• 대한영양사협회학술지
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• 제22권2호
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• pp.106-117
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• 2016

Osteoporosis is a major health problem that can lead to mortality. This study was conducted to estimate the prevalence of osteopenia and osteoporosis separately and to assess the risk factors associated with osteopenia/osteoporosis in Korean men aged 50 years and over. A total of 1,136 subjects were analyzed among the participants of the Korea National Health and Nutrition Examination Survey (KNHANES) 2010~2011 by using SPSS statistics complex samples (windows ver. 23.0). The prevalence rates of osteopenia and osteoporosis were 46.3% and 7.3%, respectively, and the mean ages of both osteopenia and osteoporosis risk groups were significantly higher than that of the normal group. The mean values for lifetime tallest height and bone mineral density in whole body, total femur, femoral neck, and lumbar spine were significantly lower in the risk group(osteopenia/osteoporosis) than in the normal group, whereas the mean values for height, body weight, BMI, waist circumference, alkaline phosphatase, parathyroid hormone, fasting blood glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides of the two groups showed no significant differences. The intakes of energy and carbohydrates were significantly higher in the risk group than in the normal group. The results of multiple logistic regression showed that being underweight and having hypercholesterolemia were significantly related with the prevalence of osteopenia/osteoporosis, whereas health habits such as smoking and exercise, chronic diseases such as obesity and hypertension, and nutrient intakes were not. These findings suggest the need for further studies to examine osteopenia/osteoporosis risk factors and outcomes specificly focused on Korean men.

• Journal of Preventive Medicine and Public Health
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• 제43권6호
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• pp.543-548
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• 2010

Objectives: The objective of this study was to calculate sample size and power in an ongoing cohort, Korea radiation effect and epidemiology cohort (KREEC). Method: Sample size calculation was performed using PASS 2002 based on Cox regression and Poisson regression models. Person-year was calculated by using data from '1993-1997 Total cancer incidence by sex and age, Seoul' and Korean statistical informative service. Results: With the assumption of relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, sample size calculation was 405 events based on a Cox regression model. When the relative risk was assumed to be 1.5 then number of events was 170. Based on a Poisson regression model, relative risk=1.3, exposure:non-exposure=1:2 and power=0.8 rendered 385 events. Relative risk of 1.5 resulted in a total of 157 events. We calculated person-years (PY) with event numbers and cancer incidence rate in the nonexposure group. Based on a Cox regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, 136 245PY was needed to secure the power. In a Poisson regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, person-year needed was 129517PY. A total of 1939 cases were identified in KREEC until December 2007. Conclusions: A retrospective power calculation in an ongoing study might be biased by the data. Prospective power calculation should be carried out based on various assumptions prior to the study.

• Fisheries and Aquatic Sciences
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• 제7권3호
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• pp.141-147
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• 2004

Sixteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in seventy marine organisms (40 species) from the Korean coast. PAHs were present in all the organisms. The level of total PAHs in the organisms varied from 0.45 to 224 ng/g dry weight and the carcinogenic PAHs varied from 0.05 to 49.8 ng/g dry weight. The PAHs residues according to the marine organisms showed a highest content in bivalve species, and followed by crustaceans, cephalopods, fish and gastropods. Human dietary intake of total PAHs through marine organism in Korea was estimated to be 4.12 ng/kg body weight/day and 0.67 ng/kg body weight/day for carcinogenic PAHs. The relative contributions of individual species to the total dietary intake of PAHs were in the order of bivalves $(53.4{\%})$, fish $(21.9{\%})$, crustaceans $(15.3{\%})$, cephalopods $(8.8{\%})$ and gastropods $(0.6{\%})$. Daily dietary intake of $PAH_{TEQ}$ expressed as a TEQ value was estimated to be 0.13 pg TEQ/kg body weight/day, which did not exceed a tolerable daily intake (TDI) proposed by the KFDA and the WHO as well as the UK toxicity committee. Lifetime cancer risk due to ingestion of marine species by the Korean adult was evaluated using the equation estimating exposure of food ingestion. Although approximately $23{\%}$ of cumulative frequency of the sampled marine species exceeded the cancer risk guideline, lifetime cancer risk associated with marine organism consumption was negligible. Results indicate that dietary intake of PAHs through the consumption of the Korean marine organisms seems to be safe for human ingestion with negligible cancer risk.

• 대한지역사회영양학회지
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• 제13권1호
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• pp.91-99
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• 2008

The present study was conducted to examine metabolic risk factors and total antioxidant capacity (TAC) of Korean females living in Seoul and to investigate the relationship between the metabolic risk factors and serum TAC. A total of 353 females aged between 20 and 64 participated in the study. Obesity indicators, blood pressure, serum lipid profile and fasting blood glucose were measured as metabolic risk factors. Ferric reducing antioxidant power (FRAP) assay was employed to determine serum TAC of subjects. Obesity indicators such as body mass index, waist circumference and waist-hip ratio were significantly higher in the participants aged $\geq$ 50 y (older group) than in the participants aged 20-49 y (younger group) (p < 0.001). Blood pressure, serum total cholesterol (TC), triglyceride (TG) and fasting blood glucose were also significantly higher in the older group than in the younger group (p < 0.001), demonstrating significant positive correlations between age and MS risk factors. The association between FRAP and MS risk factors were also investigated. FRAP values showed significant positive correlations with age (p = 0.001), serum TG (p = 0.002) and TC (p = 0.03). A tendency of positive association between FRAP and waist circumference was observed without any significant difference (p = 0.06). Increased serum FRAP with central obesity and serum lipids may be interpreted as results of activation of antioxidant defense system against oxidative stress induced by metabolic syndrome (MS) constituent factors. However, to verify the function of FRAP as a potential biomarker of susceptibility to MS various contributors to the plasma antioxidant capacity and their biological relevance related to MS should be elucidated further.

• 한국전자거래학회지
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• 제25권4호
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• pp.125-141
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• 2020

최근의 연구들에서는 투자자들의 관심이나 감정이 주식 거래행태와 주가 변동에 미치는 영향에 대한 분석들이 증가하고 있다. 본 연구에서는 투자자들의 관심과 감정을 측정하기 위해 한국의 네이버 검색지수를 이용하여, 포털 검색량과 검색의 변동성이 주가동조성 및 총위험, 체계적 위험에 미치는 영향을 분석하였다. 먼저 평균적인 검색량이 증가할수록 주가동조성은 증가하는 반면, 검색의 변동성은 주가동조성을 감소시키는 것을 관찰하였다. 다음으로 평균 검색량과 검색의 변동성은 모두 주식의 총위험과 체계적 위험을 증가시키는 것으로 나타났다. 이러한 결과는 주가를 변동시키는 사건이 발생할 경우에만 개인투자자들의 검색이 증가하기 때문인 것으로 해석된다. 이러한 결과는 포트폴리오 분석, 고정효과 회귀분석 및 동적 패널 모형에서 일관되게 관찰된다.

• 한국토양비료학회지
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• 제49권5호
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• pp.584-588
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• 2016

The current study was carried out to investigate total and inorganic arsenic (As) concentrations in 112 rice samples (husked rice and polished rice) grown around the abandoned mining areas and to estimate the potential health risk through dietary intake of rice in Korea. Mean concentrations of total As in husked rice and polished rice were 0.23 and $0.13mg\;kg^{-1}$, respectively. Also, average inorganic As concentrations in husked rice and polished rice were 0.09 and $0.05mg\;kg^{-1}$, respectively. These levels are lower than the standard guideline value ($0.2mg\;kg^{-1}$) for inorganic As in polished rice recommended by Korea Ministry of Food and Drug Safety and Codex. For health risk assessment, the average values of cancer risk probability was $5.7{\times}10^{-5}$ which was less than the acceptable cancer risk of $10^{-6}{\sim}10^{-4}$ for regulatory purpose. Also, hazard quotient values were lower than 1.0. Therefore, these results demonstrated that human exposure to inorganic As through dietary intake of rice collected from abandoned mining areas might not cause adverse health effects.

• 한국지형학회지
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• 제27권3호
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• pp.87-103
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• 2020

The purpose of this study is to evaluate the risk of cropland and man-made infrastructures in a landslide-prone area using a GIS-based method. To achieve this goal, a landslide inventory map was prepared based on aerial photograph analysis as well as field observations. A total of 550 landslides have been counted in the entire study area. For model analysis and validation, extracted landslides were randomly selected and divided into two groups. The landslide causative factors such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in the analysis. Moreover, to identify the correlation between landslides and causative factors, pixels were divided into several classes and frequency ratio was also extracted. A landslide susceptibility map was constructed using a bayesian predictive model (BPM) based on the entire events. In the cross validation process, the landslide susceptibility map as well as observation data were plotted with a receiver operating characteristic (ROC) curve then the area under the curve (AUC) was calculated and tried to extract a success rate curve. The results showed that, the BPM produced 85.8% accuracy. We believed that the model was acceptable for the landslide susceptibility analysis of the study area. In addition, for risk assessment, monetary value (local) and vulnerability scale were added for each social thematic data layers, which were then converted into US dollar considering landslide occurrence time. Moreover, the total number of the study area pixels and predictive landslide affected pixels were considered for making a probability table. Matching with the affected number, 5,000 landslide pixels were assumed to run for final calculation. Based on the result, cropland showed the estimated total risk as US $ 35.4 million and man-made infrastructure risk amounted to US $ 39.3 million.

• 대한지역사회영양학회지
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• 제25권1호
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• pp.61-70
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• 2020

Objectives: This study examined the association of the total diet quality with the incidence risk of metabolic syndrome constituents and metabolic syndrome among Korean adults. Methods: Based on a community-based cohort of the Korean Genome and Epidemiology Study (KoGES) from 2001 to 2014, data from a total of 5,549 subjects (2,805 men & 2,744 women) aged 40~69 years at the baseline with a total follow-up period of 38,166 person-years were analyzed. The criteria of the National Cholesterol Education Program Adult Treatment Panel was employed to define metabolic syndrome. The total diet quality was estimated using the Korean Healthy Eating Index (KHEI). Hazard ratios (HR) and 95% confidence intervals (CI) for risk of metabolic syndrome constituents and metabolic syndrome in relation to KHEI quintile groups was calculated by multivariate Cox proportional hazards regression model. Results: After adjusting for age, energy intake, income, education, physical activity, smoking, and drinking, the incidence of abdominal obesity and high blood pressure was significantly lower, by approximately 29.7% (P < 0.01) and 25.2% (P < 0.01), respectively, in the fifth KHEI quintile compared to the first quintile in men. A significant decreasing trend of the metabolic syndrome incidence was observed across the improving levels of KHEI (HRq5vs.q1: 0.775, 95% CIq5vs.q1: 0.619~0.971, P for trend < 0.01). In women, the incidence of abdominal obesity and metabolic syndrome was significantly lower, by approximately 29.8% (P < 0.01) and 22.5% (P < 0.05), respectively, in the fifth KHEI quintile compared to the first quintile adjusting for multiple covariates. On the other hand, the linear trend of metabolic syndrome risk across the KHEI levels did not reach the significance level. Conclusions: A better diet quality can prevent future metabolic syndrome and its certain risk factors among Korean men and women.

• 산경연구논집
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• 제9권6호
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• pp.49-55
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• 2018

Purpose - This paper examines the effect of related party transactions on crash firm-specific stock price crash risk. Ownership of a typical Korean conglomerate is concentrated in a single family. In those entities, management and board positions are often filled by family members. Therefore, a dominant shareholder can benefit from related party transactions. In Korea, firms have to report related party transactions in financial statement footnotes. However, those are not disclosed in detail. The more related party transactions are the greater information risk. Thus, companies with related party transactions are likely to experience stock price crashes. Research design, data, and methodology - 2,598 firm-year observations are used for the main analysis. Those samples are from TS2000 database from 2009 to 2013, and the database covers KOSPI-listed firms in Korea. The proxy for related party transactions (RTP) is calculated by dividing total transactions to the related-party by total sales. A dummy variable is used as a dependent variable (CRASH) in the regression model. Logistic regression is used to explain the relationship between related party transactions and crash risk. Then, the sample was separated into two groups; tunneling firms and propping firms. The relation between related party transactions and crash risk variances with features of the transaction were investigated. Results - Using a sample of KOSPI-listed firms in TS2000 database for the period of 2009-2013, I find that stock price crash risk increases as the trade volume of related-party transactions increases. Specifically, I find that the coefficient of RPT is significantly positive, supporting the prediction. In addition, this relationship is strong and robust in tunneling firms. Conclusions - The results report that firms with related party transactions are more likely to experience stock price crashes. The results mean that related party transactions increase the possibility of future stock price crashes by enlarging information asymmetry between controlling shareholders and minority shareholders. In case of tunneling, it could be seen that related party transactions are positively associated with stock crash risk. The result implies that the characteristic of the transaction influences crash risk. This study is related to a literature that investigates the effect of related party transactions on the stock market.

• 한국건설관리학회논문집
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• 제13권5호
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• pp.12-24
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• 2012

턴키계약방식(Design Build)은 설계시공 일괄계약방식으로 책임 한계가 보다 광범위하게 적용되어 프로젝트 수행 초기 설계 단계부터 설계비 부담 증가 등 일반 분리발주공사 보다 리스크 발생율이 높은 실정이다. 따라서 이번 연구에서는 턴키계약프로젝트에서 리스크요인의 분석 및 정량적 평가 방안을 연구하였다. 이 번 연구는 프로젝트참여자로부터 수집한 설문조사자료를 이용하여 통계분석을 수행한 결과 총145개의 리스크변수중 전체 참여자 그룹이 동의하는 DB프로젝트에서의 리스크변수는 25개로 나타났다. 요인분석을 통하여 이를 8가지 리스크요인으로 함축할 수 있었으며 이중 3가지 요인인 건설현장관련, 계약관련 및 설계관련 리스크요인이 72%의 가중치를 나타내었다. 리스크변수 및 리스크요인에 따른 가중치와 결합확률을 이용하여 리스크요인에 기인한 추정손실의 크기를 전체공사비에 대한 백분율로 추정한 결과 약 6%로 나타났고, 리스크 요인상호영향을 고려하면 약 10%를 나타나 리스크대응을 위하여 전체공사비의 약 6%~10%의 예비비를 계상할 필요가 있는 것으로 나타났다.