• 한국식품저장유통학회지
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• 제4권3호
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• pp.343-349
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• 1997

The rheological Voperties of biopolymers produced by Bacilli sp. K-1 and its mutant strains(KM-21, KM-83) were studied at the temperature ranges with 20∼80$^{\circ}C$, at the concenration of 2∼6%, at the pH ranges from 3.0 to 9.0 and at the shear rate of 9.3-930sec-1 The apparent viscosity of biopolymers was decreased with increasing shear rate, and thereby biopolymers showed pseudoplastic characteristics. It was found that the apparent viscosity models respected 19 temperature, concentration and both temperature and concentration were expressed by Arrhenius Model, Exponential Model and combined of the above two Models. Therefore, the apparent viscosity could be predictable by Arrhenius and Exponential Models with high R2.

• Journal of the Korean Data and Information Science Society
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• 제13권2호
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• pp.217-226
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• 2002

In this paper, we derive noninformative priors for the ratio of failure rates in exponential model. A class of priors is found by matching the coverage probabilities of one-sided Baysian credible interval with the corresponding frequentist coverage probabilities. And we prove that the noninformative prior matches the alternative coverage probabilities and is a HPD matching prior up to the second order. Finally, we provide simulated freqentist coverage probabilities under the derived noninformative prior for small samples.

• 응용통계연구
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• 제11권1호
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• pp.185-192
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• 1998

Freund(1961)가 제안한 이변량지수분포는 두 부품으로 이루어진 병렬체계의 상호종속적인 부품의 수명을 해석하는 등에 응용될 수 있어 널리 이용되고 있다. 본 연구에서는 위치모수를 가지는 이변량지수분포를 Freund 모형을 일반화시키는 차원에서 제안하고 모형의 통계적 성질 및 모수에 대한 최우추정량을 구하였다. 또한 최우추정량을 수정하여 편의는 감소시킬 수 있는 새로운 추정량을 제안하였다.

• 응용통계연구
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• 제10권1호
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• pp.105-119
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• 1997

일원배열형태의 가산 자료집합에서 각 군의 평균을 이용하여 처리효과를 비교할 수 있다. Barnwal과 Paul(1988)은 각 군의 산포모수가 같다는 가정 아래에서 처리에 따른 차이를 검정하는 우도검정통계량과 $C(\alpha)$ 통계량을 유도하였는데 본 연구에서는 이러한 가정이 만족되지 않아도 검정할 수 있도록 통계량을 일반화하였다. 또한 음이항분포 대신 Efron(1986)의 이중지수계 포아송 모형을 도입하여 새로운 통계량을 제시하였다. 모의실험을 통해 이중지수계 포아송 모형으로부터 유도된 $C(\alpha)$ 통계량이 어느 경우에나 적합함을 밝혔다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제12권2호
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• pp.119-131
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• 2008

The paper considers the computation method in the performance evaluation of cellular network in the phase-type distribution assumptions that the channel holding times induced from mobility are modeled by well-fitted distributions to reflect an actual situation. When ww consider a phase-type distribution model instead of exponential distribution, the complexity of the computation increase exponential even though the accuracy is improved. We consider an efficient numerical algorithm to compute the performance evaluations in cellular networks such as a handoff call dropping probability, new call blocking probability, and handoff arrival rate. Numerical experiment shows that numerical analysis results are well approximated to the results of simulation.

• Communications for Statistical Applications and Methods
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• 제12권1호
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• pp.149-167
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• 2005

The minimum disparity estimators introduced by Lindsay and Basu (1994) are studied empirically. An extensive simulation in this paper provides a location estimate of the small sample and supplies empirical evidence of the estimator performance for the univariate contaminated normal model. Empirical results show that the minimum generalized negative exponential disparity estimator (MGNEDE) obtains high efficiency for small sample sizes and dominates the maximum likelihood estimator (MLE) and the minimum blended weight Hellinger distance estimator (MBWHDE) with respect to efficiency at the contaminated model.

• Journal of the Korean Data and Information Science Society
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• 제20권5호
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• pp.941-948
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• 2009

We consider a life testing experiment in which several two component shared parallel system are put on test, and the test is terminated at a specified number of system failures. The bivariate data obtained from such a system level life testing can be classified into three classes: (1) the case of failed two components with known failure times, (2) the case of one censored component and the other failed component of which the failure time might be known or unknown, (3) the case of censored two components. In this thesis, the maximum likelihood estimators of parameters for Block and Basu bivariate exponential distribution under above censoring scheme are obtained. And the results of comparative studies are presented.

• Nutritional Sciences
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• 제9권3호
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• pp.201-211
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• 2006

The purpose of this study was to provide dietitians with the guidance in forecasting meal counts for a university/college foodservice facility. The forecasting methods to be analyzed were the following: naive model 1, 2, and 3; moving average, double moving average, simple exponential smoothing, double exponential smoothing, Holt's, and Winters' methods, and simple linear regression. The accuracy of the forecasting methods was measured using mean squared error and Theil's U-statistic. This study showed how to project meal counts using 10 forecasting methods for dietitians. The results of this study showed that WES was the most accurate forecasting method, followed by $na\ddot{i}ve$ 2 and naive 3 models. However, naive model 2 and 3 were recommended for using by dietitians in university/college dining facilities because of the accuracy and ease of use. In addition, the 2000 spring semester data were better than the 2000 fall semester data to forecast 2001spring semester data.

• 응용통계연구
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• 제7권2호
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• pp.313-321
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• 1994

소표본에서 하나의 확실한 이상점을 갖는 지수모형에서 permanent 이론을 도입하여 표본들의 순서통계량의 분포를 정확한 형태로 유도하고, 이 결과를 이용하여 가정된 지수모형의 위치모수와 측도모수에 대한 최우추정량과 그 짹나이프 추정량을 편의와 평균제곱오차면에서 두 추정량의 소표본 성질을 비교하였다.

• Journal of the Korean Data and Information Science Society
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• 제26권2호
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• pp.487-493
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• 2015

Time series data sometimes show violation of normal assumptions. For cases where the assumption of normality is untenable, more exible models can be adopted to accommodate heavy tails. The exponential power distribution (EPD) is considered as possible candidate for errors of time series model that may show violation of normal assumption. Besides, the use of exible models for errors like EPD might be able to conduct the robust analysis. In this paper, we especially consider EPD as the exible distribution for errors of autoregressive models. Also, we represent this distribution as scale mixture of uniform and this form enables efficient Bayesian estimation via Markov chain Monte Carlo (MCMC) methods.