• Title/Summary/Keyword: numerical testing

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Prediction of acceleration and impact force values of a reinforced concrete slab

  • Erdem, R. Tugrul
    • Computers and Concrete
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    • v.14 no.5
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    • pp.563-575
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    • 2014
  • Concrete which is a composite material is frequently used in construction works. Properties and behavior of concrete are significant under the effect of different loading cases. Impact loading which is a sudden dynamic one may have destructive effects on structures. Testing apparatuses are designed to investigate the impact effect on test members. Artificial Neural Network (ANN) is a computational model that is inspired by the structure or functional aspects of biological neural networks. It can be defined as an emulation of biological neural system. In this study, impact parameters as acceleration and impact force values of a reinforced concrete slab are obtained by using a testing apparatus and essential test devices. Afterwards, ANN analysis which is used to model different physical dynamic processes depending on several variables is performed in the numerical part of the study. Finally, test and predicted results are compared and it's seen that ANN analysis is an alternative way to predict the results successfully.

Transient Analysis of Electromagnetic Scattering From Dielectric Objects Using Time-Domain Magnetic Field Integral Equation (시간영역 자장 적분방정식을 이용한 유전체의 전자파 산란 과도해석)

  • 서정훈;정백호;한상호;안현수
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.9
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    • pp.412-417
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    • 2003
  • In this Paper, we propose a time-domain magnetic field integral equation (TD-MFIE) formulation for analyzing the transient electromagnetic response from three-dimensional (3-D) dielectric bodies. The solution method in this paper is based on the Galerkin's method that involves separate spatial and temporal testing procedures. Triangular patch basis functions are used for spatial expansion and testing functions for arbitrarily shaped 3-D dielectric structures. The time-domain unknown coefficients of the equivalent electric and magnetic currents are approximated tv a set of orthonormal basis function that is derived from the Laguerre polynomials. These basis functions are also used for the temporal testing. Numerical results computed by the proposed method are presented and compared.

Recent Developments of Wave Energy Utilization in Denmark

  • Kofoed, J.P.;Frigaard, P.;Kramer, M.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.91-98
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    • 2006
  • This paper aims at giving an overview of the developments researchers at the Department of Civil Engineering, Aalborg University, Denmark (DCE), have been involved in within the field of wave energy utilization in Denmark over the past decade. At first a general introduction is given followed by a more thorough description of three ongoing projects. These are Wave Dragon, Wave Star and Seawave Slot-cone Generator. Common for these projects are that they are being, or will soon be, tested in real sea and have benefited from the Danish Wave Energy Program. The work by the department on these projects involves substantial laboratory testing, numerical simulations and real sea prototype testing.

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The Camparative study of NHPP Extreme Value Distribution Software Reliability Model from the Perspective of Learning Effects (NHPP 극값 분포 소프트웨어 신뢰모형에 대한 학습효과 기법 비교 연구)

  • Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.2
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    • pp.1-8
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    • 2011
  • In this study, software products developed in the course of testing, software managers in the process of testing software test and test tools for effective learning effects perspective has been studied using the NHPP software. The finite failure non-homogeneous Poisson process models presented and the life distribution applied extreme distribution which used to find the minimum (or the maximum) of a number of samples of various distributions. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than automatic error that is generally efficient model could be confirmed. This paper, a numerical example of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error.

MODIFIED POSTERIOR TIME-STEP ADJUSTMENT TECHNIQUE FOR MDOF SYSTEM IN SUBSTRUCTURING PSEUDODYNAMIC TEST (부분구조 유사동적법에 있어 다자유도 시스템에 대한 수정 시간증분 조정기법)

  • 이원호;강정호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.473-480
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    • 1998
  • The substructuring pseudodynamic test is a hybrid testing method consisting of a numerical simulation of the earthquake response of an analytical model and a loading test of a specimen. The substructuring pseudodynamic testing technique has been applied to various seismic experiments since it has advantages over the shaking table test to study dynamic behaviors of relatively large scale structures. However, experimental errors are inevitable in substructuring pseudodynamic testing. Some of these errors can be monitored during the test, but, due to limitations in control system, they cannot be eliminated. For example, one cannot control exactly the displacements that are actually imposed on the structures at each time step. This paper focuses on a technique to minimize the cumulative effect of such control errors for MDOF system. For this purpose, the modified posterior adjustment of the time increment from a target value $\Delta$t$_{n}$ to an adjusted value is performed to minimize the effect of the control errors for MDOF system.for MDOF system.

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Independent Testing in Marshall and Olkin's Bivariate Exponential Model Using Fractional Bayes Factor Under Bivariate Type I Censorship

  • Cho, Kil-Ho;Cho, Jang-Sik;Choi, Seung-Bae
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1391-1396
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    • 2008
  • In this paper, we consider two components system which the lifetimes have Marshall and Olkin's bivariate exponential model with bivariate type I censored data. We propose a Bayesian independent test procedure for above model using fractional Bayes factor method by O'Hagan based on improper prior distributions. And we compute the fractional Bayes factor and the posterior probabilities for the hypotheses, respectively. Also we select a hypothesis which has the largest posterior probability. Finally a numerical example is given to illustrate our Bayesian testing procedure.

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Testing of Poisson Incidence Rate Restriction

  • Singh, Karan;Shanmugam, Ramalingam
    • International Journal of Reliability and Applications
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    • v.2 no.4
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    • pp.263-268
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    • 2001
  • Shanmugam(1991) generalized the Poisson distribution to capture a restriction on the incidence rate $\theta$ (i.e. $\theta$$\beta$, an unknown upper limit), and named it incidence rate restricted Poisson (IRRP) distribution. Using Neyman's C($\alpha$) concept, Shanmugam then devised a hypothesis testing procedure for $\beta$ when $\theta$ remains unknown nuisance parameter. Shanmugam's C ($\alpha$) based .results involve inverse moments which are not easy tools, This article presents an alternate testing procedure based on likelihood ratio concept. It turns out that likelihood ratio test statistic offers more power than the C($\alpha$) test statistic. Numerical examples are included.

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A Study on Structural Analysis of Butterfly Valve Components by Pressure Testing of the Industrial Standard (산업용 표준의 압력시험 방법에 의한 버터플라이 밸브 구성품의 구조해석에 관한 연구)

  • Shin, Myung-Seob;Yoon, Joon-Yong;Park, In-Won;Lee, Seoung-Hwan;Park, Han-Yung;Jung, Seung-Hwa
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.3
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    • pp.5-9
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    • 2011
  • Butterfly valves are widely used in current industry to control the fluid flow. They are used for both on-off and throttling applications involving large flows at relatively low pressure-drop especially in large size pipelines. In this study, we carried out the structure analysis of the butterfly valve components according to pressure testing of the industrial standard. the numerical simulation was performed by using ANSYS Workbench. The reliability of valve is evaluated under the investigation of the strain rate, the leak test and the durability of the valve.

The Fractional Bayes Factor Approach to the Bayesian Testing of the Weibull Shape Parameter

  • Cha, Young-Joon;Cho, Kil-Ho;Cho, Jang-Sik
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.3
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    • pp.927-932
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    • 2006
  • The techniques for selecting and evaluating prior distributions are studied over recent years which the primary emphasis is on noninformative priors. But, noninformative priors are typically improper so that such priors are defined only up to arbitrary constants which affect the values of Bayes factors. In this paper, we consider the Bayesian hypotheses testing for the Weibull shape parameter based on fractional Bayes factor which is to remove the arbitrariness of improper priors. Also we present a numerical example to further illustrate our results.

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Characteristic Analysis and Design of PC Probe for Eddy Current Testing (와전류탐상을 위한 PC 프로브의 특성해석 및 설계)

  • Kim Yong Taek;Lee Hyang-beom
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.965-967
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    • 2004
  • In this paper, characteristic analysis of PC(Pancake Coil) probe with the size variation is presented for eddy current testing. Characteristics of probe are numerically calculated by using the finite element method. From the numerical analysis, the optimum frequency and groups for an experiment are selected. Probes are made and experiment is performed. From the experimental results, the probe shows maximum sensitivity when the size of defect is equal to the size of probe and when the inside diameter is similar to the width of probe and when the height is low. The result can be helpful to the standard of design of PC probe for eddy current testing.

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