• The Journal of the Petrological Society of Korea
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• v.12 no.2
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• pp.79-99
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• 2003

Muscovite and biotite from 52 metasediments and 5 granites in the Hwasan area, the southwest of the Okcheon metamorphic belt and the Miwon-Jeungpyeong area, central Okcheon metamorphic belt were dated by the K-Ar and $^{40}$ Ar/$^{39}$ Ar methods. Muscovite and biotite ages from metapelitic and psammitic rocks (metasediments) of the Boeun and Pibanryeong units in the Hwasan area are concentrated in the mid-Jurassic (149-180 Ma). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for metapelitic and psammitic rocks of the Boeun and Pibanryeong units in the Miwon-Jeungpyeong area show complicated age distribution. Muscovite and biotite ages are classified by three groups, 142-194 Ma, 216-234 Ma, and 241-277 Ma. Younger (Cretaceous) ages occur only in metasediments close to Cretaceous granitic rocks in the southeastern region and the older ages of 216-277 Ma are restricted to the middle Part of the Jeungpyeong area. Most ages in the other area of the central Okcheon metamorphic belt fall between 142-194 Ma (Jurassic). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for granite from the northern part in the both the southwest and central Okcheon metamorphic belt also gave middle Jurassic ages (156-168 Ma). The similar ages from both metasediments and granites in the study areas indicate simultaneous cooling of both rocks to 300-350$^{\circ}C$ during the middle Jurassic. The state of graphitization of carbonaceous material of all metasediments in the study areas Indicates fully ordered graphite falling within a small range, from 3.353 to 3.359 ${\AA}$, which indicate amphibolite facies regional metamorphism. In the southern sector of the Boeun unit from the Hwasan area, metamorphic grade indicated by mineral paragenesis during regional intermediate-P/T metamorphism is greenschist facies. Whereas, the $d_{002}$ values for carbonaceous materials in the same sector show fully ordered graphite (ca. 500$^{\circ}C$) indicating amphibolite facies. This result with the concentration of mica ages of metasediments into the middle Jurassic, the presence of low-P/T thermal metamorphic zone (>500$^{\circ}C$) in the metasediments close to the Jurassic granite and the regional intrusion of Jurassic granites and their middle Jurassic intrusion and cooling ages may indicate the low-P/T regional thermal event during the early(\ulcorner)-middle Jurassic after main intermediate-P/T metamorphism which formed main mineral assemblage regionally in the study area. The regional thermal event failed, however, to reset the mineral assemblage of regional intermediate-P/T metamorphism except for narrow aureole (1-2 km) around Jurassic granite because e duration of thermal effect was relatively short by repid cooling of the Jurassic granite. In the middle part of the Jeungpyeong area, central Ogcheon metamorphic belt, muscovite and biotite K-Ar ages from 5 samples are 263-277 Ma and 241-249 Ma, respectively. An intermediate-P/T metamorphism is currently accepted to have occurred between 280 and 300 Ma. Therefore, the muscovite and biotite ages can be interpreted as cooling ages after Ml metamorphism indicating rapid cooling to ca 350$^{\circ}C$ between 280-300 Ma and 263-271 Ma, and biotite ages indicate slower cooling to ca. 300$^{\circ}C$ between 263-277 Ma and 241-249 Ma. However, more detail study is needed to confirm why the Permian to Triassic ages occur only in the middle Part of the Jeungpyeong area.a.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.467-467
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• 2016

암거는 일반적으로 용수나 배수용의 수로가 도로, 철도, 제방 등의 아래에 매설 된 수로를 지칭한다. 이러한 암거는 산업발전으로 사회기반시설의 신설 및 확충, 재정비 등으로 많이 활용되고 있다. 최근 들어 기후로 인한 재해가 급증하면서 이러한 시설물에 대한 안정성 및 관리에 대한 관심이 높아지고 있는 것이 현실이다. 특히 소하천은 집수면적 및 유로연장이 짧고 하상경사가 급하기 때문에 홍수에 취약하다. 즉, 빨라진 유속으로 인해 구조물 주변의 세굴에 의한 유실, 토사유출로 인한 하상퇴적, 부유물로 인한 차단으로 인해 통수에 지장을 받아 피해가 발생하게 된다. 이러한 암거시설물 피해는 2차 피해로 이어질 수 있으며 사회기반시설 파괴로 도시기능이 마비되고 인근 주변지역에 침수로 인한 재산 및 인명피해까지 발생시킬 수 있는 피해 잠재능력을 보유하고 있다. 그러나 피해에 대한 예방대책은 유지관리를 통해 지속적으로 관리하는 것이 대부분의 지침 등에 소개된 내용들이다. 본 연구에서는 암거를 대상으로 암거의 폐색으로 인해 암거주변에서 변화되는 흐름특성을 축소모형을 통해 검토하고자 하였다. 암거 축소모형실험은 1.5m 폭을 갖는 직선수로에서 수행하였으며, 암거모형은 도로암거표준도(2008)를 참조하여 $3m{\times}3m$ 수로암거를 대상으로 1/10 축소모형을 제작하였다. 암거유입부 퇴적으로 인한 암거의 차단률(차단면적/암거단면적)은 차단이 발생하지 않는 0% 조건에서부터 10%, 20%, 30%, 40%, 50% 조건에 대해 실험을 수행하였다. 실험결과 차단에 따른 암거 상류단의 수위는 차단이 없는 암거의 경우에 비해 차단율이 높아질수록 암거유입부 수위는 20.4% ~ 82.7% 상승하는 것으로 나타났다. 암거의 차단률이 40% 이상일 경우 높아진 수위로 인해 암거통로의 윗상면부까지 다다르고 있으며 50%일 경우 암거를 통과하는 흐름이 자유수면흐름이 아닌 오리피스 흐름이 발생하는 것으로 나타났다. 암거유입부 차단으로 인한 암거주변의 최대유속은 암거 직하류부에서 주로 발생하여 암거 유출부에서의 최대유속은 차단율이 증가할수록 선형적으로 증가하는 것으로 나타났으며 암거 유출부에서의 유속은 차단전의 조건(0%) 대비 4.2% ~ 35.5% 까지 상승하는 것으로 나타났다. 이와 같은 결과를 토대로 고려하였을 때 대부분 산지부에서 설치되는 암거의 경우 유속이 불가피하게 증가하게 됨으로 유속에 따른 유속조절방안(차단 및 우회시설) 및 세굴대책을 세워야 할 것으로 판단된다.

• Electronics and Telecommunications Trends
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• v.19 no.2 s.86
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• pp.127-137
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• 2004

본 논문에서는 2003년 9월, 설문조사를 통해 조사한 국내 무선랜 운영현황의 주요결과를 제시하고 있으며, 무선랜 AP의 비컨 신호의 복조를 통하여 일반 무선랜 이용자에게 운영 채널번호, 수신 신호세기, WEP 설정유무 등의 주변 무선랜 AP 정보를 제공하는 응용 소프트웨어(이하 ‘무선랜 가이더’라 함)를 소개하고 있다. 그리고 서울 도심지역에서 무선랜의 운영현황을 무선랜 가이더를 이용하여 측정하고, 그 결과를 바탕으로 도심지역의 무선랜 운영실태를 조사하였다. 특히, 주변 무선랜 AP의 운영 파악에 유용한 무선랜 가이더는 정보통신부 및 초고속 무선랜 포럼의 홈페이지를 통하여 무료로 배포될 예정으로 있다.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.151-159
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• 1994

This study was conducted to investigate the $NO_3-N$ concentration, the relationship between $NO_3-N$ and other ions, and patterns of ions in ground water used as drinking water in Cheju Island. Samples were collected from 19 wells in the northwest region, near the district of poultry complex, and 9 wells in the northeast region. In the northwest region, $NO_3-N$ concentrations in D-14 and D-202 wells near the pig farming facilities were 10.95 and 13.1 mg/L, respectively, exceeding the standard concentration of drinking water. The concentration in D-65, D-35, and D-120 wells were slightly lower than the standard concentration. However, $NO_3-N$ concentrations in the wells in the northeast region were lower than 3mg/L. In wells in the northwest region, $NO_3-N$ concentrations were negatively correlated with pH and positively correlated with $Ca^{++}$, $Mg^{++}$, $Na^+$ $Cl^-$, $SO_4^{--}$, and $Cl^-/HCO_3^-$. However, in the northeast region, they were not related with pH and the ions. The chemical compositions in D-65, D-35, and D-41 wells showed higher concentrations of $Ca^{++}$, $Mg^{++}$, $Na^+$, $Cl^-$, $NO_3-N$ and $SO_4^{--}$ than the unpolluted D-42 well. These results suggest that ground water near the pig farming complex was polluted by pig farming waste in the northwest region.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.64-73
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• 2010

This study aims to analyse the spatial characteristics and to draw the declining areas from the whole area of Chung-Cheong Province. For this purpose, the temporal and spatial conditions by the urban decline diagnosis indexes are utilized. Additionally, the spatial autocorrelation method was applied for extraction of those areas. The spatial autocorrelation method is one of the methods on exploring spatial characteristics and considering the spatial factors. We also adopted the concepts of economics and then discovered the characteristics of deprivation areas. In applying this method, the positively valued areas were classified as the complementary areas, and the negatively valued areas as the substitutional areas. The findings show the declining areas and the growing areas caused by the growth of periphery. This study supports the regeneration plan of Chung-Cheong Province in extracting depressed or activated areas and explaining the characteristics of those areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.229-229
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• 2022

우리나라의 지형 특성상 국토의 약 64%가 산지 지형이며 최근 10년 기준으로 연평균 강우량의 약 51%인 651.9mm가 여름철에 집중되고 있으며, 급격한 기후변화로 인한 집중호우와 태풍에 의한 영향으로 산사태와 토석류에 의한 생활권 주변의 도로나 주택가에 많은 피해를 발생시키고 있다. 따라서 무엇보다 토석류의 피해를 줄이기 위해 재해 발생 예상지역이나 피해 정도 및 규모에 대한 예측이 중요하며 이를 위해서는 토석류 수치모의를 통해 토석류의 피해지역을 예측할 필요가 있다고 판단된다. 본 연구에서는 태풍 미탁으로 인해 토석류가 발생한 강원도 삼척시 원덕읍을 대상으로 토석류 피해지역을 해석하기 위한 연구를 수행하기 위해 2차원 토석류 해석이 가능한 FLO-2D를 적용하여 토석류의 이동, 퇴적 및 하류부 피해해석을 수행하였다. 피해지역의 수치지도와 실측자료를 활용하여 지형자료를 구축하고 FLO-2D 모형을 이용하여 토석류 발생이 하류부에 미치는 영향을 분석하고 토석류 유동특성을 분석하여 피해지역의 실측자료와 비교분석하였다. 그 결과 모형을 통해 모의된 부분과 피해면적이 유사하게 나타났다.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1207-1213
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• 2003

Osancheon creek is located in the southwest of the middle area in Korea. Weed community around the Osancheon creek, where various disturbances exert a bad influence directly on its community by human work or nature, was surveyed phytosocialogically. Our surveys have been accomplished from June, 2003 to September, 2003. Weed communities formed around the Osancheon creek were divided into several patterns and analysed. They have been divided into 8 communities. Community A: Humulus japonica community, B: Phragmites communiscommunity, C: Persicaria thunbergii community, D: Zi=ania latifolia community, E: Miscanthus saccharilflorus community, F: Echinochica crusgalli community, G: Typha orientalis community, H: Sataria viridis community. The flora surveyed in these communities was constituted of 19 families, 36 genera, 4 varieties, and 40 species. Wild plants such as Artemisia princeps var. orientalis Erigeron annuus, Bidens frondosa, Aeschynomene indica and Oenothera odorata were mostly light loving plants and higher resistant plants against the disturbance. Our result from the ranking all surveyed areas by the Bray-Curtis ordination method was very similar to the results from phytosocialogical table work.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.915-926
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• 2016

The purpose of this study is to classify debris flow hazard zones in urbanized areas using multivariate statistical analyses and to suggest customized management strategies to each areal type. Using field survey data set in Seoul, 49 sample debris hazard zones are selected. Clustering and discriminant analyses show that debris flow hazard zones are classified into two types. Surrounding land use and land slope are major factors influencing to the categorization. The results suggest that, by considering the characteristics of each areal type, more customized management strategies for debris flow hazard are necessary. Particularly, in addition to traditional structural measures, non-structural measures including land use and development control for downstream built-up areas should be emphasized in urbanized areas to mitigate human and property damages from debris flow hazard more fundamentally.

• Journal of the Korean association of regional geographers
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• v.7 no.3
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• pp.1-13
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• 2001

This paper is to examine what implications the regionalism in Spain has for its national development during the last two centuries. Since the beginning of the nineteenth century the regionalism (including territorial nationalisms in periphery) has played a central role in the history of Spanish state-formation. On the one hand, a strong regional identity was related to a structural weakness affecting Spanish nation-building and accused of forging the separatist national movements in the Basque, Catatonia Galicia and so on. On the other hand, the regionalism has contributed to enforcing the Spanish national consciousness in complex and contradictory ways. Therefore, on the contrary to our common understandings of regionalism, the Spanish regionalism has both enforced and counteracted the Spanish nationalism. In the late 1970s after the collapse of Franco regime, the long history of the Spanish regionalism resulted in a state system based on the regional political decentralization.

• Journal of the Korean earth science society
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• v.30 no.7
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• pp.801-809
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• 2009

The Salinas Grandes borate deposit located in Jujuy state, northern Argentina can be categorized into the playatype evaporite deposit. Major borate mineral is ulexite ($NaCaB_5O_9{\cdot}H_2O$), which boron could be originated from volcanic rocks nearby playa. The eastern part of the Jujuy state in northern Argentina belongs to the Altiplano-Puna platform which shows high altitude and semiarid climate. Lots of Mesozoic and Cenozoic volcanics that are source of boron as well as playas that are the basin for borate precipitation in the area are essential for boron evaporite deposit. Therefore, the extensive explorations for the playa-type evaporite deposit are need.