Spacelab software development and integration concepts study report, volume 1

The proposed software guidelines to be followed by the European Space Research Organization in the development of software for the Spacelab being developed for use as a payload for the space shuttle are documented. Concepts, techniques, and tools needed to assure the success of a programming project are defined as they relate to operation of the data management subsystem, support of experiments and space applications, use with ground support equipment, and for integration testing

Memory management in a distributed system of single address space operating systems supporting quality of service

The choices provided by an operating system to the application developer for managing memory came in two forms: no choice at all, with the operating system making all decisions about managing memory; or the choice to implement virtual memory management specific to the individual application. The second of these choices is, for all intents and purposes, the same as the first: no choice at all. For many application developers, the cost of implementing a customised virtual memory management system is just too high. The results is that, regardless of the level of flexibility available, the developer ends up using the system-provided default. Further exacerbating the problem is the tendency for operating system developers to be extremely unimaginative when providing that same default. Advancements in virtual memory techniques such as prefetching, remote paging, compressed caching, and user-level page replacement coupled with the provision of user-level virtual memory management should have heralded a new era of choice and an application-centric approach to memory management. Unfortunately, this has failed to materialise. This dissertation describes the design and implementation of the Heracles virtual memory management system. The Heracles approach is one of inclusion rather than exclusion. The main goal of Heracles is to provide an extensible environment that is configurable to the extent of providing application-centric memory management without the need for application developers to implement their own. However, should the application developer wish to provide a more specialised implementation for all or any part of Heracles, the system is constructed around well-defined interfaces that allow new implementations to be "plugged in" where required. The result is a virtual memory management hierarchy that is highly configurable, highly flexible, and can be adapted at run-time to meet new phases in the application's behaviour. Furthermore, different parts of an application's address space can have different hierarchies associated with managing its memory

Ada (trademark) projects at NASA. Runtime environment issues and recommendations

Ada practitioners should use this document to discuss and establish common short term requirements for Ada runtime environments. The major current Ada runtime environment issues are identified through the analysis of some of the Ada efforts at NASA and other research centers. The runtime environment characteristics of major compilers are compared while alternate runtime implementations are reviewed. Modifications and extensions to the Ada Language Reference Manual to address some of these runtime issues are proposed. Three classes of projects focusing on the most critical runtime features of Ada are recommended, including a range of immediately feasible full scale Ada development projects. Also, a list of runtime features and procurement issues is proposed for consideration by the vendors, contractors and the government

State of the Art in Parallel Computing with R

R is a mature open-source programming language for statistical computing and graphics. Many areas of statistical research are experiencing rapid growth in the size of data sets. Methodological advances drive increased use of simulations. A common approach is to use parallel computing. This paper presents an overview of techniques for parallel computing with R on computer clusters, on multi-core systems, and in grid computing. It reviews sixteen different packages, comparing them on their state of development, the parallel technology used, as well as on usability, acceptance, and performance. Two packages (snow, Rmpi) stand out as particularly suited to general use on computer clusters. Packages for grid computing are still in development, with only one package currently available to the end user. For multi-core systems five different packages exist, but a number of issues pose challenges to early adopters. The paper concludes with ideas for further developments in high performance computing with R. Example code is available in the appendix.

Expert voices for change: Bridging the silos—towards healthy and sustainable settings for the 21st century

The settings approach to health promotion, first advocated in the 1986 Ottawa Charter for Health Promotion, was introduced as an expression of the ‘new public health’, generating both acclaim and critical discourse. Reflecting an ecological model, a systems perspective and whole system thinking, the approach has been applied in a wide range of geographical and organisational contexts. This paper reports on a qualitative study undertaken through in-depth interviews with key individuals widely acknowledged to have been the architects and pilots of the settings movement. Exploring the development of the settings approach, policy and practice integration, and connectedness ‘outwards’, ‘upwards’ and ‘beyond health’, it concludes that the settings approach has much to offer—but will only realise its potential impact on the wellbeing of people, places and the planet if it builds bridges between silos and reconfigures itself for the globalised 21st century