190 research outputs found
Interpenetrating Waves and Multiple Generation Shocks via the CEDT
This volume contains papers presented at the Third International Workshop on Visual Form. It covers the most important topics of current interest in the field, presenting an updated collection of results achieved by leading academic and industrial research groups from several countries. The book contains invited lectures and research papers dealing with theoretical and applicative aspects of shape perception, representation, decomposition, description and recognition, as well as related topics
Conservation-Minded Evolution of Shape
©1990 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/ISIC.1990.128457Presented at the 5th IEEE International Symposium on Intelligent Control, 5-7 September 1990, Philadelphia, PAMost natural and artificial systems rely heavily on vision to recognize, manipulate, and navigate within a world of objects. Although shape is a key element in this process, its representation and analysis have proved to be a difficult, multifaceted problem. A framework, based on conservation laws, which gives rise to computational elements for shape parts, protrusions, and bends, is proposed. The computation takes place in the context of a reaction-diffusion space and is highly robust. This scheme is ideally suited to object recognition and has applications in areas ranging from robotics to the psychology and the physiology of form
QEYSSat 2.0 -- White Paper on Satellite-based Quantum Communication Missions in Canada
We present the white paper developed during the QEYSSat 2.0 study, which was
undertaken between June 2021 and March 2022. The study objective was to
establish a technology road-map for a Canada-wide quantum network enabled by
satellites. We survey the state-of-art in quantum communication technologies,
identify the main applications and architectures, review the technical
readiness levels and technology bottlenecks and identify a future mission
scenario. We report the findings of a dedicated one-day workshop that included
Canadian stakeholders from government, industry and academia to gather inputs
and insights for the applications and technical road-map. We also provide an
overview of the Quantum EncrYption and Science Satellite (QEYSSat) mission
expected to launch in 2024-2025 and its anticipated outcomes. One of the main
outcomes of this study is that developing the main elements for a Canada-wide
quantum internet will have the highest level of impact, which includes
Canada-wide entanglement distribution and teleportation. We present and analyze
a possible future mission ('QEYSSat 2.0') that would enable a long range
quantum teleportation across Canada as an important step towards this vision.Comment: 108 pages, 38 figures, white paper to be submitted to CJ
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ARHGEF9 disease: Phenotype clarification and genotype-phenotype correlation.
ObjectiveWe aimed to generate a review and description of the phenotypic and genotypic spectra of ARHGEF9 mutations.MethodsPatients with mutations or chromosomal disruptions affecting ARHGEF9 were identified through our clinics and review of the literature. Detailed medical history and examination findings were obtained via a standardized questionnaire, or if this was not possible by reviewing the published phenotypic features.ResultsA total of 18 patients (including 5 females) were identified. Six had de novo, 5 had maternally inherited mutations, and 7 had chromosomal disruptions. All females had strongly skewed X-inactivation in favor of the abnormal X-chromosome. Symptoms presented in early childhood with delayed motor development alone or in combination with seizures. Intellectual disability was severe in most and moderate in patients with milder mutations. Males with severe intellectual disability had severe, often intractable, epilepsy and exhibited a particular facial dysmorphism. Patients with mutations in exon 9 affecting the protein's PH domain did not develop epilepsy.ConclusionsARHGEF9 encodes a crucial neuronal synaptic protein; loss of function of which results in severe intellectual disability, epilepsy, and a particular facial dysmorphism. Loss of only the protein's PH domain function is associated with the absence of epilepsy
HIV transmission dynamics and population-wide drug resistance in rural South Africa
Despite expanded antiretroviral therapy (ART) in South Africa, HIV-1 transmission persists. Integrase strand transfer inhibitors (INSTI) and long-acting injectables offer potential for superior viral suppression, but pre-existing drug resistance could threaten their effectiveness. In a community-based study in rural KwaZulu-Natal, prior to widespread INSTI usage, we enroled 18,025 individuals to characterise HIV-1 drug resistance and transmission networks to inform public health strategies. HIV testing and reflex viral load quantification were performed, with deep sequencing (20% variant threshold) used to detect resistance mutations. Phylogenetic and geospatial analyses characterised transmission clusters. One-third of participants were HIV-positive, with 21.7% having detectable viral loads; 62.1% of those with detectable viral loads were ART-naïve. Resistance to older reverse transcriptase (RT)-targeting drugs was found, but INSTI resistance remained low (<1%). Non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance, particularly to rilpivirine (RPV) even in ART-naïve individuals, was concerning. Twenty percent of sequenced individuals belonged to transmission clusters, with geographic analysis highlighting higher clustering in peripheral and rural areas. Our findings suggest promise for INSTI-based strategies in this setting but underscore the need for RPV resistance screening before implementing long-acting cabotegravir (CAB) + RPV. The significant clustering emphasises the importance of geographically targeted interventions to effectively curb HIV-1 transmission
Balancing Image Privacy and Usability with Thumbnail-Preserving Encryption
In this paper, we motivate the need for image encryption techniques that preserve certain visual features in images and hide all other information, to balance privacy and usability in the context of cloud-based image storage services. In particular, we introduce the concept of ideal or exact Thumbnail-Preserving Encryption (TPE), a special case of format-preserving encryption, and present a concrete construction. In TPE, a ciphertext is itself an image that has the same thumbnail as the plaintext (unencrypted) image, but that provably leaks nothing about the plaintext beyond its thumbnail. We provide a formal security analysis for the construction, and a prototype implementation to demonstrate compatibility with existing services. We also study the ability of users to distinguish between thumbnail images preserved by TPE. Our findings indicate that TPE is an efficient and promising approach to balance usability and privacy concerns for images. Our code and a demo are available at http://photoencryption.org
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