One proactive approach to increasing student engagement in schools is implementing Positive Behavior Intervention and Support (PBIS) strategies. PBIS focuses on prevention and concentrates on quality-of-life issues that include improved academic
achievement, enhanced social competence, and safe learning and teaching environments. This study is a replication of a study that investigated the combination of active supervision, precorrection, and explicit timing. The purpose of the study was to decrease student problem behavior, reduce transition time, and support maintenance of the intervention in the setting. Results show that active supervision, precorrection, and explicit timing decreased student problem behavior, decreased the duration of transitions in two instructional periods, and the intervention was maintained in the setting. Implications, limitations, and future research are discussed.
Keywords: active supervision, explicit timing, Positive Behavior Intervention and Support, precorrection, urban education
The present study deals with an AFCA (Adaptive Fuzzy Control Algorithm) for an Euler-Bemoulli approximation of a two-dimensional version of a cantilever beam-like orthogonal tetrahedral space truss. Transient disturbances, modeled as a unit impulse, excite all the modes of the beam. The resulting transverse displacement at the free end of the beam and its corresponding rate are observed by sensors placed there, and active control of the beam is provided by a collocated force actuator.
A design methodology, based on fuzzy logic which assumes no a priori knowledge of plant dynamics, for the closed-loop control algorithm results in relatively quick settling times, low overshoots and dying out of vibration within a few seconds. The control algorithm is enhanced and made much faster by eliminating the need of repeatedly solving the set of differential equations of motion of an emulated dynamic vibration absorber. When the control force is turned off after a mere 15 seconds, almost all the vibrational energy is dissipated as the beam returns to its undisturbed state throughout its length. In addition, the performance of the AFCA is insensitive to varying initial conditions. To examine the robustness of the control system to changes in the temporal dynamics of the cantilever beam, the transient disturbance response to a considerably perturbed plant is simulated. The Young's modulus of the beam was raised as well as lowered by 60%, substantially perturbing the natural frequencies of vibration compared to the nominal plant. The AFCA provided similar settling times and rates of vibrational energy dissipation, satisfying the aim of plant model independence.
Lloyd C. Engelbrecht (born 1927) is Professor Emeritus of Art History at the University of Cincinnati. He is author of Moholy-Nagy: Mentor to Modernism (Cincinnati: Flying Trapeze Press, 2009). He will supply addenda and corrigenda for this book on a continuing basis.