• 제목/요약/키워드: Wu model

검색결과 830건 처리시간 0.02초

수정된 Wu와 Clements-Croome의 예방보전 모형 (Modified Wu and Clements-Croome's PM model)

  • 정기문
    • Journal of the Korean Data and Information Science Society
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    • 제25권4호
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    • pp.791-798
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    • 2014
  • Wu와 Clements-Croome (2005)은 확률적 보전효과를 갖는 예방보전 모형을 제안하였는데, 그들은 각각의 예방보전 활동이 이루어진 이후에 시스템의 상태가 고장률 측면에서 새로운 것처럼 되고, 이전보다 더 급격하게 증가하는 고장률을 갖는다고 가정하였다. 그러나 예방보전 활동 이후의 시스템의 상태가 새로운 것처럼 된다는 것은 현실적으로 매우 강한 가정이라고 할 수 있다. 따라서 본 논문에서는 수정된 Wu와 Clements-Croome의 예방보전 모형을 제안하고 최적의 예방보전정책을 제시하고자 한다. 또한, 최적의 예방보전정책을 결정하기 위해서 제안된 모형에 대한 단위시간당 기대비용을 사용하였다, 즉, 단위시간당 기대비용을 최소화하는 최적의 예방보전 횟수와 주기를 결정하였다. 끝으로 수치적 예를 통해서 제안된 예방보전정책을 설명하였다.

Mechanical properties of steel-CFRP composite specimen under uniaxial tension

  • Uriayer, Faris A.;Alam, Mehtab
    • Steel and Composite Structures
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    • 제15권6호
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    • pp.659-677
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    • 2013
  • This paper introduces new specimens of Steel-Carbon Fibre Reinforced Polymer composite developed in accordance with standard test method and definition for mechanical testing of steel (ASTM-A370). The main purpose of this research is to study the behaviour of steel-CFRP composite specimen under uniaxial tension to use it in beams in lieu of traditional steel bar reinforcement. Eighteen specimens were prepared and divided into six groups, depending upon the number of the layers of CFRP. Uniaxial tensile tests were conducted to determine yield strength and ultimate strength of specimens. Test results showed that the stress-strain curve of the composite specimen was bilinear prior to the fracture of CFRP laminate. The tested composite specimens displayed a large difference in strength with remarkable ductility. The ultimate load for Steel-Carbon Fibre Reinforced Polymer composite specimens was found using the model proposed by Wu et al. (2010) and nonlinear FE analysis. The ultimate loads obtained from FE analysis are found to be in good agreement with experimental ones. However, ultimate loads obtained applying Wu model are significantly different from experimental/FE ones. This suggested modification of Wu model. Modified Wu's model which gives a better estimate for the ultimate load of Steel-Carbon Fibre Reinforced Polymer (SCFRP) composite specimen is presented in this paper.

Association Between the c.3751G>A Genetic Variant of MDR1 and Hepatocellular Carcinoma Risk in a Chinese Han Population

  • Li, Xiao-Fei;He, Hua-Bin;Zhu, Yan-Shuang;He, Jin-Ke;Ye, Wei-Wei;Chen, Yong-Xin;Lou, Lian-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.5361-5365
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    • 2013
  • The objective of this study was to evaluate the influence of a genetic variant in the multidrug resistance 1 gene (MDR1) on hepatocellular carcinoma (HCC) risk. This case-control study was conducted in a Chinese population of 645 HCC cases and 658 cancer-free controls. The genotype of the c.3751G>A genetic variant in the MDR1 gene was investigated by created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Our data demonstrated significantly differences detected in the allelic and genotypic frequencies between HCC cases and those of cancer-free controls. Association analyses indicated that there were statistically increased risk of HCC in the homozygote comparison (AA versus (vs.) GG: OR=2.22, 95% CI 1.51-3.27, ${\chi}^2$=16.90, P<0.001), dominant model (AA/GA vs. GG: OR=1.25, 95% CI 1.00-1.55, ${\chi}^2$=3.98, P=0.046), recessive model (AA vs. GA/GG: OR=2.14, 95% CI 1.47-3.09, ${\chi}^2$=16.68, P<0.001) and allele comparison (A vs. G: OR=1.33, 95% CI 1.13-1.57, ${\chi}^2$=11.66, P=0.001). The allele-A and genotype-AA may contribute to HCC susceptibility. These preliminary findings suggest that the c.3751G>A genetic variant in the MDR1 gene is potentially related to HCC susceptibility in a Chinese Han population, and might be used as a molecular marker for evaluating HCC susceptibility.

가상 공작기계의 연구 개발 - Part 2 (동절삭력 모델, 열적 거동 모델, 이송계 모델 및 통합 소프트웨어) (Development of a Virtual Machine Tool - Part 2 (Dynamic Cutting Force Model, Thermal Behavior Model, Feed Drive Model and Comprehensive Software Environment))

  • 고정훈;윤원수;강석재;조동우;안경기;윤승현
    • 한국정밀공학회지
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    • 제18권11호
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    • pp.80-85
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    • 2001
  • In Part 2, dynamic cutting force model, thermal behavior model, and feed drive model are presented for development of a virtual machine tool. Some relevant results with brief descriptions for each model are presented to verify the proposed models. Experimental results for each model agreed well with the estimated ones. The developed models in this two-part paper are partially integrated as a comprehensive software environment.

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Development of a Virtual Machine Tool - Part 2: Dynamic Cutting Force Model, Thermal Behavior Model, Feed Drive System Model, and Comprehensive Software Environment

  • Ko, Jeong-Hoon;Yun, Won-Soo;Kang, Seok-Jae;Cho, Dong-Woo;Ahn, Kyung-Gee;Yun, Seung-Hyun
    • International Journal of Precision Engineering and Manufacturing
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    • 제4권3호
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    • pp.42-47
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    • 2003
  • In Part 2 of this paper, the dynamic cutting force model, thermal behavior model, and feed drive model used in the development of a virtual machine tool (VMT) are briefly described. Some results are presented to verify the proposed models. Experimental data agreed well with the predicted results fer each model. A comprehensive software environment to integrate the models into a VMT is also proposed.

『오경문자(五經文字)』 부수 분류의 표준과 소속자의 귀속 체례 - 여가석(余嘉錫)의 『오경문자(五經文字)』 부수 평가에 대한 반박 (The Radical-rule and Arrangement System of Characters of Wu Jing Wen Zi: a Rebuttal of Yu Jiaxi's View)

  • 이경원
    • 비교문화연구
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    • 제38권
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    • pp.385-404
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    • 2015
  • Compiled in 776 by Zhang Shen, Wu Jing Wen Zi was regarded as the epitome of model book for standardized regular script in Tang Dynasty. Following early works like Shuo Wen Jie Zi, Zhang Shen adopted radical-rule for the compilation of this work. 3,250 characters were selected from the Five Classics and 160 radicals were established. Yu Jiaxi (1884-1955) harshly criticized the radical system of Wu Jing Wen Zi for being inconsistant and confusing. With careful review and analysis of examples from Wu Jing Wen Zi, this paper discusses the pupose of the compilation of this work, its unique radical-rule system, principles of arrangement of characters with the same or similar radicals, and the differentiation of variant characters. It further discusses the value of Wu Jing Wen Zi by its innovative radical-rule and effective differentiation of variant characters. It concludes with a rebuttal of Yu Jiaxi's argument and restate the necessity of reevaluation of this work even to this day.

Analytical Algorithm Predicting Compressive Stress-Strain Relationship for Concrete Confined with Laminated Carbon Fiber Sheets

  • Lee, Sang-Ho;Kim, Hyo-Jin
    • Computational Structural Engineering : An International Journal
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    • 제1권1호
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    • pp.39-48
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    • 2001
  • An analytical compressive stress-strain relationship model for circular and rectangular concrete specimens confined with laminated carbon fiber sheets (CFS) is studied. Tsai-Hill and Tsai-Wu failure criteria were used to implement orthotropic behavior of laminated composite materials. By using these criteria, an algorithm which analyzes the confinement effect of CFS on concrete was developed. The proposed analytical model was verified through the comparison with experimental data. Various parameters such as concrete strength, ply angle, laminate thickness, section shape, and ply stacking sequences were investigated. Numerical results by the proposed model effectively simulate the experimental compressive stress-strain behavior of CFS confined concrete specimens. Also, the pro-posed model estimates the compressive strength of the specimen to a high degree of accuracy.

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On Realization of 2D Discrete Systems by Fornasini-Marchesini Model

  • Xu Li;Wu Liankui;Wu Qinghe;Lin Zhiping;Xiao Yegui
    • International Journal of Control, Automation, and Systems
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    • 제3권4호
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    • pp.631-639
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    • 2005
  • In this paper, we propose a constructive realization procedure for 2D systems which may lead to a Fornasini-Marchesini local state-space model with much lower order than the existing realization procedure given by Bisiacco et al. Nontrivial examples are illustrated and the conditions for minimal realization are also discussed.

Numerical Simulation and Experiment of Pressure Pulsation in Kaplan Turbine

  • Yang, Wei;Wu, Shangfeng;Liu, Shuhong;Wu, Yulin
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년 영문 학술대회
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    • pp.729-731
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    • 2008
  • Three-dimensional unsteady simulation using RNG $\kappa-\varepsilon$ turbulence model is used in full flow passage of model Kaplan turbine. Then the pressure pulsation is obtained. Monitoring data of pressure pulsation in the turbine is obtained through experiment and is compared with the numerical simulation. And a good coherence is shown between the simulation and the experiment. Then the regularity of the pressure pulsation s distribution and transmission in the turbine is discussed in detail.

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