A self-adaptive jitter buffer adjustment method for packet-switched network is presented in this invention, which involves both positive adjustment to jitter buffer and negative adjustment to jitter buffer. The operating member is configured in the preferred embodiment to operate both the hydraulic braking unit and the shifting unit. The fingers are electrically coupled to a processor that communicates with a robot. The method includes sending the plurality of SQL change statements to the column store database upon receipt of the analytic query for updating the column store database for purposes of satisfying the query, wherein the analytic query is directed to a queried range of primary key attributes in the plurality of attributes. The relation between the first and second concentration is used as a measure of the concentration of micro-organisms in the sample.