• Journal of agricultural medicine and community health
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• v.37 no.3
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• pp.156-166
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• 2012

Objectives: This study aimed to identify the relationship among health-related quality of life of the Cheon-nam region elderly with low back pain. Methods: Data were obtained from cross-sectional surveys conducted as a part of the Community Health Survey 2008. The final analysis included data from 7,003 of the 7,070 elderly participants (aged over 65 years), as 67 responses were excluded since they were inaccurate. Data were analyzed with SPSS for Windows (ver. 19.0), using a ${\chi}^2$-test, a t-test, an ANOVA, and multiple liner regression. The significance threshold was set as p<0.05. Results: Factors related to the health-related quality of life of the elderly were low back pain, age, education level, occupation, subjective health status, subjective stress, drinking status, number of chronic diseases, and sleep duration. Further, health-related quality of life was significantly lower in elderly adults with low back pain. Conclusions: In order to improve health-related quality of life of the elderly and the development of the program for the management of low back pain will be needed to determine, it is considered necessary to study more to follow through the various analysis of in the elderly and health-related quality of life.

• Journal of Technology Innovation
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• v.27 no.3
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• pp.27-52
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• 2019

This research studied the determinants of private R&D investment by examining the innovation strategies of 481 small and medium enterprises (SMEs, their employee size is 5 or more and less than 300) in Busan, South Korea. The data is derived from the Technology Survey of Small and Medium Enterprises in 2001 and 2003. Three explanatory variables for the innovation strategies are the R&D portfolio, the organization (personnel) for R&D, and the strategic role of CEO for innovation. The technological levels of industries are controlled in the linear regression model. The dependent variable is the total private R&D investment of a firm in the given fiscal year. The empirical results indicate that the private R&D investment positively correlates with the complexity of the R&D portfolio, the formal organization for R&D team, and the increase of R&D personnel. The formal organization for R&D team and the number of R&D personnel are correlated with the increase of private R&D investment across the four groups in the manufacturing sector but not in the service sector. These findings suggest that the innovation policy needs to target firms who have complex R&D portfolios, the formal organization of R&D teams, and sufficient R&D personnel in order to increase the private R&D investment of SMEs in regions, with consideration of industrial characteristics.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.1
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• pp.1-8
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• 2014

Using the level set and the meshfree methods, we develop a topological shape optimization method applied to linear elasticity problems. Design gradients are computed using an efficient adjoint design sensitivity analysis(DSA) method. The boundaries are represented by an implicit moving boundary(IMB) embedded in the level set function obtainable from the "Hamilton-Jacobi type" equation with the "Up-wind scheme". Then, using the implicit function, explicit boundaries are generated to obtain the response and sensitivity of the structures. Global nodal shape function derived on a basis of the reproducing kernel(RK) method is employed to discretize the displacement field in the governing continuum equation. Thus, the material points can be located everywhere in the continuum domain, which enables to generate the explicit boundaries and leads to a precise design result. The developed method defines a Lagrangian functional for the constrained optimization. It minimizes the compliance, satisfying the constraint of allowable volume through the variations of boundary. During the optimization, the velocity to integrate the Hamilton-Jacobi equation is obtained from the optimality condition for the Lagrangian functional. Compared with the conventional shape optimization method, the developed one can easily represent the topological shape variations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2B
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• pp.36-43
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• 2005

This paper suggests a method to effectively apply an application model of fuzzy-neural network to the optimal load distribution algorithm, considering the complication and non-linearity of the web server environment. We use the clustering web server in the linux system and it consists of a load balancer that distributes the network loads and some of real servers that processes the load and responses to the client. The previous works considered only with the scrappy decision information such as the connections. That is, since the distribution algorithm depends on the input of the whole network throughput, it was proved inefficient in terms of performance improvement of the web server. With the proposed algorithm, it monitors the whole states of both network input and output. Then, it infers CPU and memory states of each real server and effectively distributes the requests of the clients. In this paper, the proposed model is compared with the previous method through simulations and we analysis the results to develop the optimal and intelligent load balancing model.

• Korean Journal of Culture and Social Issue
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• v.27 no.4
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• pp.435-455
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• 2021

This study aimed to examine the effect of the income change and income level during the COVID-19 pandemic on individuals' depression, and to test how those associations may differ by gender. Participants consisted of 634 adults(M_age=44.18, SD_age=13.88, 313 females) recruited through an online research company. Participants completed a set of questionnaires that measured income change, average monthly income for the past six months, and the Korean version of CES-D. The results indicated that decreases in income, but not levels of income, significantly predicted levels of depression. Furthermore, both income change and income level interacted with gender to predict depression. Specifically, income change predicted depression only for males, while income level predicted depression only for females. These findings suggest that the effects of income-related indicators on depression during the pandemic may differ by gender. The study also offers practical implications by proposing gender as a potential factor to consider in early identification and intervention to prevent depression during the pandemic.

• Journal of Industrial Convergence
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• v.20 no.8
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• pp.109-118
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• 2022

This study aims to examine the extent of lifestyle behavior changes, perceived restrictions in daily life, and their relationship during the COVID-19 pandemic. Using the 2020 Community Health Survey data, this study calculated perceived restrictions in daily life among adults in Korea during the pandemic by sociodemographic characteristics and lifestyle behavior category (physical activity, sleeping duration, drinking, smoking, social contact, public transport use, food delivery, instant food consumption). The generalized linear model examined the relationship between behavior change and perceived restriction on daily life. A total of 227,808 respondents were analyzed. 56.70% of the population perceived their daily lives restricted by 50% and more during the pandemic. The majority of the population decreased physical activity, social contact, and public transport use (52.71%, 89.70%, and 63.74%, respectively). Individuals who decreased physical activity, sleep duration, and social contact frequency, and those who increased drinking frequency, food delivery, and instant food consumption perceived greater restrictions in daily life than those who did not change respective behaviors (p<0.001). In conclusion, decreases in social contact and physical activity and increases in use of food delivery and instant food consumption were associated with greater perceived restrictions of daily life during the pandemic. Efforts to alleviate the negative impact of the pandemic on psychological well-being may need to involve attempts to improve healthy life behaviors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1C
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• pp.43-52
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• 2006

Despite several constitutive models have been proposed and applied, it is still difficult to choose a suitable model and to estimate adequate analysis parameters. Furthermore, a cyclic shear behavior under the volume change caused by the seepage is more complex. None of the constitutive model is available at present in the expression of the cyclic behavior of soil under an additional volume change condition by seepage. Therefore, a new geotechnical hybrid simulation system which can control the pore water immigration was developed. The system enables a quantitative evaluation of the residual deformation such as lateral spreading and settlement caused by the liquefaction. The seismic responses in a one-dimensional slightly inclined multilayered soil system are taken into consideration, and the soils are governed by both equation of motion and the continuity equation. Furthermore, the estimation and the selection of the soil parameter for the representation of the strong nonlinearity of the material are not required, because soil behaviors under the earthquake motions are directly introduced instead of a numerical soil constitutive model. This paper presents the concept and specifications of the system. By applying the system to an example problem, the permeability effect on the seismic response during cyclic shear is studied. The importance of the volume change characteristics of sandy soil during and after cyclic shear is shown in conclusion.

• 한국노년학
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• v.38 no.4
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• pp.1083-1105
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• 2018

The present study sought to capture day-to-day fluctuation of the daily happiness among Korean urban older adults and to examine whether the within person fluctuation of daily happiness is explained by the social and physical activities the older adults experience each day. We also examined whether the within person association between daily social, physical activities and the daily happiness varies by individual characteristics(i.e. gender, age, educational level and health). In addition, we explored the relationships between the level and fluctuation of daily happiness and the level of global happiness. The data was collected by multi-method approach, which includes general survey, daily diary method and collection of physical activity data through the activity monitors. In total, 175 urban older adults participated for seven days of daily diary survey. The data about the number of steps and the time spent on sedentary activities, light intensity physical activities and moderate to vigorous intensity physical activities were also collected during the same period from 16 sub-samples using activity monitors. Hierarchical linear modeling was applied for the analysis. The results were as below. First, the level of happiness of older adults fluctuated during a week, and the patterns of fluctuation varied by the gender and the health. Second, socializing with their children and friends elevated their levels of happiness. Also the impact of contacts with siblings on the level of daily happiness was greater for the unhealthy group compare to the healthy group. Third, older adults were happier on the days when they walked more, but the level of daily happiness decreased on the days when they spent longer time for low intensity physical activities. Lastly, the higher level of daily happiness were related to the higher level of global happiness, but the degree of fluctuation of daily happiness was not related to the level of global happiness. The implications of these results and suggestions for future research are discussed.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.193-221
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• 2017

Grouping episodes into semantically related categories is necessary for better mnemonic structure. However, the effect of grouping on memory of subordinate details was not clearly understood. In an fMRI study, we tested whether attending superordinate during semantic association disrupts or enhances subordinate episodic details. In each cycle of the experiment, five cue words were presented sequentially with two related detail words placed underneath for each cue. Participants were asked whether they could imagine a category that includes the previously shown cue words in each cycle, and their confidence on retrieval was rated. Participants were asked to perform cued recall tests on presented detail words after the session. Behavioral data showed that reaction times for categorization tasks decreased and confidence levels increased in the third trial of each cycle, thus this trial was considered to be an important insight where a semantic category was believed to be successfully established. Critically, the accuracy of recalling detail words presented immediately prior to third trials was lower than those of followed trials, indicating that subordinate details were disrupted during categorization. General linear model analysis of the trial immediately prior to the completion of categorization, specifically the second trial, revealed significant activation in the temporal gyrus and inferior frontal gyrus, areas of semantic memory networks. Representative Similarity Analysis revealed that the activation patterns of the third trials were more consistent than those of the second trials in the temporal gyrus, inferior frontal gyrus, and hippocampus. Our research demonstrates that semantic grouping can cause memories of subordinate details to fade, suggesting that semantic retrieval during categorization affects the quality of related episodic memory.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.837-847
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• 2007

1,098 pieces of photographs($1995{\sim}2002$) of men's suit style have been classified according to fashion images in order to examine features and change aspects with statistical analysis. The findings of examining features of the trend by year with test of homogeneity, correspondence analysis, biplots, correlation analysis and regression analysis are as follows: (a) there are significant differences on fashion images as the trend by yew with test of homogeneity, (b) there are remarkable differences on the fashion trend by year with correspondence analysis and biplots. (c) There are significant correlations for appearance among fashion images by its frequency through correlation analysis, and (d) it is assumed that fashion images are going to be gradually outstanding according to regression analysis.