1,111 research outputs found
SBML and Synthetic Biology
This talk describes the synthetic biology open language (SBOL)
Star Cluster Formation in Turbulent, Magnetized Dense Clumps with Radiative and Outflow Feedback
We present three Orion simulations of star cluster formation in a 1000 Msun,
turbulent molecular cloud clump, including the effects of radiative transfer,
protostellar outflows, and magnetic fields. Our simulations all use
self-consistent turbulent initial conditions and vary the mean mass-to-flux
ratio relative to the critical value over 2, 10, and infinity to gauge the
influence of magnetic fields on star cluster formation. We find, in good
agreement with previous studies, that magnetic fields of typically observed
strengths lower the star formation rate by a factor of 2.4 and reduce the
amount of fragmentation by a factor of 2 relative to the zero-field case. We
also find that the field increases the characteristic sink particle mass, again
by a factor of 2.4. The magnetic field also increases the degree of clustering
in our simulations, such that the maximum stellar densities in the strong field
case are higher than the others by again a factor of 2. This clustering tends
to encourage the formation of multiple systems, which are more common in the
rad-MHD runs than the rad-hydro run. The companion frequency in our simulations
is consistent with observations of multiplicity in Class I sources,
particularly for the strong field case. Finally, we find evidence of primordial
mass segregation in our simulations reminiscent of that observed in star
clusters like the Orion Nebula Cluster.Comment: 21 pages, 17 figures, accepted by MNRA
Dynamic Structures in SBML
This talk describes ideas on how to integrate dynamic structures in SBML
Analog MAP decoder for (8, 4) hamming code in subthreshold CMOS
Journal ArticleAn all-MOS analog implementation of a MAP decoder is presented for the (8, 4) extended Hamming code. This paper describes the design and analysis of a tail-biting trellis decoder implementation using subthreshold CMOS devices. A VLSI test chip has recently returned from fabrication, and preliminary test results indicate accurate decoding up to 20 MBit/s
CMOS analog map decoder for (8,4) hamming code
Journal ArticleAbstract-Design and test results for a fully integrated translinear tail-biting MAP error-control decoder are presented. Decoder designs have been reported for various applications which make use of analog computation, mostly for Viterbi-style decoders. MAP decoders are more complex, and are necessary components of powerful iterative decoding systems such as Turbo codes. Analog circuits may require less area and power than digital implementations in high-speed iterative applications. Our (8, 4) Hamming decoder, implemented in an AMI 0.5- m process, is the first functioning CMOS analog MAP decoder. While designed to operate in subthreshold, the decoder also functions above threshold with a small performance penalty. The chip has been tested at bit rates up to 2 Mb/s, and simulations indicate a top speed of about 10 Mb/s in strong inversion. The decoder circuit size is 0.82 mm2, and typical power consumption is 1 mW at 1 Mb/s
Analog MAP decoder for (8, 4) hamming code in subthreshold CMOS
Journal ArticleAbstract - An all-MOS analog tail-biting MAP decoder is presented for an (8,4) Hamming code. The decoder implements a probability propagation algorithm using subthreshold CMOS networks. Physical results verify the expected behavior of the decoderand demonstrate robustness of analog decoding circuits
Analog decoding of product codes
Journal ArticleAbstract - A method is presented for analog softdecision decoding of block product codes (block turbo codes). Extrinsic information is exchanged as analog signals between component row and column decoders. The component MAP decoders use low-power analog computation in subthreshold CMOS circuits to implement the sum-product algorithm. An example decoder design is presented for a (16,ll)? Hamming code
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