140 research outputs found
Designing Universal Logic Module FPGA Architectures for Use With Ambipolar Transistor Technology
Recent publications show a rise of ambipolar transistor technology research and associated implementations of multi-function logic cells in these technologies. Special properties of these technologies enable implementations of Universal Logic Modules (ULMs) using few transistors, which draws renewed interest to use such ULMs as basic logic blocks for FPGA architectures. Unlike N-input Lookup Tables (LUTs), most ULMs only implement a fixed subset of the possible Boolean functions. In this work, we first adapt the Verilog-to-Routing (VTR) 8.0 toolflow to target such reduced-function ULM primitives. We then modify VTR\u27s flagship 40nm architecture to use an ULM primitive instead of LUTs, modeling the double-gate carbon nanotube FET 8-function logic gate CNT-DR8F published by Liu et al. Using VTR\u27s extensive benchmark framework, we analyze effects caused by the limited set of function offered by these primitives. To counter some of the observed effects, we present various clustered architectures, where multiple ULM cells are combined in a logic block. We conclude with an analysis of various parameters which affect performance of the different implementations
A Hardware Perspective on the ChaCha Ciphers: Scalable Chacha8/12/20 Implementations Ranging from 476 Slices to Bitrates of 175 Gbit/s
AES (Advanced Encryption Standard) accelerators are commonly used in high-throughput applications, but they have notable resource requirements. We investigate replacing the AES cipher with ChaCha ciphers and propose the first ChaCha FPGA implementations optimized for data throughput. In consequence, we compare implementations of three different system architectures and analyze which aspects dominate the performance of those.Our experimental results indicate that a bandwidth of 175 Gbit/s can be reached with as little as 2982 slices, whereas comparable state of the art AES accelerators require 10 times as many slices. Taking advantage of the flexibility inherent in the ChaCha cipher, we also demonstrate how our implementation scales to even higher throughputs or lower resource usage (down to 476 slices), benefiting applications which previously could not employ cryptography because of resource limitations
Remote sensing of fugitive methane emissions from oil and gas production in North American tight geologic formations
In the past decade, there has been a massive growth in the horizontal drilling and hydraulic fracturing of shale gas and tight oil reservoirs to exploit formerly inaccessible or unprofitable energy resources in rock formations with low permeability. In North America, these unconventional domestic sources of natural gas and oil provide an opportunity to achieve energy self-sufficiency and to reduce greenhouse gas emissions when displacing coal as a source of energy in power plants. However, fugitive methane emissions in the production process may counter the benefit over coal with respect to climate change and therefore need to be well quantified. Here we demonstrate that positive methane anomalies associated with the oil and gas industries can be detected from space and that corresponding regional emissions can be constrained using satellite observations. On the basis of a mass-balance approach, we estimate that methane emissions for two of the fastest growing production regions in the United States, the Bakken and Eagle Ford formations, have increased by 990 ± 650 ktCH4 yr−1 and 530 ± 330 ktCH4 yr−1 between the periods 2006–2008 and 2009–2011. Relative to the respective increases in oil and gas production, these emission estimates correspond to leakages of 10.1% ± 7.3% and 9.1% ± 6.2% in terms of energy content, calling immediate climate benefit into question and indicating that current inventories likely underestimate the fugitive emissions from Bakken and Eagle Ford
Case Report: Management of a Multidrug-Resistant CMV-Strain in a Renal Transplant Recipient by High-Dose CMV-Specific Immunoglobulins, Modulation in Immunosuppression, and Induction of CMV-Specific Cellular Immunity
The management of multidrug-resistant strains of cytomegalovirus after solid organ
transplantation is challenging. This case report demonstrates the successful treatment
of a multidrug-resistant strain of cytomegalovirus that may represent a valuable option for
problematic cases. This report illustrates the emergence of a multidrug-resistant
cytomegalovirus (CMV) UL54 mutant strain in a renal transplant recipient with severe
lymphopenia and thrombocytopenia. We show that the combined treatment with highdose intravenous cytomegalovirus-specific immunoglobulins (CMV-IVIG) after the switch
to a mammalian target of rapamycin (mTOR)-inhibitor and cyclosporine A was a
successful treatment alternative to direct antiviral treatment with high-dose ganciclovir
and foscarnet. This treatment was associated with a quantitative induction of CMVspecific CD4 and CD8 T cells that showed maturation in phenotype and functionality with
decreasing viral load. Our case report illustrates that high-dose CMV-IVIG and conversion
of immunosuppressive drugs to mTOR inhibitors and cyclosporine A can be a successful
treatment in a situation where the use of direct antiviral drugs was considered insufficient
New developments on the WHIZARD event generator
We give a status report on new developments in the WHIZARD event generator,
including NLO electroweak automation for colliders, loop-induced
processes, POWHEG matching, new features in the UFO interface and the current
development for matching between exclusive photon radiation and fixed-order
LO/NLO electroweak (EW) corrections. We report on several bug fixes relevant
for certain aspects of the ILC250 Monte Carlo (MC) mass production, especially
on the normalization of matching EPA samples with full-matrix element samples.
Finally, we mention some ongoing work on efficiency improvements regarding
parallelization of matrix elements and phase space sampling, as well as plans
to revive the top threshold simulation.Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS 2023), 15-19 May 2023. C23-05-15.
Exclusive top production at a Linear Collider at and off the threshold
We review exclusive top pair production including decays at a future
high-energy lepton collider, both in the threshold region and for higher
energies. For the continuum process, we take complete QCD next-to-leading order
matrix elements for the process with leptonic W decays into account.
At threshold, we match the fixed-order relativistic QCD-NLO cross section to a
nonrelativistic cross section with next-to-leading logarithmic (NLL) threshold
resummation implemented via a form factor.Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS2017), Strasbourg, France, 23-27 October 2017. C17-10-23.
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