A new approach to quantify the lung nodule spiculation levels in CT (computed tomography) images was proposed. Firstly, two-dimensional image of nodule was generated by using the spiral scan technology. Secondly, the lung nodule was segmented in the two-dimensional image using the dynamic programming. Thirdly, based on the expanded regions from the segmented boundary, the spiculation was segmented by use of threshold segmentation. Fourthly, the feature region where spiculation may exist was extracted on the region of spiculation boundary. Finally, the edge gradient orientation histogram as a new quantitative index was extracted to quantify the spiculation levels of the lung nodule. The experimental results indicate that this index can quantify the spiculation levels accurately with better classification results.
At present, there are few studies about the link failure and reliability of software defined satellite network (SDSN). However, the inter-satellite links (ISLs) may break down because of the long distance between the satellites, the high relative moving speed and the easy interference of the wireless channel. At the same time, most researches on controller deployment in SDSN only consider the transmission delay but ignore the processing delay. To solve these problems, considering the failure probability of intersatellite link, the failure probability model of ISLs is designed, the queuing delay and processing delay are added into the delay model, and the software defined satellite network reliability analysis model based on control delay is established. This model can describe the reliability of the network against link failure. The simulation results show that the model is consistent with the actual situation and can provide some reference value for controller deployment in SDSN.
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