862 research outputs found

    A Neural Network for Image Anomaly Detection with Deep Pyramidal Representations and Dynamic Routing

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    Image anomaly detection is an application-driven problem where the aim is to identify novel samples, which differ significantly from the normal ones. We here propose Pyramidal Image Anomaly DEtector (PIADE), a deep reconstruction-based pyramidal approach, in which image features are extracted at different scale levels to better catch the peculiarities that could help to discriminate between normal and anomalous data. The features are dynamically routed to a reconstruction layer and anomalies can be identified by comparing the input image with its reconstruction. Unlike similar approaches, the comparison is done by using structural similarity and perceptual loss rather than trivial pixel-by-pixel comparison. The proposed method performed at par or better than the state-of-the-art methods when tested on publicly available datasets such as CIFAR10, COIL-100 and MVTec

    Supporting Concurrency and Multiple Indexes in Private Access to Outsourced Data

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    Data outsourcing has recently emerged as a successful solution allowing individuals and organizations to delegate data and service management to external third parties. A major challenge in the data outsourcing scenario is how to guarantee proper privacy protection against the external server. Recent promising approaches rely on the organization of data in indexing structures that use encryption and the dynamic allocation of encrypted data to physical blocks for destroying the otherwise static relationship between data and the blocks in which they are stored. However, dynamic data allocation implies the need to re-write blocks at every read access, thus requesting exclusive locks that can affect concurrency. Also, these solutions only support search conditions on the values of the attribute used for building the indexing structure. In this paper, we present an approach that overcomes such limitations by extending the recently proposed shuffle index structure with support for concurrency and multiple indexes. Support for concurrency relies on the use of several differential versions of the data index that are periodically reconciled and applied to the main data structure. Support for multiple indexes relies on the definition of secondary shuffle indexes that are then combined with the primary index in a single data structure whose content and allocation is unintelligible to the server. We show how using such differential versions and combined index structure guarantees privacy, provides support for concurrent accesses and multiple search conditions, and considerably increases the performance of the system and the applicability of the proposed solution

    Empowering Owners with Control in Digital Data Markets

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    We propose an approach for allowing data owners to trade their data in digital data market scenarios, while keeping control over them. Our solution is based on a combination of selective encryption and smart contracts deployed on a blockchain, and ensures that only authorized users who paid an agreed amount can access a data item. We propose a safe interaction protocol for regulating the interplay between a data owner and subjects wishing to purchase (a subset of) her data, and an audit process for counteracting possible misbehaviors by any of the interacting parties. Our solution aims to make a step towards the realization of data market platforms where owners can benefit from trading their data while maintaining control

    Determinação de polifenóis como subsídio para seleção de variedades do Banco Ativo de Germoplasma de Uva.

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    A proposta do presente trabalho é analisar os teores de polifenóis bioativos em variedades do Banco Ativo de Germoplasma (acessos) e/ou novas variedades em fase de criação (seleções), através da técnica de Cromatografia Líquida de Alta Eficiência (HPLC)

    Minimizing disclosure of private information in credential-based interactions : a graph-based approach

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    We address the problem of enabling clients to regulate disclosure of their credentials and properties when interacting with servers in open scenarios. We provide a means for clients to specify the sensitivity of information in their portfolio at a fine-grain level and to determine the credentials and properties to disclose to satisfy a server request while minimizing the sensitivity of the information disclosed. Exploiting a graph modeling of the problem, we develop a heuristic approach for determining a disclosure minimizing released information, that offers execution times compatible with the requirements of interactive access to Web resources

    Alginate Formulations: Current Developments in the Race for Hydrogel-Based Cardiac Regeneration

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    Cardiovascular diseases, including myocardial infarction (MI), represent the main worldwide cause of mortality and morbidity. In this scenario, to contrast the irreversible damages following MI, cardiac regeneration has emerged as a novel and promising solution for in situ cellular regeneration, preserving cell behavior and tissue cytoarchitecture. Among the huge variety of natural, synthetic, and hybrid compounds used for tissue regeneration, alginate emerged as a good candidate for cellular preservation and delivery, becoming one of the first biomaterial tested in pre-clinical research and clinical trials concerning cardiovascular diseases. Although promising results have been obtained, recellularization and revascularization of the infarcted area present still major limitations. Therefore, the demand is rising for alginate functionalization and its combination with molecules, factors, and drugs capable to boost the regenerative potential of the cardiac tissue. The focus of this review is to elucidate the promising properties of alginate and to highlight its benefits in clinical trials in relation to cardiac regeneration. The definition of hydrogels, the alginate characteristics, and recent biomedical applications are herewith described. Afterward, the review examines in depth the ongoing developments to refine the material relevance in cardiac recovery and regeneration after MI and presents current clinical trials based on alginate

    Dynamic Allocation for Resource Protection in Decentralized Cloud Storage

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    Decentralized Cloud Storage (DCS) networks represent an interesting solution for data storage and management. DCS networks rely on the voluntary effort of a considerable number of (possibly untrusted) nodes, which may dynamically join and leave the network at any time. To profitably rely on DCS for data storage, data owners therefore need solutions that guarantee confidentiality and availability of their data. In this paper, we present an approach enabling data owners to keep data confidentiality and availability under control, limiting the owners intervention with corrective actions when availability or confidentiality is at risk. Our approach is based on the combined adoption of AONT (All-Or-Nothing-Transform) and fountain codes. It provides confidentiality of outsourced data also against malicious coalitions of nodes, and guarantees data availability even in case of node failures. Our experimental evaluation clearly shows the benefits of using fountain codes with respect to other approaches adopted by current DCS networks

    Synthesis, characterization, crystal structures and in vitro antistaphylococcal activity of organotin(IV) derivatives with 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidine

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    New organotin(IV) complexes of 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp) and 5,7-diphenyl- 1,2,4-triazolo[1,5-a]pyrimidine (dptp) with 1:1 and/or 1:2 stoichiometry were synthesized and investigated by X-ray diffraction, FT-IR and 119Sn Mössbauer in the solid state and by 1H and 13C NMR spectroscopy, in so- lution. Moreover, the crystal and molecular structures of Et2SnCl2(dbtp)2 and Ph2SnCl2(EtOH)2(dptp)2 are reported. The complexes contain hexacoordinated tin atoms: in Et2SnCl2(dbtp)2 two 5,7-ditertbutyl-1,2,4- triazolo[1,5-a]pyrimidine molecules coordinate classically the tin atom through N(3) atom and the coordina- tion around the tin atom shows a skew trapezoidal structure with axial ethyl groups. In Ph2SnCl2(EtOH)2 (dptp)2 two ethanol molecules coordinate tin through the oxygen atom and the 5,7-diphenyl-1,2,4-triazolo [1,5-a]pyrimidine molecules are not directly bound to the metal center but strictly H-bonded, through N (3), to the \OH group of the ethanol moieties; Ph2SnCl2(EtOH)2(dptp)2 has an all-trans structure and the C–Sn–C fragment is linear. On the basis of Mössbauer data, the 1:2 diorganotin(IV) complexes are advanced to have the same structure of Et2SnCl2(dbtp)2, while Me2SnCl2(dptp)2 to have a regular all-trans octahedral structure. A distorted cis-R2 trigonal bipyramidal structure is assigned to 1:1 diorganotin(IV) complexes. The in vitro antibacterial activities of the synthesized complexes have been tested against a group of reference pathogen micro-organisms and some of them resulted active with MIC values of 5 μg/mL, most of all against staphylococcal strains, which shows their inhibitory effect

    A consensus-based approach for selecting cloud plans

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    An important problem when moving an application to the cloud consists in selecting the most suitable cloud plan (among those available from cloud providers) for the application deployment, with the goal of finding the best match between application requirements and plan characteristics. If a user wishes to move multiple applications at the same time, this task can be complicated by the fact that different applications might have different (and possibly contrasting) requirements. In this paper, we propose an approach enabling users to select a cloud plan that best balances the satisfaction of the requirements of multiple applications. Our solution operates by first ranking the available plans for each application (matching plan characteristics and application requirements) and then by selecting, through a consensus-based process, the one that is considered more acceptable by all applications
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