%A Lei XU %T On essential topics of BYY harmony learning: Current status, challenging issues, and gene analysis applications %0 Journal Article %D 2012 %J Front. Electr. Electron. Eng. %J Frontiers of Electrical and Electronic Engineering %@ 2095-2732 %R 10.1007/s11460-012-0190-2 %P 147-196 %V 7 %N 1 %U {https://journal.hep.com.cn/fee/EN/10.1007/s11460-012-0190-2 %8 2012-03-05 %X

As a supplementary of [Xu L. Front. Electr. Electron. Eng. China, 2010, 5(3): 281-328], this paper outlines current status of efforts made on Bayesian Ying-Yang (BYY) harmony learning, plus gene analysis applications. At the beginning, a bird’s-eye view is provided via Gaussian mixture in comparison with typical learning algorithms and model selection criteria. Particularly, semi-supervised learning is covered simply via choosing a scalar parameter. Then, essential topics and demanding issues about BYY system design and BYY harmony learning are systematically outlined, with a modern perspective on Yin-Yang viewpoint discussed, another Yang factorization addressed, and coordinations across and within Ying-Yang summarized. The BYY system acts as a unified framework to accommodate unsupervised, supervised, and semi-supervised learning all in one formulation, while the best harmony learning provides novelty and strength to automatic model selection. Also, mathematical formulation of harmony functional has been addressed as a unified scheme for measuring the proximity to be considered in a BYY system, and used as the best choice among others. Moreover, efforts are made on a number of learning tasks, including a mode-switching factor analysis proposed as a semi-blind learning framework for several types of independent factor analysis, a hidden Markov model (HMM) gated temporal factor analysis suggested for modeling stationary temporal dependence, and a two-level hierarchical Gaussian mixture extended to cover semi-supervised learning, as well as a manifold learning modified to facilitate automatic model selection. Finally, studies are applied to the problems of gene analysis, such as genome-wide association, exome sequencing analysis, and gene transcriptional regulation.