• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.439-439
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• 2009

Nowadays, source of MEMS, USN, Hybrid parts pay attention to energy harvesting. On this paper, energy harvesting was studied using piezoelectric effect. And, piezoelectric generator was designed and fabricated. Generators were designed by FEM simulation program and generators were made by attaching cymbal type metal plates on upper and bottom sides of a disc type piezoelectric ceramic. Output AC power was rectified to DC power by full bridge circuit and converted to regular voltage power by DC-DC converter. The final output power was charged to Ni-Cd battery. Using fabricated generators, output voltages dependant on thickness of ceramic, displacement of vibration, frequency of vibration were measured.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.189-197
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• 2001

This paper presents hysteresis models of damping forces of a magneto-rheological (MR) damper which is applicable to a middle-sized passenger vehicle. After manufacturing a cylindrical type of the MR damper, its field-dependant damping force and hysteresis behavior are experimentally evaluated. Three different models ; Bingham model, Bouc-Wen model and Polynomial model are provided to predict the hysteretic damping force. The damping force characteristics predicted from three different models are compared with the measured results under various excitation conditions.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.626-630
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• 2001

MPPT (maximum power point tracking) control is very important for the practical PV (photovoltaic) systems to maintain efficient power generating conditions irrespective of the deviation in the PV array insolation or/and temperature conditions. Although a plenty of researches have been done so far, most of them are too costly because of being too dependant on expensive sensors for measuring photovoltaic power and micro-processors for achieving elaborate and complicated control strategies. From this point of view, authors have been researching on sensor-less approaches for MPPT control, and have proposed two types of new control schemes 'Power Equilibrium Scheme' and 'Limit Cycle Scheme'. This paper summarises these two schemes with focussing on their :- operating principles and some results of simulation and experiments.

• Journal of the Korean Ceramic Society
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• v.29 no.7
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• pp.565-571
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• 1992

Gas sensing properties of P-N contact ceramics, composed of ZnO and CuO pairs sintered at different temperatures, were studied for 1% CO gas. Between 10$0^{\circ}C$ and 32$0^{\circ}C$ temperature range, it was observed that 2-probe current-voltage (I-V) characteristics, temperature and voltage dependence of sensivities were dependant largely upon ZnO samples. Pairs including a ZnO sample sintered at 110$0^{\circ}C$ showed maximum senitivity of 9 and 13 depending upon counterpart CuO samples, at 260~29$0^{\circ}C$. On the other hand, pairs including a ZnO samples sintered at 90$0^{\circ}C$ showed increasing sensitivity within in the measured temperature range and maximum sensitivities were about 4.

• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.95-100
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• 2000

Purpose : Primary writing tremor(PWT) can be classified as either type A or type B depending on whether tremor appeared during writing or whilst writing and also on adopting the hand postures normally used for writing. Through the clinical experience author has had an impression that PWT type B may not be purely dependant on specific writing postures. The objective of this study was to clarify whether PWT type B have writing posture-specificity or not. Results : The data indicated that type B PWT is not writing posture-specific. Various pronation and supination postures could evoke tremor as well as writing postures. Furthermore most of other pronation- and supination-related tasks could evoke tremors as well as action of writing. Conclusions : The present data suggest that PWT should be limited only on the pure form of task-spesific PWT type A.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.127-134
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• 2000

This paper presents the development of a semi-active seat damper using MR fluids and the performance analysis of seat suspension system with a MR seat damper. An annular orifice type MR seat damper is proposed for a seat suspension of a commercial vehicle. After formulating the governing equation of motion, then an appropriate size of the seat damper is designed and manufactured. Following the evaluation of field-dependant damping force characteristics, the controllability of the damping force is experimentally demonstrated in time domain by adopting PID controller. A semi-active seat suspension with the proposed MR damper is constructed and its dynamic model is established. Subsequently, vibration control capability of the semi-active suspension system is investigated by employing the sky-hook controller.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.197-209
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• 2010

Supply Chain Management have been introduced and used as strategic weapon for many companies. Large investments in the SCM was made, but many companies are not fully getting the performance from the systems. The purpose of this study is to find the determinants of SCM difussion and performance in the perspective of Innovation and Information technology Acceptance. In developing the research model, The model consists of eight independent variables(Management support, Decision Making concentration, IS strategy, training education, relative advantage, technological compatibility, task compatibility, SCM cost), two moderator variables(interorganizational and intraorganizational diffusion), three dependant variables(efficiency, effectiveness, strategic advantage).

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.231-231
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• 2004

Successful embryonic development is dependant on temporal and stage-specific expression of appropriate genes. However, information on specific gene expression during early cleavage before zygotic gene activation (ZGA) is lacking. In the present study, we compared gene expression between porcine parthenotes 2-cell and blastocyst embryos to identify the genes that are specifically or prominently expressed by employing annealing control primers (ACP)-based Gene Fishing RCR. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.5
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• pp.516-522
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• 2009

This paper proposes a new haptic cue vehicle accelerator pedal device using magnetorheological(MR) brake. As a first step, an MR fluid-based haptic cue device is devised to be capable of rotary motion of accelerator pedal. Under consideration of spatial limitation, design parameters are optimally determined to maximize control torque using finite element method. The proposed haptic cue device is then manufactured and integrated with accelerator pedal. Its field-dependant torque is experimentally evaluated. Vehicle system emulating gear shifting and engine speed is constructed in virtual environment and communicated with the haptic cue device. Haptic cue algorithm using the feed-forward control algorithm is formulated to achieve optimal gear shifting in driving. Control performances are experimentally evaluated via feed-forward control strategy and presented in time domain.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1512-1515
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• 2004

In this study, we investigated in vitro nitric oxide (NO) scavenging effect on nine herbal extracts using an NO donor S-nitroso-N-acetylpenicillamine (SNAP) compared with vitamin C. All herbal extracts effectively reduced the generation of NO radicals in a dose-dependant manner and over 65% in 10h. Especially, Ephedrae herba, Carthami flos and Lonicerae flos declined over 75% of NO scavenging effect, suggested that the herbal extracts are the powerful free radical scavengers and may be effective in clinical applications.