Bathymetry inversion using the modified gravity-geologic method: application of the rectangular prism model and Tikhonov regularization

2020 ◽  
Vol 17 (3) ◽  
pp. 377-389
Author(s):  
Jian Xing ◽  
Xin-Xi Chen ◽  
Long Ma
Keyword(s):  
Tikhonov Regularization ◽  
Modified Gravity ◽  
Rectangular Prism ◽  
Prism Model

scholarly journals MODELISASI KURSI DENGAN PENGGABUNGAN HASIL DEFORMASI BENDA-BENDA RUANG MENGGUNAKAN KURVA BEZIER

2021 ◽  
Vol 21 (2) ◽  
pp. 107
Author(s):  
Annisa Ayu Nadzira ◽  
Bagus Juliyanto ◽  
Ahmad Kamsyakawuni
Keyword(s):  
Rectangular Prism ◽  
Office Workers ◽  
Regular Hexagon ◽  
Bezier Curves ◽  
Bézier Curves ◽  
The Third ◽  
Geometric Objects ◽  
Hexagon Prism ◽  
Prism Model

Chairs are needed by humans to do some work, especially students and office workers. The parts contained in the chair are the chair legs, chair legs eats and chair backs. The purpose of this study is to obtain variations in the shape of office chairs using Bezier curves and incorporate the results of deformation of space geometric objects. In modeling this chair, it is divided into several stages, namely first, building the chair leg components. This chair leg component consists of chair wheels, connecting two wheels with tube deformation, modeling the chair leg branch components and modeling chair leg supports. Second, namely the model of the chair leg seat. Chair leg seat consists of regular hexagon prism deformation and regular quadrangle prism deformation. The third is the modelization of the back of the chair by using a rectangular prism model. The result of combining several components of the chair using one modeling axis produces 36 chair models, with special provisions, namely that the seat support parts can only be joined using a tube.

Study of a Restricted Modified Gravity on astrophysical and cosmological scales

2019 ◽  
Vol 19 (2) ◽  
pp. 447-453
Author(s):  
Nasim Derakhshanian ◽  
Amir Ghalee ◽  
◽  
Keyword(s):  
Modified Gravity

Editorial [Dark Energy and Modified Gravity]

2010 ◽  
Vol 3 (2) ◽  
pp. 12-12
Author(s):  
S. Nojiri ◽  
S. D. Odintsov
Keyword(s):  
Dark Energy ◽  
Modified Gravity

Social-Emotional Competence in Down Syndrome

2020 ◽  
Author(s):  
Amanda Dimachkie ◽  
Connie L. Kasari
Keyword(s):  
Down Syndrome ◽  
Emotional Competence ◽  
Self Regulation ◽  
Social Problem Solving ◽  
Developmental Trajectory ◽  
Social Emotional ◽  
Social Emotional Competence ◽  
Prosocial Orientation ◽  
Expression Of Emotions ◽  
Prism Model

This chapter aims to synthesize historical and contemporary literature to provide an overarching understanding of social-emotional competence in individuals with Down syndrome, where social-emotional competence refers to the skills necessary to allow for successful social relationships, as well as the ability to regulate the experience and expression of emotions. Using the framework of Rose-Krasnor’s prism model, this chapter addresses each of the four components that underlie the development of social-emotional competence: self-regulation, social awareness, prosocial orientation, and social problem-solving. The development of each of these components is described for individuals with Down syndrome, and a description of the typical developmental trajectory is given for reference. The short-term and long-term implications of each component are also discussed, as they relate to the individual’s overall social-emotional competence. This overview aims to highlight what is known regarding social-emotional competence in individuals with Down syndrome, as well as to identify areas in which knowledge is lacking.

scholarly journals A modified Tikhonov regularization method based on Hermite expansion for solving the Cauchy problem of the Laplace equation

2020 ◽  
Vol 18 (1) ◽  
pp. 1685-1697
Author(s):  
Zhenyu Zhao ◽  
Lei You ◽  
Zehong Meng
Keyword(s):  
Cauchy Problem ◽  
Laplace Equation ◽  
Tikhonov Regularization ◽  
Regularization Method ◽  
Regularization Parameter ◽  
Solution Process ◽  
Tikhonov Regularization Method ◽  
Hermite Expansion ◽  
The Cauchy Problem ◽  
Ill Posed

Abstract In this paper, a Cauchy problem for the Laplace equation is considered. We develop a modified Tikhonov regularization method based on Hermite expansion to deal with the ill posed-ness of the problem. The regularization parameter is determined by a discrepancy principle. For various smoothness conditions, the solution process of the method is uniform and the convergence rate can be obtained self-adaptively. Numerical tests are also carried out to verify the effectiveness of the method.

scholarly journals Black hole solutions in modified gravity induced by quantum metric fluctuations

2021 ◽  
Vol 31 ◽  
pp. 100756
Author(s):  
Jin-Zhao Yang ◽  
Shahab Shahidi ◽  
Tiberiu Harko ◽  
Shi-Dong Liang
Keyword(s):  
Black Hole ◽  
Modified Gravity ◽  
Black Hole Solutions ◽  
Metric Fluctuations

scholarly journals Dwarf galaxies without dark matter: constraints on modified gravity

2020 ◽  
Vol 501 (1) ◽  
pp. 254-260
Author(s):  
Ali Rida Khalifeh ◽  
Raul Jimenez
Keyword(s):  
Dark Matter ◽  
Modified Gravity ◽  
Virial Theorem ◽  
Dwarf Galaxies ◽  
Strong Support ◽  
Gravity Models ◽  
Birkhoff Theorem ◽  
Astronomical Surveys ◽  
Stringent Test ◽  
Modified Gravity Models

ABSTRACT The discovery of 19 dwarf galaxies without dark matter (DM) provides, counterintuitively, strong support for the ΛCDM standard model of cosmology. Their presence is well accommodated in a scenario where the DM is in the form of cold dark particles. However, it is interesting to explore quantitatively what is needed from modified gravity models to accommodate the presence of these galaxies and what extra degree of freedom is needed in these models. To this end, we derive the dynamics at galaxy scales (Virial theorem) for a general class of modified gravity models. We distinguish between theories that satisfy the Jebsen–Birkhoff theorem, and those that do not. Our aim is to develop tests that can distinguish whether DM is part of the theory of gravity or a particle. The 19 dwarf galaxies discovered provide us with a stringent test for models of modified gravity. Our main finding is that there will always be an extra contribution to the Virial theorem coming from the modification of gravity, even if a certain galaxy shows very small, if not negligible, trace of DM, as has been reported recently. Thus, if these and more galaxies are confirmed as devoid (or negligible) of DM, while other similar galaxies have abundant DM, it seems interesting to find modifications of gravity to describe DM. Our result can be used by future astronomical surveys to put constraints on the parameters of modified gravity models at astrophysical scales where DM is described as such.

scholarly journals A New Hybrid Inversion Method for 2D Nuclear Magnetic Resonance Combining TSVD and Tikhonov Regularization

2021 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Germana Landi ◽  
Fabiana Zama ◽  
Villiam Bortolotti
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Tikhonov Regularization ◽  
Large Scale ◽  
Regularization Parameter ◽  
High Sensitivity ◽  
Inversion Method ◽  
Nmr Relaxometry ◽  
Value Decomposition ◽  
Nuclear Magnetic

This paper is concerned with the reconstruction of relaxation time distributions in Nuclear Magnetic Resonance (NMR) relaxometry. This is a large-scale and ill-posed inverse problem with many potential applications in biology, medicine, chemistry, and other disciplines. However, the large amount of data and the consequently long inversion times, together with the high sensitivity of the solution to the value of the regularization parameter, still represent a major issue in the applicability of the NMR relaxometry. We present a method for two-dimensional data inversion (2DNMR) which combines Truncated Singular Value Decomposition and Tikhonov regularization in order to accelerate the inversion time and to reduce the sensitivity to the value of the regularization parameter. The Discrete Picard condition is used to jointly select the SVD truncation and Tikhonov regularization parameters. We evaluate the performance of the proposed method on both simulated and real NMR measurements.

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