• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1703-1709
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• 2008

The TTX(Tilting Train eXpress) has tilting mechanism that is not existed in the previous train. So, the characteristics of suspension will be different from others. For this reason, TTX needs to be investigated about the suspension in contrast with the previous suspension system. The 2nd damping ratio is very important for a tilting mechanism. Proper value of suspension characteristics should be suggested for the tilting train. In this paper, the optimization of suspension systems for TTX model is introduced by using Design of Experiments (DOE) which is the design of all information-gathering exercises where variation is present. At first, the dynamics model is made for evaluating characteristics of suspension system. Second, using evaluated value, suspension characteristics are analyzed for sensitivity analysis. Finally, using the result of a sensitivity analysis, the suspension systems are optimized.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.584-589
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• 2001

This paper presents the dynamic parameter design optimization of a suspension seat system using the genetic algorithm. At first, an equivalent 1-D.O.F. mass-spring-damper model of a suspension seat system was constructed for the purpose of its vibration analysis. Vertical vibration response and transmissibility of the equivalent model due to base excitations, which are defined in the ISO's seat vibration test codes, were computed. Furthermore, seat vibration test, that is ISO's damping test, was carried out in order to investigate the validity of the equivalent suspension seat model. Both analytical and experimental results showed good agreement each other. For the design optimization, the acceleration transmissibility of the suspension seat model was adopted as an object function. A simple genetic algorithm was used to search the optimum values of the design variables, suspension stiffness and damping coefficient. Finally, vibration ride performance test results showed that the optimum suspension parameters gives the lowest vibration transmissibility. Accordingly the genetic algorithm and the equivalent suspension seat modelling can be successfully adopted in the vibration ride quality optimization of a suspension seat system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.3
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• pp.3795-3814
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• 1975

The purpoes of this thesis is to study the effect of the variation of the beginning date of the suspension of irrigation and the length of intermittent suspension period of irrigation in the paddy field on the growth and yield of rice, so as the provide a critical limit of saving irrigation water and an irrigation method to prevent drough damage in rice cultivation. In this experiment, the rice variety adopted was NONGRIM No.29. There were seven main test plot, each test plot having a different beginning date of the suspension of irrigation. A main test plot was susdivided into five small test plots, each having a different length of the suspension period of irrigation. The results obtained in this experiment are summarized as follows: 1. The number of tillers is controlled by the treatment of the suspension of irrigation, its beginning date being early of late. The reductive effects of beginning dates of suspension upon the number of tillers. investigated on July 30, are about 84% for the treatment suspended on July 8, 87% on July 12, and 92% on July 19, respectively, in comparison with the standard plot. However. the suspenion treatments after the foregoing dates does not affect the control of their numbers. On the other hand, the lengths of intermittent suspension periods influence highly on the number of tillers to be restrained considerably, the decrease ratio ranging from 91% to 80% Both treatments on dates and periods are so intermingled that the restraining effects of suspension periods become greater as the dates of its beginning are earlier. 2. The elongation of plant hieghts also restrained considerably by the longer periods and earlier dates of suspension treatments of irrigation. Especially, the effects of the lengths of suspension periods become more serious. 3. Heading dates are delayed by two to five days through the suspension treatments of irrigation. However, the heading stage ends almost on the same day without relation to the differences between the irrigation suspension treatments. In the test plot where the suspension date of irrigation comes after the young panicle forming stage, the heading stage ends one or two days later than in the standard test plot. 4. Both culm lengths and panicle lengths show significant differences in their values, i.e., their lengths are shorter, as the begining dates of irrigation suspension are earlier and the suspension periods are longer. 5. The earlier the beginning date and the longer the period of irrigation suspension, the less is the number of panicles per hill in comparison with the standard plot. 6. The earlier the beginning date and the longer the period of irrigation suspension, the higher is the significant difference in the number of kernels per panicle in comparison with that in the standard test plot, i.e., the less is the number of kernels per panicle. 7. The earlier the beginning date and the longer the period of irrigation suspension, the lighter are the weights of rough rice and straws per hill in comparison with those in the standard plot.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.943-946
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• 2010

In this study, a front suspension system, which is mounted on the handle itself, was suggested because of its light weight and cost efficiency. The shock absorption was evaluated for the three types of suspension models; non-suspension, suspension on front forks (existing model), and suspension on handle (suggested model). The human body model was used for performing impact simulation for comparing the shock absorption for the suspension models. The result of the simulation shows that shock absorption for the proposed suspension model was not as good as that for the front fork suspension model. Nevertheless, the shock absorption observed for the proposed suspension model was significant when compared to the non-suspension model. Consequently, the proposed suspension model could be applied to lightweight bicycles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.332-339
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• 2006

A leaf spring suspension has been widely used since it can carry big load and simplicity. But one major drawback is the poor ride performance because of the friction in the system and the high stiffness coefficient. To overcome these, air spring suspension can be used. The air spring suspension system can improve the ride of the heavy vehicle significantly and also it can adjust the height to the loading and unloading. A truck with the leaf suspension system is modified with the air suspension system and the performance of the vehicle is compared using the suggested method. The existing leaf suspension can be replaced with the air suspension system to improve the performance.

• KSTLE International Journal
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• v.2 no.2
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• pp.142-145
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• 2001

The electrorheology of the chitosan adipnate suspension in silicone oil was investigated. Chitosan adipnate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the chitosan adipnate suspension exhibited a linear dependence on the volume fraction of particles and an electric field power of 1.88. The experimental results for the chitosan adipnate suspension correlated with the conduction models and this suspension was found to be an anhydrous ER fluid.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.101-103
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• 2001

Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing Ag$_2$O It has been cleared that Ag$_2$O acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.345-350
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• 1996

The suspension system plays an important role in vehicle performance. To improve suspension characteristics related to riding comfort and handling stability simultaneously, active suspension system is developed. In this study, a hybrid control scheme is proposed, the idea of which is that the sliding mode control is applied to nonlinear hydraulic system and the skyhook control is applied for controlling the motion of the suspension system. The performance of the proposed control method is evaluated by simulation and experiment of a half car active suspension system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.282-285
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• 2003

Two criteria of good vehicle suspension performance are typically their ability to provide good road handling and increased passenger comfort. So far, The existing active vehicle suspension uses pneumatic and hydraulic actuators that enhance road handling and passenger comfort. But these kinds of actuators have nonlinear characteristic less than an electromagnetic motor. In this research, we are trying to examine the feasibility and the experiment of an active vehicle suspension using electromagnetic motor in order to enhance the ride quality because existing active vehicle suspension using active power sources such as compressors, hydraulic pumps has nonlinear characteristic. Active vehicle suspension using electromagnetic motor will have the ability to behave differently on smooth and rough roads. The desired response should be soft in order to enhance ride comfort, but when the road surface is too rough the suspension should stiffen up to avoid hitting its limits.

• Transactions of Materials Processing
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• v.17 no.7
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• pp.481-485
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• 2008

The subframe type rear suspension consisting of a side member and a front/rear cross member is widely used in a medium car and full car. In the small car case, the beam of tubular type without independent suspension system is used to reduce manufacturing cost. In this study, a subframe type rear suspension by hydroforming has been developed. In designing suspension, a driving stability and durability should be considered as an important factor for the performance improvement, respectively. Thus, we focus on increasing the stiffness of suspension and decreasing the maximum stress affecting a durability cycle life. Several optimization design techniques such as shape, size, and topology optimization are implemented to meet these requirements. The shapes of rear suspension obtained from optimization are formed by using hydroforming process. Through commercial software based on the finite element, the superiority of this design method is demonstrated.