Circuit Simulation of an Analog Secure Communication based on Synchronized Chaotic Chua’s System

Abstract: This paper presents an effective technique for both synchronization and secure communication. In particular, an adaptive sliding mode observer is developed and practically implemented. Only one component of the state vector of the transmitter, that satisfies the observability matching condition, is sent to the receiver via a public channel, which is a sliding mode observer. This observer is able to estimate the state vector of the transmitter and then, reconstruct the unknown information hidden in the transmitted with inclusion encryption. Finally, the chaotic secure communication system is simulated with matlab and then practically implemented by electrical circuits with Multisim software and Ultiboard software

Impulsive Control and Synchronization of a New 5D Hyperchaotic System

This paper investigates the control and the synchronization of a new 5D hyperchaotic system. Based on the impulsive control theory, some new and less conservative criteria for the global exponential stability and asymptotical stability of impulsively controlled 5D hyperchaotic system, are obtained with varying impulsive interval. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed control and synchronization methodology

Circuit realization of a hybrid delay chaotic secure communication system over a noisy receiver

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A Heuristic for definition of shifts in an emergency department

International audienceWe propose a model that combines simulation optimization and linear programming in order to define the shift pattern that best match the arrival pattern of patients in an Emergency Department (ED). The simulation model supplies the linear programming with the staffing levels that secure the performance of the ED, expressed in terms of the average Length of Stay (LOS) of patients. The linear model determines the shift scheduling of all employees with the use of the minimum cost, including several practical constraints as experienced in practice. The model includes also a heuristic that helps ED managers to find a solution that satisfies budget restrictions. This heuristic proposes an efficient manner of reducing the staffing cost, by decreasing the staffing levels in a way that affects the performance as less as possible. The application of the developed method leads to a reduction of 8.9% in the ED average LOS with the use of the same staffing budget

Control and synchronization of Chaotic Attitude Control of Satellite with Backstepping controller

A backstepping control system is proposed to control and synchronize the attitude dynamics of a satellite subjected to deterministic external perturbations which induce chaotic motion when no control is affected in this paper. The proposed method is a systematic recursive design approach based on the choice of Lyapunov functions for constructing feedback control laws. The effectiveness of the proposed control scheme is verified by the simulated results

CGPC Control of Chaos in a Permanent Magnet Synchronous Motor Using the Gradient Conjugate and the Genetic Algorithm

In this paper, a new approach to control the chaos problem in permanent magnet synchronous motor (PMSM) is presented. This approach is based on association of a genetic algorithm to identify the parameter of the CARIMA model, and the constrained generalized predictive control (CGPC) using gradient conjugate method which are applied to control the system to a desired reference. Simulation results demonstrate the effectiveness of the proposed approach

What are we waiting for? Factors influencing completion times in an academic and peripheral emergency department

International audienceBackground: A long completion time in the Emergency Department (ED) is associated with higher morbidity and in-hospital mortality. A completion time of more than four hours is a frequently used cutoff point. Mostly, older and sicker patients exceed a completion time of four hours on the ED. The primary aim was to examine which factors currently contribute to overcrowding and a time to completion of more than four hours on the EDs of two different hospitals, namely: the VU Medical Center (VUmc), an academic level 1 trauma centre and the St. Antonius Hospital, a large community hospital in Nieuwegein. In addition, we compared the differences between these hospitals. Methods: In this observational study, the time steps in the process of diagnosing and treatment of all patients visiting the EDs of the two hospitals were measured for four weeks. Patients triaged as Emergency Severity Index (ESI) category 2/3 or Manchester Triage System (MTS) orange/yellow were followed more closely and prospectively by researchers for detailed information in the same period from 12.00-23.00 hrs. Results: In the VUmc, 89% of the patients had a completion time of less than four hours. The average completion time (n = 2262) was 2:10 hours, (median 1:51 hours, range: 0:05-12:08). In the St. Antonius Hospital, 77% of patients had a completion time shorter than four hours (n = 1656). The average completion time in hours was 2:49 (n = 1655, median 2:34, range: 0:08-11:04). In the VUmc, a larger percentage of ESI 1, 2 and 3 patients did not achieve the 4-hour target (14%, 20% and 19%) compared with ESI 4 and 5 patients (2.7% and 0%), p < 0.001. At the St. Antonius Hospital, a greater percentage of orange and yellow categorised patients exceeded four hours on the ED (32% and 28%) compared with red (8%) and green/blue (13%), p < 0.001. For both hospitals there was a significant dependency between exceeding four hours on the ED and the following: whether a consultation was performed (p < 0.001), the number of radiology tests performed (p < 0.001), and an age above 65 years. Conclusion: Factors leading to ED stagnation were similar in both hospitals, namely old age, treatment by more than one speciality and undergoing radiological tests. Uniform remedial measures should be taken on a nationwide level to deal with these factors to reduce stagnation in the EDs. Long completion time in the emergency department (ED) can lead to overcrowding and is associated with negative outcomes, such as increased risk of hospital admission and in-hospital mortality. 1 Therefore, optimising ED patient flow is an important and frequently discussed topic. Because the frequency and type of presentation