scholarly journals Optimal location of pumping wells by a mesh-free numerical method

2021 ◽  
Author(s):  
Masuod Abdi ◽  
Hossein Ebrahimi ◽  
Abolfazl Akbarpour
Keyword(s):  
Finite Difference ◽  
Objective Function ◽  
Groundwater Level ◽  
Optimization Model ◽  
Transient State ◽  
Simulation Method ◽  
Mesh Free ◽  
Pumping Wells ◽  
Before And After ◽  
Finite Difference Solution

Abstract In the present study, the optimal place to excavate extraction wells as the drawdown gets minimized was investigated in a real aquifer. Meshless local Petrov-Galerkin (MLPG) method is used as the simulation method. The closeness of its results to the observational data compared to the finite difference solution showed the higher accuracy of this method as the RMSE for MLPG is 0.757 m while this value for finite difference equaled to 1.197 m. Particle warm algorithm is used as the optimization model. The objective function defined as the summation of the absolute values of difference between the groundwater level before abstraction and the groundwater level after abstraction from wells. In Birjand aquifer which is investigated in transient state, the value of objective function before applying the optimization model was 2.808 m, while in the optimal condition, reached to 1.329 m (47% reduction in drawdown). This fact was investigated and observed in three piezometers. In the first piezometer, the drawdown before and after model enforcement was 0.007 m and 0.003 m, respectively. This reduction occurred in other piezometers as well.

COMPARISON OF TWO OPTIMIZATION MODELS FOR CONSTRUCTING PATTERNS IN THE METHOD OF LOGICAL ANALYSIS OF DATA

2020 ◽  
pp. 10-13
Author(s):  
Р.И. Кузьмич ◽  
А.А. Ступина ◽  
С.Н. Ежеманская ◽  
А.П. Шугалей
Keyword(s):  
Objective Function ◽  
Optimization Model ◽  
Logical Analysis ◽  
Optimization Models ◽  
Logical Analysis Of Data

Предлагаются две оптимизационные модели для построения информативных закономерностей. Приводится эмпирическое подтверждение целесообразности использования критерия бустинга в качестве целевой функции оптимизационной модели для получения информативных закономерностей. Информативность, закономерность, критерий бустинга, оптимизационная модель Comparison of two optimization models for constructing patterns in the method of logical analysis of data Two optimization models for constructing informative patterns are proposed. An empirical confirmation of the expediency of using the boosting criterion as an objective function of the optimization model for obtaining informative patterns is given.

Investigations Into Asperity Persistence in Heavily Loaded Contacts

1999 ◽  
Vol 121 (3) ◽  
pp. 441-448 ◽  
Author(s):  
I. Lee-Prudhoe ◽  
R. S. Sayles ◽  
A. Kaderic
Keyword(s):  
Rough Surface ◽  
Simulation Models ◽  
Simulation Method ◽  
Asperity Contact ◽  
Local Contact ◽  
Before And After ◽  
Indentation Tests ◽  
Mechanisms Of Persistence ◽  
Contact Pressures ◽  
Smooth Roller

Experimental results are presented along the lines of the early work of Moore (1948) where a hard smooth roller is pressed into a softer rough surface to study the resulting real to apparent areas of contact and their associated local contact pressures. Results are presented for a hard steel roller deforming mild-steel and aluminum-alloy rough surface specimens. An analysis of the local contact mechanics is performed before and after indentation using a recently developed numerical elastic contact simulation method which allows local asperity contact pressures and areas to be studied in detail. The method is shown to reveal the level and distribution of pressures and asperity contact areas prevalent during the indentation process, and therefore allows the contribution of elastic and plastic load support to be quantified. The persistence of asperities during such indentation tests is discussed in terms of the pressures the asperities can support in relation to reported mechanisms of persistence. Results of subsequent sub-surface stresses are also presented and discussed in terms of how the method might be used to create an elastic-plasticdeformation model that can account for asperity persistence in future numerical contact simulation models.

Numerical Simulation for Uplift Bearing Capacity and Affecting Factors of the Digging Piles in Slope Ground

2013 ◽  
Vol 423-426 ◽  
pp. 1292-1295 ◽  
Author(s):  
Xing Yun Wang ◽  
Bin Peng ◽  
Xiao Chao Tang ◽  
Lian Fan
Keyword(s):  
Numerical Simulation ◽  
Regression Analysis ◽  
Finite Difference ◽  
Bearing Capacity ◽  
Mutual Effect ◽  
Simulation Method ◽  
Affecting Factors ◽  
Slope Ratio ◽  
Nonlinear Regression Analysis ◽  
Numerical Simulation Method

Based on the numerical simulation method, this paper has established the numerical simulation method by using of finite difference software of FLAC3D through establishing interface for digging pile-soil. It can consider mutual effect of digging pile-soil. The uplift bearing capacity of the digging pile in slope ground was calculated and the affecting factors of the bearing capacity were analyzed. The results show that the uplift bearing capacity has a negative correlation with the slope ratio, and has a positive correlation with the width or height of the foundation, which can be expressed as a quadratic polynomial. But when the slope ratio is smaller than a certain extent, the capacity no longer increases. Nonlinear regression analysis of calculation data are carried out. Finally, the calculation method of uplift bearing capacity about pile in the slope is developed, which can provide a reference to specification revision and engineering.

Research on the Properties of Coaxality Error Objective Function

2009 ◽  
Vol 16-19 ◽  
pp. 1164-1168 ◽  
Author(s):  
Ping Liu ◽  
San Yang Liu
Keyword(s):  
Euclidean Space ◽  
Objective Function ◽  
Optimization Model ◽  
Dimensional Euclidean Space ◽  
Modern Theory ◽  
Minimal Point ◽  
Zone Method ◽  
Deviation Measurement ◽  
Minimum Zone ◽  
Theoretical Results

The unconstrained optimization model applying to radial deviation measurement is established for assessing coaxality errors by the positioned minimum zone method. The properties of the objective function in the optimization model are thoroughly researched. On the basis of the modern theory of convex functions, it is strictly proved that the objective function is a continuous and non-differentiable and convex function defined on the four-dimensional Euclidean space R4. Therefore, the global minimal value of the objective function is unique and any of its minimal point must be its global minimal point. Thus, any existing optimization algorithm, as long as it is convergent, can be used to solve the objective function to get the wanted values of coaxality errors by the positioned minimum zone assessment. An example is given to verify the theoretical results presented.

scholarly journals A Finite-Difference Simulation Method for Strongly Interacting Two-Layer Flow

1988 ◽  
Vol 1988 (163) ◽  
pp. 1-16 ◽  
Author(s):  
Hideaki Miyata ◽  
Masato Katsumata ◽  
Young-Gill Lee ◽  
Hisashi Kajitani
Keyword(s):  
Finite Difference ◽  
Simulation Method ◽  
Strongly Interacting ◽  
Layer Flow
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