• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.211-216
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• 2015

Large hydraulic excavator weighted 90 tons used the several pumps installed in parallel to use the hydraulic pump driving gearbox to improve fuel consumption by improving the energy efficiency of the hydraulic system. Gearbox connected to hydraulic pump supply the mechanical output to the high pressure and low pressure pump to be supplied by torque and rotation, which are the mechanical power, through a input shaft connected to large size engine of the excavator. So, gearbox connected to hydraulic pump is same as main artery in the human body and is required long life because it operates the hydraulic pump continuously during operating the engine. This study had used oil contamination analysis method to check the wear characteristics of the gearbox and frequency response characteristic analysis method to check the failure of the teeth failures of gearbox, while the test equipment adopted by the electrical feedback method to reduce the energy consumption was operating for the life assessment, in which the required power was 600 kW input power.

• Tribology and Lubricants
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• v.30 no.3
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• pp.189-198
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• 2014

This paper presents the results of an experimental investigation of the correlation between the lubrication characteristics of an engine and its fuel economy. Improving the lubrication characteristics of the engine oil is one of the most efficient ways to improve a car's fuel economy. The methods to accomplish this include lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver. In addition, it is necessary to use different methods to reduce the friction to individual lubrication areas, because different lubrication regimes are used for different engine parts. The experimental investigation in this study is based on design of experiments ; this paper presents the results of a modified Sequence VID test, which is an ASTM standard test used to measure the effects of automotive engine oils on the fuel economy of passenger cars. The results demonstrate the effects of the following lubrication factors on the fuel economy : the low temperature cranking viscosity, high-temperature high shear (HTHS) viscosity, friction modifier, polymer type and shear stability index of the viscosity index improver. Moreover, this study involves an analysis of variance based on design of experiments. The test results show that the HTHS viscosity, friction modifier and shear stability index of the viscosity index improver are more effective than the other factors. Therefore, lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver should be considered to improve fuel economy.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.49-54
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• 2018

The common rail diesel engine used in this study is a remanufactured waste engine. The fuel injection timing of the waste engine is set to be suitable for the operating conditions of the vehicle. However, the engine of a generator is operated at a constant speed and mainly at partial load. Therefore, it is necessary to change the fuel injection timing suitable for the power generation engine, and the cost and the time required for such change must be minimized as much as possible. As a result of the analysis, it was confirmed that the fuel efficiency improves according to the fuel injection timing suitable for the engine for the generator, thereby increasing the performance and fuel efficiency.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.10-15
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• 2009

Emission regulations on greenhouse gas(GHG) in automobiles have been stringent because of global warming effect. Over 90% of total GHG emission are carbon dioxides and about 20% of this $CO_2$ emission are emitted from automobiles. In this study, 110 vehicles were tested on a chassis dynamometer and $CO_2$ emissions and fuel economy were measured in order to investigate the characteristics of $CO_2$ emission factor from passenger vehicles which are the most dominant vehicle type in Korea. The characteristics of emissions in accordance with displacements, gross vehicle weight, NIER and CVS-75 speed mode were discussed. It was found that vehicles having larger displacement, heavier gross vehicle weight, automatic transmission and specially at cold start emitted more $CO_2$ emissions. From these results, correlation between $CO_2$ emission and fuel economy was also obtained. This study may contribute to evaluate domestic greenhouse gas emissions and establish national policies on climate changes in future.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.395-402
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• 2019

The development and operation of the MASS (Maritime Autonomous Surface Ship) is being actively discussed for more efficient and safer maritime transportation solutions. The autonomous navigation technology has positive aspects such as the prevention of marine accidents, improvement of fuel efficiency of ships and cost reduction, and negative aspects such as job loss, task change, and security problems. It is expected that there will be new human element issues such as the situation awareness of remote operators, because the shore-based control will be conducted when fully autonomous ships are in operation. In this paper, we consider major human element issues that should be factored in the development and operation of MASS, and suggest a method of HRA (Human Reliability Analysis) for P IFs (Performance Influencing Factors) of the remote operators that are expected according to the shore-based control.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.983-989
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• 2014

In this paper, a new active noise control method was proposed to decrease a weight of car, and to increase a fuel efficiency and to provide passengers' comfort and calmness, instead of a passive noise control method such as sound absorbing and insulating materials. The proposed method is an enhanced active noise controller operating by a bidirectional control algorithm. The algorithm is simple to implement and available to analyze mathematically with nearly equivalent complexity of computation. Through simulations for engine noises of a car, the proposed controller was verified that its performances of time and frequency domain were superior to those of both feedforward and feedback controllers, and it had better capability of controlling the noises when the impulsive disturbance was flow in and the response of secondary path was varied.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.157-163
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• 2020

Recently, fine dust has been known to cause cardiovascular diseases here, raising interest in ways to reduce emissions by efficiently using fuel from cars that cause air pollution. Accordingly, a driving assistance system was developed to save fuel by eco-driving and improve the driver's bad driving habits. The system was developed using raspberry pi, arduino and Android. Using RPM, speed, fuel injection information obtained from OBD-II, and gyro-sensor values, Fuel-Cut is induced to create an optimal inertial driving environment. It also provides various information system such as weather, driving environment, and preventing drowsy driving through GUI and voice recognition functions. It is possible to check driving records and vehicle fault information using Android application and has low overhead for message transmission using MQTT protocol optimized for IoT environment.

• Environmental and Resource Economics Review
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• v.21 no.2
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• pp.237-269
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• 2012

This study applies a discrete-continuous choice model to a national survey data set of automobile uses to investigate the potential impacts of a bonus-malus system for new cars in Korea. Not only the impacts on the discrete choice of automobile type and class but also those on the continuous decision making of car operation are analyzed. The characteristics of automobiles and individuals that determine car choice and operation are identified. The simulation based on the estimation result shows that an appropriately designed bonus-malus system can induce a reduction in energy consumption and $CO_2$ emission substantially without additional government expenditure.

• New & Renewable Energy
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• v.3 no.2 s.10
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• pp.31-39
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• 2007

화석연료의 사용으로 인한 자원고갈과 지구온난화 영향 그리고 에너지 안보문제의 해결을 위해 세계 각국들은 대체에너지 개발에 많은 노력을 기울이고 있다. 그 중 수소는 다양한 경로를 통해 생산 가능하고, 수송연료로 사용 시, 유해 물질이 거의 배출되지 않는다는 장점 때문에 가장 주목받는 대체 에너지원이다. 현재는 수소생산 기술개발을 통해 상업화시기를 앞당기려고 하는 수소에너지 시대의 진입시점이라 할 수 있다. 그러나 수소는 생산경로에 따라 다양한 환경성 및 경제성 결과를 도출 할 수 있기 때문에 다양한 평가가 요구된다. 본 연구에서는 국내 수소생산 방식으로 개발/상용화되어있는 Natural Gas Steam Reforming (NGSR), Naphtha Steam Reforming (Naphtha SR), Water Electrolysis (WE)에 대하여, Life Cycle Assessment (LCA)와 Life Cycle Costing Analysis (LCCA) 방법을 사용하여, 수소경로 전반에 대한 즉, 원료채취부터 자동차로 주행하였을 때까지의 각 대상 수소경로의 환경성과 경제성을 평가하였다. LCA와 LCCA 결과는 Naphtha SR과 NGSR 수소경로에서 지구온난화와 화석자원 소모 부문 모두 기존연료 (가솔린, 디젤)와 비교해서 개선효과가 뚜렷하게 나타났으나, WE 수소경로는 오히려 환경부하가 증가되는 것으로 나타났다. 또한 경제성 측면에서는, 수소 판매 시 가솔린과 동일한 연료세율을 부과하더라도 수소가 가솔린에 비해 가격경쟁력을 확보하게 되는데, 이는 주행 시 수소자동차의 연비가 기존 차량에 비해 월등히 좋기 때문에 연료비용의 이점 때문이다. 만약, 수소에 연료세를 부과하지 않는 다면, Naphtha SR로 생산하여 유통한 수소가 수송연료로서 가장 뛰어난 비용효율성을 갖는 것으로 나타났다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2446-2452
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• 2012

In order to meet the recently enhanced emission standards at home and abroad, it is necessary to develop the CRDI ECU control algorithm that users can adjust fuel injection timing and amount in response to their needs. Therefore, this study developed the simulator for knocking analysis that enables knocking discrimination and engine balance correction applicable to the ECU exclusive to the industrial CRDI engine. The purpose of this study is to provide the driver-oriented diagnostic service that enable drivers to diagnose vehicles directly by developing diagnostic devices for vehicles with ths use of the results of the developed simulator for knocing analysis according to the OBD-II standards. For this purpose, this study aims to improve the fuel efficiency of vehicles by proposing the S/W design method of the OBD-II diagnosis device that can provide real-time communcations with the use of wired system and bluetooth module as a wireless system to send and recevice automobile fault diagnosis signal and sensor output signal, and to suggest an improvement for engine efficiency by minimizing the generation of harmful exhaust gas.