background: the negative symptoms of schizophrenia remain a major clinical challenge. nortriptyline is a serotonin and noradrenalin reuptake inhibitor and belongs to secondary amine tricycles. the aim of this study is to evaluate the effect of nortriptyline on the negative symptoms of schizophrenia.   methods: this study is a six-week randomized placebo-control trial of nortriptyline or placebo...

The paper deals with adaptive control of a continuous stirred tank reactor (CSTR). A nonlinear model of the process is approximated by a continuous-time external linear model. The parameters of the CT external linear model of the process are estimated using a corresponding delta model. The control system with two feedback controllers is considered. The controller design is based on the polynomi...

The goal of this paper is to extend to two-dimensional optimal control systems with scalar input the classical notion of Gaussian curvature of two-dimensional Riemannian surface using the Cartan’s moving frame method. This notion was already introduced by A. A. Agrachev and R. V. Gamkrelidze for more general control systems using a purely variational approach. Then we will see that the “control...