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The inherent complexity of critical production systems, coupled with policies to preserve people's safety and health, environmental management, and the facilities themselves, and stricter laws regarding the occurrence of accidents, are the motivation to the design of Safety Control Systems that leads the mitigation functionality. According to experts, the concept of Safety Instrumented Systems (SIS) is a solution to these types of issues. They strongly recommend layers of risk reduction based on hierarchical control systems in order to manage risks, preventing or mitigating faults, or to lead the process to a safe state. Additionally some of the safety standards such as IEC 61508, IEC 61511, among others, guide different activities related Safety Life Cycle design of SIS. The IEC 61508 suggests layers of critical fault prevention and critical fault mitigation. In the context of mitigation control system, the standard provides a recommendation of activities to mitigate critical faults, by proposing control levels of mitigation. This paper proposes a method to implement the mitigation layer based on the risk analysis of the plant and the consequences of faults of its critical components. The control architecture, based on distributed and hierarchical control systems in a collaborative way, will make use of the techniques of risk analysis raised and mitigation actions, based on the knowledge of an expert, implemented by fuzzy logic. The mitigation layer therefore seeks to reduce the inherent risk in a process, and besides proposing the mitigation layer, this work aims to a further reduction of process risk on proposing an anticipatory mitigation action through temporal analysis of the evolution of the parameter used to measure the effect of the occurrence of a critical fault.

One of the most important recent improvements in cardiology is the use of ventricular assist devices (VADs) to help patients with severe heart diseases, especially when they are indicated to heart transplantation. The Institute Dante Pazzanese of Cardiology has been developing an implantable centrifugal blood pump that will be able to help a sick human heart to keep blood flow and pressure at physiological levels. This device will be used as a totally or partially implantable VAD. Therefore, an improvement on device performance is important for the betterment of the level of interaction with patient's behavior or conditions. But some failures may occur if the device's pumping control does not follow the changes in patient's behavior or conditions. The VAD control system must consider tolerance to faults and have a dynamic adaptation according to patient's cardiovascular system changes, and also must attend to changes in patient conditions, behavior, or comportments. This work proposes an application of the mechatronic approach to this class of devices based on advanced techniques for control, instrumentation, and automation to define a method for developing a hierarchical supervisory control system that is able to perform VAD control dynamically, automatically, and securely. For this methodology, we used concepts based on Bayesian network for patients' diagnoses, Petri nets to generate a VAD control algorithm, and Safety Instrumented Systems to ensure VAD system security. Applying these concepts, a VAD control system is being built for method effectiveness confirmation.

Numerical calculations were used to assess the probable microscopic distribution of the electric field along or close to the actual Si-SiO 3 interface of a metal oxide semiconductor (MOS) capacitor biased into accumulation. Silicon wafers were oxidized to 20 nm at 1150°C by rapid thermal oxidation, according to two different thermal recipes in order to yield different Si-SiO 2 interface roughnesses. After oxide removal, typical atomic force microscopy (AFM) line scans of the silicon surface were exported into the MEDICI program as a description of the Si-SiO 2 , interface in order to calculate the electric field distribution within the oxide layer of a bidimensional MOS capacitor biased into accumulation. This distribution was found to be highly inhomogeneous even for relatively smooth Si-SiO 2 interfaces, displaying strong local electric field enhancements, the spatial distribution of which will be called electronic roughness in this work. Simple local oxide thinning at the position of the protrusions cannot account for these field enhancements, thus indicating that the shape of the protrusion is dictating the electronic roughness. The electronic roughness could be correlated with electric breakdown characteristics of actual MOS capacitors prepared on these wafers.

This paper proposes a switched-capacitor converter to drive power light emitting diodes (LEDs). In contrast to conventional constant dc current drivers, the current pulse is provided by this switched-capacitor LED driver. In the present driver, the capacitor is charged and discharged through of the output circuit and the current flow direction is controlled by switch. Based on the charge control analysis, the effects of switching devices on the proposed converter are discriminated and evaluated. The experimental results demonstrated the technical feasibility of using the proposed converter for LEDs.

Part 12: Fault-Tolerant Systems; International audience; When a patient have severe heart diseases, Ventricular Assist Device (VAD) implantation may be necessary. However, the improvement of the interaction between the device and the patient’s behavior is crucial. Currently, the control of these pumps does not follow changes in patient behavior and the devices are no safe. Therefore, if VAD has no faults tolerance and no dynamic behavior according to the cardiovascular system performance, there is a serious limitation on expected results. This research investigates a mechatronic approach for this class of devices based on advanced techniques for control, instrumentation and automation to define a method for developing a hierarchical supervisory control system to control a VAD dynamically and securely. To apply this method, concepts based on Petri nets and Safety Instrumented Systems are used. This innovation reduces the interventions and unnecessary drugs, enabling a reduction of deposable material and patient hospitalization, and contributes to sustainability concept.

The advances of production technologies reflect a worldwide trend for sustainability and rational use of resources. As a consequence, some movements for industry reorganization can be observed in geographically dispersed systems with new productive systems (PSs) configurations. These PSs work with small and medium size production lots, product families with increasing variety, and hard delivery date. In this context, concepts of dispersed and collaborative productive systems (DCPSs), with new requirements for production scheduling are expected to be properly explored for improvement of PSs performance. Therefore, we here consider that productive activities can be treated as services and the SOA (service-oriented architecture) approach can be adopted for the integration of the DCPS. Then, a planning service based on time windows and a scheduling service that uses the APS (advanced planning and scheduling) heuristics is proposed to assure the expected performance of the DCPS.

Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina UNIFESP, EPM SciELO

OBJECTIVE: To describe a new more efficient method of endocardial cardiac stimulation, which produces a narrower QRS without using the coronary sinus or cardiac veins. METHODS: We studied 5 patients with severe dilated cardiomyopathy, chronic atrial fibrillation and AV block, who underwent definitive endocardial pacemaker implantation, with 2 leads, in the RV, one in the apex and the other in the interventricular septum (sub pulmonary), connected, respectively, to ventricular and atrial bicameral pacemaker outputs. Using Doppler echocardiography, we compared, in the same patient, conventional (VVI), high septal ("AAI") and bifocal ("DDT" with AV interval ~ 0) stimulation. RESULTS: The RV bifocal stimulation had the best results with an increase in ejection fraction and cardiac output and reduction in QRS duration, mitral regurgitation and in the left atrium area (p

Recent studies show the designs of automated systems are becoming increasingly complex to meet the global competitive market. Additionally, organizations have focused on policies to achieve people’s safety and health, environmental management system, and controlling of risks, based on standards. In this context, any industrial system in the event of a fault that is not diagnosed and treated correctly could be considered to pose a serious risk to people’s health, to the environment and to the industrial equipment. According to experts, the concept of Safety Instrumented Systems (SIS) is a practical solution to these types of issues. They strongly recommend layers for risk reduction based on control systems organized hierarchically in order to manage risks, preventing or mitigating faults, or to bringing the process to a safe state. Additionally, the concept of Risk and Hazard Control can be applied to accomplish the required functionalities. It is based on problem solving components and considers a cooperative way to find a control solution. In this context, the software architecture can be based on a service-oriented architecture (SOA) approach. This paper initially proposes a new architecture for design of safety control systems for critical systems, based on Safety Supervisory Control Architecture, in accordance with standards IEC 61508 and IEC 61511. Furthermore, a method is also proposed for design the control layer of risk prevention within Safety Supervisory Control Architecture.