Search results for "Global structure"

Perceiving musical tension in long chord sequences

1999

We attempted to predict perceived musical tension in longer chord sequences by hierarchic and sequential models based on Lerdahl and Jackendoff's and Lerdahl's cognitive theories and on Parncutt's sensory-psychoacoustical theory. Musicians and nonmusicians were asked to rate the perceived tension of chords which were drawn either from a piece composed for the study (Exp. 1) or from a Chopin Prelude (Exps. 2-4). In Exps. 3 and 4, several experimental manipulations were made to emphasize either the global or the local structure of the piece and to verify how these manipultions would affect the respective contribution of the models in the ratings. In all experiments, musical tension was only w…

Does Formal Musical Structure Affect Perception of Musical Expressiveness?

1996

The aim of the study was to assess the effect of systematic modifications in global musical structures on perceived expressiveness. Recorded performances of piano pieces of Bach, Mozart and Schonberg were segmented into short chunks of six seconds in average. These chunks were linked either in a forward order (Original version) or in a backward order (Inverted version). In the inverted version, the formal global structure of the pieces was destroyed, but the superficial features and the local structures inside the chunks were unaltered. Forty non-musician subjects were required to rate the musical expressiveness of these pieces on 29 semantic scales. Half listened to the three original ver…

Influence of Global Structure on Musical Target Detection and Recognition

1998

The present study adapted a paradigm used in visual perception by Biederman, Glass, and Stacy (1973) and analyzed the influence of a coherent global context on the detection and recognition of musical target excerpts. Global coherence was modified by segmenting minuets into chunks of four, two, or one bar. These chunks were either reordered (Experiments 1, 3, 4, 5) or transposed to different keys (Experiment 2). The results indicate that target detection is influenced only by a reorganization on a very local level (i.e. chunks of one bar). Context incoherence did not influence the recognition of the real targets, but rendered the rejection of wrong target excerpts (foils) more difficult. Th…

Supersymmetric Indices of 3d S-fold SCFTs

2019

Enhancement of global symmetry and supersymmetry in the infrared is one of the most intriguing phenomena in quantum field theory. We investigate such phenomena in a large class of three dimensional superconformal field theories, known as the S-fold SCFTs. Supersymmetric indices are computed for a number of theories containing small rank gauge groups. It is found that indices of several models exhibit enhancement of supersymmetry at the superconformal fixed point in the infrared. Dualities between S-fold theories that have different quiver descriptions are also analysed. We explore a new class of theories with a discrete global symmetry, whose gauge symmetry in the quiver has a different glo…

RESOLVING AMBIGUITIES IN ORIENTATION, MOTION, AND DEPTH DOMAINS

1992

Three different perceptual systems—orientation, motion, and depth—can recover a global perceptual organization from spatially correlated random multielement patterns. In all three cases the global structure composed of random elements is evaluated by mechanisms performing measurements in the energy domain within appropriately defined local space—time areas. The selective increase in energy of one fraction of the elements may dramatically change the whole perceptual organization of the stimulus. In specially devised patterns one and the same element can belong to two or more separate perceptual organizations, the perceptual salience of one of which can be reinforced by a luminance increment…

Understanding the global structure of two-level quantum systems with relaxation: Vector fields organized through the magic plane and the steady-state…

2013

A scenario for critical scalar field collapse in $AdS_3$

2014

We present a family of exact solutions, depending on two parameters $\alpha$ and $b$ (related to the scalar field strength), to the three-dimensional Einstein-scalar field equations with negative cosmological constant $\Lambda$. For $b=0$ these solutions reduce to the static BTZ family of vacuum solutions, with mass $M = -\alpha$. For $b\neq0$, the solutions become dynamical and develop a strong spacelike central singularity. The $\alpha0$ agrees qualitatively with that observed in numerical simulations of subcritical collapse. We analyze the linear perturbations of the threshold solution, $\alpha=0$, in the $\Lambda=0$ approximation, and find that it has only one unstable growing mode, whi…