Abstract: The invention relates generally to archiving data items in an information store. More particularly, the invention provides a computerized method for identifying, in a first information store, a first data item satisfying retention criteria; copying the first data item to a second information store; creating, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data type of the first data item; and replacing the first data item, in the first information store, with the second data item.

Abstract: An exemplary parallel hybrid power filter apparatus for the electrified railway is described. The apparatus may include a group of LC reactive filter being purely tuned, an additional inductance, an active power filter and a coupling transformer. The active power filter may be controlled, e.g., as a current source in a composite control manner and can be connected in parallel to the additional inductance via the coupling transformer. The power filter can be connected to the reactive filter in series to form the parallel hybrid filtering system, and may be connected to the power grid via the circuit breaker or a thyristor. This exemplary system can be installed either in the traction substations or in the locomotives directly, or performed by ameliorating the original reactive filter. The active power filter does not add significant amount of cost, and may be simple and reliable in a control manner for the capacity of the APF is so small as to be less than one percent of that of the harmonics source.

Abstract: The invention relates generally to archiving data items in an information store. More particularly, the invention provides a computerized method for identifying, in a first information store, a first data item satisfying retention criteria; copying the first data item to a second information store; creating, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data type of the first data item; and replacing the first data item, in the first information store, with the second data item.