• Title/Summary/Keyword: grey model

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Evaluating Service Reliability focused on Failure Modes (실패모드에 근거한 서비스 신뢰도 평가모델)

  • Oh, Hyung-Sool
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.3
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    • pp.133-141
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    • 2012
  • Service and manufacturing companies' efforts are increasingly focused on utilizing services to satisfy customers' needs and survive in today's competitive market environment. The value of services depends mainly on service reliability that is identified by satisfaction derived from the relationship between customer and service provider. In this paper, we extend concepts from the failure modes and effects analysis of tangible systems to services. We use an event-based process model to facilitate service design and represent the relationships between functions and failures in a service. The objective of this research is to propose a method for evaluating service reliability based on service processes using fuzzy failure mode effects analysis (FMEA) and grey theory. We define the failure mode of service as interaction ways that can be failed in a service delivery process. The fuzzy set theory is used to characterize service reliability based on linguistic terms during FMEA. Grey theory is employed to determine the degree of relation and ranking among risk factors that are represented as potential failure causes. To demonstrate implementation of the proposed method, we use a case study involving a typical automotive service operation.

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Experimental and AI based FEM simulations for composite material in tested specimens of steel tube

  • Yahui Meng;Huakun Wu;ZY Chen;Timothy Chen
    • Steel and Composite Structures
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    • v.52 no.4
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    • pp.475-485
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    • 2024
  • The mechanical behavior of the steel tube encased high-strength concrete (STHC) composite walls under constant axial load and cyclically increasing lateral load was studied. Conclusions are drawn based on experimental observations, grey evolutionary algorithm and finite element (FE) simulations. The use of steel tube wall panels improved the load capacity and ductility of the specimens. STHC composite walls withstand more load cycles and show more stable hysteresis performance than conventional high strength concrete (HSC) walls. After the maximum load, the bearing capacity of the STHC composite wall was gradually reduced, and the wall did not collapse under the influence of the steel pipe. For analysis of the bending capacity of STHC composite walls based on artificial intelligence tools, an analysis model is proposed that takes into account the limiting effect of steel pipes. The results of this model agree well with the test results, indicating that the model can be used to predict the bearing capacity of STHC composite walls. Based on a reasonable material constitutive model and the limiting effect of steel pipes, a finite element model of the STHC composite wall was created. The finite elements agree well with the experimental results in terms of hysteresis curve, load-deformation curve and peak load.

An Optimization for Flow Control Butterfly Valve using Grey Relational Analysis (회색 관계 분석을 이용한 유량 제어용 버터플라이밸브 형상 최적화)

  • Lee, Sang Beom;Lee, Dong Myung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.6
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    • pp.359-366
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    • 2014
  • This paper considered optimization method of appending a shape on a disc in an attempt to improve core functions, which are inherent in flow characteristics. The paper also verifies the optimization method of appendage shape with a Class 150 200A Butterfly valve. Then the design of experiment (DOE) with an orthogonal array is performed to analyze the effect of form parameters by grey relational analysis and analysis of mean (ANOM). And this study sets flow coefficient as an object functions for optimization, and the conventional disc model and the optimal appendage shape on disc model are compared by computational fluid analysis. The paper concludes that an optimal appendage shape on disc model achieves wider usability by a wider operating range.

Influence of Appearance Decoration on Women's Professional Image (외모 장식이 여성의 전문직 이미지에 미치는 영향)

  • Lee, Myoung-Hee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.14 no.4
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    • pp.1-16
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    • 2012
  • This study examines the influence of women's appearance decoration on professional image, preference evaluation, and inferences about age and job. For the purpose of this study, women's appearance decoration was limited to eyeglasses, earrings, hair length, and clothing color. A quasi-experimental method was used for this study. The experimental design was a $3{\times}2{\times}2{\times}4$ (eyeglasses${\times}$earrings${\times}$hair length${\times}$clothing color) factorial design. The model of stimulus photographs was a woman in her late twenties. She wore a tailored collared jacket with a white dress shirt. The subjects were 362 female college students residing in Seoul. The results of the research were as follows. First, the woman wearing glasses and earrings was perceived as more professional than the woman without glasses and earrings. The woman with short hair was evaluated to be more professional than the woman with long hair. Light grey and dark grey jackets enhanced a professional image in the woman than red and dark red jackets. The woman without glasses was preferred more than the woman wearing glasses, and the woman wearing earrings was preferred more than the woman without earrings. Second, the woman wearing wire-rimmed glasses, earrings, and grey jacket with short hair was perceived to have the highest level of professionalism. Third, the subjects perceived the woman wearing wire-rimmed glasses as looking the oldest and the woman without glasses as looking young. The subjects perceived the woman with short hair as looking younger by 3 to 4 years than the woman with long hair. Fourth, the subjects frequently considered the woman wearing the wire-rimmed glasses, the woman with short hair, and the woman wearing the grey jacket as having a professional job.

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A Comparative Study of Estimation by Analogy using Data Mining Techniques

  • Nagpal, Geeta;Uddin, Moin;Kaur, Arvinder
    • Journal of Information Processing Systems
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    • v.8 no.4
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    • pp.621-652
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    • 2012
  • Software Estimations provide an inclusive set of directives for software project developers, project managers, and the management in order to produce more realistic estimates based on deficient, uncertain, and noisy data. A range of estimation models are being explored in the industry, as well as in academia, for research purposes but choosing the best model is quite intricate. Estimation by Analogy (EbA) is a form of case based reasoning, which uses fuzzy logic, grey system theory or machine-learning techniques, etc. for optimization. This research compares the estimation accuracy of some conventional data mining models with a hybrid model. Different data mining models are under consideration, including linear regression models like the ordinary least square and ridge regression, and nonlinear models like neural networks, support vector machines, and multivariate adaptive regression splines, etc. A precise and comprehensible predictive model based on the integration of GRA and regression has been introduced and compared. Empirical results have shown that regression when used with GRA gives outstanding results; indicating that the methodology has great potential and can be used as a candidate approach for software effort estimation.

Use of multi-hybrid machine learning and deep artificial intelligence in the prediction of compressive strength of concrete containing admixtures

  • Jian, Guo;Wen, Sun;Wei, Li
    • Advances in concrete construction
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    • v.13 no.1
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    • pp.11-23
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    • 2022
  • Conventional concrete needs some improvement in the mechanical properties, which can be obtained by different admixtures. However, making concrete samples costume always time and money. In this paper, different types of hybrid algorithms are applied to develop predictive models for forecasting compressive strength (CS) of concretes containing metakaolin (MK) and fly ash (FA). In this regard, three different algorithms have been used, namely multilayer perceptron (MLP), radial basis function (RBF), and support vector machine (SVR), to predict CS of concretes by considering most influencers input variables. These algorithms integrated with the grey wolf optimization (GWO) algorithm to increase the model's accuracy in predicting (GWMLP, GWRBF, and GWSVR). The proposed MLP models were implemented and evaluated in three different layers, wherein each layer, GWO, fitted the best neuron number of the hidden layer. Correspondingly, the key parameters of the SVR model are identified using the GWO method. Also, the optimization algorithm determines the hidden neurons' number and the spread value to set the RBF structure. The results show that the developed models all provide accurate predictions of the CS of concrete incorporating MK and FA with R2 larger than 0.9972 and 0.9976 in the learning and testing stage, respectively. Regarding GWMLP models, the GWMLP1 model outperforms other GWMLP networks. All in all, GWSVR has the worst performance with the lowest indices, while the highest score belongs to GWRBF.

An Evaluation of Accidents Risk for Cargo Handling Workers in Korean Ports Using the Grey Relational Analysis & Entropy Method (회색관계분석 및 엔트로피법을 이용한 항만하역근로자의 재해위험성 평가)

  • Jang, Woon-Jae
    • Journal of Navigation and Port Research
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    • v.44 no.4
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    • pp.291-297
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    • 2020
  • In recent years, an increase in deaths and injuries of port cargo handling workers, has raised the need for more effective accident management. The purpose of this study was to evaluate the accident risk for port cargo handling workers and assess ports with high accident risk within the Korean alternative ports using the Entropy & GRA (Grey Relational Analysis). To achieve this purpose, first, 11 Korean ports were selected and the evaluative factors for their outranking evaluation by brainstorming were extracted. Second, the Grey Relational Coefficient of 11 alternative ports was calculated using the GRA. This paper, finally, determined the priority orders of accident risk through calculation of the Grey Relational Grade as the link Grey Relational Coefficient method and the weights of the evaluative factors were calculated by using the Entropy method. In the proposed model, eight criteria such as cargo worker, old cargo worker, work hours, facilities environment, steel cargo volumes, cargo volumes, injury numbers, and death numbers were collected. Busan port was identified as highest accident risk port, and so it should be a top priority to develop a plan to mitigate the risk.

Assessing the Impact of Advanced Technologies on Utilization Improvement of Substations

  • Han, Dong;Yan, Zheng;Zhang, Dao-Tian;Song, Yi-Qun
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.1921-1929
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    • 2015
  • The smart substation is the heart of a transmission system, which is particularly emphasized as the most significant composition of smart grids in China. In order to assess the functionality performance of substation technologies, this paper presents methods used to identify the most promising solutions for smart substation design and to evaluate the technical levels of available technologies. The multi-index optimization model is presented to address the issue of smart substation planning. A mathematical model of the planning decision problem is established with multiple objectives consisting of economic, reliability, and green key indices, and many kinds of concerns including physical and environmentally friendly operations are formulated as a set of constraints. With respect to the assessment of the technical level regarding integration of advanced technologies into a substation, a modified grey whitenization weight function is adopted to structure a novel grey clustering method. The proposed grey clustering approach is used to overcome the difficulty of insufficient quantitative assessment capacity for traditional methods. The evaluation of technical effects provides the classification definition for the development phase and the maturity level of the smart substation. The effectiveness of the proposed approaches in planning decision-making and evaluation of construction efforts is demonstrated with case studies involving the actual smart substation projects of Wenchongkou substation in China Southern Power Grid (CSG) and Mengzi substation in State Grid Corporation of China (SGCC).

Separation of Concerns Security Model of Component using Grey Box (그레이박스를 사용한 컴포넌트의 관심사 분리 보안 모델)

  • Kim, Young-Soo;Jo, Sun-Goo
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.5
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    • pp.163-170
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    • 2008
  • As the degree of dependency and application of component increases, the need to strengthen security of component is also increased as well. The component gives an advantage to improve development productivity through its reusable software. Even with this advantage, vulnerability of component security limits its reuse. When the security level of a component is raised in order to improve this problem, the most problematic issue will be that it may extend its limitation on reusability. Therefore, a component model concerning its reusability and security at the same time should be supplied. We suggest a Separation of Concerns Security Model for Extension of Component Reuse which is integrated with a wrapper model and an aspect model and combined with a reuse model in order to extend its security and reusability by supplying information hiding and easy modification, and an appropriate application system to verify the model's compatibility is even constructed. This application model gives the extension of component function and easy modification through the separation of conceits, and it raise its security as doll as extends its reusability.

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The Analysis of Information Transfer Efficiency in Medical Image Display

  • Kim, Jong-Hyo;Min, Byoung-Goo;Han, Man-Cheong;Lee, Choong-Woong
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.55-57
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    • 1992
  • Image display is the last step of imaging chain in which the diagnostic information is transformed into perceivable intensities and transformed to observer's eye-brain system. In this process, a certain part of information may be efficiently transfered and another part may be inefficiently transfered leading to information loss. In this study, the visual perceptual properties of image display on CRT monitor has been investigated. Psychophysical experiment of target image detection has been performed using CRT monitor for various background grey levels, and the threshold difference grey levels required for visual discrimination have been predicted by computer simulation with visual model.

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