Dasher - A data entry interface using continuous gestures and language models

Existing devices for communicating information to computers are bulky, slow to use, or unreliable. Dasher is a new interface incorporating language modelling and driven by continuous two-dimensional gestures, e.g. a mouse, touchscreen, or eye-tracker. Tests have shown that this device can be used to enter text at a rate of up to 34 words per minute, compared with typical ten-finger keyboard typing of 40-60 words per minute. Although the interface is slower than a conventional keyboard, it is small and simple, and could be used on personal data assistants and by motion-impaired computer users.

Jet diameters and velocity profiles in continuous ink-jets

Theoretical predictions of the diameters of continuous ink-jets downstream of long nozzles are generalized to include the important cases of ink-jet fluids and shorter nozzles where the velocity profile at the nozzle exit is undeveloped (non-parabolic). Comparisons of the new predictions with experiments and simulations are made for fairly long nozzles with tapered profiles and short nozzles with conical profiles; experimental and simulated profiles are also compared downstream of the nozzle exit for both industrial and large scale ink-jet print heads. Precise measurements of the un-modulated jet diameters downstream of the nozzle exit can set really useful limits to the possible shapes of the flow profile right at the nozzle exit, and in particular allow some assessment of the axial velocity gradients and fluid shear rates at the nozzle exit where direct speed measurement is usually impractical. Simulations allow further study of the relaxation of the velocity profile downstream of the nozzle exit, and are reported for both un-modulated and modulated CIJ jetting. Implications of this work include speeding up CIJ simulations, absolute calibration of the applied CIJ system modulation, and the likely magnitude of dynamic surface tension effects on observed CIJ satellite speeds.