• Journal of Preventive Medicine and Public Health
• /
• 제22권1호
• /
• pp.81-89
• /
• 1989

The authors investigated mortality rate of hospitalized CWP(coal workers' pneumoconiosis) patients. Date, which was composed of age, date of hospitalization, date of death, and radiological findings(profusion of small opacity, type of large opacity, tuberculosis, emphysema, pneumothorax, and cardiac abnormality), was gathered from medical charts and chest x-ray films at the time of hospitalization of CWP patients. Among 738 CWP patients, that were entered survey differently and have followed different period, 160 CWP patients were died during different observational period. Mean value of observational period was 203 weeks, and mean age at hospitalization was 51 years. Because of short observational period, mean survival time could not found. There was statistically significant difference of mortality rate between group of small opacity and that of large opacity. In group of small opacity 5 year survival rate was 0.80 and in group of large opacity that was 0.73. And 80 percentile survival time was 57 months in group of small opacity and that was 40 months in group of large opacity.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
• /
• pp.11-26
• /
• 1997

It has knows that the seismicity of the Korean Peninsula is relatively inactive than those of adjacent northern China and southwestern Japan. Recently the review of long term historical records and recent seismicity. In addition, it is considered that the modern society is more vulnerable to seismic hazard because of high urbanization and industrialization. From this viewpoint, the improvement and modification of the present regulation for aseismic design is strongly proposed. The purpose of the present study is to prepare seismic hazard maps for Korea to be used in improving the present regulation. The present study was performed as a cooperative project of eight Korean seismologists. Each seismologist calculated independently seismic hazard value at the given grid points based on his own judgement about methodology and seismicity. Then the values are unified with equal weight to produce a seismic hazard map. Seven seismic hazard maps for peak acceleration with 10 percentile probability of exceedance in 5, 10, 20, 50, 100, 250, 500 years are presented. This probability of exceedancd in such years corresponds to return period of 48, 95, 190, 475, 950, 2373, 4747 years, respectively. It is recommended to use a hazard map to be selected on the basis of the importance and the design level of structures.

• Advances in environmental research
• /
• 제1권2호
• /
• pp.125-142
• /
• 2012

Clean development mechanism (CDM) validity study was conducted to suggest better and more adaptable CDM scenario on water treatment plant (WTP). Potential four scenarios for CDM project; improvement of intake pumping efficiency, hydro power plant construction, solar panel construction and system optimization of mechanical mixing process were evaluated on S-WTP in Korea. Net present value (NPV) of each scenario was estimated based on sensitivity analysis with the variable factors to investigate the CDM validity percentile. Hydro power plant construction was the best option for CDM business with 97.76% validity and $1,127,069 mean profit by 9,813 $tonsCO_2e$/yr reduction. CDM validity on improvement of intake pumping efficiency was 90.2% with $124,305 mean profit by huge amount of $CO_2$ mitigation (10,347 $tonsCO_2e$/yr). System optimization of mechanical mixing process reduced 15% of energy consumption (3,184 $tonsCO_2e$/yr) and its CDM validity and mean profit was 77.25% and $23,942, respectively. Solar panel construction could make the effect of 14,094 $tonsCO_2$ mitigation annually and its CDM validity and mean profit was 64.68% and $228,487, respectively.

• 대한예방의학회:학술대회논문집
• /
• 대한예방의학회 1994년도 교수 연수회(역학)
• /
• pp.164-168
• /
• 1994

Single serologic tests may occasionally influence clinicians in making diagnoses. The antistreptolysin O (ASO) test is a frequently used tool for detecting recent Streptococcus pyogenes infection and is helpful in the diagnosis of diseases like rheumatic fever. Using data from a 1989 prospective study of 600 healthy male military recruits, in which 43% experienced S. pyogenes upper respiratory tract infection (2-dilution rise in ASO), this report compared two methods of interpreting a single ASO titer. Using the 'upper limit of normal' (80 percentile) method, recruits with an ASO titer of greater than 400 showed evidence of recent S. pyogenes infection. This method had a sensitivity and specificity of only 65.9 and 81.9% respectively. In contrast to the 'yes-no'. dichotomy of the 'upper limit of normal' method. the likelihood ratio method statistics were ASO value specific, more consistent with clinical judgment, and better emphasized the caution clinicians must use in interpreting a single ASO test.

• 근관절건강학회지
• /
• 제28권3호
• /
• pp.209-216
• /
• 2021

Purpose: This study aimed to determine the effect of knowledge and attitudes of preventive behavior plans (PBPs) on Zika virus infection among university students. Methods: Participants included 130 students from H University in Korea. Electronic self-reported questionnaires were used to collect data. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and regression analysis with SPSS/WIN 23.0. Results: The mean percentile score for knowledge was 35.52±20.63. The mean scores for attitudes and PBPs were 3.31±0.47 and 3.07±0.72, respectively, out of 5 points. Knowledge (t=-5.79, p<.001), attitudes (t=-3.17, p=.002), and PBPs (t=-2.67, p=.009) differed significantly with respect to awareness concerning Zika virus infection. The factor 'attitudes' significantly affected PBPs, with an R² value of 12.0% (β=.27, p<.001). Conclusion: Developing a correct attitude toward Zika virus infection may be key to improving preventive behaviors. Health education messages should be tailored to increase preventive behaviors against Zika virus infection. Nursing educators will benefit from partnerships with health educators and by using internet media to speed up the dissemination of Zika virus information.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
• /
• pp.429-434
• /
• 1996

K-REM［1］, which is under development as a realistic evaluation model of large break LOCA, is applied to the analysis of cold leg guillotine break of Ulchin 3&4. Fuel parameters on which statistical analysis of their effects on the peak cladding temperature (PCT) are made and system parameters on which the concept of limiting value approach (LVA) are applied, are determined from the single parameter sensitivity study. 3 parameters of fuel gap conductance, fuel thermal conductivity and power peaking factor are selected as fuel related ones and 4 parameters of axial power shape, reactor power, decay heat and the gas pressure of safety injection tank (SIT) are selected as plant system related ones. Response surface of PCT is generated from the plant calculation results and on which Monte Carlo sampling is made to get plant application uncertainty which is statistically combined with code uncertainty to produce the 95th percentile PCT. From the break spectrum analysis, blowdown PCT of 1350.23 K and reflood PCT of 1195.56 K are obtained for break discharge coefficients of 0.8 and 0.5, respectively.

• Clinical and Experimental Pediatrics
• /
• 제59권3호
• /
• pp.114-119
• /
• 2016

Purpose: This study aimed to assess the reference values and factors influencing blood lead levels among Korean adolescents. Methods: The study population consisted of 1,585 adolescents (801 males, 784 females; aged 10-19 years) who participated in the Korea National Health and Nutrition Examination Survey 2010-2013. We analyzed blood lead concentrations in relation to demographic/lifestyle characteristics for all participants. "Reference values" of blood lead levels were calculated as the upper limit of the 95% confidence interval of the 95th percentile. Results: The average "reference value" for blood lead concentrations among Korean adolescents was $2.25{\mu}g/dL$ ($2.49{\mu}g/dL$ for males, $2.07{\mu}g/dL$ for females), and the geometric mean of the blood lead concentrations was $1.34{\mu}g/dL$. Males had higher blood lead concentrations than females (male, $1.48{\mu}g/dL$; female, $1.19{\mu}g/dL$; P<0.001). Elementary school students had higher blood lead concentrations than junior and senior high school students ($1.44{\mu}g/dL$ vs. $1.31{\mu}g/dL$, P<0.001). Participants living in detached houses had higher blood lead concentrations than those living in apartments (P<0.001) and current smokers had higher concentrations than nonsmokers or participants with secondhand smoke exposure (P<0.05). Additionally, participants with excessive alcohol consumption had higher levels than non-drinkers (P<0.001). Conclusion: This study provides national reference data on blood lead concentrations stratified by demographic and lifestyle factors among Korean adolescents. Further studies are needed to elucidate the relationship between increased lead exposure and demographic factors including type of housing.

• 한국환경보건학회지
• /
• 제48권3호
• /
• pp.151-158
• /
• 2022

Background: Chemical emissions in the environment have rapidly increased with the accelerated industrialization taking place in recent decades. Residents of industrial complexes are concerned about the health risks posed by chemical exposure. Objectives: This study was performed to suggest modeling methods that take into account multimedia and multi-pathways in human exposure and risk assessment. Methods: The concentration of benzene emitted at industrial complexes in Daesan, South Korea and the exposure of local residents was estimated using the Caltox model. The amount of human exposure based on inhalation rate was stochastically predicted for various activity stages such as resting, normal walking, and fast walking. Results: The coefficient of determination (R²) for the CalTOX model efficiency was 0.9676 and the root-mean-square error (RMSE) was 0.0035, indicating good agreement between predictions and measurements. However, the efficiency index (EI) appeared to be a negative value at -1094.4997. This can be explained as the atmospheric concentration being calculated only from the emissions from industrial facilities in the study area. In the human exposure assessment, the higher the inhalation rate percentile value, the higher the inhalation rate and lifetime average daily dose (LADD) at each activity step. Conclusions: Prediction using the Caltox model might be appropriate for comparing with actual measurements. The LADD of females was higher ratio with an increase in inhalation rate than those of males. This finding would imply that females may be more susceptible to benzene as their inhalation rate increases.

• Journal of Nutrition and Health
• /
• 제7권3호
• /
• pp.27-44
• /
• 1974

A general survey of 82 perschool children and 473 school children (from 1st to 3rd grade) residing in the Dongnae area of Shindong Myun, choonseoung Gun, Kangwon Province was conducted from June 12 to 21, 1973, to obtain information concerning nutritional status, especially the protein and iron nutrition of preschool and school children in a rural area of Korea. A sample of 58 children 2 to 9 years old was selected from these 555 children for hematological, biochemical and parasitological tests. The results of these tests are presented below, 1) Both the mean body height and mean body weight of these children were higher and heavier than the averages in the Korean Physical Standards. About 39 per cent were above the 90 th percentile of the Korean Physical Standards of height and 35 per cent were above the 90th percentile of the Korean Physical Standards of weight. 2) The rate of infestation by helminthes was 67.6 per cent and there were no cases of hookworm infestation Among the ascaris-infected children, 61.6 per cent fell within an Ascaris E.P.G. count range of $501{\sim}2,000$. This was considered a rather mild intensify of ascaris infection. Nutrient loss due to helminthes was also estimated to be low. 3) The mean hemoglobin level was 11.3gm% $({\pm}0.94)$, and 68.4 per cent of the children were anemic (less than 11gm% among those 5 years old or less, less than l2gm% among those 6 years old or more). The average hematocrit value was 36.1% $({\pm}2.36)$, and only 3.5 per cent showed more than 34% on the M.C.H.C. test. These results showed that the incidence of anemia, in these rural children was high, and that in general it displayed hypochromic characteristics. 4) The average serum iron level was $78.2{\mu}g%$\;({\pm}29.8). The Proportion of the children showing less than $50{\mu}g% in the serum iron level was 5.6 per cent, while 41.8 percent revealed $450{\mu}g% or more in the TIBC determination. Transferrin saturation was below 15% in 71.4 percent of the preschool children, and in 28.6 percent of the school children. Those who had a serum iron level of $50{\mu}g% or less and a TIBC of more than $450{\mu}g% constituted 11.9 percent of the children examined. From these results, it was concluded that especially preschool children were low in iron nutrition, and that most of the anemia might be iron-deficiency anemia. 5) The mean values of total serum protein and albumin were 6.98gm% and 4.99gm% respectively. Especially in serum albumin, all children stowed more than 4 gm%. 6) The mean urinary urea nitrogen Per creatinine ratio was 11.5 $({\pm}4.2)$, and 21.8 percent had a ratio of more than 15. Considering these results, it was suggested that protein nutrition in these children was relatively good.

• 지질공학
• /
• 제27권4호
• /
• pp.367-376
• /
• 2017

최근 전 세계적으로 해저터널 건설이 활발하게 진행되고 있으며, 국내에서도 본토와 제주도를 연결하기 위한 해저터널 건설에 관심이 집중되고 있다. 해저터널의 안전한 건설을 위해서는 설계 및 시공 단계에서 단층과 같은 지질구조의 파악이 매우 중요하다. 그러나 해저터널의 경우 육상터널과는 다르게 지반조사의 한계로 인하여 지질구조의 분포에 대한 정보를 취득하는데 어려움이 있다. 본 연구의 목적은 지구통계학적 방법을 이용하여 해저지반에 발달하는 대규모 지질구조를 자동으로 도출하는 알고리즘을 개발하는 것이다. 본 연구에서 가장 중요한 것은 최적 이동창의 크기, 최적 공간통계량 종류, 최적 백분위수 기준의 결정이다. 최종적으로 도출된 최적 분석 알고리즘으로 R을 이용하여 사용자 프로그램을 개발하였다. 개발한 프로그램은 다양한 공간통계량의 변화를 쉽게 파악할 수 있도록 하였다. 또한, 공간통계량의 종류와 백분위 기준을 손쉽게 지정할 수 있도록 하여 공간통계량의 변화에 따른 지질구조 분석을 용이하게 하였다. 따라서, 지질구조선 도출 알고리즘에서 공간통계량은 이동 분산값, 분위수 기준은 상위 10%, 이동창의 크기는 $3{\times}3$ 일 때 대규모 지질구조선의 선형적인 형태가 시각적으로 가장 잘 나타나는 것을 확인할 수 있다. 특히 분위수 기준을 상위 0.5%로 할 경우 등고선 그림에서 오류값들이 거의 제거가 되는 양상을 보여준다.