Maximal Number of Edges in Geometric Graphs without Convex Polygons

Author(s):  
Chie Nara ◽  
Toshinori Sakai ◽  
Jorge Urrutia
Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 976
Author(s):  
R. Aguilar-Sánchez ◽  
J. Méndez-Bermúdez ◽  
José Rodríguez ◽  
José Sigarreta

We perform a detailed computational study of the recently introduced Sombor indices on random networks. Specifically, we apply Sombor indices on three models of random networks: Erdös-Rényi networks, random geometric graphs, and bipartite random networks. Within a statistical random matrix theory approach, we show that the average values of Sombor indices, normalized to the order of the network, scale with the average degree. Moreover, we discuss the application of average Sombor indices as complexity measures of random networks and, as a consequence, we show that selected normalized Sombor indices are highly correlated with the Shannon entropy of the eigenvectors of the adjacency matrix.


Algorithmica ◽  
2021 ◽  
Author(s):  
Gill Barequet ◽  
Minati De ◽  
Michael T. Goodrich

Patterns ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 100237
Author(s):  
Yifan Qian ◽  
Paul Expert ◽  
Pietro Panzarasa ◽  
Mauricio Barahona

2020 ◽  
Vol 102 (6) ◽  
Author(s):  
Michael Wilsher ◽  
Carl P. Dettmann ◽  
Ayalvadi Ganesh

Koedoe ◽  
2015 ◽  
Vol 57 (1) ◽  
Author(s):  
Morgan B. Pfeiffer ◽  
Jan A. Venter ◽  
Colleen T. Downs

Despite the extent of subsistence farmland in Africa, little is known about endangered species that persist within them. The Cape Vulture (Gyps coprotheres) is regionally endangered in southern Africa and at least 20% of the population breeds in the subsistence farmland area previously known as the Transkei in the Eastern Cape province of South Africa. To understand their movement ecology, adult Cape Vultures (n = 9) were captured and fitted with global positioning system/global system for mobile transmitters. Minimum convex polygons (MCPs),and 99% and 50% kernel density estimates (KDEs) were calculated for the breeding and non breeding seasons of the Cape Vulture. Land use maps were constructed for each 99% KDE and vulture locations were overlaid. During the non-breeding season, ranges were slightly larger(mean [± SE] MCP = 16 887 km2 ± 366 km2) than the breeding season (MCP = 14 707 km2 ± 2155 km2). Breeding and non-breeding season MCPs overlapped by a total of 92%. Kernel density estimates showed seasonal variability. During the breeding season, Cape Vultures used subsistence farmland, natural woodland and protected areas more than expected. In the non-breeding season, vultures used natural woodland and subsistence farmland more than expected, and protected areas less than expected. In both seasons, human-altered landscapes were used less, except for subsistence farmland.Conservation implications: These results highlight the importance of subsistence farm land to the survival of the Cape Vulture. Efforts should be made to minimise potential threats to vultures in the core areas outlined, through outreach programmes and mitigation measures.The conservation buffer of 40 km around Cape Vulture breeding colonies should be increased to 50 km.


2013 ◽  
Vol 313 (18) ◽  
pp. 1767-1782 ◽  
Author(s):  
Filip Morić
Keyword(s):  

2004 ◽  
Vol 119 (6) ◽  
pp. 691-718 ◽  
Author(s):  
Yu. V. Pokornyi ◽  
A. V. Borovskikh

2008 ◽  
Vol 39 (2) ◽  
pp. 65-77 ◽  
Author(s):  
Manuel Abellanas ◽  
Prosenjit Bose ◽  
Alfredo García ◽  
Ferran Hurtado ◽  
Pedro Ramos ◽  
...  
Keyword(s):  

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