• 한국군사과학기술학회지
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• 제11권6호
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• pp.63-73
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• 2008

The helicopter position, heading data and the direction finding data of ESM are essentially required to compensate the parallax and analyze the direction finding accuracy of heliborne ESM in flight test phase. In the case of the long test range compared with small platform like as LYNX helicopter and Jisim Island test site, the parallax compensation for direction finding accuracy calculation and GPS position error can be neglected. In this paper, the direction finding accuracy on the basis of helicopter propeller was calculated by coordinate changing between helicopter and transmitting antenna from WGS84 coordinate to navigation coordinate using helicopter position and direction finding data.

• 한국통신학회논문지
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• 제35권2A호
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• pp.196-201
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• 2010

Measurement of Quality of Service (QoS) parameters and its statistical analysis becomes a key issue for Mobile WiMAX service providers to manage the converged network efficiently and to support end-to-end QoS. In this paper, we investigate the population distribution of end-to-end one-way delay which is the most important QoS parameter in Mobile WiMAX networks. The samples are analyzed with Chi-Square Goodness-of-Fit test, Kolmogorov-Smirnov (K-S), and Anderson-Darling (A-D) test to verify the distribution of parent population. The relation with confidence level and the minimum number of sample size is also performed for logistic distribution. The statistical analysis is a promising approach for measuring the performance Mobile WiMAX networks.

• 한국농공학회지
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• 제36권1호
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• pp.63-72
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• 1994

The objective of the study is to develop weather generators for daily rainfall and small pan evaporation and to test the applicability with recorded data. Daily rainfall forecasting model(DRFM) was developed that uses a first order Markov chain to describe rainfall seque- nces and applies an incomplete Gamma function to predict the amount of precipitation. Daily evaporation forecasting model(DEFM) that adopts a normal distribution function to generate the evaporation for dry and wet days was also formulated. DRFM and DEFM were tested with twenty year weather data from eleven stations using Chi-square and Kolmogorov and Smirnov goodness of fit tests. The test results showed that the generated sequences of rainfall occurrence, amount of rainfall, and pan evaporation were statistically fit to recorded data from eleven, seven, and seven stations at the 5% level of significance. Generated rainfall data from DRFM were very close in frequency distri- bution patterns to records for stations all over the country. Pan evaporation for rainy days generated were less accurate than that for dry days. And the proposed models may be used as tools to provide many mathematical models with long-term daily rainfall and small pan evaporation data. An example is an irrigation scheduling model, which will be further detailed in the paper.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.672-677
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• 2005

The standard reference collection of strains for E. coli, the ECOR collection, was analyzed by a genome-based typing method. Seventy-one ECOR strains were subjected to repetitive extragenic palindromic PCR genome fingerprinting with BOX primers (BOX-PCR). Using a similarity value of 0.8 or more after cluster analysis of BOX-PCR fingerprinting patterns to define the same genotypes, we identified 28 genotypes in the ECOR collection. Shannon's entropy-based diversity index was 3.07, and the incident-based coverage estimator indicated potentially 420 genotypes among E. coli populations. Chi-square test of goodness-of-fit showed statistically significant association between the genotypes defined by BOX-PCR fingerprinting and the groups previously defined by multi-locus enzyme electrophoresis. This study suggests that the diversification of E. coli strains in natural populations is actively ongoing, and rep-PCR fingerprinting is a convenient and reliable method to type E. coli strains for the purposes ranging from ecology to quarantine.ine.

• International Journal of Reliability and Applications
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• 제14권1호
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• pp.27-39
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• 2013

In this article, a new model based on the Rayleigh distribution is introduced. This model is useful and practical in physics, reliability, and life testing. The statistical and reliability properties of this model are presented, including moments, the hazard rate, the reversed hazard rate, and mean residual life functions, among others. In addition, it is shown that the distributions of the new model are ordered regarding the strongest likelihood ratio ordering. Four estimating methods, namely, method of moment, maximum likelihood method, Bayes estimation, and uniformly minimum variance unbiased, are used to estimate the parameters of this model. Simulation is used to calculate the estimates and to study their properties. Finally, the appropriateness of this model for real data sets is shown by using the chi-square goodness of fit test and the Kolmogorov-Smirnov statistic.

• 가정과삶의질연구
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• 제21권2호
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• pp.31-38
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• 2003

This study was conducted to develop a Parenting Stress Scale that measures the day-to-day difficulties entailed in parenting for school-aged children. First, sixty seven items were collected as a baseline. Some of these items were pooled from existing parenting stress scales(Abidin, 1990; Kim & Kang, 1997), and the rest were generated based on interviews with parents of school-aged children. Secondly, Chi-Square tests were conducted and framer's V coefficients were calculated to determine the goodness-of-fit of the items. Twenty four items were selected from this step. The results of a factor analysis on these 24 items revealed two dimensions of this new Parenting Stress Scale, namely, 'school-related parenting stress' and 'general everyday life stress'. A test of construct validity also showed that this scale has adequate internal consistency.

• Nuclear Engineering and Technology
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• 제28권3호
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• pp.331-338
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• 1996

In the thermal-hydraulic design, the effect of fuel rod bow is quantified tv the rod bow DNBR penalty which is a key design parameter to assure the coolability of fuel assembly in the pressurized water reactor. In this work, a computer program for the evaluation of the rod bow DNBR penalty based on Westinghouse methodology is developed and its application procedure is proposed. The computer simulation is based on the Monte-Carlo method. The qualification of developed computer program is performed by a comparison of calculational result with that given by Westinghouse's document. A new application procedure is built using batch mean and batch standard deviation. The normality of sample population generated by the batch calculation is confirmed by means of a chi-square test for goodness of fit. On the view point of statistics it is effected that the more reliable design value may be produced by the new application procedure.

• 성인간호학회지
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• 제17권3호
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• pp.464-473
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• 2005

Purpose: The purpose of this study was to evaluate and compare the predictive ability of three mortality scoring systems; Acute Physiology and Chronic Health Evaluation(APACHE) III, Simplified Acute Physiology Score(SAPS) II, and Mortality Probability Model(MPM) II in discriminating in-hospital mortality for intensive care unit(ICU) patients with spontaneous intracerebral hemorrhage. Methods: Eighty-nine patients admitted to the ICU at a university hospital in Daejeon Korea were recruited for this study. Medical records of the subject were reviewed by a researcher from January 1, 2003 to March 31, 2004, retrospectively. Data were analyzed using SAS 8.1. General characteristic of the subjects were analyzed for frequency and percentage. Results: The results of this study were summarized as follows. The values of the Hosmer-Lemeshow's goodness-of-fit test for the APACHE III, the SAPS II and the MPM II were chi-square H=4.3849 p=0.7345, chi-square H=15.4491 p=0.0307, and chi-square H=0.3356 p=0.8455, respectively. Thus, The calibration of the MPM II found to be the best scoring system, followed by APACHE III. For ROC curve analysis, the areas under the curves of APACHE III, SAPS II, and MPM II were 0.934, 0.918 and 0.813, respectively. Thus, the discrimination of three scoring systems were satisfactory. For two-by-two decision matrices with a decision criterion of 0.5, the correct classification of three scoring systems were good. Conclusion: Both the APACHE III and the MPM II had an excellent power of mortality prediction and discrimination for spontaneous intracerebral hemorrhage patients in ICU.

• 한국수자원학회논문집
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• 제42권10호
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• pp.857-866
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• 2009

본 연구에서는 전국의 30년 이상의 강우관측기록을 보유하고 있는 기상청 산하 56개 강우관측소의 연 최대치 강우자료들로부터 확률분포형에 대하여 모멘트법, 최우추정법, 확률가중모멘트법을 이용하여 모수를 추정하고, 그 모수의 범위와 확률변수의 범위에 대한 적정성을 알아보았다. 적정성이 있는 모수를 대상으로 적합도 검정법인 x$^2$-검정, K-S검정, Cramer von Mises (CVM)검정, Probability Plot Correlation Coefficient (PPCC) 검정을 실시한 결과 중, 최근 연구에서 많이 이용되고 있고 표본자료의 크기가 작거나 왜곡된 자료일 경우에도 비교적 안정적인 결과를 얻을 수 있는 확률가중모멘트법과 상관계수에 의한 검정인 PPCC검정을 통과한 분포형을 우선적으로 적합도 평가 대상 분포형으로 선정하였다. 선정된 분포형을 대상으로 적합도 평가기준인 SLSC, MLL, AIC를 적용하여 적합도 평가를 실시하여 대표확률분포형 후보군을 추출하였다. 대표확률분포형 후보군으로 선정된 확률분포형에 대하여 resampling방법인 Jackknife기법을 적용하여 변동성을 파악하고, 변동성이 가장 작게 나타난 분포형을 그 지점의 대표확률분포형으로 결정하였다. 본 논문에서는 분석 결과의 분량을 감안하여 대표적으로 서울, 강릉, 대구, 전주, 부산 지점에 대해 작성하였으며, 확률강우량의 변동성이 가장 작은 확률분포형을 56개 지점의 각 지점 대표확률분포형으로 제시하였으며, Gumbel 분포(GUM)의 선정 비율이 지속기간 12시간, 24시간에 대해 각각 41 %, 32 %로 가장 높게 나타났다. 본 연구에서는 적합도 평가를 함에 있어서 객관적 정량화가 가능한 세 가지 기준과 Jackknife기법을 이용한 새로운 확률분포형 선정의 가능성을 제시하였다.

• Journal of Nutrition and Health
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• 제45권4호
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• pp.390-399
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• 2012

The objective of this study was to develop and evaluate the construct validity of a Nutrition Quotient (NQ) for children. In a previous report (Kang, et al., 2012), the food behavior checklist for children's NQ, consisting of 19 items, was grouped into a 5-factor structure according to the exploratory factor analysis: balance, diversity, moderation, regularity, and practice. In this study, the construct validity of the NQ was assessed using a confirmatory factor analysis. Elementary school students (n = 1,393) from six large cities completed the NQ test. Indicator tests suggested an adequate model fit (goodness of fit index = 0.9613; adjusted GFI = 0.95; standardized root mean square residual = 0.0464; chi-square test statistics of < 0.001 p-value, 82.1), and item loadings were significant for all subscales (p < 0.05). The standardized path coefficients were used as the weights of the items. The NQ and the 5 factor scores of the student were calculated by the obtained weights of the questionnaire items. Logistic regression was applied to find the significant factors in order to affect a specific nutrient status. The receiver operation characteristic curve analyses were performed in order to find diagnostic cut-off points of the five factors. The food behavior checklist for children's NQ would be a handy and suitable instrument for evaluating dietary behaviors of Korean children.