Results 1 to 10 of about 45,500 (166)
Complexes of ellipsoids with indicatrices of coordinate vectors in the form of surfaces
Дифференциальная геометрия многообразий фигур, 2021 The study continues in a three-dimensional affine space of complexes of three-parameter families of ellipsoids, considered earlier in a number of works by the author.
M.V. Kretov
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Determination of coordinates of the earthquake hypocenter by the method of circles
Вестник Дагестанского государственного технического университета: Технические науки, 2021 Objective. The aim of the study is to develop a method for determining the coordinates of the earthquake hypocenter using various combinations of second and fourth order figures as a geo-locus of the hypocenter position points.Method.
G. K. Aslanov, T. G. Aslanov
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Accurate Algorithms for Spatial Operations on the Spheroid in a Spatial Database Management System
Applied Sciences, 2021 Some of the most powerful spatial analysis software solutions (Oracle, Google Earth Engine, PostgreSQL + PostGIS, etc.) are currently performing geometric calculations directly on the ellipsoid (a quadratic surface that models the earth shape), with a ...
José Carlos Martínez-Llario +2 more
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Derivation of closed-form ellipsoidal X-ray mirror shapes from Fermat's principle
Journal of Synchrotron Radiation, 2022 Ellipsoidal and plane-elliptical surfaces are widely used as reflective, point-to-point focusing elements in many optical systems, including X-ray optics.
Kenneth A. Goldberg
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Normal Polytopes and Ellipsoids [PDF]
The Electronic Journal of Combinatorics, 2021 We show that: (1) unimodular simplices in a lattice 3-polytope cover a neighborhood of the boundary of the polytope if and only if the polytope is very ample, (2) the convex hull of lattice points in every ellipsoid in $\mathbb{R}^3$ has a unimodular cover, and (3) for every $d\geqslant 5$, there are ellipsoids in $\mathbb{R}^d$, such that the convex ...
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Evolutionary Mahalanobis Distance-Based Oversampling for Multi-Class Imbalanced Data Classification
Sensors, 2021 The number of sensing data are often imbalanced across data classes, for which oversampling on the minority class is an effective remedy. In this paper, an effective oversampling method called evolutionary Mahalanobis distance oversampling (EMDO) is ...
Leehter Yao, Tung-Bin Lin
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Вестник Дагестанского государственного технического университета: Технические науки, 2022 Objective. The aim of the study is to develop methods for determining the coordinates of the hypocenter of an earthquake with a known structure of the earth's crust. Method.
T. G. Aslanov, Yu. A. Sidorkina
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Ellipsoidal Collapse and Previrialization [PDF]
The Astronomical Journal, 2001 We study the non-linear evolution of a dust ellipsoid,embedded in a Friedmann flat background universe, in order to determine the evolution of the density of the ellipsoid as the perturbation to it related detaches from general expansion and begins to collapse.
Del Popolo, A, Ercan, EN, Xia, Z
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Attitude Sensor from Ellipsoid Observations: A Numerical and Experimental Validation
Sensors, 2020 The preliminary design and validation of a novel, high accuracy horizon-sensor for small satellites is presented, which is based on the theory of attitude determination from ellipsoid observations.
Dario Modenini +2 more
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Mathematics, 2023 A positively invariant set is an important concept in dynamical systems. The study of positively invariant set conditions for discrete-time systems is one interesting topic in both theoretical studies and practical applications research.
Yuyao Lei +2 more
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