Bill Segall

Tickertape: notification and communication in a single line

Proceedings. 3rd Asia Pacific Computer Human Interaction (Cat. No.98EX110), 1998

... Engineering The University of Queensland, St Lucia 4072, Australia Phone: +61 7 3365 4310 Fax... more

Efficient Ab Initio Method for the Calculation of the Non-Linear Optical Response in Semiconductors: Application to Wide-Band-Gap Semiconductors

We present first-principles calculations of the second harmonic generation coefficient based on t... more We present first-principles calculations of the second harmonic generation coefficient based on the self-consistent Linearized Muffin-Tin Orbitals (LMTO) method. The relative simplicity of the LMTO method, which uses a rather small basis orbital set, allows one to write computer codes which can easily deal with a large number of atoms and a large number of k- points required for the

Tickertape

CHI 98 conference summary on Human factors in computing systems - CHI '98, 1998

This paper describes an awareness tool called Tickertape. Tickertape is a lightweight, highly tai... more This paper describes an awareness tool called Tickertape. Tickertape is a lightweight, highly tailorable tool that provides an interface to a world of transient information via a single-line scrolling message window. We overview Tickertape, describing both its unidirectional and bidirectional message groups and its time-out feature. We then illustrate how it is being used within one organisation.

Augmenting the Workaday World with Elvin

ECSCW’ 99, 1999

This paper addresses the problem of providing effective, computer-based support for awareness and... more

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Elvin has left the building: a publish-subscribe notification service with quenching

Decoupling the production and consumption of information in software systems facilitates extensib... more Decoupling the production and consumption of information in software systems facilitates extensibility by removing explicit dependecies between components. So called "publish/subscribe" notification architectures are comprised of undirected production, and subscription to events by their ...

Instrumenting and Augmenting the Workaday World with a Generic Notification Service called Elvin

European Conference on Computer Supported Cooperative Work, 1999

This papers addresses the problem of providing effective, computer-based support for awareness an... more This papers addresses the problem of providing effective, computer-based support for awareness and interaction in the distributed workaday world. We report the story of how our content-based, pure notifcation server, called Elvin, became widely adopted in our organisation and elsewhere, augmenting the virtual work environment, and providing perceptual resources for awareness. Examples of its uses include: support for interaction via

Discourse with Disposable Computers: How and Why You Will Talk to Your Tomatoes

by Bill Segall, Simon Kaplan, and Andy Bond

International Workshop on Embedded Systems, 1999

Beyond ubiquitous computing, is the advent of dispos- able computing, occurring when the price of... more Beyond ubiquitous computing, is the advent of dispos- able computing, occurring when the price of an embed- ded computer becomes insignificant compared to the cost of goods. Current software and network architec- tures and their associated programming paradigms will not scale to this new world. The necessity of catering for the constant change in number and type of devices of

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Content Based Routing with Elvin4

Building on experience with a general-purpose notifica- tion service, we describe the design and ... more Building on experience with a general-purpose notifica- tion service, we describe the design and implementa- tion of a second-generation content-based messaging system. Elvin4 includes a novel security framework, internationalisation, a powerful subscription language, and a modular pluggable protocol stack. We discuss its evolution from previous versions, differ- ences from related work, and describe the transition in underlying ideology from notification

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Theoretical study of the formation of closed curved graphite-like structures during annealing of diamond surface

Journal of Applied Physics, 1999

In recent high resolution transmission electron microscopic studies we have found that high tempe... more In recent high resolution transmission electron microscopic studies we have found that high temperature vacuum annealing ͑1200-1800 K͒ of ultradispersed ͑2-5 nm͒ and micron size diamond produces fullerene-like graphitic species, namely, onion-like carbon and closed curved graphite structures ͑multilayer nanotubes and nanofolds͒, respectively. Here we undertake theoretical studies to help in the understanding of the experimental data for these systems. ͑1͒ Calculations of cluster models by a standard semiempirical method ͑MNDO a software package͒ are used to explain the preferential exfoliation of ͕111͖ planes over other low index diamond planes. ͑2͒ The same approach suggests the likelihood that the graphitization is initiated by a significant thermal displacement of a single carbon atom at temperatures close to the Debye temperature. ͑3͒ At the diamond-graphite interface we have observed the formation of two curved graphitic sheets from three diamond ͕111͖ planes. We suggest that the evolution of this interface proceeds by a ''zipper''-like migration mechanism with the carbon atoms of the middle diamond layer being distributed equally between the two growing graphitic sheets. ͑4͒ The observed mosaic packaging of closed curved graphite structures during the diamond surface graphitization is suggested to be a self-assembling process. This process is explained in terms of the ''stretching'' of a bowed graphite hexagonal network. The stretch is due to the fact that, if relaxed, the network would be smaller than the initially transformed hexagonal diamond ͑111͒, and to the increased separation between the separated sheet and the surface. The initial phase of the process is studied quantitatively using a molecular mechanics simulation.

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Supporting Public Availability and Accessibility with Elvin: Experiences and Reflections

Computer Supported Cooperative Work (CSCW), 2002

We provide a retrospective account of how a generic event notification service called Elvin and a... more We provide a retrospective account of how a generic event notification service called Elvin and a suite of simple client applications: CoffeeBiff, Tickertape and Tickerchat, came to be used within our organisation to support awareness and interaction. After overviewing Elvin and its clients, we outline various experiences from data collated across two studies where Elvin and its clients have been used to augment the workaday world to support interaction, to make digital actions visible, to make physical actions available beyond the location of action, and to support content and socially based information filtering. We suggest there are both functional and technical reasons for why Elvin works for enabling awareness and interaction. Functionally, it provides a way to produce, gather and redistribute information from everyday activities (via Elvin) and to give that information a perceptible form (via the various clients) that can be publicly available and accessible as a resource for awareness. The integration of lightweight chat facilities with these information sources enables awareness to easily flow into interaction, starting to re-connect bodies to actions, and starting to approximate the easy flow of interaction that happens when we are co-located. Technically, the conceptual simplicity of the Elvin notification, the wide availability of its APIs, and the generic functionality of its clients, especially Tickertape, have made the use of the service appealing to developers and users for a wide range of uses.

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Compensation in epitaxial cubic SiC films

Applied Physics Letters, 1986

Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition o... more Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition on SiC substrates are reported. The temperature dependent carrier concentrations indicate that the samples are highly compensated. Donor ionization energies, E sub D, are less than one half the values previously reported. The values for E sub D and the donor concentration N sub D, combined with results for small bulk platelets with nitrogen donors, suggest the relation E sub D (N sub D) = E sub D(O) - alpha N sub N sup 1/3 for cubic SiC. A curve fit gives alpha is approx 2.6x10/5 meV cm and E sub D (O) approx 48 meV, which is the generally accepted value of E sub D(O) for nitrogen donors in cubic SiC.

Supporting disconnectedness-transparent information delivery for mobile and invisible computing

ccgrid, 2001

As computing devices become ubiquitous and increas-ingly mobile, it is becoming apparent that the... more

Instrumenting and augmenting the workaday world with a generic notification service called Elvin

… Work (ECSCW'99), …, 1999

We address the problem of providing effective computer-based support for awareness to promote sha... more

Augmenting the Workaday World With Elvin

ECSCW'99, 1999

This paper addresses the problem of providing effective, computer-based support for awareness and... more

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Computer supported cooperative work: The journal of collaborative computing

by Emily Patterson, S. Bandini, and Bill Segall

Computer Supported Cooperative Work (CSCW), 1996

Anderson, KM, 13 Arnold, David, 447 Bandini, Stefania, 495 Barthelmess, P., 13 Bichsel, Martin, 1... more Anderson, KM, 13 Arnold, David, 447 Bandini, Stefania, 495 Barthelmess, P., 13 Bichsel, Martin, 153 Chalmers, Matthew, 389 Clases, Christoph, 39 Collins, Patricia, 55 Fitzpatrick, Geraldine, 447 Fjeld, Morten, 153 Gaver, Bill, 475 Greenberg, Saul, 411 Gutwin, Carl, 411 Halverson, Christine A., 243 Hasu, Mervi, 129 Heath, Christian, 317 Hindmarsh, Jon, 317 Kaplan, Simon, 447 Korpela, Mikko, 111 Krueger, Helmut, 153 Lauche, Kristina, 153 Luff, Paul, 317 ... Mansfield, Tim, 447 Mark, Gloria, 349 Miettinen, Reijo, 129 Mursu, Anja, 111 ...

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