An experiment (N = 74) was conducted to investigate the impact of game difficulty and player performance on game enjoyment. Participants played a First Person Shooter game with systematically varied levels of difficulty. Satisfaction with performance and game enjoyment were assessed after playing. Results are not fully in line with predictions derived from flow and attribution theory and sugges...

Improvement in ultrasound technology, including transvaginalsonography and higher frequency probes, has led to a better understanding of early pregnancy development. The first trimester ultrasound have been identified that can be used to reassure women that their pregnancy is progressing normally or abnormal them that their pregnancy will fail. The practicing radiologist and obstetrician must b...

In this paper we give sharp upper bounds on the Zagreb indices and characterize all trees achieving equality in these bounds. Also, we give lower bound on first Zagreb coindex of trees.

The paper starts with an examination and critique of Tarski’s wellknown proposed explication of the notion of logical operation in the type structure over a given domain of individuals as one which is invariant with respect to arbitrary permutations of the domain. The class of such operations has been characterized by McGee as exactly those definable in the language L∞,∞. Also characterized sim...

Breadth-first and depth-first search are basic search strategies upon which many other search algorithms are built. In this paper, we describe an approach to integrating these two strategies in a single algorithm that combines the complementary strengths of both. We show the benefits of this approach using the treewidth problem as an example.

We propose a simple but powerful approach to the verification of parameterised systems. The approach is based on modelling the reachability between parameterized states as deducibility between suitable encodings of states by formulae of first-order predicate logic. To establish a safety property, that is non-reachability of unsafe states, the finite model finder is used to find a finite counter...