130,042 research outputs found

    The Orbifold-String Theories of Permutation-Type: I. One Twisted BRST per Cycle per Sector

    Get PDF
    We resume our discussion of the new orbifold-string theories of permutation-type, focusing in the present series on the algebraic formulation of the general bosonic prototype and especially the target space-times of the theories. In this first paper of the series, we construct one twisted BRST system for each cycle jj in each twisted sector σ\sigma of the general case, verifying in particular the previously-conjectured algebra [Qi(σ),Qj(σ)]+=0[Q_{i}(\sigma),Q_{j}(\sigma)]_{+} =0 of the BRST charges. The BRST systems then imply a set of extended physical-state conditions for the matter of each cycle at cycle central charge c^j(σ)=26fj(σ)\hat{c}_{j}(\sigma)=26f_{j}(\sigma) where fj(σ)f_{j}(\sigma) is the length of cycle jj.Comment: 31 page

    A novel frequency-domain implementation of Tomlinson-Harashima precoding for SC-FDMA

    Get PDF

    Joint Tomlinson-Harashima precoding and optimum transmit power allocation for SC-FDMA

    Get PDF

    Resolving single molecule structures with Nitrogen-vacancy centers in diamond.

    Get PDF
    We present theoretical proposals for two-dimensional nuclear magnetic resonance spectroscopy protocols based on Nitrogen-vacancy (NV) centers in diamond that are strongly coupled to the target nuclei. Continuous microwave and radio-frequency driving fields together with magnetic field gradients achieve Hartmann-Hahn resonances between NV spin sensor and selected nuclei for control of nuclear spins and subsequent measurement of their polarization dynamics. The strong coupling between the NV sensor and the nuclei facilitates coherence control of nuclear spins and relaxes the requirement of nuclear spin polarization to achieve strong signals and therefore reduced measurement times. Additionally, we employ a singular value thresholding matrix completion algorithm to further reduce the amount of data required to permit the identification of key features in the spectra of strongly sub-sampled data. We illustrate the potential of this combined approach by applying the protocol to a shallowly implanted NV center addressing a small amino acid, alanine, to target specific hydrogen nuclei and to identify the corresponding peaks in their spectra

    Evaluating the Impact of Critical Factors in Agile Continuous Delivery Process: A System Dynamics Approach

    Get PDF
    Continuous Delivery is aimed at the frequent delivery of good quality software in a speedy, reliable and efficient fashion – with strong emphasis on automation and team collaboration. However, even with this new paradigm, repeatability of project outcome is still not guaranteed: project performance varies due to the various interacting and inter-related factors in the Continuous Delivery 'system'. This paper presents results from the investigation of various factors, in particular agile practices, on the quality of the developed software in the Continuous Delivery process. Results show that customer involvement and the cognitive ability of the QA have the most significant individual effects on the quality of software in continuous delivery

    A Case Report of Systemic Sclerosis Complicated by Biventricular Heart Failure, Pulmonary Hypertension and Review of Literature

    Get PDF
    Background: Systemic sclerosis (SSc) is an autoimmune connective tissue disorder whose aetiology is not fully understood. Skin fibrosis and visceral organs involvement are the hallmarks, and the heart could be disproportionately or subtly involved. Cardiovascular manifestations could include arrhythmias, pericarditis, myocardial fibrosis, pulmonary hypertension and congestive heart failure. Pulmonary involvement could cause lung fibrosis, arteriolar thickening, and pulmonary hypertension. The presence of these manifestations confers a poor prognosis. Case Report: The case report presents a 50-year-old male patient with generalized skin sclerosis, hypo and hyperpigmented skin lesions, dyspnoea at rest, displaced apical impulse, tachycardia and pan-systolic murmur at the apex radiating to the axilla. Echo cardiography features showed ejection fraction of 33.3% with dilated atrial and ventricular chambers. Conclusions: We present a case systemic sclerosis complicated by biventricular heart failure and pulmonary hypertension

    A simplified approach to quantitative coded aperture X-ray phase imaging

    Get PDF
    We recently demonstrated how quantitative X-ray phase contrast imaging may be performed with laboratory sources using the coded aperture technique. This technique required the knowledge of system parameters such as, for example, the source focal spot size and distances between elements of the imaging system. The method also assumes that the absorbing regions of the apertures are perfectly absorbing. In this paper we demonstrate how quantitative imaging can be performed without knowledge of individual system parameters and with partially absorbing apertures. We also show that this method is analogous to that employed in analyser based imaging which uses the rocking curve of an analyser crystal

    Playing the Goblin Post Office game improves movement control of the core: a case study

    Get PDF
    Movement function of the core (trunk and pelvis) can be improved in cerebral palsy, potentially leading to benefits which transfer to activities of daily living. A single child with CP diplegia played our custom made game which runs on the CAREN system. Three playing postures gradually introduced more and more joints in the legs to be controlled. Vicon cameras tracked trunk and pelvic rotations which drove a dragon towards envelope targets. Forward speed of the game was adjusted by an adaptive algorithm leading to a maximum settled speed for the various conditions. Results showed that core control improved after the six week training period. The trunk was better controlled than the pelvis, sideways rotations were better controlled than fore-aft rotations of body segments, and single plane rotations were more efficient than cross-plane rotations of the core. The quantifiable improvements suggest a good potential for our technique to improve core control which is a prerequisite for good movement control of the legs and arms

    Frequency-domain precoding for single carrier frequency-division multiple access

    Get PDF
    corecore