CFA | The conformable fractional-order accumulation |
CFD | The conformable fractional-order difference |
$ \boldsymbol X ^{(0)} $ | The non-negative original data sequence |
$ \boldsymbol X ^{(\alpha)} $ | The $ \alpha $th-order accumulated generating sequence |
$ \nu $ | The number of data used to build models |
$ n $ | The length of the total sample data |
$ a, b $ | The linear parameters of grey models |
$ \gamma $ | The exponent power in the nonlinear grey Bernoulli model |
$ \lceil\ \cdot\ \rceil $ | The ceil function |
$ \mathcal{T} $ | The transpose operator |
MFO | The moth flame optimization algorithm |