A kepstrum approach to filtering, smoothing and prediction

The kepstrum (or complex cepstrum) method is revisited and applied to the problem of spectral factorization where the spectrum is directly estimated from observations. The solution to this problem in turn leads to a new approach to optimal filtering, smoothing and prediction using the Wiener theory. Unlike previous approaches to adaptive and self-tuning filtering, the technique, when implemented, does not require a priori information on the type or order of the signal generating model. And unlike other approaches - with the exception of spectral subtraction - no state-space or polynomial model is necessary. In this first paper results are restricted to stationary signal and additive white noise

Supporting active database learning and training through interactive multimedia

The learning objectives of a database course include aspects from conceptual and theoretical knowledge to practical development and implementation skills. We present an interactive educational multimedia system based on the virtual apprenticeship model for the knowledge- and skills-oriented Web-based education of database course students. Combining knowledge learning and skills training in an integrated environment is a central aspect of our system. We show that tool-mediated independent learning and training in an authentic setting is an alternative to traditional classroom-based approaches

Comment on 'The Value of Cost Benefit Analysis of Road Projects'. Quarterly Economic Commentary Special Article, April 1985

In accepting the invitation by the editors of the Quarterly Economic Commentary to comment on Mr. Mansergh's paper it is hoped to show that his fears about cost benefit analysis and its use are unjustified. His paper proposes two important changes in cost benefit analysis. These are the treatment of labour costs as benefits and taxes as a resource rather than as a transfer payment. Labour is treated as a cost in cost benefit .. analysis because the supply price of labour is positve. Workers require a positive sum in exchange for their labour. Cost benefit analysis measures the benefits and costs to society as a whole from projects. The level of a project's benefits over its costs is the critical factor in evaluating the project. The division of the benefits between those accruing in tax revenues and elsewhere in the economy distributes the net benefits of the project. It neither increases nor reduces the level of net benefits from the, project. Transfer payments, such as taxes, are therefore excluded from cost benefit analysis. The proposed changes add two categories of benefit, labour costs and tax revenues, and delete one cost, labour. These changes would raise the rate of return on projects now rejected. They are thus inconsistent with the paper's recommendation that "a more rational result might be a reduction in the national enthusiasm for investment"..

Petrologic and oxygen-isotopic investigations of eucritic and anomalous mafic achondrites

The most common asteroidal igneous meteorites are eucrite-type basalts and gabbros rocks composed of ferroan pigeonite and augite, calcic plagioclase, silica, ilmenite, troilite, Ca-phosphate, chromite and Fe-metal. These rocks are thought to have formed on a single asteroid along with howardites and diogenites (HEDs). However, Northwest Africa (NWA) 011 is mineralogically identical to eucrites, but has an O-isotopic composition distinct from them and was derived from a different asteroid. Modern analyses with higher precision have shown that some eucrites have smaller O-isotopic differences that are nevertheless well-resolved from the group mean

The Naas Motorway Bypass - A Cost Benefit Analysis. Quarterly Economic Commentary Special Article, January 1984

The paper examines the Naas Motorway Bypass which cost £16m at 1983 prices. Twelve thousand vehicles a day using the bypass save over 10 minutes between 8 am and 8 pm and 6 minutes at other times. Five thousand vehicles a day using the present route through Naas also benefit by saving 4 minutes due to reduced congestion in the town. In addition to time savings, the bypass reduces accidents and fuel costs. Ninety-one per cent of the benefits accrue in time savings. The internal rate of return on the project is estimated at 20.51 per cent, assuming 2 per cent annual traffic and income growth. The sensitivity tests of the results show that even with zero growth in incomes and traffic for twenty years, a high proportion of leisure time savings with zero value and no increase in the value of fuel savings the project would have an internal rate of return which meets the test discount rate used by the Department of Finance. The environmental aspects of the bypass are positive in terms of noise and smoke and lead pollution reduction. The impact on farm severence and natural amenities on the motorway route has been mitigated by several design features of the bypass

Monogamy of Correlations vs. Monogamy of Entanglement

A fruitful way of studying physical theories is via the question whether the possible physical states and different kinds of correlations in each theory can be shared to different parties. Over the past few years it has become clear that both quantum entanglement and non-locality (i.e., correlations that violate Bell-type inequalities) have limited shareability properties and can sometimes even be monogamous. We give a self-contained review of these results as well as present new results on the shareability of different kinds of correlations, including local, quantum and no-signalling correlations. This includes an alternative simpler proof of the Toner-Verstraete monogamy inequality for quantum correlations, as well as a strengthening thereof. Further, the relationship between sharing non-local quantum correlations and sharing mixed entangled states is investigated, and already for the simplest case of bi-partite correlations and qubits this is shown to be non-trivial. Also, a recently proposed new interpretation of Bell's theorem by Schumacher in terms of shareability of correlations is critically assessed. Finally, the relevance of monogamy of non-local correlations for secure quantum key distribution is pointed out, although, and importantly, it is stressed that not all non-local correlations are monogamous.Comment: 12 pages, 2 figures. Invited submission to a special issue of Quantum Information Processing. v2: Published version. Open acces

Ovarian hormones induce de novo DNA methyltransferase expression in the Siberian hamster suprachiasmatic nucleus

Experiments investigated neuroanatomically localized changes in de novo DNA methyltransferase expression in the female Siberian hamster (Phodopus sungorus). The objectives were to identify the neuroendocrine substrates that exhibit rhythmic Dnmt3a and Dnmt3b expression across the oestrous cycle and examine the role of ovarian steroids. Hypothalamic Dnmt3a expression was observed to significantly increase during the transition from proestrous to oestrous. A single bolus injection of diethylstilbestrol (DES) and progesterone was sufficient to increase Dnmt3a cell numbers and Dnmt3b immunoreactive intensity in the suprachiasmatic nucleus (SCN). In vitro analyses using an embryonic rodent cell line revealed that DES was sufficient to induce Dnmt3b expression. Upregulating DNA methylation in vitro reduced expression of vasoactive intestinal polypeptide, Vip, and the circadian clock gene, Bmal1. Together, these data indicate that ovarian steroids drive de novo DNA methyltransferase expression in the mammalian suprachiasmatic nucleus and increased methylation may regulate genes involved in the circadian timing of oestrous: Vip and Bmal1. Overall, epigenetically mediated neuroendocrine reproductive events may reflect an evolutionarily ancient process involved in the timing of female fertility

Causality - Complexity - Consistency: Can Space-Time Be Based on Logic and Computation?

The difficulty of explaining non-local correlations in a fixed causal structure sheds new light on the old debate on whether space and time are to be seen as fundamental. Refraining from assuming space-time as given a priori has a number of consequences. First, the usual definitions of randomness depend on a causal structure and turn meaningless. So motivated, we propose an intrinsic, physically motivated measure for the randomness of a string of bits: its length minus its normalized work value, a quantity we closely relate to its Kolmogorov complexity (the length of the shortest program making a universal Turing machine output this string). We test this alternative concept of randomness for the example of non-local correlations, and we end up with a reasoning that leads to similar conclusions as in, but is conceptually more direct than, the probabilistic view since only the outcomes of measurements that can actually all be carried out together are put into relation to each other. In the same context-free spirit, we connect the logical reversibility of an evolution to the second law of thermodynamics and the arrow of time. Refining this, we end up with a speculation on the emergence of a space-time structure on bit strings in terms of data-compressibility relations. Finally, we show that logical consistency, by which we replace the abandoned causality, it strictly weaker a constraint than the latter in the multi-party case.Comment: 17 pages, 16 figures, small correction

Action research in physical education: focusing beyond myself through cooperative learning

This paper reports on the pedagogical changes that I experienced as a teacher engaged in an action research project in which I designed and implemented an indirect, developmentally appropriate and child‐centred approach to my teaching. There have been repeated calls to expunge – or at least rationalise – the use of traditional, teacher‐led practice in physical education. Yet despite the advocacy of many leading academics there is little evidence that such a change of approach is occurring. In my role as teacher‐as‐researcher I sought to implement a new pedagogical approach, in the form of cooperative learning, and bring about a positive change in the form of enhanced pupil learning. Data collection included a reflective journal, post‐teaching reflective analysis, pupil questionnaires, student interviews, document analysis, and non‐participant observations. The research team analysed the data using inductive analysis and constant comparison. Six themes emerged from the data: teaching and learning, reflections on cooperation, performance, time, teacher change, and social interaction. The paper argues that cooperative learning allowed me to place social and academic learning goals on an even footing, which in turn placed a focus on pupils’ understanding and improvement of skills in athletics alongside their interpersonal development