A painting device for painting a curved surface of an object, with a paint material ejection device, with a guide device and with a control device. A shield apparatus includes a plurality of elongated members each having a first end and a second end. The features sorted in this manner are transmitted to a processing device which inputs them into a decision matrix and determines as output variables from this matrix the features required for the communication relation as second features. The material of this invention is unique based on the three principle characteristics which are communicated in this application: 1) ff<0. The controller may change the predetermined characteristics over the life of the shredder to account for gradual changes to the shredder’s baseline vibration characteristics as components wear in and out.