A Living Buddha of Modern Times

Entering any Tibetan Buddhist monastery one may feel overwhelmed, struck with awe. But the worshipping seems much more pleasant at the Sepa Monastery which is hidden in deep mountains on the right bank of Tongtian River—the upper reach section of the Yangtze, in Yushu Tibetan Autonomous Prefecture of Qinghai Province. A closer observation can tell that the pleasant feeling comes from the brightness inside the main hall of the monastery, as well as from the lush woods around its buildings, which present a sweet greenness rarely seen

Unicast Network Topology Inference Algorithm Based on Hierarchical Clustering

Network topology inference is one of the important applications of network tomography.Traditional network topology inference may impact network normal operation due to its generation of huge data traffic.A unicast network topology inference is proposed to use time to live(TTL)for layering and classify nodes layer by layer based on the similarity of node pairs.Finally,the method infers logical network topology effectively with self-adaptive combination of previous results.Simulation results show that the proposed method holds a high accuracy of topology inference while decreasing network measuring flow,thus improves measurement efficiency.

Multi-level cross-layer protocol for end-to-end delay provisioning in wireless multimedia sensor networks

Rapid developments in information and communication technology in recent years have posed a significant challenge in wireless multimedia sensor networks(WMSNs).End-to-end delay and reliability are the critical issues in multimedia applications of sensor networks.In this paper we provide a new cross-layer approach for provisioning the end-to-end delay of the network at a desirable level of the packet delivery ratio(PDR),used here as a measure of network reliability.In the proposed multi-level cross-layer(MLCL)protocol,the number of hops away from the sink is used to set a level for each node.A packet is routed through the path with the minimum hop count to the sink using this level setting.The proposed protocol uses cross-layer properties between the network and medium access control(MAC)layers to estimate the minimum delay,with which a node can deliver a packet to the sink.When a node wants to send a packet,the MLCL protocol compares this minimum delay with the time to live(TTL)of a packet.If the TTL of the packet is higher than the minimum delay,the node sends the packet through the path with the minimum delay;otherwise,the node drops the packet as the node cannot deliver it to the sink within the TTL duration.This packet dropping improves network performance because the node can send a useful packet instead of an unusable packet.The results show a superior performance in terms of end-to-end delay and reliability for the proposed protocol compared to state-of-the-art protocols.