Convolutional neural networks for estimating transport parameters of fibrous materials based on micro-computerized tomography images.

This study proposes a method for estimating the transport parameters of fibrous materials from x-ray micro-computed tomography (CT) images using convolutional neural networks (CNNs). Two-dimensional (2-D) micro-CT images and numerically obtained transport parameters were used to train the CNNs; Stokes flow and potential flow were used to numerically obtain the transport parameters using geometrical models extracted from the raw CT images. Then, analogously to constructing a three-dimensional image of the fibrous material by stacking the 2-D slice images, the volumetric transport parameters of the fibrous materials were calculated using the parameters of each 2-D image predicted by the trained CNN models. The transport parameters of the fibrous volume predicted by the CNN models showed good agreement with the measured values. In addition, the sound absorption coefficient was calculated by applying both the predicted and measured transport parameters to the semi-phenomenological sound propagation model and compared with the measured sound absorption coefficient. The results of the study confirm the feasibility of predicting transport parameters of fibrous materials using a neural network model based on raw micro-CT images.

Long-term outcome of a randomized study comparing three techniques of conization: cold knife, laser, and LEEP.

OBJECTIVE: To evaluate the long-term recurrence rates and complication of different techniques of cervical ablation. METHODS: A randomized trial of three techniques of conization (cold knife, laser, and loop electrosurgical excisional procedure (LEEP)) for cervical intraepithelial neoplasia (CIN) in which 110 patients had been recruited. RESULTS: Eighty-six patients were followed-up for more than 3 years. Of these 28 had been treated with the cold knife, 29 with LEEP and 29 by laser. Five recurrences were observed, one in the cold knife group, two in the LEEP group and two in the laser group (P=NS). The only observed complication was cervical stenosis: zero cases in the laser group, one case in the LEEP group and four cases in the cold knife group (laser versus cold knife: P=0.03; LEEP versus cold knife: P=0.06). Fifty pregnancies were observed in 39 patients. First and second trimester outcomes of pregnancy were without complications. One patient treated with the LEEP presented with a premature rupture of membranes and premature labor at 36 weeks. A total of nine cesarean sections were performed with two cases for cervical dystocia. CONCLUSION: There is no major difference in obstetrical outcome between the three techniques.