• International Journal of Reliability and Applications
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• v.11 no.2
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• pp.139-151
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• 2010

The main objective of this study is to present a new approach to obtain moment inequalities for the new better than renewal used (NBRU) class of life distributions. In order to achieve our main objective, the moment inequalities for NBRU class of life distribution using the new approach has been derived and then a new test for testing exponentiality against NBRU class based on these inequalities has been constructed. Then we calculate the Pitman asymptotic efficiency for the proposed test using some alternative distributions and comparing it with the other tests. Moreover, we make a comparison between Pittman asymptotic efficiencies (PAE's) and PAE's of some other tests. A simulation study is conducted to calculate the upper critical values and the power estimate of the proposed test for some common alternatives. Finally, we apply the suggested test to some real data.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.533-537
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• 2005

A Likert scale is an often used questionnaire format. It requests respondents to specify their level of agreement to each of a list of statements. A typical question using a five-point Likert scale might make a statement. The results shows vague values. We have five-point fuzzy membership function by fuzzy valued three-point for the question and fuzzy hypothesis test the membership function by 95% confidence interval.

• International Journal of Reliability and Applications
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• v.4 no.4
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• pp.191-199
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• 2003

In the present work, a moment inequality is derived for new renewal better (worse) than used in expectation(NRBUE) (NRWUE) distributions. This inequality demonstrates that if the mean life is finite then all higher order moments exist. A new test statistics for testing exponentiality against NRBUE (NRWUE) is introduced based on this inequality. It is shown that the proposed test is simple and has high relative efficiency for some commonly used alternatives. Critical values are tabulated for sample sizes n = 5(1)30. A set of real data is used as an example to elucidate the use of the proposed test statistics for practical reliability analysis.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.169-176
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• 2015

The purpose of this paper is to study renovation plan of value chain from a user's viewpoint by making practical application of digital technology. And it is surely meaningful to investigate the important motivation factors of continuous using smart-phone, and to analyze the improving effect toward to the quality of life in continuous using smart-phone. By this study we can expect the value improving effect of user experience. The results of hypothesis testing can be summarized as follows: First, the hypothesis that positive affect has a plus effect on pragmatic value is accepted. Secondly, the hypothesis that positive affect has a plus effect on hedonic value is accepted. Thirdly, the hypothesis that negative affect has a minus effect on pragmatic value is accepted. Fourthly, the hypothesis that negative affect has a minus effect on pragmatic value is rejected. Fifthly, the hypothesis that pragmatic value has a plus effect on life satisfaction is accepted. Sixthly, the hypothesis that hedonic value has a plus effect on life satisfaction is rejected. In the competition among enterprises, user experience instead of goods themselves became influential as a differential factor. And many advanced enterprises began taking a serious view of customer's happiness and user experience improvement.

• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.141-148
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• 2020

We consider estimating the proportion of true null hypotheses in multiple testing problems. A traditional multiple testing rate, family-wise error rate is too conservative and old to control type I error in multiple testing setups; however, false discovery rate (FDR) has received significant attention in many research areas such as GWAS data, FMRI data, and signal processing. Identify differentially expressed genes in microarray studies involves estimating the proportion of true null hypotheses in FDR procedures. However, we need to account for unknown dependence structures among genes in microarray data in order to estimate the proportion of true null hypothesis since the genuine dependence structure of microarray data is unknown. We compare various procedures in simulation data and real microarray data. We consider a hidden Markov model for simulated data with dependency. Cai procedure (2007) and a sliding linear model procedure (2011) have a relatively smaller bias and standard errors, being more proper for estimating the proportion of true null hypotheses in simulated data under various setups. Real data analysis shows that 5 estimation procedures among 9 procedures have almost similar values of the estimated proportion of true null hypotheses in microarray data.

• The Korean Journal of Applied Statistics
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• v.21 no.2
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• pp.341-353
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• 2008

The bootstrap method for the score test statistic is proposed in a bivariate negative binomial distribution. The Monte Carlo study shows that the score test for testing overdispersion underestimates the nominal significance level, while the score test for "intrinsic correlation" overestimates the nominal one. To overcome this problem, we propose a bootstrap method for the score test. We find that bootstrap methods keep the significance level close to the nominal significance level for testing the hypothesis. An empirical example is provided to illustrate the results.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.605-616
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• 2021

Objectively, the purpose of this study aims to re-confirm and analyze the relationship between variables through direct relationships and mediation (i.e., career optimism (CO), organizational fairness (OF), organizational entrepreneurship commitment (OEC) on employee engagement). This study also addresses whether career optimism provides a strong-impact if it mediates other antecedent variables on employee engagement. Therefore, to test and prove this, we made observations on 200 samples comprising lecturers in Indonesia. The data collection method uses a survey both offline and online. Through the PLS-SEM approach, the statistical testing demonstration states that all hypotheses, either through direct relationship or mediation, are proven to have a positive and significant effect. Career optimism has also proven to be a substantial and positive contribution to testing employee engagement as a mediating variable. The results of seven hypothesis testing in our study confirm that the broaden-built theory and organizational theory are closely related. Therefore, this study positively contributes to human resource management's science to balance the psychological and organizational aspects. In this study, we also add that consistency and a positive attitude in a career trigger a person's career optimization in a better and more positive direction, especially for career-path and employee engagement.

• Journal of Korean Clinical Health Science
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• v.2 no.2
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• pp.148-157
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• 2014

Purpose. This study compares and analyzes customer service on customer satisfaction and customer royalty on customer satisfaction targeting the customers visiting a hospital or a clinic which is franchised or not. And it aims at helping business rationalization for a medical institution. Methods. This paper conducts a survey and selects a sample of 670 customers except the missing value targeting the customers of 4 primary health care institutions and 4 bigger health care institutions in Seoul and Gyeonggi province. It conducts frequency analysis for the purpose of investigating the respondents' generic characteristic and factor of their medical institution selection, and factor analysis, reliability analysis and regression analysis for the hypothesis testing. Results. The first hypothesis testing result is significant in level of significance of 0.01. The second one is the same as the first one, but the dummy variable shows a negative regression coefficient(-0.479). The third one is significant in level of significance of 0.01, but the forth one is not significant. And the respondents prioritize website(Home page) and convenience in use of a hospital procedure for selecting a hospital or a clinic. Conclusions. The additional analysis finds that the franchised group has more satisfaction than none franchised group. But in case of their royalty, the average of franchised and none franchised groups are not significantly different. Therefore, the results of this paper reveal to support the results of the advanced researches.

• The Korean Journal of Applied Statistics
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• v.25 no.2
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• pp.311-319
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• 2012

The simplest and the most important distribution in survival analysis is exponential distribution. Koziol and Green (1976) derived Cram$\acute{e}$r-von Mises statistic's randomly censored version based on the Kaplan-Meier product limit estimate of the distribution function; however, it could not be practical for a real data set since the statistic is for testing a simple goodness of fit hypothesis. We generalized it to the composite hypothesis for exponentiality with an unknown scale parameter. We also considered the classical Kolmogorov-Smirnov statistic and generalized it by the exact same way. The two statistics are compared through a simulation study. As a result, we can see that the generalized Koziol-Green statistic has better power in most of the alternative distributions considered.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.133-140
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• 2011

Recently, Web applications, such as Stock Image and Image Library, are developed to provide the integrated management for user's images. Image hash techniques are used for the image registration, management and retrieval as the identifier and many researches have been performed to raise the hash performance. This paper proposes GLOCAL image hashing method utilizing the hierarchical histogram which based on histogram bin population method. So far, many researches have proven that image hashing techniques based on histogram are robust image processing and geometrical attack. We modified existing image hashing method developed by our research team. The main idea is that it makes more fluent hash string if we have histogram bin of specific length as shown in the body of paper. Finally, we can raise the magnitude of hash string within same context or feature and strengthen the robustness of hash.