Seventeen male Ostrich chicks (Ostruiothio, Camelus camelus) aged one month old were brought from Radom National Park to the research farm of University of Nyala, both in Sudan, and reared indoor, concentrate rations were formulated and provided ad-libitum and water equally supplied. During the study period, chick behaviour were observed, body weight gained (g/day), feed intake (g/day), water c...

Let denote a Q-polynomial distance-regular graph with diameter d¿ 3. We show that if the valency is at least three, then the intersection number p 12 is at least two; consequently the girth is at most six. We then consider a condition on the dual eigenvalues of that must hold if is the quotient of an antipodal distance-regular graph of diameter D¿ 7; we call a pseudoquotient whenever this condi...

Nowadays the quality inspect of soft capsules is mainly by manual. Despite the intensive of this work, the accuracy of inspection by manual is very low. This paper proposed soft capsules online sorting system based on machine vision. The inspection process are following: (1) soft capsules were placed on rollers are rotating while moving. The image of each soft capsule was grabbed. (2) automatic...

A set of vertices C in a graph is convex if it contains all vertices which lie on shortest paths between vertices in C. The convex hull of a set of vertices S is the smallest convex set containing S. The hull number h(G) of a graph G is the smallest cardinality of a set of vertices whose convex hull is the vertex set of G. For a connected triangle-free graph G of order n and diameter d ≥ 3, we ...

An r-dynamic proper k-coloring of a graph G is a proper k-coloring of G such that every vertex in V (G) has neighbors in at least min{d(v), r} different color classes. The r-dynamic chromatic number of a graph G, written χr(G), is the least k such that G has such a coloring. By a greedy coloring algorithm, χr(G) ≤ r∆(G) + 1; we prove that equality holds for ∆(G) > 2 if and only if G is r-regula...

My research revolves around structural and extremal aspects of Graph Theory, particularly problems involving girth and distance, trees, cycles in graphs, and some variations of Ramsey theory. I have also done some work in generalized graph colorings and graph labellings. My other interests include graph decomposi-tions and packings, perfect graphs, matching theory, hypergraphs and coding theory...

The b-chromatic number of a graph G is the largest integer k such that G admits a proper k-coloring in which every color class contains at least one vertex that has a neighbor in each of the other color classes. We prove that every d-regular graph with at least 2d vertices has b-chromatic number d + 1, that the b-chromatic number of an arbitrary d-regular graph with girth g = 5 is at least ⌊ d+...

The b-chromatic number of a graph G is the largest integer k such that G admits a proper k-coloring in which every color class contains at least one vertex that has a neighbor in each of the other color classes. We prove that every d-regular graph with at least 2d vertices has b-chromatic number d + 1, that the b-chromatic number of an arbitrary d-regular graph with girth g = 5 is at least ⌊ d+...

It is known that bipartite distance-regular graphs with diameter D > 3, valency k > 3, intersection number c2 > 2 and eigenvalues k = θ0 > θ1 > · · · > θD satisfy θ1 6 k− 2 and thus θD−1 > 2− k. In this paper we classify non-complete distanceregular graphs with valency k > 2, intersection number c2 > 2 and an eigenvalue θ satisfying −k < θ 6 2 − k. Moreover, we give a lower bound for valency k ...

The Tree Decomposition Conjecture by Barát and Thomassen states that for every tree T there exists a natural number k(T ) such that the following holds: If G is a k(T )-edge-connected simple graph with size divisible by the size of T , then G can be edge-decomposed into subgraphs isomorphic to T . So far this conjecture has only been verified for paths, stars, and a family of bistars. We prove ...