• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.66-66
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• 2003

King George island, Antarctica, is mostly covered by ice sheet and glaciers, but the land area is focally exposed for several thousand years after deglaciation. For a mineralogical study of chemical weathering in the polar environment, glacial debris was sampled at the well-developed patterned ground which was formed by long periglaclal process. As fresh equivalents, recently exposed tills were sampled at the base of ice cliff of outlet glaciers and at the melting margin of ice cap together with fresh bedrock samples. Fresh tills are mostly composed of quartz, plagioclase, chlorite, and illite, but those derived from hydrothermal alteration zone contain smectite and illite-smectite. In bedrocks, chlorite was the major clay minerals in most samples with minor illite near hydrothermal alteration zone and interstratified chlorite-smectite in some samples. Smectite closely associated with eolian volcanic glass was assigned to alteration in their source region. Blocks with rough surface due to chemical disintegration showed weathering rinds of several millimeter thick. Comparision between inner fresh and outer altered zones did not show notable change in clay mineralogy except dissolution of calcite and some plagioclase. Most significant weathering was observed in the biotite flakes, eolian volcanic glass, sulfides, and carbonates in the debris. Biotite flakes derived from granodiorite were altered to hydrobiotite and vermiculite of yellow brown color. Minor epitactic kaolinite and gibbsite were formed in the cleaved flakes of weathered biotite. Pyrite was replaced by iron oxides. Calcite was congruently dissolved. Volcanic glass of basaltic andesite composition showed alteration rim of several micrometer thick or completely dissolved leaving mesh of plagioclase laths. In the alteration rim, Si, Na, Mg, and Ca were depleted, whereas Al, Ti, and Fe were relatively enriched. Mineralization of lichen and moss debris is of much interest. They are rich of A3 and Si roughly in the ratio of 2:1 to 3:1 typical of allophane. In some case, Fe and Ti are enriched in addition to Al and Si. Transmission electron microscopy of the samples rich of volcanic glass showed abundant amorphous aluminosilicates, which are interpreted as allophane. Chemical weathering in the King George Island is dominated by the leaching of primary phyllosilicates, carbonates, eolian volcanic glass, and minor sulfides. Authigenesls of clay minerals is less active. Absence of a positive evidence of significant authigenic smectite formation suggests that its contribution to the clay mineralogy of marine sediments are doubtful even near the maritime Antarctica undergoing a more rapid and intenser chemical weathering under more humid and milder climate.

• Journal of Radiation Protection and Research
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• v.7 no.1
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• pp.17-22
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• 1982

Measurement of the radon concentration close to the ground surface can be used in search of environmental radiation for human safety, exploration for uranium, premonitory signals from earthquakes. We can detect radons in soil gas by alpha particle track method using the plastic track detectors, cellulose nitrate (LR115-Type 2 and CA80-15, Kodak $Path\'{e}$) and CR-39. For present works, radon cups having these detectors were made in our laboratory and their conversion factor was determined. A typical conversion factor was $1tr/cm^2{\cdot}30days=1.2{\times}10^{-2}pCi/l$. In the radon cups, some of $CaSO_4$ were used as desiccant for reducing the moisture effects on plastic track detectors. With these radon cups, underground radon concentrations of Kyungpook area were measured. Average radon concentration in Daegu from Jan. 1981 to Feb. 1982 was 39.7pCi/l. From Aug. 1981 to Feb. 1982, average radon concentrations of Daegu, Angang, Kyungju, Pohang, Chungha, and Andong were 31.8pCi/l, 124.5pCi/l, 127.0pCi/l, 79.1pCi/l, 144.4pCi/l, and 70.9pCi/l, respectively. The results were compared with the environmental radiation measured by TLD method.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.35-43
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• 2009

This study was conducted to examine the genetic variations and intraspecific relationships between 9 individuals of Panax ginseng C.A Meyer by using RAPD (Randomly Amplified Polymorphic DNA) analysis. The 34 primers out of 40 random primers were amplified for all tested plants. The 48 (40%) among 244 bands derived from 34 primers shown polymorphism, and the 72 (64%) rest of bands showed similar forms. By regional groups Sangju and Andong samples located in Kyungsang buk-do showed a high similarity. However, Punggi located in Kyungsang buk-do showed higher similarity with Jinan's of Junla buk-do. In this way, it did not show that Panax ginseng from the same area has similarities. In future study we need to more specific molecular phylogenetic analysis such as AFLP technology and gene sequencing with nuclear chloroplast DNA in all samples.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.303-314
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• 2019

Surface permeability and shallow geological structures play significant roles in shaping the groundwater recharge of shallow aquifers. Surface permeability can be characterized by two concepts, intrinsic permeability and hydraulic conductivity, with the latter obtained from previous near-surface geological investigations. Here we propose a hydraulic equation via the cross-correlation analysis of the rainfall-groundwater levels using a regression equation that is based on the cross-correlation between the grain size distribution curve for unconsolidated sediments and the rainfall-groundwater levels measured in the Gyeongju area, Korea, and discuss its application by comparing these results to field-based aquifer test results. The maximum cross-correlation equation between the hydraulic conductivity derived from Zunker's observation equation in a sandy alluvial aquifer and the rainfall-groundwater levels increases as a natural logarithmic function with high correlation coefficients (0.95). A 2.83% difference between the field-based aquifer test and root mean square error is observed when this regression equation is applied to the other observation wells. Therefore, rainfall-groundwater level monitoring data as well as aquifer test are very useful in estimating hydraulic conductivity.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.722-726
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• 2011

The management standard on soil conditions in 'Fuji' apple to produce high quality fruit were not yet made. Therefore, this study was carried out to investigate the optimum soil environmental conditions of ten contents on production of high quality fruit in 'Fuji' apple. The soil and fruit characteristics were analyzed at total 60 orchards in major apple producing areas such as Chungju, Moonkyeung, yeongju, andong, yeosan and yeongcheon (10 orchards an area). The soil environmental factors affected fruit weight was highest relative contribution in saturated hydraulic conductivity of 36.5%. The bulk density and soil pH were low as relative contribution. The fruit weight was influenced by soil physical properties more than soil chemical properties. The soil environmental factors affected sugar content were hydraulic conductivity of 28.3% and organic matter content of 18.2%. The cultivation layer depth and soil pH were low as relative contribution. The fruit coloring was highest relative contribution in saturated hydraulic conductivity 55.9%. while soil pH, cation and soil texture were low. Fruit coloring was high influenced over 70% by soil physical properties. Finally, relative contribution on fruit quality related with sugar content, fruit weight, and coloring were high influenced by saturated hydraulic conductivity of 21.% and organic matter content of 18.7% but bulk density and cultivation layer depth were low relative contribution. The fruit growth and saturated hydraulic conductivity in 'Fuji' apple were very closely related. Therefore, orchard soil management to produce high quality fruit was very importance drainage management and organic matter application. We concluded that scientific soil management is possible by qualifiable of soil management factors.

• Journal of agricultural medicine and community health
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• v.46 no.4
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• pp.218-229
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• 2021

Objectives: The purpose of this study was to suggest the direction of the Healthy Village project for rural residents in accordance with the prolonged COVID-19 by investigating the digital environment for major health problems, the role of a health leader, necessary projects, and non-face-to-face projects for Healthy Village members in the COVID-19 epidemic. Methods: Telephone interview surveys were conducted with 585 residents from November 30, 2020 to December 21, 2020. Results: Health problems perceived by residents were in the order of concerns about infection (48.5%), depression (32.5%), difficulties in using medical services (9.4%), and lack of exercise (7.7%). The role of the health committee in the COVID-19 situation was "encouraging people to follow quarantine rules" with 91.3%. As a necessary health village project, there was a high demand for the provision of health products and mental health projects. 17.9% said that there is a computer or smart device connected to the Internet in their home, and 42.2% said that there is someone in the village who can easily get help if there is a problem in accessing and using Internet information. 36.9% were able to watch videos, and 22.2% were able to use the Internet through public facilities. Conclusion: In a public health crisis, where the provision of public health and medical services to rural residents is not smooth, it is necessary to manage health and quarantine through health leaders in the village, and it is required to establish a digital environment infrastructure that can conduct community participatory health village projects in a non-face-to-face environment.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.619-630
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• 2018

The purpose of this study is to investigate the existence of faults and intrusive rocks in the volcanic rock mass of Ulleung-do using magnetic anomalies. The magnetic survey data show that basaltic (mafic) rocks have high magnetic anomalies and that trachytic (felsic) rocks have low magnetic anomalies, implying that the anomaly distributions can be used to distinguish between different volcanic rock types that may be covered by regolith (such as alluvial and colluvial deposits) and other sedimentary layers. Our results show that basaltic rocks are not present within the Nari caldera. However, outside the caldera, the occurrence of high magnetic anomaly values of >$1,000{\gamma}$ is presumed to reflect the existence of basaltic craters or volcanic vents that formed prior to the eruption of the trachytic rocks. In particular, the area with anomaly values of >$1,000{\gamma}$ in the vicinity of Namyang-ri, southwest of Ulleung-do, is interpreted as having a high probability of hosting a crater and vent originating from mafic volcanism.

• Composites Research
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• v.34 no.3
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• pp.155-160
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• 2021

Metamaterials are complexes of elements that can create properties not found in naturally occurring materials, such as changing the direction of forces, creating negative stiffness, or altering vibration and impact properties. In the case of wood pile metamaterials that are easy to manufacture and have excellent performance in reducing vibration and shock in the vertical direction, basic research on variables affecting shock transmission is needed to reduce shock. Although research on impact reduction according to geometrical factors is being conducted recently, studies on the effect of material variables on impact reduction are insufficient. In this paper, finite element analysis was carried out by variablizing the geometrical properties (lamination angle, diameter, length) and material properties (modulus of elasticity, specific gravity, Poisson's ratio) of wood pile cylinders. Through finite element analysis, the shape of the wooden pile cylinder delivering impact was confirmed, and the effect of each variable on the reduction of impact force and energy was considered through main effect diagram analysis, and frequency band analysis was performed through fast Fourier transform. proceeded In order to reduce the impact force and vibration, it was found that the variables affecting the contact area of t he cylinder have a significant effect.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.83-88
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• 2022

Companies make decisions with risks such as choosing an investment plan in order to pursue profits. This study explained the decision making of the management of construction companies in South Korea using the tendency to avoid losses in the Prospect Theory. To this end, 20-year financial data of 2,881 companies engaged in real estate development, which have to bear the greatest risk among the construction industry, were collected. The collected companies were roughly classified based on the reference point, and the causal relationship between average return on equity and risk preference by group was empirically analyzed through regression analysis. As a result, it was confirmed that if the average return on equity of a company decreases for the group above the reference point, it tends to select an investment plan with low uncertainty in order not to lose additional money. In addition, it was confirmed that if the average return on equity of a company decreases for the group below the reference point, it tends to select an investment plan with high uncertainty to move to the profit area. This result is exactly consistent with the loss aversion tendency of the Prospect Theory.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.627-637
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• 2022

To know the magnitudes of extreme floods for various sizes of watersheds, massive streamflow data is fundamentally required. However, small/medium-size watersheds missed streamflow data because of the lack of gauge stations. In this study, the Streamflow Propagation Method (SPM) was applied to generate streamflow data for small/medium size watersheds with no measurements. Based on the generated streamflow data for ungauged watersheds at three different locations (i.e., Chungju Dam (CJD), Seomjin Dam (SJD), and Andong Dam (ADD) watersheds), the scale ranges of extreme floods were evaluated for different sizes of ungauged watersheds by using the specific flood distribution analysis. As a general result, a range of specific floods decreases with increasing watershed size. The distribution of the specific flood in the same size of a watershed possibly depends on the size and topography of the watershed area. The delivered equations were compared to show the relations between the specific flood and sizes of watersheds. In the comparisons of equations, the Creager envelope curve has the higher potential to represent the maximum flood distribution for each watershed. For the generalization of the maximum flood distribution for three watersheds, optimized envelop curves are obtained with lower RMSE than that of Creager envelope curve.