Adventures in the Not Quite Yet: using performance techniques to raise design awareness about digital networks

Technologists promise a future in which pervasive, distributed networks enable radical change to social and political geographies. Design of these abstract, intangible futures is difficult and carries a special risk of excluding people who are not equipped to appreciate the ramifications of these technological changes. The Democratising Technology (DemTech) project has been exploring how techniques from performance and live art can be used to help people engage with the potential of ubiquitous digital networks; in particular, how these techniques can be used to enfranchise people with little technical knowledge, but who nonetheless will have to live with the design consequences of technical decisions. This paper describes the iterative development of a performance workshop for use by designers and community workers. These workshops employ a series of simple exercises to emulate possible processes of technological appropriation: turning abstract digital networks into imaginable, meaningful webs. They were specifically designed to target a technologically excluded group, older people, but can also be used with other groups. We describe the process of workshop development and discuss what succeeded with our test groups and what failed. In offering our recommendations for working in this space, we consider the methodological issues of collaborating across science/art/design borders and how this impacted on evaluation. And we describe the final result: a recipe for a performance workshop, also illustrated on a DVD and associated website, which can be used to explore the dynamics of technical and social change in the context of people’s own lives and concerns. Keywords: Performance; Older People; Marginalisation; Person-Centred; Ubiquitous Digital Networks; Interdisciplinary; Technology; Future; Evaluation</p

Downlink Coverage and Rate Analysis of Low Earth Orbit Satellite Constellations Using Stochastic Geometry

As low Earth orbit (LEO) satellite communication systems are gaining increasing popularity, new theoretical methodologies are required to investigate such networks' performance at large. This is because deterministic and location-based models that have previously been applied to analyze satellite systems are typically restricted to support simulations only. In this paper, we derive analytical expressions for the downlink coverage probability and average data rate of generic LEO networks, regardless of the actual satellites' locality and their service area geometry. Our solution stems from stochastic geometry, which abstracts the generic networks into uniform binomial point processes. Applying the proposed model, we then study the performance of the networks as a function of key constellation design parameters. Finally, to fit the theoretical modeling more precisely to real deterministic constellations, we introduce the effective number of satellites as a parameter to compensate for the practical uneven distribution of satellites on different latitudes. In addition to deriving exact network performance metrics, the study reveals several guidelines for selecting the design parameters for future massive LEO constellations, e.g., the number of frequency channels and altitude.Comment: Accepted for publication in the IEEE Transactions on Communications in April 202

Evaluation of diversity gains for DVB-T systems

Copyright @ 2008 Eurescom GmbHThe requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed costeffectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of transmit and receive diversity gains with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using the Spirent dual channel emulator

A symbolic sensor for an Antilock brake system of a commercial aircraft

The design of a symbolic sensor that identifies thecondition of the runway surface (dry, wet, icy, etc.) during the braking of a commercial aircraft is discussed. The purpose of such a sensor is to generate a qualitative, real-time information about the runway surface to be integrated into a future aircraft Antilock Braking System (ABS). It can be expected that this information can significantly improve the performance of ABS. For the design of the symbolic sensor different classification techniques based upon fuzzy set theory and neural networks are proposed. To develop and to verify theses classification algorithms data recorded from recent braking tests have been used. The results show that the symbolic sensor is able to correctly identify the surface condition. Overall, the application example considered in this paper demonstrates that symbolic information processing using fuzzy logic and neural networks has the potential to provide new functions in control system design. This paper is part of a common research project between E.N.S.I.C.A. and Aerospatiale in France to study the role of the fuzzy set theory for potential applications in future aircraft control systems

Incentive Regulation in Theory and Practice: Electricity Distribution and Transmission Networks

Modern theoretical principles to govern the design of incentive regulation mechanisms are reviewed and discussed. General issues associated with applying these principles in practice are identified. Examples of the actual application of incentive regulation mechanisms to the regulation of prices and service quality for 'unbundled' transmission and distribution networks are presented and discussed. Evidence regarding the performance of incentive regulation in practice for electric distribution and transmission networks is reviewed. Issues for future research are identified.