scholarly journals Model for the Assessment of Seawater Environmental Quality Based on Multiobjective Variable Fuzzy Set Theory

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Lina Ke ◽  
Huicheng Zhou
Keyword(s):  
Set Theory ◽  
Environmental Quality ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Quality Evaluation ◽  
Quality Data ◽  
Water Quality Data ◽  
Seawater Quality ◽  
Variable Fuzzy Set ◽  
The Impact

With the rapid development of marine economy industry, the activities for exploring and exploiting the marine resources are increasing, and there are more and more marine construction projects, which contribute to the growing trend of eutrophication and frequent occurrence of red tide. Thus, seawater quality has become the topic which the people generally cared about. The seawater quality evaluation could be considered as an analysis process which combined the evaluation indexes with certainty and evaluation factors with uncertainty and its changes. This paper built a model for the assessment of seawater environmental quality based on the multiobjective variable fuzzy set theory (VFEM). The Qingdao marine dumping site in China is taken as an evaluation example. Through the quantitative research of water-quality data from 2004 to 2008, the model is more reliable than other traditional methods, in which uncertainty and ambiguity of the seawater quality evaluation are considered, and trade the stable results as the final results of seawater quality evaluation, which effectively solved the impact of the fuzzy boundary of evaluation standard and monitoring error, is more suitable for evaluation of a multi-index, multilevel, and nonlinear marine environment system and has been proved to be an effective tool for seawater quality evaluation.

scholarly journals Identification and Location of a Transitional Zone between an Urban and a Rural Area Using Fuzzy Set Theory, CLC, and HRL Data

2019 ◽  
Vol 11 (24) ◽  
pp. 7014 ◽  
Author(s):  
Andrzej Biłozor ◽  
Szymon Czyża ◽  
Tomasz Bajerowski
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Rural Area ◽  
Set Theory ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Transitional Zone ◽  
City Centre ◽  
The Impact ◽  
The City

Changes in land use, which accompany the development of towns, generate a transitional zone on the border between areas of urban and rural use, which—due to its complex (unspecified, fuzzy) land use—cannot be identified either as a rural or an urban area. In order to prevent the unplanned development, it should go according to plan, in line with the spatial order principles, making a coherent whole, taking into account all functional, socio-economic, cultural, as well as aesthetic factors and requirements. This paper describes studies and analyses of the fuzzy set theory applicability in studies of land use in areas around towns. The main aim of the study was to present the methodology, which employs fuzzy logic to identify and locate a transitional zone between rural and urban areas. This study dealt with the transitional zone at the junction of the urban and rural area and its parameters, which affect the type of land use. The attributes of the transitional zone were defined based on an analysis of current land use methods in areas under direct urbanisation pressure. The study was conducted in the city of Olsztyn (Poland) and on its outskirts, directly exposed to the impact of the developing city, with an area of 202.4 km2, within an 8-km radius of the city centre. The study determined the impact of individual forms of land use on the development of urban or rural use. The degree of each type of use—urban or rural—allowed for developing a fuzzy town and country model, identifying the urban investment border and its spatial dispersion, as well as identifying and locating the transitional zone between urban and rural areas. Moreover, land cover models based on the Corine land cover (CLC) data as well as high-resolution layers (HRL) impervious and canopy data were developed. The borders of urban investment determined on the basis of the fuzzy set theory assumptions, CLC, and HRL data were also identified and verified.

scholarly journals Application of two-stage fuzzy set theory to river quality evaluation in Taiwan

2003 ◽  
Vol 37 (6) ◽  
pp. 1406-1416 ◽  
Author(s):  
Shiow-Mey Liou ◽  
Shang-Lien Lo ◽  
Ching-Yao Hu
Keyword(s):  
Set Theory ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Quality Evaluation ◽  
Two Stage ◽  
River Quality

scholarly journals Reliability Analysis of the Engineering Systems Using Intuitionistic Fuzzy Set Theory

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Harish Garg ◽  
Monica Rani ◽  
S. P. Sharma
Keyword(s):  
Reliability Analysis ◽  
Set Theory ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Intuitionistic Fuzzy Set ◽  
Paper Mill ◽  
Intuitionistic Fuzzy ◽  
Reliability Parameters ◽  
Degree Of Acceptance ◽  
The Impact

The present paper investigates the reliability analysis of industrial systems by using vague lambda-tau methodology in which information related to system components is uncertain and imprecise in nature. The uncertainties in the data are handled with the help of intuitionistic fuzzy set (IFS) theory rather than fuzzy set theory. Various reliability parameters are addressed for strengthening the analysis in terms of degree of acceptance and rejection of IFS. Performance as well as sensitivity analysis of the system parameter has been investigated for accessing the impact of taking wrong combinations on its performance. Finally results are compared with the existing traditional crisp and fuzzy methodologies results. The technique has been demonstrated through a case study of bleaching unit of a paper mill.

scholarly journals A Novel Method in Surface Water Quality Assessment Based on Improved Variable Fuzzy Set Pair Analysis

2019 ◽  
Vol 16 (22) ◽  
pp. 4314 ◽  
Author(s):  
Yucheng Liu ◽  
Chuansheng Wang ◽  
Yutong Chun ◽  
Luxin Yang ◽  
Wei Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Surface Water ◽  
Fuzzy Set ◽  
Surface Water Quality ◽  
Quality Data ◽  
Set Pair Analysis ◽  
Water Quality Data ◽  
Variable Fuzzy Set ◽  
Pair Analysis

In the case of surface water pollution, it is important and necessary to accurately assess the level of contaminated water and ensure the safety of drinking water for people in disaster areas during floods. However, for the assessment of the strict requirements of drinking water, traditional assessment methods still have some limitations, such as low precision and rationality. In order to overcome these limitations, in the light of the theory of set pair analysis and variable fuzzy set, we propose an improved variable fuzzy set pair analysis method (IVFSPA), which combines the analysis framework of variable fuzzy set and set pair analysis, and has made some improvements to the fusion architecture. Firstly, we present a novel game theory comprehensive weighting method, in which the objective entropy method and the subjective analytic hierarchy process(AHP) method employed to obtain the reasonable weight. Then, based on the Nemerow index method, we improve the arithmetic form of “ P i ” (Equation P) to replace the fuzzy comprehensive evaluation method. Furthermore, we design a double judgment mode of combining the principle of maximum membership degree with the positive and negative relationship between the standard value and the measured value, which can accurately judge the evaluation level of surface water quality. Finally, to validate and verify the effectiveness of the proposed method, experiments was conducted at the representative river collection sections of Nanking, China, employing water quality data of 14 sampling sections in their rivers in Nanking during the 2017 flood. In terms of performance metcrics of precision and rationality, based on the values of “TP”, “NH3-N”, “Pb”, “AS” and “KMnO4” of “Ch-lh section/Chuhe gate” are 0.415, 3.77, 0.07, 0.23 and 7.12, respectively, the level of Ch-lh section/Chuhe gate is that the IVFSPA is Class V and the rest are class IV. Results of experiments show that our IVFSPA method can achieve a good performance, compared with other traditional methods.

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