In this work, we provide the first construction of Attribute-Based Encryption (ABE) for general circuits. Our construction is based on the existence of multilinear maps. We prove selective security of our scheme in the standard model under the natural multilinear generalization of the BDDH assumption. Our scheme achieves both Key-Policy and Ciphertext-Policy variants of ABE. Our scheme and its ...

Innovation systems perspectives on agricultural research and technological change are fast becoming a popular approach to the study of how society generates, disseminates, and utilizes knowledge. The innovation systems literature represents a significant change from the conventional, linear approach to research and development by providing an analytical framework that explores complex relations...

Using the standard real business cycle model with lump-sum taxes, we analyze the impact of fiscal policy when agents form expectations using adaptive learning rather than rational expectations (RE). The output multipliers for government purchases are significantly higher under learning, and fall within empirical bounds reported in the literature, which is in sharp contrast to the implausibly lo...

Decision-makers in an online deliberative forum require access to tools to help them understand the potential impact of proposed policies. Agent-based models can help to predict such impacts. However, the questions being asked by many existing models are not always relevant to the concerns of communities affected by proposed policies. In this exploratory paper, we outline a methodology for expl...

A new model of agent for acting in processes of diagnosis where more constraints are placed on the performance in real world domains is presented. Preferences on actions and policies are used to induce a preferred course of action by the diagnosis agent. Past experience, gathered from controlled trials, enables the experience agent to offer counterarguments for improving the diagnosis process. ...

Hard on the heels of evidence-based medicine (EBM) comes evidence-based policy and practice (EBPP). At all levels in healthcare systems there is a hunger for better knowledge to inform policy and practice. Is this yet another of the fashions and fads that continually beset the National Health Service, or does EBPP mark a development that could fundamentally change the way in which health policy...

Regions within the European Union differ substantially not only with respect to per capita GDP, but also with respect to income inequality within the regions. This paper studies the effects of different types of technology-oriented cohesion policies, aiming at the reduction of regional differences, on the convergence of regions and the dynamics of income inequality within regions. In particular...

In our research we investigate the output accuracy of discrete event simulation models and agent based simulation models when studying human centric complex systems. In this paper we focus on human reactive behaviour as it is possible in both modelling approaches to implement human reactive behaviour in the model by using standard methods. As a case study we have chosen the retail sector, and h...

This paper presents a framework for representing and distributing access control policies in distributed heterogeneous systems. Access control polices follows the RBAC (Role Based Access Control) model proposed by the NIST. The framework is based on the provisioning strategy defined by IETF, i.e., the RBAC information is represented in terms of a PIB (Policy Information Base) and distributed to...

Development assistance has a chequered past, in large part because planning for development assistance is historically such a fractured enterprise internally, and so disassociated from development assistance recipients’ assets and needs. The authors of environment-shaping offer an alternative development programme planning methodology that highlights above all else the ever-important relationsh...