scholarly journals Clifford algebra-based structure filtering analysis for geophysical vector fields

2013 ◽  
Vol 20 (4) ◽  
pp. 563-570 ◽  
Author(s):  
Z. Yu ◽  
W. Luo ◽  
L. Yi ◽  
Y. Hu ◽  
L. Yuan
Keyword(s):  
Vector Field ◽  
Clifford Algebra ◽  
El Niño ◽  
Vector Fields ◽  
El Nino ◽  
Field Analysis ◽  
Directional Information ◽  
Filtering Method ◽  
Additional Information

Abstract. A new Clifford algebra-based vector field filtering method, which combines amplitude similarity and direction difference synchronously, is proposed. Firstly, a modified correlation product is defined by combining the amplitude similarity and direction difference. Then, a structure filtering algorithm is constructed based on the modified correlation product. With custom template and thresholds applied to the modulus and directional fields independently, our approach can reveal not only the modulus similarities but also the classification of the angular distribution. Experiments on exploring the tempo-spatial evolution of the 2002–2003 El Niño from the global wind data field are used to test the algorithm. The results suggest that both the modulus similarity and directional information given by our approach can reveal the different stages and dominate factors of the process of the El Niño evolution. Additional information such as the directional stability of the El Niño can also be extracted. All the above suggest our method can provide a new powerful and applicable tool for geophysical vector field analysis.

Classification of El Niño and La Niña years for water resources management in Alberta

2018 ◽  
Vol 45 (12) ◽  
pp. 1093-1098
Author(s):  
Zahidul Islam
Keyword(s):  
Water Resources ◽  
Water Resources Management ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Simple Method ◽  
Resources Management ◽  
La Nina

Classification of El Niño and La Niña years in a historical time period is necessary to analyze their impacts on hydrology and water resources management. In this study, various El Niño-Southern Oscillation (ENSO) indices, and how they are used to classify El Niño or La Niña years have been reviewed. Based on the review, a simple method of classifying El Niño or La Niña years has been proposed.

scholarly journals Finitely curved orbits of complex polynomial vector fields

2007 ◽  
Vol 79 (1) ◽  
pp. 13-16
Author(s):  
Albetã C. Mafra
Keyword(s):  
Vector Field ◽  
Gaussian Curvature ◽  
Algebraic Curve ◽  
Vector Fields ◽  
Complex Polynomial ◽  
Holomorphic Foliations ◽  
Holomorphic Curve ◽  
Polynomial Vector ◽  
Polynomial Vector Fields

This note is about the geometry of holomorphic foliations. Let X be a polynomial vector field with isolated singularities on C². We announce some results regarding two problems: 1. Given a finitely curved orbit L of X, under which conditions is L algebraic? 2. If X has some non-algebraic finitely curved orbit L what is the classification of X? Problem 1 is related to the following question: Let C <FONT FACE=Symbol>Ì</FONT> C² be a holomorphic curve which has finite total Gaussian curvature. IsC contained in an algebraic curve?

scholarly journals Classification of Ricci solitons on Euclidean hypersurfaces

2014 ◽  
Vol 25 (11) ◽  
pp. 1450104 ◽  
Author(s):  
Bang-Yen Chen ◽  
Sharief Deshmukh
Keyword(s):  
Riemannian Manifold ◽  
Vector Field ◽  
Riemannian Manifolds ◽  
Potential Field ◽  
Vector Fields ◽  
Ricci Soliton ◽  
Position Vector ◽  
Ricci Solitons ◽  
Euclidean Submanifolds

A Ricci soliton (M, g, v, λ) on a Riemannian manifold (M, g) is said to have concurrent potential field if its potential field v is a concurrent vector field. Ricci solitons arisen from concurrent vector fields on Riemannian manifolds were studied recently in [Ricci solitons and concurrent vector fields, preprint (2014), arXiv:1407.2790]. The most important concurrent vector field is the position vector field on Euclidean submanifolds. In this paper we completely classify Ricci solitons on Euclidean hypersurfaces arisen from the position vector field of the hypersurfaces.

scholarly journals Del trastorno del diálogo tónico a la inestabilidad psicomotriz: Taxonomía diagnóstica

2022 ◽  
Vol 11 ◽  
pp. 4
Author(s):  
Franco Boscaini ◽  
Javier Cachón Zagalaz ◽  
Arturo Díaz Suárez
Keyword(s):  
El Niño ◽  
El Nino ◽  
The Body ◽  
Common Element ◽  
Clinical Material ◽  
Diagnostic Classification ◽  
The Relationship

The goal of this work is to deepen the relationship between hyperactivity and tonic dialogue, by considering the body as a common element of communication even if their psychomotor manifestations and meanings are different during development. While tonic dialogue is vital for the child in the constitution of the attachment bond, psychomotor instability is the expression of a difficulty in relating to reality. In the clinic it is difficult to place instability in international diagnostic classifications, due to the multi-problematic nature and variability of expressions of it. Research confirms the consequences of a disorder of tonic dialogue, constituting a model on which future behaviors will be organized. The authors hypothesize that each stage of the body communication, if lived with difficulty, constitutes a matrix on which diversified expressions of instability will be structured. The intent, therefore, is to collect theoretical-clinical material in order to subsequently make a diagnostic classification of psychomotor instability. El objetivo de este trabajo es profundizar en la relación entre hiperactividad y diálogo tónico al considerar el cuerpo como elemento común de comunicación, aunque sus manifestaciones psicomotoras y significados sean diferentes durante el desarrollo. Mientras que el diálogo tónico es vital para que el niño establezca el vínculo de apego, la inestabilidad psicomotora es la expresión de una dificultad para relacionarse con la realidad. La complejidad y variabilidad de los cuadros clínicos dificulta su ubicación en las clasificaciones diagnósticas internacionales. La investigación luego confirma las consecuencias del trastorno del diálogo tónico, constituyendo un modelo sobre el que se organizarán los comportamientos futuros. Los autores plantean la hipótesis de que cada etapa del diálogo tónico, si se vive con dificultad, constituye una matriz sobre la que se estructurarán diversas expresiones de inestabilidad. La intención es recopilar material teórico-clínico para posteriormente realizar una clasificación diagnóstica de la inestabilidad psicomotora.

scholarly journals About Formal Normal Form of the Semi-Hyperbolic Maps Germs on the Plane

2021 ◽  
Vol 38 ◽  
pp. 54-64
Author(s):  
P. A. Shaikhullina ◽  
Keyword(s):  
Vector Field ◽  
Normal Form ◽  
Vector Fields ◽  
The Other ◽  
Time Shift ◽  
Saddle Node ◽  
Dimension 2 ◽  
The One

There are consider the problem of constructing an analytical classification holomorphic resonance maps germs of Siegel-type in dimension 2. Namely, semi-hyperbolic maps of general form: such maps have one parabolic multiplier (equal to one), and the other hyperbolic (not equal in modulus to zero or one). In this paper, the first stage of constructing an analytical classification by the method of functional invariants is carried out: a theorem on the reducibility of a germ to its formal normal form by "semiformal" changes of coordinates is proved. The one-time shift along the saddle node vector field (the formal normal form in the problem of the analytical classification of saddle-node vector fields on a plane) is chosen as the formal normal form.

scholarly journals The Geometry of Tangent Bundles: Canonical Vector Fields

Geometry ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Tongzhu Li ◽  
Demeter Krupka
Keyword(s):  
Vector Field ◽  
Linear Combination ◽  
Tangent Bundle ◽  
Vector Fields ◽  
Complete Classification ◽  
Constant Coefficients ◽  
Vertical Lift ◽  
Tangent Bundles ◽  
Canonical Vector

A canonical vector field on the tangent bundle is a vector field defined by an invariant coordinate construction. In this paper, a complete classification of canonical vector fields on tangent bundles, depending on vector fields defined on their bases, is obtained. It is shown that every canonical vector field is a linear combination with constant coefficients of three vector fields: the variational vector field (canonical lift), the Liouville vector field, and the vertical lift of a vector field on the base of the tangent bundle.

scholarly journals Toward a classification of the Central Pacific El Niño

2012 ◽  
Vol 3 (2) ◽  
pp. 979-998
Author(s):  
M. Pascolini-Campbell ◽  
D. Zanchettin ◽  
O. Bothe ◽  
C. Timmreck ◽  
D. Matei ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Central Pacific ◽  
Natural Climate Variability ◽  
Central Pacific El Niño ◽  
Robust Identification ◽  
Time Period ◽  
Natural Climate

Abstract. We investigate the various methods currently available for distinguishing between the Central Pacific (CP) El Niño (or "El Niño Modoki") and the canonical El Niño by considering 10 different methods and 5 sea surface temperature (SST) datasets from 1880 to 2010. Years which are classified as CP El Niños with the greatest convergence between method and SST dataset are considered to provide a more robust identification of these events. The results identify 13 yr which are classified the most consistently as CP events: 1885/1886, 1914/1915, 1940/1941, 1958/1959, 1963/1964, 1968/1969, 1977/1978, 1986/1987, 1991/1992, 2002/2003, 2003/2004, 2004/2005 and 2009/2010. Our findings also indicate the persistence of CP events throughout the time period investigated, inciting the role of multidecadal natural climate variability in generating CP El Niños.

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