1,599 research outputs found
Learning more effectively from experience
Developing the capacity for individuals to learn effectively from their experiences is an important part of building the knowledge and skills in organizations to do good adaptive management. This paper reviews some of the research from cognitive psychology and phenomenography to present a way of thinking about learning to assist individuals to make better use of their personal experiences to develop understanding of environmental systems. We suggest that adaptive expertise (an individual’s ability to deal flexibly with new situations) is particularly relevant for environmental researchers and practitioners. To develop adaptive expertise, individuals need to: (1) vary and reflect on their experiences and become adept at seeking out and taking different perspectives; and (2) become proficient at making balanced judgements about how or if an experience will change their current perspective or working representation of a social, economic, and biophysical system by applying principles of “good thinking.” Such principles include those that assist individuals to be open to the possibility of changing their current way of thinking (e.g., the disposition to be adventurous) and those that reduce the likelihood of making erroneous interpretations (e.g., the disposition to be intellectually careful). An example of applying some of the principles to assist individuals develop their understanding of a dynamically complex wetland system (the Macquarie Marshes in Australia) is provided. The broader implications of individual learning are also discussed in relation to organizational learning, the role of experiential knowledge for conservation, and for achieving greater awareness of the need for ecologically sustainable activity
An Extensible Benchmarking Infrastructure for Motion Planning Algorithms
Sampling-based planning algorithms are the most common probabilistically
complete algorithms and are widely used on many robot platforms. Within this
class of algorithms, many variants have been proposed over the last 20 years,
yet there is still no characterization of which algorithms are well-suited for
which classes of problems. This has motivated us to develop a benchmarking
infrastructure for motion planning algorithms. It consists of three main
components. First, we have created an extensive benchmarking software framework
that is included with the Open Motion Planning Library (OMPL), a C++ library
that contains implementations of many sampling-based algorithms. Second, we
have defined extensible formats for storing benchmark results. The formats are
fairly straightforward so that other planning libraries could easily produce
compatible output. Finally, we have created an interactive, versatile
visualization tool for compact presentation of collected benchmark data. The
tool and underlying database facilitate the analysis of performance across
benchmark problems and planners.Comment: Submitted to IEEE Robotics & Automation Magazine (Special Issue on
Replicable and Measurable Robotics Research), 201
Q-based design equations for resonant metamaterials and experimental validation
Practical design parameters of resonant metamaterials, such as loss tangent,
are derived in terms of the quality factor of the resonant effective medium
permeability or permittivity. Through electromagnetic simulations of loop-based
resonant particles, it is also shown that the of the effective medium
response is essentially equal to the of an individual resonant particle.
Thus, by measuring the of a single fabricated metamaterial particle, the
effective permeability or permittivity of a metamaterial can be calculated
simply and accurately without requiring complex simulations, fabrication, or
measurements. Experimental validation shows that the complex permeability
analytically estimated from the measured of a single fabricated
self-resonant loop agrees with the complex permeability extracted from
parameter measurements of a metamaterial slab to better than 20%. This
equivalence reduces the design of a metamaterial to meet a given loss
constraint to the simpler problem of the design of a resonant particle to meet
a specific constraint. This analysis also yields simple analytical
expressions for estimating the loss tangent of a planar loop magnetic
metamaterial due to ohmic losses. It is shown that
is a strong lower bound for magnetic loss tangents for frequencies not too far
from 1 GHz. The ohmic loss of the metamaterial varies inversely with the
electrical size of the metamaterial particle, indicating that there is a loss
penalty for reducing the particle size at a fixed frequency
Rigidity around Poisson Submanifolds
We prove a rigidity theorem in Poisson geometry around compact Poisson
submanifolds, using the Nash-Moser fast convergence method. In the case of
one-point submanifolds (fixed points), this immediately implies a stronger
version of Conn's linearization theorem, also proving that Conn's theorem is,
indeed, just a manifestation of a rigidity phenomenon; similarly, in the case
of arbitrary symplectic leaves, it gives a stronger version of the local normal
form theorem; another interesting case corresponds to spheres inside duals of
compact semisimple Lie algebras, our result can be used to fully compute the
resulting Poisson moduli space.Comment: 43 pages, v3: published versio
Weakly Picard mappings
summary:In this paper we generalize the well known converse to the contraction principle due to C. Bessaga, dropping the uniqueness of the fixed point from its hypotheses. Some properties of weakly Picard mappings are given
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