• 대한수학회보
• /
• 제50권5호
• /
• pp.1567-1586
• /
• 2013

In this paper, we study the Einstein multiply warped products with a semi-symmetric non-metric connection and the multiply warped products with a semi-symmetric non-metric connection with constant scalar curvature, we apply our results to generalized Robertson-Walker spacetimes with a semi-symmetric non-metric connection and generalized Kasner spacetimes with a semi-symmetric non-metric connection and find some new examples of Einstein affine manifolds and affine manifolds with constant scalar curvature. We also consider the multiply warped products with an affine connection with a zero torsion.

• Communications for Statistical Applications and Methods
• /
• 제16권2호
• /
• pp.349-361
• /
• 2009

In this paper, we derive the approximate maximum likelihood estimators of the shape parameter and the scale parameter in a Weibull distribution under multiply Type-II censoring by the approximate maximum likelihood estimation method. We develop three modified empirical distribution function type tests for the Weibull distribution based on multiply Type-II censored samples. We also propose modified normalized sample Lorenz curve plot and new test statistic.

• Journal of the Korean Data and Information Science Society
• /
• 제25권1호
• /
• pp.195-209
• /
• 2014

In this paper, we derive the estimators of the location parameter and the scale parameter in a logistic distribution based on multiply type-II censored samples by the approximate maximum likelihood estimation method. We use four modified empirical distribution function (EDF) types test for the logistic distribution based on multiply type-II censored samples using proposed approximate maximum likelihood estimators. We also propose the modified normalized sample Lorenz curve plot for the logistic distribution based on multiply type-II censored samples. For each test, Monte Carlo techniques are used to generate the critical values. The powers of these tests are also investigated under several alternative distributions.

• Mass Spectrometry Letters
• /
• 제4권1호
• /
• pp.21-23
• /
• 2013

The effects of trifluoroacetic acid (TFA) were evaluated on the generation of multiply charged ions of cytochrome c in a 2-nitrophloroglucinol (2-NPG) matrix in high-vacuum, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of 1% TFA in the 2-NPG matrix solution was more effective in generating multiply charged protein ions than matrix solutions containing 0.1% or 0% TFA. Regarding the matrix itself, with 1% TFA, 2-NPG was significantly more effective in generating multiply charged ions than 2,5-dihydroxybenzoic acid (2,5-DHB). The maximum charge state of cytochrome c was +8 when using a 2-NPG matrix containing 1% TFA.

• Journal of the Korean Data and Information Science Society
• /
• 제25권3호
• /
• pp.633-641
• /
• 2014

The exponential distibution is one of the most popular distributions in analyzing the lifetime data. In this paper, we propose multiply Type I hybrid censoring. And this paper presents the statistical inference on the scale parameter for the exponential distribution when samples are multiply Type I hybrid censoring. The scale parameter is estimated by approximate maximum likelihood estimation methods using two different Taylor series expansion types ($AMLE_I$, $AMLE_{II}$). We also obtain the maximum likelihood estimator (MLE) of the scale parameter ${\sigma}$ under the proposed multiply Type I hybrid censored samples. We compare the estimators in the sense of the root mean square error (RMSE). The simulation procedure is repeated 10,000 times for the sample size n=20 and 40 and various censored schemes. The $AMLE_{II}$ is better than $AMLE_I$ in the sense of the RMSE.

• Communications for Statistical Applications and Methods
• /
• 제27권4호
• /
• pp.413-430
• /
• 2020

The multiply Type-II hybrid censoring scheme is disadvantaged by an experiment time that is too long. To overcome this limitation, we propose a generalized multiply Type-II hybrid censoring scheme. Some estimators of the scale parameter of the exponential distribution are derived under a generalized multiply Type-II hybrid censoring scheme. First, the maximum likelihood estimator of the scale parameter of the exponential distribution is obtained under the proposed censoring scheme. Second, we obtain the Bayes estimators under different loss functions with a noninformative prior and an informative prior. We approximate the Bayes estimators by Lindleys approximation and the Tierney-Kadane method since the posterior distributions obtained by the two priors are complicated. In addition, the Bayes estimators are obtained by using the Markov Chain Monte Carlo samples. Finally, all proposed estimators are compared in the sense of the mean squared error through the Monte Carlo simulation and applied to real data.

• Communications for Statistical Applications and Methods
• /
• 제19권5호
• /
• pp.697-704
• /
• 2012

The maximum likelihood(ML) estimation of the scale parameters of an exponential distribution based on progressive Type II censored samples is given. The sample is multiply censored (some middle observations being censored); however, the ML method does not admit explicit solutions. In this paper, we propose multiply progressive Type II censoring. This paper presents the statistical inference on the scale parameter for the exponential distribution when samples are multiply progressive Type II censoring. The scale parameter is estimated by approximate ML methods that use two different Taylor series expansion types ($AMLE_I$, $AMLE_{II}$). We also obtain the maximum likelihood estimator(MLE) of the scale parameter under the proposed multiply progressive Type II censored samples. We compare the estimators in the sense of the mean square error(MSE). The simulation procedure is repeated 10,000 times for the sample size n = 20 and 40 and various censored schemes. The $AMLE_{II}$ is better than MLE and $AMLE_I$ in the sense of the MSE.

• Journal of the Korean Data and Information Science Society
• /
• 제20권2호
• /
• pp.273-281
• /
• 2009

갭모형은 구매전 기대와 구매후 성과 사이의 차이가 고객만족도와 같은 종속변수에 대한 영향을 이해하려는 기대불일치 패러다임에 근거한 것이다. 이러한 패러다임과는 달리 Bhote는 갭모형 대신에 곱모형을 제안하였다. 곱모형은 구매전 중요도와 구매후 성과를 곱하여 구하는 고객만족도지수에 근거한 것이다. 본 연구는 Bhote의 곱모형을 외식업에 적용한 것이다. 본 연구의 목적은 곱모형에 의한 외식업의 서비스품질의 5차원이 고객만족도, 재방문의도, 및 고객애호도를 설명하는 모형의 독립변수로 적합한지의 여부를 검정하는 것이다. 모형검정을 위해 회귀분석의 F-값이 활용되었다. 분석결과 곱모형은 적합한 것으로 나타났다.

• 소음진동
• /
• 제7권4호
• /
• pp.637-644
• /
• 1997

In this paper, a method of finite element analysis is presented for efficient calculation of vibration characteristics of not only simply interconnected structure with cyclic symmetry but also multiply interconnected structure with cyclic symmetry by using discrete Fourier trandform by means of a computer with small memory in a short time. Simply interconnected structure means it is composed of substructures which are adjacent themselves in circumferential direction. First, a mathematical model of multiply interconnected structure with cyclic symmetry is defined. The multiply interconnected structure is partitioned into substructures with the same goemetric configuration and constraint eqauations to be satisfied on connecting boundaries are defined. Nodal displacements and forces are transformed into complex forms through discrete Fourier transform and then finite element analysis is performed for just only a representative substructure. In free vibration analysis, natural frequencies of a whole structure can be obtained through a series of calculation for a substructure along the number of nodal diameter. And in forced vibration analysis, forced response of whole structure can be achieved by using inverse discrete Fourier transform of results which come from analysis for a substructure.

• 펄프종이기술
• /
• 제37권4호통권112호
• /
• pp.38-43
• /
• 2005

Natural Com Starch(NCS) spray system has been widely used In multiply board mill for the better bonding strength between board layers. However the unsuitable NCS spray system could lead to a drop in plybond efficiency of multiply board. It could also result in the accumulation of unretained-starch in the white water system, which could not only rise in BOD and COD level but also reduce the effects of rosin-alum sizing system and other additives. In this study, the simple and rapid method by UV-spectroscopy for measuring the starch contents in the white water was proposed, and the quantitative analysis for dissolved starch content in white water was carried out in two kinds of board production process. It could be confirmed that about 150 ppm of oxidized starch was retained in white water dewatered from undertop ply of multiply board process, and about 470 ppm of natural starch was dissolved in white water originated from unsuitable spraying system in the multiply board production lines for cup base paper.