potent DNA adducts that can cause gene mutations. Production of DNA adducts may be neutralized by glutathione S transferase (GST) along with other phase I and phase II enzyme systems. The existence of null type of GST among the population increases the susceptibility to various disorders and diseases. The present study focuses on the impact of high tobacco usage and possible null type mutation in GST loci. Methods: Genotypes of GST were detected by multiplex polymerase chain reaction in unrelated 504 volunteers of high tobacco using natives of Gujarat. Allelic frequencies were calculated using Statistical Package for Social Studies-16 software. Hardy Weinberg Equilibrium (HWE) was calculated using Chi square test. Two sided Fisher's significance test was used to compare allelic frequencies of different populations. Results: The frequency of homozygous null genotype of GSTM1 and GSTT1 were 20% (95% CI 16.7-23.9) and 35.5% (95% CI 31.4-39.9) respectively. The GSTM1 and GSTT1 null allele frequency distribution in the Gujarat population was significantly deviating from HWE. GSTT1 null frequency of Gujaratians was significantly higher and different to all reported low tobacco using Indian ethnics, while GSTM1 was not differing significantly. Conclusion: Tobacco usage significantly influences the rate of mutation and frequency of GSTT1 and M1 null types among the habituates. The rate of mutation in GSTT1 loci was an undeviating response to the dose of tobacco usage among the population. This mutational impact of tobacco on GSTT1 postulates the possible gene - environment interaction and selection of null genotype among the subjects to prone them under susceptible status for various cancers and even worst to cure the population with GSTT1 dependent drugs.

• 대한수학회논문집
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• 제33권4호
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• pp.1097-1102
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• 2018

Let A and B be matrices which are polynomials in r pairwise commuting nilpotent matrices over a field. We give a sufficient condition for the null space of $A^i$ to equal that of $B^i$ for all i, in particular, for A and B to be similar.

• Journal of Nutrition and Health
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• 제41권7호
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• pp.594-601
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• 2008

Panax ginseng C.A. Meyer (Panax ginseng) has been used for several thousand years to prolong longevity in Asian countries. Ginsenosides are the most active components isolated from ginseng and belong to damarane saponin which are separated into protopanaxadiol and protopanaxtriol. To evaluate the complex effect of ginsenoside in apo E null mice, ginseng extract were intraperioneally (i.p.) injected and provided high-cholesterol diet for 12 weeks. Ginseng extract came from were i.p. injected with dose of 100 mg/kg/day for 4 weeks in the last experimental duration. Ginseng extract used experiment was abundant Rb1, Rc, Re, and Rg1 and PD：PT ratio was 1.2. The high-cholesterol diet induced liver damage was significantly reduced by ginseng extract. Results from plasma lipid profiles and atherogenic index were improved by ginseng extracts. The GE group significantly decreased plasma TG and TC by 73% and 61% compared to apo E (-/-) group. Also ginseng extract tend to decrease lipid profiles and lipidperoxidation contents in liver and heart. Ginseng extract with an abundant amount of Rg1 significantly suppressed the apoptosis induction of cardiac tissue. In conclusion, ginseng extract (PD：PT = 1) was improved lipid profiles and anti-oxidant effects.

• Journal of the Korean Data and Information Science Society
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• 제9권2호
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• pp.289-298
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• 1998

We investigate the distribution of likelihood ratio test(LRT) of null hypothesis a sample is from single gamma with unknown shape and scale against the alternative hypothesis a sample is from a mixture of two gammas, each with unknown scale and unknown (but equal) scale. To obtain stable maximum likelihood estimates(MLE) of a mixture of two gamma distributions, the EM(Dempster, Laird, and Robin(1977))and Modified Newton(Jensen and Johansen(1991)) algorithms were implemented. Based on EM, we made a simple structure likelihood equation for each parameter and could obtain stable solution by Modified Newton Algorithms. Simulation study was conducted to investigate the distribution of LRT for sample size n = 25, 50, 75, 100, 50, 200, 300, 400, 500 with 2500 replications. To determine the small sample distribution of LRT, I considered the model of a gamma distribution with shape parameter equal to 1 + f(n) and scale parameter equal to 2. The simulation results indicate that the null distribution is essentially invariant to the value of the shape parameter. Modeling of the null distribution indicates that it is well approximated by a gamma distribution with shape parameter equal to the quantity $0.927+1.18/\sqrt{n}$ and scale parameter equal to 2.16.

• Journal of applied mathematics & informatics
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• 제32권5_6호
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• pp.687-695
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• 2014

In this article we introduce the zweier double sequence spaces $_2Z^I$(M), $_2Z_0^I$(M) and $_2Z_{\infty}^I$(M) using the Orlicz function M. We study the algebraic properties and inclusion relations on these spaces.

• 한국정보과학회논문지:소프트웨어및응용
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• 제41권8호
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• pp.598-604
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• 2014

본 연구는 주요변수를 선정하는 기법을 개발하기 위해서 단계적 회귀와 변수들의 효율성을 평가하기 위해 사용되는 자료봉합분석을 결합한 새로운 방법을 제안하였다. 이를 위해서 먼저 단계적 회귀를 이용하여 중요 변수들을 일차적으로 선정하고, 선정된 각 변수들의 중요도를 이해하기 위해 귀무가설을 세웠고, 중요 변수를 선택하기 위해 Kruskal-Wallis 검정을 사용했다. 또한 해당되는 변수를 Conover-Inman 검정을 사용하여 변동이 발생하는 각 변수들의 우선순위를 결정하였다. 따라서 그 결과, 많은 변수들과 DEA(Data Envelopment Analysis)의 한계를 극복하기 위해 원래 계획된 변수들 중 기준에 의해 원래 유지된 변수와 높은 연관성을 가진 변수들을 남기는 방식으로 변수를 선정하는 기법을 개발한 Jenkins의 기존연구에서는 I2, I4, I5, I6 변수가 누락되었고 I1, I3 변수만이 DEA에 사용되었지만, 본 논문에서 제안된 모델의 효율성 결과로는 I2와 I4 변수를 각각 유지하였다. 본 연구는 다른 문헌에서 단계적 변수의 선택을 보여주기 위해 같은 데이터 집합을 사용하였는데, 여기서 Jenkins의 연구와 같이 변수 I6과 I1, I2를 삭제하였고, I3, I4, I5는 유지하였다. 결론적으로 단계적 회귀 DEA 모델을 사용하여 긴 계산적 절차 없이 변수 선택이 가능함을 발견했으며 기존 연구의 데이터를 적용하여 제안된 모델을 검증하였다. 개발한 DEA모델 결과는 상호 변수에 따라 포함되거나 생략할 수 있기 때문에 실제 현실 상황에서의 지식과 경영적 판단에 매우 유용할 것이다.

• Journal of the Korean Statistical Society
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• 제7권1호
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• pp.17-26
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• 1978

For testing $\beta_i=\beta, i=1,...,k$, in the regression model $Y_{ij} = \alpha_i + \beta_ix_{ij} + e_{ij}, j=1,...,n_i$, a simple and robust test based on Kendall's tau is proposed. Its asymptotic distribution is proved to be chi-square under the null hypthesis and noncentral chi-square under an appropriate sequence of alternatives. For the optimal designs, the asymptotic relative efficiency of the proposed procedure with respect to the least squares procedure is the same as that of the Wilcoxon test with respect to the t-test.

• 응용통계연구
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• 제23권6호
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• pp.1115-1124
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• 2010

두 비율비교 비열등성 임상시험(non-inferiority trial)에서의 검정은 두 비율간에 차이가 없다는 영가설에 근거한 정규근사 산출식이 흔히 사용 된다. 본 연구에서는 두 비율차이가 영이 아니라는 가설에서 유도된 Miettinen과 Nurminen이 제안한 우도 스코어검정(likelihood score test)과 Farrington과 Manning의 검정 그리고 비대칭도(skewness)을 보정한 Gart와 Nam이 제안한 검정방법을 소개하고 모의실험을 통하여 제 1종 오류와 검정력을 비교하여 비열등성 임상시험에서 검정방법의 결정에 가이드라인을 제시하고자 한다.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2002년도 Language, Information, and Computation Proceedings of The 16th Pacific Asia Conference
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• pp.237-248
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• 2002

This paper investigates the internal structure of finite small clauses (FSC). I will propose that a FSC is base-generated at Spec-CP and a null operator is involved to check the formal features of the embedded T and turn a sentence into a predicate.