The basic clue of Wittgenstein s Tractatus Logico Philosophicus is that the real world is the summation of facts and the probable world is the summation of the state of affairs.

Study on Decision Support System of Optimal Control of Breakdown State of City Water Supply Network;

Based on the analysis of breakdown state in network, simplified model for optimal control of breakdown state was put forward.

With mobile computing,after disconnection,mobile clients execute transactions locally based on the cached data,after reconnection,the transactions in the mobile clients will be submitted as the tentative transactions to the stable hosts to re-execute.