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2021 ◽  
Author(s):  
Emna Krichene ◽  
Wael Ouarda ◽  
Habib Chabchoub ◽  
Ajith Abraham ◽  
Abdulrahman M. Qahtani ◽  
...  

A newly introduced method called Taylor-based Optimized Recursive Extended Exponential Smoothed Neural Networks Forecasting method is applied and extended in this study to forecast numerical values. Unlike traditional forecasting techniques which forecast only future values, our proposed method provides a new extension to correct the predicted values which is done by forecasting the estimated error. Experimental results demonstrated that the proposed method has a high accuracy both in training and testing data and outperform the state-of-the-art RNN models on Mackey-Glass, NARMA, Lorenz and Henon map datasets.


2021 ◽  
Author(s):  
Emna Krichene ◽  
Wael Ouarda ◽  
Habib Chabchoub ◽  
Ajith Abraham ◽  
Abdulrahman M. Qahtani ◽  
...  

A newly introduced method called Taylor-based Optimized Recursive Extended Exponential Smoothed Neural Networks Forecasting method is applied and extended in this study to forecast numerical values. Unlike traditional forecasting techniques which forecast only future values, our proposed method provides a new extension to correct the predicted values which is done by forecasting the estimated error. Experimental results demonstrated that the proposed method has a high accuracy both in training and testing data and outperform the state-of-the-art RNN models on Mackey-Glass, NARMA, Lorenz and Henon map datasets.


2021 ◽  
Vol 2119 (1) ◽  
pp. 012138
Author(s):  
D A Samoshkin ◽  
A Sh Agazhanov ◽  
S V Stankus

Abstract In the present article, the heat capacity of Inconel 617, one of the most promising superalloys, was investigated. The measurements were carried out in the temperature range from 300 to 1270 K of the solid state. The method of differential scanning calorimetry was applied using DSC 404 F1 Pegasus calorimeter. The estimated error of the received data was 2-4% depending on the temperature. The fitting equations for the temperature dependences of the heat capacity and the reference table of recommended values have been received for use in various engineering and scientific tasks.


Author(s):  
Fredrik Ekre ◽  
Fredrik Larsson ◽  
Kenneth Runesson ◽  
Ralf Jänicke

AbstractNumerical model reduction (NMR) is used to solve the microscale problem that arises from computational homogenization of a model problem of porous media with displacement and pressure as unknown fields. The reduction technique and an associated error estimator for the NMR error have been presented in prior work, where both spectral decomposition (SD) and proper orthogonal decomposition (POD) were used to construct the reduced basis. It was shown that the POD basis performs better w.r.t. minimizing the residual, but the SD basis has some advantageous properties for the estimator. Since it is the estimated error that will govern the error control, the most efficient procedure is the one that results in the lowest error bound. The main contribution of this paper is further development of the previous work with a proposed combined basis constructed using both SD and POD modes together with an adaptive mode selection strategy. The performance of the combined basis is compared to (i) the pure SD basis and (ii) the pure POD basis via numerical examples. The examples show that it is possible to find a combination of SD/POD modes which is improved, i.e. it yields a smaller estimate, compared to the cases of pure SD or pure POD.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Felix G. Rebitschek ◽  
Gerd Gigerenzer ◽  
Gert G. Wagner

AbstractThis study provides the first representative analysis of error estimations and willingness to accept errors in a Western country (Germany) with regards to algorithmic decision-making systems (ADM). We examine people’s expectations about the accuracy of algorithms that predict credit default, recidivism of an offender, suitability of a job applicant, and health behavior. Also, we ask whether expectations about algorithm errors vary between these domains and how they differ from expectations about errors made by human experts. In a nationwide representative study (N = 3086) we find that most respondents underestimated the actual errors made by algorithms and are willing to accept even fewer errors than estimated. Error estimates and error acceptance did not differ consistently for predictions made by algorithms or human experts, but people’s living conditions (e.g. unemployment, household income) affected domain-specific acceptance (job suitability, credit defaulting) of misses and false alarms. We conclude that people have unwarranted expectations about the performance of ADM systems and evaluate errors in terms of potential personal consequences. Given the general public’s low willingness to accept errors, we further conclude that acceptance of ADM appears to be conditional to strict accuracy requirements.


2021 ◽  
Vol 2057 (1) ◽  
pp. 012116
Author(s):  
Yu M Kozlovskii ◽  
S V Stankus

Abstract The experimental results of the study of thermal expansion of nickel-chrome alloy in the temperature range of 293.15–1400 K are presented. The phase transformation of the first kind in the alloy is observed. The estimated error of the obtained data is 3%. Approximation equations and a table of reference values for the temperature dependence of the studied properties are obtained.


Author(s):  
Bayu Elwanto Bagus Dewanto ◽  
Retnadi Heru Jatmiko

Estimation of aboveground carbon stock on stands vegetation, especially in green open space, has become an urgent issue in the effort to calculate, monitor, manage, and evaluate carbon stocks, especially in a massive urban area such as Samarinda City, Kalimantan Timur Province, Indonesia. The use of Sentinel-1 imagery was maximised to accommodate the weaknesses in its optical imagery, and combined with its ability to produce cloud-free imagery and minimal atmospheric influence. The study aims to test the accuracy of the estimated model of above-ground carbon stocks, to ascertain the total carbon stock, and to map the spatial distribution of carbon stocks on stands vegetation in Samarinda City. The methods used included empirical modelling of carbon stocks and statistical analysis comparing backscatter values and actual carbon stocks in the field using VV and VH polarisation. Model accuracy tests were performed using the standard error of estimate in independent accuracy test samples. The results show that Samarinda Utara subdistrict had the highest carbon stock of 3,765,255.9 tons in the VH exponential model. Total carbon stocks in the exponential VH models were 6,489,478.1 tons, with the highest maximum accuracy of 87.6 %, and an estimated error of 0.57 tons/pixel.


Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2040
Author(s):  
Cristina Puente ◽  
Maria Ana Sáenz-Nuño ◽  
Augusto Villa-Monte ◽  
José Angel Olivas

The number of satellites and debris in space is dangerously increasing through the years. For that reason, it is mandatory to design techniques to approach the position of a given object at a given time. In this paper, we present a system to do so based on a database of satellite positions according to their coordinates (x,y,z) for one month. We have paid special emphasis on the preliminary stage of data arrangement, since if we do not have consistent data, the results we will obtain will be useless, so the first stage of this work is a full study of the information gathered locating the missing gaps of data and covering them with a prediction. With that information, we are able to calculate an orbit error which will estimate the position of a satellite in time, even when the information is not accurate, by means of prediction of the satellite’s position. The comparison of two satellites over 26 days will serve to highlight the importance of the accuracy in the data, provoking in some cases an estimated error of 4% if the data are not well measured.


2021 ◽  
Vol 77 (9) ◽  
pp. 537-543
Author(s):  
Christopher M. Crittenden ◽  
Antonio G. DiPasquale

5α,14α-Androstane (C19H32) crystallizes in two different polymorphic forms in the same vapor diffusion experiment. The major form (Form I) crystallizes as thin plates in the space group P21, with Z = 4. These plates are twinned along a long c axis of length 43 Å and readily suffer from radiation damage when diffracted. The minor form (Form II) crystallizes as fine needles in the space group P212121, Z = 3. In the minor form, 5α,14α-androstane cocrystallizes with 5α,14α-androstan-17-one, an oxidation product of 5α,14α-androstane. The presence of 5α,14α-androstan-17-one in the minor form of the crystals was confirmed by HR-MS. Form II can be crystallized as a pure form without the ketone impurity using a different solvent system. High level density functional theory (DFT) lattice free energy calculations were performed and show that both pure forms are isoergic within the estimated error of the calculations.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xining Wu ◽  
Zihan Niu ◽  
Zhonghui Xu ◽  
Yuxin Jiang ◽  
Yixiu Zhang ◽  
...  

Abstract Background Accurate estimation of fetal weight is important for prenatal care and for detection of fetal growth abnormalities. Prediction of fetal weight entails the indirect measurement of fetal biometry by ultrasound that is then introduced into formulae to calculate the estimated fetal weight. The aim of our study was to evaluate the accuracy of fetal weight estimation of Chinese fetuses in the third trimester using an automated three-dimensional (3D) fractional limb volume model, and to compare this model with the traditional two-dimensional (2D) model. Methods Prospective 2D and 3D ultrasonography were performed among women with singleton pregnancies 7 days before delivery to obtain 2D data, including fetal biparietal diameter, abdominal circumference and femur length, as well as 3D data, including the fractional arm volume (AVol) and fractional thigh volume (TVol). The fetal weight was estimated using the 2D model and the 3D fractional limb volume model respectively. Percentage error was defined as (estimated fetal weight - actual birth weight) divided by actual birth weight and multiplied by 100. Systematic errors (accuracy) were evaluated as the mean percentage error (MPE). Random errors (precision) were calculated as ±1 SD of percentage error. The intraclass correlation coefficient (ICC) was used to analyze the inter-observer reliability of the 3D ultrasound measurements of fractional limb volume. Results Ultrasound examination was performed on 56 fetuses at 39.6 ± 1.4 weeks’ gestation. The average birth weight of the newborns was 3393 ± 530 g. The average fetal weight estimated by the 2D model was 3478 ± 467 g, and the MPE was 3.2 ± 8.9. The average fetal weights estimated by AVol and TVol of the 3D model were 3268 ± 467 g and 3250 ± 485 g, respectively, and the MPEs were − 3.3 ± 6.6 and − 3.9 ± 6.1, respectively. For the 3D TVol model, the proportion of fetuses with estimated error ≤ 5% was significantly higher than that of the 2D model (55.4% vs. 33.9%, p < 0.05). For fetuses with a birth weight < 3500 g, the accuracy of the AVol and TVol models were better than the 2D model (− 0.8 vs. 7.0 and − 2.8 vs. 7.0, both p < 0.05). Moreover, for these fetuses, the proportions of estimated error ≤ 5% of the AVol and TVol models were 58.1 and 64.5%, respectively, significantly higher than that of the 2D model (19.4%) (both p < 0.05). The inter-observer reliability of measuring fetal AVol and TVol were high, with the ICCs of 0.921 and 0.963, respectively. Conclusion In this cohort, the automated 3D fractional limb volume model improves the accuracy of weight estimation in most third-trimester fetuses. Prediction accuracy of the 3D model for neonatal BW, particularly < 3500 g was higher than that of the traditional 2D model.


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