Representing older people: towards meaningful images of the user in design scenarios

Designing for older people requires the consideration of a range of difficult and sometimes highly personal design problems. Issues such as fear, loneliness, dependency, and physical decline may be difficult to observe or discuss in interviews. Pastiche scenarios and pastiche personae are techniques that employ characters to create a space for the discussion of new technological developments and as a means to explore user experience. This paper argues that the use of such characters can help to overcome restrictive notions of older people by disrupting designers' prior assumptions. In this paper, we reflect on our experiences using pastiche techniques in two separate technology design projects that sought to address the needs of older people. In the first case pastiche scenarios were developed by the designers of the system and used as discussion documents with users. In the second case, pastiche personae were used by groups of users themselves to generate scenarios which were scribed for later use by the design team. We explore how the use of fictional characters and settings can generate new ideas and undermine rhetorical devices within scenarios that attempt to fit characters to the technology, rather than vice versa. To assist in future development of pastiche techniques in designing for older people, we provide an array of fictional older characters drawn from literary and popular culture.</p

Ten misconceptions about minimalism

We describe ten common misconceptions about the minimalist approach to documentation design. For each, we analyze how the misconception arises from plausible interpretations of minimalist principles and heuristics. We then clarify how each misconception deviates from minimalism, as we understand it. Analysis and discussion of creative elaborations of minimalism-including "misconceptions"-can promote a sharper concept of what minimalism is

Failure of Gauge Invariance in the Nonperturbative Formulation of Massless Lorentz-Violating QED

We consider a Lorentz-violating modification to the fermionic Lagrangian of QED that is known to produce a finite Chern-Simons term at leading order. We compute the second order correction to the one-loop photon self-energy in the massless case using an exact propagator and a nonperturbative formulation of the theory. This nonperturbative theory assigns a definite value to the coefficient of the induced Chern-Simons term; however, we find that the theory fails to preserve gauge invariance at higher orders. We conclude that the specific nonperturbative value of the Chern-Simons coefficient has no special significance.Comment: 8 pages, very minor change

Dynamical solutions of warped six dimensional supergravity

We derive a new class of exact time dependent solutions in a warped six dimensional supergravity model. Under the assumptions we make for the form of the underlying moduli fields, we show that the only consistent time dependent solutions lead to all six dimensions evolving in time, implying the eventual decompactification or collapse of the extra dimensions. We also show how the dynamics affects the quantization of the deficit angle.Comment: 18 pages, no figure, typos corrected, references added, the final versio

Sharing the Office, Sharing the Care? Designing for Digitally-mediated Collaborative Childcare in the Workplace

open3This paper presents findings from a participatory design process for a collaborative childcare service based on co-worker participation and supported by a digital sharing platform. We conducted semi-structured interviews, focus groups and co-design workshops with 41 employees and HR managers of six knowledge organizations. We investigated their views on participative forms of welfare, the factors that can sustain or hinder collaboration among co-workers and the role technology can play in sustaining these practices. The findings shed light on perceived values and potential barriers of social and organizational arrangements as well as the mediating role of interpersonal trust, social exchange and reciprocity. Furthermore, the results provide insights on how digital platforms can support orchestration and management of collaborative practices grounded on employee participation and on the interplay between work and family life spheres.openLeonardi, Chiara; Schiavo, Gianluca; Zancanaro, MassimoLeonardi, Chiara; Schiavo, Gianluca; Zancanaro, Massim

Kerr/CFT Correspondence in the Low Energy Limit of Heterotic String Theory

We investigate the recently proposed Kerr/CFT correspondence in the context of heterotic string theory. The Kerr/CFT correspondence states that the near-horizon states of an extremal four (or higher) dimensional black hole could be identified with a certain chiral conformal field theory under the conjecture that the central charges from the non-gravitational fields vanish. The corresponding Virasoro algebra is generated by a class of diffeomorphisms which preserves the appropriate boundary conditions on the near-horizon geometry. To understand the chiral conformal field theory, we consider the class of extremal Kerr-Sen black hole (that contains three non-gravitational fields) as a class of solutions in the low energy limit (effective field theory) of heterotic string theory. We derive the expression of the conserved charges for the extremal Kerr-Sen solutions that contain dilaton, abelian gauge filed and antisymmetric tensor filed. We confirm and extend the validity of the conjecture (that the central charges from the non-gravitational fields vanish) for theories including antisymmetric tensor fields. We combine the calculated central charges with the expected form of the temperature using the Cardy formula to obtain the entropy of the extremal black hole microscopically; in agreement with the macroscopic Bekenstein-Hawking entropy of the extremal black hole.Comment: 14 pages, a few sentences added to the introduction, version to appear in JHE

Illusory Decoherence

If a quantum experiment includes random processes, then the results of repeated measurements can appear consistent with irreversible decoherence even if the system's evolution prior to measurement was reversible and unitary. Two thought experiments are constructed as examples.Comment: 10 pages, 3 figure

The General Warped Solution with Conical Branes in Six-dimensional Supergravity

We present the general regular warped solution with 4D Minkowski spacetime in six-dimensional gauged supergravity. In this framework, we can easily embed multiple conical branes into the warped geometry by choosing an undetermined holomorphic function. As an example, for the holomorphic function with many zeroes, we find warped solutions with multi-branes and discuss the generalized flux quantization in this case.Comment: 1+19 pages, no figure, JHEP style, version to appear in JHE

Chern-Simons like term generation in an extended model of QED under external conditions

The possibility of a Chern-Simons like term generation in an extended model of QED, in which a Lorentz and CPT non-covariant interaction term for fermions is present, has been investigated at finite temperature and in the presence of a background color magnetic field. To this end, the photon polarization operator in an external constant axial-vector field has been considered. One-loop contributions to its antisymmetric component due to fermions in the linear order of the axial-vector field have been obtained. Moreover, the first nontrivial correction to the induced CS term due to the presence of a weak constant homogeneous color magnetic field has been derived.Comment: RevTex, 10 pages with 3 figure