We propose a new two-parameter discrete model, called Type-II half-logistics exponential (DTIIHLE) distribution using the survival discretization approach. The DTIIHLE can be utilized to model COVID-19 data. parameters are estimated maximum likelihood method. A simulation study is conducted evaluate performance of estimators. usefulness proposed evaluated two real-life data sets. provides super...

We define a Wigner distribution function for a one-dimensional finite quantum system, in which the position and momentum operators have a finite (multiplicity-free) spectrum. The distribution function is thus defined on discrete phase-space, i.e. on a finite discrete square grid. These discrete Wigner functions possess a number of properties similar to the Wigner function for a continuous quant...

In this paper, we propose a recursive method for structural learning of directed acyclic graphs (DAGs), in which a problem of structural learning for a large DAG is first decomposed into two problems of structural learning for two small vertex subsets, each of which is then decomposed recursively into two problems of smaller subsets until none subset can be decomposed further. In our approach, ...

An acyclic edge coloring of a graph G is a proper edge coloring such that no bichromatic cycles are produced. The acyclic chromatic index a(G) of G is the smallest integer k such that G has an acyclic edge coloring using k colors. Fiamčik (1978) and later Alon, Sudakov and Zaks (2001) conjectured that a(G) ≤ ∆ + 2 for any simple graph G with maximum degree ∆. Basavaraju and Chandran (2009) show...

The notion of a competition graph was introduced by J. E. Cohen in 1968. The competition graph C(D) of a digraph D is a (simple undirected) graph which has the same vertex set as D and has an edge between two distinct vertices x and y if and only if there exists a vertex v in D such that (x, v) and (y, v) are arcs of D. For any graph G, G together with sufficiently many isolated vertices is the...

In this paper we introduce the recursively directed hypercubes, and analyze some of their structural properties. We show that every recursively directed hypercube is acyclic, and has a unique pair of source and sink nodes. The main contribution of the paper is an analysis of distances between the nodes in such a graph. We show that the distance from the source node to any other node, and from a...

This paper studies dynamic complexity under definable change operations in the DynFO framework by Patnaik and Immerman. It is shown that for changes definable by parameter-free firstorder formulas, all (uniform) AC1 queries can be maintained by first-order dynamic programs. Furthermore, many maintenance results for single-tuple changes are extended to more powerful change operations: (1) The re...

Let D ∈ D(n, p) denote a simple random digraph obtained by choosing each of the ` n 2 ́ undirected edges independently with probability 2p and then orienting each chosen edge independently in one of the two directions with equal probability 1/2. Let mas(D) denote the maximum size of an induced acyclic subgraph in D. We obtain tight concentration results on the size of mas(D). Precisely, we show ...

It is well known that chordal graphs are exactly the graphs of acyclic simplicial complexes . In this note we consider the analogous class of graphs associated with acyclic cubical complexes . These graphs can be characterized among median graphs by forbidden convex subgraphs . They possess a number of properties (in analogy to chordal graphs) not shared by all median graphs . In particular , w...