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Chunhui Hou

Publications and source records attributed to Chunhui Hou.

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Resilient Hierarchical Power Control for Hybrid GFL/GFM Microgrids Under Mixed Cyber-Attacks and Physical Constraints

Hybrid microgrids integrating Grid-Following (GFL) and Grid-Forming (GFM) inverters present complex control challenges arising from the decoupling between long-term economic dispatch and real-time dynamic regulation, as well as the distinct physical limitations of heterogeneous inverters under cyber uncertainties. This paper proposes a Resilient Hierarchical Power Control (RHPC) strategy to unify these conflicting requirements within a cohesive framework. A standardized power increment mechanism is developed to bridge the tertiary and secondary layers, ensuring that real-time load fluctuations are compensated strictly according to the optimal economic ratios derived from the tertiary layer. To address the strict active power saturation constraints of GFL units, a dynamic activation scheme coupled with projection operators is introduced, which actively isolates saturated nodes from the consensus loop to prevent integrator wind-up and preserve the stability of the GFM backbone. Furthermore, the proposed framework incorporates a multi-scale attention mechanism and LSTM-based predictors into the secondary control protocol, endowing the system with robustness against unbounded False Data Injection (FDI) attacks and packet losses. Rigorous theoretical analysis confirms that the system achieves Uniformly Ultimately Bounded (UUB) convergence, and simulations on a modified IEEE 33-bus system demonstrate that the proposed strategy significantly improves power sharing accuracy and operational resilience in both grid-connected and islanded modes compared to conventional methods.

eess.SY

CTCF-mediated transcriptional regulation through cell type-specific chromosome organization in the β-globin locus

The principles underlying the architectural landscape of chromatin beyond the nucleosome level in living cells remains largely unknown despite its potential to play a role in mammalian gene regulation. We investigated the 3-dimensional folding of a 1 Mbp region of human chromosome 11 containing the β-globin genes by integrating looping interactions of the insulator protein CTCF determined comprehensively by chromosome conformation capture (3C) into a polymer model of chromatin. We find that CTCF-mediated cell type specific interactions in erythroid cells are organized to favor contacts known to occur in vivo between the β-globin locus control region (LCR) and genes. In these cells, the modeled β-globin domain folds into a globule with the LCR and the active globin genes on the periphery. By contrast, in non-erythroid cells, the globule is less compact with few but dominant CTCF interactions driving the genes away from the LCR. This leads to a decrease in contact frequencies that can exceed 1000-fold depending on the stiffness of the chromatin and the exact positioning of the genes. Our findings show that an ensemble of CTCF contacts functionally affects spatial distances between control elements and target genes contributing to chromosomal organization required for transcription.

q-bio.GN