• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.292-301
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• 1999

• Mycobiology
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• v.43 no.1
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• pp.14-23
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• 2015

The influences of temperature and nutritional conditions on the mycelium growth of oyster mushroom Pleurotus ostreatus (PO) and Pleurotus cystidiosus (PC) were investigated in laboratory experiment during the summer season of 2014. The results of the experiment indicated that potato dextrose agar (PDA) and yam dextrose agar (YDA) were the most suitable media for the mycelium growth of oyster mushroom PO while four media (PDA, YDA, sweet potato dextrose agar, and malt extract agar medium) were not significantly different in supporting mycelium growth of oyster mushroom PC. The optimal temperature for mycelium growth of both oyster mushroom species was obtained at $28^{\circ}C$. Mycelium growth of oyster mushroom PO was improved by carbon sources such as glucose, molasses, and at 1~5% sucrose concentration, mycelium colony diameter of mushroom PO was achieved the highest value. Whereas glucose, dextrose, and sucrose as carbon sources gave the good mycelium growth of oyster mushroom PC, and at 1~3% sucrose concentration, mycelium colony diameter of PC was achieved the maximum value. Ammonium chloride concentrations at 0.03~0.09% and 0.03~0.05% also gave the greatest values in mycelium colony diameter of mushroom PO and PC. Brown rice was found to be the most favourable for mycelium growth of two oyster mushroom species. In addition, sugarcane residue, acasia sawdust and corn cob were selected as favourable lignocellulosic substrate sources for mycelium growth of both oyster mushrooms.

• Management & Information Systems Review
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• v.9
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• pp.65-80
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• 2002

As the growth of Internet business, many web sites have been developed their own Internet business strategies. Yet, many web sites have difficulties to make profit. In this paper, an economic model is developed to analyze web sites' quality and pricing strategies when they initiate their services as free services and develop advertising services and other charged services. By analyzing the economic model, optimal quality and prices was found. And by analyzing the optimal strategy, I found that web sites should properly decide their market share on initial customer. Finally, the importance of web sites' productivity to make profit is emphasized.

• Journal of applied mathematics & informatics
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• v.6 no.1
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• pp.127-142
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• 1999

This paper develops a methematical model for growth and exploitation of a schooling fish species using a realistic catch-rate function and imposing a tax on the catch to control harvesting. Fishing effort is assumed to depend on the net revenue. The steady states of the system are determined and their local and global stabil-ity are discussed. Taking the tax as a control variable; the optimal harvest policy is formulated and solved as a control problem. The results are illustrated with the help of a numerical example.

• Korean Management Science Review
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• v.18 no.2
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• pp.87-96
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• 2001

Mobility of service users makes Registration and Paging (R/P) procedures indispensable features in mobile communication networks. Importance of optimizing the configuration of R/P areas has been increased by the growth of R/P related signaling. Given the network topology (cell locations and adjacency between them) and R/P related traffics generated by each cell, we deal with the problem of finding optimal R/P areas minimizing the amount of R/P related signalling while the constraints on paging channel capacity and network configurations are satisfied.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.13 no.1
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• pp.7-14
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• 1987

Production of shikonin derivatives through cell suspension culture of Lithospermum erythrorhizon was investigated. Optimal concentrations of IAA and kinetin on the growth of cell suspension were 0.2 and 0.1 ppm respectively. Pigment content was markedly increased when aluminum oxide was added to the production medium and its optimal concentration was 1.5g/70ml medium. The most effective concentration of IAA was 0.5 ppm and the production of pigment did not depend on the kinetin concentration.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.98-106
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• 2014

This study was carried out to evaluate the plant growth rate according to the wavelength characteristics of LED light sources. In order to achieve this, red, green, blue and white LEDs were arrayed in a rectangle array consisting of LED modules which can be combined with each other.. This can facilitate the selection of the optimal characteristics of the light from monochromatic red, green, blue and white LEDs or mixed LEDs for plant growth. Experiments to evaluate the growth rate according to the wavelength characteristics of the LEDs with several plants, in this case ice plants, lettuce, barley, broccoli and chives, were performed.

• Mycobiology
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• v.33 no.1
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• pp.12-14
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• 2005

The culture conditions for the enhanced mycelial growth of Ramaria botrytis was investigated. The optimal temperature and pH for the mycelial growth were $24^{\circ}C$ and 5.0, respectively. It was shown that starch was best of several carbon sources in Czapek-Dox medium as a minimal medium for the enhanced mycelial growth. Organic nitrogen sources were better than inorganic ones for mycelial growth. The appropriate vitamin and mineral salt were biotin and FeCl3, respectively. When this strain was cultured with $FeCl_3$ for 30 days, 19.23 g/l of dry mycelium of R. botrytis was obtained.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.181-184
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• 2001

The biological fixation of carbon dioxide using microalgae have many advantages over chemicals and remove carbon dioxide simultaneously. A ketocarotenoid astaxanthin is hyper-accumulated in the green freshwater microalga, Haematococcus pluvialis. In the present study, the combine effects of carbon dioxide concentration and light intensity on the growth of H. pluvilais were investigated. The carbon dioxide concentration above 10% caused a severe inhibition and around 5% is optimal for growth. Adaptation to high concentration of carbon dioxide enhanced the $CO_2$ tolerance. Specific growth rate calculated differently based upon cell number or dry weight because of the distinctive life cycle patterns of H. pluvialis : small-sized motile green cell and thick cell walled red cyst cell. Based on the light dependence of H. pluvialis, internally illuminated air-lift photobioreactor was designed and operated. Gradual increase of light supply gave more active growth and more effective productivity of astaxanthin than constant light supply.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.153-156
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• 2003

The MRS medium is widely used as an optimized medium for the growth of Lactobacillus spp. and also used for the growth of Leuconostoc spp. Leuconostoc mesenteroides shows quite different physicochemical properties compared to Lactobacilli spp. and it is one of the major strain of kimchi fermenting microorganisms with its usefulness in our traditional foods and availability in biotechnology in the future, specifically tailor-made medium is necessary for the growth of Leuconostoc mesenteroides. Sequential experimental designs (Plackett-Burman, fractional factorial, steepest ascent, central composite design and response surface methodology) were introduced to optimize and improve the Leuconostoc medium. Fifteen medium ingredients were investigated and fructose, sodium acetate and ammonium citrate were determined to give a critical and positive effect for cell-growth. The yield of biomass using the optimal medium was improved more than that of the MRS medium and the result of fed-batch culture showed the capability of the improvement in cell mass similar to the E.coli system.