4,610 research outputs found
Cognitive architectures as Lakatosian research programmes: two case studies
Cognitive architectures - task-general theories of the structure and function of the complete cognitive system - are sometimes argued to be more akin to frameworks or belief systems than scientific theories. The argument stems from the apparent non-falsifiability of existing cognitive architectures. Newell was aware of this criticism and argued that architectures should be viewed not as theories subject to Popperian falsification, but rather as Lakatosian research programs based on cumulative growth. Newell's argument is undermined because he failed to demonstrate that the development of Soar, his own candidate architecture, adhered to Lakatosian principles. This paper presents detailed case studies of the development of two cognitive architectures, Soar and ACT-R, from a Lakatosian perspective. It is demonstrated that both are broadly Lakatosian, but that in both cases there have been theoretical progressions that, according to Lakatosian criteria, are pseudo-scientific. Thus, Newell's defense of Soar as a scientific rather than pseudo-scientific theory is not supported in practice. The ACT series of architectures has fewer pseudo-scientific progressions than Soar, but it too is vulnerable to accusations of pseudo-science. From this analysis, it is argued that successive versions of theories of the human cognitive architecture must explicitly address five questions to maintain scientific credibility
Providing Self-Aware Systems with Reflexivity
We propose a new type of self-aware systems inspired by ideas from
higher-order theories of consciousness. First, we discussed the crucial
distinction between introspection and reflexion. Then, we focus on
computational reflexion as a mechanism by which a computer program can inspect
its own code at every stage of the computation. Finally, we provide a formal
definition and a proof-of-concept implementation of computational reflexion,
viewed as an enriched form of program interpretation and a way to dynamically
"augment" a computational process.Comment: 12 pages plus bibliography, appendices with code description, code of
the proof-of-concept implementation, and examples of executio
Ariel - Volume 8 Number 1
Executive Editor
James W. Lockard, Jr.
Issue Editor
Michael J. Grimes
Business Manager
Neeraj K. Kanwal
Managing Editor
Edward H. Jasper
University News
Richard J. Perry
World News
William D.B. Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Associate
Brenda Peterson
Photography
Robert D. Lehman, Jr.
Graphics
Christine M. Kuhnl
Ariel - Volume 4 Number 6
Editors
David A. Jacoby
Eugenia Miller
Tom Williams
Associate Editors
Paul Bialas
Terry Burt
Michael Leo
Gail Tenikat
Editor Emeritus and Business Manager
Richard J. Bonnano
Movie Editor
Robert Breckenridge
Staff
Richard Blutstein
Mary F. Buechler
J.D. Kanofsky
Rocket Weber
David Maye
Coupling molecular spin states by photon-assisted tunneling
Artificial molecules containing just one or two electrons provide a powerful
platform for studies of orbital and spin quantum dynamics in nanoscale devices.
A well-known example of these dynamics is tunneling of electrons between two
coupled quantum dots triggered by microwave irradiation. So far, these
tunneling processes have been treated as electric dipole-allowed
spin-conserving events. Here we report that microwaves can also excite
tunneling transitions between states with different spin. In this work, the
dominant mechanism responsible for violation of spin conservation is the
spin-orbit interaction. These transitions make it possible to perform detailed
microwave spectroscopy of the molecular spin states of an artificial hydrogen
molecule and open up the possibility of realizing full quantum control of a two
spin system via microwave excitation.Comment: 13 pages, 9 figure
Cognitively-inspired Agent-based Service Composition for Mobile & Pervasive Computing
Automatic service composition in mobile and pervasive computing faces many
challenges due to the complex and highly dynamic nature of the environment.
Common approaches consider service composition as a decision problem whose
solution is usually addressed from optimization perspectives which are not
feasible in practice due to the intractability of the problem, limited
computational resources of smart devices, service host's mobility, and time
constraints to tailor composition plans. Thus, our main contribution is the
development of a cognitively-inspired agent-based service composition model
focused on bounded rationality rather than optimality, which allows the system
to compensate for limited resources by selectively filtering out continuous
streams of data. Our approach exhibits features such as distributedness,
modularity, emergent global functionality, and robustness, which endow it with
capabilities to perform decentralized service composition by orchestrating
manifold service providers and conflicting goals from multiple users. The
evaluation of our approach shows promising results when compared against
state-of-the-art service composition models.Comment: This paper will appear on AIMS'19 (International Conference on
Artificial Intelligence and Mobile Services) on June 2
Electrically driven single electron spin resonance in a slanting Zeeman field
The rapidly rising fields of spintronics and quantum information science have
led to a strong interest in developing the ability to coherently manipulate
electron spins. Electron spin resonance (ESR) is a powerful technique to
manipulate spins that is commonly achieved by applying an oscillating magnetic
field. However, the technique has proven very challenging when addressing
individual spins. In contrast, by mixing the spin and charge degrees of freedom
in a controlled way through engineered non-uniform magnetic fields, electron
spin can be manipulated electrically without the need of high-frequency
magnetic fields. Here we realize electrically-driven addressable spin rotations
on two individual electrons by integrating a micron-size ferromagnet to a
double quantum dot device. We find that the electrical control and spin
selectivity is enabled by the micro-magnet's stray magnetic field which can be
tailored to multi-dots architecture. Our results demonstrate the feasibility of
manipulating electron spins electrically in a scalable way.Comment: 25 pages, 6 figure
Internal representations, external representations and ergonomics: towards a theoretical integration
Early Galactic Evolution of Carbon, Nitrogen and Oxygen
We present results on carbon, nitrogen, and oxygen abundances for a sample of
unevolved metal-poor stars with metallicities in the range -0.3< [Fe/H]< -3.
Oxygen abundances derived from different indicators are compared showing
consistently that in the range 0.3 >[Fe/H]>-3.0, the [O/Fe] ratio increases
from approximately 0 to 1. We find a good agreement between abundances based on
the forbidden line, the OH and IR triplet lines when gravities based on
Hipparcos} parallaxes are considered for the sample stars. Gravities derived
from LTE ionization balance in metal-poor stars with [Fe/H]< -1 are likely too
low, and could be responsible for an underestimation of the oxygen abundances
derived using the [OI] line. [C/Fe] and [N/Fe] ratios appear to be constant,
independently of metallicity, in the same range. However, they show larger
scatter than oxygen at a given metallicity, which could reflect the larger
variety of stellar production sites for these other elements.Comment: 10 pages, 3 figures, To appear in the proceedings of the conference
"The Chemical Evolution of The Milky Way: Stars versus Clusters", eds. F.
Matteucci and F. Giovannelli, Vulcano, Italy, September 20-24 199
- …
