Methods and apparatus for analyzing tasks performed by computer users by gathering usage data, converting logged usage data into a uniform format, determining or defining task boundaries, and determining a task analysis model by clustering similar tasks together. The method includes passing a metal vapor to a shaping apparatus and condensing the metal vapor within the shaping apparatus to form selectively-shaped metal nanoparticles. By taking the advantage of additive property of Poisson process, the method integrates spatial neighbor information by aggregating temporal data in various areas, and iteratively estimating the event location and the radius of event impact by examining the posterior probability base on the aggregated data. The process may be repeated to form a series of compacted lifts comprising a pier. The front handle section and the rear handle section form a channel that accommodates a window shade wrapped about a rod.