D IPARTIMENTO DI I NGEGNERIA INFORMATICA AUTOMATICA E GESTIONALE A NTONIO R UBERTI Master of Science in Engineering in Computer Science (MSE-CS) (MSE-CS) Seminars in Software and Services for the Information Society Umberto Nanni Social Networks – A case study Umberto Nanni Seminars of Software and Services for the Information Society 1
A case study: social networking in TLC node: subject of interest arc: frequency / volume of communication in a given time communication in a given time window weighted arc: measured value unweighted arc: the threshold is exceeded problems: quantitative thresholds dynamic over time dynamic over time goal: identification of a “community” and roles within the community Umberto Nanni Seminars of Software and Services for the Information Society 2
Analysis of telephone traffic (India, 53 mln users) • Call graph: G call • SMS graph: G • SMS graph: G sms out in nucleus Umberto Nanni Seminars of Software and Services for the Information Society 3
Social Networks in telephone traffic • fixed network: properties less focused, because the phone is used by several people because the phone is used by several people • mobile traffic: more distinct properties – suitable for a social network interpretation G call : Call Graph G call : Call Graph G sms : SMS Graph G sms is more “social” than G call Umberto Nanni Seminars of Software and Services for the Information Society 4
Call Graph: G call • degree distributions g in , g out follow Power Law • g in similar to G int , but g out different from G int • g in similar to G int , but g out different from G int and G mail • diameter < 13 → Small World Phenomenon • page-rank: p ( i ) = q/N + (1 − q ) ∑ [ j : j→i] p ( j ) /d out ( j ) p ( j ) /d out ( j ) • dimension of SCC: 1 giant component, then Power Law Umberto Nanni Seminars of Software and Services for the Information Society 5
Some results on G call Bow tie nodes % of total IN 8.5 • nucleus (SCC) 63 • OUT 18.7 • TENDRIL, TUBE and DISC 9.8 • out in nucleus Umberto Nanni Seminars of Software and Services for the Information Society 6
Some results on G sms • G sms • about half number of nodes of G call • about half number of nodes of G call • about one third of arcs of G call • reciprocity (G call )= 30% • reciprocity(G sms )= 60% sms • distribution of cliques: very different between G call and G sms Umberto Nanni Seminars of Software and Services for the Information Society 7
Where to start from ... Umberto Nanni Seminars of Software and Services for the Information Society 8
Property (from extremal graph theory) Each dense component (50%) has very often (90%) a complete nucleus of small dimension (3 or 4). complete nucleus of small dimension (3 or 4). A possible algorithmic approach (a heuristics, since the problem is untractable, in general): a. find for nucleus’: small complete connected components of small size (3 o 4) small size (3 o 4) b. expand each nucleus as much as possible, by finding nodes connected to all (or most of) the nodes in the nucleus Umberto Nanni Seminars of Software and Services for the Information Society 9
Analysis of a social network A. Identification of basic communities (clusters) – identification of complete subgraphs of small cardinality (NUCLEUS’) (NUCLEUS’) – progressive expansion of the nuclei, to embrace the community B. Identification of social patterns – sequential analysis of communication events within the community C. Identification of roles within the community – role in the events of communication and sequences D. Identification of community related – classification of communities according to the social patterns Umberto Nanni Seminars of Software and Services for the Information Society 10
Communities and churning – a sequential analysis Umberto Nanni Seminars of Software and Services for the Information Society 11
Communities and churning – a sequential analysis Umberto Nanni Seminars of Software and Services for the Information Society 12
Communities and churning – a sequential analysis Umberto Nanni Seminars of Software and Services for the Information Society 13
Communities and churning – a sequential analysis Umberto Nanni Seminars of Software and Services for the Information Society 14
Communities and churning – a sequential analysis stable contended open contest Umberto Nanni Seminars of Software and Services for the Information Society 15
Procedure Control information for verification • historical analysis of churning: MNP + CDR identification of communities identification of communities sequence analysis of events within the community individuating roles Dynamic behavior of the Network • automatic activation of the recalculation when the • automatic activation of the recalculation when the traffic graph shows deviation from the available traffic graph shows deviation from the available Possible improvements may come from exogenous kills (e.g., a psychologist) Umberto Nanni Seminars of Software and Services for the Information Society 16
Some examples Umberto Nanni Seminars of Software and Services for the Information Society 17
Social Network and marketing – miniglossary • social marketing : marketing for social interest • word of mouth : (it: passaparola) • influencer marketing : based on influential people • engagement marketing : involvement of customer in marketing • viral marketing : exploitation of a social network for disseminating a brand or a product for disseminating a brand or a product • stealth marketing : hidden marketing (unfair) • astroturfing : hidden marketing simulating a spontaneous positive opinion (unfair) Umberto Nanni Seminars of Software and Services for the Information Society 18
Viral Marketing 1. there is an offer of products and / or services (those not covered by the business) business) 2. common motivations and behaviors can be exploited 3. there is an easy way to communicate to others the message 4. existing forms of communication can be 4. existing forms of communication can be used 5. there exists a scalable solution 6. others' resources are available Umberto Nanni Seminars of Software and Services for the Information Society 19
Viral Marketing: a masterpiece Tohato (Japan) launches two types of chips • Habanero (hot like the fire of hell) • Habanero (hot like the fire of hell) • Satan Jorquia (spicy like a fatal bazooka) Umberto Nanni Seminars of Software and Services for the Information Society 20
Recommend
More recommend
