22 research outputs found
Dealing with mobility: Understanding access anytime, anywhere
The rapid and accelerating move towards the adoption and use of mobile technologies has increasingly provided people and organisations with the ability to work away from the office and on the move. The new ways of working afforded by these technologies are often characterised in terms of access to information and people ‘anytime, anywhere’. This paper presents a study of mobile workers that highlights different facets of access to remote people and information, and different facets of anytime, anywhere. Four key factors in mobile work are identified from the study: the role of planning, working in ‘dead time’, accessing remote technological and informational resources, and monitoring the activities of remote colleagues. By reflecting on these issues, we can better understand the role of technology and artefact use in mobile work and identify the opportunities for the development of appropriate technological solutions to support mobile workers
On Energy Distribution of Two Space-times with Planar and Cylindrical Symmetries
Considering encouraging Virbhadra's results about energy distribution of
non-static spherically symmetric metrics in Kerr-Schild class, it would be
interesting to study some space-times with other symmetries. Using different
energy-momentum complexes, i.e. M{\o}ller, Einstein, and Tolman, in static
plane-symmetric and cylindrically symmetric solutions of Einstein-Maxwell
equations in 3+1 dimensions, energy (due to matter and fields including
gravity) distribution is studied. Energy expressions are obtained finite and
well-defined. calculations show interesting coincidences between the results
obtained by Einstein and Tolamn prescriptions. Our results support the
Cooperstock hypothesis about localized energy.Comment: LaTex, 9 pages: corrected typos, added reference
Energy-momentum Distribution in Static and Non-static Cosmic String Space-times
We elaborate the problem of energy-momentum in general relativity by
energy-momentum prescriptions theory. In this regard, we calculate
M\oller,Landau-Lifshitz, Papapetrou, Einstein, Bergman, Tolman, and Weinberg's
energy-momentum complexes in static and nonstatic cosmic string space-times. We
obtain strong coincidences between the results. These coincidences can be
considered as an extension of Virbhadra's viewpoint that different
energy-momentum prescriptions may provide some basis to define a unique
quantity. In addition, our results disagree with Lessner's belief about
M\oller's prescription and support the Virbhadra's conclusion about the power
of Einstein's prescription.Comment: LaTeX, 5 page: added reference