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REGULAR D-OPTIMAL SPRING BALANCE WEIGHING DESIGNS: CONSTRUCTION

100%

Ceranka B.

Acta Universitatis Lodziensis. Folia Oeconomica

2014

tom 3

nr 302

Spring balance weighing design there is the model of experiment in that the result of experiment we can present as linear combination of unknown measurements of objects with factors of this combination equal to zero or one. In the paper we consider such designs under the basic assumption that the errors of measurements are uncorrelated and they have different variances, that means the measurements are taken in different conditions or by used different measurement equipment. We consider D-optimal designs , i.e. the designs in that the determinant of the information matrix for the design attains the maximal value. We give the bounds of its value according to the number of objects in experiment, is it odd or even. The theoretical considerations we illustrate with example of construction of respectively design.

Notes on D‑optimal Spring Balance Weighing Designs

60%

Ceranka B. , Graczyk M.

Acta Universitatis Lodziensis. Folia Oeconomica

2018

tom 5

nr 338

183-194

Sprężynowy układ wagowy to model doświadczenia, którego wynik można opisać jako liniową kombinację nieznanych miar obiektów o współczynnikach równych zero lub jeden. W artykule rozważamy układy, dla których błędy pomiarów są nieskorelowane i mają różne wariancje. Rozważamy D‑optymalne sprężynowe układy wagowe, tzn. takie układy, w których wyznacznik macierzy informacji układu jest maksymalny. Podano górne ograniczenie jego wartości oraz warunki konieczne i dostateczne, przy spełnieniu których to ograniczenie jest osiągnięte. Ponadto zaprezentowane zostały metody konstrukcji macierzy D‑optymalnych układów.

Spring balance weighing design is a model of an experiment in which the result can be presented as a linear combination of unknown measurements of objects with factors of this combination equalling zero or one. In this paper, we assume that the variances of measurement errors are not equal and errors are not correlated. We consider D‑optimal designs, i.e. designs in which the determinant of the information matrix for the design attains the maximal value. The upper bound of its value is obtained and the conditions for the upper bound to be attained are proved. The value of the upper bound depends on whether the number of objects in the experiment is odd or even. Some methods of construction of regular D‑optimal spring balance weighing designs are demonstrated.

Regression Points in Non-Intrusive Polynomial Chaos Expansion Method and D-Optimal Design

60%

Szepietowska K. , Magnain B. , Lubowiecka I. , Florentin E.

Machine Dynamics Research

2017

tom Vol. 41, No. 2

5--16

The paper addresses selected issues of uncertainty quantification in the modelling of a system containing surgical mesh used in ventral hernia repair. Uncertainties in the models occur due to variability of abdominal wall properties among others. In order to include them, a nonintrusive regression-based polynomial chaos expansion method is employed. Its accuracy depends on the choice of regression points. In the study, a relation between error of mean, standard deviation, 95th percentile and location of regression points is investigated in the models of implants with a single random variable. This approach is compared with a classic choice of points based on the D-optimality criterion.

Multi objective optimization of soil erosion parameters using response surface method (RSM) in the Emamzadeh watershed

41%

Shirazi M. , Khademalrasoul A. , Safeddin Ardebili S. M.

Acta Geophysica

2020

tom Vol. 68, no. 2

505--517

Soil erosion is one of the most leading environmental and public health problems in the world which dislodges considerable volumes of soil annually. In order to control soil erosion, several soil factors should be taken into account. Regarding the importance of soil properties on erosion occurrence, it is necessary to focus on soil properties. The aim of this study is to evaluate the efect of physical parameters that consist of sand %, silt %, clay %, SP % and stone % along with hydraulic properties including theta s, theta r, alpha n and Ks (cm/day) on the amount of soil erosion in Emamzadeh watershed. The above-mentioned factors were optimized using response surface methodology. The soil texture in the study area is mostly silty clay loam, and the main soil orders are Entisols and Inceptisols. Moreover, the main land use in the study area is forest–rangeland. The results proved that both physical and hydraulic valuables illustrated a signifcant efect on all of the independent parameters. The optimized values of diferent physical parameters were 60.241 for sand, 14 for silt, 41.025 for clay, 58.729% for SP and 3.83% for stone. A theta r of 0.09, theta s of 0.457 alpha of 0.014, n of 1.3 and Ks of 46.01 were found to be optimal values. The results of this study indicated that at optimal studied parameters, the values of the soil erosion before and after application of management scenarios were found to be 11.537 and −2.253, respectively. Results show that both physical and hydraulic parameters have signifcant efects at the 1% level on the soil erosion before and after application of management scenarios. The obtained results could assist policy-makers with decisions aimed at minimizing soil erosion in this watershed. In summary, using the simulation–optimization techniques helps to evaluate the efect of management scenarios, then select and apply the best one to minimize the soil erosion outcomes.