• Kyungpook Mathematical Journal
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• 제50권2호
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• pp.213-228
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• 2010

A weighted version of the geometric mean of k ($\geq\;3$) positive invertible operators is given. For operators $A_1,{\ldots},A_k$ and for nonnegative numbers ${\alpha}_1,\ldots,{\alpha}_k$ such that $\sum_\limits_{i=1}^k\;\alpha_i=1$, we define weighted geometric means of two types, the first type by a direct construction through symmetrization procedure, and the second type by an indirect construction through the non-weighted (or uniformly weighted) geometric mean. Both of them reduce to $A_1^{\alpha_1}{\cdots}A_k^{{\alpha}_k}$ if $A_1,{\ldots},A_k$ commute with each other. The first type does not have the property of permutation invariance, but satisfies a weaker one with respect to permutation invariance. The second type has the property of permutation invariance. We also show a reverse inequality for the arithmetic-geometric mean inequality of the weighted version.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.32-37
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• 2001

This paper describes a noble fault diagnosis method using inter node search technique in PN model. First, a complicated fault system is modeled as PN graphic expressions. Next, to find out sources for faults on which we focus, the PN model is analyzed using the backward chaining of T-invariance. In this step, the technique of inter node search is applied for reducing some range of sources in a fault. Also, colnposing method of incidence matrix in PN is proposed. Then, it makes the diagnosis system to very flelible system because new knowledges about the sources in a fault can be added easily to conventional systems. Finally, the proposed method is applied to the automobile trouble diagnosis system to confirm the validity of the method.

• International Journal of Computer Science & Network Security
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• 제21권5호
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• pp.211-216
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• 2021

This study intended to test the structure of the latent factor of a subjective happiness scale and the stability of invariance across groups of students' classifications (gender and students' status). In the large, non-clinical sample (619), students completed the subjective happiness scale. The (CFA) confirmatory factor analysis was used to investigate the factor-structure of the measure, and multiple-group confirmatory factor analysis (MGCFA) model was used to test the stability of invariance across groups of students classifications. The findings of the CFA indicated support for the original one-factor model. Additional analyses of the MGCFA method support the measurement (configural, metric and strong) invariant and practical invariant components of this model. There was an invariant across gender. There was partially invariant across groups of students' statuses. The scale exists in both groups to assess the same concepts of (single and married), excluding Items 3 and 4. Given that this study is the first investigation for the structure of the subjective happiness scale.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.97-101
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• 2022

The perceiving a calling scale is composed of three constructs: transcendent sermon, meaningful and prosocial aspects. Based on the multiple group confirmatory factor analysis from the structural equation model, we confirmed the measurement invariance between Christians and non-Christians at the scale level. Furthermore, to investigate the mean difference between Christians and non-Christians, we performed latent mean analysis. The results showed that the three-factor structure is equivalent across Christians and non-Christians, and further confirmed metric invariance and scalar invariance. Thus, the perceived calling scale is applicable to both Christians and non-Christians without biases. We also examined mean differences between the two groups. Christians demonstrated significantly higher scores on the three factors but no difference on the living a calling. This study provided meaningful information in understanding calling, and we discussed limitations and future directions.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.149-156
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• 2021

This study intended to test the structure of the latent factor of an effectiveness scale and the stability of invariance across groups of students' classifications (gender and levels of education). In the large, non-clinical sample (850), students completed the effectiveness scale. The (CFA) confirmatory factor analysis was used to investigate the factor-structure of the measure, and multiple-group confirmatory factor analysis (MGCFA) model was used to test the stability of invariance across groups of students' classifications. The findings of the CFA indicated support for the original four-factor model. Additional analyses of the MGCFA method support the measurement (configural, metric and strong) invariant and practical invariant components of this model. There was an invariant across gender. There was partially invariant across groups of levels of education. The scale exists in groups of levels of education assess the same concepts of, excluding Items 15 and 10. Given that this study is the first investigation for the structure of the effectiveness scale.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.17-34
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• 2021

This study aimed to examine the Factor Structure of the teacher satisfaction scale (TSS) with distance education during the Covid-19 pandemic, as well as affirming the (Factorial Invariance) according to gender variable. It also aimed at identifying the degree of satisfaction according to some demographic variables of the sample. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia. The (TSS) was applied to a random sample representing the study population consisting of (2399) respondents. The results of the study showed that the scale consists of five main factors, with a reliability value of (0.94). The scale also showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the third level (Scalar-invariance) of the Measurement Invariance across the gender variable. The results also showed that the average response of the study sample on the scale reached (3.74) with a degree of satisfaction, as there are no statistically significant differences between the averages of the study sample responses with respect to the gender variable. While there were statistically significant differences in the averages with respect to the variable of the educational level in favor of the middle school and statistically significant differences in the averages attributed to the years of experience variable in favor of those whose experience is less than (5) years.

• 정보보호학회논문지
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• 제18권6A호
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• pp.139-149
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• 2008

조직이나 기관에서 수집한 개인정보를 통계 분석, 공공 의료 연구 등을 목적으로 배포할 때는 데이터에 포함된 개인의 민감한 정보가 노출되지 않도록 보호해야 한다. 한편, 배포되는 데이터는 가능한 정확한 통계 정보를 제공해야 한다. k-anonymity와 l-diversity 모델은 이러한 프라이버시 침해 문제 해결을 위해 제안되었다. 그러나 두 모델은 데이터에 삽입과 삭제가 발생하지 않는 정적인 데이터를 단 한번 배포하는 상황을 가정하기 때문에 삽입과 삭제가 발생하는 동적인 데이터에 그대로 적용할 수 없다. 동적인 데이터의 프라이버시 보호 문제를 해결하기 위해 최근 m-invariance 모델이 제안되었다. 그러나 m-invariant 일반화 기법은 일반화로 인해 통계 정보로써 데이터의 품질을 저하시킨다는 단점이 있고, 배포된 데이터 중 일부 개인의 민감한 속성이 노출되었을 경우에 그 영향이 다른 부분으로 전이된다. 본 논문에서는 일반화를 사용하지 않으면서 간단한 삽입과 삭제 연산을 지원하는 동적 데이터의 배포 기법을 제안한다. 제안 기법은 데이터의 품질을 높이면서 m-invariance와 동등한 수준의 프라이버시 보호 정도를 제공한다.

• 응용통계연구
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• 제23권1호
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• pp.73-79
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• 2010

Missing values for unit root processes are imputed by the most recent observations. Treating the imputed observations as if they are complete ones, semiparametric unit root tests are extended to missing value situations. Also, an invariance principle for the partial sum process of the imputed observations is established under some mild conditions, which shows that the extended tests have the same limiting null distributions as those based on complete observations. The proposed tests are illustrated by analyzing an unequally spaced real data set.

• 대한수학회논문집
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• 제29권2호
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• pp.295-310
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• 2014

This paper provides a study of lightlike submanifolds of a generalized Robertson-Walker (GRW) space-time. In particular, we investigate lightlike submanifolds with curvature invariance, parallel second fundamental forms, totally umbilical second fundamental forms, null sectional curvatures and null Ricci curvatures, respectively.

• 대한수학회지
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• 제33권4호
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• pp.801-811
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• 1996

Let $Z^d$ denote the set of all d-tuples of integers$(d \geq 1, a positive integer)$. The points in $Z^d$ will be denoted by $\underline{m},\underline{n}$, etc., or sometime, when necessary, more explicitly by $(m_1, m_2, \cdots, m_d)$, $(n_1, n_2, \cdots, n_d)$ etc. $Z^d$ is partially ordered by stipulating $\underline{m} \underline{<}\underline{n} iff m_i \leq n_i$ for each i, $1 \leq i \leq d$.