• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1028-1034
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• 1989

A method of analysis of the steady-state performance of induction motor with supply voltage controlled by cyclically-triggered inline thyristors is presented. Phase-variable model and asymmetrical components are not used in this analysis. Instead, Fast Fourier Transform technique and the method of multiple reference frames are employed to obtain the constant-speed performance of I.M. easily.

• Journal for History of Mathematics
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• v.23 no.1
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• pp.79-88
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• 2010

G$\ddot{o}$del's proof attempts to establish the existence of God by the definition that God is a being having all positive properties. The proof uses here second order modal logic system $S_5$ with the axiom ${\diamondsuit}{\Box}p{\rightarrow}{\Box}p$. We review the G$\ddot{o}$del's own version and prove his ontological theorems.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.56-60
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• 1991

Free Cantilever Method(FCM) is one of the most effective construction methods when precast prestressed concrete box girders are erected in the construction site. The special feature of FCM is that precast segments are erected in cantilever on the pier and connected in the middle of span to form the complete superstructure. Therefore each structural subsystem will be shown in each construction step and it should be analyzed for design whenever the segment is erected. In this study, the computer program was developed to optimally design the P.C box girder bridge considering tile construction sequence and verified by comparing the calculated results with the data of existing P.C box girder bridges. the sensitivity analysis was performed to show the efficiency of the developed program.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.206-208
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• 2000

0.65 mol% MgO-doped LiNbO$_3$single crystals were grown by CZ method. The obtained single crystals were colorless and transparent. Noncritically phase-matched second harmonic generation (SHG) of 532-nm radiation from 1064-nm in MgO-doped LiNbO$_3$has been investigated by using pulsed Nd:YAG laser. The phase-matching temperature was room temperature. SHG conversion efficiencies were typically achieved higher than 50% at the phase-matching temperature with no photorefractive damage in the region of fundamental power density which was used in this experiment. The thermo-birefringence coefficient and the electro-birefringence coefficient of SHG were calculated from the temperature phase-matching profile with the electric field.

• Journal of Microbiology
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• v.40 no.2
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• pp.161-165
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• 2002

Isolation frequency of microorganisms from marine sources was examined with different media and samples collected from the coastal area of Cheju Island. From sea water samples, about 1% of microorganisms from the total number of bacteria were recovered. Microorganisms were cultured at the much lower frequency of 10$\^$-4/-10$\^$-6/ from other marine sources such as sediment, sponges and corals. The frequency of duplicated isolation was examined with 140 morphologically different colonies isolated on different media. Fourteen percent of them exhibited the same morphology on two different media. The duplication frequency of the isolates among three different media was 33%.

• Proceedings of the Korean Fiber Society Conference
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• 1993.06b
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• pp.353-357
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• 1993

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.74-78
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• 1992

This paper describes an intelligent system to automatic evaluation of eddy current(EC) signal for Inspection of steam generator(SG) tubes in nuclear power plant. Some features of the intelligent system design in the proposed system are : (1) separation of representation scheme ,or event capturing knowledge in EC signal and for structural inspection knowledge in SG tubes inspection; (2) each representation scheme is implemented in different methods, one is syntactic pattern grammar and the other is rule based production. This intelligent system also includes an data base system and an user interface system to support integration of the hybrid knowledge processing methods. The intelligent system based on the proposed concept is useful in simplifying the knowledge elicitation process of the rule based production system, and in increasing the performance in real time signal inspection application.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.343-349
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• 1987

This study was executed to investigate proper storage conditions for freshness of lunch-box and prevention of lunch-box borne illness. When boiled rice was put into the empty lunch-box without cooling, temperature of the lunch-box was $70^{\circ}C$ to be able to destroy vegetative cell of microoganism in the lunch-box. Temperature of the side-dish canister that is placed on the hot lunch-box was increased from $15^{\circ}C$ to $53^{\circ}C$. The use of the insulator(one to two layer) between the lunch-box and side-dish canister was effective in insulation of the heat that is conducted from the hot lunch-box to the side-dish canister. The insulation layer(asbestos) was also effective to inhibit the decrease of pH value and growth of microoganisms in the toiled rice and side-dish during storage of the lunch-box. The number of microoganisms in the lunch-box covered without cooling was less than in the case of lunch-box covered after cooling; however, the amount of generation in condensed water that is responsible for swelling of boiled rice in the lunch-box occurred much more in the one than in the other, and was a little generated in the case of high temperature storage, insulator use, and when covering the lunch-box after cooling, and pre-evaporation by stirring boiled rice in the cooking pot before filling it. In addition, inserting the heat insulators on and bottom of the lunch-box the boiled rice can be eaten without coldness in winter season.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.181-185
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• 2000

A marine microorganism, strain 96CJ10356 produced exopolysaccharide, designated as EPS-R. To optimize culmize culture conditions for the production of EPS-R, carbon and nitrogen sources, mineral salts, temperature, and pH were exmined. From this study, STN medium for the production of EPS-R was suggested as follows; sucrose 20g, typtone 10g, NaCl 10g, MgSO45g, CaCl21g, KH2PO4 76mg, K2HPO4 83mg, FeCl2 5mg, MnCl2 1mg, NaMoO4 1mg, and ZnCl2 1mg per liter at pH 7.0. About 9.23g/L of EPS-R was obtained from STN medium after cultivation for 120h at $25^{\circ}C$ in a 5-liter jar fermentor with an aearation rate of 0.17 vvm. Apparent viscosity and flocculation activity of the culture broth were increased with the production of EPS-R and the maximal values were 415 cP and 1400 unit/mL against 0.5% activated carbon, respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.101-104
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• 1990

The program which could determine cross-sectional dimensions of the box girder bridge at tile stage of preliminary design was developed using the optimal technique in this study. It could minimize the cost and time required in the design of box girder bridges and the construction with the prestressed precast segmental method. Objective cost function consisted of four independent variables such as widths and depth of the cross-section. The Nelder-Mead method was used to solve the nonconstrained nonlinear problem like this.