34 results about "Analysis of covariance" patented technology

The present invention provides a system for evaluating a correlation between a plurality of time-series data. The system includes a calculating section which calculates characteristic quantities indicating symmetry of a diagram drawn by a graph, on which data values included in the plurality of time-series data are plotted in a multidimensional space in which each coordinate axis represents the data value of each time-series data; and an evaluating section which evaluates the correlation between the plurality of time-series data, based on the calculated characteristic quantities.

The invention discloses a satellite non-linear relative movement deviation propagation analysis method. The method comprises steps that a main satellite and a secondary satellite are assigned, a reference satellite absolute track state at the initial time, a two-satellite nominal relative movement state and a probability density function of initial relative movement state deviation are inputted, first-order and second-order state transfer tensors used for analyzing and forecasting a satellite relative movement state and deviation are calculated according to a non-linear relative movement equation considering J2 perturbation, a covariance analysis method is utilized for Gauss distribution, an analytic result is further outputted, otherwise, Gauss and model calculation is utilized, and an analytic result is outputted. A J2 perturbation item and a second-order non-linear item are considered, the method can be utilized for long-time high-precision analysis forecast of relative movement state deviation of two distant satellites, the acquired deviation information can be used for formation satellite bump probability calculation and bump early warning, and the method further has properties of accurate and reasonable design, small method analysis computational complexity and good applicability to actual engineering tasks.

The invention relates to a spacecraft robust rendezvous trajectory design method considering uncertain factors. With utilization of the characteristic of constructing an uncertain factor propagation equation rapidly and precisely according to a covariance analysis method, influences on a nominal track by uncertain factors are analyzed. A robust optimization problem is constructed by using the analysis results as the constraints of the optimization problem. Calculation is carried out based on a genetic algorithm to realize the robust rendezvous trajectory design. Therefore, the traditional optimal system rendezvous determination problem is transformed into a robust rendezvous problem considering uncertain factors; and calculation is carried out based on the genetic algorithm, so that an objective of the robust rendezvous trajectory design is achieved.

The invention discloses a local curved surface change factor based scattered point cloud data compaction processing method. The local curved surface change factor based scattered point cloud data compaction processing method comprises the steps of 1 reading measured point cloud data, 2 calculating a central point of a point cloud, 3 searching dynamic K neighborhood points of the central point based on cubic grids and accordingly establishing the topological relation of scattered point cloud, 4 adopting a variance component method to calculate curved surface change factors of a k neighborhood of the central point, 5 determining the compaction rate of each cubic grid in the k neighborhood of the central point and performing even compaction in within a k neighborhood range. The topological relation of the scattered point cloud is established by establishing the dynamic K neighborhood point information of the scattered point cloud. Complicated curvature calculation is replaced by the curved surface change factors. The compaction ratio is adjusted according to the curved surface change factors Xi, even compaction within the k neighborhood range is achieved, the detail characteristic of high curvature can be protected, and planar characteristic of low curvature is also protected when the compaction degree is high. Point cloud data processing and curved surface reconstruction efficiency and accuracy are improved.

The invention discloses a point cloud simplification method based on survival probability. In the method, the original point cloud data is read, the topological relationship is established for the original point cloud data based on the kdtree algorithm, and the radius r range of each data point is obtained. All the neighborhood points within; Based on the principal component analysis method, multi-threaded parallel computing is used to perform covariance analysis on each data point and its neighborhood points to obtain a covariance matrix; all data points are divided into boundary points or boundary points according to whether they are boundary points or Non-boundary points, sort the non-boundary points according to the curvature, and divide them into high curvature points and low curvature points according to the predetermined threshold; according to the predetermined simplification ratio and n 1 , n 2 , n 3 The size of the calculation of boundary points, high curvature points and low curvature points need to delete the number of points; based on multi-threaded parallel computing to traverse each data point of the point cloud, each time a random number between 0 and 1 is randomly generated , comparing the random number with the survival probability to obtain the simplified point cloud data.

The present invention discloses a method for analyzing anomalies of a semiconductor processing system, providing an analysis of each process step of a plurality of process steps for each of a plurality of processed wafers and in a plurality of tools An analysis of variance was performed on the production history associated with each tool, and critical process steps were identified. A regression analysis is performed on multiple measurements of multiple wafers at each process step and key measurement parameters are determined. An analysis of covariance is performed on the key measurement parameters and key process steps, and the key process steps are sorted based on the f-ratio, wherein the abnormalities of the key process steps are sorted. Also, the plurality of tools associated with each of the critical process steps are ranked based on an orthogonal t ratio associated with the analysis of covariance, wherein the anomalies for each tool associated with the critical process steps are ranked. The present invention also provides 2D / 3D analysis for abnormal tool and stage diagnosis.