• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.11a
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• pp.109-112
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• 2009

Various environmental problems due to the rapid industralization and urbanization have been worsened as much as to threaten the environmental restitution of globe and become a critical international issue. Korean government presented the green growth as a new state vision for 60 years afterwards and is making efforts to solve the environmental problems. Daegu metropolitan city has faced various environmental problems including overpopulation of cities, traffic pollution, household wastes and green zone problem because of urbanization for the last decades. As such urbanism continues, the quality of residential environment is rapidly deteriorating and the intensive use of land leads to increase of building area raising the temperature of cities. Therefore there have been demands for the healthy, pleasant and satisfying residential environment and the improvement of residential environment and such recognition rises from society in full measure. Nevertheless the current residential complex concentrates only on raising the efficiency of land use. Related laws in the past(Daegu Metropolitan City, Urban Planning Municipal Ordinance as of October 10, 2003) tried to prepare a standard to segmentalize the building-to-land ratio, floor area ratio and regulations of number of floors vertically, but currently it is abolished and the regulations are becoming eased. The purpose of this study was to analyze the characteristics of the floating wind before and after the vertical segmentation of residential areas(Daegu Metropolitan City, Urban Planning Municipal Ordinance as of October 10, 2003) by using KLAM_21, a model that enables analysing and predicting the flow and generation of clod wind, and to present a plan to improve the quality of residential areas afterwards when developing building lot and re-developing housing areas.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.118-126
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• 2016

International construction market have quantitatively increased and have reached up to 700 Bil. US$ through active effort of construction firms and government. In spite of this increase, substantiality issue has been constantly disputed due to qualitative problems such as lack of capability and technical shortage. To overcome these problems, many methods in performing quantitative growth and qualitative substantiality of overseas construction are being researched which showed that selection of subcontractors in general contractor is regarded as a very important success factor. However, it is difficult to make a reasonable decision for selecting the subcontractors due to the lack of evaluation standards and reliability. This study proposes an improved evaluation system through adjustment of the evaluation indicators using correlations analysis and multiple regression analysis with pre-qualification and performance evaluation of 121 firms in 6 countries.

• Environmental Engineering Research
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• v.12 no.2
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• pp.64-71
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• 2007

The necessity of disinfecting playground soil is an important issue, because pathogenic protozoa, bacteria, and parasite eggs remain viable for several months and can infect children. UV irradiation has been used to decontaminate water but its effectiveness on soil is unclear. We determined the efficacy of UV radiation for inactivation of an indicator bacteria, E. coli (strain ATCC 8739), on playground soil. While 99% inactivation of E. coli in the soil was readily achieved by UV radiation within 55 min at $0.4\;mW\;cm^{-2}$, complete inactivation was not achieved, even after prolonged treatment at $4\;mW\;cm^{-2}$. This was attributed to the irregular surface of the soil. A small number of E. coli escaped the UV radiation because they were situated in indentations or under small particles on the soil surface. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the surface characteristics of the soil is the major limiting factor in the inactivation of E. coli by UV radiation. Thus UV treatment may not be adequate for disinfecting some soils and should be carefully evaluated before being used on playground soils.

• Environmental Engineering Research
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• v.15 no.2
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• pp.123-126
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• 2010

Modeling non-point pollution across multiple scales has become an important environmental issue. As a more representative and practical approach in quantifying and qualifying surface water, a modular neural network (MNN) was implemented in this study. Two different site-scales ($1.5\;{\times}\;10^5$ and $1.62\;{\times}\;10^6\;m^2$) with the same plants, soils, and paddy field management practices, were selected. Hydrologic data (rainfall, irrigation and surface discharge) and water quality data (time-series nutrient loadings) were continuously monitored and then used for the verification of MNN performance. Correlation coefficients (R) for the results predicted from the networks versus measured values were within the range of 0.41 to 0.95. The small block could be extrapolated to the large field for the rainfall-surface drainage process. Nutrient prediction produced less favorable results due to the complex phenomena of nutrients in the drainage water. However, the feasibility of using MNN to generate improved prediction accuracy was demonstrated if more hydrologic and environmental data are provided. The study findings confirmed the estimation accuracy of the upscaling from a small-segment block to large-scale paddy field, thereby contributing to the establishment of water quality management for sustainable agriculture.

• Korean Journal of Social Welfare
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• v.65 no.2
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• pp.5-28
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• 2013

This study was to examine the effects of individual and environmental character among adults with intellectual disabilities on self-determination and to address issue of self determination in practical terms. This study was analyzed by the Structural Equations Models with 219 individuals with intellectual disabilities in residential home in the Metropolitan area, the Yeongnam area, the Honam area. The results showed that individual factors such as adaptive behavior and provider-user relationship recognition, and environmental factors such as institution size and institution location were directly affected to the self-determination of them. The opportunity was a full mediating effect in this process. In conclusion, this study stated how importance of the consumerism. Also it was suggested that some practical strategies to improve their self-determination in changing residential environment and support methods of the service in way to emphasis their opportunities.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.407-418
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• 2020

Mass mortality of mariculture fish due to high summer temperatures is a major issue in the mariculture industry in many coastal waters of Korea, yet measures to mitigate the impact are generally limited. We injected a micro-bubble of liquefied oxygen into the bottom of rockfish cages (about 6-8 m deep) in order to maximize the dispersal of micro-bubbled seawater and reduce fish mortality. The injection of low-temperature oxygen in micro-bubbles lowered the water temperature at the injection area by as much as 1℃ and increased dissolved oxygen concentration by 0.5 ppm. In early August, following a week with persistent high water temperature (above 28.5℃), there was an increase in fish mortality despite the micro-bubble system, which resulted in approximately 7% death of the total introduced fish population. However, this mortality appeared to be much lower than mortality reported in a neighboring mariculture facility (approximately 50% mortality). We also estimated the volume that can be recirculated with pumped seawater using a micro-bubble system. We suggest that this approach of injecting liquefied oxygen through a micro-bubble system may reduce fish mortality during high temperature periods.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.539-546
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• 2013

Cement industry in 1997 began to use industrial waste in cement factory for purpose of resource recycling. However recently, environmental hazard of the cement in accordance with recycling of industrial waste have been raised a problem by contamination around the cement factory and heavy metal leaching in cement. In particular, the presence of $Cr^{6+}$ in cement has become a critical issue, the studies for minimizing of $Cr^{6+}$ in cement have been performed. But, in domestic, most of the research on heavy metal leaching was carried out from the perspective of the cement. Environmental safety assessment in terms of concrete is needed because cement is used to the concrete material. Therefore, this paper was evaluated heavy metals leaching of deteriorated concrete by severe conditions. test result showed that $Cr^{6+}$ were not detected from all the variables.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.12
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• pp.615-641
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• 1999

Trade and the environment emerged as a major and complex issue for trade negotiators in the final stages of the Uruguay Round negotiations. The agreements and other international measures employing trade measures and trade sanctions for achieving global environmental objectives are Vienna Convention on the Protection of the Ozone Layer(1985), the Montreal Protocol on Substances that deplete the Ozone Layer(1987), The Framework Convention on Climate Change(1992), the Convention on Biological Diversity(1992), the Basel Convention on the Control of Transboundary Movement of Hazardous Waste and their Disposal(1992), the Convention on International Trade in Endangered Species of Wild Faunna and Flora(1975), the Rio Declaration, the Agenda 21, etc. The texts of the World Trade Organization(WTO) incorporated certain provisions which were designed to reflect some of the environmental concerns are Trade-Related Aspects of Intellectual Properity Rights(TRIPs), Trade-Related Investment Measures (TRIMs), the General Agreement on Trade in Services(GATS), and Technical Barriers to Trade(TBT) There is the possibility of conflict between multilateral environmental agreements and WTO agreements granting waivers against trade measures and sanctions. This remains a possibility, especially between countries which are Member of WTO and which are not Members of the relevant multilateral environment agreements, and countries which are Members of both the WTO and the relevant MEAs. Measures taken under the trade-related provisions of MEAs could potentially give rise to conflicts under obligations arising in WTO texts. If the parties in dispute are WTO members while they are not members of MEAs, the WTO provisions can be granted a certain priority in terms of international norms and vice versa. When the parties concerned are both WTO members and MEAs, it will be rational to grant the WTO provisions a priority. However, such measures should neither constitute a means of arbitrary or unjustifiable discrimination between countries where similar conditions prevail, nor create a disguised restriction on trade. Also any trade measures taken should be necessary to prevent developments in trade from endangering the effectiveness of an MEA and they should be proportional and least trade restrictive.

• Environmental Engineering Research
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• v.11 no.1
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• pp.14-27
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• 2006

The proper management of discarded electronic devices (often called electronic-waste) is an emerging issue for solid waste professionals throughout the world because of the large growth of the waste stream, and the content of toxic metals in them, most notably heavy metals such as lead. Notebook computers are becoming one of the major components of discarded computer devices and will continue to increase in the waste stream in the future. While the computers hold great promise for recycling, a substantial amount of this waste is often disposed in municipal solid waste (MSW) landfills. The toxicity characteristic leaching procedure (TCLP) is commonly used to simulate worse case leaching conditions where a potentially hazardous waste is assumed to be disposed along with municipal solid waste in a landfill with actively decomposing materials overlying an aquifer. The objective of this study was to examine leaching potential of lead from discarded notebook computers using the scale-up TCLP, other standard leaching tests such as California waste extraction test (Cal WET), and the synthetic precipitation leaching procedure (SPLP) and actual landfill leachates as leaching solution. The scale-up TCLP is a modified TCLP (where the device was disassembled and leached in or near entirety) to meet the intent of the TCLP. The results showed that the scale-up TCLP resulted in relatively high lead found in the leachate with an average of 23.3 mg/L. The average level was less than those by the standard TCLP and WET (37.0 mg/L and 86.0 mg/L, respectively), but much greater than those by the SPLP and the extractions with the landfill leachates (0.55 mg/L and 1.47 mg/L, respectively). The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead were identified as major factors that controlled the amount of lead leached from notebook computers. Based on the results obtained by a number of leaching tests in this study, notebook computers may present a potential leaching risk to the environment and human health upon land disposal. However, further investigation is still needed to assess the true risk posed by the land disposal of discarded notebook computers.

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.541-550
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• 2013

Noise is defined to be unwanted (or undesirable) sounds, and it can be subdivided into occupational and environmental noises. The occupational noise is largely emitted from workplaces, but the environmental noise is produced from various sources such as transportation, construction, and even neighborhood. Transportation, particularly road vehicles, has been recognized to play a major role in emitting environmental noise and having adverse effects on urban communities. Considering this issue, this research investigated how severe the impacts of road traffic noise on a variety of land uses in a highly urbanized area, Fulton County, Georgia, United States. Daytime and nighttime road traffic noise maps were derived with Traffic Noise Model that was developed by Federal Highway Administration at United States Department of Transportation. Individual noise maps were overlaid on three-tiered land use type maps in order to evaluate the magnitude of noise impacts on the study area, as a noise exposure assessment. This study found that many land use parcels and buildings were exposed to noise levels exceeding the guideline values of the World Health Organization and the Atlanta Code of Ordinance. Therefore, it would be required to take an action that can protect many urban residents from ill effects of road traffic noise.