42 research outputs found
Developing criteria for Cesarean Section using the RAND appropriateness method
<p>Abstract</p> <p>Background</p> <p>Cesarean section rates are increasing worldwide, and a rapid increase has been observed in Iran. Disagreement exists between clinicians about when to use cesarean section. We aimed to identify the appropriateness criteria for the use of cesarean section in Iran.</p> <p>Method</p> <p>A consensus development study using a modified version of the RAND Appropriateness Method (RAM). We generated scenarios from valid clinical guidelines and expert opinions. A panel of experts participated in consensus development: first round via mail (12 members), second round face-to-face (9 members). We followed the RAM recommendations for the development of the scenario lists, rating scales, and statistical analyses.</p> <p>Results</p> <p>294 scenarios relevant to cesarean section were identified. 191 scenarios were considered appropriate, of which 125 scenarios were agreed upon. The panel found cesarean inappropriate for 21% of scenarios, and 'equivocal' for 14% of scenarios.</p> <p>Conclusion</p> <p>RAM is useful for identifying stakeholder views in settings with limited resources. The participants' views on appropriateness of certain indications differed with available evidence. A large number of scenarios without agreement may partly explain why it has been difficult to curb the growth in cesarean section rate.</p
1,2-Dimethyl-N-butanesulfonic acid imidazolium hydrogen sulfate as efficient ionic liquid catalyst in the synthesis of indeno fused pyrido[2,3-d]pyrimidines
Indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidin-4,6-(5H,11H)dione derivatives were synthesized regioselectively in high yields by a three-component reaction of 1,3-indanedione, aromatic aldehydes and 2,6-diaminopyrimidin-4(3H)-one in the presence of 1,2-dimethyl-N-butanesulfonic acid imidazolium hydrogen sulfate ([DMBSI]HSO4) ionic liquid as green and reusable catalyst. This protocol produced the desired products in high yields (87–95%) and short reaction times (3–6 min)
Optimal control of EGR system in gasoline engine based on Gaussian process
The contribution described in this paper is concentrated on the integration of exhaust gas recirculation (EGR) system into the process of combustion in an optimal manner. In practice, deriving a state-space model of this actuator is an energetic task as a result of involving some uncertain chemical reactions. To alleviate the effect of unobserved phenomena, which does not seem to be easy in modeling, an improved Gaussian Process (GP) is represented for identifying such dynamics. In this approach, practical modification in general formulation of GP is provided based on proportional feedback gain adjustment. Afterwards, the obtained model is considered for design of optimal model-based control strategy. The whole aim is focused on achieving a green economically gasoline engine by optimizing the trend of fuel consumption. Eventually, simulation results illustrate the effectiveness of proposed structure in EGR systems.Mechatronic Systems Desig
Novel particle swarm optimization algorithm based on president election: Applied to a renewable hybrid power system controller
Particle swarm optimization has been a popular and common met heuristic algorithm from its genesis time. However, some problems such as premature convergence, weak exploration ability and great number of iterations have been accompanied with the nature of this algorithm. Therefore, in this paper we proposed a novel classification for particles to organize them in a different way. This new method which is inspired from president election is called President Election Particle Swarm Optimization (PEPSO). This algorithm is trying to choose useful particles and omit functionless ones at initial steps of algorithm besides considering the effects of all generated particles to get a directed and fast convergence. Some preparations are also done to escape from premature convergence. To validate the applicability of our proposed PEPSO, it is compared with the other met heuristic algorithm including GAPSO, Logistic PSO, Tent PSO, and PSO to estimate the parameters of the controller for a hybrid power system. Results verify that PEPSO has a better reaction in worst conditions in finding parameters of the controller.Mechatronic Systems Desig