• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.169-180
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• 2008

As a major component of a power plant, a turbine generator must have sufficient reliability. Longer blades have lower natural frequency, thereby requiring that the design of the shaft and blade takes into account the coupling of the blade vibration mode, nodal diameter k=0 and k=1 with vibration of the shaft. The present work analyzes the coupling of the translation motion of the shaft with in-plane vibration of the blades with k=1 modes. At a rotational speed ${\Omega}_1=|{\omega}_s-{\omega}_b|$, the resonance of the blades has a relatively large amplitude. A violent coupled resonance was observed at a rotational speed ${\Omega}_2=|{\omega}_s+{\omega}_b|$. Resonance in blade vibration at ${\Omega}_1=|{\omega}_s-{\omega}_b|$ was experimentally confirmed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.433-434
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• 2006

The limited slip differential(LSD) is a device which enables the driving force to be transmitted from one slipping wheel to another wheel in such case that the car is stuck in clay or snow. When the unwanted slipping occurs on one wheel, the LSD temporarily restraints the differential motion to transmit the driving force in the other wheel. So far, many types of LSD were developed such as mechanical lock type, disk clutch type, viscous coupling type, torsion type and multiple clutch type. we designed a new type of the hydraulic LSD which uses the principle of trochoid gear pump.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.488-490
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• 1997

This study is focused on the design and performance test of shaking table using stepping motor. Stepping motor can control the motion accurately with generated pulses and is applied to the shaking table. Earthquakes like El Centro and Taft are used as inputs to the shaking table. First, the number of pulses are calculated and sent to pulse generator. Then, the generator controls the table according to the pulse signs. It is shown that the measured signals from the table are in very good agreement with input signals of scale-downed earthquakes of El Centro and Taft. This table will be used for the experimental study of small-scaled building structures with tuned mass dampers under earthquakes.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.186-195
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• 1999

This study is focused on the design and performance test of an earthquake simulator using stepping motor. Stepping motor which controls the motion accurately with generated pulses is applied to the earthquake simulator. Earthquakes like El Centro and Taft are used as inputs to the earthquake simulator. First the number of pulses are calculated and sent to pulse generator, . Then the generator controls the simulator according to the pulse sings, It is shown that the measured signals from the simulator are in very good agreement with input signals of scale-downed earthquakes of El Centro and Taft. This simulator will be used for the experimental study of small-scaled building structures with tuned mass dampers under earthquakes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.585-594
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• 2013

In this study, laboratory experiments and numerical simulations were conducted to test the performance of resonance power buoy system proposed by Kweon et al.(2010). The system is composed of a linear generator and a mooring buoy. The mover of the linear generator mainly has heave motion driven by vertical oscillation of the buoy. In this system, the velocity discrepancy between the mover and the buoy makes electricity. However, ocean wave energy as a natural resource around Korean peninsula is comparatively small and the driving force for producing electricity is not enough for commercialization. Therefore, it is necessary that the buoy motion be amplified by using resonance characteristics. In order to verify the resonance effects on the test power buoy, the experimental investigations were conducted in the large wave flume (length of 110 m, width of 8 m, maximum depth of 6 m) equipped with regular and random plunger wave generator. The resonance draft of test power buoy is designed for the corresponding period of incident wave, 1.96 sec. Regular wave test results show that the heave response amplitude operator(RAO) by a test buoy has the amplification of 5.66 times higher compared to the wave amplitude at the resonance period. Test results of random waves show that the buoy has the largest spectrum area of 20.73 times higher at the point of not the resonance period but the shorter one of 1.85 sec. Therefore this study suggests the resonance power buoy for wave power generation for commercial application in the case of the coastal and oceanic area with smaller wave energy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.225-231
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• 2000

Dimensional synthesis of planar and spatial mechanisms mostly requires solution-finding, procedure for a system of polynomial equations. In case the system is nonlinear, numerical techniques like Newton-Raphson are often used. But there are no logical ways for finding all possible solutions in such iterative methods. In this paper, algebraic elimination is used to get all solutions for the synthesis of 5-SS spatial mechanism with seven prescribed positions. The proposed algorithm is more suitable for computer implementation and takes less time than existing one. Two numerical examples are given to demonstrate the implemented algorithm.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.954-960
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• 2009

In this paper, we propose "SenseMessenger" as a novel interaction method to capture and play tactile sense to let users feel enhanced sense experience. To improve this, we reconstructed the process of making cocktail to be digitalized for reinforcing the quality of user's experience, and designed cup-shaped devices, Sense Messenger, which is consist of Sense-recorder, Sense-player, and Sense-table. And, using these devices with common users, we discussed future applications.

• Progress in Superconductivity and Cryogenics
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• v.1 no.2
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• pp.8-14
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• 1999

In this study, acoustic emission(AE) technique has been applied to detecting quench which is one of the serious peoblems to assure the integrity of superconducting coil at cryogenic temperature. The characteristics of AE parameters have been analyzed by correlating with the number of quenches, whinding tension of superconducting coil and charge rate of transport current. The quench localization was also performed using AE signals and there was also good correlation between quench current and AE parameters such as AE energy and AE events. In this study, it was confirmed that AE signals were mainly due to the conductor motion which caused by premature quenching. It was also found that optimized winding tension at superconducting coil was needed to prevent quench caused by conductor motion.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.387-392
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• 1992

This paper presents a local trajectory generation method which is based on a sequence of reference posture-velocities and the efficient low level control algorithm which constructs the complete smooth curve from the trajectory specification. The reference trajectory generator(RTG) which is in between the local path planner(LPP) and the robot motion controller(RMC) generates a sequence of set-points for each path segments from the LPP and pass it to the RMC. The RMC controls the motions of vehicle which should follow the sequence. In the feedback controller of VMC, the method which compensates robot posture-velocity error correctly is used. These methods are implemented on indoor autonomous vehicle, 'ALIVE' mobile robot. The ALIVE mobile robot system is implemented on the 32bit VME bus system: the two VME CPU's are used for RTG and RMC, while the 80C196KC-based VME board is used for motor controller.

• Journal of the military operations research society of Korea
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• v.9 no.2
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• pp.45-55
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• 1983

Film data photographed by Motor Drive Camera were gathered and recorded in the FM Tape Recorder via computer-aided Location Analyzer and Voltage Generator. The recorded analogue data are converted into digital voltage values corresponding to the location of 14 landmarks by Analog-to-Digital Converter attached to digital computer. Using these converted values, the human motions were reproduced by CalComp Plotter and computer screen. This author concludes that any human motions can be analyzed by computer and we can find some methods of improvements of motions in work places, sports science, or operations of military equipments.