• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4681-4702
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• 2016

Recently, Massive energy consumption in Cloud Storage System has attracted great attention both in industry and research community. However, most of the solutions utilize single method to reduce the energy consumption only in one aspect. This paper proposed an energy effective gear-shifting mechanism (E2GSM) in Cloud Storage System to save energy consumption from multi-aspects. E2GSM is established on data classification mechanism and data replication management strategy. Data is classified according to its properties and then be placed into the corresponding zones through the data classification mechanism. Data replication management strategies determine the minimum replica number through a mathematical model and make decision on replica placement. Based on the above data classification mechanism and replica management strategies, the energy effective gear-shifting mechanism (E2GSM) can automatically gear-shifting among the nodes. Mathematical analytical model certificates our proposed E2GSM is energy effective. Simulation experiments based on Gridsim show that the proposed gear-shifting mechanism is cost effective. Compared to the other energy-saved mechanism, our E2GSM can save energy consumption substantially at the slight expense of performance loss while meeting the QoS of user.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.160-166
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• 2013

This paper proposes a driver supportive device with haptic cue function which can be applicable for vehicles adopting manual transmission system to transmit gear-shifting information to a driver by kinesthetic forces. This haptic cue function is implemented on accelerator pedal by utilizing magnetorheological(MR) fluid and clutch mechanism. In order to achieve this goal, an MR clutch mechanism is devised to be capable of rotary motion of accelerator pedal. The proposed MR clutch is then optimally designed and manufactured under consideration of spatial limitation of vehicles. After transmission torque is experimentally evaluated according to field intensity. The manufactured MR clutch is integrated with accelerator pedal and electric motor to establish the haptic cue device. Control performances are experimentally evaluated via a simple feed-forward control algorithm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.1
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• pp.54-61
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• 2014

This paper proposes a driver supportive device with haptic cue function which can transmit optimal gear shifting timing to a driver without requiring the driver's visual attention. Its performance is evaluated under vehicle model considering automotive engine, transmission and vehicle body. In order to achieve this goal, a torque feedback device is devised and manufactured by adopting the MR (magnetorheological) fluid and clutch mechanism. The manufactured MR clutch is then integrated with the accelerator pedal to construct the proposed haptic cue device. A virtual vehicle emulating a four-cylinder four-stroke engine, manual transmission system of a passenger vehicle and vehicle body is constructed and communicated with the manufactured haptic cue device. Control performances including torque tracking and fuel efficiency are experimentally evaluated via a simple feed-forward control algorithm.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.59-64
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• 2024

In this study, we conducted research on a miniaturized transmission system suitable for ultra-compact electric vehicles, such as electric arts or small electric cars. While conventional electric vehicles eliminate multi-gear transmissions and control motor output or secure initial driving force through reducers, in vehicles like electric karts or compact electric cars, which have relatively small battery capacities, the driving range can be reduced or the motor can be stressed epending on the loading state. Therefore, in this study, we developed a low stage ratio 0.625 and high stage ratio 1.6 a two-stage transmission system that can change gears as needed, considering factors such as slope conditions and loading status, by applying the continuously variable transmission (CVT) mechanism. Based on the selected gear ratios, we designed the transmission and created a test rig to verify the power transmission efficiency of the developed transmission. Using the test rig, we varied the rotational speed and load of the transmission to confirm its power transmission characteristics and also examined the heat generation characteristics during shifting and operation. As a result, developed a two-stage transmission with a CVT structure.