• 한국광학회지
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• 제14권1호
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• pp.97-102
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• 2003

이차원 표면 플라즈몬의 공명 흡수와 포토 마스크를 이용하여 11-MUA(11-Mercaptoundecanoic acid)와 11-MUOH(11-Mercaptoundecanol) 둥으로 이루어진 자기조립 단분자막(Self-Assembled Monolayer; SAM)의 다채널 영상을 얻었다. 통상의 Photoresist를 이용한 리토그래피 대신에 Thiol bonding의 광산화를 이용하여 패터닝 과정을 줄이고, 백색광 및 대역통과 필터(λ$_{0}$=633nm)를 이용하여 입사광으로써 레이저를 사용할 때 나타나는 간섭무늬를 줄였다. 이로부터 나타나는 이차원 영상의 명암을 정량적으로 보정하면 수 나노미터(nm) 두께의 변화를 측정할 수 있다. 또한 표면 플라즈몬 공명법은 국소화된 근접장 (소산장)을 이용하는 방법으로서, 통상 많이 이용되는 형광법 등에서 나타나는 광탈색(Photobleaching)이나 소광(Quenching) 현상이 없이 시료의 처리가 간단하고, 영상 신호의 시간에 따른 변화가 극히 적으며, 실시간으로 신호의 변화를 측정할 수 있다는 장점이 있다.

• 대한디지털의료영상학회논문지
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• 제16권1호
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• pp.49-59
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• 2014

For this study, this researcher conducted a questionnaire survey of college students as juniors who were majoring in radiology at universities located in Daegu and Gyeongbuk. The distribution and collection of the questionnaire copies were made from April 2nd to 30th, 2013 when the researcher explained the purpose of this study to those students and asked them to fill in the documents. Out of the distributed coies, 220 were finally collected and analyzed. The findings of this study can be summarized as follows. 1. Concerning conventional images of the radiological technologists, the male college students of radiology were most affirmative about 'being rational and logical' and 'doing business with putting patients first' while, the female ones of the same major, 'being accurate in doing business' and 'being reliable'. 2. Regarding social images of the radiological technologists. the male college students of radiology were most affirmative about 'being highly intellectual' while, the female ones of the same major, 'being attractive in profession'. 3. In terms of professional images of the radiologist, the college students, irrespective of gender, were most affirmative about 'having highly professional skills' and 'having expertise'. 4. In relation to personal images of the radiologist, both the male and female college students of radiology were most affirmative about 'being kind', but most negative about 'being egocentric'. 5. The radiology students' perceived images of the radiological technologists, and their self-esteem were statistically, significantly correlated with each other. Among those images, conventional ones were found most correlated with self-esteem.

• ETRI Journal
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• 제41권1호
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• pp.84-92
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• 2019

Recent advances in digital holography in the far-infrared region of the spectrum have demonstrated the potential use of digital holography in homeland security as a tool to observe hostile environments in which smoke, flames, and dust impair vision. However, to make this application practical, it is necessary to simplify the optical setup. Here, we show an off-axis, self-reference scheme that spills the reference beam out from the object beam itself and avoids the need for a complex interferometric arrangement. We demonstrate that this scheme allows the reconstruction of high-quality holograms of objects captured under visible as well as far-infrared light exposure. This could pave the way to the industrialization of holographic systems to enable users to see through fire. Moreover, the quantitative nature of the holographic signal is preserved. Thus, the reported results demonstrate the possibility to use this setup for optical metrology.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.638-642
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• 2015

We present a simple method to determine the focal distances of lenses with the Talbot self-images. This method uses only one grating, and a priori knowledge of the period of the grating is replaced with a linear relation between the (de)magnified periods of the Talbot images and the lens-to-grating distance. A thick lens whose effective focal length is 500 mm was used to validate the method, and the focal distance of the converging beam was determined with the difference of 0.15% for the nominal focal distance of 521.9 mm. The determined period of the grating with the difference of 0.2% also supports the validation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.995-998
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• 2013

본 논문에서는 자기 조직화 기능을 갖는 Kohonen의 SOM(Self Organization Map) 신경회로망에 2단계의 학습과정을 활용하여 항공영상에서 물체를 인근의 물체와 효과적으로 구별하기 위한 접근방법을 제안하고 실제의 항공영상에 적용하여 기존의 고전적인 K-means 알고리즘 및 원래의 SOM 알고리즘보다 우수함을 보인다.

• 대한조선학회논문집
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• 제47권3호
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• pp.342-349
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• 2010

This paper is a foundation work in developing a software for generating infrared images from a scene with various objects. The spectral radiance received by a remote sensor is consisted of the self-emitted, reflected and scattered components. In general, the self-emitted component is the most important part for generating Infrared signatures from the object. In this paper, the infrared image generation considering various surface temperature and optical surface property of a flat plate is demonstrated in MWIR($3{\sim}5{\mu}m$) and LWIR($8{\sim}12{\mu}m$) regions for different spatial resolutions of the images. Resulting spectral radiance values in the MWIR($3{\sim}5{\mu}m$) and LWIR($8{\sim}12{\mu}m$) regions arrived at the infrared sensor are compared numerically and graphically by recognizing that they are strongly dependent on the surface conditions such as the surface temperature and the surface emissivity. And these infrared images are also shown to be strongly dependent on the resolutions of the infrared imaging devices as well. This study reveals that the surface conditions are more dependent on the radiance level from the surface while the resolution of the imaging device is more responsible for identifying the shape of object.

• 한국방사선학회논문지
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• 제17권5호
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• pp.775-782
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• 2023

본 연구는 대학에서 고가의 장비로 MRI 기계를 설치, 관리 및 운영에 현실적인 한계를 극복하고자 가상현실(VR)을 자기공명영상장치에 접목하여 콘텐츠를 개발 및 활용하여 가상현실(VR) 체험 교육을 실시하고 향후 의료기관에서도 실제 검사와 유사한 실습을 제공하는 임상 기반 교육용 체험 시스템 개발을 진행하였다. 가상현실 기반 교육용 시스템을 체험한 학생을 대상으로 설문을 진행하여 체험 중 발생할 수 있는 부작용을 파악한 후 교육을 전혀 경험하지 못한 학생들을 대상으로 자기주도학습 능력 및 학업적 자기효능감 조사를 실시하여 가상현실 기반 실습이 학습에 미치는 영향을 분석하였다. 자기주도학습 능력 조사에 대한 분석에서는 교육을 경험한 학생 집단과 경험하지 않은 학생 집단 간의 평균에 차이가 없었으나, 학업적 자기효능감을 분석한 결과에서는 집단별 평균에 유의한 차이가 있었으며, 가상현실 교육 시스템 체험 후 자기평가에서 자기공명영상 학습에 대한 자신감이 향상되었다. 가상현실 기반의 실습 교육을 진행할 경우 새로운 학습방법 제공 및 시간과 공간에 구애받지 않고 언제 어디서나 반복될 수 있는 교육의 기회도 제공할 수 있어 효율적인 실습 시스템을 제공할 수 있을 것으로 사료된다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제35권3호
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• pp.197-209
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• 2024

Objectives: In this functional magnetic resonance imaging study, we aimed to investigate the differences in brain activation between individuals with autism spectrum disorder (ASD) and typically developing (TD) individuals during perspective taking. We also examined the association between brain activation and empathic and interoceptive abilities. Methods: During scanning, participants from the ASD (n=17) and TD (n=22) groups were shown pain stimuli and asked to rate the level of the observed pain from both self- and other-perspectives. Empathic abilities, including perspective taking, were measured using an empathic questionnaire, and three dimensions of interoception were assessed: interoceptive accuracy, interoceptive sensibility, and interoceptive trait prediction errors. Results: During self-perspective taking, the ASD group exhibited greater activation in the left precuneus than the TD group. During other-perspective taking, relative hyperactivation extended to areas including the right precuneus, right superior frontal gyrus, left caudate nucleus, and left amygdala. Brain activation levels in the right superior frontal gyrus while taking other-perspective were negatively correlated with interoceptive accuracy, and those in the left caudate were negatively correlated with perspective taking ability in the ASD group. Conclusion: Individuals with ASD show atypical brain activation during perspective taking. Notably, their brain regions associated with stress reactions and escape responses are overactivated when taking other-perspective. This overactivity is related to poor interoceptive accuracy, suggesting that individuals with ASD may experience difficulties with the self-other distinction or atypical embodiment when considering another person's perspective.

• 방사선산업학회지
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• 제9권3호
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• pp.153-159
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• 2015

Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB non-destructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

• 한국정보통신학회논문지
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• 제24권9호
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• pp.1144-1149
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• 2020

유방조직확장기의 Magnetic Valve는 MRI 검사 시 영상 인공물이 발생하여 MRI 검사가 제한적이다. MRI 검사가 필요한 유방조직확장기 삽입 환자에 대해 영상 인공물이 진단영역에 미치는 영향을 평가한다. 자체 제작한 팬텀과 실제 임상 조건을 이용하여 영상 인공물 측정을 실시하였다. 영상 인공물은 1.5 Tesla와 3.0 Tesla 환경에 따라 상이하게 측정되었으며, C-spine, L-spine 검사 시 영상 인공물의 영향이 T-spine에 비해 상대적으로 적었다. 유방암 전이로 인한 MRI 검사가 꼭 필요한 경우 주로 1.5 Tesla에서 Head & Neck 검사와 L-spine 아래 부위를 검사 할 수 있으나 일부 시퀀스에서는 영상 인공물로 인한 왜곡이 발생할 수 있다. 유방조직확장기 삽입 환자의 MRI 검사는 안전성 측면에서는 3.0T는 피하고 1.5T에서 조건부로 가능하다.