Dual-Graph Attention Convolution Network for 3-D Point Cloud Classification.

Three-dimensional point cloud classification is fundamental but still challenging in 3-D vision. Existing graph-based deep learning methods fail to learn both low-level extrinsic and high-level intrinsic features together. These two levels of features are critical to improving classification accuracy. To this end, we propose a dual-graph attention convolution network (DGACN). The idea of DGACN is to use two types of graph attention convolution operations with a feedback graph feature fusion mechanism. Specifically, we exploit graph geometric attention convolution to capture low-level extrinsic features in 3-D space. Furthermore, we apply graph embedding attention convolution to learn multiscale low-level extrinsic and high-level intrinsic fused graph features together. Moreover, the points belonging to different parts in real-world 3-D point cloud objects are distinguished, which results in more robust performance for 3-D point cloud classification tasks than other competitive methods, in practice. Our extensive experimental results show that the proposed network achieves state-of-the-art performance on both the synthetic ModelNet40 and real-world ScanObjectNN datasets.

[Short-term outcomes of radical resection of rectal carcinoma: hand-assisted laparoscopy versus traditional laparoscopic approach].

OBJECTIVE: To study the feasibility of hand-assisted laparoscopic radical resection of rectal carcinoma and compare the short-term outcomes of HALS versus traditional laparoscopy approach. METHODS: Clinical data of 42 cases of rectal carcinoma between January 2010 and March 2011 were enrolled in this study. Nineteen cases underwent HALS total mesorectal excision and 23 cases underwent traditional laparoscopy approach. RESULTS: All the operations were successfully accomplished without conversions to open surgery. The mean operation time of the HALS group was shorter than that of the traditional laparoscopic group (152 min vs. 168 min, P=0.009). Incision length was significantly longer in the HALS group (5.6 cm vs. 4.5 cm, P=0.000). The median overall costs were lower in HALS group (26 000 RMB vs. 29 000 RMB, P=0.008). The number of lymph nodes in resected specimen, intra-operative blood loss, length of hospital stay, time to passage of flatus were comparable between the two groups. CONCLUSIONS: Hand-assisted laparoscopic surgery has the advantages of laparoscopic surgery including minimal invasiveness, safety, and quicker postoperative recovery.