• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.3-5
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• 2017

가상 현실 시장은 꾸준한 성장을 하고 있다. 가상 현실 시장이 성장함에 따라 게임 엔진을 이용한 가상 현실콘텐츠 뿐만 아니라 실제 특수 디바이스를 이용하여 촬영한 $360^{\circ}$ 비디오 콘텐츠 시장도 성장하고 있다. 하지만 실제로 촬영한 $360^{\circ}$ 비디오같은 경우 4D 가상 현실 콘텐츠를 즐기기 위해서는 먼저 특수 장치와 $360^{\circ}$ 비디오 간의 이벤트를 정의해야 하는 성가심이 있다. 이러한 불편함을 극복하기 위해 물리적 감각 효과를 일으키는 객체를 인식하고 서술하는 기법을 제시한다. $360^{\circ}$비디오 내의 감각 효과를 일으키는 객체를 인식하고 좌표계 내에 위치를 설정하여 사용자와의 거리가 임계값 이하면 효과를 일으키게 하여 사전에 콘텐츠를 확인하고 감각 효과를 미리 설정하는 번거로움을 없앨 수 있다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.157-162
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• 1998

양전자 단층 촬영장치(PET)에 사용되는 주요 양전자 방출 핵종들의 생성 단면적을 평가하였다. 평가한 생성 반응들은 $^{14}$ N(p,$\alpha$)$^{11}$ C,$^{16}$ O(p,$\alpha$)$^{13}$N, $^{14}$ N(d,n)$^{15}$ O,$^{18}$ O(p,n)$^{18}$ F,$^{20}$ Ne(d,$\alpha$)$_{18}$ F 이며, 입사 입자의 에너지 범위는 반응 문턱 에너지부터 약 150 MeV까지이다. 또한 하전입자 범 모니터용 표준 단면적으로서 $^{27}$ Al에 d 및 $^3$He, $\alpha$가 반응하여 $^{22}$ Na가 생성되는 반응의 단면적들을 입사 에너지 약 120 MeV까지 평가하였다. 실험치를 fitting하게나 ALICE95 코드를 이용하여 이론적 계산을 수행하였는데, 평가 단면적의 표준 편차는 10-30%이다 이들 평가 단면적들은 가속기를 이용한 PET용 핵종의 생산율 계산 및 빔 모니터의 표준 단면적으로 사용하기에 적절한 것으로 판단된다.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.235-236
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• 2007

CCD(Charge-Coupled Device) 혹은 CMOS (Complementary Metal Oxide Semiconductor)와 같은 소자를 이용하여 빛을 전기적 신호인 Image로 재구성하는 촬상소자(Color Capture Device)는 촬영환경이 어두워지면 Dynamic Range가 작아지고, Noise가 상대적으로 심해진다[1][2]. 본 논문에서는 촬영 환경이 어두울 때, Resolution을 Preserving하는 Pixel Pitch가 큰 촬상 소자와 Motion Blur를 억제하는 Exposure Time이 긴 촬상 소자의 조합을 신호처리로 구현하여, 신호의 Power를 향상시켜 Dynamic Range를 키우고 Noise의 Boost-up을 억제하여 SNR(Signal to Noise Ratio)을 향상시키는 방식으로, 촬상 장치의 감도를 향상시켜 화질을 개선하는 방법을 제안한다.

• Annual Conference of KIPS
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• 2023.11a
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• pp.271-273
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• 2023

불수의적인 혀 움직임과 떨림은 다른 신체 부위의 떨림증상이 없이 혀만 움직이는 증상을 말하며, 신경 정신과적 문제와 한의학의 기혈허약 등의 증상에 의해 발생할 수 있다. 혀 영상 촬영 장치로 정면과 측면의 혀를 연속을 촬영하여 혀의 움직임과 떨림을 탐색하려 한다. 혀의 표면은 코너와 같은 특징점을 구하기 어려운 모양이므로 혀의 움직임의 특성을 찾아내는 것은 매우 어려운 일이다. 움직임을 추적하는 방법 중에서 Farnebäck optical flow 방법은 모든 픽셀에 대해서 optical flow를 계산하여 혀의 움직임을 추적할 수 있었다. 이러한 움직임의 크기를 정면과 측면 영상에 대해서 구할 수 있었고, 움직임의 방향도 구할 수 있었다. 혀의 움직임과 떨림에 대한 위치별 정보와 세기 정보를 이용하여 건강상태를 진단할 수 있을 것으로 생각된다.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.421-427
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• 2016

We aim to offer basic materials about infection management through conducting bacterial contamination test about general radiography equipment and CT equipment installed in ER of three general hospitals with 100 sickbeds or more located in Gyeongsangbuk-do Province, and suggest management plan. It had been conducted from 1st December 2015 to 31st December, and objects were general radiography equipment and CT equipment of emergency room located in Gyeongsangbuk-do Province. For general radiography equipment, sources were collected from 4 places such as upper side of control box which employees use most, upper side of exposure button, whole upper side of table which is touching part of patient's skin, upper side of stand bucky's grid, and where patients put their jaws on. For CT equipment, sources were collected from 3 places such as upper side of control box which radiography room employees use most, X-ray exposure button, whole upper side of table which is touching part of patient's skin, and gantry inner. Surface contamination strain found at general radiography equipment in emergency room of radiology are Providencia stuartii(25%), Stenotrophomonas maltophilia(18%), Enterobacter cloacae(8%), Pseudomonas species(8%), Staphylococcus epidermidis(8%), Gram negative bacilli(8%), and ungrown bacteria at incubator after 48 hours of incubation (67%) which is the biggest. Most bacteria were found at upper side of stand bucky-grid and stand bucky of radiology's general radiography equipment, and most sources of CT equipment were focused at patient table, which means it is contaminated by patients who have various diseases, and patients who have strains with decreased immunity may get severe diseases. Thus infection prevention should be made through 70% alcohol disinfection at both before test and after test.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.1
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• pp.15-22
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• 2017

With the advance of Internet Technology, various social network services are created and used by users. Especially, the use of smart devices makes that multimedia contents can be used and distributed on social network services. However, since the crime rate also is increased by users with illegal purposes, there are needs to protect contents and block illegal usage of contents with multimedia forensics. In this paper, we propose a multimedia forensic technique which is identifying the video source. First, the scheme to acquire the sensor pattern noise (SPN) using morphology filtering is presented, which comes from the imperfection of photon detector. Using this scheme, the SPN of reference videos from the reference device is estimated and the SPN of an unknown video is estimated. Then, the similarity between two SPNs is measured to identify whether the unknown video is acquired using the reference device. For the performance analysis of the proposed technique, 30 devices including DSLR camera, compact camera, camcorder, action cam and smart phone are tested and quantitatively analyzed. Based on the results, the proposed technique can achieve the 96% accuracy in identification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.594-596
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• 2022

This paper relates to a system for pre-processing high-definition images acquired through a camera mounted on an unmanned aerial vehicle(UAV) and transmitting them to a server through a mobile communication network. In the case of the existing UAV system for image acquisition service, the acquired image was stored in the external storage device of the camera mounted on the UAV, and the image was checked by directly moving the storage device after the flight was completed. In the case of this method, there is a limitation in that it is impossible to check whether image acquisition or pre-processing is properly performed before directly checking image data through an external storage device. In addition, since the data is stored only in an external storage device, there is a disadvantage that data sharing is cumbersome. In this paper, to solve the above problems, we propose a system that can remotely check images in real time. Furthermore, we propose a system and method capable of performing pre-processing such as geo-tagging and transmission through a mobile communication network in addition to image acquisition through shooting in an UAV.

• Conservation Science in Museum
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• v.3
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• pp.1-7
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• 2001

The gilded bronze Sarria reliquary(National Treasure No. 325-1) excavated from a five story tower in Songlim Temple is considered as a very important Sarria reliquary of Unified Silla Dynasty Kingdom along with glass Sarria containers excavated in package. It was found that this Sarria container was in a very weak condition in the conservation dept. of National Museum of Korea due to the wearing of the inside wood and the decay of the gilded bronze, so a conservation treatment was conducted by focusing on the prevention of further decay and wearing. Also because there is little information about Sarria reliquary, detailed investigation by means of precision actual measurements, microscopic examination and X-ray photography was carried out.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.383-387
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• 2013

Diagnostic imaging systems play a critical role in obtaining anatomical images, which increases the frequency of inspection all over the world. However the likelihood that patients are exposed to relatively high radiation dose increases, which may lead to an increase of patient dose due to unnecessary radiation exposure unless appropriate management is accompanied. Thus the revised edition of IEC 60601-2-44 which is constancy tests for CT equipment which is designated as special medical equipment and is subject to safety management was studied. The results suggested the 3rd has been revised rationally in order to overcome the limitations in the 2nd by adopting clear and enhanced references, which implies the replacement of IEC 60601-2-44 2nd edition with IEC 60601-2-44 3rd will prevent the patients from the harm from improper medical equipment.

• Journal of Broadcast Engineering
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• v.17 no.3
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• pp.491-502
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• 2012

Flat panel-based parallax barrier or lenticular based 3D display devices that have been developed recently are designed to feel depth. In order to see a three-dimensional(3D) image by the display device, a multi-view image displayed on the flat panel must be regenerated from images of multi-views using a subsampling method. Previous subsampling methods are focused on reducing crosstalk. In this paper, we focus on a misalignment that is occurred on manufacture process of slanted parallax barrier based autostereoscopic display device. Therefore, we propose a interleaving method that considers tilt of slanted parallax barrier, aperture size, and distance between an autostereoscopic display device and a viewer to see a 3D image regardless of a viewer position.