We extend the logic and semantics of authorization due to Abadi, Lampson, et al. to support restricted delegation. Our formal model provides a simple interpretation for the variety of constructs in the Simple Public Key Infrastructure (SPKI), and lends intuition about possible extensions. We discuss both extensions that our semantics supports and extensions that it cautions against.

By introducing a set of trust attributes, the proposed W3 Trust Model combines a vertically trusted public key infrastructure with a horizontal referral Web classification. It provides a mechanism to assess both the trust and the transitivity of trust of web contents in a heterogeneous environment.

The development of Public Key Infrastructures (PKIs) is highly desirable to support secure digital transactions and communications throughout existing networks. It is important to adopt a particular trust structure or PKI model at an early stage as this forms a basis for the PKI’s development. Many PKI models have been proposed but use only natural language descriptions. We apply a simple forma...

The identification of plausible epistemic approaches in science as well as the social problem definitions with which scientists implicitly work is essential for the quality of a deliberative public policy. While responding to the Nanofutures project, I will reflect on the essential elements of such a policy.

On 1 July 1993 Victoria became the first Australian state to use casemix information to set budgets for its public hospitals commencing with casemix funding for inpatient services. Victoria's casemix funding approach now embraces inpatient, outpatient and rehabilitation services.

Public health programmes pose some very important ethical problems. One of the most pressing is the possible conflict between individual interests (and rights) and collective interests, which becomes particularly important in the public health surveillance setting. The present article first looks at the definitions of "public health surveillance" in a historical context and then identifies the ...

China has long been stuck in applying traditional data envelopment analysis (DEA) models to measure technical efficiency of public hospitals without bias correction of efficiency scores. In this article, we have introduced the Bootstrap-DEA approach from the international literature to analyze the technical efficiency of public hospitals in Tianjin (China) and tried to improve the application o...

Public-private partnership (PPP) initiatives are extending around the world, especially in Europe, as an innovation to traditional public health systems, with the intention of making them more efficient.There is a varied range of PPP models with different degrees of responsibility from simple public sector contracts with the private, up to the complete privatisation of the service. As such, we ...

Housing reform in urban China has introduced market mechanisms into a previously welfare-oriented housing system. Although microlevel factors such as household characteristics begin to shape housing behavior in urban China as is the case in the West, macrolevel constraints and opportunities defined by not only housing stocks and housing markets but also local government behaviors continue to be...

This paper introduces the concept of a ‘harm chain’ as a mechanism to further broaden the way in which firms and public policy makers consider potential negative outcomes from marketing activities. The purpose of conceptualizing a ‘harm chain’ is to examine specifically the creation of harm within networks of marketing exchanges that might occur throughout preproduction, production, consumption...