scholarly journals Optimal Partially Replicated Cube, Star and Center Runs in Face-centered Central Composite Designs

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
M. P. Iwundu
Keyword(s):  
Central Composite Designs ◽  
Face Centered ◽  
Composite Designs ◽  
Central Composite

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
Keyword(s):  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Second Order ◽  
The Face ◽  
Central Composite Designs ◽  
Face Centered ◽  
Composite Designs ◽  
Central Composite ◽  
Exact Designs

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.

scholarly journals OPTIMIZING CURING CONDITIONS IN FLAME RETARDANT TREATMENT FOR COTTON FABRIC

2019 ◽  
Vol 2019 ◽  
pp. 91-95
Author(s):  
Huong- Thi NGUYEN ◽  
Hong Khanh – Thi VU
Keyword(s):  
Cotton Fabric ◽  
Curing Temperature ◽  
Response Models ◽  
Curing Conditions ◽  
Flammability Characteristics ◽  
Central Composite Designs ◽  
Face Centered ◽  
Composite Designs ◽  
Central Composite ◽  
Design Experiments

The study of the influence of curing conditions on the properties of the cotton fabric treated with Pyrovatex CP New (PR) and Knittex FFRC was carried out with 10 experiments. The central composite designs type face centered (CCF) was used to design experiments. In these experiments, the curing temperature was varied from 160o C to 180o C and the curing time from 60-120 seconds. The chemical uptake rate, vertical flammability characteristics, LOI value, tensile strength of the untreated and treated samples were determined. Based on the results, 5 response models between the determined properties of the treated fabric and two studied variables were found. From these models, the optimal curing temperature and time were found with the highest fire resistance efficiency and minimum loss for the mechanical properties. They are 180o C and 113.7 seconds

scholarly journals Evaluation and Comparison of Three Classes of Central Composite Designs

2021 ◽  
pp. 31-47
Author(s):  
Fidelia Chinenye Kiwu-Lawrence ◽  
Lawrence Chizoba Kiwu ◽  
Desmond Chekwube Bartholomew ◽  
Chukwudi Paul Obite ◽  
Akanno Felix Chikereuba
Keyword(s):  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Central Composite Designs ◽  
Face Centered ◽  
Composite Designs ◽  
Composite Face ◽  
Central Composite

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.

scholarly journals Construction of Modified Central Composite Designs for Non-standard Models

2018 ◽  
Vol 7 (5) ◽  
pp. 95
Author(s):  
Iwundu, M. P.
Keyword(s):  
Loss Function ◽  
Information Matrix ◽  
Missing Observations ◽  
Design Efficiency ◽  
Central Composite Designs ◽  
Standard Models ◽  
Alternative Designs ◽  
Composite Designs ◽  
Hat Matrix ◽  
Central Composite

The use of loss function in studying the reduction in determinant of information matrix due to missing observations has effectively produced designs that are robust to missing observations. Modified central composite designs are constructed for non-standard models using principles of the loss function or equivalently first compound of (I ) matrix associated with hat matrix . Although central composite designs (CCDs) are reasonably robust to model mis-specifications, efficient designs with fewer design points are more economical. By classifying the losses due to missing design points in the CCD portions, where there are multiple losses associated with specified CCD portions, the design points having less influence may be deleted from the full CCD. This leads to a possible increase in design efficiency and offers alternative designs, similar in the structure of CCDs, for non-standard models.

scholarly journals An approach to measuring rotatability in central composite designs

2015 ◽  
Vol 3 (2) ◽  
pp. 126
Author(s):  
Emmanuel Ohaegbulem ◽  
Polycarp Chigbu
Keyword(s):  
New Approach ◽  
Measure Design ◽  
Central Composite Designs ◽  
Composite Designs ◽  
Central Composite

<p>An approach to measure design rotatability and a measure, that quantifies the percentage of rotatability (from 0 to 100) in the central composite designs are introduced. This new approach is quite different from the ones provided by previous authors which assessed design rotatability by the viewing of tediously obtained contour diagrams. This new approach has not practical limitations, and the measure is very easy to compute. Some examples were used to express this approach.</p>

scholarly journals Optimal Prediction Variance Capabilities of Inscribed Central Composite Designs

2020 ◽  
pp. 1-8
Author(s):  
Julius C. Nwanya ◽  
Kelechukwu C. N. Dozie
Keyword(s):  
Central Composite Design ◽  
Design Space ◽  
Optimal Prediction ◽  
Prediction Variance ◽  
Central Composite Designs ◽  
Scaled Prediction Variance ◽  
Composite Designs ◽  
Central Composite

This study looks at the effects of replication on prediction variance performances of inscribe central composite design especially those without replication on the factorial and axial portion (ICCD1), inscribe central composite design with replicated axial portion (ICCD2) and inscribe central composite design whose factorial portion is replicated (ICCD3). The G-optimal, I-optimal and FDS plots were used to examine these designs. Inscribe central composite design without replicated factorial and axial portion (ICCD1) has a better maximum scaled prediction variance (SPV) at factors k = 2 to 4 while inscribe central composite design with replicated factorial portion (ICCD3) has a better maximum and average SPV at 5 and 6 factor levels. The fraction of design space (FDS) plots show that the inscribe central composite design is superior to ICCD3 and inscribe central composite design with replicated axial portion (ICCD2) from 0.0 to 0.5 of the design space while inscribe central composite design with replicated factorial portion (ICCD3) is superior to ICCD1 and ICCD2 from 0.6 to 1.0 of the design space for factors k = 2 to 4.

Sign in / Sign up

Export Citation Format

Share Document