• Journal of the Korean Society for Nondestructive Testing
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• v.10 no.1
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• pp.29-37
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• 1990

In this study the disbonding tests of adhesively bonded Al/Al honeycomb structures were performed by ultrasonic methods. Ultrasonic C-scan squiter method and ultrasonic surface wave attenuation measuring method were applied for the detection of skin/core disbonding. The bonding quality of Al/Al honeycomb structures could be well evaluated by properly controlled ultrasonic parameters.

• Physical Therapy Korea
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• v.26 no.3
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• pp.106-114
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• 2019

Background: It is difficult to assess whether community-dwelling frail older adults may remain pre-frail status or improve into a robust state without being directly checked by health care professionals. The health information perceived by older adults is considered to be one of best sources of potential concerns in older adult population. An online measurement system combined with item response theory (IRT) and computer adaptive testing (CAT) methods is likely to become a realistic approach to remotely monitor physical activity status of frail older adults. Objects: This article suggests an approach to provide a precise and efficient means of measuring physical activity levels of community-dwelling frail older adults. Methods: Article reviews were reviewed and summarized. Results: In comparison to the classical test theory (CTT), the IRT method is empirically aimed to focus on the psychometric properties of individual test items in lieu of the test as a whole. These properties allow creating a large item pool that can capture the broad range of physical activity levels. The CAT method administers test items by an algorithm that select items matched to the physical activity levels of the older adults. Conclusion: An online measurement system combined with these two methods would allow adequate physical activity measurement that may be useful to remotely monitor the activity level of community-dwelling frail older adults.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.1
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• pp.27-32
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• 1998

This paper is written to introduce a multimedia tutoring system for nondestructive testing using personal computer. Nondestructive testing, one of the chief methods for inspecting welds and many other components, is very difficult for the NDT inspectors to understand its technical basis without a wide experience. And it is necessary for considerable repeated education and training for keeping their knowledge. The tutoring system that can simulate NDT works is suggested to solve the above problem based on reasonable condition. The tutoring system shows basic theories of nondestructive testing in a book-style with video images and hyper-links, and it offers practices, in which users can simulate the testing equipment. The book-style and simulation practices provide effective and individual environments for learning nondestructive testing.

• Genomics & Informatics
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• v.14 no.4
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• pp.187-195
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• 2016

In genetic association studies with high-dimensional genomic data, multiple group testing procedures are often required in order to identify disease/trait-related genes or genetic regions, where multiple genetic sites or variants are located within the same gene or genetic region. However, statistical testing procedures based on an individual test suffer from multiple testing issues such as the control of family-wise error rate and dependent tests. Moreover, detecting only a few of genes associated with a phenotype outcome among tens of thousands of genes is of main interest in genetic association studies. In this reason regularization procedures, where a phenotype outcome regresses on all genomic markers and then regression coefficients are estimated based on a penalized likelihood, have been considered as a good alternative approach to analysis of high-dimensional genomic data. But, selection performance of regularization procedures has been rarely compared with that of statistical group testing procedures. In this article, we performed extensive simulation studies where commonly used group testing procedures such as principal component analysis, Hotelling's $T^2$ test, and permutation test are compared with group lasso (least absolute selection and shrinkage operator) in terms of true positive selection. Also, we applied all methods considered in simulation studies to identify genes associated with ovarian cancer from over 20,000 genetic sites generated from Illumina Infinium HumanMethylation27K Beadchip. We found a big discrepancy of selected genes between multiple group testing procedures and group lasso.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.84-86
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• 2005

The digital systems such as PLC or DCS have been applied to non-safety systems of nuclear power plants because of many difficulties in using analog systems. Nowadays, digital systems have been applied to safety systems of the plants such as reactor protection system. One of the main advantages of digital systems is applicability of automatic testing methods to the systems. The protection system requires high-reliability and high-availability because it shall minimize the propagation of abnormal or accident conditions of nuclear power plants. The calculation of reliability and availability of systems depends on the maintenance period of the system. In general, the maintenance period of the protection system is one-month in case of the manual test. However, the cycle of test can be shortened in several hours by using automatic periodic testing. The reliability and availability of the system is better when test period is shortened because the reliability and availability is inverse proportion to the test period. In this research, we developed the automatic periodic testing method for KNICS Reactor Protection System, which can test the system automatically without an operator or a tester. The automatic testing contained all functions of reaction protection systems from analog-to-digital conversion function of the bistable Processor to the coincident trip function of the coincident processor. By applying the automatic periodic testing to reaction system, the maintenance cost can be cut down and the reliability can be increased.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.281-297
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• 2021

Purpose: The purpose of this study was to select factors affecting the global competitiveness of testing and certification bodies and to develop evaluation indicator. Methods: Considering the industrial characteristics of Korea, the electrical and electronic test and certification field was selected as the research subject. As a research method, various factors were extracted through exploratory research such as theoretical considerations on the competitiveness of testing and certification bodies and analysis of the growth process of global testing and certification bodies, and focused interviews and surveys were conducted with conformity assessment experts. Results: The 16 factors affecting the global competitiveness of testing and certification institutions were identified. Among the 4 PEST factors, the technological factor had the highest importance, followed by the economic factor, the social factor, and the political factor. The average of the 16 factors was 0.0625, and the 8 factors above the average included 4 technological factors, 3 economic factors, and 1 social factor, but did not include political factors. The factor with the greatest weight was Standardization Capability for Testing & Certification 0.105. Conclusion: It can be used to evaluate the global competitiveness level of domestic testing and certification bodies using evaluation indicators and to establish strategies for strengthening global competitiveness.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.1
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• pp.1-10
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• 2002

The actual specific migration data for antioxidants and di-ethylhexyl adipate from plastic food packaging materials being used for fatty food and at high temperature into various food simulants were obtained and compared in accordance with the testing methods and conditions in EU, USA and Korea or Japan. In the case of food packaging material for high temperature use, especially in a thick film such as polypropylene in $450{\mu}m$ thickness, a significant difference in the migration value for antioxidants was observed depending on the migration testing condition and simulants used as defined in the each country areas. Considering the reduction factor of 2 to 5 as being currently applied in EU and USA regulations, the migration values obtained by testing methods of Korea or Japan can exhibit actually higher than those of EU and USA. The migration testing conditions are required to be specified diversely according to the actual exposure temperature of packaging materials.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.549-562
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• 2000

Default Bayes factors are computed to test the equality of one Poisson population mean and the equality of two independent Possion population means. As default priors are assumed Jeffreys priors, noninformative improper priors, and default Bayes factors such as three intrinsic Bayes factors of Berger and Pericchi(1996, 1998), the arithmetic, the median, and the geometric intrinsic Bayes factor, and the factional Bayes factor of O'Hagan(1995) are computed. The testing results by each default Bayes factor are compared with those by the classical method in the simulation study.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.61-64
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• 1993

This study is aimed to analyze the influencing factor on the non-destructive testing by measuring rebound number of schmidt hammer and ultrasonic pulse velocity according to the variation of recycled aggregate kinds. And this study is to provide the reference data on application of practical use.

• Communications for Statistical Applications and Methods
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• v.7 no.1
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• pp.151-164
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• 2000

In this paper we consider the Bayesian hypothese testing for independence and symmetry in Freund's bivariate exponential model with censored data In Bayesian testing problem we use the noninformative priors for parameters which are improper and are defined only up to arbitrary constants. And we use the recently proposed hypotheses testing criterion called the intrinsic Bayes factor. Also we derive the arithmetic and median intrinsic Bayes factors and use these results of analyze some data sets.