Abstract: Disclosed herein are a catalyst for hydrocracking reaction of high molecular weight components in bio-oil, a method for preparing the same and a method for bio-oil upgrading using the same. The catalyst includes a zeolite carrier; and at least one metal selected from the group consisting of nickel (Ni), ruthenium (Ru) and cerium (Ce) supported on the carrier. The catalyst promotes the hydrocracking of high molecular weight compounds contained in the bio-oil, but also inhibits the polymerization reaction of the decomposed product, thereby more effectively enhancing the hydrocracking reaction of the bio-oil.

Abstract: A method for managing energy in a sensor network environment using a spanning tree includes the steps of collecting amount of remaining energy of nodes at a predetermined cycle by a base station in a region having a number of clusters a number of nodes forming a spanning tree in each cluster; assigning a number of links for connecting the nodes to each cluster; determining a maximum number of allowable links of the nodes; and updating the spanning tree based on the maximum number of allowable links.

Abstract: Provided are a node device and a method for deciding a shortest path using a spanning tree. The node device includes: a node division unit dividing the node device into sub-nodes as many as the number of nodes connected to the node device when the node device operates an edge node that is located at an end of a backbone network and is in charge of reformatting and routing frames; a spanning tree generation unit generating as many spanning trees as the number of sub-nodes, wherein each of the spanning trees comprises a shortest path to reach the other edge nodes constructing the backbone network from each of the sub-nodes; and a first path decision unit deciding a shortest path from a source node to a predetermined destination node, as a path to be used, based on the spanning trees that are generated by the spanning tree generation unit. The shortest path that is obtained based on the plurality of spanning trees is used as a path to be used such that throughput of traffic is 3 times and 1.

Abstract: A method for managing energy in a sensor network environment using a spanning tree includes the steps of collecting amount of remaining energy of nodes at a predetermined cycle by a base station in a region having a number of clusters a number of nodes forming a spanning tree in each cluster; assigning a number of links for connecting the nodes to each cluster; determining a maximum number of allowable links of the nodes; and updating the spanning tree based on the maximum number of allowable links.