• 제어로봇시스템학회논문지
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• 제11권10호
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• pp.823-829
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• 2005

We have newly constructed an in silico model of fermentative metabolism for Lactococcus lactis in order to analyze the characteristics of metabolite flux for dynamic network. A rigorous mathematical model for metabolic flux has been developed and simulation researches have been performed by using GEPASI program. In this simulation task, we were able to predict the whole flux distribution trend for lactate metabolism and analyze the flux ratio on the pyruvate branch point by using metabolic flux analysis(MFA). And we have studied flux control coefficients of key reaction steps in the model by using metabolic control analysis(MCA). The role of pyruvate branch seems to be essential for the secretion of lactate and other organic byproducts. Then we have made an effort to elucidate its metabolic regulation characteristics and key reaction steps, and find an optimal condition for the production of lactate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.63.1-63.1
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• 2005

• Archives of Pharmacal Research
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• 제29권6호
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• pp.476-478
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• 2006

In order to construct a benzofuran library, we developed a model study of benzbromarone. Synthesis has been achieved in 53% overall yield, starting from phenol via the key intermediate 2-ethylbenzofuran which was afforded by intramolecular Wittig reaction.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.325-328
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• 1999

In the reactions of the enolates of various 2-piperidineacetates with iodomethane or trisyl azide, the anti isomer was always predominant over the syn one, independent of the stereochemistry of the piperidineacetates. The piperidineacetates having OTBDMS moiety at C5 proceeded more diastereoselectively than the compounds without the substituent. The diastereoselectivity could be explained by perpendicular model for the electrophilic substitution reaction.

• 한국물환경학회지
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• 제24권2호
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• pp.239-246
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• 2008

In this study, an optimized deterministic water-quality model was constructed to estimate water quality of a river and lake in the upstream basin of a dam. A stochastic water-quality analysis using reliability analysis technique was applied to the model. The model was tested in the 13.9 km reach from Maeil stage station of Kyechun to Hoengsung Dam of Sum River. After finding hydraulic characteristics from nonuniform flow analysis, Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization technique for model calibration was applied to determine optimum reaction parameters, and model verification was performed based on these. The stochastic model, using Mean First­Order Second­-Moment (MFOSM) and Monte-Carlo methods, was applied to the same reach as the deterministic study. Variations of discharge and water quality in headwater were considered, as well as variations of hydraulic coefficients and reaction coefficients. The statistical results of output variables from MFOSM were similar to those from the Monte-Carlo method. Risk analysis using MFOSM and Monte-Carlo methods presented the probabilities of some locations in the Hoengsung Lake violating existing water-quality standards in terms of DO and BOD.

• 한국ITS학회 논문지
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• 제9권1호
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• pp.101-110
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• 2010

본 연구는 고속도로에서 발생하는 비반복적 정체 중 교통사고로 인하여 발생하는 돌발상황에 대한 운영관리 부족 및 처리시간에 대한 정보제공 요구증가에 따라 이에 대응할 수 있는 돌발상황 처리시간 예측모형개발을 개발하였다. 돌발상황 처리시간 예측모형을 개발하기에 앞서 종속변수인 사고처리시간을 사고등급 A, B, C등급으로 구분하였으며, 독립변수로는 교통량, 사고차량수, 사고시간대 등 총 15개 변수를 적용하여 모형을 개발하였다. 모형도출결과 돌발상황 처리시간에 영향을 미치는 주요변수로는 교통량, 중차량포함여부, 사고시간대가 도출되었다. 또한 돌발상황 처리시간 예측모형에서 영향 변수로 도출된 변수들을 토대로 의사결정나무를 구축하였으며, 이때 CHAID기법을 적용하였다. 그 결과 1차적으로 사고등급 A, B등급과 C등급으로 구분되었으며, 2차적으로는 도로의 교통량으로 분리되었다. 본 연구를 통하여 도출된 돌발상황 처리시간 예측모형과 의사결정나무를 통하여 향후 고속도로 돌발상황 발생시 도로이용자들에게 보다 신속하고 실효성있는 교통정보를 제공하는데 기여할 수 있을 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1160-1165
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• 2004

The purpose of this study was to calculate three dimensional angular displacements, moments and joint reaction forces of the ankle joint during the waist pulling, and to assess the ankle joint reaction forces according to different perturbation modes and different levels of perturbation magnitude. Ankle joint model was assumed 3-D ball and socket joint which is capable of three rotational movements. We used 6 cameras, force plate and waist pulling system. Two different waist pulling systems were adopted for forward sway with three magnitudes each. From motion data and ground reaction forces, we could calculate 3-D angular displacements, moments and joint reaction forces during the recovery of postural balance control. From the experiment using falling mass perturbation, joint moments were larger than those from the experiment using air cylinder pulling system with milder perturbation. However, JRF were similar nevertheless the difference in joint moment. From this finding, we could conjecture that the human body employs different strategies to protect joints by decreasing joint reaction forces, like using the joint movement of flexion or extension or compensating joint reaction force with surrounding soft tissues. Therefore, biomechanical analysis of human ankle joint presented in this study is considered useful for understanding balance control and ankle injury mechanism.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.309-315
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• 2010

A grilled-type shrimp flavor was developed through the Maillard reaction to reduce or mask fish odor or off-flavor in seafood. Model systems were created by using enzymatic hydrolysate of shrimp and adding precursors to increase flavor quality and stability. Amino acid precursors such as cysteine and methionine, sugar precursors such as glucose, xylose, ribose, and sucrose, and one particular compound of glucosamine were tried and their flavor qualities were tested by sensory evaluation. Also, the optimum reaction condition was investigated using the pH values of pH 5, 6, 7, and 8 with reaction times of 1 hr, 2 hr and 3 hr after the best precursors were determined. The best condition of the precursors for grilled-type shrimp flavor was the mixtures of methionine, threonine, xylose, and glucosamine. The optimum reaction condition was at pH 8.0 and 2 hr reaction time.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.304-308
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• 2010

Boiled-type shrimp flavor was developed using Maillard reaction to reduce or mask fish odor or off-flavor in seafood. Model systems were created using enzymatic hydrolysate of shrimp and adding precursor compounds to increase flavor quality and stability. Amino acid precursors of cysteine and methionine and sugar precursors such as glucose, xylose, ribose and sucrose were tried and their flavor qualities were tested by sensory evaluation. After the optimal precursors were determined, the optimum reaction condition was investigated using pHs of 5, 6, 7, and 8 and reaction times of 1, 2 and 3 hours. The best precursors for boiled-type shrimp flavor were methionine and sucrose. The optimum reaction condition was pH 8.0 and a one hour reaction time.

• Bulletin of the Korean Chemical Society
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• 제20권10호
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• pp.1136-1144
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• 1999

The collision-induced reaction of gas-phase atomic hydrogen with hydrogen atoms chemisorbed on a silicon (001)-(2×1) surface is studied by use of the classical trajectory approach. The model is based on reaction zone atoms interacting with a finite number of primary system silicon atoms, which then are coupled to the heat bath, i.e., the bulk solid phase. The potential energy of the Hads‥Hgas interaction is the primary driver of the reaction, and in all reactive collisions, there is an efficient flow of energy from this interaction to the Hads-Si bond. All reactive events occur on a subpicosecond scale, following the Eley-Rideal mechanism. These events occur in a localized region around the adatom site on the surface. The reaction probability shows the maximum near 700K as the gas temperature increases, but it is nearly independent of the surface temperature up to 700 K. Over the surface temperature range of 0-700 K and gas temperature range of 300 to 2500 K, the reaction probability lies at about 0.1. The reaction energy available for the product states is small, and most of this energy is carried away by the desorbing H2 in its translational and vibrational motions. The Langevin equation is used to consider energy exchange between the reaction zone and the bulk solid phase.