Nonmonotonic Trust Management for P2P Applications

Community decisions about access control in virtual communities are non-monotonic in nature. This means that they cannot be expressed in current, monotonic trust management languages such as the family of Role Based Trust Management languages (RT). To solve this problem we propose RT-, which adds a restricted form of negation to the standard RT language, thus admitting a controlled form of non-monotonicity. The semantics of RT- is discussed and presented in terms of the well-founded semantics for Logic Programs. Finally we discuss how chain discovery can be accomplished for RT-.Comment: This paper appears in the proceedings of the 1st International Workshop on Security and Trust Management (STM 2005). To appear in ENTC

From Kontrollverlust to Kontrollgewinn : rediscovering a meso-Level normative hierarchy for integrated water management in England using on-line activities

This paper presents a unique study into how to identify a meso-level normative (i.e., institutional) hierarchy of procedures that aim to deliver the ecological status of waterbodies in the UK. Using traditional survey and workshop methods, the majority of recent studies concentrate on engagement practices between macro- (government bodies) and micro- (local residents) level structures, which can be potentially replicated elsewhere. Meso-level elements (middle-level structures of control) are often regarded as ‘subjective institutional change’, e.g., failures to implement programs locally or misinterpretations of reflexive dialogs with communities. Nevertheless, it is often only meso-level structures that are capable of promoting and replicating policies elsewhere. At the same time, there is increasing appeal by governmental departments for communities to ‘selforganize’ and take responsibility for prioritizing environmental tasks, which themselves might be instigated by local trusts and voluntary organizations, the existence of which remains largely unaccounted for by central offices. The recent proliferation of Twitter accounts, with the prominent themes of water, ecology and ecosystems, which include people, organizations, businesses and ‘bots’ of various types, presents new opportunities for digital methods to gain insights into structures and functions of these virtual communities. We hypothesize that our methods can produce invaluable insights into the ‘crafting’ of environmental institutions through approaches commonly ignored by traditional ‘analog’ meso-level mechanisms. We use the example of Integrated Catchment Management in the UK, and specifically the Tamar Catchment in southwest England, in order to demonstrate how well Twitter can capture this transitory meso-level environmental political system

Funding Culture: An Analysis of Historic Site Preservation Policy

This paper examines the way in which public funding and tax policies are applied to federally recognized historic preservation sites and how that application influences the a variety of stakeholder communities including tax payers, historical organizations, historic property owners, and municipalities

Shibboleth-based access to and usage of grid resources

Security underpins grids and e-research. Without a robust, reliable and simple grid security infrastructure combined with commonly accepted security practices, large portions of the research community and wider industry will not engage. The predominant way in which security is currently addressed in the grid community is through public key infrastructures (PKI) based upon X.509 certificates to support authentication. Whilst PKIs address user identity issues, authentication does not provide fine grained control over what users are allowed to do on remote resources (authorization). In this paper we outline how we have successfully combined Shibboleth and advanced authorization technologies to provide simplified (from the user perspective) but fine grained security for access to and usage of grid resources. We demonstrate this approach through different security focused e-science projects being conducted at the National e-Science Centre (NeSC) at the University of Glasgow. We believe that this model is widely applicable and encourage the further uptake of e-science by non-IT specialists in the research communitie

Building communities for the exchange of learning objects: theoretical foundations and requirements

In order to reduce overall costs of developing high-quality digital courses (including both the content, and the learning and teaching activities), the exchange of learning objects has been recognized as a promising solution. This article makes an inventory of the issues involved in the exchange of learning objects within a community. It explores some basic theories, models and specifications and provides a theoretical framework containing the functional and non-functional requirements to establish an exchange system in the educational field. Three levels of requirements are discussed. First, the non-functional requirements that deal with the technical conditions to make learning objects interoperable. Second, some basic use cases (activities) are identified that must be facilitated to enable the technical exchange of learning objects, e.g. searching and adapting the objects. Third, some basic use cases are identified that are required to establish the exchange of learning objects in a community, e.g. policy management, information and training. The implications of this framework are then discussed, including recommendations concerning the identification of reward systems, role changes and evaluation instruments

Single sign-on and authorization for dynamic virtual organizations

The vision of the Grid is to support the dynamic establishment and subsequent management of virtual organizations (VO). To achieve this presents many challenges for the Grid community with perhaps the greatest one being security. Whilst Public Key Infrastructures (PKI) provide a form of single sign-on through recognition of trusted certification authorities, they have numerous limitations. The Internet2 Shibboleth architecture and protocols provide an enabling technology overcoming some of the issues with PKIs however Shibboleth too suffers from various limitations that make its application for dynamic VO establishment and management difficult. In this paper we explore the limitations of PKIs and Shibboleth and present an infrastructure that incorporates single sign-on with advanced authorization of federated security infrastructures and yet is seamless and targeted to the needs of end users. We explore this infrastructure through an educational case study at the National e-Science Centre (NeSC) at the University of Glasgow and Edinburgh

Semantic-based policy engineering for autonomic systems

This paper presents some important directions in the use of ontology-based semantics in achieving the vision of Autonomic Communications. We examine the requirements of Autonomic Communication with a focus on the demanding needs of ubiquitous computing environments, with an emphasis on the requirements shared with Autonomic Computing. We observe that ontologies provide a strong mechanism for addressing the heterogeneity in user task requirements, managed resources, services and context. We then present two complimentary approaches that exploit ontology-based knowledge in support of autonomic communications: service-oriented models for policy engineering and dynamic semantic queries using content-based networks. The paper concludes with a discussion of the major research challenges such approaches raise

Business in the World of Water

The book aims to: 1) clarify and enhance understanding by business of the key issues and drivers of change related to water; 2) promote mutual understanding between the business community and non-business stakeholders on water management issues; and 3) support effective business action as part of the solution to sustainable water management. The report poses three scenarios about the possible future of water in 2025 which serve as catalysts for exploration into how businesses can contribute to sustainable water management

Supporting security-oriented, inter-disciplinary research: crossing the social, clinical and geospatial domains

How many people have had a chronic disease for longer than 5-years in Scotland? How has this impacted upon their choices of employment? Are there any geographical clusters in Scotland where a high-incidence of patients with such long-term illness can be found? How does the life expectancy of such individuals compare with the national averages? Such questions are important to understand the health of nations and the best ways in which health care should be delivered and measured for their impact and success. In tackling such research questions, e-Infrastructures need to provide tailored, secure access to an extensible range of distributed resources including primary and secondary e-Health clinical data; social science data, and geospatial data sets amongst numerous others. In this paper we describe the security models underlying these e-Infrastructures and demonstrate their implementation in supporting secure, federated access to a variety of distributed and heterogeneous data sets exploiting the results of a variety of projects at the National e-Science Centre (NeSC) at the University of Glasgow