To address the problems in Opportunistic Networks that nodes employing routing algorithms based on epidemic mechanism cant sense their neighboring nodes timely and many redundant data packets permeate through the network, an efficient routing algorithm based on XOR network coding was proposed (Xor Network Coding based Epidemic Routing, XNCER). When a node gets a Hello message, it broadcasts, instead of unicasting, a SV(Summary Vector) packet, in return, to all its neighboring nodes. Therefore, the data transmission can be initiated immediately, and the XOR network coding can also be leveraged so as to enhance the efficiency of data transmission. Moreover, the packets destined to the one hop neighboring nodes obtain the priority in transmission, and are determined whether to be deleted based on the ACK mechanism running in the MAC layer in order to cut down the memory overhead and restrain redundant packets from dissemination. Theoretical analysis and extensive simulation results show that the new algorithm obtains an overall improvement in terms of network overhead, average end-to-end delay as well as delivery rate. The novel algorithm can effectively solve the problems of sensing neighboring nodes and data redundancy.

This passage mainly introduces about the design of liquid level and boundary measuring control at sewage re-flooding craft in small split oil field. In order to achieve automatically cutting flooding and re-flooding in the procedure in small split oil-field, the scheme is to test liquid level and boundary by using high performance to price ratio new double level gauge, to utilize electric valve instead of mechanical valve and to choose PLC to control system logic. Eventually, it will reduce the labor intensity.