Extremum Seeking Control (ESC)

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Maximum power Point Tracking control of thermoelectric generation system using extremum seeking control method

Maximum power Point Tracking control of thermoelectric generation system using extremum seeking control method

Abstract: This study proposes and implements maximum power Point Tracking (MPPT) control on thermoelectric generation system using an extremum seeking control (ESC) algorithm. The MPPT is applied to guarantee maximum power extraction from the TEG system. The work has been carried out through modelling of thermoelectric generator/dc-dc converter system using Matlab/Simulink. The effectiveness of ESC technique has been assessed by comparing the results with those of the Perturb and Observe (P&O) MPPT method under the same operating conditions. Results indicate that ESC MPPT method extracts more power than the P&O technique, where the output power of ESC technique is higher than that of P&O by 0.47 W or 6.1% at a hot side temperature of 200 ◦ C. It is also noted that the ESC MPPT based model is almost fourfold faster than the P&O method. This is attributed to smaller MPPT circuit of ESC compared to that of P&O, hence we conclude that the ESC MPPT method outperforms the P&O technique.

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EXTREMUM SEEKING CONTROL OF UNCERTAIN SYSTEMS

EXTREMUM SEEKING CONTROL OF UNCERTAIN SYSTEMS

In the literature there are mainly four types of extremum seeking schemes: perturbation based, sliding mode based, numerical optimization based, and gradient based extremum seeking algorithms. In the perturbation based extremum seeking algorithms studied in [1] - [3], a perturbation is added to the search signal. By observing the effect of the pertur- bation on the performance function measurement, it is determined whether to increase or decrease the search signal to reach its optimum value and hence maximize (or minimize) the performance function. It is assumed that the shape, i.e. the gradient of the perfor- mance function is unknown. In the seminal paper of Krstic and Wang [1], stability proof for this type of extremum seeking control is given with the tools of averaging and singular perturbations.

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Power Maximization and Control of Variable Speed Wind Turbine System Using Extremum Seeking

Power Maximization and Control of Variable Speed Wind Turbine System Using Extremum Seeking

Maximizing the power capture is an important issue to the turbines that are installed in low wind speed area. In this paper, we focused on the modeling and control of variable speed wind turbine that is composed of two-mass drive train, a Squirrel Cage Induction Generator (SCIG), and voltage source converter control by Space Vector Pulse Width Modulation (SPVWM). To achieve Maximum Power Point Tracking (MPPT), the reference speed to the generator is searched via Extremum Seeking Control (ESC). ESC was designed for wind turbine region II operation based on dither-modulation scheme. ESC is a model-free method that has the ability to increase the captured power in real time under turbulent wind without any requirement for wind measure- ments. The controller is designed in two loops. In the outer loop, ESC is used to set a desired reference speed to PI controller to regulate the speed of the generator and extract the maximum electrical power. The inner control loop is based on Indirect Field Orientation Control (IFOC) to decouple the cur- rents. Finally, Particle Swarm Optimization (PSO) is used to obtain the op- timal PI parameters. Simulation and control of the system have been accom- plished using MATLAB/Simulink 2014.

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Energetic Optimization of Variable Speed Wind Energy Conversion Systems by Extremum Seeking Control

Energetic Optimization of Variable Speed Wind Energy Conversion Systems by Extremum Seeking Control

To overcome challenges attached with the conventional power control and optimization algorithms and to remove the dependence of the MPPT algorithm on the system modelingand identification, we propose ES algorithm, which is a non model-based real-time optimization technique to MPPT of WECS. First, we present ES without the inner-loop control to clarify the advantages of the proposed controller on the closed-loop performance of the system. The proposed models for power coefficient and turbine power in (3) and (4) are for simulation purposes. In this paper, we assume that we have access to turbine power measurements and we can manipulate the turbine speed through the MC. Furthermore, we do not have a model of the power coefficient or turbine power. However, we know that the turbine power map has one MPP under any wind speed, which helps us to present the following assumption.

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Extremum Seeking Control Scheme for WECS Using Matrix Converter
K Prashanth & Mr  M Ramakrishna

Extremum Seeking Control Scheme for WECS Using Matrix Converter K Prashanth & Mr M Ramakrishna

Renewable energy applications have brought a new fo- cus on the capabilities of ES algorithms. In this article we present applications of ES in two types of energy conver- sion systems for renewable energy sources: wind and solar energy. The goal for both is maximum power point track- ing (MPPT), or, the extraction of the maximum feasible energy from the system under uncertainty and in the ab- sence of a priori modeling knowledge about the systems. For the wind energy conversion system (WECS), MPPT is performed by tuning the set point for the turbine speed using scalar ES. The outer ES loop tunes the turbine speed to maximize power capture for all wind speeds within the subrated power operating conditions. The inner-loop non- linear control maintains fast transient response through a matrix converter, by regulating the electrical frequency and voltage amplitude of the stator of the (squirrel-cage) induction generator. Simulation results are presented to show the effectiveness of the proposed design.

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Power Optimization and Control in Wind Energy Conversion Systems using Fractional Order Extremum Seeking

Power Optimization and Control in Wind Energy Conversion Systems using Fractional Order Extremum Seeking

wind energy conversion systems (WECS) has caught a big attention from early days. The methods widely used are model based power optimization algorithms as the outer loop and linear control methods in the inner loop. The method of extremum seeking control is a non model based optimization concept to extract maximum power from WECS in their subrated region. Induction generators are used widely in WECS since they are relatively inexpensive, robust and require a little maintenance.. When operated using vector control techniques fast dynamic response and accurate torque control is obtained with the help of a matrix converter. In this paper, inner loop nonlinear control based on the principle of field oriented control (FOC) and feedback linearization is used along with maximum power point tracking (MPPT) in the outer loop. The proposed MPPT method is Fractional Order Extremum Seeking Control (FOESC).The convergence speed of FOESC is faster than the Integer Order ESC. Simulation results are presented to show the effectiveness of the proposed model .

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Energy efficient autonomous solar water pumping system for permanent magnet synchronous motors

Energy efficient autonomous solar water pumping system for permanent magnet synchronous motors

From the software perspective, the control of the pumping system to ensure an efficient MPPT and maximise the energy extraction is usually IP protected by manufacturers, and little information is usually available. The contribution in this paper is a verified and effective MPPT strategy, based on a modifica- tion of the well-known FOC using extremum seeking control. The resulting control system has minimum complexity, easy tuning and can be quickly developed and embedded also in commercial solutions.

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Anti tumor pharmacological evaluation of extracts from stellera chamaejasme L based on hollow fiber assay

Anti tumor pharmacological evaluation of extracts from stellera chamaejasme L based on hollow fiber assay

We tested the classic death receptors, Fas, TNFR1 and their ligands Fas-L, TNF-α. The Fas/Fas-L system was a key regulator of apoptosis. The results showed that ESC, ESC-2 had no significant effects on Fas/Fas-L pathway which was not consistent with the in vitro results. Maybe after the metabolism in vivo, the targets of ESCs changed. TNFR1/ TNF-α signal system was another im- portant death receptor pathway which was not observed in our in vitro experiment. TNF-α was a multifunctional cytokine, mainly involving in inflammation and immune responses. It had a direct cytotoxic effect on tumor cells and could cause tumor necrosis. Recent researches had demonstrated that TNF-α inhibited certain tumor cell proliferation and induced apoptosis of tumor cells [18]. But few study focused on the role of endogenous tumor TNF-α, some scholars believed that the endogenous TNF-α could promote tumor cells to produce oxygen free radical ions, causing DNA damage or fracture [19,20] and was conducive to the treatment of tumors. Down- regulation of endogenous TNF-α to increase sensitivity of exogenous TNF-α (produced by other cells) on tumor cells was believed to be another reason of TNF-α killing

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Rescuing macrophage normal function in spinal cord injury with embryonic stem cell conditioned media

Rescuing macrophage normal function in spinal cord injury with embryonic stem cell conditioned media

Embryonic stem cells (ESCs) have shown therapeutic potential to remyelinate axons as ESC derived oligo- dendrocyte precursor cells (OPCs) can generate func- tional myelin in situ [13]. Their application in SCI though may have limited success due to the risk of tumor formation after transplantation and immune re- jection [14, 15]. Our previous studies have shown that ESCs produce factors can induce anti-inflammatory phenotype in macrophages [16, 17]. Upon ESC stimula- tion, phagocytic function was enhanced and macro- phages expressed multiple angiogenic growth factors and proteinases promoting angiogenesis [16, 17]. These properties correspond with the characteristics required for successful treatment for SCI pathology, driving us to investigate the novel application of ESC derived factors for treating inflammation in acute murine SCI.

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Extremum of the Vertex Gutman Index of the Extended Stars

Extremum of the Vertex Gutman Index of the Extended Stars

The extended-star (and the star) is a typical tree and also a widely used data structure. According to its structural characteristics, we studied the extremum of the vertex-Gutman index of the extended-stars, and obtained the distribution of the vertex-Gutman index: the vertex-Gutman index has the maximum at the center which is the vertex with the maximum degree and has minimum at the vertices nearest the center.

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2018 ESC Guidelines for the diagnosis and management of syncope

2018 ESC Guidelines for the diagnosis and management of syncope

The content of these European Society of Cardiology (ESC) Guidelines has been published for personal and educational use only. No commercial use is authorized. No part of the ESC Guidelines may be translated or reproduced in any form without written permission from the ESC. Permission can be obtained upon submission of a written request to Oxford University Press, the publisher of the European Heart Journal and the party authorized to handle such permissions on behalf of the ESC (journals.permissions@oxfordjournals.org). Disclaimer. The ESC Guidelines represent the views of the ESC and were produced after careful consideration of the scientific and medical knowledge and the evidence available at the time of their publication. The ESC is not responsible in the event of any contradiction, discrepancy and/or ambiguity between the ESC Guidelines and any other official recom- mendations or guidelines issued by the relevant public health authorities, in particular in relation to good use of healthcare or therapeutic strategies. Health professionals are encour- aged to take the ESC Guidelines fully into account when exercising their clinical judgment, as well as in the determination and the implementation of preventive, diagnostic or therapeutic medical strategies; however, the ESC Guidelines do not override, in any way whatsoever, the individual responsibility of health professionals to make appropriate and accurate decisions in consideration of each patient’s health condition and in consultation with that patient and, where appropriate and/or necessary, the patient’s caregiver. Nor do the ESC Guidelines exempt health professionals from taking into full and careful consideration the relevant official updated recommendations or guidelines issued by the competent public health authorities, in order to manage each patient’s case in light of the scientifically accepted data pursuant to their respective ethical and professional obligations. It is also the health professional’s responsibility to verify the applicable rules and regulations relating to drugs and medical devices at the time of prescription.

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Is the presence of control related to help-seeking behavior? A test of Johnson’s assumptions regarding sex-differences and the role of control in intimate partner violence

Is the presence of control related to help-seeking behavior? A test of Johnson’s assumptions regarding sex-differences and the role of control in intimate partner violence

reports to verify any information that was investigated. It should also be noted that very few filled in the help seeking behavior so future research would need to try and obtain a sample to gain a better response rate. Future research in this area should involve more studies that gather data from both partners so as to be able to confirm or challenge each other’s reports. From this it would open up the ability to learn more about the violent resistance and mutual violent control types that Johnson’s described that have only been tested rarely (e.g. Bates et al., 2014). These patterns of relationship aggression could be the key to gaining a fuller understanding of relational aggression. The results of this study have shown that both men and women are equally likely to be categorised as either high or low control so Johnson’s patriarchal explanation of intimate terrorism needs to be revised. It should be noted however that whilst there are assumptions made about perpetration based samples yielding different results to victimization based samples this was not supported by Sullivan et al. (2010) who found that when these two groups were compared in a sample of African-American women there were no significant differences for physical aggression, psychological aggression or injury.

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              here  to download PDF version of the article !

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We observed elevated mean score in the domains of NCS and MPR on BHSS subscales. This indicates concerns for autonomy and under estimation of seriousness of headache were major barriers in help seeking. It underscores need to enquire and address any autonomy related factors in patients with headache. Less help-seeking has been observed in experimental or correlational research, when problems are highly ego-central, non-normative and when autonomy is perceived to be threatened [7,8,29]. In this study, a significantly elevated level of disability is consistent with the previous report and may be possibly due to elevated score on subscales of BHSS (e.g., NCS and MPR) that may contribute in delaying treatment seeking, till severity had significant impact on their life [30].

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Performance of hospitals according to the ESC ACCA quality indicators and 30-day mortality for acute myocardial infarction: national cohort study using the United Kingdom Myocardial Ischaemia National Audit Project (MINAP) register

Performance of hospitals according to the ESC ACCA quality indicators and 30-day mortality for acute myocardial infarction: national cohort study using the United Kingdom Myocardial Ischaemia National Audit Project (MINAP) register

The recoding, measurement, and reporting of within and between country performance against validated QIs representing class 1 indi- cated care is the critical next step in the international effort to reduce the burden and variation in premature deaths due to cardiovascular disease across Europe. This study provides good evidence for the application of the ESC ACCA QIs for AMI to clinical registries for the evaluation of cardiovascular care and outcomes; demonstrating their significant inverse association with mortality. Furthermore, this study identified potentially modifiable variation within a high performing health system and sets a road map for the development of standardized data collection in other ESC member countries. Greater and more uniform adherence to guideline-indicated care will result in improved and less varied mortality from AMI.

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Antimicrobial susceptibility/resistance and NG MAST characterisation of Neisseria gonorrhoeae in Belarus, Eastern Europe, 2010–2013

Antimicrobial susceptibility/resistance and NG MAST characterisation of Neisseria gonorrhoeae in Belarus, Eastern Europe, 2010–2013

N. gonorrhoeae has developed antimicrobial resistance (AMR) to all drugs previously recommended for treat- ment of gonorrhoea. In vitro (low-level and high-level) and rare treatment failures have now emerged to the last remaining option for first-line empirical monotherapy in most countries globally, that is, the extended-spectrum cephalosporin (ESC) ceftriaxone [5-18]. Therefore, en- hanced and quality assured surveillance of gonococcal AMR, nationally and internationally, is essential to moni- tor the AMR trends, identify emerging AMR and inform a regular update of the STI management and treatment guidelines locally, nationally and globally. This is in strict concordance with the global action plan and European response plan to combat gonococcal AMR published by the WHO [19,20] and the European Centre for Disease Prevention and Control (ECDC) [21], respectively.

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Development of New Sensors for Determination of Escitalopram Oxalate in Dosage Forms and Biological Fluids

Development of New Sensors for Determination of Escitalopram Oxalate in Dosage Forms and Biological Fluids

Appliances Corporation (SPIMACO), Al-Qassim Pharmaceutical Plant, Saudi Arabia. The Pharmaceutical preparation Cipralex ® tablets (10 mg ESC/tablet) were manufactured by H. Lundbeck A/S (Denmark) and were purchased from commercial sources. Tetrahydrofuran (THF) 97.0% and dioctyl phthalate (DOP) 99.0% were provided by Fluka – Switzerland. Poly vinyl chloride (PVC) high molecular weight, phosphomolybdic acid (PMA) 99.99% phosphotungstic acid (PTA) 99.99% and ammonium reineckate (ARK) 95.00% were supplied by Aldrich, Germany. Urine samples were obtained from healthy volunteers. Serum samples (Multi -Serum Normal, Ranbdox laboratories UK) were obtained from commercial sources.

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ESC improves

ESC improves

A practical approach for developing an ESC for advanced 4 in-wheels EV is taken here. Initially non-linear vehicle model is developed and analyzed the yaw control for electric vehicle with four in wheel motors. Based on sliding mode control law a controller is designed to track the yaw rate. To verify the proposed controller simulation is done here that shows enhanced stability of the vehicle. Experiment has been done to find out the possibility of generation of differential torque in terms of wheel speed based on the demand from controller. The controller calculated differential torque using sensor data and reference vehicle model transformed it to wheel speed is achieved by the test bench to reduce chassis physical error, human error and cost. Simulation and experiment has shown promising result in this stage for a suitable type ESC for In-wheel motor EV to go further for real time test on the racing track in future.

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Original Article Indoleamine 2,3-dioxygenase-1 (IDO1) in human endometrial stromal cells induces macrophage tolerance through interleukin-33 in the progression of endometriosis

Original Article Indoleamine 2,3-dioxygenase-1 (IDO1) in human endometrial stromal cells induces macrophage tolerance through interleukin-33 in the progression of endometriosis

Abstract: In the peritoneal fluid, macrophages and their secretory cytokines are essential for endometriosis, but the factors that favor their involvement in the endometriosis-associated inflammatory response are still elusive. Given the anomalous expression of indoleamine 2,3-dioxygenase-1 (IDO1) in endometrial stromal cells (ESCs) and its potentially important roles in immune modulation, we aimed to determine the effects of IDO1 in ESCs on macro- phages and the mechanism of those effects. Normal ESCs and ectopic ESCs transfected with the SD11-IDO1 shRNA (short hairpin RNA) or vector-only plasmid SD11 were subsequently co-cultured with peripheral blood (PB)-derived monocytes (PBMC)-driven macrophages directly and indirectly. Cytokine production was determined by analyzing the supernatant of the co-culture unit by enzyme-linked immunosorbent assay (ELISA). The phenotypes and the phagocytic ability of the macrophages were determined by flow cytometry. Compared to normal ESCs, the PBMC- driven macrophages co-cultured with ectopic ESCs displayed lower phagocytic ability. Additionally, macrophages co-cultured with ectopic ESCs exhibited higher levels of CD163 and CD209 and lower levels of HLA-DR and CD11c. Moreover, both the intracellular expression and extracellular secretion of interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) were significantly increased, while that of IL-12p70 was decreased in macrophages after being co-cultured with ectopic ESCs. However, there was no significant difference in macrophage phagocytic ability, immunophenotype or cytokine secretion between the direct and indirect co-culture units. Reversely, SD11-IDO1 shRNA transfection of ectopic ESCs could abrogate the decreased phagocytic ability and alternative activation of macrophages in ectopic ESC-macrophage co-culture unit, suggesting that higher IDO1 in ectopic ESCs was indis- pensable for the induction of macrophage tolerance. Furthermore, the decrease in phagocytic macrophages and alternatively activated macrophages induced by IDO1 in ectopic ESCs was reversed by the addition of an IL-33 inhibitor, that is, soluble ST2 (sST2). Therefore, through the activation of IL-33, the increased expression of IDO1 in ectopic ESCs contributed to the truncated phagocytic ability of macrophages in endometriosis.

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Dynamic simulation of combined extremum seeking 
		control system for grinding mixing unit automatic vibration suppression

Dynamic simulation of combined extremum seeking control system for grinding mixing unit automatic vibration suppression

Taken into account these features, the control system (functional diagram is shown in Figure-4) on the first cycle of material feeding which is determined by the appropriate signal of the SCADA system, identifies the drift of the static map by providing training search by using extremum memorizing method at a constant counterweight motion speed and reverse zone defined the necessary immunity. The trajectory of the drift (dotted curve) at this motion is the sliding average value of the integrated control actions applied to the actuators. In the process of teaching it is memorizing the current values of vibration (in the memory block M1) and the integrated value of control actions (in the memory M2), which after the end of the grinding cycle (which is defined in the mass comparator CM with equal masses of feed and discharged material, measured by feed sensor FS and discharge sensor DS, respectively) are averaged and stored their median values instead of using the current by using drift identification block IDB.

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Barriers to cardiovascular risk prevention and management in Germany – an analysis of the EURIKA study

Barriers to cardiovascular risk prevention and management in Germany – an analysis of the EURIKA study

Actual German control rates of the main risk factors were 36.3% for hypertension, 30.4% for dyslipidemia (total cholesterol and LDL-c), 40.6% for type-2 diabetes (HbA 1c ), and 28.8% for obesity (based on BMI). Although there were only a few statistically significant differences in control rates between Germany and the ROE (Figure 3), the control of dyslipidemia was worse in Germany (odds ratio [OR]: 0.74; 95% confidence interval [CI]: 0.52–1.04). By contrast, the control of dyslipidemia was particularly good in the UK (OR: 3.60; 95% CI: 2.16–4.27), and Belgium (OR: 1.69; 95% CI: 1.22–2.34). Countries with particularly good con- trol of hypertension (France and Greece) used more angio- tensin receptor blockers (ARB: 54.4%/59.1% vs 32.2% in Germany), fewer beta blockers (26.5%/23.5% vs 53.9%), and fewer ACE inhibitors (16.4%/25.4% vs 47.0%). In Belgium, where control of blood glucose was particularly effective, there was a pronounced use of metformin in comparison to Germany (69.4% vs 55.9%). Gross differences in the use of lipid-lowering drugs were not found, although control rates were higher in Belgium and the UK. Overall, there was a trend to overestimate control rates among physicians in participating countries.

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