scholarly journals The Reconciliation of Multiple Conflicting Estimates: Entropy-Based and Axiomatic Approaches

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 815
Author(s):  
João Rodrigues ◽  
Michael Lahr
Keyword(s):  
First Principles ◽  
Axiomatic Approach ◽  
Data Reconciliation ◽  
Arithmetic Average ◽  
Weighted Arithmetic ◽  
Harmonic Average ◽  
Alternative Setting ◽  
Axiomatic Approaches ◽  
Reconciliation Method ◽  
The Ideal

When working with economic accounts it may occur that multiple estimates of a single datum exist, with different degrees of uncertainty or data quality. This paper addresses the problem of defining a method that can reconcile conflicting estimates, given best guess and uncertainty values. We proceeded from first principles, using two different routes. First, under an entropy-based approach, the data reconciliation problem is addressed as a particular case of a wider data balancing problem, and an alternative setting is found in which the multiple estimates are replaced by a single one. Afterwards, under an axiomatic approach, a set of properties is defined, which characterizes the ideal data reconciliation method. Under both approaches, the conclusion is that the formula for the reconciliation of best guesses is a weighted arithmetic average, with the inverse of uncertainties as weights, and that the formula for the reconciliation of uncertainties is a harmonic average.

On the Possibility of Passivation of Si(100) by Adsorption of Group-VI Atoms

1990 ◽  
Vol 193 ◽  
Author(s):  
Efthimios Kaxiras
Keyword(s):  
First Principles ◽  
Relative Strength ◽  
Energy Costs ◽  
First Principles Calculations ◽  
Qualitative Information ◽  
Group Vi ◽  
Covalent Bonds ◽  
Large Dispersion ◽  
Monolayer Coverage ◽  
The Ideal

ABSTRACTThe possibility of passivating the Si(100) surface by adsorption of Group-VI atoms (S and Se) is investigated through first-principles calculations. The structure of the ideal (1×1) configuration with the Si surface dangling bonds saturated by full monolayer coverage is examined in detail. The Group-VI adsorbates form covalent bonds to the substrate with bond-lengths very close to the sums of the covalent radii. The bond-angles are larger than in bulk configurations of the Group-VI elements. The ideal (1×1) configuration gives rise to a surface electronic state with large dispersion spanning the entire band-gap of Si. Deviations from this configuration by in-phase or out-of-phase tilting of the adsorbate atoms result in energy costs which can give qualitative information on the relative strength of adsorbate-adsorbate and adsorbate-substrate interactions.

scholarly journals Three-dimensional numerical simulation of mechanical properties of soil-tire mixture by discrete element method

2019 ◽  
Vol 92 ◽  
pp. 14011
Author(s):  
Mohsen Asadi ◽  
Ahmad Mahboubi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Damping Ratio ◽  
Strain Curve ◽  
Young Modulus ◽  
Engineering Properties ◽  
Triaxial Tests ◽  
Sand Particle ◽  
Arithmetic Average ◽  
Harmonic Average

Soil engineering properties can be improved employing different methods. Among them is mixing soil with tire derived additives (TDA). TDAs generally increase some parameters of mixture such as damping ratio, permeability, ductility and also in some cases shear strength. Various properties of TDAs from mechanical properties to their geometry can affect the mixture behavior. In this paper using the YADE platform, simulations of triaxial tests on sand tire mixtures are presented. To take compressibility into consideration, each rubber crumb particle is made of several spheres connected elastically to each other. For sand particle generation the clump technique was employed. Shapes of both sand and rubber particles are inspired from real grains. As properties of sand and rubber are different, especially Young modulus, rubber sand interaction is considered as soft rigid contact. Therefor harmonic average and arithmetic average was used to compute contact Young modulus (and then stiffness). The model was validated by comparison of results of triaxial tests simulation on pure rubber sample with literature ones which both exhibited linear stress-strain curve. Then triaxial tests with different sand to rubber ratio were simulated to see whether harmonic average or arithmetic average gives the best match to literature. The results show shear strength reduces by decreasing of sand to rubber ratio. This is the same as what is reported in literature.

scholarly journals Hybrid Weighted Arithmetic and Geometric Aggregation Operator of Neutrosophic Cubic Sets for MADM

Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 278 ◽  
Author(s):  
Lilian Shi ◽  
Yue Yuan
Keyword(s):  
Decision Making ◽  
Weighted Average ◽  
Aggregation Operator ◽  
Aggregation Operators ◽  
Arithmetic Average ◽  
Weighted Arithmetic ◽  
Geometric Average ◽  
Multi Attribute Decision Making

Neutrosophic cubic sets (NCSs) can express complex multi-attribute decision-making (MADM) problems with its interval and single-valued neutrosophic numbers simultaneously. The weighted arithmetic average (WAA) and geometric average (WGA) operators are common aggregation operators for handling MADM problems. However, the neutrosophic cubic weighted arithmetic average (NCWAA) and neutrosophic cubic geometric weighted average (NCWGA) operators may result in some unreasonable aggregated values in some cases. In order to overcome the drawbacks of the NCWAA and NCWGA, this paper developed a new neutrosophic cubic hybrid weighted arithmetic and geometric aggregation (NCHWAGA) operator and investigates its suitability and effectiveness. Then, we established a MADM method based on the NCHWAGA operator. Finally, a MADM problem with neutrosophic cubic information was provided to illustrate the application and effectiveness of the proposed method.

scholarly journals Die kombinering van ekonomiese vooruitskattings in die Suid-Afrikaanse konteks

1989 ◽  
Vol 20 (4) ◽  
pp. 178-183
Author(s):  
C. B. Calitz ◽  
E. V.D.M. Smit
Keyword(s):  
South African ◽  
Relative Accuracy ◽  
Forecasting Accuracy ◽  
Arithmetic Average ◽  
Weighted Arithmetic ◽  
Combining Forecasts ◽  
Combination Of Forecasts ◽  
Economic Forecasts

In the literature on forecasting, consensus has been reached about improved forecasting accuracy brought about by the combination of two or more forecasts for a given variable. No consensus, however, exists about the exact way in which the various forecasts in the combination should be weighed. The evidence points towards simple weighing schemes. The present study utilizes South African macro-economic forecasts published by seven forecasters on eight variables to evaluate the benefits to be gained from combining forecasts and to evaluate the relative accuracy of a number of combination schemes. The results confirm the current views on the combination of forecasts in so far as combining forecasts have led to increased accuracy in forecasting. It further confirms the viewpoint that a simple or weighted arithmetic average of individual forecasts seems to be acceptable as instruments for combining forecasts.

scholarly journals First-Principles Determination Of The Effects Of Boron And Sulfur On The Ideal Cleavage Fracture In Ni3Al

1995 ◽  
Vol 409 ◽  
Author(s):  
Sheng N. Sun ◽  
Nicholas Kioussis ◽  
Mikael Ciftan ◽  
A. Gonis
Keyword(s):  
Cleavage Fracture ◽  
First Principles ◽  
Cleavage Plane ◽  
Full Potential ◽  
Fracture Properties ◽  
Electronic Mechanism ◽  
Strain Relationship ◽  
First Time ◽  
The Ideal

AbstractThe effects of boron and sulfur impurities on the ideal cleavage fracture properties of Ni3Al under tensile stress are investigated for the first time using the full-potential linearmuffin- tin-orbital (FLMTO) total-energy method, with a repeated slab arrangement of atoms simulating an isolated cleavage plane. Results for the stress-strain relationship, ideal cleavage energies, ideal yield stress and strains with and without impurities are presented, and the electronic mechanism underlying the contrasting effects of boron and sulfur impurities on the ideal cleavage of Ni3Al is elucidated.

Properties of comprehensive incidence degrees

2014 ◽  
Vol 4 (3) ◽  
pp. 426-435 ◽  
Author(s):  
Yong Wei ◽  
Kefang Zeng
Keyword(s):  
System Analysis ◽  
Weighted Average ◽  
Grey System Theory ◽  
Grey System ◽  
Content Type ◽  
Arithmetic Average ◽  
Power Product ◽  
Weighted Arithmetic ◽  
Geometric Average ◽  
Weighted Geometric Average

Purpose – The purpose of this paper is to study the properties of comprehensive incidence degrees of closeness incidence degrees and similitude incidence degrees. Design/methodology/approach – Based on the new definitions of the closeness incidence degree and the similitude incidence degree, the properties of comprehensive incidence of closeness incidence and similitude incidence are studied in this paper. It is proved that weighted arithmetic average of two closeness incidence degrees as well as power product (including weighted geometric average) of two closeness incidence degrees is still closeness incidence degree; and arithmetic weighted average of two similitude incidence degrees as well as power product (including weighted geometric average) of two similitude incidence degrees is still similitude incidence degree. Mixed weighted arithmetic average of closeness incidence degree and similitude incidence degree and mixed power product (including weighted geometric average) of closeness incidence degree and similitude incidence degree are closeness incidence degrees. Findings – The result shows that the effect of closeness incidence degree is stronger than similitude incidence degree. As long as the weight of closeness incidence degree is not equal to zero, the comprehensive incidence degree results are closeness incidence degrees. Practical implications – Grey incidence degrees have been widely applied in many fields, such as the test of grey model's forecasting effect, the system analysis and so on. The obtained result in this paper is to illustrate two kinds of incidence degrees are incompatible, namely there does not exist both closeness and similitude incidence degree. Originality/value – The paper succeeds in showing that the attempt to get comprehensive incidence degree by arithmetic or geometric weighted average of closeness incidence degree and similitude incidence degree to reflect both closeness and similarity is in vain. And it is undoubtedly a new development in grey system theory.

Robert Solow’s Non-Walrasian Conception of Economics

2020 ◽  
Vol 52 (5) ◽  
pp. 827-861
Author(s):  
Matthieu Ballandonne ◽  
Goulven Rubin
Keyword(s):  
General Equilibrium ◽  
Common Sense ◽  
First Principles ◽  
Axiomatic Approach ◽  
Complex Model ◽  
General Equilibrium Theory ◽  
Partial Models ◽  
History Of ◽  
Do So

The neoclassical synthesis has been defined as a bridge between Keynes-ian theory and Walrasian general equilibrium theory. The aim of this article is to show that founders of the neoclassical synthesis were not homogenous in their appraisal of the importance of Walrasian theory. To do so, we focus on Robert Solow’s contributions as a case study and examine the history of his lifelong criticism of what he called “axiomatics.” According to Solow, the axiomatic approach aims at founding economics on one general and complex model based on first principles or axioms. In contrast, Solow advocated the use of a diversity of simple and partial models, which have practical utility, are realistic in their crucial assumptions, consider institutions and the evolving nature of the economy, and rely on common sense microfoundations. We conclude by suggesting that Solow can be characterized as Cournotian.

Application of Data Reconciliation Method to Increase CCPP Performance Test Result Accuracy

2015 ◽  
Author(s):  
Zengqian Wang ◽  
Jingjin Ji ◽  
Xinghao Wang ◽  
Bo Sun ◽  
Lei He ◽  
...  
Keyword(s):  
Uncertainty Analysis ◽  
Power Output ◽  
Performance Test ◽  
Heat Rate ◽  
Performance Data ◽  
Data Reconciliation ◽  
Acceptance Test ◽  
Analysis Method ◽  
Reconciliation Method ◽  
Test Result

Performance acceptance test for gas-steam Combined Cycle Power Plant (CCPP) is of great significance for both equipment manufacturer and customer. The influence of measurement error on the calculation of guaranteed performance data as power output and heat rate can lead to unnecessary loss for either party. Commonly used uncertainty analysis method based on ASME PTC 19.1 would require all measuring instrumentation working at designed accuracy range. Meanwhile, due to the complexity of CCPP system and large number of measuring items, and as well the propagation of measurement and data reduction error, the uncertainty of corrected performance data could be significant. In this paper, process data reconciliation method based on VDI 2048 is introduced. With access to complete performance test data from a CCPP project, data reconciliation calculation is performed with an appropriate thermodynamic model. Several measurement values with gross error are identified and verified in heat balance calculation. Moreover, after recalculating with the reconciled data instead of raw data for the corrected power output and heat rate, comparison with the common uncertainty analysis method is also carried out. It is shown that with this reconciliation method, it is not only possible to find out gross errors such as instrumentation drift, but also able to dramatically increase the test result accuracy, which is of great value for both manufacturer and customer.

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