• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.583-592
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• 2020

This study assessed source depletion in the vadose zones of contaminated sites. The possible range of infiltration rate in Korea was statistically analyzed. The results showed a trend of decreasing leachate concentration of 13 pollutants used for risk assessment. Among them, benzene, ethylbenzene, toluene, and xylene showed a lower leachate concentration in groundwater over time due to their low distribution coefficient and also possible biodegradation effects. The average values of the relative concentration could be taken as a default index due to a very small range of uncertainties. In the case of heavy metals, it was shown that the leachate concentration in a pollutant does not decrease over time. Considering the annually different infiltration, a site-specific source-depletion scenario was applied to Cheongju in North Chungcheong Province. The result was expressed as a time series of the relative concentration of the leachate concentration, and this was compared to the trend by averaged Korean infiltration. Finally, an open-source code that used Python was used to help calculate the leachate concentration by this site-specific infiltration scenario.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.62-68
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• 2012

This study evaluated the screening level assessment of ecological health using four biomarkers and four bioindicators of Misgurnus anguillicaudatus as a indicator species in agricultural area of South Korea during May-June 2011. The endocrine disrupting chemical (EDC) indicators, such as vitellogenin (VTG) and gonado-somatic index (GSI), were not significantly changed in the agricultural site (p>0.05), indicating no effects. The biomarkers and bioindicators were compared between two sites of reference site (RS) and the agricultural site (AS) for screening assessment of ecological health. The ethoxyresorufin-O-deethylase (EROD) activity, acetylcholinesterase (AChE) activity, and DNA damage were significantly changed in the AS compared with the RS (p<0.05). But the individual level bioindicators such as condition factor (CF), hepato-somatic index (HSI), and gonado-somatic index (GSI) were not significantly different from reference site (RS). These results may indicate impairments of ecological health by toxic chemicals and environmental conditions. Current this study is based on screening assessment of biochemical and individual level biomarkers and bioindicators, so further study is required additional biomarkers and population or community level bioindicators for more specific health assessments in agricultural areas.

• Journal of the Korean Institute of Rural Architecture
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• v.26 no.2
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• pp.65-72
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• 2024

In order to analyze the impact of fine dust generated from a construction waste intermediate processing site on the surrounding areas, diverse types of samples were collected from inside the site and surrounding areas. The impact analysis results of samples are as follows. (1) Compared to the air quality management standards by the Ministry of Environment, the concentration of fine dust within the site was 30 to 46% for PM10 and 14 to 42% for PM2.5, which was not much different from the general air quality level. (2) It was found that PM10 within the site may have a partial effect on the air quality, but when the blocking facilities in the site, wheel washing facilities at vehicle entry and exit route, and sprinkler during working were maintained, the impact on the nearby area was not high. (3) In the case of PM2.5, its concentration was influenced more by the exhaust fumes from work vehicles than fine dust generated during construction waste processing. Since the PM2.5 concentrations in the site and surrounding area were not much different from the general air quality, there was little correlation with the work impact of construction waste intermediate processing sites. (4) Pb, an indicator of heavy metal components, was within 50ng/m³ in all three sites, which was 10% of the domestic management standard and equivalent to the general air quality level. The complaints from residents in nearby areas were filed using indicators based on visual and experiential information in their daily lives, so even if the survey results of environmental impact by the construction intermediate waste processing site are lower than the standard, nearby residents can feel it better than such numerical information. Therefore, specific activities to reduce find dusts should be continuously continued.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.745-754
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• 2012

The correlations between Large Early Release Frequency (LERF) and Early Fatality need to be investigated for risk-informed application and regulation. In Regulatory Guide (RG) -1.174, while there are decision-making criteria using the measures of Core Damage Frequency (CDF) and LERF, there are no specific criteria on LERF. Since there are both huge uncertainties and large costs needed in off-site consequence calculation, a LERF assessment methodology needs to be developed, and its correlation factor needs to be identified, for risk-informed decision-making. A new method for estimating off-site consequence has been presented and performed for assessing health effects caused by radioisotopes released from severe accidents of nuclear power plants in this study. The MACCS2 code is used for validating the source term quantitatively regarding health effects, depending on the release characteristics of radioisotopes during severe accidents. This study developed a method for identifying correlations between LERF and Early Fatality and validates the results of the model using the MACCS2 code. The results of this study may contribute to defining LERF and finding a measure for risk-informed regulations and risk-informed decision-making.

• The Journal of the Korea Contents Association
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• v.10 no.1
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• pp.334-342
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• 2010

The purpose of this study was to evaluate web-sites related to infant health at day-care centers. A total of 87 web-sites were ultimately selected through Internet search engines, and educare sites. The basis of assessment in which standards and items were amended for the assessment of health information in previously used, and purpose, content, pertinence, accuracy, confidence, utility, authority, interactivity and continuance was assessed. Though the total score were 32 point, mean score was relatively low, 20.39 point. The score of accuracy and authority was relatively low while that of confidence and interactivity was high. As a result, it was revealed that there were no specific infant health related web-site with reliability guaranteed. Therefore, there is a need to develop a web-site providing accurate health information for infant at day-care centers. It is expected that these results can be utilized as a data for developing reliable web-site related infant health.

• Journal of the Korea Institute of Building Construction
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• v.1 no.2
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• pp.154-164
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• 2001

This research is aiming to specify the requirement of the investment such as intial cost, running cost earning rate to make effective investment considering the purpose of remodeling and economical value of store building enough to meet the initial purpose of remodeling. The review of earning for economical evaluation was performed by the on-site auditing on the structure and function of the building and applying the assessment simulation program, which is to find the possible business model to identify the requirement of building owner through case study. After the research, the following results are obtained. First, it is important that many aspects should be carefully analysis and the best method should be selected as characteristics of remodeling can be defer each other in their implementations. Second, though the remodeling of exist building to promote the functions has been applied, no suitable assessment tool has bee developed for deciding the level of remodeling in the view of economical efficiency so far. Third, the economical benefit was evaluated by analysing annual earning rate which is applied by investment items and recovery period for the investment. More specific date base should be established to apply the suggested economic acessments in business enough ti forecast the future circumstances. More researches should be promoted on the area continuously as well as the integrated economic evaluation of remodeling on existing building.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.15-22
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• 2001

The key part in risk assessments for disposal sites of solidified/stabilized (S/S) wastes is to predict the contaminant transport from the S/S wastes to the environment under dynamically changing field conditions after characterizing chemical leaching properties of the ash, to evaluate the risk from the predictions, and finally to decide the risk is acceptable. In this paper, a risk assessment framework for disposal and reuse of S/S wastes was developed considering two limiting cases of contaminant leaching. Two types of waste characterization procedures that can determine waste-specific variables for the two limiting cases were developed and verified by applying them to a landfill site of the Municipal Solid Waste incinerator ash solidified/stabilized by cement.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.386-400
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• 2022

Seismic fragility analysis, a part of seismic probabilistic risk assessment (SPRA), is commonly used to establish the relationship between a representative property of earthquakes and the failure probability of a structure, component, or system. Current guidelines on the SPRA of nuclear power plants (NPPs) used worldwide mainly reflect the earthquake characteristics of the western United States. However, different earthquake characteristics may have a significant impact on the seismic fragility of a structure. Given the concern, this study aimed to investigate the effects of earthquake characteristics on the seismic fragility of concrete containments housing the OPR-1000 reactor. Earthquake time histories were created from 30 ground motions (including those of the 2016 Gyeongju earthquake) by spectral matching to the site-specific response spectrum of Hanbit nuclear power plants in South Korea. Fragility curves of the containment structure were determined under the linear response history analysis using a lumped-mass stick model and 30 ground motions, and were compared in terms of earthquake characteristics. The results showed that the median capacity and high confidence of low probability of failure (HCLPF) tended to highly depend on the sustained maximum acceleration (SMA), and increase when using the time histories which have lower SMA compared with the others.

• Journal of Environmental Impact Assessment
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• v.16 no.1
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• pp.59-68
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• 2007

Urban streams have been severely degraded with wastewater and concrete structure over a prolonged period. The Chonggyecheon Restoration Project recovered a stream in the downtown Seoul with landscaping, plantings and bridges after the cover concrete and elevated asphalt road were removed. The project has been criticized partly because it is not an ecological restoration but rather the development of an urban park with an unnaturally straight flowing stream, artificial building structures, and artificial water pumping from the Han River. Nevertheless, the public have praised the project and almost 100,000 visitors per day come to see the reeds, catfish, and ducks. The stream restoration project is attractive to central and regional government decision makers because it increases the public concern of landscape amenity. Several projects such as Sanjichon and Kaeumjungchon are on going and proposed. These projects have a common and different respect in scope and procedure. The Chonggyecheon project in the process of environmental impact assessment (EIA) and prior environmental review system (PERS) reviewed the environmental impacts before development. Kaeumjungchon in the PERS and Sanjichon without EIA and PERS are reviewed. EIA and PERS systems contribute to checking the ecological sustainability of the restoration projects. A stream restoration project is a very complex task, so an integrated approach from plan to project is needed for ecologically sound restoration. Ecological stream restoration requires 1) an assessment of the entire stream ecosystem 2) establishing an ecologically sound management system of the stream reflecting not only benefits for people but also flora and fauna; 3) developing the site-specific design criteria and construction techniques including habitat restoration, flood plains conservation, and fluvial management; 4) considering the stream watershed in land use plan, EIA, PERS, and strategic environmental assessment (SEA). Additionally the process needs to develop the methodologies to enhance stakeholder's participation during planning, construction, and monitoring.

• Earthquakes and Structures
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• v.20 no.2
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• pp.133-148
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• 2021

The paper presents a simplified force-based seismic design procedure for the preliminary design of steel haunch retrofitting for the seismic upgrade of deficient RC frames. The procedure involved constructing a site-specific seismic design spectrum for the site, which is transformed into seismic base shear coefficient demand, using an applicable response modification factor, that defines base shear force for seismic analysis of the structure. Recent experimental campaign; involving shake table testing of ten (10), and quasi-static cyclic testing of two (02), 1:3 reduced scale RC frame models, carried out for the seismic performance assessment of both deficient and retrofitted structures has provided the basis to calculate retrofit-specific response modification factor Rretrofitted. The haunch retrofitting technique enhanced the structural stiffness, strength, and ductility, hence, increased the structural response modification factor, which is mainly dependent on the applied retrofit scheme. An additional retrofit effectiveness factor (ΩR) is proposed for the deficient structure's response modification factor Rdeficient, representing the retrofit effectiveness (ΩR=Rretrofitted /Rdeficient), to calculate components' moment and shear demands for the retrofitted structure. The experimental campaign revealed that regardless of the deficient structures' characteristics, the ΩR factor remains fairly the unchanged, which is encouraging to generalize the design procedure. Haunch configuration is finalized that avoid brittle hinging of beam-column joints and ensure ductile beam yielding. Example case study for the seismic retrofit designs of RC frames are presented, which were validated through equivalent lateral load analysis using elastic model and response history analysis of finite-element based inelastic model, showing reasonable performance of the proposed design procedure. The proposed design has the advantage to provide a seismic zone-specific design solution, and also, to suggest if any additional measure is required to enhance the strength/deformability of beams and columns.