• Environmental Analysis Health and Toxicology
• /
• v.24 no.3
• /
• pp.261-270
• /
• 2009

To make measurable regulatory decisions of chemicals, it is necessary to consider their effect on the human health and ecosystem. In principle, this is based on relevant toxicity studies conducted by accepted guidelines. However, current regulatory programs in various countries confront challenges related to risk assessment of large numbers of chemicals within the restricted resources and time. Therefore there is a need for more efficient approach to limit the number of tests to be conducted. This promotes the development of powerful nontesting methods (e.g. (Q)SARs) and permits to use the predicted data for regulatory purpose. In this article, current status of non-testing methods in various chemical regulatory programs was reviewed in terms of their application and research activity on them. Finally, their usefulness associated with development of domestic regulatory program was suggested.

• Journal of the Korean Institute of Gas
• /
• v.16 no.1
• /
• pp.22-25
• /
• 2012

Welding and/or fusion in polyethylene(PE) system made on site is focused on the control of the welding or fusion process to follow proper procedure. The process control is important, but it is not sufficient for the long term reliability of a pipe system. To achieve the rate of failure close to zero, Non Destructive Testing(NDT) is necessary in addition to joining process control. For electrofusion joints several non-destructive testing methods are available. The ultrasonic phased array technique is possible to detect various defects including wire deviations and regions with lack of fusion. In this studies, testing was carried to detect the defect after electrofusion joining of polyethylene piping is utilized by the ultrasonic phased array technique. From testing data, ultrasonic phased array technique is recommended as a reliable non-destructive testing method.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.2
• /
• pp.128-134
• /
• 2014

Infrared thermography is an emerging approach to non-contact, non-intrusive, and non-destructive inspection of various solid materials such as metals, composites, and semiconductors for industrial and research interests. In this study, data processing was applied to infrared thermography measurements to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, raw images were often not appropriate. Thus, various data analysis methods were used at the pre-processing and processing levels in data processing programs for quantitative analysis of defect detection and characterization; these increased the infrared non-destructive testing capabilities since subtle defects signature became apparent. A 3D finite element simulation was performed to verify and analyze the data obtained from both the experiment and the image processing techniques.

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

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.4
• /
• pp.308-314
• /
• 2016

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.841-846
• /
• 2002

Development on non-destructive testing methods were performed to evaluate the effectiveness of crack repair for test beams induced a crack. Cracked beams are repaired with expoxy and microcement, and then they are tested by two methods, the ultrasonic pulse velocity method and the transfer function method. It is proved that the ultrasonic pulse velocity method is very valid for the evaluation of the effectiveness on expoxy repair, and the transfer function method is very applicable to evaluate the effectiveness on microcement repair.

• Communications for Statistical Applications and Methods
• /
• v.8 no.3
• /
• pp.787-795
• /
• 2001

In this paper, Bayesian hypothesis testing procedures are proposed under the non-informative prior distributions, which can be thought as the Bayesian counterparts of the classical ones in the sense of using the concept of significance level. The performances of proposed procedures are compared with those of classical procedures through several examples.

• International Journal of Highway Engineering
• /
• v.15 no.3
• /
• pp.65-74
• /
• 2013

PURPOSES: This study is to evaluate the dynamic modulus changes of permeable asphalt mixtures by using non-destructive impact testing method and to compare the dynamic moduli of permeable asphalt mixtures through repeated freezing and thawing conditions. METHODS: For the study, non-destructive impact testing method is used in order to obtain dynamic modulus of asphalt specimen and to confirm the change of dynamic modulus before and after freezing and thawing conditions. RESULTS : This study has shown that the dynamic moduli of asphalt concrete specimens consisting of 10%, 15% and 20% porosity are reduced by 11.851%, 1.9564%, 24.593% after freezing and thawing cycles. CONCLUSIONS : Non-destructive impact testing method is very useful and has repeatability. Specimen with 15% porosity has high durability than others.

• Journal of Applied Reliability
• /
• v.17 no.3
• /
• pp.224-235
• /
• 2017

Purpose: Reliability is the most important factor to detect defects as wind turbines are deployed in large blades. The methods of detecting defects are various, such as non-destructive inspection and thermal imaging inspection. We propose the phased array ultrasonic testing method of non-destructive testing. Methods: We propose the active pressure mechanism for wind power blade. The phase array ultrasonic inspection method is used for fault detection inner blade surface. Controlled pressure of mechanism with respect to z-axis is important for guarantee the result of phase array ultrasonic inspection. The model based control and proposed mechanism are utilized for overall system stability and effectiveness of system. Result: The result of proposed pressure mechanism B is more stable than A. Convergence speed is also faster than A. Conclusion: We confirmed the performance of the proposed constant pressure mechanism through experiments. Non-destructive testing was applied to the specimen to confirm the reliability of detecting defects.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2002.05a
• /
• pp.191-194
• /
• 2002

The tensile properties of materials can be obtained just in accordance with conventional tensile testing methods which are described in several standards. However, the standard testing methods cannot be applicable due to the destructive testing procedure and specimen size requirement for some cases including on-service facility materials. Therefore, simple, non-destructive and advanced indentation technique was proposed. This test measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation and fracture. In this paper, the research trend of non-destructive evaluation of tensile properties using advanced indentation system and its application fields are reviewed and discussed.