• The Journal of the Petrological Society of Korea
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• v.21 no.4
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• pp.397-403
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• 2012

Fe-REE deposits occurred in Jaeunri, Hongcheon formed by carbonatitic melts consist of 3 parts such as northern, middle and southern ore bodies showing discontinuous distribution, and extension shape of ore bodies can be figured through field survey and geometric analysis. Foliations in gneiss around northern and middle ore bodies represent NNE, whereas toward south its direction changes gradually from NE to ENE and finally N-S direction appears in southern ore body. From Jaeungyo to Saemaeulgyo geometric analysis from field work gives that fold shape in this area is open synclinal fold concavely and gently to NW with $45^{\circ}$ northwestward plunging axis, in contrast small scale anticline with $45^{\circ}$ northwestward plunging axis in Yagsooteo area near western part of Saemaeulgyo. Dragging effect could be occurred on these folds by WNW trending dextral strike-slip fault from Yagsooteo to Saemaeulgyo. New ore body can be confirmed from folding structure estimated by trend of foliation, and thus unidentified ore body may be exist under alluvial surface from middle to southern ore body and its distribution could show reversed "ㄱ", one of Korean consonants, considering with estimated strike and dip of foliations. This estimated extension of ore body figured out by structural analysis in the studied area works an important role for measuring of ore reserve and selecting of drilling site to find new ore body.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.497-504
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• 2013

This research uses numerical analysis to examine the tunnel portal landscape affecting the brightness level of interior lighting when designing lights for road tunnels through the L20 method. In order to extract the brightness recognition per form of a tunnel entrance and to evaluate the effects of the characteristics of the materials of facilities near a tunnel portal, brightness analysis was conducted by filming brightness on a video photometer called Hi-land Elf System, and a surface brightness photometer called LMK Mobile Advanced. Tunnels in Korea are mostly distributed in mountain areas; thus, the ratio occupied by the sky, which has the highest brightness within the angle of L20, is close to zero, while most of the ratio was occupied by brightness by the area near the tunnel entrance or road surface. However, for a tunnel portal retaing wall, which allows the width of a tunnel entrance to seem wider within the L20 angle, appeared to be have higher brightness compared to nearby areas or the surface, which is an element increasing the tunnel portal brightness within the tunnel, and the road facilities near the tunnel portal appeared to have an effect on the brightness as well. Thus, when designing tunnel lights based on brightness, the form of the tunnel entrance and the area width, material, and color of areas near the tunnel portal appeared to affect outside brightness and become an element affecting the establishment of the brightness level of the interior lights of tunnels. Consequently, reviewing such matters is a prerequisite when designing tunnel portal landscape.

• The Journal of the Petrological Society of Korea
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• v.6 no.1
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• pp.1-18
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• 1997

Andesitic pyroclastics and lava flows are deposited as a part of composite volcanoes by Cretaceous volcanic activity in Geojae Island, off the coast of Korea. The andesitic pyroclastics are composed of tuff breccia and lapilli tuff minor intercalated tuff. Lava flows are divided into dense and porphyritic andesite containing phenocrysts of plagioclase, pyroxene, and/or hornblende. The andesitic rocks represent charactersitcs of carc-alkaline BAR association with basalt, basaltic andesite, andesite, and dacite to rhyolite. Major element variations of the volcanic rocks show that $Al_2O_3$, total FeO, CaO, MgO and $TiO_2$ decrease with increasing $SiO_2$ but $K_2O$ and total alkalis increase, and represent differntiation trend of calc-alkaline rock series. In spider diagram, contents of Sr, K, Rb, Ba, and Th are relatively high, but contents of Nb, P, Ti and Cr are low. These petrochemcial characteristics are similar to those of rocks from island arc or continental margein related to plate subduction. Chondrite-normalized REE patterns of volcanic rocks are paralle to subparallel, with LREE enriched than HREE, and show gradual increase of negative Eu anomaly from basalt to dacite and rhyolite, suggesting comagmatic fractional crystallization with minor effects of assimilation and magma mixing. Andesitic rocks are assumed medium-K orogenic andesites that formed in the tectomagmatic environment of subduction zone under normal continental margin arc.

• Journal of the Korean association of regional geographers
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• v.15 no.1
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• pp.16-35
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• 2009

This paper is to compare the contexts and old place names in old county maps of Goryeong-hyeon(高靈縣) according to the four types of maps. 23 maps covering Goryeong-hyeon were collected from the old county-map atlas(郡縣地圖帖) and Eupji(邑誌). The first type(named 'picture county map') included 8 county-maps in which information of military, and administrative contents are mainly mapped. The second type(named '1-ri grid system map') included 4 county maps in which information about beacon routes and road systems were regarded as very important. The third type(named '20-ri grid-system map(方眼地圖)' included 4 county-maps which were drawn as same scale with 20-ri(里) grids. The fourth type(named 'local county-map(地方郡縣地圖)' included 5 county maps which were drawn by local mappers. Types of toponyms which were included in maps are different by the propose of map-drawing. In the picture county maps, place names from military, and administrative contents are written. In the 1-ri grid system county maps, place names especially from military and transportation are fluent. In the 20-ri grid system county maps, generic name from natural environment, such as mountains are very fluent. In the local county maps, city-walls and castles are drawn exaggeratively and detailed generic name from warehouses and villages are written in those maps. This study shows that Daedongyeo-jido was drawn on the basis of 20-ri grid system county maps with the supplementation of geographical information.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.1
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• pp.51-64
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• 2002

To investigate long-period wave responses in Sokcho Harbor and Cheongcho lagoon, field measurements were made for long-and short-period waves and current velocities using a Directional Waverider, a ultrasonic-type wave gauge, four pressure-type wave gauges, and a current meter. From the data analysis, it was found that the Helmholtz resonant periods of Sokcho Harbor and Cheongcho lagoon are about 13.6 and 54.5 minutes, respectively, and the dominant period of wave induced current in the passage between Sokcho Harbor and Cheongcho lagoon is about 55.2 minutes which depends on Helmholtz resonant condition of the Cheongcho lagoon. It was also found that the energy level of the far-infra-gravity waves during storm conditions is very high compared with that during calm sea conditions. To investigate relationships between far-infra-gravity waves and short-period waves at offshore station, regression analyses were carried out especially for 1) heights, 2) periods, 3) direction and height, 4) height and period between short-and far-infra-gravity waves, respectively. The results showed that the long-period wave height is highly correlated with the short-period wave height. However, no special trend was found for the other relations. In the future far-infra-gravity wave heights on return period around Sokcho Harbor region can be suggested by using extreme value analyses of long term measured data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.22-33
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• 2021

In the case of open phase faults caused by the disconnection of distribution feeders interconnected to a PV system, many problems can occur depending on the core type and wiring method of the grid-connected transformers. Moreover, open phase faults are difficult to detect because the open phase voltage of the existing protection relay (Open Phase Relay (47)) can be maintained, even though a disconnection fault occurred, depending on the wiring method and the iron core type of the grid-connected transformer for a PV system. Therefore, this paper proposes a novel algorithm to detect open phase faults by comparing the currents and phases between the primary and secondary sides of a grid-connected transformer. In addition, this paper presents the modeling of a distribution system and protection devices for detecting open phase faults using PSCAD/EMTDC S/W, and implements a test protection device for detecting open phase faults based on the above-mentioned modeling. The simulation and test results confirmed that the proposed algorithm is useful for detecting open phase faults according to the wiring method and iron core type of grid-connected transformer for a PV system because operation slope and unbalance rate of the primary current exceed the setting value (30[%]) of the protection device.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.129-140
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• 2019

The purpose of our study is to confirm the usefulness of our new youth entrepreneurship program. In this study, I suggest design thinking as a new Youth entrepreneurship program which is consist of 9 dimensions: opportunity discovery, opportunity utilization, creativity capacity, career preparation behavior, entrepreneurship, entrepreneurial intention, self-preservation, social problem solving, and educational program objectives. To verify this new program, I conduct a pilot test in middle school and high school; the sample target is randomly selected one class in each school. My main finding is two. First, our new program successfully improves Youth entrepreneurship. Particularly, the improvement of opportunity utilization and entrepreneurial intention are prominent. As reasons, studies about food industry entrepreneurship is an unfamiliar subject for adolescent. Considering that entrepreneurial intention rapidly changes after the experience of entrepreneurial education, researchers need to focus on this variable. Second, I confirm the effects of gender, motivation, prior experience, interest oneself and other's recommendation about the entrepreneurship program. As a result, gender and prior experience do not have an important influence. On the other hand, voluntary interest and other's recommendation are influential. The most important factor is the influence of a teacher. Therefore, researchers need to examine the more specific mechanism of each dimension in the future.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.567-578
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• 2018

A nondestructive petrological investigation was carried out to identify the original location and form of the Gyeongju Seated Stone Buddha with Square Pedestals in the Blue House (so-called Stone Buddha in the Blue House). The Statue is a representative stone Buddha statue of Silla (9th century) but its original location is controversial and some parts were missing. Based on the petrological observation, magnetic susceptibility and gamma spectrometry, its stone material was identified as medium-grained alkali feldspar granite. This kind of granites are widely found in the Namsan, Gyeongju. It is very likely that the Namsan granites are the source of rock of the Stone Buddha. The Yudeoksa (Igeosaji temple site) and Namsan are possible to be the original home of the Buddha Statue since there are petrologically identical alkali feldspar granite outcrop distributed in Namsan and stone heritage made of the same stone type in both places. An investigation on the square middle stone base in the Chuncheon National Museum reveals that it is less likely to be the missing part of the Buddha statue as the stone base is fine- to medium-grained pink feldspar granite and has different magnetic susceptibility from the Buddha statue. This study confirmed the contribution and significance of petrological investigation to identification of stone heritage in Korea.

• Clean Technology
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• v.25 no.3
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• pp.198-205
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• 2019

The adsorption equilibrium, kinetic, and thermodynamic parameters of brilliant green adsorbed by coconut based granular activated carbon were determined from various initial concentrations ($300{\sim}500mg\;L^{-1}$), contact time (1 ~ 12 h), and adsorption temperature (303 ~ 323 K) through batch experiments. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Harkins-Jura, and Elovich isotherm models. The estimated Langmuir dimensionless separation factor ($R_L=0.018{\sim}0.040$) and Freundlich constant ($n^{-1}=0.176{\sim}0.206$) show that adsorption of brilliant green by activated carbon is an effective treatment process. Adsorption heat constants ($B=12.43{\sim}17.15J\;mol^{-1}$) estimated by the Temkin equation corresponded to physical adsorption. The isothermal parameter ($A_{HJ}$) by the Harkins-Jura equation showed that the heterogeneous pore distribution increased with increasing temperature. The maximum adsorption capacity by the Elovich equation was found to be much smaller than the experimental value. The adsorption process was best described by the pseudo second order model, and intraparticle diffusion was a rate limiting step in the adsorption process. The intraparticle diffusion rate constant increased because the dye activity increased with increases in the initial concentration. Also, as the initial concentration increased, the influence of the boundary layer also increased. Negative Gibbs free energy ($-10.3{\sim}-11.4kJ\;mol^{-1}$), positive enthalpy change ($18.63kJ\;mol^{-1}$), and activation energy ($26.28kJ\;mol^{-1}$) indicate respectively that the adsorption process is spontaneous, endothermic, and physical adsorption.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.541-550
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• 2019

An emergency generator is key equipment for fire-fighting to supply power to fire-fighting facilities, which protect property and people in cases of fire accidents. A rated load test for emergency generators must be carried out by connecting an emergency load to the generator in accordance with related regulations. However, a no-load test has been performed for emergency generators in general since serious problems can occur when the main power is cut off, including the damage of customer devices and shut down of critical loads. Therefore, this paper proposes a load test method for an emergency generator using energy storage system (ESS) without the interruption of main power. The emergency power system was also modeled based on PSCAD/EMTDC software, and a 200-kW scale ESS load test device was implemented. The simulation and test results show that the load test method is useful and practical for an emergency power supply system.