86,539 research outputs found
A fibered power theorem for pairs of log general type
Let f: (X, D)→B be a stable family with log canonical general fiber. We prove that, after a birational modification of the base B → B, there is a morphism from a high fibered power of the family to a pair of log general type. If in addition the general fiber is openly canonical, then there is a morphism from a high fibered power of the original family to a pair openly of log general type
On the foundation of monopoly in bilateral exchange
We address the problem of monopoly in general equilibrium in a mixed version of a monopolistic two-commodity exchange economy where the monopolist, represented as an atom, is endowed with one commodity and “small traders,” represented by an atomless part, are endowed only with the other. First we provide an economic theoretical foundation of the monopoly solution in this bilateral framework through a formalization of an explicit trading process inspired by Pareto (Cours d’économie politique. F. Rouge Editeur, Lausanne, 1896) for an exchange economy with a finite number of commodities, and we give the conditions under which our monopoly solution has the geometric characterization proposed by Schydlowsky and Siamwalla (Q J Econ 80:147–153, 1966). Then, we provide a game theoretical foundation of our monopoly solution through a two-stage reformulation of our model. This allows us to prove that the set of the allocations corresponding to a monopoly equilibrium and the set of the allocations corresponding to a subgame perfect equilibrium of the two-stage game coincide. Finally, we compare our model of monopoly with a bilateral exchange version of a pioneering model proposed by Forchheimer (Jahrbuch für Gesetzgebung, Verwaltung und Volkswirschafts im Deutschen Reich 32:1–12, 1908), known as a model of “partial monopoly” since there a monopolist shares a market with a“competitive fringe.” Journal of Economic Literature Classification Numbers: D42, D51
Localization of self-generated synthetic footstep sounds on different walked-upon materials through headphones
This paper focuses on the localization of footstep sounds interactively generated during walking and provided through headphones. Three distinct experiments were conducted in a laboratory involving a pair of sandals enhanced with pressure sensors and a footstep synthesizer capable of simulating two typologies of surface materials: solid (e.g., wood) and aggregate (e.g., gravel). Different sound delivery methods (mono, stereo, binaural) as well as several surface materials, in the presence or absence of concurrent contextual auditory information provided as soundscapes, were evaluated in a vertical localization task. Results showed that solid surfaces were localized significantly farther from the walker’s feet than the aggregate ones. This effect was independent of the used rendering technique, of the presence of soundscapes, and of merely temporal or spectral attributes of sound. The effect is hypothesized to be due to a semantic conflict between auditory and haptic information such that the higher the semantic incongruence the greater the distance of the perceived sound source from the feet. The presented results contribute to the development of further knowledge toward a basis for the design of continuous multimodal feedback in virtual reality applications
Quantum GestART: identifying and applying correlations between mathematics, art, and perceptual organization
Mathematics can help analyze the arts and inspire new artwork. Mathematics can also help make transformations from one artistic medium to another, considering exceptions and choices, as well as artists' individual and unique contributions. We propose a method based on diagrammatic thinking and quantum formalism. We exploit decompositions of complex forms into a set of simple shapes, discretization of complex images, and Dirac notation, imagining a world of “prototypes” that can be connected to obtain a fine or coarse-graining approximation of a given visual image. Visual prototypes are exchanged with auditory ones, and the information (position, size) characterizing visual prototypes is connected with the information (onset, duration, loudness, pitch range) characterizing auditory prototypes. The topic is contextualized within a philosophical debate (discreteness and comparison of apparently unrelated objects), it develops through mathematical formalism, and it leads to programming, to spark interdisciplinary thinking and ignite creativity within STEAM
Towards a Semantic Architecture for the Internet of Musical Things
The Internet of Musical Things is an emerging research area that relates to the network of Musical Things, which are computing devices embedded in physical objects dedicated to the production and/or reception of musical content. In this paper we propose a semantically-enriched Internet of Musical Things architecture which relies on a semantic audio server and edge computing techniques. Specifically, a SPARQL Event Processing Architecture is employed as an interoperability enabler allowing multiple heterogeneous Musical Things to cooperate, relying on a music-related ontology. We technically validate our architecture by implementing an ecosystem around it, where five Musical Thing prototypes communicate between each other
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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