• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 추계학술대회 논문집
• /
• pp.628-633
• /
• 2004

we studied the structural weak areas of an electric car bogie frame by finite element analysis. The bogie frame under consideration is a part of the standard electric car with aluminium car body. Vertical, torsional. lateral and longitudinal loadings were applied. Numerical results were compared with the experimental results. The two results are in a good agreement.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.144-149
• /
• 2008

In this paper, vibration sources of a car-holder are identified and the car vibrations are reduced by structural modification. For vibration identification, vibration signals are measured by an accelerometer when the car is moving. From some experiments and finite element analyses, it is also found that resonances occur because the natural frequencies of the car exist in usual driving speed range. To shift the natural frequencies outside the driving speed range, the connection part is modified to increase stiffness. It is verified that considerable amount of vibration are reduced by the structural modification.

• 품질경영학회지
• /
• 제44권3호
• /
• pp.661-676
• /
• 2016

Purpose: This study proposes to derive the quality characteristics recognized by the consumer for the smart car. The study contributes to the policy of the country automotive industry. This study confirms the impact on the customer satisfaction from the quality attribute. This study provides the information necessary for the establishment and management strategies of the Korean auto industry. Methods: This study was conducted adequate theoretical research on the subject first. Kano presents a model for the kind of smart car technology. Set the operational definitions for measuring and developing the questionnaire. Subjected to statistical analysis using the collected data, and carry out analysis Kano. It interprets the results of the study on the basis of the data obtained through the analysis. Results: Directly related to safety smart car technology improves customer satisfaction. Conclusion: The quality characteristics are required for user-centric Smart car.

• 대한산업공학회지
• /
• 제42권1호
• /
• pp.73-79
• /
• 2016

The purpose of this study is to understand human sensory and emotional response according to car noise. This study investigated human stress levels from car noise based on the data of electro-encephalogram (EEG) and subjective evaluation analysis data. Since there are few previous works on the effect of car noise on human's reaction, more profound research about the effect of car noise on driver's emotion would be worth performing. Subjects were exposed to five different kinds of car noises. EEG data were collected while the subject was exposed to noise. In order to process EEG data, FFT analysis was used to separate the collected EEG data into ${\alpha}$-wave and ${\beta}$-wave. Also, survey was performed to carry out subjective evaluation. The results of the subjective evaluation were closely correlated to those found in the EEG signal analysis. The results from this study may provide useful information for mitigating car noise induced stress.

• 한국시스템다이내믹스연구
• /
• 제13권4호
• /
• pp.33-55
• /
• 2012

The research is to identify important diffusion factors and their effects on green car diffusion process using system dynamics perspectives and a causal-loop analysis. Through a deep review on previous research, we have found the important factors of green car diffusion process. Price, driving range, network effect, recharge system, fuel cost had important facilitation on consumer attraction and green car diffusion. Based on the review, we have constructed a causal loop diagram explaining hybrid car diffusion process. We have found 3 important reinforcing loops in the causal loop diagram. Loop for learning & economies of scale(supply side), loop for network effect(consumer side), and loop for battery development(technology side) had most significant roles in the whole diffusion process. Through a deliberate analysis on the 3 causal loops, we have found meaningful results. First, there seems to exist a critical mass in the diffusion. Second, of the 3 loops, the battery technology had most significant role. Third, not consumer installed base but sales must be a standard to decide whether the critical mass is achieved or not. Based on these findings, several meaningful implications are suggested for the government and corporations related to the green car industries.

• 한국소음진동공학회논문집
• /
• 제18권11호
• /
• pp.1192-1198
• /
• 2008

In this paper, the vibration and shock of an HDD car-holder are reduced through vibration analysis and a structural modification. In order to identify the exciting frequency components of vibration and shock, vibration signals are measured and analyzed from the wind shield or dashboard. In addition, the modal test for the current HDD car-holder is performed to investigate the dynamic characteristics of the car-holder. From these experiments, it is found that the exciting frequencies coincide to the natural frequencies of the car-holder. For the purpose of avoiding resonance, some FEM simulations are carried out and then structural modifications are made for the car-holder. Based on the results of simulations, a prototype of new car-holder are manufactured and tested to demonstrate the reduction of vibration and shock. It is verified by the test that a considerable amount of vibration and shock are reduced.

• 한국철도학회논문집
• /
• 제6권3호
• /
• pp.149-155
• /
• 2003

The development of railway vehicles involves the proper selection of design parameters not only to achieve high speed but also to reduce the vibration of the train. In this study an analytical model of a freight car is developed to find the critical speed. The freight car can generate the snake motion of the lateral and yawing motion of the car body, the bogie, and the wheelset. Numerical analysis for the nonlinear equation motions with 17 degrees of freedom showed the running stability and critical speed due to the snake motion. Also, the vibration modes of the freight car was calculated using ADAMS/RAIL, which showed that the critical speed have the yawing modes of the car body and the bogie. Finally this paper shows that the snake motion of the vehicle can be controlled with the modifications of the design parameters.

• 한국자동차공학회논문집
• /
• 제14권5호
• /
• pp.79-83
• /
• 2006

The present low speed crash regulations and RCAR test for insurance estimate do not tend to reflect car crash occurred on a road. Therefore, car makers are trying to readjust test standard be similar to a real situation. Passenger cars and SUV vehicles on the market will be subject to this study for car to car crash. In addition, we will discuss improvement of test methods for a low speed crash and direction of bumper design by performing this impact analysis.

• 한국자동차공학회논문집
• /
• 제7권6호
• /
• pp.241-247
• /
• 1999

This study presents the structural analysis of car a seat frame by the finite element method. The load-deformation characteristics of seat frame are simulated according to the test requirements by FMVSS. Three dimensional modeling technique is applied to the components of the seat frame. The shell, solid , gap and rigid elements are employed to model the car seat frame assembly. Numerical results show that the recliner and kunckle plate are identified as the possible weak part of frame, and the results are well consistent with the experimental static load test. The current analysis model can provide useful informations to design a new car seat and can reduce the overall design cost and time.

• 동서간호학연구지
• /
• 제27권2호
• /
• pp.177-184
• /
• 2021

Purpose: Traffic accidents are the major cause of death in children. Car seat usage in children is important to reduce the risk of death or injury caused by traffic accidents. This study aims to analyze the trends of car seat use among children ages under 6. Methods: This study adopted a cross-sectional study utilizing the Korea National Health and Nutrition Examination Survey from 2015 to 2019. In total, 1,999 responses were included for the analysis. Factors associated with car seat use were age, sex, body weight, height, family type, household income, and monthly household income. Regression analysis was used to compare the car seat use before and after the revision of the Road Traffic Act (2015~2018 vs. 2019). Results: We found that car seat use was increasing by year, age, region, and household income. Car seat use was higher after fines increased in 2019. Age and body weight had negative association with car seat use, while height and household income had positive association with car seat use. Conclusion: Car seat use increased from 2015 to 2019 and is associated with different ages among children and household income. Further education and promotion that describes the safety benefits to children from car seat use are needed.