• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.79-84
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• 2007

Recently it is strongly required to develop the better fuel economy as well as basic power performance based on strict emission legislation. This paper focuses on studies of the engine cooling and ancillaries system among fuel economy factors in the developing stage. Firstly through the analysis of the current specifications, it is assessed whether each components may be designed properly, not overdesigned. Secondly, it is predicted how the fuel economy of each components can be improved. Finally the results are confirmed by vehicle field test equppted with the updatedcomponents. This study found good agreementbetween the prediction and the field test on the vehicle fuel economy improvements of the heavy duty engine vehicle with updated components such as engine cooling and ancilliaries.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.193-193
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• 2018

현재 우리나라는 레저선박 및 중소형 선박, 연안소형어선에 대부분 사용되는 재질은 강도가 높고 내양품성이 우수한 FRP를 사용하고 있다. 하지만 FRP선박의 폐선 시 환경문제와 자원재활용, 선체중량에 연비 및 대기오염등에 의해 소형선박 중심으로 알루미늄선 전환이 이루어지고 있다. 본 연구에서는 알루미늄 선체가 적용된 멀티하우스보트에 알루미늄선 구조기준에 따른 슬래밍하중을 적용하여 구조 강도평가를 실시하였으며, 그 결과를 통해 각 부재별 민감도 평가를 수행하여 알루미늄 구조강도기준을 만족함과 동시에 중량 저감을 하여 실제 선박설계에 적용시키고자 한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.92-99
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• 2013

High oil price and global warming problem are being continued all over the world. For this reason, fuel economy and emission of greenhouse gas are regulated by law in many countries. Therefore many companies are researching and producing hybrid electric vehicles (HEVs) which substitute conventional internal combustion engine vehicle. However, these researches and productions are restricted to mainly passenger cars. Because of cost and physical problems, commercial vehicles are difficult to evaluate fuel economy. So simulations are important and it is necessary to know how sensitive parameters that enter into simulation affect. In this paper, forward simulations using AVL Cruise were conducted for analysis of fuel economy for parallel hybrid bus and were repeated by changing each parameter. Based on these results, root mean square errors (RMSE) are calculated for analysis of fuel economy sensitivity. The number of target parameters are 15. These parameters were classified with high and low sensitivity parameter relatively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.2
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• pp.135-141
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• 2001

차량 충돌시 자동차의 시트는 승객 및 운전자를 보호해야 한다. 따라서 자동차시트는 충분한 강도를 가져야 하며 이것은 여러 가지 법규에 의해서 제재되고 있다. 물리적 실험 결과가 법규에 정한 규정치를 만족시키기 위해 과대설계 될 수 있다. 그러나 이것은 연비를 줄이기 위한 경량화의 만족이라는 설계요구에 상충한다. 본 논문에서는 헤드레스트 강도시험을 시뮬레이션하고 과대 설계되어 있다고 판단되는 어퍼암을 최적화 모델로 최적설계를 수행하였다. 순차 이차 계획법인 PLBA 알고리즘과 민감도 해석을 위하여 직접근사해석법을 사용하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.689-694
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• 2018

Recently, fuel consumption efficiency has become the most important issue in the vehicle development process due to the problem of environmental pollution. The air flow patterns of the vehicle body line and rear part are the most important elements affecting the fuel consumption efficiency. Especially, the airflow pattern of the vehicle rear part is the most important design factor to be considered in rear spoiler design. In this paper, the control factors affecting the airflow of the rear spoiler are determined, the airflow sensitivity of these control factors are tested and, then, the optimized control factors to reduce the airflow drag force are proposed. The model of optimized control factors is tested and the values of the optimized control factors are changed by analyzing the S/N ratio and mean value. Finally, the new modified model incorporating the optimized control factors is tested in an air flow tunnel and its ability to decrease the air drag and reduce the cost is verified.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.244-244
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• 2017

Recently, A study is actively underway to apply to various industries, which are one of the major changes in the key drivers of the industry 4.0.. The data generated by the ship include various indicators such as the fuel volume, engine power, ground speed, speed, speed, main engine rpm, DFOC, SFOC, and FOC. This paper analyzes the sensitivity of the Gathering data and analyzes the impact energy efficiency of the vessel operation by analyzing the influence among each parameter, using the mathematical models, you create an surrogate model using the math model, comparative analysis of actual measurement data and predictive results were analyzed. Through the use of big data analysis technology, it is possible to identify the sensitivity between the energy efficiency related variables of the ship, The possibility of utilization of fuel efficiency indicators using of the surrogate model is identified.

• Environmental and Resource Economics Review
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• v.23 no.2
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• pp.281-304
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• 2014

This research presents that exogenous characteristics of consumers affect eco-friendly vehicle preference. The car consumers are classifies into two groups by their characteristics - sex, age, and fuel expense. To find differences in the preference for eco-friendly vehicle, marginal utilities and compensate variations of vehicle attributes are estimated. The results suggest that there are significant differences in marginal utilities and compensate variations. However, the compensate variation is more reliable standard to test the preference differences because utility is a subjective measure. Men and old people have stronger preference for the fuel efficiency than women and young people. High fuel expense people have more preference for short time charging vehicles than low fuel expense people. In addition, gasoline vehicles are more attractive to young people than old people.

• Journal of IKEEE
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• v.21 no.3
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• pp.174-184
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• 2017

This paper proposes a torque predictive control for dynamic performance improvement of clamping force in electro-mechanical brake (EMB) for railroad cars. In general, pneumatic braking system (PBS) is used for railroad cars. It is sensitive depending on environmental changes and it has increasing idle running time because of slow dynamic response. Additionally, the PBS has low braking efficiency in case braking torque more than standard value is applied to the brake system such as emergency braking. In order to overcome these disadvantages of the PBS, the EMB is used for the railroad cars. The EMB for railroad cars has advantages that increasing the fuel efficiency and design flexibility because it is able to decrease vehicle weight of railroad cars and secure space for design. In this paper, control method for dynamic performance improvement of clamping force in EMB for railroad car is proposed. The effectiveness of the proposed control method is verified by the simulation results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.54-68
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• 2015

The advantage of electric taxies is that people who are not familiar with electric vehicle(EV) can have easily experience to ride EV. So, EV taxi would be a reasonable strategy for triggering EV market expansion. However, the EV taxi can be adopted by taxi companies with financial benefits. Therefore the feasibility study should be required by analyzing the cost with the points of view of the taxi company. In this study we suggested the methodology for feasibility study of the EV taxi based on the real taxi data and presented political implication. According to the study result, EV taxies could have economic value under the specific conditions such that the government subsidy is added to the purchase price of the vehicle. Also, the charging time should be used as drivers' rest time or mealtime in order not to consider the loss cost. We suggest that the new feasibility study which compares an EV taxi with other alternative vehicles such as PHEV or with an old EV taxi is needed as the future works.