• 한국환경보건학회지
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• 제35권1호
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• pp.21-35
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• 2009

The Asian dust storms which originated in the deserts of Mongolia and China transported particles to Korea and led to a high concentration of atmospheric particulate matters (PM) of more than $1000{\mu}g/m^3$ throughout the country in the spring, of 2007. Public concern, in Korea, about the possible adverse effects of these dust events has increased, as these dust storms can contain various air pollutants emitted from heavily industrialized eastern China. The objectives of this study were to understand the concentration characteristics of PM as a function of particle size between the Asian dust storm episodes and non-Asian dust period and to consider the mass size distribution of PM in the Asian dust storms and their water soluble ion species on the potential, possible effects on deposition levels in the three regions (nasopharyngeal, tracheobronchial, and alveolar) of the human respiratory system. The size distribution of PM mass concentration during the Asian dust storms showed a peak in the coarse particle region due to the long-range transport of soil particles from the deserts of Mongolia and China, which was identified by HYSPLIT-4 model for backward trajectory analysis of air arriving in the sampling site of Iksan. During the non-Asian dust period, there were two different types in PM size distribution: bimodal distribution when low concentrations of $PM_{2.5}$ were observed, while unimodal distribution having a peak in fine particle region when high concentrations of $PM_{2.5}$ were showed. This unimodal distribution with high concentrations of fine particulate and secondary air pollutants such as ${SO_4}^{2-}$, ${NO_3}^-$, ${NH_4}^+$ was found to be due to the long-range transport of air pollutants from industrialized eastern China. During the Asian dust storms, the mean concentrations of PM that can be deposited in the nasopharyngeal, tracheobronchial, and alveolar region were $128.8{\mu}g/m^3$, $216.5{\mu}g/m^3$, and $89.6{\mu}g/m^3$, respectively. During the non-Asian dust period, the mean concentrations of PM that can be deposited in the nasopharyngeal, tracheobronchial, and alveolar region were $8.4{\mu}g/m^3$, $9.5{\mu}g/m^3$ and $38.5{\mu}g/m^3$, respectively.

• 대한토목학회논문집
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• 제31권2D호
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• pp.217-225
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• 2011

현재 우리나라는 자동차 보유대수가 지속적으로 증가함에 따라 교통 혼잡 문제와 환경 문제가 심각한 실정이다. 환경적으로 지속가능한 교통과 녹색 교통수단에 대한 관심이 증대되면서 최근 정부는 자전거이용 활성화 정책을 추진하고 있다. 이에 맞추어 자전거 이용자들이 느끼는 서비스수준을 분석할 수 있는 모형의 개발이 요망된다. 본 연구에서는 자전거도로 이용자들에 영향을 미치는 인자들 중 퍼지적 성격을 지닌 자전거도로 폭, 대면횟수, 보행자 교통량을 선택하여 자전거도로 서비스수준 분석을 위한 ANFIS 모형을 구축하였다. 이렇게 구축된 모형의 예측력은 실측치와 추론치를 비교함으로써 평가하였다. 결정계수 $R^2$와 오차 및 분산정도를 나타내는 척도인 평균절대오차(MAE)와 평균제곱근오차(MSE)가 각각 0.987, 0.142, 0.032로 나타났으며, 모형의 설명력이 높은 것으로 평가된다. 본 연구에서의 자전거도로 서비스수준이 KHCM에 의한 평가치보다 1~3단계 낮게 나타났다. 이는 본 연구에서 추정 된 서비스수준이 보행자 교통량 이외에 자전거도로 폭과 대면횟수를 고려한 이용자가 느끼는 만족도에 기초하여 서비스수준을 도출하였기 때문으로 판단된다.

• Smart Structures and Systems
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• 제20권5호
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• pp.549-562
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• 2017

The US railroad network carries 40% of the nation's total freight. Railroad bridges are the most critical part of the network infrastructure and, therefore, must be properly maintained for the operational safety. Railroad managers inspect bridges by measuring displacements under train crossing events to assess their structural condition and prioritize bridge management and safety decisions accordingly. The displacement of a railroad bridge under train crossings is one parameter of interest to railroad bridge owners, as it quantifies a bridge's ability to perform safely and addresses its serviceability. Railroad bridges with poor track conditions will have amplified displacements under heavy loads due to impacts between the wheels and rail joints. Under these circumstances, vehicle-track-bridge interactions could cause excessive bridge displacements, and hence, unsafe train crossings. If displacements during train crossings could be measured objectively, owners could repair or replace less safe bridges first. However, data on bridge displacements is difficult to collect in the field as a fixed point of reference is required for measurement. Accelerations can be used to estimate dynamic displacements, but to date, the pseudo-static displacements cannot be measured using reference-free sensors. This study proposes a method to estimate total transverse displacements of a railroad bridge under live train loads using acceleration and tilt data at the top of the exterior pile bent of a standard timber trestle, where train derailment due to excessive lateral movement is the main concern. Researchers used real bridge transverse displacement data under train traffic from varying bridge serviceability levels. This study explores the design of a new bridge deck-pier experimental model that simulates the vibrations of railroad bridges under traffic using a shake table for the input of train crossing data collected from the field into a laboratory model of a standard timber railroad pile bent. Reference-free sensors measured both the inclination angle and accelerations of the pile cap. Various readings are used to estimate the total displacements of the bridge using data filtering. The estimated displacements are then compared to the true responses of the model measured with displacement sensors. An average peak error of 10% and a root mean square error average of 5% resulted, concluding that this method can cost-effectively measure the total displacement of railroad bridges without a fixed reference.

• 기본간호학회지
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• 제3권2호
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• pp.153-169
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• 1996

This study was designed to identify, describe and classify orientations of cancer patient's family members to death and to identify factors related to their attitudes on death. Death to the male is understood as a comprehensive system and believed to be highly subjective experience. Therefore attitude on death is affected by personalities. As an attempt to measure the subjective meaning toward death, the unstructured Q-methodology was used. Korean Death Orientation Questonaire prepared by Kim was used. Item-reliability and Sorting-reliability were tested. Forty five cancer patients' family members hospitalized in one university medical center in Seoul were sampled. Sorting the 65 Q-itmes according to the level of personal agreement ; A forced normal distribution into the 11 levels, were carried out by the 45 P-samples. The demographic data and information related to death orientation of the P-sample was collected through face to face in depth interviews. Data was gathered from August 30 till September 22, 1995. The Z-scores of the Q-items were computed and principal component factor analysis was carried out by PC-QUANL Program. Three unique types of the death orientation were identified and labeled. Type I consists of twenty P-samples. Life and death was accepted as people's destiny, They firmly believed the existence of life after life. They kept aloof from death and their concern was facing the and of the life with dignity, They were in favor of organ donation. Type II consists of Nine P-Samples. They considered that death was the end of everything and did not believed the life after life. They were very concerned about the present life. Type III consists of Sixteen P-samples. They regarded the death as a natural phenomena. And they considered that the man is just a traveller and is bound to head for the next life which is believed to be free of agony, pain or darkness. They neither feared death nor its process. Their conserns were on the activities to prepare themselves for the eternal-life after death. Thus, it was concluded that there were three distinctiven type of attitudes on death among cancer patient family members, and their death attitudes were affected by demographic and socio-cultural factors such as sex, education, and religion.

• 한국토양비료학회지
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• 제51권2호
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• pp.101-110
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• 2018

There is an increasing concern over arsenic (As) contamination in rice since Codex Committee on Contaminants in Food (CCCF) discuss on maximum levels for As in rice in 2010. This study was conducted to reduce As concentration in rice by soil amendment treatments in paddy field soils contaminated by As. The selected four amendments were poultry manure, agri-lime, steel slag, and gypsum with the addition of 3% or 5% (w/w) on a dry basis. The As reduction effect could not be verified, as a result of the pot test by adding poultry manure to the paddy soil around the mine located in Yesan. Among the agri-lime treated rice cultivated pots, the As concentration increased up to 32.1%. On the other hand, the content of As in the sample pots treated with steel slag and gypsum decreased by 65.4% and 63.4%, respectively. On the basis of the results of these pot experiments, the field test was carried out in the As polluted rice field around the mine located in Yesan, and when the four amendments were treated, the As content in the brown rice reduced in all the amendment treatments compared with the control plot. The As reduction in brown rice of the amendment was confirmed to be higher efficiency by the order of gypsum > steel slag > poultry manure > agri-lime. As a result of pot experiments using paddy soil around the mine located in Seosan, As stabilization efficiency in rice and As reduction effect could not be determined by comparison to the control. From the rice cultivated from agri-lime treated pot, As concentration increased by 15.8% in rice. On the other hand, the As content of the pots treated with steel slag and gypsum decreased by 39.1% and 60.2%, respectively. In conclusion, distinguished As reducing effectiveness could be expected by soil amendment treatments for rice cultivation.

• 한국자원식물학회지
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• 제22권6호
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• pp.558-570
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• 2009

The vascular plants in Jeju composed of 21 families 62 genera, 190 species, 7 varieties with 197 taxa in Pteridophyta, 3 families 5 genera, 7 species, 3 forma with 10 taxa in gymnosperm (Coniferophyta) and 143 families 703 genera, 1,622 species, 114 varieties and 47 forma with 1,783 taxa in Endospermae. The total number of taxa was 1,990 consisting 167 families, 770 genera, 1,818 species, 121 varieties and 50 forma. Three families, 4 genera 4 species and 1 variety in Pteridophyta and 1 family, 1 genus I species, 1 forma of Coniferophyta were endemic to Jeju. Five families, 8 genera and 8 species in the Monocotyledonae of Endospermae and 23 families, 32 genera, 21 species, 16 varieties and 7 forma and 44 taxa in Cholipetalae, and 9 families, 24 genera, 12 species, 13 varieties and 7 forma, total 32 taxa in Sympetalae were endemic to Jeju. Total 90 taxa with 41 families, 69 genera, 46 species, 29 varieties and 15 forma were drawn up as endemic plants in Jeju. As the numbers show on, Jeju has more biodiversity especially plant diversity than any other places in Korea. It was an important region in regard to geographical position. The rarity on plants from Jeju has been assessed based on the IUCN red list categories and criteria at both regional and global levels. There was one species in each extinct (EX) and extinct in the Wild (EW). The EX and EW species were Rhododendron saisiuense Nakai (Ericaceae) and Asplenium antiquum Makino (Aspleniaceae), respectively. Three taxa, Rhododendron dauricum L. (Ericaceae), Lycopodium sieboldii Miq., and Lycopodiella cernua (L.) Serm (Lycopodiaceae) were species that is extinct in the region (RE). Sixty-one taxa were critically endangered (CR), 13 were endangered (EN), and 83 were vulnerable (VU) at regional level. The taxa listed on a Red List corresponds 26.9% of total taxa in Jeju. At global level, there were 19 taxa in CR, 4 in EN, and 1 in VU (Vulnerable) as the category of threat. The rest taxa (133 taxa) were classified as Least Concern (LC). According to the results of the assessment, conservation measures must be taken for total of 157 species that were categorized in threaten including one of EX, one of EW and three extinct in the region immediately. Of 157 species, 61 were CR, 13 are EN and 83 were VU.

• 한국식품과학회지
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• 제44권6호
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• pp.666-672
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• 2012

본 연구에서는 버섯류의 중금속 함량 실태조사를 통해 우리나라 국민이 식품으로써 버섯을 섭취할 경우 중금속 노출수준에 따른 위해성을 평가하였다. 버섯류의 중금속 함량 실태조사를 위해 국내 유통 중인 버섯류 17개 품목, 536건을 수거하였으며 버섯류 중 납 함량을 조사한 결과, 생물버섯은 평균 0.005(큰 느타리)-0.026(송이) mg/kg이었고 건조버섯은 평균 0.014(느타리)-16.411(석이) mg/kg이었다. 카드뮴 함량은 생물버섯의 경우 평균 0.002(팽이)-0.205(노루궁뎅이) mg/kg이었고 건조버섯은 평균 0.021(동충하초)-2.650(신령) mg/kg이었다. 따라서, 국내 유통 중인 버섯류의 중금속 함량은 타 문헌과 유사하거나 낮은 수준이었다. 노출 및 위해성 평가를 위해 버섯별 섭취를 통한 중금속 노출량을 산출한 후, Joint FAO/WHO Expert Committee on Food Additives(JECFA)에서 설정한 PTWI 또는 PTMI값 대비 위해도를 평가하였다. 버섯 섭취로 인한 전체국민의 평균 납 노출량은 $0.053{\mu}g/day$으로 PTWI 대비 0.03% 수준이었으며, 카드뮴 평균 노출량은 $0.168{\mu}g/day$으로 PTMI 대비 0.37% 수준이었다. 따라서, 국내 유통되는 버섯을 식품으로써 섭취할 경우 전체국민의 중금속 평균노출수준은 JECFA의 인체노출안전기준보다 낮은 위해도를 보임으로써, 우리나라 국민은 버섯에 존재하는 중금속의 위해성으로부터 안전한 것으로 사료된다.

• 한국건설관리학회논문집
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• 제8권4호
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• pp.128-136
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• 2007

1997년 교토의정서 체결과 같은 국제적 차원의 환경관련 규제와 관심이 고조됨에 따라, 많은 연구들이 효과적으로 친환경성을 평가할 수 있는 도구나 기술의 필요성을 강조해왔다. 본 연구는 건설 프로젝트의 친환경성을 평가하는 도구의 일환으로 건설현장의 폐기물 관리 성과 평가 툴을 구축하고자 한다. 이 평가 툴의 목적은 폐기물 저감 및 재활용 확대 측면에서 건설현장의 폐기물 관리 성과가 어느 정도 수준인지 정량적으로 평가하는 것이다. 본 연구에서는 평가 툴을 구축하기 위한 기반으로서, 선행연구에서 파악된 폐기물 관리 성과 요인의 성과 수준을 정량적으로 산정하기 위해 전문가 면담 및 설문을 통해 각 요인별 관리 행위 수준과 이들의 중요도를 파악하였다. 또한, 선행연구에서 제시한 평가 툴 구축 개념을 기반으로 실질적으로 전산화된 평가 툴을 개발하여 개별 건설현장 차원에서의 평가가 용이하도록 했다. 특히, 평가의 결과로서 제시되는 최종지표(TI) 및 지표등급(IR)은 건설현장의 폐기물 관리 수준을 정량적으로 비교 평가할 수 있는 기준이 될 수 있다. 폐기물 관리 성과 평가 툴은 건설현장의 폐기물 관리효과를 증진시키기 원하는 시공자 측면뿐만 아니라, 발주자 측면에서도 일정정도의 폐기물 관리수준을 객관적으로 요구할 수 있으므로 그 활용범위가 넓을 것으로 판단된다. 실제 현장에서의 적용가능성과 신뢰도를 검증하는 등의 세부적인 연구가 뒤따른다면 보다 효과적인 건설폐기물 관리방안이 될 수 있을 것이다.

• 한국항해항만학회지
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• 제40권3호
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• pp.121-128
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• 2016

본 연구는 항만배후단지 개발 및 임대방식의 변화를 겪고 있는 인천신항 항만배후지를 대상으로 하여, 기업 관점에서 고려하는 배후단지 입주결정요인을 도출하고, Fuzzy-AHP를 통해 입주결정 요인에 대한 우선순위를 분석하여 향후 인천신항 배후단지의 진입을 활성화하기 위한 방향을 제시하고자 하였다. 인천신항 배후단지 입주 결정요인들의 종합적인 가중치 순위를 평가하면 비용요인인 임대료 수준이 10.2%로 가장 높은 순위를 차지하였다. 다음으로 시장요인인 항만의 처리물동량이 8.2%, 배후시장의 규모가 7.3%, 비용요인인 내륙 운송비 절감이 7.1%, 입지요인인 내륙교통 운송망과의 연계성이 6.7%, 자유무역지역의 지정 및 규모가 6.4% 순으로 나타났다. 인천신항 배후단지 입주를 결정할 기업측면에서 보면 임대료 수준을 타 지역 항만의 배후지에 비교하여 매력적으로 제공할 필요성이 있다. 또한 수도권 화주의 가장 큰 고민 사항인 내륙운송비를 절감하고, 인천항에서 미주 및 구주항로로 직접 연결할 수 있는 항로개설이 필요하다.

• 한국해안·해양공학회논문집
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• 제30권3호
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• pp.103-113
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• 2018

경험모의기법을 통해 국내 서남해안의 조석과 해일특성을 고찰하였다. 그 결과 인천, 군산, 목포, 완도 등은 조석지배해역이고 여수, 통영, 부산 등은 해일지배해역으로 구분되었다. 조석지배해역에서는 태풍해일이 발생하지 않아도 50년 이하의 빈도를 갖는 극치해면고가 형성될 수 있는 반면 해일지배해역에서는 10년 빈도에서만 태풍해일 없이 극치해면고가 형성될 수 있는 양상을 보이고 있다. 각 해역에서 빈도별로 평균적인 상황으로 어느 정도의 조위에 어느 정도의 해일이 겹쳐 극치해면고가 형성되는지 고찰한 결과 이 역시 해역별로 구분되는 특성을 보이고 있다. 이와 함께 설계조위 산정을 위한 세 가지 방법을 비교고찰한 결과 약최고고조위방법은 과다설계의 우려가 매우 큰 비현실적인 결과를 보이고 있으며, 확률분포함수방법은 대형태풍이 소조기나 저조시 발생할 경우 해당자료가 결과에 반영되지 않거나 매우 축소된 결과가 도출될 우려가 있다는 단점이 있다. 이러한 단점들을 해결함과 동시에 서해안과 같이 조석이 지배적인 해역에 적합한 방법으로 경험모의기법의 적용성을 확인하였다.