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50 results about "Time-series segmentation" patented technology

Time-series segmentation is a method of time-series analysis in which an input time-series is divided into a sequence of discrete segments in order to reveal the underlying properties of its source. A typical application of time-series segmentation is in speaker diarization, in which an audio signal is partitioned into several pieces according to who is speaking at what times. Algorithms based on change-point detection include sliding windows, bottom-up, and top-down methods. Probabilistic methods based on hidden Markov models have also proved useful in solving this problem.

Judgment and prediction method of driving behavior intention

The present invention relates to the field of traffic safety, in particular to a judgment and prediction method of driving behavior intention based on the implicit Markov model (HMM), aiming to overcome the defect that the existing driving behavior intention recognition and prediction technology does not take into account the dynamics and continuity of driving behavior, as well as complex behaviors such as lane changing, car following and braking and the like. The judgment and prediction method of driving behavior intention obtains time series segmentation data from cluster analysis of dynamic driving data, the linear direction HMM, lateral HMM and speed classification model are trained respectively, and the obtained identification results are regarded as the observation sequence of behavior recognition layer; Then, off-line training is performed to deal with normal or emergency braking, normal or emergency lane change, normal or dangerous driving behavior, and multi dimensional discrete HMM model; according to the model parameters and the observation sequence, the next time step driving behavior can be predicted. The judgment and prediction method of driving behavior intention takes the complexity and continuity of driving behavior into account and can dynamically judge and predict the driving behavior intention and warn the dangerous behavior, and accordingly can be applied to driving behavior evaluation and driving assistance system.
Owner:BEIJING JIAOTONG UNIV

Abnormal alarm data detection method based on multivariate time series

ActiveCN106368813AImprove efficiency in handling alarmsReduce nuisance alarmsMachines/enginesEngine componentsAlgorithmMinimum time
The invention discloses an abnormal alarm data detection method based on a multivariate time series. The abnormal alarm data detection method based on the multivariate time series comprises the steps that data of multiple correlated variables are extracted from historical data, the multivariate time series is established and standardized, and the symbol direction between the variables in the normal state is calculated; time series segmentation description based on key turning points is determined, the minimum time interval is set, and key turning point searching is conducted; the piecewise linearity of the multivariate time series is represented, a fitting error is determined according to the orthorhombic distance between a data point and each segment, a loss function threshold value is set, the number of the segments is optimized, and an optimized segmentation result is obtained; and based on the optimized segmentation result, correlation analysis is conducted on all the segments of the multivariate time series, the symbol direction between the segment variables is extracted, and abnormal data with the symbol direction inconsistent with the symbol direction in the normal state are detected. By adoption of the abnormal alarm data detection method based on the multivariate time series, favorable conditions are provided for designing of a dynamic alarm threshold value of a multivariable alarm system, and thus disturbance alarms are reduced.
Owner:SHANDONG UNIV OF SCI & TECH

Time series trend feature extraction method based on important point double evaluation factor

The invention discloses a time series trend feature extraction method based on an important point double evaluation factor, comprising: regarding a time series piecewise linear representation as basis, defining an important point as an alternative set of time series segmentation points, calculating an important point distance factor and a trend factor, using the distance factor to measure the relative degree of difference and using the trend factor to measure its impact on the overall trend globally, using a comprehensive evaluation model to evaluate the importance of each important point to the overall trend to select the segmentation points, and finally connecting adjacent segmentation points to obtain a segmented trend representation of the time series. The invention proposes the concept of a time series important point distance factor, and combines the two evaluation factors to evaluate the important points of the time series, which overcomes the shortcomings of single evaluation functions and locality of the existing piecewise linearization method, may effectively weaken the noise interference, retain the time series change trend feature, and has fast processing speed and higher extraction precision than the existing method when the number of segments is the same.
Owner:CENT SOUTH UNIV

Structural health monitoring multivariate data anomaly diagnosis method based on convolutional neural network and transfer learning

The invention provides a structural health monitoring multivariate data anomaly diagnosis method based on a convolutional neural network and transfer learning, and the method comprises the steps: carrying out the time series segmentation data visualization processing of the multivariate monitoring data of a certain large-scale structure A, converting the data into a time domain response image, carrying out the manual marking according to the time domain response image data corresponding to a data segment, selecting samples of various abnormal types with manual marks to form a data set A; inputting the data set A into a convolutional neural network model A for anomaly detection, and training the model A; visualizing and manually marking multivariate monitoring data of a certain large structure B to form a data set B; and adding a data set B on the basis of the model A, carrying out transfer learning training, so that the generalization performance of a classification model is improved, a convolutional neural network model can adapt to data of different distributions, and the model trained through transfer learning serves as a multivariate data anomaly detector; the method can solve the problem that there is no detection method for structural health monitoring multivariate data at present.
Owner:HARBIN INST OF TECH

A Lifetime Prediction Method Based on Change Point Detection of Correlated Synchronized Time Series Signals

The invention discloses a life prediction method based on the change point detection of an associated synchronous time series signal, which is used to solve the life prediction problem under the interactive influence of large time scale and multi-dimensional time series. First, the original multi-dimensional synchronous time series is resampled to obtain the equivalent time series signal after scale reduction; secondly, a likelihood function is constructed for the sampled signal with the change point vector, piecewise slope and piecewise variance as parameters ; Then, for different values ​​of the number of change points, the maximum likelihood estimation is used to estimate the best value of the change point vector, piecewise slope and piecewise variance; The change point vector corresponding to the selected optimal number of change points divides the original time series into a plurality of local time series that are not constant zero and have only one change point, and repeatedly construct the likelihood function and In the step of optimal change point estimation, the final change point position of the original time series is obtained; finally, the signal at which the final change point is located is determined, and the time series at the tail of each dimension signal is obtained, which is used for parameter estimation required for subsequent life prediction.
Owner:BEIHANG UNIV

Gain Estimation Method of Dynamic System Based on Steady-state Value of Historical Data

ActiveCN109753634BEstimates are accurate and validComplex mathematical operationsData segmentAlgorithm
The invention provides a dynamic system gain estimation method based on a historical data steady-state value, and the method comprises the steps: firstly, dividing an input time sequence and an outputtime sequence into short data segments through employing a linear segmentation representation method, and finding out data segments with input and output being in a steady state at the same time; calculating input and output steady-state values from the data segment under the steady-state condition; elements, in the steady-state values, associated with the same steady-state gain in statistical significance are found, the elements are divided into one group, the steady-state gain of each group is estimated, and interval estimation of estimation parameters is given. According to the method, theinput and output steady-state values can be automatically found in the historical data sample, a plurality of steady-state gains under different working conditions can be accurately and effectively estimated, verification is carried out through a visualization method, and the problems that the time consumption for searching the steady-state values is long, the steady-state values are easily influenced by nonlinearity and the steady-state gain change is difficult to detect are solved.
Owner:SHANDONG UNIV OF SCI & TECH

Unsupervised non-intrusive load identification method and system based on power theme discovery

The invention discloses an unsupervised non-intrusive load identification method based on power theme discovery. The method comprises the following steps: collecting total active power signals at a home entry to form a load power time sequence; filtering power peaks of a non-fluctuation section from an original active power time sequence by adopting a median filtering preprocessing method; detecting the key points (an important extreme point and an important trend turning point) of the load power time sequence, and marking in the time sequence; segmenting the time sequence into a plurality of subsequences with different lengths based on the key points; and storing subsequently extracted subsequences in a subsequence list, matching the extracted subsequences with templates in an electric appliance load mark template library in a template matching mode, and finally achieving unsupervised non-intrusive load recognition. According to the invention, subsequences which frequently appear in a time sequence and have any duration can be autonomously found, load events corresponding to the start-stop process of the electric appliance can be detected, and a complex power change mode in the operation process of the electric appliance can be found.
Owner:TIANJIN UNIV
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