Difference between revisions of "Team:CAU China/Model"

In our project, we develop a mathematical method to decide which pathway we could use because we have several candidates and need to conduct a scientific and rational method to find out the most suitable one. Therefore, an Analytic Hierarchy Process (AHP) is performed. By doing so, we can combine our subjective and objective factors into consideration and finally get the one from candidates.

1.2 Construct hierarchy model

To use the AHP model, we need to list our candidates first. Combining with our project design and references we have read, we finally select 3 candidate pathways, which are Astaxanthin pathway, Ginsenosides pathway1, and Cannabinoid pathway2 respective- ly. In addition, during our discussion and interviews with different expertise, we select 5 most critical criteria we need to consider. Thanks for our human practice working, we can finally determine the criteria we need to use in our AHP model.

By using 3 candidates and 5 criteria, the hierarchy model is established. (Figure 1)

After having the hierarchy structure, we further construct comparison matrix. When comparing the relative importance of the ith element to the jth element to the factor above, we use the quantified relative weight $a_{ij}$ to describe. Suppose there are a total of n elements to participate in the comparison, then matrix $ A={\{a_{ij}\}}_{n\times n}$ called comparison matrix. The value of $a_{ij}$ in the comparison matrix is assigned according to the following scale.

• $a_{ij}=1$ which implies that element $i$ and element $j$ have the same importance to the previous level factor.
• $a_{ij}=3$ which implies that element $i$ is slightly more important than element $j$.
• $a_{ij}=5$ which implies that element $i$ is more important than element $j$.
• $a_{ij}=7$ which implies that element $i$ is much more important than element $j$.
• $a_{ij}=9$ which implies that element $i$ is extremely more important than element $j$.
• $a_{ij}=9$ which implies that element $i$ is extremely more important than element $j$.
• $a_{ij}=2n, n=1,2,3,4$ which implies that the importance of the elements $i$ and $j$ is between $a_{ij}=2n-1$ and $a_{ij}=2n+1$.
• $a_{ij}=\frac{1}{n}, n=1,2,\cdots,9,$ if and only if $a_{ij}=n$.

1. Dai, Z., Liu, Y., Zhang, X., Zhang, X., Shi, M., Wang, D., . . . Huang, L. (2013). Metabolic engineering of saccharomyces cerevisiae for production of ginsenosides. Metabolic Engineering, 20, 146-156. doi:10.1016/j.ymben.2013.10.004
2. Luo, X., Reiter, M. A., d'Espaux, L., Wong, J., Denby, C. M., Lechner, A., . . . Keasling, J. D. (2019). Complete biosynthesis of cannabinoids and their unnatural analogues in yeast. Nature, 567(7746), 123-126. doi:10.1038/s41586-019-0978-9