• Journal of the Korean earth science society
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• v.28 no.2
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• pp.240-247
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• 2007

Geological information can be used for various purposes, such as the mine development, landuse, environmental protection, construction industry, and the development of water resource. Although geological information is highly useful for developing industrial raw materials, national land management and people's welfare, there is no unified public institution in charge of collecting and managing geological information at the national level. Thus, the government is to collect geological information, to construct database and to utilize and to distribute the information in a long-term and systematic way, the purpose of this study is to propose strategies for establishing an integrated geological information management system. In this study, we A) analyzed the current state and management of geological information in Korea and other countries; B) surveyed demand for geological information and analyzed correlations; C) drew up a conceptual diagram of the national integrated geological information management system; and D) developed strategies for establishing the national integrated geological information management system.

• Photonics industry news
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• s.38
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• pp.10-13
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• 2007

현재 조명용 LED 광원모듈의 세계시장규모는 약 200억불로 Osram, GE, Philips 등의 다국적기업이 시장의 70-80%를 독점하고 있으며, 국내업체는 기술력 부족 등으로 세계 시장진입을 못하고 있는 실정이다. 국내시장 규모는 약 6,000억원 규모로 약 80%이상을 Osram, GE, Philips 등으로부터 수입하고 있는 실정이다. 특히, 백색조명용 LED 광원모듈은 세계적으로 기술개발 단계이거나 시장진입 초기로서 동 개발제품의 기술을 국내업체가 이전해 온다면 반도체 조명시장 조기진입 및 세계시장 선점에도 크게 기여 할 것으로 예상된다. 우리나라에서도 차기 LED조명시장을 염두에 두고 한국광기술원을 중심으로 연구에 박차를 가하고 있다. LED/반도체조명연구사업부가 개발한 2,500 루멘급 백색조명용 LED 광원모듈 시제품의 개발 성공은 백색조명용 LED 광원모듈의 핵심 원천기술 확보에 한발 더 나아가 결과이며, 시제품 개발결과가 조명제품으로 이어진다면 2010년에는 3,000억원의 무역역조가 개선될 것으로 전망하고 있다. 또한, 국내 최초로 개발된 3mW급 380nm UV(자외선) LED는 위폐감지기, 살균기 등 의료.환경.바이오산업 등에 적용 가능하며, 조명용 백색 LED 제작을 위한 펌핑광원으로 활용이 가능하다. 아울러 20mW 급 380nm UV LED 개발이 완료되는 2008년에는 반도체조명산업과 의료/환경산업 등에 활용되어 약 연 10억불 이상의 수입대체 효과를 가져 올 수 있을 것으로 예상된다. 한국광기술원 LED/반도체조명연구사업부는 다양한 LED 광원모듈의 연구개발을 통해 원천기술을 확보하고 LED광원 모듈의 국산화에 일익을 담당하고 있다.

• Journal of IKEEE
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• v.3 no.2 s.5
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• pp.178-185
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• 1999

Geological structures such as fault and fracture patterns provide important information about preliminary exploration of mineralized areas and geological characterization. They may be recognized and interpreted from satellite images as line-like features usually referred to as lineaments. A proposed filtering method taking the sums azimuth angle into account is utilized, by which linear edges from low contrast areas where features extend parallel to the sun direction and in mountain shadow can be effectively extracted. Then, generalized Hough transform is applied to extract lineaments which correspond to fault and fracture patterns.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.196-197
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• 2009

지하에 전류를 흘려보내 분극현상을 유도하고, 이 유도분극 현상을 측정하는IP탐사는 금속 광물 탐사에서 널리 이용되고 있다. 특히 광대역주파수를 이용하는SIP탐사는 IP탐사에서 측정하는 전기비저항과 더불어 위상정보까지 제공해 줄 수 있어 금속광물의 종류를 구분하는 등 보다 효과적인 탐사 방법으로 제시되고 있다. 이 연구는 최근 원자재가 급등에 따른 국내 외 광산개발에 필요한 자원탐사 기술 개발의 일환으로 광석 중에 포함되어 있는 금속광물의 SIP 효과에 대한 기초적 연구를 수행한 것이다. 암석의 SIP를 측정 시스템은 GDP-32 system과 Lab transmitter(Zonge)를 사용하여 구성하였으며, 주파수에 따른 IP 효과를 측정하기 위하여 KCl 0.01 mol 용액으로 포화시킨 Glass beads에 황철석 분말의 중량비를 증가 시키면서 SIP를 측정하였다. 실험에 사용된 Glass beads의 직경은 $0.75{\sim}1.0\;mm$의 범위이고, 황철석은 원광석을 분쇄하여 $20{\sim}25$ mesh를 통과한 분말을 사용하였다. 실험방법은 아크릴 수지로 만든 육면체 시료홀더를 사용하여 처음에는 KCl 0.01 mol 용액으로 포화시킨 Glass beads의 SIP를 측정하고, 그 다음에 Glass beads 내에 황철석 분말을 중량비로 $1{\sim}10%$까지 증가 시키면서 SIP를 측정하였다. 이 때 사용한 주파수 대역은 $0.016{\sim}1024\;Hz$ 이며, 측정결과로부터 전기비저항과 Phase를 산출하여 도시하였다.

• Geophysics and Geophysical Exploration
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• v.5 no.2
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• pp.93-98
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• 2002

A three dimensional model for the orebody of an operating mine in Korea was constructed by using a program called '3-D Modeler'. The program allows the user to interactively construct a 3-D model of an orebody from its horizontal cross-sections. The 3-D Modeler is easily able to combine and display various spatial data for model construction. The result of modeling is strongly influenced by control points that correlate to the adjacent horizontal cross-sections. The control points are determined by comparing the geometrical shape of the adjacent cross-sections in conjunction with the geological features of the orebody. The resulting model can be evaluated in viewing the constructed object in three dimensional space or more closely evaluated by inspecting the cross-section. The model can iteratively be improved by modifying the shape of the cross-section and by using this new cross-section for the model building.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.424-431
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• 1996

This study was carried out to provide information for establishing counter measures of soil pollution through analysis of Cd. Cu, Pb, and Zn in paddy soils and brown rice. Cadmium, Cu, Pb, and Zn contents in soils were analyzed and distribution maps for these heavy metals were prepared. Heavy metal contents in brown rice were also measured. Average contents of Cd, Cu, Pb, and Zn in surface paddy soils extracted with 0.1 N HCl were 7.4, 35.8, 98.9, and $118.8mg\;kg^{-1}$, respectively. These were 9 times (Cu) to 50 times (Cd) higher than the background level of heavy metals in unpolluted paddy soils in Korea. The contents of Pb and Zn were lower than those measured in 1980, whereas Cd content did not decrease. The levels of heavy metal contamination in paddy soils may not affect growth or yield of rice plant, however, Cd contents indicated a level of serious concern to humans. The average contents of Cd, Cu, Pb, and Zn in brown rice were 0.38, 2.38, 1.31 and $22.31mg\;kg^{-1}$, respectively.

• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.322-331
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• 2007

In this study, electrical resistivity tomography (ERT) were conducted to find the mineralized zone at the Geumpung mine in Dojeon-ri, Susan-myeon, Jecheon-si, Chungcheongbuk-do. The deviation of the inclined borehole was measured to obtain the exact positions of the electrodes for correcting apparent resistivity values from ERT. Geophysical loggings such as resistivity and natural gamma were conducted to obtain the properties of the material near the borehole. Measurements of the physical properties of the cores, such as porosity, water content, density, susceptibility, resistivity were performed to analyze the correlation between physical properties and resistivity. Grade analysis for core sample was also conducted to identify relationship between grade and resistivity. Rock property analysis shows that the resistivity is more dominated by susceptibility and grade than by porosity and water content in the mineralized zone. The results of ERT are well consistent with geophysical logging data and geologic column. So ERT is powerful method to identify conductive mineralized zone.

• Economic and Environmental Geology
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• v.44 no.3
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• pp.203-215
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• 2011

Geochemical and mineralogical properties of a contamited soil should be taken into account to decide a remediation strategy for a given contaminant because development and optimization of soil remedial technologies are based on geochemical and mineralogical separation techniques. The objective of this study was to investigate the geochemical and mineralogical characteristics of arsenic-contaminated soils. The arsenic-contaminated soil samples were obtained from Chonam gold mine, Gwangyang, Chonnam, Particle size analysis, sequential extraction, and mineralogical analyses were used to characterize geochemical and mineralogical characteristics of the As-contaminated soils. Particle size analyses of the As-contaminated soils showed the soils contained 17-36% sand, 25-54% silt, 9-28% clay and the soil texture were sandy loam, loam, and silt loam. The soil pH ranged from 4.5 to 6.6. The amount of arsenic concentrations from the sequential soil leaching is mainly associated with iron oxides (1 to 75%) and residuals (12 to 91%). Major minerals of sand and silt fractions in the soils were feldspar, kaolinite, mica, and quartz and minor mineral of which is an iron oxide. Major minerals of clay fraction were composed of illite, kaolinite, quartz, and vermiculite. And minor minerals are iron oxide and rutile. The geochemical and mineralogical analyses indicated the arsenic is adsorbed or coprecipitated with iron oxides or phyllosilicate minerals. The results may provide understanding of geochemical and mineralogical characteristics for the site remediation of arsenic-contaminated soils.

• Geophysics and Geophysical Exploration
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• v.24 no.4
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• pp.180-193
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• 2021

The complex resistivity method is an exploration technique that can obtain various characteristic information of underground media by measuring resistivity and phase in the frequency domain, and its utilization has recently increased. In this paper, a three-dimensional inversion algorithm for the CR data was developed to increase the utilization of this method. The Poisson equation, which can be applied when the electromagnetic coupling effect is ignored, was applied to the modeling, and the inversion algorithm was developed by modifying the existing algorithm by adopting comlex variables. In order to increase the stability of the inversion, a technique was introduced to automatically adjust the Lagrangian multiplier according to the ratio of the error vector and the model update vector. Furthermore, to compensate for the loss of data due to noisy phase data, a two-step inversion method that conducts inversion iterations using only resistivity data in the beginning and both of resistivity and phase data in the second half was developed. As a result of the experiment for the synthetic data, stable inversion results were obtained, and the validity to real data was also confirmed by applying the developed 3D inversion algorithm to the analysis of field data acquired near a hydrothermal mine.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.1 s.6
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• pp.31-41
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• 1996

The analysis of environmental change followed by cultural development is useful for determining development plan hereafter. This study aimed for quantitative analysis about urban sprawl within 10 years, from 1984 to 1994, at Kwangju city, and to extract characteristics of change. For this purpose, we performed land cover classifications using Landsat TM data. And to evaluate influence of urbanization, we carried out surface temperature analysis using TM band 6 data. From the change analysis in land cover, it wa found that expansion of urban areas amounted to 3% and get accomplished by exploitation of farm land area, and that a rice paddy fields were changed to vinyl house areas considerably. In the regional aspect, development was concentrated on Kwangsan-ku which had been incorperated into Kwangju city in 1988. The results from temperature analysis showed that there was close correlation between surface temperature and land cover types, and that urbanization would influnce temperature to rise $0.3^{\circ}C$ in summer. As a results, we can prove that satellite data is very effective for environmental change analysis.