• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.196-208
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• 2015

This study analyzed the characteristics of sewer flow and its water quality, and investigated changes in the characteristics in three areas where the sewer rehabilitation projects have been carried out. In S1 area, the patterns of the flow became regular and the range of the fluctuation decreased after the sewer rehabilitation. The flow and its BOD concentration increased. The infiltration/inflow and exfiltration showed clear distinction before and after the sewer rehabilitation in this area. In S2 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased considerably after the sewer rehabilitation. Big decrement in stormwater inflow but small in exfiltration appeared in this area. In S3 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased in a small rate in this area.

• Journal of Soil and Groundwater Environment
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• v.26 no.1
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• pp.1-7
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• 2021

Air-water interfacial area is of great importance for the analysis of contaminant mass transfer processes occurring in the soil systems. Capillary bundle model has been proposed to estimate the specific air-water interfacial areas in unsaturated soils. In this study, the measured air-water interfacial areas of a soil (loam) using the gaseous interfacial tracer technique were compared to those from capillary bundle model. The measured values converged to the specific solid surface area (7.6×104 ㎠/㎤) of the soil. However, the simulated air-water interfacial areas based on the capillary bundle model deviated significantly from those measured. The simulated values were substantially over-estimated at low end of the water content range, whereas the model under-estimated the air-water interfacial area for the most of the water content range. This under-estimation is considered to be caused by the nature of the capillary bundle model that replaces the soil pores with a bundle of glass capillaries and thus no surface roughness at the inner surface of the capillaries is taken into account for the estimation of the air-water interfacial area with the capillary bundle model. Subsequently, appropriate correction is necessary for the capillary bundle model to estimate the air-water interfacial area in soils. Since the soil-moisture release curve data is the basis of the capillary bundle model, the model can be of use due to its simplicity, while the gaseous tracer technique requires complicated experimental equipment followed by moment analysis of the breakthrough curves. The size distribution profile of the pores filled with gas estimated by the water retention curve was found to be similar to that of particle size at different size range. The shifted distribution of gas-filled pores toward smaller size side compared to the particle size distribution was also found.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.41-54
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• 2013

In this paper, We collected location based services of the user's past moving paths through the GPS. Using the collected by location-based services through the analysis of the similarity between the user's of service level agreement recommended of mobile contact area(SLA) proposed that can be. S-RCA method based on Service Level Agreement of the users in order to provide the service user's path distance, time, and to predict the direction of the movement paths and collect. The data collected by the interests and requirements of users through classification with the same interests and the needs of users to move between the analysis of the similarity between the path is used to analyze the results of analysis of the path-specific tolerance range (distance, time, and space) is determined according to the difference in the contact area. From a small area of the error range for users first to recommended and through their smartphones recommended contact area (S-RCA) to meet with the other party to make a choice of recommended methods. We verify through experiments that proposed method(S-RCA) a valid and reliable mobile contact area were recommended.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.5
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• pp.3-13
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• 2005

The present study examined the 3 dimensional space distribution characteristics of sea water intrusion using data available from previous observations. For this study, we used 3D FEMWATER, which is a 3 dimensional finite element model. The target area was around Daechang-ri, Gimje-si, Jeollabuk-do. The area is relatively easy to formulate a conceptual model and has observation wells in operation for surveying sea water intrusion. Considering the uncertainty of numerical simulation, we analyzed sensitivity to hydraulic conductivity, which has a relatively higher effect. According to the result of the analysis, the variation of TDS concentration had an error range of $-1,336{\~}+107 mg/{\iota}$. Taking note that the survey data from observation wells were collected when the boundary between fresh water and sea water in the aquifer was in equilibrium, we set the range of time for numerical simulation and estimated the spatial distribution of TDS concentration as the range of sea water intrusion. According to the result of estimation, the spatial distribution of TDS concentration calculated when 1,440 days were simulated was taken as the range of sea water intrusion. Using the result of calculation, we can draw not only vertical views for a certain section but also horizontal views of different depth. These views will be greatly helpful in understanding the spatial distribution of the range of sea water intrusion. In addition, the result of this study can be used rationally in proposing an optimal quantity of water pumping through investigating the moving route of sea water intrusion over time in order to prevent excessive water pumping and to maintain an optimal number of water pumping wells per interval.

• Journal of Environmental Science International
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• v.22 no.3
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• pp.347-358
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• 2013

The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan in Jeju Island, which is known as background area in Korea, from March 2010 to February 2011. The obtained results of asian dust events and non-asian dust period have been compared. The results show that the entire averaged aerosol number concentration from APS measurement during asian dust events and non-asian dust period are about 341 particles/$cm^3$ and 240 particles/$cm^3$, respectively. During asian dust events, the number concentration in small size ranges(${\leq}0.4{\mu}m$) are similar to non-asian dust period, however, those in large size ranges(${\geq}0.7{\mu}m$) are very higher than non-asian dust period. The contributions of the size resolved number concentration(23 channel in $0.25{\sim}10.0{\mu}m$) to total number concentration in that range are dramatically decreased with increased particle size. The contributions of smaller size ranges(${\leq}0.4{\mu}m$) during asian dust events are very low compared with non-asian dust period, on the other hand, those of larger size ranges(${\geq}0.4{\mu}m$) are higher than non-asian dust period. The number concentration in each size range are strongly correlated with the concentration in adjacent size range. And the total aerosol number concentration are depended on the number concentration in range of smaller than $0.58{\mu}m$ during non-asian dust period and asian dust events. On the other hand, $PM_{10}$ mass concentration has mainly affected with the number concentration in range of smaller than $1.0{\mu}m$ during non-asian dust period, however, during asian dust events, the mass concentration has mainly affected with the number concentration in range of $0.65{\sim}3.0{\mu}m$.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.162-173
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• 2015

The current study analyzed the home range size of the Common Kestrel (Falco tinnunculus) by observation using the natural markings in the suburban area of Busan from December 2009 to May 2010. In all, 26 individual kestrels were observed in the study area, of which 14 individual kestrels were frequently observed (more than five times) and 12 were observed less frequently (less than five times). Mean home range sizes of the 14 frequently observed kestrels were estimated using two different methods (minimum convex polygon (MCP) method and fixed kernel (FK) method): 34.49 ha(2.74-163.96 ha) by 100% MCP, 41.35 ha(3.54-99.02 ha) by the 95% FK, 14.33 ha(0.20-31.57 ha) by the 75% FK and 5.75 ha(0.52-14.74 ha) by the 50% FK. The mean home range size was larger for males than for females estimated at 51.50 ha(15.04-163.96 ha) and 11.80ha(2.74-24.48 ha), respectively, by the 100 % MCP method and 8.02 ha(2.38-14.74 ha) and 2.72 ha (0.52-4.28 ha), respectively, by the 50 % Fixed Kernel method. The home range sizes by sexes in breeding pairs differed during the wintering and breeding seasons; the sizes decreased among females but increased among males during the breeding season. Such differences of home range sizes between sexes could be attributed to parental role division during the breeding season. Females stay in the nest or next to it during laying, incubating, and feeding activities, and males go far away from their nest sites to forage areas for their fledglings for most of the breeding period.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.351-356
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• 2002

Groundwater recharge rate was estimated by applying the groundwater level fluctuation method utilizing Theis (1937) approach with specific yield estimation technique of Shevenell (1996) and the temperature method using observed data from National Groundwater Observation Stations. Results based on analysis of water level observation data of 10 alluvium wells reveal that the recharge rates for 5 wells of Kum river area range 3.7~25.0% and those for 5 wells of Nakdong river area range 3.6~21.7%. Results obtained from the temperature method based on water temperature data indicated that the upward flow resulted from evapotranspiration is dominant for 4 wells of the Kum river area and 5 wells of the Nakdong river area. The other wells showed the downward flow which is related to groundwater recharge in these areas.

• Transactions on Electrical and Electronic Materials
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• v.12 no.5
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• pp.204-208
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• 2011

In this paper, the design area of a fabricated solar cell has been analyzed with respect to its charge density. The mathematical calculation used for charge-density derivation was obtained from the 2001 version of a MATHCAD program. The parameter range for the calculations was ${\pm}1{\times}10^{17}cm^{-3}$, which is in the normal parameter range for n-type doping impurities ($7.0{\times}10^{17}cm^{-3}$) and also for p-type impurities ($4.0{\times}10^{17}cm^{-3}$). Therefore, it can be said that the fabricated solar-cell design area has a direct effect on charge-density changes.

• Asian Journal of Turfgrass Science
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• v.11 no.4
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• pp.271-280
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• 1997

The short green period of zoysiagrass has been a problem in using for turf. This study was performed to check growth response of several wintergrasses under sunny and shady area in Korea. Wintergrasses of 5 species, 27 cultivars introduced from U.S.D.A., were used in this study. After establishment, two fluctuations of top growth were observed which varied according to the species; first, due to drought in May, second, due to high temperature and humidity from July to August. Red fescues and perennial ryegrasses showed severe growth retardation in sunny area during summer period. Kentucky bluegrasses and tall fescues maintained good Qualities nearly all the year round arid showed slight disease infections. Kentucky bluegrass 'Kenblue' and red fescue 'Agram' grown under shady area showed higher photosynthetic ability than under sunny area, except the temperature range from 30˚C to 40 ˚C under 40,000 lux light in red fescue 'Agram'. And the phorosynthesis was decreased at the temperature range from 35 ˚C to 40 ˚C. Key words: Wintergrass, Top growth, Visual rating, Photosynthesis, Poa pratensis. Festuca arundinacea, Pestuca rubra. Lolium perenne, Agrostis stolonifera.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.89-100
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• 2021

This study compared the voice range profiles (VRPs) with glissando and simplified VRP methods with 57 men who were in premutation (8-13 years), mutation (11-16 years), and postmutation (10-24 years) stages. The difference between modal and falsetto areas measured in two VRP methods was also compared. As the results, the average fundamental frequency (F0) was in the order of premuaton>mutation>postmutation. The maximum F0 (F0max), the range of F0 (F0range), the maximum intensity (Imax), and the range of intensity (Irange) were the lowest in the mutation stage, and these variables were higher in falsetto area than in modal area in both methods. In addition, most variables of VRP in glissando were higher than in simplified VRP, but the differences were not significant. This study showed that, in men in mutation stage, due to the temporary anatomical and physiological changes of the larynx, the mechanism of the vocal folds vibration changes and VRP shows a different pattern from that of other age groups. Both the VRPs of glissando and simplifed VRP are suitable for clinical practice by experienced examiners. And it is necessary to measure not only the falsetto area but also the modal area when measuring VRP.