1,654 research outputs found

    Computational Video Enhancement

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    During a video, each scene element is often imaged many times by the sensor. I propose that by combining information from each captured frame throughout the video it is possible to enhance the entire video. This concept is the basis of computational video enhancement. In this dissertation, the viability of computational video processing is explored in addition to presenting applications where this processing method can be leveraged. Spatio-temporal volumes are employed as a framework for efficient computational video processing, and I extend them by introducing sheared volumes. Shearing provides spatial frame warping for alignment between frames, allowing temporally-adjacent samples to be processed using traditional editing and filtering approaches. An efficient filter-graph framework is presented to support this processing along with a prototype video editing and manipulation tool utilizing that framework. To demonstrate the integration of samples from multiple frames, I introduce methods for improving poorly exposed low-light videos to achieve improved results. This integration is guided by a tone-mapping process to determine spatially-varying optimal exposures and an adaptive spatio-temporal filter to integrate the samples. Low-light video enhancement is also addressed in the multispectral domain by combining visible and infrared samples. This is facilitated by the use of a novel multispectral edge-preserving filter to enhance only the visible spectrum video. Finally, the temporal characteristics of videos are altered by a computational video resampling process. By resampling the video-rate footage, novel time-lapse sequences are found that optimize for user-specified characteristics. Each resulting shorter video is a more faithful summary of the original source than a traditional time-lapse video. Simultaneously, new synthetic exposures are generated to alter the output video's aliasing characteristics

    Digital droplet PCR and IDAA for the detection of CRISPR indel edits in the malaria species <i>Anopheles stephensi</i>

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    CRISPR/Cas9 technology is a powerful tool for the design of gene-drive systems to control and/or modify mosquito vector populations; however, CRISPR/Cas9-mediated nonhomologous end joining mutations can have an important impact on generating alleles resistant to the drive and thus on drive efficiency. We demonstrate and compare the insertions or deletions (indels) detection capabilities of two techniques in the malaria vector mosquito Anopheles stephensi: Indel Detection by Amplicon Analysis (IDAA™) and Droplet Digital™ PCR (ddPCR™). Both techniques showed accuracy and reproducibility for indel frequencies across mosquito samples containing different ratios of indels of various sizes. Moreover, these techniques have advantages that make them potentially better suited for high-throughput nonhomologous end joining analysis in cage trials and contained field testing of gene-drive mosquitoes

    Reconsidering "the love of art" : evaluating the potential of art museum outreach

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    Art museums have long been identified as bastions of social and cultural exclusion. This conclusion was best evidenced by the large-scale 1967 French study by Bourdieu and Darbel demonstrating the exclusionary nature of “The Love of Art.” However, in recent years there have been increasing efforts to reach out to a broader range of visitors beyond conventional audiences. The present study investigates the impacts of an outreach program at a UK art museum, which sought to engage socially excluded young mothers. This study employs ethnographic research methods on a longitudinal basis to develop qualitative insights about the program seeking to mitigate cultural exclusion. While the study’s findings uphold many longstanding critiques of art museums’ conventional approaches, the study also indicates that carefully designed outreach activities can overcome such limitations and enhance cultural engagement. Thus, art museums’ limited appeal is tied to problematic public engagement practices that can be changed

    Quantum-noise--randomized data-encryption for WDM fiber-optic networks

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    We demonstrate high-rate randomized data-encryption through optical fibers using the inherent quantum-measurement noise of coherent states of light. Specifically, we demonstrate 650Mbps data encryption through a 10Gbps data-bearing, in-line amplified 200km-long line. In our protocol, legitimate users (who share a short secret-key) communicate using an M-ry signal set while an attacker (who does not share the secret key) is forced to contend with the fundamental and irreducible quantum-measurement noise of coherent states. Implementations of our protocol using both polarization-encoded signal sets as well as polarization-insensitive phase-keyed signal sets are experimentally and theoretically evaluated. Different from the performance criteria for the cryptographic objective of key generation (quantum key-generation), one possible set of performance criteria for the cryptographic objective of data encryption is established and carefully considered.Comment: Version 2: Some errors have been corrected and arguments refined. To appear in Physical Review A. Version 3: Minor corrections to version

    Quantum Nonlocality without Entanglement

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    We exhibit an orthogonal set of product states of two three-state particles that nevertheless cannot be reliably distinguished by a pair of separated observers ignorant of which of the states has been presented to them, even if the observers are allowed any sequence of local operations and classical communication between the separate observers. It is proved that there is a finite gap between the mutual information obtainable by a joint measurement on these states and a measurement in which only local actions are permitted. This result implies the existence of separable superoperators that cannot be implemented locally. A set of states are found involving three two-state particles which also appear to be nonmeasurable locally. These and other multipartite states are classified according to the entropy and entanglement costs of preparing and measuring them by local operations.Comment: 27 pages, Latex, 6 ps figures. To be submitted to Phys. Rev. A. Version 2: 30 pages, many small revisions and extensions, author added. Version 3: Proof in Appendix D corrected, many small changes; final version for Phys. Rev. A Version 4: Report of Popescu conjecture modifie

    Dynamics of monatomic liquids

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    We present a theory of the dynamics of monatomic liquids built on two basic ideas: (1) The potential surface of the liquid contains three classes of intersecting nearly-harmonic valleys, one of which (the ``random'' class) vastly outnumbers the others and all whose members have the same depth and normal mode spectrum; and (2) the motion of particles in the liquid can be decomposed into oscillations in a single many-body valley, and nearly instantaneous inter-valley transitions called transits. We review the thermodynamic data which led to the theory, and we discuss the results of molecular dynamics (MD) simulations of sodium and Lennard-Jones argon which support the theory in more detail. Then we apply the theory to problems in equilibrium and nonequilibrium statistical mechanics, and we compare the results to experimental data and MD simulations. We also discuss our work in comparison with the QNM and INM research programs and suggest directions for future research.Comment: 53 pages, 16 figures. Differs from published version in using American English spelling and grammar (published version uses British English

    Implementation of PSMA PET/CT and alignment of ordering to SNMMI appropriate use criteria in a large network system

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    INTRODUCTION: The Society of Nuclear Medicine and Molecular Imaging (SNMMI) provides appropriate use criteria (AUC) for prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) which include guidance on imaging in newly diagnosed prostate cancer and in patients with biochemically recurrent (BCR) disease. This study aims to examine trends in PSMA implementation and the prevalence and outcomes of scans ordered in scenarios deemed rarely appropriate or not meeting SNMMI AUC. METHODS: We retrospectively identified patients who were diagnosed with presumptive National Comprehensive Cancer Network unfavorable intermediate, high, or very high risk prostate cancer, patients who underwent staging for BCR, and all patients staged with PSMA between July 2021 and March 2023. Positivity was validated by adherence to a predetermined reference standard. RESULTS: The frequency of PSMA use increased in initial staging from 24% to 80% and work-up of BCR from 91% to 99% over our study period. In addition, 5% (17/340) of PSMA scans ordered for initial staging did not meet AUC and 3% (15/557) of posttreatment scans were deemed rarely appropriate. Initial staging orders not meeting SNMMI AUC resulted in no positivity (0/17), while rarely appropriate posttreatment scans were falsely positive in 75% (3/4) of cases. Urologists (53%, 17/32) comprised the largest ordering specialty in rarely appropriate use. CONCLUSION: The frequency of PSMA use rose across the study period. A significant minority of patients received PSMA PET/CT in rarely appropriate scenarios yielding no positivity in initial staging and significant false positivity post-therapy. Further education of providers and electronic medical record-based interventions could help limit the rarely appropriate use of PET imaging

    HST/ACS Emission Line Imaging of Low Redshift 3CR Radio Galaxies I: The Data

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    We present 19 nearby (z<0.3) 3CR radio galaxies imaged at low- and high-excitation as part of a Cycle 15 Hubble Space Telescope snapshot survey with the Advanced Camera for Surveys. These images consist of exposures of the H-alpha (6563 \AA, plus [NII] contamination) and [OIII] 5007 \AA emission lines using narrow-band linear ramp filters adjusted according to the redshift of the target. To facilitate continuum subtraction, a single-pointing 60 s line-free exposure was taken with a medium-band filter appropriate for the target's redshift. We discuss the steps taken to reduce these images independently of the automated recalibration pipeline so as to use more recent ACS flat-field data as well as to better reject cosmic rays. We describe the method used to produce continuum-free (pure line-emission) images, and present these images along with qualitative descriptions of the narrow-line region morphologies we observe. We present H-alpha+[NII] and [OIII] line fluxes from aperture photometry, finding the values to fall expectedly on the redshift-luminosity trend from a past HST/WFPC2 emission line study of a larger, generally higher redshift subset of the 3CR. We also find expected trends between emission line luminosity and total radio power, as well as a positive correlation between the size of the emission line region and redshift. We discuss the associated interpretation of these results, and conclude with a summary of future work enabled by this dataset.Comment: 18 pages, 12 figures, accepted for publication in ApJ
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