• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.42-55
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• 2008

To evaluate the accuracy of currents measured by HF radar in the coastal sea off Keum River estuary, we compared the facing radial vectors of two HF radars, and HF radar-derived currents with in-situ measurement currents. Principal component analysis was used to extract regression line and RMS deviation in the comparison. When two facing radar's radial vectors at the mid-point of baseline are compared, RMS deviation is 4.4 cm/s in winter and 5.4 cm/s in summer. When GDOP(Geometric Dilution of Precision) effect is corrected from the RMS deviations that is analyzed from the comparison between HF radar-derived and current-metermeasured currents, the error of velocity combined by HF radar-derived current is less than 5.1 cm/s in the stations having moderate GDOP values. These two results obtained from different method suggest that the lower limit of HF radar-derived current's accuracy is 5.4 cm/s in our study area. As mentioned in previous researches, RMS deviations become large in the stations located near the islands and increase as a function of mean distance from the radar site due to decrease of signal-to-noise level and the intersect angle of radial vectors. We found that an uncertain error bound of HF radar-derived current can be produced from the separation process of RMS deviations using GDOP value if GDOP value for each component is very close and RMS deviations obtained from current component comparison are also close. When the current measured in the stations having moderate GDOP values is separated into tidal and subtidal current, characteristics of tidal current ellipses analyzed from HF radar-derived current show a good agreement with those from current-meter-measured current, and time variation of subtidal current showed a response reflecting physical process driven by wind and density field.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.67-82
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• 2008

This study was performed to investigate changes in benthic environment and macrobenthic polychaete communities in Gamak Bay where various environmental quality improvement projects have been implemented in recent years. Field surveys were carried out in February, 2005 and February, 2006 and twenty stations were selected to explore whether or not there were between-year differences in biotic and abiotic variables. Of 10 environmental variables measured, only three variables including dissolved oxygen (DO), total ignition loss (IL), acid volatile sulfide (AVS) showed significant between-year differences. Specifically, IL and AVS were, on average, 1.5 and 3 times lower in 2006 compared to those in 2005, respectively, which was more pronounced in the northern part of the bay. A total of 95 polychaete species was sampled from the two sampling occasions. Between-year differences in the number of species, abundance, and diversity were varied from place to place. In the northern part of the bay, fewer species were found in 2006 rather than in 2005, but diversity increased in 2006 due to the reduction in dominance of a few species. On the contrary, in the central part of the bay, the number of species, abundance and diversity prominently increased in 2006. In the southern part of the bay, all the biological indices maintained similarly during the two years. Dominant species in 2005 were such opportunistic or organic pollution indicator species as Lumbrineris longifolia, Capitella capitata, Mediomastus californiensis, Pseudopolydora paucibranchiata, etc. and most of them were mainly distributed in the northern part of the bay and in the proximity of it. In 2006, however, Euchone alicaudata, L. longifolia, Paraprionospio pinnata, Flabelligeridae sp., etc. were dominant and distributed mainly in the central part of the bay. Multivariate analyses showed that the whole polychaete community could be divided into 5 groups reflecting the geographical positions of the sampling stations and temporal variation particularly in the northern part of the bay. According to the results of BIO-ENV procedure, TOC (${\rho}=0.52$) and AVS (${\rho}=0.49$) as a single variable best explained the polychaete community structure. The best combination was made by such variables as TOC, AVS, sorting coefficient, and water temperature (${\rho}=0.60$). In conclusion, between-year differences in biotic and abiotic variables imply that recent efforts for the environmental improvement produced positive influences on the benthic environment of Gamak Bay, particularly the northern part of the bay.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.110-126
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• 2024

This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.4
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• pp.24-38
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• 2024

Five species of plants (Pimpinella brachycarpa (Kom.) Nakai, Hylotelephium erythrostictum (Miq.) H. Ohba, Magnolia sieboldii K. Koch, Sanguisorba hakusanensis Makino, Agastache rugosa (Fisch. & Mey.) Kuntze) native to the clean area of Mt. Jiri were selected. The collection period was from May to September 2021, and the five species plants were collected in their native habitats with flowers in full bloom. The collected plants were extracted with 70% EtOH and 17 kinds of polyphenol components were analyzed. Next, flowers, leaves and roots were separated from plants, extracted with 70% EtOH for each part and experiments were conducted on DPPH, ABTS, total polyphenols, and total flavonoids. The results are as follows. 1. There were a total of 13 polyphenol components contained in the 5 species of plants native to Mt. Jiri. Among them, the total content of the most detected substance was Sanguisorba hakusanensis Makino, which was 126.2 ppm, and the main substance was ellagic acid (=ELA), which was 122.4 ppm. 2. As a result of examining the DPPH radical scavenging activity, the flowers, stems, and roots of Sanguisorba hakusanensis Makino showed the best scavenging activity, while the flower extracts of other plants showed good scavenging activity. 3. The highest ABTS radical scavenging activity was Sanguisorba hakusanensis Makino flower extract at 13.5 ㎍/㎖, followed by roots at 16.8 ㎍/㎖ and leaves at 22.6 ㎍/㎖;. Although such a large ABTS radical scavenging activity could not be confirmed in other plants, the flower extract was overall better than the leaf and root extracts of other parts. 4. The highest total polyphenol content was found in the leaves of Magnolia sieboldii K. Koch, at 161.4mg GAE/g, followed by the highest content in the roots of Magnolia sieboldii K. Koch and the roots of Agastache rugosa (Fisch. & Mey.) Kuntze, at 130.0mg GAE/g. Also, the lowest was found to be Sanguisorba hakusanensis Makino. 5. The total flavonoid content was 186.2mg CAE/g in the roots of Agastache rugosa (Fisch. & Mey.) Kuntze, 166.9mg CAE/g in the flowers, and the lowest was 116.1mg CAE/g in the leaves. As shown in the results above, Sanguisorba hakusanensis Makino has excellent antioxidant efficacy and has a high polyphenol content, so it is expected to be fully utilized in the cosmetics industry in the future.

• Sim-seong Yeon-gu
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• v.38 no.2
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• pp.269-304
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• 2023

The purpose of this paper is to present the psychological meaning of the creation myths by utilizing related myths, analysand's dreams, active imagination, and artwork to reveal the creative function of the unconscious. The creation myth is the phenomenon of projection when a new order is demanded in the chaotic phase of personal and human history. Depending on the attitude of the ego, it can be a sign of a reconstruction/alteration of consciousness or an invasion. Related literature such as Jung, von Franz, Neumann, Harding, and Edinger, domestic papers, and case reports are introduced to identify the background for this research. The psychological meaning of 'darkness' in creation myths is regarded as unconscious that is too dark to see. The Eskimo creation myth and an analysand's dreams of being blind and wandering in darkness are discussed in relation to nigredo in Alchemy. The psychological meaning of 'massa confusa' regards Uroboros, pleroma, early childhood experience, and a psychological womb in which everything is contained in one. With related myths and unconscious materials, a discussion is followed on how this realm can be a precursor of creation but also be trapped in an abyss. The psychological meaning of 'separation of world parent' is related to splitting one into two when unconscious contexts were touched before it became consciousness. Related myths, 'the world created between heaven and earth,' 'celestial being descending to the earth,' and 'the legend of relocation of a mountain,' as well as clinical material, are examined. Then this paper discusses the clinical implications of the separation of heaven and earth occurring on its own, that the creator's emotional aspects, such as loneliness and anxiety, are involved, and that delayed separation leads to the death of creatura and sudden separation leads to the death of the chaos. Then, the meaning of 'separation of world parent' is discussed in relation with separatio, the alchemical process of acquiring light/consciousness from darkness/unconsciousness. The psychological meaning of the creation of 'land/island' refers to the emergence of consciousness, the contents of the unconscious material into the realm of the ego. Related myths, such as the 'body of the monster/dragon becoming land' and analysand's dreams, are introduced, referring to the embodiment of Mercurius. This is followed by discussing related myths in creating the land to coagulatio in alchemy and utilizing creative work such as active imagination, art, music, and dance that can coagulate or concretize unconscious material in clinical approaches. Finally, myths of resurfaced land after the Flood or the complete destruction of the world in relation to the reconstruction of ego are discussed with related clinical material to show the importance of the analyst/therapist/supervisor's mental stability and capacity.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.411-422
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• 2024

Naked oat is particularly vulnerable to cold weather among cereal crops, and frequent lodging due to their long culm length. Also it is difficult to cultivate in double cropping system with rice because of late maturity in Korea. In this study, we charaterized 71 naked oat germplasms including two control varieties with agronomic traits, to select superior resources and use them for the improvement of exsiting varieties. The maturity date was May 26th for 'Joyang' and June 1st for 'Daeyang', and there were 5 resources including IT302003, which was earlier than Daeyang. In the case of culm length, the distribution ranged from 62 to 124 cm, and there were 13 resources, including IT209241, that were shorter than 'Joyang' (84 cm) and 'Daeyang' (83 cm). In correlation analysis of agronomic traits, the highest positive correlation (r=0.89) was observed between days to heading and days to maturity. In addition, culm length and spike length (r=0.72) and days to heading (r=0.50) showed a positive correlation. However, Barley yellow dwarf virus(BYDV) and grain yield (r=-0.30), lodging tolerance and liter weight (r=-0.37) showed a negative correlation. Cluster analysis, resources with similar traits such as liter weight, husk ratio, days to heading, and days to maturing were subclassified. Through this analysis, 6 resources, including IT302002 (X345-1-B4-20-1), which had short culm length, early maturity, and cold tolerance compared to 'Joyang' and 'Daeyang', were selected. Among the selected excellent resources, the avenanthramide content of the four resources was IT302002 (325.18 ㎍/g), K000010 (557.3㎍/g), K253299 (447.33 ㎍/g), and K253301 (440.49 ㎍/g), respectively, which was higher than 'Daeyang' (301.97 ㎍/g). These excellent resources will be used as breeding materials for the development of new varieties in the future.

• Economic and Environmental Geology
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• v.57 no.4
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• pp.397-416
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• 2024

This study assessed the hydrogeological properties of the deep geological environment to develop safety criteria for the natural barriers used in the deep geological disposal of high-level radioactive waste in Korea. The assessment focused on the distribution and trends of hydraulic conductivity and permeability properties appropriate for the domestic geological environment, using various in-situ hydraulic test data collected for groundwater development and management. To develop a depth-hydrogeological property relationship model suitable for domestic conditions, the study reviewed various international research examples and applied a representative model that explains the trends of hydraulic conductivity and permeability with depth. The development of the model suitable for Korea involved applying ensemble regression analysis to account for the uncertainty of various factors in the collected data. The results confirmed that existing international depth-hydrogeological property relationship models adequately describe the characteristics of the domestic geological environment. Considering the preferred hydrogeological criteria suggested by countries like Sweden, Germany, and Canada, there is a high likelihood that a suitable geological environment exists in Korea. Additionally, the application of hydrogeological criteria indicative of low-permeability environments showed that suitable conditions for disposal construction increase at depths greater than 300 m, where the influence of fractures on groundwater flow might be minimal at depths exceeding 500 m. This research can serve as foundational information for establishing hydrogeological safety standards for natural barriers in Korea according to international regulatory guidelines.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.374-392
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• 2024

In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10^-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10^-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

• The Journal of Engineering Geology
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• v.34 no.3
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• pp.367-379
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• 2024

We analyzed the changes in the properties of the Mudeungsan tuff by conducting an artificial weathering experiment based on the climatic conditions of Mudeungsan National Park, to evaluate the long-term stability of the columnar jointing in the tuff. The climate of Mudeungsan National Park over 20 years suggests the temperature conditions for freeze-thaw are -20 to 30℃. The change in tuff properties due to weathering were estimated by measuring the elastic wave velocity, which was measured after every 40 freeze-thaw cycles. Based on the origin of the Mudeungsan tuff and fracture distribution in the tuff, the elastic wave velocity in samples from 24 locations was measured at regular intervals in the axial and radial directions. The axial elastic wave velocity of the Mudeungsan tuff is 5,187~5,367 m/s, and the radial elastic wave velocity is 4,001~5,290 m/s. As a result of 200 freeze-thaw cycles, the axial elastic wave velocity decreased by 5.53% for sample MT-1, 4.89% for MT-2, and 5.36% for MT-3. The radial elastic wave velocity decreased by 20.00% for MT-1, 17.02% for MT-2, and 19.84% for MT-3. The decrease in elastic wave velocity due to the freeze-thaw cycles is greater for low values of elastic wave velocity. For the axial elastic wave velocity, the weathering is accelerated after 120 cycles and, for the radial elastic wave velocity, weathering actively progresses from the start of the freeze-thaw cycles. In summary, for a low elastic wave velocity, experimental weathering results in a large decrease in elastic wave velocity. In addition, the Mudeungsan tuff and its columnar joints have a distinct anisotropy.

• Journal of Practical Agriculture & Fisheries Research
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• v.26 no.3
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• pp.32-44
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• 2024

Five species, including Synurus plamatopinnatifidus (Makino) Kitam, Lindera obtusiloba Blume, Acorus gramineus Sol., Swertia japonica (Schult.) Griseb., and Valeriana fauriei Briq., native to Mt. Jiri, were collected from their habitats from April to October 2022. The collected plants were analyzed for 17 types of polyphenol components in the whole plant, and the antioxidant activities of DPPH and ABTS were measured according to the parts of the leaves and roots, and the contents of total polyphenol and total flavonoid were measured. Based on these results, we hope that they will be used as basic data for the development of antioxidant cosmetic raw materials targeting the five plants native to Mt. Jiri with high antioxidant efficacy. 1. The polyphenol components contained in the five species of plants native to Mt. Jiri were 12 types, including catechin and quercetin. Among them, the total polyphenol content of A. gramineus was 39.5ppm, and the variety with the lowest polyphenol content was S. japonica with 5.9ppm. 2. DPPH radical scavenging activity was confirmed by EC₅₀ value. As a result, the variety with the highest DPPH radical scavenging activity was L. obtusiloba leaves at 35.31㎍/mL. The variety with the lowest scavenging activity was V. fauriei at 262.69㎍/mL for the leaves and 278.99㎍/mL for the roots. 3. ABTS radical scavenging activity was confirmed by EC₅₀ value. The variety with the highest scavenging activity was L. obtusiloba roots at 55.79㎍/mL and 58.85㎍/mL for leaves. The variety with the lowest scavenging activity was S. japonica leaves at 576.5㎍/mL. 4. The variety with the highest total polyphenol content was L. obtusiloba leaves at 158.72mg/g, and the variety with the lowest content was V. fauriei leaves at 0.13mg/g. Therefore, there was a large difference in the total periphenol content by variety. 5. The variety with the highest total flavonoid content was L. obtusiloba leaves at 163.75mg GAE/g, and the other varieties showed low contents at 17.67~41.38mg GAE/g.