8,587 research outputs found
Translating Feedforward Neural Nets to SOM-like Maps
A major disadvantage of feedforward neural networks is still the difficulty to gain insight into their internal functionality. This is much less the case for, e.g., nets that are trained unsupervised, such as KohonenÂżs self-organizing feature maps (SOMs). These offer a direct view into the stored knowledge, as their internal knowledge is stored in the same format as the input data that was used for training or is used for evaluation. This paper discusses a mathematical transformation of a feed-forward network into a SOMlike structure such that its internal knowledge can be visually interpreted. This is particularly applicable to networks trained in the general classification problem domain
On the determination of probability density functions by using Neural Networks
It is well known that the output of a Neural Network trained to disentangle
between two classes has a probabilistic interpretation in terms of the
a-posteriori Bayesian probability, provided that a unary representation is
taken for the output patterns. This fact is used to make Neural Networks
approximate probability density functions from examples in an unbinned way,
giving a better performace than ``standard binned procedures''. In addition,
the mapped p.d.f. has an analytical expression.Comment: 13 pages including 3 eps figures. Submitted to Comput. Phys. Commu
Crack detection in a rotating shaft using artificial neural networks and PSD characterisation
Peer reviewedPostprin
New Models of Technology Assessment for Development
This report explores the role that ânew modelsâ of
technology assessment can play in improving the lives of
poor and vulnerable populations in the developing world.
The ânew modelsâ addressed here combine citizen and
decision-maker participation with technical expertise. They
are virtual and networked rather than being based in a
single office of technology assessment (as was the case in
the United States in the 1970s-90s). They are flexible
enough to address issues across disciplines and are
increasingly transnational or global in their reach and
scope. The report argues that these new models of
technology assessment can make a vital contribution to
informing policies and strategies around innovation,
particularly in developing regions. They are most beneficial
if they enable the broadening out of inputs to technology
assessment, and the opening up of political debate around
possible directions of technological change and their
interactions with social and environmental systems.
Beyond the process of technology assessment itself, the
report argues that governance systems within which these
processes are embedded play an important role in
determining the impact and effectiveness of technology
assessment. Finally, the report argues for training and
capacity-building in technology assessment
methodologies in developing countries, and support for
internationally co-ordinated technology assessment
efforts to address global and regional development
challenges
Artificial Neural Network Representations for Hierarchical Preference Structures
In this paper, we introduce two artificial neural network formulations that can be used to predict the preference ratings from the pairwise comparison matrices of the Analytic Hierarchy Process (AHP). First, we introduce a modified Hopfield network that can be used to exactly determine the vector of preference ratings associated with a positive reciprocal comparison matrix. The dynamics of this network are mathematically equivalent to the power method, a widely used numerical method for computing the principal eigenvectors of square matrices. However, we show that the Hopfield network representation is incapable of generalizing the preference patterns, and consequently is not suitable for approximating the preference ratings if the preference information is imprecise. Then we present a feed-forward neural network formulation that does have the ability to accurately approximate the preference ratings. A simulation experiment is used to verify the robustness of the feed-forward neural network formulation with respect to imprecise pairwise judgments. From the results of this experiment, we conclude that the feed-forward neural network formulation appears to be a powerful tool for analyzing discrete alternative multicriteria decision problems with imprecise or fuzzy ratio-scale preference judgments
Cash & Compassion: The Somali Diaspora's Role in Relief, Development & Peacebuilding
This research report, commissioned by UNDP Somalia, is based on work done in six diaspora hubs (Dubai, London, Minneapolis, Nairobi, Oslo, and Toronto) as well as in Somaliland, Puntland and South/Central Somalia. It examines the involvement of Somalis in the diaspora in dynamics in their country of origin, including collective and social remittances. Volume 1 contains the full report. Volume 2 contains the research guides, terms of reference and other annexes
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