• Title, Summary, Keyword: Model test

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A Study on the Resistance Test Method for Planning Hull Model using the High Speed Towing Carriage (무인고속전차를 이용한 활주선 모형의 저항시험 기법 연구)

  • Lee, Young-Gill;Ha, Yoon-Jin;Jeong, Kwang-Leol;Chae, Soon-Jae
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.5
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    • pp.349-355
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    • 2014
  • The resistance test of a high speed craft such as planing ship is performed with a high speed towing carriage instead of ordinary towing carriage because of the speed limitation. In the resistance test using high speed towing carriage, the model ship is fixed to the carriage to restrain the running attitude for enough measuring time. Such method is called fixed model test method. In the fixed model test method, to get the appropriate running attitude, the model test is iteratively repeated until the trim moment and lift force are close to zero. In this research, trim free model test method is investigated to reduce the number of iteration. And, the limitation of towing speed range in the trim free model test method is investigated.

A Research on Dynamic Tension Response of Model Mooring Chain by Forced Oscillation Test (강제동요 시험을 이용한 모형 계류삭의 동적 응답 연구)

  • Kim, Hyun-Joe;Hong, Sa-Young;Hong, Sup;Cho, Suk-Kyu
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.134-141
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    • 2002
  • A series of forced oscillation test on model mooring chain was carried out to investigate dynamic tension characteristics. The model test was conducted at two different water depth to gather basic data for 'truncated mooring test' and 'hybrid mooring test'. The truncated and hybrid mooring test are highly recommended to overcome the limitation of water depth in model test recently. The resultant tension RAO gives good possibility of approximation of dynamic tension by equivalent weight adjustment for the ratio of water depth in different water depth. Because the hybrid mooring test is the adequate combination of model test and simulation, accurate simulation model on mooring system is essential. The simulation results show good agreement with model test results.

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Prediction of Mechanical Behavior for Carbon Black Added Natural Rubber Using Hyperelastic Constitutive Model

  • Kim, Beomkeun
    • Elastomers and Composites
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    • v.51 no.4
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    • pp.308-316
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    • 2016
  • The rubber materials are widely used in automobile industry due to their capability of a large amount of elastic deformation under a force. Current trend of design process requires prediction of functional properties of parts at early stage. The behavior of rubber material can be modeled using strain energy density function. In this study, five different strain energy density functions - Neo-Hookean model, Reduced Polynomial $2^{nd}$ model, Ogden $3^{rd}$ model, Arruda Boyce model and Van der Waals model - were used to estimate the behavior of carbon black added natural rubber under uniaxial load. Two kinds of tests - uniaxial tension test and biaxial tension test - were performed and used to correlate the coefficients of the strain energy density function. Numerical simulations were carried out using finite element analysis and compared with experimental results. Simulation revealed that Ogden $3^{rd}$ model predicted the behavior of carbon added natural rubber under uniaxial load regardless of experimental data selection for coefficient correlation. However, Reduced Polynomial $2^{nd}$, Ogden $3^{rd}$, and Van der Waals with uniaxial tension test and biaxial tension test data selected for coefficient correlation showed close estimation of behavior of biaxial tension test. Reduced Polynomial $2^{nd}$ model predicted the behavior of biaxial tension test most closely.

Remarks on correlated error tests

  • Kim, Tae Yoon;Ha, Jeongcheol
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.2
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    • pp.559-564
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    • 2016
  • The Durbin-Watson (DW) test in regression model and the Ljung-Box (LB) test in ARMA (autoregressive moving average) model are typical examples of correlated error tests. The DW test is used for detecting autocorrelation of errors using the residuals from a regression analysis. The LB test is used for specifying the correct ARMA model using the first some sample autocorrelations based on the residuals of a tted ARMA model. In this article, simulations with four data generating processes have been carried out to evaluate their performances as correlated error tests. Our simulations show that the DW test is severely dependent on the assumed AR(1) model but isn't sensitive enough to reject the misspecified model and that the LB test reports lackluster performance in general.

Extracting Reusable Test Cases from Modified MATLAB Simulink Model (변경된 MATLAB Simulink 모델로부터 재사용 가능 테스트 케이스 도출)

  • Park, Geon Gu;Han, Hye Jin;Chung, Ki Hyun;Choi, Kyung Hee
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.6
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    • pp.235-242
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    • 2019
  • This paper proposes a reusable test case extraction technique for modified MATLAB Simulink/Stateflow (SL/SF) model. Creating test cases for complicated SL/SF model like ECU(Electrical Control Unit) of automotive, requires a lot of time and effort. An intuitive way to reduce to create new test cases whenever the model changes, is to reuse some test cases which have been generated for the original model. In this paper, we propose a method to define reusable test cases in SL/SF after defining model behavior and judging model equality by test cases. The proposed technique is evaluated using a commercial automotive controller model.

The Movable Hydraulic Model Test for Exchange of Intake Weir in the Nakdong River (낙동강 취수보개체를 위한 이동상 수리모형실험)

  • 김성원
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.35-42
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    • 2000
  • In this study, the movable bed model testing was carried out so as to analyze bed profile changes including predicting scouring and deposition of bed profile and to solve hydraulic problems affecting with bed and both-bank between upstream and downstream of intake weir in the Nakdong river channel. The movable bed model testing consists of fundamental test, movable model test and numerical analysis method respectively. The fundamental test was enforced to analyze relationship of discharge and sediment load in the tilting flume. When the movable model test was worked, it was shown that sediment budget between input sediment load and output sediment load was balanced exactly. As a result of movable model test, it was presented that scouring and deposition changes in quantities between the upstream and downstream of modification weir were less than those of nature and planning weir. Finally, numerical analysis method was operated by 1-dimensional bed profile changes model ; HEC-6 model so as to complement unsolving hard problems during movable model test. So, modification weir will sustained the stable bed profile changes than any other weirs in the study channel.

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High-Level Test Generation for Asynchronous Circuits Using Signal Transition Graph (신호 전이그래프를 이용한 비동기회로의 상위수준 테스트 생성)

  • 오은정;김수현;최호용;이동익
    • Proceedings of the IEEK Conference
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    • pp.137-140
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    • 2000
  • In this paper, we have proposed an efficient test generation method for asynchronous circuits. The test generation is based on specification level, especially on Signal Transition Graph(STG)〔1〕 which is a kind of specification method for asynchronous circuits. To conduct a high-level test generation, we have defined a high-level fault model, called single State Transition Fault(STF) model on STG and proposed a test generation algorithm for STF model. The effectiveness of the proposed fault model and its test generation algorithm is shown by experimental results on a set of benchmarks given in the form of STG. Experimental results show that the generated test for the proposed fault model achieves high fault coverage over single input stuck-at fault model with low cost. We have also proposed extended STF model with additional gate-level information to achieve higher fault coverage in cost of longer execution time.

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A Study of Enhanced Test Maturity Model with Test Process Improvement (테스트 프로세스 개선모델을 통한 테스트 성숙도 모델 (Test Maturity Model) 확장에 관한 연구)

  • Kim, Ki-Du;Kim, Young-Chul
    • The KIPS Transactions:PartD
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    • v.14D no.1
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    • pp.57-66
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    • 2007
  • Organizations of Software development are very important issue on enhancement of a software quality as rapid progress of software industry. Especially there are diverse attempts for enhancement of test maturity of the software organization through some kinds of the test maturity model. But the current test maturity models based on CMM(Capability Maturity Model) lack part of actual testing measurement and only measure level of test maturity. To solve these problems, we suggest 'double V-model' to execute both software development process and test process simultaneously, and also 'test attributes to Maturity Levels Correlation Matrix' for evaluating level of test maturity included with definitions of test attribute and level. That is, we enhance TMM(Test Maturity Model) adopted with 'Improvement Suggestion' of TPI(Test Process Improvement) which is easy the evaluation of test maturity of organization and gives the direction of improvement to level up the test maturity for the measured organization. As a result, we will contribute to level up the test maturity of the organization.

Study on the Design, Manufacture, and Pressure Test of a Pressure Vessel Model (내압용기 모형의 설계, 제작 및 압력시험에 관한 연구)

  • Joung, Tae-Hwan;Lee, Jae-Hwan;Lee, Chong-Moo;Hykudome, Tadahiro;Sammut, Karl;Nho, In-Sik
    • Journal of Ocean Engineering and Technology
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    • v.21 no.6
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    • pp.101-106
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    • 2007
  • In this paper, the authors demonstrate a new idea to take the place of the real pressure vessel test, which should be carried out in a high pressure experiment unit before the real sea trial test. The idea is to make a pressure vessel model as a replica of the real pressure vessel test, which can reduce the cost of making a pressure vessel and large pressure experiment unit. The pressure vessel model was designedbased on linear-elastic, buckling equations and Finite Element Analysis. The manufactured pressure vessel model was investigated and monitored while the pressure test was being conducted. After the test, the result and the validity of the pressure vessel model as a replica of the real pressure vessel test was studied.

Seismic Test of a 1/2 Scale Model of Wood House with Tiled Roof (기와집 1/2 축소 모델의 지진 실험)

  • Ryu, Hyeuk;Kim, Jae-Kwan;Jeon, Bong-Hee;Kim, Byung-Hyun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.362-367
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    • 2003
  • To improve the reliability of seismic hazard assessment of historic earthquake, shaking table test of a 1/2 scale model of wood house with tiled roof was performed. Scaled model was constructed through rigorous verification process to have quantitative relationship between the intensity of earthquake and damage state. The completed model was mounted on a shaking table and subjected to the dynamic tests. Two kinds of tests were performed: exploratory test and fragility test. The exploratory test was done with low intensity shaking. In the fragility test, the behavior of the model was carefully monitored while increasing the shaking intensity. The construction details of the model are provided and test procedures are reported. Finally important test results are presented and their implications are discussed.

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