• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.360-364
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• 2006

The physical characteristics of suspended solid in urban watersheds are estimated and are described the accumulation processes on the urban surface. And build up the accumulation model which has two parameters and three constants. Two parameters are $p_0\;and\;p_{max'}$, and three constants are landuse, clean and traffic constant. Suggested model is applied three industry watershed which has variable area. And simulated results are compared with observed data. The model estimates the real phenomenon and the results are pretty good. The simulated accumulation mass are 1.20, 0.96 and $2.88g/m^2$. The differences of simulation and observation data are about 30%.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.51-56
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• 1997

Abstract Over 4.1 billion tons of non-hazardous solid wastes are generated in the United States annually. This equals to about 16 tons of wastes per person, per year. Disposal of the wastes is a national concern due to many factors such as environmental issues, costs, and public views. South Carolina, like many other states, had a home of many military bases which were ordered to be closed. The contaminated soil was vitrified and tested for suitability in the asphalt mixes. For mix design purposes, a total of 75 specimens were made and tested. For moisture susceptibility testing, a total of 32 samples were made and tested. The results indicate that the mixtures made with sample B produced dry and wet that were comparable with the controlled mixture. At this point and with in this limited study, use of 5% of sample B in asphalt mixture is recommended in several applications such as parking lots, walking paths and drive ways.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.539-544
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• 2000

A simple analytic model is proposed here to analyze the concentration deficit field caused by a large area of vegetated area. With non-dimensional deposition velocity chosen as small parameter, the regular perturbation method is exploited to derive the mass balance equation and the dynamic equations for the concentration deficit field, Analytic solutions to those equations are obtained in a closed form for several cases of interest, assuming that the concentration field is stationary and the plume can be nicely approximated as Gaussian for a point source. The results suggest that quite a negligible fraction (less than 1%) of the gaseous air pollutants emitted into the air is removed by the vegetated area of which width is 4 km in wind-wise direction, the typical dimension of the Restricted Development Zones around the metropolitan regions in South Korea.

• KCID journal
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• v.10 no.2
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• pp.62-70
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• 2003

Three small-scale sediment traps were built on sloping potato fields at the alpine belt in Korea to examine the sediment and non-point source pollutant reducing capabilities of the traps. Throughout the research period from January 2002 to December 2002,

• KCID journal
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• v.21 no.1
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• pp.99-108
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• 2014

This study investigated the effects of NPS(non point source) pollution reduction of sediment traps through field experiments. Various sizes of 4 sediment traps were applied in a upland field located in Gunwi and assessed the infiltration and storage effects as well as NPS pollution reduction effects of this technique. The characteristics of deposited soil in the sediment traps were also analyzed including distribution of particle size, soil texture, and chemical properties. The results showed that slightly different composition of soil particle size from each sediment trap with high proportion of 0.15mm and 0.25mm ranges of soil particle diameters, while the loamy sand is the main types of deposited soils in the sediment traps. Decreased NPS pollution were observed from the water quality analysis of the samples taken from the sediment traps. Further research need to be proceeded continuously to improve this technique in order to utilize on upland fields for management of agricultural NPS pollutions.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.607-610
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• 2003

The object of this study is to analyze the characteristics of pollutant loadings on rainy day compared with normal day in the Mangyeong catchment area of Saemangeum tidal reclaimed area. On rainy day, the concentrations of BOD, COD, T-N and T-P are smaller than those on normal day, in spite of the pollutant loading themselves are increased significantly on rainy day due to non point source pollution, such as CSOs(combined sewage overflows), runoff from agricultural land use and so on.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.280-283
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• 2003

In this paper, there was finding laser beam focal length using the camera at the work with laser preprocess. A process have some similarity that the laser direct writing was condition of unused other light source in order to a partical object of working substrate, so we worked finding focal length using yellow light. As we found focal lengths from three points of substrate edges, The focal length of all substrates was able to be computed by calculating a plane equation using these three point. Also we make a device and software that can automatically perform all of the processes.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.709-717
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• 2006

This research was conducted to figure out the feasibility of several sorption materials to treat various pollutants in road runoff. In advance of the major feasibility test with various sorption materials, the separation process with $1.2{\mu}m$ filter was conducted and showed that slight portion of pollutants was removed(Orgamic pollutant - 20%, Nutrient salt - 50%, Heavy metals - 0~30%). To remove dissolved pollutants in runoff, various materials were tested through an isotherm sorption experiment. As a result, GAC showed most effective material among them to lessen most contaminants such as organic compounds and nutrients. On the other hand, ion-exchange resin and Zeolite showed limited usefulness on the some heavy metals. Freundlich model was most suitable for the current experiment data, and the amount of adsorbent (GAC) could calculated based on this model.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.989-994
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• 2011

Nitrate contamination of groundwater is a common problem throughout intensive agriculture areas (non-point source pollution). Current processes (e.g. ion exchange and membrane separation) for nitrate removal have various disadvantages. The objective of this study was to evaluate electrochemical method such as electroreduction using bipolar ZVI packed bed electrolytic cell to remove nitrate from groundwater at field pilot. In addition ammonia stripping tower continuously removed up to 77.0% of ammonia. Bipolar ZVI packed bed electrolytic cell also removed E.coli. In the field pilot experiment for groundwater in 'I' city (average nitrate 30~35 mg N/L, pH 6.4), maximum 99.9% removal of nitrate was achieved in the applied 600 V.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.8
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• pp.1-5
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• 2014

Conoscopic holography, which consists of two circular polarizers and an uniaxial crystal, is incoherent holographic technology for three-dimensional display and non-contact diagnosis. In this paper, we derive the longitudinal and lateral intensities from point-source hologram made by conoscopic holography. Also, the longitudinal and lateral resolutions of conoscopic holography will be obtained from the longitudinal and lateral intensities, respectively, according to Rayleigh criterion.