• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.259-261
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• 2005

The needs of improving the performance of wet shotcrete has become one of the most important issues in the tunnel field. The aim of this paper is to research the construction method of reinforced shotcrete using structural polymer fiber which exhibits a high quality in toughness and durability for the support of tunnel.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.382-387
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• 2003

In this paper, a neural networks-based damage detection method using the modal properties is presented, which can effectively reduce the effect of the modeling errors in the baseline finite element model from which the training patterns for the networks are to be generated. The differences or the ratios of the mode shape components between before and after damage are used as the input to the neural networks in this method, since they are found to be less sensitive to the modeling errors than the mode shapes themselves. Results of laboratory test on a simply supported bridge model and field test on a bridge with multiple girders confirm the applicability of the present method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.97-103
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• 2006

A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. The scattering from heterogeneity may affect the waveforms of R-waves in concrete, which may make the R-waves dispersive. Conventional one-sided techniques do not consider the scattering dispersion of R-waves in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. The present method is applied to monitor the strength development of early-age concrete. A series of experiments were performed on early-age concrete specimens with various curing conditions. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures and to monitor the strength development of early-age concrete.

• Proceedings of the Safety Management and Science Conference
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• 2007.11a
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• pp.9-19
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• 2007

This study deals with the improvement of production process on a flow production system with the consideration of six sigma. We analyze the production process and survey the important factors of improvement of productivity. Using a six sigma, we find strategic point and suggest a reformation of production process. We applied a simulation technique to simulate the production line proposed by the result of the Six sigma. With the result of the simulation, this study analyzes the propriety of production line and proposes the alternatives of new production process.

• Journal of Applied Reliability
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• v.15 no.2
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• pp.124-130
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• 2015

A stress-strength analysis is used to assess the reliability of a multi-pulse rocket motor system. Main stress is found to be thermal during explosion and the distribution is obtained by simulation. The strength distribution is derived from the results of actual specimen tests. The failure rate of barrier type pulse separation device is estimated.

• YAKHAK HOEJI
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• v.38 no.3
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• pp.345-350
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• 1994

Fourteen melandrin derivatives(I-XIV) were investigated on analgesic, anti-inflammatory and antiviral activities . Compound I [N-(p-hydroxybenzoyl)-5-hydroxyanthranilic acid methvl ester], Xll [N-(2-phenoxypropionyl)-5-hydroxy anthranilic acid propyl ester and XIV [N-(2-phenoxypropionyl)-5-hydroxyanthranilic acid exhibited analgesic activity in tail pressure and Randall-Selitto method. But no anti-inflammatory activity was shown. Compound I exhibited weak antiviral activity on Herpes simplex virus type I F strain by virus-induced cytopathic effect(CPE) assay and it's selectivity index(Sl) was 8.17.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.58-63
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• 2005

It is an emergency which is in the process of existing using of passenger compartment equipment of the rolling stock to sprout and interphone wiring and by the fire sensor which perceives the smoke in the use passenger car ceiling the receiver which is to driver's cabin it leads and the fire occurrence alarm voice sprouts carried on shoulder but, by no. of the car indication ramp it divides the corresponding vehicle and from inside the passenger compartment of the rolling stock from fire occurrence hour driver's cabin corresponding passenger no. of the car. It is accurate and in order it will be able to perceive. It will be able to confront initially quickly with the technique which it composes. It is regarding the fire safety surveillance system it will be able to embody at the expense which is cheap in order to use existing wiring.

• Natural Product Sciences
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• v.7 no.3
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• pp.87-89
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• 2001

The unripe fruit extract of Juglans mandshurica showed significant inhibition on aspirin and indomethacin induced gastric lesion at an oral dose of 1000 mg/kg. The extract did not show inhibition of aspirin induced ulcer and Shay ulcer at the doses of 500 and 1000 mg/kg. The results indicate that the extract had a gastroprotective activity.

• Korean Journal of Pharmacognosy
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• v.17 no.2
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• pp.184-188
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• 1986

The preliminary antifertility test of Dictamnus albus(Rutaceae) showed that a methanol extract of root bark decreased fertility in rats when administered orally on days $1{\sim}10$ postcoitum. Hexane, chloroform, butanol and aqueous fractions from the methanol extract, were tested to produce the result that only the hexane fraction exhibited positive activity. The hexane fraction was subfractionated into acidic, alkaloidal and neutral subtractions and tested. Neutral subtraction showed positive activity. From the neutral subtraction, fraxinellone was isolated as an active principle. The timed-dosing experiments revealed that antifertility activity of fraxinellone appeared to be exerted after tubal exit of the ova to prevent implantations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1907-1911
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• 2000

In this paper, classical vibration theories are summarized to design engine mount system of passenger vehicles. The vibrational characteristics of powertrain system and its equation of motion are introduced. Based upon the equation, the concept of the center of gravity, the principle inertia axis, the elastic center, and the elastic axis are defined and some new concepts are suggested. The theory of mode decoupling and the relationship between TRA (Torque Roll Axis) and roll mode are also reexamined to support the design concept of engine mount systems.