• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.871-881
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• 2023

This study investigates the geomorphic changes and Bed Relief Index of the river downstream of the Yeongju Dam by Nays2DH, a two-dimensional numerical model, in order to grasp the dynamics of the downstream river while applying various flow patterns such as pulse discharge. It shows that the geomorphic and the bed elevations changes are the largest under the condition of the normalized pulse discharge. The total change in the riverbed is 29.88 m for uniform flow, 27.46 m for normalized hydrograph, 29.63 m for pulse flow and 31.87 m for pulse flow with normalized hydrograph which result in the largest variation in scour and deposition. The Bed Relief Index (BRI) increases with time under conditions of uniform flow, pulse flow and pulse flow with normalized hydrograph. However, BRI increased rapidly until 30 hrs after the peak flow (14 hrs), but decreased from 56 hrs under the condition of normalized hydrograph. Therefore, the condition of normalized hydrograph gives greater dynamics than the condition of a single flood or constant flow, and the dynamics increase downstream than upstream, resulting in an effect on improving the environment of the river downstream of the dam.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.442-450
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• 2024

Objective : Cerebral hyperperfusion syndrome (CHS) manifests as a collection of symptoms brought on by heightened focal cerebral blood flow (CBF), afflicting nearly 30% of patients who have undergone superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis. The aim of this study was to investigate whether the amalgamation of magnetic resonance imaging (MRI) fluid-attenuated inversion recovery (FLAIR) and apparent diffusion coefficient (ADC) imaging via MRI can discern cerebral hyperemia after STA-MCA anastomosis surgery. Methods : A retrospective study was performed of patients who underwent STA-MCA anastomosis due to Moyamoya disease or atherosclerotic steno-occlusive disease. A protocol aimed at preventing CHS was instituted, leveraging the use of MRI FLAIR. Patients underwent MRI diffusion with FLAIR imaging 24 hours after STA-MCA anastomosis. A high signal on FLAIR images signified the presence of hyperemia at the bypass site, triggering a protocol of hyperemia care. All patients underwent hemodynamic evaluations, including perfusion MRI, single-photon emission computed tomography (SPECT), and digital subtraction angiography, both before and after the surgery. If a high signal intensity is observed on MRI FLAIR within 24 hours of the surgery, a repeat MRI is performed to confirm the presence of hyperemia. Patients with confirmed hyperemia are managed according to a protocol aimed at preventing further progression. Results : Out of a total of 162 patients, 24 individuals (comprising 16 women and 8 men) exhibited hyperemia on their MRI FLAIR scans following the procedure. SPECT was conducted on 23 patients, and 11 of them yielded positive results. All 24 patients underwent perfusion MRI, but nine of them showed no significant findings. Among the patients, 10 displayed elevations in both CBF and cerebral blood volume (CBV), three only showed elevation in CBF, and two only showed elevation in CBV. Follow-up MRI FLAIR scans conducted 6 months later on these patients revealed complete normalization of the previously observed high signal intensity, with no evidence of ischemic injury. Conclusion : The study determined that the use of MRI FLAIR and ADC mapping is a competent means of early detection of hyperemia after STA-MCA anastomosis surgery. The protocol established can be adopted by other neurosurgical institutions to enhance patient outcomes and mitigate the hazard of permanent cerebral injury caused by cerebral hyperemia.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.1
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• pp.22-34
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• 2024

The following are the results of this study, which examined changes in the size of the burial mounds of the 61 Joseon Dynasty royal tombs and the perception of the formative aesthetics of the burial mounds' elevations. First, the diameter of the burial mounds of the Joseon Dynasty royal tombs at the time of their construction was 7.08 to 10.78m. Among the three types of burial mounds, the formal burial mounds with a folding screen-like stonework were large, the burial mounds without stonework were mostly small, and the burial mounds with railing stone-like stonework varied in size. Second, the highly intensive management and repair activities from the Joseon Dynasty to today changed the size and shape of burial mounds. As a result, the size of the burial mounds is now 7.30 to 16.70m. Third, compared to the construction time, the diameters of most of the burial mounds with railing stone-like stonework and without stonework mostly increased. At the same time, there were cases where the diameter of the burial mounds with folding screen-like stonework decreased. Fourth, while the change in the height of the burial mounds with a folding screen-like stonework was small, that of the other two types was large, which is deemed to be in the same direction as the change in the burial mound diameter. Fifth, the perception of the ideal burial mound during the Joseon Dynasty was confirmed because the elevation of the burial mound described in 「Gaesu Dogam Uigwe (Renovation Office Protocol)」 is higher than the information recorded in numbers. Sixth, the Cultural Heritage Administration's managers chose more diverse burial mounds as ideal shapes than the expert group. The burial mounds most frequently selected by the Cultural Heritage Administration staff were lower in height than those selected by the expert group, showing a managerial tendency. In contrast, the expert group preferred the shape of the burial mounds with a high height and a rounded top.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.2
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• pp.20-32
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• 2024

The purpose of this study was to divide cultural assets distributed in Shandong Province, China into five periods and identify the spatial distribution of each cultural asset type and its relationship with the natural environment, such as elevation, slope, and water system. As a result of the study, cultural properties before the Jin dynasty had a high distribution ratio of urban relics such as villages and tombs, and in Jin·Han~Su·Tang dynasty, tombs, ruins, stone caves, and stone carvings. In the Song and Yuan dynasties, there were many cultural properties such as relics, architectural and landscape cultural properties, and in the Ming and Qing dynasties, there were many cultural properties such as buildings, and they were more spatially distributed and distributed. After the Qing Dynasty, commemorative sites, political and defense-related buildings were distributed throughout Shandong, and many cultural assets were located in coastal cities on the east side of Shandong Province. It was found that the types of cultural assets were influenced not only by the social environment of each era but also by the natural environment. Except for cultural assets related to religion, such as grottoes and stone carvings, most cultural assets were located at low elevations and low slopes, and cultural assets were often distributed within 5km of water systems.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.89-97
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• 1986

To clarify the soil characteristics and genesis of the clayey terrace soils in Yeongnam area, the study were carried out with 9 typifying pedons of toposequential terrace soils in Yeongcheon (inland area) and Yeongil (coastal area) region. The results of soil genesis oriented investigations on soil mineralogical compositions and weathering characteristics were summarized as follows; 1. The contents of heavy minerals contained in sand fraction of the terrace soils were less than 5%, but the content in soil layers considered to be originated from other than terrace deposits had 9.8-16.2%. The content of feldspars in light minerals were higher in Yeongcheon sequence while the Yeongil sequence were characterized by having higher content in quartz. The ratios of quartz/feldspars in the soil layers where expecting lithological discontinuity, were different from that of terrace deposits. 2. The resistate index of maturity ranged around 76.7-29.9 in Yeongcheon area and around 85.6-67.2 in Yeongil area. The indices increased with the elevations of terraces. 3. The molar ratios of $SiO_2/Al_2O_3$ in clay fraction were around 1.93-2.65. The parent materials of the terrace deposits judged by the ratios of $Al_2O_3/TiO_2$ and $Fe_2O_3/Al_2O_3$ were considered to be the felsic materials. 4. The compositions of clay minerals detected by X-ray diffractogram and D.T.A. thermogram were dominated by kaolin and illite with subsidiary minerals of vermiculite, quartz, vermiculite intergrading to illite etc. It was distinguished from terrace deposits that by having higher amount of kaolin and montmorin minerals in the substrata of Bancheon soils in Yeongcheon area and Upyeong soils in Yeongil area, respectively.

• Journal of Korean Society of Forest Science
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• v.74 no.1
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• pp.67-81
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• 1986

To investigate the stand structure of the stocked broad-leaved forests in Korea, 1,000 plots, allocated by systematic sampling method, were interpreted on the aerial photographs accompanied with ground survey. Total area of the stocked broad-leaved forests except Jeju island was 818,286ha and the percentage to total forest area was 12.7%. Total stock volume of the stocked broad-leaved forests was $38,890,779m^3$ and the percentage to total stocked forest volume was 27.4%. Mean number of trees per ha was 947 trees/ha, basal area was $11.17m^3/ha$, DBH was 11.30cm, tree height was 7.65m, stock volume was $44.96m^3/ha$, and current annual volume increment was $3.64m^3/ha$ in total land. The 64.7, 79.8 and 52.7 percent of the stocked broad-leaved forest area were distributed at elevations of 300-900m, in slope degree of above 25, and in northern aspect, respectively. Standfactors were apt to get better with the increase of distance from the car road way and the village, and with the increase of elevation belt.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.171-177
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• 2013

The purpose of this study is to find a scheme to scale down the KMA (Korea Meteorological Administration) digital precipitation maps to the grid cell resolution comparable to the rural landscape scale in Korea. As a result, we suggest two steps procedure called RATER (Radar Assisted Topography and Elevation Revision) based on both radar echo data and a mountain precipitation model. In this scheme, the radar reflection intensity at the constant altitude of 1.5 km is applied first to the KMA local analysis and prediction system (KLAPS) 5 km grid cell to obtain 1 km resolution. For the second step the elevation and topography effect on the basis of 270 m digital elevation model (DEM) which represented by the Parameter-elevation Regressions on Independent Slopes Model (PRISM) is applied to the 1 km resolution data to produce the 270 m precipitation map. An experimental watershed with about $50km^2$ catchment area was selected for evaluating this scheme and automated rain gauges were deployed to 13 locations with the various elevations and slope aspects. 19 cases with 1 mm or more precipitation per day were collected from January to May in 2013 and the corresponding KLAPS daily precipitation data were treated with the second step procedure. For the first step, the 24-hour integrated radar echo data were applied to the KLAPS daily precipitation to produce the 1 km resolution data across the watershed. Estimated precipitation at each 1 km grid cell was then regarded as the real world precipitation observed at the center location of the grid cell in order to derive the elevation regressions in the PRISM step. We produced the digital precipitation maps for all the 19 cases by using RATER and extracted the grid cell values corresponding to 13 points from the maps to compare with the observed data. For the cases of 10 mm or more observed precipitation, significant improvement was found in the estimated precipitation at all 13 sites with RATER, compared with the untreated KLAPS 5 km data. Especially, reduction in RMSE was 35% on 30 mm or more observed precipitation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.73-87
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• 2018

A variety of micro meteorological variables such as air temperature, wind, solar radiation and latent heat at Gwangneung forests (conifer and broadleaved forests) and AWS (Automated Weather Station) of Pocheon urban area were used to quantify the air temperature reduction effect of forests, which is considered to be an eco-friendly solution for reducing the urban heat island intensity during summer. In June, July and August of 2016 and 2017, the average maximum air temperature differences between above and below canopy of forests, and between the forests and urban areas were $-1.9^{\circ}C$ and $-3.4^{\circ}C$ respectively, and they occurred at 17:00. However, there was no difference between conifer and broadleaved forests. The effect of air temperature reduction by the forests was positively correlated with accumulated evapotranspiration and solar radiation from 14:00 to 17:00 and showed a negative correlation with wind speed. We have developed a model to quantify the effect of air temperature reduction by forests using these variables. The nighttime air temperature reduction effect by forests was due to the generation of cold air from radiative cooling and the air temperature inversion phenomenon that occurs when the generated cold air moves down the side of mountain. The model was evaluated in Seoul by using 28 AWSs. The evaluation shows that the air temperature of each district in Seoul was negatively correlated with the area and size of the surrounding tall vegetation that drives vegetation evapotranspiration during the day. During the night, however, the size of the surrounding tall vegetation and the elevations of nearby mountains were the main influencing factors on the air temperature. Our research emphasizes the importance of the establishment and management of urban forests and the composition of wind roads from mountains for urban air temperature reduction.

• Journal of Life Science
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• v.24 no.10
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• pp.1092-1101
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• 2014

In this study, the distribution patterns of Quercus mongolica and Q. serrata in Korea were investigated, and the possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Seorak was inferred by flavonoid analyses. The most critical factor in the vertical and horizontal distribution patterns of Q. mongolica and Q. serrata was the temperature, in accordance with latitude and altitude. The species showed a zonal distribution, with a Q. mongolica zone in the upper area and a Q. serrata zone in the lower area. In Mt. Seorak, Central Korea, the range of the vertical distribution of Q. mongolica was generally above an altitude of 100 m, whereas that of Q. serrata was an altitude of 0-400 m (-500) and rarely above an altitude of 500 m. However, in Mt. Jiri, Southern Korea, Q. serrata was found up to an altitude of 1,000~1,200 m, whereas the frequency of Q. mongolica was reduced at lower elevations and the species was rare below an altitude of 300 m, although pure stands were found on higher mountain slopes above an altitude of 1,200 m. The altitudinal distribution of the two species overlapped, where the two species occurred together. The leaf flavonoid constituents of thirty-four individuals of Q. mongolica and Q. serrata in Mt. Seorak and Mt. Jiri, Korea were examined. Twenty-four flavonoid compounds were isolated and identified. These were glycosylated derivatives of flavonols kaempferol, quercetin, isorhamnetin, myricetin. Five compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside, a high concentration of three acylated compounds (kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and quercetin 3-O-galactoside), and a relatively low concentration or lack of rhamnosyl flavonol compounds. Intraspecific variations, however, were found in the flavonoid profiles of Q. mongolica and Q. serrata, and the flavonoid profiles of individuals belonging to the two species in a hybrid zone (sympatric zone) tended to be similar, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through introgressive hybridization between Q. mongolica and Q. serrata in Mt. Seorak.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.54-64
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• 2006

Chromated copper arsenate (CCA), a wood preservative, has been widely used to protect wood products from attacks by bacteria, fungi and insects. However, the use of CCA is currently forbidden or limited to some applications in many countries because the toxic elements (Cr, Cu, and As) of CCA are released into the environments during outdoor uses, which may cause adverse health effects on humans and ecological systems. This study was conducted to investigate the distributions of chromium, copper and arsenic in soils adjacent to two CCA-treated wood structures. In a 7 month old pond entry structure, ten surface soil samples (0-2.5 cm) were collected at lateral distances of 0, 0.5, and 1 m from the stairway, and nine surface soil samples were collected beneath the deck. Nine top soil samples were taken from a 2 year old sound barrier structure at lateral distances of 0, 1, and 2 m. Background surface soil samples were also collected from each structure. Samples were analyzed for some physicochemical properties such as pH, electrical conductivity, organic matter content, and soil texture. Following the extraction of the elements with a microwave digestion system, samples were analyzed for Cr, Cu, and As. The concentrations of the three elements in soils adjacent to the structures were significantly elevated compared to the background levels, indicating that the elements have been leached out of the structures. Released e1ements showed lateral concentration gradients within 1 m. The elevations of the three elements in soils underneath the deck did not seem different (background-corrected concentrations: Cr, 5.01 mg/kg; Cu, 5.50 mg/kg; As, 4.91 mg/kg), while the elements in soils near the sound barrier were elevated in the order of As>Cu>Cr with measured concentrations of 49.7, 44.7 and 52.5 mg/kg, respectively. Background As, Cu, and Cr concentrations near the sound barrier were 9.88, 30.8, and 46.5 mg/kg, respectively. These results showed that CCA constituents are released into the environment and it is suggested that risk assessment need to be conducted to investigate harmful effects of the released elements on humans and ecological systems.