Swarm Intelligence for Solving a Traveling Salesman Problem

Learning from the social behavior of animals, like bees or ants, opens the field for Swarm Intelligence (SI) algorithms. They can be applied to solve optimization problems, like the Traveling Salesman Problem (TSP). For SI algorithms, each member of the swarm benefits from the whole swarm and the whole swarm benefits from each individual member. The members communicate either directly or indirectly with each other in order to find an optimal solution. This paper presents an overview of three state-of-the-art SI algorithms, namely, the Ant Colony Optimization (ACO), the Particle Swarm Optimization (PSO), and the Bee Colony Optimization (BCO) for solving a TSP. All three algorithms have been implemented and tested. They have been evaluated with respect to the balance between exploration and exploitation

Experimental Validation of Entropy Driven Swarm Exploration under Sparsity Constraints with Sparse Bayesian Learning

Increasing the autonomy of multi-agent systems or swarms for exploration missions requires tools for efficient information gathering. This work studies this problem from theoretical and experimental perspectives and evaluates an exploration system for multiple ground robots that cooperatively explore a stationary spatial process. For the distributed model, two conceptually different distribution paradigms are considered. The exploration is based on fusing distributively gathered information using Sparse Bayesian Learning (SBL), which permits representing the spatial process in a compressed manner and thus reduces the model complexity and communication load required for the exploration. An entropy-based exploration criterion is formulated to guide the agents. This criterion uses an estimation of a covariance matrix of the model parameters, which is then quantitatively characterized using a D-optimality criterion. The new sampling locations for the agents are then selected to minimize this criterion. To this end, a distributed optimization of the D-optimality criterion is derived. The proposed entropy-driven exploration is then presented from a system perspective and validated in laboratory experiments with two ground robots. The experiments show that SBL together with the distributed entropy-driven exploration is real-time capable and leads to a better performance with respect to time and accuracy compared with similar state-of-the-art algorithms

Characterization of parameters and strategies used by physical therapists in difficult mechanical ventilation weaning

Objective: To characterize the main strategies and parameters used by physical therapists in difficult mechanical ventilation weaning. Methods: Cross-sectional study including all the physical therapists working in adult Intensive Care Units in three public hospitals in Fortaleza-CE. A questionnaire with closed questions related to difficult mechanical ventilation weaning was applied, with either one or multiple answers. The data was treated with descriptive and non-parametric analysis. Results: Among the parameters mostly used by the 56 interviewed physical therapists for the difficult weaning, were found: current volume reduction (26 - 46.4%) and desaturation during aspiration (17 - 30.4%). It was observed that 38 (67.9%) alternate T-tube and continuous positive airway pressure (CPAP) as strategies for difficult weaning, and 28 (50%) reported reducing the pressure support. There was no statistical difference between the strategies used in the studied hospitals, neither correlation between strategies and parameters. Conclusion: It was found that physical therapists have been performing similar strategies, which are also shown in the literature, but this is not the case with the parameters. The parameters used are not supported by the literature

Knowledge and experience of physiotherapists on non-invasive ventilation

Objective: To compare knowledge and experience in non-invasive ventilation (NIV) among physiotherapists of hospital wards and adult Intensive Care Units (ICU). Methods: A study conducted from August/2007 to August/ 2008, in four public hospitals in Fortaleza-CE, Brazil, with 116 physiotherapists (42/wards and 76/ICU) on their practical and theoretical knowledge on NIV, with open and closed questions. The data was analyzed using descriptive statistics through SPSS (Statistical Package for Social Sciences) version 17. Results: Regarding the use of NIV, 22 of 42 physiotherapists from the wards and one of 74 from the ICU never administered it (p<0.05); 19 (45%) of physiotherapists from the wards and 58 (78%) from the ICU answered correctly on NIV as first choice; 18 (43%) physiotherapists from the wards and 64 (86%) from the ICU answered properly on physiological effects (p<0.05); 21 (50%) physiotherapists from the wards and 68 (92%) from the ICU answered appropriately on indications of NIV (p <0.05); 19 (45%) physiotherapists from wards and 71 (96%) from ICU answered correctly on contraindications of NIV (p <0.05); 8 (19%) physiotherapists in the wards and 36 (49%) in the ICU considered infrastructure satisfactory. In the ICU, 68 (92%) physiotherapists believed they were able to monitor NIV, in wards 13 (31%) did it (p <0.05). Conclusions: Physiotherapists of the ICU showed more experience regarding the administration of NIV; they had the knowledge and believed they were more apt to use it than those of the wards. As the physiotherapist is directly involved in this therapeutics, the knowledge and practice of NIV can be better exploited in the ICU and wards

Conhecimento e experiência de fisioterapeutas sobre ventilação não invasiva - doi:10.5020/18061230.2011.p214

Objective: To compare knowledge and experience in non-invasive ventilation (NIV) among physiotherapists of hospital wards and adult Intensive Care Units (ICU). Methods: A study conducted from August/2007 to August/ 2008, in four public hospitals in Fortaleza-CE, Brazil, with 116 physiotherapists (42/wards and 76/ICU) on their practical and theoretical knowledge on NIV, with open and closed questions. The data was analyzed using descriptive statistics through SPSS (Statistical Package for Social Sciences) version 17. Results: Regarding the use of NIV, 22 of 42 physiotherapists from the wards and one of 74 from the ICU never administered it (pObjetivo: Comparar conhecimento e experiência em ventilação não invasiva (VNI), entre fisioterapeutas das enfermarias e das Unidades de Terapia Intensiva (UTI) adulto. Métodos: Estudo realizado entre agosto/2007 e agosto/2008, em quatro hospitais de Fortaleza-CE, Brasil, com 116 fisioterapeutas (42/enfermarias e 74/UTI) sobre conhecimento prático e teórico em VNI, com questões abertas e fechadas. Os dados foram analisados através do software SPSS (Statistical Package for Social Sciences) 17.0. Resultados: Sobre utilização da VNI, 22 dos 42 fisioterapeutas das enfermarias e um dos 74 das UTI nunca administraram VNI (