A New Strategy-Based PID Controller Optimized by Genetic Algorithm for DTC of the Doubly Fed Induction Motor

Proportional Integral Derivative (PID) is the most popular controller used in automatic systems, because of its robustness, ability to adapt the behaviors of the system, making them converge toward its optimum. These advantages are valid only in the case of the linear systems, as they present poor robustness in nonlinear systems. For that reason, many solutions are adopted to improve the PID robustness of the nonlinear systems. The optimization algorithm presents an efficient solution to generate the optimums PID gains adapting to the system’s nonlinearity. The regulation speed in the Direct Torque Control (DTC) is carried out by the PID controller, which caused many inconveniences in terms of speed (overshoot and rejection time), fluxes, and torque ripples. For that, this work describes a new approach for DTC of the Doubly Fed Induction Motor (DFIM) powered by two voltage inverters, using a PID controller for the regulation speed, based on a Genetic Algorithm (GA), which has been proposed for adjustment and optimizing the parameters of the PID controller, using a weighted combination of objective functions. To overcome the disadvantages cited at the beginning, the new hybrid approach GA-DTC has the efficiency to adapt to the system’s nonlinearity. This proposed strategy has been validated and implemented on Matlab/Simulink, which is attributed to many improvements in DFIM performances, such as limiting speed overshoot, reducing response time and the rate of Total Harmonic Distortion (THD) of the stator and rotor currents, and minimizing the rejection time of speed and amplitude of the torque and flux ripples.

An Efficient Load Balancing Method by Using Machine Learning-Based VM Distribution and Dynamic Resource Mapping

In cloud computing, balancing the load among VMs and resources is a major research area, which still needs attention. The primary aim of this research is to expand an effective cloud load balancing approach, enhance the reaction time, lessen the ready time, premiere utilization of sources as well lessen the activity rejection time. The proposed MLBL method is primarily based on the SVM and Ksuggest clustering method. In the proposed MLBL technique SVM classification method used to create activity businesses based totally at the size. Later Kmethod clustering technique is used to create the institution of Virtual machines based totally on their usage of CPU and number one memory (RAM). We are providing an MLBL method based totally on system learning-based VM distribution and dynamic aid mapping. In cloud computing, VMs are scheduled to hosts as in keeping with their utilization (a host which has better availability of memory) without thinking about common utilizations. The proposed technique divides the assets into various organizations as well as VMs and then follow dynamic aid mapping. The proposed MLBL technique creates VMs clusters to execute comparable task agencies that enhance the QoS and ideal utilization of sources in addition to lessen the process rejection time.

The reliability of use of combined homograft and autograft in management of major burns

Background: The aim of the study to present the reliability of application of intermingled skin homoograft and autograft in major deep burn cases in comparison with using homograft only. Early excision and skin graft closure of major burns is a life-saving procedure that reduces morbidity and mortality of severe burns. Patients suffering major burns lack adequate donor site skin graft to resurface burn wounds so they need another substitutes for coverage as homograft.Methods: This cohort prospective study was conducted at Menoufia University Hospitals from January 2017 to January 2019 and with follow up 6 months. The population of the study was 54 patients with major deep burns. After stabilization they were divided into 2 groups, the first underwent homograft and the second underwent combined homograft and autograft. They vary between children and adults. Follow up done over 6 months regarding rejection, need of another graft and mortalityResults: Our study was undergone on 54 patients; 30 patients homograft (55.5%) and 24 patients combined grafts (44.5%). Forty eight patients survived, and six patients died (12.5%), with a mean age 26.3 years (range, 1-50). There was statistically significant difference between 2 groups regarding rejection time, need of another graft, percentage of rejected area and mortality.Conclusions: Combined homografts and autografts is considered gold standard in management of major burns with lack of adequate autograft. It is superior to use of homograft only regarding morbidity, mortality and need for another graft.

Modification of the Hyperacute Reaction in the Rat by Sulphinpyrazone

It has been found that guinea-pig hearts are rejected in hyperacute fashion by the rat. By using inbred strains this model has been found to be markedly reproducible. Electron microscopic studies show that the platelet plays a critical role in the rejection process. An important point is that endothelial cell damage morphologically occurs subsequent to platelet contraction.Flow studies demonstrate that flow through the coronary arteries ceases abruptly between 2 and 3 minutes; this co-inciding with platelet aggregation in the vessels. The heart continues to beat for 10–12 minutes, and then suffers an ischaemic death.30 transplants were performed as controls to fully monitor flow, E. C. G. and microscopic events during the reaction.Ten transplants were performed in rats pre-treated with 150 mgs/kg. Sulphinpyrazone orally daily for 6 days and then transplanted, and ten were performed in rats transplanted and then given 400 mgs/kg sulphinpyrazone I–V before release of the clamps preventing revasularisation of the heart.It was found that rejection time was not significantly changed from the controls (12–14 minutes), but flow studies showed that the coronary circulation remained patent for 5–6 minutes, i.e. twice the time of the control studies, with subsequent delay of E. C. G. changes.