Abstract: A generation device includes a memory, and processing circuitry coupled to the memory and configured to sense anomaly of a network based on information having a plurality of items related to communication in the network, identify a cause of anomaly corresponding to each piece of the information when anomaly is sensed, and generate, based on values of the items in the information and the cause of anomaly identified, a cause-of-anomaly pattern for each predetermined set of pieces of the information.

Abstract: A filter device 2 is provided with: a filter body 3 equipped with a filtering material 30; and a mesh-like filter cover 5 that is mounted to the filter body 3 in such a manner as to cover at least part of a filtering surface 32 of the filtering material 30. The filter cover 5 is provided with: a purification part 50 which includes multiple layers formed by folding a single sheet of metal mesh material and which has a rectangular shape that is substantially identical to that of the filtering surface 32 in a plan view; and a first leg 51 and a second leg 52 which intersect with the purification part 50 in a side view. The metal mesh material has a finely corrugated surface formed thereon. The entire outer peripheral edge 59 of the filter cover 5 is completely fitted within the filtering surface 32.