• Nuclear Engineering and Technology
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• v.29 no.1
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• pp.78-84
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• 1997

The specific purpose of this study is to develop the numerical guide for the cost-benefit analysis of ORE ($/person-Sv reduction) to meet the criterion of ALARA in the design stage of the KNGR. In deriving the guide, the risk factor which is defined by the risk to unit collective radiation exposure dose (deaths/person-Sv) and the monetary value of human life ($/death) are required. The risk factor has been estimated from various clinical data accumulated for a number of years and continuously modified. And the monetary value of human life is usually quantified using the human capital approach. In this study, the risk to radiation exposure perceived by a group of people is investigated through an extensive poll survey conducted among university students in order to modify the existing risk factor for radiation exposure. And in evaluating the monetary value of human life, the QOL factor is introduced in order to incorporate the degree of public welfare or quality of life. As a result of study, a value within the range of 151, 000~172, 000 dollars per person-Sv reduction is recommended as the appropriate interim numerical guide for cost-benefit analysis of ORE to meet the criterion of ALARA in the design stage of the KNGR. A poll survey was also conducted in order to see whether the public acceptance cost of nuclear power should be incorporated in developing the guide, and the result of study shooed that such a cost does not need to be considered.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.1-8
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• 2020

In recent years, hydrogen has received much attention as an alternative energy source to fossil fuels. In order to ensure safety from the increasing number of hydrogen refueling stations, prevention methods have been required. In this regard, this study suggested an approach to reduce the risk of hydrogen refueling station by increasing Safety Integrity Level (SIL) for a Steam Methane Reformer (SMR) in On-Site Hydrogen Refueling Station. The worst scenario in the SMR was selected by HAZOP and the required SIL for the worst scenario was identified by LOPA. To verify the required SIL, the PFDavg.(1/RRF) of Safety Instrumented System (SIS) in SMR was calculated by using realistic failure rate data of SIS. Next, several conditions were tested by varying the sensor redundancy and proof test interval reduction and their effects on risk reduction factor were investigated. Consequently, an improved condition, which were the redundancy of two-out-of-three and the proof test interval of twelve months, achieved the tolerable risk resulting in the magnitude of risk reduction factor ten times greater than that of the baseline condition.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.825-835
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• 2008

Multivariate GARCH(MGARCH) has been useful in financial studies and econometrics for modeling volatilities and correlations between components of multivariate time series. An obvious drawback lies in that the number of parameters increases rapidly with the number of variables involved. This thesis tries to resolve the problem by using dimension reduction technique. We briefly review both factor models for dimension reduction and the MGARCH models including EWMA (Exponentially weighted moving-average model), DVEC(Diagonal VEC model), BEKK and CCC(Constant conditional correlation model). We create meaningful portfolios obtained after reducing dimension through statistical factor models and fundamental factor models and in turn these portfolios are applied to MGARCH. In addition, we compare portfolios by assessing MSE, MAD(Mean absolute deviation) and VaR(Value at Risk). Various financial time series are analyzed for illustration.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1257-1264
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• 2011

Delirium is a neuropsychiatric disorder accompanying symptoms of hallucination, drowsiness, and tremors. It has high occurrence rates among elders, heart disease patients, and burn patients. It is a medical emergency associated with increased morbidity and mortality rates. That s why early detection and prevention of delirium ar significantly important. And This mental illness like delirium occurred by complex interaction between risk factors. In this paper, we identify risk factors and interactions between these factors for delirium using multi-factor dimensionality reduction (MDR) method.

• Journal of the Korean Society of Food Culture
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• v.24 no.5
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• pp.518-524
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• 2009

This study was conducted to investigate the effects of fast food customer's perceived risks on risk reduction behavior, attitude and purchase intention. A total of 268 usable surveys were collected using a stratified random sampling method. Descriptive analysis and factor analysis was then conducted using SPSS 12.0, and a Cronbach's $\alpha$ was generated to estimate the internal consistency of the survey items. Multiple regression analysis was used to evaluate the relationships among variables. The results indicated that fast food safety and monetary risks had a negative effect on customer feelings and satisfaction with fast food, which had a positive effect on buying purpose and recommendation purpose. Conversely, obesity and monetary risks only had a negative effect on buying purpose. An improved menu more effectively reduced the risk perceived by the fast-food customers than an improved image.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.867-876
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• 2013

Metabolic syndrome has been known as a major factor of cardiovascular disease. Several metabolic disorders, particularly chronic disease is complex, and from individuals that appear in our country, the prevalence of the metabolic syndrome is increasing gradually. Therefore, this study, using a multi-factor dimensionality reduction method, checks the major single risk factor of metabolic syndrome and suggests a new diagnosis results of metabolic syndrome. Data of 3990 adults who responded to all the questionnaires of health interview are used from the database of the 5th Korea national health and nutrition examination survey conducted in 2010. As the result, the most dangerous single risk factor for metabolic syndrome was waist circumference and the most dangerous combination factors were waist circumference, triglyceride, and hypertension. This is the result of a new diagnosis of the metabolic syndrome. Especially, waist circumference, low HDL-cholesterol and hypertension were the most dangerous combination for male. In particular, the combination of waist circumference, triglyceride and diabetes was dangerous for obese people.

• Environmental Engineering Research
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• v.20 no.3
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• pp.212-222
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• 2015

Experiments were conducted on the immobilization of eight heavy metals (HMs) (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during 20-day rotary drum composting of water hyacinth. The Tessier sequential extraction procedure was used to investigate the fractionation of HMs. The eco-toxicity risk of HMs was assessed by risk assessment code (RAC). In the results, the bioavailability factor (BAF) for different HMs presented in the following order: Mn > Zn = Fe > Cu > Cr > Cd = Pb > Ni. The total concentration of Pb was higher than that of Zn, Cu, Mn, Cd and Cr; however, its BAF was the lowest among these HMs. These results confirmed that the eco-toxicity of HMs depends on bioavailable fractions rather than on the total concentration. The greatest reduction in bioavailability and eco-toxicity risk of HMs occurred in lime 1% and 2% as compared to control and lime 3%. The eco-toxicity risk of Fe, Ni, Pb, Cd and Cr was reduced from low risk to zero risk by rotary drum composting. These studies demonstrated the high efficiency of the rotary drum for degrading compost materials and for reducing the bioavailability and eco-toxicity risk of HMs during the composting process.

• Journal of Ginseng Research
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• v.45 no.5
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• pp.546-554
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• 2021

Background: Diabetes mellitus and hypertension often occur together, amplifying cardiovascular disease (CVD) risk and emphasizing the need for a multitargeted treatment approach. American ginseng (AG) and Korean Red Ginseng (KRG) species could improve glycemic control via complementary mechanisms. Additionally, a KRG-inherent component, ginsenoside Rg3, may moderate blood pressure (BP). Our objective was to investigate the therapeutic potential of coadministration of Rg3-enriched Korean Red Ginseng (Rg3-KRG) and AG, added to standard of care therapy, in the management of hypertension and cardiometabolic risk factors in type-2 diabetes. Methods: Within a randomized controlled, parallel design of 80 participants with type-2 diabetes (HbA1c: 6.5-8%) and hypertension (systolic BP: 140-160 mmHg or treated), supplementation with either 2.25 g/day of combined Rg3-KRG + AG or wheat-bran control was assessed over a 12-wk intervention period. The primary endpoint was ambulatory 24-h systolic BP. Additional endpoints included further hemodynamic assessment, glycemic control, plasma lipids and safety monitoring. Results: Combined ginseng intervention generated a mean ± SE decrease in primary endpoint of 24-h systolic BP (-3.98 ± 2.0 mmHg, p = 0.04). Additionally, there was a greater reduction in HbA1c (-0.35 ± 0.1% [-3.8 ± 1.1 mmol/mol], p = 0.02), and change in blood lipids: total cholesterol (-0.50 ± 0.2 mmol/l, p = 0.01), non-HDL-C (-0.54 ± 0.2 mmol/l, p = 0.01), triglycerides (-0.40 ± 0.2 mmol/l, p = 0.02) and LDL-C (-0.35 ± 0.2 mmol/l, p = 0.06) at 12 wks, relative to control. No adverse safety outcomes were observed. Conclusion: Coadministration of Rg3-KRG + AG is an effective addon for improving BP along with attaining favorable cardiometabolic outcomes in individuals with type 2 diabetes. Ginseng derivatives may offer clinical utility when included in the polypharmacy and lifestyle treatment of diabetes. Clinical trial registration: Clinicaltrials.gov identifier, NCT01578837;

• Journal of agricultural medicine and community health
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• v.23 no.2
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• pp.193-204
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• 1998

Cardiovascular diseases are the leading cause of death and disability in Korea. Their risk factors can be classified as either modifiable or nonmodifiable and among modifiable factors are high bood pressure, elevated blood cholesterol, obesity and cigarette smoking. The purpose of this study was to evaluate the risk factors for the cardiovascular diseases in a rural community and to get basic data for the development of a community-based rick reduction intervention program. Evaluation involved population-based, cross-sectional samples of adult residents in a rurual community. We measured blood pressure, body fat percent by bioelectric impedance fatness analyzer and serum cholesterol and interviewed adult residents over 20-year-old age. Blood pressure was checked twice and hypertension was classified by the sixth report of the Joint National Committee on Detection. Evaluation, and Treatment of High Blood Pressure. The Cutpoints for high blood cholesterol was used National Cholesterol Treatment Guidelines and those for obesity was 25% in male. 30% in female. The results were as follows: 1. Prevalence of definitive hypertension was 59.7% in males and 54.4% in female. 2. Prevalence of hypercholesterolemia was 14.3% in male and 18.2% in female. 3. Prevalence of obese was 10.7% in male and 41.1% in female. 4. Among definitive hypertension, hypercholesterolemia, and obesity 52.1% possessed one risk factor, 12.6% two risk factors and 2.5% three risk factors in males. In females 41.4% possessed one risk factor and 27.6%. 5.7% respectively. 5. The smoking rate was 65.8% in males and 5.2% in females. Our results are used effectively for the community-based intervention towards cardiovascukr diseases risk reduction. However, because of limitations in our study design, further datas are needed including other risk factors and in-person clinical datas.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.395-404
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• 2022

Purpose: Small-scale construction sites have insufficient systematic safety management activities, and due to the characteristics of the construction site, the production structure is complex due to external environmental factors, and the risk of construction equipment is very high. We would like to propose a checklist method among practical risk assessment techniques that can derive risk factors for disaster prevention at small construction sites and reduce disasters. Method: Risk factors were derived by analyzing literature research and disaster cases, and detailed work for a checklist of risk assessment suitable for small-scale construction sites was classified based on risk factor items. Result: Hazard factors were divided into 6 major categories, and 29 detailed types of work were classified based on actual work types, and 80 detailed works were classified accordingly. Conclusion: By arranging risk factors suitable for small-scale construction sites according to the classification system, the lack of expertise in the construction site can be supplemented, and risk factors can be derived more easily and disaster reduction can be expected through establishment of safety measures.