“…Recently, an impulsive positive observer has been developed for continuous-time positive linear systems (Xiao et al, 2017). Positive observers have been extended for other types of positive systems such as switched systems (Wang et al, 2016), quadratic systems (Okamoto et al, 2016), time-delay systems (Trinh et al, 2017), linear impulsive delayed systems (Hu et al, 2017), and positive 2D discrete-time systems (Shen and Wang, 2017). Moreover, there are few articles presenting observers for uncertain positive systems (Chen and Lam, 2014; Chen et al, 2014; Li and Lam, 2012), and also in the presence of unknown input or disturbances (Shafai et al, 2015).…”