• Title/Summary/Keyword: fuzzy factor method

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Remaining service life estimation of reinforced concrete buildings based on fuzzy approach

  • Cho, Hae-Chang;Lee, Deuck Hang;Ju, Hyunjin;Kim, Kang Su;Kim, Ki-Hyun;Monteiro, Paulo J.M.
    • Computers and Concrete
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    • v.15 no.6
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    • pp.879-902
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    • 2015
  • The remaining service life (RSL) of buildings has been an important issue in the field of building and facility management, and its development is also one of the essential factors for achieving sustainable infrastructure. Since the estimation of RSL of buildings is heavily affected by the subjectivity of individual inspector or engineer, much effort has been placed in the development of a rational method that can estimate the RSL of existing buildings more quantitatively using objective measurement indices. Various uncertain factors contribute to the deterioration of the structural performance of buildings, and most of the common building structures are constructed not with a single structural member but with various types of structural components (e.g., beams, slabs, and columns) in multistory floors. Most existing RSL estimation methods, however, consider only an individual factor. In this study, an estimation method for RSL of concrete buildings is presented by utilizing a fuzzy theory to consider the effects of multiple influencing factors on the deterioration of durability (e.g., concrete carbonation, chloride attack, sulfate attack), as well as the current structural condition (or damage level) of buildings.

An Improved Automated Spectral Clustering Algorithm

  • Xiaodan Lv
    • Journal of Information Processing Systems
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    • v.20 no.2
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    • pp.185-199
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    • 2024
  • In this paper, an improved automated spectral clustering (IASC) algorithm is proposed to address the limitations of the traditional spectral clustering (TSC) algorithm, particularly its inability to automatically determine the number of clusters. Firstly, a cluster number evaluation factor based on the optimal clustering principle is proposed. By iterating through different k values, the value corresponding to the largest evaluation factor was selected as the first-rank number of clusters. Secondly, the IASC algorithm adopts a density-sensitive distance to measure the similarity between the sample points. This rendered a high similarity to the data distributed in the same high-density area. Thirdly, to improve clustering accuracy, the IASC algorithm uses the cosine angle classification method instead of K-means to classify the eigenvectors. Six algorithms-K-means, fuzzy C-means, TSC, EIGENGAP, DBSCAN, and density peak-were compared with the proposed algorithm on six datasets. The results show that the IASC algorithm not only automatically determines the number of clusters but also obtains better clustering accuracy on both synthetic and UCI datasets.

Critical Success Factors of TQM Implementation in Vietnamese Supporting Industries

  • TRANG, Tran Van;DO, Quang Hung
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.391-401
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    • 2020
  • The objective of this study is to prioritize the Total Quality Management (TQM) factors based on fuzzy Analytical Hierarchy Process (AHP) method in Vietnamese supporting industries. Through an in-depth literature review, eight criteria were identified. These criteria were then divided into 32 sub-criteria. The fuzzy AHP is used to determine the percent weightings of eight categories of performance criteria that were identified via a review of the quality-management literature. These criteria include management commitment, role of the quality department, training and education, continuous improvement, quality policies, quality data and reporting, communication to improve quality, and customer satisfaction orientation. An empirical analysis of the criteria of each stage using the fuzzy AHP methodology and the expert opinion of quality management are used to evaluate the percent weightings of the criteria and sub-criteria that are synonymous with TQM implementation. The results showed that management commitment is the most critical factor; among sub-criteria, supports and responsibilities of top management is the most important. The study also identified the rank order of critical success factors of TQM. The findings suggest a generic hierarchy model for organizations to prioritize the critical factors and formulate strategies for implementing TQM in supporting industries, as well as other industries in Vietnam.

Estimation of non-working days due to weather condition using fuzzy numbers (퍼지값을 이용한 기후요소 작업불능일 산정에 관한 연구)

  • Kim, Joo-Heon;Choi, Hee-Bok;Shin, Yoon-Seok;Cho, Hun-Hee;Kang, Kyung-In
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.349-352
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    • 2008
  • Weather condition is the uncontrolled factor to influence the project duration. Determining non-working days due to it incorrectly leads to often change the project duration and increase the total cost as well as causing the dispute among stakeholders. When making decision of non-working days, it is important to consider the expert's experience according to the characteristic of the site and local area. Therefore this paper presented the method to estimate non-working days due to wether condition by using fuzzy numbers reflecting expert's subjective experience.

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Learning Method of the ADALINE Using the Fuzzy System (퍼지 시스템을 이용한 ADALINE의 학습 방식)

  • 정경권;김주웅;정성부;엄기환
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.1
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    • pp.10-18
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    • 2003
  • In this paper, we proposed a learning algorithm for the ADALINE network. The proposed algorithm exploits fuzzy system for automatic tuning of the weight parameters of the ADALINE network. The inputs of the fuzzy system are error and change of error, and the output is the weight variation. We used different scaling factor for each weights. In order to verify the effectiveness of the proposed algorithm, we peformed the simulation and experimentation for the cases of the noise cancellation and the inverted pendulum control. The results show that the proposed algorithm does not need the learning rate and improves 4he performance compared to the Widrow-Hoff delta rule for ADALINE.

The Analysis of Assessment Factors for Offshore Wind Port Site Evaluation (해상풍력 전용항만 입지선정 평가항목에 관한 연구)

  • Ko, HyunJeung
    • Journal of Korea Port Economic Association
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    • v.28 no.3
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    • pp.27-44
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    • 2012
  • The offshore wind farm is increasingly attractive as one of future energy sources all over the world. In addition, the capacity of an offshore wind turbine gets larger and its physical characteristics are big and heavy. In this regard, a special port is necessary to assemble, store, and transport the offshore wind systems, supporting to form the offshore wind farms. Thus, this study aims to provide a policy maker which evaluation factors can significantly affect to the optimal site selection of a offshore wind port. For this, Fuzzy-AHP method is applied to capture the relative weights. The results of this study can be summarized as follows. Five criteria in level I was defined such as the accumulation factor, the regional factor, the economic factor, the location factor, and the consortium factor. Of these, the accumulation factor(37.4%), the location factor(34.2%), and the economic factor( 24.5%) were analyzed by major factors. In level II, three assessment items of each factor were selected so that total fifteen items were formed. To sum up, the site selection of offshore wind port should consider the density of the wind industry, cargo volume of securing the economic operation of terminals, the development degree of offshore wind related industry, and the proximity to the offshore wind farms. In other words, the construction of offshore wind port should be paid attention to considering not only the proximity to offshore wind farms but also the preference of turbine manufacturing companies.

Stress Intensity Factor Analysis System for 3D Cracks Using Fuzzy Mesh (퍼지메쉬를 이용한 3차원 균열에 대한 응력확대계수 해석 시스템)

  • Lee, Joon-Seong;Lee, Eun-Chul;Choi, Yoon-Jong;Lee, Yang-Chang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.1
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    • pp.122-126
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    • 2008
  • Integrating a 3D solid modeler with a general purpose FEM code, an automatic stress intensity factor analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. Finally, the complete finite element(FE) model generated, and a stress analysis is performed. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.

Copula entropy and information diffusion theory-based new prediction method for high dam monitoring

  • Zheng, Dongjian;Li, Xiaoqi;Yang, Meng;Su, Huaizhi;Gu, Chongshi
    • Earthquakes and Structures
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    • v.14 no.2
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    • pp.143-153
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    • 2018
  • Correlation among different factors must be considered for selection of influencing factors in safety monitoring of high dam including positive correlation of variables. Therefore, a new factor selection method was constructed based on Copula entropy and mutual information theory, which was deduced and optimized. Considering the small sample size in high dam monitoring and distribution of daily monitoring samples, a computing method that avoids causality of structure as much as possible is needed. The two-dimensional normal information diffusion and fuzzy reasoning of pattern recognition field are based on the weight theory, which avoids complicated causes of the studying structure. Hence, it is used to dam safety monitoring field and simplified, which increases sample information appropriately. Next, a complete system integrating high dam monitoring and uncertainty prediction method was established by combining Copula entropy theory and information diffusion theory. Finally, the proposed method was applied in seepage monitoring of Nuozhadu clay core-wall rockfill dam. Its selection of influencing factors and processing of sample data were compared with different models. Results demonstrated that the proposed method increases the prediction accuracy to some extent.

On the Evaluation of Physical Distribution Service in Ports (항만물류서비스의 평가에 관하여)

    • Journal of Korean Port Research
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    • v.10 no.2
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    • pp.17-29
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    • 1996
  • It is required to consider pricing and non-pricing factors and external economy in order to achieve the objects of physical distribution system in a port. Recently, among the three factors, much attention has been paid to non-pricing factor in the system. Although physical distribution service in a port(PDSP)has been frequently mentioned in documents and literature related to port and shipping studies, few study on it has not been systematically and scientifically made due to the following problems; $\circ$ there are not proper criteria to evaluate level and quality of PDSP and as a result it is difficult to set up a unified standard for doing so. $\circ$ algorithms to evaluate problems with complex and ambiguous attributes and multiple levels in PDSP are not available. This thesis aims to establish a paradigm to evaluate PDSP and to abvance existing decision making methods to deal with complex and ambiguous problems in PDSP. To tackle the first purpose, extensive and thorough literature survey was carried out on general physical distribution service, which is a corner stone to handle PDSp. In addition, through interviews and questionnaire to the expert, it have extracted 82 factors of physical distribution service in a port. They have been classified into 6 groups by KJ method and each group defined by the expert's advice as follows; a. Potentiality b. Exactness c. safety d. Speediness e. Convenience f. Linkage Prior to the service evaluation, many kinds of its attributes must be identified on the basis of rational decision owing to complexity and ambiguity inherent in PDSP. An analytical hierarchy process (AHP) is a method to evaluate them but it is not applicable to PDSP that have property of non-additivity and overlapped attributes. Therefore, probablility measure can not be used to evaluate PDSP but fuzzy measure is required. Hierarchical fuzzy integral method, which is merged AHP with fuzzy measure, is also not effective method to evaluate attributes because it has vary complicated way to calculate fuzzy measure identification coefficient of attributes. A new evaluation algorithm has been introduced to solve problems with multi-attribute and multi-level hierarchy, which is called hierarchy fuzzy process(HFP).Analysis on ambiguous aspects of PDSP under study which is not easy to be defined is prerequisite to evaluate it. HFP is different from algorithm existed in that it clarified the relationship between fuzzy measure and probability measure adopted in AHP and that it directly calculates the family of fuzzy measure from overlapping coefficient and probability measure to treat and evaluate ambiguous and complex aspects of PDSP. A new evaluation algorithm HFP was applied to evaluate level of physical distribution service in the biggest twenty container port in the world. The ranks of the ports are as follows; 1. Rotterdam Port, 2. Hamburg Port, 3. Singapore Port, 4. Seattle Port, 5. Yokohama Port, 6. Long beach Port, 7. Oakland Port, 8. Tokyo Port, 9. Hongkong Port, 10. Kobe Port, 11. Los Angeles Port, 12. New york Port, 13. Antwerp Port, 14. Felixstowe Port, 15. Bremerhaven Port, 16. Le'Havre Port, 17. Kaoshung Port, 18. Killung Port, 19. Bangkok Port, 20. Pusan Port

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Optimal Design of Fuzzy Relation-based Fuzzy Inference Systems with Information Granulation (정보 Granules에 의한 퍼지 관계 기반 퍼지 추론 시스템의 최적 설계)

  • Park Keon-Jun;Ahn Tae-Chon;Oh Sung-kwun;Kim Hyun-Ki
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.1
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    • pp.81-86
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    • 2005
  • In this study, we introduce a new category of fuzzy inference systems based on information granulation to carry out the model identification of complex and nonlinear systems. Informally speaking, information granules are viewed as linked collections of objects (data, in particular) drawn together by the criteria of proximity, similarity, or functionality Granulation of information with the aid of Hard C-Means (HCM) clustering help determine the initial parameters of fuzzy model such as the initial apexes of the membership functions and the initial values of polynomial functions being used in the premise and consequence part of the fuzzy rules. And the initial parameters are tuned effectively with the aid of the genetic algorithms(GAs) and the least square method (LSM). An aggregate objective function with a weighting factor is also used in order to achieve a balance between performance of the fuzzy model. The proposed model is evaluated with using a numerical example and is contrasted with the performance of conventional fuzzy models in the literature.