Search results for "interval"
showing 10 items of 1703 documents
Minimizing uncertainties with improved power system stability using wide area fuzzy-2 logic based damping controller
2017
In this paper, a centralized Wide Area Damping Controller (WADC) is synthesized based on Interval Type-2 Fuzzy Logic controller. The disturbance is symbolized as distributed in the network with application of momentarily disturbance to the generator in area 1 for few cycles. The response of tie-line active power flow from area-1 to area-2, rotor speed change, rotor mechanical angle deviation, positive sequence voltage are examined by considering the test system with conventional PSS (CPSS), fuzzy type-1 based controller and fuzzy type-2 based controller. The proposed controller performance is analyzed and compared with fuzzy type-1 based controller and CPSS. The simulation results are used …
Intraoral Cameras as a Computer-Aided Diagnosis Tool for Root Canal Orifices
2011
The aim of this study was to evaluate the diagnostic advantage of a new software tool in combination with an intraoral camera for automatic detection of root canal orifices in life videos via the access cavity of extracted human molars. The performance of a predoctoral dental student analyzing the images of the camera (without automatic detection) was compared with that of an experienced observer. Sensitivity and confidence intervals were provided and compared with histological slices of 200 teeth used for evaluation. The software's sensitivity for detection of root canal orifices was 0.957 (95 percent confidence interval: 0.936 to 0.972). The sensitivity for the observer was 0.906 (95 perc…
Application of model quality evaluation to systems biology
2008
Application of model quality evaluation to the quasispecies models is presented. These models are useful for the analysis of the DNA and RNA evolution and for the description of the population dynamics of viruses and bacteria. An estimate of the parameters together with their interval of variability is computed and the quality evaluation is tested on the basis of the model prediction error capability.
Perceived statistical knowledge level and self-reported statistical practice among academic psychologists
2018
Introduction: Publications arguing against the null hypothesis significance testing (NHST) procedure and in favor of good statistical practices have increased. The most frequently mentioned alternatives to NHST are effect size statistics (ES), confidence intervals (CIs), and meta-analyses. A recent survey conducted in Spain found that academic psychologists have poor knowledge about effect size statistics, confidence intervals, and graphic displays for meta-analyses, which might lead to a misinterpretation of the results. In addition, it also found that, although the use of ES is becoming generalized, the same thing is not true for CIs. Finally, academics with greater knowledge about ES sta…
Energy saving in WWTP: Daily benchmarking under uncertainty and data availability limitations
2016
Efficient management of Waste Water Treatment Plants (WWTPs) can produce significant environmental and economic benefits. Energy benchmarking can be used to compare WWTPs, identify targets and use these to improve their performance. Different authors have performed benchmark analysis on monthly or yearly basis but their approaches suffer from a time lag between an event, its detection, interpretation and potential actions. The availability of on-line measurement data on many WWTPs should theoretically enable the decrease of the management response time by daily benchmarking. Unfortunately this approach is often impossible because of limited data availability. This paper proposes a methodolo…
An Adaptive Metamodel-Based Optimization Approach for Vehicle Suspension System Design
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/965157 The performance index of a suspension system is a function of the maximum and minimum values over the parameter interval. Thus metamodel-based techniques can be used for designing suspension system hardpoints locations. In this study, an adaptive metamodel-based optimization approach is used to find the proper locations of the hardpoints, with the objectives considering the kinematic performance of the suspension. The adaptive optimization method helps to find the optimum locations of the hardpoints efficiently as it may be unachie…
Guaranteed tuning of PID controllers for parametric uncertain systems
2004
This paper presents a methodology for tuning the controller of a parametric uncertain plant in order to guarantee the satisfaction of specifications. These specifications are defined by means of an interval reference model that represents the set of satisfactory time or frequency behaviors. The controller synthesis is then formulated as a set-inclusion problem in the frequency domain. Interval techniques for the solution of constraint satisfaction problems are applied to design fixed-structure controllers in a guaranteed manner. In particular, PID controllers are considered since they are widely used in industry.
Differences in Stress and Coping During the COVID-19 Pandemic in Families With and Without Children With Developmental Disorders or Chronic Conditions
2021
Objectives: To compare COVID-19-induced stress and coping in families with and without children diagnosed with developmental disorders or chronic conditions.Methods: In this mixed-method design study, an online survey collected information on parental stress levels before and during COVID-19, sources of stress, and coping strategies using open-ended questions. Qualitative answers were categorized thematically. Multiple linear regression models were built for the association between changes in stress levels (during-before COVID-19) and sources of stress for parents of children of both groups.Results: Answers of 1,827 parents were analyzed; of these, 186 (9.75%) had children with diagnosed pr…
Set-valued consensus for distributed clock synchronization
2009
This paper addresses the clock synchronization problem in a wireless sensor network (WSN) and proposes a distributed solution that consists of a form of consensus, where agents are able to exchange data representing intervals or sets. The solution is based on a centralized algorithm for clock synchronization, proposed by Marzullo, that determines the smallest interval that is in common with the maximum number of measured intervals. We first show how to convert such an algorithm into a problem involving only operations on sets, and then we convert it into a set–valued consensus. The solution is valid for more general scenarios where agents have uncertain measures of e.g. the position of an o…
Inference for the interclass correlation in familial data using small sample asymptotics
2012
Inference on the parent-offspring correlation coefficient is an important problem in the analysis of familial data, and point estimates and likelihood based inference are available in the literature. In this work, corrections for the signed log-likelihood ratio test statistics are proposed, based on small sample asymptotics, in order to achieve accurate small sample performance. The corrected statistic can be used for hypothesis testing as well as for interval estimation.