Statements on chaos control designs, including a fractional order dynamical system, applied to a MEMS comb-drive actuator

In this work, we deal with a micro electromechanical system (MEMS), represented by a micro-accelerometer. Through numerical simulations, it was found that for certain parameters, the system has a chaotic behavior. The chaotic behaviors in a fractional order are also studied numerically, by historical time and phase portraits, and the results are validated by the existence of positive maximal Lyapunov exponent. Three control strategies are used for controlling the trajectory of the system: State Dependent Riccati Equation (SDRE) Control, Optimal Linear Feedback Control, and Fuzzy Sliding Mode Control. The controls proved effective in controlling the trajectory of the system studied and robust in the presence of parametric errors.

Checklist de cirurgias da OMS: análise da segurança e comunicação da equipe cirúrgica de um hospital escola

WHO has launched the “Safe Surgery Saves Lives” program with the purpose to reduce damage to surgical patients and define safety standards specifically in order to reduce such patients’ morbi-mortality by providing surgery teams and hospital managers with orientation about the standards of safe surgery and a uniform service evaluation instrument for national and international surveillance. Hence, this study aimed at applying the WHO safe-surgery checklist to the surgical specialties of a university hospital and evaluating the team’s opinion about the influence of its application on the safety of surgical process and on the team’s interpersonal communication. It was a descriptive, analytical, qualitative field study conducted in the surgery facilities of a university hospital in a public establishment in São Paulo state. The checklist was applied to eight surgical specialties, resulting in a total number of 30 surgeries. Its application was conducted by the researcher in three phases: Sign in, Time out, Sign Out. Next, one member of the surgery team was invited to voluntarily participate in the study by signing an informed consent form and answering guiding questions. Thirty members of the surgery team participated in the study. Bardin’s Content Analysis Method was used to organize and analyze the data. As regards the safety provided by the checklist, the following thematic categories emerged: “It reduces risk and possible complications”; “It standardizes conducts and reviews safety steps”; “It allows for better understanding of the process”; and “It provides safety to the team as a whole”. The category “It is not included in the institution’s routine” emerged from the subjects’ statements when they understood that, in this form, the checklist does not provide safety to surgical procedures. As regards communication, two thematic categories emerged: ...(Complete abstract click electronic access below)