In order to solve the problem of insufficient available training data in the classification task of breast mass and calcification, a multi-view model based on secondary transfer learning was proposed combining with imaging characteristics of mammogram. Firstly, CBIS-DDSM (Curated Breast Imaging Subset of Digital Database for Screening Mammography) was used to construct the breast local tissue section dataset for the pre-training of the backbone network, and the domain adaptation learning of the backbone network was completed, so the backbone network had the essential ability of capturing pathological features. Then, the backbone network was secondarily transferred to the multi-view model and was fine-tuned based on the dataset of Mianyang Central Hospital. At the same time, the number of positive samples in the training was increased by CBIS-DDSM to improve the generalization ability of the network. The experimental results show that the domain adaption learning and data augmentation strategy improves the performance criteria by 17% averagely and achieves 94% and 90% AUC (Area Under Curve) values for mass and calcification respectively.
Concerning the large-scale concurrent video stream scheduling problem of low resource utilization and load imbalance under cloud environment, a Video-on-Demand (VOD) scheduling policy based on Ant Colony Optimization (ACO) algorithm named VodAco was proposed. The correlation of video stream expected performance and server idle performance was analyzed, and a mathematical model was built based on the definition of comprehensive matching degree, then ACO method was adopted to hunt the best scheduling schemes. The contrast experiments with Round Robin (RR) and greedy schemes were tested on CloudSim. The experimental results show that the proposed policy has more obvious advantages in task completion time, platform resources occupancy and node load balancing performance.
Signatures indentification of security and attack forecast are integrant function parts of network security field, and the description and definition of attack models and other security signatures request special language. But there exist many questions on the current such languages, such as solitary function of language and weak adaptablility; lack of openness and semantic coherence, and absent reuse ablility. In order to improve this state, the ontology's modeling means were used. It was demonstrated that ontology's language is fit for the description and definition of attack models and other security signatures by a representative attack.
The network structure design for Ad hoc is different from those of the traditional ones. The node structure was expounded and some typical network structures were compared firstly. Then a kind of protocol stack for Ad hoc was given. Different from other models, there was a middleware layer between transmission layer and net layer in this model, which shielded the OS and network’s low layers details and enhanced the reliability and security of communications at the same time.