1. An apparatus for searching a communication network including an asymmetry node for a route, the asymmetry node being a node on which path restriction for restricting a connectable path is imposed, the apparatus comprising:
a memory configured to store topology information indicating a connection relationship between nodes on the communication network, cost information storing a link cost of a link connecting each pair of adjacent nodes on the communication network, and asymmetry-node information indicating the path restriction imposed on the asymmetry node; and
a processor configured:
to search for one or more first routes coupling a starting point node and an ending point node in the communication network, based on the topology information,
to determine, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on the asymmetry-node information, and
to determine, based on the cost information, a second route that has a minimum sum of the link costs among one or more third routes for which it is determined that signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node.
2. The apparatus of claim 1, wherein
the processor determines, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on the asymmetry node information and information on links of the asymmetry node that are included in the each first route.
3. The apparatus of claim 1, wherein
the processor determines whether or not the second route includes a first pair of links connecting adjacent nodes between which signals travel forth and back;
the processor changes the cost information stored in the memory by increasing link costs of the first pair of links when it is determined that the second route includes the first pair of links; and
the processor determines, based on the changed cost information, a fourth route that has a minimum sum of link costs among the one or more third routes.
4. The apparatus of claim 3, wherein
the processor determines whether or not the fourth route includes the first pair of links; and
the processor determines, when it is determined that the fourth route includes the first pair of links, that there exists no route through which signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node.
5. The apparatus claim 3, wherein
the processor performs a repetition process including:
determining whether or not the fourth route includes the first pair of links;
changing the cost information stored in the memory by increasing link costs of the first pair of links when it is determined that the fourth route includes the first pair of links; and
determining, based on the changed cost information, a fifth route that has a minimum sum of link costs among the one or more third routes.
6. The apparatus of claim 3, wherein
the processor changes link costs of the first pair of links to a sum of link costs of all links included in the communication network.
7. A method for searching a communication network including an asymmetry node for a route, the asymmetry node being a node on which path restriction for restricting a connectable path is imposed, the method comprising:
searching for one or more first routes coupling a starting point node and an ending point node in the communication network, based on topology information indicating a connection relationship between nodes on the communication network;
determining, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on asymmetry node information indicating the path restriction imposed on the asymmetry node; and
determining a second route that has a minimum sum of link costs among one or more third routes for which it is determined that signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on cost information storing a link cost of a link connecting each pair of adjacent nodes on the communication network.
8. The method of claim 7, further comprising
determining, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on the asymmetry node information and information on links of the asymmetry node that are included in the each first route.
9. The method of claim 7, further comprising:
determining whether or not the second route includes a first pair of links connecting adjacent nodes between which signals travel forth and back;
changing the cost information by increasing link costs of the first pair of links when it is determined that the second route includes the first pair of links; and
determining, based on the changed cost information, a fourth route that has a minimum sum of link costs among the one or more third routes.
10. The method of claim 9, further comprising:
determining whether or not the fourth route includes the first pair of links; and
determining, when it is determined that the fourth route includes the first pair of links, that there exists no route through which signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node.
11. The method of claim 9, further comprising
performing a repetition process including:
determining whether or not the fourth route includes the first pair of links;
changing the cost information by increasing link costs of the first pair of links when it is determined that the fourth route includes the first pair of links; and
determining, based on the changed cost information, a fifth route that has a minimum sum of the link costs among the one or more third routes.
12. The method of claims 9, further comprising
changing link costs of the first pair of links to a sum of link costs of all links included in the communication network.
13. A computer readable recording medium having stored therein a program causing a computer to execute a search process for searching a communication network including an asymmetry node for a route, the asymmetry node being a node on which path restriction for restricting a connectable path is imposed, the search process comprising:
searching for one or more first routes coupling a starting point node and an ending point node in the communication network, based on topology information indicating a connection relationship between nodes on the communication network;
determining, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on asymmetry node information indicating the path restriction imposed on the asymmetry node; and
determining a second route that has a minimum sum of link costs among one or more third routes for which it is determined that signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on cost information storing a link cost of a link connecting each pair of adjacent nodes on the communication network.
14. The computer readable recording medium of claim 13, wherein the search process further comprises
determining, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on the asymmetry node information and information on links of the asymmetry node that are included in the each first route.
15. The computer readable recording medium of claim 13, wherein the search process further comprises:
determining whether or not the third route includes a first pair of links connecting adjacent nodes between which signals travel forth and back;
changing the cost information by increasing link costs of the first pair of links when it is determined that the second route includes the first pair of links; and
determining, based on the changed cost information, a fourth route that has a minimum sum of link costs among the one or more third routes.
16. The computer readable recording medium of claim 15, wherein the search process further comprises:
determining whether or not the fourth route includes the first pair of links; and
determining, when it is determined that the fourth route includes the first pair of links, that there exists no route through which signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node.
17. The computer readable recording medium of claim 15, wherein the search process further comprises
performing a repetition process including:
determining whether or not the fourth route includes the first pair of links;
changing the cost information by increasing link costs of the first pair of links when it is determined that the fourth route includes the first pair of links; and
determining, based on the changed cost information, a fifth route that has a minimum sum of link costs among the one or more third routes.
18. The computer readable recording medium of claim 15, wherein the search process further comprises
changing link costs of the first pair of links to a sum of link costs of all links included in the communication network.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for restoring mercury sorption effectiveness of a carbon sorbent, the method comprising:
exposing the carbon sorbent to a salt solution comprising at least one of bromine, a bromine compound, or a combination thereof, wherein exposing includes removing contaminants collected on the carbon sorbent and wherein exposing includes modifying a carbon edge structure to form carbocations such that the modified carbon edge structure accepts electrons from neutral mercury atoms, the salt solution having an associated cation, and wherein the associated cation is an ammonium, aluminum, boron, zinc, or iron cation;
dewatering to remove the carbon sorbent from the salt solution, wherein dewatering produces water; and
drying the carbon sorbent.
2. The method of claim 1, wherein the carbon sorbent includes constituents derived from a flue gas stream.
3. The method of claim 1, wherein the contaminants include sulfuric acid.
4. The method of claim 1, further comprising agitating the carbon sorbent and the solution.
5. The method of claim 1, further comprising using a promoter to promote sorption activity.
6. The method of claim 5, wherein the promoter includes a protonic hydro halide acid.
7. The method of claim 5, wherein the promoter includes a Lewis acid.
8. The method of claim 1, wherein dewatering is via a centrifugal-based, a gravity-based, or a filtration-based method.
9. The method of claim 1, wherein drying is via a mild thermal treatment.
10. The method of claim 1, further comprising treating the water with calcium salts or magnesium salts.
11. The method of claim 10, further comprising subjecting the treated water to an exchange with a cation resin in a proton form to remove excess of calcium ions or magnesium ions and to replace the calcium ions or magnesium ions with hydrogen ions.
12. The method of claim 11, further including using the treated water to form the salt solution.
13. The method of claim 1, wherein the carbon sorbent is activated carbon sorbent, powdered Norit FGD sorbent, an aerogel carbon film sorbent, or a carbon filter having fine carbon particles imbedded on a polymer fiber matrix.
14. The method of claim 1, wherein the associated cation is ammonium.
15. A method for restoring mercury sorption effectiveness of a carbon sorbent used for treating a flue gas, the method comprising:
contacting at least a portion of the carbon sorbent with a solution, the solution comprising at least one of bromine, a bromine compound, or a combination thereof, wherein contacting includes removing contaminants collected on at least a portion of the carbon sorbent, wherein contacting includes modifying a carbon edge structure of the carbon sorbent to form carbocations such that the modified carbon edge structure accepts electrons from neutral mercury atoms, and wherein the solution includes an associated cation, the associated cation being an ammonium, aluminum, boron, zinc, or iron cation; and
removing the carbon sorbent from the solution.
16. The method of claim 15, further comprising drying the carbon sorbent.
17. The method of claim 15, further comprising removing other constituents from the carbon sorbent.
18. The method of claim 17, wherein the other constituents comprise constituents from the flue gas.
19. The method of claim 15, wherein the carbon sorbent includes activated carbon sorbent, powdered Norit FGD sorbent, an aerogel carbon film sorbent, or a carbon filter having fine carbon particles on a matrix.
20. A method for restoring mercury sorption effectiveness of a carbon sorbent used for treating a gas, the method comprising:
contacting at least a portion of the carbon sorbent with a solution, the solution comprising at least one of bromine, a bromine compound, or a combination thereof, wherein contacting includes removing contaminants collected on at least a portion of the carbon sorbent, wherein contacting includes modifying a carbon edge structure of the carbon sorbent to form carbocations such that the modified carbon edge structure accepts electrons from neutral mercury atoms, and wherein the solution includes an associated cation, the associated cation being an ammonium, aluminum, boron, zinc, or iron cation; and
removing the carbon sorbent from the solution.