81 research outputs found
"Shifting Perspectives in Two Mid-Twentieth Century Robinsonades"
No full text© 2019, The Author(s). The attached document (embargoed until 30/09/2021) is an author produced version of a chapter published in DIDACTICS AND THE MODERN ROBINSONADE: NEW PARADIGMS FOR YOUNG READERS uploaded in accordance with the publisher’s self- archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it
"Shifting Perspectives in Two Mid-Twentieth Century Robinsonades"
No full text© 2019, The Author(s). The attached document (embargoed until 30/09/2021) is an author produced version of a chapter published in DIDACTICS AND THE MODERN ROBINSONADE: NEW PARADIGMS FOR YOUNG READERS uploaded in accordance with the publisher’s self- archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it
Energy-efficient acceleration of MPEG-4 compression tools
No full textWe propose novel hardware accelerator architectures for the most computationally demanding algorithms of the MPEG-4 video compression standard-motion estimation, binary motion estimation (for shape coding), and the forward/inverse discrete cosine transforms (incorporating shape adaptive modes). These accelerators have been designed using general low-energy design philosophies at the algorithmic/architectural abstraction levels. The themes of these philosophies are avoiding waste and trading area/performance for power and energy gains. Each core has been synthesised targeting TSMC 0.09
μm TCBN90LP technology, and the experimental results presented in this paper show that the proposed cores improve upon the prior art
Efficient hardware architectures for MPEG-4 core profile
No full textEfficient hardware acceleration architectures are proposed for the most demandingMPEG-4 core profile algorithms, namely; texture motion estimation (TME), binary motion estimation (BME)and the shape adaptive discrete cosine transform (SA-DCT). The proposed ME designs may also be used for H.264, since both architectures can handle variable block sizes. Both ME architectures employ early termination techniques that reduce latency and save needless memory accesses and power consumption. They also use a pixel subsampling technique to facilitate parallelism,
while balancing the computational load. The BME datapath also saves operations by using Run Length Coded (RLC) pixel addressing. The SA-DCT module has a re-configuring multiplier-less serial datapath using adders and multiplexers only to improve area and power. The SA-DCT packing steps are done using a minimal switching addressing scheme with guarded evaluation. All three modules have been synthesised targeting the WildCard-II FPGA benchmarking platform adopted by the MPEG-4 Part9 reference hardware group
Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices
No full textThis 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
Optimisation of constant matrix multiplication operation hardware using a genetic algorithm
No full textThe efficient design of multiplierless implementations of constant matrix multipliers is challenged by the huge solution search spaces even for small scale problems. Previous approaches tend to use hill-climbing algorithms risking sub-optimal results. The three-stage algorithm proposed in this paper partitions the global constant matrix multiplier into its constituent dot products, and all possible solutions are derived for each dot product in the first two stages. The third stage leverages the effective search capability of genetic programming to search for global solutions created by combining dot product partial solutions. A bonus feature of the algorithm is that the modelling is amenable to hardware acceleration. Another bonus feature is a search space reduction early exit mechanism, made possible by the way the algorithm is modelled. Results show an improvement on state of the art algorithms with future potential for even greater savings
Direct Observation of the Activation of MscL in Tethered Lipid Bilayers by an Antimicrobial Peptide
No full textData and Python code to support the manuscript "Direct Observation the Activation of MscL in Tethered Lipid Bilayers by an Antimicrobial Peptide". Abstract: Hypothesis Membrane proteins serve a wide range of vital roles in the functioning of living organisms. They account for approximately 20% to 30% of the genomes across bacterial, archaeal, and eukaryotic organisms. They are responsible for many cellular functions, such as signaling, ion and molecule transport, binding and catalytic reactions. Compared to other classes of proteins, determining membrane protein structures remains a challenge, in large part due to the difficulty in establishing experimental conditions that can preserve the correct conformation and function of the protein in isolation from its native environment. Many therapeutics target membrane proteins which are accessible on the surface of cells. Here we hypothesize that the observed efficacy of antimicrobial peptides (AMPs) that interact with bacterial membranes may in part be associated with their triggering of MscL (Mechansensitive Ion Channel of Large Conductance) gating. We further conjecture that the insertion of peptides into the membrane induces significant changes in membrane tension and/or curvature, leading to prolonged gating of the MscL channels.
Experiments We present realistic model membrane systems containing MscL. We investigated the ion channel in lipid vesicles and in a planar lipid bilayer. We developed a novel method for protein-lipid planar bilayer formation, avoiding the use of detergents. By using a polymeric tether our planar membrane mimetic was not constrained by the underlying solid substrate, making it sufficiently flexible to allow for increases in bilayer curvature and changes in membrane tension. We used quartz crystal microbalance with dissipation (QCM-D), and polarised neutron reflectivity (PNR) to show the formation of MscL containing phospholipid bilayers, tethered with a high density PEG layer onto gold substrates from vesicle rupture. The MscL containing vesicles were separately characterised with small angle neutron scattering (SANS).
Findings MscL was expressed into vesicles using cell free protein expression. Analysing these vesicles with small angle neutron scattering, the radius of gyration of the protein was determined to be between 26-29~\AA{}, consistent with the crystal structure of individual MscL channels. The MscL composition of the formed bilayer was 14\%v/v, close to the initial volume composition of the vesicles at ~13.6% and a protein protrusion extending ca. 46~\AA{} into the solvent was determined by PNR. Addition of 1.6 and 3.2 uM pexiganan resulted in a decrease in the protrusion of MscL (from ~46 to ~38~\AA{}). To our knowledge, these findings represent the first direct experimental evidence of a structural change in the C-terminus containing protrusion of MscL, triggered by an antimicrobial peptide. This adds to our understanding of antimicrobial peptide action in therapeutic treatments.Jupyter notebooks containing code to fit polarized neutron reflectivity data
Tether_bilayer_only_model-RefNX_volumes_final-Copy3.ipynb
MscL_1p6_PXG_model-RefNX_volumes_final.ipynb
MscL_3p2_PXG_model-RefNX_volumes_final.ipynb
SANS model fits and data
LysoPC
LysoPCmodel_1level_GP.csv
SANS_LysoPC_D2O.txt
MscLVesicle
MscLVesicle_2levelGPmodelfit.csv
SANS_MscLVesicle_D2O.txt
MscLVesicle post Lyso-PC
MscLVesicle_model_2level_GP.csv
SANS_MscLVesicle_LysoPC_D2O.txt
MscLVesicle post PXG
MscLvesicleafterPXG_model_2levelGP.csv
SANS_MscLVesicleafterPXG_D2O.txt
MscLVesicle(pre-PXG)
MscLVesicle_model_2level_GP.csv
SANS_MscLVesicle_D2O.txt
Neutron reflectivity datafiles used in the Jupyter notebooks
IvsQ_26838_26839_26840_IvsQ_26838_1_IvsQ_26839_1_IvsQ_26840_1.dat.txt
IvsQ_26841_26842_26843_IvsQ_26841_1_IvsQ_26842_1_IvsQ_26843_1.dat.txt
IvsQ_26841_26842_26843_IvsQ_26841_2_IvsQ_26842_2_IvsQ_26843_2.dat.txt
IvsQ_26844_26845_26846_IvsQ_26844_1_IvsQ_26845_1_IvsQ_26846_1.dat.txt
IvsQ_26844_26845_26846_IvsQ_26844_2_IvsQ_26845_2_IvsQ_26846_2.dat.txt
POLLREFfinalIvsQ_26838_26839_26840_IvsQ_26838_1_IvsQ_26839_1_IvsQ_26840_1.dat
POLLREFfinalIvsQ_26838_26839_26840_IvsQ_26838_2_IvsQ_26839_2_IvsQ_26840_2.dat
POLLREFfinalIvsQ_26854_26855_26856_IvsQ_26854_1_IvsQ_26855_1_IvsQ_26856_1.dat.txt
POLLREFfinalIvsQ_26854_26855_26856_IvsQ_26854_2_IvsQ_26855_2_IvsQ_26856_2.dat.txt
POLLREFfinalIvsQ_26860_26861_26862_IvsQ_26860_1_IvsQ_26861_1_IvsQ_26862_1.dat.txt
POLLREFfinalIvsQ_26860_26861_26862_IvsQ_26860_2_IvsQ_26861_2_IvsQ_26862_2.dat.txt
POLLREFfinalIvsQ_26863_26864_26865_IvsQ_26863_1_IvsQ_26864_1_IvsQ_26865_1.dat.txt
POLLREFfinalIvsQ_26863_26864_26865_IvsQ_26863_2_IvsQ_26864_2_IvsQ_26865_2.dat.txt
POLLREFfinalIvsQ_26875_26876_26877_IvsQ_26875_1_IvsQ_26876_1_IvsQ_26877_1.dat.txt
POLLREFfinalIvsQ_26875_26876_26877_IvsQ_26875_2_IvsQ_26876_2_IvsQ_26877_2.dat.txt
POLLREFfinalIvsQ_26878_26879_26880_IvsQ_26878_1_IvsQ_26879_1_IvsQ_26880_1.dat.txt
POLLREFfinalIvsQ_26878_26879_26880_IvsQ_26878_2_IvsQ_26879_2_IvsQ_26880_2.dat.txt
POLLREFfinalIvsQ_26881_26882_26883_IvsQ_26881_1_IvsQ_26882_1_IvsQ_26883_1.dat.txt
POLLREFfinalIvsQ_26881_26882_26883_IvsQ_26881_2_IvsQ_26882_2_IvsQ_26883_2.dat.tx
Towards an optimised VLSI design algorithm for the constant matrix multiplication problem
No full textThe efficient design of multiplierless implementations of constant matrix multipliers is challenged by the huge solution search spaces even for small scale problems. Previous approaches tend to use hill-climbing algorithms risking sub-optimal results. The proposed algorithm avoids this by exploring parallel solutions. The computational complexity is tackled by modelling the problem in a format amenable to genetic programming and hardware acceleration. Results show an improvement on state of the art algorithms with future potential for even greater savings
FPGA-based conformance testing and system prototyping of an MPEG-4 SA-DCT hardware accelerator
No full textTwo FPGA implementations of a shape adaptive discrete cosine transform (SA-DCT) accelerator are presented in this paper: one PCI-based and the other AMBA-based. The former is used for conformance testing with the MPEG-4 standard requirements. The latter is an alternative platform for system prototyping and has an architecture more representative of a mobile device. The proposed accelerator meets real time constraints on both platforms with a gate count of approximately 40k, and outperforms the optimised reference software implementation by 20/spl times/. It is estimated that the accelerator consumes 250mW on a Virtex-E FPGA and 79mW on a Virtex-II FPGA in the worst case scenario
"James Bond Studies: Evolutions of a Critical Field"
No full text© 2017, The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0
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