• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.491-499
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• 2008

It is really urgent to develop wastewater treatment system which is economically efficient, occupies small area for buildup, can be easily operated, discharges small amount of sludge due to the more strict water quality standard, the expensive water and energy cost and so on. This study on treatment of wastewater including nonbiodegadable materials using white-rot fungus biofilm were designed to investigate the submerged type of biofilm, hydraulic retention times, recycle rates, and module turning times. Removal efficiencies of fully exposed biofilm type in atmosphere are similar to submerged biofilm of aeration type. The optimum conditions of white-rot fungus biofilm of fully exposed type in atmosphere are HRT 3$\sim$4 hr, recycle rate 6$\sim$10 Q, module turning times 0.5$\sim$2 times/min. At this time, removal efficiencies of organics were COD$_{Cr}$ 65.0$\sim$69.9%, NBDCOD 70.4$\sim$72.7%, BOD$_5$ 88.8$\sim$90.1%, SS 84.2$\sim$90.4%. Moreover average effluent concentration of BOD$_5$(8.9 mg/L) satisfied water quality standard of heavy water(BOD$_5$ less than 10 mg/L) but concentration of NBDCOD(29.6 mg/L) was higher than water quality standard of heavy water(NBDCOD less than 20 mg/L).

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.444-455
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• 2015

In relation to the utilization and disposal of dredged sediment caused by coastal dredging project, we diagnosed the status of legal standard and system, and proposed the improvement plan. Dredging costal sediment distinguished the usage and the disposal by the Standard for the Beneficial Usage of Dredged Sediment. The site where disposal has been completed could be used as a site for developmental project. In case of the usage of dredged sediment for reclamation, we found that the adaptation of the Standard for Beneficial Usage of Dredged Sediment is appropriate for reclamation considering the characteristic of soil, the differences of variables, and the distinction of standard analysis methods. The current the Standard for Beneficial Usage of Dredged Sediment requires the improvement with the usage of dredging coastal sediment in the following. First, the Standard needs to include the standard of the discrimination for reclamation. Second, the current Standard is necessary to be divided by two levels, it needs to be mitigated considering human health risk. Third, it is necessary to consider both the marine environmental impact assessment and mitigation plan near coastal dredging area.

• Journal of Environmental Policy
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• v.9 no.4
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• pp.103-123
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• 2010

Many former industrial cities such as Cleveland, Ohio are trying to transform their identities from blue-collar manufacturing centers to white-collar professional hubs. As a result, the re-use of land previously occupied by industrial firms has been on the rise as an important sustainable land-use strategy in the United States. Ohio's Cuyahoga County offers a Brownfield Redevelopment Fund to overcome the environmental barriers inherent in re-use in order to obtain full use of underutilized properties in the county. This study estimates externality effects of brownfield redevelopment projects (BRPs) on nearby housing sales prices in Cuyahoga County. Typical hedonic regression models that employ "difference-in-difference" techniques are used to compare proximal housing sale prices before and after the completion of BRPs.

• Geotechnical Engineering
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• v.12 no.2
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• pp.19-32
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• 1996

Based on Trifuilac's empirical model to transform earthquake acceleration time history in the time domain into Fourier amplitude spectrum in the frequency domail an earthquake scaling technique for simulating the earthquake record of certain magnitude as the required magnitude earthquake was suggested. Also, using the earthquake record of magni dude(M) 5.8, the simulated earthquake of magnitude(M) 8.0 was established and its application to dynamic testing system was proposed. The earthquake scaling technique could be considered by several terms : earthquake magnitude(M), earthquake intensity(MMI), epicentral distance, recording site conditions, component direction and confidence level required by the analysis. Albo, it had an application to the various earthquake records. The simulated earthquake in this study was established by two orthogonal horizontal components of earthquake acceleration-time history. The simulated earthquake shaking could be applied to the dynamic pile load test for the model tension pile and the model compressive open -ended piles driven into the pressure chamber. In the static pile load test, behavior of two piles was very different and after model tension pile experienced 2 or 3 successive slips of the pile relative to the soil, it was failed completely. During the simulated earthquake shaking, dynamic behavior and pile capacity degradation of two piles were very different.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.273-288
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• 1997

A three dimensional sea-land breeze model and Lagrangian particle dispersion model have been employed for the study on the mesoscale atmospheric dispersion of radioactive materials released from Wolsung NPPs. In this study, atmospheric dispersion simulations are carried out under two synoptic weather conditions : the geostrophic flow is a weak northerly wind(CASE 1) and a strong northerly wind(CASE 2) on a clear day in spring. The results show that atmospheric dispersion is affected by sea-land breeze and the recirculation of particles by the change of wind direction between sea breeze and land breeze plays an important role in atmospheric concentration distribution of radoactive materials.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.27-34
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• 2004

The reclaimed waste layer in a completed refuse small landfill site was stabilized by JSP(Jumbo Special Pattern System) method. There were some variations of landfill gases(LFGs) after the stabilization. This study investigated the landfill gases emitted from a open dumping landfill site. We measured concentration of landfill gases before and after the construction, and 28 months later. As a result, the concentrations of $H_2S$ and $NH_3$ gases before the construction were 123.51ppm and 171.54ppm, respectively. These values were higher than TWA(Time Weighted Average) values. But the concentrations of $H_2S$ and $NH_3$ gases after the construction were 55.59ppm and 20.51ppm, and they also decreased 9.04ppm and 11.82ppm in 28 months. $CH_4$ and other landfill gases after the construction were little or a little detected in the landfill site. Hence we found out that concentrations or classes of landfill gases causing some problems extremely decreased by way of the stabilization.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.37-47
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• 2005

The purpose of this study is to estimate the bearing capacity and settlement characteristics of the weathered granite masses, and on the process to achieve the purpose, in the first place, the weathered degree according to the absorption index was examined and reviewed, then plate bearings test in in-situ depth were tested, and finally the result was compared and examined with the result of the existing, estimate method and pressuremeter test. In order to achieve the purpose of this study, a typical area distributed with weathered granite masses, gyeonggi area, was chosen as a sample site for testing, and in the result, it appeared and found out that the more the weathered degree increases when the plate bearing test are tested, the more the bearing capacity decreases a numerical indexes and the more greatly the width of the decrease of bearing capacity increases around the boundary of specific, weathered degrees. Also, In the result from estimating the bearing capacity of weathered granite masses by the existing, suggested formula, it appeared that there is a tendency that the more the weathered degree increases, the more similar the bearing capacity becomes with the result of plate bearing tests.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5C
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• pp.201-208
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• 2010

In this study, the ground settlement was investigated by using monitoring data of the test sites where vacuum consolidation method and surcharge method were applied for improving deep soft soil. The monitoring data are chosen in ${\bigcirc}{\bigcirc}$ area port construction site reclaimed with very soft dredged clay. These data are analyzed to compare the consolidation characteristics between the different loading methods for soil improvement. Through analysis of the loading time, it is shown that the ground settlement reaches its allowable value under vacuum consolidation loading by about 45% faster than that of the surcharge loading consolidation. This could be explained that vacuum consolidation method makes the isotropic consolidation condition so that the time for reaching a certain final preloading without soil failure can be shortened.

• Resources Recycling
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• v.26 no.2
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• pp.80-88
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• 2017

Globally, there has been a lot of research related to recycling coal ash from power plant stations. This research is happening because there is a considerable shortage of sites for reclamation of increased coal ash every year. In addition, a variety of environmental pollutants have appeared because of mining activity. Abandoned coal mine, pits, and mine tailing piles caused pollutants to come to the surface resulting in serious damage for humans and the environment. Therefore in this study, we investigated whether or not coal ashes have the ability to prevent several environmental problems by mining in Korea and a manageable form recycling coal ashes. In overseas countries, there is a sufficient field of applicable cases where coal ash is used for neutralizing AMD (Acid Mine Drainage), covering of the waste materials, grouting, and soil amendments. However in Korea, since the coal ash is classified as a 'waste', there is an insufficient field applicable cases so far. Therefore it is necessary to establish a specific standard and management system for the utilization of coal ash based on the relevant precedent cases applied abroad in order to prevent environmental pollution caused by mining activity in Korea.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.150-165
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• 2013

This study aims to investigate the original position, the writer of signboard handwriting and the period of Wibongmun and Joyangru in order to restore Wibongmun and Joyangru which have been designated as tangible cultural properties (有形文化財). They also have to be moved in the Gangwon Provincial Office. Wibongmun and Joyangru were established as government offices in chuncheon(春川官衙) and they were used as attached buildings in Chunceon (春川離宮) in 1890. Wibongmun was moved to Gangwon Provincial Office 5 times and Joyangru was moved twice. In order to move them back to the original place, by using the topographic map made by the Japanese Government-General in Korea, we find out Joyangru was located in the exit of Gangwon Provincial Office and greenhouse and we also figure out Wibongmun was located in the garden. While we study historical evidence on handwriting, we also find out the handwriting of Joyangmun was written by Songhaong (松下翁) Jo, Yun-Hyeong (曺允亨). Especially, Joyangru had played a role as a government office and it may be called 'Joyangru' after reconstructing 'Joyangmun' when attached buildings were established. Through this study, we found that the first period and reason of establishing Wibongmun and Joyangru was at least before 1788. Through this study, we can find the period of both and its historic meaning more clearly.