Bulletin of Computational Applied Mathematics

18

Authors: Cemil Tunç, Osman Tunç

The authors of this article deal with a first order non-linear Volterra integro-differential equation (NVIDE). To this end, the conditions are obtained which are sufficient for stability (S), boundedness (B), and for every solution x of (NVIDE) is integrable. For properties of solutions of (NVIDE) considered three new theorems on (S), (B) and integrability properties of solutions are proved. The methods of the proofs involve constructing of a suitable Lyapunov functional (LF) which gives meaningful results for the problems to be investigated. The conditions to be given involve nonlinear improvement and extensions of those conditions found in the literature. An example is provided to illustrate the effectiveness of the proposed results. The results obtained are new and complements that found in the literature.

24

Authors: Sujit Kumar Sardar, Sugato Gupta, Bijan Davvaz

The soft category theory offers a way to study soft theories developed so far more generally. The main purpose of this paper is to introduce the basic algebraic operations in soft categories, and for that we introduce some algebraic operations, like intersection and union, in categories. Also, the notion of composition of soft functors is introduced to form category of all soft categories.

33

Authors: Emrah Altun, Haitham M. Yousof, Gholamhoss G. Hamedani

In this paper, we introduced a new flexible extension of the Generalized Half-Normal lifetime model as well as a new log-location regression model based on the proposed model. Some useful characterization results are presented and some mathematical properties are derived. The maximum likelihood method is used to estimate the model parameters by means of a graphical Monte Carlo simulation study. We show that the new log-location regression lifetime model can be very useful in analysing real data and provide more realistic fits than other regression models. Index plot of the modified deviance residual and Q-Q plot for modified deviance residual are presented to illustrate that our new model is more appropriate to HIV data set than other competitive models like log-odd log-logistic generalized half-normal regression model and log-generalized half-normal regression model. The sensitivity analysis is used via the index plot of generalized cook distance to discover the possible influential observations.