• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.991-996
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• 2017

Gait stability is partly characterized by an extended stance phase that comprises 60 of the gait ％ cycle. In this study, a gait pattern was employed for a crank drive system that allows for stable lower limb kinematics during stand-up cycling. A quick return mechanism was applied to the crank system to allow for a slow rotation of the crank during the stance phase and for a quick return during the swing phase. Design parameters for the quick return crank mechanism were defined, and kinematic simulations were performed to understand the behavior of the mechanism. To evaluate the design, an experimental instrument was fabricated, and the cycling motion was analyzed. The results indicated that this new drive system can stabilize the center of mass of the user. This study can contribute to the development of a stand-up bicycle that allows for more comfortable leg kinematics.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.241-243
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.354.2-354
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.415.1-415
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• 2002

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.554-557
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• 2010

Pay Per Drive System can be a new solution for improving the traffic congestion and air pollution by not only taxing on the driving distance but also taxing different proportion with driver' s location and time. Thus it gives us new concept of the area and time of traffic jam, as a result, we can find a natural and efficient transportation mechanism and reduced air pollution. Also this system can trace the driver' s location by GPS, it can provide Black Box function on every car on the road. We propose the method of advanced transportation service by Pay Per Drive System.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.86-94
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• 2012

VANETs can provide traffic warring service to help drivers drive safely based on the information of the traffic condition. The driver can drive safely through the warning service information provided by the VANET and know the traffic condition exactly more than through only the sight of driver. In this paper we suggest a new mechanism of updating the table to broadcast the message more rapidly based on the table driven method as the way of sending the emergency message in the VANETs. When updating the table, nodes sends only based on the message transmission success rate. In the result of simulation we could find that the suggested mechanism would reduce the delay time of the emergency message broadcast compared to the existing mechanism.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.694-699
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• 2002

As the demand for slim laptops requires ion'-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method far anti-vibration mechanism with respect to the existing servo gain plot. This method verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.833-839
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• 2002

As the demand for slim laptops requires low-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method for anti-vibration mechanism with respect to the existing servo gain plot. Thismethod verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.59-68
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• 2009

The field oriented control of induction motors is widely used in high performance applications. However, detuning caused by parameter disturbance still limits the performance of these drives. In order to accomplish variable speed operation, conventional PI-like controllers are commonly used. These controllers provide limited good performance over a wide range of operation, even under ideal field oriented conditions. This paper is proposed high performance control of induction motor drive using multi adaptive fuzzy controller. This controller has been performed for speed control with fuzzy adaptation mechanism (FAM)-PI, current control with model reference adaptive fuzzy control(MFC) and estimation of speed using ANN. The proposed control algorithm is applied to induction motor drive system using FAM-PI, MFC and ANN controller. The performance of proposed controller is evaluated by analysis for various operating conditions using parameters of induction motor drive. Also, this paper is proposed the analysis results to verify the effectiveness of this controller.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1003-1005
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• 2000

The switched reluctance drive provides a good adjustable steed characteristics like a D.C series motor. However, because of the torque production mechanism, it also has some disadvantage such as higher torque ripple and fluctuation in speed. To reduce torque ripple and to control speed precisely at low condition current level technique is adopted. The SRM drive with current control of invariable frequency and phase swichting control has good speed regulation characteristics. Digital control system with an 80c196kc micro-controller is used to realize this drive system. Test results show that the control system has the goof ability to achive precise speed control at low speed.