14,491 research outputs found
Replicode: A Constructivist Programming Paradigm and Language
Replicode is a language designed to encode short parallel programs and executable models, and is centered on the notions of extensive pattern-matching and dynamic code production.
The language is domain independent and has been designed to build systems that are modelbased and model-driven, as production systems that can modify their own code. More over, Replicode supports the distribution of knowledge and computation across clusters of computing nodes.
This document describes Replicode and its executive, i.e. the system that executes Replicode constructions. The Replicode executive is meant to run on Linux 64 bits and Windows 7 32/64 bits platforms and interoperate with custom C++ code.
The motivations for the Replicode language, the constructivist paradigm it rests on, and the higher-level AI goals targeted by its construction, are described by Thórisson (2012), Nivel and Thórisson (2009), and Thórisson and Nivel (2009a, 2009b).
An overview presents the main concepts of the language. Section 3 describes the general structure of Replicode objects and describes pattern matching. Section 4 describes the execution model of Replicode and section 5 describes how computation and knowledge are structured and controlled. Section 6 describes the high-level reasoning facilities offered by the system. Finally, section 7 describes how the computation is distributed over a cluster of computing nodes.
Consult Annex 1 for a formal definition of Replicode, Annex 2 for a specification of the executive, Annex 3 for the specification of the executable code format (r-code) and its C++ API, and Annex 4 for the definition of the Replicode Extension C++ API
NASA SBIR abstracts of 1991 phase 1 projects
The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included
Bioinspired symmetry detection on resource limited embedded platforms
This work is inspired by the vision of flying insects which enables them to detect and locate a set of relevant objects with remarkable effectiveness despite very limited
brainpower. The bioinspired approach worked out here focuses on detection of symmetric objects to be performed by resource-limited embedded platforms such as micro air vehicles. Symmetry detection is posed as a pattern matching problem which is solved by an approach based on the use of composite correlation filters. Two variants of the approach are proposed, analysed and tested in which symmetry detection is cast as 1) static and 2) dynamic pattern matching problems. In the static variant, images of objects are input to two dimentional spatial composite correlation filters. In the dynamic variant, a video (resulting from platform motion) is input to a composite correlation filter of which its peak response is used to define symmetry. In both cases, a novel method is used for designing the composite filter templates for symmetry detection. This method significantly reduces the level of detail which needs to be matched to achieve good detection performance. The resulting performance is systematically quantified using the ROC analysis; it is demonstrated that the bioinspired detection approach is better and with a lower computational cost compared to the best state-of-the-art solution hitherto available
Toward Guaranteed Illumination Models for Non-Convex Objects
Illumination variation remains a central challenge in object detection and
recognition. Existing analyses of illumination variation typically pertain to
convex, Lambertian objects, and guarantee quality of approximation in an
average case sense. We show that it is possible to build V(vertex)-description
convex cone models with worst-case performance guarantees, for non-convex
Lambertian objects. Namely, a natural verification test based on the angle to
the constructed cone guarantees to accept any image which is sufficiently
well-approximated by an image of the object under some admissible lighting
condition, and guarantees to reject any image that does not have a sufficiently
good approximation. The cone models are generated by sampling point
illuminations with sufficient density, which follows from a new perturbation
bound for point images in the Lambertian model. As the number of point images
required for guaranteed verification may be large, we introduce a new
formulation for cone preserving dimensionality reduction, which leverages tools
from sparse and low-rank decomposition to reduce the complexity, while
controlling the approximation error with respect to the original cone
Spinning gravitating objects in the effective field theory in the post-Newtonian scheme
We introduce a formulation for spinning gravitating objects in the effective
field theory in the post-Newtonian scheme in the context of the binary inspiral
problem. We aim at an effective action, where all field modes below the orbital
scale are integrated out. We spell out the relevant degrees of freedom, in
particular the rotational ones, and the associated symmetries. Building on
these symmetries, we introduce the minimal coupling part of the point particle
action in terms of gauge rotational variables, and construct the spin-induced
nonminimal couplings, where we obtain the leading order couplings to all orders
in spin. We specify the gauge for the rotational variables, where the
unphysical degrees of freedom are eliminated already from the Feynman rules,
and all the orbital field modes are integrated out. The equations of motion of
the spin can be directly obtained via a proper variation of the action, and
Hamiltonians may be straightforwardly derived. We implement this effective
field theory for spin to derive all spin dependent potentials up to
next-to-leading order to quadratic level in spin, namely up to the third
post-Newtonian order for rapidly rotating compact objects. In particular, the
proper next-to-leading order spin-squared potential and Hamiltonian for generic
compact objects are also derived. For the implementations we use the
nonrelativistic gravitational field decomposition, which is found here to
eliminate higher-loop Feynman diagrams also in spin dependent sectors, and
facilitates derivations. This formulation for spin is thus ideal for treatment
of higher order spin dependent sectors.Comment: 47 pages, 4 figures, publishe
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