Results 1  10
of
110
The Synthesis and Rendering of Eroded Fractal Terrains
, 1989
"... Mountain View, California 9403 In standard fractal terrain models based on fractional d Brownian motion the statistical character of the surface is, by esign, the same everywhere. A new approach to the synthesis p of fractal terrain height fields is presented which, in contrast to revious techniq ..."
Abstract

Cited by 105 (2 self)
 Add to MetaCart
Mountain View, California 9403 In standard fractal terrain models based on fractional d Brownian motion the statistical character of the surface is, by esign, the same everywhere. A new approach to the synthesis p of fractal terrain height fields is presented which, in contrast to revious techniques, features locally independent control of the f f frequencies composing the surface, and thus local control o ractal dimension and other statistical characteristics. The new f i technique, termed noise synthesis, is intermediate in difficulty o mplementation, between simple stochastic subdivision and s n Fourier filtering or generalized stochastic subdivision, and doe ot suffer the drawbacks of creases or periodicity. Varying the w local crossover scale of fractal character or the fractal dimension ith altitude or other functions yields more realistic first approxm imations to eroded landscapes. A simple physical erosion odel is then suggested which simulates hydraulic and thermal ...
Cues to deception
 Psychological Bulletin
, 2003
"... Do people behave differently when they are lying compared with when they are telling the truth? The combined results of 1,338 estimates of 158 cues to deception are reported. Results show that in some ways, liars are less forthcoming than truth tellers, and they tell less compelling tales. They also ..."
Abstract

Cited by 79 (0 self)
 Add to MetaCart
Do people behave differently when they are lying compared with when they are telling the truth? The combined results of 1,338 estimates of 158 cues to deception are reported. Results show that in some ways, liars are less forthcoming than truth tellers, and they tell less compelling tales. They also make a more negative impression and are more tense. Their stories include fewer ordinary imperfections and unusual contents. However, many behaviors showed no discernible links, or only weak links, to deceit. Cues to deception were more pronounced when people were motivated to succeed, especially when the motivations were identity relevant rather than monetary or material. Cues to deception were also stronger when lies were about transgressions. Do people behave in discernibly different ways when they are lying compared with when they are telling the truth? Practitioners and laypersons have been interested in this question for centuries (Trovillo, 1939). The scientific search for behavioral cues to deception is also longstanding and has become especially vigorous in the past few decades. In 1981, Zuckerman, DePaulo, and Rosenthal published the first
Representing word meaning and order information in a composite holographic lexicon
 Psychological Review
, 2007
"... The authors present a computational model that builds a holographic lexicon representing both word meaning and word order from unsupervised experience with natural language. The model uses simple convolution and superposition mechanisms (cf. B. B. Murdock, 1982) to learn distributed holographic repr ..."
Abstract

Cited by 57 (6 self)
 Add to MetaCart
The authors present a computational model that builds a holographic lexicon representing both word meaning and word order from unsupervised experience with natural language. The model uses simple convolution and superposition mechanisms (cf. B. B. Murdock, 1982) to learn distributed holographic representations for words. The structure of the resulting lexicon can account for empirical data from classic experiments studying semantic typicality, categorization, priming, and semantic constraint in sentence completions. Furthermore, order information can be retrieved from the holographic representations, allowing the model to account for limited word transitions without the need for builtin transition rules. The model demonstrates that a broad range of psychological data can be accounted for directly from the structure of lexical representations learned in this way, without the need for complexity to be built into either the processing mechanisms or the representations. The holographic representations are an appropriate knowledge representation to be used by higher order models of language comprehension, relieving the complexity required at the higher level.
Neural blackboard architectures of combinatorial structures in cognition
 Behavioral and Brain Sciences
, 2006
"... Human cognition is unique in the way in which it relies on combinatorial (or compositional) structures. Language provides ample evidence for the existence of combinatorial structures, but they can also be found in visual cognition. To understand the neural basis of human cognition, it is therefore e ..."
Abstract

Cited by 28 (2 self)
 Add to MetaCart
Human cognition is unique in the way in which it relies on combinatorial (or compositional) structures. Language provides ample evidence for the existence of combinatorial structures, but they can also be found in visual cognition. To understand the neural basis of human cognition, it is therefore essential to understand how combinatorial structures can be instantiated in neural terms. In his recent book on the foundations of language, Jackendoff formulated four fundamental problems for a neural instantiation of combinatorial structures: the massiveness of the binding problem, the problem of 2, the problem of variables and the transformation of combinatorial structures from working memory to longterm memory. This paper aims to show that these problems can be solved by means of neural ‘blackboard ’ architectures. For this purpose, a neural blackboard architecture for sentence structure is presented. In this architecture, neural structures that encode for words are temporarily bound in a manner that preserves the structure of the sentence. It is shown that the architecture solves the four problems presented by Jackendoff. The ability of the architecture to instantiate sentence structures is illustrated with examples of sentence complexity observed in human language performance. Similarities exist between the architecture for sentence structure and blackboard architectures for combinatorial structures in visual cognition, derived from the structure of the visual cortex. These architectures are briefly discussed, together with an example of a combinatorial structure in which the blackboard architectures for language and vision are combined. In this way, the architecture for language is grounded in perception. 2 Content
Global Level Spacings Distribution for Large Random Matrices from Classical Compact Groups: Gaussian Fluctuations
 Ann. of Math
, 1997
"... We study the levelspacings distribution for eigenvalues of large N \Theta N matrices from the Classical Compact Groups in the scaling limit when the mean distance between nearest eigenvalues equals 1. Defining by jN (s) the number of nearest neighbors spacings, greater than s ? 0 (smaller than s ? ..."
Abstract

Cited by 15 (5 self)
 Add to MetaCart
We study the levelspacings distribution for eigenvalues of large N \Theta N matrices from the Classical Compact Groups in the scaling limit when the mean distance between nearest eigenvalues equals 1. Defining by jN (s) the number of nearest neighbors spacings, greater than s ? 0 (smaller than s ? o ) we prove functional limit theorem for the process (j N (s) \Gamma IEj N (s))=N 1=2 , giving weak convergence of this distribution to some Gaussian random process on [0; 1) . The limiting Gaussian random process is universal for all Classical Compact Groups. It is Holder continuous with any exponent less than 1=2 : Numerical results suggest it not to be a standard Brownian bridge. Our methods can be also applied to study nlevel spacings distribution. AMS Subject classification : Probability theory and stochastic processes 1 Introduction and Formulation of Main Results The idea that statistical behavior of eigenvalues of large random matrices would give an information about spectra...
Methods for realistic landscape imaging
, 1993
"... There are five fundamental concerns in the synthesis of realistic imagery of fractal landscapes: 1) convincing geometric models of terrain; 2) efficient algorithms for rendering those potentiallylarge terrain models; 3) atmospheric effects, or aerial perspective, to provide a sense of scale; 4) sur ..."
Abstract

Cited by 14 (0 self)
 Add to MetaCart
There are five fundamental concerns in the synthesis of realistic imagery of fractal landscapes: 1) convincing geometric models of terrain; 2) efficient algorithms for rendering those potentiallylarge terrain models; 3) atmospheric effects, or aerial perspective, to provide a sense of scale; 4) surface textures as models of natural phenomena such as clouds, water, rock strata, and so forth, to enhance visual detail in the image beyond what can be modelled geometrically; and 5) a global context in which to situate the scenes. Results in these five areas are presented, and some aspects of the development of computer graphics as a new process and medium for the fine arts are discussed. Heterogeneous terrain models are introduced, and preliminary experiments in simulating fluvial erosion are presented to provide fractal drainage network features. For imaging detailed terrain models we describe grid tracing, a time and memoryefficient algorithm for ray tracing height fields. To obtain aerial perspective we develop geometric models of aerosol density distributions with efficient integration schemes for determining scattering and extinction, and an efficient Rayleigh scattering approximation. We also describe physicallybased models of the rainbow and mirage. Proceduralism is an underlying theme of this work; this is the practice of abstracting models of complex form and behaviors into relatively terse algorithms, which are evaluated in a lazy fashion. Procedural textures are developed as models of natural phenomena such as mountains and clouds, culminating a procedural model of an Earthlike planet which in the future may be explored interactively in a virtual reality setting.
A Dimension Space for the Design of Interactive Systems within their Physical Environments
 Physical Environments, DIS2000, 1719 August 2000, ACM Publ
, 2000
"... This paper introduces a Dimension Space describing the entities making up richly interactive systems. The Dimension Space is intended to help designers understand both the physical and virtual entities from which their systems are built, and the tradeoffs involved in both the design of the entities ..."
Abstract

Cited by 10 (4 self)
 Add to MetaCart
This paper introduces a Dimension Space describing the entities making up richly interactive systems. The Dimension Space is intended to help designers understand both the physical and virtual entities from which their systems are built, and the tradeoffs involved in both the design of the entities themselves and of the combination of these entities in a physical space. Entities are described from the point of view of a person carrying out a task at a particular time, in terms of their attention received, role, manifestation, input and output capacity and informational density. The Dimension Space is applied to two new systems developed at Grenoble, exposing design tradeoffs and design rules for richly interactive systems.