317 research outputs found

    Internal model controller based PID with fractional filter design for a nonlinear process

    Get PDF
    In this paper, an Internal model Controller (IMC) based PID with fractional filter for a first order plus time delay process is proposed. The structure of the controller has two parts, one is integer PID controller part cascaded with fractional filter. The proposed controller has two tuning factors λ, filter time constant and a, fractional order of the filter. In this work, the two factors are decided in order to obtain low Integral Time Absolute Error (ITAE). The effectiveness of the proposed controller is studied by considering a non linear (hopper tank) process. The experimental set up is fabricated in the laboratory and then data driven model is developed from the experimental data. The non linear process model is linearised using piecewise linearization and two linear regions are obtained. At each operating point, linear first order plus dead time model is obtained and the controller is designed for the same. To show the practical applicability, the proposed controller is implemented for the proposed experimental laboratory prototype

    A web-based course assessment tool with direct mapping to student outcomes

    Get PDF
    The assessment of curriculum outcomes is an essential element for continuous academic improvement. However, the collection, aggregation and analysis of assessment data are notoriously complex and time-consuming processes. At the same time, only few developments of supporting electronic processes and tools for continuous academic program assessment and curriculum performance feedback have emerged. In this paper, we introduce a novel course assessment process supported by a Web based interface that articulates and streamlines the assessment data collection, performance evaluation and tracking of remedial recommendations. To close the assessment loop, the Web interface provides also a mechanism to follow up on the implementation of remedial recommendations and analyzes their associated reflective actions during the subsequent course assessment cycle. A guide to map assessment instruments to the course and overall program outcomes is advocated by the proposed tool to propagate the course assessment results towards higher educational objectives (e.g., student outcomes) in a dashboard-like assessment interface. This approach streamlines improvements in education through reflecting the achievement of course outcomes on the achievement of higher educational objectives.In addition, the tool maps the course outcomes to the corresponding course outlines to facilitate the detection of areas where revisions in the instruction and content is needed, and to best respond to recommendations and remedial actions. We provide a methodical approach as well as a Web-based automation of the assessment process, which we evaluate in the context of our regular academic assessment cycles that have eventually led to a successful international accreditation experience. The collected assessment data shows a significant improvement in the achievement rate of the student outcomes after deploying the tool

    Effect of antioxidants supplementations in salt-induced dyslipidaemia in albino rats

    Get PDF
    Cardiovascular disease (CVD) is associated with many risk factors including oxidative stress and dyslipidaemia. The current work evaluated the effects of antioxidants supplementation on salt-induced dyslipidaemia in albino rats. Rats were divided into 10 groups of 7 rats each. Groups 2-10 were fed 8% salt diets for 5 weeks while group 1 served as control and were fed normal rat feed. Water was provided to all the groups ad libitum. The animals in groups 3-10 were then supplemented with vitamin A; vitamin C; vitamin E; Cu; Mn; Zn; vitamins A, C and E combined and Cu, Mn and Zn combined respectively for additional 4 weeks simultaneously with salt loading. Group 2 was not supplemented and served as the negative control. Serum levels of total cholesterol, triacylglyceride, low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, high density lipoprotein (HDL) cholesterol and glucose were estimated. The results indicated that the vitamins reduced significantly serum lipid profiles and the atherogenic index by up to 80%. The serum glucose levels of the rats supplemented with antioxidant vitamins and minerals were also significantly (P<0.05) lowered compared with the negative control group. These results suggest that the reduction of serum lipid profile and glucose level may be due to regulation of cholesterol and lipoprotein metabolism and increased insulin sensitivity as a result of the supplementations. It may thus suggest that the antioxidants may provide protection against CVDs and metabolic syndrome in salt-induced dyslipidaemia in rats

    Smart meter security: Vulnerabilities, threat impacts, and countermeasures

    Get PDF
    © Springer Nature Switzerland AG 2019. Advanced Metering Infrastructure (AMI) is the aggregation of smart meters, communications networks, and data management systems that are tailored to meet the efficient integration of renewable energy resources. The more complex features and soundless functionalities the AMI is enhanced with, the more cyber security concerns are raised and must be taken into consideration. It is imperative to assure consumer’s privacy and security to guarantee the proliferation of rolling out smart metering infrastructure. This research paper analyzes AMI from security perspectives; it discusses the possible vulnerabilities associated with different attack surfaces in the smart meter, their security and threat implications, and finally it recommends proper security controls and countermeasures. The research findings draw the foundation upon which robust security by design approach is geared for the deployment of the AMI in the future

    An efficient algorithm to calculate intrinsic thermoelectric parameters based on Landauer approach

    Full text link
    The Landauer approach provides a conceptually simple way to calculate the intrinsic thermoelectric (TE) parameters of materials from the ballistic to the diffusive transport regime. This method relies on the calculation of the number of propagating modes and the scattering rate for each mode. The modes are calculated from the energy dispersion (E(k)) of the materials which require heavy computation and often supply energy relation on sparse momentum (k) grids. Here an efficient method to calculate the distribution of modes (DOM) from a given E(k) relationship is presented. The main features of this algorithm are, (i) its ability to work on sparse dispersion data, and (ii) creation of an energy grid for the DOM that is almost independent of the dispersion data therefore allowing for efficient and fast calculation of TE parameters. The inclusion of scattering effects is also straight forward. The effect of k-grid sparsity on the compute time for DOM and on the sensitivity of the calculated TE results are provided. The algorithm calculates the TE parameters within 5% accuracy when the K-grid sparsity is increased up to 60% for all the dimensions (3D, 2D and 1D). The time taken for the DOM calculation is strongly influenced by the transverse K density (K perpendicular to transport direction) but is almost independent of the transport K density (along the transport direction). The DOM and TE results from the algorithm are bench-marked with, (i) analytical calculations for parabolic bands, and (ii) realistic electronic and phonon results for Bi2Te3Bi_{2}Te_{3}.Comment: 16 Figures, 3 Tables, submitted to Journal of Computational electronic

    Associations Among Androgens, Estrogens, and Natriuretic Peptides in Young Women Observations From the Dallas Heart Study

    Get PDF
    ObjectivesWe sought to determine if natriuretic peptides are associated with estrogen and androgen status in a population study of young women without known cardiac disease.BackgroundCirculating concentrations of plasma B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are higher in women than in men, and they may be influenced by estrogens and androgens.MethodsCardiac magnetic resonance imaging, dual energy X-ray absorbtiometry, and measurements of BNP, NT-proBNP, follicle-stimulating hormone (FSH), total testosterone, and sex hormone-binding globulin (SHBG), were performed in 682 women (ages 35 to 49 years) participating in the Dallas Heart Study.ResultsIn multivariable analyses adjusting for age, race/ethnicity, body mass index (BMI), serum creatinine, left ventricular mass and left ventricular ejection fraction <55%, menopausal status, and FSH were not associated with BNP and NT-proBNP. In contrast, higher SHBG was associated with higher BNP and NT-proBNP, while the free androgen index and calculated free testosterone were inversely associated with BNP and NT-proBNP (p < 0.0001 for each). Addition of SHBG or any measure of free testosterone to the multivariable models modified the effect of BMI and lean mass, such that measures of body composition were no longer significantly associated with BNP or NT-proBNP.ConclusionsAmong young women, measures of free testosterone were independently and inversely associated with BNP and NT-proBNP. These results suggest that circulating free testosterone, not estradiol, mediates gender differences in natriuretic peptides. In addition, the association between higher BMI and lean body mass with natriuretic peptides may be mediated by testosterone
    corecore