• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.10
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• pp.968-973
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• 2012

Slam testing is a mandatory testing process to evaluate the fatigue resistance of a door plate module before delivering it to car makers. This process is very hard job to complete it since the testing facilities are considerably expensive and the required testing time is relatively very long, i.e. more than eight days for a single specimen. In this paper, an accelerated testing method of a door plate module is proposed using vibration test equipment instead of the current one by exposing to the critical excitation of a door glass. Under the proposed excitation method, the similar testing result can be evaluated within less than two hours. The suitability of the proposed testing method was demonstrated by comparing failure modes of both the current testing method and the proposed one.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.291-298
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• 2003

The resonant column testing is a laboratory testing method to determine the shear modulus and the material damping factor of soils. The method has been widely used for many applications and its importance has been increased. Since the establishment of the testing method in 1963, the low-technology electronic devices for testing and data acquisition have limited the measurement to the amplitude of the linear spectrum. The limitations of the testing method were also attributed to the assumption of the linear-elastic material in the theory of the resonant column testing and to the use of the wave equation for the dynamic response of the specimen. For the better theoretical formulation of the resonant column testing, this study derived the equation of motion and provided its solution. This study also proposed the improved data reduction and analysis method for the resonant column testing, based on the advanced data acquisition system and the proposed theoretical solution for the resonant column testing system. For the verification of the proposed data reduction and analysis method, the numerical simulation of the resonant column testing was performed by the finite element analysis. Also, a series of resonant column testing were peformed for Joomunjin sand, which verified the feasibility, of the proposed method and showed the limitations of the conventional data reduction and analysis method.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.257-260
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• 2005

A general electric acceleration testing method for estimation of chloride diffusion coefficient is RCPT and CTH. Also, this testing methods have merit that reduce the testing time. In this paper, an experimental study is executed to investigate the effect of testing method on coefficient of chloride diffusion and it is compared with RCPT and CTH. According to this experiment results, W/C ratio and testing method influence chloride diffusion coefficient of concrete. As W/C ratio is increased, diffusion coefficient in concrete is also increased. Diffusion coefficient obtained by each testing method show the different values. However, there is no remarkable difference between the two testing method.

• Journal of the Korea Society of Computer and Information
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• v.23 no.2
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• pp.9-16
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• 2018

Recently, as various IP set-top boxes based on Android OS have been widely used in general households and public facilities, complaints about services and set-top boxes have continued to increase as much as other smart devices. In order to reduce this problem, the manufacturer performs the testing work before the product is commercialized. However, the testing can reduce potential defects in the product, but it can not prove that the product is free of defects. Therefore, the quality of the product can vary depending on how effective testing techniques are introduced. In this paper, we propose a new exploratory testing method that minimizes test case creation time and makes it easier to plan and execute test while simultaneously learning how to run the product under test. Using the first proposed method, the test time is reduced by about 16.7 hours and the defect detection rate is 25.4% higher than the formal specification-based testing method. Informally, the test time was shortened by about 4.7 hours and the defect detection rate was 13% higher than the informal experience-based testing method.

• Smart Structures and Systems
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• v.4 no.6
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• pp.809-828
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• 2008

Real-time hybrid testing is an attractive method to evaluate the response of structures under earthquake loads. The method is a variation of the pseudodynamic testing technique in which the experiment is executed in real time, thus allowing investigation of structural systems with time-dependent components. Real-time hybrid testing is challenging because it requires performance of all calculations, application of displacements, and acquisition of measured forces, within a very small increment of time. Furthermore, unless appropriate compensation for time delays and actuator time lag is implemented, stability problems are likely to occur during the experiment. This paper presents an approach for real-time hybrid testing in which time delay/lag compensation is implemented using model-based response prediction. The efficacy of the proposed strategy is verified by conducting substructure real-time hybrid testing of a steel frame under earthquake loads. For the initial set of experiments, a specimen with linear-elastic behavior is used. Experimental results agree well with the analytical solution and show that the proposed approach and testing system are capable of achieving a time-scale expansion factor of one (i.e., real time). Additionally, the proposed method allows accurate testing of structures with larger frequencies than when using conventional time delay compensation methods, thus extending the capabilities of the real-time hybrid testing technique. The method is then used to test a structure with a rate-dependent energy dissipation device, a magnetorheological damper. Results show good agreement with the predicted responses, demonstrating the effectiveness of the method to test rate-dependent components.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.133-144
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• 2003

The resonant column testing is a laboratory testing method to determine the shear modulus and material damping factor of soils. The method has been widely used for many applications and its importance has increased. Since the first use of the testing method in 1960's, the low-technology electronic devices fir testing and data acquisition have limited the measurement only to the amplitude of the linear spectrum. The limitations of the testing method are also attributed to the assumption of linear-elastic material in the theory of the resonant column testing and also to the incomplete understanding of the dynamic behaviour of the resonant column testing device. Recently, Joh et al. proposed a theory to overcome the limitations of the resonant column testing by deriving the equation of motion and providing its solution for the resonant column testing device. This study proposed the improved data reduction and analysis method for the resonant column testing, thanks to the advanced data acquisition system and the new theoretical solution for the resonant column testing system. For the verification of the proposed data reduction and analysis method, the numerical simulation of the resonant column testing was performed by the finite element analysis. Also, a series of resonant column testing were performed fir Joomunjin sand, which verified the feasibility of the proposed method and revealed the limitations of the conventional data reduction and analysis method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.459-462
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• 2002

The conventional thermal insulator and power transformer testing is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also thermal testing is able to offer the standard judgement of relative degradation level of outside HV machine. There it is very useful method compare to previous conventional thermal testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, thermal testing of Power transformer is measured with partial temperature distribution in real time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.69-72
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• 2002

The conventional thermal insulator and power transformer testing is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also thermal testing is able to offer the standard judgement of relative degradation level of outside HV machine. There it is very useful method compare to previous conventional thermal testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, thermal testing of power transformer is measured with partial temperature distribution in real time.

• Geomechanics and Engineering
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• v.31 no.6
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• pp. 583-597
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• 2022

Frost heave can cause uneven ground uplift that may damage geo-infrastructure. To assist damage-prevention strategies, standard frost heave testing methods and frost susceptibility criteria have been established and used in various countries. ASTM International standard testing method is potentially the most useful standard, as abundant experimental data have been acquired through its use. ASTM International provides detailed recommendations, but the method is expensive and laborious because of the complex testing procedure requiring a freezing chamber. A simple frost heave testing method using a temperature-controllable cell has been proposed to overcome these difficulties, but it has not yet been established whether a temperature-controllable cell can adequately replace the ASTM International recommended apparatus. This paper reviews the applicability of the ASTM International testing method using the temperature-controllable cell. Freezing tests are compared using various soil mixtures with and without delivering blow to depress the freezing point (as recommended by ASTM International), and it is established that delivering blow does not affect heave rate, which is the key parameter in successful characterization of frost susceptibility. As the freezing temperature decreases, the duration of supercooling of pore water shortens or is eliminated; i.e., thermal shock with a sufficiently low freezing temperature can minimize or possibly eliminate supercooling.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2832-2839
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• 1997

In this paper, a testing architecture and procedure that an idle ATM virtual channel can be utilized for TCP channel is proposed. Four kinds or methodologies for protocol conformance testing have been standardized in ISO. Remote testing method used popularly have some disadvantages that developer must operate system manually in case of System Under Test (SUT) active testing and we cannot control and observe Implementation Under Test (IUT) often. It is proper to adopt distribute testing method than remote test in order to maximize test coverage and optimize fault coverage for conformance testing in ATM systems, and it is required that TCP channel is prepared for distribute testing method. The proposed architecture can adopt distributed testing method without extra physical channel for testing control. Also we can maximize the test coverage and implement the automation of testing without intervention of operator sustaining normal operation of ATM equipment.