An IEEE 802.11ah network has been designed to service a wide range of sensor network applications where a single access point (AP) covers a transmission range of up to 1 km and needs to support more than 80 0 0 nodes. As a result, it has much more hidden node pairs compared to conventional 802.11a/b/g/n/ac networks. In addition, since nodes in power saving mode wake up simultaneously to send fr...

Given two undirected trees T and P , the Subtree Homeomorphism Problem is to find whether T has a subtree t that can be transformed into P by removing entire subtrees, as well as repeatedly removing a degree-2 node and adding the edge joining its two neighbors. In this paper we extend the Subtree Homeomorphism Problem to a new optimization problem by enriching the subtree-comparison with node-t...

The internet architecture based on TCP/IP protocols faces now new challenges, as wireless access becomes ubiquitous and enables new mobility scenarios. Such a scenario arises in the intelligent transportation application area in which fast moving vehicles communicate with a distributed roadside infrastructure. We assume that the infrastructure nodes are connected in a meshed wireline broadband ...

A burnt pancake graph is a variant of Cayley graphs and its topology is suitable for massively parallel systems. However, for a burnt pancake graph, there is much room for further research. Hence, in this study, we focus on n-burnt pancake graphs and propose an algorithm to obtain n disjoint paths from a source node to n destination nodes in polynomial order time of n, n being the degree of the...

We consider the family of graph problems called node-deletion problems, defined as follows: For a fixed graph property l7, what is the minimum number of nodes which must be deleted from a given graph so that the resulting subgraph satisfies l7? We show that if l7 is nontrivial and hereditary on induced subgraphs, then the node-deletion problem for n is NP-complete for both undirected and direct...

In this paper we deal with the Critical Node Problem (CNP), i.e., the problem of searching for a given number K of nodes in a graph G, whose removal minimizes the (weighted or unweighted) number of connections between pairs of nodes in the residual graph. In particular, we study the case where the physical network represented by graph G has a hierarchical organization, so that G is a tree. The ...

It is well-known that the tight lower bounds determine the effectiveness of the brancn and bound method for the NP-hard problems. In this paper, we present a new lower bounding procedure for the capacitated arc routing problem (CARP), one of the arc routing problems. They give the tight lower bounds and it is easy to develop an exact algorithm usinl~ their network structures.

Genetic Algorithm (GA) and other Evolutionary Algorithms (EAs) have been successfully applied to solve constrained minimum spanning tree (MST) problems of the communication network design and also have been used extensively in a wide variety of communication network design problems. Choosing an appropriate representation of candidate solutions to the problem is the essential issue for applying ...

We state a combinatorial optimization problem whose feasible solutions define both a decomposition and a node labeling of a given graph. This problem offers a common mathematical abstraction of seemingly unrelated computer vision tasks, including instance-separating semantic segmentation, articulated human body pose estimation and multiple object tracking. Conceptually, the problem we state gen...

This article studies the polyhedral structure of the 4-node network design problem (NDP). Using a theorem from the previous work of this author, the facets of the 4-node NDP can be translated into facets of larger size problems. The knowledge of complete polyhedral description of the 4-node NDP is important because it implies complete knowledge of 4-partition-based facets of larger NDPs. After ...