• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1442-1447
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• 2003

Computer is a very powerful machine which is widely using for data processing, DB construction, peripheral device control, image processing etc. Consequently, many researches and developments have progressed for high performance processing unit, and other devices. Especially, the core units such as semiconductor parts are rapidly growing so that high-integration, high-performance, microminiat turization is possible. The packaging in the semiconductor industry is very important technique to de determine the performance of the system that the semiconductor is used. In this paper, the inspection of the inner defects such as delamination, void, crack, etc. in the semiconductor packages is studied. ESPI which is a non-contact, non-destructive, and full-field inspection method is used for the inner defect inspection and its results are compared with that of C-Scan method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.622-628
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• 2004

In general, Reinforced Slopes by Shotcrete are difficult to inspect because of stiff Slope and highly Working Area. So the Inspection Techniques are needed by the Non-contact and Non-destructive. On this Study, Appling the safety method to finding the weak zones(cavity area, dampness area, etc.) by using the Infrared Thermal Technique That is detecting the Detail Thermal Difference on the Surface of Reinforced Slopes by Shotcrete.

• 비파괴검사학회지
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• 제31권6호
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• pp.626-634
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• 2011

The investigation of concrete structure typically relies on visual inspection which is one of the basic inspection techniques. Image processing techniques play a crucial role in the growing field of automatic surface inspection technique. However, kinds of inspection equipment, environmental condition and detection algorithm have much influence on the reliability of inspection result. This paper proposes a verification method and testing procedure for the reliability of inspection results and surveys characteristics of image acquisition systems and crack inspection algorithms.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.514-522
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• 2022

Non-destructive testing (NDT) technology is a widely used inspection method for agricultural products. Compared with the conventional inspection method, there is no extensive sample preparation for NDT technology, and the sample is not damaged. In particular, NDT technology is used to inspect the internal structure of agricultural products infested by pests. The introduction and spread of pests during the import and export process can cause significant damage to the agricultural environment. Until now, pest detection in agricultural products and quarantine processes have been challenging because they used external inspection methods. However, NDT technology is advantageous in these inspection situations. In this pilot study, we investigated the feasibility of X-ray computed tomography (X-ray CT) and magnetic resonance imaging (MRI) to identify pest infestation in agricultural products. Three kinds of artificially pest-infested fruits (mango, tangerine, and chestnut) were non-destructively inspected using X-ray CT and MRI. X-ray CT was able to identify all pest infestations in fruits, while MRI could not detect the pest-infested chestnut. In addition, X-ray CT was superior to the quarantine process than MRI based on the contrast-to-noise ratio (CNR), image acquisition time, and cost. Therefore, X-ray CT is more appropriate for the pest quarantine process of fruits than MRI.

• 한국구조물진단유지관리공학회 논문집
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• 제11권1호
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• pp.95-102
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• 2007

박리, 박락 및 들뜸현상과 같은 결함으로 노후화된 숏크리트 자체가 통행차량이나 시설물에 위험요소로 존재함으로써 이에 대한 피해예방이 요구되는 실정이다. 그러나 급격한 경사와 고소작업 등으로 인해 접근이 곤란하며, 외관상으로는 숏크리트 내부 상황 파악이 힘들다는 한계가 지적되고 있다. 본 연구에서는 이러한 기술적 한계를 극복하고자 적외선 열화상을 이용하여 숏크리트면의 미소한 열이동을 측정해 표면에서 관찰할 수 없는 내부의 결함을 조사하고자 하였다. 현장조사, 측정자료 분석과 내시경 카메라를 이용한 현장조사 작업을 통해 검증을 실시한 결과 숏크리트의 과도한 피복으로 인해 습윤부의 정확한 판정은 불가하였으나 내부의 공동부위를 비파괴 비접촉 방식에 의해 효과적으로 추출할 수 있었다.

• Journal of the Korean Statistical Society
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• 제7권1호
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• pp.27-43
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• 1978

This paper deals with the problem of obtaining a minimum cost acceptance sampling plan for destructive testing. The cost model is constructed under the assumption that the sampling procedure takes the following form; 1) lots rejected on the first sample are acreened with a non-destructive testing, 2) the screening is assumed to be imperfect, and therefore, after the screening, a second sample is taken to determine whether to accept the lot of to scrap it. The usual sampling procedures for destructive testing can be regarded as special cases of the above one. Utilizing Hald's Bayesian approach, procedures for finding the global optimal sampling plans are given. However, when the lot size is large, the global plan is very different to obtain even with the aid of an electronic computer. Therefore a method of finding suboptimal plan is suggested. An example with uniform prior is also given.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.510-514
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• 2002

The 3-dimensional measuring machine by using an ultrasonic sensor is used one of the NDE(Non Destructive Examination). It is applied to the inspection of pipelines, boreholes, pressure vessel and tank, and so on. In particular when a harsh environment prohibits the use of moving mechanical parts. The 3-dimensional measuring machine by using an ultrasonic sensor, which measure 1-dimensional information and 2-dimensional information simultaneously from a target of inspection, and then reembody 3-dimensional information. So we can find the situation in progress and predict remaining life and corrosion without destructive examination. It's a point of excellence that the 3-dimensional measuring machine is portable.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.811-816
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• 2000

The joint treatment of concrete is one of the technical problems in top down construction method. Joints created with the top down construction result in serious weakness from the aspects of both structural and water-barrier function. Ultrasonic method was used for the inspection of top down construction joints of column in SRC structure in this study. As a result it has been verified that the semi-direct measurement method is more effective than the other methods for detecting the voids of construction joints.

• Journal of Welding and Joining
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• 제35권2호
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• pp.63-70
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• 2017

As the Non Destructive Test (NDT) for the welded structure, PT(Penetration Test). MT(Magnetic Test), RT (Radioisotope Test) and UT(Ultrasonic Test) methods are widely used in practice. These NDT methods have been developed toward high efficiency, low cost, real time, and high precise new NDT. For example, RT methods are developed to CT(Computed Tomography)and DR(Digital Radiography), and UT metheds are developed into Phased array, Guide wave, TOFD method. Moreover, the Infrared thermography and Laser ultrasonic technique are newly developed for applying in high temperature objects as the non-contact NDT methods. In this review paper the new high efficiency NDT methods for the welded structure are introduced and the trend of NDT rules applying in welded structure are described.

• Composites Research
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• 제30권6호
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• pp.356-364
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• 2017

복합재 격자 구조는 동일한 무게를 갖는 다른 구조에 비해 더 큰 하중을 견딜 수 있다는 장점으로 인해 다양한 분야에 적용이 시도되고 있다. 최근, 국내에서도 복합재 격자 구조 제작을 위한 기술 개발이 이루어지고 있으며 이에 복합재 격자 구조를 빠르고 정밀하게 검사할 수 있는 비파괴검사 기술의 개발 역시 필요하게 되었다. 본 논문에서는 초음파전파 영상화 시스템들을 활용하여 복합재 격자 구조에 빠르고 정밀한 비파괴검사를 하기 위한 연구를 수행하였다. 레이저 펄스에코 초음파전파 영상화 시스템을 통해 스킨에 쌓여 있는 복합재 격자 구조의 내부 리브 구조를 관찰할 수 있었고 접착분리를 검출할 수 있는 가능성을 확인하였다. 또한 검사시간을 줄이기 위해 주파수 영역을 최적화 하기 위한 밴드 디바이더를 개발 적용하였으며, 검사 결과의 질을 향상시키기 위해 곡률 보상 알고리즘을 개발하였다. 유도파 초음파전파 영상화 시스템으로는 리브 구조에 있는 층간분리 결함을 확인할 수 있었으며, 다중 소스 초음파전파영상을 통해 검사 영역을 확대시켰고 가변시간창 진폭 이미지 알고리즘을 통해 결함을 강조시킬 수 있도록 했다. 이와 같은 결과들을 통해 격자구조에 최적화 된 초음파전파 영상화 시스템의 지속적인 개발이 이뤄지면 복합재 격자 구조의 대량생산에 이은 고속 정밀 비파괴검사가 이뤄질 수 있을 것으로 판단된다.