• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.105-108
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• 2003

To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g/L YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 ${\mu}g/mL$, which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced $q_{hTPO}$ and increased culture longevity. In addition YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells.

• Journal of Microbiology and Biotechnology
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• v.5 no.3
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• pp.149-153
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• 1995

A simple and low-cost medium was developed for the growth of Bifidobacterium longum KFRI 977. Of three bifidobacterial strains, B. longum KFRI 977 (ATCC 15707) showed the best growth in MRSC broth containing 0.3% oxgall, grew well in partially anaerobic condition, exhibited highest $\beta$-galactosidase activity, and was inhibitory against Clostridium perfringens KFRI 434. Of three developed media, the population of B. longum KFRI 977 was highest (1.9$\times$$10^9$/ml) in ISP based medium. The composition of ISP based medium is ISP (5%), glucose (1%), L-cysteine HCI (0.05%), Trypticase peptone (0.5%), yeast extract (0.5%), $MgSO_4$ (0.05%), Tween-80 (0.1%), and phosphate buffer (pH 7.0). Hydrolysis of ISP by Protease A was unnecessary, and the use of phosphate buffer (pH 7.0) prevented the formation of protein precipitate. Associative culture of B. longum KFRI 977 with Lactobacillus acidophilus KFRI 233 was proven to be deleterous to the growth of B. longum KFRI 977.

• Journal of the Korean Home Economics Association
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• v.39 no.12
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• pp.107-127
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• 2001

The objectives of this study were to investigate how the types of awareness of cost and benefit of consumer complaining behavior about the private educational institute services were classified, how different demographic and consumer complaining rebated characteristics were according to the types of awareness of cost and benefit about consumer complaining behavior, and what were the determinant factors of the types of awareness of cost and benefit about consumer complaining behavior. The survey of this study was conducted by means of self-administered questionnaire with 546 university students living in Seoul and Cheongjoo. They had an experience of studying in the private educational institute in recent two years. Major findings were as following: (1) The types of awareness of cost and benefit of consumer complaining behavior about the private educational institute services were classified into four - awareness of high cost and low benefit, high cost and high benefit, low cost and medium benefit, medium cost and medium benefit. (2) The attitude about complaints, the confidence of success about complaint, and the knowledge about complaints were different significantly according to the types of awareness of cost and benefit about consumer complaining behavior. (3) The types of awareness of cost and benefit about consumer complaining behavior were different significantly according to only a school year among demographic characteristics. (4) The determinant factors of the types of awareness of cost and benefit about consumer complaining behavior were the attitude about complaints, the confidence of success about complaints, the knowledge about complaints, and the major field of study.

• Ocean and Polar Research
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• v.35 no.4
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• pp.407-414
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• 2013

One of the most important challenges facing the Spirulina mass cultivation industry is to find a way to reduce the high production costs involved in production. Although the most commercial medium (Zarrouk's medium) for Spirulina cultivation is too expensive to use, it contains higher amount of $NaHCO_3$ (16.80 g $L^{-1}$), trace metals and vitamin solutions. The purpose of this study was to increase the efficiency of Spirulina platensis biomass production by developing a low-cost culture medium at an isolated tropical island such as Chuuk State, Federated States of Micronesia (FSM). This study set out to formulate a lowcost medium for the culture of S. platensis, by substituting nutrients of Zarrouk's medium using fertilizer- grade urea and soil extract with a different concentration of carbon source under natural weather condition. In order to select a low-cost culture medium of S. platensis, 10 culture media were prepared with different concentrations of nitrogen (urea and $NaNO_3$) and $NaHCO_3$. The highest maximum specific growth rate (${\mu}max$) and mass production were 0.50 $day^{-1}$ and 1.05 g $L^{-1}$ in modified medium ($NaHCO_3$ 7.50 g $L^{-1}$, urea 2.00 g $L^{-1}$ without $NaNO_3$) among all the synthesized media. Protein (56.14%) and carbohydrate (16.21%) concentrations of the lyophilized standard samples were estimated with highest concentration of glutamic acid (14.93%). This study revealed that the use of a low concentration of urea and $NaHCO_3$ with soil extract was an affordable medium for natural mass cultivation in the FSM.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.812-819
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• 2014

The proposed technical work attempts to compare the two key technologies of power distribution, i.e. direct current (DC) and alternating current (AC) in a fiscal manner. The DC versus AC debate has been around since the earliest days of electric power. Here, at least four types of a low voltage DC (LVDC) distribution are examined as an alternative to the existing medium voltage AC (MVAC) distribution with an economic assessment technique for a project investment. Besides, the sensitivity analysis will be incorporated in the overall economic analysis model to cover uncertainties of the input data. A detailed feasibility study indicates that many of the common benefits claimed for an LVDC distribution will continue to grow more profoundly as it is foreseen to arise with the increased integration of renewable energy sources and the proliferation of energy storage associated with the enhanced utilization of uninterruptible power supply (UPS) systems.

• The Journal of Fisheries Business Administration
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• v.8 no.2
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• pp.1-19
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• 1977

The results analyzed of the actual state of medium size two-boat trawler fishery based on the cost expended in 1975 are as follows: According to the calculation of interest, the total cost of this fishery comes to ￦ 55,353,807, and in this account, the production cost comes to ￦ 49,747,383 (89.9%) and the material cost comes to ￦ 27,027,662(48.8%), the labour cost comes to ￦ 10,381,013 (18.8%) the expenses, ￦12,338,708(22.3%) and commision and interest comes to ￦ 5,606,424 (10.1%). As above the fishery comes is 90% of production cost for the expense of production. The ratio of cost element to the total cost 100 is as follow: Fuel: 23.6%, allocation: 14.3%, fishing gear: 14.1%, boat repair: 13.0%, fish box: 8.5%, ice: 14.1%, commission: 6.9%, food cost: 4.5%, interest: 3.2%, transportation fee: 2.8%, consumption: 2.6%, tax: 2.5%, depreciation: 2.4%, administrative expense: 1.6%. The unit cost of catches to each box, including the interest, cames to ￦ 2,167 and not calculating the interest it comes to ￦ 2,098. The cost production to each kg comes to ￦ 114 including interest, without interest, it comes ￦110. When the production cost comes to 90.6%, it comes to 9.4% of total revenue. The reason which this fishery brings low income is that the boats are almost old and semi-diesel engine is used. So, fuel expense and repaire expenses needs too much. Acconding to above this fishery needs to replace new boat and new engine. And new are for this fishery needs to bring under cultivation in order to bring good income with the new method for this fishery. Specially, this fishery brings low income from July to September because of its rest from labour. And so, the expenses, item, and account of money, and the trust money the cost element are not showed in August.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1531-1541
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• 2023

Lipase is a well-known and highly in-demand enzyme. During the last decade, several lipase optimization studies have been reported. However, production costs have always been a bottleneck for commercial-scale microbial enzyme production. This research aimed to optimize the conditions for lipase production by Limtongozyma siamensis DMKU-WBL1-3 via a One-Factor-At-a-Time (OFAT) approach combined with statistical methods while using a low-cost substrate. Results suggest that low-cost substrates can be substituted for all media components. An optimal medium was found, using response surface methodology (RSM) and central composite design (CCD), to consist of 0.50% (w/v) sweet whey, 0.40% (w/v) yeast extract (food grade), and 2.50% (v/v) palm oil with the medium pH adjusted to 4 under shaking flask cultivation. From an economic point of view, this work was successful in reducing production costs while increasing lipase productivity. The medium costs were reduced by 87.5% of the original cost while lipase activity was increased by nearly 6-fold. Moreover, lipase production was further studied in a 2-L stirred-tank fermentor. Its activity was 1,055.6 ± 0.0 U/ml when aeration and agitation rates were adjusted to 1 vvm and 170 rpm, respectively. Interestingly, under this optimal lipase production, the yeast showed accumulated lipids inside the cells. The primary fatty acid is a monounsaturated fatty acid (MUFA) that is typically linked to health benefits. This study hence reveals promising lipase production and lipid accumulation by L. siamensis DMKU-WBL1-3 that are worthy of further study.

• KSBB Journal
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• v.7 no.2
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• pp.96-101
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• 1992

A low serum medium(LSM) suitable for the growth of a self-constructed hybridoma cell line, KA112, was established by selecting ingredients to replace serum. Insulin and sodium pyruvate was important for the growth of cell line KA112. Various basal media were tested and DMEM gave the most favorable result. Low serum medium (LSM) developed in this work showed cell line stability in the culture for more than 6 months and exhibited cell growth equivalent to that carried out in medium supplemented with 7% FBS. LSM was found to be applicable to the suspension culture of KA112. The reduction of serum level down to 1%(V/V) FBS in LSM resulted in a substantial saving in the cost of media preparation for large scale culture.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.303-309
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• 2009

Switched Reluctance Motor(SRM) has become popular for industrial application, particularly for low medium drives due to the advantages of SRM over the other ac motors: SRM can be manufactured with low cost because it has a simple structure. But, asymmetric bridge converter that generally is used for driving requires two discrete switching devices and freewheeling diodes per phase, and cause the SRM drives to be complicated and to increase the cost of overall system. Therefore, this paper suggests a new type of 4-switch converter for SRM. 4-switch converter topology is studied to provide a possibility for the realization of low cost 3-phase SRM drive system. For effective utilization of the developed system, a new current control algorithm is designed and implemented to produce the desired dynamic performance. With the developed power conversion circuit and control scheme, it is expected that the proposed system can be widely used in commercial applications with reduced system cost.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.483-489
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• 2004

The purpose of this paper is to establish the policy for the abroad promotion of small-medium and venture businesses. The core strategy is enhancing the total sales trough the low management cost and low advertisement cost. The Partnership Management by the Export Cooperation Organisation is a model which is maximize the outputs and profits at the same time minimize the fixed costs, advertisement costs etc. The effect of synergy from the grand exhibition and partnership management will be a critical momentum to the national business that concrete and diversify the export.