• 한국기계가공학회지
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• 제19권2호
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• pp.97-102
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• 2020

To prevent vibration of a vehicle's interior parts due to external impacts, the vehicle should be designed to reduce vibration and increase rigidity. In this paper, we conducted a vehicle test in which the vibration characteristics of a seatbelt resulting from the impact of a person closing a car door were measured and analyzed. A correlation analysis was performed using the finite analysis method. Based on this, a sensitivity analysis was performed, and an improved model was designed. We compared the natural frequencies and mode shapes of the improved and the initial models, which confirmed that the natural frequency of the improved model was more than 10 Hz higher than that of the initial model. Moreover, the response frequency of the improved model was three times higher than the input frequency applied in the vehicle test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.735-741
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• 2011

In the early phase of vehicle development, CAE is conducted as tool for vehicle performance assessment. To maintain acceptable road noise performance, solution for reduced vehicle sensitivity is required. Chassis interface dynamic stiffness characteristics are key component to isolating vibration and noise of road from the vehicle interior. This research provide how to set up the optimized dynamic characteristics under noise effect through DFSS study. CAE-based DOE is performed to build prediction math model, CMS process involves DOE to achieve very fast run times while giving results very comparable. Minimized $95^{th}$ percentile of performance distribution is applied to minimize vehicle sensitivity and road noise levels variation during the optimization process. Finally, the results of optimization were reviewed for performance and robustness.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.451-459
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• 2018

This work presents an approach for modeling of electric vehicle considering the vehicle dynamics, drive train, rotational wheel and load dynamics. The system is composed of IPMSM (Interior Permanent Magnet Synchronous Motor) coupled with the wheels through a drive train. Generally, IPMSM is controlled by ordinary PID controllers. Performance of the ordinary PID controller is not satisfactory owing to the difficulties of optimal gain selections. To overcome this problem, a new type of fuzzy logic gain tuner for PID controllers of IPMSM is required. Therefore, in this paper fuzzy logic based gain tuning method for PID controller is proposed and compared with some previous control techniques for the better performance of electric vehicle with an optimal balance of acceleration, speed, travelling range, improved controller quality and response. The model was developed in MATLAB/Simulink, simulations were carried out and results were observed. The simulation results have proved that the proposed control system works well to remove the transient oscillations and assure better system response in all conditions.

• 한국소음진동공학회논문집
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• 제21권7호
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• pp.674-681
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• 2011

In the early phase of vehicle development, CAE is conducted as tool for vehicle performance assessment. To maintain acceptable road noise performance, solution for reduced vehicle sensitivity is required. Chassis interface dynamic stiffness characteristics are key component to isolating vibration and noise of road from the vehicle interior. This research provide how to set up the optimized dynamic characteristics under noise effect through DFSS study. CAE-based DOE is performed to build prediction math model, CMS process involves DOE to achieve very fast run times while giving results very comparable. Minimized 95th percentile of performance distribution is applied to minimize vehicle sensitivity and road noise levels variation during the optimization process. Finally, the results of optimization were reviewed for performance and robustness.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1993년도 추계학술대회논문집
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• pp.243-251
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• 1993

With the recent issuance of a dynamic side impact test regulation in the Federal Motor Vehicle Safety Standard in the United States of America, many aspects of occupant protection in side impact crashes have been under investigation. Many investigations of real world accidents, crash test results and simulation studies have established that in side impact crashes of passenger cars, thoracic and pelvic injuries of occupant are, large part, caused by occupants' impact against the interior side of the vehicle, primarily the door. This paper is concerned with the development of a lumped mass computer model, which simulates the interaction of a struck car door and an adjacent seated occupant in side impacr, based CTP code which has been successfully used in vehicle and occupant simulation. New model developments include elimination of influence of vehicle side structure stiffness in the occupant injury responses. The model was used to investigated the effect of various door padding characteristics on occupant responses to improve vehicle safety performance. The evaluation of different crush properties of door padding have also focused to understand of behavior of impacted occupant. Results from simulations, The effects of both material coefficients $C_{f}$ and p were illustrated in terms of occupant injury criteria TTI and pelvis.

• 대한기계학회논문집A
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• 제40권2호
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• pp.229-236
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• 2016

본 연구에서는 자주박격포의 다물체동역학 모델을 만든 뒤, 포탄의 탄도학을 고려하여 시뮬레이션 하였다. 자주박격포 모델은 박격포 모델 및 차량 모델로 구성하였으며, 상용 다물체 해석 프로그램인 RecurDyn 을 사용하였다. 차량 모델은 6 자유도 강체플랫폼으로 모델링 하였으며, 박격포 발사 직후의 움직임에는 강내탄도학을 적용하였다. 강내탄도학 해석의 결과를 바탕으로, 포신을 떠난 후의 강외탄도 해석을 수행하였다. 몬테카를로 기법을 활용한 반복 해석으로 발사각과 차량 동특성에 의한 변동이 고려된 탄착점의 분산도를 구하여 사격정확도를 제시하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.134-139
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• 2005

This paper presents a robust design of vehicle interior noise using Taguchi method and a substructure synthesis method with a hybrid model. Firstly, the proposed method identifies the critical process of the concerned interior noise through a TPA (Transfer Path Analysis). Secondly, a strategy for a robust design is discussed, in which the major noise factor among uncertainties in the process is quality distribution of rubber bushes connecting a cradle and a trimmed body. Thirdly, a virtual test model fer the process is developed by applying a substructure synthesis method with a hybrid modeling approach. Fourthly, virtual tests are carried out according to the predefined tables of orthogonal array in Taguchi robust design process. The process was performed under 2 sub-steps. The first step is sensitivity analysis of 31 panels, and the other step is weight optimization of mass dampers on sensitive panels. Finally, two vehicles with the proposed countermeasures were validated. The proposed method reduces 87.5% of trials of measurements due to the orthogonal arrays and increases robustness by 8.6dB of S/N ratio and decreases $5\;dB(A){\sim}10\;dB(A)$ of interior noise in the concerned range of RPM.

• 한국주거학회논문집
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• 제28권2호
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• pp.23-33
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• 2017

This study was aimed to assess accessibility situation of pedestrian environment of University-C focusing on accessibility of manual wheelchair users and to develop accessibility campus map. During March and April 2016, barrierfree design application situation of pedestrian environment and building entrances were investigated using a structured checklist and a digital distance and slope meter. Major findings are as follow. (1) Except one case, widths of all pedestrian routes (both sidewalk and non-sidewalk routes) exceeded 2 meters. (2) As for sidewalk and driveway contact point condition, there were many spots lacking curb ramp or alterative ramp that are accessible for manual wheelchair users. (3) More than half of non-sidewalk pedestrian routes did not have bollard to separate pedestrian and vehicle flows, and more than 92% of the bollards installed were too close for wheelchair users to pass or too far to prevent vehicle access. (4) More than 59 percent of the building entrances were found impossible for manual wheelchair users to access without any assistance, and one third of the buildings did not have any single accessible entrance. Based on the study findings, campus accessibility map was developed by the researchers and disseminated through university homepage. Using the campus accessibility map, users can plan their accessible paths ahead the trip.

• 대한기계학회논문집A
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• 제38권4호
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• pp.385-391
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• 2014

차륜형전투차량은 보병부대의 전투력 강화와 기동성 향상을 목적으로 운용하는 군용차량이다. 전투차량은 운용 특성상 험난한 지형의 주행이 불가피하고 높은 무게 중심으로 인해 전복 사고의 위험성이 크다. 이러한 이유로 전투차량의 내부는 전복 사고에 따른 승무원의 안전성을 고려하여 설계해야 할 필요가 있다. 하지만 실제 차량을 이용한 시험은 현실적으로 많은 어려움이 있다. 따라서 본 연구에서는 차륜형전투차량의 전복 시험을 모사하여 승무원의 안전성을 측정하기 위한 컴퓨터 시뮬레이션 및 모델링 방법에 관한 연구를 수행한다. 본 논문의 연구 범위는 전투차량 전복 시험 조건, 전투차량 유한요소 모델링, 유한요소 인체 더미의 적용 방법, 전복 시험 시뮬레이션, 시뮬레이션 적용 시 발생 가능한 문제와 해결 방안 제시, 인체 상해치 계산 및 평가를 포함한다.

• 한국환경보건학회지
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• 제30권5호
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• pp.481-486
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• 2004

Vehicle occupant exposure to air pollutants has been a subject of concern in recent years because of higher levels of air pollutants inside gasoline or diesel-using vehicle, comparing to the surrounding atmosphere. Contrary to previous studies, fuel of vehicles operated in this study was liquefied petroleum gas (LPG). This study examined the potential exposure and removal efficiency of selected volatile organic compounds (VOCs), nitrogen dioxide ($NO_2$) and respirable suspended particle (RSP) by commercial air cleaning device inside vehicle under different ventilation conditions. Vehicle concentrations inside of benzene, toluene, m,p-xylene, $NO_2$ and RSP were lower under the low ventilation condition. This was indicated that outdoor air pollutants could affect the vehicle air quality inside in case metropolitan cities such as Daegu. The urban vehicle concentrations inside of benzene, toluene, m,p-xylene, $NO_2$ and RSP with air cleaning device were higher than those without air cleaning device. This means that the use of air cleaning device equipped with activated carbon filter, which was used in this study, in the interior of vehicles could be expected to reduce the vehicle occupants exposure to air pollutants effectively. In batch type reactor of laboratory scale, removal efficiencies of air cleaning device used were $97.0\%,\;95.7\%,\;94.6\%\;and\;85.5\%$ respectively in benzene, toluene, m,p-xylene and $NO_2$.