In multi-agent systems, software agents are modelled to possess characteristics and behaviour borrowed from human societies. Norms are expectations of behaviours of the agents in a society. Norms can be established in a society in different ways. In human societies, there are several types of norms such as moral norms, social norms and legal norms (laws). In artificial agent societies, the desi...

We establish lower bounds for norms and CB-norms of elementary operators on B(H). Our main result concerns the operator Ta,bx = axb + bxa and we show ‖Ta,b‖ ≥ ‖a‖‖b‖, proving a conjecture of M. Mathieu. We also establish some other results and formulae for ‖Ta,b‖cb and ‖Ta,b‖ for special cases. Our results are related to a problem of M. Mathieu [13, 14] asking whether ‖Ta,b‖ ≥ c‖a‖‖b‖ holds in ...

Norms in human societies are expectations of behaviours of the individuals. In human societies, there are several types of norms such as moral norms, social norms and legal norms (laws). In multi-agent systems, software agents are modelled as possessing characteristics and behaviour borrowed from human societies. In order to design and develop robust artificial agent societies, it is important ...

The aim of the research was to gain increased knowledge regarding the sexual risk behaviour of school-going young people in South Africa after two decades of HIV-education in schools, to contribute to the development of improved HIV prevention strategies. In collaboration with the Department of Education, a sample of 5305 learners (between 10 and 18 years in Grades 5-12) from high-risk communit...

Although the suicidal and self-harming behaviour of individuals is often associated with similar behaviours in people they know, little is known about the impact of perceived social norms on those behaviours. In a range of other behavioural domains (e.g., alcohol consumption, smoking, eating behaviours) perceived social norms have been found to strongly predict individuals' engagement in those ...

Many couples in the Islamic Republic of Iran rely on coital withdrawal for contraception. The purpose of this cross-sectional study was to use the theory of planned behaviour to explore factors that influence withdrawal users' intent to switch to oral contraception (OC). Participants were 336 sexually active, married women, who were current users of withdrawal and were recruited from 5 public f...