• 한국치위생학회지
• /
• 제17권3호
• /
• pp.539-551
• /
• 2017

Objectives: The purpose of this study was to investigate the changes in factors on unmet dental scaling rate before and after the national health insurance. Methods: This study used the $2^{nd}$ data from the Community Health Survey. The study participants numbered 209,341 in 2011 and 219,517 in 2013.The average age was $51{\pm}17$ in 2011 and $52{\pm}17$ in 2013. Data were analyzed by descriptive statistics, chi -squared test and logistic regression using SPSS 23.0. Results: The scaling experienced rate of Korean adults has fallen by 3.5% from 66% to 69.5%. Logistic regression analysis showed that 2.7 times more 'people who were educated at elementary school level or lower' did not use dental scaling compared to higher educated children. Agriculture, forestry and fisheries workers did not use scaling at 2.0 times. Local residents with an income of less than one million won did not use 1.7times scaling. Local residents of 'no private insurance' did not use scaling at 1.5 times. In the case of the predisposing factors, the 20s had less than 1.8 times scaling compared to 50s. In the case of needs factor, local residents who experienced 'bad oral health status' and 'dental calculus' were treated scaling 1.3 times less compared to people with good oral health status and normal periodontal symptoms. Conclusions: In Korea, local residents are less frequently treated scaling due to enabling factors such as accessibility. In addition, predisposing factors such as age and sex, and oral health status and periodontal symptoms were related to not using the dental scaling. Therefore, the universality of health care services should be considered so that people who need periodontal care can use scaling.

• 한국환경복원기술학회지
• /
• 제18권3호
• /
• pp.65-77
• /
• 2015

The urban park has important functions as a habitat for wildlife as well as open space of rest and community for people. This study was carried out to find what factors of structure and vegetation of urban parks could affect forest bird species diversity in Cheonan city. The study surveyed bird and vegetation species in 26 urban parks, Cheonan city. A correlation analysis and multiple linear regressions were performed to test whether habitat structure and vegetation were the major correlate with species diversity. The results showed the Dujeong park was the most high bird species diversity (H' = 2.13), and the Dujeong-8 park (H' = 2.02) and the Cheongsa park (H' = 1.73) were considerably higher than the other urban parks. The variables that were strongly correlated with bird species diversity were park area, number of subtree species, canopy of shrub, number of shrub species, shape index, canopy of subtree, canopy of tree, and impervious surface ratio. The regression of bird species diversity against the environmental variables showed that 3 variables of park area, canopy of subtree, and canopy of tree were included in the best model. Model variable selection was broadly similar for the 5 optimal models. It means park area and multi-layer vegetation were the most consistent and significant predictor of bird species diversity, because urban parks were isolated by built-up areas. Especially the subtree coverage that provides shelter and food for forest birds was an important variable. Therefore, to make parks circular-shaped and abundant multi-layer vegetation, which could be a buffer to external disturbances and improve the quality of habitats, may be used to enhance species diversity in creation and management of urban parks.

• Journal of Biosystems Engineering
• /
• 제42권4호
• /
• pp.258-264
• /
• 2017

Purpose: This study determines the spray characteristics and effective spray width of a tractor-mounted commercial boom sprayer through experiments. Methods: Performance tests were conducted to investigate the spray characteristics of the nozzles on a commercial boom sprayer. The flow rate and spray width of a single nozzle were measured at three levels of spray pressure (0.5, 0.7, and 1.0 MPa) and spray height (15, 30, and 45 cm), respectively. The average value of three repetition tests was used as the representative value. A coefficient of variation (CV) was used as an index of spray uniformity, and the width that guarantees CV values of approximately 15% was determined as the effective spray width. The spray characteristics of the overall boom sprayer were derived analytically by superimposing the spray characteristics of a single nozzle. Results: The test results for a single nozzle showed that the spray width tended to increase as the spray height and spray pressure increased. The effective spray width for a single nozzle was the largest at a spray pressure of 1.0 MPa and spray height of 45 cm, which resulted in a coverage of 84 cm of width. The effective spray width for the entire boom sprayer was also the largest at the spray pressure of 1.0 MPa and spray height of 45 cm, with a magnitude of 424.5 cm. The chemical spraying work in an actual field was simulated by applying a spray width of 400 cm. As a result of the operation for three swaths, the CV value was less than 10% for 1,200 cm of the overall spray width, which meant that uniform application was achieved. Conclusions: It was reasonable to set the effective spray width of the boom sprayer used in this study to 400 cm.

• 한국환경복원기술학회지
• /
• 제11권5호
• /
• pp.92-103
• /
• 2008

Development of new approaches to achieve naturally good ecological potential of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials to prevent slope failure and erosion, in the area with highly erodible soil. As a result on the type analysis of gabion systems already installed in road cut-slopes, gabion systems were generally established to prevent slope failure. Existing gabion systems can be divided into monolithic and modular system and can be divided into ten subtypes according to the purpose of establishment and combination of other measures. As a result on the monitoring of erosion amount from forest road cut-slopes in the test applications, the order of erosion amount from largest to smallest is as follows : the curved road cut-slope site where normal gabion system was established ($7,911cm^3$); the control site ($7,632cm^3$); the straight road cut-slope site where normal gabion system was established ($7,301cm^3$); the curved road cut-slope site where the new gabion system was established ($5,684cm^3$); and the straight road cut-slope site where the new gabion system ($5,325cm^3$). Therefore, the result shows that the new gabion system is more effective than the normal gabion system to reduce erosion amount from forest ! road cut-slopes. During the study period, vegetation coverages of the straight and curved road cut-slope site where the new gabion system was established were about 45% and about 36%, so average vegetation coverage of the sites where the new gabion systems was established was higher than the sites where the normal gabion systems was established. Therefore, it was concluded that the new gabion system can be more effective for cut-slope revegetation.

• 보건행정학회지
• /
• 제22권2호
• /
• pp.207-224
• /
• 2012

This study estimates the total health expenditure of ambulatory dental care and explores the factors related to disbursements. The study used two waves of a 2008 Korea Health Panel (KHP) survey, of which each wave is composed of 7866 households and 24,659 persons. The KHP includes missing expanses of reimbursement data of the National Health Insurance (NHI), such as out-of-pocket, drugs, and private health insurance. The study estimates total monthly ambulatory dental expenditure and the sub-special categories of dental care. For influential factors analyses, the study exploits log-linear model with age, gender, education, job, equivalence income, the status of chronic diseases, means-tested benefit recipients, private insurance, and the composite deprivation index as independent variables. The total monthly outpatient health spending is estimated to be 102,468 won per household, and for dental, each household spends 31,115 won per month. Older age, means-test recipients, non-regular workers are more likely to spend less money on dental care, whereas private insurers, high income, and those who live in less deprived areas are more likely to spend more money for dental services. From the study we found that the KHP data are more suitable to estimate the total amount of health care markets, especially when the NHI coverage is low, such as for dental care in Korea.

• 한국항공우주학회지
• /
• 제41권12호
• /
• pp.931-939
• /
• 2013

본 논문에서는 항공기 날개의 개념 설계에서 적용하기에 적합한 양력선 방법을 찾고 정확성과 적용범위를 분석한다. Prandtl의 양력선 이론에서 발전된 두 가지 양력선 방법으로서 얇은 익형의 가정을 갖고 3/4 시위의 제어점에서 속도경계조건을 부여하는 Weissinger방법과 3차원 와류 양력법칙을 적용한 Phillips의 방법을 택하였다. 계산 대상은 타원형 날개, 후퇴각이 있는 날개, 그리고 상반각과 비틀림이 있고 후퇴각 없는 테이퍼 날개이다. 계산을 통해 포텐셜 유동의 공력 데이터로 날개의 순환분포, 내리흐름 분포, 양력과 유도항력을 추출하여 이론식 결과 및 풍동시험 데이터와 비교하였다. Weissinger 방법은 날개의 형상에 상관없이 정확도와 신뢰성 있는 결과를 보여주지만 Phillips 방법은 후퇴각이 있는 날개에서는 부정확한 결과를 나타내었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권9호
• /
• pp.4122-4143
• /
• 2018

Because of the increment in network scale and test expenditure, simulators gradually become main tools for research on key problems of wireless networking, such as radio resource management (RRM) techniques. However, existing simulators are generally event-driven, causing unacceptably large simulation time owing to the tremendous number of events handled during a simulation. In this article, a mass-processing framework for RRM simulations is proposed for the scenarios with a massive amount of terminals of Internet of Things accessing 5G communication systems, which divides the time axis into RRM periods and each period into a number of mini-slots. Transmissions within the coverage of each access point are arranged into mini-slots based on the simulated RRM schemes, and mini-slots are almost fully occupied in dense scenarios. Because the sizes of matrices during this process are only decided by the fixed number of mini-slots in a period, the time expended for performance calculation is not affected by the number of terminals or packets. Therefore, by avoiding the event-driven process, the proposal can simulate dense scenarios in a quite limited time. By comparing with a classical event-driven simulator, NS2, we show the significant merits of our proposal on low time and memory costs.

• 한국병원경영학회지
• /
• 제22권2호
• /
• pp.58-69
• /
• 2017

Recently, with the increase in the number of private health insurance subscribers, interest in overuse of the medical service is increasing. This study analyzed the impacts of private health insurance (PHI) on medical institution selection in outpatient service utilization among persons with arthritis. In order to control patients' health status, we extracted outpatient episodes with the same disease (KCD6, M13) from Korea Health Panel. The unit of analysis was an outpatient visit with arthritis in 2014 (n=23,363). In the light of insurance coverage, we redefined three type of private health insurance (ex, indemnity, fixed benefit, and non-insured) as a test variable and two type of medical institution (ex, hospital and physician visit) as a dependent variable. We conducted a probit regression analysis to identify the impacts of PHI on medical institution selection controlling for heteroscedasticity. The results of this study showed that the insured with indemnity were more likely to choose hospital departments than clinics (marginal effect=0.0475, p=0.000). The impact of participation of fixed benefit PHI was not as clear as that of indemnity type (marginal effect=0.0162, p=0.047). In conclusion, this study confirmed that PHI, particularly indemnity type has a significant impact on the selection of medical institutions. Healthcare policy makers should consider that PHI not only affects the overall quantitative increase in healthcare utilization, but also influences the selection of medical institutions.

• Safety and Health at Work
• /
• 제4권3호
• /
• pp.166-176
• /
• 2013

Background: Effective policy implementation is essential for a healthy workplace. The Ryan-Kossek 2008 model for work-life policy adoption suggests that supervisors as gatekeepers between employer and employee need to know how to support and communicate benefit regulations. This article describes a workplace intervention on a national employee benefit, Family and Medical Leave Act (FMLA), and evaluates the effectiveness of the intervention on supervisor knowledge, awareness, and experience with FMLA. Methods: The intervention consisted of computer-based training (CBT) and a survey measuring awareness and experience with FMLA. The training was administered to 793 county government supervisors in the state of Oregon, USA. Results: More than 35% of supervisors reported no previous training on FMLA and the training pre-test revealed a lack of knowledge regarding benefit coverage and employer responsibilities. The CBT achieved: (1) a significant learning effect and large effect size of d = 2.0, (2) a positive reaction to the training and its design, and (3) evidence of increased knowledge and awareness regarding FMLA. Conclusion: CBT is an effective strategy to increase supervisors' knowledge and awareness to support policy implementation. The lack of supervisor training and knowledge of an important but complex employee benefit exposes a serious impediment to effective policy implementation and may lead to negative outcomes for the organization and the employee, supporting the Ryan-Kossek model. The results further demonstrate that long-time employees need supplementary training on complex workplace policies such as FMLA.

• 산업경영시스템학회지
• /
• 제22권51호
• /
• pp.199-210
• /
• 1999

The number of car accident is Recently on the increase in Korea because of the explosive increase of cars, the poor road condition, the lack of safety facility, and others. The insurant with a accident has to decide whether receiving a insurance or not. In this paper, we represent a reasonable decision support material by calculating the approximate insurance fee based on the discount rate and premium additive rate, which is changed by the accident type and the accident expenditure. Practically, there is difference in the standard insurance rate and premium additive rate according to the accident type and the accident expenditure in Korea. The premium additive rate is assessed considering the number of accident, the pattern of accident, and the reason of accident for 3 years. In this paper, we represent a decision making method considering not only the first-time car accident but also the future car accident. For considering the repeated accident, we analyzed the real data accumulated until the year of 1996 from S Insurance Company, and estimated the probability density function between the first and the second-time accident, and executed the goodness of fit test using ARENA and STATISTICA software. Using this conditional PDF, we can calculate the insurance fee next 3 years and compare the insurance fee with the equivalent present value of cash flows. The program performing this analysis is represented, and written in VISUAL BASIC Language. We tried to suggest an accurate guideline for the insurant to decide the insurance coverage rationally, and tried to correct a wrong idea of dependence on the car insurance only by the amount of the accident expenditure. And we expect this study can generally be applied to many different accident types under the uncertain circumstances in our daily life.