Results 11  20
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193
Graph indexing: Tree + delta >= graph
 In VLDB
, 2007
"... Recent scientific and technological advances have witnessed an abundance of structural patterns modeled as graphs. As a result, it is of special interest to process graph containment queries effectively on large graph databases. Given a graph database G, and a query graph q, the graph containment qu ..."
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Cited by 51 (6 self)
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Recent scientific and technological advances have witnessed an abundance of structural patterns modeled as graphs. As a result, it is of special interest to process graph containment queries effectively on large graph databases. Given a graph database G, and a query graph q, the graph containment query is to retrieve all graphs in G which contain q as subgraph(s). Due to the vast number of graphs in G and the nature of complexity for subgraph isomorphism testing, it is desirable to make use of highquality graph indexing mechanisms to reduce the overall query processing cost. In this paper, we propose a new costeffective graph indexing method based on frequent treefeatures of the graph database. We analyze the effectiveness and efficiency of tree as indexing feature from three critical aspects: feature size, feature selection cost, and pruning power. In order to achieve better pruning ability than existing graphbased indexing methods, we select, in addition to frequent treefeatures (Tree), a small number of discriminative graphs (∆) on demand, without a costly graph mining process beforehand. Our study verifies that (Tree+∆) is a better choice than graph for indexing purpose, denoted (Tree+ ∆ ≥Graph), to address the graph containment query problem. It has two implications: (1) the index construction by (Tree+∆) is efficient, and (2) the graph containment query processing by (Tree+∆) is efficient. Our experimental studies demonstrate that (Tree+∆) has a compact index structure, achieves an order of magnitude better performance in index construction, and most importantly, outperforms uptodate graphbased indexing methods: gIndex and CTree, in graph containment query processing. 1.
LargeScale Malware Indexing Using FunctionCall Graphs
"... A major challenge of the antivirus (AV) industry is how to effectively process the huge influx of malware samples they receive every day. One possible solution to this problem is to quickly determine if a new malware sample is similar to any previouslyseen malware program. In this paper, we design ..."
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Cited by 51 (0 self)
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A major challenge of the antivirus (AV) industry is how to effectively process the huge influx of malware samples they receive every day. One possible solution to this problem is to quickly determine if a new malware sample is similar to any previouslyseen malware program. In this paper, we design, implement and evaluate a malware database management system called SMIT (Symantec Malware Indexing Tree) that can efficiently make such determination based on malware’s functioncall graphs, which is a structural representation known to be less susceptible to instructionlevel obfuscations commonly employed by malware writers to evade detection of AV software. Because each malware program is represented as a graph, the problem of searching for the most similar malware program in a database to a given malware sample is cast into a nearestneighbor search problem in a graph database. To speed
Fast besteffort pattern matching in large attributed graphs
 In KDD
, 2007
"... We focus on large graphs where nodes have attributes, such as a social network where the nodes are labelled with each person’s job title. In such a setting, we want to find subgraphs that match a user query pattern. For example, a ‘star ’ query would be, “find a CEO who has strong interactions with ..."
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Cited by 51 (13 self)
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We focus on large graphs where nodes have attributes, such as a social network where the nodes are labelled with each person’s job title. In such a setting, we want to find subgraphs that match a user query pattern. For example, a ‘star ’ query would be, “find a CEO who has strong interactions with a Manager, a Lawyer, and an Accountant, or another structure as close to that as possible”. Similarly, a ‘loop ’ query could help spot a money laundering ring. Traditional SQLbased methods, as well as more recent graph indexing methods, will return no answer when an exact match does not exist. Our method can find exact, as well as nearmatches, and it will present them to the user in our proposed ‘goodness ’ order. For example, our method tolerates indirect paths between, say, the ‘CEO ’ and the ‘Accountant ’ of the above sample query, when direct paths do not exist. Its second feature is scalability. In general, if the query has nq nodes and the data graph has n nodes, the problem needs polynomial time complexity O(n nq), which is prohibitive. Our GRay (“Graph XRay”) method finds highquality subgraphs in time linear on the size of the data graph. Experimental results on the DLBP authorpublication graph (with 356K nodes and 1.9M edges) illustrate both the effectiveness and scalability of our approach. The results agree with our intuition, and the speed is excellent. It takes 4 seconds on average for a 4node query on the DBLP graph.
Mining closed relational graphs with connectivity constraints
 Proc. KDD'05
"... Relational graphs are widely used in modeling large scale networks such as biological networks and social networks. In this kind of graph, connectivity becomes critical in identifying highly associated groups and clusters. In this paper, we investigate the issues of mining closed frequent graphs wi ..."
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Cited by 48 (9 self)
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Relational graphs are widely used in modeling large scale networks such as biological networks and social networks. In this kind of graph, connectivity becomes critical in identifying highly associated groups and clusters. In this paper, we investigate the issues of mining closed frequent graphs with connectivity constraints in massive relational graphs where each graph has around 10K nodes and 1M edges. We adopt the concept of edge connectivity and apply the results from graph theory, to speed up the mining process. Two approaches are developed to handle different mining requests: CloseCut, a patterngrowth approach, and Splat, a patternreduction approach. We have applied these methods in biological datasets and found the discovered patterns interesting.
Taming Verification Hardness: An Efficient Algorithm for Testing Subgraph Isomorphism
"... Graphs are widely used to model complicated data semantics in many applications. In this paper, we aim to develop efficient techniques to retrieve graphs, containing a given query graph, from a large set of graphs. Considering the problem of testing subgraph isomorphism is generally NPhard, most of ..."
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Cited by 47 (8 self)
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Graphs are widely used to model complicated data semantics in many applications. In this paper, we aim to develop efficient techniques to retrieve graphs, containing a given query graph, from a large set of graphs. Considering the problem of testing subgraph isomorphism is generally NPhard, most of the existing techniques are based on the framework of filteringandverification to reduce the precise computation costs; consequently various novel featurebased indexes have been developed. While the existing techniques work well for small query graphs, the verification phase becomes a bottleneck when the query graph size increases. Motivated by this, in the paper we firstly propose a novel and efficient algorithm for testing subgraph isomorphism, QuickSI. Secondly, we develop a new featurebased index technique to accommodate QuickSI in the filtering phase. Our extensive experiments on real and synthetic data demonstrate the efficiency and scalability of the proposed techniques, which significantly improve the existing techniques. 1.
Gstring: A novel approach for efficient search in graph databases
 In ICDE
, 2007
"... Graphs are widely used for modeling complicated data, including chemical compounds, protein interactions, XML documents, and multimedia. Information retrieval against such data can be formulated as a graph search problem, and finding an efficient solution to the problem is essential for many applica ..."
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Cited by 42 (5 self)
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Graphs are widely used for modeling complicated data, including chemical compounds, protein interactions, XML documents, and multimedia. Information retrieval against such data can be formulated as a graph search problem, and finding an efficient solution to the problem is essential for many applications. A popular approach is to represent both graphs and queries on graphs by sequences, thus converting graph search to subsequence matching. Stateoftheart sequencing methods work at the finest granularity – each node (or edge) in the graph will appear as an element in the resulting sequence. Clearly, such methods are not semantic conscious, and the resulting sequences are not only bulky but also prone to complexities arising from graph isomorphism and other problems in searching. In this paper, we introduce a novel sequencing method to capture the semantics of the underlying graph data. We find meaningful components in graph structures and use them as the most basic units in sequencing. It not only reduces the size of resulting sequences, but also enables semanticbased searching. In this paper, we base our approach on chemical compound databases, although it can be applied to searching other complicated graphs, such as protein structures. Experiments demonstrate that our approach outperforms stateoftheart graph search methods. 1.
On Graph Query Optimization in Large Networks
"... The dramatic proliferation of sophisticated networks has resulted in a growing need for supporting effective querying and mining methods over such largescale graphstructured data. At the core of many advanced network operations lies a common and critical graph query primitive: how to search graph ..."
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Cited by 32 (3 self)
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The dramatic proliferation of sophisticated networks has resulted in a growing need for supporting effective querying and mining methods over such largescale graphstructured data. At the core of many advanced network operations lies a common and critical graph query primitive: how to search graph structures efficiently within a large network? Unfortunately, the graph query is hard due to the NPcomplete nature of subgraph isomorphism. It becomes even challenging when the network examined is large and diverse. In this paper, we present a high performance graph indexing mechanism, SPath, to address the graph query problem on large networks. SPath leverages decomposed shortest paths around vertex neighborhood as basic indexing units, which prove to be both effective in graph search space pruning and highly scalable in index construction and deployment. Via SPath, a graph query is processed and optimized beyond the traditional vertexatatime fashion to a more efficient pathatatime way: the query is first decomposed to a set of shortest paths, among which a subset of candidates with good selectivity is picked by a query plan optimizer; Candidate paths are further joined together to help recover the query graph to finalize the graph query processing. We evaluate SPath with the stateoftheart GraphQL on both real and synthetic data sets. Our experimental studies demonstrate the effectiveness and scalability of SPath, which proves to be a more practical and efficient indexing method in addressing graph queries on large networks. 1.
A novel spectral coding in a large graph database
 In Proceedings of the International Conference on Extending Database Technology
, 2008
"... Retrieving related graphs containing a query graph from a large graph database is a key issue in many graphbased applications, such as drug discovery and structural pattern recognition. Because subgraph isomorphism is a NPcomplete problem [4], we have to employ a filterandverification framework ..."
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Cited by 30 (2 self)
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Retrieving related graphs containing a query graph from a large graph database is a key issue in many graphbased applications, such as drug discovery and structural pattern recognition. Because subgraph isomorphism is a NPcomplete problem [4], we have to employ a filterandverification framework to speed up the search efficiency, that is, using an effective and efficient pruning strategy to filter out the false positives (graphs that are not possible in the results) as many as possible first, then validating the remaining candidates by subgraph isomorphism checking. In this paper, we propose a novel filtering method, a spectral encoding method, i.e. GCoding. Specifically, we assign a signature to each vertex based on its local structures. Then, we generate a spectral graph code by combining all vertex signatures in a graph. Based on spectral graph codes, we derive a necessary condition for subgraph isomorphism. Then we propose two pruning rules for subgraph search problem, and prove that they satisfy the nofalsenegative requirement (no dismissal in answers). Since graph codes are in numerical space, we take this advantage and conduct efficient filtering over graph codes. Extensive experiments show that GCoding outperforms existing counterpart methods. 1.
Scalable mining of large diskbased graph databases
 In the Proceedings of ACM KDD04
, 2004
"... Mining frequent structural patterns from graph databases is an interesting problem with broad applications. Most of the previous studies focus on pruning unfruitful search subspaces effectively, but few of them address the mining on large, diskbased databases. As many graph databases in application ..."
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Cited by 29 (2 self)
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Mining frequent structural patterns from graph databases is an interesting problem with broad applications. Most of the previous studies focus on pruning unfruitful search subspaces effectively, but few of them address the mining on large, diskbased databases. As many graph databases in applications cannot be held into main memory, scalable mining of large, diskbased graph databases remains a challenging problem. In this paper, we develop an effective index structure, ADI (for adjacency index), to support mining various graph patterns over large databases that cannot be held into main memory. The index is simple and efficient to build. Moreover, the new index structure can be easily adopted in various existing graph pattern mining algorithms. As an example, we adapt the wellknown gSpan algorithm by using the ADI structure. The experimental results show that the new index structure enables the scalable graph pattern mining over large databases. In one set of the experiments, the new diskbased method can mine graph databases with one million graphs, while the original gSpan algorithm can only handle databases of up to 300 thousand graphs. Moreover, our new method is faster than gSpan when both can run in main memory.
GADDI: Distance index based subgraph matching in biological networks
 In Proceedings of the 12th international conference on extending database technology (EDBT’09
, 2009
"... Currently, a huge amount of biological data can be naturally represented by graphs, e.g., protein interaction networks, gene regulatory networks, etc. The need for indexing large graphs is an urgent research problem of great practical importance. The main challenge is size. Each graph may contain ..."
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Cited by 25 (2 self)
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Currently, a huge amount of biological data can be naturally represented by graphs, e.g., protein interaction networks, gene regulatory networks, etc. The need for indexing large graphs is an urgent research problem of great practical importance. The main challenge is size. Each graph may contain thousands (or more) vertices. Most of the previous work focuses on indexing a set of small or medium sized database graphs (with only tens of vertices) and finding whether a query graph occurs in any of these. In this paper, we are interested in finding all the matches of a query graph in a given large graph of thousands of vertices, which is a very important task in many biological applications. This increases the complexity significantly. We propose a novel distance measurement which reintroduces the idea of frequent substructures in a single large graph. We devise the novel structure distance based approach (GADDI) to efficiently find matches of the query graph. GADDI is further optimized by the use of a dynamic matching scheme to minimize redundant calculations. Last but not least, a number of real and synthetic data sets are used to evaluate the efficiency and scalability of our proposed method. 1.