• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 2010년도 춘계학술대회
• /
• pp.465-470
• /
• 2010

Korea government declared that "low carbon, green growth" through green technologies and clean energy to be the new national vision for the next 60 years(President's Liberation Day speech on Aug. 15, 2008). And succeeding "Green New Deal" plan involves nine core projects including energy saving, recycling, clean energy development. It is because hydrogen fuel cell vehicles, using electricity from chemical reaction of hydrogen and oxygen, let out water which is a by-product of such chemical reaction instead of emitting harmful particulate and gases such as NOX, SOX and CO2 that hydrogen fuel cell vehicles and its technology are drawing public attention as one of the sensible solutions in accomplishing "low carbon, green growth" agenda. Nevertheless There are many chances that let the people have a practical experience of hydrogen fuel cell vehicles. Sometimes new products, including hydrogen fuel cell vehicles, made by advanced technology can not penetrate through the market when it faces public skepticism that is stimulated from lack of knowledge and experience. That is the reason why not only cost benefit analyses and scientific risk assessments but also public acceptance studies toward hydrogen fuel cell vehicles have to be performed [Schulte, 2004]. This research address a need for comprehensive study on factors influencing public acceptance of hydrogen fuel cell car, specifically focusing on impacts of personal experience related to governmental science and technology policy toward public acceptance.

• 수산해양기술연구
• /
• 제51권3호
• /
• pp.321-332
• /
• 2015

In an attempt to find the improvement of the fishing efficiency according to the hull form remodeling for the 3 tuna purse seiner, the Catch-Per-Unit-Effort (CPUE) for that undertaken before (2008) and after (2010) was analyzed. In addition, the CPUE of 6 similar ships operated same period and same fishing ground. As result, it came to verify that the three modified ships had a significant value on the CPUE. An another index for the improvement of fishing efficiency is the rate of reduction of fuel oil consumption for the modified ships. Fuel oil consumption per day in service speed as comparing with the original ships were reduced 2.1%, 4.0% and 5.1% on the modified ship A, B, and C respectively. And each ship's service speed was increased 1.0 kt, 0.6 kt, and 0.4 kt according to the modified ship A, B, and C in due order. In the conclusion, the remodeling job with newly equipped bulbous bow, lengthened slipway and enlarged rudder area were improved fairly much on fuel oil efficiency, the ship's speed, and in the end, that led to the improving fishing efficiency. Hence, the remodeling of tuna purse seiner come to improve not only the fishing performance, but contribute to the reduction of operating cost by saving energy for the fisheries industry.

• 한국항해항만학회지
• /
• 제40권4호
• /
• pp.165-171
• /
• 2016

IMO에서는 선박온실가스 규제를 위해 2013년부터 현존선의 선박에너지효율관리계획인 SEEMP (Ship Energy Efficiency Management Plan)의 시행을 강제화하고 있다. SEEMP에서 권고하는 에너지절감기술 가이드라인은 크게 하드웨어적인 장비의 탑재 및 개조 또는 소프트웨어적인 기술을 통한 연료유 절감효과로 구분된다. 신조선의 경우 하드웨어적인 기술구현이 용이하지만 현존선의 경우 운항상 제약으로 인해 소프트웨어적인 에너지 절감기술 구현이 적용되고 있다. IT기반의 선박에너지절감 시스템 성능평가를 위해 해상시험을 수행하였고, 시스템 적용 전후의 항차데이터를 이용하여 연료유 절감효과를 비교 분석 하였다. 또한, SEEMP에서 자발적인 사용을 권고하고 있는 선박 경제운항 지표 (EEOI, Ship Energy Efficiency Operation Indicator) 분석을 통한 성능평가 결과를 제시하였다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2002년도 춘계학술대회 논문집
• /
• pp.149-153
• /
• 2002

The commutator of an automotive fuel pump motorhas been produced through various processes such as forging, segmenting, and assembling. And the conventional method producing the commutator of an automotive fuel pump motor is not appropriate for saving material and cost, because it makes each segment separated one by one. Therefore a new process design is required in order to avoid the assembling process. In this study, a new process design of the commutator has been carried out to save material and manufacturing time by FE analysis. In the FE analysis, three forging processes are proposed for producing copper(ASTM C11000) commutator of an automotive fuel pump motor. And forging experiments are performed to make an unsegmented commutator in order to verify the theoretically proposed process. And then, in order to get the final product the forged commutator is passed through various postprocessing such as machining, bending, resin forming, and shearing process. From the experimental result the forging process proposed from the FE analysis is verified to be an economical method for producing the commutator for an automotive fuel pump motor.

• 전력전자학회논문지
• /
• 제24권1호
• /
• pp.40-48
• /
• 2019

Hybrid electric propulsion systems (H-EPSs) are an intermediate step for integrated full electric propulsion warships. H-EPSs are a dynamic combination of mechanical and electrical propulsion systems to achieve the required mission performances. The system modes could adapt to meet the requirement of the various operation conditions of a warship. This paper presents a configuration and operating modes of H-EPSs considering the operation conditions of a destroyer class warship. The system has three propulsion modes, namely, motoring mode, generating mode [power take off (PTO) mode], and mechanical mode. The PTO mode requires a careful fuel efficiency analysis because the fuel consumption rate of propulsion engines may be low compared with the generator's engines depending on the loading power. Therefore, the calculation of fuel consumption according to the operating modes is performed in this study. Although the economics of the PTO mode depends on system cases, it has an advantage in that it ensures the reliability of electric power in case of blackout or minimum generator operation.

• 한국수소및신에너지학회논문집
• /
• 제25권3호
• /
• pp.311-318
• /
• 2014

Performance degradation of a battery in 20 kWh energy storage system (ESS) under various operating conditions was studied. And energy saving of the ESS was also monitored by connecting with 20 kW photovoltaic (PV). PV-connected ESS saved 5~7% of energy consumption in 2013 compared to that without such system in 2012. As charge-discharge cycle increased, capacity decreased and the performance degradation was glaringly obvious after 40 cycles. And as charge and discharge rate increased, the performance degradation was more serious. After 50 charge-discharge cycles, a lot of degraded product was deposited on the surface of anode and cathode electrodes, and the cathode side was more contaminated. Therefore, in order to maintain the cell performance, it was more important to protect the degradation of the cathode side.

• 한국항해항만학회지
• /
• 제37권2호
• /
• pp.137-142
• /
• 2013

The displacement Deep-V catamaran concept was developed in Newcastle University(UNEW) through development of the systematic Deep-V catamaran series. One of the most important Deep-V catamaran launched to date is Newcastle University's own multi-purpose research vessel, The Princess Royal. The vessel was launched in 2011 and enhanced the Deep-V catamaran concept further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. It was however identified that the vessel has substantial amount of dynamic trim that limited the visibility of the captain. The dynamic trim also increased the wave-making resistance thereby preventing the vessel from attaining its maximum speed in certain sea states. This paper therefore presents the application of devices such as Trim Tabs, Interceptors, Transom Wedges and Integrated Transom Wedges-Tabs to control the dynamic trim and improvement of fuel efficiency of the vessel. All of these energy saving devices were fitted into a model for tests in Newcastle University's Towing Tank. Model test verification confirmed that the optimum appendage was the interceptors, they produced a 5% power saving and 1.2 degree trim reduction at 15 knots, and investigations of full scale trials will be scheduled with and without application of device to compare the improvement of performance.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권8호
• /
• pp.1157-1163
• /
• 2008

Fuel represents a significant portion of the operating costs of voyages of the vessel. Under this situation, dramatic increase in fuel price caused a problem that earnings of ship becomes decreased seriously. Pumps in a cooling system of the vessel are often operated inefficiently. The reasons will vary from process to process and application to application. Inefficiency of pumps is one of the reason for making the cost of operating the vessel increased. This paper suggests energy-effective cooling system that controls sea water pumps with inverters to reduce energy consumption in vessel by conducting simulation with LabVIEW. Results shows that electric energy consumption of pumps are significantly deceased. If this energy-effective cooling system is applied to other systems which need cooling, it could be useful in reducing electric energy wastage.

• International Journal of Automotive Technology
• /
• 제8권6호
• /
• pp.791-798
• /
• 2007

The hydraulic hybrid vehicle(HHV) is an application of hydrostatic transmission technology to improve vehicle fuel economy and emissions. A relatively lower energy density of hydraulic accumulator and complicated coordinating operations between two power sources require a special energy management strategy to maximize the fuel saving potential. This paper presents a new type of configuration for parallel HHV to minimize the disadvantages of the hydraulic accumulator, as well as a methodology for developing an energy management strategy tailored specially for PHHV. Based on an analysis of the optimal energy distribution between two power sources over a representative urban driving cycle with a Dynamic Programming(DP) algorithm, a fuzzy-based optimal torque management strategy is designed and developed to control the torque distribution. Simulation results demonstrates that the optimal torque management strategy maximizes the advantages of this hybrid type of configuration, and the high power density characteristics of hydraulic technology effectively improve the robustness of the energy management strategy and fuel economy of the PHHV.

• 한국안전학회지
• /
• 제30권6호
• /
• pp.132-138
• /
• 2015

This study examined the relative effects of feedback frequency and specificity of Eco-IVIS(eco in-vehicle information system) on the fuel-efficiency and workload. Eighty participants randomly assigned into four experimental groups (high frequency/specific, high frequency/global, low frequency/specific, and low frequency/global feedback) and they drove 16.4Km motorway under the each feedback condition. The dependent variable were fuel efficiency and Drive Activity Load Index which measured participants' subjective ratings of driving workload. The results showed that high frequent feedback was more effective for increasing fuel-efficiency than low frequent feedback, however, there was no significant difference of fuel-efficiency between specific and global feedback. Although, overall DALI score was comparable among four experimental conditions, visual demand score was significant higher under the high frequent feedback condition than low frequent feedback.