The vulnerability of public spaces: challenges for UK hospitals under the 'new' terrorist threat

This article considers the challenges for hospitals in the United Kingdom that arise from the threats of mass-casualty terrorism. Whilst much has been written about the role of health care as a rescuer in terrorist attacks and other mass-casualty crises, little has been written about health care as a victim within a mass-emergency setting. Yet, health care is a key component of any nation's contingency planning and an erosion of its capabilities would have a significant impact on the generation of a wider crisis following a mass-casualty event. This article seeks to highlight the nature of the challenges facing elements of UK health care, with a focus on hospitals both as essential contingency responders under the United Kingdom's civil contingencies legislation and as potential victims of terrorism. It seeks to explore the potential gaps that exist between the task demands facing hospitals and the vulnerabilities that exist within them

Group membership in asynchronous distributed environments using logically ordered views

A group membership protocol ensures agreement and consistent commit actions among group members to maintain a sequence of identical group views in spite of continuous changes, either voluntary or otherwise, in processors' membership status. In asynchronous distributed environments, such consistency among group views must be guaranteed using messages over a network which does not bound message delivery times. Assuming a network that provides a reliable, FIFO channel between any pair of processors, one approach to designing such a protocol is to centralize the responsibility to detect changes, ensure agreement, and commit them consistently in a single manager process. This approach is complicated by the fact that a protocol to elect a new manager with a consistent membership proposal must be executed when the manager itself fails. In this report, we present a membership protocol based on ordering of group members in a logical ring that eliminates the need for such centralized responsibility. Agreement and commit actions are token-based and the protocol ensures that no tokens are lost or duplicated due to changes in membership. The cost of committing a change is 2n point-to-point messages over FIFO channels where n is the group size. The protocol correctness has been proven formally. Agreement, Asynchronous, Commit, Distributed, Failure, Group Membership, Logical Ring, Reliable Multicast, TokenMonterey, California. Naval Postgraduate Schoolhttp://archive.org/details/groupmembershipi00shukMonterey, California. Naval Postgraduate SchoolNAApproved for public release; distribution is unlimited