TY - GEN
T1 - Skynets
T2 - 20th ACM Conference on Information and Knowledge Management, CIKM'11
AU - Cao, Huiping
AU - Candan, Kasim
AU - Sapino, Maria Luisa
PY - 2011
Y1 - 2011
N2 - Query processing over weighted data graphs often involves searching for a minimum weighted subgraph - a tree - which covers the nodes satisfying the given query criteria (such as a given set of keywords). Existing works often focus on graphs where the edges have scalar valued weights. In many applications, however, edge weights need to be represented as ranges (or intervals) of possible values. In this paper, we introduce the problem of skynets, for searching minimum weighted subgraphs, covering the nodes satisfying given query criteria, over interval-weighted graphs. The key challenge is that, unlike scalars which are often totally ordered, depending on the application specific semantics of the ≤ operator, intervals may be partially ordered. Naturally, the need to maintain alternative, incomparable solutions can push the computational complexity of the problem (which is already high for the case with totally ordered scalar edge weights) even higher. In this paper, we first provide alternative definitions of the ≤ operator for intervals and show that some of these lend themselves to efficient solutions. To tackle the complexity challenge in the remaining cases, we propose two optimization criteria that can be used to constrain the solution space. We also discuss how to extend existing approximation algorithms for Steiner trees to discover solutions to the skynet problem. For efficient calculation of the results, we introduce a novel skyline union operator. Experiments show that the proposed approach achieves significant gains in efficiency, while providing close to optimal results.
AB - Query processing over weighted data graphs often involves searching for a minimum weighted subgraph - a tree - which covers the nodes satisfying the given query criteria (such as a given set of keywords). Existing works often focus on graphs where the edges have scalar valued weights. In many applications, however, edge weights need to be represented as ranges (or intervals) of possible values. In this paper, we introduce the problem of skynets, for searching minimum weighted subgraphs, covering the nodes satisfying given query criteria, over interval-weighted graphs. The key challenge is that, unlike scalars which are often totally ordered, depending on the application specific semantics of the ≤ operator, intervals may be partially ordered. Naturally, the need to maintain alternative, incomparable solutions can push the computational complexity of the problem (which is already high for the case with totally ordered scalar edge weights) even higher. In this paper, we first provide alternative definitions of the ≤ operator for intervals and show that some of these lend themselves to efficient solutions. To tackle the complexity challenge in the remaining cases, we propose two optimization criteria that can be used to constrain the solution space. We also discuss how to extend existing approximation algorithms for Steiner trees to discover solutions to the skynet problem. For efficient calculation of the results, we introduce a novel skyline union operator. Experiments show that the proposed approach achieves significant gains in efficiency, while providing close to optimal results.
KW - graph search
KW - incomparable edge weights
KW - interval weighted graph
KW - minimum spanning tree
KW - skyline union
UR - http://www.scopus.com/inward/record.url?scp=83055179349&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=83055179349&partnerID=8YFLogxK
U2 - 10.1145/2063576.2063833
DO - 10.1145/2063576.2063833
M3 - Conference contribution
AN - SCOPUS:83055179349
SN - 9781450307178
T3 - International Conference on Information and Knowledge Management, Proceedings
SP - 1775
EP - 1784
BT - CIKM'11 - Proceedings of the 2011 ACM International Conference on Information and Knowledge Management
Y2 - 24 October 2011 through 28 October 2011
ER -