Extending tabletops to support flexible collaborative interactions

Tabletops have been used to support a range of colocated activities, from games to image sorting. However, their limited display space and resolution can restrict the kinds of collaborative interactions that take place. Our research is concerned with how to extend the tabletop by integrating it with other spaces and artifacts in the physical world. Our goal is to design workspaces that support a wider range of collaborative tasks, determining which are well suited to the tabletop and which are better performed using physical representations and spaces. We describe a physicaldigital space that we built for this purpose and then a study that compared how groups collaborate on a design task when using this versus solely the tabletop. The findings showed that extending the tabletop into a physical space enabled groups to collaborate more easily and flexibly

Ninja: Non identity based, privacy preserving authentication for ubiquitous environments

How should Ubicomp technologies be evaluated? While lab studies are good at sensing aspects of human behavior and revealing usability problems, they are poor at capturing context of use. In-situ studies are good at demonstrating how people appropriate technologies in their intended setting, but are expensive and difficult to conduct. Here, we show how they can be used more productively in the design process. A mobile learning device was developed to support teams of students carrying out scientific inquiry in the field. An initial in-situ study showed it was not used in the way envisioned. A contextualized analysis led to a comprehensive understanding of the user experience, usability and context of use, leading to a substantial redesign. A second in-situ study showed a big improvement in device usability and collaborative learning. We discuss the findings and conclude how in-situ studies can play an important role in the design and evaluation of Ubicomp applications and user experiences

Complete Genome Sequence of the Complex Carbohydrate-Degrading Marine Bacterium, Saccharophagus degradans Strain 2-40T

The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40) is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catalytic and substrate-binding modules. We hypothesize that many of these features are adaptations that facilitate depolymerization of complex polysaccharides in the marine environment. This is the first sequenced genome of a marine bacterium that can degrade plant cell walls, an important component of the carbon cycle that is not well-characterized in the marine environment

Equal opportunities: Do shareable interfaces promote more group participation than single users displays?

Computers designed for single use are often appropriated suboptimally when used by small colocated groups working together. Our research investigates whether shareable interfaces–that are designed for more than one user to inter-act with–can facilitate more equitable participation in colocated group settings compared with single user displays. We present a conceptual framework that characterizes Shared Information Spaces (SISs) in terms of how they constrain and invite participation using different entry points. An experiment was conducted that compared three different SISs: a physical-digital set-up (least constrained), a multitouch tabletop (medium), and a laptop display (most constrained). Statistical analyses showed there to be little difference in participation levels between the three conditions other than a predictable lack of equity of control over the interface in the laptop condition. However, detailed qualitative analyses revealed more equitable participation took place in the physical-digital condition in terms of verbal utterances over time. Those who spoke the least contributed most to the physical design task. The findings are discussed in relation to the conceptual framework and, more generally, in terms of how to select, design, and combine different display technologies to support collaborative activities

An investigation of isolated bursts of solar radio noise

The literature on isolated bursts and possible mechanisms of origin has been critically reviewed, and observations point to a mechanism involving omission of electromagnetc radiation from plasma oscillations in the solar corona excited by outward travelling disturbances. Solar noise observations on 125 Mc./s. recorded at Rhodes University during the period November 26 1957 - February 6 1958 have been analysed by the author for isolated bursts, and these observations show the same general features reported by previous investigators. In interpretation of these records particular attention has been devoted to two aspects of isolated bursts; namely the preponderance on single frequency records of double-humped bursts, and the shape of isolated burst profiles. The authors suggests that a probable explanation of double-humped bursts observed on any frequency f is that the first hump represents omission at or near the level of zero refractive index for f radiation, and that the second hump corresponds to harmonic omission at the f/2 level. Source velocities may be calculated from the time delay between the peaks and an average value of 2 x 10⁴ km./sec. was obtained from an analysis of 21 double-humped bursts. This value is in very good agreement with that deduced by Wild (1950b) from the rate of frequency drift of peak intensity of isolated bursts. Simple isolated bursts had decay profiles which are approximatley exponential in shape, and this is usually interpreted in terms of the natural decay of plasma oscillations in the medium of origin. The author has verified that the exponential function is a good fit to the observed decay profiles, but shows that a relation of the form I - ¹/n (superscript) ⋉ t (where I is intensity and t is time) fits just as well. An alternative model is suggested which would lead to an exponential-like decay profile which is not determined by the natural decay of plasma oscillations. The work concludes with some suggestions for further research