•In this paper, model reference adaptive system technique has been used for speed estimation in sensorless speed control of synchronous motor.•This paper studies a novel MRAS observer, considering ...the saliency of PMSM. The MRAS technique is simple and it requires less computation time.•A novel stator resistance estimator is incorporated into the sensorless drive to compensate the effects of stator resistance variation.•The real time implementation concept on the digital signal processor (DSP) board of the VFOC design and SVPWM inverter technique are illustrated.•Results show that the proposed MRAS technique can satisfactorily estimate the position and speed of PMSM with saliency.
In this paper, model reference adaptive system (MRAS) technique has been used for speed estimation in sensorless speed control of interior permanent magnet synchronous motor (IPMSM) with space vector pulse width modulation (SVPWM). Most of the current researches studying the MRAS technique are based on non-saliency PMSM model and ignore the difference between d- and q-axes inductances. This paper studies a novel MRAS observer, considering the saliency of PMSM. However, this sensorless speed control shows great sensitivity to stator resistance and system noise, particularly, during low-speed operation. A novel stator resistance estimator is incorporated into the sensorless drive to compensate the effects of stator resistance variation. A stability-analysis method of this novel MRAS estimator is shown. Stable and efficient estimation of rotor speed at low region will be guaranteed by simultaneous identification of IPMSM. The stability of proposed stator resistance estimator is checked through Popov's hyperstability theorem. The proposed observer is experimentally tested using a 1.1-kW motor drive; stable operation at very low speeds under different loading conditions is demonstrated. The real time implementation concept on the digital signal processor (DSP) board of the VFOC design and SVPWM inverter technique are illustrated. Results show that the proposed MRAS technique can satisfactorily estimate the position and speed of PMSM with saliency.
Our study aimed to determine the efficacy and safety of colistin in the treatment of ventilator-associated pneumonia (VAP) caused by pan-drug-resistant Pseudomonas aeruginosa or Acinetobacter ...baumanii. Pairwise, retrospective exposed-unexposed study. Combined medical and surgical intensive care unit of Habib Bourguiba University Hospital (Sfax, Tunisia). Sixty patients with VAP caused by pan-drug-resistant A. baumanii or P. aeruginosa matched to 60 controls with VAP caused by A. baumanii or P. aeruginosa susceptible to imipenem. All patients had normal renal function at the onset of antibiotic therapy. Case patients were treated by colistin intravenously and control patients were treated by imipenem intravenously. Baseline characteristics were similar between the colistin and imipenem groups. The mean duration of antibiotic therapy for VAP was 9.5+/-3.8 days (range 5-22 days) with colistin and 8.9+/-2.8 days (range 5-20 days) with imipenem (p=0.32). A favorable clinical response to antibiotic therapy for VAP occurred in 45 patients (75%) in the colistin group and in 43 patients (71.7%) in the imipenem group (p=0.68). The time to resolution of infectious parameters after the initiation of antibiotic therapy was not statistically different between the two groups. During the antibiotic course, none of the patients in either group developed renal failure. We conclude that colistin can be a safe and effective option in the treatments of VAP caused by pan-drug-resistant P. aeruginosa or A. baumanii.
In this paper, an improved Type2-PCM clustering algorithm based on improved adaptive particle swarm optimization called Type2-PCM-IAPSO is proposed. Firstly, a new clustering algorithm called ...Type2-PCM is proposed. The Type2-PCM algorithm can solve the problems encountered by fuzzy c-means algorithm (FCM), Gustafson-Kessel algorithm (G-K), possibilistic c-means algorithm (PCM) and NPCM (sensitivity to noise or aberrant points and local minimal sensitivity). . . etc. Secondly, we combined our Type2-PCM algorithm with the improved adaptive particle swarm optimization algorithm (IAPSO) to ensure proper convergence to a local minimum of the objective function. The effectiveness of the two proposed algorithms Type2-PCM and Type2-PCM-IAPSO was tested on a system described by a different equation, Box-Jenkins gas furnace, dryer system and the convection system. The validation tests used showed good performance of these algorithms. However, their average square error test (MSE) shows a better behaviour of the Type2-PCM-IAPSO algorithm compared to the FCM, G-K, PCM, FCM-PSO, Type2-PCM-PSO, RKPFCM and RKPFCM-PSO algorithms.
This article presents a fuzzy sliding-mode control scheme for a class of Takagi-Sugeno (T-S) fuzzy which are subject to norm-bounded uncertainties in each subsystem. The proposed stabilization method ...can be adopted to explore T-S uncertain fuzzy systems (TSUFS) with various local control inputs. Firstly, a new design is proposed to transform TSUFS into sliding-mode dynamic systems. In addition, the proposed stabilization condition for the sliding-mode dynamic system can be formulated in terms of linear matrix inequalities (LMIs) using the Lyapunov functions. Finally, the validity of the proposed design strategy is demonstrated through the simulation of an inverted pendulum on a cart. According to simulation results, the performance indexes of the proposed method can achieve satisfactory results with minimum energy control effort, faster response, and zero steady-state error.
Our study aimed to determine the efficacy and safety of colistin in the treatment of ventilator-associated pneumonia (VAP) caused by pan-drug-resistant Pseudomonas aeruginosa or Acinetobacter ...baumanii.
Pairwise, retrospective exposed-unexposed study.
Combined medical and surgical intensive care unit of Habib Bourguiba University Hospital (Sfax, Tunisia).
Sixty patients with VAP caused by pan-drug-resistant A. baumanii or P. aeruginosa matched to 60 controls with VAP caused by A. baumanii or P. aeruginosa susceptible to imipenem. All patients had normal renal function at the onset of antibiotic therapy.
Case patients were treated by colistin intravenously and control patients were treated by imipenem intravenously.
Baseline characteristics were similar between the colistin and imipenem groups. The mean duration of antibiotic therapy for VAP was 9.5+/-3.8 days (range 5-22 days) with colistin and 8.9+/-2.8 days (range 5-20 days) with imipenem (p=0.32). A favorable clinical response to antibiotic therapy for VAP occurred in 45 patients (75%) in the colistin group and in 43 patients (71.7%) in the imipenem group (p=0.68). The time to resolution of infectious parameters after the initiation of antibiotic therapy was not statistically different between the two groups. During the antibiotic course, none of the patients in either group developed renal failure.
We conclude that colistin can be a safe and effective option in the treatments of VAP caused by pan-drug-resistant P. aeruginosa or A. baumanii.
Many scientific researchers have proposed the control of the induction motor without speed sensor. These methods have the disadvantage that the variation of the rotor resistance causes an error of ...estimating the motor speed. Thus, simultaneous estimation of the rotor resistance and the motor speed is required. In this paper, a scheme for estimating simultaneously the rotor resistance and the rotor speed of an induction motor using fuzzy logic has been developed. We present a method which is based on two adaptive observers using fuzzy logic without affecting each other and a simple algorithm in order to facilitate the determination of the optimal values of the controller gains. The control algorithm is proved by the simulation tests. The results analysis shows the characteristic robustness of the two observers of the proposed method even in the case of variation of the rotor resistance.
Background
Minor head injury is one of the major diagnoses requiring management in emergency departments (ED) but its squeals are not well studied in our country.
Objective
To describe the prevalence ...of post-concussive syndrome and its impacts on life activities, up to 6 months of follow-up, among patients having a minor head injury and discharged from ED.
Methods
A prospective bi-centric study including adults having a minor head trauma and consenting to be followed up to 6 months after discharge. The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) was used at baseline, after 15 days, at 1 month, at 3 months and at 6 months post-injury to assess concussive symptoms. We also used the Rivermead Head Injury Follow-up Questionnaire (RHFUQ) to describe impacts of minor head trauma on life activities.
Results
There were 130 consenting patients at baseline interview. Proportion of patients describing post-concussive symptoms at baseline was 71/130. At 6 months of follow-up, post-concussive syndrome was diagnosed among 21.4 % of participants. Sustaining symptoms at 6 months post-injury were mainly anger and irritability (12.5 %). Correlations between high RPQ sum rates since 15 days’ post-injury call and the sum total rates of RHFUQ were significant. The major significant impact of minor head trauma at 6 months of follow-up was among domestic activities.
Conclusion
The two most important findings of this study were the huge proportion of patients having minor head injury and discharged from ED without any explanation of possible symptoms after head trauma and the unknown impacts on life activities.
Viper envenomation is common in North Africa. Cardiac complications are not common features of snakebites, the clinical picture of which is usually dominated by toxin-associated neurological, ...hematological, and vascular damage. There are rare reports of acute myocardial infarction and/or ischemia caused by snakebites, while myocarditis after envenomation has not yet been reported, to our knowledge. We report the case of a 43-year-old woman admitted to our intensive care unit after viper envenomation complicated by acute heart failure with acute pulmonary edema, in a state of cardiogenic shock, accompanied by multi-organ failure, intravascular disseminated coagulation, and neurological damage. Some of the mechanisms that may be involved in this heart failure are discussed, including the possibility of acute myocarditis.
HELLP syndrome is an acronym for Hemolysis, Elevated Liver enzymes and Low Platelets. It is generally considered in the literature as a particular clinical form of pre-eclampsia, a severe ...complication of the second half of pregnancy. However, this syndrome can occur in isolation in the absence of pre-eclampsia symptoms. Its pathophysiology remains still unclear. The clinical picture is often incomplete and fruste at first. To date, its diagnosis and management is still the subject of much controversy. Associated or not with a vascular and renal manifestations, the HELLP syndrome is a high-risk maternal disorder. The objective of this article is to review the pathophysiological and clinical data and current treatment.
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