A method for preparing a multi-lingual personal identification card includes receiving a multi-lingual text comprising Latin-based characters in a Latin-based language and non-Latin-based characters in a non-Latin-based language. The two or more tasks may be executed in parallel on three or more processors in a way that balances a processing load of executing the two or more tasks among the three or more processors. A ring piston is rotatably fitted over the eccentric part such that an outer surface of the ring piston is in contact with an inner surface of the compression chamber. The cross section of the submerged portion is streamline shaped to help further minimize the resistance.