• Economic and Environmental Geology
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• v.44 no.3
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• pp.239-246
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• 2011

Groundwater in small islands is used as main water resource but the overuse of groundwater may cause seawater intrusion and temperature decrease in geothermal wells. This study aimed to characterize the hydrogeology of Maeum-ri area in Seokmo Island of Ganghwagun using long-term monitoring at groundwater wells and geothermal wells. In the monitoring period seasonal water level change, consistent drop or increase of water levels are not detected. The groundwater temperature about 10m below ground surface shows year cycle variation having two to five months difference with ambient temperature cycle. The storativity was calculated by tidal method. The storativity estimated by adapting tidal efficiency factor showed some larger values than that by using tidal time lag. The result suggested that the tidal method assuming several assumptions on aquifer condition may produce broad ranges but the calculated ranges at this application are reasonable. The similar shape of groundwater level change and tidal effects was observed at several wells clustered east-south-east direction which may implicate the distribution of vertical fracture system strongly related with groundwater flow channels. The applied methodology and study results will bc valuable to evaluate optimal pumping rate for the preservation of groundwater resources, and to manage geothermal development.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.1
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• pp.16-23
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• 2019

Fine particulate matter known as PM 2.5 refers to the atmospheric particulate matter that has a diameter less than 2.5 micrometer identified as dangerous element for human health and its concentration can provide us a clear picture about air dust concentration. Humans stay indoor almost 90% of their life time and also there is no official indoor dust concentration data, so our study is focused on measuring the indoor air quality. Indoor dust data monitoring is very important in hospital environments beside that other places can also be considered for monitoring like classrooms, cements factories, computer server rooms, petrochemical storage etc. In this paper, visible light communication system is proposed by Manchester encoding technique for electromagnetic interference (EMI)-free indoor dust monitoring. Important indoor environment information like dust concentration is transferred by visible light channel in wide range. An average voltage-tracking technique is utilized for robust light detection to eliminate ambient light and low-frequency noise. The incoming light is recognized by a photo diode and are simultaneously processed by a receiver micro-controller. We can monitor indoor air quality in real-time and can take necessary action according to the result.

• Structural Engineering and Mechanics
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• v.47 no.5
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• pp.623-641
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• 2013

The fiber-reinforced polymer (FRP) composite panel, with the benefits of light weight, high strength, good corrosion resistance, and long-term durability, has been considered as one of the prosperous alternatives for structural retrofits and replacements. Although with these advantages, a further application of FRPs in bridge engineering may be restricted, and that is partly due to some unsatisfied thermal performance observed in recent studies. In this regard, Kansas Department of Transportation (DOT) conducted a field monitoring program on a bridge with glass FRP (GFRP) honeycomb hollow section sandwich panels. The temperatures of the panel surfaces and ambient air were measured from December 2002 to July 2004. In this paper, the temperature distributing behaviors of the panels are firstly demonstrated and discussed based on the field measurements. Then, a numerical modeling procedure of temperature fields is developed and verified. This model is capable of predicting the temperature distributions with the local environmental conditions and material's thermal properties. Finally, a parametric study is employed to examine the sensitivities of several temperature influencing factors, including the hollow section configurations, environmental conditions, and material properties.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.633-641
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• 1999

Reaction by neighbours to odours is increasingly affecting operations of existing animal farming operations and may adversely constrain the further development of the animal production industry in some parts of Australia. It is critical that the scale of such odour impact on the rural-urban interface be estimated to provide useful information both for environmental protection and animal farming operations. Furthermore, the information can be used to modify odour reduction strategies as economic conditions change. The Centre for Water and Waste Technology at The University of New South Wales has developed a comprehensive set of odour control techniques in the course of its research and development effort over the past eight years. Techniques have been developed for odour sampling at point, area and volume sources, monitoring environmental parameters such as ventilation rate, shed temperature, shed humidity, litter water content and ambient meteorological condition, olfactometry and odour dispersion modelling. The work has paved the way for the establishment of odour reduction strategies based on best environmental management practice and advanced odour abatement technologies.

• Asian Journal of Atmospheric Environment
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• v.10 no.4
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• pp.197-207
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• 2016

Large quantities of air pollutants are released into the atmosphere and hence, must be monitored and routinely assessed for their health implications. This paper proposes a stochastic technique to predict unobserved hazardous air pollutants (HAPs), especially Benzo[a]pyrene (BaP), which can have negative effects on human health. The proposed approach constructs a nearest-neighbor structure by incorporating the linkage between BaP and meteorology and meteorological effects. This approach is adopted in order to predict unobserved BaP concentrations based on observed (or forecasted) meteorological conditions, including temperature, precipitation, wind speed, and air quality. The effects of BaP on human health are examined by characterizing the cancer risk. The efficient prediction provides useful information relating to the optimal monitoring period and projections of future BaP concentrations for both industrial and residential areas within Korea.

• Journal of the Korean earth science society
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• v.29 no.5
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• pp.396-407
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• 2008

Hydrogeologic properties of a well field around middle mountainous areas in Pyosun, Jeju volcanic island were examined based on water level monitoring, geologic logging and pumping test data. Due to the alternating basaltic layers with varying permeability in the subsurface, it is difficult to analyze the hydraulic responses to artificial pumping and/or natural precipitation. The least permeable layer, detrital materials with clay, is found at a depth of 200 m below surface, but it is not an upper confining bed for lower main aquifer. Nevertheless, this layer may serve as a natural barrier to vertical percolation and to contaminant migration. Water levels of the production wells are dominantly affected by pumping frequently, while those of the remote observation wells are controlled by ambient precipitation. Results of pumping tests revealed a possible existence of horizontal anisotropy of transmissivity. However, some results of this study include inherent limitations enforced by field conditions such as the consistent of groundwater production and the set of time periods for the cessation of the pumping prior to pumping tests.

• Journal of Environmental Science International
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• v.22 no.12
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• pp.1589-1598
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• 2013

The objective of this study was to evaluate associations between airborne manganese and blood manganese in a general population of South Korean adults. The concentrations of airborne manganese in total suspended particulate (TSP) were calculated from data obtained from ambient air-monitoring stations (AAMSs) located in South Korea. Blood manganese data obtained Korean National Health and Nutrition Examination Survey (KNHANES) using a rolling sampling design involving a complex, stratified, multistage, probability cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. Airborne manganese geometric means was 46.10 $ng/m^3$, blood manganese geometric means were 1.19 ${\mu}g/d{\ell}$ for male and 1.40 ${\mu}g/d{\ell}$ for female. In multiple linear regression analysis of log transformed blood manganeseas a continuous variable on airborne manganese, after adjusting for covariates including gender, age, job, smoking and drinking status, education level, BMI (body mass index). Airborne manganese was positively associated with blood manganese with statistical significance. The present study confirms that airborne manganese is a possible contributor to the increase of blood manganese in the adult general population.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.320-328
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• 1993

Gaseous pollutants in Namsan Nos. 1, 2, and 3 tunnels and Pukak tunnel were measured along the road by an air-monitoring van from the evening of February 9 to the morning of February 12 in 1993. Average concentrations of pollutants in Namsan tunnels were 9.2-13.5 ppm CO and 0.037-0.047 ppm SO$_{2}$. Average concentrations of SO$_{2}$ in Pukak tunnel was 0.79 ppm, higher than those in Namsan tunnels, due to the traffic of heavy-duty buses and trucks. The pollutant concentrations in Namsan tunnesl could be explained by emission of passenger cars using unleaded gasolin and LPG taxies. Average concentration of NO$_{x}$ in Namsan tunnels was at least 1.1 ppm, estimated from the emission factor of pasenger cars using unleaded gasoline. Pollutant concentrations in Namsan No. 3 tunnel were higher at the exit because of the piston action of air mass in the tunnel provided by the traffic. Fans installed at Namsan and Pukak tunnes could be useful, but their flushing action of ambient air in the tunnel was not clearly observed.d.

• Toxicological Research
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• v.31 no.4
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• pp.355-361
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• 2015

The aim of this study was to investigate whether genetic polymorphisms of CYP2E1, GSTM1, and GSTT1 and lifestyle habits (smoking, drinking, and exercise) modulate the levels of urinary styrene metabolites such as mandelic acid (MA) and phenylglyoxylic acid (PGA) after occupational exposure to styrene. We recruited 79 male workers who had received chronic exposure in styrene fiberglass-reinforced plastic manufacturing factories. We found that serum albumin was significantly correlated with blood styrene/ambient styrene (BS/AS), urinary styrene (US)/AS, and US/BS ratios as well as urinary metabolites, that total protein correlated with US/MA and US/PGA ratios, and that low density lipoprotein (LDL)-cholesterol significantly correlated with US/BS, US/MA, and US/PGA ratios. Multiple logistic regression analyses using styrene-metabolizing enzyme genotypes and lifestyle habits as dependent variables and blood and urine styrene concentrations and urine styrene metabolite levels as independent variables revealed that $CYP2E1^*5$ was associated with the MA/US ratio and GSTM1 with US/BS, that a smoking habit was associated with US/AS and MA/US ratios and MA and PGA levels, and that regular exercise was correlated with PGA/US. In conclusion, the results suggested that genetic polymorphisms of styrene-metabolizing enzymes, lifestyle behaviors, and albumin and LDL-cholesterol serving as homeostasis factors together are involved in styrene metabolism.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.E1
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• pp.1-11
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• 2005

The concentration levels of gaseous elemental mercury (GEM) in ambient air have been investigated from a monitoring station located in Yang Jae district of Seoul, Korea for a long-term period covering 1997 through 2002. The mean concentration of Hg, if computed based on its hourly measurement data for this six-year period, was $5.32\pm3.53 ng m^{-3} (N = 27,170)$. The inspection of the diurnal distribution patterns indicated the presence of notably high concentration levels during nighttime relative to daytime (e.g., the mean hourly value as high as $9 ng m^{-3}$ in winter nighttime). When divided seasonally, the highest mean of $6.12 ng m^{-3}$ was also observed during winter followed by spring, fall, and summer. The results of our analysis confirmed the relative dominance of winter (seasonally) or nighttime (diurnally), while exhibiting a complicated trend on a long-term basis. Examination of our data over a different temporal scale consistently indicated that dynamic changes in Hg concentrations occurred through time in line with changes in the strength and diversity of the source processes. It is thus acknowledged that the presence of unusually high Hg levels is the consequence of intense man-made activities, while such signatures can vary in a competitive manner.