342 research outputs found
Research methodology of grazing
Throughout Europe, grass is the main feed for dairy cattle. This report presents the main results of the first meeting of the European Grassland Federation (EGF) Working Group Grazing in Kiel on 29 August 2010. The theme of the meeting was "Research methodology of grazing". There were three sessions: - setting the scene; - modelling of grazing; and - field measurements
Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices
This paper addresses the problem of accelerating large artificial neural networks (ANN), whose topology and weights can evolve via the use of a genetic algorithm. The proposed digital hardware architecture is capable of processing any evolved network topology, whilst at the same time providing a good trade off between throughput, area and power consumption. The latter is vital for a longer battery life on mobile devices. The architecture uses multiple parallel arithmetic units in each processing element (PE). Memory partitioning and data caching are used to minimise the effects of PE pipeline stalling. A first order minimax polynomial approximation scheme, tuned via a genetic algorithm, is used for the activation function generator. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design
Linux kernel compaction through cold code swapping
There is a growing trend to use general-purpose operating systems like Linux in embedded systems. Previous research focused on using compaction and specialization techniques to adapt a general-purpose OS to the memory-constrained environment, presented by most, embedded systems. However, there is still room for improvement: it has been shown that even after application of the aforementioned techniques more than 50% of the kernel code remains unexecuted under normal system operation. We introduce a new technique that reduces the Linux kernel code memory footprint, through on-demand code loading of infrequently executed code, for systems that support virtual memory. In this paper, we describe our general approach, and we study code placement algorithms to minimize the performance impact of the code loading. A code, size reduction of 68% is achieved, with a 2.2% execution speedup of the system-mode execution time, for a case study based on the MediaBench II benchmark suite
Cache Based Power Analysis Attacks on AES
International audienceThis paper describes possible attacks against software implementations of AES running on processors with cache mechanisms, particularly in the case of smart cards. These attacks are based on sidechannel information gained by observing cache hits and misses in the current drawn by the smart card. Two dierent attacks are described. The first is a combination of ideas proposed in [2] and [11] to produce an attack that only requires the manipulation of the plain text and the observation of the current. The second is an attack based on specific implementations of the xtime function [10]. These attacks are shown to also work against algorithms using Boolean data masking techniques as a DPA countermeasure
Effectiveness of interventions targeting self-regulation to improve adherence to chronic disease medications: a meta-review of meta-analyses
Adherence to chronic disease medication regimens depends in part on successful self-regulation. However, the overall benefit of interventions targeting self-regulatory mechanisms is not well-understood. Accordingly, we conducted a meta-review of meta-analyses assessing the effect of interventions targeting self-regulation on medication adherence. For this meta-review, meta-analyses appearing between January 2006 and March 2019 were eligible if they included experimental trials that assessed the effect of an intervention targeting self-regulation on adherence to chronic disease medication. A systematic literature search of multiple databases for published and unpublished literature identified 16,001 abstracts. Twelve meta-analyses met eligibility criteria and had variable quality according to AMSTAR 2 item completion (M = 50%; range: 31–66%). Overall, meta-reviews showed small to medium effect sizes for interventions that targeted self-monitoring, provided personalised feedback on adherence, or involved complete self-management. Other interventions, such as goal setting, barrier identification and problem solving, and stress management showed little evidence of improving adherence. Only a limited number of self-regulation intervention components were able to be evaluated. Additional research is needed to advance the understanding of the efficacy of adherence interventions focussed on self-regulation by expanding the scope of self-regulation elements targeted (e.g., emotion regulation)
Register traffic analysis for streamlining inter-operation communication in fine-grain parallel processors
Constructive and destructive use of compilers in elliptic curve cryptography
Although cryptographic software implementation is often performed by expert programmers, the range of performance and security driven options, as well as more mundane software engineering issues, still make it a challenge. The use of domain specific language and compiler techniques to assist in description and optimisation of cryptographic software is an interesting research challenge. In this paper we investigate two aspects of such techniques, focusing on Elliptic Curve Cryptography (ECC) in particular. Our constructive results show that a suitable language allows description of ECC based software in a manner close to the original mathematics; the corresponding compiler allows automatic production of an executable whose performance is competitive with that of a hand-optimised implementation. In contrast, we study the worrying potential for naïve compiler driven optimisation to render cryptographic software insecure. Both aspects of our work are set within the context of CACE, an ongoing EU funded project on this general topic
Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments
Multi-core processing environments have become the norm in the generic computing environment and are being considered for adding an extra dimension to the execution of any application. The T2 Niagara processor is a very unique environment where it consists of eight cores having a capability of running eight threads simultaneously in each of the cores. Applications like General Atomic and Molecular Electronic Structure (GAMESS), used for ab-initio molecular quantum chemistry calculations, can be good indicators of the performance of such machines and would be a guideline for both hardware designers and application programmers. In this paper we try to benchmark the GAMESS performance on a T2 Niagara processor for a couple of molecules. We also show the suitability of using a middleware based adaptation algorithm on GAMESS on such a multi-core environment
Elastic and inelastic SU(3)-breaking final-state interactions in B decays to pseudoscalar mesons
We discuss all contributions from Zweig-rule-satisfying SU(3)-breaking final
state interactions (FSIs)in the B -> PP decays (neglecting charmed intermediate
states), where PP=pi pi, pi K, KK, pi eta (eta'), and K eta (eta'). First,
effects of SU(3) breaking in rescattering through Pomeron exchange are studied.
Then, after making a plausible assumption concerning the pattern of SU(3)
breaking in non-Pomeron FSIs, we give general formulas for how the latter
modify short-distance (SD) amplitudes. In the SU(3) limit, these formulas
depend on three effective parameters characterizing the strength of all
non-Pomeron rescattering effects. We point out that the experimental bounds on
the B -> K^+K^- branching ratio may limit the value of only one of these FSI
parameters. Thus, the smallness of the B -> K^+K^- decay rate does not imply
negligible rescattering effects in other decays. Assuming a vanishing value of
this parameter, we perform various fits to the available B -> PP branching
ratios. The fits determine the quark-diagram SD amplitudes, the two remaining
FSI parameters and the weak angle gamma. While the set of all B -> PP branching
ratios is well described with gamma around its expected SM value, the fits
permit other values of gamma as well. For a couple of such good fits, we
predict asymmetries for the B -> K pi, pi^+ eta (eta'), K^+ eta (eta') decays
as well as the values of the CP-violating parameters S_{pi pi} and C_{pi pi}
for the time-dependent rate of B^0(t) -> pi^+ pi^-. Apart from a problem with
the recent B^+ -> pi^+ eta asymmetry measurement, comparison with the data
seems to favour the values of gamma in accordance with SM expectations.Comment: 27 pages, 5 figure
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