121 research outputs found

    Análisis del impacto de Twitter y Weibo en la comunicación en la crisis del COVID-19 en España Y China

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    [ES] COVID-19 ha ejercido una enorme presión sobre los ciudadanos, los recursos y la economía de muchos países de todo el mundo. Las medidas de alienación social, las prohibiciones de viaje, el autoaislamiento y los fracasos comerciales están cambiando la estructura de la sociedad global. A medida que las personas se ven obligadas a abandonar lugares públicos, las redes sociales se convierten en los ojos de las personas que miran el mundo. Todas las tendencias relacionadas con COVID-19 se difunden en línea, como en las plataformas de redes sociales como Twitter y Weibo. En la actualidad, COVID-19 es el mayor problema al que se enfrenta el mundo. Por tanto, el contenido de mi trabajo final de master trata sobre el impacto de las redes sociales en la propagación de COVID-19.[EN] COVID-19 has put enormous pressure on citizens, resources and the economy of many countries around the world. Social alienation measures, travel bans, self-isolation, and business failures are changing the fabric of global society. As people are forced to leave public places, social media becomes the eyes of people looking at the world. All trends related to COVID-19 are being spread online, such as on social media platforms like Twitter and Weibo. Currently, COVID-19 is the biggest problem facing the world. Therefore, the content of my final master thesis deals with the impact of social networks on the spread of COVID-19.Feng, S. (2020). Análisis del impacto de Twitter y Weibo en la comunicación en la crisis del COVID-19 en España Y China. Universitat Politècnica de València. http://hdl.handle.net/10251/159396TFG

    Multiresolution Feature Guidance Based Transformer for Anomaly Detection

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    Anomaly detection is represented as an unsupervised learning to identify deviated images from normal images. In general, there are two main challenges of anomaly detection tasks, i.e., the class imbalance and the unexpectedness of anomalies. In this paper, we propose a multiresolution feature guidance method based on Transformer named GTrans for unsupervised anomaly detection and localization. In GTrans, an Anomaly Guided Network (AGN) pre-trained on ImageNet is developed to provide surrogate labels for features and tokens. Under the tacit knowledge guidance of the AGN, the anomaly detection network named Trans utilizes Transformer to effectively establish a relationship between features with multiresolution, enhancing the ability of the Trans in fitting the normal data manifold. Due to the strong generalization ability of AGN, GTrans locates anomalies by comparing the differences in spatial distance and direction of multi-scale features extracted from the AGN and the Trans. Our experiments demonstrate that the proposed GTrans achieves state-of-the-art performance in both detection and localization on the MVTec AD dataset. GTrans achieves image-level and pixel-level anomaly detection AUROC scores of 99.0% and 97.9% on the MVTec AD dataset, respectively

    Non-covalent interactions in electrochemical reactions and implications in clean energy applications

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    Understanding and controlling non-covalent interactions associated with solvent molecules and redox-inactive ions provide new opportunities to enhance the reaction entropy changes and reaction kinetics of metal redox centers, which can increase the thermodynamic efficiency of energy conversion and storage devices. Here, we report systematic changes in the redox entropy of one-electron transfer reactions including [Fe(CN)6]3-/4-, [Fe(H2O)6]3+/2+and [Ag(H2O)4]+/0induced by the addition of redox inactive ions, where approximately twenty different known structure making/breaking ions were employed. The measured reaction entropy changes of these redox couples were found to increase linearly with higher concentration and greater structural entropy (having greater structure breaking tendency) for inactive ions with opposite charge to the redox centers. The trend could be attributed to the altered solvation shells of oxidized and reduced redox active species due to non-covalent interactions among redox centers, inactive ions and water molecules, which was supported by Raman spectroscopy. Not only were these non-covalent interactions shown to increase reaction entropy, but they were also found to systematically alter the redox kinetics, where increasing redox reaction energy changes associated with the presence of water structure breaking cations were correlated linearly with the greater exchange current density of [Fe(CN)6]3-/4-.United States. Department of Energy. Office of Basic Energy Science (Award Number DE-SC0001299/DE-FG02-09ER46577)Hong Kong (China). Innovation and Technology Commission (Project No. ITS/ 020/16FP)United States. Department of Energy (Contract No. DE-AC02-5CH11231

    N-phosphorylation of amino acids by trimetaphosphate in aqueous solution-learning from prebiotic synthesis

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    Inspired by a reactivity study between sodium trimetaphosphate (P(3)m) and amino acids in prebiotic chemistry, a one-step reaction with efficient purification procedure in aqueous media has been developed for the synthesis of N-phosphono-amino acids (NPAA). P(3)m was used to phosphorylate amino acids to NPAA with yields of 60 similar to 91%. The by-products, inorganic polyphosphates, were recycled to regenerate the phosphorylation reagent P(3)m.Ministry of Science and Technology [2006DFA43030]; Chinese National Natural Science Foundation [20572061, 20732004

    Minimising efficiency roll-off in high-brightness perovskite light-emitting diodes.

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    Efficiency roll-off is a major issue for most types of light-emitting diodes (LEDs), and its origins remain controversial. Here we present investigations of the efficiency roll-off in perovskite LEDs based on two-dimensional layered perovskites. By simultaneously measuring electroluminescence and photoluminescence on a working device, supported by transient photoluminescence decay measurements, we conclude that the efficiency roll-off in perovskite LEDs is mainly due to luminescence quenching which is likely caused by non-radiative Auger recombination. This detrimental effect can be suppressed by increasing the width of quantum wells, which can be easily realized in the layered perovskites by tuning the ratio of large and small organic cations in the precursor solution. This approach leads to the realization of a perovskite LED with a record external quantum efficiency of 12.7%, and the efficiency remains to be high, at approximately 10%, under a high current density of 500 mA cm-2

    Platforms for Parallel Processing of Task on GPU

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    Import 05/08/2014Tato bakalářská práce se zabývá zpracováním úloh na grafické kartě. Konkrétním typem úloh jsou paralelní třídící algoritmy. V první části práce se vyskytuje popis technologií CUDA a OpenCL, ve kterých je později třídící algoritmus implementován. Dále je rozebrán princip daného algoritmu a jeho implementace. Následuje profilování a optimalizace třídícího algoritmu. V poslední částí je testování algoritmů na různých grafických kartách a porovnání obou technologií.This thesis deals with the processing tasks to the graphics card. Specific types of tasks are selected sorting algorithms. The first part includes description CUDA and OpenCL technology in which sorting algorithm is implemented. Next it is described the principle of the algorithm and its implementation. Next step is profiling and optimization of sorting algorithm. The last part includes testing these algorithms on different graphics cards and a comparison of both technologies.460 - Katedra informatikydobř

    A correlation analysis of HHV infection and its predictive factors in an HIV-seropositive population in Yunnan, China

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    Human herpesviruses (HHVs) have a particularly high prevalence in certain high-risk populations and cause increased morbidity and mortality in patients with acquired immunodeficiency syndrome (AIDS). Screening and treating subclinical HHV infections reduce human immunodeficiency virus (HIV) infection incidence, disease progression, and transmission. However, there are few studies on HHVs, HIV coinfection rates, and their related risk factors. We aimed to clarify the prevalence of all eight HHVs in peripheral blood samples collected from HIV-positive patients, and explore the association of HHV infection in HIV-positive patients in an HIV-seropositive population in Yunnan. We recruited 121 HIV-positive patients with highly active antiretroviral therapy (HAART) and 45 healthy individuals. All the eight HHVs were detected using polymerase chain reaction and their epidemiological information and clinical data were collected and statistically analyzed. A high prevalence of HHVs (89.3%) was observed in individuals with HIV infections and with herpes simplex virus (HSV)-2 (65.3%), and HSV-1 (59.5%) being the most common. Coinfection with more than two different HHVs was more common in patients with HIV infections receiving HAART (72.7%) than in healthy controls. Older age, being married, higher HIV-1 plasma viral loads, and use of antiviral protease inhibitors were independently correlated with an increased frequency of HHVs, but we found no association with CD4 count, WHO HIV clinical stage, and HIV infection duration. Our findings are of great significance for the prevention of HHV opportunistic infection in patients with AIDS and their clinical treatment

    The Genomes of Oryza sativa: A History of Duplications

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    We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped super-scaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000–40,000. Only 2%–3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism (SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family
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