Grouping problems are hard to solve combinatorial optimisation problems which require partitioning of objects into a minimum number of subsets while a given objective is simultaneously optimized. Selection hyper-heuristics are high level general purpose search methodologies that operate on a space formed by a set of low level heuristics rather than solutions. Most of the recently proposed selec...

The hyper-Kirchhoff index is introduced when the hyper-Wiener operator is applied to the resistance-distance matrix of a connected graph. We give lower and upper bounds for the hyper-Kirchhoff index, and determine the n-vertex unicyclic graphs with the smallest, the second and the third smallest as well as the largest, the second and the third largest hyper-Kirchhoff indices for n ≥ 5. We also ...

The strong matching preclusion number of a graph is the minimum number of vertices and edges whose deletion results in a graph that has neither perfect matchings nor almost-perfect matchings. This is an extension of the matching preclusion problem that was introduced by Park and Ihm. The generalized (n, k)-star graph was introduced to address scaling issues of the star graph, and it has many de...

The (n, k)-star graph is a generalization of the n-star graph. It has better scalability than the n-star graph and holds some good properties compared with the hypercube. This paper focuses on the design of the fault-tolerant routing algorithm for the (n, k)-star graph. We adopt the idea of collecting the limited global information used for routing on the n-star graph to the (n, k)-star graph. ...

This paper proposes the design of Star Schema of a Data Warehouse and conversion to its equivalent Graph based Multi Dimensional Data Model (GMDDM Model). Design of Star Schema facilitates in constructing Graph based Multi Dimensional Data Model. The GMDDM model defines a set of graph based constructs that are used to specify the conceptual level design of Data Warehouse. Data warehouse represe...

The hyper-velocity star S5-HVS1, ejected 5 Myr ago from the Galactic Center at 1800 km/s, was most likely produced by tidal break-up of a tight binary supermassive black hole SgrA*. Taking Monte Carlo approach, we show that former companion S5-HVS1 main-sequence between 1.2 and 6 solar masses captured into highly eccentric orbit with pericenter distance in range 1-10 AU semimajor axis about $10...

The Cartesian product of interconnection networks has been investigated recently as a method for combining desirable properties of component networks. This paper presents a unified framework for obtaining and comparing properties of a virtually unlimited number of product networks. This work complements results appeared in the literature for product networks and conducts a comparative study bet...

We show star images obtained with a miniature “densified pupil imaging interferometer” also called a hyper-telescope. The formation of such images violates a “golden rule of imaging interferometers” which appeared to forbid the use of interferometric arrangements differing from a Fizeau interferometer. These produce useless images when the sub-apertures spacing is much wider than their size, ow...