• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.468-473
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• 2009

The antibiotic meroparamycin was produced in the free culture system of Streptomyces sp. strain MAR01. Five solid substrates (rice, wheat bran, Quaker, bread, and ground corn) were screened for their ability to support meroparamycin production in solid-state fermentation. In batch culture, wheat bran recorded the highest antibacterial activity with the lowest residual substrate values. The highest residual substrate values were recorded for both ground corn and Quaker. On the other hand, no antibacterial activity was detected for rice as a solid substrate. The use of the original strength of starch-nitrate medium in the solid-state fermentation gave a lower antibacterial activity compared with the free culture system. Doubling the strength of this medium resulted in the increase in the activity to be equivalent to the free culture. The initial pH (7.0) of the culture medium and 2 ml of spore suspension (1 ml contains $5{\times}10^{9}spores/ml$) were the optima for antibiotic production. The water was the best eluent for the extraction of the antibiotic from the solid-state culture. Ten min was enough time to extract the antibiotic using a mixer, whereas, 60 min was required when shaking was applied. Semicontinuous production of meroparamycin using a percolation method demonstrated a more or less constant antibacterial activity over 4 runs ($450-480{\mu}g/ml$). The semicontinuous production of the antibiotic was monitored in a fixed-bed bioreactor and the maximum activity was attained after the fourth run ($510{\mu}g/ml$) and the overall process continued for 85 days.

• KSBB Journal
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• v.24 no.1
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• pp.70-74
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• 2009

For continuous culture of cellulolytic enzymes production to saccharify food wastes, refill concentration of Mandel's medium for continuous culture was 0.5%, and refill intervals were determined to 12 hours by analysis of COD and total nitrogen concentration after 4-days batch culture in flask level. As a result, amylase and FPase productivities were 3.5 and 1.0 U/L.hr, respectively. In 10 L bioreactor, the batch culture mode was compared with fed-batch, fill-and-draw for continuous production of cellulolytic enzyme. Enzyme productivities were most high at batch culture and followed by fed-batch culture. Amylase and FPase activities were 42.3 and 5.6 U/L.hr at batch culture, and 23.0, 2.8 U/L.hr at fed-batch culture, respectively. As a result, in continuous cultivation of cellulolytic enzymes by T. inhamatum KSJ1, the mode of fed-batch was most effective in 10 L bioreactor.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1505-1515
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• 2009

A new method to semicontinuously determine $PM_{2.5}$ ionic species with a short time resolution is described in detail. In this system, a particle collection section (mixing part, particle collection chamber, and air/liquid separator) was developed. A Y-type connector was used to mix steam and an air sample. The particle collection chamber was constructed in the form of a helix coil and was cooled by a water circulation system. Particle size growth occurred due to the high relative humidity and water absorbed particles were efficiently collected in it. Liquid samples were drained out with a short residence time (0.08-0.1 s). The air/liquid separator was also newly designed to operate efficiently when the flow rate of the air sample was 16.7 L $min^{-1}$. For better performance, the system was optimized for particle collection efficiency with various types of test aerosols such as ($NH_4)_2SO_4,\;NaCl,\;NH_4HSO_4,\;and\;NH_4NO_3$. The particle collection efficiencies were almost 100% at different concentration levels in the range over 500 nm in diameter but 50-90% in the range of 50-500 nm under the following experimental conditions: 15 coil turns, a water flow rate for steam generation of 0.65 mL $min^{-1}$, and an air sample flow rate of 16.7 L $min^{-1}$. Finally, for atmospheric applications, chemical compositions of $PM_{2.5}$ were determined with a time resolution of 20 min on January 11-24, 2006 in Seoul, Korea, and the chemical characteristics of $PM_{2.5}$ ions were investigated.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.358-363
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• 1994

This paper presents the improvement of the SCHMM using discrete VQ and One-Pass algorithm for keywords recognition in Korean continuous speech. The SCHMM using discrete VQ is a simple model that is composed of a variable mixture gaussian probability density function with dynamic mixture number. One-Pass algorithm is improved such that recognition rates are enhanced by fathoming any undesirable semisyllable with the low likelihood and the high duration penalty, and computation time is reduced by testing only the frame which is dissimilar to the previously testd frame. In recognition experiments for speaker-dependent case, the improved One-Pass algorithm has shown recognition rates as high as 99.7% and has reduced compution time by about 30% compared with the currently abailable one-pass algorithm.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.179-182
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• 2007

In this paper, we introduce the concepts of fuzzy (r, s)-semi-preopen sets and fuzzy (r, s)-semi-precontinuous maps on intuitionistic fuzzy topological spaces in Sostak's sense. The relations among fuzzy (r, s)-semicontinuous, fuzzy (r, s)-precontinuous, and fuzzy (r, s)-semi-precontinuous maps are discussed. The concepts of fuzzy (r, s)-semi-preinterior, fuzzy (r, s)-semi-preclosure, fuzzy (r, s)-semi-preneighborhood, and fuzzy (r, s)-quasi-semi-preneighborhood are given. Using these concepts, the characterization for the fuzzy (r, s)-semi-precontinuous map is obtained. Also, we introduce the notions of fuzzy (r, s)-semi-preopen and fuzzy (r, s)-semi-preclosed maps on intuitionistic fuzzy topological spaces in Sostak's sense, and then we investigate some of their characteristic properties.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.213-216
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• 2007

In this paper. we study the controllability for the semilinear fuzzy integrodifferential equations with nonlocal condition and forcing term with memory in $E_N$ by using the concept of fuzzy number whose values are normal, convex, upper semicontinuous and compactly supported interval in $E_N$.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.4
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• pp.499-503
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• 2003

This paper we study the exact controllability for the nonlinear fuzzy control system in $E_N^n$by using the concept of fuzzy number of dimension n whose values are normal, convex, upper semicontinuous and compactly supported surface in $E_N^n$

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.168-171
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• 2000

This paper is concerned with fuzzy number whose values are normal, convex, upper semicontinuous and compactly supported interval in E$\_$N/ We study continuously initial observability for the following fuzzy system. x(t)=a(t)x(t)+f(t,x(t)), x(0)=x$\_$0/, y(t)=$\_$${\alpha}$/∏(x(t)), where a: [0, T]\longrightarrowE$\_$N/ is fuzzy coefficient, initial value x$\_$0/$\in$E$\_$N/ and nonlinear funtion f: [0, T]${\times}$E$\_$N/\longrightarrowE$\_$N/ satisfies a Lipschitz condition. Given fuzzy mapping ∏: C([0, T]: E$\_$N/)\longrightarrowY and Y is an another E$\_$N/.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.40-44
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• 2004

In this paper we study the existence and uniqueness of fuzzy solutions for the nonlinear fuzzy integro-differential equations on $E^{n}_{N}$ by using the concept of fuzzy number of dimension n whose values are normal, convex, upper semicontinuous and compactly supported surface in $E^{n}_{N}$. $E^{n}_{N}$ be the set of all fuzzy numbers in $R^{n}$ with edges having bases parallel to axis $x_1$, $x_2$, …, $x_n$.

• Communications of the Korean Mathematical Society
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• v.17 no.4
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• pp.681-691
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• 2002

We study categorical properties of the category SWQOS (S$\^$U/WQOS, S$\^$L/WQOS, resp) of (upper, lower, resp.) semi-continuous quasi-ordered spaces and the subcategory SWPOS (S$\^$U/WPOS, S$\^$L/WPOS, resp.) of (upper, lower, resp.) semicontinuous partially ordered spaces. We show that the categories S$\^$U/WPOS, S$\^$L/WPOS and SWPOS are closed under the formation of initial mono-sources in the category TQOS of topological quasi-ordered spaces, and they we mono-topological, complete and cocomplete epireflective subcategories of the category TQOS. We obtain their MacNeille and universal initial completions, as well as those of subcatego.ies S$\^$U/WQOS(S$\^$L/WQOS) and SWQOS, in which the topologies are T$\_$0/ and T$_1$, respectively.