Discursive absence: the case for community radio

The case for community radio must address a range of different areas - legislation, frequencies, regulatory structures, finance, public demand and political will – which, taken together, may be regarded as the discursive field of dominant mainstream broadcasting. Without campaigning pressure there is no discursive space for a notion which challenges the established norms. The article illustrates this with the example of the British campaign for community radio which had to overcome obstacles that can still be found in many settings today. In the early 1980s British activists faced the additional problem that radio received little attention within academic media studies

Community media : field, theory, policy

The submission consists of twenty-three outputs, spanning over three decades. These range from books and chapters to reports, journal articles and edited publications. The accompanying commentary aims to set the submitted work in context, demonstrate that it constitutes a coherent whole, and that it makes an independent and original contribution to knowledge and the advancement of the academic field of community media within the discipline of media studies. A number of overlapping contexts are summarised: the socio-historical setting in which the practice of electronic community media first emerged; the ‘personal/professional’ context in which reflection on practical experience led to developments in theory and policy analysis; the academic context of the development of British media studies where at first radio was marginalised and there was no discursive space for the notion of community media, then a later stage where a wider range of theoretical contexts brought community and alternative media into the academic frame. Three main sections discuss, respectively, the candidate’s contribution to the identification and categorisation of community media, the application to it of theoretical perspectives, and the development of policy analysis. All three areas, it is argued, were part of a wider strategy aimed at bringing recognition to the field and which involved activities outside the scope of the submission (advocacy, interventions in mainstream media) but which are part of the context of the submitted work. For that reason an appendix (B) lists all the candidate’s publications on the subject, while others list conference presentations and other relevant activities. In addition, the documentation includes a brief career summary and statements by co-authors

Community media policy

The chapter examines the history of the struggle for the recognition of community media by governments across the world and presents a case study of community radio in the UK to illuminate the challenges faced by community broadcasters. He concludes by arguing for an increased role for academics in support of community media policy

Robustness of the Thirty Meter Telescope Primary Mirror Control System

The primary mirror control system for the Thirty Meter Telescope (TMT) maintains the alignment of the 492 segments in the presence of both quasi-static (gravity and thermal) and dynamic disturbances due to unsteady wind loads. The latter results in a desired control bandwidth of 1Hz at high spatial frequencies. The achievable bandwidth is limited by robustness to (i) uncertain telescope structural dynamics (control-structure interaction) and (ii) small perturbations in the ill-conditioned influence matrix that relates segment edge sensor response to actuator commands. Both of these effects are considered herein using models of TMT. The former is explored through multivariable sensitivity analysis on a reduced-order Zernike-basis representation of the structural dynamics. The interaction matrix ("A-matrix") uncertainty has been analyzed theoretically elsewhere, and is examined here for realistic amplitude perturbations due to segment and sensor installation errors, and gravity and thermal induced segment motion. The primary influence of A-matrix uncertainty is on the control of "focusmode"; this is the least observable mode, measurable only through the edge-sensor (gap-dependent) sensitivity to the dihedral angle between segments. Accurately estimating focus-mode will require updating the A-matrix as a function of the measured gap. A-matrix uncertainty also results in a higher gain-margin requirement for focus-mode, and hence the A-matrix and CSI robustness need to be understood simultaneously. Based on the robustness analysis, the desired 1 Hz bandwidth is achievable in the presence of uncertainty for all except the lowest spatial-frequency response patterns of the primary mirror

Adaptive Hexapod Simulator Motion Based on Aircraft Stability

This paper determined the feasibility of an adaptive hexapod simulator motion algorithm based on aircraft roll stability. An experiment was conducted that used a transport aircraft model in the Vertical Motion Simulator at NASA Ames Research Center. Eighteen general aviation pilots flew a heading-capture task and a stall task consecutively under four motion configurations: baseline hexapod, adaptive hexapod, optimized hexapod, and full motion. The adaptive motion was more similar to the baseline hexapod motion in the heading-capture task when the aircraft was more stable, and more similar to the optimized hexapod motion in the stall task when the aircraft was more unstable. Pilot motion ratings and task performance in the heading-capture task under the adaptive hexapod motion were more similar to baseline hexapod motion compared to optimized hexapod motion. However, motion ratings and task performance in the stall task under the adaptive motion were not significantly more similar to the optimized hexapod motion compared to baseline hexapod motion. Motion ratings and overall task performance under optimized hexapod motion as opposed to baseline hexapod motion were always more similar to the full motion condition. This paper showed that adaptive motion based on aircraft stability is feasible and can be implemented in a straightforward way. More research is required to test the adaptive motion algorithm in different tasks

Standing Swells Surveyed Showing Surprisingly Stable Solutions for the Lorenz '96 Model

The Lorenz '96 model is an adjustable dimension system of ODEs exhibiting chaotic behavior representative of dynamics observed in the Earth's atmosphere. In the present study, we characterize statistical properties of the chaotic dynamics while varying the degrees of freedom and the forcing. Tuning the dimensionality of the system, we find regions of parameter space with surprising stability in the form of standing waves traveling amongst the slow oscillators. The boundaries of these stable regions fluctuate regularly with the number of slow oscillators. These results demonstrate hidden order in the Lorenz '96 system, strengthening the evidence for its role as a hallmark representative of nonlinear dynamical behavior.Comment: 10 pages, 8 figure

A diagnosis of low-order dynamics in the atmosphere of Mars

Introduction: There is considerable evidence that shows that the Martian atmosphere behaves in a more regular fashion than its terrestrial counterpart [1, 2, 3, 4]. This evidence leads to the hypothesis of theMartian climate attractor being of a relatively low dimension, which, in turn, would imply the possibility of describing the state of the atmosphere by means of a relatively few degrees of freedom. We explore this hypothesis by assuming that the atmospheric total energy (TE), i.e. the sum of kinetic energy and total potential energy (gravitational potential energy plus internal energy), is confined in a few coherent structures which dynamically interact nonlinearly with each other