Towards a real-time microscopic emissions model

This article presents a new approach to microscopic road traffic exhaust emission modelling. The model described uses data from the SCOOT demand-responsive traffic control system implemented in over 170 cities across the world. Estimates of vehicle speed and classification are made using data from inductive detector loops located on every SCOOT link. This data feeds into a microscopic traffic model to enable enhanced modelling of the driving modes of vehicles (acceleration, deceleration, idling and cruising). Estimates of carbon monoxide emissions are made by applying emission factors from an extensive literature review. A critical appraisal of the development and validation of the model is given before the model is applied to a study of the impact of high emitting vehicles. The article concludes with a discussion of the requirements for the future development and benefits of the application of such a model

The Mariner 5 flight path and its determination from tracking data

Mariner 5 flight path and its determination from tracking dat

Chapter 7 Epilogue: Systems Approaches and Systems Practice

Each of the five systems approaches discussed in this volume: system dynamics (SD), the viable systems model (VSM), strategic options development and analysis (SODA), soft systems methodology (SSM) and critical systems heuristics (CSH) has a pedigree. Not in the sense of the sometimes absurd spectacle of animals paraded at dog shows. Rather, their pedigree derives from their systems foundations, their capacity to evolve and their flexibility in use. None of the five approaches has developed out of use in restricted and controlled contexts of either low or high levels of complicatedness. Neither has any one of them evolved as a consequence of being applied only to situations with either presumed stakeholder agreement on purpose, or courteous disagreement amongst stakeholders, or stakeholder coercion. The compilation is not a celebration of abstract methodologies’, but of theoretically robust approaches that have a genuine pedigree in practice

The Quality of Life scale for Children (QoL-C)

This is the author's version of the article, which has been published in final form at http://dx.doi.org/10.1108/JCS-05-2013-0019Purpose – There is a lack of valid and reliable generic measures of Health-Related Quality of Life (HRQoL) for children under eight. The purpose of this paper is to assess the psychometric properties of the newly formulated Quality of Life Scale for Children (QoL-C), which uses a pictorial response format. Design/methodology/approach – In total, 335 primary school children completed the QoL-C on two occasions, two weeks apart. Children aged four to seven were interviewed one-to-one while children aged eight to nine completed the measure as a class activity. Test-re-test reliability, convergent validity and child-parent concordance were assessed. Findings – Only one child refused to complete the QoL-C, which suggests the measure is user-friendly. Test-re-test reliability was moderate for the measure's total score (intraclass correlation coefficient =0.48, 95 percent CI 0.39, 0.57) but low to fair for individual items (K from 0.13 to 0.37). Internal consistency was moderate (α=0.42 time one, 0.53 time two). A small significant correlation was found between the QoL-C and Child Health Meter in the expected direction (r=−0.32), suggesting convergent validity. There was low concordance between the children's QoL-C responses and parent's responses (r=0.19) to a parallel measure. Research limitations/implications – The results suggest that further development of this measure is needed. However, the findings indicate that one-to-one support increases the reliability of very young children's responses. The use of pictures, emoticons and minimal text used in the QoL-C should be investigated further. Originality/value – Low parent-child concordance underscores the importance of younger children getting the opportunity to share their views about their HRQoL

A new bound on axion-like particles

Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in the spectra of astrophysical sources. We use deep (370 ks), short frame time Chandra observations of the bright nucleus at the centre of the radio galaxy M87 in the Virgo cluster to search for signatures of light ALPs. The absence of substantial irregularities in the X-ray power-law spectrum leads to a new upper limit on the photon-ALP coupling, $g_{a\gamma}$: using a conservative model of the cluster magnetic field consistent with Faraday rotation measurements from M87 and M84, we find $g_{a \gamma} < 2.6\times10^{-12}$ GeV$^{-1}$ at 95% confidence level for ALP masses $m_a \leq 10^{-13}$ eV. Other consistent magnetic field models lead to stronger limits of $g_{a \gamma} \lesssim 1.1$--$1.5 \times 10^{-12}$ GeV$^{-1}$. These bounds are all stronger than the limit inferred from the absence of a gamma-ray burst from SN1987A, and rule out a substantial fraction of the parameter space accessible to future experiments such as ALPS-II and IAXO

Epilogue: systems approaches and systems practice

Each of the five systems approaches discussed in this volume: system dynamics (SD), the viable systems model (VSM), strategic options development and analysis (SODA), soft systems methodology (SSM) and critical systems heuristics (CSH) has a pedigree. Not in the sense of the sometimes absurd spectacle of animals paraded at dog shows. Rather, their pedigree derives from their systems foundations, their capacity to evolve and their flexibility in use. None of the five approaches has developed out of use in restricted and controlled contexts of either low or high levels of complicatedness. Neither has any one of them evolved as a consequence of being applied only to situations with either presumed stakeholder agreement on purpose, or courteous disagreement amongst stakeholders, or stakeholder coercion. The compilation is not a celebration of abstract ‘methodologies’, but of theoretically robust approaches that have a genuine pedigree in practice

A direct image of the obscuring disk surrounding an active galactic nucleus

Active galactic nuclei (AGN) are generally accepted to be powered by the release of gravitational energy in a compact accretion disk surrounding a massive black hole. Such disks are also necessary to collimate powerful radio jets seen in some AGN. The unifying classification schemes for AGN further propose that differences in their appearance can be attributed to the opacity of the accreting material, which may obstruct our view of the central region of some systems. The popular model for the obscuring medium is a parsec-scale disk of dense molecular gas, although evidence for such disks has been mostly indirect, as their angular size is much smaller than the resolution of conventional telescopes. Here we report the first direct images of a pc-scale disk of ionised gas within the nucleus of NGC 1068, the archetype of obscured AGN. The disk is viewed nearly edge-on, and individual clouds within the ionised disk are opaque to high-energy radiation, consistent with the unifying classification scheme. In projection, the disk and AGN axes align, from which we infer that the ionised gas disk traces the outer regions of the long-sought inner accretion disk.Comment: 14 pages, LaTeX, PSfig, to appear in Nature. also available at http://hethp.mpe-garching.mpg.de/Preprint

Ch. 6. Critical Systems Heuristics: The Idea and Practice of Boundary Critique

Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This chapter, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation’ versus ‘system’, ‘is’ versus ‘ought’ judgements, concerns of ‘those involved’ versus ‘those affected but not involved’, stakeholders’ ‘stakes’ versus ‘stakeholding issues’, and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique

Critical systems heuristics

Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This paper, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation’ versus ‘system’, ‘is’ versus ‘ought’ judgements, concerns of ‘those involved’ versus ‘those affected but not involved’, stakeholders’ ‘stakes’ versus ‘stakeholding issues’, and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique. Parts of the account of the NRUA-Botswana study in Section 6.2 of the present paper are reproduced from an earlier publication by one of the authors (Reynolds 2007); we are grateful to the publishers of Edge Press, Point Reyes, CA, for granting us permission to reproduce this material. We do not need the systems concept at all if we are not interested in handling systems boundaries critically