• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1648-1653
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• 1999

A strain of potential producer of fibrinolytic enzyme was isolated from shrimp Jeot-Gal, a tiny salted shrimps, and identified as Bacillus sp.. The preliminary experiment showed an enzyme yield of 18 U/mL in medium for screening. The carbon, nitrogen and salts significantly influenced the fibrinolytic enzyme production. An optimized medium containing 2% skim milk, 2% soluble starch and 3% NaCl (pH 7.5) after 72 hrs fermentation time at $37^{\circ}C$ yielded 3-fold increase in enzyme production, 62 U/mL.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.512-515
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• 2005

An in vitro study was conducted to determine the effect of C18-polyunsaturated fatty acid on direct incorporation into the rumen bacteria, bio-hydrogenation and production of CLA in vitro. Sixty milligrams of linoleic acid ($C_{18:2}$) or linolenic acid ($C_{18:3}$) were absorbed into the 0.5 g cellulose powder was added to the 150 ml culture solution consisting of 120 ml McDougall's buffer and 30 ml strained rumen fluid. Four uCi of 1-$^{14}C_{18:2}$ or 1-$^{14}C_{18:3}$ (1 uCi/15 mg each fatty acid) were also added to the corresponding fatty acids to estimate the direct incorporation into the bacterial lipids. The culture solution was then incubated anaerobically in a culture jar with stirrer at 39$^{\circ}C$ for 12 h. Ammonia concentration and pH of the culture solution were slightly influenced by the fatty acids. Amount of fatty acid incorporated into the bacteria was 1.20 mg and 0.43 mg/30 ml rumen fluid for $C_{18:2}$ and $C_{18:3}$, respectively during 12 h incubation. Slightly increased CLA (sum of cis-9, trans-11 and cis-10, trans-12 $C_{18:2}$) was obtained from the $C_{18:3}$ addition compared to that from $C_{18:2}$ after 12 h incubation in vitro.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.894-896
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• 1999

PID 제어는 50년의 역사를 갖기 때문에 현장의 사용자는 이 제어방식에 익숙해져 있으며, 제어장치의 구성이 간단하며 제어기의 최적동조가 가능하므로 많은 분야에서 사용되고 있다[1]. 그러나 PID 제어기에 의해서 얻은 결과에 대하여 만족하기 위해서는 많은 시행착오를 겪어야 한다. 또한 만족하는 결과를 얻었다고 할지라도 외란, 플랜트의 동특성이 바뀌는 경우 시스템을 추종하지 못하기 때문에 파라미터를 재조정하여야 한다. 유전 알고리즘은 자연세계의 진화 현상에 기초한 계산모델로서 John Holland에 의해서 1975년에 개발된 전역적인 최적화 알고리즘이며[1][2], 비선형 고차원, 불연속, 다중모드, 노이즈 함수 등에 대하여 강건함을 보여주고, 복잡한 탐색 공간에서 최적 값을 스스로 발견하는 학습 능력을 갖는다. 이 방법은 재생산, 교배, 돌연변이를 통하여 최적해를 찾은 방법으로 1989년에 D. E. Goldgerg에 의해서 체계적으로 정리된 후 여러 분야에서 응용되고 있다[3][4]. 그러나 유전 알고리즘은 목적함수만을 이용하여 해집단을 탐색하기 때문에 숙련운전자가 원하는 제어 특성 명세인 상승시간, 정착시간, 초과량(oveshoot) 둥을 구체적으로 명시하여 제어에 반영할 수 없다. 또한, 유전 알고리즘은 입력 값이 크게 바뀔 경우 다른 시스템으로 인식하여 새로운 탐색을 수행하는 단점을 가지고 있다. 본 논문은 첫째, 기준모델을 도입하여 플랜트의 성능을 기준모델로 표현하여 플랜트가 요구하는 성능지표를 정량적으로 규정하는 것이 가능하였다. 또한, 이것은 미지 플랜트 동특성을 식별하기 위한 신호로 사용되어, 플랜트의 정보를 얻는데 이용되었다. 즉, 기준모델과 플랜트 출력사이의 추종 오차 정보가 적응기구인 PID 유전제어기의 입력으로 사용되며, 구형파 입력의 경우에도 기준모델과 플랜트의 출력차는 크게 변하지 않는다. 따라서, 유전 알고리즘의 목적함수에 기준 모델을 제안 적용하여 안정적이고, 세밀한 제어를 수행하였다. 둘째, PID의 간단하면서 확실한 제어가 가능하다는 점과 전역적인 최적값을 찾을 수 있는 유전 알고리즘을 적용하여 고속제어를 요하는 직류 서보 모터(DC Servo Motor) 운전 시 실시간 파라미터 동조에 적용하였다.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.1022-1031
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• 2008

Pound cakes were prepared with Citrus mandarin powder(CMP) cultivated in JeJu Island, Korea. The impact of CMP amount level, which was incorporated into wheat flour by the ration of 0, 5, 10, 15, and 20% based on a flour weight, on the rheology and sensory profile of the pound cakes was measured. Moisture content of 13.70%, crude protein 5.12%, crude lipid 1.30%, crud ash 1.92%, respectively. Also evaluation was performed on the changes in physicochemical properties of the pound cakes during storage at 4 and $30^{\circ}C$. According to the amylogram, gelatinization temperature of the control dough was $63.35^{\circ}C$ and those of the dough with CMP were $63.85{\sim}66.55^{\circ}C$. Maximum viscosity of the dough was 686 B.U in the control, those were 575 B.U, 553 B.U, 504 B.U and 401 B.U in the dough with 5, 10, 15, and 20% CMP, respectively. The retrogradation degree(setback value) of CMP dough was $31{\sim}57%$ lower than that of the control dough under the same conditions. Water holding capacity of pound cake was increased gradually in proportion to the amount of CMP. The CMP addition decreased the brightuess(L) of pound cakes but increased redness(a) and yellowness(b). Hardness of pound cakes was significantly increased by CMP addition, while springiness, adhesiveness and cohesiveness were decreased. Based on sensory evaluation, pound cakes added with CMP were not significantly different in color and texture, while that of 10% CMP was significantly high in taste, flavor, and overall preferences, compared to the control. pH of pound cake with CMP was decreased during storage, showing that pH of CMP samples was lower than the control. Titrated acidity of pound cake with CMP was increased rapidly from storage for 10 days, which the changes in degree was fast in accordance with CMP amount. The Hunter's color value of pound cake with CMP was decreased, as the storage time proceeded. In the samples prepared with CMP, the firmness, adhesiveness, gumminess and chewiness was increased as the storage time proceeded, while springiness and cohesiveness was decreased.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1501-1509
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• 2012

A novel bacterial strain, MG7, with high cellulase activity was isolated and identified by morphological characteristics and molecular phylogeny analysis as Paenibacillus barcinonensis. Maximum production of cellulase by MG7 was observed at pH 7.0 and $35^{\circ}C$. The enzyme was purified with a specific activity of 16.88 U/mg, the cellulase activity was observed in a zymogram, and its molecular mass (58.6 kDa) was confirmed by SDS-PAGE. The purified enzyme showed maximum activity at pH 6.0 and $65^{\circ}C$ and degraded cellulosic substrates such as carboxy methyl cellulose (CMC), Avicel, filter paper, and ${\beta}$-glucan. The enzyme showed stability with 0.5% concentration of various surfactants. The $K_m$ and $V_{max}$ of cellulase for CMC and Avicel were found to be 0.459mg/ml and 10.46mg/ml/h, and 1.01 mg/ml and 10.0 mg/ml/h, respectively. The high catalytic activity and its stability to temperature, pH, surfactants, and metal ions indicated that the cellulase enzyme by MG7 is a good candidate for biotechnological applications.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.45-50
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• 2000

For the maximum production of pullulan from glucose as a carbon source, the effects of glucose concentration, pH and dissolved oxygen concentration on the cell growth and mass production of high-molecular weight pullulan by A. pullulans ATCC 42023 were evaluated. A. pullulans showed optimum pullulan productivity when glucose concentration was 0.3M (54g/L). And inhibitory effects on the cell growth and the pullulan production were observed at the glucose concentration higher than 0.3M (54g/L). The influence of pH control and dissolved oxygen on the pullulan production and growth of A. pullulans was studied. In shake-flasks, maximum pullulan production was obtained with $11.98g/{\ell}$ when initial pH was 6.5. In the batch fermentation, the maximum pullulan production of $13.31g/{\ell}$ was obtained with constant pH 4.5. And it was found that pullulan yield and synthesis rate increased with oxygen availability. For the production of commercially useful pullulan with high-molecular weight, a mixed carbon source, which was a mixture of glucose and glucosamine, was used for the pullulan fermentation with A. pullulans. On the basis of 5% mixed carbon source, culture with 3% glucosamine with 2% glucose was optimum condition for the production of high (M.W.> 1,000,000) and medium (M.W.> 200,000) molecular weight pullulan with considerable yields of cell mass and product. And the influence of pH control on the molecular weight of pullulan was studied in batch fermentation. It was found that the productivity of high-molecular weight pullulan with pH control at 6.5 was higher than that with no pH control.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1998.10a
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• pp.168-168
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• 1998

• Communications of the Korean Mathematical Society
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• v.17 no.3
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• pp.467-474
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• 2002

Let A be C(D), A(D), P(T), C(T), or H$\^$$\infty$/(U). We evaluate the quotient group GL(A) by exp(A).

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.11a
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• pp.141-142
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• 2007

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.115-115
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• 2002