9,523 research outputs found
Bibliography of computational models of rat spatial behavior
A bibliography of computational models of rat spatial behavior
Torsion and the second fundamental form for distributions
The second fundamental form of Riemannian geometry is generalised to the case
of a manifold with a linear connection and an integrable distribution. This
bilinear form is generally not symmetric and its skew part is the torsion. The
form itself is closely related to the shape map of the connection. The
codimension one case generalises the traditional shape operator of Riemannian
geometry
Alternative kinetic energy metrics for Lagrangian systems
We examine Lagrangian systems on R-n with standard kinetic energy terms for the possibility of additional, alternative Lagrangians with kinetic energy metrics different to the Euclidean one. Using the techniques of the inverse problem in the calculus of variations we find necessary and sufficient conditions for the existence of such Lagrangians. We illustrate the problem in two and three dimensions with quadratic and cubic potentials. As an aside we show that the well-known anomalous Lagrangians for the Coulomb problem can be removed by switching on a magnetic field, providing an appealing resolution of the ambiguous quantizations of the hydrogen atom
Introduction: The Third International Conference on Epigenetic Robotics
This paper summarizes the paper and poster contributions
to the Third International Workshop on
Epigenetic Robotics. The focus of this workshop is
on the cross-disciplinary interaction of developmental
psychology and robotics. Namely, the general
goal in this area is to create robotic models of the
psychological development of various behaviors. The
term "epigenetic" is used in much the same sense as
the term "developmental" and while we could call
our topic "developmental robotics", developmental
robotics can be seen as having a broader interdisciplinary
emphasis. Our focus in this workshop is
on the interaction of developmental psychology and
robotics and we use the phrase "epigenetic robotics"
to capture this focus
Humanoid Theory Grounding
In this paper we consider the importance of using a humanoid physical form for a certain proposed kind of robotics, that of theory grounding. Theory grounding involves grounding the theory skills and knowledge of an embodied artificially intelligent (AI) system by developing theory skills and knowledge from the bottom up. Theory grounding can potentially occur in a variety of domains, and the particular domain considered here is that of language. Language is taken to be another “problem space” in which a system can explore and discover solutions. We argue that because theory grounding necessitates robots experiencing domain information, certain behavioral-form aspects, such as abilities to socially smile, point, follow gaze, and generate manual gestures, are necessary for robots grounding a humanoid theory of language
A generalization of Szebehely's inverse problem of dynamics in dimension three
Extending a previous paper, we present a generalization in dimension 3 of the
traditional Szebehely-type inverse problem. In that traditional setting, the
data are curves determined as the intersection of two families of surfaces, and
the problem is to find a potential V such that the Lagrangian L = T - V, where
T is the standard Euclidean kinetic energy function, generates integral curves
which include the given family of curves. Our more general way of posing the
problem makes use of ideas of the inverse problem of the calculus of variations
and essentially consists of allowing more general kinetic energy functions,
with a metric which is still constant, but need not be the standard Euclidean
one. In developing our generalization, we review and clarify different aspects
of the existing literature on the problem and illustrate the relevance of the
newly introduced additional freedom with many examples.Comment: 23 pages, to appear in Rep. Math. Phy
A generalization of Szebehely's inverse problem of dynamics
The so-called inverse problem of dynamics is about constructing a potential
for a given family of curves. We observe that there is a more general way of
posing the problem by making use of ideas of another inverse problem, namely
the inverse problem of the calculus of variations. We critically review and
clarify different aspects of the current state of the art of the problem
(mainly restricted to the case of planar curves), and then develop our more
general approach.Comment: 21 pages, to appear in Rep. Math. Phy
Shape maps for second order partial differential equations
We analyse the singularity formation of congruences of solutions of systems
of second order PDEs via the construction of \emph{shape maps}. The trace of
such maps represents a congruence volume whose collapse we study through an
appropriate evolution equation, akin to Raychaudhuri's equation. We develop the
necessary geometric framework on a suitable jet space in which the shape maps
appear naturally associated with certain linear connections. Explicit
computations are given, along with a nontrivial example
Time-dependent kinetic energy metrics for Lagrangians of electromagnetic type
We extend the results obtained in a previous paper about a class of
Lagrangian systems which admit alternative kinetic energy metrics to
second-order mechanical systems with explicit time-dependence. The main results
are that a time-dependent alternative metric will have constant eigenvalues,
and will give rise to a time-dependent coordinate transformation which
partially decouples the system
The United States, The United Nations, and Micronesia: Questions of Procedure, Substance, and Faith
This study first considers the procedural requirements for proper termination and concludes that Security Council approval is required. Second, this writing identifies the major issues that should be considered if the proposed termination of the Trusteeship Agreement for Micronesia is subjected to Security Council review. Two basic concerns should be the propriety of the division of the Trust Territory into four separate entities and the legitimacy of the agreements between the new governments and the United States for continuing relations as either commonwealth or freely associated states. The history of and practice under the trusteeship system indicate that the particular arrangements for commonwealth and free association statuses do not fit neatly into recognized categories of self-governance. Nonetheless, as a general matter, the arrangements are within the broader realm of acceptable relations because they reflect the free choices of the Micronesian peoples
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