Long baseline vector determinations and intercomparisons

The East Coast very long baseline interferometry (VLBI) group has performed about 60 experiments over the last 10 years in the process of developing and exploiting advanced VLBI techniques. Of those, the most recent 14 experiments are briefly described

Adaption of structured analysis design techniques methodology for construction project planning

The construction industry has been heavily criticised by researchers and governmental organisations for its performance especially excessive delay. Ballard and Howell (2003) indicated that only about 50% of the tasks on weekly work plans are completed by the end of the plan week. This is a result of a lack of either effective project planning or effective production control. It therefore seems the traditional approach of planning is insufficient to meet the current demand and complexity of construction projects. This paper proposes to critically evaluate the adaptation of Structured Analysis Design Techniques (SADT) methodology as a tool for project planning. SADT which was further developed into IDEF (Integrated Definition) techniques claims to be a complete methodology to provide the means of understanding complex production systems and aid the implementation of change. The use of this methodology has led to process improvement. The research uses a literature review followed by interviews with academics and practitioners to investigate their knowledge and understanding of SADT (IDEFO). The results of the interviews indicated that SADT (IDEFO) methodology is seldom known and used in the construction industry. However, this study indicates that SADT methodology appears to be an effective project planning tool. This study contributes to the limited project planning techniques in construction industry by exploring the possible adaption of SADT

Critical mutation rate has an exponential dependence on population size in haploid and diploid populations

Understanding the effect of population size on the key parameters of evolution is particularly important for populations nearing extinction. There are evolutionary pressures to evolve sequences that are both fit and robust. At high mutation rates, individuals with greater mutational robustness can outcompete those with higher fitness. This is survival-of-the-flattest, and has been observed in digital organisms, theoretically, in simulated RNA evolution, and in RNA viruses. We introduce an algorithmic method capable of determining the relationship between population size, the critical mutation rate at which individuals with greater robustness to mutation are favoured over individuals with greater fitness, and the error threshold. Verification for this method is provided against analytical models for the error threshold. We show that the critical mutation rate for increasing haploid population sizes can be approximated by an exponential function, with much lower mutation rates tolerated by small populations. This is in contrast to previous studies which identified that critical mutation rate was independent of population size. The algorithm is extended to diploid populations in a system modelled on the biological process of meiosis. The results confirm that the relationship remains exponential, but show that both the critical mutation rate and error threshold are lower for diploids, rather than higher as might have been expected. Analyzing the transition from critical mutation rate to error threshold provides an improved definition of critical mutation rate. Natural populations with their numbers in decline can be expected to lose genetic material in line with the exponential model, accelerating and potentially irreversibly advancing their decline, and this could potentially affect extinction, recovery and population management strategy. The effect of population size is particularly strong in small populations with 100 individuals or less; the exponential model has significant potential in aiding population management to prevent local (and global) extinction events

A cost-benefit analysis of pathways to work for new and repeat incapacity benefits claimants

This latest research forms part of a comprehensive independent evaluation of Pathways to Work. The report is based on a cost-benefit analysis conducted by a consortium of researchers from the Institute for Fiscal Studies, the University of Maryland, Baltimore County and the Policy Studies Institute. It examines whether the financial benefits from Pathways are larger or smaller than its costs and the generalisability of some of the quantitative findings. The estimates of costs and benefits relate to new and repeat incapacity benefits claimants in the seven original Jobcentre Plus districts. The overall findings provide a favourable impression of the financial benefits of the Pathways to Work for new and repeat incapacity benefits claimants, for the Exchequer and hence, for society as a whole

Interferometric tracking system for the tracking and data relay satellite

This report documents construction and testing of the Interferometric Tracking System project developed under the NASA SBIR contract NAS5-30313. Manuals describing the software and hardware, respectively entitled: 'Field Station Guide to Operations' and 'Field Station Hardware Manual' are included as part of this final report. The objective of this contract was to design, build, and operate a system of three ground stations using Very Long Baseline Interferometry techniques to measure the TDRS orbit. The ground stations receive signals from normal satellite traffic, store these signals in co-located computers, and transmit the information via phone lines to a central processing site which correlates the signals to determine relative time delays. Measurements from another satellite besides TDRS are used to determine clock offsets. A series of such measurements will ultimately be employed to derive the orbital parameters, yielding positions accurate to within 50 meters or possibly better

Optimization of controlled environments for hydroponic production of leaf lettuce for human life support in CELSS

A research project in the food production group of the Closed Ecological Life Support System (CELSS) program sought to define optimum conditions for photosynthetic productivity of a higher plant food crop. The effects of radiation and various atmospheric compositions were studied

Two-fluid model of the solar corona

A simple model of the lower corona which allows for a possible difference in the electron and proton temperatures is analyzed. With the introduction of a phenomenological heating term, temperature and density profiles are calculated for several different cases. It is found that, under certain circumstances, the electron and proton temperatures may differ significantly

Perspectives: nursing education - from vision to action in changing world

There is consensus that there are shared contemporary issues within nursing and nurse education that require collective consideration and, on occasion, shared solutions. Nonetheless, in the complex world in which we live, taking time to reflect on our work can become lost in the need to meet many competing demands. A conference can be expensive and time consuming, and as time pressures and deadlines loom risk becoming a short trip to present a paper rather than fuller engagement. With this in mind, we offer perspectives on our learning from The Federation of European Nurse Educators (FINE) 11th International FINE Conference in Malta (21–23 February 2018) and some opportunities and challenges facing nursing education today. FINE is a membership organisation, which, since its inception in 1994, has facilitated knowledge exchange and discussion around contemporary challenges in nursing education. Attendees came from 22 nations and five continents to share best practice and educational research innovation. This paper offers insight into key themes that emerged from the conference and the opportunities, innovations and challenges facing nursing education today. We include examples of papers debating these themes. In conclusion, we reflect on our experiences and offer benefits of global networking nursing education

The implementation and use of Ada on distributed systems with high reliability requirements

The use and implementation of Ada in distributed environments in which reliability is the primary concern were investigated. In particular, the concept that a distributed system may be programmed entirely in Ada so that the individual tasks of the system are unconcerned with which processors they are executing on, and that failures may occur in the software or underlying hardware was examined. Progress is discussed for the following areas: continued development and testing of the fault-tolerant Ada testbed; development of suggested changes to Ada so that it might more easily cope with the failure of interest; and design of new approaches to fault-tolerant software in real-time systems, and integration of these ideas into Ada