• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.157-164
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• 2000

It is known that residual aligning torque of tires causes vehicle pull. There is, however, only a little literature available which shows how the residual aligning torque of tires causes vehicle pull. In this paper, a vehicle model in two degrees of freedom was adopted for the analysis of a vehicle under the straight-ahead motion. The analysis with this vehicle model clearly shows the effect of residual aligning torque of tires on vehicle pull. In order to show the validity of the analysis, a vehicle commercially available was selected. This vehicle was modeled in 137 degrees of freedom system with multibody dynamics software. Vehicle pull simulation results show that vehicle model drifts in lateral direction due to the residual aligning torque of tires. Vehicle test results with the car were also included.

• Korea Trade Review
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• v.47 no.6
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• pp.71-96
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• 2022

This research will study the conversion intention of the users in China from fuel vehicle to new energy vehicles through the empirical methods. To this end, a questionnaire survey was conducted with car users as the object, combined with the theory of user migration and the PPM model to analyze the impact of fuel vehicle users' conversion intention to new-energy vehicles factor. The results showed that purchase experience contains the moderating effect, in which perceived risk and switching costs had a greater impact on the groups without purchase experience, whereas social identity, perceived value, personal attitude, and willingness to switch had a greater impact on groups with the purchase experience. Among all five factors, perceived risk had no discernible impact on the switching intention, but social identity, perceived value, attitude toward switching, and switching costs all had discernible impact on the switching intention. This study expects to come out with sustainable advises for the future growth of new energy vehicles from the study of car users' switching intention and the collective difference test of purchasing experience.

• Agricultural and Biosystems Engineering
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• v.4 no.1
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• pp.34-38
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• 2003

A mathematical model was developed for estimating the mechanical interrelation between characteristics of soil and main design factors of a tracked vehicle, and predicting the tractive performance of the tracked vehicle. Based on the mathematical model, a computer simulation program (TPPMTV) was developed in the study. The model considered the continuous change in tension for the whole track of a tracked vehicle, the analysis of shape and tension of the track segment between sprocket and first roadwheel, and the side thrust on both sides of grouser by the active earth pressure theory in predicting the tractive performance of a tracked vehicle. Also, the model contained not only sinkage depth of the track but the pressure distribution under the track in analyzing the side thrust. The effectiveness of the developed model was verified by performing the draw bar pull tests with a tracked vehicle reconstructed for test in loam soil with moisture content of 18.92％. The predicted drawbar pulls by the model were well matched to the measured ones. Such results implied that the model developed in the study could estimate the drawbar pulls well at various soil conditions, and would be very useful as a simulation tool for designing a tracked vehicle and predicting its tractive performance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.140-151
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• 2000

Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. in the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert\`s knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program, two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.20-32
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• 1995

Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. In the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert's knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program. two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.183-190
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• 2005

During normal operating conditions, a motor vehicle is constantly subjected to a variety of forces, which can adversely affect its straight-ahead motion performance. These forces can originate both from external sources such as wind and road and from on-board sources such as tires, suspension, and chassis configuration. One of the effects of these disturbances is the phenomenon of vehicle lateral-drift during straight-ahead motion. This paper examines the effects of road crown, tires, and suspension on vehicle straight-ahead motion. The results of experimental studies into the effects of these on-board and external disturbances are extremely sensitive to small changes in test conditions and are therefore difficult to guarantee repeatability. This study was therefore conducted by means of computer simulation using a full vehicle model. The purpose of this paper is to gain further understanding of the straight-ahead maneuver from simulation results, some aspects of which may not be obtainable from experimental study. This paper also aims to clarify some of the disputable arguments on the theories of vehicle straight-ahead motion found in the literature. Tire residual aligning torque, road crown angle, scrub radius and caster angle in suspension geometry, were selected as the study variables. The effects of these variables on straight-ahead motion were evaluated from the straight-ahead motion simulation results during a 100m run in free control mode. Examination of vehicle behavior during straight-ahead motion under a fixed control mode was also carried out in order to evaluate the validity of several disputable arguments on vehicle pull theory, found in the literature. Finally, qualitative comparisons between the simulation results and the test results were made to support the validity of the simulation results.