Computational complexity continuum within Ising formulation of NP problems

A promising approach to achieve computational supremacy over the classical von Neumann architecture explores classical and quantum hardware as Ising machines. The minimisation of the Ising Hamiltonian is known to be NP-hard problem yet not all problem instances are equivalently hard to optimise. Given that the operational principles of Ising machines are suited to the structure of some problems but not others, we propose to identify computationally simple instances with an ‘optimisation simplicity criterion’. Neuromorphic architectures based on optical, photonic, and electronic systems can naturally operate to optimise instances satisfying this criterion, which are therefore often chosen to illustrate the computational advantages of new Ising machines. As an example, we show that the Ising model on the Möbius ladder graph is ‘easy’ for Ising machines. By rewiring the Möbius ladder graph to random 3-regular graphs, we probe an intermediate computational complexity between P and NP-hard classes with several numerical methods. Significant fractions of polynomially simple instances are further found for a wide range of small size models from spin glasses to maximum cut problems. A compelling approach for distinguishing easy and hard instances within the same NP-hard class of problems can be a starting point in developing a standardised procedure for the performance evaluation of emerging physical simulators and physics-inspired algorithms.

New Perspectives on Classical Meanness of Some Ladder Graphs

In this study, we investigate a new kind of mean labeling of graph. The ladder graph plays an important role in the area of communication networks, coding theory, and transportation engineering. Also, we found interesting new results corresponding to classical mean labeling for some ladder-related graphs and corona of ladder graphs with suitable examples.

Face Bimagic Labeling On Some Graphs

The existence of face bimagic labeling of types (1,0,1), (1,1,0) and (0,1,1) for double duplication of all vertices by edges of a ladder graph is proved. Also if G is (1, 0, 1) face bimagic, except for three sided faces then double duplication of all vertices by edges of G is face bimagic.

Grup Automorfisma Graf Tangga dan Graf Lingkaran

Abstrak. Automorfisma dari suatu graf G merupakan isomorfisma dari graf G ke dirinya sendiri, yaitu fungsi yang memetakan dirinya sendiri. Automorfisma suatu graf dapat dicari dengan menentukan semua kemungkinan fungsi yang satu-satu, onto serta isomorfisma dari himpunan titik pada graf tersebut. Artikel ini difokuskan pada penentuan banyaknya fungsi pada graf tangga dan graf lingkaran yang automorfisma serta grup yang dibentuk oleh himpunan automorfisma dari kedua graf tersebut. Jenis penelitian ini merupakan penelitian dasar atau penelitian murni dan metode yang digunakan adalah studi literatur. Hasil penelitian ini menunjukkan bahwa graf tangga membentuk grup abelian berorde-2, graf tangga membentuk grup dihedral berorde-8, dan graf tangga membentuk grup abelian berorde-4. Sedangkan graf lingkaran membentuk grup dihedral berorde-2n.Kata Kunci: Automorfisma, Graf Lingkaran, Graf Tangga, GrupAbstract. An automorphism of a graph G is an isomorphism of graph G to itself i.e. the function that maps onto itself. An automorphism of a graph can be looked for by determining all possible functions which is one-to-one, onto, and isomorphism from vertex set at the graph. This article is focused on determining the number of automorphism functions on ladder graph and cycle graph and the groups formed by the two graphs. The tipe of this research is basic research or pure research and the research method used is literarture review. The result show that ladder graph forms an abelian group of order 2, ladder graph forms a dihedral group of order 8, and ladder graph forms an abelian group of order 4. In other side, cycle graph , forms a dihedral group of order 2n.Keywords: Automorphism, Cycle Graph, Ladder Graph, Group

Zero Forcing Number of Some Families of Graphs

The work is devoted to the study of the zero forcing number of some families of graphs. The concept of zero forcing is a relatively new research topic in discrete mathematics, which already has some practical applications, in particular, is used in studies of the minimum rank of the matrices of adjacent graphs. The zero forcing process is an example of the spreading process on graphs. Such processes are interesting not only in terms of mathematical and computer research, but also interesting and are used to model technical or social processes in other areas: statistical mechanics, physics, analysis of social networks, and so on. Let the vertices of the graph G be considered white, except for a certain set of S black vertices. We will repaint the vertices of the graph from white to black, using a certain rule.Colour change rule: A white vertex turns black if it is the only white vertex adjacent to the black vertex.[5] The zero forcing number Z(G) of the graph G is the minimum cardinality of the set of black vertices S required to convert all vertices of the graph G to black in a finite number of steps using the ”colour change rule”.It is known [10] that for any graph G, its zero forcing number cannot be less than the minimum degree of its vertices. Such and other already known facts became the basis for finding the zero forcing number for two given below families of graphs:A gear graph, denoted W2,n is a graph obtained by inserting an extra vertex between each pair of adjacent vertices on the perimeter of a wheel graph Wn. Thus, W2,n has 2n + 1 vertices and 3n edges.A prism graph, denoted Yn, or in general case Ym,n, and sometimes also called a circular ladder graph, is a graph corresponding to the skeleton of an n-prism.A wheel graph, denoted Wn is a graph formed by connecting a single universal vertex to all vertices of a cycle of length n.In this article some known results are reviewed, there is also a definition, proof and some examples of the zero forcing number and the zero forcing process of gear graphs and prism graphs.