2,908 research outputs found
Device facilitates centering of workpieces in lathe chuck
Spring loaded device used in conjunction with a standard dial indicator facilitates centering a workpiece in an independent four-jaw lathe chuck
Comparison of echo state network output layer classification methods on noisy data
Echo state networks are a recently developed type of recurrent neural network
where the internal layer is fixed with random weights, and only the output
layer is trained on specific data. Echo state networks are increasingly being
used to process spatiotemporal data in real-world settings, including speech
recognition, event detection, and robot control. A strength of echo state
networks is the simple method used to train the output layer - typically a
collection of linear readout weights found using a least squares approach.
Although straightforward to train and having a low computational cost to use,
this method may not yield acceptable accuracy performance on noisy data.
This study compares the performance of three echo state network output layer
methods to perform classification on noisy data: using trained linear weights,
using sparse trained linear weights, and using trained low-rank approximations
of reservoir states. The methods are investigated experimentally on both
synthetic and natural datasets. The experiments suggest that using regularized
least squares to train linear output weights is superior on data with low
noise, but using the low-rank approximations may significantly improve accuracy
on datasets contaminated with higher noise levels.Comment: 8 pages. International Joint Conference on Neural Networks (IJCNN
2017
Beyond the Tutorial: Complex Content Models in Fedora 3
4th International Conference on Open RepositoriesThis presentation was part of the session : Fedora User Group PresentationsDate: 2009-05-21 08:30 AM – 10:00 AMThe University of Wisconsin Digital Collections Center recently began a pilot project to create a digital collection of learning objects stored in a Fedora 3.1 repository. This pilot project is the proof-of-concept of many ideas and discussions, extending back for over five years, concerning the problem of storing, searching, and retrieving heterogeneous objects and object types, linked together in complex relations, in a way that is loosely coupled with front-end user display applications. During the course of this presentation, we will describe the issues we've confronted implementing increasingly rich digital collections over the past decade (including some real-life examples of complex digital objects), models we have developed with to resolve many of those issues, and how we have started implementing those models in Fedora 3.1, using the new Content Model functionality
A Review of Welding in Space and Related Technologies
Deployment of welding and additive manufacturing (AM) technologies in the space environment has the potential to revolutionize how orbiting platforms are designed, manufactured, and assembled. These technologies offer the option for repair of sustained damage to habitat structures on space missions, as astronauts would be able to manufacture new parts (using welding-derived AM processes suitable for use in the external space environment) and weld cracks. An added benefit is that required repairs can be achieved more economically, as new parts need not be shipped from Earth. With further maturation of in-space welding capabilities, astronauts could operate under given standards and weld damaged structures rather than rely on cargo resupply. This Technical Memorandum (TM) begins by reviewing the available literature relevant to welding in space, focusing on solidification, heat and mass transfer, and fluid flows in microgravity. This survey considers research on the effects of welding in microgravity on a material system. The various in-space welding devices that have been previously designed and tested are examined to determine their capabilities and shortcomings, with a focus on the results of their individual welding experiments. Safety measures are discussed to protect the orbiting International Space Station (ISS) and crew during welding operations. Finally, the state of the art is examined by focusing on current approaches to AM and on-orbit welding that are being developed by several companies in conjunction with NASA
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