• 제목/요약/키워드: point sampling

검색결과 825건 처리시간 0.029초

Source Proximity and Meteorological Effects on Residential Ambient Concentrations of PM2.5, Organic Carbon, Elemental Carbon, and p-PAHs in Houston and Los Angeles, USA

  • Kwon, Jaymin;Weisel, Clifford P.;Morandi, Maria T.;Stock, Thomas H.;Turpin, Barbara
    • 한국환경과학회지
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    • 제25권10호
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    • pp.1349-1368
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    • 2016
  • Concentrations of fine particulate matter ($PM_{2.5}$) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. $PM_{2.5}$ mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the $PM_{2.5}$ constituents' regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven $PM_{2.5}$ constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the $PM_{2.5}$ constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to $PM_{2.5}$ mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.

비선형 점탄소성 모델을 이용한 2차압밀이 포함된 수정압축지수개발 (Suggestion of Modified Compression Index for secondary consolidation using by Nonlinear Elasto Viscoplastic Models)

  • 최부성;임종철;권정근
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1115-1123
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    • 2008
  • When constructing projects such as road embankments, bridge approaches, dikes or buildings on soft, compressible soils, significant settlements may occur due to the consolidation of these soils under the superimposed loads. The compressibility of the soil skeleton of a soft clay is influenced by such factors as structure and fabric, stress path, temperature and loading rate. Although it is possible to determine appropriate relations and the corresponding material parameters in the laboratory, it is well known that sample disturbance due to stress release, temperature change and moisture content change can have a profound effect on the compressibility of a clay. The early research of Tezaghi and Casagrande has had a lasting influence on our interpretation of consolidation data. The 24 hour, incremental load, oedometer test has become, more or less, the standard procedure for determining the one-dimensional, stress-strain behavior of clays. An important notion relates to the interpretation of the data is the ore-consolidation pressure ${\sigma}_p$, which is located approximately at the break in the slope on the curve. From a practical point of view, this pressure is usually viewed as corresponding to the maximum past effective stress supported by the soil. Researchers have shown, however, that the value of ${\sigma}_p$ depends on the test procedure. furthermore, owing to sampling disturbance, the results of the laboratory consolidation test must be corrected to better capture the in-situ compressibility characteristics. The corrections apply, strictly speaking, to soils where the relation between strain and effective stress is time independent. An important assumption in Terzaghi's one-dimensional theory of consolidation is that the soil skeleton behaves elastically. On the other hand, Buisman recognized that creep deformations in settlement analysis can be important. this has led to extensions to Terzaghi's theory by various investigators, including the applicant and coworkers. The main object of this study is to suggestion the modified compression index value to predict settlements by back calculating the $C_c$ from different numerical models, which are giving best prediction settlements for multi layers including very thick soft clay.

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백두대간 중부권역 천연림의 산림피복형 분류와 종다양성 (The Classification and Species Diversity of Forest Cover Types in the Natural Forest of the Middle Part of Baekdudaegan)

  • 황광모;정상훈;김지홍
    • 한국산림과학회지
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    • 제104권1호
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    • pp.14-25
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    • 2015
  • 본 연구는 백두대간 중부권역의 구룡산, 소백산, 백화산, 속리산, 백학산 등 5지역을 대상으로 복잡 다양한 천연림 군집을 분류하고 산림피복유형을 집약하기 위해 실시되었다. 점표본법을 이용하여 1,114개의 표본점에서 식생자료를 수집하였으며, 조사된 식생자료를 바탕으로 Cluster 분석을 실시하였다. 그 결과 총 27개 군집으로 분류되었으며, 분류된 군집의 상층 수종구성의 유사성을 바탕으로 신갈나무림형, 중생혼합림형, 굴참나무림형, 소나무림형, 기타활엽수림형, 졸참나무림형, 아고산대림형 등 총 7개의 산림피복유형으로 집약하였다. 연구 대상지에서 신갈나무림형이 가장 넓게 분포하였고, 산림피복유형마다 신갈나무의 구성 비율이 증가함에 따라 종다양성지수가 낮아지는 경향을 나타내었다. 중생혼합림형과 기타활엽수림형은 계곡에 많이 분포하였고, 신갈나무림형과 소나무림형은 능선 부위에 많이 분포하는 것으로 조사되었다.

성인여성의 월경곤란증과 월경에 대한 태도 (Dysmenorrhea and Menstrual Attitudes in Adult Women)

  • 이은희;김증임;김혜원;이혜경;이숙희;강남미;허명행;박영숙
    • 여성건강간호학회지
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    • 제9권2호
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    • pp.105-112
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    • 2003
  • The survey was conducted to look out the characteristics of menstruation and it's management, menstrual attitudes and degree of dysmenorrhea in the adult women. The subjects were 601 women, aged 20 year old and over, selected by convenient sampling. The results were as follows; 1. The mean age of the subjects was 29.1 years, the subjects were consisted of 346 unmarried and 304 delivery experienced person. 2. The characteristics of menstruation were as follows ; irregular 167 person(27.8%), painful 451 person(75%), mean score of pain was 5.9 point and first day was most severe(45.1%). On the while, they have used the method to manage the pain such as "endure 50.8%", "to have a medicine 31.5%". 3. Menstrual attitudes were as follows; attitudes was negative such as it was meaningful as a woman (78.9%), only for birth a baby (51.6%), and menstruation was acceptable (42.9%), hope to get away(28.8%). 4. The degree of dysmenorrhea was a significant difference by age(F=4.0, P<0.01). Especially, in the subcategory, it was significant except for water retension. That is, lower concent ration(F=2.60, p<0.05), negative affect(F=3.09, p<0.05), behavior change(F=6.41, p<0.050), pain(F=3.89, p<0.01), autonomic nerve response(F=2.80, p<0.05). We can conclude there were many women to have negative attitudes to menstruation and first day was most severe dysmenorrhea and it was different by age. From this results, we may suggest as follows; 1. We suggest the program for women to have a positive attitudes will be developed. 2. We can suggest that we need to develop the active and effective method to control dysmenorrhea in the first day during menstruation.

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헤어리스마우스 피부 국소에 적용된 $^{125}I-rhEGF$의 피부흡수 및 체내 분포 (Dermal Absorption and Body Distribution of $^{125}I-rhEGF$ in Hairless Mice)

  • 이정욱;정석재;이민화;심창구
    • 약학회지
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    • 제41권6호
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    • pp.737-748
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    • 1997
  • Distribution of rhEGF in the skin, plasma and several organ tissues following topical application of $^{125}I-rhEGF$ (0.4${\mu}$Ci) solution in 25% Pluronic F-127 on 154$mm^2$ normal and damaged (burned and stripped) skins of hairless mice was examined. The radioactivity in the stripped skin tissues increased as a function of time, and was 10-20 times higher than that in the normal and burned skins. The fractions of intact drug in the skin tissues were 40-60% for the normal and burned skins, and 60-80% for the stripped skin. It indicates that the stratum corneum layer behaves as a barrier for the dermal penetration of the drug. The radioactivity in the plasma was much higher for the stripped skin than for the normal and burned skins. However, the concentration of intact drug in the stripped skin was comparable to those in the normal and burned skins indicating most severe degradation (or metabolism) of the drug in the stripped skin. As a result, the fraction of intact drug in the plasma was lowest for the stripped skin (<10%). Body organ distribution of the drug was much higher for the stripped skin. The concentration in the stomach. Both in total radioactivity and intact drug, showed more than 10-times higher value than in the other organs (liver, kidney and spleen). The fraction of intact drug in each organ tissue was below 10-20%. And generally lowest for the stripped skin. The lowest fraction of the drug for the stripped skin could not be explained by the activity of the aminopeptidases in the skin since it was lower for the stripped skin than for the normal skin. Thereover, the fraction of intact drug appears to be determined by the balance between dermal uptake and systemic elimination of the drug, for example. The mechanism of dermal uptake of rhEGF was examined by topical applying 200${\mu}$l of 25% Pluronic F-127 solution containing 0.4 ${\mu}$Ci of $^{125}I-rhEGF$ and 0.14${\mu}$Ci of $^{14}C$-inulin (a marker of passive diffusion). The radioactivity of $^{125}I-rhEGF$ at each sampling time point (0.5, 1, 2, 4 and 8hr) was correlated (p<0.05) with the corresponding radioactivity of $^{14}C$-inulin. It appears to indicate the rhEGF may be uptaken into the skins mainly by the passive diffusion. This hypothesis was supported by the constant specific binding of EGF to the skin homogenates regardless of the skin models. Receptor mediated endocytosis (RME) appears to contribute negligibly, if any, to the overall uptake process.

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경기도 김포시 모기의 계절적 발생소장 및 얼룩날개모기 유충 발생원의 생태학적 특성 (Seasonal Prevalence of Mosquitoes and Ecological Characteristics of Anopheline Larval Occurrence in Gimpo, Gyeonggi Province, Republic of Korea)

  • 김용기;이철민;이정분;배양섭
    • 한국응용곤충학회지
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    • 제51권4호
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    • pp.305-312
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    • 2012
  • 본 연구는 김포시에서 모기성충의 계절적 발생소장과 얼룩날개모기류 유충의 발생을 파악하기 위해서 실시되었다. 성충모기는 6지점에서 유문등을 이용하여, 2008년 5월부터 9월까지 조사되었다. 조사결과 8속 16종 48,919마리가 채집되었다. 금빛숲모기(Aedes vexans nipponii)가 43%로 가장 많았고, 중국얼룩날개모기(Anophels sinensis)가 34%, 작은빨간집모기(Culex tritaeniorhynchus)가 14%로 이 3 우점종이 전체의 91%를 차지했다. 얼룩날개모기류의 계절적 발생소장은 작은빨간집모기와 비교하여 다른 피크를 보였다. 얼룩날개모기류 유충은 203지점 중 138지점(63%)에서 확인되었다. 지점당 정량조사 결과에서 평균유충밀도는 연꽃 재배지가 6.9개체로 가장 높았으며, 다음으로 수로가 4.5개체, 미나리꽝이 3.4개체, 유수지가 3.2개체, 휴경논이 3.1개체, 논이 1.8개체, 습지가 1.4개체, 하천이 0.2개체 순이었다. 유충밀도와 용존산소량, 산도, 염분도, 흡밀원(축사, 돈사, 계사) 사이에 유의한 관계성은 없었다. 최근린평균거리분석(ANNA)의 결과에서, 유충 조사지점간 분포패턴은 전체 조사지점간과 4.0개체 이상 확인된 지점간에서 각각 밀집분포와 불규칙분포였다. 하성면에서는 유충이 3.0 개체 이상 확인된 지점간 분산분포를 나타냈다.

한국 중소수출기업의 인터넷 마케팅 전략과 성과에 관한 연구 (Internet Marketing Strategy and Performance in the Korean Small Export Firms)

  • 고경순
    • 통상정보연구
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    • 제4권1호
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    • pp.107-128
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    • 2002
  • 한국 중소수출기업의 인터넷을 이용한 수출마케팅 전략과 성과와의 관계를 밝히기 위하여 본고에서는 우선 이론적 배경을 바탕으로 한 연구모형의 개발 및 연구가설이 설정되었다. 이렇게 설정된 연구가설은 설문조사를 통한 자료수집과 MANOVA에 의한 통계분석을 통하여 검정되었다. 그 결과, 주로 세일즈와 광고에 적용되는 커뮤니케이션 효과계층의 고전적인 AIDA 모델을 준용한 수출성과와 인터넷 수출마케팅전략 변수간에는 거의 대부분의 경우 통계적으로 유의미한 관계가 있음을 발견하였다. 특히 AIDA의 효과계층 중 최종 수출계약성과에 비하여 그 이전 단계인 커뮤니케이션 효과가 더 크다는 사실을 확인한 것이 이 논문의 주요한 의의라고 여겨진다. 이라한 결과는 한국의 중소수출기업이 인터넷을 이용한 마케팅 전략을 짜는데 있어서 의미있는 시사점과 유의사항을 제공하고 있으며, 차후 연구자를 위한 하나의 준거가 될 수 있을 것으로 기대된다.

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인슐린의존형 당뇨병 환아 어머니의 돌봄 경험 (Caring Experience of Mothers with IDDM Children)

  • 최미혜
    • 대한간호학회지
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    • 제28권1호
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    • pp.81-92
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    • 1998
  • This study is to define the caring experience of mothers with insulin-dependent diabetes mellitus children, by finding core category, contextual factors, ntervening factors, and the patterns of caring, and to velop a practice theory on it. Research method followed grounded theory methodology by Strauss & Corbin. Subjects were six mothers. whose children have had insulin-dependent diabetes mellitus for 4 months to 14 years by the interview time. They were selected by theoretical sampling. Data were collected from September, 1995 to January, 1996. Interview were done by long interview technique and observation. Each interview took 50 minutes to 2 hours. Content of interview was recorded and transcribed later. Based on the results of previous interview, content of next interview was planned until data reached to the saturation point. Results were as follows : One hundred and forty concepts were found. These concepts were grouped into thirty-three categories, and then to ten categories. Mothers with diabetic child were revealed to face “being overwhelmed by burden”. Overwhelming by burden is found to be progressed through the cycle production-coping-decrease or in crease process. Mothers showed four patterns of adaptation in caring the diabetic children. 1) If mothers felt large amount of overwhelming by burden because of difficulty of caring and unsympathizing but they had sufficient support, no condition of the child, and their coping mechanism was positive, most of them overcome with strong will, but some fell into burnout. 2) If mothers felt large amount of overwhelming by burden because of difficulty of caring, unsympathizing, insufficient support. serious condition of the child, and their coping mechanism was negative, they fell into burnout by coping with feeling. 3) If mothers felt small amount of overwhelming by burden because of little difficulty of caring and sympathizing, sufficient support. no serious condition of the child, but their coping was negative, most of them fell into burnout by coping with feeling, but some overcome. 4) If mothers felt small amount of overwhelming by burden because of little difficulty of caring and unsympathizing, sufficient support, no serious condition of the child, and their coping was positive, they overcome with strong will. On the basis of the above result, in order to help mothers take good care of their children, nursing assesment and intervention on life readjustment, and getting support should be required. Especially, through understanding mothers' personalities, individual support consistent with each of them should be required. Therefore education. counseling, mutual support and exchange of information will have to be accomplished.

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농촌 소유역에서 EMC를 이용한 오염물질 부하량 산정기법의 개발 (Development of the EMC-based Empirical Model for Estimating Pollutant Loads from Small Agricultural Watersheds)

  • 김영철;김건하;이동률
    • 한국수자원학회논문집
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    • 제36권4호
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    • pp.691-703
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    • 2003
  • 본 논문에서는 유역과 강우특성을 통합하여 오염물질 부하량을 계산할 수 있는 접근방법을 제시하였다. 이 기법의 기본적인 개념은 특정유역에서 강우시 발생하는 오염물질의 유량 가중평균 농도, 즉 EMC 변화는 오로지 강우패턴에 의해 결정된다는 가정에 기초하고 있다. 이러한 가정은 적어도 유역의 토지이용에 급격한 변화가 없고(적어도 강우가 집중되는 경작기간동안) 점 오염원이 적은 농촌유역에서는 타당하다. 따라서, 다양한 농촌유역과 강우 패턴 조건에서 조사된 많은 EMC 자료가 있다면 EMC와 토지이용, 그리고 강우특성 사이의 유용한 경험적인 관계식을 도출할 수 있을 것이다. 이러한 목적을 달성하기 위하여 9개의 서로 다른 유역에서 51개의 독립적인 강우사상에서 조사된 EMC 자료를 이용하여 강우시 발생하는 EMC 값을 예측할 수 있는 도구를 개발하였다. 통계학적인 검토결과 개발된 경험식은 실제 측정한 EMC 값을 양호한 수준에서 예측할 수 있는 것으로 판명되었을 뿐만 아니라 EMC 자료와 유효 강우량에 기초하여 강우일, 주, 월, 년 단위의 부하량을 산출이 가능하였다. 또한, EMC 값과 유효 강우량에 의해 계산된 부하량으로부터 산출한 원 단위를 기존의 잘 알려진 경험적 원 단위와 비교 평가하였다.

비만 중.고등학생의 스트레스와 대처방법에 관한 연구 (Study on the Obese Students' Stress and Coping Method in Middle and High Schools)

  • 김이순
    • 지역사회간호학회지
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    • 제12권3호
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    • pp.732-745
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    • 2001
  • This study attempted to identify obese students' stress and coping method in middle and high schools. The data were collected from the total of 600 obese students from middle and high schools in Pusan. The author used a convenience sampling method. The data collection was done from March 2 to April 30. 2001. The analysis of the data was done with SPSS Win(10.0) for descriptive statistics. t-test. and ANOVA. The instrument used for the obese students' stress and coping method was a questionnaire developed by Kim. Yi-Soon and Kim. Young-Hae(200l). The tool was composed of 65 items (33stress items: 32coping method items) with the five-point Likert scale. The results were as follow: 1. The average score of stress was 2.49 (SD = .86) points in the male students. and 2.83(SD= .86) points in the female students. The subcategories were: (outward appearance), (boyfriend/girlfriend), (occurrence of an outbreak of a disease), (relationship within the family), (an obese appearance), (difficulty in exercise). The highest degree of stress came from 'an obese appearance' for the male students (mean=2.64. SD=0.87) and (mean=2.64. SD=0.87) for the female students. 2. The subcategories of the coping method were: (be concerned about other matters), (recreation activities), (self-violence), (relaxation), (hobby activities), (avoid a situation), (communication), (music), (negative behavior), (positive thinking). The highest degree of coping method were (recreation activities) in the male students (mean=3.07. SD=0.86) and (music) in the female students (mean=3.47. SD=1.01). 3. The results comparing stress with demographic variables were significant for gender (t=7.010. p=0.000). grades at school (F=2.918. p=0.02l), degree of obesity (F=5.205. p=0.006). grades (F=2.550. p=0.027). standard of living(F=8.277. p=0.000). the state of health (F=2.882, p=0.022), relationship with the father (F=4.790, p=0.001), relationship with the mother (F=6.080, p=0.000), and the educational level of the father (F=3.192, p=0.013). 4. The results comparing the coping method with demographic variables were significant for gender (t=4.597. p=0.000). These findings contribute to the understanding of the degree of stress and the type of coping methods of obese students in middle and high schools. Therefore, the result of this study aids in an effective nursing intervention to improve the mental health program for the obese.

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