• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.72-89
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• 2012

This study aimed to reconsider the theory that the renowned Amisan(峨眉山) terraced garden at north of Gyotaejeon(交泰殿) was artificially made, by reviewing the historical records and drawings. It has been widely accepted that Amisan was made of the digged soil from Gyeonghoeji(慶會池). But several arguments about artificial mountain theory of Amisan that completely not be found in historical records have been raised in this study. The results were summarized as follows; the inherent contradiction in existing opinion, the discordance between the time of building Gyeonghoeji and Gyotaejeon, the existence of the mountain range which connect Baekaksan and Amisan appeared in Dohyeong(圖形), historical documents written in the years of kingdoms of Youngjo(英祖) and Gojong(高宗), a high position seen from Heungbogjeon(興復殿) in the north Amisan through the wall in the east but impassable, an opinion about realization Amisan as geomantic term of Amisa(蛾眉砂) at the time of Gyeongbok Palace reconstruction, and preservation of the mountain range in Gyeongbok Palace that comes from the result of the arguments in main mountain of Gyeongbok Palace in the year of Sejong(世宗). In addition, it was investigated why the slop in the north of Gyotaejeon was named as Aminsan and why the artificial mountain theory is appeared and made a conclusion that the Amisan comes from the change of the pronunciation of the geomantic term "Amisa", and modeling the yijing[意景] of Amisan which is a sacred place of Taoism and Buddhism in Sichuan[四川] of Chinaand the view of construction to mean defeating a spirit of smallpox which had to be cured. And it seems to be a result which retroactively applied the artificial mountain theory of Amisanis the technique of 'constructing mountain with digged pond dirt' to the relationship between Gyeonghoeji and Amisan. The greater part of mountain range which was connecting with Baekaksan and Amisan was seriously disconnected with large scale of exposition by the Japanese colonial period in 1915. But low slope is kept about 70 meters along the trail northeast of Gyotaejeon. Accordingly, it is judged that the range has not been entirely destroyed. And according to the result of elevation analysis, discontinuous slope form certain axis is found, so the mountain range of Amisan is approximately estimated. This basic research about the mountain range of Amisan might provide a critical clue about restoration of topography in Gyeongbok Palace.

• Journal of Life Science
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• v.22 no.10
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• pp.1407-1414
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• 2012

Hormone replacement therapy (HRT) is an effective regimen that has been found to prevent these diseases in postmenopausal women. However, HRT is accompanied by an increased risk of unfavorable outcomes. This study was conducted to evaluate the effects of Eisenia Bicyclis extract on lipids in ovariectomized rats. Fifty 7-week-old female Sprague-Dawley rats were randomly assigned to four groups: sham-operated rats (SHAM), ovariectomized rats (OVX-CON), and ovariectomized rats that were treated with Eisenia bicyclis extracts. The extract-treated diets were fed to the rats for 6 weeks after operation. Antioxidant effects were measured by DPPH free radical scavenging activity. Antioxidant activity of the ethanol extract increased in a dose-dependent manner and was about 55.9% in a concentration of 100 ${\mu}g/ml$. We measured the total cholesterol content, triglyceride content, HDL-cholesterol content, LDL-cholesterol content, atherosclerotic index, cardiac risk factor in serum, and anti-platelet aggregation and blood rheology. The total cholesterol and triglyceride concentration in serum increased for the OVX-control group, but supplementation with the E. bicyclis extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the OVX-EB200 group was significantly lower than the OVX-CON group. In addition, the blood passage times in rats that received the E. bicyclis extract were more rapid than the times in the untreated group (OVX-CON). Microscopic evaluation revealed that whole blood passed more smoothly through the microchannels in rats in the E. bicyclis extract supplement groups. Our results clarified the effects of E. bicyclis extract on serum lipid content in ovariectomized rats, and consequently we expect positive effects from providing E. bicyclis extract to postmenopausal women with cardiovascular disease.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.1
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• pp.1-28
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• 2019

This study analyzed the density and mortality rate of Korean fir at 9 sites where individuals of Korean firs were marked into the live and dead trees with coordinates on orthorectified aerial images by digital photogrammetric system. As a result of the analysis, Korean fir in each site showed considerable heterogeneity in density and mortality rate depending on the location within site. This make it possible to assume that death of Korean fir can occur by specific factors that vary depending on the location. Based on the analyzed densities and mortality rates of Korea fir, we investigated the correlation between topographic factors such as altitude, terrain slope, drainage network, solar radiation, aspect and the death of Korean fir. The density of Korean fir increases with altitude, and the mortality rate also increases. A negative correlation is found between the terrain slope and the mortality rate, and the mortality rate is higher in the gentle slope where the drainage network is less developed. In addition, it is recognized that depending on the aspect, the mortality rate varies greatly, and the mean solar radiation is higher in live Korean fir-dominant area than in dead Korean fir-dominant area. Overall, the mortality rate of Korean fir in Mt. Halla area is relatively higher in areas with relatively low terrain slope and low solar radiation. Considering the results of previous studies that the terrain slope has a strong negative correlation with soil moisture and the relationship between solar radiation and evaporation, these results lead us to infer that excess soil moisture is the cause of Korean fir mortality. These inferences are supported by a series of climate change phenomena such as precipitation increase, evaporation decrease, and reduced sunshine duration in the Korean peninsula including Jeju Island, increase in mortality rate along with increased precipitation according to the elevation of Mt. Halla and the vegetation change in the mountain. It is expected that the spatial patterns in the density and mortality rate of Korean fir, which are controlled by topography such as altitude, slope, aspect, solar radiation, drainage network, can be used as spatial variables in future numerical modeling studies on the death or decline of Korean fir. In addition, the method of forest distribution survey using the orthorectified aerial images can be widely used as a numerical monitoring technique in long - term vegetation change research.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.579-593
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• 2021

In order to understand the types of vegetation in warm temperate-climate zones, vegetation was investigated in several island areas in Jeollanam-do (Jindo, Wando, Gangjin, Goheung, and Yeosu). The evaluation standard for degraded level of warm temperate forests were proposed based on the importance percentage (IP) in canopy layer of the evergreen broad-leaf forests and the number of arboreal evergreen broad-leaf species. Through these measurements, the restoration types and techniques for each degraded level were estimated, and it is intended to be used in establishing restoration plans for the southwest coast island area. The vegetation was analyzed using the two-way indicator species analysis (TWINSPAN) method using survey data of 307 plots. As a result, it was divided into 8 communities, and the appearance characteristics of evergreen broad-leaf species were identified in each community. Community I was located on the lower slope at an altitude of 86.6 m, and Neolitsea sericea and Castanopsis sieboldii were dominant. Communities II and III were the vegetation types that appear on the coast below an altitude of 10.5 to 22.5 m, and Machilus thunbergii, Cinnamomum japonicum, N. sericea, and C. sieboldii were dominant. Communities IV and V were vegetation types that appeared in the lower and middle slops between the altitudes of 71.9 to 153.4m, and C. sieboldii was dominant. In community VI, the N. sericea was dominant in the lower and middle slops at an altitude of 166.9 m. The last communities VII and VIII were the vegetation types that appeared on the middle slop at an altitude of 187.8 to 246.2 m. Also, Quercus acuta and Q. salicina were present. In summary, the evergreen broad-leaf forests dominated by M. thunbergii, C. japonicum, and N. sericea appeared mainly in the coastal areas of the lowlands. The community of C. sieboldii was distributed higher inland than this community. The communities that appeared mainly in the inland highlands at levels above these two communities were Q. acuta and Q. salicina. The degraded level was classified as 0 to V, according to the IP of arboreal evergreen broad-leaf species and the number of arboreal evergreen broad-leaf species. According to the degraded level, the restoration types (preservation, induction, improvement, creation) and the restoration techniques were determined.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.9-21
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• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2206-2217
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• 1971

Spillway and discharge channel of reservoirs require the Control of Large volume of water under high pressure. The energies at the downstream end of spillway or discharge channel are tremendous. Therefore, Some means of expending the energy of the high-velocity flow is required to prevent scour of the riverbed, minimize erosion, and prevent undermining structures or dam it self. This may be accomplished by Constructing an energy dissipator at the downstream end of spillway or discharge channel disigned to dissipated the excessive energy and establish safe flow Condition in the outlet channel. There are many types of energy dissipators, stilling basins are the most familar energy dissipator. In the stilling basin, most energies are dissipated by hydraulic jump. stilling basins have some length to cover hydraulic jump length. So stilling basins require much concrete works and high construction cost. Flip bucket type energy dissipators require less construction cost. If the streambed is composed of firm rock and it is certain that the scour will not progress upstream to the extent that the safety of the structure might be endangered, flip backet type energy dissipators are the most recommendable one. Following items are tested and studied with bucket radius, $R=7h_2$,(medium of $4h_2{\geqq}R{\geqq}10h_2$). 1. Allowable upstream channel slop of bucket. 2. Adequate bucket lip angle for good performance of flip bucket. Also followings are reviwed. 1. Scour by jet flow. 2. Negative pressure distribution and air movement below nappe flow. From the test and study, following results were obtained. 1. Upstream channel slope of bucket (S=H/L) should be 0.25<H/L<0.75 for good performance of flip bucket. 2. Adequated lip angle $30^{\circ}{\sim}40^{\circ}$ are more reliable than $20^{\circ}{\sim}30^{\circ}$ for the safety of structures.