• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.76-81
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• 2000

In this Paper, an improved L-Expressnet Protocol is proposed by supplementing slot-extension function. This protocol is Proposed to complement the shortcomings of the conventional protocol which is used for the medium access control (MAC) in LAN. We analyzed the protocol in channel utilization viewpoint and compared the result with that of the conventional L-Expressnet medium access control (MAC) protocol. From this result. we showed that the channel utilization of the improved L-Expressnet protocol added slot-extension function is superior to that of the conventional Protocol.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.392-397
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• 2022

Methane is one of the major greenhouse gases, recently, the biotechnological conversion from methane to high-value added chemicals have emerged as an effort to reduce methane gas emission. In this study, we optimized ectoine bio-milking conditions in which cells were repeatedly used to improve intracellular and extracellular ectoine yield from methane by using Methylomicrobium alcaliphilum 20ZDP2. First, the cultivation and intracellular ectoine accumulation conditions were optimized with respect to the growth phase and medium salinity to achieve the highest yield of synthesis. Second, ectoine excretion was optimized by determining the ectoine secretion time (15 min) in appropriate medium salinity under hypoosmotic conditions (1% NaCl). Finally, bio-milking of ectoine was successfully repeated more than 10 times using M. alcaliphilum 20ZDP2, and the ectoine yield was improved up to 129.29 mg/ DCW g.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.644-648
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• 2001

The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of the media is a key factor for improving in vitro mass production of entomopathogenic nematodes. This study reports the effect of medium concentration. The medium is a combination of carbohydrates, lipids, proteins, sats, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus liminescens. The overall optimal medium concentration for nematode recovery, hermaphrodite size, bacterial mass, infective juveniles (IJs) yield, and doubling time was 84 g/l. At this concentration rate, the doubling time of IJs production and the biomass of symbiotic bacteria was 1.6 days and 12.8 g/l, respectively. The maximum yield of $2.4{\times}{10^5}IJs/ml$ was attained within a one-generation cycle (eight days). The yield coefficient was $2.8{\times}{10^6}$ IJs/g medium, and the maximum productivity was $3.1{\times}{10^7}$ IJs per day. Medium concentration affected two independent factors, recovery and hermaphrodite size, which in turn influenced the final yield.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.33-54
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• 2016

In the modern society based on information and communication, which is exposed to the risks of a lot of information security breaches, corporate information assets may be an economical scale in a country. Most of damages derived from corporate technological information leak often occur in small and medium corporations. Although many information security managers in corporations have focused on certification systems such as information security management system, small and medium corporations are poorly aware of the information security, and their environments surrounding it should be also improved. In addition, it is difficult to expect spontaneous participations in it, since the sustainable information security management systems are often not forced to be certified. Thus, the purpose of this study is to examine plans to improve small and medium corporations' technological protections by using some component of the information security management system. On the basis of this examination, it also attempts to discuss some methods for effective and efficient information security in the small and medium corporations' technological protections.

• Journal of Life Science
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• v.12 no.1
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• pp.19-21
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• 2002

The pathway of embryos formed anther culture in herbaceous peony was influenced by addition of 2,4-D. MS medium with 2,4-Dichlorophenoxy acetic acid (2,4-D) alone did not arise direct embryogenesis, but was proliferate callus. Embryos through calli were produced on medium containing 0.2 mg/1 zeatin or without growth regulators. Direct embryogenesis was obtained from MS basal medium. However, after the anthers were cultured on medium with 0.1 mg/1 2,4-D, 3 g/1 AC, 30 g/1 sucrose, 2 g/1 gelrite for 40 days. Its efficiency (32.3 %) was markedly improved when anthers cultured on medium without 2,4-D. Embryo morphology was also affected by the 2,4-D used in medium. The induction of normal embryos with two cotyledons was higher in the embryos formed through direct embryogenesis than those formed callus. The embryos formed from calli were mainly showed abnormal embryo with one, three, four cotyledons or hors and bowling pin type.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.137-142
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• 2000

Calli were induced from the explants of infloresence, petiole and leaf blade of Cnidium officinale on MS medium with 2.4-D, while embryogenic callus was induced only from inflorescence explants. Somatic embryos of 78 per explant were formed during subculture of the explants on medium without 2.4-D after culture on medium with 2 mg/L 2.4-D. Cotyledonary variation, cup-shaped cotyledon of 49% and other abnormal cotyledons of 13.5 % was observed on the somatic embryos. However this variation could be overcomed by the addition of activated charcoal onto culture medium. Somatic embryos at cotyledonary stage germinated on MS basal medium but the germination rate was very poor, blow 50 %. Somatic embryos on the medium with activated charcoal showed improved germinaton.

• The Journal of Society for e-Business Studies
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• v.19 no.4
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• pp.195-204
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• 2014

Recent, Secure the small and medium-sized enterprises from advanced and intelligence cyber threat, 24 hours of prevention, detection and analysis is essential. Small and Medium Business monitoring center is operated by government financial support to protect and prevent these threats. Currently it provides security to about 900 small and medium-sized enterprises. This paper studies abnormal and attack packets from small and medium-sized businesses[enterprises] which is monitored by Small and Medium Business monitoring center and provides improvement of security control for small and medium-sized enterprises.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1747-1756
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• 2013

The aim of this paper was to study the effect of spent medium recycle on Spodoptera exigua Se301 cell line proliferation, metabolism, and baculovirus production when grown in batch suspension cultures in Ex-Cell 420 serum-free medium. The results showed that the recycle of 20% of spent medium from a culture in mid-exponential growth phase improved growth relative to a control culture grown in fresh medium. Although both glucose and glutamine were still present at the end of the growth phase, glutamate was always completely exhausted. The pattern of the specific glucose and lactate consumption and production rates, as well as the specific glutamine and glutamate consumption rates, suggests a metabolic shift at spent medium recycle values of over 60%, with a decrease in the efficiency of glucose utilization and an increase in glutamate consumption to fuel energy metabolism. Baculovirus infection provoked a change in the metabolic pattern of Se301 cells, although a beneficial effect of spent medium recycle was also observed. Both growth rate and maximum viable cell density decreased relative to uninfected cultures. The efficiency of glucose utilization was dramatically reduced in those cultures containing the lowest percentages of spent medium, whereas glutamine and glutamate consumption was modulated, thereby suggesting that infected cells were devoted to virus replication, retaining their ability to incorporate the nutrients required to support viral replication. Recycle of 20% of spent medium increased baculovirus production by around 90%, thus showing the link between cell growth and baculovirus production.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.7-11
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• 1995

Protoplasts were isolated from hypocotyl tissues of 5-day-old Brassica oleracea var capitata Green Challenger seedlings. Several media were used for protoplast culture and shoot regeneration. The shoot-regeneration rapacity of protoplast derived callus depended on the initial culture medium. Protoplasts were cultured in liquid medium (B5 medium supplemented with CaCl2, 2H2O 600mg/L, g1ucose 20g/L, D-mannito1 70g/L, NAA lmg/L, BA lmg/L, 2.4-D 0.25 mg/L)at 27$^{\circ}C$ under the dark After 5 to 10 days, cultlues were diluted with medium with a reduced osmotic stabilizer and then transferred to illuminated conditions. The culture medium was changed with the fresh medium at 7- to 10-day-intervals until the formation of microcallus. Hypocotyl protoplast-derived callus proliferated when transferred to MS medium supplemented with NAA lmg/L, BA 1mg/L and GA$_3$ 0.02mg/L. Upon transfer to MS basal medium without growth regulators, roots were produced. In an attempt to increase the regeneration frequency, 10g/L polyvinylpyrrolidone was added to the regeneration medium, but the shoot regeneration was mot improved. The regenerated whole plants were acclimated in a sterized soilless mixture(vermiculite 2;perlite 2;peat moss1) in a culture room.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.343-349
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• 2012

The use of growth medium is often recommended milkweed seedlings to grow and develop after emergence, and it is affected by growth medium and local habitat conditions. The effects of growth medium and partial shade on early growth of milkweed under drought stress (Calotropis procera L.) were studied in a field experiment. A split-split plot experimental design with three replications was carried out in the nursery. The main treatment plot was divided into two levels of shade; (no shading and partial shading). Sub treatment plot1 included growth medium at four levels (G1 = clay [suitable for milkweed growth], G2 = clay + sand, G3 = clay + perlite, G4 = clay + perlite + sand) and sub treatment plot2 included drought (irrigation intervals) at six levels (D1 = 2 [control], D2 = 4, D3 = 6, D4 = 8, D5 = 10, and D6 = 12 days per for three month). The results showed that drought stress significantly decreased emergence percentage, shoot length, shoot dry weight (SDW1), root dry weight (RDW), seedling dry weight (SDW2) and vigor index (VI). The use of growth medium increased all seedling characteristics. The G3 (clay + perlite) growth medium showed the highest performance, especially in terms of emergence percentage and seedling dry weight. Partial shade improved shoot length, shoot dry weight, and vigor index. Our results showed that the best treatment for high-vigor milkweed seedlings under drought stress was G3 (clay + perlite) growth medium and partial shade.