Non-negative Matrix Factorization (NMF), especially with sparseness constraints, plays a critically important role in data engineering and machine learning. Hoyer (2004) presented an algorithm to compute NMF with exact sparseness constraints. The exact sparseness constraints depends on a projection operator. In the present work, we first give a very simple counterexample, for which the projecti...

Special thanks to Aapo Hyvärinen, Patrik O. Hoyer and Takashi Washio. 2 Abstract • Linear structural equation models (linear SEMs) can be used to model data generating processes of variables. • We review a new approach to learn or estimate linear structural equation models. • The new estimation approach utilizes non-Gaussianity of data for model identification and uniquely estimates much wider...

Serotonin 5-HT 2C receptors belong to the 5-HT 2 family, which includes 5-HT 2A and 5-HT 2B receptors. All three share similarities in their molecular structure, pharmacology, and signal transduction pathways (Barnes and Sharp 1999; Hoyer et al. 1994). Initially named 5-HT 1C, based on the conventions for naming serotonin receptors at the time of its discovery, it was later renamed 5-HT 2C rece...