814 research outputs found
Fault tolerant hypercube computer system architecture
A fault-tolerant multiprocessor computer system of the hypercube type comprising a hierarchy of computers of like kind which can be functionally substituted for one another as necessary is disclosed. Communication between the working nodes is via one communications network while communications between the working nodes and watch dog nodes and load balancing nodes higher in the structure is via another communications network separate from the first. A typical branch of the hierarchy reporting to a master node or host computer comprises, a plurality of first computing nodes; a first network of message conducting paths for interconnecting the first computing nodes as a hypercube. The first network provides a path for message transfer between the first computing nodes; a first watch dog node; and a second network of message connecting paths for connecting the first computing nodes to the first watch dog node independent from the first network, the second network provides an independent path for test message and reconfiguration affecting transfers between the first computing nodes and the first switch watch dog node. There is additionally, a plurality of second computing nodes; a third network of message conducting paths for interconnecting the second computing nodes as a hypercube. The third network provides a path for message transfer between the second computing nodes; a fourth network of message conducting paths for connecting the second computing nodes to the first watch dog node independent from the third network. The fourth network provides an independent path for test message and reconfiguration affecting transfers between the second computing nodes and the first watch dog node; and a first multiplexer disposed between the first watch dog node and the second and fourth networks for allowing the first watch dog node to selectively communicate with individual ones of the computing nodes through the second and fourth networks; as well as, a second watch dog node operably connected to the first multiplexer whereby the second watch dog node can selectively communicate with individual ones of the computing nodes through the second and fourth networks. The branch is completed by a first load balancing node; and a second multiplexer connected between the first load balancing node and the first and second watch dog nodes, allowing the first load balancing node to selectively communicate with the first and second watch dog nodes
Three-dimensional nuclear spin positioning using coherent radio-frequency control
Distance measurements via the dipolar interaction are fundamental to the
application of nuclear magnetic resonance (NMR) to molecular structure
determination, but they only provide information on the absolute distance
and polar angle between spins. In this Letter, we present a protocol
to also retrieve the azimuth angle . Our method relies on measuring the
nuclear precession phase after application of a control pulse with a calibrated
external radio-frequency coil. We experimentally demonstrate three-dimensional
positioning of individual carbon-13 nuclear spins in a diamond host crystal
relative to the central electronic spin of a single nitrogen-vacancy center.
The ability to pinpoint three-dimensional nuclear locations is central for
realizing a nanoscale NMR technique that can image the structure of single
molecules with atomic resolution.Comment: 5 pages, 4 figure
High-bandwidth microcoil for fast nuclear spin control
The active manipulation of nuclear spins with radio-frequency (RF) coils is
at the heart of nuclear magnetic resonance (NMR) spectroscopy and spin-based
quantum devices. Here, we present a microcoil transmitter system designed to
generate strong RF pulses over a broad bandwidth, allowing for fast spin
rotations on arbitrary nuclear species. Our design incorporates: (i) a planar
multilayer geometry that generates a large field of 4.35 mT per unit current,
(ii) a 50 Ohm transmission circuit with a broad excitation bandwidth of
approximately 20 MHz, and (iii) an optimized thermal management for removal of
Joule heating. Using individual 13C nuclear spins in the vicinity of a diamond
nitrogen-vacancy (NV) center as a test system, we demonstrate Rabi frequencies
exceeding 70 kHz and nuclear pi/2 rotations within 3.4 us. The extrapolated
values for 1H spins are about 240 kHz and 1 us, respectively. Beyond enabling
fast nuclear spin manipulations, our microcoil system is ideally suited for the
incorporation of advanced pulse sequences into micro- and nanoscale NMR
detectors operating at low (<1 T) magnetic field.Comment: 8 pages, 5 figures. Submitted to Rev. Sci. Inst
Influence of Oscillating Flow on Hyporheic Zone Development
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86886/1/j.1745-6584.2010.00794.x.pd
Image Classification using Textural Neural Networks
This paper presents backpropagation neural networks that utilize texture information to accurately classify photographic images. Training with minimum sets is shown to yield excellent results
Image Classification using Textural Neural Networks
This paper presents backpropagation neural networks that utilize texture information to accurately classify photographic images. Training with minimum sets is shown to yield excellent results
Method and apparatus for eliminating unsuccessful tries in a search tree
A circuit switching system in an M-ary, n-cube connected network completes a best-first path from an originating node to a destination node by latching valid legs of the path as the path is being sought out. Each network node is provided with a routing hyperswitch sub-network, (HSN) connected between that node and bidirectional high capacity communication channels of the n-cube network. The sub-networks are all controlled by routing algorithms which respond to message identification headings (headers) on messages to be routed along one or more routing legs. The header includes information embedded therein which is interpreted by each sub-network to route and historically update the header. A logic circuit, available at every node, implements the algorithm and automatically forwards or back-tracks the header in the network legs of various paths until a completed path is latched
Noise-based core monitoring and diagnostics: overview of the cortex project
This paper gives an overview of the CORTEX project, which is a Research and Innovation Action
funded by the European Union in the Euratom 2016-2017 work program, under the Horizon 2020
framework. CORTEX, which stands for CORe monitoring Techniques and EXperimental validation
and demonstration, aims at developing an innovative core monitoring technique that allows
detecting anomalies in nuclear reactors, such as excessive vibrations of core internals, flow
blockage, coolant inlet perturbations, etc. The technique is based on primarily using the inherent
fluctuations in neutron flux recorded by in-core and ex-core instrumentation (often referred to as
neutron noise), from which the anomalies will be differentiated depending on their type, location
and characteristics. In addition to be non-intrusive and not requiring any external perturbation of the
system, the method allows the detection of operational problems at a very early stage. Proper
actions could thus be taken by utilities before such problems have any adverse effect on plant safety
and reliability
Acoustical Boundary Location through Texture Analysis of Multibeam Bathymetric Sonar Data
Texture analysis is performed on multibeam sonar signal returns discriminated angularity by beamforming. A collection of fourteen texture features are computed via co-occurrence matrices and data reduction is then performed using a principal components transformation. Acoustical boundaries (boundaries between regions with homogeneous acoustical properties) are evident from the features. Results indicate that seafloor bottom characteristics can be extracted from these texture features
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