An information processing apparatus including inter-class node insertion means for inserting an input vector into a network as an inter-class insertion node. The apparatus further includes a winner node learning time calculation means for incrementing, when an edge is connected between a first winner node and a second winner node, learning time of a node for the first winner node by a predetermined value. The apparatus includes load balancing means for detecting, for each predetermined cycle according to the total number of input vectors, a node where the value of the learning time is relatively large and unbalanced, inserting a new node into a position near the node that has been detected and the adjacent node of the node that has been detected, reducing the learning time of the node that has been detected and the learning time of the adjacent node of the node that has been detected, deleting an edge between the node that has been detected and the adjacent node of the node that has been detected, connecting an edge between the node that has been newly inserted and the node that has been detected, and connecting an edge between the node that has been newly inserted and the adjacent node of the node that has been detected.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. An information processing apparatus that has a network structure in which nodes described by multidimensional vectors and edges that connect the nodes are arranged and successively receives input vectors which belong to arbitrary classes and learns input distribution structures of the input vectors, the information processing apparatus comprises: inter-class node insertion means for searching a node located at a position that is the closest to the input vector that is input as a first winner node and a node located at a position that is the second closest to the input vector that is input as a second winner node and inserting an inter-class insertion node having the input vector into the network based on a distance between the input vector and the first winner node and a distance between the input vector and the second winner node; winner node learning time calculation means for incrementing learning time of the node for the first winner node by a predetermined value; weight vector update means for updating the weight vector of the first winner node and the weight vector of an adjacent node that is directly connected to the first winner node to make them further closer to the input vector; and load balancing means for detecting a node where the value of the learning time is relatively large and unbalanced, inserting a new node having a weight vector based on the weight vector of the node that has been detected and the adjacent node of the node that has been detected into the network, reducing the learning time of the node that has been detected and the learning time of the adjacent node of the node that has been detected, deleting an edge between the node that has been detected and the adjacent node of the node that has been detected, connecting an edge between the node that has been newly inserted and the node that has been detected, and connecting an edge between the node that has been newly inserted and the adjacent node of the node that has been detected. 2. The information processing apparatus according to claim 1, further comprising: edge connection determination means for determining, when it is determined in the inter-class node insertion determination means that the inter-class node insertion should not be executed, a sub-cluster to which the first winner node belongs and a sub-cluster to which the second winner node belongs based on a sub-cluster label of the node that is given, and when the result of the determination shows that the first winner node and the second winner node belong to sub-clusters different from each other, further determining, regarding the node densities of the first winner node and the second winner node, whether at least one of a condition of the node density for the first winner node based on an average node density of the sub-cluster including the first winner node and a condition of the node density for the second winner node based on an average node density of the sub-cluster including the second winner node is satisfied; edge connection means for (1) connecting, when the result of the determination in the edge connection determination means shows that at least one of the first winner node and the second winner node does not belong to any sub-cluster or the first winner node and the second winner node belong to one sub-cluster, an edge between the first winner node and the second winner node or (2) connecting, when the result of the determination in the edge connection determination means shows that at least one of the conditions of the node densities of the first winner node and the second winner node is satisfied, an edge between the first winner node and the second winner node and not connecting, when at least one of the conditions of the node densities of the first winner node and the second winner node is not satisfied, an edge between the first winner node and the second winner node; node density calculation means for calculating, based on an average distance from a node to be noted and an adjacent node of the node to be noted, a node density of the node to be noted; and sub-cluster determination means for giving sub-cluster labels different from each other to an apex, which is a node that has a locally maximum node density, giving the sub-cluster label the same as the sub-cluster label given to the adjacent node where the node density is maximum to all the nodes to which the sub-cluster labels have not been given, generating a Voronoi region based on a reference apex having a node density larger than a predetermined threshold among the apices, and when the sub-cluster including the reference apex and the sub-cluster including apices other than the reference apex have an overlapping region and the condition of the average node density of the nodes located in the overlapping region is satisfied in the Voronoi region that has been generated, giving a sub-cluster label of the sub-cluster including the reference apex as a sub-cluster label of the sub-cluster including other apices. 3. The information processing apparatus according to claim 1, further comprising an inter-node distance calculation expression including a weighted first distance calculation expression that calculates a distance between nodes based on an Euclidean distance and a weighted second distance calculation expression that calculates a distance between nodes based on a distance measure other than the Euclidean distance, wherein: the information processing apparatus normalizes the first distance calculation expression using a minimum distance value and a maximum distance value based on the Euclidean distance between arbitrary two nodes in the network; the information processing apparatus normalizes the second distance calculation expression using a minimum distance value and a maximum distance value based on the other distance measure between arbitrary two nodes in the network; the information processing apparatus decreases the weight of the first distance calculation expression as the number of dimensions of the input vector increases; and the information processing apparatus calculates the distance between the input vector and the node or the distance between arbitrary two nodes in the network using the inter-node distance calculation expression. 4. The information processing apparatus according to claim 3, wherein the second distance calculation expression calculates the distance between the nodes based on a cosine distance. 5. The information processing apparatus according to claim 3, further comprising node density update determination means for checking whether at least one value of the minimum distance value and the maximum distance value between the two nodes based on the Euclidean distance and the minimum distance value and the maximum distance value between the two nodes based on the other distance measure has been changed, and when the at least one value has been changed, determining to update the node density, wherein the node density calculation means (1) calculates each component of the vector of the distance of the first winner node from the adjacent node using each of the first distance calculation expression and the second distance calculation expression, (2) calculates a vector of a point value of the node density of the first winner node based on the vector of the distance of the first winner node that has been calculated from the adjacent node, (3) calculates a vector of an accumulated point value of the node density of the first winner node based on the vector of the point value of the node density of the first winner node that has been calculated, (4) calculates the node density of the first winner node based on the vector of the accumulated point value of the node density of the first winner node that has been calculated, (5) when the result of the determination in the node density update determination means shows that the node density should be updated, based on the minimum distance value and the maximum distance value between the two nodes based on the Euclidean distance before and after the changes and the minimum distance value and the maximum distance value between the two nodes based on the other distance measurement before and after the changes, for all the nodes that exist in the network, updates the vector of the accumulated point value of the node density of the node to be noted, and (6) re-calculates the node density of the node to be noted based on the vector of the accumulated point value of the node density of the node to be noted that has been updated. 6. An information processing method in an information processing apparatus that has a network structure in which nodes described by multidimensional vectors and edges that connect the nodes are arranged and successively receives input vectors which belong to arbitrary classes and learns input distribution structures of the input vectors, the information processing method executing the steps of: by inter-class node insertion means, searching a node located at a position that is the closest to the input vector that is input as a first winner node and a node located at a position that is the second closest to the input vector that is input as a second winner node and inserting an inter-class insertion node having the input vector into the network based on a distance between the input vector and the first winner node and a distance between the input vector and the second winner node; by winner node learning time calculation means, incrementing, learning time of the node for the first winner node by a predetermined value; by weight vector update means, updating the weight vector of the first winner node and the weight vector of an adjacent node that is directly connected to the first winner node to make them further closer to the input vector; and by load balancing means, detecting a node where the value of the learning time is relatively large and unbalanced, inserting a new node having a weight vector based on the weight vector of the node that has been detected and the adjacent node of the node that has been detected into the network, reducing the learning time of the node that has been detected and the learning time of the adjacent node of the node that has been detected, deleting an edge between the node that has been detected and the adjacent node of the node that has been detected, connecting an edge between the node that has been newly inserted and the node that has been detected, and connecting an edge between the node that has been newly inserted and the adjacent node of the node that has been detected. 7. The information processing method according to claim 6, further executing the following steps of: by edge connection determination means, determining, when it is determined in the inter-class node insertion determination means that the inter-class node insertion should not be executed, a sub-cluster to which the first winner node belongs and a sub-cluster to which the second winner node belongs based on a sub-cluster label of the node that is given, and when the result of the determination shows that the first winner node and the second winner node belong to sub-clusters different from each other, further determining, regarding the node densities of the first winner node and the second winner node, whether at least one of a condition of the node density for the first winner node based on an average node density of the sub-cluster including the first winner node and a condition of the node density for the second winner node based on an average node density of the sub-cluster including the second winner node is satisfied; by edge connection means, (1) connecting, when the result of the determination in the edge connection determination means shows that at least one of the first winner node and the second winner node does not belong to any sub-cluster or the first winner node and the second winner node belong to one sub-cluster, an edge between the first winner node and the second winner node or (2) connecting, when the result of the determination in the edge connection determination means shows that at least one of the conditions of the node densities of the first winner node and the second winner node is satisfied, an edge between the first winner node and the second winner node and not connecting, when at least one of the conditions of the node densities of the first winner node and the second winner node is not satisfied, an edge between the first winner node and the second winner node; by node density calculation means, calculating, based on an average distance from a node to be noted and an adjacent node of the node to be noted, a node density of the node to be noted; and by sub-cluster determination means, giving sub-cluster labels different from each other to an apex, which is a node that has a locally maximum node density, giving the sub-cluster label the same as the sub-cluster label given to the adjacent node where the node density is maximum to all the nodes to which the sub-cluster labels have not been given, generating a Voronoi region based on a reference apex having a node density larger than a predetermined threshold among the apices, and when the sub-cluster including the reference apex and the sub-cluster including apices other than the reference apex have an overlapping region and the condition of the average node density of the nodes located in the overlapping region is satisfied in the Voronoi region that has been generated, giving a sub-cluster label of the sub-cluster including the reference apex as a sub-cluster label of the sub-cluster including other apices. 8. The information processing method according to claim 6, wherein: the information processing apparatus further comprises an inter-node distance calculation expression including a weighted first distance calculation expression that calculates a distance between nodes based on an Euclidean distance and a weighted second distance calculation expression that calculates a distance between nodes based on a distance measure other than the Euclidean distance, and the information processing method comprises: normalizing the first distance calculation expression using a minimum distance value and a maximum distance value based on the Euclidean distance between arbitrary two nodes in the network; normalizing the second distance calculation expression using a minimum distance value and a maximum distance value based on the other distance measure between arbitrary two nodes in the network; decreasing the weight of the first distance calculation expression as the number of dimensions of the input vector increases; and calculating the distance between the input vector and the node or the distance between arbitrary two nodes in the network using the inter-node distance calculation expression. 9. The information processing method according to claim 8, wherein the second distance calculation expression calculates the distance between the nodes based on a cosine distance. 10. The information processing method according to claim 8, further executing the step of checking, by node density update determination means, whether at least one value of the minimum distance value and the maximum distance value between the two nodes based on the Euclidean distance and the minimum distance value and the maximum distance value between the two nodes based on the other distance measure has been changed, and when the at least one value has been changed, determining to update the node density, wherein the node density calculation means (1) calculates each component of the vector of the distance of the first winner node from the adjacent node using each of the first distance calculation expression and the second distance calculation expression, (2) calculates a vector of a point value of the node density of the first winner node based on the vector of the distance of the first winner node that has been calculated from the adjacent node, (3) calculates a vector of an accumulated point value of the node density of the first winner node based on the vector of the point value of the node density of the first winner node that has been calculated, (4) calculates the node density of the first winner node based on the vector of the accumulated point value of the node density of the first winner node that has been calculated, (5) when the result of the determination in the node density update determination means shows that the node density should be updated, based on the minimum distance value and the maximum distance value between the two nodes based on the Euclidean distance before and after the changes and the minimum distance value and the maximum distance value between the two nodes based on the other distance measurement before and after the changes, for all the nodes that exist in the network, updates the vector of the accumulated point value of the node density of the node to be noted, and (6) re-calculates the node density of the node to be noted based on the vector of the accumulated point value of the node density of the node to be noted that has been updated. 11. A non-transitory computer readable medium comprising causing a computer to execute the information processing according to claim 6.