• 한국미생물·생명공학회지
• /
• 제48권1호
• /
• pp.48-56
• /
• 2020

This study aimed to optimize the culture conditions to improve the crude biosurfactant activity of Bacillus pumilus IJ-1, using a 3³ full-factorial design of response surface methodology (RSM). It was found that submerged fermentation of B. pumilus improved the activity of the crude biosurfactant. The factors selected for optimization were NaCl concentration, temperature, and tryptone concentration. Response surface analysis revealed that the fitted quadratic model was statistically significant and produced an adequate R² value (0.9898) and a low probability value (<0.0001). The optimum level for each factor was found to be 0.567% (w/v) NaCl, 21.851℃ and 0.765% (w/v) tryptone, respectively. Crude biosurfactant activity was found to be most affected by tryptone concentration; then temperature, and finally NaCl concentration. Our results may potentially facilitate large-scale biosurfactant production from B. pumilus IJ-1.

• 생명과학회지
• /
• 제33권3호
• /
• pp.268-276
• /
• 2023

본 연구는 carvedilol과 ivabradine의 이층정 제형 개발에 있어 carvedilol 속방층의 제형조건을 최적화하기 위해 수행되었다. Full-factorial design of experiments를 사용하여 carvedilol 속방층(wet granulation part)의 첨가제(microcrystalline cellulose, citric acid, crospovidone) 및 타정 시 공정변수(main compression)를 확인하였고 각 독립변수에 대한 7가지 종속변수(함량, 함량 균일성, 경도, 마손도, 붕해, 용출(pH 1.2 및 6.8)를 design expert software를 사용하여 평가하였다. Design of experiments (DoE) 실험에서 도출된 Analysis of Variance (ANOVA) 결과를 통해 main compression은 경도, 마손도, 붕해 시간에 유의한 영향을 주었고, microcrystalline cellulose는 마손도, 용출에 주요한 영향을 주었음을 확인하였다. 또한, citric acid는 마손도, crospovidone은 마손도, 용출에 주요한 영향을 주었음을 확인하였다. DoE실험 결과를 종합하여 최종적으로 도출된 설계공간에 따라 microcrystalline cellulose (약 18.0-32.0 mg), citric acid (약 0.5-12.0 mg), main compression (약 615-837 kgf)의 최적의 범위 내에서 초기 위험평가에서 평가된 모든 위험요인이 제거된 carvedilol 속방층의 최적 제조 범위를 확인하였다.

• 한국생산제조학회지
• /
• 제20권1호
• /
• pp.28-33
• /
• 2011

In this paper, structural design for 2kW class composite blade is performed by using design of experiment(DOE). A full factorial design is applied to meet the design specifications at the manufacturing process. The analysis of variance(ANOVA) is made in order to determine the significance of effects in an analysis. Structural analysis by using of commercial software ABAQUS is performed to compute the displacement and safety factor of filament wound composite blade. The results show that the proposed method is suitable to analyze the factors at the design of wind turbine blade.

• Archives of Pharmacal Research
• /
• 제11권3호
• /
• pp.185-196
• /
• 1988

The inflence of hydrophilic vehicles on percutaneous absorption rate of griseofulvin was studied using intact skin of full thickness of hairless rat. The in vitro absorption rates were used as the characteristics for deciding the optimum formula of ointment vehicles. The optimum formula of vehicle compositions for maximum absorption rate was obtained from the polynomial regression equation and the two graphical techniques, contour graph and partial derivative graph. It was composed of sodium lauryl sulfate (1.65 W /W%), white petrolatum (16.5 W /W%), propylene glycol (12.0 W /W%), and stearyl alcohol (19.6W /W%). The experimental value obtained from the optimum formula and the prediction value were 33.99 and 33.87 ${\mu}g/\sqrt{min}$, respectively. From these results, it was believed that optimum formula for semisolid dosage forms could be obtained from the application of the optimization technique used in this study.

• 한국정밀공학회지
• /
• 제33권8호
• /
• pp.611-616
• /
• 2016

Computational fluid dynamic simulation based on the ABAQUS software was conducted to observe the inside flow of slot-die nozzle. The slot-die nozzle was modeled as 3-dimensional structure and three significant parameters were determined: inlet velocity of fluid, reservoir angles, number of strips none of which have been mentioned previously in the literature. The design of experiment, full factorial analysis was performed within determined design and process levels. The simulation result shows the inlet fluid velocity is most significant factor for the flows of inside nozzle. As an interaction effect, reservoir angle is closely related with number of strip that should address when the nozzle is designed. Moreover, the optimized values of each determined parameter were obtained as 35 mm/s of inlet velocity, 3 of strip numbers, and $22^{\circ}$ of reservoir angles. Based on these parameters, the outlet velocity was obtained as 0.53% of outlet uniformity which is improved from 8.67% of nominal results.

• 한국연초학회지
• /
• 제20권1호
• /
• pp.131-138
• /
• 1998

In order to minimize the trial frequency in the new filter cigarette design, we studied the relationship between smoke yield and tipping materials of cigarette. A three levels full factorial design involving filament denier (X1,2.5-3.3d), Porosity of the acetate filter plug wrap (X2, 3,500-16,000CU) and porosity of the tip paper (X3, 400-1,200CU) was used. Three independent factors (Xl, X2, X3) were chosen for their effects on the various responses and the function was expressed in terms of a quadratic polynomial equation, Y : $\beta$o + $\beta$1Xl + $\beta$2X2 + $\beta$3X3 + $\beta$11Xl2 + $\beta$22X22+ $\beta$33X32 + $\beta$12X1X2 + $\beta$13XIX3 $\beta$23X2X3 which measures the linear, quadratic, and interaction effects. Twenty-nine trial numbers were obtained as a results of using a three levels full factorial design and it was analyzed by the multiple regression analysis with backward stepwise in STATISTICA/pc under restricted conditions. Tar yields of the cigarette was affected by porosity of tip paper (0.66), filament denier (0.47) and porosity of plug wrap (0.28) in the decreasing order, and linear effect of tip paper porosity (B3) and filament denier (91) were significant at a level of 0.01($\alpha$). The filament denier and tipping paper porosity interaction F ratio among three factors had a P-value of 0,000041, indicating higher interaction between these factors. Based on the analysis of variance, the model fitted for Tar (Y1) was significant at 5% confidence level and the coefficient of determination (0.96) was the proportion of variability in the data fitted for by the model.

• 한국국방경영분석학회지
• /
• 제33권1호
• /
• pp.59-74
• /
• 2007

컴퓨터 시뮬레이션 모델은 일반적으로 복잡할 뿐더러 운용 시 많은 시간이 소요된다. 따라서 분석의 편의를 위해 좀 더 간단한 메타모델을 수립할 필요가 있다. 본 논문에서는 워게임 모델 JANUS를 사용하여 전차 전투 상황을 묘사하고 이에 대한 메타모델을 수립하였다. 메타모델을 수립하기 위해, 데이터 수집방법으로는 8가지의 실험계획법을, 모델링 방법으로는 2차 반응표면분석과 인공신경망을 고려하였다. 수립된 메타모델의 상대적 성능은 예측치의 평균제곱오차를 기준으로 비교하였다. 본 논문에서 고려한 전투상황에 대해서는 대체적으로 2차 반응표면 모형이 인공신경망 모형보다 더 높은 정확도를 보였으며, 실험계획법으로는 직교배열이나 최대최소거리 기준을 적용한 라틴 하이퍼큐브 계획법이 우수한 성능을 보였다.

• 소성∙가공
• /
• 제33권2호
• /
• pp.103-111
• /
• 2024

With the increasing global interest in carbon neutrality, the automotive industry is also transitioning to the production of eco-friendly cars, specifically electric vehicles. In order to achieve comparable driving distances to internal combustion engine vehicles, the application of high-capacity battery packs has led to an increase in vehicle weight. To achieve light-weighting and durability requirements of automotive components simultaneously, there is a demand for research on the application of Ultra-High Strength Steel (UHSS). However, when manufacturing chassis components using UHSS, there are challenges related to fracture defects due to lower elongation compared to regular steel sheets, as well as spring-back issues caused by high tensile strength. In this study, a simulated specimen that is not affected by the property changes of four materials was designed to improve formability of the rear cross member, which is the most challenging automotive chassis component. The influence and correlation of material-specific variables were analyzed through finite element analysis (FEA) for each material with tensile strength of 440, 590, 780, and 980 MPa grades, resulting in the development of a predictive equation. To validate the equation, the simulated specimens of 980 MPa grade were produced from the test molds. Then the reliability of the FEA and predictive equation was verified with measured specimen data using a 3D scanner. The results of this study can be proposed to improve the formability of UHSS chassis components in future researches.

• 한국해양공학회지
• /
• 제33권1호
• /
• pp.50-60
• /
• 2019

Recently, problems with excessive vibration of the radar masts of large bulk carriers and crude oil tankers have frequently been reported. This paper explores a design method to avoid the resonance of a radar mast installed on a large ship using various design of experiment (DOE) methods. A local vibration test was performed during an actual sea trial to determine the excitation sources of the vibration related to the resonant frequency of the radar mast. DOE methods such as the orthogonal array (OA) and Latin hypercube design (LHD) methods were used to analyze the Pareto effects on the radar mast vibration. In these DOE methods, the main vibration performances such as the natural frequency and weight of the radar mast were set as responses, while the shape and thickness of the main structural members of the radar mast were set as design factors. From the DOE-based Pareto effect results, we selected the significant structural members with the greatest influence on the vibration characteristics of the radar mast. Full factorial design (FFD) was applied to verify the Pareto effect results of the OA and LHD methods. The design of the main structural members of the radar mast to avoid resonance was reviewed, and a normal mode analysis was performed for each design using the finite element method. Based on the results of this normal mode analysis, we selected a design case that could avoid the resonance from the major excitation sources. In addition, a modal test was performed on the determined design to verify the normal mode analysis results.