A circulating system for a linear guideway comprises a slide block, a slide rail, two cover plates, two end caps and plural rolling elements. The method and apparatus adapts the timing of a maximum or substantially elevated rate of infusion to correlate with the collection of image data corresponding to the center of k-space. A predetermined pattern of elongate conductors can be longitudinally disposed on the insulative strip in at least two rows along the longitudinal length and electrically isolated from each other. The MTJ device is offset with respect to the metal pad. The candidate searcher applies the mask to a section of a foreground region of the image to determine the presence of a structureobject by counting the number of intersections between the mask and the section of the foreground region. The method for updating GPS ephemeris data includes the following steps: first, the navigation device counting down a predetermined time; next, searching a GPS ephemeris data server through a network interface; then performing a download from the GPS ephemeris data server so as to update the GPS ephemeris data in the navigation device.