• 응용통계연구
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• 제24권5호
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• pp.861-869
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• 2011

최근 유전학에서 주요 목표중 하나는 복합질환에 영향을 미치는 유전적 요인을 찾아내는 것이다. 유전자좌간의 상호작용이 있을 때에는 단일 유전자좌 분석으로는 이러한 목표를 달성하기 어려우므로, 유전자-유전자간 상호작용이나 유전자-환경인자간 상호작용분석을 고려할 필요가 있다. 자주 사용되는 MDR(multifactor dimensionality reduction)방법은 데이터를 고위험군과 저위험군으로 각각 병합하여 사용하므로 특정 유전자형에서 차이가 나는 경우에는 이를 찾아내기 어렵다. 본 연구에서는 이러한 점을 보완하도록 유전자형 조합에서의 대조군과 질환군의 상대위험도를 이용하여 유전자-유전자간 상호작용을 탐색하는 방법을 제안하였다. MDR 공개데이터와 8가지 유전모형으로부터 생성한 모의자료의 분석을 통해 방법의 유용성을 확인하였다.

• 성인간호학회지
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• 제29권1호
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• pp.1-11
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• 2017

Purpose: The purpose of this study was to identify the factors and the relative risk associated with admission of patients with diabetes mellitus (DM). Methods: The sample included one hundred twenty-eight patients with type II DM. Seventy-seven patients who were admitted within six months of a hospitalization to one hospital from the first of February to the 31st of August 2014, were compared with fifty-one patients who regularly attended an outpatient clinic and had no hospitalizations. Results: Hospitalization probabilities among patients who had only diet and exercise or took oral diabetic medication were 0.03 (p=.004) and 0.21 (p=.007) times independently lower than the ones with insulin injection. The risks for hospitalization increases 6.33 times if there is absence of a spouse (p=.027) whereas the presence of a spouse seems to make hospitalization less likely. The risk among the ones having diabetic complications was 5.15 times higher than ones having no recognition of the complications (p=.040). For every one point increase in self-efficacy and every 1 mg/dL increase in high density lipoprotein (HDL) cholesterol, there was a 0.84 (p=.005) and a 0.96 (p=.036) decrease in hospitalization risk, respectively. Conclusion: Nurses should be sensitive to the risk groups of hospital admission among patients with DM including no spouse, insulin injection, diabetic complications, low self-efficacy, and low HDL cholesterol.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.245-253
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• 2017

The relative displacement of a piping system installed between isolated and nonisolated structures in a severe earthquake might be larger when without a seismic isolation system. As a result of the relative displacement, the seismic risks of some components in the building could increase. The possibility of an increase in seismic risks is especially high in the crossover piping system in the buildings. Previous studies found that an elbow which could be ruptured by low-cycle ratcheting fatigue is one of the weakest elements. Fatigue curves for elbows were suggested based on component tests. However, it is hard to find a quantitative evaluation of the ultimate state of piping elbows. Generally, the energy dissipation of a solid structure can be calculated from the relation between displacement and force. Therefore, in this study, the ultimate state of the pipe elbow, normally considered as failure of the pipe elbow, is defined as leakage under in-plane cyclic loading tests, and a failure estimation method is proposed using a damage index based on energy dissipation.

• 응용통계연구
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• 제20권2호
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• pp.357-371
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• 2007

경쟁위험(competing risk) 하에서의 누적 발생함수(cumulative incidence function)는 일반적으로 비모수적 방법으로 추정된다. 그러나 관심 있는 원인에 의한 사건이 다른 원인에 의한 사건보다 상대적으로 적게 발생하는 경우에 비모수적 방법으로 추정된 누적발생함수는 이산성으로 인해 다소 정확하지 않게 된다. 이와 같은 경우에 Bryant와 Diagnam(2004)는 관심 있는 원인에 대한 원인특정적 위험함수(cause-specific hazard function)를 모수적으로 모형화하고 다른 원인에 의한 사건은 비모수적으로 추정하는 준모수적 방법을 제안했다. 본 연구에서는 준모수적 누적발생함수 추정량을 재표현하고 와이블분포모형과 대수 정규분포모형으로 확장하였다. 또한 대수 정규분포 원인특정적 위험모형일 경우 누적 발생함수에 대한 비모수적 추정량, 와이블분포 준모수적 추정량과 대수 정규분포 준모수적 추정량의 효율성을 비교하며 준모수적 추정량의 성능과 모형 오설정이 미치는 영향을 살펴보았다.

• 대한지역사회영양학회지
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• 제9권6호
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• pp.695-705
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• 2004

The risks of the metabolic syndrome (MS) is known to be related to the dietary behavior. The objective of this study is to evaluate the association between the relative risks of MS and the dietary habit and to provide the ideal dietary habits for prevention of chronic disease of the middle-aged. Healthy subjects aged 40-64 years (male n=122, female n=173) were recruited throughout Seoul area. MS was defined according to NCEP-ATP III criteria except central obesity, and Asia-Pacific Area criteria for central obesity (2000) was adapted. Subjects were stratified into 3 groups according to the number of total risk factors:'MS group' was defined as the subjects who have three or more risk factors, 'Risk group' was defined as ones to have one or two risk factors, and 'Healthy group' defined as ones with no risk factor. In this study, 'Health group' comprised of $40.7\%$, the percentage of 'Risk group' was $49.0\%$, and the 'MS group' was $9.5\%$ of the total subjects. The MS incidence was associated with low education (p<0.001), low economic status (p<0.05), and low self-assessed health recognition (p<0.05). The risk of MS increased with adverse life styles such as cigarette smoking (p<0.05), irregular meal time (p<0.05), skipping lunch (p<0.05), low interests in balanced diet (p<0.05), and higher salt intake (p<0.01). Healthy group self-evaluated nutritional knowledge more highly (p<0.05) and scored higher nutritional knowledge (p<0.001). However, there was no difference in overall nutritional behavior among the three groups, which implies that nutritional education method should be developed for the subjects to practice their teaming efficiently.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권4호
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• pp.373-382
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• 2000

Individual genetic susceptibilities to cancers may result from several factors including differences in xenobiotics metabolism to chemical carcinogens, DNA repair, altered oncogenes and suppressor genes, and environmental carcinogen exposures. Among them, genetic polymorphisms of metabolizing enzymes to chemical carcinogens have been recognized as a major important host factors in human cancers. They have two main types of enzymes: the phase I cytochrome P-450 mediating enzymes (CYPs) and phase II conjugating enzymes. The purpose of this study is to determine the frequencies of genotypes of phase I (CYP1A1 and CYP2E1) and phase II (NAT2) metabolizing enzymes in healthy control and head and neck cancer patients of Korean and to identify the relative high risk genotypes of these metabolizing enzymes to head and neck cancer in Korean. The author has analyzed 132 head and neck cancer patients and 113 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results were as following; 1. The frequencies of genotypes of CYP1A1, CYP2E1 and NAT2 in healthy control were as following; CYP1A1 exon 7 polymorphism; Ile/Ile: Ile/Val: Val/Val = 59.3%: 36.3%: 4.4% CYP2E1 Pst I polymorphism, C1/C1: C1/C2: C2/C2 = 61.1%: 32.1%: 6.2% NAT2 polymorphism; F/F: F/S: S/S = 43.4%: 48.7%: 8.0% 2. In analysis of phase I enzyme, Val/Val genotype in CYP1A1 exon 7 polymorphism and C2/C2 genotype in CYP2E1 Pst I polymorphism were associated with relative high risks to head and neck cancers (Odds' ratio: 2.09 and 1.37, respectively). 3. Among the genotypes of NAT2 enzyme polymorphism, S/S genotype of NAT2 enzyme had 1.03 times of relative risk to head and neck cancers. 4. In combined genotyping of CYP1A1, CYP2E1, and NAT2 enzymes polymorphisms, the patients with Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator had higher relative risks than the patients with each baseline of combined genotypes (Odds' ratio: 2.82, 1.98 and 2.1, respectively). These results suggest the combined genotypes of Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator were more susceptible to head and neck cancers in Korean. And genotyping of metabolizing enzymes could be useful for predicting individual susceptibility to head and neck cancer.

• Environmental Analysis Health and Toxicology
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• 제25권2호
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• pp.169-177
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• 2010

Ecological risk assessment (ERA) has been used to establish environmental quality standards or evaluate ecological risk in site-specific areas. The scope of ERA was expanded based on regions, and the concept of regional-scale ecological risk assessment was recently introduced in developed countries. In the present study, regional ERA approaches of relative risk model (RRM), contaminants in aquatic and terrestrial ecosystems (CATS) model, and procedure for ecological tired assessment of risks (PETAR) in advanced countries were extensively investigated. Regional ERA was compared with traditional ERA process. Stressors, receptor and response in traditional ERA were replaced with sources of stressors, habitats, and ecological impacts, respectively in regional ERA. This study introduces the concept and assessment process of regional ERA, and provides a wide perspective how the relative ERA could be applied in Korean ecosystem.

• 대한인간공학회지
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• 제30권2호
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• pp.375-379
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• 2011

Objective: The aim of this paper is to introduce the Directive 2002/44/EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from vibration. Background: Human beings interact with machinery, and contact with vibration is commonplace. Unfortunately, continuous exposure to mechanical vibration can lead to physical injury. And standards are needed for identifying those at risk and for taking steps to mitigate the problem and reduce risk of injury. Method: The contents of the Directive were summarized and discussed, especially against its ISO counterparts. Results: The Directive deals with minimum safety and health prescriptions relative to workers' exposure to risks due to mechanical vibration. This directive specifies exposure limit values and action values. It also specifies employers' obligations with regard to determining and assessing risks, sets out the measures to be taken to reduce or avoid workers' exposure. Finally, it details how to make exposed workers aware of this issue. Conclusion: In spite of some limitations, it has recently been transcribed into all national laws of member States of European union. Application: The results of the paper might help to establish or update the domestic standards on vibration.

• 미생물학회지
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• 제37권2호
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• pp.101-108
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• 2001

환경에서 병원성 미생물의 발생에 관련된 자료를 분석하는 일은 잠재적 보건 위해성을 판단하고 그에 따른 적절한 조치를 취하는데 종종 결정적인 역할을 한다. 이러한 일들은 과거에는 주로 정성적이고, 주관적인 방법으로 이루어 졌지만, 최근에는 정량적 위해성 평가(Quantitative Risk Assessment: QRA)로 이루어지는데, 이러한 QRA는 병원성 미생물로부터의 감염이나 발병, 또는 치사율 등의 위해성을 정량적인 방법으로 표현하는 접근법이다. 따라서, 이와 같은 정보는 정책 결정권자가 위해성의 확대와 비용부담, 그리고 적절한 조치를 취했을 때 기대할 수 있는 이점을 결정하는데 보다 더 잘 이용할 수 있다. 본 문에서는 위해성 분석의 과제에 대한 일반적인 배경을 살펴보고 문제해결 과정에서 미생물 위해성 평가가 어떻게 활용 가능한지를 살펴보았다.

• Safety and Health at Work
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• 제12권2호
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• pp.174-183
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• 2021

Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.