15,982 research outputs found
Rechargeable battery which combats shape change of the zinc anode
A rechargeable cell or battery is provided in which shape change of the zinc anode is combatted by profiling the ionic conductivity of the paths between the electrodes. The ion flow is greatest at the edges of the electrodes and least at the centers, thereby reducing migration of the zinc ions from edges to the center of the anode. A number of embodiments are disclosed in which the strength and/or amount of electrolyte, and/or the number and/or size of the paths provided by the separator between the electrodes, are varied to provide the desired ionic conductivity profile
Fuse and switch functions combined within a single housing
Fuswitch provides both switch and fuse functions within a single housing. A mercury capillary is used to alternately vaporize and condense the mercury within a reservoir. The housing is impervious to mercury and the fuse portion of the device operates on the principle of the self-healing mercury fuse
Learning functional object categories from a relational spatio-temporal representation
Abstract. We propose a framework that learns functional objectcategories from spatio-temporal data sets such as those abstracted from video. The data is represented as one activity graph that encodes qualitative spatio-temporal patterns of interaction between objects. Event classes are induced by statistical generalization, the instances of which encode similar patterns of spatio-temporal relationships between objects. Equivalence classes of objects are discovered on the basis of their similar role in multiple event instantiations. Objects are represented in a multidimensional space that captures their role in all the events. Unsupervised learning in this space results in functional object-categories. Experiments in the domain of food preparation suggest that our techniques represent a significant step in unsupervised learning of functional object categories from spatio-temporal patterns of object interaction.
Stably free modules over virtually free groups
Let be the free group on generators and let be a finite
nilpotent group of non square-free order; we show that for each the
integral group ring has infinitely many stably free
modules of rank 1.Comment: 9 pages. The final publication is available at
http://www.springerlink.com doi:10.1007/s00013-012-0432-
A continued fraction generator for smooth pulse sequences
Digital circuit produces rational output pulse rate at fraction of continuous input pulse rate. Output pulses have average rate with least possible deviation from absolute correct time spacing. Circuit uses include frequency synthesizing, fraction generation, and approximation of irrational sequences
Active Learning with Statistical Models
For many types of machine learning algorithms, one can compute the
statistically `optimal' way to select training data. In this paper, we review
how optimal data selection techniques have been used with feedforward neural
networks. We then show how the same principles may be used to select data for
two alternative, statistically-based learning architectures: mixtures of
Gaussians and locally weighted regression. While the techniques for neural
networks are computationally expensive and approximate, the techniques for
mixtures of Gaussians and locally weighted regression are both efficient and
accurate. Empirically, we observe that the optimality criterion sharply
decreases the number of training examples the learner needs in order to achieve
good performance.Comment: See http://www.jair.org/ for any accompanying file
Microwave diode amplifiers with low intermodulation distortion
Distortions can be greatly reduced in narrow-band applications by using the second harmonic. The ac behavior of simplified diode amplifier has negative resistance depending on slope of equivalent I-V curve
Giant Dielectric Permittivity of Electron-Doped Manganite Thin Films, Ca(1-x)La(x)MnO(3) ($0<= x<= 0.03)
A giant low-frequency, in-plane dielectric constant, eps~10^6, for epitaxial
thin films of Ca(1-x)La(x)MnO(3) (x<=0.03) was observed over a broad
temperature range, 4K <= T 300K. This phenomenon is attributed to an internal
barrier-layer capacitor (IBLC) structure, with insulating boundaries between
semiconducting grains. The room-temperature eps increases substantially with
electron (La) doping. The measured values of eps exceed those of conventional
two-phase IBLC materials based on (Ba,Sr)TiO(3) as well as recently discovered
CaCu(3)Ti(4)O(12) and (Li,Ti) doped NiO.Comment: 5 pages, 4 fig.s, J. Appl. Phys., Jan. 15, 2005 (in press
Quantum Teichmuller theory and representations of the pure braid group
We adapt some of the methods of quantum Teichm\"uller theory to construct a
family of representations of the pure braid group of the sphere.Comment: 15 pages. Several typos corrected. To appear in Communications in
Contemporary Mathematic
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