Triggering patterns of topology changes in dynamic attributed graphs
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The document discusses the concept of triggering patterns in dynamic graphs, which are sequences of attribute variations that may lead to structural changes in networks over time. It outlines a mining approach for identifying these patterns through a methodology involving discretization, transformation of vertex descriptive sequences, and evaluation of growth rates and coverage. The paper also presents quantitative and qualitative experiments on various datasets to validate the proposed methods and their effectiveness in detecting triggering events.
![Triggering patterns
Assessing the diffusion potential of a pattern?
Coverage of a triggering pattern
Gaggr = (V,Eaggr) an aggregated graph of the dynamic graph
The coverage of a pattern P is defined by:
COV(P,∆,Gaggr) = SUPP(P,∆)∪{v ∈ V | ∃w ∈ SUPP(P,∆)s.t.(w,v) ∈ Eaggr}
It naturally follows that SUPP(P,∆) ⊆ COV(P,∆).
Example
ρ(P,∆) =
COV(P,∆,Gaggr)
SUPP(P,∆)
∈ [1,|V|]
To distinguish the patterns supported by a group of isolated
vertices (values close to 1) to the ones supported by very
connected vertices (much higher values than 1).
M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 9](https://image.slidesharecdn.com/asonam14-talk-140812064429-phpapp01/85/Triggering-patterns-of-topology-changes-in-dynamic-attributed-graphs-9-320.jpg)
Triggering patterns of topology changes in dynamic attributed graphs
- 1. Triggering Patterns of Topology Changes in Dynamic Graphs M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet The 2014 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM) Beijing, China, August 17-20, 2014 LABORATOIRE D’INFORMATIQUE EN IMAGE ET SYSTÈMES D’INFORMATION UMR 5205 CNRS / INSA de Lyon / Université Claude Bernard Lyon 1
- 2. Context & motivation Networks structurally change over time: How to describe these dynamics? a: 2 b: 0 c: 6 deg: 2 u5 u3 u4 u2 a: 7 b: 4 c: 5 deg: 1 a: 2 b: 1 c: 6 deg: 2 u1 u5 u3 u4 u2 a: 7 b: 5 c: 2 deg: 1 a: 5 b: 4 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 8 b: 5 c: 1 deg: 4 a: 5 b: 5 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 1 deg: 4 a: 6 b: 5 c: 2 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 0 deg: 4 a: 7 b: 5 c: 1 deg: 4 u1 u5 u3 u4 u2 1 a+ b+ c- deg+ a+ b+ c- deg+ u1 a: 4 b: 1 c: 5 deg: 1 2 3 4 5 6 Intuition Consider attributed graphs evolving through time The variation of some attribute values (entities attributes) of a node can lead in several cases to a structural change (topological attributes) M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 2
- 3. Context & motivation a: 2 b: 0 c: 6 deg: 2 u5 u3 u4 u2 a: 7 b: 4 c: 5 deg: 1 a: 2 b: 1 c: 6 deg: 2 u1 u5 u3 u4 u2 a: 7 b: 5 c: 2 deg: 1 a: 5 b: 4 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 8 b: 5 c: 1 deg: 4 a: 5 b: 5 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 1 deg: 4 a: 6 b: 5 c: 2 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 0 deg: 4 a: 7 b: 5 c: 1 deg: 4 u1 u5 u3 u4 u2 1 a+ b+ c- deg+ a+ b+ c- deg+ u1 a: 4 b: 1 c: 5 deg: 1 2 3 4 5 6 A new pattern domain a+ Updating his status more often b+ giving positive opinions about others c− receiving less negative opinions from the others deg+ is often followed by an increase of user’s popularity {a+,b+},{c+},{deg+} is a triggering pattern A problem rooted in pattern mining and graph analysis M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 3
- 4. Triggering patterns Outline 1 Triggering patterns 2 Method and algorithm 3 Experiments 4 Conclusion M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 4
- 5. Triggering patterns Dynamic attributed graphs Dynamic attributed graph Let G = {G1,...,Gt} be a sequence of t static attributed graphs Gi = (V,Ei,F) with T = {1,...,t} the set of timestamps V the set of vertices Ei the set of edges that connect vertices of V at time i ∈ T (Ei ⊆ V ×V) F the set of numerical attributes that map each vertex-time pair to a real value: ∀f ∈ F, f : V ×T → R. a: 2 b: 0 c: 6 deg: 2 u5 u3 u4 u2 a: 7 b: 4 c: 5 deg: 1 a: 2 b: 1 c: 6 deg: 2 u1 u5 u3 u4 u2 a: 7 b: 5 c: 2 deg: 1 a: 5 b: 4 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 8 b: 5 c: 1 deg: 4 a: 5 b: 5 c: 5 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 1 deg: 4 a: 6 b: 5 c: 2 deg: 2 u1 u5 u3 u4 u2 a: 9 b: 6 c: 0 deg: 4 a: 7 b: 5 c: 1 deg: 4 u1 u5 u3 u4 u2 1 a+ b+ c- deg+ a+ b+ c- deg+ u1 a: 4 b: 1 c: 5 deg: 1 2 3 4 5 6 M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 5
- 6. Triggering patterns Characterizing vertices behaviors Vertex descriptive sequence A discretization function gives a variation symbol to a vertex/attribute/time triple, e.g. discr(v,d,i) = + if d(v,i)−d(v,i−1) ≥ 2 and i > 1 − if d(v,i)−d(v,i−1) ≤ −2 and i > 1 /0 otherwise The set of all variations for a vertex v at time i is an itemset vars(v,i) = {ddiscr(v,d,i),∀d ∈ D}. A vertex v is described by a sequence δ(v) = vars(v,1),...,vars(v,t) . ∆ = {δ(v) | v ∈ V} is the set of all sequences. Example δ(u1) = {a+,b+},{c−},{deg+} ∆ = {δ(u1),δ(u2),δ(u3),δ(u4),δ(u5)} M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 6
- 7. Triggering patterns Pattern domain Triggering pattern A triggering pattern is a sequence P = L,R L is a sequence of sets of descriptor variations: L = X1,...,Xk with ∀j ≤ k, Xj ⊆ (D×S) R a single topological variation, R ∈ (M ×S) Its support is SUPP(P,∆) = {v ∈ V | P δ(v)} where p q means that p is a super-sequence of q Example L = {a+,b+},{c−} R = {deg+} SUPP( L,R ,∆) = {u1,u3} M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 7
- 8. Triggering patterns Assessing the strength of a pattern? Triggering pattern growth rate Let P = L,R , we denote by ∆R ⊆ ∆ the set of vertex descriptive sequences that contain R. The growth rate of P is given by: GR(P,∆R ) = |SUPP(L,∆R)| |∆R| × |∆∆R| |SUPP(L,∆∆R)| G. Dong and J. Li. Efficient mining of emerging patterns: Discovering trends and differences. In KDD, pages 43–52, 1999. M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 8
- 9. Triggering patterns Assessing the diffusion potential of a pattern? Coverage of a triggering pattern Gaggr = (V,Eaggr) an aggregated graph of the dynamic graph The coverage of a pattern P is defined by: COV(P,∆,Gaggr) = SUPP(P,∆)∪{v ∈ V | ∃w ∈ SUPP(P,∆)s.t.(w,v) ∈ Eaggr} It naturally follows that SUPP(P,∆) ⊆ COV(P,∆). Example ρ(P,∆) = COV(P,∆,Gaggr) SUPP(P,∆) ∈ [1,|V|] To distinguish the patterns supported by a group of isolated vertices (values close to 1) to the ones supported by very connected vertices (much higher values than 1). M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 9
- 10. Triggering patterns The problem The triggering pattern mining problem Given a dynamic attributed graph G a minimum growth rate threshold minGR a minimum coverage threshold minCov the problem is to find all triggering patterns P = L,R with |COV(P,∆)| ≥ minCov GR(P,∆R) ≥ minGR. M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 10
- 11. Method and algorithm Outline 1 Triggering patterns 2 Method and algorithm 3 Experiments 4 Conclusion M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 11
- 12. Method and algorithm Methodology Dynamic attributed graph ↓ Choice of an appropriate discretization procedure ↓ Transformation Database of vertex descriptive sequences ↓ Mining closed sequential patterns w.r.t. coverage ↓ Build triggering pattern candidates Triggering pattern candidates ↓ Growth rate computation Triggering patterns Interpretation & vizualisation M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 12
- 13. Method and algorithm TRIGAT Algorithm TRIGAT Require: G = {(V,Ei,F)}, minGr, minCov, Gaggr Ensure: P the set of closed triggering patterns ∆ ← {δ(v)|v ∈ V} I ← all covering 1-item sequences Filter ∆ with only covering 1-item sequences for all s ∈ I do C ←TRIGAT_enum(s,∆|s,Gaggr,minCov) end for Eliminate non-closed sequences from C C ← prefix closed patterns s,Xk ∈ C, s.t.Xk ∈ (M ×S) for all P = s,Xk ∈ C do Add P to P if GR( s,Xk ,∆Xk ) ≥ minGr end for M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 13
- 14. Method and algorithm TRIGAT Procedure TRIGAT_ENUM Require: s = S1,...,S ,∆|s,Gaggr, minCov Ensure: C the set of covering sequences of prefix s 1: if not closed_based_prunnable(s) then 2: insert s in C 3: end if 4: Scan ∆|s, find every covering item α ∈ (D×S) such that s can be extended to S1,...,S −1,{S ∪α} or S1,...,S ,α 5: for all valid α do 6: s ← S1,...,S −1,{S ∪α} 7: TRIGAT_enum(s,D|s,Gaggr,minCov) 8: s ← S1,...,S ,α 9: TRIGAT_enum(s,D|s,Gaggr,minCov) 10: end for M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 14
- 15. Experiments Outline 1 Triggering patterns 2 Method and algorithm 3 Experiments 4 Conclusion M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 15
- 16. Experiments Quantitative experiments Running times Distribution of support, GR, ... Scalability First qualitative assessments Synchronous/asynchronous events Dense/sparse yet covering |V| |F| |T| |D| S I degsum densitysum DBLP 2723 45 9 360 34.4 6.6 14.7 0.005 RITA1 220 8 30 30 16.3 5.1 15.7 0.07 RITA2 234 8 24 39 4.5 1.8 17 0.07 RITA3 280 6 8 87 28.3 6.5 15.9 0.05 del.icio.us 1867 121 5 400 31 1.6 11 0.003 M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 16
- 17. Experiments Quantitative results M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 17
- 18. Experiments The DBLP dataset Detecting asynchronous events Scientific careers of researchers with different experiences Rank Pattern Support Coverage Growth rate ρ 1 {closeness− 1 },{IEEETransKnowlDtEn+},{numCliques+ 1 } → {numCliques− 1 } 15 578 87.4 38.5 2 {clustering++ 1 ,degree++ 1 },{Journal++,eigenvector++ 2 } → {eigenvector++ 3 } 31 546 71.6 17.6 3 {ICDE+,numCliques+ 1 } → {numCliques− 1 } 22 606 64.1 27 4 {eigenvector++ 1 ,degree++ 1 },{VLDB++,degree++ 2 } → {degree++ 3 } 29 580 63.8 20 5 {eigenvector++ 1 ,clustering++ 1 },{Journal++,eigenvector++ 2 } → {eigenvector++ 3 } 36 619 59.3 17.19 6 {ACMTransDBSys+},{numCliques+ 1 } → {numCliques− 1 } 20 547 58.3 27.35 7 {eigenvector++ 1 },{Journal++,betweennes++ 3 } → {betweennes++ 4 } 20 587 58.4 29.35 8 {eigenvector++ 1 },{VLDB++,degree++ 2 } → {degree++ 3 } 30 623 56.47 20.7 9 {SIGMOD−},{numCliques+ 1 } → {numCliques− 1 } 32 754 53.3 23.56 10 {closeness− 1 },{SIGMOD−},{numCliques+ 1 } → {numCliques− 1 } 18 552 52.4 30.6 M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 18
- 19. Experiments The R.I.T.A. dataset Synchronous events RITA1: daily in September 2001 {#Canceled+}{Degree−,Closeness−,NumCliques−, Pagerank−,Betweennes−} → Degree+ with sup = 5, cov = 144 AIRPORTS THAT ABSORB THE TRAFFIC TWO DAYS AFTER RITA2: monthly in (sept. 2000 ; Sept. 2002 ) {#Canceled+}{#Canceled−},{numCliques−,Betweeness+} → numCliques+ with sup = 8, cov = 61 A "BACK TO NORMAL" AROUND MARCH 2002 RITA3: Aug./Sept. 2005 (Katrina Hurricane) THE MOST DISCRIMINANT APPEARS DURING KATRINA M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 19
- 20. Experiments The del.ico.us dataset What are the most triggering attributes? how-to, tutorial, web design, visualization “teaching triggering” video, community “social triggering” M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 20
- 21. Conclusion Outline 1 Triggering patterns 2 Method and algorithm 3 Experiments 4 Conclusion M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 21
- 22. Conclusion Conclusion Triggering patterns in dynamic graphs Sequences of variation of vertex attribute values that may trigger topological changes Closed sequential pattern mining Growth rate: gives the discrimination power of a sequence to explain a topological change Coverage: tells us about the diffusion potential Main challenge Which aggregated graph to choose when computing the coverage? Patterns image can have (a)-synchronous sequences 2|T| aggregated graphs are possible!! M. Kaytoue, Y. Pitarch, M. Plantevit, C. Robardet Triggering Patterns in Dynamic Graphs 22