• 한국식품영양과학회지
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• 제27권1호
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• pp.51-56
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• 1998

A bacteium, KP-6408, capable of hydrolyzing fibrin was isolated from Chungkook-jang, which was possibly identified as a strain of Bacillus sp. The effects of culture condition and medium composition on the enzyme production were investigated. Among nitrogen sources tested, yeast extract was the most effective for the enzyme production, and the level of the concentration for the optimal enzyme production was 0.2%(w/v). For carbon sources, glucose was the best for the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the organism at the liquid medium of the initial pH 8.0 and temperature of 4$0^{\circ}C$. In Chungkook-jang fermentation, the enzyme was maximally produced when incubated at 35$^{\circ}C$ for 24 hrs using soybean as a solid medium. The addition of various rice starch to the soybean in Chungkook-jang fermentation lowered the enzyme production.

• 한국식품영양과학회지
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• 제32권2호
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• pp.181-184
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• 2003

G. persimonensis-KJ145를 차용하여 BC 생산과 식초생산에 미치는 에탄올의 영향을 조사하였다. 그 결과 사과쥬스배지에 에탄올을 2%(v/v) 첨가하였을 때 BC의 생산성이 가장 좋았으며, 7%(v/v)를 첨가하였을 때 총산의 함량이 가장 높았다. BC와 식초를 동시 생산하기 위해서는 에탄올을 5%(v/v) 첨가하는 것이 가장 좋을 것으로 생각되며 발효과정 중의 식초 품질 변화에 대한 보다 자세한 연구가 요구되었다. BC와 식초 생산에 가장 효과적인 질소원은 CSL인 것으로 조사되었고 최적 농도는 15%(w/v)이었다. 배양시간의 영향을 조사한 결과 14일간 배양하는 것이 가장 많은 양의 BC를 생산하였으며, 최적조건에서 생산되는 BC 생산량은 7.55 g/L이었다.

• 미생물학회지
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• 제41권2호
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• pp.130-134
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• 2005

Monascus purpureus KCCM 60016을 이용하여 다량의 색소생산 변이주를 개발하고 생산조건에 대하여 조사하였다. 자외선 조사로 M. purpureus KCCM 60016으로부터 돌연변이를 유도한 결과, 색소생성이 우수한 P-57 변이주를 분리하였다. 분리된 P-57 변이주는 고체 배양에서 현미를 기질로 했을 때 색소생성이 가장 우수한 것으로 나타났으며, 색소생성의 최적 배양조건은 배양온도 $30^{\circ}C,\;90\%$의 배양습도에서 30일간 배양이 가장 우수했다. 이상의 조건에서 배양한 적색색소, 오렌지색소와 황색색소의 양은 각각 160.0 unit, 193.6 unit와 141.6 units-나타났다.

• 품질경영학회지
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• 제32권3호
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• pp.109-125
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• 2004

This paper deals with an optimal process control problem in production of hull structural steel plate with high defective rate. The main quality characteristic(dependent variable) is the internal quality(defect) of plates and is dependent on process parameters(independent variables). The dependent variable(quality characteristics) has three categorical ordinal data and there are 35 independent variables(29 continuous variables and 6 categorical variables). In this paper, we determine the main factors and to develop the mathematical model between internal quality predicted probabilities and the main factors. Secondly, we find out the optimal process condition of main factors through analysis of variance(ANOVA) using simulation. We consider three models to obtain the main factors and the optimal process condition: linear, quadratic, error models.

• 대한기계학회논문집
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• 제16권12호
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• pp.2216-2225
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• 1992

본 연구에서는 제약조건중 절삭조건 뿐만 아니라 작업 가공 목표, 즉 현장에 서 중요시하는 표면조도를 제약조건에 첨가하여 가공조건의 최적화를 꾀하였다. 또 한 앞의 논문들에서 적응제어나 R-T-F의 개념으로 경제성으로 고려한 최적 절삭 조건 을 구하였으나 본 논문에서는 국내 업체의 노무비 및 간접비로 최소 가공비를 구하고, 이에 대응하는 최적 절삭 속도 및 최대 생산율을 검토하였다. 그리고 이송변화에 따 른 최적 절삭 속도의 영향을 검토하여 생산 가공의 경제성을 제고하였다. 또한 각 업체의 선삭작업에 해당하는 입력 데이터만으로 경제성을 고려한 최적 절삭 조건의 자 동 설정을 하기 위한 프로그램을 구축하였다. 그러므로 이와같은 방법으로 현재 업 체의 장비와 인원만으로 기계 가공의 최적 조건 선정을 자동화 하므로써 생산성 향상 과 원가 절감의 효과를 극대화 할 수 있을 것으로 기대된다.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.46-51
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions. Among lipases functioning under extreme conditions, alkaline lipase is useful in detergent industry. Lipase from yeast strain Yarrowia lipolytica NRRL Y-2178 was most active under alkaline condition, and initial medium pH for most lipase production was also alkaline [Lee et al., 2007, J Microbiol Biotechnol, 17(6)]. High lipase production was achieved using Y. lipolytica NRRL Y-2178. Optimal incubation time for lipase production at $25^{\circ}C$ was 72 h. Optimal temperature, when incubated for 72 h, was $27.5^{\circ}C$. Lipase production but not cell growth was very sensitive to concentrations of glucose and glycerol as efficient carbon sources, showing optimal concentrations of 1.0 and 1.5% (w/v), respectively. Lipase production was highly stimulated by $Ca^{2+},\;K^+,\;and\;Na^+$, but was inhibited by $Co^{2+},\;Cu^{2+},\;Mn^{2+},\;Na^+,\;and\;Fe^{2+}$. Maximum lipase production at 0.1 mM $Ca^{2+}$ for 72 h incubation at $27.5^{\circ}C$ was 649 units/mL.

• KSBB Journal
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• 제13권5호
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• pp.491-496
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• 1998

The production of fibrinolytic enzyme from Bacillus subtilis BK-17 was studied in the shake flask cultures. The important medium components studied include nitrogen source, carbon source and inorganic salts. The environmental conditions include initial pH, temperature, shaking speed and working volume. Among various N-sources, C-sources and inorganic salts tested, soybean flour, D-glucose and Na2HPO4 gave the best results, and their optimal concentrations were 1.5%, 0.5% and 0.05%, respectively. The optimal pH and temperature were 9.0 and 37$^{\circ}C$. With decreasing working volume in the range of 25∼100ml in the 250ml flask or increasing shaking speed in the range of 100∼300rpm, the enzyme production was greatly enhanced. The enzyme activity under the optimal conditions was about 1400I.U./ml with urokinase as a standard.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1215-1220
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• 2004

Reactive distillation (RD) is a combination process where both separation and reaction are considered simultaneously in a single vessel. This kind of combination to enhance the overall performance is not a new attempt in the chemical engineering areas. The recovery of ammonia in the classic Solvay process for soda ash of the 1860s may be cited as probably the first commercial application of RD. The RD system has been used for a long time as a useful process and recently the importance of the RD is enlarged more and more. In addition to that, the application fields of RD are diversely diverged. To make the most of the characteristic of RD system, we must decide the best operating condition under which the process shows the most effective productivity and should decide the best control algorithm which satisfies an optimal operating condition. Phosgene which is a highly reactive chemical is used for the production of isocyanates and polycarbonates. Because it has high reactivity and toxicity, its utilization is increasingly burdened by growing safety measures to be adopted during its production. Dimethyl Carbonate (DMC) was proposed as a substitute of phosgene because it is non-toxic and environmentally benign chemical. In this study, RD is used for DMC production process and the transesterification is performed inside of column to produce DMC. In transesterification, the methanol and ethylene carbonate (EC) are used as the reactants. This process use homogeneous catalyst and the azeotrope exists between the reactant and product. Owing to azeotrope, we should use two distillation columns. For this DMC production process, we can suggest two configurations. One is EC excess process and the other is methanol excess process. From the comparison of steady state simulation results where the Naphtali-Sandholm algorithm is used, it showed the better performance to use the methanol excess process configuration than EC excess process. Then, the dynamic simulation was performed to be based on the steady state simulation results and the optimal control system was designed. In addition to that, the optimal operating condition was suggested from previous results.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.130-136
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• 1998

참당귀 세포(Angelica gigas H4)를 현탁배양하여 면역 증강성 다당을 생산하기 위한 최적배지 설계 및 생산조건 최적화 연구를 수행하였다. 우선 세포의 성장에 가장 좋은 배지로서 Schenk and Hildebrandt(SH) 배지를 선택하여 배양한 결과 $25^{\circ}C$, 암배양조건에서 각각 15.8g DCW/l와 0.85 g/l의 세포 및 다당을 얻을 수 있었다. 한편 다당 생산용 배지의 개발을 위하여 여러 가지 식물세포배양용 배지 중에서 다당 생산능이 가장 높은 배지로서 Gamborg B5 배지를 선정하였으며 B5 배지를 변형하여 면역증강성 다당생산을 위한 최적배지(PPM)를 개발하였다. 그리고 최적배지를 이용한 당귀 세포증식과 다당 생산을 위한 최적 pH는 6.0-6.5, 배양온도는 $20^{\circ}C$, 그리 고 광조건보다는 암조건이 좋은 것으로 밝혀졌다. 상기 최적조건에서의 최대 세포증식과 다당생산은 각각 14.8 g/l, 1.5 g/l 이었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.211-214
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• 2002

The optimal condition for the production of DXAMase, containing the both characteristics of dextranase and amylase, was studied based on different levels of pH, temperature, and aeration rate. Response surface methodology was applied to find the optimatic condition showing the relationship between the fermentation response(dextranase and amylase activity of DXAMase) and the fermentation variables(pH, temperature, and agitation rate). In case of dextranase activity, the condition of pH 4.06, $28.08^{\circ}C$, and 235.14 rpm showed the highest activity, 2.26 U/ml, and for amylase activity, the condition of pH 4.01, $27.96^{\circ}C$, and 212.01 rpm showed the highest activity, 3.52 U/ml. For the production of DXAMase, dextranase and amylase, the optimum condition was pH 4.06, $28.08^{\circ}C$, and 234.80 rpm.