id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
aiti-15175	Xiaomei Ni; David Chua Sing Ngie; Wanzhen Wang; Miaomiao Xin; Qiu Man; Liangyu Tian; Jingzhe Sun	Remaining Useful Life Prediction of Milling Tool Based on Improved PSO-MultiAM-BiLSTM	2025	16	.pdf	application/pdf	6312	311	51	# Information entropy −�%�� �2 :%�� �; �� Pulse factor ������1 ∑ � �� �� Willison amplitude 1<�|� =� − � |> �� Teager energy ? = � � − � A�BC=� Kurtosis factor 1 ∑ ��� − �̅�3� ���1 ∑ ��� − �̅��� �� − 3 (2) Frequency domain features The four features of center of gravity frequency (FC), mean square frequency (MSF), root mean square frequency (RMSF), and frequency variance (VF) were extracted mainly by fast Fourier transform (FFT) in the frequency domain, and the specific calculation formula is shown in Table 4. oo W h x b (5) ( )tanh= ×t t th o C (6) where Wf and Wi are the corresponding connection weight matrices; bf, bi and bC are the bias vectors; xt is the input data at the current moment; ht-1 is the hidden layer value at the previous moment; σ is the sigmoid activation function and the value interval is [0,1]; Ct-1 is the last moment cell state; Ct is the current cell state; and ��� is the temporary cell candidate value.	cache/aiti-15175.pdf	txt/aiti-15175.txt