• 대한수학회지
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• 제33권3호
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• pp.641-650
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• 1996

Let G denote an upper semicontinuous(usc) decomposition of an (n + k)-manifold M into closed, connected n-manifolds. What can be said about the decomposition space B = M/G\ulcorner What regularity properties are possessed by the decomposition map $p : M \to B \ulcorner$ Certain forms of these questions have been addressed by D. Coram and pp. Duvall [C-D].

• 대한수학회논문집
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• 제26권4호
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• pp.649-660
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• 2011

S. M. Saperstone and M. Nishihama [6] had showed both continuity and stability of the orbital and limit set maps, K(x) and L(x), where K and L are considered as maps from X to $2^X$. The main purpose of this paper is to extend continuity and stability for dynamical systems to general dynamical systems.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제19권3호
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• pp.263-271
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• 2012

We introduce the concept of fuzzy $r$-minimal ${\beta}$-open set on a fuzzy minimal space and basic some properties. We also introduce the concept of fuzzy $r-M$ ${\beta}$-continuous mapping which is a generalization of fuzzy $r-M$ continuous mapping and fuzzy $r-M$ semicontinuous mapping, and investigate characterization for the continuity.

• KSBB Journal
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• 제24권1호
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• pp.70-74
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• 2009

본 연구에서는 음식물쓰레기를 당화시키기 위해 섬유소분해효소를 효율적으로 배양하고자 먼저 refill하는 멘델배지의 농도를 0.5%로, 새로운 배지의 주입시간을 12시간으로 결정하였다. Flask 레벨에서는 fill-and-draw 방법으로 12시간 단위로 연속배양한 결과, amylase 활성은 300시간까지 1.0 U/mL 내외로 유지되었으며, FPase 활성은 156시간까지 0.40 U/mL 이상으로 유지되었다. 이때의 효소생산성은 amylase 3.49 U/L. hr, FPase 1.02 U/L. hr 이었다. 10 L에서는 batch, fed-batch, fill-and-draw 방법으로 효소를 생산한 결과 batch에서 가장 높은 효소생산성을 나타내었으며, 그다음은 fed-batch 이었다. Batch에서의 효소생산성은 amylase 42.30 U/L. hr, FPase 5.60 U/L. hr, fed-batch에서는 각각 23.03, 2.76 U/L. hr 이었다. 그리하여 T. inhamatum KSJ1을 이용한 섬유소분해효소의 연속배앙에서 10 L 생물반응기에서 fed-batch 빙법이 가장 효율적이었다.

• Nonlinear Functional Analysis and Applications
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• 제26권4호
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• pp.749-780
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• 2021

In this paper, we give the notion of M(., .)-𝜂-proximal mapping for a nonconvex, proper, lower semicontinuous and subdifferentiable functional on Banach space and prove its existence and Lipschitz continuity. As an application, we introduce and investigate a new system of variational-like inclusions in Banach spaces. By means of M(., .)-𝜂-proximal mapping method, we give the existence of solution for the system of variational inclusions. Further, propose an iterative algorithm for finding the approximate solution of this class of variational inclusions. Furthermore, we discuss the convergence and stability analysis of the iterative algorithm. The results presented in this paper may be further expolited to solve some more important classes of problems in this direction.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.347-351
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• 2002

Benzoate produced from the degradative pathways of various aromatic chemicals is generally recognized as a pollutant compound. However, various bacterial strains isolated as benzoate degraders have exhibited certain limits to their functions, including a loss of viability and degradability when cultivated in a broth medium for a longer time. Accordingly, immobilization techniques have been utilized to overcome such problems, and the current study examined the use of alginate and polyurethane for immobilizing Klebsiella oxytoca C302 to extend its viability and degradability of benzoate. The organism was well encapsulated by both matrices and the immobilized cells showed a high stability as regards their viability and degradability of 2 mM benzoate in a MM2 broth medium during cultivation for longer than 60 h in a semicontinuous batch system.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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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.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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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.

• 한국수산과학회지
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• 제40권2호
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• pp.95-101
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• 2007

We investigated the growth and phosphate uptake of a toxic dinoflagellate, Gymnodinium catenatum, isolated from Yeosuhae Bay, South Korea. A short-term phosphate uptake experiment revealed that its maximum uptake and the half-saturation constant were 1.39 pmol/cell/hr and $2.65{\mu}M$, respectively. In a semicontinuous culture, the maximum specific growth rate and minimum phosphorus cell quota of G. catenatum were 0.39/day and 1.27 pmol/cell, respectively. Thus, G. catenatum is a poor competitor in terms of inorganic nutrient use and is unlikely to form blooms in Yeosuhae Bay.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.306-312
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• 2006

Two culture modes, continuous and semi-continuous, of the decolorization fungus, Geotrichum candidum Dec 1, were compared to obtain a high treatment efficiency of molasses decolorization and a large productivity of peroxidase (DyP) to simultaneously decolorize dyes and molasses. The continuous culture of G. candidum Dec 1 using a 5-I jar-fermentor showed high DyP activity at a low dilution ratio of $0.005h^{-1}$, and decolorization ratio of molasses of 80% was obtained concomitantly. Therefore, a semi-continuous culture was performed by repeated refill and draw. In this mode, approximately 1.5 liters of the culture broth was replaced per cycle when the decolorization ratio of molasses was near 80%. The molasses medium (1.0 liter per day) was treated and the peroxidase productiveity in the drawn culture broth was 26.6U/day, whereas the peroxidase productiveity was 17.9U/day in the continuous culture with a dilution rate of $0.005h^{-1}$. The semi-continuous treatment system was an efficient decolorization method for the strain, G. candidum Dec 1.