An Experimental Study of External Memory Algorithms for Connected Components

We empirically investigate algorithms for solving Connected Components in the external memory model. In particular, we study whether the randomized O(Sort(E)) algorithm by Karger, Klein, and Tarjan can be implemented to compete with practically promising and simpler algorithms having only slightly worse theoretical cost, namely Borůvka’s algorithm and the algorithm by Sibeyn and collaborators. For all algorithms, we develop and test a number of tuning options. Our experiments are executed on a large set of different graph classes including random graphs, grids, geometric graphs, and hyperbolic graphs. Among our findings are: The Sibeyn algorithm is a very strong contender due to its simplicity and due to an added degree of freedom in its internal workings when used in the Connected Components setting. With the right tunings, the Karger-Klein-Tarjan algorithm can be implemented to be competitive in many cases. Higher graph density seems to benefit Karger-Klein-Tarjan relative to Sibeyn. Borůvka’s algorithm is not competitive with the two others

Assyrian Merchants meet Nuclear Physicists: History of the Early Contributions from Social Sciences to Computer Science. The Case of Automatic Pattern Detection in Graphs (1950s-1970s)

Community detection is a major issue in network analysis. This paper combines a socio-historical approach with an experimental reconstruction of programs to investigate the early automation of clique detection algorithms, which remains one of the unsolved NP-complete problems today. The research led by the archaeologist Jean-Claude Gardin from the 1950s on non-numerical information and graph analysis is retraced to demonstrate the early contributions of social sciences and humanities. The limited recognition and reception of Gardin's innovative computer application to the humanities are addressed through two factors, in addition to the effects of historiography and bibliographies on the recording, discoverability, and reuse of scientific productions: (1) funding policies, evidenced by the transfer of research effort on graph applications from temporary interdisciplinary spaces to disciplinary organizations related to the then-emerging field of computer science; and (2) the erratic careers of algorithms, in which efficiency, flaws, corrections, and authors’ status, were determining factors

Borders: Itineraries on the Edges of Iran

This collection of essays stands as the first volume of the new Eurasiatica series entirely devoted to the vast territories of Iranian culture, understood in the widest sense possible and in an open chronological perspective. Explicitly refusing any fetishization of particularism, it contains fourteen studies organized in thematic pairs: a sequence of interrelated itineraries exploring several heterogeneous borderlands – from Avestan philology to film studies – starting from plural, competing and coexisting ideas of Iran.Questa raccolta di saggi costituisce il primo volume della nuova serie Eurasiatica, interamente dedicata ai vasti territori della cultura iraniana, intesi nel senso più ampio possibile e in una prospettiva cronologica aperta. Rifiutando esplicitamente qualsiasi feticizzazione del particolarismo, contiene quattordici studi organizzati in coppie tematiche: una sequenza di itinerari interconnessi che esplorano diverse frontiere eterogenee - dalla filologia avestana agli studi cinematografici - a partire dalle molteplici visioni, concorrenti e coesistenti, dell'Iran