208,481 research outputs found
Formal Verification of an Iterative Low-Power x86 Floating-Point Multiplier with Redundant Feedback
We present the formal verification of a low-power x86 floating-point
multiplier. The multiplier operates iteratively and feeds back intermediate
results in redundant representation. It supports x87 and SSE instructions in
various precisions and can block the issuing of new instructions. The design
has been optimized for low-power operation and has not been constrained by the
formal verification effort. Additional improvements for the implementation were
identified through formal verification. The formal verification of the design
also incorporates the implementation of clock-gating and control logic. The
core of the verification effort was based on ACL2 theorem proving.
Additionally, model checking has been used to verify some properties of the
floating-point scheduler that are relevant for the correct operation of the
unit.Comment: In Proceedings ACL2 2011, arXiv:1110.447
A Better Understanding of the Performance of Rate-1/2 Binary Turbo Codes that Use Odd-Even Interleavers
The effects of the odd-even constraint - as an interleaver design criterion -
on the performance of rate-1/2 binary turbo codes are revisited. According to
the current understanding, its adoption is favored because it makes the
information bits be uniformly protected, each one by its own parity bit. In
this paper, we provide instances that contradict this point of view suggesting
for a different explanation of the constraint's behavior, in terms of distance
spectrum
Evolution of oil droplets in a chemorobotic platform
Evolution, once the preserve of biology, has been widely emulated in software, while physically embodied systems that can evolve have been limited to electronic and robotic devices and have never been artificially implemented in populations of physically interacting chemical entities. Herein we present a liquid-handling robot built with the aim of investigating the properties of oil droplets as a function of composition via an automated evolutionary process. The robot makes the droplets by mixing four different compounds in different ratios and placing them in a Petri dish after which they are recorded using a camera and the behaviour of the droplets analysed using image recognition software to give a fitness value. In separate experiments, the fitness function discriminates based on movement, division and vibration over 21 cycles, giving successive fitness increases. Analysis and theoretical modelling of the data yields fitness landscapes analogous to the genotype–phenotype correlations found in biological evolution.
, Trevor Hinkley, James Ward Taylor Kliment Yane
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