309 research outputs found

    On Bogovski\u{\i} and regularized Poincar\'e integral operators for de Rham complexes on Lipschitz domains

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    We study integral operators related to a regularized version of the classical Poincar\'e path integral and the adjoint class generalizing Bogovski\u{\i}'s integral operator, acting on differential forms in RnR^n. We prove that these operators are pseudodifferential operators of order -1. The Poincar\'e-type operators map polynomials to polynomials and can have applications in finite element analysis. For a domain starlike with respect to a ball, the special support properties of the operators imply regularity for the de Rham complex without boundary conditions (using Poincar\'e-type operators) and with full Dirichlet boundary conditions (using Bogovski\u{\i}-type operators). For bounded Lipschitz domains, the same regularity results hold, and in addition we show that the cohomology spaces can always be represented by CC^\infty functions.Comment: 23 page

    The Role of the Superior Order GLCM in the Characterization and Recognition of the Liver Tumors from Ultrasound Images

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    The hepatocellular carcinoma (HCC) is the most frequent malignant liver tumor. It often has a similar visual aspect with the cirrhotic parenchyma on which it evolves and with the benign liver tumors. The golden standard for HCC diagnosis is the needle biopsy, but this is an invasive, dangerous method. We aim to develop computerized,noninvasive techniques for the automatic diagnosis of HCC, based on information obtained from ultrasound images. The texture is an important property of the internal organs tissue, able to provide subtle information about the pathology. We previously defined the textural model of HCC, consisting in the exhaustive set of the relevant textural features, appropriate for HCC characterization and in the specific values of these features. In this work, we analyze the role that the superior order Grey Level Cooccurrence Matrices (GLCM) and the associated parameters have in the improvement of HCC characterization and automatic diagnosis. We also determine the best spatial relations between the pixels that lead to the highest performances, for the third, fifth and seventh order GLCM. The following classes will be considered: HCC, cirrhotic liver parenchyma on which it evolves and benign liver tumors

    Early resistance change and stress/electromigration evolution in near bamboo interconnects

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    A complete description for early resistance change and mechanical stress evolution in near-bamboo interconnects, related to the electromigration, is given in this paper. The proposed model, for the first time, combines the stress/vacancy concentration evolution with the early resistance change of the Al line with a near-bamboo microstructure, which has been proven to be a fast technique for prediction of the MTF of a line compared to the conventional (accelerated) stres

    Semantic multimedia remote display for mobile thin clients

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    Current remote display technologies for mobile thin clients convert practically all types of graphical content into sequences of images rendered by the client. Consequently, important information concerning the content semantics is lost. The present paper goes beyond this bottleneck by developing a semantic multimedia remote display. The principle consists of representing the graphical content as a real-time interactive multimedia scene graph. The underlying architecture features novel components for scene-graph creation and management, as well as for user interactivity handling. The experimental setup considers the Linux X windows system and BiFS/LASeR multimedia scene technologies on the server and client sides, respectively. The implemented solution was benchmarked against currently deployed solutions (VNC and Microsoft-RDP), by considering text editing and WWW browsing applications. The quantitative assessments demonstrate: (1) visual quality expressed by seven objective metrics, e.g., PSNR values between 30 and 42 dB or SSIM values larger than 0.9999; (2) downlink bandwidth gain factors ranging from 2 to 60; (3) real-time user event management expressed by network round-trip time reduction by factors of 4-6 and by uplink bandwidth gain factors from 3 to 10; (4) feasible CPU activity, larger than in the RDP case but reduced by a factor of 1.5 with respect to the VNC-HEXTILE

    A Comparison between Neural Networks and Traditional Forecasting Methods: A Case Study

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    Forecasting accuracy drives the performance of inventory management. This study is to investigate and compare different forecasting methods like Moving Average (MA) and Autoregressive Integrated Moving Average (ARIMA) with Neural Networks (NN) models as Feed-forward NN and Nonlinear Autoregressive network with eXogenous inputs (NARX). Data used to forecast is acquired from inventory database of Panasonic Refrigeration Devices Company located in Singapore. Results have shown that forecasting with NN offers better performance in comparison with traditional methods

    Resolvent Estimates in L^p for the Stokes Operator in Lipschitz Domains

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    We establish the LpL^p resolvent estimates for the Stokes operator in Lipschitz domains in RdR^d, d3d\ge 3 for 1p1/2<12d+ϵ|\frac{1}{p}-1/2|< \frac{1}{2d} +\epsilon. The result, in particular, implies that the Stokes operator in a three-dimensional Lipschitz domain generates a bounded analytic semigroup in LpL^p for (3/2)-\varep < p< 3+\epsilon. This gives an affirmative answer to a conjecture of M. Taylor.Comment: 28 page. Minor revision was made regarding the definition of the Stokes operator in Lipschitz domain

    STUDIES ON THE ATTACK PRODUCED BY THE CAMERARIA OHRIDELLA DESHKA-DIMIĆ SPECIES

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    The horse-chestnut leaf miner (Cameraria ohridella Deschka-Dimić) is a rather dangerous invasive pest because the larvae create galleries in the foliar apparatus of theAesculus hippocastanum L. horse-chestnut, and compromise the aesthetic aspect of the tree.During 2016 and 2017 in the southern area of Oltenia, there were made observations and determinations regarding the degree of damage and the monitoring of theCameraria ohridella Deschka-Dimić species under the microclimate conditions offered by Constantin Poroineanu Park in Caracal.Throughout the entire experimental period, a total number of 9649 adults were captured on the installed traps, out of which 4726 adults were captured in 2016 and more than 4923 adults were captured in 2017.The degree of infestation of the horse-chestnut leaves produced by theCameraria ohridella Deschka-Dimić species was obtained on the basis of the number of galleries/leaf/leaflet made by larvae in an average sample of 100 leaves. The number of galleries per leaf was of 20.9 in 2016 and 54.2 in 2017, the average of the years of research being of 37.5, and the number of galleries per leaflet fluctuated between 2.9 in 2016 and 7.7 in 2017, with an average of the years of research of 50.3
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