Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
2016
Design and analysis of networks have many applications in the engineering sciences. This dissertation seeks to contribute to the methods used in the analysis of networks with a view towards assisting decision making processes. Networks are initially considered as objects in the category of graphs and later as objects in the category of hypergraphs. The connection with the category of simplicial pairs become apparent when the topology is analyzed using homological algebra. A topological ranking is developed that measures the ability of the network to stay path-connected. Combined with the analysis of cover ideals of hypergraphs, the topological ranking demonstrates the non-trivial decisions that needs to be considered in system design. All the methods developed here have an underlying common structure, namely that they all appear at solution sets for systems of polynomials. These solution sets are called algebraic varieties.
IAEME PUBLICATION, 2021
The importance of networks can be very well considered by the role they have played in electronics and electrical engineering. The theories of mathematics are known to be emerged from in corporation of communicative theory and signal processing; The role of networking remains the same. Communication networks depends largely on the part played by the nodes as they have a very pivotal role. Apart from aforesaid points theory of graphs still stands high among all the research methodologies. We can say that Zagreb indices are the products of the concept of vertex degrees. M-Polynomials have a got a new dimensions from different chemical compounds that proved themselves result oriented in the indices related to topology. And there is no doubt in it that the results we got from the amalgamation of chemical compounds and networks associated themselves with various chemical properties and bioactivities. The article is supposed to give a considerable focus on the derivation of M-Polynomials for the Block Shift (BS) and Hierarchical Hypercube (HH) Networks. In addition to it, the indices based on topology and the degrees have been derived from M-Polynomial of BS and HH network. The last portion of the article presents tabulation and graphs in order to show the comparison of different M-Polynomials and indices related to topology of BS and HH networks.
2016
Discrete models of gene regulatory networks have gained popularity in computational systems biology over the last dozen years. However, not all discrete network models reflect the behaviors of real biological systems. In this work, we focus on two model selection methods and algebraic geometry arising from these model selection methods. The first model selection method involves biologically relevant functions. We begin by introducing k-canalizing functions, a generalization of nested canalizing functions. We extend results on nested canalizing functions and derived a unique extended monomial form of arbitrary Boolean functions. This gives us a stratification of the set of n-variable Boolean functions by canalizing depth. We obtain closed formulas for the number of n-variable Boolean functions with depth k, which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions. We characterize the set of k-canalizing functions as an algebraic variety in...
2009
Abstract In studies of survivable networks, it is important to be able to differentiate network topologies by means of a robust numerical measure that indicates the levels of immunity of these topologies to failures of their nodes and links. Ideally, such a measure should be sensitive to the existence of nodes or links which are more important than others, for example, if their failures cause the network's disintegration.
Systems & Control Letters, 2017
In this paper, we present a method for finding the algebraic connectivity of network-of-networks having a graph product structure. The network consists of several homogeneous (identical) subsystems connected with each other according to an interconnection graph. We show that the algebraic connectivity can be calculated from properties of graphs corresponding to the subsystem and the interconnection. Furthermore, we indicate that the algebraic connectivity of the entire system does not exceed those of the subsystem and the interconnection.
2008 47th IEEE Conference on Decision and Control, 2008
We take a structural approach to the problem of designing the edge weights in an undirected graph subject to an upper bound on their total, so as to maximize the algebraic connectivity. Specifically, we first characterize the eigenvector(s) associated with the algebraic connectivity at the optimum, using optimization machinery together with eigenvalue sensitivity notions. Using these characterizations, we obtain an alternative finite-search algorithm for finding the optimal design in tree graphs that is quadratic in the number of vertices, and further address update of the design upon addition of a new vertex. We also obtain a suite of results concerning the topological and eigen-structure of optimal designs for bipartite and general graphs. In turn, we obtain a lower-bound on the optimal algebraic connectivity in terms of the graph's diameter, and also describe how our structural insights can inform and be meshed with numerical solution techniques. Finally, an example concerning flow-network design is presented.
We study the geometry and topology of the rank stratification for polynomial system solving, i.e., the set of pairs (system, solution) such that the derivative of the system at the solution has a given rank. Our approach is to study the gradient flow of the Frobenius condition number defined on each stratum.
2007
We study the algebraic connectivity in relation to the graph's robustness to node and link failures. Graph's robustness is quantified with the node and the link connectivity, two topological metrics that give the number of nodes and links that have to be removed in order to disconnect a graph. The algebraic connectivity, i.e. the second smallest eigenvalue of the Laplacian matrix, is a spectral property of a graph, which is an important parameter in the analysis of various robustness-related problems. In this paper we study the relationship between the proposed metrics in three well-known complex network models: the random graph of Erdős-Rényi, the smallworld graph of Watts-Strogatz and the scale-free graph of Barabási-Albert. From [11] it is known that the algebraic connectivity is a lower bound on both the node and the link connectivity. Through extensive simulations with the three complex network models, we show that the algebraic connectivity is not trivially connected to graph's robustness to node and link failures. Furthermore, we show that the tightness of this lower bound is very dependent on the considered complex network model.
arXiv: Combinatorics, 2016
In this paper, we study the notion of chordality and cycles in hypergraphs from a commutative algebraic point of view. The corresponding concept of chordality in commutative algebra is having a linear resolution. However, there is no unified definition for cycle or chordality in hypergraphs in the literature, so we consider several generalizations of these notions and study their algebraic interpretations. In particular, we investigate the relationship between chordality and having linear quotients in some classes of hypergraphs. Also we show that if C is a hypergraph such that C is a vertex decomposable simplicial complex or I(C) is squarefree stable, then C is chordal according to one of the most promising definitions.
Proceedings of the IEEE, 2018
Algebraic graph theory is a cornerstone in the study of electrical networks ranging from miniature integrated circuits to continental-scale power systems. Conversely, many fundamental results of algebraic graph theory were laid out by early electrical circuit analysts. In this paper we survey some fundamental and historic as well as recent results on how algebraic graph theory informs electrical network analysis, dynamics, and design. In particular, we review the algebraic and spectral properties of graph adjacency, Laplacian, incidence, and resistance matrices and how they relate to the analysis, networkreduction, and dynamics of certain classes of electrical networks. We study these relations for models of increasing complexity ranging from static resistive DC circuits, over dynamic RLC circuits, to nonlinear AC power flow. We conclude this paper by presenting a set of fundamental open questions at the intersection of algebraic graph theory and electrical networks.
Setting n = 2, we obtain c31 = 1, since (6) = r(-4, 6) vanishes, as do all the terms on the right save and , which are -r(2) and r(2), respectively. Setting n = 3, we obtain, similarly, c41 = 1.
Discrete Applied Mathematics, 1993
We deal with directed hypergraphs as a tool to model and solve some classes of problems arising in Operations Research and in Computer Science. Concepts such as connectivity, paths and cuts are defined. An extension of the main duality results to a special class of hypergraphs is presented. Algorithms to perform visits of hypergraphs and to find optimal paths are studied in detail. Some applications arising in propositional logic, And-Or graphs, relational data bases and transportation analysis are presented.
Mathematics
There are numeric numbers that define chemical descriptors that represent the entire structure of a graph, which contain a basic chemical structure. Of these, the main factors of topological indices are such that they are related to different physical chemical properties of primary chemical compounds. The biological activity of chemical compounds can be constructed by the help of topological indices. In theoretical chemistry, numerous chemical indices have been invented, such as the Zagreb index, the Randić index, the Wiener index, and many more. Hex-derived networks have an assortment of valuable applications in drug store, hardware, and systems administration. In this analysis, we compute the Forgotten index and Balaban index, and reclassified the Zagreb indices, A B C 4 index, and G A 5 index for the third type of hex-derived networks theoretically.
Computers, Materials & Continua
In various fields, different networks are used, most of the time not of a single kind; but rather a mix of at least two networks. These kinds of networks are called bridge networks which are utilized in interconnection networks of PC, portable networks, spine of internet, networks engaged with advanced mechanics, power generation interconnection, bio-informatics and substance intensify structures. Any number that can be entirely calculated by a graph is called graph invariants. Countless mathematical graph invariants have been portrayed and utilized for connection investigation during the latest twenty years. Nevertheless, no trustworthy evaluation has been embraced to pick, how much these invariants are associated with a network graph or subatomic graph. In this paper, it will discuss three unmistakable varieties of bridge networks with an incredible capacity of assumption in the field of computer science, chemistry, physics, drug industry, informatics and arithmetic in setting with physical and manufactured developments and networks, since Contraharmonic-quadratic invariants (CQIs) are recently presented and have different figure qualities for different varieties of bridge graphs or networks. The study settled the geography of bridge graphs/networks of three novel sorts with two kinds of CQI and Quadratic-Contraharmonic Indices (QCIs). The deduced results can be used for the modeling of the above-mentioned networks.
ArXiv, 2021
Algebraic connectivity is one way to quantify graph connectivity, which in turn gauges robustness as a network. In this paper, we consider the problem of maximising algebraic connectivity both local and globally over all simple, undirected, unweighted graphs with a given number of vertices and edges. We pursue this optimization by equivalently minimizing the largest eigenvalue of the Laplacian of the ‘complement graph’. We establish that the union of complete subgraphs are largest eigenvalue local minimizer graphs. Further, under sufficient conditions satisfied by the edge/vertex counts we prove that this union of complete components graphs are, in fact, Laplacian largest eigenvalue global maximizers; these results generalize the ones in the literature that are for just two components. These sufficient conditions can be viewed as quantifying situations where the component sizes are either ‘quite homogeneous’ or some of them are relatively ‘negligibly small’, and thus generalize know...
Physica A: Statistical Mechanics and its Applications, 2014
h i g h l i g h t s
Electronic Journal of Linear Algebra, 1998
Dedicated to Hans Schneider on the occasion of his seventieth birthday.
Discrete Applied Mathematics, 1992
We deal with directed hypergraphs as a tool to model and solve some classes of problems arising in Operations Research and in Computer Science. Concepts such as connectivity, paths and cuts are defined. An extension of the main duality results to a special class of hypergraphs is presented. Algorithms to perform visits of hypergraphs and to find optimal paths are studied in detail. Some applications arising in propositional logic, And-Or graphs, relational data bases and transportation analysis are presented.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.