• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1155-1163
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• 2016

This paper deals with an estimation procedure of variance components in a mixed effects model by projections. Projections are used to obtain sums of squares instead of using reductions in sums of squares due to fitting both the assumed model and sub-models in the fitting constants method. A projection matrix can be obtained for the residual model at each step by a stepwise procedure to test the hypotheses. A weighted least squares method is used for the estimation of fixed effects. Satterthwaite's approximation is done for the confidence intervals for variance components.

• Journal of the Korean Society for information Management
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• v.12 no.2
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• pp.213-223
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• 1995

It has known that different representations of either queries or documents, or different retrieval techniques retrieve different sets of documents. Recent works suggest that significant improvements in retrieval performance can be achieved by combining multiple representations or multiple retrieval techniques. In this paper we propose a simple method for retrieving different documents within a single query representation, a single document representation and a single retrieval technique. We classify the types of documents, and describe the properties of weighting schemes. Then. we explain that different properties of weighting schemes may retrieve different types of documents. Experimental results show that significant improvements can be obtained by combining the retrieval results form different properties of weighting schemes.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.683-692
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• 2006

IT투자 성과의 정량화에 대한 필요성이 높아짐에 따라 많은 학계와 연구단체에서 IT투자 성과의 화폐가치 전환 및 정량적 평가를 위한 다양한 측정방법들을 개발하여 제시하고 있으며, 이들 기법을 활용하여 IT투자 성과를 정량적으로 평가하는 기업들이 점차 늘고 있다. 그러나 이와 같은 IT투자성과의 정량적 평가 기법을 도입한 기업의 실무자들은 화폐가치로 전환되어 도출된 결과들이 가시적으로 확인될 수 있는 것이 아니기 때문에 IT가 제공하는 실 효과를 제대로 반영하여 평가되었는지에 대하여 확신하지 못하고 있다. 이에 본 연구는IT투자 성과의 정량적 평가 결과를 기존의 많은 연구를 통해 IT투자 성과의 정성적인 평가로 입증된 사용자 만족도로써 설명이 가능한지를 사례 기업의 정량적 평가결과와 사용자 만족도를 분석함으로써 상관관계를 파악하였다. 사례 연구 결과, 다음과 같은 시사점을 도출하였다. 첫째, 정보화 효과금액은 사용자 만족도와 상관관계가 있다. 둘째, 합리적인 정보화효과금액의 도출을 위해서는 조직 내에서 시스템의 효과를 정량화할 수 있는 지표 개발 및 화폐전환데이터의 관리가 중요하다. 셋째, IT ROI는 시스템간의 성과를 비교하는 것에는 부적절하며 개별시스템의 성과 및 효율성 측정 기준으로 사용한다. 넷째, 정량적 평가가 여전히 시스템의 전략적인 부분 등에 대한 평가에는 미흡하기 때문에 이를 보완하기 위한 방법으로 사용자 만족도의 사용이 가능하다.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.38-43
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• 1992

The Hammett's substituent constants were interpreted for substituted stilbenes by HMO method. The appropriate quantum chemical indices are chosen as independent contribution of the inductive and the resonance effects for substituent constants. It has been found that theoretical values, ${\sigma}_p{^{th}}$, defined as sum of the net charge, self atom polarizability and difference in HOMO energy between substituted- and unsubstituted-stilbenes, correlated with experimental Hammett's substituent constants. The dipole moments were found to be correlated with differences in ${\sigma}_p{^{th}}$ between two substituents for disubstituted stilbenes. It has been also found that transition optical spectra, ${\lambda}_{max}$ of the substituted stilbenes depend on difference between the HOMO and the LUMO energy as expected.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.185-192
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• 1993

Abstract Electrorheological effect on the dispersive system of polarizable fine powder/dielectric oil has been investigated. ER effect was explained divided into following 3 mechanisms; (1) surface conductance, (2) bulk conductance, and (3) induced polarization. Mathematical model which predicts the interactive force between two fine particles in the electrorheological fluid has been introduced based on the induced polarization mechanism. This model may provide guide to select materials for strong ER effect. The attractive force between two particles was calculated using the above model for the selected 7 materials such as ceramics, ferrites, polymers etc. From the calculation result, it was found that the ceramics and ferrites are good materials which show a strong ER effect.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.353-362
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• 2017

The purpose of this study aimed to investigate the mediating effect of self-esteem between attachment and depression in adolescents. The study specified theoretical assumptions based on internal working model and vulnerability model. The data were analyzed by structural equation modeling. A total of 2,058 adolescent data from 2015 Korean Children and Youth Panel Survey was used in this study. The results showed parent attachment, peer attachment, and teacher attachment did not have direct effects on adolescent depression, but have indirect effects. Self-esteem had direct and mediating effect on depression. The implications were discussed in relation to interpersonal relationships and self-esteem of adolescents for depression prevention.

• Journal of Venture Innovation
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• v.5 no.1
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• pp.129-143
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• 2022

The purpose of this study is to examine the mediating effect of perception of society and evaluation of oneself in the relationship between self-compassion and life satisfaction. A survey was conducted on 215 full-time workers along with self-compassion scales, life satisfaction scales, social well-being and core self-evaluation. As a result of the study, social well-being and core self-evaluation completely mediated the relationship between self-compassion and life satisfaction, and the difference of indirect effects between social well-being and core self-evaluation was not significant. These results show that the effect of self-compassion improving life satisfaction can be explained through social well-being and core self-evaluation. The implications and limitations of this study for future research were discussed.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.4
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• pp.529-547
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• 2010

In den vergangenen Jahren ist im deutschsprachigen Raum eine Reihe von Studien entstanden, die sich mit wirtschaftlichen Auswirkungen von Hochschulen beschaeftigen, wobei vor allem die nachfrageorientierten regionaloekonomischen Ausgabeeffekte im Mittelpunkt stehen. Zu diesen Nachfrageeffekten gehoeren Auswirkungen der hochschulbedingten Ausgaben auf den Umsatz, die Beschaeftigung und das Einkommen. Sie lassen sich jeweils in direkte und indirekte Effekte aufgliedern und entstehen in der so genannten Phase der Leistungserstellung der Hochschule. Ziel dieser Arbeit ist es, angelehnt an bisherige Studien die regionalwirtschaftlich bedeutsamen Effekte der ausgewaehlten deutschen Hochschulen zu identifizieren und nachzuweisen. In der vorliegenden Untersuchung konnte festgestellt werden, dass die deutsche Hochschule einen wirtschaftlichen Stabilitaetsfaktor fuer die Region darstellt und traegt durch die Erhoehung des regionalen Einkommens und der Beschaeftigungseffekte erheblich zum Wohlstand in der Hochschulregion bei.

• Journal of the Korean Magnetics Society
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• v.22 no.2
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• pp.66-72
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• 2012

The findings of ferromagnetic superconductor have attracted much attention not only for fundamental research to investigate how the antagonistic properties of ferromagnetism and superconductivity coexist peacefully but also for potential technological applications. Firstly, in order to help for understanding the ferromagnetic superconductor, I have explained the orbital and paramagnetic pair-breaking effects of magnetic field, which breaks the superconducting Cooper pairs. In addition to such effects of magnetic field, the singlet Cooper pairs become unstable upon going through the ferromagnetic materials by the proximity effect. The proximity effect occurs at the interface of thin films composing of superconductor and ferromagnet and leads to have very short penetration depth of Cooper pairs. However, a type of odd-frequency triplet in comparison with the singlet could be very stable and has a longer effective depth. It needs to be explored for the innovative spintronic devices. Finally, various ferromagnetic superconductors coexist and the lower-dimensional materials under the Quantum confinement effect have been introduced.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.4
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• pp.65-77
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• 2017

We Investigated the Two Additional Effects Regarding the Causal Relationship between the Perceived Risks of cloud Services on the Intention to use the Abandonment Option. First, we Empirically Tested the Moderation Effect of IS Maturity on the Causal Relationship between these Two Variables. Second, we also Investigated the Mediation Effect of Cloud Service Satisfaction on the same Causal Relationship. We could find the Moderation and Mediation Effect only on the Influence of Relational Risk (Which Occurs from the Power Abuse of Cloud Service Providers) on the Intention to sue the Abandonment Option. So, we have better Understanding when and how the Abandonment Option is Attractive in Reducing the Potential Influence of the Relational Risk in using the Cloud Services.