176 research outputs found

    Forgetting in Answer Set Programming with Anonymous Cycles

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    FORGET (PTDC/CCI-INF/32219/2017). NOVA LINCS (UID/CEC/04516/2019).It is now widely accepted that the operation of forgetting in the context of Answer Set Programming [10, 18] is best characterized by the so-called strong persistence, a property that requires that all existing relations between the atoms not to be forgotten be preserved. However, it has been shown that strong persistence cannot always be satisfied. What happens if we must nevertheless forget? One possibility that has been explored before is to consider weaker versions of strong persistence, although not without a cost: some relations between the atoms not to be forgotten are broken in the process. A different alternative is to enhance the logical language so that all such relations can be maintained after the forgetting operation. In this paper, we borrow from the recently introduced notion of fork [1] – a conservative extension of Equilibrium Logic and its monotonic basis, the logic of Here-and-There – which has been shown to be sufficient to overcome the problems related to satisfying strong persistence. We map this notion into the language of logic programs, enhancing it with so-called anonymous cycles, and we introduce a concrete syntactical forgetting operator over this enhanced language that we show to always obey strong persistence.publishe

    Multilayer Plasmonic Nanostructures for Improved Sensing Activities Using a FEM and Neurocomputing-Based Approach

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    In order to obtain optimized elementary devices (photovoltaic modules, power transistors for energy efficiency, high-efficiency sensors) it is necessary to increase the energy conversion efficiency of these devices. A very effective approach to achieving this goal is to increase the absorption of incident radiation. A promising strategy to increase this absorption is to use very thin regions of active material and trap photons near these surfaces. The most effective and cost-effective method of achieving such optical entrapment is the Raman scattering from excited nanoparticles at the plasmonic resonance. The field of plasmonics is the study of the exploitation of appropriate layers of metal nanoparticles to increase the intensity of radiation in the semiconductor by means of near-field effects produced by nanoparticles. In this paper, we focus on the use of metal nanoparticles as plasmonic nanosensors with extremely high sensitivity, even reaching single-molecule detection. The study conducted in this paper was used to optimize the performance of a prototype of a plasmonic photovoltaic cell made at the Institute for Microelectronics and Microsystems IMM of Catania, Italy. This prototype was based on a multilayer structure composed of the following layers: glass, AZO, metal and dielectric. In order to obtain good results, it is necessary to use geometries that orthogonalize the absorption of light, allowing better transport of the photocarriers—and therefore greater efficiency—or the use of less pure materials. For this reason, this study is focused on optimizing the geometries of these multilayer plasmonic structures. More specifically, in this paper, by means of a neurocomputing procedure and an electromagnetic fields analysis performed by the finite elements method (FEM), we established the relationship between the thicknesses of Aluminum-doped Zinc oxide (AZO), metal, dielectric and their main properties, characterizing the plasmonic propagation phenomena as the optimal wavelengths values at the main interfaces AZO/METAL and METAL/DIELECTRIC

    Модель оценивания уровня опасности ситуаций в задачах функционирования сложных объектов

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    Запропоновано модель оцінювання інформаційного забезпечення особи, що приймає рішення (ОПР), яка ґрунтується на дослідженні якісних показників інформованості: повноти, достовірності та своєчасності інформованості ОПР. На основі цих показників сформовано рівень небезпеки ситуації під час функціонування складних об’єктів. Для реалізації моделі використовувалися методи однопараметричної класифікації з операціями перетину нечітких множин і сильного перетину, методи інтервальної класифікації з операціями об'єднання і перетину нечітких множин, а також з операціями сильного об'єднання і перетину нечітких множин. Запропоновані методи дозволяють класифікувати ситуації для інформування ОПР про обгрунтованість і безпеку прийняття рішення за наявного інформаційного забезпечення. Розроблена модель базується на дослідженні якісних показників інформованості ОПР і може бути застосована для оцінювання рівня небезпеки ситуацій в задачах функціонування складних об'єктів.The model of information support estimation of the decision maker (DM) based on a study of qualitative indicators of informedness, which characterizes the completeness, accuracy and timeliness of DM informedness , is presented. On the basis of these characteristics the level of danger situations in the operation of complex objects is formed. In implementing the model are used the methods of one-parameter classification with operations of fuzzy sets and strong intersections, as well as methods of interval classification with the operations of union and intersection of fuzzy sets, and also with operations of strong union and intersection of fuzzy sets. The proposed methods allow classifying the situation to inform DM about the validity and security of the decision with the available information support. The proposed model is based on a study of qualitative characteristics of informedness of DM and can be used to estimate the level of danger situations in the problems of the complex objects operation.Предложена модель оценивания информационного обеспечения лица, принимающего решения (ЛПР), основанная на исследовании качественных показателей информированности: полноты, достоверности и своевременности информированности ЛПР. На основе этих показателей сформирован уровень опасности ситуаций при функционировании сложных объектов. Для реализации модели использовались методы однопараметрической классификации с операциями пересечения нечетких множеств и сильного пересечения, методы интервальной классификации с операциями объединения и пересечения нечетких множеств, а также с операциями сильного объединения и пересечения нечетких множеств. Предложенные методы позволяют классифицировать ситуации для информирования ЛПР об обоснованности и безопасности принятия решения при имеющемся информационном обеспечении. Разработанная модель базируется на исследовании качественных показателей информированности ЛПР и может быть применена для оценивания уровня опасности ситуаций в задачах функционирования сложных объектов

    Adapting a HEP Application for Running on the Grid

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    The goal of the EU IST int.eu.grid project is to build middleware facilities which enable the execution of real-time and interactive applications on the Grid. Within this research, relevant support for the HEP application is provided by Virtual Organization, monitoring system, and real-time dispatcher (RTD). These facilities realize the pilot jobs idea that allows to allocate grid resources in advance and to analyze events in real time. In the paper we present HEP Virtual Organization, the details of monitoring, and RTD. We present the way of running the HEP application using the above facilities to fit into the real-time application requirements

    Application of <sup>14</sup>C analyses to source apportionment of carbonaceous PM<sub>2.5</sub> in the UK

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    Determination of the radiocarbon (&lt;sup&gt;14&lt;/sup&gt;C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM&lt;sub&gt;2.5&lt;/sub&gt; were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of &lt;sup&gt;14&lt;/sup&gt;C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO&lt;sub&gt;2&lt;/sub&gt;, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM&lt;sub&gt;2.5&lt;/sub&gt; samples was 0.50 (range 0.27–0.66, n = 26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and for the high values of these two parameters to be associated with air-mass back trajectories arriving in Birmingham from over land. Using a five-compartment mass balance model on fraction contemporary carbon in OC and EC, the following average source apportionment for the TC in these PM&lt;sub&gt;2.5&lt;/sub&gt; samples was derived: 27% fossil EC; 20% fossil OC; 2% biomass EC; 10% biomass OC; and 41% biogenic OC. The latter category will comprise, in addition to BVOC-derived SOC, other non-combustion contemporary carbon sources such as biological particles, vegetative detritus, humic material and tyre wear. The proportion of total PM&lt;sub&gt;2.5&lt;/sub&gt; at this location estimated to derive from BVOC-derived secondary organic aerosol was 9–29%. The findings from this work are consistent with those from elsewhere in Europe and support the conclusion of a significant and ubiquitous contribution from non-fossil biogenic sources to the carbon in terrestrial aerosol

    Characteristics and comparative clinical outcomes of prisoner versus non-prisoner populations hospitalized with COVID-19

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    Prisons in the United States have become a hotbed for spreading COVID-19 among incarcerated individuals. COVID-19 cases among prisoners are on the rise, with more than 143,000 confirmed cases to date. However, there is paucity of data addressing clinical outcomes and mortality in prisoners hospitalized with COVID-19. An observational study of all patients hospitalized with COVID-19 between March 10 and May 10, 2020 at two Henry Ford Health System hospitals in Michigan. Clinical outcomes were compared amongst hospitalized prisoners and non-prisoner patients. The primary outcomes were intubation rates, in-hospital mortality, and 30-day mortality. Multivariable logistic regression and Cox-regression models were used to investigate primary outcomes. Of the 706 hospitalized COVID-19 patients (mean age 66.7 ± 16.1 years, 57% males, and 44% black), 108 were prisoners and 598 were non-prisoners. Compared to non-prisoners, prisoners were more likely to present with fever, tachypnea, hypoxemia, and markedly elevated inflammatory markers. Prisoners were more commonly admitted to the intensive care unit (ICU) (26.9% vs. 18.7%), required vasopressors (24.1% vs. 9.9%), and intubated (25.0% vs. 15.2%). Prisoners had higher unadjusted inpatient mortality (29.6% vs. 20.1%) and 30-day mortality (34.3% vs. 24.6%). In the adjusted models, prisoner status was associated with higher in-hospital death (odds ratio, 2.32; 95% confidence interval (CI), 1.33 to 4.05) and 30-day mortality (hazard ratio, 2.00; 95% CI, 1.33 to 3.00). In this cohort of hospitalized COVID-19 patients, prisoner status was associated with more severe clinical presentation, higher rates of ICU admissions, vasopressors requirement, intubation, in-hospital mortality, and 30-day mortality

    Applying the resources and supports in self-management framework to examine ophthalmologist-patient communication and glaucoma medication adherence

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    Little is known about how ophthalmologist-patient communication over time is associated with glaucoma patient long-term adherence. The purpose of our study was to examine the association between provider use of components of the resources and supports in self-management model when communicating with patients and adherence to glaucoma medications measured electronically over an 8-month period. In this longitudinal prospective cohort study, the main variables studied were ophthalmologist communication-individualized assessment, collaborative goal setting and skills enhancement. Patients with glaucoma who were newly prescribed or on glaucoma medications were recruited from six ophthalmology clinics. Patients’ baseline and next follow-up visits were videotape-recorded. Patients were interviewed after their visits. Patients used medication event monitoring systems (MEMS) for 8 months after enrollment into the study, and adherence was measured electronically using MEMS for 240 days after their visits. Two hundred and seventy-nine patients participated. Patient race and regimen complexity were negatively associated with glaucoma medication adherence over an 8-month period. Provider communication behaviors, including providing education and positive reinforcement, can improve patient adherence to glaucoma medications over an 8-month period

    Minimal residual disease assessment in B-cell precursor acute lymphoblastic leukemia by semi-automated identification of normal hematopoietic cells:A EuroFlow study

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    Presence of minimal residual disease (MRD), detected by flow cytometry, is an important prognostic biomarker in the management of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, data-analysis remains mainly expert-dependent. In this study, we designed and validated an Automated Gating &amp; Identification (AGI) tool for MRD analysis in BCP-ALL patients using the two tubes of the EuroFlow 8-color MRD panel. The accuracy, repeatability, and reproducibility of the AGI tool was validated in a multicenter study using bone marrow follow-up samples from 174 BCP-ALL patients, stained with the EuroFlow BCP-ALL MRD panel. In these patients, MRD was assessed both by manual analysis and by AGI tool supported analysis. Comparison of MRD levels obtained between both approaches showed a concordance rate of 83%, with comparable concordances between MRD tubes (tube 1, 2 or both), treatment received (chemotherapy versus targeted therapy) and flow cytometers (FACSCanto versus FACSLyric). After review of discordant cases by additional experts, the concordance increased to 97%. Furthermore, the AGI tool showed excellent intra-expert concordance (100%) and good inter-expert concordance (90%). In addition to MRD levels, also percentages of normal cell populations showed excellent concordance between manual and AGI tool analysis. We conclude that the AGI tool may facilitate MRD analysis using the EuroFlow BCP-ALL MRD protocol and will contribute to a more standardized and objective MRD assessment. However, appropriate training is required for the correct analysis of MRD data.</p

    Exploring the Design Space of Static and Incremental Graph Connectivity Algorithms on GPUs

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    Connected components and spanning forest are fundamental graph algorithms due to their use in many important applications, such as graph clustering and image segmentation. GPUs are an ideal platform for graph algorithms due to their high peak performance and memory bandwidth. While there exist several GPU connectivity algorithms in the literature, many design choices have not yet been explored. In this paper, we explore various design choices in GPU connectivity algorithms, including sampling, linking, and tree compression, for both the static as well as the incremental setting. Our various design choices lead to over 300 new GPU implementations of connectivity, many of which outperform state-of-the-art. We present an experimental evaluation, and show that we achieve an average speedup of 2.47x speedup over existing static algorithms. In the incremental setting, we achieve a throughput of up to 48.23 billion edges per second. Compared to state-of-the-art CPU implementations on a 72-core machine, we achieve a speedup of 8.26--14.51x for static connectivity and 1.85--13.36x for incremental connectivity using a Tesla V100 GPU
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