scholarly journals Research on Fuzzy Plastic Constitutive Model Based on Membership Function

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xigang Wang ◽  
Liling Jin ◽  
Mingfu Fu
Keyword(s):  
Stress State ◽  
Cyclic Loading ◽  
Yield Point ◽  
Membership Function ◽  
Yield Function ◽  
Loading Path ◽  
Fuzzy Mathematics ◽  
Model Based ◽  
Plastic Yield ◽  
The Membership Function

Soil has no obvious yield point, and the classical elastoplastic theory contradicts the uncertainty of the plastic yield point of the soil. Therefore, a fuzzy plastic Cambridge model based on the membership function was designed by combining the fuzzy mathematics with the Cambridge model. This model made the plastic membership function to correspond with the fuzzy yield function. The plastic strain at any stress state was calculated using the fuzzy Cambridge model and was compared with the indoor triaxial test results, and they were in good agreement. Therefore, it is appropriate to use fuzzy mathematics to express the unobvious soil yield property. The characteristics of soil yield in any stress state is reflected by the fuzzy plastic theory, which indicates that there is entirely no elasticity at any stress state. Moreover, the varying degrees of plasticity and the degree of plastic yield were uniquely determined by the plastic membership function. The fuzzy plastic model used the membership function change to replace the complex hardening. Additionally, the cyclic loading path was clear and appropriate for the cyclic loading and unloading calculations.

Applying of Electrical Imaging Survey (EIS) to Evaluate Leachate Pollution in Underground Area of Informal Landfill

2014 ◽  
Vol 878 ◽  
pp. 739-745
Author(s):  
Song Du ◽  
Di Wang ◽  
Zi Shen Mou ◽  
Jing Jin ◽  
Rui Jiang Zhao ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Membership Function ◽  
Fuzzy Mathematics ◽  
Sanitary Landfill ◽  
Specific Resistivity ◽  
Borehole Data ◽  
Electrical Imaging ◽  
The Membership Function

An informal landfill is an open dump that pollutes the underground environment because it lacks an impervious liner. The leakage of such a landfill is unidirectional and thus difficult to directly test. This study uses electrical imaging survey to evaluate the pollution of the underground environment of an informal landfill for municipal solid waste in Beijing. We hypothesize that every location has a specific resistivity resulting from the leachate. We use the membership function of fuzzy mathematics to quantitatively represent the pollution of the underground environment in the sanitary landfill. The results are consistent with borehole data.

scholarly journals A Cultural and Functional Approach to the Assessment of Logical Thinking Ability in English Writing

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Cao Juan
Keyword(s):  
Influencing Factors ◽  
Membership Function ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Fuzzy Mathematics ◽  
Logical Thinking ◽  
English Writing ◽  
Thinking Ability ◽  
And Function ◽  
The Membership Function

The analysis of influencing factors of logical thinking ability in English writing is the key effective factor of evaluating logical thinking ability in English writing. In order to accurately evaluate logical thinking ability in English writing, this paper studies the evaluation method of logical thinking ability in English writing from the perspective of culture and function. This paper analyzes the relationship between the influencing factors of logical thinking ability in English writing. The factors of text structure and language expression reflect the culture and function of logical thinking ability in English writing, respectively, which have a direct impact on logical thinking ability in English writing. From these two aspects, 15 evaluation indexes are selected to construct the evaluation system of logical thinking ability in English writing. Considering the significant fuzziness of logical thinking ability in English writing from the perspective of culture and function, the comprehensive evaluation method of fuzzy mathematics is used for the process, the evaluation criteria are determined, the evaluation matrix is constructed, and the membership function is calculated, to complete the comprehensive evaluation of fuzzy mathematics based on the membership function and weight matrix. The experimental results show that this method can accurately evaluate the logical thinking ability of English writing and can be effectively used in the area of research.

Fuzzy Comprehensive Analysis and Assessment about Slope Stability Based on the Mutation Theory

2011 ◽  
Vol 243-249 ◽  
pp. 2647-2652
Author(s):  
Wen Fang Liu ◽  
Hong Mei Li ◽  
Bei Ping Tian
Keyword(s):  
Slope Stability ◽  
Membership Function ◽  
Recursion Formula ◽  
Comprehensive Analysis ◽  
Fuzzy Mathematics ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
Mutation Theory ◽  
Multi Level ◽  
The Membership Function

This article will use the mutation theory with qualitative and quantitative analysis, and utilizes the membership function of fuzzy mathematics, then decomposes the slope stability assessment to multi-level objectives, and then carries on quantification recursion computation according to recursion formula. As a result, we can figure out the total mutation membership function value of the slope stability according to the different factors of the slope, finally we can carry on tne fuzzy comprehensive analysis and assessment about slope stability.

Integrated Evaluation on Soil Nutrients in Spring Maize (Zea mays) Field Subjected to Limited Irrigation

2013 ◽  
Vol 389 ◽  
pp. 67-72
Author(s):  
Heng Jia Zhang ◽  
Jun Hui Li
Keyword(s):  
Soil Nutrients ◽  
Irrigation Management ◽  
Soil Nutrient ◽  
Fuzzy Mathematics ◽  
Available Nitrogen ◽  
Maize Field ◽  
Spring Maize ◽  
Significant Difference ◽  
One Year ◽  
The Membership Function

An experiment was conducted to explore the integrated evaluation on soil nutrients in spring maize field subjected to limited irrigation (LI) in oasis region. The soil organic matter (SOM), soil total and available nitrogen (STN and SAN) and phosphorus (STP and SAP), and soil available potassium (SAK) in 0~40 cm increment at harvest of maize subjected to LI were selected as the evaluation factors to calculate the weighing coefficient of each soil nutrient and the IEI for soil nutrients using the membership function in fuzzy mathematics. At maize harvest, differences were not significant (p>0.05) in SOM, STN, STP, SAP, and SAK within 0~40 cm increment among treatments and CK, but significant difference (p<0.05) was found in SAN, with the maximum SAN maintained in MI5, which was respectively 187.3%, 96.8%, and 41.2% higher over MI2 valued the minimum, MI1, and CK. The IEI was improved by 12.4% to 22.3% in all the other treatments and CK compared to the minimum marked in MI4, with the maximum valued in MI3 treatments. Therefore, after one year experiment, the optimized irrigation management was maintained in MI3 treatment due to its maximum IEI in all the LI regimes.

Possibility-Based Design Optimization Method for Design Problems With Both Statistical and Fuzzy Input Data

2005 ◽  
Vol 128 (4) ◽  
pp. 928-935 ◽  
Author(s):  
Liu Du ◽  
K. K. Choi ◽  
Byeng D. Youn ◽  
David Gorsich
Keyword(s):  
Design Optimization ◽  
Optimum Design ◽  
Membership Function ◽  
Input Data ◽  
Performance Measure ◽  
Sufficient Data ◽  
Design Problems ◽  
Fuzzy Variables ◽  
Fuzzy Input ◽  
The Membership Function

The reliability based design optimization (RBDO) method is prevailing in stochastic structural design optimization by assuming the amount of input data is sufficient enough to create accurate input statistical distribution. If the sufficient input data cannot be generated due to limitations in technical and/or facility resources, the possibility-based design optimization (PBDO) method can be used to obtain reliable designs by utilizing membership functions for epistemic uncertainties. For RBDO, the performance measure approach (PMA) is well established and accepted by many investigators. It is found that the same PMA is a very much desirable approach also for the PBDO problems. In many industry design problems, we have to deal with uncertainties with sufficient data and uncertainties with insufficient data simultaneously. For these design problems, it is not desirable to use RBDO since it could lead to an unreliable optimum design. This paper proposes to use PBDO for design optimization for such problems. In order to treat uncertainties as fuzzy variables, several methods for membership function generation are proposed. As less detailed information is available for the input data, the membership function that provides more conservative optimum design should be selected. For uncertainties with sufficient data, the membership function that yields the least conservative optimum design is proposed by using the possibility-probability consistency theory and the least conservative condition. The proposed approach for design problems with mixed type input uncertainties is applied to some example problems to demonstrate feasibility of the approach. It is shown that the proposed approach provides conservative optimum design.

scholarly journals Controllable Effective Threshold Based Fusion Coverage Algorithm in Mobile Sensor Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Lu ◽  
Na Sun
Keyword(s):  
Sensor Networks ◽  
Membership Function ◽  
Network Lifetime ◽  
Physical Parameters ◽  
Network Coverage ◽  
Target Node ◽  
Effective Threshold ◽  
Coverage Quality ◽  
Monitoring Area ◽  
The Membership Function

The coverage quality and network lifetime are two key parameters in the research of sensor networks. The coverage quality shows direct influences on the network lifetime. Meanwhile, it is influenced by many other factors such as physical parameters and environmental parameters. To reveal the connection between the coverage quality and the parameters of target node concerned, a fusion coverage algorithm with controllable effective threshold is proposed based on the sensing probability model. We give the model for the membership function of coverage intensity as well as the prediction model for the fusion operator. The range for the effective threshold is presented according to the membership function model. Meanwhile, the maximum of the effective coverage intensity for the target nodes within the monitoring area is derived. The derivation of the maximal fusion coverage intensity is elaborated utilizing a processing function on the distances from the target node to the ones in the sensor node set. Furthermore, we investigate different network properties within the monitoring area such as network coverage quality, the dynamic change of parameters, and the network lifetime, based on the probability theory and the geometric theory. Finally, we present numerical simulations to verify the performances of our algorithm. It is shown under different settings that, compared with the demand coverage quality, the proposed algorithm could improve the network coverage quality by 15.66% on average. The simulation experiment results show that our proposed algorithm has an average improvement by 10.12% and 13.23% in terms of the performances on network coverage quality and network lifetime, respectively. The research results are enlightening to the edge coverage and nonlinear coverage problems within the monitoring area.

scholarly journals Undrained Pore Pressure Development on Cohesive Soil in Triaxial Cyclic Loading

2019 ◽  
Vol 9 (18) ◽  
pp. 3821 ◽  
Author(s):  
Andrzej Głuchowski ◽  
Emil Soból ◽  
Alojzy Szymański ◽  
Wojciech Sas
Keyword(s):  
Stress State ◽  
Cyclic Loading ◽  
Pore Pressure ◽  
Cohesive Soil ◽  
Soil Samples ◽  
Test Results ◽  
Soil Behavior ◽  
Pressure Development ◽  
Undrained Conditions ◽  
Excess Pore

Cohesive soils subjected to cyclic loading in undrained conditions respond with pore pressure generation and plastic strain accumulation. The article focus on the pore pressure development of soils tested in isotropic and anisotropic consolidation conditions. Due to the consolidation differences, soil response to cyclic loading is also different. Analysis of the cyclic triaxial test results in terms of pore pressure development produces some indication of the relevant mechanisms at the particulate level. Test results show that the greater susceptibility to accumulate the plastic strain of cohesive soil during cyclic loading is connected with the pore pressure generation pattern. The value of excess pore pressure required to soil sample failure differs as a consequence of different consolidation pressure and anisotropic stress state. Effective stresses and pore pressures are the main factors that govern the soil behavior in undrained conditions. Therefore, the pore pressure generated in the first few cycles plays a key role in the accumulation of plastic strains and constitutes the major amount of excess pore water pressure. Soil samples consolidated in the anisotropic and isotropic stress state behave differently responding differently to cyclic loading. This difference may impact on test results analysis and hence may change the view on soil behavior. The results of tests on isotropically and anisotropically consolidated soil samples are discussed in this paper in order to point out the main features of the cohesive soil behavior.

FUZZY CLUSTERING OF FEATURE VECTORS WITH SOME ORDINAL VALUED ATTRIBUTES USING GRADIENT DESCENT FOR LEARNING

2008 ◽  
Vol 16 (02) ◽  
pp. 195-218
Author(s):  
ROELOF K. BROUWER
Keyword(s):  
Objective Function ◽  
Membership Function ◽  
Fuzzy Clustering ◽  
Gradient Descent ◽  
Ratio Scale ◽  
Interval Scale ◽  
Real Numbers ◽  
Fuzzy C Means Clustering ◽  
Feature Values ◽  
The Membership Function

There are well established methods for fuzzy clustering especially for the cases where the feature values are numerical of ratio or interval scale. Not so well established are methods to be applied when the feature values are ordinal or nominal. In that case there is no one best method it seems. This paper discusses a method where unknown numeric variables are assigned to the ordinal values. Part of minimizing an objective function for the clustering is to find numeric values for these variables. Thus real numbers of interval scale and even ratio scale for that matter are assigned to the original ordinal values. The method uses the same objective function as used in fuzzy c-means clustering but both the membership function and the ordinal to real mapping are determined by gradient descent. Since the ordinal to real mapping is not known it cannot be verified for its legitimacy. However the ordinal to real mapping that is found is best in terms of the clustering produced. Simulations show the method to be quite effective.

An Analytical Solution to Metal Plane Problem in Terms of Orthotropic Anisotropy and Strain Hardening

2010 ◽  
Vol 97-101 ◽  
pp. 348-356
Author(s):  
Yao He Liu ◽  
Guo Feng Yi ◽  
Jian Ming Xiong
Keyword(s):  
Stress State ◽  
Analytical Solution ◽  
Plane Stress ◽  
Yield Criterion ◽  
Research Result ◽  
Yield Condition ◽  
Plane Stress State ◽  
Yield Function ◽  
Anisotropic Parameter ◽  
Symmetric Plane

In this paper, the yield condition of Hill’s orthotropic yield criterion under axial symmetric plane stress state was discussed. The yield function of orthotropic material was proposed and the analytical solution to meet the condition of equations of equilibrium and compatibility under axial symmetric plane stress state is obtained, in which the conditions of power hardening materials was considered. The research result indicates that hardening coefficient and anisotropic parameter have substantial influence over stress and strain. However, in the presence of the coefficient R90=H/F，the influence appears to be quite weak.

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