• 대한토목학회논문집
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• 제31권2D호
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• pp.285-293
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• 2011

국내 하수처리시설의 발전으로 인해 최근 유지관리 측면에서의 중요성이 높아지고 있으나, 국내 여건의 부족으로 인해 하수처리 시설의 자산관리가 제대로 정착되지 못하고 있다. 현재 수많은 하수처리시설이 가동 중에 있음에도 불구하고 운영비용의 정확한 통계와 분석, 특히 대수선비와 보수비에 있어서는 대부분의 지방자치단체에서 일반 경상수선비 또는 보수비 하나로만 집계하고 있으며, 민간투자사업으로 시행되고 있는 사업들은 정부기관이나 어떠한 민간기관에서도 운영비용 산정에 있어 명확한 기준에 의해 분석이 이루어지지 못하고 있는 실정에 있다. 본 연구에서는 현재 수행된 하수처리시설 대수선비를 자산화 할 경우의 영향을 분석하여 자산관리의 효율성을 분석하였다. 또한 대수선비 산정에 있어서의 현행 문제점을 분석하고, 제도개선 방안을 제시하였다.

• 토지주택연구
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• 제13권2호
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• pp.141-150
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• 2022

정부는 증가하는 건설폐기물의 발생량을 줄이고 재활용을 극대화하기 위해서 폐기물처분 분담금제도를 도입하였다. 이로 인해 폐기물 처리비가 상승할 수밖에 없어 발주처와 건설폐기물처리자간에 분쟁이 커지고 있으며, 건설폐기물 처리비의 현실화를 모두 주장하고 있다. 따라서 본 연구에서는 건설폐기물 관리의 문제점을 파악하고 개선점을 찾기 위해 현장조사를 실시하였다. 설문조사는 공공기관과 폐기물 관리업체 관련자를 대상으로 실시하고 건설폐기물의 업무, 제도, 처리비용, 처리방법 등으로 구분하여 분석하고, 그 결과를 제안하였다. 본 연구결과는 공공기관의 건설폐기물 지침규정과 폐기물처리 대가의 변경을 위한 기본 자료로 활용되었다.

• 환경위생공학
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• 제16권2호
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• pp.1-8
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• 2001

The water treatment by electrochemical method was performed to increase the yield of production. Continuous plug flow reactor was operated to treat poultry and domestic wastewaters. Experimental results were compared with experimental results of the wastewater treatment by chemical coagulation, they were increased over 10% in the removal efficiency of COD and the production rate of sludge was reduced by 30%. Ozone utilized to degrade or change the organic chemical structures, which removal efficiency increased to 20% in the electro-coagulation reactor. Economic evaluation was performed to estimate total cost of electro-coagulation reactor in comparison with that of chemical coagulation method. The total cost to treat 1000 ton/day of domestic wastewater was reduced by 50%.

• Membrane and Water Treatment
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• 제11권5호
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• pp.363-374
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• 2020

Membrane distillation (MD) is a process used for water desalination. However, its commercialization is still hindered by its increased specific cost of production. In this work, several process configurations comprising Direct Contact and Permeate Gap distillation membrane units (PGMD/DCMD) were investigated to maximize the production rate and consequently reduce the specific water cost. The analysis was based on a cost model and an experimentally validated MD model. It was revealed that the best achievable water cost was approximately 5.1 $/㎥ with a production rate of 8000 ㎥/y. This cost can be further decreased to approximately 2 $/㎥ only if the heating and cooling energies are free of cost. Therefore, it is necessary to decrease the MD capital investment to produce pure water at economical prices.

• 환경위생공학
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• 제5권1호
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• pp.83-92
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• 1990

Adapting two step aeration system to a waste water treatment of W-paper manufactory as Full-Scale Plants, we drew a following conclusion from its practical working. 1. Because BOD removal efficiency was 20% in A-Stage, 90% in B-Stage and total removal efficiency was 97%. It worked treatment plant well and was suitable for effluent water standard as well. Because COD removal efficiency was 42% in A-stage, 71% in B-stage and the total removal efficiency was 94% COD control was possible in effluent water quality. 2. Treatment efficiency according to a load capacity was average 20% in 1.401 BOD kg/m3/d load of A-Stage and average 90% in 0.273 BOD kg/$\textrm {m}^3$ / d load of B-Stage. 3. Treatment efficiency according to a ratio of F/M was 2.657--5.024 kg BOD/kg MLSS/d in A-Stage and BOD removal efficiency was 16-261 in the same stage. The ratio of F/M was 0.068-0.094 kg BOD /kg MLSS/d and BOD removal efficiency ratio was 85-94%. Therefore treatment efficiency could be kept stably and volume of aeration tank could be reduced wholly. 4. Treatment efficiency according to MLSS appeared BOD 20%. COD 42%, in A-Stage and removal efficiency appeared BOD 90%, COD 71% in B-Stage. They were suitable for plan condition. 5. Because of working of complemented treatment plant by AB-Process. 20,000,000 Won a month was saved than the ordinary working cost. Therefore, it was assumed that invested cost could be recollected in 19 months or so consequently.

• 상하수도학회지
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• 제27권1호
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• pp.11-20
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• 2013

This Study includes the information of integrated discussion and economies of scale on local governments' sewerage treatment plant through translog function based on the reality reports of sewerage treatment plant operation published by Ministry of Environment and sewerage statistics data from 2005 to 2010. Based on analysis results from the data of 35 local governments in Jeollanamdo and Jeollabukdo, which are selected as pilot project areas of sewerage facility integration by Ministry of Environment and have low percent of sewered population, it shows the existence of economies of scale. The economies of scale on sewerage treatment show the loss of approximately 22,211 thousand ton/day in sewage treatment, it is 1.7 times compared to the average treatment amount of 35 local governments as of 2010. It means the economies of scale can be achieved by lowering operation cost along with large scale integration in installation, operation and maintenance due to the features of sewerage industry as one of network industry.

• 반도체디스플레이기술학회지
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• 제16권4호
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• pp.59-62
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• 2017

In this paper, atmospheric pressure plasma treatment was proposed for high performance indium gallium zinc oxide thin film transistor (IGZO TFT). RF Ar plasma treatment is performed at room temperature under atmospheric pressure as a simple and cost effective channel surface treatment method. The experimental results show that field effect mobility can be enhanced by $2.51cm^2/V{\cdot}s$ from $1.69cm^2/V{\cdot}s$ to $4.20cm^2/V{\cdot}s$ compared with a conventional device without plasma treatment. From X-ray photoelectron spectroscopy (XPS) analysis, the increase of oxygen vacancies and decrease of metal-oxide bonding are observed, which suggests that the suggested atmospheric Ar plasma treatment is a cost-effective useful process method to control the IGZO TFT performance.

• Journal of Preventive Medicine and Public Health
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• 제29권2호
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• pp.347-357
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• 1996

Although occupational low back pain accounts for $20\sim40%$ of all occupational illness and injury, there are limited numbers of studies regarding the effectiveness of back school program. The objective of this study was to evaluate the economic benefit of back school program for early return to work of occupational low back pain patients in the current occupational injury compensation and management system. The cost-benefit analysis in this study was conducted to evaluate the relative magnitude of benefit to cost. The total cost was estimated by calculating the value of components in back school program according to governmental budget protocol. The back school program was consisted of three major approaches, pain center, work-hardening program and funcional restoration program and each of components had various facilities and experts. The total amount of cost was estimated as 250,866,220 won per year. The most promising type of back school program were quite intensive (a 3 to 5-week stay in a specialized center), therefore, if we adopted the 5-week stay course, 10 courses could be held in a year. Following to the medical act, 20 patients per doctor could participate in a each course, ie, total 200 patients in a year. As a result, we could estimate the cost of 1,254,331 won a patient. We estimated the benefit by using data of a few local labor offices about average medical treatment beneficiary and off-duty beneficiary of 46 occupational low back pain patients in 1994. Ullman and Larsson (1977) mentioned that the group of chronic low back pain patients who participated in back school program needed less time to recover by 48.4% of beneficiary duration. And in the trying to estimate the benefit, we asked 10 rehabilitation board certificate doctors about reduction proportion of treatment cost by introducing back school program. The answered reduction proportions were in the range of $30\sim45%$, average 39%. As a final result, we could see that the introduction of back school program in treatment of chronic occupational low back pain patients could produce the benefit to cost ratio as 3.90 and 6.28. And we could conclude that the introduction of back school program was beneficial to current occupational injury compensation and management system.

• 한국해양환경ㆍ에너지학회지
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• 제15권4호
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• pp.330-336
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• 2012

본 연구에서는 2007년도에 주요 연안 어장에서 이루어진 해저침적쓰레기 분포 조사 지역 중 왕등도를 포함한 5개 어장에서의 침적쓰레기 조사 결과와 그 수거처리 비용 추정 결과에 대해 소개한다. 주요 대상 해역의 해저면 특성에 따라 침적쓰레기 인양에 적합한 인양틀의 종류를 선택하여 사용하였으며, 관계자들의 자문을 얻어 설정한 조사 대상 어장 구역에 대하여 인양 조사 횟수와 수거된 총 쓰레기량을 고려한 전체 해저 침적쓰레기량을 추산하였다. 그 결과 왕등도 인근 해역에 대해 약 686 $kg/km^2$의 침적쓰레기량을 구할 수 있었다. 각 구역에서의 쓰레기 추정량에 근거하여 수거 및 운반에 필요한 적정 선단 규모를 가정하고, 처리에 이르기까지 소요되는 장비, 인건비 등 제반 경비를 계산한 결과 왕등도의 경우 총 247톤의 추정 해양 침적쓰레기에 대하여 약 39억원의 수거 및 처리 비용을 도출하였다.

• Journal of Korean Neurosurgical Society
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• 제57권6호
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• pp.455-459
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• 2015

Objective : A cost comparison of the surgical clipping and endovascular coiling of unruptured intracranial aneurysms (UIAs), and the identification of the principal cost determinants of these treatments. Methods : This study conducted a retrospective review of data from a series of patients who underwent surgical clipping or endovascular coiling of UIAs between January 2011 and May 2014. The medical records, radiological data, and hospital cost data were all examined. Results : When comparing the total hospital costs for surgical clipping of a single UIA (n=188) and endovascular coiling of a single UIA (n=188), surgical treatment [$mean{\pm}$standard deviation (SD) : \$8,280,000{\pm}1,490,000$] resulted in significantly lower total hospital costs than endovascular treatment ($mean{\pm}SD$ : \$11,700,000{\pm}3,050,000$, p<0.001). In a multi regression analysis, the factors significantly associated with the total hospital costs for endovascular treatment were the aneurysm diameter (p<0.001) and patient age (p=0.014). For the endovascular group, a Pearson correlation analysis revealed a strong positive correlation (r=0.77) between the aneurysm diameter and the total hospital costs, while a simple linear regression provided the equation, y (\)=6,658,630+855,250x (mm), where y represents the total hospital costs and x is the aneurysm diameter. Conclusion : In South Korea, the total hospital costs for the surgical clipping of UIAs were found to be lower than those for endovascular coiling when the surgical results were favorable without significant complications. Plus, a strong positive correlation was noted between an increase in the aneurysm diameter and a dramatic increase in the costs of endovascular coiling.