• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.818-822
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• 2003

We propose a software-reliability growth model incoporating the amount of uniform and Weibull testing efforts during the software testing phase in this paper. The time-dependent behavior of testing effort is described by uniform and Weibull curves. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, the model is formulated by a nonhomogeneous Poisson process. Using this model the method of data analysis for software reliability measurement is developed. The optimum release time is determined by considering how the initial reliability R(x|0) would be. The conditions are $R(x|0)>R_o$, $R_o>R(x|0)>R_o^d$ and $R(x|0)<R_o^d$ for uniform testing efforts. Ideal case is $R_o>R(x|0)>R_o^d$. Likewise, it is $R(x|0){\geq}R_o$, $R_o>R(x|0)>R_o^{\frac{1}{g}$ and $R(x\mid0)<R_o^{\frac{1}{g}}$ for Weibull testing efforts. Ideal case is $R_o>R(x|0)>R_o^{\frac{1}{g}}$.

• Journal of Power System Engineering
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• v.14 no.4
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• pp.56-62
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• 2010

This paper is concerned with the stochastic nature of elevated temperature tensile strength and creep rupture time in 18Cr-8Ni stainless steels. The Weibull statistical analysis using the NRIM data sheet has been performed to investigate the effects of variability of the elevated temperature tensile strength and creep rupture time on the testing temperature. From those investigations, the distributions of temperature tensile strength and creep rupture time were well followed in 2-parameter Weibull. The shape parameter and scale parameter for the Weibull distribution of tensile strength were decreased with increasing the testing temperature. For the creep rupture time, generally, the shape parameter were decreased with increasing the testing temperature.

• Journal of Korean Society for Quality Management
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• v.36 no.4
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• pp.1-6
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• 2008

As more and more data are collected one may ask whether the data collected within a short period of time are same. In this case traditional hypothesis testing of $H_o:{\mu}_1={\mu}_2$ vs $H_1:{\mu}_1{\neq}{\mu}_2$ is used to determine whether the data are same when there is no knowledge about equivalence testing. However, this type of hypothesis testing has the undesirable property of penalizing higher precision. So TOST is to be performed in the event of equivalence testing. In this study equivalence testing is introduced where one can find the applications in industry. Traditional two sample t testing is to be compared with the equivalent testing and the procedure to perform the equivalence testing is to be presented along with an example. Finally equivalence testing in terms of the other parameters such as variance, proportion or failure rate is to be sought.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.4
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• pp.156-163
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• 2009

Recently a standard software platform for automotive, AUTOSAR, has been developed to manage growing software complexity and improve software reuseability. However reuse of testing system and test data are difficult because they are dependant on implementation language and testing phases. In this paper, we suggest a automated testing approach for AUTOSAR software component using a standardized testing language, TTCN-3. AUTOSAR defines the AUTOSAR XML Schema for the data exchange format so that it is possible to automatically convert AUTOSAR model into TTCN-3 testing model. Therefore our approach is to present generation techniques for the TTCN-3 testing system from a AUTOSAR XML description. With the proposed testing techniques we can reduce time and effort to build the testing system and reuse testing environment.

• 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 Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.304-307
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• 2000

This paper presents a numerical simulation study for remote parallel pseudo-dynamic testings using Internet. In this testing method, experimental facilities located at different places can be parallelly used for testing a large-scale structure with many components subjected to severe nonlinear behavior. Example analysis is carried out on a base- isolated bridge for earthquake loading. The results indicate that the time required for data communication between two facilities located 250km apart through Internet for t 000 time steps is about 20 minutes, which is fairly equivalent to the time required for pseudo-dynamic testing. This testing method can be more powerful, as the data transmitting technique through Internet improves.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.521-528
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• 2003

This paper presents the results of a cooperative research on remote parallel pseudo-dynamic testing on a base-isolated bridge with multiple piers using Internet between KAIST, Korea and Kyoto Univ., Japan. Experimental facilities located at two institutions were parallelly used to test the nonlinear behavior of the base-isolators. Two data communication schemes for parallel tests were developed and the performance is compared. The results indicate that the elapsed time may vary widely depending on the data communication and testing schemes : i.e. 1-25sec for each time step. But it is fairly comparable with the time required for pseudo-dynamic testing. The testing method can become more powerful, as the data communication and monitoring techniques through Internet improve further.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.6
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• pp.635-641
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• 2011

In ultrasonic testing of dissimilar metal welds, application of phased array technique in terms of incident beam focusing is not easy because of complicated material structures formed during the multi-pass welding process. Time reversal(TR) techniques can overcome some limitations of phased array since they are self-focusing that does not depend on the geometrical and physical properties of testing components. In this paper, we test the possibility of TR focusing on a defect within anisotropic, heterogeneous austenitic welds. A commercial simulation software is employed for TR focusing and imaging of a side-drilled hole. The performance of time reversed adaptive focal law is compared with those of calculated focal laws for both anisotropic and isotropic welds.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.136-142
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• 2017

Purpose: In this paper, we propose a test method for evaluating the life time of the inverter which is one of the main internal configuration systems in order to evaluate the life time of the power supply for the vehicle. Methods: The performance and failure criteria required for the development of the accelerated life test method were established and the Taguchi method was used to derive the stress factors affecting performance and reliability. Results: The major stress of the product degradation were considered to be high temperature. Conclusion: The acceleration factor was estimated through a two-level high temperature test and a test methods was designed to guarantee the accelerated life time of the inverter.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.60
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• pp.73-81
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• 2000

The testing processes for VLSI finished devices are considerably complex because they require different types of ATE to be linked together. Due to the interaction effect between two or more linked ATEs, it is difficult to trace down the cause of the unexpected longer ATE setup time and random yields, which frequently occur in the VLSI circuit-testing laboratory. The goal of this paper is to develop and demonstrate the methodology designed to eliminate the possible interaction factors that might affect the random yields and/or unexpected longer setup time as well as increase the productivity. The statistical method such as design of experiment or multivariate analysis cannot be applied to the final testing floor here directly due to the environmental constraints. Expanded product data information (PDI) is constructed by combining product data information and ATE control information. An architecture utilizing expanded PDI is designed, which enables the engineer to conduct statistical approach investigation and reduce the setup time, as well as increase yield.