• Journal of Korean Society for Quality Management
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• v.26 no.4
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• pp.101-110
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• 1998

The mean residual life function is the expected remaining life of an item at age $\chi$. The problem of trend change in the mean residual life is great interest in the reliability and survival analysis. In this paper we develop a new test statistic for testing whether or not the mean residual life changes its trend based on a complete sample. Monte Carlo simulations are conducted to compare the perfor mance of our test statistic with that of previously known tests.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.17-27
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• 2022

The purpose of this study is to identify the effects of change of social relations due to COVID-19 on life satisfaction and to examine mediating effect of leisure satisfaction in the relationship between change of social relations due to COVID-19 and life satisfaction of older people. This study utilized 2021 Social Survey data and 7,203 older persons aged over 65 years were analyzed. Multiple regression analyses were used for the analyses and significance of mediating effect was tested using bootstrapping methods. Study findings showed that change of social relations due to COVID-19 had a significant effect on life satisfaction of older people. That is, those who experienced increasing distance from neighbors and friends reported lower level of life satisfaction. Also, leisure satisfaction partially mediated the effects of change of social relations due to COVID-19 on life satisfaction. Results of this study suggest that various interventions are needed to prevent a decrease of quality of life of older people in times during which social distancing can be necessary like COVID-19 pandemic.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.123-132
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• 2015

The purpose of the study was to examine the structural relationship among job satisfaction, economic condition satisfaction, change of self-worth and quality of life of Elderly Employment Program participants. An analysis was conducted on the data of the '2012 Elderly Employment Program Participants Survey'. The major findings were as follows. The job satisfaction, economic condition satisfaction, change of self-worth had positive effects to quality of life. The job satisfaction had mediator effect to quality of life through economic condition satisfaction and change of self-worth. Also, change of self-worth had indirect effect between economic condition satisfaction and quality of life. Based on the results, the implications for Elderly Employment Program practice and policy were suggested.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.43-52
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• 2001

The purpose of this study is to fined out the characteristics of using & change of the residential space according to the children age and family life cycle. The results of this study are as follows: The first, as children grow up, children's activity space changed from living room to the private room, and housing condition was related to the frequency of each activity. The second, as children grow up, family's sleeping pattern changed, and this change effected the number of private rooms for sleeping and the use of the extra room. The third, changes of the using of dwelling space come out several pattern, increasing bedroom number through reconstruction, exchange of An-band and children room, parents' sleeping space move to living room, and change the function of rooms. The change pattern of the correspondence to the housing needs differed from each family life cycle stage.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.263-291
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• 2003

The purpose of this paper is to analyse the change in the productivity of Korean life insurance industry by Generalized Malmquist productivity indices. Generalized Malmquist indices will be decomposed into three components such as pure efficiency change, scale efficiency change, and technical change. The principal findings indicate an overall increase in productivity driven more by technical progress than pure technical efficiency and scale efficiency.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.195-202
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• 2002

The problem of trend change in the mean residual life is great Interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend Is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

• Journal of Korean Society for Quality Management
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• v.30 no.4
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• pp.78-85
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• 2002

The problem of trend change in the mean residual life is great interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

• Journal of Life Science
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• v.10 no.2
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• pp.9-11
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• 2000

Lipopolysaccharide (LPS) and cell wall protein-A (CWP-A) were extracted from the cell wall of Vibrio vulnificus, Escherichia coli and Salmonella typhimurium. LPSs and CWP-As were injected into rat and the changes of the following blood components were examined. The change of the number of white blood cell (WBC), red blood cell (RCB), platelet (PLT), blood urea nitrogen (BUN) and blood glucose in rat blood and interferon (IFN) activity change by LPS and CWP-A were measured. WBC, RETI, PTT, and BUN were increased and RBC and blood glucose were increased slightly, but PLT was decreased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.43-53
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• 2024

This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO₂ and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO₂ and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.867-876
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• 2005

The purposes of this study were, 1) to investigate the causal relationship between customer's life-style and motivation of eating-out, and 2) to research the causal nexus between motivation of eating-out and satisfaction of attributes to choose the restaurant. Reliability analysis, factor analysis, and Structure Equation Model(SEM) were adapted by Windows SPSS 10.0 and Amos 4.0. Life-style was divided into 7 factors and eating-out motivation into 5. Life-style influenced significantly each motivation of eating-out. It had positive influence on 'Reception and congratulation', 'Change of dietary life', 'Economic saving', "'Preference motivation', and 'Advertisement and companion's need', but negative influence on 'Reception and congratulation', 'Change of dietary life', and 'Preference motivation'. Customer's motivation of eating-out also influenced significantly the attributes. Factorl 'Reception and congratulation' had positive influence on all attributes except for 'Transportation convenience and distance to the shop'. Factor 2 'Change of dietary life' had negative influence on 'Food's taste, quantity, price', 'Sanitation and cleanness', and 'Staff's service quality' Factor 3 "Economic saving' had positive influence on 'Food's taste, quantity, price' and 'Transportation convenience and distance to the shop'. factors 'Advertisement and companion's need' had positive influence on 'Atmosphere of restaurant' and negative influence on 'Food's taste, quantity, price'.