Abstract: Extreme event performance evaluation using real-time hysteresis monitoring. A structure is monitored using one or more sensors. One or more inter-story Hysteresis Loops for the structure are generated in real-time using data from the sensors, thus enabling rapid decision making regarding the structure's condition.

Abstract: Disclosed are flexible disk packs formed of disks which have an engagement section along their periphery, this section being adapted to be engaged by associated partition wedge means; in one embodiment each disk is made identical and includes a "partition edge"; then the disks are stacked so that each edge occupies a unique angular position in the stack--this facilitating engagement of any edge by the wedge, according to when the wedge is activated; whereby to effect pack-partition and exposure of a "selected" disk surface for transducer access.

Abstract: Method and apparatus for providing coarse and fine radial positioning of a multiple head assembly relative to the concentric tracks of a rotatable magnetic disk. In addition to a plurality of data heads, the head assembly also includes a pair of position sensing heads having skewed core gaps disposed at an angle with respect to each other. These position sensing heads are used for prerecording concentric position control tracks on the disk as well as for subsequent sensing of position control information during both coarse and fine positioning operations. The position control information prerecorded in the position control tracks is specially chosen so as to provide a pair of pulse trains during position sensing having characteristics such that highly accurate and reliable control of head position can be achieved based upon a detection of the coincidence relationship between predetermined pulses of the respective pulse trains.

Abstract: Data is recorded on a magnetic recording disk with data transducers adjustably positioned relative to respective "data zones," each zone comprising a prescribed number of adjacent data tracks. A family of such transducers may be mounted together as a unitary recording head which is positionable radially over an excursion approximating the width of the (multi-track) data zones. A typical head reciprocation excursion approximates from one dozen to several dozen mils; thus, the heads are aptly mounted on flexure pivots and reciprocated directly by electro-magnetic means which are mechanically isolated from the head array.