Results 41 to 50 of about 3,792,347 (201)

Urysohn ultrametric spaces and isometry groups. [PDF]

, 2009
In this dissertation we study a special sub-collection of Polish metric spaces: complete separable ultrametric spaces. Polish metric spaces have been studied for quite a long while, and a lot of results have been obtained.
Shao, Chuang
core   +1 more source

Totally bounded ultrametric spaces generated by labeled rays

Applied General Topology
We will say that a tree T is almost a ray if T is the union of a ray and a finite tree. Let l be a non-degenerate labeling of the vertex set V of almost a ray T and let dI be the corresponding ultrametric on V.
Oleksiy Dovgoshey, Valentino Vito
doaj   +1 more source

Metric and ultrametric spaces of resistances

Discrete Applied Mathematics, 2010
In 1987, \textit{A. D. Gvishiani} and \textit{V. A Gurvich} [``Metric and ultrametric spaces of resistances'', Russ. Math. Surv. 42, No. 6, 235--236 (1987); translation from Usp. Mat. Nauk 42, No. 6, 187--188 (1987; Zbl 0708.90028)] briefly reported results that established conditions under which effective resistances in an undirected graph satisfy a ...
openaire   +1 more source

Bird community seasonality and long‐term changes in migrant birds across a large savanna protected area in South Africa

Ibis, EarlyView.
Migratory bird species fascinate humanity but also contribute significantly to the ecosystems they visit in various ways (e.g. food web structures) and can thus be considered good environmental indicators. Although protected areas (PAs) should play an important role in the conservation of migratory species, this is not always achieved; for example ...
Rion E Lerm, Dave I Thompson, David A Ehlers Smith, Colleen T Downs   +3 more
wiley   +1 more source

Bounded distortion homeomorphisms on ultrametric spaces [PDF]

, 2010
It is well-known that quasi-isometrics between R-trees induce power quasi-symmetric homeomorphisms between their ultrametric end spaces. This paper investigates power quasi-symmetric homeomorphisms between bounded, complete, uniformly perfect ...
Martínez Pérez, Álvaro, Martínez-Pérez, Álvaro, Manuel A. Morón, Hughes, Bruce, Morón, Manuel A., Álvaro Martínez-Pérez, Bruce Hughes, Alonso Morón, Manuel   +7 more
core   +1 more source

A deeper look into the diversity of suckermouth catfishes (Mochockidae: Chiloglanis Peters 1868) of southern Africa, with the description of four new species

Journal of Fish Biology, EarlyView.
Abstract Suckermouth catfishes of the genus Chiloglanis Peters 1868 are small and predominantly rheophilic fishes endemic to Africa. This genus is quite diverse, with over 70 species distributed across most river systems on the continent, except for the Cape Fold ecoregion and most of northern Africa.
Tadiwa Isaac Mutizwa, Tholoana Ntokoane, Albert Chakona   +2 more
wiley   +1 more source

Quantum ultra-walks: Walks on a line with hierarchical spatial heterogeneity

Physical Review Research, 2020
We discuss the model of a one-dimensional, discrete-time walk on a line with spatial heterogeneity in the form of a variable set of ultrametric barriers.
Stefan Boettcher
doaj   +1 more source

Nested Hoare Triples and Frame Rules for Higher-order Store [PDF]

Logical Methods in Computer Science, 2011
Separation logic is a Hoare-style logic for reasoning about programs with heap-allocated mutable data structures. As a step toward extending separation logic to high-level languages with ML-style general (higher-order) storage, we investigate the ...
Jan Schwinghammer, Lars Birkedal, Bernhard Reus, Hongseok Yang   +3 more
doaj   +1 more source

Vicariance and dispersal in the Aegean Archipelago: Molecular phylogeography reveals the origin and divergence times of Hydropsyche (Trichoptera: Hydropsychidae) species

Journal of Systematics and Evolution, EarlyView.
Divergence times of Greek Hydropsyche lineages fall mostly within the Pliocene‐Pleistocene, rejecting ancient vicariance. Widespread species show shallow divergences consistent with dispersal, while island endemics exhibit deeper isolation patterns supporting a mixed vicariance‐dispersal model.
Anastasia Lampou, Paraskevi Niki Lampri, Cesc Múrria, Ioannis Karaouzas, Nikolaos Skoulikidis, Núria Bonada   +5 more
wiley   +1 more source

Ultrametric Distance in Syntax [PDF]

, 1995
Phrase structure trees have a hierarchical structure. In many subjects, most notably in Taxonomy such tree structures have been studied using ultrametrics.
Roberts, Mark D.
core