Sliding mode based droop control strategies for parallel-connected inverters in railway vehicles

This paper deals with the design of sliding mode based droop control strategies for parallel-connected inverters in railway vehicles. Indeed, the presence of auxiliary devices, which can be connected and disconnected at any time instant, makes the introduction of parallel modules an efficient solution. Among the possible techniques, droop control represents an efficient and easy-to-implement approach. However, each inverter is affected by load variations, nonlinearities and unavoidable modelling uncertainties, thus making the use of sliding mode controllers perfectly adequate for this kind of application. More specifically, relying on a sliding surface designed on the basis of a voltage-current droop characteristic, two second order sliding mode (SOSM) control algorithms, belonging to the class of Super-Twisting and Suboptimal SOSM control, are proposed

DNA-binding factors shape the mouse methylome at distal regulatory regions

Methylation of cytosines is an essential epigenetic modification in mammalian genomes, yet the rules that govern methylation patterns remain largely elusive. To gain insights into this process, we generated base-pair-resolution mouse methylomes in stem cells and neuronal progenitors. Advanced quantitative analysis identified low-methylated regions (LMRs) with an average methylation of 30%. These represent CpG-poor distal regulatory regions as evidenced by location, DNase I hypersensitivity, presence of enhancer chromatin marks and enhancer activity in reporter assays. LMRs are occupied by DNA-binding factors and their binding is necessary and sufficient to create LMRs. A comparison of neuronal and stem-cell methylomes confirms this dependency, as cell-type-specific LMRs are occupied by cell-type-specific transcription factors. This study provides methylome references for the mouse and shows that DNA-binding factors locally influence DNA methylation, enabling the identification of active regulatory regions