• 한국식품영양과학회지
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• 제41권3호
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• pp.390-395
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• 2012

산수유의 추출조건별 추출물의 최적 추출조건을 설정하기 위해 중심합성법에 따라 마이크로웨이브에너지(30, 60, 90, 120 및 150 watt), 에탄올 농도(0, 25, 50, 75 및 100%), 추출시간별(1, 3, 5, 7 및 9분)로 추출조건에 따라 생리활성을 측정하였다. 이때 반응표면의 회귀식 $R^2$값이 전자공여작용, tyrosinase 저해효과, SOD 유사활성, 총 폴리페놀 함량에서 각각 0.8937, 0.9254, 0.9552와 0.9708로 분석되었다. 4차원 반응표면분석에 의해 superimposing 하여 최적 추출조건을 얻은 범위는 산수유의 경우 마이크로웨이브 에너지 78~98 watt, 에탄올 농도 3~33%, 추출시간 3.6~9분으로 예측되었다.

• 한국환경보건학회지
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• 제26권4호
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• pp.97-104
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• 2000

The purpose of this is made an examination of phosphorus loading model for eutrophication response in the Yongsan lake. For the model, we measured the total amount of nutrients derived from the Yongsan river watershed, inflow rate to the Yongsan lake, water quality, and water budget from January to December in 1999. The total amount of precipitation in the Yongsan river watershed was 4,951.7$\times$10$^{6}$ ㎥/y and inflow amount was 2,569.7$\times$10$^{6}$ ㎥/y, therefore the outflow rate of the Yongsan river watershed was 51.9%. The develop loading of total nitrogen was 86,928.1kg/d and that of total phosphorus was 22,007.6kg/d at the Yongsan river watershed, But, as the inflow loading of total nitrogen was 33,962kg/d and the inflow loading of total phosphorus was 2,218kg/d to the Yongsan lake. so each infolw rate was 39.0% and 10.1%. The hydraulic residence time was 34days, total phosphorus loading [L(P)] on the surface area was 23.398g/㎥/y, the hydraulic load( $Q_{s}$) of inflow water was 74.269m/y, the reserve rate of phosphorus in the lake was 0.359, and the settinh velocity of phosphorus was 0.114m/d at the Yongsan lake. Mathematical model of phosphorus loading to estimate the responses of eutrophication at the Yongsan lake is [ $P_{j}$] = 0.838 [L(P)/Q.(1+√ $T_{w}$)$^{-1}$ ] . ] . .

• Food Science and Biotechnology
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• 제16권2호
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• 생명과학회지
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• 제24권4호
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• pp.419-427
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• 2014

인진쑥(Artemisia capillaris Thunbl)의 항산화적 특성을 조사하기 위하여 반응표면분석법에 의하여 열수추출특성을 모니터링하여 최적 추출조건을 설정하였다. 총 페놀성화합물 함량에 대한 최적조건은 $94.50^{\circ}C$, 2.06 hr 및 시료에 대한 용매비 25.03 ml/g, 전자공여능에 대한 최적조건은 $91.82^{\circ}C$, 2.90 hr 및 20.88 ml/g으로 나타났고, 아질산염 소거능(pH 1.2)에 대한 최적조건은 $97.36^{\circ}C$, 2.75 hr 및 15.19 ml/g등으로 각각 나타났다. 각 변수에 대한 회귀식을 도출하여 인진쑥의 총 페놀성화합물 함량, 전자공여능 및 아질산염 소거능(pH 1.2)에 대한 최적 추출조건을 superimposing 한 결과, 추출온도 $90{\sim}95^{\circ}C$, 추출시간 2.5~3.5 hr 및 시료에 대한 용매비 17~24 ml/g의 범위로 각각 예측되었다.

• 대한기계학회논문집A
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• 제29권8호
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• pp.1051-1060
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• 2005

Nonlinear Response Optimization using Equivalent Static Loads (NROESL) method/algorithm is proposed to perform optimization of non-linear response structures. The conventional method spends most of the total design time on nonlinear analysis. The NROESL algorithm makes the equivalent static load cases for each response and repeatedly performs linear response optimization and uses them as multiple loading conditions. The equivalent static loads are defined as the loads in the linear analysis, which generates the same response field as those in non-linear analysis. The algorithm is validated for the convergence and the optimality. The proposed algorithm is applied to a simple mathematical problem to verify the convergence and the optimality.

• KSBB Journal
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• 제26권4호
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• pp.341-346
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• 2011

This work is focused on the possibility of marine biomass Codium fragile as renewable resources for production of levulinic acid. In an effort to optimize the reaction conditions of levulinic acid production from Codium fragile, response surface methodology was applied. A total of 18 individual experiments were designed to investigate the effect of reaction temperature, catalyst amount, and reaction time. As a result, 4.26 g/L levulinic acid from Codium fragile was produced in the condition of $160.7^{\circ}C$ of reaction temperature, 3.9% of sulfuric acid, and 39.1 min of reaction time. This result will provide the useful information for chemical production from marine resource.

• Transactions on Electrical and Electronic Materials
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• 제4권1호
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• pp.24-28
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• 2003

We have studied the influence of rubbing angles with respect to in-plane field direction on electro-optic characteristics of in-plane switching (IPS) liquid crystal display. The results show that the threshold voltage increases and the operational voltage decreases as the rubbing angle increases. Further, the total response time and also response times associated with grey-to-grey transitions become fast as the rubbing angle decreases.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.500-510
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• 1996

A Direct injection -mixing total -flow -control sprayer was developed and evaluated . The system provided precise application rates and minimized operator exposure to chemicals as well as providing a possibility for recycling container so f unused chemicals that can causes environmental contamination. Chemicals were metered and injected proportionally to the diluent flow rate to provide constant concentrations. The main diluent flow was varied in response to changes in travel speed. Experimental variables of the sprayer were the control interval, the sensitivity of flow regulating valve, the tolerance of control object and the sensitivity of the injection pump system. The optimal performance of the flow control system was with an average response time of 8.5 sec at an absolute steady state of error of 0.067 L/min (0.8% of flow rate). The average response time of the injection rate was -0.53 sec and the coefficient of variation (CV) of concentration was 3.2%.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.429-436
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• 2005

This paper presents a precise and stable time integration method for dynamic analysis of vibration or multibody systems. A total system is divided into several subsystems and their responses are calculated separately, while the coupling effect is treated equivalently as constant force during time steps. By using iterative procedure to improve equivalent coupling forces, a precise and stable solution is obtained. Some examples such as a seismic response and multibody analyses were carried out to demonstrate its usefulness.

• 한국식품과학회지
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• 제35권6호
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• pp.1104-1109
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• 2003

초임계 이산화탄소를 이용하여 감귤박으로부터 ${\beta}$-cryptoxanthin을 포함한 carotenoids의 추출수율을 극대화하기 위하여, 주요 요인 변수인 추출 압력, 추출시간, 보조용매의 농도 등 추출 조건을 반응표면분석법에 의해 최적화하였다. Total carotenoids와 ${\beta}$-cryptoxanthin의 추출수율에 대한 반응표면 회귀방정식의 $R^2$는 각각 0.9789과 0.9796이었고, 1% 이내의 수준에서 유의성이 인정되었다. 추출조건에 따라 예측된 정상점은 안장점이었으며 능선분석을 실시한 결과 total carotenoids과 ${\beta}$-cryptoxanthin의 최대 추출수율은 각각 61.1%와 95.8%로 예측되었으며, 이 때의 추출 압력, 추출시간, ethanol의 농도는 각각 33.4MPa/39.6min/18.6%와 37.3 MPa/41.0 min/17.0%이었다. Total carotenoids의 추출수율은 추출 압력의 증가에 따라 증가하였지만 압력이 높을수록 일정한 값에 도달하는 경향을 보인 반면, 추출시간과 보조용매의 농도 증가에 따라 연속적으로 증가하였다. ${\beta}-Cryptoxanthin$의 추출수율은 추출 압력, 추출시간, 보조용매의 농도 증가에 따라 연속적으로 증가하였다. 감귤박으로부터 carotenoids의 추출에는 추출시간과 보조용매의 농도 사이의 상호작용이 중요한 역할을 하였다.