1,484 research outputs found

    Demonstration of Inexact Computing Implemented in the JPEG Compression Algorithm using Probabilistic Boolean Logic applied to CMOS Components

    Get PDF
    Probabilistic computing offers potential improvements in energy, performance, and area compared with traditional digital design. This dissertation quantifies energy and energy-delay tradeoffs in digital adders, multipliers, and the JPEG image compression algorithm. This research shows that energy demand can be cut in half with noisesusceptible16-bit Kogge-Stone adders that deviate from the correct value by an average of 3 in 14 nanometer CMOS FinFET technology, while the energy-delay product (EDP) is reduced by 38 . This is achieved by reducing the power supply voltage which drives the noisy transistors. If a 19 average error is allowed, the adders are 13 times more energy-efficient and the EDP is reduced by 35 . This research demonstrates that 92 of the color space transform and discrete cosine transform circuits within the JPEG algorithm can be built from inexact components, and still produce readable images. Given the case in which each binary logic gate has a 1 error probability, the color space transformation has an average pixel error of 5.4 and a 55 energy reduction compared to the error-free circuit, and the discrete cosine transformation has a 55 energy reduction with an average pixel error of 20

    Effects of Channel Mismatches on Beamforming and Signal Detection

    Get PDF
    Tuner gain measurements of a multichannel receiver are reported. A linear regression model is used to characterize the gain, as a function of channel number, tuner set-on frequency, and intermediate frequency. Residual errors of this model are characterized by a t distribution. Very strong autocorrelation of tuner gain at various frequencies is noted. Tuner performance from one channel to the next is diverse; several defects at specific frequencies are noted. The Wilcoxon signed rank test is used to test normality of tuner gain among devices; normality is rejected. Antenna directivity and phase pattern measurements are also reported. An antenna element pattern is presented, along with residual errors. An array pattern model is constructed using steering vectors. Simulated gain and phase mismatches are used to predict their effects on antenna beamforming and signal detection

    Panel No. 2: Arbitration in Consumer Transactions

    Get PDF
    The use of arbitration in the consumer context has been particularly controversial. The presentations will address whether the FAA (“Federal Arbitration Act”) should be amended to ban pre-dispute provisions for arbitration in the adhesive circumstances of consumer traditions; recent litigation surrounding UBER’s use of an arbitral clause in its service contracts; and existing and potential controversies associated with the use of on-line arbitration

    Panel No. 2: Arbitration in Consumer Transactions

    Get PDF
    The use of arbitration in the consumer context has been particularly controversial. The presentations will address whether the FAA (“Federal Arbitration Act”) should be amended to ban pre-dispute provisions for arbitration in the adhesive circumstances of consumer traditions; recent litigation surrounding UBER’s use of an arbitral clause in its service contracts; and existing and potential controversies associated with the use of on-line arbitration

    Detectors—The ongoing revolution in scanning transmission electron microscopy and why this important to material characterization

    Get PDF
    Detectors are revolutionizing possibilities in scanning transmission electron microscopy because of the advent of direct electron detectors that record at a high quantum efficiency and with a high frame rate. This allows the whole back focal plane to be captured for each pixel in a scan and the dataset to be processed to reveal whichever features are of interest. There are many possible uses for this advance of direct relevance to understanding the nano- and atomic-scale structure of materials and heterostructures. This article gives our perspective of the current state of the field and some of the directions where it is likely to go next. First, a wider overview of the recent work in this area is given before two specific examples of its application are given: one is imaging strain in thin films and the other one is imaging changes in periodicity along the beam direction as a result of the formation of an ordered structure in an epitaxial thin film. This is followed by an outlook that presents future possible directions in this rapidly expanding field

    A flavour of omics approaches for the detection of food fraud

    Get PDF
    Food fraud has been identified as an increasing problem on a global scale with wide-ranging economic, social, health and environmental impacts. Omics and their related techniques, approaches, and bioanalytical platforms incorporate a significant number of scientific areas which have the potential to be applied to and significantly reduce food fraud and its negative impacts. In this overview we consider a selected number of very recent studies where omics techniques were applied to detect food authenticity and could be implemented to ensure food integrity. We postulate that significant reductions in food fraud, with the assistance of omics technologies and other approaches, will result in less food waste, decreases in energy use as well as greenhouse gas emissions, and as a direct consequence of this, increases in quality, productivity, yields, and the ability of food systems to be more resilient and able to withstand future food shocks

    Atomic Structure and Dynamics of Single Platinum Atom Interactions with Monolayer MoS

    Get PDF
    We have studied atomic level interactions between single Pt atoms and the surface of monolayer MoSâ‚‚ using aberration-corrected annular dark field scanning transmission electron microscopy at an accelerating voltage of 60 kV. Strong contrast from single Pt atoms on the atomically resolved monolayer MoSâ‚‚ lattice enables their exact position to be determined with respect to the MoSâ‚‚ lattice, revealing stable binding sites. In regions of MoSâ‚‚ free from surface contamination, the Pt atoms are localized in S vacancy sites and exhibit dynamic hopping to nearby vacancy sites driven by the energy supplied by the electron beam. However, in areas of MoSâ‚‚ contaminated with carbon surface layers, the Pt atoms appear at various positions with respect to the underlying MoSâ‚‚ lattice, including on top of Mo and in off-axis positions. These variations are due to the Pt bonding with the surrounding amorphous carbon layer, which disrupts the intrinsic Pt-MoSâ‚‚ interactions, leading to more varied positions. Density functional theory (DFT) calculations reveal that Pt atoms on the surface of MoSâ‚‚ have a small barrier for migration and are stabilized when bound to either a single or double sulfur vacancies. DFT calculations have been used to understand how the catalytic activity of the MoSâ‚‚ basal plane for hydrogen evolution reaction is influenced by Pt dopants by variation of the hydrogen adsorption free energy. This strong dependence of catalytic effect on interfacial configurations is shown to be common for a series of dopants, which may provide a means to create and optimize reaction centers

    Quantifying the Performance of a Hybrid Pixel Detector with GaAs:Cr Sensor for Transmission Electron Microscopy

    Get PDF
    Hybrid pixel detectors (HPDs) have been shown to be highly effective for diffraction-based and time-resolved studies in transmission electron microscopy, but their performance is limited by the fact that high-energy electrons scatter over long distances in their thick Si sensors. An advantage of HPDs compared to monolithic active pixel sensors (MAPS) is that their sensor does not need to be fabricated from Si. We have compared the performance of the Medipix3 HPD with a Si sensor and with a GaAs:Cr sensor using primary electrons in the energy range of 60 - 300keV. We describe the measurement and calculation of the detectors' modulation transfer function (MTF) and detective quantum efficiency (DQE), which show that the performance of the GaAs:Cr device is markedly superior to that of the Si device for high-energy electrons.Comment: 15 pages + references, 13 figure

    Designer diatom episomes delivered by bacterial conjugation.

    Get PDF
    Eukaryotic microalgae hold great promise for the bioproduction of fuels and higher value chemicals. However, compared with model genetic organisms such as Escherichia coli and Saccharomyces cerevisiae, characterization of the complex biology and biochemistry of algae and strain improvement has been hampered by the inefficient genetic tools. To date, many algal species are transformable only via particle bombardment, and the introduced DNA is integrated randomly into the nuclear genome. Here we describe the first nuclear episomal vector for diatoms and a plasmid delivery method via conjugation from Escherichia coli to the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. We identify a yeast-derived sequence that enables stable episome replication in these diatoms even in the absence of antibiotic selection and show that episomes are maintained as closed circles at copy number equivalent to native chromosomes. This highly efficient genetic system facilitates high-throughput functional characterization of algal genes and accelerates molecular phytoplankton research
    • …
    corecore