Search results for " estimation"
showing 10 items of 562 documents
Development and evaluation of image-series for portion size estimation in dietary assessment among adults
2021
AbstractPortion size images are advantageous in dietary assessment. The aim of the present study was to develop and validate new culturally specific image-series for portion size estimation to be used in a new Norwegian version of a British web-based dietary assessment tool (myfood24). Twenty-three image-series of different foods, each containing seven portion size images, were created and validated in a group of adults (n41, 58 % female) aged 19–44 (median 23), out of which 63 % had higher (tertiary) education. The participants compared 46 portions of pre-weighed foods to the portion size images (1886 comparisons in total). Portion size estimations were either classified as correct, adjace…
Online Estimation of the Mechanical Parameters of an Induction Machine Using Speed Loop characteristics and Recursive Least Square Technique
2022
This paper presents a novel approach for estimation of mechanical parameters, inertia and friction coefficient of an Induction Machine (IM) using speed loop characteristics and Recursive Least Square (RLS) estimator. Using the 5th order dynamic equation for Induction Machine and the forgetting factor based RLS algorithm the technique herein proposed employs the speed of the machine and the torque as the inputs for the estimator. Results obtained compares the estimated parameters with the actual parameters under multiple step varying and exponentially varying scenarios. Upon analyzing the results, the validity and the effectiveness of the proposed identification technique is confirmed
Comparing Alternative Algorithms to Analyze the Beerkan Infiltration Experiment
2014
The increasing interest in the Beerkan Estimation of Soil Transfer parameters (BEST) procedure of soil hydraulic characterization justifies an assessment of alternative methods to analyze infiltration data. The BEST-slope and BEST-intercept algorithms allow estimation of soil sorptivity, S, and saturated soil hydraulic conductivity, Ks, using the transient part of the experimental infiltration curve and the slope and the intercept, respectively, of the linear portion of this curve. With reference to 401 runs performed in Sicily (Italy) and Burundi, this investigation showed that these two algorithms differed by the number of successful runs (positive S and Ks values), with BEST-intercept yi…
Determining hydraulic properties of a loam soil by alternative infiltrometer techniques
2015
Testing infiltrometer techniques to determine soil hydraulic properties is necessary for specific soils. For a loam soil, the water retention and hydraulic conductivity predicted by the BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization was compared with data collected by more standard laboratory and field techniques. Six infiltrometer techniques were also compared in terms of saturated soil hydraulic conductivity, Ks. BEST yielded water retention values statistically similar to those obtained in the laboratory and Ks values practically coinciding with those determined in the field with the pressure infiltrometer (PI). The unsaturated soil hyd…
DETERMINING THE SATURATED HYDRAULIC CONDUCTVITY OF A LOAM SOIL WITH DIFFERENT INFILTROMETER TECHNIQUES
2015
The saturated soil hydraulic conductivity, Ks, is one of the most important soil hydraulic properties since it controls many hydrological processes. This hydrodynamic parameter depends on soil texture and structure and it is very difficult to measure. Infiltrometer techniques are becoming very popular to determine Ks in the field but testing alternative approaches is necessary for specific soil types. For a loam soil, the estimated Ks values with six infiltrometer techniques were compared. The so-called BEST procedure of soil hydraulic characterization, the pressure infiltrometer (PI), single head experiments with both the tension infiltrometer (TI) and the mini disk infiltrometer (MDI), th…
Parameter identification of linear induction motor model in extended range of operation by means of input-output data
2012
This paper proposes a technique for the off-line estimation of the electrical parameters of the equivalent circuit of linear induction machines (LIM), taking into consideration the end effects, and focuses on the application of an algorithm based on the minimization of a suitable cost function involving the differences of measured and computed by simulation inductor current components. This method exploits an entire start-up transient of the LIM to estimate all the 4 electrical parameters of the machine (Rs, L s, σ Ls, Tr). It proposes also a set of tests to be made to estimate the variation of the magnetic parameters of the LIM versus the magnetizing current as well as the magnetizing curv…
Distributed estimation and control of water distribution networks by logical consensus
2014
In this study we present a methodology for backflow detec- tion through the interpretation of results from a network of Automatic Meter Reading. The approach is based on the so– called logical consensus theory and consists of a distributed failure detection and system reconfiguration. The effective- ness of the proposed method is showed through simulation within a prototypical water distribution network.
Objective Bayesian point and region estimation in location-scale models.
2007
Point and region estimation may both be described as specific decision problems. In point estimation, the action space is the set of possible values of the quantity on interest; in region estimation, the action space is the set of its possible credible regions. Foundations dictate that the solution to these decision problems must depend on both the utility function and the prior distribution. Estimators intended for general use should surely be invariant under one-to-one transformations, and this requires the use of an invariant loss function; moreover, an objective solution requires the use of a prior which does not introduce subjective elements. The combined use of an invariant informatio…
Survey data and Bayesian analysis: a cost-efficient way to estimate customer equity
2014
We present a Bayesian framework for estimating the customer lifetime value (CLV) and the customer equity (CE) based on the purchasing behavior deducible from the market surveys on customer purchasing behavior. The proposed framework systematically addresses the challenges faced when the future value of customers is estimated based on survey data. The scarcity of the survey data and the sampling variance are countered by utilizing the prior information and quantifying the uncertainty of the CE and CLV estimates by posterior distributions. Furthermore, information on the purchase behavior of the customers of competitors available in the survey data is integrated to the framework. The introduc…
The effect of education on migration: evidence from school reform
2010
A polytechnic, higher education reform took place in Finland in the 1990s. It gradually transformed former vocational colleges into polytechnics and expanded higher education to all Finnish regions. We implement instrumental variables estimators that exploit the exogenous variation in the regional availability of polytechnic education together with matriculation exam scores. Our IV results show that polytechnic graduates have a higher migration probability than those of vocational college graduates. However, a master’s degree did not increase migration propensity in comparison with a polytechnic degree. We also find that an increase in the availability of polytechnic education did not reduc…