Object detection in remote sensing images plays an important role in both military and civilian remote sensing applications. Objects in remote sensing images are different from those in natural images. They have the characteristics of scale diversity, arbitrary directivity, and dense arrangement, which causes difficulties in object detection. For objects with a large aspect ratio and that are oblique and densely arranged, using an oriented bounding box can help to avoid deleting some correct detection bounding boxes by mistake. The classic rotational region convolutional neural network (R2CNN) has advantages for text detection. However, R2CNN has poor performance in the detection of slender objects with arbitrary directivity in remote sensing images, and its fault tolerance rate is low. In order to solve this problem, this paper proposes an improved R2CNN based on a double detection head structure and a three-point regression method, namely, TPR-R2CNN. The proposed network modifies the original R2CNN network structure by applying a double fully connected (2-fc) detection head and classification fusion. One detection head is for classification and horizontal bounding box regression, the other is for classification and oriented bounding box regression. The three-point regression method (TPR) is proposed for oriented bounding box regression, which determines the positions of the oriented bounding box by regressing the coordinates of the center point and the first two vertices. The proposed network was validated on the DOTA-v1.5 and HRSC2016 datasets, and it achieved a mean average precision (mAP) of 3.90% and 15.27%, respectively, from feature pyramid network (FPN) baselines with a ResNet-50 backbone.

With growing data volume for large-scale virtual screening, the associated data processing and management meet challenges. We have developed UCAPF, A unified platform for large-scale virtual screening. The platform provides a parallel processing framework for large-scale virtual screening data. It also enables scheduling of heterogeneous parallel architectures and hierarchical storage of massive data. The processing framework improves data quality. On the CASF-2016 dataset, the standardized molecules processed by UCAPF showed a 9.5% to 14.62% improvement in scoring performance and a 7.9% to 34.6% improvement in ranking performance compared to the raw molecules. For massive data processing, the framework provides parallel efficiency of 81.20% for molecule standardized processing and 79.51% for docking result processing on a 72-unit Hadoop cluster. In addition, the distributed database for data management improves the ability to retrieve 10,094 molecules from seventy million docking result data by a factor of 2.40 compared to the single-node storage model. Finally, we analyze the variation of input/output (I/O) over time for different phases of virtual screening to reflect the effectiveness of the scheduling strategy and tiered storage for the heterogeneous parallel architecture.