Maxwell's formulation - differential forms on euclidean spacegreentask
One of the greatest advances in theoretical physics of the nineteenth
century was Maxwell’s formulation of the the equations of electromag-
netism. This article uses differential forms to solve a problem related
to Maxwell’s formulation. The notion of differential form encompasses
such ideas as elements of surface area and volume elements, the work
exerted by a force, the flow of a fluid, and the curvature of a surface,
space or hyperspace. An important operation on differential forms is
exterior differentiation, which generalizes the operators div, grad, curl
of vector calculus. the study of differential forms, which was initiated
by E.Cartan in the years around 1900, is often termed the exterior
differential calculus.However, Maxwells equations have many very im-
portant implications in the life of a modern person, so much so that
people use devices that function off the principles in Maxwells equa-
tions every day without even knowing it
Published by:
Wang Jing
School of Physical and Mathematical Sciences
Nanyang Technological University
jwang14@e.ntu.edu.sg
Numerical methods by Jeffrey R. Chasnovankushnathe
This document contains lecture notes for an introduction to numerical methods course. It covers several topics:
- IEEE floating point arithmetic and number representations in computers. Different number formats like single and double precision are discussed.
- Root finding methods like bisection, Newton's and secant methods. Their convergence properties are analyzed.
- Solving systems of linear and nonlinear equations using Gaussian elimination and Newton's method.
- Numerical integration techniques like the midpoint, trapezoidal and Simpson's rules for evaluating integrals. Adaptive integration methods are introduced.
- Numerical solutions to ordinary differential equations using Euler, Runge-Kutta and shooting methods to solve initial and boundary value problems.
The document provides an overview of key concepts in algebra including:
1) Real numbers which are made up of rational and irrational numbers. Real numbers have properties like closure under addition and multiplication.
2) Exponents and radicals including laws involving integral, zero, fractional exponents and radicals.
3) Polynomials which are algebraic expressions made up of variables and coefficients, and can be added or subtracted by combining like terms.
Maxwell's formulation - differential forms on euclidean spacegreentask
One of the greatest advances in theoretical physics of the nineteenth
century was Maxwell’s formulation of the the equations of electromag-
netism. This article uses differential forms to solve a problem related
to Maxwell’s formulation. The notion of differential form encompasses
such ideas as elements of surface area and volume elements, the work
exerted by a force, the flow of a fluid, and the curvature of a surface,
space or hyperspace. An important operation on differential forms is
exterior differentiation, which generalizes the operators div, grad, curl
of vector calculus. the study of differential forms, which was initiated
by E.Cartan in the years around 1900, is often termed the exterior
differential calculus.However, Maxwells equations have many very im-
portant implications in the life of a modern person, so much so that
people use devices that function off the principles in Maxwells equa-
tions every day without even knowing it
Published by:
Wang Jing
School of Physical and Mathematical Sciences
Nanyang Technological University
jwang14@e.ntu.edu.sg
Numerical methods by Jeffrey R. Chasnovankushnathe
This document contains lecture notes for an introduction to numerical methods course. It covers several topics:
- IEEE floating point arithmetic and number representations in computers. Different number formats like single and double precision are discussed.
- Root finding methods like bisection, Newton's and secant methods. Their convergence properties are analyzed.
- Solving systems of linear and nonlinear equations using Gaussian elimination and Newton's method.
- Numerical integration techniques like the midpoint, trapezoidal and Simpson's rules for evaluating integrals. Adaptive integration methods are introduced.
- Numerical solutions to ordinary differential equations using Euler, Runge-Kutta and shooting methods to solve initial and boundary value problems.
The document provides an overview of key concepts in algebra including:
1) Real numbers which are made up of rational and irrational numbers. Real numbers have properties like closure under addition and multiplication.
2) Exponents and radicals including laws involving integral, zero, fractional exponents and radicals.
3) Polynomials which are algebraic expressions made up of variables and coefficients, and can be added or subtracted by combining like terms.
Delaunay triangulation from 2-d delaunay to 3-d delaunaygreentask
The document discusses Delaunay triangulation in 2D and 3D. It covers several key topics:
1. Computing the circumcenter of a triangle and using it to find cavities when inserting a new point.
2. Improving the algorithm to find which edges can form new balls/triangles by recording edges as cavities are found.
3. The complexity of finding cavities and balls, and how finding balls can be optimized.
4. Extending the 2D Delaunay triangulation concepts like cavity detection to 3D meshes. This involves operations to recover missing geometry and merge the cavity mesh.
6. 关键词:束缚数(bondage number),控制数 (domination number),连通的平面图 (connected planar graph),度(degree),顶 点(vertex)
Abstract:
Given a nonempty graph G, a set D of its vertices is a dominating set if every vertex of G is in D or adjacent to a vertex in D. The dominating number γ(G) of a graph G is defined t be the minumum size of a dominating set of G. If E is a edge set of G, the bondage number b(G) of a nonempty graph is defined to be the cardinality of the smallest set E of edges of G such that the graph G-E has domination number greater than that of G.
Kang and Yuan proved b(G)≤8 for every connected planar graph G. Carlson and Develin presented a simple, intuitive proof that b(G)≤ min{8, △(G)+2}for all planar graphs G. In this paper, we conject that b(G) ≤ △+1 when 3≤△≤6. Since it is not very easy, we will consider △≤3 first especially for a connected planar graph.
11. 第二章 与束缚数有关研究成果
2.1 some lemmas
Lemma 1 (Euler’s formula). 如果G可以嵌入有向 平面类g的表面,同时假设G是连通的图,那么
∣V(G)∣-∣E(G)∣+∣F(G)∣=2-2g
其中F(G)为在类g嵌入图G的表面集。
我们可以很容易的意识到这么一个问题,当G为连通平面 图时,Euler’s formula 可以化为
∣V(G)∣-∣E(G)∣+∣F(G)∣=2。
12. Lemma 2(Hartnell and Tall[6]). 如果G是一个图,
u和v 是图G中相邻的一对顶点集,那么我么可以得到
b(G)≤d(u)+d(v)-1-∣N(u)∩N(v)∣.
更进一步,这暗示着b(G)≤δ(G)+△(G)-1.
Lemma3(Fischermann et al.[4]).如果G是一个平面图,
3≤g(G)≤∞,同时c(G)为截边集,那么
( )( ( ) 2) ( )
( )
( ) 2
g G n G c G
m G
g G
21. 证明3:
如果G为连通平面图,那么吧b(G)≤8。
证明:如果我们有b(G)≥9,我们根据lemma2,每一条xy 边需要满足d(x)+d(y)≥10。与前面相同,对每一条边ei, 它的曲率为vi+fi-1;在计算fi,在决定面的边的时候,我们忽 略垂直边。例如,我们将要考虑的是有三个面的有垂直边的 三角形,而不是有5个的。如果ei只有一个顶点度为1,我们 就可得到a1=a2=∞而且fi=0。
因为lemma2,那唯一的四倍组成部分(d(x),d(y), a1,a2),它的曲率为正(up to interchange of x and y and a1 and a2)结果如下:;;
(1,k,∞,∞), where k 9, and ;
22. (2,k,3,4), where k 9, and ;
(3,k,3,3), where k 9, and ;
(3,k,3,4), where k=8,9,10, or 11, and ;
(4,k,3,3), where k=8,9,10, or 11, and ;
and(5,7,3,3), where .
我们称这样的边为问题边,设G中的问题边的的集合为 P(G)。对每一个顶点x,我们定义:
()() ()() ()(1)1/2(1) iiiiiiexyPGexyPGdxdyxVfvf
23. 现在,我们应用Euler‘s Formula,我们能够得到
无论如何,我们称每个顶点的和α(x)为非正的。如果一个顶点
没有问题边,那么α(x)≤0。当一个顶点有一个问题边符合它,那
么d(x)≥7。
如果d(x)=7,哪么每一个问题边的形式为(5,7,3,30并且 。通过
lemma2,边xu和xv分享两个相邻顶点u,v。边xu和xv有价值 ,因
此每个对α(x)贡献至多-1/42.因为每一个问题边至少有一个这样的边,
我们可以得到α(x)<0
如果d(x)≥8,因为每一个问题边有一个至多度为4的顶点,两个
这样顶点的距离表明b(G)≤,那么我们有至少一条问题边。
如果x有一个度为1,3,或者4的相邻顶点,那么它有至少7个相邻顶
点度数为6。因为d(x)=8,d(y)≥6,而且a1,a2≥3,那么每一个x
和高度数顶点之间
的边满足 .
( ) ( )
( ) ( 1) 2
i
i i
v V G e E G
v v f
1 1/ 24 i i v f
31. 应用图论(Graph Theory)的产生和发展经历了二百多年的历史, 到现在已经有广泛的应用。而Bondage number作为图论中的一个 猜想,虽然从提出到现在不到30年,但它的应用领域几乎涉及方方 面面,尤其是生产管理,军事,交通运输,计算机和通讯网络方面, 因为他们需要涉及大量的离散性问题。
Bondage number 及其相关问题将在物理,化学,运筹学,计算机 科学,电子学,信息论,控制论,网络理论,社会科学及经济管理 等几乎所有学科领域中各方面应用的研究都得到“爆炸性发展”。 本文与Bondage number 有关的结果也会有很大的应用。
3.3 本文应用
32. [1] D. Bauer, F. Harry, J. Nieminen and C.L. Suffel, Domination alteration sets in graphs, Discrete Math. 47 (1983), pp. 153–161. Article | PDF (737 K) | MathSciNet | View Record in Scopus | Cited By in Scopus (24)
[2] J.E. Dunbar, T.W. Haynes, U. Teschner and L. Volkmann, Bondage insensitivity and reinforcement. In: T.W. Haynes, S.T. Hedetniemi and P.J. Slater, Editors, Domination in Graphs: Advanced Topics, Dekker, New York (1998), pp. 249–259.
[3] J.F. Fink, M.J. Jacobson, L.F. Kinch and J. Roberts, The bondage number of a graph, Discrete Math. 86 (1990), pp. 47–57. Abstract | PDF (653 K) | MathSciNet | View Record in Scopus | Cited By in Scopus (26)
[4] M. Fischermann, D. Rautenbach and L. Volkmann, Remarks on the bondage number of planar graphs, Discrete Math. 260 (2003), pp. 57–67. Abstract | PDF (139 K)
参考文献
33. [5] R. Frucht and F. Harary, On the corona of two graphs, Aequationes Math. 4 (1970), pp. 322–324.
[6] B.L. Hartnell and D.F. Rall, Bounds on the bondage number of a graph, Discrete Math. 128 (1994), pp. 173–177. Abstract | PDF (316 K) | MathSciNet | View Record in Scopus | Cited By in Scopus (14)
[7] L. Kang and J. Yuan, Bondage number of planar graphs, Discrete Math. 222 (2000), pp. 191–198. Abstract | PDF (78 K) | View Record in Scopus | Cited By in Scopus (9)
[8] U. Teschner, A counterexample to a conjecture on the bondage number of a graph, Discrete Math. 122 (1993), pp. 393–395. Abstract | PDF (113 K) | MathSciNet | View Record in Scopus | Cited By in Scopus (8)
[9] U. Teschner, A new upper bound for the bondage number of graphs with small domination number, Australas. J. Combin. 12 (1995), pp. 27–35. MathSciNet
[10] U. Teschner, New results about the bondage number of a graph, Discrete Math. 171 (1997), pp. 249–259. Abstract | PDF (501 K) | MathSciNet | View Record in Scopus | Cited By in Scopus (9)
[11]Kelli Carlson, Mike Devclin , On the bondage numbber of Planar and directed Grophs, American Institure of Mathemaitcs, 360 Portage Ave, Palo Alto, CA 94306-244.USA
[12] L.Lovasz,M.D.Plummer,Natching Theory, Elsevier, Amsterdam, 1986
[13]J.A. Bondy, U.S.R. Murty, Graph Theory with Applications, Elsevier , Amsterdam, 1976