3 results about "Abnormality detection" patented technology

The invention provides an abnormality detection method and device based on log graph modeling. The method and the device are applied to a nonsocial network. The method particularly includes: buildinga bipartite graph according to a key field of abnormal data annotated in advance in the nonsocial network, wherein left-side nodes of the bipartite graph correspond to multiple user accounts while right-side nodes of the same correspond to parameter combinations during business interface requesting; extracting features from the bipartite graph, and splicing the extracted features to form a featurevector; performing k-means cluster processing on the basis of the abnormal data and the feature vector to acquire optimal cluster number; according to the optimal cluster number, using a Gaussian mixing model to fit dark industry feature probability distribution; when receiving incoming data, calculating dark industry probability of the data according to feature vector of the incoming data and the Gaussian mixing model, and judging whether the data are abnormal or not according to the dark industry probability and the dark industry feature probability distribution. When the data are judged abnormal, access behaviors of users can be intervened timely, so that network attacks by hackers can be avoided.

There is provided an abnormality detection device and a fixing structure which are suitable for detecting an abnormality of a fastener such as a bolt or a nut. An abnormality detection device detects an abnormality of a fixing structure including a bolt, a nut, and a washer which include a conductor and fix steel plates to each other, and a spacer which includes an insulator and is disposed between the steel plates and the washer, the abnormality detection device including: a transmission antenna that radiates electromagnetic waves to the fixing structure; a reception antenna that receives electromagnetic waves reflected by the fixing structure; and an abnormality detector that changes a frequency of the electromagnetic waves radiated from the transmission antenna to acquire frequency characteristics of standing waves received by the reception antenna and detects an abnormality of the fixing structure by comparing the frequency characteristics with frequency characteristics in a normal state.