• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.798-806
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• 2020

Dental sealant is a procedure to prevent dental caries on the occlusal surface of healthy teeth. Raw data from the 6th-7th Korean National Health and Nutritional Examination Survey (KNHANES) were analyzed. This study was conducted to provide basic data which is necessary for the national health care project and for expanding the standards of coverage for the Dental sealant procedure. In this study, subjects were a total of 4,366 children from the age of 6 to 18 and surveyed for the Amount of Received Dental sealant and rate of Received Dental sealant. In 2012, the coverage rate for pit and fissure sealing procedures differed significantly in terms of age, residential area and average monthly income. This coverage varied as per average monthly income in 2014 and as per age and average monthly income in 2017 (P < 0.05). In 2014, average monthly income had a significant influence on the coverage rate, while age and average monthly income had a significant influence on it in 2017 (P < 0.05). These findings suggest that in order to increase the sealing procedure coverage, continuous promotion of dental sealant projects, reduction of copayments, inclusion of varied tooth types and age groups, expansion of coverage to isolated areas and inclusion of socially disadvantaged groups are necessary.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.75-89
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• 2023

As the Mekong River basin is a nationally shared river, it is difficult to collect precipitation data, and the quantitative and qualitative quality of the data sets differs from country to country, which may increase the uncertainty of hydrological analysis results. Recently, with the development of remote sensing technology, it has become easier to obtain grid-based precipitation products(GPPs), and various hydrological analysis studies have been conducted in unmeasured or large watersheds using GPPs. In this study, rainfall-runoff simulation in the Mekong River basin was conducted using the SWAT model, which is a quasi-distribution model with three satellite GPPs (TRMM, GSMaP, PERSIANN-CDR) and two GPPs (APHRODITE, GPCC). Four water level stations, Luang Prabang, Pakse, Stung Treng, and Kratie, which are major outlets of the main Mekong River, were selected, and the parameters of the SWAT model were calibrated using APHRODITE as an observation value for the period from 2001 to 2011 and runoff simulations were verified for the period form 2012 to 2013. In addition, using the ConvAE, a convolutional neural network model, spatio-temporal correction of original satellite precipitation products was performed, and rainfall-runoff performances were compared before and after correction of satellite precipitation products. The original satellite precipitation products and GPCC showed a quantitatively under- or over-estimated or spatially very different pattern compared to APHPRODITE, whereas, in the case of satellite precipitation prodcuts corrected using ConvAE, spatial correlation was dramatically improved. In the case of runoff simulation, the runoff simulation results using the satellite precipitation products corrected by ConvAE for all the outlets have significantly improved accuracy than the runoff results using original satellite precipitation products. Therefore, the bias correction technique using the ConvAE technique presented in this study can be applied in various hydrological analysis for large watersheds where rain guage network is not dense.

• The Korean Journal of Applied Statistics
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• v.37 no.3
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• pp.297-309
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• 2024

This paper evaluates the performance of the neural network autoregressive model combined with an exponential smoothing model, called the NNARX+ETS model. The combined model utilizes the components of ETS as exogenous variables for NNARX, to forecast time series data using artificial neural networks. The main idea is to enhance the performance of NNAR using only lags of the original time series data, by combining traditional time series analysis methods with the neural networks through NNARX. We employ two real data for performance evaluation and compare the NNARX+ETS with NNAR and traditional time series analysis methods such as ETS and ARIMA (autoregressive integrated moving average) models.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.379-392
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• 2015

Freight flow data in Korea has been collected for a variety of purposes by various organizations. However, since the representation and format of the data varies, it has not been substantially used for freight analyses and furthermore for freight policies. In order to increase the applicability of those data sets, it is required to bring them in a table and compare for finding the differences. Then, it is shown that the raw data can be aggregated by a particular criterion such as mode, origin and destination, and type commodity. This study aims to examine the freight data issue in terms of three different points of view. First, we investigated various freight volume data sets which are released by several organizations. Second, we tried to develop formulations for freight volume data. Third, we discussed how to apply the formulations to network models in which particular OR (Operations Research) techniques are used. The results emphasized that some data might be useless for modeling once they are aggregated. As a result of examining the freight volume data, this study found that 14 organizations share their data sets at various aggregation levels. This study is not an ordinary research article, which normally includes data analysis, because it seems to be impossible to conduct extensive case studies. The reason is that the data dealt in this study are diverse. Nevertheless, this study might guide the research direction in the freight transport research society in terms of data issue. Especially, it can be concluded that this study is a timely research because the governmemt has emphasized the importance of sharing data to public throughout 'government 3.0' for research purpose.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.251-258
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• 2007

Airborne Lidar (light detection and ranging) can be an effective alternative in forest inventory to overcome the limitations of conventional field survey and aerial photo interpretation. In this study, we attempt to develop methodologies to identify individual trees and to estimate tree height from airborne Lidar data. Initially, digital elevation model (DEM) data representing the exact ground surface were generated by removing non-ground returns from the multiple-return laser point clouds, obtained over the coniferous forest site of rugged terrain. Based on the canopy height model (CHM) data representing non-ground layer, individual tree heights are extracted through pseudo-grid method and moving window filtering algorithm. Comparing with field survey data and aerial photo interpretation on sample plots, the number of trees extracted from Lidar data show over 90% accuracy and tree heights were underestimated within 1.1m in average at two plantation stands of pine (Pinus koraiensis) and larch (Larix leptolepis).

• Korean Educational Research Journal
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• v.41 no.2
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• pp.25-53
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• 2020

Purpose: School safety has recently become an important issue. In order to make a school environment safer, surveillance cameras have been installed in the facilities. The number of installations has been increasing rapidly since they have been considered widely recognizable and highly effective. However, conflicts between faculty and staff in installing and operating the system have also been increasing. In terms of school safety, these individuals'' cooperation is more than necessary. It is judged that looking into how they perceive the system could provide us with some suggestions on how to manage the related issues. The purpose of this study is to understand the perspective of faculty over closed-circuit television (CCTV) and make suggestions by analyzing their actions. Approach: In order to achieve the research objectives, I surveyed administrative actions such as the processing of official documents and CCTV policies for teachers and administrative staff of public schools in the Sejong Office of Education. In addition, I analyzed the behavior of those managing personal information and school safety-related documents along with the degree of complying with the policies. Finding: First, the correspondence rate of documents was high when there were designated document processors. Second, the acceptance level of documents in preschool was relatively low when there were designated processors. Third, the degree of accepting the policies and complying with them was higher in newly established schools than in existing schools. I found differences in the perception of how to handle the CCTV operations and the related work among the two groups of participants. In addition, I made suggestions on how to resolve the conflicts between them. Value: In this study, the education authorities quantified and measured the recognition and acceptance of faculty and staff regarding CCTV at each school level. Results showed that the active role of education authorities can make positive changes in how faculty and staff perceive the CCTV system and the problems surrounding it through school administrative action. In this regard, these results are meaningful in reducing the conflicts among the two groups and improving the organizational culture.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.218-228
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• 2013

The objective of this study was to investigate the prevalence rate and correlates of weight control behaviors among adolescents in Korea. We analyzed data on 37,472 adolescents aged 12-18 years from the 2011 7th Korea Youth Risk Behavior web-based Survey. The results of this study was as following. First, the prevalence rate of healthy, unhealthy and extreme weight control behaviors was significantly higher in girls than in boys. Second, in both genders, healthy and unhealthy weight control behaviors were more common among obese adolescents than non-obese adolescents. But, use of diet pills were not prescription by doctor was more common in underweight boys and obese girls than others. Third, gender, school, family affluence scale, mother's education level, body shape perception(BSP), weight status predicted prevalence rate of healthy weight control behaviors. Gender, school, region, father's education level, BSP predicted prevalence rate of unhealthy weight control behaviors. Gender, school, BSP, weight status predicted prevalence rate of extreme weight control behaviors. These findings suggest the needs to design appropriate prevention program that can induce healthy weight control behaviors.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.336-344
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• 2015

This study evaluated the association between metabolic syndrome(MetS), its components and depression among Korean community-dwelling older adults. We analyzed data from the fifth Korea National Health and Nutrition Examination Survey(KNHANES-V) 2010-2012. This study was a descriptive study of 3,755 Korean elderly, aged 65 years and older. A modified version of the criteria of the National Cholesterol Education Program, Adult Treatment Panel III was used to define MetS. Depressive symptoms were assessed using the questionnaire of the KNHANES-V. Multiple regression analyses performed the association between MetS, its components and depression. MetS was not statistically associated depressive symptoms, but low high-density lipoprotein cholesterol(HDL-C) was statistically associated depressive symptoms(Odds raio[OR]=1.26, 95%Confidence Interval [CI]=1.002-1.584) in older adults. Among elderly women, MetS(OR=1.36, 95%CI=1.029-1.792), elevated fasting glucose(OR=1.41, 95%CI=1.070-1.851), low HDL-C(OR=1.21, 95%CI=1.078-1.746) were statistically associated depressive symptoms. In conclusion, present study showed an association between MetS and depressive symptoms in Korean community dwelling elderly women but not in men.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.225-235
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• 2020

The Korean government is attempting to promote technology-based start-ups and venture firms that can lead to new national growth engines being developed. Although government support policies focus on improving survival rates, strategic tools for sustainability management based on a continuing company's assumption are also relevant. Previous studies indicate corporate social responsibility (CSR) as an important strategic tool for the management of corporate sustainability. This research is an exploratory study that seeks to empirically analyze the applicability of such CSR to venture firms. Existing previous studies have been carried out by large companies and surveys, and there are limitations that do not reflect the characteristics of companies. To complement the shortcomings of previous studies and propose practical consequences, this study conducted an empirical analysis using raw data from government approval statistics to identify the growth stages of venture firms. Using the 2018 Survey of Korea Venture Firms, we identified the growth stages of domestic venture firms and used the data envelopment analysis (DEA) to investigate the effect of CSR activities on managerial efficiency. The analysis found that CSR during start-up and early growth cycles did not affect managerial performance. The organization that conducted enthusiastic CSR activities performed better than those that did not perform CSR activities since the rapid growth era. Ultimately, the scale efficiency of venture business was the highest from the rapid growth era when the CSR was not done. This study is a pioneering study that found that after the period of high growth, venture firms' CSR activities can affect managerial performance. Therefore, it is important to advise applicable policies and business decision-makers that CSR practices can be a tactical resource for improving performance of management.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.319-327
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• 2016

The objective of this study is to identify the secular trend in age at menarche and to investigate the factors influence the early menarche(<12 years old) among Korean middle and high school girls. We analyzed data from the Korean Youth Risk Behavior Web-based Survey(KYRBWS) 2006-2014. This study was a descriptive study of 216,917 Korean middle and high school girls born between 1988 and 2002. Linear trends test performed to assess the trend age at menarche and percentage of early menarche. Multiple logistic regression analysis was to assess the risk factors influence the early menarche. Mean age at menarche decreased from $12.61{\pm}1.32$ years for middle and high school girls born 1988 to $11.88{\pm}0.75$ years for those born 2002(p for trends<.001). Percentage of early menarche increased from 19.7% to 25.2% between 1988 and 2002(p for trends<.001). Living in city, higher stress level, short sleep duration, and higher body mass index were associated with an early menarche among middle and high school girls(all p<.001). We found that age at menarche is still falling in the Korean adolescents, and it need intervention strategies to control the early menarche.