Biblio
Deep learning has made remarkable achievements in various domains. Active learning, which aims to reduce the budget for training a machine-learning model, is especially useful for the Deep learning tasks with the demand of a large number of labeled samples. Unfortunately, our empirical study finds that many of the active learning heuristics are not effective when applied to Deep learning models in batch settings. To tackle these limitations, we propose a density weighted diversity based query strategy (DWDS), which makes use of the geometry of the samples. Within a limited labeling budget, DWDS enhances model performance by querying labels for the new training samples with the maximum informativeness and representativeness. Furthermore, we propose a beam-search based method to obtain a good approximation to the optimum of such samples. Our experiments show that DWDS outperforms existing algorithms in Deep learning tasks.
Traditionally, power grid vulnerability assessment methods are separated to the study of nodes vulnerability and edges vulnerability, resulting in the evaluation results are not accurate. A framework for vulnerability assessment is still required for power grid. Thus, this paper proposes a universal method for vulnerability assessment of power grid by establishing a complex network model with uniform weight of nodes and edges. The concept of virtual edge is introduced into the distinct weighted complex network model of power system, and the selection function of edge weight and virtual edge weight are constructed based on electrical and physical parameters. In addition, in order to reflect the electrical characteristics of power grids more accurately, a weighted betweenness evaluation index with transmission efficiency is defined. Finally, the method has been demonstrated on the IEEE 39 buses system, and the results prove the effectiveness of the proposed method.