• Tunnel and Underground Space
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• v.25 no.4
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• pp.320-331
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• 2015

This paper presents a case study of an enhanced geothermal system(EGS) demonstration project conducted in $Gro{\ss}$ $Sch{\ddot{o}}nebeck$, Northerm Germany, focusing on hydraulic stimulation. The project was conducted with doublet system in sandstone and volcanic formations at 4 - 4.4 km depth. Under normal faulting to strike-slip faulting stress regime, hydraulic stimulations were conducted at injection and production wells by massive waterfrac and gel-proppant fracturing. Injectivity index increased from $0.97m^3/(hr^*MPa)$ to $7.5m^3/(hr^*MPa)$ and productivity index increased from $2.4m^3/(hr^*MPa)$ to $10.1m^3/(hr^*MPa)$ by a series of hydraulic stimulations at both wells. After circulation tests through injection and production wells, however, productivity index decreased from $8.9m^3/(hr^*MPa)$ to $0.6m^3/(hr^*MPa)$ in two years. Slip tendency analysis for the stimulation in volcanic layer estimated the required pressure for shear slip and its preferred orientations and it showed reasonable match with actual stimulation results. Through the microseismicity observation for the stimulation of volcanic formation, only 80 seismic events with its moment magnitudes in -1.8<$M_W$<-1.0 were observed, which are unexpectedly low for EGS hydraulic stimulation.

• Economic and Environmental Geology
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• v.13 no.3
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• pp.185-192
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• 1980

The rocks exposed in the investigation area are andesite of Late Cretaceous age, and syenite and aplitic granite of Bulgugsa Series of Early Cretaceous Period, which is intruded in the older andesitic rock. The strike and dip of major joint is $N10^{\circ}$ to $60^{\circ}E$, and $70^{\circ}SE$ to vertical respectively. According to seismic exploration, lower velocity zone, deemed to be fractured and/or crushed zone, is appeared along the gully center of east flank of the area. Test drilling shows that andesite bedrock is mostly very hard, massive, and very fine to medium grained and has almost 100 percent RQD and core recovery. In comparision with andesitic bedrock, intruded syenite cores show that it is highly crush especially at the depth from 55m to 63m.

• Economic and Environmental Geology
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• v.17 no.1
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• pp.1-15
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• 1984

The tin and tungsten deposits are embedded around the age unknown Buncheon granite gneiss which intruded the Precambrian schists, gneiss and amphibolites in Bonghwa-Uljin area. Pegmatite dike swarm developed intermittently about 4km along the southern border of Buncheon granite gneiss at Wangpiri area. Thickness of pegmatite dikes range from 0.5 to 15m. Pegmetite is consisted of quartz, microcline, albite, muscovite and frequently topaz, tourmaline, garnet, fluorite, fluorapatite and lepidolite. Pegmatite dikes are greisenized, albitized and microclinized along dike walls. Cassiterites are irregularly disseminated through the intensely greienized and albitized parts of the pegmatite. Cassiterite crystals are mainly black to dark brown and contain considerable Ta and Nb. Average Ta and Nb contents of the four cassiterite samples are 5300 and 3400 ppm. The Ssangjeon tungsten deposits is embedded within the pegmatite dike developed along the northern contact of Buncheon granite gneiss with amphibolite. This pegmatite developed 2km along the strike and thickness varies from 10 to 40m. Mineral constituents of the pegmatite are quartz, microcline, plagioclase, muscovite, biotite, tourmaline and garnet. Ore minerals are ferberite and scheelite with minor amount of molybdenite, arsenopyrite, pyrrhotite, pyrite, chalcopyrite, sphalerite, galena, pentlandite, bismuthinite, marcasite, and fluorite. Color and occurrence of quartz reveals that quartz formed at three different stages; quartz I, the earliest milky white quartz formed as a rock forming mineral of simple pegmatite; quartz II, gray to dark gray quartz which replace the minerals associated with quartz I; quartz III, the latest white translucent quartz which replace the quartz I and H. All of the ore minerals are precipitated during the quartz II stage. Fluid inclusion in quartz I and II are mainly gaseous inclusions and liquid inclusions are contained in quartz III and fluorite. Salinities of the inclusion in quartz I and II ranges from 4.5 to 9.5 wt. % and 5.1 to 6.0 wi. % equivalent NaCl respectively. Salinities of the inclusion in fluorite range from 3.5 to 8.3 wt. % equivalent NaCl. Homogenization temperatures of the inclusion in quartz I, II and III range from 415 to $465^{\circ}C$, from 397 to $441^{\circ}C$ and 278 to $357^{\circ}C$. Data gathered in this study reveals that tin and tungsten mineralization in this area are one of prolonged event after the pegmatite formation around Buncheon granite gneiss.

• Economic and Environmental Geology
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• v.45 no.4
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• pp.465-476
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• 2012

The Anatolia peninsula consists of several continental fragments that include the Pontide Block in north and the Anatolide-Touride Block in south as well as the Arabian Platform in southeast. These continental blocks were joined together into a single landmass in the late Tertiary. During most of the Phanerozoic these continental blocks were separated by paleo-oceans, such as Paleo-Tethys and Neo-Tethys. The Pontide Block in north show Laurasian affinities, and was only slightly affected by the Alpide orogeny; they preserve evidence for the Variscan and Cimmeride orogenies. The Pontic Block is composed of the Strandja, Istanbul and Sakarya zones that were amalgamated into a single terrane by the mid Cretaceous times. The Anatolide-Tauride Block in south shows Gondwana affinities but was separated from Gondwana in the Triassic and formed an extensive carbonate platform during the Mesozoic. The Anatolide-Tauride Block was intensely deformed and partly metamorphosed during the Alpide orogeny; this leads to the subdivision of the Anatolide-Tauride Block into several zones on the basis of the type and age of metamorphism and deformation. The Arabian Platform in southeast forms the northernmost extension of the Arabian Plate that shows a stratigraphy similar to the Anatolide-Tauride Block with a clastic-carbonate dominated Palaeozoic and a carbonate dominated Mesozoic succession. A new tectonic era started in Anatolia Peninsula in the Oligocene-Miocene after the final amalgamation of these continental blocks and plate. This neotectonic phase is characterized by extension, and strike-slip faulting, continental sedimentation, and widespread calcalkaline magmatism, which played a very important role in producing beautiful landscapes of the Anatolia Peninsula today.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.449-459
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• 2010

We performed numerical simulations of the excavation of an underground structure (the Giheung Tunnel) in order to evaluate the rate of groundwater flow into the structure and to estimate the groundwater level around the structure. The tunnel was constructed in Precambrian bedrock in Gyeonggi Province, South Korea. Geological and electrical resistivity data, as well as hydraulic test data, were used for the numerical modeling. The modeling took into account the strike-slip faults that cross the southern part of Giheung Tunnel, as these structures influence the discharge of groundwater into the tunnel. The transient modeling estimated a groundwater flow rate into the tunnel of $306\;m^3$/day, with a grout efficiency of 40%, yielding good agreement between the calculated change in groundwater level (6.20 m) and that observed (6.30 m) due to tunnel excavation.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.329-338
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• 2010

The foundation area for tram contains biotite gneiss, quartzo-feldspathic gneiss, calc-silicate rock, and porphyroblastic gneiss of the pre-Cambrian Kyeonggi gneiss complex. These rocks record at least three stages of deformation, as indicated by fold sets of contrasting orientations (D1-D3). Joints are generally steeply dipping and strike NW-SE to WNW-ESE. The Gonjiam Fault, which strikes WNW-ESE, follows a river in the area. The fault possesses a 3-m-wide fracture zone, a 10-m-wide damage zone, and is 15 km long. Two tunnels have been constructed through the biotite gneiss. The geometric relationship between discontinuities (e.g., joints and foliation) and tunneling direction reveals that set 3 of the AA tunnel is unstable but that BB tunnel is relatively safe.

• Journal of Conservation Science
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• v.16 s.16
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• pp.39-51
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• 2004

The standing Buddha named Taehwa 4 yew in the Jincheon were sculptured with rock cliff of the dark grey shale. Front of the Buddha statue shows $N40^{\circ}W$ strike with nearly vertical dip toward the back side. Rock blocks of the Buddha statue well developed with bedding and laminations whereas rock surface distributed into the various irregular discontinuities. Sculptured lines of the Buddha were uncertain because of degradation and exfoliations on the rock surface. The surface near the Buddha statue is highly contaminated with lichen and mosses, and accelerate physical and biological weathering owing to the roots of weed and bush along the fracture systems. For the conservational treatment, we treated with primary wet cleaning by air gun and secondary cleaning treatment using distilled water. Separated rock surface and fractured parts fasten and/or fill up the boundaries of the rock blocks using epoxy resin for conservation of rock properties. Some brittle surface was treatment with water repellent consolidant of ethyl silicates, and heterogeneous surface carried out color matching by acrylic pigments. Upper part of the Buddha statue dig out small ditch for rain water drainage, and near surface of the Buddha statue treat removal works for lichen, weeds and bush. The duration capacity of the Buddha constituting rocks are degraded by various weathering factors, therefore we suggest that this Buddha statue have need to do long term monitoring and synthetic conservation researches.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.151-159
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• 2012

The potential repository domains for A-KRS (Advanced Korean Reference Disposal System for High Level Wastes) in geological characteristics of KURT (KAERI Underground Research Tunnel) facility site were proposed to develop a repository system design and to perform the safety assessment. The host rock of KURT facility site is one of major Mesozoic plutonic rocks in Korean peninsula, two-mica granite, which was influenced by hydrothermal alteration. The topographical features control the flow lines of surface and groundwater toward south-easterly and all waters discharge to Geum River. Fracture zones distributed in study site are classified into order 2 magnitude and their dominant orientations are N-S and E-W strike. From the geological features and fracture zones, the potential repository domains for A-KRS were determined spatially based on the following conditions: (1) fracture zone must not cross the repository; and (2) the repository must stay away from the fracture zones greater than 50 m. The western region of the fracture zones in the N-S direction with a depth below 200 m from the surface was sufficient for A-KRS repository. Because most of the fracture zones in N-S direction were inclined toward the east, we expected to find a homogeneous rock mass in the western region rather than in the eastern region. The lower left domain of potential domains has more suitable geological and hydrogeological conditions for A-KRS repository.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.273-283
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• 2018

The purpose of this study is to analyze the optimum driver selection according to shaft intensity, shaft length and shaft weight that are determining factors of driver shot. To achieve the above purpose, the subject were participate with handicap zero 10 male pro golfer and mean score 90(handicap about 18) amateur 10 male golfer. The used club limited number 1 driver, we tested 24 driver which is shaft intensity, length, weight, total weight and swing weight. Dependent variable was strike ball speed, flying distance and head speed. The findings can be summarized as follows. First, There is a significantly difference in CPM. Ball speed, head speed and flying distance according to driver shaft intensity were found to be the best when CPM is 230<. Second, There is a significantly difference in shaft length. Ball speed, and head speed according to driver shaft length were found to be the best at 46 inch and flying distance were found to be the best at 45 inch. Third, There is not significantly difference in SW. Ball speed and flying distance according to driver shaft weight were found to be the best with 65g. In the case of head speed, it was the fastest with 50g shaft. Four, total variables were significantly difference between in pro and amateur golfer. In conclusion, there would be differences in individual physical condition but the best result was found with a driver of CPM 230<, shaft length 46inch, and shaft weight 65g.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.78-85
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• 2012

This paper takes precautions proposals against prospective disasters from the space weather maximum in 2013. The space weather maximum could wreak havoc in this world. A geomagnetic space storm sparked by a solar eruption like the one that flared toward earth is bound to strike again and could wreak havoc across the modern world. Despite of the fact that not only researches by colleges and institutions current researches have been focusing on warning systems of space communication and the earth network systems, but also management and control systems are not situated for the space weather blasters. The purpose of the study is that the damage reduces methods implementation on the ultimate space weather communication systems by above lists proposed type analysis. In result, the implementation of the communication disaster management systems deals with the smart IT converged GIS analysis on the flare, solar proton event, geomagnetic storm to the effects of the geomagneticsphere, ionosphere and troposphere from solar maximum. This research can provide affective methods for the saving lives and property protections that implementation of the disaster prediction and disaster prevention systems adapts smart IT systems and converged high tech information systems using decision making support systems of the GIS methodology.