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        검색결과 845

        561.
        2020.07 KCI 등재 서비스 종료(열람 제한)
        The characteristics of heavy metal ion (Ni2+, Zn2+, and Cr3+) adsorption by zeolite synthesized from Jeju scoria using the fusion and hydrothermal method, were studied. The synthetic zeolite was identified as a Na-A zeolite by X-ray diffraction analysis and scanning electron microscopy images. The equilibrium of heavy metal ion adsorption by synthetic zeolite was reached within 60 min for Ni2+ and Zn2+, and 90 min for Cr3+. The uptake of heavy metal ions increased with increasing pH in the range of pH 3-6 and the uptake decreased in the order of Cr3+ > Zn2+ > Ni2+. For initial heavy metal concentrations of 20-250 mg/L at nonadjusted pH, the adsoption of heavy metal ions was well described by the pseudo second-order kinetic model and was well fitted by the Langmuir isotherm model. The maximum uptake of heavy metal ions obtained from the Langmuir model, decreased in the order of Zn2+ > Ni2+ > Cr3+, differing from the effect of pH on the uptake, which was mainly based on the different pH of the solutions.
        562.
        2020.05 KCI 등재 서비스 종료(열람 제한)
        This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM2.5 and PM10 were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM2.5 and PM10, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM2.5 and from 45.1% to 29.1% in PM10, despite the exclusion of organic matter and elemental carbon.
        563.
        2020.03 KCI 등재 서비스 종료(열람 제한)
        제주특별자치도는 한 해 약 1,500만명의 관광객이 입도하는 대한민국의 대표적인 관광지이다. 또한 화산섬이라는 특수성으로 현무암과 같은 고유의 재료와 문화적 특성 및 경관을 보유하고 있다. 따라서 본 연구는 지역 고유의 문화를 고려하고 레지블 디자인, 유니버설 디자인이 적용된 안내사인 개발을 통해 경관 저해를 방지하고 관광활성화에 기여하고자 한다. 본 연구의 공간적 범위는 제주특별자치도 전역으로 연구의 내용적 범위는 안내사인 현황분석과 관광형 안내사인 공공시설물 디자인 개발이다. 연구의 방법은 문헌조사를 통한 일반현황 조사, 현장조사를 통한 공공시설물 현황조사, 선진사례 조사, 디자인 연구개발은 디자인 기본 구상, 관광형 안내사인 개발이다. 본 연구의 내용 및 결론은 다음과 같다. 첫 번째, 제주특 별자치도는 한반도와 다른 지형적, 기후적 특성을 보이는 서정적 분위기를 매력으로 하는 관광지로 경관의 연속성을 위해 곳곳에 분포한 현무암을 공공시설물의 재료로 적극 활용하되 시설물의 특성에 따라 다양한 방법을 통해 각각의 고유 이미지를 형성하였다. 두 번째, 강한 해풍의 영향을 고려하여 내식성이 우수한 재료를 사용하고 돌출부를 최소화한 구조를 설계 하였다. 세 번째, 외국인 관광객이 지속적으로 방문하는 도시로 관광객의 편의성 향상을 위해 표준화된 표기체계와 다국어 표기 등의 정보 범용성을 확보하였다. 본 연구는 제주특별자치도가 가지고 있는 지역 고유의 경관을 강화하는 관광형 공공 시설물 개발의 기초가 되는 연구라는 점에서 의의가 있으며 향후 다양한 품목의 관광형 공공시설물 표준디자인을 개발하는 데 기여할 것이라고 본다.
        564.
        2020.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the spatio-temporal patterns of summertime thermal environments in the two subtropical cities (Jeju and Seogwipo) of Jeju Island, Korea are examined. Long-term average data from Jeju and Seogwipo show that higher human sensible temperature (HST) than air temperature (T) due to the high humidity effects associated with warm sea surface temperature around Jeju Island is most distinct during mid-summer period (late July-early August). Comparatively, their trend analyses reveal that summertime intra-seasonal changes with more increasing HST than T are most obviously observed in late summer (late September-early October) and regionally in Seogwipo. According to the hourly temperature-humidity data measured at approximately 30 HOBO temperature-humidity sensors deployed in the two subtropical cities during 2019 summer, the greater HST than T during mid-summer period maximizes up to 6.2°C and 7.0°C across the urban areas of Jeju and Seogwipo, respectively in early afternoon, leading to consecutive inter-daily heat wave events. The examination of their spatial patterns demonstrates that bioclimatic heat waves in these two subtropical cities are affected primarily by the urban heat island phenomenon. However, it should not be overlooked that local moisture advection from the warm ocean adjacent to the subtropical cities can modify the stronger heat wave pattern toward urban cores. It is also notable that according to comparisons of local HST and T distributions between impervious urban cores and neighboring urban parks, not only the size of green space but also other ecological properties including species of vegetation may be crucial factors to the mitigation of hot thermal environments in subtropical cities during summers.
        565.
        2020.02 KCI 등재 서비스 종료(열람 제한)
        Seasonal changes in the CO2 fixation rate and water-use efficiency in the leaves of six evergreen and two deciduous broad-leaved tree species on Jeju Island, Korea, were measured using a portable photosynthesis analyzer, to identify which species are most efficient in taking up CO2 from the air. The CO2 fixation rate was high in the deciduous species in spring and summer and decreased in fall, whereas it was high in the evergreen species in summer and fall and decreased in winter. The rate remained high in the deciduous tree Prunus yedoensis from spring to fall (> 7.1 μmol CO2/m2/s) and in two evergreen trees, Castanopsis cuspidata var. sieboldii and Cinnamomum camphora, in summer and fall (7.0 9.9 μmol CO2/m2/s). Therefore, these tree species fix atmospheric CO2 effectively. The water-use efficiency was higher in evergreen species than in deciduous species regardless of the season. Exceptionally, it was high in the deciduous species Zelkova serrata in spring and summer (> 100 μmol CO2/mol H2O), suggesting that Z. serrata is a useful tree for dry conditions due to its tolerance of water stress. The regressions of the CO2 fixation rate versus the evaporation rate and stomatal conductance were linear and non-linear, respectively. This suggests that the stomatal activity of leaves plays an important part in CO2 fixation of plants. In conclusion, C. cuspidata var. sieboldii, C. camphora, and P. yedoensis should be planted along roads or in urban spaces for the greening of cities and mitigation of CO2 concentrations in the air.
        566.
        2020.01 KCI 등재 서비스 종료(열람 제한)
        To determine the size distributions of water-soluble inorganic ionic species (WSIS) in roadside aerosols, sampling experiments were carried out in the urban roadside area of Jeju City on August 2018 and January 2019 by using the eight-stage cascade impactor sampler. The mass of roadside aerosols were partitioned at 57% in fine fraction, 36-37% in coarse fraction, and 6-7% in giant fraction, regardless of summer and winter. The mass concentrations of WSIS except for Na+ and SO42- in roadside aerosols were higher in winter than in summer. The size distributions of Na+, Mg2+, Ca2+ and Cl- were characterized by bimodal types with coarse particle mode peaking around 3.3-4.7㎛ and 5.8-9.0㎛ . The size distributions of NO3 - and K+ shifted from a single fine mode peaking around 0.7-1.1㎛ in winter to bimodal and/or trimodal types with peaks around coarse mode in summer. SO4 2- and NH4 + showed a single fine mode peaking around 0.7-1.1㎛ . The MMAD of roadside aerosols was lower than that of Na+, Mg2+, Ca2+ and Cl-. Based on the marine enrichment factors and the ratio values of WSIS and the corresponding value for sea water, the composition of roadside aerosols in Jeju City may be practically affected by terrestrial sources rather than marine source.
        567.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        We used numerical models to reliably analyze the groundwater flow and hydraulic conductivity on Jeju Island. To increase reliability, improvements were made to model application factors such as hydraulic watershed classification, groundwater recharge calculation by precipitation, hydraulic conduction calculation using the pilot point method, and expansion of the observed groundwater level. Analysis of groundwater flow showed that the model-calculated water level was similar to the observed value. However, the Seogwi and West Jeju watersheds showed large differences in groundwater level. These areas need to be analyzed by segmenting the distribution of the hydraulic conductivity. Analyzing the groundwater flow in a sub watershed showed that groundwater flow was similar to values from equipotential lines; therefore, the reliability of the analysis results could be improved. Estimation of hydraulic conductivity distribution according to the results of the groundwater flow simulation for all areas of Jeju Island showed hydraulic conductivity > 100 m/d in the coastal area and 1 45 m/d in the upstream area. Notably, hydraulic conductivity was 500 m/d or above in the lowlands of the eastern area, and it was relatively high in some northern and southern areas. Such characteristics were found to be related to distribution of the equipotential lines and type of groundwater occurrence.
        568.
        2019.11 KCI 등재 서비스 종료(열람 제한)
        All of the animals and the plants in ecosystem are intimately connected to one another and the changes of forests and surroundings affect directly wild animals. This study was conducted at Hangyeong-myeon Cheongsu-ri located in the western part of Jeju Island belonging to Hangyeong·Andeok Gotjawal Zone and Jocheon-eup Seonheul-ri located in the eastern part of Jeju Island belonging to Jocheon·Hamdeok Gotjawal Zone. The survey on advent of birds was carried out twice a month from January 2014 to December 2015. We divided habitat environments into three survey sites such as a forest, a shrub forest and a farmland. A total of 65 species and 4,802 individuals were observed during the survey period. In a forest, 36 species and 1,287 individuals were observed while A shrub forest had 40 species and 1,554 individuals. And in a farmland, 41 species and 1,961 individuals were observed. The only 10 species were observed in forest and the only 7 species in shrub forest and the only 10 species in farmland. The species diversity and the evenness of a farmland were the highest, and the species richness was the highest in a shrub forest, and the dominance of a forest was the highest among the three areas. The similarity index between a shurb forest and a farmland was high while that between a forest and a farmland was low. The similarity index related with breeding appeared that a forest and a farmland was different from each other.
        569.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        Ensemble verification and prediction of low-level wind shear (LLWS) are an important matter for airplane landing and management. In this study, we compared the prediction performance of LLWS forecasts of ensemble mean, multiple regression model and long short-term memory (LSTM), which belong to the family of recurrent neural network based on the grid points over the Jeju area. The prediction skills of methods were compared by mean absolute error. We found that the prediction skills of forecasts of LSTM were better than the bias-corrected forecasts in terms of deterministic prediction.
        570.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        최근의 예멘 난민 사태는 국제난민 이슈가 한국인의 일상으로 다가올 때 타나는 시민사회의 충격파를 보여주었다. 10여 년간 다문화 정책에 투여한 정부의 재정과 시민단체의 인식 개선 노력이 무색할 정도로 제주도 예멘 난민 이슈는 반(反)다문화주의 현상을 심화시켰다. 이 논문은 세계시민성 관점에서의 이주민 성원권 개념을 바탕으로 예멘 난민을 둘러싸고 나타난 다양한 논쟁의 교차점을 분석하였고 다문화교육이 나아가야 할 방향을 비판적으로 고찰하였다. 난민과 이주민의 성원권에 관한 논의 실종, 난민 권리에 대한 이해와 학습의 부재, 그리고 이질성을 가진 타자의 사회 참여에 대한 현재의 다문화교육의 이슈와 문제를 분석하였으며, 궁극적으로 난민 문제를 보편적인 성원권과 인권의 실천이라는 관점에서 담아내기 위한 다문화교육의 재구조화를 주장하였다.
        571.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        The adsorption and leaching characteristics of five ionic pesticides including four acidic pesticides (2,4-D, dicamba, MCPA, and MCPP) and one amphoteric pesticide (imazaquin) in agricultural soils were investigated. Soils around spring waters that were heavily affected by pesticide run-off and soils around wells considering the regional characteristics in Jeju Island were collected at 24 stations. The Freundlich constant, KF value, which is a measure of the adsorption capacity, decreased in the order of 2,4-D > MCPA > MCPP > dicamba > imazaquin. The adsorption capacity of these ionic pesticides decreased with increasing pH owing to the effects of ionization of pesticides and different ionizable functional groups of soils. The leaching of ionic pesticides in the soil column showed a reverse relationship with their adsorption in soils, namely, the ionic pesticides were leached more quickly for the pesticides with lower adsorption capacity. The groundwater contamination potential of the ionic pesticides was evaluated in the order of imazaquin > MCPA > MCPP > dicamba > 2.4-D according to the groundwater ubiquity score based on soil Koc and the half-life of the pesticide.
        572.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        We computed parameters that affect velocity distribution by applying Chiu’s two-dimensional velocity distribution equation based on the theory of entropy probability and acoustic doppler current profiler (ADCP) of Jungmun-stream, Akgeun-stream, and Yeonoe-stream among the nine streams in Jeju Province between July 2011 and June 2015. In addition, velocity and flow were calculated using a surface image velocimeter to evaluate the parameters estimated in the velocity observation section of the streams. The mean error rate of flow based on ADCP velocity data was 16.01% with flow calculated using the conventional depth-averaged velocity conversion factor (0.85), 6.02% with flow calculated using the surface velocity and mean velocity regression factor, and 4.58% with flow calculated using Chiu’s two-dimensional velocity distribution equation. If surface velocity by a non-contact velocimeter is calculated as mean velocity, the error rate increases for large streams in the inland areas of Korea. Therefore, flow can be calculated precisely by utilizing the velocity distribution equation that accounts for stream flow characteristics and velocity distribution, instead of the conventional depth-averaged conversion factor (0.85).
        573.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to identify the problems of the underground watersheds on Jeju Island, and to establish the hydraulic groundwater basin to be used as basis for the analysis of the groundwater model. In order to evaluate the adequacy of the groundwater basin on Jeju Island, a correlation analysis between elevation and groundwater level was conducted using data from 125 observation wells. The analysis, conducted with an elevation step of 100 m, exhibited values of R2 in the range 0.1653-0.8011. No clear correlation was observed between elevation and groundwater level. In particular, the eastern and western areas showed an inverse proportionality between elevation and groundwater level. The Kriging technique was used to analyze the underground water level data and to define the equipotential lines for all areas of Jeju Island. Eight groundwater watersheds were delineated by considering the direction of groundwater flow, the positions of the observation wells, and the long and short axes of the watersheds.
        574.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of legume cover crop culture on earthworm fauna in organic farmland. We compared sod culture with two kinds of legume crops of hairy vetch and crimson clover on organic citrus orchard to natural sod culture and conventional orchards in Jeju Island. We analyzed the soil characteristics and investigated the density of earthworms from the orchards. Organic matter content did not show much difference in soil analysis between organic and conventional orchard. But the biomass of earthworms in organic orchards is 3.8 times to 7.0 times higher than that in conventional cultivated orchards, and individuals of earthworms on organic orchards were 2.3~18 times higher than conventional orchards. The biomass of earthworms on hairy vetch and crimson clover cultivation was 44.8 g, 47.2 g in 2016, and 78.7 g, 31.8 g in 2017, respectively, which were higher than 32.8 g and 9.5 g of those on natural sod cultivation. Through this study, we found that hairy vetch and crimson clover cultivation improve the earthworm occurrence density in the soil on organic citrus orchard.
        575.
        2019.01 KCI 등재 서비스 종료(열람 제한)
        The adsorption properties of Cs+ and Cu2+ ions were evaluated by using a polysulfone scoria zeolite (PSf-SZ) composite with synthetic zeolite synthesized from Jeju volcanic rocks (scoria). In order to investigate the adsorption properties, various parameters, such as pH, contact time, reaction rate, concentration, and temperature in aqueous solutions, were evaluated by tests carried out in batch experiments. The adsorption capacities of Cs+ and Cu2+ ions increased between pH 2 but achieved equilibrium at pH 4 and above. The adsorption rate increased rapidly up to the initial 24 h, after which it plateaued ; the adsorption rate then sustained at equilibrium from 48 h. The adsorption kinetics of Cs+ and Cu2+ ions were described better by the pseudo-second-order kinetic model than the pseudo-first-order kinetic model. The Langmuir model fitted the adsorption isotherm data better than the Freundlich model. The maximum adsorption capacities of Cs+ and Cu2+ ions obtained from the Langmuir model were 53.8 mg/g and 84.7 mg/g, respectively. The calculated thermodynamic parameters showed that the adsorption of Cs+ and Cu2+ ions on PSf-SZ was feasible, spontaneous and endothermic reaction.
        576.
        2019.01 KCI 등재후보 서비스 종료(열람 제한)
        이 글은 제주지역에 거주하는 여성결혼이민자를 대상으로 제주 방언으로 제작된 TV 드라마를 활용하여 제주 방언 교육과 문화 교육을 통합할 수 있는 방안을 살펴보고자 하였다. 드라마 ‘멩질 먹게 저 오라’는 모든 대사를 제주 방언으로 구사하고 있고, 등장인물은 여성결혼이민자가 늘상 만나는 친근한 인물들로 설정되었다. 이러한 설정은 여성결혼이민자가 드라마를 학습 도구로 활용할 때 큰 거부감이나 어려움 없이 드라마의 내용을 받아들이는 장치로 작용할 것이다. 이 드라마의 모든 대사에는 표준어 자막이 사용되었다. 이는 여성결혼이민자가 제주 방언을 제대로 알아듣지 못한다고 해도 드라마의 내용을 이해하는 데에 문제가 없다는 점을 내포한다. 오히려 이 자료로 교육이 제대로만 이루어진다면 표준어와 방언 교육의 효과를 동시에 거두고 아울러 제주 지역민의 사유 체계를 담아내는 문화까지 학습하여 일석삼조의 효과를 볼 수 있을 것이라고 생각된다. 드라마 ‘멩질 먹게 저 오라’로 여성결혼이민자의 표준어 교육과 동시에 제주 방언 교육이 이루어진다면 제주지역에 거주하고 있는 여성 결혼이민자들의 의사소통의 장애를 조금이나마 해결할 수 있을 것이 다. 또한 문화 교육의 측면에서도 제주만의 독특한 문화를 제대로 담아내고 있는 이 드라마를 자료로 활용한다면 여성결혼이민자가 제주 사회에서 하나의 구성원으로 적응하는 데에 도움이 되리라 판단하여 ‘멩질 먹게 저 오라’를 활용한 언어ㆍ문화 교육 방법을 모색해보았다.
        577.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        In this study, PAN-SZ (polyacrylonitrile scoria zeolite) beads were prepared by immobilizing Na-A zeolite (SZ-A) synthesized from Jeju volcanic rocks (scoria) on the polymer PAN. FT-IR and TGA analysis results confirmed that the SZ-A was immobilized in the PAN-SZ beads. SEM images showed that the PAN-SZ beads are a spherical shape with 2 mm diameter and exhibit a porous inner structure inside the bead. The most suitable mixing ratio of PAN to SZ-A as the adsorbent for removing Sr ions was PAN/SZ-A = 0.2 g/0.3 g. The adsorption kinetic data for Cu and Sr ions were fitted well with the pseudo-second-order model. The Cu and Sr ion uptakes followed a Langmuir isotherm model and the maximum adsorption capacities at 20℃ were 84.03 mg/g and 75.19 mg/g, respectively. The amount of Sr ion adsorbed by SZ-A on the PAN-SZ beads was about 160 mg/g, which was similar to that adsorbed by SZ-A powder. Thus, the PAN-SZ beads prepared in this study are considered to be effective adsorbents for removing metal ions in aqueous solutions.
        578.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        Waste management in Jeju Province, Korea, has recently emerged as an urgent problem. The increasing waste discharge requires more landfills but, since it is an island, the available land is restricted. Accordingly, an efficient waste management urgently requires environmentally sustainable policies. In this article, the waste discharge characteristics (such as the amount of waste, its composition, etc.) of Jeju Province have been compared with those in the rest of Korea. The current industrial waste management of two cities on the Island, Jeju City and Seogwipo City, has been also analyzed to suggest policies for an efficient management. The local government’s endeavor to enhance environmental awareness of the community has been known to reduce the private cost of policy compliance, and have individuals recognize the results of their policy compliance. Policies to achieve the above are then proposed.
        579.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        The residential population of Jeju Island has increased more than 10% for last 10 years. Especially, the tourist population is more than twice comparing to 2005. The population growth of Jeju has brought about large-scale urban development and increased land demands for tourism services. The goal of this study is to analyze the human, social, and environmental status of Jeju Island and to evaluate the environmental capacity of land use using ecological footprint (EF) model. This study shows the changes in ecological deficits of Jeju Island through estimating ecological productive land (EPL) considering EF from 2005 to 2015. The categories of total EF consists of food land, built-up land, forestry, and energy consumption. In order to reflect the characteristics of resort island, we consider not only residential population but also tourist population who can increase land demands. The outputs of this study also provide the potential excess demands of EPL and suggest needs of sustainable management plans for the limited land of Jeju Island.
        580.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 LPS로 유도된 RAW 264.7 세포에서 다양한 약용식품으로 사용되고 있는 올리브 잎과 가지 추출물의 항염증 효과를 확인하였다. 올리브 잎과 가지 추출물은 각각 RAW 264.7 세포에 대하여 세포독성을 나타내지 않았고, LPS 자극에 의한 NO 및 PGE2 생성을 농도 의존적으로 억제했다. 또한, 올리브 추출물은 LPS 자극으로 분비된 TNF-α, IL-1β 및 IL-6의 전염증성 cytokine의 분비량을 억제하였으며, 특히 200 μg/mL 농도에서 올리브 가지 추출물이 잎 추출물 보다 IL-6를 억제하는 것으로 나타났다. 대표적인 염증 관련 신호 전달 경로 인자인 iNOS 및 COX-2의 발현을 검토한 결과 올리브 추출물은 iNOS의 발현을 농도의존적으로 현저히 감소시키는 것으로 관찰되었으나, 각각의 올리브 추출물이 COX-2 발현에는 영향을 미치지 않은 것으로 관찰되었다. 이와 같은 결과는 올리브 각 부위별 추출물은 모두 iNOS 및 NO 조절 경로를 조절하는 것으로 사료되나 iNOS 및 COX-2 단백질 발현은 병립적이지 않을 수 있음을 제시하고 있다. 본 연구 결과로 올리브 추출물이 독성과 부작용이 적은 항염증 효능을 가진 기능성 화장품 소재로써 개발 가능성이 있다고 사료된다.