• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.41-48
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• 2000

In this study, we have investigated the effect of the various operating conditions on the removal fluorine in the rinsed water for the semiconductor industry by using electrolysis process. The removal efficiency of fluorine was irrelevant to initial pH, and carbon anode was high-level treatment in the effect of various electrodes. Fluorine included in the wastewater is treated by the addition of a Ca(OH)2, removal efficiency of electrolysis was increased about 40%. Besides the removal efficiency of fluorine was increased as the current density was increased and this treatment system could reduce both the total sludge and running costs. The feasibility of the electrochemical treatment to the fluorine containing wastewater was verified from this study.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.201-205
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• 2010

Earthwork is an essential initial work discipline in construction projects and open to significant impacts of several factors such as weather, site conditions, soil conditions, underground installations and available construction machinery, calling for careful planning by managers. However, selection and combination of construction machinery and equipment for earthwork still depends on experience or intuition of managers in construction sites, with much room left for proper management in terms of cost, schedule and environmental load control. This research aims to analyze the performance of earthwork equipment and establish relations among various factors affecting a model for optimizing selection and combination of earthwork equipment as a precursor to the development of such model. We expect the conclusions herein to contribute to optimizing selection and combination of earthwork equipment and provide basic inputs for the development of applicable model that can save costs, reduce schedule and mitigate environmental load.

• The Journal of Fisheries Business Administration
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• v.32 no.2
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• pp.1-22
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• 2001

In recent years Korea fisheries have been much more influenced than ever before by domestic and foreign environmental changes such as market liberalization, sustainability, efficiency and effectiveness of domestic fisheries, fisher's welfare etc. Under the wide range of environmental changes, government is carrying out various fisheries policies. However, it seems insufficient to accomplish policy goals under the existing policy instruments. The main focus of the paper is to investigate structural changes and policy directions of fisheries finance in Korea after asian economic crisis. The results of the study are as follows; Fisheries sector in whole economy has been lowering in its proportion. To survive in emerging global competition, fisheries sector is needed structural reformation. In particular the strategy that increases operative efficiency and effectiveness on government financial policy in fisheries sector is much expected. Also, it is necessary to minimize costs, to reform institution and management for increasing efficiency and effectiveness.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.16-20
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• 2003

Nitrogen(N) and phosphorus(P) in surface streams mainly lead to euthrophication. It aggravates water quality and consequently increases the purification costs. As a resolution of water contamination caused by household drainage through irrigation route by 70% of the 1,300 community residents in Eum-Am Myun, Seo-San city, was implemented biological self-purification method by growing Oenanthe Javanica along the polluted water tunnel. The contaminated water was efficiently purified after passing the dropwort field; DO conc. of effluent water was increased 8.3∼61.9% after through the drop wort field. HRT of experiment system was changed 0.05∼1.50/day. 50% of BOD was eliminated at the range above 12 mg/l of Influent BOD conc. Also, 50% of COD was eliminated at the range above 30 mg/l of Influent COD conc. Finnally, the influent T-N loading at range below 1.5 g/m$^3$/d reduced 50% of Influent T-N conc., and so did influent T-P loading at the range below 0.03 g/m$^3$/dwas reduced 50% of Influent T-P conc.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.157-162
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• 2003

Boeun-gun is hard to develop, because of large numbers of mountains and vast distribution of limited development districts. However it is easy to access from the entire country, and there are large conservation area such as national park and dams. Short-term plans such as attraction of tourists can be established using these advantages. Long-term plans can be planed with stable establishment of continuous considerations and supports. These supports will be rewarded while it demands some time and costs. Private owned mountains can be converted from negligence upkeep of property to utilization of mountains with basic consideration of mountain conservation. This may contribute the essential function of mountain.

• Environmental and Resource Economics Review
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• v.9 no.4
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• pp.663-700
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• 2000

한강은 서울 지역을 관통하고 있다는 점에서 수도권의 수자원 이용과 폐수 수용체로서의 한강의 역할이 실로 막대하다. 이런 맥락에서 한강에서의 수질오염문제는 주요한 사회경제적 문제 중의 하나로 부각되고 있다. 한강 수질 악화를 방지하기 위한 관리 방안이 이미 시행중에 있으나 여전히 한강 수질 오염은 문제로 남아 있는 실정이다. 이를 감안하여 보다 나은 관리책에 대한 요구에 부응하기 위하여 본 논문은 기존의 수질기준을 최소비용으로 달성하는 비용 효과적인 방식을 시스템 최적화 분석 기법에 접목하는 모델을 구축하고 있다. 이 모델은 우리 나라에 두드러진 수문학적 특징, 즉 자정능력상의 계절적 차이가 지역적 특성과 오염 처리 기술상의 다양함, 그리고 기존의 법적 제도적 특정들과 어떻게 연결되어 얼마나 처리 비용상의 절약을 유도해 낼 수 있는지에 관한 정책정보를 제공해 줄 수 있게 고안되었다. 연구의 결과치에 의하면, 표적 지천상의 지역적 안배와 처리 공정상의 기술-비용적 차이를 고려하고 비갈수기에 처리시설을 신축적으로 운영할 경우 한강 수계에서 BOD 부하량 삭감비용은 상당한 정도( 예로, 1992년 물가수준에서 매일 3,000만 원 이상) 절감 가능한 것으로 나타나고 있다.

• Journal of Environmental Impact Assessment
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• v.18 no.1
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• pp.31-39
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• 2009

A lot of data which are used in environment analysis of air pollution have characteristics that are distributed continuously in space. In this point, the collected data value such as precipitation, temperature, altitude, pollution density, PM10 have spatial aspect. When geostatistical data analysis are needed, acquisition of the value in every point is the best way, however, it is impossible because of the costs and time. Therefore, it is necessary to estimate the unknown values at unsampled locations based on observations. In this study, spatial interpolation method such as local trend surface model, IDW(inverse distance weighted), RBF(radial basis function), Kriging were applied to PM10 annual average concentration of Seoul in 2005 and the accuracy was evaluated. For evaluation of interpolation accuracy, range of estimated value, RMSE, average error were analyzed with observation data. The Kriging and RBF methods had the higher accuracy than others.

• Journal of the Korea Society of Computer and Information
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• v.22 no.7
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• pp.9-16
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• 2017

In this paper, we propose a development method of portable Automatic Test Equipment based on PXIe platform. Legacy VME form factor structured test equipment has limited reuse and expansion of modules due to unapplied bus specification. In particular, these limitations can cause development periods and costs to increase, and the reliability of environmental conditions is lacking due to non-standard modules. The test equipment of the proposed PXIe platform can use diverse COTS modules to shorten the development period and minimize the instability between developments. The PXIe development module works with standard Xilinx FPGAs, PXIe Windows device drivers, and applications on standard PXIe buses. The use of standard bus and COTS modules increases scalability and reusability, enabling rapid development and excellent maintenance. Through the test, we show the proposed test equipments can be implemented efficiently between the development processes and proved their reliability through function tests and environmental tests.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.31
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• pp.19-24
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• 2006

Green gas emissions Trading System(ETS) came into effect in the Europe last year 2005. All transport modes have tried to reduce green gas emission and EU member countries are promoting the use of environmental friendly transport mode to avoid economic loss due to green gas emission. Besides ETS, rapidly rising of oil price and peak oil urge to invest more in the environmental friendly public transport mode and to discourage the use of private cars. The operation of KTX is estimated to bring external cost reduction up to 570 bil. won in 2004 based on European external unit costs of transport modes. This result implies that the expansion of high speed rail network and reconsideration of East-West high speed rail network which is not considered because of weak economic validity is required.

• Environmental and Resource Economics Review
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• v.10 no.1
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• pp.1-23
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• 2001

This paper reviews a single trip decision to visit individual sites of a natural park within a random utility framework as an alternative to travel cost model. The model is applied to a 1998 survey of on-site visitors to Mu Deung Mt. neighboring Kwang Ju. city. Out of four sites considered, the model seemed to provide a reasonable description of behavior for three sites. In addition to travel costs as an implicit price, variables reflecting characteristics of each site also influenced decisions to visit the site. Moreover, benefits estimates derived from the RUM implied that visitors placed three times higher values on a site based on cultural inheritance compared with those of two recreational sites.