5,310 research outputs found
User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience
A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitorsâ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further
step towards an iterative design that considers the user interaction a central point. The paper discusses
how such an environment allows designers and developers to experiment with different systemâs behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the
developments that followed that first experience: our findings seem still valid despite the passed time
Osculating spaces to secant varieties
We generalize the classical Terracini's Lemma to higher order osculating
spaces to secant varieties. As an application, we address with the so-called
Horace method the case of the -Veronese embedding of the projective 3-space
Higher secant varieties of embedded in bi-degree
Let denote the Segre-Veronese embedding of via the sections of the sheaf . We study
the dimensions of higher secant varieties of and we prove
that there is no defective secant variety, except possibly for
values of . Moreover when is multiple of , the
secant variety of has the expected dimension for
every .Comment: 8 page
Smart Conversational Agents for Reminiscence
In this paper we describe the requirements and early system design for a
smart conversational agent that can assist older adults in the reminiscence
process. The practice of reminiscence has well documented benefits for the
mental, social and emotional well-being of older adults. However, the
technology support, valuable in many different ways, is still limited in terms
of need of co-located human presence, data collection capabilities, and ability
to support sustained engagement, thus missing key opportunities to improve care
practices, facilitate social interactions, and bring the reminiscence practice
closer to those with less opportunities to engage in co-located sessions with a
(trained) companion. We discuss conversational agents and cognitive services as
the platform for building the next generation of reminiscence applications, and
introduce the concept application of a smart reminiscence agent
Rational curves on fibered Calabi-Yau manifolds
We show that a smooth projective complex manifold of dimension greater than
two endowed with an elliptic fiber space structure and with finite fundamental
group always contains a rational curve, provided its canonical bundle is
relatively trivial. As an application of this result, we prove that any
Calabi-Yau manifold that admits a fibration onto a curve whose general fibers
are abelian varieties always contains a rational curve
Evidence of anomalous dispersion of the generalized sound velocity in glasses
The dynamic structure factor, S(Q,w), of vitreous silica, has been measured
by inelastic X-ray scattering in the exchanged wavevector (Q) region Q=4-16.5
nm-1 and up to energies hw=115 meV in the Stokes side. The unprecedented
statistical accuracy in such an extended energy range allows to accurately
determine the longitudinal current spectra, and the energies of the vibrational
excitations. The simultaneous observation of two excitations in the acoustic
region, and the persistence of propagating sound waves up to Q values
comparable with the (pseudo-)Brillouin zone edge, allow to observe a positive
dispersion in the generalized sound velocity that, around Q=5 nm-1, varies from
6500 to 9000 m/s: this phenomenon was never experimentally observed in a glass.Comment: 5 pages, 3 figures. To appear in Phys. Rev.
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