• Korean Journal of Remote Sensing
• /
• v.34 no.5
• /
• pp.749-762
• /
• 2018

In this study, the changes of the sunshine environment due to the construction of buildings were analyzed by season. Using a geographic information system (GIS) data, the topography and the buildings were constructed around Pukyong National University (PKNU) in Busan. The numerical model was performed for a week in each season, before and after the construction of buildings. Even before the construction of the high-rise building complex, the area of sunshine block is wide due to the apartment complex located in the southeast of the PKNU campus and the mountain in the south. After the construction, the sunshine-blocked area became wider after the sunrise and before the sunset. The area of sunshine block after 1 hour at sunrise increased by 1.60%, 1.50%, 1.58% and 1.36% in the vernal equinox, summer solstice, autumnal equinox and winter solstice, respectively. The building complex in the east (south) of the PKNU campus made shadow in more than 1,000 m (750 m) toward the west (east) just before the sunrise (sunset). Especially, the sunshine duration in PKNU campus decreased by 46.61%, 22.75%, 58.56%, and 11.31% in the vernal equinox, summer solstice, autumnal equinox and winter solstice, respectively. The analysis of the sunshine duration for a dormitory building showed that the construction of the building complex in the south of the PKNU campus reduced the sunshine area of the western (southern) wall of the dormitory by 30.91% (49.45%) for a winter week.

• Journal of the Korean earth science society
• /
• v.33 no.7
• /
• pp.658-671
• /
• 2012

This study is to develop teaching materials for the geological fieldwork of Jeokbyeokgang area located in the national park of the Byeonsan-bando National Park, Buangun, Jeonbuk, Korea. The developed teaching materials are used in middle school science to effectively teach the fieldwork of the area. The sedimentary succession of Jeokbyeokgang area in the Cretaceous age, Mesozoic, represents the large-scale and distinctive sedimentary structures on sea cliffs, which are worth developing as teaching materials for the earth science fieldwork. The area of Jeokbyeokgang also comprises various geological structures related to the advanced learning programs as well as those within the curriculum of earth science in middle school level. A five-step fieldwork model was applied to 20 students in middle school earth science. This study quantitatively analyzed students' responses to the process of the fieldwork activity. Results indicated that the fieldwork activity using the developed teaching materials was effective in helping the students to improve their self-directed learning and practical understanding of earth science.

• Journal of the Korean earth science society
• /
• v.34 no.7
• /
• pp.669-680
• /
• 2013

Ozone sensitivity analysis with respect to $NO_x$ is conducted around the south-eastern area of the Korean Peninsula. WRF-CMAQ modeling system is used to simulate a local circulation and high ozone episode day. To analyze the sensitivity, the adjoint model for CMAQ is adopted in this study. The purpose of current study is to investigate the location that affects a day time ozone concentration of these receptors on the high ozone episode day. Adjoint sensitivity analysis for Daegu shows two areas of influence. One is the range from the neighboring location to Pohang and it affects mainly on the same day as receptor time. The other is the remote south-eastern area from Daegu. This remote influence area suggests that $NO_x$ emitted on the previous day can change the ozone concentration at receptor time. The influence area for Busan, on the other hand, is originated only from the emission on the previous day because the sea-breeze occurred on the episode day makes low influence of surrounding emission. The cross sectional analysis reveals that $NO_x$ advection is important not only near the surface of land but also around the height of boundary layer.

• Journal of Korea Water Resources Association
• /
• v.42 no.9
• /
• pp.715-724
• /
• 2009

In case of inclined crest groyne, flow constriction with water is different. Therefore, it is proper to apply to narrow channel or there is a risk of overflow with water level rising caused by installation of groynes. This study were conducted experiments on inclined crest groyne. Main factors of inclined crest groyne are angles of crests slope and changes of water level. Velocity profile around groyne was measured by LSPIV (Large Scale Particle Image Velocimetry). Flow fields around groyne were analyzed focused on main channel and recirculation area. From the results, Thalweg change has little an effect on rate length and height of recirculation rises on increasing rate length. Length of recirculation area was about 12$\sim$16 times of rate length of groyne. Maximum velocity in main channel area was measured about 1.45$\sim$2.1 times of approach velocity and has little an effect on crest angle of groyne. Back water velocity recirculation area was decreased on approach velocity. This result presents to make stable flow to bank protection.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.5
• /
• pp.406-414
• /
• 2010

The impact of rainfall events on the sanitary indicator bacteria density of the shellfish-growing waters in Geoje Bay and Jaran Bay in Korea was investigated. The shellfish-growing area in Geoje Bay, which is a nearly closed basin, was not affected significantly, except near the stream mouth after 11.5 mm of rainfall in 1 day. However, most of the shellfish-growing water in the bay was polluted by fecal coliform bacteria after rain as heavy as 43.0 mm, and the levels of fecal indicator bacteria in some of the sea near the coast did not recover completely until 24 hours after the rainfall. By contrast, in Jaran Bay, which has no significant pollution source in the drainage area, although 9.3-490 MPN/100 mL of fecal coliform bacteria were detected near the stream mouth after rainfall of 33.5 and 81.0 mm, a very low level of the indicator bacteria was detected in the designated shellfish-growing area. During the investigation, the correlations between the sanitary indicator bacteria density and physical parameters, such as salinity and turbidity, were evaluated. Both the total coliform and fecal coliform densities were inversely correlated with salinity. Turbidity was positively correlated with the indicator bacteria density. The survey results suggest that for more efficient management of the shellfish-growing areas located in coastal areas, such as shellfish harvesting after rainfall, a detailed investigation of the effects of rainfall on the bacterial water quality in each growing area is needed.

• Journal of Environmental Science International
• /
• v.12 no.11
• /
• pp.1181-1187
• /
• 2003

Hibiscus hamabo, called "Hwang-geun", growing about 3m in height is a deciduous shrub or subtree of Malvaceae. Because the number of these species is very limited in the world, the Ministry of Environment has designated H. hamabo as a preserved plant. The Korea Forest Service also protects it strictly by law since H. hamabo is an out-of-the-way plant and possibly may be exterminated soon in Korea. Investigation for distribution and ecological characteristics of the habitat for H. hamabo was carried out on Soan Island. Two wild H. hamabo were found at the forest edge (equation omitted) along the sea coast located in the southern part of Soan Island and this was the first report in the Korean academic world. These two wild H. hamabos were growing in a naturally inhibited area. The diameters at the base were 12cm and 15cm. The Tree heights were 150cm and 210cm and the number of branches of each wild H. hamabo was 4 and 7. However, the present condition of these plants was not good. Environmental conditions of the naturally inhibited area of H. hamabo were very mild because it is located at the edge of the forest and is always sunny during the daytime since the slope of the inhibited area is facing South. The ground drained very well since the soil was made of gravels and sand. Because the percent of vegetation of the subtree layer where H. hamabo was growing was 40%, the cover degree and sociability of flex crenata trees and Eurya japonica were found to be high. In the naturally inhibited area of H. hamabo, a dominant value of Rubus parvifolius in the lower part of the herb layer was very high and many plants in Compositae, such as Artemisia princeps var. orientalis and Erigeron annuus, were also present. A dominant value of liana, such as Vitis thunbergii var. sinuata, Rosa multiflora, Clematis terniflora and Hedera rhombea, and Gramineae plants that rhizomes were well developed and aggressively propagated, such as Miscanthus sinensis var. purpurascens, Phragmites communis, Spodiopogon cotulifer and Oplismenus undulatifolius which were surveyed as high, too. These results imply that H. hamabo might be exterminated soon through a natural selection if the proper management of the naturally inhibited area of H. hamabo is not conducted continually.

• Journal of the Korean Society of Radiology
• /
• v.12 no.6
• /
• pp.769-776
• /
• 2018

According IEC 60601-1 ed3.1 and IEC 60601-2-45 regulation, diagnostic X-ray equipment should be display to measured and calculated air kerma area product. On the clinical X ray equipment, air kerma area product dosimeter would like to have an evidence for dosimeter accuracy and energy dependency. This study was performed to indirect calibration and energy dependency test for attached type air kerma area product (KAP) dosimeter by RQR standards beam quality. On the RQR5 beam quality, attached KAP dosimeter error showed -7.5%, respectably. On the RQR9 beam quality, attached KAP dosimeter error showed -10.4%, respectably. All RQR beam quality, average absolute error was $8.30%{\pm}2.85%$, respectably. On this study, attached KAP dosimeter was satisfied to IEC 60580 and AAPM TG 190. This calibration method of KAP dosimeter will help to performance maintain for clinical KAP dosimeter.

• Korean Journal of Environment and Ecology
• /
• v.33 no.2
• /
• pp.131-167
• /
• 2019

Securing reference information (inventory) is essential for proper conservation and management of protected areas. Moreover, the investigation results should be available for comparison and evaluation. For this study, we established seven investigational lattices and carried out the field examinations to obtain comparable data in the Donggang river basin ecological and scenery conservation area, We conducted a total of 16 field surveys and identified a total of 830 taxa that is composed of 127 families, 408 genera, 716 species, 10 subspecies, 88 varieties, and 16 forms. We identified a total of 487 taxa in the 6th investigational lattice and 457 taxa in the 4th. We observed 6 species (grade II) designated by the Ministry of Environment as the endangered plants, one "species to monitor" designated by the Ministry of Environment, and 23 taxa designated as endemic species. Regarding the floristic characteristics plants, 15 taxa of grade V, 27 taxa of grade IV, 38 taxa of grade III, 31 taxa of grade II, and 19 taxa of grade I were identified. The 6th investigational lattice showed the largest number of taxa at 70. A total of 58 taxa were identified as the naturalized plant, and the 6th investigational lattice showed the most at 35 taxa. The Donggang river basin ecological and scenery conservation area was assessed to be an extremely important area to conserve and maintain plants species diversity not only in the regional scale but also national scale.

• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.655-666
• /
• 2020

This study evaluated the characteristics of arsenic production in groundwater through microbial community analysis of groundwater contaminated with high arsenic in Haman area. Groundwater in Haman area is contaminated with arsenic in the range of 0-757.2 ㎍/L, which represents the highest arsenic contamination concentration reported in Korea as natural groundwater pollution source. Of the total 200 samples, 29 samples (14.5%) showed higher arsenic concentration than that of 10 ㎍/L, which is the standard for drinking water quality, and 8 samples (4%) found in wells with 80-100 m depth were above 50 ㎍/L. In addition, seven wells with arsenic concentration more than 100 ㎍/L located in the northern part of Haman. As a result of microbial community analysis for high arsenic-contaminated groundwater, the microbial community compositions were significantly different between each sample, and Proteobacteria was the most dominant phyla with an average of 61.5%. At the genus level, the Gallinonella genus was predominant with about 12.8% proportion, followed by the Acinetobacter and Methermicoccus genus with about 7.8 and 7.3%, respectively. It is expected that high arsenic groundwater in the study area was caused by a complex reaction of geochemical characteristics and biogeochemical processes. Therefore, it is expected that the constructed information on geochemical characteristics and microbial communities through this study could be used to identify the origin of high arsenic groundwater and the development of its controlling technology.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.4
• /
• pp.299-314
• /
• 2021

In this study, we investigated the effect of temperature on specific surface area and electrochemical properties when lignin-based porous carbon (LBPC) with potassium hydroxide (KOH) is activated. After preparing LBPCs using lignin-polyacrylonitrile (PAN) copolymer, which was synthesized by graft polymerizing lignin and acrylonitrile as a precursor, activated LBPCs (KA-LBPC-6, 7, 8, 9) were manufactured by activating LBPC with KOH at 600℃, 700℃, 800℃ and 900℃. To identify the surface characteristics of KA-LBPC, observations were made with a scanning electron microscopy (SEM), and the pore characteristics were identified via specific surface area analysis. The electrochemical properties were analyzed using a three-electrode system. The experiment has shown that micropores formed by activation can be observed in SEM images. KA-LBPC-7 had the best pore characteristics among KA-LBPCs, with a specific surface area of 2480.1 m²/g, a micropore volume of 0.64 cm³/g, and a mesopore volume of 0.76 cm³/g. KA-LBPC-7 showed the best electrochemical properties with a specific capacitance of 151.3 F/g at the scan rate of 2 mV/s.