The fol­low­ing is the short abstract of my PhD The­sis. For those of you inter­ested in the full PhD dis­ser­ta­tion, please take a look at AMS Dot­torato web­site. Com­ments, sug­ges­tions, feed­backs are always well appreciated!

Com­plex Net­works analy­sis turn out to be a very promis­ing field of research, tes­ti­fied by many research projects and works that span dif­fer­ent fields. Those analy­sis have been usu­ally focused on char­ac­ter­ize a sin­gle aspect of the sys­tem and a study that con­sid­ers many infor­ma­tive axes along with a net­work evolve is lacking.

We pro­pose a new mul­ti­di­men­sional analy­sis that is able to inspect net­works in the two most impor­tant dimen­sions, space and time. To achieve this goal, we stud­ied them sin­gu­larly and inves­ti­gated how the vari­a­tion of the con­sti­tut­ing para­me­ters dri­ves changes to the net­work as a whole.

By focus­ing on space dimen­sion, we char­ac­ter­ized spa­tial alter­ation in terms of abstrac­tion lev­els. We pro­posed a novel algo­rithm that, by apply­ing a fuzzi­ness func­tion, can recon­struct net­works under dif­fer­ent level of details. We ver­i­fied that sta­tis­ti­cal indi­ca­tors depend strongly on the gran­u­lar­ity with which a sys­tem is described and on the class of networks.

We keep fixed the space axes and we iso­lated the dynam­ics behind net­works evo­lu­tion process. We detected new instincts that trig­ger social net­works uti­liza­tion and spread the adop­tion of novel com­mu­ni­ties. We for­mal­ized this enhanced social net­work evo­lu­tion by adopt­ing spe­cial nodes (called sirens) that, thanks to their abil­ity to attract new links, were able to con­struct effi­cient con­nec­tion pat­terns. We sim­u­lated the dynam­ics of the sys­tem by con­sid­er­ing three well-known growth models.

Apply­ing this frame­work to real and syn­thetic net­works, we showed that the sirens, even when used for a lim­ited time span, effec­tively shrink the time needed to get a net­work in mature state. In order to pro­vide a con­crete con­text of our find­ings, we for­mal­ized the cost of set­ting up such enhance­ment and pro­vided the best com­bi­na­tions of system’s para­me­ters, such as num­ber of sirens, time span of uti­liza­tion and attractiveness.

Source code and libraries of the net­work evo­lu­tion sim­u­la­tor fix­ing the space dimen­sion are also available.

Related posts:

Mul­ti­di­men­sional analy­sis of com­plex net­works