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22. 75 let Jednoty čsl. matematiků a fysiků /
- Creator:
- Čupr, Karel,
- Type:
- text and články jubilejní
- Subject:
- Matematika, společnosti vědecké, matematika, fyzika, české a československé vědecké instituce a společnosti, vysoké školy, Československo 1918-1945, dějiny přírodních věd, and české země 1848-1918
- Language:
- Czech
- Rights:
- unknown
23. A Cauchy-Pompeiu formula in super Dunkl-Clifford analysis
- Creator:
- Yuan, Hongfen
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, super Dunkl-Dirac operator, Stokes formula, Cauchy-Pompeiu integral formula, Morera's theorem, Painlevé theorem, 13, and 51
- Language:
- English
- Description:
- Using a distributional approach to integration in superspace, we investigate a Cauchy-Pompeiu integral formula in super Dunkl-Clifford analysis and several related results, such as Stokes formula, Morera's theorem and Painlevé theorem for super Dunkl-monogenic functions. These results are nice generalizations of well-known facts in complex analysis., Hongfen Yuan., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
24. A characterization of a certain real hypersurface of type (A2) in a complex projective space
- Creator:
- Kim, Byung Hak, Kim, In-Bae, and Maeda, Sadahiro
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, ruled real hypersurface, nonflat complex space form, real hypersurfaces of type (A2) in a complex projective space, geodesics, structure torsion, Hopf manifold, 13, and 51
- Language:
- English
- Description:
- In the class of real hypersurfaces M²n−¹ isometrically immersed into a nonflat complex space form Mn(c) of constant holomorphic sectional curvature c (≠ 0) which is either a complex projective space ℂPn(c) or a complex hyperbolic space ℂHn(c) according as c > 0 or c < 0, there are two typical examples. One is the class of all real hypersurfaces of type (A) and the other is the class of all ruled real hypersurfaces. Note that the former example are Hopf manifolds and the latter are non-Hopf manifolds. In this paper, inspired by a simple characterization of all ruled real hypersurfaces in Mn(c), we consider a certain real hypersurface of type (A2) in ℂPn(c) and give a geometric characterization of this Hopf manifold., Byung Hak Kim, In-Bae Kim, Sadahiro Maeda., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
25. A characterization of the Riemann extension in terms of harmonicity
- Creator:
- Bejan, Cornelia-Livia and Eken, Şemsi
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, harmonické tenzorové pole, Semi-Riemannian manifold, cotangent bundle, natural Riemann extension, harmonic tensor field, 13, and 51
- Language:
- English
- Description:
- If (M,∇) is a manifold with a symmetric linear connection, then T*M can be endowed with the natural Riemann extension g¯ (O. Kowalski and M. Sekizawa (2011), M. Sekizawa (1987)). Here we continue to study the harmonicity with respect to g¯g¯ initiated by C. L.Bejan and O.Kowalski (2015). More precisely, we first construct a canonical almost para-complex structure PP on (T*M, g¯) and prove that P is harmonic (in the sense of E.Garciá-Río, L.Vanhecke and M. E.Vázquez-Abal (1997)) if and only if g¯ reduces to the classical Riemann extension introduced by E.M. Patterson and A.G. Walker (1952)., Cornelia-Livia Bejan, Şemsi Eken., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
26. A curvature identity on a 6-dimensional Riemannian manifold and its applications
- Creator:
- Euh, Yunhee, Park, Jeong Hyeong, and Sekigawa, Kouei
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, Chern-Gauss-Bonnet theorem, curvature identity, locally harmonic manifold, 13, and 51
- Language:
- English
- Description:
- We derive a curvature identity that holds on any 6-dimensional Riemannian manifold, from the Chern-Gauss-Bonnet theorem for a 6-dimensional closed Riemannian manifold. Moreover, some applications of the curvature identity are given. We also define a generalization of harmonic manifolds to study the Lichnerowicz conjecture for a harmonic manifold "a harmonic manifold is locally symmetric" and provide another proof of the Lichnerowicz conjecture refined by Ledger for the 4-dimensional case under a slightly more general setting., Yunhee Euh, Jeong Hyeong Park, Kouei Sekigawa., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
27. A Fiedler-like theory for the perturbed Laplacian
- Creator:
- Rocha, Israel and Trevisan, Vilmar
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, perturbed Laplacian matrix, Fiedler vector, algebraic connectivity, graph partitioning, 13, and 51
- Language:
- English
- Description:
- The perturbed Laplacian matrix of a graph G is defined as DL = D−A, where D is any diagonal matrix and A is a weighted adjacency matrix of G. We develop a Fiedler-like theory for this matrix, leading to results that are of the same type as those obtained with the algebraic connectivity of a graph. We show a monotonicity theorem for the harmonic eigenfunction corresponding to the second smallest eigenvalue of the perturbed Laplacian matrix over the points of articulation of a graph. Furthermore, we use the notion of Perron component for the perturbed Laplacian matrix of a graph and show how its second smallest eigenvalue can be characterized using this definition., Israel Rocha, Vilmar Trevisan., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
28. A History of Discrete Optimization /
- Creator:
- Durnová, Helena,
- Type:
- text and studie
- Subject:
- Matematika, matematika, dějiny matematiky, grafy, teorie grafů, přehledná zpracování světových dějin (chronologicky), and matematika, kybernetika
- Language:
- English
- Rights:
- unknown
29. A new algorithm for approximating the least concave majorant
- Creator:
- Franců, Martin, Kerman, Ron, and Sinnamon, Gord
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, algoritmy, mathematics, algorithms, least concave majorant, level function, spline approximation, 13, and 51
- Language:
- English
- Description:
- The least concave majorant, $\hat F$, of a continuous function $F$ on a closed interval, $I$, is defined by $ \hat F (x) = \inf\{ G(x) G \geq F, G \text{ concave}\},\quad x \in I. $ We present an algorithm, in the spirit of the Jarvis March, to approximate the least concave majorant of a differentiable piecewise polynomial function of degree at most three on $I$. Given any function $F \in\mathcal{C}^4(I)$, it can be well-approximated on $I$ by a clamped cubic spline $S$. We show that $\hat S$ is then a good approximation to $\hat F$. We give two examples, one to illustrate, the other to apply our algorithm., Martin Franců, Ron Kerman, Gord Sinnamon., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
30. A new continuous dependence result for impulsive retarded functional differential equations
- Creator:
- Federson, Márcia and Mesquita, Jaqueline Godoy
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, diferenciální rovnice, mathematics, differential equations, retarded functional differential equation, impulse local existenc, impulse local existence uniqueness, continuous dependence on parameters, 13, and 51
- Language:
- English
- Description:
- We consider a large class of impulsive retarded functional differential equations (IRFDEs) and prove a result concerning uniqueness of solutions of impulsive FDEs. Also, we present a new result on continuous dependence of solutions on parameters for this class of equations. More precisely, we consider a sequence of initial value problems for impulsive RFDEs in the above setting, with convergent right-hand sides, convergent impulse operators and uniformly convergent initial data. We assume that the limiting equation is an impulsive RFDE whose initial condition is the uniform limit of the sequence of the initial data and whose solution exists and is unique. Then, for sufficient large indexes, the elements of the sequence of impulsive retarded initial value problem admit a unique solution and such a sequence of solutions converges to the solution of the limiting Cauchy problem., Márcia Federson, Jaqueline Godoy Mesquita., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public