Variable domain transformation for linear PAC analysis of mixed-signal systems

This paper describes a method to perform linear AC analysis on mixed-signal systems which appear strongly nonlinear in the voltage domain but are linear in other variable domains. Common circuits like phase/delay-locked loops and duty-cycle correctors fall into this category, since they are designed to be linear with respect to phases, delays, and duty-cycles of the input and output clocks, respectively. The method uses variable domain translators to change the variables to which the AC perturbation is applied and from which the AC response is measured. By utilizing the efficient periodic AC (PAC) analysis available in commercial RF simulators, the circuit’s linear transfer function in the desired variable domain can be characterized without relying on extensive transient simulations. Furthermore, the variable domain translators enable the circuits to be macromodeled as weakly-nonlinear systems in the chosen domain and then converted to voltage-domain models, instead of being modeled as strongly-nonlinear systems directly

Housing and council tax benefits administration in England: a long-term perspective on the performance of the local government delivery system

This paper evaluates the performance of the Council Tax and Housing Benefits Administration Services delivered by local authorities since the current system for the delivery of these benefits was introduced. During this period the performance of local government has been regulated and influenced by four successive national delivery regimes imposed by central governments namely Compulsory Competitive Tendering (CCT); Best Value (BV); Comprehensive Performance Assessments (CPA) and Comprehensive Area Assessments (CAA). An earlier paper (XXXX et al. forthcoming) examined the CPA period in detail and found a significant improvement in performance across all types of authorities in all parts of the country during this period. The current paper is intended to complement this earlier analysis and provide a longer term perspective on the performance of the benefits service under successive regimes between 1993 and 2010. The findings show that under CCT the performance of the system was poor, there were wide variations in individual local authority’s performance, with many acknowledged inadequacies in the system and unacceptably high levels of fraud. However in this period and in the subsequent BV period the antecedents of some of the tools and techniques subsequently used to drive improvement in the CPA era were either put in place or were being developed

Comprehensive performance assessment and public services improvement in England? A case study of the benefits administration service in local government

The purpose of this paper is to independently evaluate the impact of the Comprehensive Performance Assessment regime on one particular public service, namely the provision of Council Tax and Housing Benefits distributed by local authorities throughout the course of the regime. This service was assessed in every iteration of the CPA methodologies and it included one of the few key performance indicators (KPIs) where the definition of the performance indicator, the means of collection and the public reporting of its results, remained the same throughout the CPA period between 2002 and 2008

The applicability of MFD thrusters to satellite power systems

The high power self field MPD thruster uses electromagnetic forces rather than electrostatic to accelerate a neutral plasma. The most attractive application of MPD thrusters to satellite power systems is in the area of electric propulsion for a cargo orbit transfer vehicle (COTV). Calculations were performed in order to compare the performance of a COTV using an ion or MPD propulsion system. Results show that the MPD propulsion system gives a shorter trip time with the same power and payload when compared to the ion thruster propulsion system at either value of specific impulse. More important than the trip time benefit may be the advantage a MPD propulsion system provides in system simplicity. Another interesting COTV concept using MPD thrusters is the use of a remote power supply located on the Earth, at GEO, or somewhere in between to transmit power to the COTV in a microwave transmission. The specific impulse at thrust levels of tens of newtons makes a MPD propulsion system a candidate for stationkeeping and attitude control of large space structures such as a SPS

Fast, non-monte-carlo estimation of transient performance variation due to device mismatch

This paper describes an efficient way of simulating the effects of device random mismatch on circuit transient characteristics, such as variations in delay or in frequency. The proposed method models DC random offsets as equivalent AC pseudo-noises and leverages the fast, linear periodically time-varying (LPTV) noise analysis available from RF circuit simulators. Therefore, the method can be considered as an extension to DC match analysis and offers a large speed-up compared to the traditional Monte-Carlo analysis. Although the assumed linear perturbation model is valid only for small variations, it enables easy ways to estimate correlations among variations and identify the most sensitive design parameters to mismatch, all at no additional simulation cost. Three benchmarks measuring the variations in the input offset voltage of a clocked comparator, the delay of a logic path, and the frequency of an oscillator demonstrate the speed improvement of about 100-1000x compared to a 1000-point Monte-Carlo method

Quality of life: Conceptual challenges in exploring the role of ICT in active ageing

The chapter aims to examine the definitional challenges associated with the term quality of life, measurement challenges, the challenges associated with enhancing quality of life, and the role of information and communication technologies (ICT) in quality of life in old age, and finally comments on the challenges of a modern information society for older people. The term quality of life started as a social scientific index of the relative well-being of whole populations, i.e. the state of states. Nowadays quality of life is more likely to be viewed as an individualized aspect of the modern psyche. This shift in conceptualization is problematic in that, if quality of life is individualized, it cannot be meaningful to assess it in the same way for everyone. Nevertheless, over the years a vast range of methods of measuring quality of life has emerged, leading to several measurement challenges. Wealth, health and social relations have all been found to be prime determinants of subjective quality of life; for ICT to enhance quality of life for older people they need to mediate the relationships between these three important factors and quality of life. To date there is relatively little evidence that ICT has improved the quality of life of older people. Suggestions are made as to why ICT is unlikely to influence life quality for older citizens. The chapter is drawn to a close by asking if quality of life is a meaningless term and if the future is bleak for old people in a modern information society. The answer to both questions is no

A new effect in the low magnetic field ultrasonic attenuation of impure superconducting niobium

Low magnetic field ultrasonic attenuation of impure superconducting niobiu

On being a mentor

This article explores issues relating to mentoring students, particularly ophthalmic nursing students. It highlights the importance of mentorship in learning in practice, which in turn is critical to students' education in a competency-based profession. It considers the factors essential in successful mentoring, including two-way feedback, and the importance of mentors understanding the nature of the psychological processes involved and how to assess students' learning and competencies. It also highlights the crucial gate-keeping role of mentors in ensuring that students are fit to practise, and the importance of nurse mentors themselves being fit to practise

Cross-correlation of the unresolved X-ray background with faint galaxies

At the faint end of the deepest X-ray surveys, a population of X-ray luminous galaxies is seen. In this paper, we present the results of a cross-correlation between the residual, unresolved X-ray photons in a very deep X-ray survey and the positions of faint galaxies, in order to examine the importance of these objects at even fainter flux levels. We measure a significant correlation on all angular scales up to ~1 arcmin. This signal could account for a significant fraction of the unresolved X-ray background, approximately 35 per cent if the clustering is similar to optically selected galaxies. However, the angular form of the correlation is seen to be qualitatively similar to that expected for clusters of galaxies and the X-ray emission could be associated with hot gas in clusters or with QSOs within galaxy clusters rather than emission from individual faint galaxies. The relative contribution from each of these possibilities cannot be determined with the current data.Comment: 7 pages LaTeX including 9 EPS figures. Uses mn.sty. Accepted for publication by MNRA