Ambiguity in the Determination of the Free Energy for a Model of the Circle Map

We consider a simple model to describe the widths of the mode locked intervals for the critical circle map. Using two different partitions of the rational numbers, based on Farey series and Farey tree levels respectively, we calculate the free energy analytically at selected points for each partition. It is found that the result of the calculation depends on the method of partition. An implication of this is that the generalized dimensions $D_q$ are different for each partition except when $q=0$, i.e. only the Hausdorff dimension is the same in each case.Comment: 14 page

Open Source Software the Trenches: Lessons from a Large-Scale OSS Implementation

This paper describes the implementation of an information systems infrastructure using open source software (OSS) in a large Irish public sector organization, Beaumont Hospital. The study identifies the primary organizational drivers in Beaumont’s move to OSS, namely principle and pragmatism. It also discusses some of the problems encountered, such as the change in mind-set required when deploying OSS solutions, and resistance from staff who feared being deskilled by moving away from popular proprietary systems. The study reveals a radical shift in open source deployment from invisible horizontal infrastructure systems to highly visible vertical applications. The first phase of OSS implementation is estimated to lead to cost savings of i13 million over five years. These details are useful in that few studies have quantified the savings from OSS deployment. Given that Beaumont was already receiving academic pricing discounts for many of their original proprietary closed source applications, the savings for a typical commercial organization could be even higher. Also, in many cases, the extra functionality available in the OSS systems deployed allowed for a richer feature set overall. Buoyed by the success of this first phase, Beaumont is planning a second phase of OSS implementation for an overall hospital information system, a financial systems suite, and is even considering developing their payroll system in an open source fashion. The study also identifies how a typical company can contribute back to the OSS community in their own unique way, by distributing applications developed from their own particular domain of expertise, rather than having to make code contributions to the code base of GNU/Linux or Apache as might have been assumed to be the case. Indeed, free access to source code played a very limited role in Beaumont’s motivation, where given the budgetary constraints, zero cost was of more concern than open source

SIMULATION COMPARISON OF STATISTICAL METHODS USED IN ASSESSING VACCINE EFFICACY IN VETERINARY BIOLOGICS

In veterinary biologics, clinical studies conducted to support the licensure of a vaccine generally include a demonstration of efficacy in the species of interest. Typically, these studies are designed to assess a vaccine’s ability to prevent or mitigate clinical disease. Study designs utilize two or more treatment groups, and often incorporate blocking structure restrictions to accommodate animal housing or litter-related effects. When assessing a vaccine’s ability to prevent clinical disease, the prevented fraction (PF), a function of the group proportions of affected animals, is often utilized. Typically the sample size per treatment group is limited, and each block is represented by only a few experimental units per treatment group. Thus, it is a common occurrence for group proportion estimates to be 0 or 1 at the block level. Typical methods utilized in analyzing study data include generalized linear mixed model with delta method for confidence interval (GLMM), Cochran-Mantel-Haenszel (CMH) and Gart & Nam (GN). Through simulation, we compare the performance characteristics (power, bias, coverage) of these methods for a range of study designs, sample sizes and PF values, including an assessment of type 1 error rates. Simulation results suggest CMH generally performs well whereas the GN can perform poorly with regards to type 1 error. GLMM performance varies, depending on the simulated situation. Further, upon closer investigation of GN simulated results, it was determined that the method does not always result in a unique solution

3-D CFD Simulation and Validation of Oxygen-Rich Hydrocarbon Combustion in a Gas-Centered Swirl Coaxial Injector using a Flamelet-Based Approach

Injector design is a critical part of the development of a rocket Thrust Chamber Assembly (TCA). Proper detailed injector design can maximize propulsion efficiency while minimizing the potential for failures in the combustion chamber. Traditional design and analysis methods for hydrocarbon-fuel injector elements are based heavily on empirical data and models developed from heritage hardware tests. Using this limited set of data produces challenges when trying to design a new propulsion system where the operating conditions may greatly differ from heritage applications. Time-accurate, Three-Dimensional (3-D) Computational Fluid Dynamics (CFD) modeling of combusting flows inside of injectors has long been a goal of the fluid analysis group at Marshall Space Flight Center (MSFC) and the larger CFD modeling community. CFD simulation can provide insight into the design and function of an injector that cannot be obtained easily through testing or empirical comparisons to existing hardware. However, the traditional finite-rate chemistry modeling approach utilized to simulate combusting flows for complex fuels, such as Rocket Propellant-2 (RP-2), is prohibitively expensive and time consuming even with a large amount of computational resources. MSFC has been working, in partnership with Streamline Numerics, Inc., to develop a computationally efficient, flamelet-based approach for modeling complex combusting flow applications. In this work, a flamelet modeling approach is used to simulate time-accurate, 3-D, combusting flow inside a single Gas Centered Swirl Coaxial (GCSC) injector using the flow solver, Loci-STREAM. CFD simulations were performed for several different injector geometries. Results of the CFD analysis helped guide the design of the injector from an initial concept to a tested prototype. The results of the CFD analysis are compared to data gathered from several hot-fire, single element injector tests performed in the Air Force Research Lab EC-1 test facility located at Edwards Air Force Base

Report From the Field: The RICTA Meeting Video

A short video produced about the founding meeting of RICTA has been made available for viewing online. The new Canadian research network RICTA Research on ICT with Aboriginal Communities held its first meeting in Balmertown, Ontario, with videoconference links to 10 locations across the country

Restorative Practices in Institutional Settings: The Challenges of Contractualised Support within the Managed Community of Supported Housing

Supported housing services provide help to some of the most vulnerable in society, yet across the world face increasing pressures from residualisation in the form of service reduction and stretched budgets. In response to these challenges, providers of supported housing and other similar community-focused services have sought alternative and innovative methods of engagement. This paper reports on one such example, the Restorative Communities Programme, which took place in 2018 in a residential supported housing setting for males aged 16–25. Designed as a five-week programme, it aimed to offer a proactive intervention promoting the benefits of restorative thinking. The research team observed the sessions and conducted follow-up qualitative interviews after two weeks and one year. This paper considers the challenges and success of the programme, reflecting particularly on issues of contractualised support and its impact on participation, and the dynamics of running such programs within the ‘managed community’ of a supported housing project. As such, the paper provides a useful analysis for others exploring the development and use of restorative projects in institutional settings, such as prisons, probation, and schools, and particularly those services struggling with the pressures of residualisation

Are Police-Led Social Crime Prevention Initiatives Effective?: A Process and Outcome Evaluation of a UK Youth Intervention

Police-led interventions with ‘at risk’ young people, raise a number of debates around policing in society including the allocation of resources at a time of fiscal austerity, the extent to which the police should prioritise the safety and wellbeing of young people, and the role that the police should take in preventing youth crime. This article explores the impact and effectiveness of a police-led social crime prevention initiative in England. It adopts the QUALIPREV approach by Rummens et al (2016) on behalf of the European Crime Prevention Network to analyse the data allowing for a detailed and replicable analysis of core aspects including police engagement, risk management, offending rates and police-community relations. Drawing on comparisons between the UK case study and previous studies on police-led social crime prevention projects in Australia and Canada, the article identifies a number of common challenges for schemes of this nature including problems with multi agency working, developing a clear project identity, unequal resources across different locations, and the difficulty in recruiting and retaining volunteers. However, there were also significant benefits to such schemes, including positive impacts on offending rates, engagement of at risk young people, and wider benefits to the communities within which the young people live, including participation, volunteering and reduction in risks of community harm. A cost-benefit analysis also shows such scheme have the potential to offer significant savings to the criminal justice system as a whole