• Structural Monitoring and Maintenance
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• 제10권2호
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• pp.175-190
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• 2023

This article aims to quantitatively predict the snowmelt in extreme cold regions, considering a combination of grayscale and neural models. The traditional non-equidistant GM(1,1) prediction model is optimized by adjusting the time-distance weight matrix, optimizing the background value of the differential equation and optimizing the initial value of the model, and using the BP neural network for the first. The adjusted ice forecast model has an accuracy of 0.984 and posterior variance and the average forecast error value is 1.46%. Compared with the GM(1,1) and BP network models, the accuracy of the prediction results has been significantly improved, and the quantitative prediction of the ice sheet is more accurate. The monitoring and maintenance of the structure by quantitative prediction model by gray models was clearly demonstrated in the model.

• 한국지반공학회논문집
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• 제16권3호
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• pp.5-13
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• 2000

본 연구에서 흙(사질토)-구조물의 경계면에 대한 거동특성을 분석하기 위하여 교란상태개념(DSC)을 수정 및 보완하였다. 제안한 DSC모델에서는 변형중인 재료는 상대적으로 손상되지 않은 상태(RI)와 완전 파괴된 상태(FA)가 혼합되어있다는 가정에 기초를 두고 있다. RI 상태는 HiSS모델을 이용하였고, FA 상태는 한계상태모델을 이용하였다. 이런 DSC 모델을 Biot이론에 기초한 기존 유한요소 프로그램에 접목하였다. 본 연구에서 수저한 유한요소 프로그램을 이용하여 실제 경계면 실험(두 가지 하중조건: 정하중, 동하중)에 대하여 모의실험을 수행하였다. 또한 그 결과와 실내시험결과를 비교 검토하였다. DSC모델을 이용한 유한요소해석은 실제 실내시험 결과와 유사한 경향을 보였다. 본 연구의 결과를 통하여, DSC모델을 흙-구조물 경계면 해석에 비교적 합리적인 결과를 제공한다고 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.10027-10031
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• 2014

Background: We investigated the risk of cancer mortality according to obesity status and metabolic health status using sampled cohort data from the National Health Insurance system. Materials and Methods: Data on body mass index and fasting blood glucose in the sampled cohort database (n=363,881) were used to estimate risk of cancer mortality. Data were analyzed using a Cox proportional hazard model (Model 1 was adjusted for age, sex, systolic blood pressure, diastolic blood pressure, total cholesterol level and urinary protein; Model 2 was adjusted for Model 1 plus smoking status, alcohol intake and physical activity). Results: According to the obesity status, the mean hazard ratios were 0.82 [95% confidence interval (CI), 0.75-0.89] and 0.79 (95% CI, 0.72-0.85) for the overweight and obese groups, respectively, compared with the normal weight group. According to the metabolic health status, the mean hazard ratio was 1.26 (95% CI, 1.14-1.40) for the metabolically unhealthy group compared with the metabolically healthy group. The interaction between obesity status and metabolic health status on the risk of cancer mortality was not statistically significant (p=0.31). Conclusions: We found that the risk of cancer mortality decreased according to the obesity status and increased according to the metabolic health status. Given the rise in the rate of metabolic dysfunction, the mortality from cancer is also likely to rise. Treatment strategies targeting metabolic dysfunction may lead to reductions in the risk of death from cancer.

• 대한안전경영과학회지
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• 제16권3호
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• pp.451-469
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• 2014

The purpose of this study is to implement and develop the integrated Economic Value Added (EVA) and Time-Driven Activity-Based Costing (TDABC) model to seek both improvement of Net Operating Profit Less Adjusted Tax (NOPLAT) and reduction of Capital Charge (CC). Net Operating Profit Less Adjusted Tax (NOPLAT) can be maximized by reducing the indirect cost of an unused resource capacity increased by Cost Capacity Ratio (CCR) of TDABC. On the other hand, Capital Charge (CC) can be minimized by improving the efficiency of Invested Capital (IC) considered by Weighted Average Cost of Capital (WACC) of EVA. In addition, the integrated system of TDABC using Balance Scorecard (BSC) and EVA is developed by linking between the lagging indicators and the three leading indicators. The three leading indicators include customer, internal process and growth and learning perspectives whereas the lagging indicator includes NOPLAT and CC in terms of financial perspective. When the Critical Success Factor (CSF) of BSC is cascading as a cause and an effect relationship, time driver of TDABC and capital driver of EVA can be used efficiently as Key Performance Indicator (KPI) of BSC. For a better understanding of the proposed EVA/TDABC model and BSC/EVA/TDABC model, numerical examples are derived from this paper. From the proposed model, the time driver of TDABC and the capital driver of EVA are known to lessen indirect cost from comprehensive income statement when increasing the efficiency of operating IC from the statement of financial position with unified KPI cascading of aligned BSC CSFs.

• 한국치위생학회지
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• 제20권4호
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• pp.435-445
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• 2020

Objectives: This study investigated the relationship between obesity and dental caries of Korean adolescents. Methods: Data from the Korea National Health and Nutrition Examination Survey (KNHNES VI) (2013 to 2015) were used and targeted adolescents aged 13 to 18 years. For statistical analysis, the SPSS 18.0 program was used, and the significance level was set at 0.05. Results: For the general and health-related characteristics, female students (p=0.001) showed higher decayed, missing, and filled teeth (DMFT) index than male students. Furthermore, DMFT showed higher tendency, as age was higher (p<0.001). Smoking (p=0.011) and drinking experience (p=0.027) revealed higher DMFT. The dental caries experience was significantly different among students who were female (p=0.033), older (p=0.001), and overweight or underweight (p=0.022). In the BMI for the general and health-related characteristics, male students had higher obesity rate than female students (p=0.003), and obese subjects had higher dental checkup in the last year (p=0.013). In multiple linear regression analysis of obesity and DMFT, the unadjusted model showed that the obesity group's DMFT was about 0.8 higher than that of the normal group (p=0.024). However, statistical significance was not shown in the adjusted models. In the logistic regression analysis of obesity and dental caries experience, the unadjusted model 1 (1.93 times), the adjusted model 2 (1.79 times), and model 3 (1.76 times) showed significantly higher dental caries experience. Conclusions: Both obesity and dental caries are related to diet habits and lifestyles and have a negative impact on adult health. Therefore, it is necessary to create a healthy social environment around the adolescent, and proper intervention through education is required to form healthy habits.

• 한국콘텐츠학회논문지
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• 제21권2호
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• pp.395-405
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• 2021

본 연구는 원격 PBL 수업에서 몰입수준에 대한 성취목표지향성과 학습동기의 관계에서 흥미 수준의 매개 효과를 탐색하기 위해서 수행되었다. 선행연구 분석을 통해 몰입과 관련된 학습 요인들을 분석하여 이론적으로 구조모형을 구성하였다. 이론적으로 구성된 구조모형 검증을 위해 교직과목을 수강하는 사범학부 59명의 학생을 대상으로 하였다. 자료수집은 원격으로 PBL 수업을 수행한 이후 몰입, 성취목표지향성, 학습동기, 흥미수준을 설문을 통해 수집하였고, 수집된 자료는 구조방정식 모형 분석 방법을 사용하여 몰입에 대한 성취목표지향성과 학습동기, 흥미수준의 영향의 구조적 관계에 대해 분석하였다. 그 결과 본 연구에서 제안한 구조적 모형이 타당한 것으로 검증되었다. 이에 성취목표지향성과 학습동기의 영향을 흥미수준이 매개하여 몰입에 영향을 주는 것으로 검증되었으며, 성취목표지향성의 영향을 흥미수준이 매개하는 경로가 가장 큰 영향력을 가지고 있는 것으로 검증되었다. 이에 원격 PBL수업을 운영할 때, 학습자들의 성취목표 지향성을 고려하여 흥미수준을 조절한다면 몰입수준을 조절할 수 있다는 시사점을 제시할 수 있다.

• 대한예방한의학회지
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• 제25권2호
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• pp.85-98
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• 2021

Objectives : This study aimed to analyze characteristics of the Korean Medicine users aged 19-39 years, the determinants of Korean Medicine use and effects of Korean Medicine use experience on behavioral intentions among youths. Methods : We studied Korean Medicine Utilization and Herbal Medicine Consumption Survey(2017) data set by complex-sample survey data analysis. In order to derive the characteristics of younger users, Rao-scott χ² test and t-test were conducted. Through multiple logistic regression model adjusted by general characteristic variables, the determinants and behavioral intentions of the Korean Medicine utilization among youths were derived. Results : Fist of all, young users and non-users have significant differences in socio-demographic characteristics and perception on Korean Medicine. Among the general characteristic variables, region, age, marital status, occupation, chronic disease, and private health insurance plans had an effect on the Korean Medicine use in young people(Model II). And adjusted by general characteristic variables as control variables, awareness of Korean Medicine and perception of safety of herbal medicine were deduced as determinants of Korean Medicine use(Model III). Secondly, Korean Medicine use experience increased intentions to use and recommend Korean Medicine services(Model IV-1, 3). Conclusions : In order to increase the use of Korean Medicine among young people, Korean Medicine institutions should strive to increase users' satisfaction, and public health insurance coverage for Korean Medicine services needs to be expanded.

• 한국병원경영학회지
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• 제12권3호
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• pp.47-67
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• 2007

This paper aims at suggesting several ways lo change financial vulnerability and to improve managerial capability of local public hospitals (LPHs) in Korea through the identification of factors affecting profitability. Several findings of the research are as follows: To begin with, LPHs exhibited a statistically significant difference in their profitability from one another, according to tile analyses of their profitable margins from tile general characteristics. It depends on the number of hospitals in the area, the population of the hospital-built area, the number of competing hospitals, the number of staff per 100 beds, the opening of special clinic, the educational function, and the capacity of rooms. However, there was no variable in the managerial characteristics, presenting a significant difference, in contrast with hospitals which have been managed by private companies and made a great amount of profits. Second, according to the analyses of profit differences in behavioral effort-characteristics, a statistically significant difference was revealed upon the basis of the efforts to improve the clinic service, invite special patients, and shorten the period of being hospitalized. Third, the result of analyses about the difference of profitability from medical care and finance is statistically significant in the rate of labor cost, the rate of management cost, bed-occupancy rate, and the period of being hospitalized. Fourth, according to the analyses of the factors influencing the net profit ratio of the entire capital, Adjusted explanatory power(Adjusted $R^2$) was shown up to 65.2%, which is high. To compare the adjusted explanatory power stage by stage, the first stage model applying only two variables such as structural and strategic characteristics exhibited 23.8%, and the second stage model adding financial characteristics showed 51.5%. The explanatory power was much improved up to 65.2% when the third stage model incorporated the outcome of medical care performance. When the return on investment(ROI) was examined by using the multi-variate linear regression analysis at the final model of third stage, it was found that ROI had a positive relationship with the increase rate of patients, labor costs per doctor, and medical care rate of socially protected inpatients. However, it revealed that ROI had a negative relationship with the ratio of labor costs, the number of patients per managerial staff, and occupancy rate of rooms, respectively. The research suggests that in order for LPHs to increase profitability, LPH, should make efforts not only to attract patients to the hospitals without any discrimination of the patients depending on their financial status, but also to develop efficient management methods to reduce labor costs.

• 한국환경보건학회지
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• 제45권1호
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• pp.30-41
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• 2019

Objectives: The effects of particulate matter and ozone on health are being reported in a number of studies. These effects are likely to be stronger on the elderly population, but studies in this regard are scarce. The purpose of this study was to examine the effects of particulate matter ${\leq}2.5{\mu}m$ and ozone on the acute health status of the elderly population. Methods: In order to analyze the health status of the elderly population, the NHIS-Senior Cohort data was used. In this study of people 60 years or older in Seoul, the number of outpatient visits and ER visits between 2002 and 2013 were calculated. Each disorder and the lag effect were analyzed separately. Particulate matter and ozone were analyzed using both the single exposure model and the adjusted multi-exposure model. Results: In the single exposure analysis with PM2.5 as the exposure variable, with each increase of $10{\mu}g/m^3$, the number of outpatient visits increased by 1.0081 times, vascular disease 1.0065 times, chronic pulmonary disease 1.0086 times, and diabetes 1.0055 times. In the multi-exposure model adjusting for ozone, the number of outpatient visits increased by 1.0066 times. There was a one-day lag effect and 1.0066 times increase between PM2.5 and ER visits in the multi-exposure model and 1.0057 times when adjusted for ozone (p value <0.10). There was a one-day lag effect in all multi-exposure models with ozone as the main variable, and when the particulate matter was adjusted, there was a one-day delay and 1.0143 times increase in ER visits. Conclusions: In our study, an increase in the number of outpatient and ER visits in the elderly population in accordance with the increase in PM2.5 and ozone was found. The association found in our study could also produce a socioeconomic burden. Future studies need to be performed in regards to younger populations and other air pollutants.

• 설비공학논문집
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• 제17권11호
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• pp.1060-1071
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• 2005

Passive gas dispersions over a 1/1000 scale terrain model at Eiffel type wind tunnel were reproduced by numerical simulation. Large eddy simulation was used to treat the sub-grid scale turbulences. The terrain features were represented by millions of point forces densely distributed over the solid surface using the virtual boundary method. The model simulations agreed very well with the experiments in a consistent fashion for all wind directions. The measured profiles of the wind speeds as well as the tracer gas concentrations were nicely simulated by the CFD model at most locations scattered over the model terrain. With scale factor adjusted and the thermal stratification effects incorporated, the CFD model was expected to provide reliable information on pollutant dispersions over the real complex terrains.