scholarly journals Alternative Second-Order N-Point Spherical Response Surface Methodology Design and Their Efficiencies

2016 ◽  
Vol 5 (4) ◽  
pp. 22
Author(s):  
Mary Paschal Iwundu

The equiradial designs are studied as alternative second-order N-point spherical Response Surface Methodology designs in two variables, for design radius ρ = 1.0. These designs are seen comparable with the standard second-order response surface methodology designs, namely the Central Composite Designs. The D-efficiencies of the equiradial designs are evaluated with respect to the spherical Central Composite Designs. Furthermore, D-efficiencies of the equiradial designs are evaluated with respect to the D-optimal exact designs defined on the design regions of the Circumscribed Central Composite Design, the Inscribed Central Composite Design and the Face-centered Central Composite Design. The D-efficiency values reveal that the alternative second-order N-point spherical equiradial designs are better than the Inscribed Central Composite Design though inferior to the Circumscribed Central Composite Design with efficiency values less than 50% in all cases studied. Also, D-efficiency values reveal that the alternative second-order N-point spherical equiradial designs are better than the N-point D-optimal exact designs defined on the design region supported by the design points of the Inscribed Central Composite Design. However, the N-point spherical equiradial designs are inferior to the N-point D-optimal exact designs defined on the design region supported by the design points of the Circumscribed Central Composite Design and those of the Face-centered Central Composite Design, with worse cases with respect to the design region of the Circumscribed Central Composite Design.

Author(s):  
Fidelia Chinenye Kiwu-Lawrence ◽  
Lawrence Chizoba Kiwu ◽  
Desmond Chekwube Bartholomew ◽  
Chukwudi Paul Obite ◽  
Akanno Felix Chikereuba

Three classes of Central Composite Design: Central Composite Circumscribed Design (CCCD), Central Composite Inscribed Design (CCID) and Central Composite Face-Centered Design (CCFD) in Response Surface Methodology (RSM) were evaluated and compared using the A-, D-, and G-efficiencies for factors, k, ranging from 3 to 10, with 0-5 centre points, in other to determine the performances of the designs under consideration. The results show that the CCDs (CCCD, CCFD and CCID) are at their best when the G-efficiency is employed for all the factors considered while the CCID especially behaves poorly when using the A- and D-efficiencies.


2016 ◽  
Vol 8 (4) ◽  
pp. 40
Author(s):  
Iwundu M. P.

<p>Useful numerical evaluations associated with three categories of Response Surface Methodology designs are presented with respect to five commonly encountered alphabetic optimality criteria. The first-order Plackett-Burman designs and the  Factorial designs are examined for the main effects models and the complete first-order models respectively. The second-order Central Composite Designs are examined for second-order models. The A-, D-, E-, G- and T-optimality criteria are employed as commonly encountered optimality criteria summarizing how good the experimental designs are. Relationships among the optimality criteria are pointed out with regards to the designs and the models. Generally the designs do not show uniform preferences in terms of the considered optimality criteria. However, one interesting finding is that central composite designs defined on cubes and hypercubes with unit axial distances are uniformly preferred in terms of E-optimality and G-optimality criteria.</p>


Author(s):  
Christine Clark ◽  
Robert C. Williges

Selected response surface methodology (RSM) designs that are viable alternatives in human performance research are discussed. Two major RSM designs that are variations of the basic, blocked, central-composite design have been selected for consideration: (1) central-composite designs with multiple observations at only the center point, and (2) central-composite designs with multiple observations at each experimental point. Designs of the latter type are further categorized as: (a) designs which collapse data across all observations at the same experimental point; (b) between-subjects designs in which no subject is observed more than once, and observations at each experimental point may be multiple and unequal or multiple and equal; and (c) within-subject designs in which each subject is observed only once at each experimental point. The ramifications of these designs are discussed in terms of various criteria such as rotatability, orthogonal blocking, and estimates of error.


Author(s):  
Robert C. Williges

Simplified formulae for determining the coded value of α are presentedfor rotatable, blocked orthogonal second–order designs in which all data points are replicated an equal number of times. These three central–composite design parameters are compared, and the advantages and limitations of orthogonal designs are presented.


2012 ◽  
Vol 195-196 ◽  
pp. 360-363
Author(s):  
Chun Gang Chen ◽  
Fen Xia Han ◽  
Yuan Zhang ◽  
Yu Zhong Shi

The extraction of flavonoids from clovers was optimized to maximize flavonoid yield Y in this study. A central composite design of response surface methodology involving extracting time, liquid-solid ratio, extracting temperature and ethanol concentration was used, and second-order model for Y was employed to generate the response surfaces. The optimum condition for Y was determined as follows: extracting time 24min, liquid-solid ratio 20, extracting temperature 80°C, and ethanol concentration 72%. Under the optimum condition, the flavonoid yield was 2.49%.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1370
Author(s):  
Zhenfeng Lin ◽  
Ziwei Pan ◽  
Yuhao Zhao ◽  
Lin Qian ◽  
Jingtao Shen ◽  
...  

PPy-Fe3O4/Kaolin was prepared with polypyrrole functionalized magnetic Kaolin by a simple, green, and low cost method to improve the agglomeration and low adsorption capacity of Kaolin. PPy-Fe3O4/Kaolin was employed to remove Hg2+ and the results were characterized by various methods. Relevant factors, including solution pH, dosage of adsorbent, concentration (C0), and temperature (T), were optimized by Response Surface Methodology (RSM) and Central Composite Designs (CCD). The optimal results show that the importance for adsorption factors is pH > T > C0 > dosage, and the optimal adsorption conditions of PPy-Fe3O4/Kaolin are pH = 7.2, T = 315 K, C0 = 50 mg/L, dosage of 0.05 g/L, and the capacity is 317.1 mg/g. The adsorption process conforms to the pseudo-second-order and Langmuir models. Dubinin–Radushkevich model shows that adsorption process is spontaneous and endothermic. Moreover, the adsorption of mercury by PPy-Fe3O4/Kaolin was achieved mainly through electrostatic attraction, pore diffusion, and chelation between amino functional groups and Hg2+. PPy-Fe3O4/Kaolin has excellent reproducibility, dispersity, and chemical stability, and it is easy to be separated from solution through an external magnetic field. The experiments show that PPy-Fe3O4/Kaolin is an efficient and economical adsorbent towards mercury.


2011 ◽  
Vol 201-203 ◽  
pp. 2513-2516 ◽  
Author(s):  
Han Gao ◽  
Gui Fang Xu ◽  
Yuan Yuan Fan ◽  
Hai Juan Nan ◽  
Su Fang Fu

The fermentation process of pear vinegar was optimized to maximize the amount of acetate in this study. A central composite design of response surface methodology involving inoculation rate, temperature, time was used, and second-order model for the amount of acetate was employed to generate the response surface. The optimum condition for the fermentation process was determined as follows: inoculation rate 8.65 %, temperature 30.17 °C, time 7.44 d. The obtained amount of acetate at the optimum condition was 9.53%.


2012 ◽  
Vol 524-527 ◽  
pp. 2306-2309
Author(s):  
Guang Lei Li ◽  
Su Juan Du ◽  
Jie Zeng

The preparation of sweet potato distarch phosphates which possess low digestibility was optimized in this study. A central composite design of response surface methodology involving STMP concentration, pH, phosphorylation temperature and time was used, and second-order model for starch digestibility was employed to generate the response surface. The optimum condition for preparation of sweet potato distarch phosphates was as follows: STMP concentration 3%, pH 10, phosphorylation temperature 40°C, and phosphorylation time 3h. The starch digestibility of sweet potato distarch phosphates was yield of 0.5508±0.0003 (n=3) under these conditions.


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