• Proceedings of the Korean Society of Radiological Science
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• 1994.05a
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• pp.41-43
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• 1994

• Proceedings of the Korean Society of Radiological Science
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• 1992.05a
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• pp.30.2-32
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• 1992

• The Journal of the Korean dental association
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• v.39 no.2 s.381
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• pp.104-108
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• 2001

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.132-133
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• 2011

• Proceedings of the Korean Society of Radiological Science
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• 2002.10a
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• pp.20.1-20.2
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• 2002

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.518-519
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• 2016

AOI 검사기는 SMT 공정 상에서 PCB (printed Circuit Board) 상의 부품들을 카메라로 촬영하고 촬영된 영상을 2D 혹은 3D 형태의 이미지로 재구성하고 분석하여 이상 여무를 판단하는 장비다. 검사를 하고자 하는 PCB의 크기가 카메라가 촬영할 수 있는 영역 보다 큰 경우가 대부분이기 때문에 PCB 상에 마운트 되어 있는 부품들을 모두 촬영하기 위해서는 여러 차례 나누어 촬영해야 할 필요가 있으며 이 때문에 PCB 상에 촬영해야 하는 부품들을 가능한 FOV에 많이 포함될 수 있도록 여러 FOV 영역으로 나누고 이렇게 나누어진 FOV 영역들을 최적의 경로로 이동하며 촬영할 수 있도록 하기 위한 알고리즘이 필요하다. 기존 논문들은 대부분 이 문제를 해결하기 위한 알고리즘에 대해 다루어 왔다. 일반적으로 생산이 진행되는 시점에서는 검사해야 할 PCB에 대한 정보 (PCB의 크기, 부품의 위치, 크기, 종류 등)는 이미 정해져 있기 때문에 경로 계획 최적화 수행은 PCB 정보에 변동이 없다면 한차례만 하면 된다. 하지만 검사를 할 수 있도록 Teaching 하는 단계에서는 PCB 정보가 지속적으로 변경될 수 있으며 이에 따라 최적화를 여러 차례 수행해야 할 필요성이 있다. 최적화를 위한 처리 시간은 부품의 개수, PCB 상에서의 분포정도등에 따라 증가하기 때문에 PCB 정보가 변경될 때 마다 최적화를 수행하게 되면 비효율적으로 처리 시간이 증가하게 된다. 본 논문에서는 이 문제에 대해 연구하고 해결책을 제시하였다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.53-56
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• 2010

An aerial multi-looking camera system equips itself with five separate cameras which enables acquiring one vertical image and four oblique images at the same time. This provides diverse information about the site compared to aerial photographs vertically. However, multi-looking Aerial Camera for building a 3D spatial information don't use a large-size CCD camera, do uses a medium-size CCD camera, if acquiring forward, backward, left and right imagery of Certain objects, Aerial photographing set overlap and sidelap must be considered. Especially, Sideward-looking camera set up by the sidelap to determine whether a particular object can be acquisition Through our research we analyzed of sideward footprint and aerial photographing efficiency of Multi-view imagery by sidelap changing.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.273-279
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• 2012

Purpose : This study was aimed to calculate effective dose from cone beam CT and compare effective dose from periapical and panoramic radiography for mesiodens. Materials and Methods : Upper anteiror periapical, panoramic radiography and cone-beam CT were taken for diagnosis of mesiodens. The effective dose were calculated by using an anthropomorphic phantom loaded with thermoluminescent dosimeters at the 23 sites related to sensitive organs. Results : The highest absorbed doses were received by the mandibular body, parotid gland and cheek from periapical, panoramic and cone-beam CT, respectively. The effective doses for periapical, panoramic radiography and cone-beam CT measured 2, 18 and 48 ${\mu}Sv$. Conclusion : Cone-beam CT, although providing additional diagnostic benefits, exposes patients to higher levels of radiation than conventional periapical and panoramic radiography.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.203-209
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• 2013

Digital Radiography (DR) has improved a quality of resolution based on a wide dynamic range, high detective quantum efficiency (DQE), and modulation transfer function (MTF), compared with film/screen(F/s). Unlike expectation that a low level of radiation can be used in examination, high level of signal to noise ratio(SNR) due to over-exposure caused increase of exposed dose to patients. Also, the auto exposure control (AEC) using Kilovolage(kVp) in F/S can cause over-exposure. Hence, in this study, we proposed a proper method for using DR, in which effect of tubing Kilovolage on device's image, DR MTF measurement with changes of tubing current (mA), and the quantitative evaluation of skull phantom captured images' PSNR were evaluated. Changes of contrast with tubing Kilovolage can be improved by retouching, and MTF changes according to tubing current(1.41~1.39 lp/mm in 50% area, and 3.19~2.8 lp/mm in 10% area) does not influence on resolution of image. As a result, high tubing Kilovoltage, and tubing current will be suitable to use of DR.

• Journal of Oral Medicine and Pain
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• v.37 no.2
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• pp.125-133
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• 2012

TMJ Osteoarthritis is a degenerative disease caused by overload on joint tissue, and often accompany with local tenderness on the joint, crepitus by mandibular movement, restriction of mandibular movement, and anterior openbite. In general, panoramic radiography, TMJ panoramic radiography, and transcranial radiography are conducted to diagnose osteoarthritis after clinical examination, however, these radiographic evaluations are limited in detecting minute bony changes of early pathologic lesion. The aim of this pilot study was to evaluate the limitation and usefulness of several TMJ imaging techniques, so we compare the findings from clinical examination, plain film radiographs, tomograph, and bone scan from 81 patients with temporomandibular joint disorder. The proportion of patients showing same findings in plain film radiographs, TMJ tomograph, and bone scan was high, however, it is desirable that clinician should conduct phased imaging examinations according to the clinical findings due to the possibilities of false negative findings in diagnosis of osteoarthritis.