Best-case performance of quantum annealers on native spin-glass benchmarks: How chaos can affect success probabilities

Recent tests performed on the D-Wave Two quantum annealer have revealed no clear evidence of speedup over conventional silicon-based technologies. Here, we present results from classical parallel-tempering Monte Carlo simulations combined with isoenergetic cluster moves of the archetypal benchmark problem-an Ising spin glass-on the native chip topology. Using realistic uncorrelated noise models for the D-Wave Two quantum annealer, we study the best-case resilience, i.e., the probability that the ground-state configuration is not affected by random fields and random-bond fluctuations found on the chip. We thus compute classical upper-bound success probabilities for different types of disorder used in the benchmarks and predict that an increase in the number of qubits will require either error correction schemes or a drastic reduction of the intrinsic noise found in these devices. We outline strategies to develop robust, as well as hard benchmarks for quantum annealing devices, as well as any other computing paradigm affected by noise.Comment: 8 pages, 5 figure

Vehicle to Everything Communication using VLC

Autonomous vehicles are currently self contained. However, we are coming to an age where there will be so many smart vehicles on the road, they will need a way to communicate with each other. In addition, the radio frequency spectrum is crowded and additional communication methods are needed to keep up with future needs. With these two ideas, this paper looks into a very new and developing form of communication - visible light communication - to provide an alternative to traditional radio waves for vehicular communication. We analyze the viability of this system as a proof-of-concept for the technology. We also present a design-prototype of a VLC vehicular transmitter and receiver to establish a wireless communication channel. We hope that our work can help provide a foundation for such a system being used in vehicles in a connected network

Capturing Genetic Variation during Ecological Restorations: An Example from Kankakee Sands in Indiana

Genetic variation in populations, both natural and restored, is usually considered crucial for response to short term environmental stresses and for long term evolutionary change. To have the best chance of successful long-term survival, restored populations should reflect the extant variation found in remnants, but restored sites may suffer from genetic bottlenecks as a result of founder effects. Kankakee Sands is a large-scale restoration being conducted by The Nature Conservancy (TNC) in northwestern Indiana. Our goal was to test for loss of genetic variation in restored plant populations by comparing them with TNC’s seed source nursery and with local remnant populations that were the source of nursery seed and of the first few restored sites. Allozyme analysis of Baptisia leucantha, Asclepias incarnata, Coreopsis tripteris, and Zizia aurea showed low levels of allozyme diversity within all species and reductions in polymorphism, alleles per locus, and expected heterozygosity between remnants and restorations for all species except A. incarnata. Almost all lost alleles were rare; restored populations contained almost 90% of alleles at polymorphic loci that occurred in remnants at frequencies greater than one percent. Allele frequencies for most loci did not differ between remnants and restored sites. Most species showed significant allele frequency differentiation among remnant populations and among restored sites. Our results indicate that seed collection techniques used at Kankakee Sands captured the great majority of allozyme variation present in seed source remnant populations

Microsatellite Markers for the Study of Mixed Mating in Hibiscus Aponeurus and H. Flavifolilus from Kenya

In a mixed mating system, plants use both self- and cross-pollination to produce seeds. Observations of pollinator behavior from populations of two Kenyan Hibiscus species suggest that H. aponeurus uses self-pollination at higher rates than does the co-occurring H. flavifolius. To begin testing this hypothesis, we sought to develop a suite of variable genetic loci to use in measuring levels of selfing and outcrossing in natural populations. We tested five microsatellite primer pairs from each of four Hibiscus species for amplification in H. aponeurus and H. flavifolius. Eight loci were subsequently tested for genetic variation, but were found to be monomorphic in both species. Gene sequencing suggested that evolutionary changes within these loci could account for the lack of inter-individual variation.Partiall funded by grants DEB-0344519 and DBI-0963244 to AS from the National Science Foundatio

dAUTOMAP:decomposing AUTOMAP to achieve scalability and enhance performance

AUTOMAP is a promising generalized reconstruction approach, however, it is not scalable and hence the practicality is limited. We present dAUTOMAP, a novel way for decomposing the domain transformation of AUTOMAP, making the model scale linearly. We show dAUTOMAP outperforms AUTOMAP with significantly fewer parameters.Comment: Presented at ISMRM 27th Annual Meeting & Exhibition (Abstract #658