Basic avionics module design for general aviation aircraft

The design of an advanced digital avionics system (basic avionics module) for general aviation aircraft operated with a single pilot under IFR conditions is described. The microprocessor based system provided all avionic functions, including flight management, navigation, and lateral flight control. The mode selection was interactive with the pilot. The system used a navigation map data base to provide operation in the current and planned air traffic control environment. The system design included software design listings for some of the required modules. The distributed microcomputer uses the IEEE 488 bus for interconnecting the microcomputer and sensors

Evaluation of Tweedie exponential dispersion model densities by Fourier inversion

The Tweedie family of distributions is a family of exponential dispersion models with power variance functions V (μ) = μ^p for p not between (0, 1). These distributions do not generally have density functions that can be written in closed form. However, they have simple moment generating functions, so the densities can be evaluated numerically by Fourier inversion of the characteristic functions. This paper develops numerical methods to make this inversion fast and accurate. Acceleration techniques are used to handle oscillating integrands. A range of analytic results are used to ensure convergent computations and to reduce the complexity of the parameter space. The Fourier inversion method is compared to a series evaluation method and the two methods are found to be complementary in that they perform well in different regions of the parameter space

The monic integer transfinite diameter

We study the problem of finding nonconstant monic integer polynomials, normalized by their degree, with small supremum on an interval I. The monic integer transfinite diameter t_M(I) is defined as the infimum of all such supremums. We show that if I has length 1 then t_M(I) = 1/2. We make three general conjectures relating to the value of t_M(I) for intervals I of length less that 4. We also conjecture a value for t_M([0, b]) where 0 < b < 1. We give some partial results, as well as computational evidence, to support these conjectures. We define two functions that measure properties of the lengths of intervals I with t_M(I) on either side of t. Upper and lower bounds are given for these functions. We also consider the problem of determining t_M(I) when I is a Farey interval. We prove that a conjecture of Borwein, Pinner and Pritsker concerning this value is true for an infinite family of Farey intervals.Comment: 32 pages, 5 figure

Research into learning and teaching in higher education: underground and undervalued?

Previous studies have drawn attention to the challenges faced by researchers undertaking research into learning and teaching in higher education. These challenges are particularly highlighted at times of national measurement of research excellence. It is against the context of the UK Research Excellence Framework (REF), that this paper presents findings from a recent survey of research into higher education in Scottish Higher Education Institutions. Discussion focuses on the underground and undervalued nature of some of this research. Researchers are often based within disciplines and their research is not always well known within wider higher education research discourse. Many academics face pressure to prioritise publishing within their main discipline over publishing research into higher education. There is also a lack of capacity within some Scottish institutions to return research into higher education within the forthcoming REF exercise. The wider implications of these findings are then examined

Higher Education Research in Scotland: Report of a Survey Undertaken by Universities Scotland Educational Development Sub-Committee

The aim of this study was to gain an insight into a range of higher educational research taking place across Scotland with a particular focus on the nature, expertise, support and dissemination of this research. For the purposes of this study, we used the term ‘research into higher education’ to refer to a range of higher educational research activity that included: research into higher education policies and practice, pedagogical research, research into learning and teaching taking place in higher education and research about transition from further education or school into higher education. The findings point to the underground nature of pedagogic research taking place in Scotland. Many researchers are based within disciplines and their pedagogic research is disseminated in a variety of settings that do not always make it easily accessible within generic higher education research discourse. Pedagogic research is also apparently undervalued, with many academic staff experiencing pressure to prioritise publishing within their main discipline over and above pedagogic research. In addition there appears to be a lack of capacity within Scottish institutions to maximise the profile of higher educational research in the forthcoming UK Research Excellence Framework (REF) exercise

A high-speed distortionless predictive image-compression scheme

A high-speed distortionless predictive image-compression scheme that is based on differential pulse code modulation output modeling combined with efficient source-code design is introduced. Experimental results show that this scheme achieves compression that is very close to the difference entropy of the source

A note on modelling cross correlations: hyperbolic secant regression

The problem of determining if a bivariate normal correlation changes with respect to time or some other covariate is considered. It is assumed that the means and standard deviations of the normal random variables can be consistently estimated from the entire data run, and do not need to be re-estimated for each covariate value. A new estimator of a bivariate normal correlation is given that has useful performance down to samples of size one. This allows regression type modelling of the correlation without unnecessary loss of resolution. The arc-tanh transformation of this estimator has a symmetric Fisher’s z-distribution about the arc-tanh correlation. A method of smoothing the correlation estimates is given using moving average smoothers of the sufficient statistics from which the correlation estimator is calculated