A New Consumerism: The influence of social technologies on product design

Social media has enabled a new style of consumerism. Consumers are no longer passive recipients; instead they are assuming active and participatory roles in product design and production, facilitated by interaction and collaboration in virtual communities. This new participatory culture is blurring the boundaries between the specific roles of designer, consumer and producer, creating entrepreneurial opportunities for designers, and empowering consumers to influence product strategies. Evolving designer-consumer interactions are enabling an enhanced model of co-production, through a value-adding social exchange that is driving changes in consumer behaviour and influencing both product strategies and design practice. The consumer is now a knowledgeable participant, or prosumer, who can contribute to user–centered research through crowd sourcing, collaborate and co-create through open-source or open-innovation platforms, assist creative endeavors by pledging venture capital through crowd funding and advocate the product in blogs and forums. Social media- enabled product implementation strategies working in conjunction with digital production technologies (e.g. additive manufacture), enable consumer-directed adaptive customisation, product personalisation, and self-production, with once passive consumers becoming product produsers. Not only is social media driving unprecedented consumer engagement and significant behavioural change, it is emerging as a major enabler of design entrepreneurship, creating new collaborative opportunities. Innovative processes in design practice are emerging, such as the provision of digital artifacts and customisable product frameworks, rather than standardised manufactured solutions. This paper examines the influence of social media-enabled product strategies on the methodology of the next generation of product designers, and discusses the need for an educational response

Folded Strings Falling into a Black Hole

We find all the classical solutions (minimal surfaces) of open or closed strings in {\it any} two dimensional curved spacetime. As examples we consider the SL(2,R)/R two dimensional black hole, and any 4D black hole in the Schwarzschild family, provided the motion is restricted to the time-radial components. The solutions, which describe longitudinaly oscillating folded strings (radial oscillations in 4D), must be given in lattice-like patches of the worldsheet, and a transfer operation analogous to a transfer matrix determines the future evolution. Then the swallowing of a string by a black hole is analyzed. We find several new features that are not shared by particle motions. The most surprizing effect is the tunneling of the string into the bare singularity region that lies beyond the black hole that is classically forbidden to particles.Comment: 28 pages plus 4 figures, LaTeX, USC-94/HEP-B

Affiliation, equilibrium existence and the revenue ranking of auctions

We consider private value auctions where bidders’ types are dependent, a case usually treated by assuming affiliation. We show that affiliation is a restrictive assumption in three senses: topological, measure-theoretic and statistical (affiliation is a very restrictive characterization of positive dependence). We also show that affiliation’s main implications do not generalize for alternative definitions of positive dependence. From this, we propose new approaches to the problems of pure strategy equilibrium existence in first-price auctions (PSEE) and the characterization of the revenue ranking of auctions. For equilibrium existence, we slightly restrict the set of distributions considered, without loss of economic generality, and offer a complete characterization of PSEE. For revenue ranking, we obtain a characterization of the expected revenue differences between second and first price auctions with general dependence of types

Separability criteria based on the Bloch representation of density matrices

We study the separability of bipartite quantum systems in arbitrary dimensions using the Bloch representation of their density matrix. This approach enables us to find an alternative characterization of the separability problem, from which we derive a necessary condition and sufficient conditions for separability. For a certain class of states the necessary condition and a sufficient condition turn out to be equivalent, therefore yielding a necessary and sufficient condition. The proofs of the sufficient conditions are constructive, thus providing decompositions in pure product states for the states that satisfy them. We provide examples that show the ability of these conditions to detect entanglement. In particular, the necessary condition is proved to be strong enough to detect bound entangled states.Comment: 17 pages, no figures; Section 4.2 improved; final version: minor changes, added references, to appear in QI