29 research outputs found

    Moduli spaces of rank 2 instanton sheaves on the projective space

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    We study the irreducible components of the moduli space of instanton sheaves on P3\mathbb{P}^3, that is rank 2 torsion free sheaves EE with c1(E)=c3(E)=0c_1(E)=c_3(E)=0 satisfying h1(E(2))=h2(E(2))=0h^1(E(-2))=h^2(E(-2))=0. In particular, we classify all instanton sheaves with c2(E)4c_2(E)\le4, describing all the irreducible components of their moduli space. A key ingredient for our argument is the study of the moduli space T(d){\mathcal T}(d) of stable sheaves on P3\mathbb{P}^3 with Hilbert polynomial P(t)=dtP(t)=d\cdot t, which contains, as an open subset, the moduli space of rank 0 instanton sheaves of multiplicity dd; we describe all the irreducible components of T(d){\mathcal T}(d) for d4d\le4.Comment: 22 page

    THEORETICAL RESEARCHES ON THE FORCES AND STRESSES IN COUPLING DEVICES - REVIEW

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    This paper presents a synthesis of theoretical researches carried out in Romania and worldwide on forces and stresses in coupling devices.

    Drone-Based AI and 3D Reconstruction for Digital Twin Augmentation

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    Digital Twin is an emerging technology at the forefront of Industry 4.0, with the ultimate goal of combining the physical space and the virtual space. To date, the Digital Twin concept has been applied in many engineering fields, providing useful insights in the areas of engineering design, manufacturing, automation, and construction industry. While the nexus of various technologies opens up new opportunities with Digital Twin, the technology requires a framework to integrate the different technologies, such as the Building Information Model used in the Building and Construction industry. In this work, an Information Fusion framework is proposed to seamlessly fuse heterogeneous components in a Digital Twin framework from the variety of technologies involved. This study aims to augment Digital Twin in buildings with the use of AI and 3D reconstruction empowered by unmanned aviation vehicles. We proposed a drone-based Digital Twin augmentation framework with reusable and customisable components. A proof of concept is also developed, and extensive evaluation is conducted for 3D reconstruction and applications of AI for defect detection

    RESEARCH ON THE DEVELOPMENT OF A CONSERVATIVE TECHNOLOGY, USING OPTIMIZED ACTIVE BODIES FOR SOIL TILLAGE

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    Conservative agriculture has grown particularly in developed countries over the past20 years, due to intensive use of soils to obtain higher yields, by means of the processing works, maintenance, herbicides, etc. (even several times during a year), which in time led to the degradation and destruction of the structure and properties of soils. In this context, this paper presents the research conducted in order to develop a conservative technology based on optimized active bodies for soil tillage, to be mounted on a complex aggregate, in order to reduce wear, deformation and increase its lifetime

    Moduli spaces of rank 2 instanton sheaves on the projective space

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO , FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOWe study the irreducible components of the moduli space of instanton sheaves on P 3 , that is rank 2 torsion free sheaves E with c1(E) = c3(E) = 0 satisfying h 1 (E(−2)) = h 2 (E(−2)) = 0. In particular, we classify all instanton sheaves with c2(E) ≤ 4, describing all the irreducible components of their moduli space. A key ingredient for our argument is the study of the moduli space T (d) of stable sheaves on P 3 with Hilbert polynomial P(t) = dt, which contains, as an open subset, the moduli space of rank 0 instanton sheaves of multiplicity d; we describe all the irreducible components of T (d) for d ≤ 4.2912399424CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO , FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO , FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO303332/2014-0 , 2014/14743-82016/03759-
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