• Journal of the Korean Statistical Society
• /
• 제31권3호
• /
• pp.277-299
• /
• 2002

Most statistical designs, such as orthogonal designs and optimal designs, are based on a specific statistical model. It is very often that the experimenter does not completely know the underlying model between the response and the factors. In computer experiments, the underlying model is known, but too complicated. In this case we can treat the model as a black box, or model to be unknown. Both cases need a space filling design. The uniform design is one of space filling designs and seeks experimental points to be uniformly scattered on the domain. The uniform design can be used for computer experiments and also for industrial experiments when the underlying model is unknown. In this paper we shall introduce the theory and method of the uniform design and related data analysis and modelling methods. Applications of the uniform design to industry and other areas are discussed.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제3B권2호
• /
• pp.84-89
• /
• 2003

The finite element method (FEM) is typically used in the process of motor design. However, the FEM requires computation time, Therefore, decreasing the number of FEM simulations may also decrease the simulation cost. Several optimal design methods overcoming this problem have been recently studied. This paper investigates the optimal design of the magnet pole of a BLDC motor through reducing simulation cost. The optimization minimizes the magnet volume and limits the average and cogging torques to certain values. In this paper, the response surface methodology and Taguchi's table for reducing the number of FEM simulations are used to approximate two constraints. The optimization result shows that the presented strategy is satisfactorily performed.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVI)
• /
• pp.68-72
• /
• 2005

Leuconostoc citreum is one of the representative strains of Leuconostoc spp. that show fast growth rates in fermented vegetables. Sequential experimental designs including the Plackett-Burman design, fractional factorial design, steepest ascent analysis, central composite design and response surface methodology were introduced tooptimize and improve the medium for Leuconostoc citreum. Fifteen medium ingredients were examined and glucose (20 g/l), yeast extract (12.5 g/l), sodium acetate trihydrate (6.12 g/l), potassium phosphate (42.55 g/l) and dibasic ammonium citrate (4.12 g/l)were chosen as the best components to give a critical and positive effect for cell-growth. The biomass was increased to 2.79 g/l (169%), compared to the 1.65 g/l in MRS medium.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권4호
• /
• pp.278-284
• /
• 2004

Leuconostoc citreum is one of the representative strains of Leuconostoc spp. that show fast growth rates in fermented vegetables. Sequential experimental designs including the Plackett-Burman design, fractional factorial design, steepest ascent analysis, central composite design and response surface methodology were introduced to optimize and improve the medium for L. citreum. Fifteen medium ingredients were examined and glucose ($20 g/\ell$), yeast extract ($12.5g/\ell$), sodium acetate trihydrate ($6.12g/\ell$), potassium phosphate ($42.55g/\ell$), and dibasic ammonium citrate ($4.12g/\ell$), were chosen as the best components to give a critical and positive effect for cell-growth. The biomass was increased to ($2.79g/\ell$), (169%), compared to the $1.65g/\ell$ in MRS medium.

• 한국해양바이오학회지
• /
• 제6권1호
• /
• pp.31-40
• /
• 2014

The production of astaxanthin in the microalga Haematococcus pluvialis has been investigated using a sequential methodology based on the application of two types of statistical designs. The employed preliminary experiment was a fractional factorial design $2^6$ in which the factors studied were: excessive irradiance and nitrate starvation, phosphate deficiency, acetate supplementation, salt stress, and elevated temperature. The experimental results indicate that the amount of astaxanthin accumulation in the cells can be enhanced by excessive irradiance and nitrate starvation whereas the other factors tested did not yield any enhancement. In the subsequent experiment, a central composite design was applied with four variables, light intensity, nitrate, phosphate, and acetate, at five levels each. The optimal conditions for the highest astaxanthin production were found to be $1040{\mu}E/(m^2{\cdot}s)$ light intensity, 0.04 g/L nitrate, 0.31 g/L phosphate, 0.05 g/L acetate concentration.

• Journal of the Korean Data and Information Science Society
• /
• 제20권6호
• /
• pp.1015-1027
• /
• 2009

대수기하학적 접근이란 실험계획에서의 공간 내의 점들 즉, 기하학적 대상인 다양체에 대한 문제를 다항식을 매개로 하여 아이디얼 즉, 대수적 문제로 전환하고자 한 것이라 할 수 있다. 지금까지의 연구는 완전요인실험으로부터 효율적인 부분요인실험을 선택하는 절차에 집중되어 왔다. 본 논문에서는 지금까지 연구 방법의 역의 과정을 추정해 보기로 한다. 한 부분요인실험이 선택되었을 때, 그 실험의 교락구조를 그뢰브너 기저를 구한 후 해석한다. 다음으로 그뢰브너 기저를 생성자로 활용하여 선택된 부분실험의 집합을 구별하기 위한 다항함수인 지시함수를 구하는 절차를 알아보기로 한다. 실제로 몇 가지 부분요인실험을 예로 택하여 그 과정을 수행하였다. 연산은 CoCoA 대수연산 소프트웨어를 이용하였다.

• 지역사회간호학회지
• /
• 제23권2호
• /
• pp.201-211
• /
• 2012

Purpose: The purpose of this study is to evaluate the effects of a local community based multi-factorial program for high-risk younger and older elderly people. Methods: The quasi-experimental research design (pretest-post test) was employed. Participants were recruited in Seoul and a total of 98 elders completed an 8-week multi-factorial program for preventing frailty. Descriptive statistics, $x^2$-test and GLM were used in the data analysis with SPSS/WIN 15.0. Results: The high-risk elderly people in the younger and older stages showed differences in IADL, TUG and BMI, and after being provided with the multi-factorial program for preventing frailty, some effects were shown on improving the total score of frailty, a physical function, TUG, BMI, depression, subjective feeling of health, and social interaction. Conclusion: The 8-week multi-factorial program for preventing frailty had positive effects on improving physical, emotional and social functions of the high-risk elderly people. It is necessary to evaluate the effects after individual intervention as well as group intervention and to evaluate the effects of the program by setting a control group in the future.

• Design & Manufacturing
• /
• 제15권1호
• /
• pp.41-47
• /
• 2021

The Fine Blanking process is an effective precision shearing process that can obtain a smooth cutting surface and high product precision through a single blanking process. It is widely used in various manufacturing fields. However, shearing through this fine blanking process is only intended to minimize burrs, die rolls and fracture surfaces and does not completely remove them. Therefore, it is necessary to study the minimization of burrs, die rolls and fracture surfaces in the fine blanking process. In this study, a study was conducted on the relationship between the fracture surface and process conditions that occurred during product production using the fine blanking process. For this purpose, the shape of the V-ring indenter, the distance to the punch, and the pressure force, clearance, shear rate, and physical properties of the material were selected as process and design variables, and the relationship with the fracture surface according to each process and design condition was tested. It was analyzed through the Experimental Design Method.

• Computers and Concrete
• /
• 제31권6호
• /
• pp.545-559
• /
• 2023

In this study, an experimental investigation was conducted to assess the influence of ground granulated blast furnace slag (GGBS) and silica fume (SF) on the fresh and hardened properties of grout specimens and preplaced aggregate concrete (PAC). Grout proportions were optimized statistically using a factorial design and were applied to 10 mm and 20 mm coarse aggregates to produce PAC. The results demonstrate that GGBS has a more significant effect on the compressive strength of grout compared to SF, with a small increase or decrease in the GGBS content having a greater influence on the compressive strength of grout than SF. The water to binder ratio had the most significant effect on the compressive strength of PAC, followed by the coarse aggregate size and sand to binder ratio. An empirical relationship to predict the compressive strength of PAC was proposed through an experimentally derived factorial design along with a statistical analysis of collectively obtained data and a deep literature review. The results predicted by the empirical relationship were in good agreement with those of PAC produced for verification.

• 마케팅과학연구
• /
• 제10권
• /
• pp.91-110
• /
• 2002

본 연구에서는 기업이 준거가격 광고의 단서에 대한 이론을 적용하여 소비자들에게 어떻게 효과적으로 커뮤니케이션 해야 할 것인지에 초점을 두고 있다. 여러 서비스산업 중 여행상품을 대상으로 정보유형을 조절변수로 하여, 가격단서(외적 준거가격)와 지식수준의 독립변수가 소비자지각의 종속변수에 어떠한 영향을 미치는지에 대해 살펴보았으며, 이러한 변수들의 관계를 이용하여 외적 준거가격의 제시여부와 지식수준의 높고 낮음, 긍정적 정보와 부정적 정보제공을 통한 8개 집단간의 요인실험설계(factorial design)를 실시하였다. 연구결과 서비스의 준거가격 광고에서 가격단서(외적준거가격)를 제시받은 소비자들이 미제시한 소비자들보다 가격-품질지각이 높아지고, 서비스에 대한 지각가치를 높게 지각한다는 사실이 발견되었다. 또한, 긍정적인 정보보다는 부정적인 정보에 노출되었을 때, 지식수준이 낮은 소비자는 지식수준이 높은 소비자보다 가격-품질지각이 높게 나타나는 것을 확인활 수 있었다.