• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.5
• /
• pp.80-89
• /
• 2022

In order to solve the limitations of horizontal thermal environment improvement, this study compared the thermal environment of the indoor and outdoor of a building in summer according to the presence or absence of a green curtain, a vertical greening method. In the summer of 2021, the air temperature, relative humidity, wind speed, and shortwave and longwave radiation were measured at a central point inside a building and the grass field outside of the building to determine the human thermal sensation index, PET and UTCI. As a result, the green curtain showed an average 1.6℃ cooler air temperature during the daytime, but it did not have an effect at night. For relative humidity, it showed higher humidity indoors by an average of 5.6% and 1.0% during the daytime and at night, respectively. Wind speed was 1.4-1.8 ms^-1 and 1.4-1.5 ms^-1 higher outdoors on average during the daytime and at night, respectively, showing a high value outdoors regardless of whether a green curtain was installed. The green curtain showed an average indoor mean radiant temperature reduction effect of 4.7℃ during the daytime, but it did not have an effect at night. In PET and UTCI, the green curtain reduced the indoor PET by about a 1/3 level, an average of 2.1℃, and the indoor UTCI by about a 1/6 level, an average of 1.1℃, during the daytime. However, no effects appeared in PET and UTCI at night. For landscape planning, a green curtain can effectively modify the thermal environment during the daytime in summer.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.1
• /
• pp.20-28
• /
• 2014

The three air quality monitoring sites, analysed simultaneously PM-10 and PM-2.5, ie. Ihyeondong in industrial area, Manchondong in residential area, Pyeongnidong in streetside, among 13 air quality monitoring sites in Daegu area, were investigated the concentration distribution characteristics of PM-2.5 and PM-10 in the last 2 years (2011~2012). PM-10 concentrations exceeded annual average reference value ($50{\mu}g/m^3$) in Ihyeondong ($52.5{\mu}g/m^3$) and Pyeongnidong ($60.9{\mu}g/m^3$) but satisfied in Manchondong ($44.9{\mu}g/m^3$). All PM-2.5 concentrations exceeded EPA annual standard value of the United States ($15{\mu}g/m^3$) in three points, but also exceeded new control annual standard value ($25{\mu}g/m^3$) coming into effect in 2015. Seasonal concentration of PM-10 appeared the order of spring > winter > fall > summer, and in the case of PM-2.5, the order was winter > spring > fall > summer. Monthly concentrations of PM-10 and PM-2.5 were highest in February and lowest in September. Diurnal concentrations of PM-10 and PM-2.5 increased from 7:00 AM, and recorded the highest concentration between 10:00 AM and 11:00 AM. And after 6:00 PM it lowered continuously and tended to show fixed concentrations from evening until early morning. In addition, the concentration of fine particles during the week was higher than the weekend. The fluctuation in industrial area was larger than the residential area. At the PM-2.5/PM-10 ratio, summer was generally high, spring was the lowest. And, when yellow sand occurred, it was 0.32 to 0.42. It was very low compared to 0.54 to 0.64 during non-yellow sand times. This paper for the state and the characteristics of Daegu' fine particles (PM-10, PM-2.5) will be valuable to future researches of fine particles and air pollution management.

• Journal of Environmental Impact Assessment
• /
• v.20 no.6
• /
• pp.915-925
• /
• 2011

Following the industrialization and urbanization in Korea, algal bloom causes aesthetic displeasure and many other problems such as taste and odor, coloration, scum, increase in pH, filter-bed blockage. There were some cases involving human death by microcystins during summertime in foreign countries. In Korea, Harmful cyanobacteria such as Microcystis and Anabaena develop in summer in the Daecheong reservoir, one of the main water resources, with the retention time of above 200 days. To better control algal bloom, the Ministry of Environment has been running algal bloom alert system from 1998 for the Daecheong reservoir, which needs to be improved to reflect the characteristics of river-type lakes. For this reason, we try to find new measures to improve an algal bloom alert system for each water zone considering the characteristics of harmful cyanobacteria in this study.

• Journal of Korean Society on Water Environment
• /
• v.29 no.2
• /
• pp.155-164
• /
• 2013

To confirm the relationship between climate change and Stephanodiscus in Mulgeum station of Nakdong River, Korea, this study was conducted. The temperature in crease by climate change was observed in the study site, where the temperature was gradually increased in most seasons, except for summer season. The mass proliferation of Stephanodiscus constantly appeared in every year, especially between November and March, and when Stephanodiscus abundance was above 90% in phytoplankton biomass. Among this period, phytoplankton biomass was high related with water temperature ($r^2$=0.249, P<0.01) than nutrient factors such as nitrogen and phosphorus in the study site. Finally, temperature by climate change can be regarded as the affecting factor for chl. a variation, because temperature was strongly related with water temperature ($r^2$=0.748, P<0.01). From 1997 to 2010, the annual maximum phytoplankton biomass was recorded in the range of temperature from $4.8^{\circ}C$ to $8.4^{\circ}C$, and the range was regarded as the temperature condition for the optimal growth of Stephanodiscus in the study site. On the optimal growth temperature, the trend of monthly average temperature corresponded to the trend of chl. a variation from November to March. In future, the increase of temperature by climate change can prolong Stephanodiscus blooming period in winter and spring seasons.

• Korean Journal of Veterinary Service
• /
• v.36 no.3
• /
• pp.209-216
• /
• 2013

A total of 301 samples of bovine liver, spleen and omasum were collected from butchers and restaurants in Gwangju, Korea during 2012 and all samples were subjected to bacteriological examination and antibiotic residues. Also, this study was performed to survey the consciousness for hygiene of livestock workers who are handling bovine by-products in Gwangju. The detection rate of aerobic plate count (APC) was higher in summer than in other seasons in all by-products (P=0.000). The detection rate of E. coli count was lower in the liver than the spleen and omasum (P=0.000). Twenty four of the samples (8.0%) were contaminated with S. aureus while one spleen sample (0.3%) was contaminated with L. monocytogenes and finally 10 (3.3%) of the liver and omasum samples were contaminated with Cl. perfringens. Five of the twenty-four S. aureus isolates harbored enterotoxin gene. However, the cpe gene of Cl. perfingens was not detected among any of the 10 isolates. Antibiotic residues were not detected in the liver samples. The consciousness survey's results showed that most of them (58.8%) were safe.

• Journal of Korean Society on Water Environment
• /
• v.31 no.6
• /
• pp.723-731
• /
• 2015

We investigated the spatial and temporal patterns of water quality in the Gangjung-Goryoung weir that is located in the middle area of the Nakdong river, Korea. The monitoring results indicated that there are discernible vertical differences in water quality during the pre- and post-monsoon periods (May to September). During this period, it was observed that the weak thermal stratification formed at the maximum level, and pH, Chl-a, and DO concentrations in the surface layer were higher than those in the bottom layer. This vertical difference was especially noticeable for DO concentrations: there were DO depletions at the bottom layer in late June to early August. During the summer monsoon period with heavy rainfall, there was a decline in vertical differences in water quality. From this study, it was suggested that continuous monitoring of vertical profiles could become a useful tool for identifying the spatial and temporal distributions of water quality and for developing the best management policy for water quality in the Nakdong river.

• Journal of Korean Society on Water Environment
• /
• v.28 no.6
• /
• pp.796-803
• /
• 2012

Potential feasibility of nutrients removal and biofuel production with microalgae was evaluated in batch culture. Distribution of microalgae in fresh water including reservoir and river was investigated to search for the species with high content of lipid that could converted into biofuel. Green algae, Chlorella and Scenedesmus sp., these are known as species containing high lipid content for biodiesel production, were observed in both summer and autumn season. However another highly lipid-containing species, botryococcus sp. was not observed in this study. In mixed culture of microalgae using synthesized wastewater medium, green algae were found to be dominant, comparing to other species of diatoms and blue-green algae. And microalgae were also capable of removing nitrogen and phosphorus in batch experiments. During the culture period of 14 days, removal efficiencies of nitrate and phosphorus were 30% and 82%, respectively. Furthermore, content of the intracellular lipid extracted from algae cell was as favorable as 12-30% in the mixed culture where Scenedesmus and Chlorella sp. were dominant. Therefore the mixed culture of microalgae could be applied to biofuel production and tertiary wastewater treatment, even though there are economic barriers to overcome.

• Korean Journal of Veterinary Service
• /
• v.31 no.2
• /
• pp.219-227
• /
• 2008

Swine ascariasis is one of the major parasitic diseases to cause economic losses. This study was carried out to investigate the prevalence of Ascaris suum from slaughtered pigs and return the result to the farm (Feed - back). A total of 8,121 pigs (315 farms) were examined from January to November in 2007. The prevalence of farms detected with milk-spots was 42.9% (135 / 315 farms), and that of pigs with milk-spots was 7% (565 / 8,121 heads). Among 565 pigs with milk-spots, the pigs with grade 1 and grade 2 were 380 and 185, respectively. The percentage of pigs and farms detected with adult worm were 0.6% (45/8,121) and 7.3% (23/315) respectively. There was no statistical difference in affection rateamong seasons. The rate was 5.0% in spring, 8.8% in summer, 8.2% in autumn and 6.3% in winter. There was no enough difference in pig infection rate based on piggery type. The prevalence of milk-spots in stolic type and in sawdust one were 15% and 18.5%, respectively.

• Korean Journal of Environment and Ecology
• /
• v.6 no.2
• /
• pp.180-192
• /
• 1993

This study was conducted to investigate bird community and to suggest a proper way how to manage and protect bird community in Sobaeksan National Park. The survey was carried over 3 main trail districts by line transect method to figure out influence factor of inhabitation of wild birds from February to October in 1992. The study results as follows: The observed birds were belong to 9 orders l2 families 58 species, they also have Sparrow Hawk dccipiter nisus, Kestrel Faleo tinnunculus(natural monument no. 323). Scops Owl I'otus scops(natural monument no. :324), Black Woodpecker Dryoaepus martius(natural monument no. 242. R). White-backed Woodpecker Dendroaepos leuotes(R) and Gray-backed Thrush Turdus hortulorum(R). These birds a]so classified into 31 species for residents. 17 species for summer visitor, 6 species for winter visitor. 4 species for passage migrant, respectively. Species richness was 38 species at spry, 33 species at summer. 26 species at autumn and 22 species at winter. The density was 3.00 ea /ha at spring, 2.37 ea /ha at summer, 3.62 ea /ha at autumn and 2.88 ea /ha at winter. Breeding bird community in Sobaeksan National Park was dominated by Hole, Bush-nesting guild and Canopy-foraging guild. Natural vegetation of 900m altitude in 1st section and the grassy plain in 2nd section are to be protected absolutely for the habituation of wild birds. Species richness in 3rd section was higher than any other section owe to a various habitat such as valley. open lands, orchid, farm land and forest etc. Food plants and broad-leaved forest is to be managed for the provision of opulent food resources in autumn and winter, user is to be managed for the successful propagation of wild birds in spring and autumn.

• Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.104-116
• /
• 2019

Background: The composition of wild bird populations in temperate zones greatly varies depending on phenological changes rather than other environmental factors. Particularly, wild birds appearing in wetlands fluctuate greatly due to the crossover of species arriving for breeding during the summer and for wintering. Therefore, to understand the changes to species composition related to phenology, we conducted this basic analysis of populations to further the cause of the protection of wetland-dependent wild birds. Methods: It is wrong to simply divide a wild bird population investigation into seasons. This study identifies species composition and indicator species that change along with seasons. Wetlands to be surveyed are protected by natural monuments and wetland inventory and are in a state close to nature. In order to identify as many species as possible in wetlands, a survey was conducted in both shallow and deep wetlands. The water depth varied in these areas, ranging from 0.2 to 2.0 m, allowing for both dabbling and diving ducks to inhabit the area. Surveys were conducted using line-transect and distance sampling methods and were conducted at intervals of 2 weeks. The survey was conducted under the following three categories: the eco-tone and emergent zone, the submergent zone, and the water surface. The survey was conducted along a wetland boundary by observing wild birds. A PC-ord program was used for clustering, and the SAS program was used to analyze the changes in species composition. The data strongly indicates that day length is the main factor for seasonal migration periods, despite the fact that climate change and increasing temperatures are often discussed. Results and conclusions: The indicator species for determining seasons include migrant birds such as Ardea cinerea, Alcedo atthis, Anas penelope, and Poiceps ruficollis, as well as resident birds such as Streptopelia orientalis and Emberiza elegans. Importantly, increases in local individual counts of these species may also serve as indicators. The survey results of seasonal fluctuations in temperate zones shows that spring (April to June), summer (July to September), autumn (October), and winter (November to March) are clearly distinguishable, even though spring and summer seasons tend to overlap, leading to the conclusion that additional research could more clearly identify fluctuation patterns in species composition and abundance in the study area.