• Title/Summary/Keyword: Model-based Testing

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A Study on the Techniques for Sailing Yacht Model Tests with Sailing Condition (항주자세를 고러한 세일링 요트의 선형기법 시험연구)

  • Sim, Sang-Mog;Kim, Dong-Joon;Kang, Byung-Yoon
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.1 s.145
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    • pp.32-42
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    • 2006
  • This study aims at establishing a technique for sailing yachts model tests with sailing condition. It is very important to estimate a ship's potential speed performance before building a real ship. Several methods are used to estimate a ship's potential speed performance such as using parent ship data, standard vessel chart and model test. Model test is the most precise among these options. In korea. model testing is widely used with general vessels but not with sailing yachts. Because sailing yachts are propelled with heeling and leeway. using the wind. another method is needed to estimate their speed. The new model test. which is different from tests for upright general vessels, is in a great demand. In this paper. we describe a test method for the sailing yacht model test. based on Masuyama's equation of motion. And we describe choosing scale ratio. production process and materials of the model. Also. various ways of measuring instruments. attaching jigs and adjusting calibration are described so that they can be utilized as useful data for model testing.

A Study for Lifetime Predition of Expansion Joint Using HILS (HILS 기법을 적용한 신축관 이음 수명예측에 관한 연구)

  • Oh, Jung-Soo;Cho, Sueng-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.138-142
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    • 2018
  • This study used HILS to test an expansion joint, which is vulnerable to the water hammer effect. The operation data for the HIL simulator was the length rate of the expansion joint by the water hammer, which was used for life prediction based on the vibration durability. For the vibration durability test, the internal pressure of the expansion joint was assumed to be a factor of the durability life, and the lifetime prediction model equation was obtained by curve fitting the lifetime data at each pressure. During the test, the major failure modes of crack and water leakage occurred on the surface of the bellows part. The lifetime prediction model typically follows an inverse power law model. The pressure is a stress factor, and the model is effective in only a specific environment. Therefore, another stress factor such as temperature will be added and considered for a mixed lifetime prediction model in the future.

Bayesian Test for the Intraclass Correlation Coefficient in the One-Way Random Effect Model

  • Kang, Sang-Gil;Lee, Hee-Choon
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.3
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    • pp.645-654
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    • 2004
  • In this paper, we develop the Bayesian test procedure for the intraclass correlation coefficient in the unbalanced one-way random effect model based on the reference priors. That is, the objective is to compare two nested model such as the independent and intraclass models using the factional Bayes factor. Thus the model comparison problem in this case amounts to testing the hypotheses $H_1:\rho=0$ versus $H_2:{\rho}{\neq}0$. Some real data examples are provided.

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Testing the domestic financial data for the normality of the innovation based on the GARCH(1,1) model

  • Lee, Tae-Wook;Ha, Jeong-Cheol
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.809-815
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    • 2007
  • Since Bollerslev(1986), the GARCH model has been popular in analysing the volatility of the financial time series. In real data analysis, practitioners conventionally put the normal assumption on the innovation random variables of the GARCH model, which is often violated. In this paper, we analyse the domestic financial data based on the GARCH(1,1) model and among existing normality tests, perform the Jarque-Bera test based on the residuals. It is shown that the innovation based on the GARCH(1,1) model dose not follow the normality assumption.

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Time-Temperature Superposition Behavior for Accelerated Fatigue Lifetime Testing of Polycarbonate(PC) (폴리카보네이트(PC)의 가속 피로수명 시험을 위한 시간-온도 호환성)

  • Kim Gyu-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.8 s.251
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    • pp.976-984
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    • 2006
  • Time-temperature superposition has been studied to determine the long-term fatigue life over millions of cycles for glassy polymers. π le superposition is supposed to make an accelerated lifetime testing (ALT) technique possible. Dog-bone shaped specimens made of carbon filled Polycarbonate (PC) were tested under fatigue, based on the stress-lifetime approach (S-N curve). Fatigue-induced localized yield-like deformation is considered as the defect leading to fatigue and its evolution behavior is characterized by a modified energy activation model in which temperature is considered as fatigue acceleration factor. This model allows the reduced time concept to account for effects of different temperature in short-term fatigue data to determine long-term fatigue life through the use of time-temperature superposition that is applicable under a low frequency and isothermal conditions. The experimental results validated that the proposed technique could be a possible method for accelerated lifetime testing (ALT) of time-dependent polymeric materials.

A Study of Structural Safety Diagnosis using Frequency Domain Analysis of Impact-Echo Method (충격반향기법의 주파수영역 해석을 이용한 구조물 안전진단에 관한 연구)

  • 안제훈;서백수
    • Tunnel and Underground Space
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    • v.14 no.1
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    • pp.35-42
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    • 2004
  • Impact-echo is a method for non-destructive testing of concrete structure. This method is based on the use of impact-generated stress wave which is propagated and reflected from internal flaws within concrete structure and external surface. In this study, we performed non-destructive testing using impact-echo methods for safety diagnosis of civil engineering and building structures. There are testing cases for the three models having one-dimensional form ; The first case is the measurement of thickness change of the model, the second is the detection of cavity in the model, and the third is the predictions of the lining thickness and the position of the cavity under tunnel lining condition.

A Study on the Imperfect Debugging of Logistic Testing Function (로지스틱 테스트함수의 불완전 디버깅에 관한 연구)

  • Che, Gyu-Shik;Moon, Myung-Ho;Yang, Kye-Tak
    • Journal of Advanced Navigation Technology
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    • v.14 no.1
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    • pp.119-126
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    • 2010
  • The software reliability growth model(SRGM) has been developed in order to estimate such reliability measures as remaining fault number, failure rate and reliability for the developing stage software. Almost of them assumed that the faults detected during testing were eventually removed. Namely, they have studied SRGM based on the assumption that the faults detected during testing were perfectly removed. The fault removing efficiency, however, is imperfect and it is widely known as so in general. It is very difficult to remove detected fault perfectly because the fault detecting is not easy and new error may be introduced during debugging and correcting. Therefore, We want to study imperfect software testing effort for the logistic testing effort which is thought to be the most adequate in this paper.

Assessment of compressive strength of high-performance concrete using soft computing approaches

  • Chukwuemeka Daniel;Jitendra Khatti;Kamaldeep Singh Grover
    • Computers and Concrete
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    • v.33 no.1
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    • pp.55-75
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    • 2024
  • The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.

Proposal : Improvement of Testing Frontier Capability Assessment Model through Comparing International Standards in Software Product and Software Testing Process Perspective (소프트웨어 제품과 프로세스 관점에서 국제표준과 비교를 통한 테스팅 프론티어 역량평가 모델 개선 방안)

  • Yoon, Hyung-Jin;Choi, Jin-Young
    • KIISE Transactions on Computing Practices
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    • v.21 no.2
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    • pp.115-120
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    • 2015
  • The Testing Frontier Capability Assessment Model (TCAM) is based on ISO/IEC 9126, TMMi and TPI. Since ISO/IEC 9126, TMMi and TPI were made over 10 years ago, TCAM faces the problem that it can not assess and analyze the capability of small businesses that employ new software development methods or processes, for example Agile, TDD(Test Driven Development), App software, and Web Software. In this paper, a method to improve the problem is proposed. The paper is composed of the following sections: 1) ISO/IEC 9126, ISO/IEC 25010 and ISO/IEC/IEEE 29119 part 2 review 2) TCAM review 3) software product quality perspective comparison, and analysis between ISO/IEC 9126, ISO/IEC 25010 and TCAM 4) comparison, and analysis between ISO/IEC/IEEE 29119 part2 and TCAM and 5) proposal for the improvement of TCAM.

Separating Signals and Noises Using Mixture Model and Multiple Testing (혼합모델 및 다중 가설 검정을 이용한 신호와 잡음의 분류)

  • Park, Hae-Sang;Yoo, Si-Won;Jun, Chi-Hyuck
    • The Korean Journal of Applied Statistics
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    • v.22 no.4
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    • pp.759-770
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    • 2009
  • A problem of separating signals from noises is considered, when they are randomly mixed in the observation. It is assumed that the noise follows a Gaussian distribution and the signal follows a Gamma distribution, thus the underlying distribution of an observation will be a mixture of Gaussian and Gamma distributions. The parameters of the mixture model will be estimated from the EM algorithm. Then the signals and noises will be classified by a fixed threshold approach based on multiple testing using positive false discovery rate and Bayes error. The proposed method is applied to a real optical emission spectroscopy data for the quantitative analysis of inclusions. A simulation is carried out to compare the performance with the existing method using 3 sigma rule.