Bat Population Dynamics

A new metaheuristic based back-propagation algorithm known as Bat-BP is presented in this paper. The proposed Bat-BP algorithm successfully solves the problems like slow convergence to global minima and network stagnancy in back-propagation neural network (BPNN) algorithm. In this paper, the bat population is increased from 10 to 500 bats to detect the performance decline or incline in the Bat-BP algorithm by performing simulations on XOR and OR datasets. The simulation results show that the convergence rate to global minimum in Bat-BP is directly proportional with an increase in bats on 2-bit XOR dataset. In case of 3-bit XOR and 4-bit OR datasets, the results deteriorated with an increase in the bat population.

Graphical abstract Abstract In this study vegetation composition of understorey species of Malam Jabba forest is evaluated by multivariate analysis. Thirteen stands were quantitatively sampled by point centered quarter method. Environmental variables were recorded and correlate them with vegetation characteristic. In 13 stands 49 understory species were recorded. Multivariate techniques were employed to assess the vegetation groups and underlying group structure. Agglomerative Cluster analysis (Ward's method) discloses four main groups of vegetation while Principle Component Analysis (PCA) clearly ordinate these groups on all three axes. The most common species distributed in all four groups were Among the environmental variables elevation and slope played an overriding role in the distribution of vegetation. The relationships between the six PCA ordination axes with environmental factors generally showed few significant relations, only axis 2 showed marked relationship with all edaphic variables (except pH), suggesting that the edaphic gradient has an overriding role in the composition and distribution of understorey vegetation. Some other environmental factors showed weak correlations with ordination axes, it could be spurious correlation. Malam Jabba forests are highly disturbed due to civil war and anthropogenic causes. Slope of the forests prove to be an overriding role in the distribution of vegetation as evaluated by analysis of variance.