Supporting informal communication and closeness through video snapshots

As organisations grow and the physical distance between individuals increases, the simple informal communication that is essential for creativity declines. This paper presents a prototype system that was designed to increase informal communication by restoring awareness between physically distant employees. The key representation of individuals within this prototype was through frequently updated video snapshots. Users of the system reported feeling 'closer' to each other. We also suggest further experiments to assess the effects of video snapshots on trust

Informal, desktop, audio-video communication

Audio-Video systems have been developed to support many aspects and modes of human communication, but there has been little support for the informal, ongoing nature of communication that occurs often in real life. Most existing systems implement a call metaphor. This presents a barrier to initiating conversation that has a consequent effect on the formality of the resulting conversation. By contrast, with informal communication the channel is never explicitly opened or closed. This paper examines the range of previous systems and seeks to build on these to develop plans for supporting informal communication, in a desktop environment

Africa RISING: Innovation for development highlights

Poster prepared for a share fair, Addis Ababa, May 201

Human gravity-gradient noise in interferometric gravitational-wave detectors

Among all forms of routine human activity, the one which produces the strongest gravity-gradient noise in interferometric gravitational-wave detectors (e.g. LIGO) is the beginning and end of weight transfer from one foot to the other during walking. The beginning and end of weight transfer entail sharp changes (time scale τ∼20 msec) in the horizontal jerk (first time derivative of acceleration) of a person’s center of mass. These jerk pairs, occurring about twice per second, will produce gravity-gradient noise in LIGO in the frequency band 2.5 Hz≲f≲1/(2τ)≃25 Hz with the form sqrt[Sh(f)]∼0.6×10-23 Hz-1/2(f/10 Hz)-6[∑i(ri/10 m)-6]1/2. Here the sum is over all the walking people, ri is the distance of the i’th person from the nearest interferometer test mass, and we estimate this formula to be accurate to within a factor 3. To ensure that this noise is negligible in advanced LIGO interferometers, people should be prevented from coming nearer to the test masses than r≃10 m. A r≃10 m exclusion zone will also reduce to an acceptable level gravity gradient noise from the slamming of a door and the striking of a fist against a wall. The dominant gravity-gradient noise from automobiles and other vehicles is probably that from decelerating to rest. To keep this below the sensitivity of advanced LIGO interferometers will require keeping vehicles at least 30 m from all test masses

Parton Distributions

I discuss our current understanding of parton distributions. I begin with the underlying theoretical framework, and the way in which different data sets constrain different partons, highlighting recent developments. The methods of examining the uncertainties on the distributions and those physical quantities dependent on them is analysed. Finally I look at the evidence that additional theoretical corrections beyond NLO perturbative QCD may be necessary, what type of corrections are indicated and the impact these may have on the uncertainties.Comment: Invited talk at "XXI International Symposium on Lepton and Photon Interactions at High Energies," (Fermilab, Chicago, August 2003). 12 pages, 21 figure