Consider the following problem. Given a discrete-time linear system, find, if possible, linear state-feedback control laws such that under these laws all trajectories originating in the non-negative orthant of the state space remain non-negative while asymptotically deteriorating to the origin. This problem is called feedback stabilizability-holdability problem (FSH). If, in addition, the requi...

In positive feedback mechanisms, the response to a stimulus does not stop or reverse it but instead keeps the sequence of events going up. At first glance, this would appear to be a counter to the principle of homeostasis, since a positive feedback loop has no obvious means of stopping. Not surprisingly, therefore, the positive feedback is less common in nature than the negative one. A positive...

The paper is concerned with patchy vector fields, a class of discontinuous, piecewise smooth vector fields that were introduced in [A-B] to study feedback stabilization problems. We prove the stability of the corresponding solution set w.r.t. a wide class of impulsive perturbations. These results yield the robusteness of patchy feedback controls in the presence of measurement errors and externa...

The stabilization of nonholonomic systems have focused a lot of attention this last years [see e.g. survey papers 1, 2], in particular because it fails to exist linearizing feedback transformation or static continuous stabilizing state feedback [3] despite they are open-loop controllable [4]. The two main strategies adopted to stabilize these systems are time-varying feedbacks [see e.g. 5, 6, 7...

This paper addresses the design of multimedia presentation of language learning material for Freshman English writing course at a University in Taiwan. The material is used to assist teacher’s instruction, and serves as the preliminary step regarding the implementation of instructional strategies in the language teaching course for digital learning materials. Feedbacks from students are collect...

This study examined relations between felt authenticity and transformational leadership behaviors of 184 Christian faith community leaders. Felt authenticity was examined across 4 roles associated with transformational leadership behaviors: inspirational motivation in the visionary leader role, idealized influence in the positive role model role, intellectual stimulation in the champion of chan...