• 한국자동차공학회논문집
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• 제22권5호
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• pp.59-65
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• 2014

Diesel engines have the superior combustion efficiency and fuel economy that they are widely used for industry, heavyduty vehicles, etc. However, its exhaust emissions have become the major concerns due to their environmental impacts. Moreover, the depletion of fossil fuels is the main issue. Therefore, it is important to look for alternative sources of energy. Bio-diesel is one of the ideal energy which has proved to be ecofriendly for more than fossil fuels. The experimental tests analysed the engine performance and emission characteristics of a diesel engine using diesel and biodiesel blended of BD25, BD45 and BD65, in order to study the use of clean fuel to meet the increasingly stringent emission regulations. The engine performance was examined by using engine dynamometer while an exhaust gas analyzer was used to examine the emission characteristics. The effect of biodiesel on engine performance were lower to diesel through comparing their HP and torque but fuel consumption was slightly increased because of biodiesel has lower heating value and higher density than diesel. However, due to the better lubricity, the brake thermal efficiency of biodiesel was higher than diesel. The emission characteristics were strongly affected by the blending ratio of diesel and biodiesel. The results showed that the smoke opacity, hydrocarbons (HC) and carbon monoxide (CO) emissions decreased while the nitrogen oxides (NOX) slightly increased.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.103-110
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• 2015

Nitro-aromatic Compounds (NACs) of explosives are structurally non-degradable materials that have an adverse effect to humans and ecosystems in case of emissions in natural due to the strong toxicity. In this study, batch test in the laboratory-scale has been conducted to find some process parameters of alkaline hydrolysis by considering the characteristics of NACs which are unstable in a base status and field application evaluation have been performed on the batch test results. Based on the experimental results of both laboratory and pilot-scale test, the optimum conditions of parameters for the alkaline hydrolysis of soils contaminated with explosives were pH 12.5, above the solid-liquid ratio 1 : 3, above the room temperature and 30 minute reaction time. In these four process parameters, the most important influencing factor was pH, and the condition of above pH 12.0 was necessary for high contaminated soils (more than 60 mg/kg). In the case of above pH 12.5, the efficiency of alkaline hydrolysis was very high regardless of the concentrations of contaminated soils. At pH 11.5, the removal efficiency of TNT was increased from 76.5% to 97.5% when the temperature in reactor was elevated from room temperature to 80℃. This result shows that it is possible to operate the alkaline hydrolysis at even pH 11.5 due to increased reaction rate depending on temperature adjustment. The results found in above experiments will be able to be used in alkaline hydrolysis for process improvement considering the economy.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.163-170
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• 2016

디젤 자동차의 배기가스 규제는 매년 지속적으로 강화되고 있다. 최근 HC, CO, NOx, PM에 대한 배기 규제는 매우 엄격한 기준을 적용하고 있다. 향후에는, 입자상 물질의 수량규제로 더욱 강화될 것으로 예상되고 있다. 이에 따라, 현재 대부분의 디젤 차량은 PM 저감을 위해 배기후처리징치(DPF)를 적용해 왔다. 엔진의 주행거리가 증가함에 따라, 엔진 배기가스에 포함된 재와 soot이 DPF내부에 축적된다. 축적된 재와 soot은 DPF 손상이나 엔진 성능 악화의 원인이 된다. 그러므로 효율적인 DPF의 클리닝은 엔진관리 측면에서 매우 중요한 부분이다. 만약 엔진이 주기적 클리닝을 통해 관리가 잘 된다면 엔진의 출력과 연비를 개선하고, 유지관리 비용을 절감할 수 있다. 따라서, 본 연구에서는 DPF 내부에 누적된 재와 soot을 효과적으로 클리닝 할 수 있는 고효율 DPF 클리닝 방법 및 장치의 개발을 수행하였고, 그 결과를 제시하였다.

• Journal of Biosystems Engineering
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• 제36권5호
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• pp.303-313
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• 2011

This study was conducted to investigate the effects of axle weight distribution and inflation pressure of tire on the fuel economy of tractors as well as operational range of tractor engine in terms of engine speed and power when a 4WD tractor of 38.2 kW rated power at 2500 rpm is used for plowing and flooded-field rotavating in paddy fields. (1) Plowing operation required an average engine power of 9.6~13.5 kW which equals 25~35% of rated PTO power. Engine speed ranged from 1,320.4 to 1,737.4 rpm, work velocity from 3.4 to 4.8 km/h, and fuel consumption from 3.2 to 4.2 L/h, respectively. (2) Flooded-field rotavating required an average engine power of 11.5~18.5 kW which equals 30~48.4% of rated PTO power. Out of this 6.2~12.2 kW was used for PTO power. Engine speed ranged from 1,557 to 2,067 rpm, work velocity from 2.5~5.4 km/h and fuel consumption from 3.2~5.5 L/h, respectively. (3) Axle weight distribution, inflation pressure of tire and moisture content of soil did not affect significantly the specific volumetric fuel consumption but affected significantly the fuel consumption per unit area of operation. Fuel savings amounted to 65% in plowing operation and 20% in flooded-field rotavating when the axle weight distribution and inflation pressure of tire were optimally adjusted. (4) Optimal adjustment of axle weight distribution and inflation pressure of tire are expected to save fuel consumption by 10~65% per unit area of operation in plowing and 10~20% in flooded-field rotavating.

• 한국콘텐츠학회논문지
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• 제20권5호
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• pp.595-608
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• 2020

이 연구는 노후산업단지를 도시첨단산업단지로 조성하기 위한 계획요소를 도출하기 위해 도시첨단산업단지 조성의 문제점과 혁신체계이론, 외부효과이론을 바탕으로 핵심 계획요인을 선정하고, 델파이 조사를 통하여 최종 입지선정 계획요소를 도출하였다. 연구결과 노후산업단지 재생의 장점을 최대한 활용하여 조성사업의 효율성을 높일 수 있는 효율성 관련 계획요소, 산업단지 분양률과 경쟁력을 강화하기 위한 기업수요 요인 관련 계획요소, 입주기업의 인적자원을 유지하여 지식의 축적과 활용을 촉진하기 위한 근로자 관련 계획 요소, 인접지역과의 연계성 강화를 통한 협력적 관계형성을 위한 계획 요소 등 총 4개 영역에서 19개의 최종 요소가 도출 되었다. 이러한 계획요소들은 도시첨단산업단지 조성의 문제점으로 나타난 분양률 저조와 개발 불균형에 따른 지역 내 갈등 해결 및 지역 혁신체계 구축을 통한 지역 경제 활성화에 도움이 될 것이다.

• 통상정보연구
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• 제11권2호
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• pp.173-201
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• 2009

As a result of overemphasizing the goods sector in trade structure, Korea does not meet properly the global trend which has the key role of 'trade in services' as the service economy have been expanded. Hereafter, it is easily forecasted that trade in services will be one of the main factors for Korea's competitiveness and engine of growth. Nevertheless, because Korea does not equip the concreteness of governance for trade in services, it is possible that the efficiency deterioration of trade volume, confusion of Korea's trade policy, conflict among trading countries, and discordance between the interested parties may be occurred. This paper analyzes the governance system of Korea for trade in services in order to enhance the competitiveness reflecting the importance of trade in services and to draw some strategies for remodeling the service governance system. It is expected to raise the efficiency of Korea's trade policy by constructing the systematic governance for trade in services, and to remove lots of latent risks during global transactions by improving the imbalance between manufacturing and service part for the development of trade in services in Korea. Analysis revealed itself the result that Korea is weak enough to can not identify the governance system about trade in services. Except 'Extent of Services' article of the Foreign Trade Act, Korea has not prepared the governance system for trade in services so that governance system have been scattered overly or decentralized. Problems about trade in services are not limited to enterprise's side, but extended to all the players including government agency whole, academic world and research institute. Therefore, the governance of trade in services should be strengthened and systematized by making the model law for trade in services(provisional name : Master Law for Trade in Services or Promotion Law for Trade in Services) by formatting type of fundamental law or separate legislation. If the bill legislation does not meet the conditions, the Foreign Trade Act should be totally reformed to Omnibus Trade Act concept including trade in services.

• 아태비즈니스연구
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• 제9권2호
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• pp.75-103
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• 2018

The tax system in Korea is the so-called one-item-one-tax law which has separate tax law for each taxation according to tax law. The common and procedural aspects of these tax laws are the same or similar, but they are separately prescribed by the National Tax Basic Act and the Local Tax Act. These legal systems complicate the tax law and increase the cost of tax cooperation, resulting in tax inefficiency. In this study, the National Tax Act and the laws of the Local Tax Act are integrated and presented. It is proposed that the common provisions should be integrated into a single law and the unique matters should be defined in each of the National Tax Basic Act and Local Tax Basic Act, by comparing and analyzing the provisions of the National Tax Basic Act and the Local Tax Basic Act. The integration of the common elements of the National Tax Basic Act and the Local Tax Act is expected to improve tax efficiency by reducing tax complexity and tax cooperation costs. In addition, the National Tax Act and the Local Tax Act are expected to maintain the characteristics of the National Tax Basic Act and the Local Tax Act when they are specified in the National Tax Basic Act and the Local Tax Basic Act. This study is expected to be a research that can reduce tax inefficiency and help convenience of taxpayer and tax administration.

• 대한조선학회논문집
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• 제50권3호
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• pp.145-152
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• 2013

Recently, with oil price jumping and environmental issues, Green ship is paid deep attention to by ship owner, operator, builder, class and government. Fuel efficiency and reduction of $CO_2$ emissions are expected to have a strong influence on the design and operation of merchant ships. Many ship owners and operators are seeking the more economic method by the best operating route and the application of reliable and effective energy saving devices. With the Energy Efficiency Design Index (EEDI) in 2013 attention will more than ever be focused at achieving maximum fuel economy in the hydrodynamic design of hull forms, their appendages and propellers. IMO requirements for $CO_2$ emission for ships will now be implemented for vessels ordered from 1st January 2013. So far, a lot of new idea and patents have been proposed, tested, claimed and applied for various kinds of ship type. This paper shows numerical and experimental work related to a study on a energy saving devices particularly for fuller ship such as merchant vessel of Tanker and Bulker. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction.

• 대한기계학회논문집A
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• 제40권11호
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• pp.963-970
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• 2016

본 연구는 가속페달에 반력을 생성하여 운전자의 경제운전을 유도하기 위한 에코페달의 설계와 성능 검증을 다룬다. 에코페달의 제어로직은 사전에 설정된 "허용가속도"를 바탕으로 현재 속도에서 허용되는 연료소비량을 정하고 이를 실제 연료소비량과 비교하여 에코페달의 작동을 결정하는 방식을 제안하였다. 폐달 반력은 운전자가 충분히 인지하되 불쾌감을 느끼지 않아야 하며, 차량의 정상 거동에 간섭이 없어야 한다. 스텝형과 램프형 반력 등과 같이 페달 답력이 급속하게 증가하는 형태의 반력은 반력 작동이 멈춘 직 후 운전자의 답력에 의한 급작스러운 가속 현상 때문에 적용이 어렵고, 이러한 문제가 없는 진동형 반력을 채택하였다. 진동형 반력의 주파수, 진폭, 작동시간은 운전자의 주관적 평가와 연비 향상 효과를 고려하여 결정하였다. 본 연구에서 제안된 에코페달을 차량에 장착하여 주행시험을 실시한 결과 고속도로와 시내주행에서 각각 13%와 15%의 연비향상 효과를 보여주었다.

• 한국콘텐츠학회논문지
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• 제13권11호
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• pp.433-440
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• 2013

건설CALS시스템은 건설 공사의 기획 설계 시공 단계에서 발생되는 다양한 정보를 발주처와 시공업체에 제공하는 업무지원 시스템으로써 건설CALS포탈, 건설인허가, 건설사업관리, 시설물유지관리, 용지보상인 5개 단위 시스템으로 구성되어있다. 국토교통부 및 관련 연구진들은 CALS시스템의 중장기 운영 전략 수립 및 최신 IT기술 접목과 같은 서비스 개선 방안을 제시하는 등 시스템 활용률을 높이고자 많은 자원을 투자 하였다. 그러나 단위 시스템의 서로 상이한 개발 환경을 고려하지 않은 서비스 개선 방안들이 전체 시스템의 유지관리 및 개발비용을 증가시키고 데이터 처리속도를 감소시키는 원인 중 하나로 파악되었다. 이에 본 연구에서는 단위 시스템의 개발 환경을 통일 시킬 수 있는 전자정부 표준프레임워크를 소개하고 SW개발비용 산정도구인 기능점수(Function Point)를 이용하여 건설CALS시스템에 전자정부 표준 프레임워크의 적용 가능성 및 경제적 효율성을 분석하였다.