A family A of sets is said to be intersecting if any two sets in A intersect (i.e. have at least one common element). A is said to be centred if there is an element common to all the sets in A; otherwise, A is said to be non-centred. For any r ∈ [n] := {1, ..., n} and any integer k ≥ 2, let Sn,r,k be the family {{(x1, y1), ..., (xr, yr)} : x1, ..., xr are distinct elements of [n], y1, ..., yr ∈...

Let F be a set system on [n] with all sets having k elements and every pair of sets intersecting. The celebrated theorem of Erdős–Ko–Rado from 1961 says that, provided n ≥ 2k, any such system has size at most ( n−1 k−1 ) . A natural question, which was asked by Ahlswede in 1980, is how many disjoint pairs must appear in a set system of larger size. Except for the case k = 2, solved by Ahlswede ...

In this note, we investigate some properties of local Kneser graphs defined in [8]. In this regard, as a generalization of the Erdös-Ko-Rado theorem, we characterize the maximum independent sets of local Kneser graphs. Next, we present an upper bound for their chromatic number.

We present a new algorithm to solve the conjugacy problem in Artin braid groups, which is faster than the one presented by Birman, Ko and Lee [3]. This algorithm can be applied not only to braid groups, but to all Garside groups (which include finite type Artin groups and torus knot groups among others).

M Me el li is ss sa a J J A Ar rm ms st tr ro on ng g, , A Al la an n R R B Be er rk ko ow wi it tz z, , L Le ee e A A D Dy ye er r, , a an nd d J Ja as so on n T Ta ay yl lo or r Please note: This article was downloaded from Frontiers e-View, a service that publishes fully edited and formatted manuscripts before they appear in print in Frontiers in Ecology and the Environment. Readers are stro...

Body, Text, and Stone: The Crafting and Connoisseurship of Inkstones in Eighteenth-Century China Dorothy Ko Barnard College, Columbia University I’m writing a book that traces the movement of one class of object (the inkstone) and two groups of people (artisans 1 and scholars) through four locales (Zhaoqing肇慶, on the southern edge of the empire; Fuzhou, on the southeastern seaboard; Suzhou, at ...

A brief historical background to the currently ascending interest in evolutionary and coevolutionary theory is sketched, and the concept of society–nature coevolution is positioned in this broader field. The significance of society–nature coevolutionary pathways for transition to sustainability is highlighted with Schellnhuber’s heuristic ‘theater world’ for representing paradigms of sustainabl...

Özet. Günümüz i dünyasının rekabetçi ko ulları özellikle yazılım endüstrisindeki organizasyonların geli tirdikleri ürünleri hızla pazara sunmalarını, aynı zamanda de i en gereksinimlere kar ılık vermelerini gerektirmektedir. Çevik yakla ımlar dü ük maliyet, yüksek üretkenlik ve kalite vaatleri göz önünde bulundurularak pek çok yazılım organizasyonu tarafından son yıllarda uygulanmaya ba lanmı t...

Geleitet von der Fragestellung, wie sich die aktuellen inhaltlichen und technologischen Konzepte des sog. Web2.0 auf universitäre Infrastrukturen übertragen und dabei neue Potenziale sowohl für traditionelle als auch informelle Lernkontexte umsetzen lassen, wurde an der Universität Paderborn die ko-aktive Lernund Arbeitsumgebung koaLA entwickelt. In diesem Papier beschreiben wir, welche Überleg...