• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.3
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• pp.125-129
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• 1982

Most A/D converters which encode baseband signals of several magahertz band width to accuracies such as 8 bits are complez and therefore expensive. This letter suggests that a simple fast digital encoder can be formed the combination of V.C.O. and digital discriminator, automatically elimnating the complex logic process of conventional fast baseband A/D converters. The techique is suitable for encoding video signals to 8bits.

• Journal of Biomedical Engineering Research
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• v.9 no.1
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• pp.109-116
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• 1988

In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(${\Delta}$Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.405-408
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• 2003

The soild phase microextraction(SPME)fiber which contains 100${\mu}{\textrm}{m}$ polydimethyl siloxane of a stationary phase was used for the analysis of volatile organic compounds contained in aqueous solution. volatile organic compounds, which were spiked in blank water and extracted by the headspace SPME techique, were analyzed by gas chromatography/flame ionization detector(GC/FID). The optimu condition of SPME fiber is determined that the analytes were extracted for 40min from extracts by using PDAfS100${\mu}{\textrm}{m}$ fiber. This new method could have wide application for the analysis of VOCs in aqueous solution.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.879-882
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• 1988

This paper describes a fast security analysis techique for voltage security assessment. The new method identifies the location of buses with potential voltage problems and thereby defines a voltage-sensitive subnetwork for contingency screening. The efficieny of this method is derived from the use of a voltage subnetwork to drastically reduce the number of bus voltages to be solved; and subsequently from the use of compensation techniques and sparse-vectors methods for screening. Results demonstrating the effectiveness of the method on the IEEE-14 bus model system are presented.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.175-182
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• 2001

Five reinforced concrete frames were constructed and tested to study the structural performance of retrofitting effect reinforced concrete frame during and load revesals simultaneously. All specimens were modeling in one-third scale size. Experimental research was carried out to develop and evaluate the hysteretic behavior of reinforced concrete frame designed by high performance techniques, using carbon fiber plate, ALC panel, steel plate system with or without stiffener. Experimental programs wore carried to evaluate the structural performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Specimens(RFCP, RFAR, RFSR, RFSR-S), designed by the improvement of earthquake-resistant performance, were attained more load-carrying capacity, energy dissipation capacity, and stable hysteretic behavior.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.42-42
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• 1996

Adrenal chromaffin cells secrete catecholamine in response to acetylcholine. The secretory response has absolute requirement for extracellular calcium, indicating that $Ca^{2+}$ influx through voltage operated $Ca^{2+}$ channels (VOCC) is the primary trigger of the secretion cascade. Although the existence of various types of $Ca^{2+}$ channels has been explore using patch clamp techique in adrenal chromaffin cells, the contribution of different types of $Ca^{2+}$ channels to catecholamine secretion remains to be establised. (omitted)omitted)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.173-176
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• 1998

We experimentally investigated the dielectric relaxation phenomena of a liquid crystal monolayers by the Displacement current techique and displacement current flowing across monolayers is analyzed using rod-like molecular model. It is revealed that the dielectric reaxation time $\tau$ of monolaters in the isotropic polar orientational phase is determined using a linear relashionship between the monolayers compression speed $\alpha$ and the molecular area. The dielectric relaxation time of phospholipid monolayers was examined on the basis of the analysis developed here.

• Journal of The Korea Institute of Healthcare Architecture
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• v.10 no.2
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• pp.71-82
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• 2004

The purpose of this study is to analyze the wind velocity ratio in respect of layout types of housing in multi-family housing. The wind velocity ratio is a difference of wind velocity between on the leeward and on the windward side of multi-family housing. The layout types of housing are grid layout pattern of linear type, mixture pattern of Linear type + tower type and layout pattern of tower type. The planning of wind flow is an induced technique to increase in wind velocity in the city and multi-family housing. This study investigates wind velocity ratio into layout types of housing. consequently, analysis were basic design data for the planning techique of wind flow suggested.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.7
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• pp.566-570
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• 2010

Electro-optic modulators based on 25 monolayer langmuir-blodgett films of vinylidene fluoride and trifluoroethylene, P(VDF-TrFE), were fabricated. The LB films were prepared by transferring the monolayers on to an ITO coated glass with a surface pressure of 5 dyne/cm by use of the langmuir-schaefer deposition method. Measurement of the electro-optic coefficient has been carried out using a simple reflection techique. The E/O coefficient was found to be 154.9 pm/V and that value remained stable for at least 50 days.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.574-574
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• 2003

I. Objectives Newly all-in-one adhesives were developed for reducing the techique sensitivity and chair time, but lots of concerns were made on bondability, longevity, and microleakage. The object of this study was to measure micro leakage and marginal quality of all-in-one adhesives using electrochemical method and SEM analysis quantitatively. II. Materials and Methods After making Class V cavities, they were bulk filled with Heliomolar(＃A1) after surface treatment with three adhesives：Adper Prompt (Group 1), One up bond F (Group 2), Xeno III(Group 3).(omitted)