Abstract: VM file management includes detecting a user request to access to a virtual machine (VM) and searching a pre-defined list to determine whether the user requesting access is identified on the list. If so, a file-level snapshot is generated prior to enabling modification of a VM file by the user. The file-level snapshot includes a user attribute and is added as the top layer of a stack. The user attribute indicates a role of the user for whom the file-level snapshot is created. Each layer of the stack contains one or more other file-level snapshots. The VM file is written in the file's entirety to the snapshot in response to the user modifying the VM file. Based on the user attribute of each snapshot, a set of snapshots is selected from the stack, and the VM is modified by merging the VM files belonging to the set of snapshots selected.

Abstract: There is provided a protection apparatus for protecting an electrical network. The protection apparatus comprises: at least one protection device configured to protect the electrical network from a fault in response to a or a respective protection criterion being met; and a controller configured to: receive real-time information on a change in topological structure of the electrical network; perform an online determination of the real-time impedance or admittance matrix of the electrical network based on the change in topological structure of the electrical network; and adapt the or each protection criterion based on the real-time impedance or admittance matrix.

Abstract: There is provided a protection apparatus for protecting an electrical network. The protection apparatus comprises: at least one protection device configured to protect the electrical network from a fault in response to a or a respective protection criterion being met; and a controller configured to: receive real-time information on a change in topological structure of the electrical network; perform an online determination of the real-time impedance or admittance matrix of the electrical network based on the change in topological structure of the electrical network; and adapt the or each protection criterion based on the real-time impedance or admittance matrix.