David Aristoff's homepage Title: Theodorus Spiral, Vector Algebra, and System Monitoring

Abstract: "Theodorus Spiral" can be expressed as a diagonal matrix and then further as a vector. Vectors have magnitude and directions. The directions of a vector carries composition information of a system. Ratios of present and previous cosine values are used for system successive trend analysis. Our trend analysis model has been tested by investment management. Furthermore, a time chain (Bai-Jameson Chain) based on trends (ratios of cosines) is developed for system prediction and monitoring.