260 research outputs found
Self-healing in Wireless Sensor Networks
No full textThe development of small wireless sensors and smart-phones, which include various sound, video, motion and location sensors, has facilitated new pervasive applications such as healthcare, buidling and environmental monitoring or animal tracking. Devices may not be easily accessed for maintenance and users may be non-technical, thus, the systems need to be self-managing and self-healing with respect to faults and errors. In this thesis we investigate models and mechanisms for detection and recovery from faults and propose an adaptation framework to facilitate their deployment and maintenance
Author Obliged to Submit Paper before 4 July: Policies in an Enterprise Specification
No full textAbstract Specifying policies doesn't occur in splendid isolation but as part of refining an enterprise specification. The roles, the tasks, and the business processes of an ODP community provide the basic alphabet over which we write our policies. We illustrate this through exploring a conference programme committee case study. We discuss how we might formulate policies and show how policies are refined alongside the refinement of the overall system specification, developing notions of sufficiency and necessity. Policy delegation is also discussed and we categorise different forms of delegating an obligation
A policy based management architecture for large scale active communication systems.
No full textAn initial design for a policy based management system combining conventional hierarchical control and significant local autonomy is described. A critical part of the design is a scheme of partial guarantees for policy distribution and execution. This scheme renders explicit the non-determinism that is implicit in policy based control schemes that include conflict resolution, and to some extent replaces the need for conflict resolution. Some preliminary implementations of the design are described, and implications for further work are discussed
Architectural and Representational Requirements for Seeing Processes, Proto-affordances and Affordances
No full textThis paper, combining the standpoints of philosophy and
Artificial Intelligence with theoretical psychology, summarises several
decades of investigation by the author of the variety of functions of vision
in humans and other animals, pointing out that biological evolution has
solved many more problems than are normally noticed. For example, the
biological functions of human and animal vision are closely related to the
ability of humans to do mathematics, including discovering and proving
theorems in geometry, topology and arithmetic. Many of the phenomena
discovered by psychologists and neuroscientists require sophisticated controlled
laboratory settings and specialised measuring equipment, whereas
the functions of vision reported here mostly require only careful attention
to a wide range of everyday competences that easily go unnoticed. Currently
available computer models and neural theories are very far from
explaining those functions, so progress in explaining how vision works
is more in need of new proposals for explanatory mechanisms than new
laboratory data. Systematically formulating the requirements for such
mechanisms is not easy. If we start by analysing familiar competences,
that can suggest new experiments to clarify precise forms of these competences,
how they develop within individuals, which other species have
them, and how performance varies according to conditions. This will
help to constrain requirements for models purporting to explain how the
competences work. For example, Gibson’s theory of affordances needs
a number of extensions, including allowing affordances to be composed
in several ways from lower level proto-affordances. The paper ends with
speculations regarding the need for new kinds of information-processing
machinery to account for the phenomena
Smarter choices ?changing the way we travel. Case study reports
No full textThis report accompanies the following volume:Cairns S, Sloman L, Newson C, Anable J, Kirkbride A and Goodwin P (2004)Smarter Choices ? Changing the Way We Travel. Report published by theDepartment for Transport, London, available via the ?Sustainable Travel? section ofwww.dft.gov.uk, and from http://eprints.ucl.ac.uk/archive/00001224/
Policy based roles for distributed systems security
No full text03.02.14 KB. OK to add accepted paper to spiral, author retains copyrigh
A proposal for a study of motive processing
No full textThis was a contribution to the Cognition and Affect project that led to the Ph.D. thesis of the first author (Luc P. Beaudoin). This paper was mostly written by the first author, although it is based on and develops ideas of the second author. The nursemaid scenario was first described by the second author (Sloman, 1986). The first author was in the process of implementing the model described in the paper.Thanks to Aluizio Arujo, Peter Greenfield, Inman Harvey, Tim Read, Edmund Shing, Sharon Wood, and Shiu Yuen for reading and commenting on drafts. The first author was supported by the Commonwealth Scholarship Commission in the United Kingdom, and FCAR of Quebec
The Ponder policy specification language
No full text04.12.14 KB. Ok to add accepted version to spiral, 12 months embargo expired.The Ponder language provides a common means of specifying security policies that map onto various access control implementation mechanisms for firewalls, operating systems, databases and Java. It supports obligation policies that are event triggered condition-action rules for policy based management of networks and distributed systems, Ponder can also be used for security management activities such as registration of users or logging and auditing events for dealing with access to critical resources or security violations. Key concepts of the language include roles to group policies relating to a position in an organisation, relationships to define interactions between roles and management structures to define a configuration of roles and relationships pertaining to an organisational unit such as a department. These reusable composite policy specifications cater for the complexity of large enterprise information systems. Ponder is declarative, strongly-typed and object-oriented which makes the language flexible, extensible and adaptable to a wide range of management requirements
Specification of Management Policies
No full textThis report builds on previous work which has been presented earlier (Sloman, 1993), and introduces a system architecture and policy language format, and provides some example policies. 2 System Architectur
CONSTRUCTING DISTRIBUTED SYSTEMS IN CONIC
No full textThe Conic environment provides a language-based approach to the building of distributed systems which combines the simplicity and safety of a language approach with the flexibility and accessibility of an operating systems approach. It provides a comprehensive set of tools for program compilation, configuration, debugging, and execution in a distributed environment. A separate configuration language is used to specify the configuration of software components into logical nodes. This provides a concise configuration description and facilitates the reuse of program components in different configurations. Applications are constructed as sets of one or more interconnected logical nodes. Arbitrary, incremental change is supported by dynamic configuration. In addition, the system provides user-transparent datatype transformation between heterogeneous processors. Applications may be run on a mixed set of interconnected computers running the Unix operating system and on base target machines with no resident operating system. The basic principles adopted in the construction of the Conic environment are outlined and the configuration and run-time facilities provided are described.Published versio
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