• Advances in Energy Research
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• 제8권3호
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• pp.145-153
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• 2022

Recent concerns about rising fuel prices and greenhouse gas emissions have focused attention on alternative energy sources, particularly in the transport sector. Transportation consumes 40% of overall fuel usage. As a result, a growing majority of researches on Electric Vehicles (EVs) and their Energy Management Systems (EMS) have been done. In order to enhance the performance and to meet the needs of drivers, more information regarding the EMS is needed. A new Energy Management System is proposed using a FOPID controller. To put the concept into practice, state equations are utilised. The fifth-order state-space model under study is a linked model with several inputs and outputs and the transfer matrices are calculated for decoupling the system. Utilizing these transfer matrices to decouple the system and FOPID controller is used to tune the system. The tuned parameters are minimized using a Particle Swarm Optimization (PSO) approach with Integral Time Absolute Error (ITAE) as the goal. When the suggested FOPID system's results are compared to those of PID-controlled systems, a sizable improvement is observed, which is explained by the results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2015-2020
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• 2007

Diesel is an excellent candidate fuel for fuel cell applications due to its high hydrogen density and well-established infrastructure. But, it is hard to guarantee desirable performance of diesel reformer because diesel reforming has several problems such as sulfur poisoning of catalyst and carbon deposition. We have been focusing on diesel autothermal reforming(ATR) for substantial period. It is reported that ATR of diesel has several technical advantages such as relatively high efficiency and fuel conversion compared to steam reforming(SR) and partial oxidation(POX). In this paper, we investigate characteristics of diesel reforming under various ratios of reactants(oxygen to carbon ratio, steam to carbon ratio) for improvement of reforming performances(high reforming efficiency, high fuel conversion, low carbon deposition). We also exhibit calculated heat balance of autothermal reformer at each condition to help thermal management of SOFC system.

• 동력기계공학회지
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• 제17권6호
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• pp.5-10
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• 2013

Diesel engines have the advantages of good fuel efficiency and low emissions. Therefore, car makers have been developed various kinds of diesel engine management system to clean up emissions while improving fuel efficiency. One of them is the common rail system. In the common rail system, diesel fuel is injected into the combustion chamber at ultra high pressures up to 1,800 bar to ensure more complete combustion for cleaner exhaust gas, and highly precise multiple injection reduces NOx emission, combustion noise and vibration. Generally speaking, common rail system consists of booster pump, high pressure pump, common rail, injectors, control valves, and sensors. The high pressure pump receives low pressure fuel from the booster pump and supply high pressure fuel to injectors through the high pressure common injection rail. Therefore, high pressure pump has an important role in common rail system. In this paper, we have investigated the performance of high pressure pump of common rail system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3001-3006
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• 2008

Recently, the internal combustion engines have focused on reducing both the CO2 emissions in order to cope with severe regulations for greenhouse effect. Therefore, various new technologies have been developed in many countries. Among them, the cooling system is spotlighted because it has great effect on fuel efficiency. However, the present engine cooling system is almost same as one of the 50 years ago. The needs for high performance and compact size make it important to improve engine cooling system, down-sizing and control method of coolant flow. Thus, low fuel consumption technology such as control and synthetic management of cooling system was necessary to satisfy with these needs. In this study, we applied electric thermostat to improve the fuel economy. The fuel consumption was compared after driving FTP-75 mode on both conditions which were with a conventional wax thermostat and with a electric thermostat. The coolant temperature of opening the electric thermostat is higher.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.497-505
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• 2021

Water management is essential to improve the performance of proton exchange membrane fuel cells. This study targets to understand the characteristics of water concentration in proton exchange membrane fuel cells at a dynamic load variable environment. The fuel cell model was developed to simulate nonlinear water transport in membrane by the MATLAB/Simulink^® (MathWorks, Natick, MA, USA) platform, and it calculates water content in membrane, ionic conductivity, and predicts fuel cell performance through one-dimensional analysis.

• 유기물자원화
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• 제28권3호
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• pp.45-49
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• 2020

본 연구는 하수슬러지와 건조연료를 혼합한 혼합물에 대해 토지개량효과를 검토하기 위한 연구이다. 혼합물은 하수슬러지와 건조연료를 중량대비 1:1 비율로 혼합하여 만들었다. 1개의 대조군(0 %)부지와 혼합물을 10 %, 20 %, 30 % 시비한 3개의 비교군을 조성하였다. 토양의 유효인산 함량변화는 혼합물을 시비한 비율에 따라 상관관계가 높은 것으로 확인되었다(P<0.05). 케나프를 90일 재배 후 수확량을 비교한 결과 10 %투입된 배지에서 줄기의 길이가 대조군 대비 73 %증가를 보였으며, 잎 수확량의 경우 20 %배지에서 227 % 가장 높은 증가율을 보였다. 30 %에서는 다른 배지보다 꽃의 개화가 먼저 된 것으로 보아 성장률이 다른 배지보다 빠른 것으로 판단되며 엽록소 함량은 71.6(SPAD)으로 가장 높은 수치를 보여 조단백질의 함량이 다른 배지에 비해 높을 것으로 판단된다. 따라서 건조연료 혼합물의 투입을 통해 전체적으로 식물이 생육하기 좋은 토질로 개선하는데 효과가 있는 것으로 사료된다.

• 한국대기환경학회지
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• 제22권1호
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• pp.127-134
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• 2006

In Korea, the number of recreational vehicle (RV) has been increased dramatically recent year. Now there are emission regulations for RV which include pollutants such as CO, HC, NOx, PM. However considering the trend of preferring RV, there needs more strict strategies to control emissions from this type of vehicle. For that reason, we studied emission characteristics of RV and provided basic emission data to evaluate the contribution of RV to the total air pollutant emissions and to establish RV emission management plan. A total of 21 RV were tested on the chassis dynamometer system ranging from small to large engine displacement by vehicle speed, fuel types, regulations and fuel efficiency in order to investigate the characteristics of CO, HC, NOx and PM. For the test modes, 10 different driving speed modes and CVS-75 mode were used. On the basis of this study, RV pollutants emission factors and management strategies will be proposed.

• 한국생산제조학회지
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• 제22권6호
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• pp.908-912
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• 2013

Because of their longer operating times and larger size relative to conventional fans, the cooling fans mounted in buses consume larger amounts of energy. Most of the cooling fans mounted in a bus are connected to the engine by a viscous clutch. A viscous cooling fan's speed is determined by its fluid temperature, which is affected by the air flow through the radiator. The fan does not react immediately to the coolant temperature and in doing so causes unnecessary energy consumption. Therefore, the fuel economy of buses using viscous fans can be improved by changing to an electric cooling fan design, which can be actively controlled. In addition, electric power consumption is increased by using electric cooling fans. Thus, when electric fans are applied in conjunction with the alternator management system (AMS), the fuel economy is further enhanced. In this study, simulations were performed to predict coolant temperature and cooling fan speeds. Simulations were performed for both viscous and electric cooling fans, and power consumption was calculated. Additionally, fuel economy was calculated applying both the alternator management system and the electric cooling fan.

• 한국수소및신에너지학회논문집
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• 제19권4호
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• pp.313-321
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• 2008

Dynamics of the proton exchange membrane fuel cell is specially important when the system is frequently working on transient conditions. Even though the dynamics of proton exchange membrane fuel cell for residential power generation is less critical than that of PEMFC for transportation application, the system dynamics of PEMFC for RPG can be very important for daily start-up and stop. In particular, thermal management of the PEMFC for RPG is very important because the heat generation from electrochemical reaction is delivered to the home for hot water usages. Additionally, the thermal management is also very important for heat balance of the system and temperature control of the fuel cell. The objective of this study is to develop a dynamic system model for the study of PEMFC performance over various BOP options. Basic simulation results will be presented.

• 한국컴퓨터정보학회논문지
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• 제19권2호
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• pp.233-241
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• 2014

본 논문에서는 "Co-word" 특허분석방법과 "기술로드맵(technique road-map)" 그리고 특허활성화 라이프 사이클그래프 및 추세분석을 활용하여 ITS(Intelligent Transportation System)의 미래녹색기술에 대해 예측한다. 분석 결과 미래의 ITS 녹색 기술 분야의 발달로 탄소배출 절감 효과가 발생하기 때문에 환경 보호에 도움을 줄 것으로 예측 되었으며, 미래의 ITS 녹색 기술은 fuel saving 분야에 대한 성장이 클 것으로 예상되었다. 또한 fuel saving 분야는 미래의 IT 기술과의 융합으로 인해 더욱 실용적인 기술 분야로 발전할 수 있을 것으로 예측 되었다.