• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1012-1017
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• 2004

노후된 상수도 관망의 최적개량 계획수립을 위하여 국내에서 가장 많이 쓰이는 모형은 관거의 교체, 갱생, 유지보수 비용 등과 같은 인자를 이용한 경제성분석에 의한 모형이다. 국내 적용된 대부분의 모형은 Shamir 등(1979)의 모형을 근간으로 하고 있으나, 모형에서 사용되는 여러 인자 중 관거의 유지보수 비용에 대한 국내 연구는 미비한 실정이다. 본 연구에서는 6년간의 대구광역시 지역의 누수보수기록자료를 이용해 국내 적용 가능한 유지보수 비용 함수를 유도하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1464-1468
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• 2004

누후된 상수도 관망의 최적개량 계획수립을 위하여 많은 모형들이 개발되었으며, 이러한 모형들은 수리학적 타당성을 비롯한 다양한 인자들을 복합적으로 고려한다. 관망의 수리학적 타당성을 검토하기 위해서는 관망해석을 통해 절점 압력변화 등이 계획기간동안 만족되어야 하며, 이를 위해서는 관거의 노후정도에 따라 변하는 Hazen-Williams C상수의 변화를 고려하여야 한다. 그러나 Hazen-Williams C상수의 변화는 관거의 매설지역, 통수년수, 수질 등과 같은 여러 가지 복합적인 인자에 의해 차이가 있으며 실제 유량 및 압력자료 등에 대한 조사에 의해 매설된 관거의 C상수를 추정하여야 한다. 그러나, 내상 지역의 모든 관거에 대하여 유량과 압력을 조사하는 것은 경제적인 문제를 비롯한 여러 가지 이유로 불가능하므로 본 연구에서는 실측된 몇몇 지점의 유량 및 압력 변화에 따라 대상지역에 매설된 관거의 C상수 변화를 추정하는 알고리즘을 제시하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.123-131
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• 2009

The study decided the improvement depth of soft ground of deep mixing method through 2 and 3 dimension finite element method and following results were acquired. 1. 2 dimension analysis shows settlement 10% more estimated than 3 dimension analysis. 2. When the rate of replacement is under 5%, the settlement sharply increased. 3. The most economical design for the levee was decided 3.0m for width direction, 6.0m for length direction and 8.0m for improvement depth. 4. When the soft ground is developed through deep mixing method, the decision of improvement should be decided through 3 dimension analysis than 2 dimension analysis.

• Journal of Korea Fishing Vessel Association
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• v.43
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• pp.31-37
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• 1990

• 지반과기술
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• v.6 no.2
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• pp.4-13
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• 2009

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1204-1208
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• 2005

우리나라의 경우 근래에 들어 도시지역 내배수시설에 대한 문제점들을 개선하기 위하여 정비사업이 활발히 이루어지고 있으나 시설물에 대한 과거 자료의 데이타베이스(database)화가 전무한 실정이며 정비사업을 시행함에 있어서 체계적인 정비사업 시행이 이루어지지 않고 있다. 따라서 본 연구에서는 내배수시설의 수리$\cdot$수문 해석 모듈을 이용하여 우수배제 목적의 합리적 근거를 마련하고, 현재 표본지역의 중요지점에서만 관측되는 불명수에 대하여 근거별로 불명수를 배분하는 불명수 산정모형과 도시 유출 모형을 이용하여 차집관거별로 발생하는 CSOs 발생량을 추정하는 도시 유출 모형 연계 모형을 구축하여 통합한 내배수시설 노후도 평가 모델을 개발하였다. 또한, 시설물 개량사업의 효율성을 높이기 위하여 수리$\cdot$수문 해석 모듈과 노후도 평가모델이 연계된 최적 개$\cdot$보수 scheduling 모델을 구축함으로써 최적개량 의사결정 시스템을 구축하였으며, 구축된 시스템은 실제 사업지역에의 적용성을 검토하여 GUI(Graphical User Interface)를 통한 의사결정 시스템인 내배수시설 유지관리시스템을 구축하였다.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.161-168
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• 1990

In order to investigate systematically characteristics of improved Kochujang in comparision with traditional Kochujang, changes of components in curing of two Kochujangs, enzyme activities of koji and Meju, and effects of salt and red pepper were measured. And it was found that the large differences of amino nitrogen and reducing sugar contents were appeared in the initial stage of the curing period, but the changes were parallel thereafter. The protease activity of koji was maximum in weak acidic pH and that of Meju was maximum in neutral pH. The optimum condition of substrate digestion was three hours at $60^{\circ}C$, and that was more effective than curing at room temperature. The activities of protease and saccharogenic amylase were decreased remarkably by adding salt and red pepper, Therefore, to decompose starch and protein effectively, the addition of salt and red pepper after substrate digestion was more favorable.

• Journal of the Korean GEO-environmental Society
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• v.2 no.2
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• pp.59-64
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• 2001

Recently, the application of shallow mixing method using hardening agent has increased because of the advantage of securing trafficability, reducing the working period, solving environmental problems caused by dumped and replaced soil, etc. In this paper, three types of representative hardening agents in Korea are used to achieve the optimum of ground improvement. 1he unconfined compression tests are carried out with specimens under various mixing ratios and curing periods of hardening agent to assess the stabilizing ability. The unconfined strengths on site were estimated with various mixing ratios based on the results of the laboratory tests. It was estimated that the improved strength on site was higher than that of the required strength $5.0kgf/cm^2$.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.271-278
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• 2009

This study was conducted to investigate the effect of the mixture ratio of the inorganic soil amendments on the soil physicochemical properties. In this experiment, three kinds of soil amendments which had similar pH, EC and particle size, the A, B and C, were tested. The mixture ratio of soil amendment were 0%, 3%, 5%, 7% and 10% (V/V) incorporated with sand which met to the USGA(United State of Golf Association) particle standard. To analyze the effects of amendment on chemical soil properties, pH, EC(electrical conductivity) and CEC(cation exchangeable capacity) were measured. The porosity, bulk density and hydraulic conductivity also measured to analyze the changes of physical properties. In the chemical properties, pH was significantly related to the mixture ratios of amendments, A and C(P<0.05), CEC and EC also related to the ratios of C(P<0.01). When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of each amendment were 3% in A and B, and 7~10% in C. To analyze the corelation of mixture ratio versus to physical character, volume of porosity was significantly related to the ratio of B (P<0.05), and showed similar corelation in porosity and hydraulic conductivity with ratio of C(P<0.05). These results indicate that types and mixture ratio of inorganic soil amendments should affect on soil physio-chemical properties of root zone on USGA sand green.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.205-210
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• 2010

This study was conducted to investigate the effect of the mixed ratio of the soil amendments, peat, humate, peatmoss and zeolite, on the soil physicochemical properties. The mixed ratios of soil amendments were 0%, 3%, 5%, 7% and 10% (v/v) incorporated with sand which met to the USGA (United State of Golf Association) recommendation. It was measured pH, EC and CEC as a chemical properties. Porosity, capillary porosity, air-filled porosity, bulk density and hydraulic conductivity were also measured to analyze the changes of physical properties. Chemical properties were significantly different by mixture ratios of peat, humate, peatmoss and zeolite. When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of peat, humate and peatmoss were 5%, 3% and 7%, respectively. Air-filled porosity was factor involved in soil physical properties by blending with soil amendments and it was affected on volume of porosity and hydraulic conductivity. To analyze the corelation of mixture ratio versus to physical characters, the ratio of peat and peatmoss was significantly related to capillary porosity and hydraulic conductivity (P<0.05), that of humate hydraulic conductivity (P<0.01), and that of zeolite air-filled porosity and volume of porosity (P<0.05). These results could be used as a basic data for construction USGA sand green.