Infrared regulators and SCETII

We consider matching from SCETI, which includes ultrasoft and collinear particles, onto SCETII with soft and collinear particles at one loop. Keeping the external fermions off their mass shell does not regulate all IR divergences in both theories. We give a new prescription to regulate infrared divergences in SCET. Using this regulator, we show that soft and collinear modes in SCETII are sufficient to reproduce all the infrared divergences of SCETI. We explain the relationship between IR regulators and an additional mode proposed for SCETII.Comment: 9 pages. Added discussion about relationship between IR regulators and messenger mode

Identifying common problems in the acquisition and deployment of large-scale software projects in the US and UK healthcare systems

Public and private organizations are investing increasing amounts into the development of healthcare information technology. These applications are perceived to offer numerous benefits. Software systems can improve the exchange of information between healthcare facilities. They support standardised procedures that can help to increase consistency between different service providers. Electronic patient records ensure minimum standards across the trajectory of care when patients move between different specializations. Healthcare information systems also offer economic benefits through efficiency savings; for example by providing the data that helps to identify potential bottlenecks in the provision and administration of care. However, a number of high-profile failures reveal the problems that arise when staff must cope with the loss of these applications. In particular, teams have to retrieve paper based records that often lack the detail on electronic systems. Individuals who have only used electronic information systems face particular problems in learning how to apply paper-based fallbacks. The following pages compare two different failures of Healthcare Information Systems in the UK and North America. The intention is to ensure that future initiatives to extend the integration of electronic patient records will build on the ‘lessons learned’ from previous systems

Applying the lessons of the attack on the World Trade Center, 11th September 2001, to the design and use of interactive evacuation simulations

The collapse of buildings, such as terminal 2E at Paris' Charles de Gaule Airport, and of fires, such as the Rhode Island, Station Night Club tragedy, has focused public attention on the safety of large public buildings. Initiatives in the United States and in Europe have led to the development of interactive simulators that model evacuation from these buildings. The tools avoid some of the ethical and legal problems from simulating evacuations; many people were injured during the 1993 evacuation of the World Trade Center (WTC) complex. They also use many concepts that originate within the CHI communities. For instance, some simulators use simple task models to represent the occupants' goal structures as they search for an available exit. However, the recent release of the report from the National Commission on Terrorist Attacks upon the United States (the '9/11 commission') has posed serious questions about the design and use of this particular class of interactive systems. This paper argues that simulation research needs to draw on insights from the CHI communities in order to meet some the challenges identified by the 9/11 commission

The Hidden Human Factors in Unmanned Aerial Vehicles

In April 2006, an Unmanned Aerial Vehicle crashed near Nogales, Arizona. This incident is of interest because it triggered one of the most sustained studies into the causes of failure involving such a vehicle. The National Transportation Safety Board together with the US Customs and Border Protection agency under the Department of Homeland Security worked to identify lessons learned from this mishap. The crash at Nogales is also of interest because it illustrates an irony of Unmanned Aircraft Systems operations; the increasing reliance on autonomous and unmanned operations is increasing the importance of other aspects of human-system interaction in the cause of major incidents. The following pages illustrate this argument using an accident analysis technique, Events and Causal Factors charting, to identify the many different ways in which human factors contributed to the loss of this Predator B aircraft

On Power Suppressed Operators and Gauge Invariance in SCET

The form of collinear gauge invariance for power suppressed operators in the soft-collinear effective theory is discussed. Using a field redefinition we show that it is possible to make any power suppressed ultrasoft-collinear operators invariant under the original leading order gauge transformations. Our manipulations avoid gauge fixing. The Lagrangians to O(lambda^2) are given in terms of these new fields. We then give a simple procedure for constructing power suppressed soft-collinear operators in SCET_II by using an intermediate theory SCET_I.Comment: 15 pages, journal versio

Lessons from the evacuation of the World Trade Center, Sept 11th 2001 for the future development of computer simulations

This paper provides an overview of the state of the art in evacuation simulations. These interactive computer based tools have been developed to help the owners and designers of large public buildings to assess the risks that occupants might face during emergency egress. The development of the Glasgow Evacuation Simulator is used to illustrate the existing generation of tools. This system uses Monte Carlo techniques to control individual and group movements during an evacuation. The end-user can interactively open and block emergency exits at any point. It is also possible to alter the priorities that individuals associate with particular exit routes. A final benefit is that the tool can derive evacuation simulations directly from existing architects models; this reduces the cost of simulations and creates a more prominent role for these tools in the iterative development of large-scale public buildings. Empirical studies have been used to validate the GES system as a tool to support evacuation training. The development of these tools has been informed by numerous human factors studies and by recent accident investigations. For example, the 2003 fire in the Station nightclub in Rhode Island illustrated the way in which most building occupants retrace their steps to an entrance even when there are alternate fire exits. The second half of this paper uses this introduction to criticise the existing state of the art in evacuation simulations. These criticisms are based on a detailed study of the recent findings from the 9/11 Commission (2004). Ten different lessons are identified. Some relate to the need to better understand the role of building management and security systems in controlling egress from public buildings. Others relate to the human factors involved in coordinating distributed groups of emergency personnel who may be physically exhausted by the demands of an evacuation. Arguably the most important findings centre on the need to model the ingress and egress of emergency personnel from these structures. The previous focus of nearly all-existing simulation tools has been on the evacuation of building occupants rather than on the safety of first responders1

Neumann and Bargmann systems associated with an extension of the coupled KdV hierarchy

An eigenvalue problem with a reference function and the corresponding hierarchy of nonlinear evolution equations are proposed. The bi-Hamiltonian structure of the hierarchy is established by using the trace identity. The isospectral problem is nonlinearized as to be finite-dimensional completely integrable systems in Liouville sense under Neumann and Bargmann constraints

JJ-pairing Interactions of Fermions in a Single-jj Shell

In this talk I shall introduce our recent works on general pairing interactions and pair truncation approximations for fermions in a single-j shell, including the spin zero dominance, features of eigenvalues of fermion systems in a single-j shell interacting by a $J-$pairing interaction.Comment: 10 pages and 4 figures, international symposiu

Review-discussion: historical knowledge and historical narratives in the Severan period: Adam M. Kemezis, Greek Narratives of the Roman Empire under the Severans: Cassius Dio, Philostratus, and Herodian, Greek Culture in the Roman World

No abstract available

Safety arguments for next generation location aware computing

Concerns over the accuracy, availability, integrity and continuity of Global Navigation Satellite Systems (GNSS) have limited the integration of GPS and GLONASS for safety-critical applications. More recent augmentation systems, such as the European Geostationary Navigation Overlay Service (EGNOS) and the North American Wide Area Augmentation System (WAAS) have begun to address these concerns. Augmentation architectures build on the existing GPS/GLONASS infrastructures to support locationbased services in Safety of Life (SoL) applications. Much of the technical development has been directed by air traffic management requirements, in anticipation of the more extensive support to be offered by GPS III and Galileo. WAAS has already been approved to provide vertical guidance against ICAO safety performance criteria for aviation applications. During the next twelve months, we will see the full certification of EGNOS for SoL applications. This paper identifies strong similarities between the safety assessment techniques used in Europe and North America. Both have relied on hazard analysis techniques to derive estimates of the Probability of Hazardously Misleading Information (PHMI). Later sections identify significant differences between the approaches adopted in application development. Integrated fault trees have been developed by regulatory and commercial organisations to consider both infrastructure hazards and their impact on non-precision RNAV/VNAV approaches using WAAS. In contrast, EUROCONTROL and the European Space Agency have developed a more modular approach to safety-case development for EGNOS. It remains to be seen whether the European or North American strategy offers the greatest support as satellite based augmentation systems are used within a growing range of SoL applications from railway signalling through to Unmanned Airborne Systems. The key contribution of this paper is to focus attention on the safety arguments that might support this wider class of location based services