Learn More
Spatial databases have been increasingly and widely used in recent years. The R-tree proposed by Guttman is probably the most popular dynamic index structure for eciently retrieving objects from a spatial database according to their spatial locations. However, experiments show that only about 70% storage utilization can be achieved in Guttman's R-tree and(More)
—A metering scheme enables a web server to measure the number of visits from clients. In addition, a proof needs to be presented by the server as evidence corresponding to this measured number. In this letter, we propose an efficient metering scheme that incorporates the hash-chaining technique and the digital signature algorithm to provide a nonrepudiation(More)
In a group-oriented threshold cryp-tosystem, each group, instead of each individual member within the group, publishes a single group public key. An outsider can use this group public key to send encrypted messages to the group. However, the received encrypted messages can only be decrypted properly when the number of participating members is larger than or(More)
Available online xxxx a b s t r a c t Vertical thin-GaN LED was successfully fabricated on the GaN LED epi-layers grown on the patterned-sapphire substrate with the pyramidal pattern by low-temperature Cu/Sn/Ag wafer bonding at 150 °C. An inverted pyramidal pattern formed on the n-GaN surface after the GaN epi-layer was transferred onto Si wafer, which(More)
  • 1