• 주택과사람들
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• 통권199호
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• pp.34-35
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• 2006

선진국에서는 선시공 후분양이 일반적이다. 후분양은 소비자가 지어진 주택을 살펴보고 아파트를 살 수 있어 유리하지만 대규모 주택을 짓는 건설사는 사업 초기에 자금 압박이 크다. 시민 사회단체에서는 선시공 후분양이 주택 값을 내릴 수 있는 묘안처럼 이야기하지만 선분양, 후분양 모두 장단점이 있다.

• 주택과사람들
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• 통권198호
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• pp.36-37
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• 2006

선진국에서는 선시공 후분양이 일반적이다. 후분양은 지어진 주택을 소비자가 살펴보고 아파트를 살 수 있어 유리하지만 대규모 주택을 짓는 건설사는 사업 초기에 자금 압박이 클 수 있다. 시민 사회단체에서는 선시공 후분양이 주택값을 내릴 수 있는 묘안처럼 이야기하지만 선분양, 후분양 모두 장단점이 있다.

• 한국분무공학회지
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• 제9권1호
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• pp.15-20
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• 2004

The post injection effect to enhance aftertreatment devices' performance is essential to meet future stringent emission standards by controlling exhaust gas temperature and emission pollutants. The test has been made with commercial common rail diesel engine by post injection manipulation, to optimize exhaust gas temperature while guarantee low fuel penalty. The optimization was done at 1500, 2000 and 2500[rpm] for 2, 4[bar] condition which show low exhaust gas temperature. The main purpose of this test is dedicated to understand mechanism of exhaust gas temperature rise while optimizing

• 한국분무공학회지
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• 제22권2호
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• pp.87-95
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• 2017

Recently, as the interest in environmental issues have increased around the world, the regulation on vehicle exhaust have been tightened in each country. To satisfy such tightened exhaust regulation, automotive manufactures are forced to equipped Diesel Particulate Filter (DPF) at Diesel vehicles. If DPF is used for a long time, DPF regeneration should be performed. The objective of this study is to research on post injection for DPF regeneration. The result of the study was that it was desired that retarding post injection timing, lower load of engine and smaller the amount of main fuel injection, for DPF regeneration. Oil dilution was tended to increase as load was lower, amount of post injection was increased, and post injection timing was retarded.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.193-201
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• 2014

A numerical study has been carried out to analyze the combustion characteristics in heavy duty diesel engine with post injection for reducing NO emission. For verification of numerical study results, calculated cylinder pressure was matched to experimental data. In this study, post injection timing and amount of post injection were modified as parameters, but the total amount of injection fuel was maintained. As the results, maximum cylinder pressure increases above minimum 2% by post injection and end of pressure curve is decreased rapidly. The more dwell time and amount of post injection fuel are, the more pressure drop occurs. And trade-off relation of NO and soot are appeared. In the results, NO was reduced without deterioration of cylinder pressure under condition of $10^{\circ}$ CA dwell time and main 60%, post 40% fuel portion.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.179-182
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• 2012

Effect of double post injections on diesel PCCI combustion with focus on HC emission was investigated in a single-cylinder direct-injection diesel engine. The ISFC, HC and CO emissions were reduced by single or double post injections. The application of double post injections could also improve the trade-off relationship between NOx and HC emissions under wide EGR rate range.

• 한국건설관리학회논문집
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• 제5권6호
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• pp.218-225
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• 2004

주택건설시장에서 정부의 후분양 방식 도입이 점차 가시화되고 있는 상황에서 더 이상 기존의 건설금융 기법으로는 건설환경의 변화에 대처할 수 없게 되어 자금의 유동성 및 사업 자금 확보에 어려움을 겪을 것으로 예상된다. 결과적으로 주택건설산업에서 분양대금 수입의 시기변화에 따라 선분양의 장점이었던 건설금융 및 사업안정성 확보가 어려워지기 때문으로, 시장충격의 완화를 위한 방안마련 및 건설 자금조달을 위한 건설금융의 활성화가 전제되어야 할 것이다. 따라서, 본 연구에서는 분양을 통해 공급되는 공동주택으로 시행사-건설업체 도급방식의 계약으로 이루어진 주택공급사업을 대상으로 하였으며, 건설 SWOT 분석을 통하여 주택분양사업의 후분양 전환시 선분양 자금을 대체할 수 있는 자금조달 기법으로서 프로젝트 파이낸싱의 기대효과 및 적절한 활용방안에 관한 연구를 수행하였다. 본 연구의 결과는 주택분양사업에서 프로젝트 파이낸싱을 활용할 경우, 자금조달 및 사업위험 감소를 위한 전략 수립 시 기초적 인 자료로서 활용이 가능할것으로 기대된다.

• 한국자동차공학회논문집
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• 제19권2호
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• pp.78-83
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• 2011

Diesel engine has many advantages such as high thermal efficiency, low fuel consumption and low emission of CO2. However, the diesel engine faced with strengthened emission regulation about NOx and PM. To suppress NOx emission, after-treatment systems such as Lean NOx Trap (LNT), Selective Catalytic Reduction (SCR) are considered as a more practical strategy. This paper investigated the performance of Lean NOx trap of the 4 stroke diesel engine which had a LNT catalyst. Characteristic of exhaust emission at NEDC mode was analyzed. From this result, the effect of nozzle attaching degree, injection quantity and gas flow change on NOx conversion performance was clarified.

• 한국입자에어로졸학회지
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• 제8권2호
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• pp.55-68
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• 2012

Particulate matters (PM) which are collected into a diesel particulate filter (DPF) system have to be periodically removed by thermal oxidation. In this report, we fabricated an electrohydrodynamic-assisted pressure-swirl nozzle to spray diesel droplets finer. Atomization performance of the nozzle was evaluated using both experimental and numerical methods. Two types of nozzle designs, the charge induction type and the charge injection type, were tested. While the former generated diesel droplets of $400\;{\mu}m$ at an applied electric potential over 10 kV, the latter presented the droplets smaller than $23\;{\mu}m$ at an applied electric potential of 8 kV. The numerical simulation results showed that the reduced size of droplets caused higher evaporation of droplets and therefore the increased temperature, which would eventually increase the regeneration performance of the DPF system.

• 한국자동차공학회논문집
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• 제12권5호
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• pp.40-57
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• 2004

The effects of triple (pilot, main and after) injection on combustion and emission characteristics in a HSDI (High-Speed Direct Injection) diesel engine were investigated using a single-cylinder optical diesel engine equipped with a common-rail injection system. The pilot injection affected the spray and combustion evolution of the following main injection. It was found that the pilot injection reduced the ignition delay, which led to lowered NOx (Nitric Oxides) level, and increased IMEP (Indicated Mean Effective Pressure) due to slow combustion pace during an expansion stroke. The after-injection was shown to be effective in reducing PM (Particulate Matter) even when a small amount of fuel was added. The results suggest that a proper combination of individual injection strategy could bring about a good synergetic effect on engine performance and emission.