• 제목/요약/키워드: Spatial Heterogeneity

검색결과 203건 처리시간 0.026초

Quantification of Total Mercury in Antarctic Surface Snow using ICP-SF-MS: Spatial Variation from the Coast to Dome Fuji

  • Han, Yeong-Cheol;Huh, Young-Sook;Hong, Sung-Min;Hur, Soon-Do;Motoyama, Hideaki;Fujita, Shuji;Nakazawa, Fumio;Fukui, Kotaro
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4258-4264
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    • 2011
  • The total mercury concentration ($Hg_T$) of surface snow samples collected along a ~1500 km transect in east Queen Maud Land was determined using inductively coupled plasma sector field mass spectrometry to address the behavior of Hg on the Antarctic Plateau. Due to the volatile nature of mercury, measures were taken against Hg loss from standard solutions by choosing appropriate container material and stabilizing agents. Glass bottles with Teflon-lined caps were superior to Teflon and polyethylene containers in protecting against Hg loss, but addition of gold chloride ($AuCl_3$) or bromine chloride (BrCl) was necessary to ensure preservation of Hg. As Hg loss was also observed in snowmelt samples, our analysis may underestimate the actual amount of HgT in the snow. Even so, the measured HgT was still very low (< 0.4-10.8 pg $g^{-1}$, n = 44) without a signal of depositional enhancement accompanying photo-oxidation of atmospheric elemental mercury in austral midsummer. Moreover, the dynamic variation along the traverse implies spatial and temporal heterogeneity in its source processes.

원격탐사자료를 활용한 지표면 조도계수 통합의 영향: 홍수유출 변화를 중심으로 (Impacts of Surface Roughness Integration Using Remote Sensing Data: Concentration of Flood Flow Variation)

  • 강신욱;유승엽;이길하;황만하
    • 대한공간정보학회지
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    • 제15권2호통권40호
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    • pp.33-42
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    • 2007
  • 원격탐사 자료를 이용한 토지피복도로부터 유역의 식생상황을 고려한 지표면 조도계수를 추정하기 위한 물리적 기반의 지표면 조도계수 추정방법을 제안하였다. 사전 연구로써 지표면 조도계수의 변화에 따른 첨두유량, 유출체적, 첨두시간에 대한 반응을 분석하기 위하여 NWS-PC 모형을 사용하였다. predominant, arithmetic mean, aggregation 방법으로 구해진 지표면 조도계수가 강우-유출 모형의 매개변수에 미치는 영향을 분석하였다. 지표면 조도계수에 대한 민감도 분석에서는 첨두유량이 약 10%의 변화를 나타내었고, 유출체적의 경우 약 2%의 변화를 나타내었다. 첨두시간은 지표면 조도계수에 비례하여 증가하는 것으로 나타났다. 물리적 기반의 aggregation 방법에 의해 구한 지표면 조도계수를 사용하였을 때의 강우-유출 모의결과는 STDEV, RMSE, NSE, PME 통계량에서 나은 결과를 보였지만, 각각의 통합 방법에 대해 크게 다른 결과를 보이지는 않았다. 그러나, 모형에서 지표면 조도계수의 설정에 따라 기저유량을 표현하는 하층부의 매개변수는 민감하게 변화하는 것으로 나타났다.

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Deprivation and Mortality at the Town Level in Busan, Korea: An Ecological Study

  • Choi, Min-Hyeok;Cheong, Kyu-Seok;Cho, Byung-Mann;Hwang, In-Kyung;Kim, Chang-Hun;Kim, Myoung-Hee;Hwang, Seung-Sik;Lim, Jeong-Hun;Yoon, Tae-Ho
    • Journal of Preventive Medicine and Public Health
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    • 제44권6호
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    • pp.242-248
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    • 2011
  • Objectives: Busan is reported to have the highest mortality rate among 16 provinces in Korea, as well as considerable health inequality across its districts. This study sought to examine overall and cause-specific mortality and deprivation at the town level in Busan, thereby identifying towns and causes of deaths to be targeted for improving overall health and alleviating health inequality. Methods: Standardized mortality ratios (SMRs) for all-cause and four specific leading causes of death were calculated at the town level in Busan for the years 2005 through 2008. To construct a deprivation index, principal components and factor analysis were adopted, using 10% sample data from the 2005 census. Geographic information system (GIS) mapping techniques were applied to compare spatial distributions between the deprivation index and SMRs. We fitted the Gaussian conditional autoregressive model (CAR) to estimate the relative risks of mortality by deprivation level, controlling for both the heterogeneity effect and spatial autocorrelation. Results: The SMRs of towns in Busan averaged 100.3, ranging from 70.7 to 139.8. In old inner cities and towns reclaimed for replaced households, the deprivation index and SMRs were relatively high. CAR modeling showed that gaps in SMRs for heart disease, cerebrovascular disease, and physical injury were particularly high. Conclusions: Our findings indicate that more deprived towns are likely to have higher mortality, in particular from cardiovascular disease and physical injury. To improve overall health status and address health inequality, such deprived towns should be targeted.

오염원에 대한 유도분극탐사 반응 및 사례 소개 (Induced Polarization Surveys of Contaminants and Introduction to Case Studies)

  • 김빛나래;;유희은;조아현;송서영;조성오;정인석;남명진
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제25권2_spc호
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    • pp.86-100
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    • 2020
  • Analyzing and monitoring environmental contaminants based on geophysical exploration techniques have become important and it is now widely applied to delineate spatial distribution geophysical characteristics in wide area. Among the techniques, induced polarization (IP) method, which measures polarization effects on electrical potential distribution, has drawn much attention as an effective tool for environmental monitoring since IP is sensitive to changes in biochemical reactions. However, various reactions stemming from the presence of multiple contaminants have greatly enhanced heterogeneity of polluted sites to result in highly variable electrical characteristics of the site. Those contaminants influence chemical and physical state of soil and groundwater to alter electrical double layer, which in turn influences polarization of the media. Since biochemical reactions between microbes and contaminants result in various IP effects, IP laboratory experiments were conducted to investigate IP responses of the contaminated soil samples under various conditions. Field IP surveys can delineate the spatial distribution of contamination, while providing additional information about electrical properties of a target medium, together with DC resistivity. Reviewing IP effects of contaminants as well as IP surveys can serve as a good starting point for the application of IP survey in site assessment for environmental remediation.

Responses of an herbaceous community to wild boar (Sus scrofa coreanus Heude) disturbance in a Quercus mongolica forest at Mt. Jeombong, Korea

  • Lyang, Doo-Yong;Lee, Kyu-Song
    • Journal of Ecology and Environment
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    • 제33권3호
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    • pp.205-216
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    • 2010
  • This research identified a disturbance regime caused by wild boar in a mature Quercus mongolica forest and analyzed the impact of this disturbance on the structure and distribution of herbaceous plants in Mt. Jeombong, Korea. We demonstrate that disturbance by wild boar was most frequent from winter to early spring, but also occurred year round. Areas which were frequently disturbed by wild boar included the mountain ridge, the mild slope on the north face, and sites with high concentration of Erythronium japonicum. The disturbance cycle by the wild boar in this region was estimated at approximately 2.8 years. The wild boar's reduced the community's species diversity and herbaceous coverage, and increased its evenness. This disturbance reduced the coverage of spring ephemeral; Veratrum nigrum var. ussuriense, Symplocarpus niponnicus, Anemone koraiensis and Corydalis turtschaninovii were particularly sensitive. In addition, summer green herbaceous plants such as Astilbe chinensis, Ainsliaea acerifolia, Meehania urticifolia, and Pimpinella brachycarpa were sensitive to the wild boar's. It was found that wild boar ate E. japonicum most selectively of all plants in this investigation area. In conclusion, together with micro-topography, wind, formation of gaps of a forest and rearrangement of litter layer, wild boar's disturbance is an important factor influencing the dynamic changes of an herbaceous community in a mature temperate hardwood forest.

도시노인의 여가공간과 생활세계 (Life World and Experiences of Spaces of Urban Elderly in Korea)

  • 한경혜;윤성은
    • 한국지역사회생활과학회지
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    • 제20권1호
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    • pp.103-121
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    • 2009
  • Increased consensus among gerontologists exist on the need to pay greater attention to the reciprocal relationship between the social and spatial in order to understand the construction of aged identity and everyday lives of old people. With urbanization, spaces are increasingly age-graded and as a consequence, urban elders are socially isolated from the community. In this study, we examine the social interaction patterns in various places specifically designated for the elderly, such as the Senior Center, Senior Welfare Center, and Hall for the Aged in Seoul. Main purpose of this study is to understand everyday life experiences of space the elderly people residing in the city go through. Data were gathered through qualitative, case study method. Results show that such spaces were important sites for social interaction for urban elderly who lacked social spaces after retirement and active parenting role. Also, it was shown that each place presents different contexts for social interactions and certain components of social class differences existed. Heterogeneity within the participants of each place was also observed. Quite strong stereotypes about certain places were also observed among the urban elders. Based on these results, importance of developing a 'community perspective' in the study of old age is discussed.

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Dosimetric Impact of Ti Mesh on Proton Beam Therapy

  • Cho, Shinhaeng;Goh, Youngmoon;Kim, Chankyu;Kim, Haksoo;Jeong, Jong Hwi;Lim, Young Kyung;Lee, Se Byeong;Shin, Dongho
    • 한국의학물리학회지:의학물리
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    • 제28권4호
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    • pp.144-148
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    • 2017
  • When a high density metallic implant is placed in the path of the proton beam, spatial heterogeneity can be caused due to artifacts in three dimensional (3D) computed tomography (CT) scans. These artifacts result in range uncertainty in dose calculation in treatment planning system (TPS). And this uncertainty may cause significant underdosing to the target volume or overdosing to normal tissue beyond the target. In clinical cases, metal implants must be placed in the beam path in order to preserve organ at risk (OARs) and increase target coverage for tumors. So we should introduce Ti-mesh. In this paper, we measured the lateral dose profile for proton beam using an EBT3 film to confirm dosimetric impact of Ti-mesh when the Ti-mesh plate was placed in the proton beam pathway. The effect of Ti-mesh on the proton beam was investigated by comparing the lateral dose profile calculated from TPS with the film-measured value under the same conditions.

On the Spatial and Temporal Variability of L-band Polarimetric SAR Observations of Permafrost Environment in Central Yakutia

  • Park, Sang-Eun
    • 대한원격탐사학회지
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    • 제33권1호
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    • pp.47-60
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    • 2017
  • The permafrost active layer plays an important role in permafrost dynamics. Ecological patterns, processes, and water and ice contents in the active layer are spatially and temporally complex depending on landscape heterogeneity and local-scale variations in hydrological processes. Although there has been emerging interest in the application of optical remote sensing techniques to permafrost environments, optical sensors are significantly limited in accessing information on near surface geo-cryological conditions. The primary objective of this study was to investigate capability of L-band SAR data for monitoring spatio-temporal variability of permafrost ecosystems and underlying soil conditions. This study exploits information from different polarimetric SAR observables in relation to permafrost environmental conditions. Experimental results show that each polarimetric radar observable conveys different information on permafrost environments. In the case of the dual-pol mode, the radar observables consist of two backscattering powers and one correlation coefficient between polarimetric channels. Among them, the dual-pol scattering powers are highly sensitive to freeze/thaw transition and can discriminate grasslands or ponds in thermokarst area from other permafrost ecosystems. However, it is difficult to identify the ground conditions with dual-pol observables. Additional backscattering powers and correlation coefficients obtained from quad-pol mode help understanding seasonal variations ofradar scattering and assessing geo-cryological information on soil layers. In particular, co-pol coherences atHV-basis and circular-basis were found to be very usefultools for mapping and monitoring near surface soil properties.

Reproduction Strategies of Clonal Plants of Potentilla conferta in Uzbekistan and Mongol

  • Huh, Man-Kyu;Lee, Byeong-Ryong
    • 한국환경과학회지
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    • 제21권11호
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    • pp.1297-1305
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    • 2012
  • Clonal plants combine sexual and clonal reproduction, which contribute differently to plant fitness. Reproductive analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Potentilla conferta Bunge, a herbaceous rhizomatic clonal distributed in hot sand dunes. We investigated the reproduction system of P. conferta at two populations in Mongol and three natural populations in Uzbekistan. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Some morphological characteristics between Mongolia and Uzbekistan populations showed a slight heterogeneity of variance. Especially, the length of internodes (LFI and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two countries (P<0.05). P. conferta of Uzbekistan has most ramets at short distance intervals 30~100 cm. In light conditions, P. conferta of Uzbekistan was significantly less resilience than P. conferta of Mogol. In drought conditions, although there was not shown significant difference, P. conferta in Uzbekistan was less resilience than that in Mogol. The core analysis indicates that P. conferta in Uzbekistan is the more resistant than that of Mongol and seems to do by sexual reproduction strategy during several strong environmental disadvantages such as drought events.

현대복식에 나타난 매너리즘(Mannerism)적 경향에 관한연구 (A study on the Mannerism tendencies in the Contemporary Costume)

  • 안선경
    • 복식
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    • 제33권
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    • pp.157-173
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    • 1997
  • The Mannerism which was born on Italy in 16th century was the critical trend of art influencing the political economical and psychological trends and was the first mo-dality which respected the individual sense of artist. The cultural situation of that time es-pecially the alienation of men is similar to the pluralism of value the coexistency of conflict the acceptance of heterogeneity and uncer-tainty I modern century. This paper analysed the pattern of change in the trend of Mannerism in modern costume by comparing current trend from the past focus-ing th fact that the over-all situation in this century is similar to that of Mannerism in 16th century. In this paper the author suggests the Defor-mation Ambiguity and Irreglarity as the character of manneristic trend which has re-solved the sense of alienation of men by paradoxic expression. The results of comparing the characteristic of mannerism to the modern costume is followd; 1. The Deformation in modern costume is grossly subdivided to the transfrmation of morphology the transformation of scale and the breakdown of equilibrium 2. The ambiguity in the modern costume can be subdivided to the eclecticistic expression and the ambiguity of spatial concept(between inner and outer garments). 3. The illogiclities in modern costume are the technique of illusion structural illogicality and the collage technique.

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