[IEEE 2011 IEEE International Conference on Computer Applications and Industrial Electronics (ICCAIE) - Penang, Malaysia (2011.12.4-2011.12.7)] 2011 IEEE International Conference on Computer Applications and Industrial Electronics (ICCAIE) - Transient analysis of ambient vibration-based micro-electro-mechanical systems (MEMS) piezoelectric energy harvester using ANSYS and COVENTORWARE approaches