1 Motivation An ad-hoc network is a multihop wireless network in which mobile hosts communicate over a shared, scarce wireless channel. An ad-hoc network is characterized by the absence of a wired backbone or any sort of centralized network management system to maintain routes as hosts move or turn oo or on. Since routes change quickly not only because end nodes move but also because intermedia...

the binary and ternary codes spanned by the rows of the point by block incidence matrices of some 2-designs and their complementary and orthogonal designs are studied. a new method is also introduced to study optimal codes.

Recently, there has been a proliferation of studies investigating the relationship between diversity and outcomes such as social cohesion and civic mindedness. This article addresses several common problems in this field and, using data for British neighbourhoods, elaborates on the experiences of both white British and ethnic minority respondents. We conclude that, if anything, diversity should...