• 치위생과학회지
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• 제15권6호
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• pp.712-720
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• 2015

본 연구는 65세 이상 노인들의 치아건강도와 선호식품과의 관련성을 알아보고자 국가통계자료인 2010년과 2011년 국민건강영양조사 원시자료를 분석하여 다음과 같은 결론을 얻었다. 채소류, 과일류, 기타식품의 선호도가 높은 사람은 T-health 지수와 FS-T 지수가 높았고, ST와 PT도 많은 반면, 채소류, 과일류, 기타식품의 선호도가 낮은 사람은 MT가 많은 것으로 나타났다. T-health 지수는 곡류, 과일류, 기타식품, 65~69세, 70~74세, 소득분위 중하위권과 하위권에서 유의하였고, ST는 곡류, 기타식품, 65~69세, 70~74세, 소득분위 중하위권에서 유의한 영향을 미쳤다(p<0.05). FS-T 지수는 과일류, 유지 및 당류, 기타식품, 65~69세, 70~74세, 소득분위 중하위권과 하위권에서 유의하였으며, PT 및 MT는 곡류, 과일류, 65~69세, 70~74세, 소득분위 중하위권과 하위권에서 유의한 영향을 미쳤다(p<0.05). 이상의 결과를 종합하면, 65세 이상 노인들의 치아건강도와 식품의 선호도는 밀접한 연관성이 있는 것으로 조사되었다. 특히, 노인들의 치아건강도에 따라 선호식품에 차이가 있으며, 노인들의 치아건강상태가 영양불균형을 초래하는 위험요인으로 작용될 수 있다는 것에 주목할 필요가 있다. 따라서 노인들을 비롯한 모든 연령층에서 치아건강을 유지하기 위한 노력이 필요하며, 생애에 걸쳐 구강건강관리 를 할 수 있는 프로그램 마련이 필요할 것으로 판단되었다.

• 한국환경보건학회지
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• 제45권3호
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• pp.247-257
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• 2019

Objectives: The Korea Ministry of Environment regulates concentrations of hazardous air pollutants (HAPs) through Atmosphere Environmental Standards to protect public health from HAPs. However, simply determining the exceedance of HAP concentrations has several limitations and more comprehensive assessment is required. In addition, integrated risk assessment is needed considering exposure in all microenvironments, including outdoor as well as indoor environments. The purpose of this study was to assess the differences in risk by sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk for Koreans. Methods: In this study, we calculated time-weighted average exposure concentrations for benzene and $PM_{10}$ among preschool-age children, students, housewifes, workers, and the elderly using residential time and concentrations for indoor (house, school or workplace, other), outdoor, and transport by the meta-analysis method. The risk assessments were conducted by excess cancer risk and disease death risk using 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool-age children, students, housewifes, workers, and the elderly spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in their house, workplace, or school, respectively. The more than 99% excess cancer risk for benzene exceed 1.0E-06 in all sub-populations and lifetime. The acute disease death risk for $PM_{10}$ for housewifes and workers for lifetime were 3.35E-04 and 3.18E-04, and chronic disease death risks were 2.84E-03 and 2.70E-03, respectively. Conclusions: The risk of benzene and $PM_{10}$ by sub-population group and for the lifetime of housewifes and workers were assessed. Benzene showed risky results for this study. All disease death risks of $PM_{10}$ were higher than 1.0E-04 and showed different risks by sub-population. This study can be used as a basis for lifetime exposure and risk assessment to benzene and $PM_{10}$.

• 한국환경보건학회지
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• 제45권2호
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• pp.113-125
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• 2019

Objectives: Although the risk assessments for nitrogen dioxide ($NO_2$) and ozone ($O_3$) have been extensively studied, most of the existing risk assessments were limited mainly to indoor environments such as workplaces, schools, and multi-use facilities. Therefore, integrated risk assessment is needed to consider exposure in all microenvironments, including outdoors. The purpose of this study was to assess the differences in risk among sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk of Koreans. Methods: In this study, we estimated time-weighted average exposure concentrations of $NO_2$ and $O_3$ for preschool children, students, housewives, workers, and seniors using residential time and indoor concentrations (house, school or workplace, other), outdoors, and transport by meta-analysis method. The risk for $NO_2$ and $O_3$ were assessed by hazard quotient using reference concentrations 30 and 60 ppb, respectively. The risk assessments were conducted through 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool children, students, housewives, workers, and seniors spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in a house, school, or workplace, respectively. The risk assessment for the lifetime of a housewife and a worker showed that 33.8 and 28.4% of hazard quotients of $NO_2$ exceed 1, respectively, and more than 99% of hazard quotient of $O_3$ were less than 1. Conclusions: The risk of $NO_2$ and $O_3$ by sub-population group and for the lifetime of housewives and workers were assessed. The risk for $NO_2$ was higher than for $O_3$ and showed a different risk by sub-population group. Both $NO_2$ and $O_3$ showed a higher risk for housewives than for workers. This study can be used as a basis for lifetime exposure and risk assessment for $NO_2$ and $O_3$.

• 한국학교ㆍ지역보건교육학회지
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• 제20권1호
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• pp.1-14
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• 2019

Objectives: There are few studies which reflects of each generation's own features, of the New Middle Age and the Elderly's hearing status and their quality of life even though the population of old age has been weighted as baby boom generation's entering into old age. This study is to identify the effects of the new middle age and the elderly's hearing status on their quality of life and to prepare the customized health policies for their health promotion and quality of life improvement as well as the base line data for hearing enhancement programs. Methods: This study was analyzed using the data of the 7th term of the National Health and Nutrition Survey of the Disease Management headquarters. Out of 8,150 adults over the age of 50 who participated in the hearing test, 3,306 were selected and analyzed. Results: At the result of identifying the correlation of hearing status and the quality of life between the New Middle Age and the Elderly, it was confirmed that hearing loss affects low quality of life. The average of quality of life between the New Middle Age and the Elderly was 0.95 and 0.85 each, resulting in higher quality of life in New Middle Age than in the Elderly. The factors affecting the quality of life of the New Middle Age were the level of the education, household income, the type of health insurance, subjective health status. The factors affecting the quality of life of the Elderly were gender, the type of health insurance, subjective health status. Conclusion: Hearing loss of the New Middle Age and the Elderly affects their low quality of life. Therefore the development and the provision of policy program is needed, so as to maintain and manage hearing through age-specific health education. It is expected that the second half of the New Middle Age's life will be much happier, if not taking the treatment-oriented approach of hearing loss only but strengthening the education needed for the maintenance and the management of healthy hearing at their work place, where 50 and 60 generations' workforce has been increased.

• 한국농공학회논문집
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• 제63권4호
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• pp.87-96
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• 2021

Determining design rainfall is the first step to plan an agricultural drainage facility. The objective of this study is to evaluate whether the current method for parameter estimation is reasonable for computing the design rainfall. The current Gumbel-Kendall (G-K) method was compared with two other methods which are Gumbel-Chow (G-C) method and Probability weighted moment (PWM). Hourly rainfall data were acquired from the 60 ASOS (Automated Synoptic Observing System) stations across the nation. For the goodness-of-fit test, this study used chi-squared (𝛘²) and Kolmogorov-Smirnov (K-S) test. When using G-K method, 𝛘² statistics of 18 stations exceeded the critical value (𝑥²_a=0.05,df=4=9.4877) and 10, 3 stations for G-C method, PWM method respectively. For K-S test, none of the stations exceeded the critical value (D^a=0.05_n=0.19838). However, G-K method showed the worst performances in both tests compared to other methods. Subsequently, this study computed design rainfall of 48-hour duration in 60 ASOS stations. G-K method showed 5.6 and 6.4% higher average design rainfall and 15.2 and 24.6% higher variance compared to G-C and PWM methods. In short, G-K showed the worst performance in goodness-of-fit tests and showed higher design rainfall with the least robustness. Likewise, considering the basic assumptions of the design rainfall estimation, G-K is not an appropriate method for the practical use. This study can be referenced and helpful when revising the agricultural drainage standards.

• 응용통계연구
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• 제35권2호
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• pp.229-250
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• 2022

포트폴리오 최적화 이론의 초석인 Markowitz의 평균-분산 포트폴리오 모형 (1952)이 발표된 이후로 많은 분야에서 포트폴리오 최적화에 대한 다양한 연구가 진행되었다. 기존의 평균-분산 포트폴리오 모형은 주로 목적함수나 제약식에 비선형 볼록 형태를 포함한다. 이를 Dantzig의 선형계획법을 적용하여 선형으로 변환시켜 알고리즘 계산 시간을 효율적으로 감소시켰다. 또한 시계열 데이터 특성을 반영하여 시간에 따른 가중치를 고려하는 가우시안 커널 가중치 공분산을 제안하였다. 여기에 일정 부분은 벤치마크에 투자하고 나머지는 포트폴리오 최적화 모형으로 제안된 자산들에 투자하는 퍼터베이션 방법을 적용하여 평균 수익률과 위험도를 목적에 맞게 조절하도록 하였다. 또한, 본 논문에서는 안정적이면서도 적은 자산을 보유하게 포트폴리오를 구성하여 관리비용(management costs)과 거래비용(transaction costs)를 낮출 수 있는 Dantzig-type 퍼터베이션 포트폴리오 모형을 제안하였다. 제안된 모형의 성능은 5개의 실제 데이터 세트로 벤치마크 포트폴리오와 비교 분석하여 평가하였다. 최종적으로 제안한 최적화 모형은 벤치마크보다 높은 기대수익률이나 낮은 위험도를 갖는 포트폴리오를 구성하여 퍼터베이션 목적을 만족하며, 투자한 자산의 수와 시간에 따른 자산 구성 변화를 일정 수준 이하로 조절하는 희소하며 안정적인 결과를 얻었다.

• Investigative Magnetic Resonance Imaging
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• 제25권4호
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• pp.313-322
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• 2021

Purpose: To find diagnostic image features, to compare diagnostic performance of multiphase CT versus gadoxetic acid disodium-enhanced MRI (GAD-MRI), and to evaluate the impact of analyzing Liver Imaging Reporting and Data System (LI-RADS) imaging features, for distinguishing combined hepatocellular-cholangiocarcinoma (CHC) from hepatocellular carcinoma (HCC). Materials and Methods: Ninety-six patients with pathologically proven CHC (n = 48) or HCC (n = 48), diagnosed June 2008 to May 2018 were retrospectively analyzed in random order by three radiologists with different experience levels. In the first analysis, the readers independently determined the probability of CHC based on their own knowledge and experiences. In the second analysis, they evaluated imaging features defined in LI-RADS 2018. Area under the curve (AUC) values for CHC diagnosis were compared between CT and MRI, and between the first and second analyses. Interobserver agreement was assessed using Cohen's weighted κ values. Results: Targetoid LR-M image features showed better specificities and positive predictive values (PPV) than the others. Among them, rim arterial phase hyperenhancement had the highest specificity and PPV. Average sensitivity, specificity, and AUC values were higher for MRI than for CT in both the first (P = 0.008, 0.005, 0.002, respectively) and second (P = 0.017, 0.026, 0.036) analyses. Interobserver agreements were higher for MRI in both analyses (κ = 0.307 for CT, κ = 0.332 for MRI in the first analysis; κ = 0.467 for CT, κ = 0.531 for MRI in the second analysis), with greater agreement in the second analysis for both CT (P = 0.001) and MRI (P < 0.001). Conclusion: Rim arterial phase hyperenhancement on GAD-MRI can be a good indicator suggesting CHC more than HCC. GAD-MRI may provide greater accuracy than CT for distinguishing CHC from HCC. Interobserver agreement can be improved for both CT and MRI by analyzing LI-RADS imaging features.

• 한국입자에어로졸학회지
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• 제17권4호
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• pp.91-106
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• 2021

Daily PM_2.5 was collected during summer period in 2020 in Gwangju to investigate its chemical and light absorption properties. In addition, real-time light absorption coefficients were observed using a dual-spot 7-wavelength aethalometer. During the study period, SO₄^2- was the most important contributor to PM_2.5, accounting for on average 33% (10-64%) of PM_2.5. The chemical form of SO₄^2- was appeared to be combination of 70% (NH₄)₂SO₄ and 30% NH₄HSO₄. Concentration-weighted trajectory (CWT) analysis indicated that SO₄^2- particles were dominated by local pollution, rather than regional transport from China. A combination of aethalometer-based and water-extracted brown carbon (BrC) absorption indicated that light absorption of BrC due to aerosol particles was 1.6 times higher than that due to water-soluble BrC, but the opposite result was found in absorption Ångström exponent (AAE) values. Lower AAE value by aerosol BrC particles was due to the light absorption of aerosol BrC by both water-soluble and insoluble organic aerosols. The BrC light absorption was also influenced by both primary sources (e.g., traffic and biomass burning emissions) and secondary organic aerosol formation. Finally the ATR-FTIR analysis confirmed the presence of NH₄⁺, C-H groups, SO₄^2-, and HSO₄^2-. The presence of HSO₄^2- supports the result of the estimated composition ratio of inorganic sulfate ((NH₄)₂SO₄) and bisulfate (NH₄HSO₄).

• 한국의료질향상학회지
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• 제28권1호
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• pp.45-54
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• 2022

Purpose: The study aims to identify the theme list and priority criteria of patient safety theme reports in South Korea. Methods: The survey was conducted twice, and the importance of each criterion and theme was measured on a nine-point scale using the Delphi technique by a panel of 19 patient safety experts. The criteria included severity, universality, preventability, and organizational-social impact. Descriptive statistics such as frequency, percentage, mean, standard deviation, median, and interval quartile range were used to analyze the data. Results: The parameters were assigned a weighted average of 35% for severity, 20% for universality, 30% for preventability, and 15% for organizational-social impact, respectively. The final top three rankings were surgery safety, blood transfusion safety, and medication safety. In addition to expert opinion, for the theme that is selected based on the priority ranking, one to five sub-topics can be derived from the theme based on the priority ranking, societal demands, or the yearly priority list of patient safety incidents. Conclusion: It is recommended that the official patient safety center distribute the report in the form of a summary that can be utilized nationwide at medical institutions, government institutions, and other places. Updates, as well as accumulated theme reports, will serve as the baseline data for the proposal of the system and for the policy designed to implement and improve institutions' safety practices as a standard of domestic patient safety practice guidelines.

• 한국습지학회지
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• 제24권1호
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• pp.44-51
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• 2022

본 연구에서는 TOPSIS(Techniques for Order Performance by Similarity to Ieal Solution)을 이용하여 낙동강수계 34개 지천에서의 수질측정망 설치 지점에 대하여 평가하였다. 낙동강수계에서는 지난 2011년부터 195개 지천에서 수질 및 유량을 측정하고 있다. 특히, 34개 중점관리지점은 오염원이 많고 수질이 불량한 지역으로서 지속적인 수질이 관리가 필요하다. 관리가 필요한 지점 선정을 위해 평가항목은 10개 지표를 선정하였으며 선정된 지표를 표준화하고, 엔트로피 방법(Entropy Method)을 이용하여 가중치를 부여하였다. 가중치 산정결과, 인근 측정망 유무가 가장 크고 평균 수질과 산업단지 유무도 높은 가중치를 얻었다. 평가결과, 상위 지점은 인근 측정망이 없고 산업단지와 폐수처리시설이 있고 평균 수질이 타 지점보다 높은 지점이다. 평가된 자료는 향후 낙동강수계에서의 신규 수질측정망 설정 및 지속적인 지류에서의 수질 관리를 위해 필요한 연구 결과로 판단된다.