• ETRI Journal
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• v.44 no.5
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• pp.816-825
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• 2022

Nondestructive testing, which can monitor a product's interior without disassembly, is becoming increasingly essential for industrial inspection. Computed laminography (CL) is widely used in this application, as it can reconstruct a product, such as a printed circuit board, into a three-dimensional (3D) high-magnification image using X-rays. However, such high-magnification scanning environments can be affected by minute vibrations of the CL device, which can generate motion artifacts in the 3D reconstructed image. Since such vibrations are irregular, geometric corrections must be performed at every scan. In this paper, we propose a geometry calibration method that can correct the geometric information of CL scans based on the image without using geometry calibration phantoms. The proposed method compares the projection and digitally reconstructed radiography images to measure the geometric error. To validate the proposed method, we used both numerical phantom images at various magnifications and images obtained from real industrial CL equipment. The experiment results confirmed that sharpness and contrast-to-noise ratio (CNR) were improved.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.3
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• pp.306-312
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• 2017

Press rolls are constantly exposed to physical and heat stresses on their surface and are prone to crack, bruise, and spall if the accumulated stress goes beyond the critical point. Such surface phenomenon can cause them to lose their functionality and eventually lead to a halted production line. Eddy current testing can be considered a useful method to investigate the surface of the roll. The method involves the application of a high intensity magnetic field onto the surface of the roll, and thereby finding any early stage of possible defects. When the method was applied for roll inspection, the cross section of the sensor was regulated as per the overall testing speed. A smaller cross sectional area implied a better resolution but a longer testing time. In this paper, a convenient method to increase both overall system resolution and inspection speed of eddy current roll inspection is suggested by using a devised array sensor structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.309-310
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• 2006

This paper is about the development of surface inspection of bearing inner and outer race using machine vision. Before this system is developed, most inspections are performed by workers' naked eye. To improve both the inconvenience and incorrectness, another new tester is introduced. This system has the three sections mainly. First one is the mechanism section which transfers bearing manufactured from previous process line to the testing process in plant. Another is the inspection system which is composed of two parts: computer vision and measurement system using laser diode which inspects the defects of the bearing inner or outer race. The other is the pneumatic cylinder part controlled by Programmable Logic Controller(PLC). The system which is developed shows favorable results, and that has the advantage of convenience and correctness compared to previous system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.94-101
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• 2014

Recently, in order to reduce the time required to replace an optical jumper cord, many researchers are using a field-installable connector and applying the ferrule polishing method, ferrule mechanical contact method, or ferrule fusion contact method. However, the process of arranging the length of the optical fiber, i.e., inserting the optical fiber into the ferrule by hand and checking its cross section, takes 60% of the time required for the entire process, which increases the overall cost. Therefore, in order to make this task more cost-effective, we will develop an automated inspection system with automatic cross-sectional arrangement of a field-installable connector. This system will be able to decrease the failure rate from 10% to 2% compared with the conventional method when cutting the optical fiber inserted into the ferrule. It will also improve the productivity by decreasing the test time by 28% compared with the conventional method. Our studies showed that it was possible to reduce the production costs and improve the quality of a field-installable connector, and we expect it to dominate the market.

• Journal of The Korea Institute of Healthcare Architecture
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• v.25 no.1
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• pp.17-27
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• 2019

Purpose: Clinical laboratory in hospital has taken a great role in protection of chronic disease. as well as diagnosis and treatment, And laboratory layout has been considered by the management and laboratory section more than the function and workflow. Methods: So this study figures out the workflows of laboratory sections in the recently upgraded Laboratory Medicine, and searches the functional relationships and spatial block diagram between each disciplines as follows. Literature review and expert adviser has been conducted. Results: 1) Laboratory type of Laboratory Medicine is divided into routine and specialized laboratory according to the workflow by automated or specialized test. 2) The general workflow consists of specimen collection, specimen classification, test by discipline, test report, and specimen disposal. 3) Though the function of each laboratory section is very complicated and specific, the characteristics and the workflow can be shown in detail by each lab through [Figure 4], [Figure 5], [Figure 6], [Figure 7], and [Figure 8]. 4) Functional relationship diagram can be displayed to the adjacency and relation between each laboratory and support spaces. 5) The spatial block diagram could be presented as shown in [Figure 10], in which the emergency lab lay in front side, routine lab in the central open area, and specialized lab in the behind side. Implications: This study can be used as a useful data in planning and designing a Laboratory Medicine Department.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.84-91
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• 2015

In this paper, to overcome disadvantages of existing lining boards, the parametric studies to evaluate safety and verify performance of newly suggested lining boards was performed. Since the calculated stresses of steel plates are lower than the allowable stress for considered all analytical variables, end reinforcement locations, and crane rail loads, it can be concluded that the suggested lining board is structurally safe. Where, "$3,000{\times}2,000{\times}6t$" was select to be optimized cross-section and the reinforcement from the end to 200mm to the internal direction looks like the best case. In addition, the suggested lining board is economical since the steel amount per unit area compared to existing lining board is reduced by 36% and it can apply to the lining structural system of subway and underpass since construction speed is past due to the less installation number of lining boards.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.17 no.2
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• pp.131-155
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• 2013

Objectives A study on the importance of observing face color in the Dongeuibogam and the other things to know when we observe face color. Methods We used Deyuk Dongeuibogam of Dongeuibogam publishing company from original photographic edition. Results (1) In all section(ex. Naekyungpyeon, Oehyeongpyeon and Japbyoungpyeon), the chapters related with observing face color were fifty-one. In Naekyungpyeon, the chapters related with observing face color were nineteen(37%). In Oehyeongpyeon, the chapters related with observing face color were ten(20%). In Japbyoungpyeon, the chapters related with observing face color were twenty-two(43%). In all section(ex. Naekyungpyeon, Oehyeongpyeon and Japbyoungpyeon), the statements related with observing face color were three-hundred and nine. In Naekyungpyeon, the statements related with observing face color were sixty-four(21%). In Oehyeongpyeon, the statements related with observing face color were fifty-two(17%). In Japbyoungpyeon, the statements related with observing face color were one hundred ninety-three(62%). (2) In each chapter, the number of statement related with observing face color was studied. Pediatric Chapter (75) were the most common, followed by The way of finding the cause of a disease (27) Face (26) Cold (24) Weak&Fatigue (12) Phlegm, Jaundice (8) Nose, Worm, Chronic indigestion (7) Mouth&Tongue, Woman, Stool (6) Bodyshape, Liver, Heart, Kidney, Cough (5) Eye, Carbunculosis (4) Blood, Voice, Spleen, Lung, Chest, Fire, Edema, Detoxification (3) in order. (3) In each section(ex. Naekyungpyeon, Oehyeongpyeon and Japbyoungpyeon), the rate of chapter related with observing face color was studied. Naekyungpyeon(73%) was the highest. Japbyoungpyeon(61%). Oehyeongpyeon(38%) was the lowest. Conclusions The importance of each chapter for observing face color in the Dongeuibogam was studied. In addition, the entire ocular inspection, the part ocular inspection, moisture and the difference of skin according to the personal constitution should be considered. There are not only the important parts of the past that does not mean but also the unimportant parts of the past that are meaningful now. Additional studies will be needed for the latter.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.23-31
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• 2018

Recently, there was an collision accident of vehicle-concrete median barrier and unfortunately, passengers were killed by exceeded capacity of concrete median. Therefore, improving the capacity of concrete median barrier is need to reduce damage. Accordingly, in this study, appropriate collision model verified by using the FE analysis program LS-Dyna and recommend a concrete median barrier section. The improvement parameters such as wire mesh diameter, steel plate, rubber pad were selected for improved capacity of the median barrier. Finally, section of concrete median barrier improved wire mesh diameter decreased volume loss, section of concrete median barrier improved rubber pad accepted impact loading and increased elastic area.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.75-81
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• 2011

Recently prestressed concrete bridges are generally used instead of reinforced concrete. PSC is more durable than RC because it can reduce crack problems, reinforcement corrosion, leakage and carbonation etc. And also PSC is more effective because there is no crack in tension area, and the entire concrete section is considered in section analysis. And it can reduce section size because vertical component by prestressing force can reduce the shear force. However, using high strength concrete can increase the self weight of bridge because of it's higher density. So the hollowed PPC girder with light weight aggregate can be a alternative. In this study the hollowed PPC girder with light weight aggregate is designed and the performance of hollowed PPC girder is evaluated by experimental tests as well as numerical analysis. As a result, The hollowed PPC girder of light aggregate behaved fully elastically under service load of 110kN, and the plastic behavior was showed after elastic behavior through experimental test, and it can be also estimated by numerical analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.1-9
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• 2015

Transverse steel bars are used in the plastic hinge zone of columns to insure adequate confinement, prevention of longitudinal bar buckling and ductile behavior. Fabrication and placement of rectangular hoops and cross-ties in columns are difficult to construct. Details of reinforcement for rectangular section require a lot of rectangular hoops and cross-ties. In this paper, to solve these problems, the new lateral confinement method using oblong hoop is proposed for the transverse confinement of the flared column. It can be the alternative for oblong cross-section and flared column with improved workability and cost-efficiency. The final objectives of this study are to suggest appropriate oblong hoop details and to provide quantitative reference data and tendency for seismic performance or damage assessment based on the drift levels such as residual deformation, elastic strain energy. This paper describes factors of seismic performance such as ultimate displacement/drift ratio, displacement ductility, response modification factor, equivalent viscous damping ratio and effective stiffness.