Functional Control Synthesis of Single-Phase Low Power Motor Drives

In the paper an electric drive system of series-wound universal motor powered by semiconductor converter is considered.The system characteristics and calculation procedure using spectral method of Solodovnikov and aligning procedure areshown. We derived and displayed expressions for two-dimensional non-stationary transfer functions and non-stationaryspectral characteristics of output variables of automated control system of single-phase series-wound universal motorpowered by semiconductor converter. We also show results of electromagnetic calculation of the electric drive system ofseries-wound universal motor powered by semiconductor converter for various firing angles ? of the converter, as welldependences of conduction angle ?t for varied values of rotational speed ? and load torque on the shaft of the moto

Association of BMI, lipid-lowering medication, and age with prevalence of type 2 diabetes in adults with heterozygous familial hypercholesterolaemia: a worldwide cross-sectional study

Background: Statins are the cornerstone treatment for patients with heterozygous familial hypercholesterolaemia but research suggests it could increase the risk of type 2 diabetes in the general population. A low prevalence of type 2 diabetes was reported in some familial hypercholesterolaemia cohorts, raising the question of whether these patients are protected against type 2 diabetes. Obesity is a well known risk factor for the development of type 2 diabetes. We aimed to investigate the associations of known key determinants of type 2 diabetes with its prevalence in people with heterozygous familial hypercholesterolaemia. Methods: This worldwide cross-sectional study used individual-level data from the EAS FHSC registry and included adults older than 18 years with a clinical or genetic diagnosis of heterozygous familial hypercholesterolaemia who had data available on age, BMI, and diabetes status. Those with known or suspected homozygous familial hypercholesterolaemia and type 1 diabetes were excluded. The main outcome was prevalence of type 2 diabetes overall and by WHO region, and in relation to obesity (BMI ≥30·0 kg/m2) and lipid-lowering medication as predictors. The study population was divided into 12 risk categories based on age (tertiles), obesity, and receiving statins, and the risk of type 2 diabetes was investigated using logistic regression. Findings: Among 46 683 adults with individual-level data in the FHSC registry, 24 784 with heterozygous familial hypercholesterolaemia were included in the analysis from 44 countries. 19 818 (80%) had a genetically confirmed diagnosis of heterozygous familial hypercholesterolaemia. Type 2 diabetes prevalence in the total population was 5·7% (1415 of 24 784), with 4·1% (817 of 19 818) in the genetically diagnosed cohort. Higher prevalence of type 2 diabetes was observed in the Eastern Mediterranean (58 [29·9%] of 194), South-East Asia and Western Pacific (214 [12·0%] of 1785), and the Americas (166 [8·5%] of 1955) than in Europe (excluding the Netherlands; 527 [8·0%] of 6579). Advancing age, a higher BMI category (obesity and overweight), and use of lipid-lowering medication were associated with a higher risk of type 2 diabetes, independent of sex and LDL cholesterol. Among the 12 risk categories, the probability of developing type 2 diabetes was higher in people in the highest risk category (aged 55–98 years, with obesity, and receiving statins; OR 74·42 [95% CI 47·04–117·73]) than in those in the lowest risk category (aged 18–38 years, without obesity, and not receiving statins). Those who did not have obesity, even if they were in the upper age tertile and receiving statins, had lower risk of type 2 diabetes (OR 24·42 [15·57–38·31]). The corresponding results in the genetically diagnosed cohort were OR 65·04 (40·67–104·02) for those with obesity in the highest risk category and OR 20·07 (12·73–31·65) for those without obesity. Interpretation: Adults with heterozygous familial hypercholesterolaemia in most WHO regions have a higher type 2 diabetes prevalence than in Europe. Obesity markedly increases the risk of diabetes associated with age and use of statins in these patients. Our results suggest that heterozygous familial hypercholesterolaemia does not protect against type 2 diabetes, hence managing obesity is essential to reduce type 2 diabetes in this patient population. Funding: Pfizer, Amgen, MSD, Sanofi-Aventis, Daiichi-Sankyo, and Regeneron

MULTI-AGENT APPROACH TO THE DEVELOPMENT OF MANAGEMENT SYSTEM OF THE PROCESS OF THE DISTRIBUTED FURNITURE DESIGN

Custom-made industrial production of cabinet furniture, focused on the needs of end-user of furniture products, imposes a number of stringent requirements on the process of designing new products. As a basic condition ensuring the fulfillment of these requirements, a modern concept of a virtual furniture design bureau (VFDB) is proposed, within which the distributed (combined) design of furniture products and ensembles is implemented. For effective development of distributed projects in a multi-agent environment of VFDB, it is necessary to use a management system that ensures coordination of the work of project participants, monitoring the current state of the project, notifying project participants about various situations in project work, etc. A feature of this control system is its invariance, i.e. independence from the design tools used in the work on the project, as well as the possibility of its dynamic adjustment to the specific structure of the design process. It is proposed to use a serial-parallel pipeline of the design as a conceptual model of the distributed design process.</jats:p

Three-dimensional vibrations of wind turbines

Abstract In this paper authors consider three-dimensional vibrations of a wind energy farms (WEF) of tower type VTR 50 Arctic. Low-frequency vibration of a WEF composed of a tower and rotor is considered in the out of balance condition. The method of analysis is based on the theory of mechanical oscillations and the theory of elastic shafts. We consider the tower as a shaft and the rotor as a rigid body. Using the Lagrange’s equations for elastic structures in combination with computer simulation provides for the novelty and efficiency of the suggested method. The unique nonlinear equation is deduced and solved using the Wolfram Mathematica.</jats:p