Radon Potential Mapping in Groundwater using Logistic Regression: a Case Study in Goesan, Korea

( Da Eun Kwon ),( Jae Hong Hwang ),( Jae Hyuk Jeong ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The purpose of this study is to calculate the relationship between spatial factors and radon levels in groundwater, and to integrate these relationships to create a radon potential map of Goesan, where in Korea, through probabilistic models and geographic information system. Radon in groundwater is affected by topographical, geological and geochemical factors, and many related factors can be identified by frequency ration. Spatial databases such as radon, topographical, geological and geochemical data in the study area are collected by GIS. The relationship between radon levels and these factors is assessed by logistic regression, one of the statistical models. And the related factors are overlayed to create radon potential map. This radon potential map is verified against the existing radon gas generation, 70% of the total radon generations are used for mapping and the remaining 30% are used for model validation. The radon concentration unit in the study area is Bq / L and the average of radon concentration used in mapping is 119 Bq / L. The US Environmental Protection Agency (US EPA) standard which is 148 Bq / L is 24.37% higher than the average of radon concentration used in mapping. The radon potential map constructed in this study can be an important reference for potential exposure about radon in groundwater.

와이파이 무선통신을 이용한 라돈 모니터링 시스템의 구현

윤성하(Sung-Ha Yun),김정용(Chungyong Kim),김규식(Gyu-Sik Kim) 대한전자공학회 2017 전자공학회논문지 Vol.54 No.12

사람이 연간 노출되는 방사선의 82%가 자연방사선에 의한 것인데 대부분이 라돈이다. 실내의 라돈 농도를 적절하게 제어할 수 있다면 폐암의 발생확률을 30%나 억제할 수 있다고 알려져 있다. 본 논문에서는 핀 포토다이오드 센서를 이용해 구현된 라돈 카운터에 와이파이 무선통신 모듈을 장착하고 네이버 지도를 이용한 라돈 감시 시스템을 구축하였다. 이로써, 라돈농도에대한 데이터베이스 구축과 환경부에서 추진하고 있는 라돈맵 작성에 인건비 절감과 효율성 증대 등에 큰 도움이 될 것으로 생각된다. 또한, 실험을 통해 와이파이 무선통신이 오류없이 데이터 송수신을 하였음을 확인하였고 향후 국가적인 라돈 모니터링 시스템 구축에 크게 도움이 될 것으로 판단된다. The 82% of radiation exposed to people is the natural radiation. Most of the natural radiation is radon. If we properly control the concentration of radon indoors, the probability of occurrence of lung cancer could be decreases to be 70%. In this paper, we connected a Wi-Fi wireless communication module to the PIN photodiode radon counter and implemented the radon monitoring system using a Naver map. So, we think that our developed system would be very helpful for the construction of radon concentration database and for the labor charge reduction and efficiency improvement in making the radon map of Korean government. Also, we confirmed that the Wi-Fi wireless communication worked fairly well without errors through some experimental studies.

α-completely positive maps on locally C*-algebras, Krein modules and Radon-Nikodym theorem

허재성,지운식,김영이 대한수학회 2013 대한수학회지 Vol.50 No.1

In this paper, we study α-completely positive maps between locally C*-algebras. As a generalization of a completely positive map, an α-completely positive map produces a Krein space with indefinite metric, which is useful for the study of massless or gauge fields. We construct a KSGNS type representation associated to an α-completely positive map of a locally C*-algebra on a Krein locally C*-module. Using this construction, we establish the Radon-Nikodym type theorem for α-completely positive maps on locally C*-algebras. As an application, we study an extremal problem in the partially ordered cone of α-completely positive maps on a locally C*-algebra.

α-COMPLETELY POSITIVE MAPS ON LOCALLY C^*-ALGEBRAS, KREIN MODULES AND RADON-NIKODÝM THEOREM

Heo, Jaeseong,Ji, Un Cig,Kim, Young Yi Korean Mathematical Society 2013 대한수학회지 Vol.50 No.1

In this paper, we study ${\alpha}$-completely positive maps between locally $C^*$-algebras. As a generalization of a completely positive map, an ${\alpha}$-completely positive map produces a Krein space with indefinite metric, which is useful for the study of massless or gauge fields. We construct a KSGNS type representation associated to an ${\alpha}$-completely positive map of a locally $C^*$-algebra on a Krein locally $C^*$-module. Using this construction, we establish the Radon-Nikod$\acute{y}$m type theorem for ${\alpha}$-completely positive maps on locally $C^*$-algebras. As an application, we study an extremal problem in the partially ordered cone of ${\alpha}$-completely positive maps on a locally $C^*$-algebra.

논문 : 단양지역 지하수중 자연방사성물질 우라늄과 라돈의 산출과 분포특징

조병욱 ( Byong Wook Cho ),김문수 ( Moon Su Kim ),김태승 ( Tae Seung Kim ),윤욱 ( Uk Yun ),이병대 ( Byeong Dae Lee ),황재홍 ( Jae Hong Hwang ),추창오 ( Chang Oh Choo ) 대한지질공학회 2013 지질공학 Vol.23 No.4

단양지역 지하수 100개공을 대상으로 자연방사성물질인 우라늄과 라돈의 산출특징을 규명하고, 주요 성분들과의 관련성을 요인분석을 통하여 해석하였으며, 지질별 자연방사성물질의 정밀함량분포도를 작성하였다. 단양지역 지하수는 대부분 Ca-Na-HCO3가 우세한 유형을 보여 칼슘-나트륨-중탄산형의 지하수의 특징을 가진다. 우라늄의 함량은 0.02~251.0 g/L 범위이며, 평균 3.85 μg/L인데 미국의 음용기준치(MCL)인 30 μg/L를 초과한 지하수는 1%에 불과하다. 백악기 화강암과 선캄브리아기 변성암 지역의 지하수에서 우라늄 함량이높게 나타나며, 퇴적암류에서는 상대적으로 낮다. 라돈 함량은 13~28,470 pCi/L 범위, 평균 2,397 pCi/L인데, 전체의 15%가 미국의 음용제안치(AMCL)인 4,000 pCi/L를 초과한다. 라돈은 백악기 화강암류 지하수에서 가장 높고, 퇴적암 지하수에서 상당히 낮다. 우라늄과라돈은 서로 관련성이 없다. 자연방사성물질은 pH, 심도, Eh, EC 및 주요 성분들과 의미있는 상관성은 보여주지 않는다. 요인분석 결과에 의하면, 우라늄과 라돈간의 상관계수는 0.15를 보여 이들의 거동특성은 서로 관련성이 거의 없다. 그 외에 이들은 여타 수질성분과 무관하다. 다만 라돈은 SiO2와 0.68, HCO3와는 -0.48의 상관계수를 나타낼 뿐이다. 요인분석 결과에 의하면 특정한 요인이 자연방사성원소의 거동특성에 크게 영향을 주지 않으므로 이들은 다소 독립적인 거동특성을 보여준다. 지질에 따른 자연방사성물질 정밀함량분포도는 향후 전국적인 자연방사성물질의 분포와 지질특성에 관한 데이터베이스 구축에 유용하게 활용될 예정이다. Natural radionuclides in groundwater in the Danyang area were investigated to characterize the behaviors of uranium and radon with respect to lithology and physico-chemical components, which can aid our understanding of their occurrence, properties, and origins. To this end, a total of 100 groundwater samples were collected and analyzed, and radionuclide levels were used to construct detailed concentration maps. The water type of the groundwater, assessed using a Piper diagram, is mainly Ca-Na-HCO3. The concentrations of uranium range from 0.02 to 251.0 μg/L (average, 3.85 μg/L) and only 1% exceed USEPA`s MCL (Maximum Contaminant Level). Uranium is enriched in groundwaters of Cretaceous granites and Precambrian metamorphic rocks, whereas it is depleted in groundwaters of sedimentary rocks. The concentrations of radon range from 13 to 28,470 pCi/L (average, 2397 pCi/L). Only 15% of the samples exceed AMCL (Alternative Maximum Contaminant Level) of 4000 pCi/L. The radon concentration is highest in groundwater of Cretaceous granites and lowest in groundwater of sedimentary rocks. In conclusion, the distribution and occurrence of radionuclides are intimately related to the basic geological characteristics of the rocks in which the radiogenic minerals are primarily contained. The behavior of uranium is only weakly related to that of radon (correlation coefficient = 0.15). There are also weak correlations between radionuclides and the main chemical components, pH, EC, Eh, and well depth. Of note, the correlation coefficient between radon and SiO2 is 0.68, and that between radon and HCO3 is -0.48. Factor analysis shows that radionuclides behave somewhat independently of each other because there are no significant factors that control the behavior of chemical components as well as radionuclides. The detailed concentration maps during this study will be used to establish useful database of radionuclide distribution and geological properties throughout Korea.

논산지역 지하수중 우라늄과 라돈의 수리지질학적 특성과 정밀함량분포

조병욱,추창오,김문수,김태승,한진석,윤욱,이병대,황재홍 대한지질공학회 2013 지질공학 Vol.22 No.4

A total of 100 groundwater samples were collected from the Nonsan area and the behaviors of uranium and radon as natural radionuclides were investigated with respect to other physicochemical components in the groundwater in order to understand their occurrence, properties, and origins. Radionuclide levels were used to construct detailed concentration maps. The concentration of uranium ranges from 0 to 378 μg/L, with an average of 8.57 μg/L, standard deviation of 42.88 μg/L, and median of 0.56 μg/L. The correlation coefficient between uranium and radon is 0.42, whereas these radionuclides show no relation with other physicochemical components in groundwater. It is noteworthy that the uranium level in most samples (97% of the samples) is less than 30 μg/L, where the bedrock of the aquifer is granite or complex rocks located along the boundary between granite and metamorphic rocks. In the Okcheon metamorphic belt, the uranium concentration of most groundwater is less than 1 μg/L. Radon levels varies from 128 to 9,140 pCi/L, with an average of 2,186 pCi/L, standard deviation of 1,725 pCi/L, and median of 1,805 pCi/L. High radon levels (> 4,000 pCi/L) are most common in regions of Jurassic granite, whereas low radon areas are found in regions of sedimentary rock. In conclusion, the distribution and occurrence of radionuclides are intimately related to the basic geological characteristics of the rocks in which the radiogenic minerals are primarily contained. 논산지역 100개의 지하수공을 대상으로 자연방사성 원소인 우라늄과 라돈 함량을 분석하고, 지하수의 주요 수질특성항목과의 관련성을 검토하여 이들의 산출실태와 원인을 연구하였다. 또한 이를 바탕으로 방사성물질 정밀함량분포도를 작성하였다. 우라늄은 불검출에서부터 최대 378 μg/L까지 범위가 넓게 나타난다. 평균치는 8.57 μg/L, 표준편차 42.88 μg/L, 중앙값은 0.56 μg/L으로서 매우낮다. 우라늄과 라돈의 상관계수는 0.42로서 약간 관련성이 있으나, 이들과 기타 수질항목들과는 거의 무관하다. 지하수의 우라늄함량 분포도를 살펴보면 우라늄 함량은 97%가 30 μg/L 이하의 값을 가지며, 30 μg/L 이상인 지점의 지질은 주로 화강암 또는 화강암과 변성암의 경계 부분이며, 옥천대지역 지하수의 우라늄 함량은 대부분 1 μg/L 이하로 낮게 나타났다. 논산지역 100개 지하수 전체의 라돈 함량은 128~9,140 pCi/L 범위, 평균 2,186 pCi/L, 표준편차 1,725 pCi/L, 중앙값은 1,805 pCi/L로 나타났다. 라돈 함량이4,000 pCi/L 이상인 지역은 거의 쥬라기 화강암 지역에 있다. 전체적으로 라돈 함량이 높은 지역은 쥬라기 화강암지역이며, 낮은 지역은 퇴적암지역이다. 지하수중 방사성물질의 함량은 기본적으로 함우라늄광물을 배태하는 지질과 밀접한 관련을 가진다.

논문 : 논산지역 지하수중 우라늄과 라돈의 수리지질학적 특성과 정밀함량분포

조병욱 ( Byeong Wook Cho ),김문수 ( Moon Su Kim ),김태승 ( Tae Seung Kim ),한진석 ( Jin Seok Han ),윤욱 ( Uk Yun ),이병대 ( Byeong Dae Lee ),황재홍 ( Jae Hong Hwang ),추창오 ( Chang Ho Choo ) 대한지질공학회 2012 지질공학 Vol.22 No.4

논산지역 100개의 지하수공을 대상으로 자연방사성 원소인 우라늄과 라돈 함량을 분석하고, 지하수의 주요 수질특성항목과의 관련성을 검토하여 이들의 산출실태와 원인을 연구하였다. 또한 이를 바탕으로 방사성물질 정밀함량분포도를 작성하였다. 우라늄은 불검출에서부터 최대 378 μg/L까지 범위가 넓게 나타난다. 평균치는 8357μg/L, 표준편차 42.88μg/L, 중앙값은 0.56μg/L으로서 매우 낮다. 우라늄과 라돈의 상관계수는 0.42로서 약간 관련성이 있으나, 이들과 기타 수질항목들과는 거의 무관하다. 지하수의 우라늄함량 분포도를 살펴보면 우라늄 함량은 97%가 30μg/L 이하의 값을 가지며, 30μg/L 이상인 지점의 지질은 주로 화강암 또는 화강암과 변성암의 경계 부분이며, 옥천대지역 지하수의 우라늄 함량은 대부분 1μg/L 이하로 낮게 나타났다. 논산지역 100개 지하수 전체의 라돈 함량은 128~9,140Ci/L 범위, 평균 2,186pCi/L, 표준편차 1,725pCi/L, 중앙값은 1,805pCi/L로 나타났다. 라돈 함량이 4,000pCi/L 이상인 지역은 거의 쥬라기 화강암 지역에 있다. 전체적으로 라돈 함량이 높은 지역은 쥬라기 화강암지역이며, 낮은 지역은 퇴적암지역이다. 지하수증 방사성물질의 함량은 기본적으로 함우라늄광물을 배태하는 지질과 밀접한 관련을 가진다. A total of 100 groundwater samples were collected from the Nonsan area and the behaviors of uranium and radon as natural radionuclides were investigated with respect to other physicochemical components in the groundwater in order to understand their occurrence, properties, and origins. Radionuclide levels were used to construct detailed concentration maps. The concentration of uranium ranges from 0 to 378μg/L, with an average of 8.57μg/L, standard deviation of 42.88μg/L, and median of 0.56μg/L. The correlation coefficient between uranium and radon is 0.42, whereas these radionuclides show no relation with other physic-ochemical components in groundwater, It is noteworthy that the uranium level in most samples (97% of the samples) is less than 30μg/L, where the bedrock of the aquifer is granite or complex rocks located along the boundary bctween granite and metamor-phic rocks. In the Okcheon metamorphic belt, the uranium concentration of most groundwater is less than 1μg/L. Radon levels vares from 128 to 9,140 pCi/L, with an average of 2,186pCi/L, standard deviation of 1,725pCi/L, and median of 1,805pCi/L. High radon levels(> 4,000pCi/L) are most common in regions of Jurassic granite, whereas low radon areas are found in regions of sedimentary rock. In conclusion, the distribution and occurrence of radionuclides are intimately related to the basic geological characteristics of the rocks in which the radiogenic minerals are primarily contained.

라돈 우선관리 대상 지역 선정에 적합한 공간분석모형의 선정 및 활용에 대한 연구

남궁선주,최길용,홍형진,윤단기,김윤신,박시현,김윤관,이철민 한국환경보건학회 2019 한국환경보건학회지 Vol.45 No.1

Objective: The aims of this study were to provide the basic data for establishing a precautionary management policy and to develop a methodology for selecting a radon management priority target area suitable for the Korean domestic environment. Methods: A suitable mapping method for the domestic environment was derived by conducting a quantitative comparison of predicted values and measured values that were calculated through implementation of two models such as IDW and RBF methods. And a qualitative comparison including the clarity of information transmission of the written radon map was carried out. Results: The predicted and measured values were obtained through the implementation of the spatial analysis models. The IDW method showed the lowest in the calculated mean square error and had a higher correlation coefficient than the other methods. As results of comparing the uncertainty using the jackknife concept and the concept of error distance for comparison of the differences according to the model interpolation method, the sum of the error distances showed a modest increase compared with the RBF method. As a result of qualitatively comparing the information transfer clarity between the radon maps prepared with the predicted values through the model implementation, it was found that the maps plotted using the predicted values by the implementation of the IDW method had greater clarity in terms of highness and lowness of radon concentration per area compared with the maps plotted by other methods. Conclusions: The radon management priority area suggests selecting a metropolitan city including an area with a high radon concentration.

지하역사 깊이에 따른 라돈 농도 분포

조민영,이동현,신석범,이정우,이정학,서성철 한국냄새환경학회 2020 실내환경 및 냄새 학회지 Vol.19 No.4

We investigated the distributions of airborne radon concentration on the platforms of the stations of Seoul Metro by the underground depth of each subway line, and explored the correlation between the radon concentration and the depth and geological conditions around each underground station. The measurements of radon levels were performed in 254 subway stations within Seoul Metro Lines 1 to 8 using the passive sampler (RADUET). Radon concentration data from 2007 to 2017, as well as the depth of each subway station were obtained from the Seoul Metro corporation. The geological information of each subway station were purchased from the Korea Institute of Geoscience and Mineral Resources. Student t-test and correlation analyses were performed to compare the levels of radon by the depth of subway stations, and to investigate the association of radon levels based on geological information. The geometric mean concentration of the all subway stations was 27.9 Bq/m3 ( range, 3 . 7Bq/ m3~124.0 Bq/m3). The depth of Lines 5-8 (geometric mean, –20.3 m) was significantly deeper by about 50% or more than that of Lines 1-4 (–13.1 m) (P<0.01). The radon levels increased significantly in deeper depths and as the number of Lines increased (P<0.05). A significant higher mean concentration of radon above the igneous rock (33.0 Bq/m3) was observed, comparing to that of non-igneous rock (27.5 Bq/m3) (P<0.00001). Our findings indicate that the deeper the subway is built or the more it is constructed on the granite area, the more careful management, including frequent ventilation and measurement monitoring, is necessary.

Distribution Characteristics of Radon in Busan Metropolitan City Subway Stations

조은정,강태연,유은철 환경독성보건학회 2021 한국독성학회 심포지움 및 학술발표회 Vol.2021 No.10