Response Surface Methodology Basic, the Central Composite Design Explained

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[@azanhk1]

Please dont close this channel ..its important for me

[@neilbryanclosa462]

Thank you for this great video.

[@digilockmech3487]

Thanks for a wonderful lecture. One query- how to find the number of centre run in central composite design? Please mention the formula or give some references

[@waliiid3215]

In the value of alpha, I think we should multiply in 1-√2 (0.41), and the value becomes 16 de add it to 40 or we take directly the value of alpha 56.

[@abdelrahmanalrafee4536]

I agree with you

[@engr.anthonyonokwai6930]

Thanks for a wonderful lecture. Kindly explain the method used in determining the number centre points in central composite design? Mostly when the number is factors is 5. Please mention the formula or give some references. Thanks

[@TheOpenEducator]

You will find more here: www.theopeneducator.com/doe

[@TheOpenEducator]

CORRECTIONS: The alpha value for the quarter fraction of 8 factors = 2.828.

[@gianlucachaffey4422]

When I enter the Low and High in Minitab (e.x. 0.5, 2) and generate the axial points, I get negative values (e.x. -0.0113446 ). It is not possible to add negative material to a chemical experiment (you cannot add negative yeast to make bread). What is the best way to adjust this number? If the smallest amount I can potentially use has a value of 0.2, can I use that? How would that impact the results of the analysis?

[@hibaaissi5919]

Hello, thank you for sharing the video. Please can I use afla=1?

[@TheOpenEducator]

Yes, you can. Check this one if you plan to use 1 for alpha www.theopeneducator.com/doe/Response-Surface-Methodology/Box-Behnken-Response-Surface-Methodology

[@preetisolanki4606]

what is the meaning of -0.133 in the CCD. In my knowledge this value shows lower axial point, but how i incorporate in production optimization process. please reply.

[@TheOpenEducator]

Here is the answer to your question www.theopeneducator.com/doe/Response-Surface-Methodology/Design-Response-Surface-Methodology

[@preetisolanki4606]

@@TheOpenEducator I understand all the concept. how i add -0.133 of any component(Na2Co3) in production medium?

[@preetisolanki4606]

@@TheOpenEducator thanks for rply

[@TheOpenEducator]

@@preetisolanki4606 need more details to answer your question

[@sumitmeghraj]

How many center points we should take? any standards

[@TheOpenEducator]

As low as one point is fine depending on the experiment. However, it is easier to run study on the Center Point. Therefore, replicating the study in the Center Point will help us to see the "Lack-of-fit" as well as improve the power of the experiment. There is no standard for the number of replicates at the Center Point that I know use widely.

[@aytenkurnaz4594]

How can I analysis 3 data ? I mean 3 factor 3 level

[@TheOpenEducator]

Three factors (independent variables) and one response (dependent variable) would make the response surface a four-dimensional problem. You can create response surface for each level of the third factor using two other factors as independent variables, x and y, and one response as a dependent variable, z. It is possible to use program like Matlab or SAS to stack the response surface for each level of the third factor. I am not sure you can do it Minitab!

[@mlab398]

How can I design pre-requisite experiment

[@13579Josiah]

What does "rotating a design" mean? Why is this desireable?

[@TheOpenEducator]

We have discussed the "rotatability" on this page www.theopeneducator.com/doe/Response-Surface-Methodology/Design-Response-Surface-Methodology . Figures 7, 8, and 9 explain the rotatability, especially functional advantages for RSM.

[@13579Josiah]

@@TheOpenEducator Awesome! One thing I'm not sure on is: can we build a regression model using just a 2^k factorial design or do we have to do a response surface methodology to fit a regression model? Thanks!

[@zaxozaxo7044]

Hu