Group Sequential Communication (GSC): Especificação e Análise de Desempenho de umMecanismo de Comunicação de Tempo Real Compatível ao Padrão IEEE 802.11/11e Aplicado à Automação Industrial

This thesis proposes the specification and performance analysis of a real-time communication mechanism for IEEE 802.11/11e standard. This approach is called Group Sequential Communication (GSC). The GSC has a better performance for dealing with small data packets when compared to the HCCA mechanism by adopting a decentralized medium access control using a publish/subscribe communication scheme. The main objective of the thesis is the HCCA overhead reduction of the Polling, ACK and QoS Null frames exchanged between the Hybrid Coordinator and the polled stations. The GSC eliminates the polling scheme used by HCCA scheduling algorithm by using a Virtual Token Passing procedure among members of the real-time group to whom a high-priority and sequential access to communication medium is granted. In order to improve the reliability of the mechanism proposed into a noisy channel, it is presented an error recovery scheme called second chance algorithm. This scheme is based on block acknowledgment strategy where there is a possibility of retransmitting when missing real-time messages. Thus, the GSC mechanism maintains the real-time traffic across many IEEE 802.11/11e devices, optimized bandwidth usage and minimal delay variation for data packets in the wireless network. For validation purpose of the communication scheme, the GSC and HCCA mechanisms have been implemented in network simulation software developed in C/C++ and their performance results were compared. The experiments show the efficiency of the GSC mechanism, especially in industrial communication scenarios.

Atendimento Pré-hospitalar Móvel. Mapeando Riscos e Prevenindo Erros

The attention with safety of the patients is important in the quality of the nursing and health care. In the pre-hospital care, such care is essential on site with the purpose of avoiding possible consequences to the individual, ensuring a fast and appropriate care, with improvement of the morbidity and reduction of the mortality. This medical attention is equally associated with the significant risks of adverse events and serious mistakes, which can be reduced with the awareness of the professionals, organization and quality management. It is a descriptive, transversal research, of quantitative approach, with the objective of identifying the risks for the safety of the patient during the mobile pre-hospital care under the view of the nurses, in a city of the Brazilian Northeast. The sample was formed by 23 nurses. The inclusion criteria: to have at least two years of experience and accept to participate on the research. The data collection was done in two steps, first photo collection, through the adapted method of photographic analysis, and the second with the application of questionnaire, divide in two parts: socio-professional data and digital photo punctuation instrument of the patient s safety. The majority of the nurses had an average working time in the mobile pre-hospital care of six years and six months, in the age group of 38 to 53 years old (69,56%) and with Lato sensu specialization (73,91%), being (29,41%) emergency and (29,41%) in intensive care. The (74%) have the Advance Cardiac Life Support (ACLS) and (100%) have the Pre-Hospital Trauma Life Support (PHTLS); (91, 30%) know the thematic safety of the patient. On the pictures it was observed a bigger variability of the categories (risks) where 44% of variance emerged on the first picture of the research. The pictures 4 and 9 with the average below 5 were classified as very insecure, while pictures 7 and 3 with an average above 7, very secure. On the results of risks observed for the patient s safety in the mobile pre-hospital care five categories emerged: organization and packaging of the equipment and materials, routines and specificities in the mobile pre-hospital care, risks on the management of medications, for traumas and infections. Starting from the analysis of these risks, it was proposed ten steps for the safety in the mobile pre-hospital care: 1- Identify the patient; 2- Safety related to prevention of infection; 3- Safety in the management of medications; 4- Safety and standardization of the packaging of equipment and materials; 5- Attention to the specificities of the mobile pre-hospital care; 6- Incentive and value the participation of the patient and family; 7- Promote the communication with the central of regulation; 8- Prevention of traumas and falls; 9- Protect the skin from additional injuries; 10- Understand the benefit of all the equipment in the ambulance. The multiple risks and their emerged combinations on the research indicate a variety of actions to be developed and stimulated, like the use of steps for the patient s safety in the mobile pre-hospital care which contributes with the aid and management of risks, reduction of mistakes, disabilities and death