• 자원환경지질
• /
• 제39권6호
• /
• pp.771-786
• /
• 2006

임하호는 다른 댐보다 고탁수 현상이 심하고 한번 탁수가 발생되면 수개월간 지속되는 양상을 보인다. 고탁수의 원인은 다양한 종류의 부유물질에 의한 것이며 이 부유물질은 미립의 점토광물과 조암광물 입자들이다. 이 미립자들은 홍수시 유수에 의해 떠내려 온 임하댐 유역의 암석 풍화물이며 유역일대의 특이한 지질과 밀접한 관계가 있다. 그러므로 근본적으로 임하댐 유역의 지질의 종류, 성질, 분포, 구조 등의 일반상태를 조사하고 이 가운데 점토를 공급하는 특이 지질을 찾아내어 탁도를 증가시키는 암석 풍화물이 임하호로 유입되는 경로를 조사하였다. 또한 임하호 내에서의 고탁수를 일으키는 부유물질의 종류와 거동상태를 감정함으로서 탁도 증가의 근본적인 원인을 제시하였다.

• 자원환경지질
• /
• 제28권5호
• /
• pp.527-533
• /
• 1995

A disadvantage of Fourier analysis is that frequency information can only be extracted for the complete duration of a signal f(t). Since the Fourier transform integral extends over all time, from $-{\infty}$ to $+{\infty}$), the information it provides arises from an average over the whole length of the signal. If there is a local oscillation representing a particular feature, this will contribute to the calculated Fourier transform $F({\omega})$, but its location on the time axis will be lost There is no way of knowing whether the value of $F({\omega})$ at a particular ${\omega}$ derives from frequencies present throughout the life of f(t) or during just one or a few selected periods. This disadvantage is overcome in wavelet analysis which provides an alternative way of breaking a signal down into its constituent parts. The main advantage of the wavelet transform over the conventional Fourier transform is that it can not only provide the combined temporal and spectral features of the signal, but can also localize the target information in the time-frequency domain simultaneously. The wavelet transform distinguishes itself from Short Time Fourier Transform for time-frequency analysis in that it has a zoom-in and zoom-out capability.

• 자원환경지질
• /
• 제28권4호
• /
• pp.425-431
• /
• 1995

Genetic algorithms are so named because they are analogous to biological processes. The model parameters are coded in binary form. The algorithm then starts with a randomly chosen population of models called chromosomes. The second step is to evaluate the fitness values of these models, measured by a correlation between data and synthetic for a particular model. Then, the three genetic processes of selection, crossover, and mutation are performed upon the model in sequence. Genetic algorithms share the favorable characteristics of random Monte Carlo over local optimization methods in that they do not require linearizing assumptions nor the calculation of partial derivatives, are independent of the misfit criterion, and avoid numerical instabilities associated with matrix inversion. An additional advantage over converntional methods such as iterative least squares is that the sampling is global, rather than local, thereby reducing the tendency to become entrapped in local minima and avoiding the dependency on an assumed starting model.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권6호
• /
• pp.56-68
• /
• 2013

Community drinking water (CDW), mostly naturally flowing groundwater, plays important roles in supplying drinking water for urban and rural residents in Korea. Over 1,600 CDW facilities are distributed throughout the country, many of them situated in the outskirts of metropolitan cities. A large proportion of Korean people have become dependent on CDW for drinking due to a distrust of piped water's quality and a strong belief in the special medicinal effects of some CDWs. However, administrative and official management and the control of CDW facilities have been inadequate when compared with the strict examination and control of commercial bottled water, which is physically treated groundwater from deep bedrock aquifers. In this study, even though signs of anthropogenic contamination were not generally found, the tested chemical compositions of selected CDWs featured high enrichment of some constituents including Ca, Mg, Na, and HCO3 with natural origins such as water-rock interactions. Careless consumption of particular CDWs, which has no scientific basis, will not guarantee health improvement. Consequently, more intensive management of CDW facilities and a long-term interdisciplinary examination of the health effects of CDWs are needed to effectively protect people's health.

• 자원환경지질
• /
• 제40권5호
• /
• pp.705-711
• /
• 2007

우리가 생활하면서 부딪히는 수많은 판단들 속에서 특히 인간의 권리에 대한 사안은 민감하게 다루어진다. 특히 사실로 입증된 것만 인정하는 증거재환주의에 의해 물리적 증거의 확보 여부는 범죄수사과정에서 필수적임에 따라 과학수사의 중요성 및 수요는 증가하고 있다. 과학수사지질학은 지질학과 과학수사와의 융합 분야로, 과학수사를 위하여 지질학적 지식 및 기법을 바탕으로 물리적 증거를 비교 분석하여 범죄용의자와 범죄사건의 연관성을 파악함으로써 법정에서 유용한 자료로 활용된다. 1970년대 후반 과학수사지질학의 학문적 체계를 구축한 이래로 과학수사지질학의 연구대상은 암석, 광물, 토양, 퇴적물 등의 토양학적 증거에서 역사적 유물, 지뢰, 사체 등의 사회 문화적, 정치적, 군사적, 의학적 대상으로 확대되고 있다. 과학수사지질학의 역할이 단순 위치추적에서 고고학적 학설 증명, 역사적 사실 입증, 환경오염 원인 규명, 연대기적 식생 분포 및 인류학적 발생 규명 등으로 폭넓게 작용할 수 있음을 의미하고, 이는 발전된 지질학적 방법론을 적용할 수 있으며 다양한 과학수사지질학적 수요를 만족시킬 수 있다. 과학수사지질학의 연구 활동은 과학수사 전문기관을 중심으로 이루어지고 있으나, 우리나라 국립과학수사연구소의 과학수사 활동 분포에서 과학수사지질학적 비중은 극히 일부분으로 나타나고 있다. 따라서 전문 지질자원 연구기관을 중심으로 우리나라 지질학적 특성에 기반을 둔 연구방법 확보, 연구결과 활용사례 발굴 등 과학수사지질학의 역할 정립을 위한 체계적인 논의를 이끌어 낼 필요가 있다고 사료된다.

• Wind and Structures
• /
• 제18권1호
• /
• pp.37-56
• /
• 2014

The evaluation of pressure fields acting on slender structures under wind loads is currently performed in experimental aerodynamic tests. For wind-sensitive structures, in fact, the knowledge of global and local wind actions is crucial for design purpose. This paper considers a particular slender structure under wind excitation, representative of most common high-rise buildings, whose experimental wind field on in-scale model was measured in the CRIACIV boundary-layer wind tunnel (University of Florence) for several angles of attack of the wind. It is shown that an efficient reduced model to represent structural response can be obtained by coupling the classical structural modal projection with the so called blowing modes projection, obtained by decomposing the covariance or power spectral density (PSD) wind tensors. In particular, the elaboration of experimental data shows that the first few blowing modes can effectively represent the wind-field when eigenvectors of the PSD tensor are used, while a significantly larger number of blowing modes is required when the covariance wind tensor is used to decompose the wind field.

• 자원환경지질
• /
• 제1권1호
• /
• pp.70-73
• /
• 1968

In Korea, ground water exploration by the electric method as a major prospecting tool has been carried out mainly in alluvial deposits, So it is considered to be important to understand the principle concerning the electrical and hydrological properties of alluvium. Factors which affect on the electrical and hydrological properties of alluvium were investigated. Major elements in ground water exploration are porosity and dermeability for most alluvial deposits with exceptions in some particular areas. Much water yield can be expected where alluvial materials have large porosity and small particle size while large particle size in necessary for good permeability. Problem is to locate the points which have comparatively large porosity and good permeability at a time. It is known that electrical resistivity method is proved useful to solve the above problem. The conclusion is: Localities which have greater alluvium thickness(7 to 10m) and 200 to 500 ohm -m of real resistivity value are suitable for well site in alluvial deposits in Korea where alluvium thickness is comparatively small(less than 10m in generaa) and bedrock formations are mainly composed of granite gneiss and granite.

• 자원환경지질
• /
• 제33권3호
• /
• pp.229-237
• /
• 2000

The structure of Euiseong Sub-basin and boundary of sub-basins were examined by analytical aeromagentci anomaly data. Magnetic lineaments have trends of NE-SW, NWW-SEE and NEE-SWW. The NE-SW lineaments in the sedimentary formations and pre-Cretaceous basement are assoicated with the direction of expansion of basin and the lineaments in the volcanic rocks and intrusives indicate the direction of structural weakness ones such as fault, which were major gateways of igneous activities. Euiseong Subbasin is bounded by pre-existing Andong Fault, pre-Cretaceous basement in the west, NE-SW lineament from Jyungsan to Angang, and NW-SE lineament connecting southwestern boundary of Palgongsan Granite and Jeokje Fault. In particular , the NW-SE lineament , which caused upheavel of pre-Cretaceous rocks, on Jeokje Fault is inferred as a boundary between Euiseong and Milyang Sub-basins.

• 지질공학
• /
• 제25권3호
• /
• pp.323-329
• /
• 2015

Shale gas reserves in China are large, although shale gas production is still in its infancy. This paper reviews Chinese national policies and guidelines related to shale gas development, in particular those related to recent progress in the development of shale gas reserves in Sichuan Province and Chongqing since February 2015. In addition, three large-scale R&D projects related to shale gas development, funded by the Government of China, are introduced, and the scope of the work in each project is described.

• 자원환경지질
• /
• 제21권3호
• /
• pp.319-329
• /
• 1988

As a factor which can help to understand the genesis of (mata) sedimentary and/or hydrothermal uranium depisits, an interpretation of the role of organic matter associated with uranium mineralization, was attempted with the literature published up to the end of 1986. Laboratory studies, in which diageneis and metamorphism are artificially simulated, can help to elucidate how uranium with particular organic materials are formed and destroyed. Similarly, research involving a variety of techniques is needed to characterize both the soluble organic extracts (bitumen) and the insoluble organic matter (kerogen), separated from uranium ores and associated rocks. In the presence of clay minerals and amorphous oxy-hydroxde minerals, an understanding of the role of organic matter must be prudent and may require the incorporation of multidisciplinary approach (mineralogy, inorganic geochemistry ...).