• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.77-86
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• 2020

In this study, the importance of implied strength correction for shallow depths at a region of moderate to low seismicity with primary focus on its effect upon site natural period and mean period of the ground motion is investigated. In addition to the most commonly used Modified Kondner-Zelasko (MKZ) model, this paper uses a quadratic/hyperbolic (GQ/H) model that can capture the stress - strain response at large strains as well as small strain stiffness dependence. A total of six site profiles by downhole tests are used and 1D site response analyses are performed using three input motions with contrasting mean periods. The difference between non-corrected and corrected analyses is conditional on the site period as well as mean ground motion period. The effect of periods is analyzed by correlating them with the effective peak ground acceleration, maximum shear strains and amplification factors. The comparative study reveals that the difference is more prominent in soft sites with long site periods. Insignificant differences are observed when soil profiles are subjected to ground motion with very short mean period.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.436-448
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• 2020

This study aims to determine the effect of e-cigarettes on oral health by investigating the association between the use of different tobacco products and oral health among Korean adults aged 19 years and older. Data from the 2017 Community Health Survey were used for the study. Respondents were divided into four groups: non-smokers, cigarette smokers, e-cigarette smokers, and users of both products. A sample of 228,357 respondents was selected for analysis. Twenty-four questionnaires with missing values (non-response or refusal) were excluded from the sample. A regression analysis was performed with oral as the dependent variable. A multivariate regression analysis showed a significant difference between cigarette smokers and users of both products when compared to the non-smokers. However, e-cigarette users showed a significant when the variables were correlated with age and gender. There was no significant difference in other dependent variables in a multivariate regression analysis. The results of the study indicated no association between e-cigarette use and oral health. More research is needed on factors such as amount and intensity of e-cigarette use.

• Journal of Labour Economics
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• v.39 no.3
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• pp.99-124
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• 2016

This study analyzed the effects of labor unions on the wages of Korean female workers using 'Korean Labor and Income Panel Study.' In the estimation we considered the self-selection bias due to the women's labor force participation decision and a plausible non-response bias from not answering the question about the company size in terms of number of employees. By fixed effect estimation we found that labor unions in Korea do not increase the wages of both the female union workers and non-union workers who work at a company in which a union is organized comparing to female workers who work at company without a union. This results indicates that female workers who work in the company with labor union tend to have unobserved characteristics that are positively correlated with both wages and the probability to enter the company with labor union. We also came to the conclusion that there is no free-rider effects of non-union workers.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.6
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• pp.261-270
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• 2017

With the development of smart on-devices and communication technology, demand for non-stop services is increasing. Therefore, the high availability for continuously providing services in the event of system failure has been spotlighted. Meanwhile, because most internet-based services are provided by using TCP, an efficient TCP session recovery technique for providing non-stop services is required. However, the existing TCP session recovery techniques are inefficient because it has a high recovery cost or does not support failover operation, To solve these problems, in this paper, we propose a TCP session recovery technique for high availability in smart on-devices. For this, we first recover the TCP session without re-establish the TCP session by correcting a sequence number and a acknowledgment number. Second, we synchronize the TCP session recovery data between the master and the server, and then we operate the failover operation when master server fails. Finally, we provide the non-stop service to peer by using the virtual IP number and the transmission of GARP (Gratuitous ARP) packet.

• Journal of Nutrition and Health
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• v.54 no.5
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• pp.501-514
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• 2021

Purpose: The purpose of this study was to provide basic data for the management of atopic dermatitis (AD) in adults by analyzing the relationship between AD and intake of soft drinks in adults. Methods: This study was conducted on 5,931 adults aged 19 to 64 who completed the food frequency questionnaire (FFQ) for participants in the Korea National Health and Nutrition Examination Survey VII-3 and VII-1. Subjects were divided into an AD-diagnosed group and a non-AD group according to the diagnosis of AD. In addition, the group diagnosed with AD was divided into a 'symptom-AD' group and a 'no symptom-AD' group. The amount, frequency of intake, and nutritional status of soft drinks were analyzed using the FFQ. Results: Compared with the nutrient intake per 1,000 kcal of energy consumption, fat intake was higher in the AD-diagnosed group than in the non-AD group, and carbohydrate, dietary fiber, calcium, phosphorus, iron, potassium, vitamin A, thiamin, and vitamin C were lower in AD-diagnosed group. The daily intake of soft drinks and the percentage of 'more than 0.5 servings per day' were also higher in the AD-diagnosed group than in the non-AD group. Also, the frequency of the intake of soft drinks was significantly higher in the AD-diagnosed group than in the non-AD group. The odds ratio of AD symptoms due to the intake of soft drinks increased 2.6 times when the intake was 'less than 0.5 serving per day'. Conclusion: AD in adults appears to be related to malnutrition and excessive consumption of soft drinks, and the current prevalence of AD symptoms may also be related to the intake of soft drinks. Based on these results, we suggest that one of the ways to manage AD in adults would be to limit their intake of soft drinks.