• 한국인구학
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• 제25권2호
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• pp.163-192
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• 2002

주거밀도는 개인 및 가구의 주거수준을 보여주는 중요한 질적 주거복지 지표다. 이러한 측면에서 주거밀도는 이민자들이 현지 사회로 동화 되어가는 정도를 간접적으로 보여준다. 본 연구에서는 1980년과 1990년의 PUMS(Public Use Microdata Sample)를 사용하여 미국 내의 주요 아시아 세 인종집단(한국인, 중국인, 일본인)의 과밀여부와 추이를 분석하고 있다. 본 연구에서는 1980년과 1990년 주거밀도의 나이효과와 이민효과를 분리하기 위하여 이중생잔모형(Double Cohort Method)을 사용하여 이민자들의 생애주기와 경제적 수준 변화에 따른 10년 동안의 주거밀도 변화추이를 밝혔다. 분석결과는 이민기간이 이민자들의 주거복지 수준에 가장 큰 영향을 끼치는 것으로 나타났다. 이민기간이 10-20년인 1970년대 이민자는 1970년 이전 이민자보다 과밀가구에 살 확률이 높았고 1970년 이전 이민자는 미국출생자보다 높아 현지사회의 거주기간이 중요한 요인임을 알 수 있다 한국인은 이민초기에는 과밀가구에 살 확률이 크지만 거주기간이 증가하면서 그 확률이 급격히 감소하였다. 소득수준이 높을수록, 남자에 비해 여자가 과밀가구에 살 확률이 낮게 나타났다. 과밀가구에 살 확률이 높은 경우는 자가가구에 비해 차가가구, 미국출생자에 비해 1970년대 이민자, 그리고 15-24세 집단에 비해 35-44세 집단과 45-54세 집단이었다. 주거밀도라는 측면에서 분석한 미국내 한국인의 주거복지 변천 과정은 중국인과는 비슷한 수준의 변화론 경험하고 있지만 일본인보다는 낮은 수준의 상향 이동을 경험하고 있었다. 이것은 이민 당시의 국력수준의 차이에 따른 개인의 재산축적 정도, 현지 사회에서 사용 가능한 인적자원의 차이, 그리고 미국사회 동화에 대한 문화적 차이 등이 복합적으로 작용하고 있는 것으로 판단된다.

• 한국항공우주학회지
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• 제49권9호
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• pp.781-789
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• 2021

본 연구에서는 소형무인기(≤25kg)가 도심 지역에서 비행하고자 할 때 요구되는 고장 빈도를 무인기 추락 시 발생할 수 있는 지상 인명 피해를 기반으로 정량적으로 분석하였다. 도심 지역의 인구 밀도, 차량 교통량, 건폐율, 건물 층수 데이터 및 무인기 추락 궤적 모델링을 이용하여 특정 위치에서 무인기 추락 시 인명 피해를 계산하였고 이를 바탕으로 각 무인기 추락 위치에서 안전성 목표값을 만족하기 위한 최대 허용 가능 무인기 고장 빈도를 계산하였다. 이를 통해 각 무인기 추락 위치별 고장 빈도 요구사항을 맵 형태로 도출할 수 있었다. 최종적으로 최대 허용 가능 무인기 고장 빈도를 몇 구간으로 구분하여 각 구간별 도심 지역 비행 가능 영역을 분석하였다. 영월 지역을 대상으로 했을 때 인구 주거 지역 접근을 위해서는 최소 10^-4 (failure/flight hour) 이하의 무인기 고장 빈도가 요구됨을 확인하였다.

• Nutrition Research and Practice
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• 제6권4호
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• pp.349-356
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• 2012

Several studies have been conducted on dietary patterns based on carbohydrate nutrition in Asian populations. We examined the cross-sectional associations in dietary patterns based on carbohydrate nutrition, including the glycemic index (GI) with dyslipidemia and diabetes among the Korean adult population. We analyzed 9,725 subjects (3,795 men and 5,930 women, ${\geq}$ 20 years) from the Fourth Korea National Health and Nutrition Examination Survey. Dietary information was collected using single 24-hour recall. Reduced rank regression was used to derive dietary patterns from 22 food groups as predictor variables and four dietary factors related to the quantity and quality of carbohydrates as response variables. Two dietary patterns were identified: 1) the balanced pattern was characterized by high intake of various kinds of foods including white rice, and 2) the rice-oriented pattern was characterized by a high intake of white rice but low intake of vegetables, fruits, meat, and dairy products. Both patterns had considerable amounts of total carbohydrate, but GI values differed. The rice-oriented pattern was positively associated with hypertriglyceridemia in men and low high density lipoprotein-cholesterol in both men and women. The balanced pattern had no overall significant association with the prevalence of dyslipidemia or diabetes, however, men with energy intake above the median showed a reduced prevalence of diabetes across quintiles of balanced pattern scores. The results show that dietary patterns based on carbohydrate nutrition are associated with prevalence of dyslipidemia and diabetes in the Korean adult population.

• 환경영향평가
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• 제17권3호
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• pp.167-176
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• 2008

Korea has made the rapid economical development under the condition with the high population density and low available land. In this context, conservation of land environment, connected directly with living quality of human, has mostly ignored. Prior Environment Review System(PERS) is the one to investigate the locational validity, environmental impacts, harmony with surrounding environment, from the early stage of administrative plan or development project. PERS was amended to include SEA(Strategic Environment Assessment) system on June 1, 2006. But, several problems, including the loss of administrative ability, cost, and time, have been appeared, since the system is applied to all administrative plans without any distinction and plans or projects are delayed generally. In this study, the weaknesses of PERS were indicated through the comprehensive analysis including literature survey, study of legal and internet database, and the recently published PERS reports. Based on that, the improvement schemes were suggested to be harmonized with the nature of SEA. This study was mainly focused on a PERS for the designation of conservational area of hot-spring wells, conducted by authors.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.243-247
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• 2002

Prolonged exercise is known to increase steady-state serum high-density lipoprotein cholesterol (HDL-cholesterol) and apolipoprotein AI(apo AI) concentrations. We investigated the effect of adaptation to endurance exercise on the association of the genetic polymorphism in the apo AI gene with these biochemical parameters. 108 male subjects were randomly selected from a group of elite athletes, and 65 male samples used as sedentary control group from Korean general population. The genetic polymorphism in the apo AI gene locus was detected by polymerase chain reaction(PCR) and DNA digestion with Msp I restriction endonuclease. The genotype frequency for the Msp I RFLP was significantly different between the elite athletes and sedentary controls(P<0.05). There were, however, no significant associations between the Msp I RFLP of the apo AI gene and the biochemical parameters in elite athletic group. Therefore, our findings indicate that the Msp I RFLP of the apo AI gene was not associated with the serum apo AI and HDL-cholesterol concentrations in Korean male elite athletes.

• 대기
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• 제20권4호
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• pp.495-503
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• 2010

Satellite data have an intrinsic problem due to a number of various physical parameters, which can have a similar effect on measured radiance. Most evaluations of satellite performance have relied on comparisons with limited spatial and temporal resolution of ground-based measurements such as soundings and in-situ measurements. In order to overcome this problem, a new way of satellite data evaluation is suggested with statistical tools such as empirical orthogonal function(EOF), and singular value decomposition(SVD). The EOF analyses with OMI and OMI HCHO over northeast Asia show that the spatial pattern show high correlation with population density. This suggests that human activity is a major source of as well as HCHO over this region. However, this analysis is contradictory to the previous finding with GOME HCHO that biogenic activity is the main driving mechanism(Fu et al., 2007). To verify the source of HCHO over this region, we performed the EOF analyses with vegetation and HCHO distribution. The results showed no coherence in the spatial and temporal pattern between two factors. Rather, the additional SVD analysis between $NO_2$ and HCHO shows consistency in spatial and temporal coherence. This outcome suggests that the anthropogenic emission is the main source of HCHO over the region. We speculate that the previous study appears to be due to low temporal and spatial resolution of GOME measurements or uncertainty in model input data.

• 한국환경보건학회지
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• 제39권2호
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• pp.159-165
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• 2013

Objective: This study was carried out in order to estimate atmospheric Polychlorinated Biphenyls (PCBs) concentrations using pine needles as a passive air sampler (PAS) in urban, semi-rural and rural regions. Methods: One-year old pine needles were collected to analyze their PCBs concentrations ($C_p$, pg/g dry) at the end of December. PCBs concentrations in ambient air ($C_a$, $pg/m^3$) were calculated with the $logK_{oa}-log(C_p/C_a)$) model. Results: PCBs concentrations in ambient air ($C_a$) were high in the order of urban, semi-rural and rural regions. The lower-chlorinated PCBs showed a higher concentration in ambient air. However, the distribution of PCBs congeners was similar in all three regions. Correlation between $C_a$ and the population density of the three regions was significant ($R^2$=0.9834, p<0.001). Conclusions: It was concluded that although the production and use of PCBs was banned in the1970s, PCBs are currently being produced unintentionally by human activities.

• Computers and Concrete
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• 제21권4호
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• pp.377-384
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• 2018

The accelerated increase of the population growth rate in the world and the current lifestyle based on consumerism considerably increased the amount of waste generated by the human activity. Specifically, e-plastic waste causes significant damage to the environment because of its difficult degradation process. This paper aims to establish the feasibility of using e-plastic waste in concrete as a partial replacement of coarse mineral aggregate. Considering a control mix without e-plastic waste designed for a compressive strength of 21 MPa, tests on concrete mixes with 40, 50 and 60% of e-plastic waste aggregate to determine the fresh and hardened properties were carried out. A reduction in the compressive strength as the percentage of e-plastic waste increases was observed, the maximum reduction being 44% with respect to the control mix. In addition, a significant reduction as much as 22% in the density of the concrete mixes with e-plastic waste was recorded, which means that lighter elements can be produced with this type of concrete. Two new equations based on regression analysis of the experimental data from this study were proposed. These equations estimate the reduction in the compressive strength of concrete mixes with e-plastic waste aggregate at 14 and 28 days. A cost analysis and a practical alternative to introduce this waste material into the market are also presented.

• The Korean Journal of Ecology
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• 제5권4호
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• pp.187-203
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• 1982

The results obtained from te field investigations of Chuja Island conducted for 5 days from July 18 to 22, 1980 and from August 12 to 16, 1981 are summarized as follows: Vascular plants of this island disclosed by the present study consisted of 86 families, 210 genera, 228 species, 38 varieties and 4 래금. Nineteen species of evergreen broad-leaved trees were discovered, including Litsea japonica Juss, Camellia japonica L. and Machilus thunbergii Sieb. et Zucc. These indeciduous latifoliate trees were preserved in poor condition. Ten-twenty years old Pinus thunbergii was confirmed to be the predominant species. Seaside plants encountered were 6 species, including Vitex rotundifolia L. Fil. and Asterspathullfoius Max., but they were poorly distributed. Naturalized plants comprised a total of 12 species. This varied number of species is considered attributable to the frequent access of men owing to convenient marine traffic. the destruction of vegetation of this island may be attributed to human interference (loggin for boat construction, building and charcoal materials) ever escalated by high population density. It is worthy of noting that Bochmeria penosa Nakai et Stake which forms a large community in this island can be used as textile resources.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.806-813
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• 2018

$^{222}Rn$ exists in nature in the form of a rare radioactive gas. In terms of environmental radiation, issues regarding $^{222}Rn$ have persisted because of its radiological hazardousness. Ulju County is one of the regions of Ulsan metropolitan city, with a population of 227,699. Ulju County has the highest density of industrial complexes in Korea. In this study, $^{222}Rn$ radioactivity concentration was measured and analyzed in 57 schools in Ulju County using 114 passive LR-115 type detectors to secure radiological safety and confirm basic information for reduction of resident exposure to $^{222}Rn$. The effective dose of $^{222}Rn$ was assessed to find the actual risk of the concentration surveyed in schools to human beings. The dose depended on four factors: subjects, $^{222}Rn$ concentration, dose coefficient, and time. The individuals subjected to dose estimation were classified into three types: students, teachers, and office workers. The subjects had different dwelling locations and times. The findings demonstrate that the radiological hazard to students and workers at schools in Ulju County owing to $^{222}Rn$ is negligible in terms of $^{222}Rn$ activity recommendation level.