A method of fabricating a SOI wafer having a gate-quality, thin buried oxide region is provided. The current face position is estimated based on the position of the ambient information that is most similar to the ambient information obtained from previous detections. Each power module comprises a DC voltage source, a DC-DC converter, and an output switching circuit. Thus, the polymer material is controlled extremely well and the function and physical properties of the polymer material are greatly enhanced. Generally, the steeper the depression wall, the more strength is provided to the structure. The multiple web servers may be arranged to form a web farm.