Chun-Biu Li

Nyckelord: NATURVETENSKAP; NATURAL SCIENCES; Clustering analysis; Fuzzy clustering; Graph-based methods; Clustering validation; Time series analysis; Change point detection; Computational Mathematics; beräkningsmatematik; Sammanfattning: This thesis presents state-of-the-art developments in the field of unsupervised learning, particularly in clustering analysis.

Abstract Organ sizes and shapes are highly reproducible, or robust, within a species and individuals. Arabidopsis thaliana sepals, which are the leaf-like organs that enclose flower buds, have consistent size and shape, which indicates robust development. Counterintuitively, variability in cell growth rate over time and between cells facilitates robust development because cumulative cell growth averages to a uniform rate.

Abstract Living tissues display fluctuations -- random spatial and temporal variations of tissue properties around their reference values -- at multiple scales. It is believed that such fluctuations may enable tissues to sense their state or their size. Recent theoretical studies developed specific models of fluctuations in growing tissues and predicted that fluctuations of growth show long-range correlations. Here we elaborated upon these predictions and we tested them using experimental data.