• 천문학회보
• /
• 제42권1호
• /
• pp.30.1-30.1
• /
• 2017

In the hope to detect low-surface brightness features (${\mu}_{r^{\prime}}{\sim}27\;mag\;arcsec^{-2}$), we carried out KASI-Yonsei Deep Imaging Survey for Clusters (KYDISC) targeting 14 local clusters at 0.016 < z < 0.145 using Magellan/IMACS telescope and CFHT/MegaCam. Out of 1450 cluster galaxies, 18% of galaxies show the signatures of galaxy mergers. We explore merger-driven changes from various point-of-view. We first examine color-magnitude relations, and find that galaxies related to recent mergers are populated more on blue color than their counterparts. Besides, we find the extremely low frequency of mergers on low-mass red-sequence galaxies, suggesting a migration of red galaxies into the green-valley region through merger-driven star-formation. We also study the mass-size relation of our sample, finding a larger galaxy size in galaxies related to recent mergers. Our results suggest that mergers can simultaneously change properties of galaxies, making outliers on galactic scaling relations.

• 천문학회보
• /
• 제43권1호
• /
• pp.49.2-49.2
• /
• 2018

Flux calibration for narrow band photometric data gives us an opportunity to get a line flux of extended targets. We developed flux calibration processes for narrow band photometry using broad band filters as a continuum indicator. We derived parameters for color correction and zero point correction including color terms. Applying our method, we successfully subtracted continuum emissions and calibrated the emission lines from an FU Ori type object, V960 Mon.

• 대한기관식도과학회지
• /
• 제3권1호
• /
• pp.159-163
• /
• 1997

The complications of deep neck infection have become much less common in the antibiotic era. The vascular complications of deep neck infection can have devasting consequences. Most commonly, the internal carotid artery is involved, although the common carotid and external carotid artery can also be affected.0 the cases of patients with a protracted course, recurrent bleeding, cranial neuropathies, or trismus, the presence of vascular complications must be considered. Appropriate imaging should be carried out to allow the localization of the infection and ascertain the status of the vessels in the neck The vascular structures can be imaged with duplex doppler or color doppler flow ultrasound to see the flow between the mass and vessels. Also angiography plays a key role in the diagnosis and management of vascular complication of deep neck infection. Prompt diagnosis and treatment of these patients is necessary to prevent significant hemmorrhagic complications. We experienced a case of pseudoaneurysm of the common carotid artery secondary to deep neck infection treated successfully with surgical excision in 45-year-old-male.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2003년도 하계학술발표회
• /
• pp.82-83
• /
• 2003

PC의 대량 보급과 인터넷 케이블 망의 전지역적 구축을 통해 디지털 정보의 교류가 활발히 이루어지고 있다. 이에 따라 아날로그 이미지를 디지털화 하는 디지털 카메라나 스캐너와 같은 이미지 입력 장치와, 디지털 이미지를 눈으로 볼 수 있게 하는 모니터나 프린터와 같은 이미지 출력 장치로 구성되는 디지털 이미징 장치들의 사용이 일상화되고 있다. TV나 컴퓨터 모니터를 통한 인터넷 상품 구매는 이미 보편화되어 있고, 스캐너를 사용하여 사진을 스캔하여 수정이나 합성 등의 편집을 한 후 이미지를 웹에 올리거나 사진 프린터로 다시 뽑는 일에도 익숙해져 있다. (중략)

• Journal of the Optical Society of Korea
• /
• 제19권3호
• /
• pp.303-310
• /
• 2015

An image-space telecentric lens for an intra-oral 3D scanner was designed and fabricated for dental application. Since a telecentric function can provide the same results regardless of image plane position, it helps to realize a more accurate image for an intra-oral scanner. The performance of the designed lens meets the required properties for HD resolution. In particular, lateral color is corrected within 1 pixel. This system achieves depth of focus of more than 3 mm. For user convenience, the developed system consists of a prism part and an imaging part. Both parts are optimized to reduce the front size and weight of the system. In order to make the parallax sights, parallax angle was determined to be 8 degrees between two optical systems.

• Annals of Occupational and Environmental Medicine
• /
• 제34권
• /
• pp.26.1-26.13
• /
• 2022

It is important to assess the blood flow of fingers in the verification of hand-arm vibration syndrome. In the Republic of Korea, most assessments of the blood flow in the fingers are performed using a cold provocation test with finger skin color change. However, this test is a non-objective method with a relatively low sensitivity, leading to possible social and legal problems. Thus, we reviewed the characteristics of several tests that assess the blood flow in the fingers. Among these tests, using the radioactive isotope method, Raynaud's scan has a relatively higher sensitivity and specificity than other tests, provides objective results, and is approachable in many hospitals. So we suggest using Raynaud's scan as an alternative test when cold provocation test with finger skin color change is negative in vibration exposed worker.

• ETRI Journal
• /
• 제29권5호
• /
• pp.697-699
• /
• 2007

Spatiograms are histograms augmented with spatial means and covariances to capture a richer description of the target. We present a particle filtering framework for region-based tracking using spatiograms. Unlike mean shift, the framework allows for non-differentiable similarity measures to compare two spatiograms; we present one such similarity measure, a combination of a recent weighting scheme and histogram intersection. Experimental results show improved performance with the new measure as well as the importance of global spatial information for tracking. The performance of spatiograms is compared with color histograms and several texture histogram methods.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
• /
• pp.170.2-170.2
• /
• 2015

Enormous interest in trivalent rare-earth (RE) ions activated luminescent materials has been gaining owing to their promising applications in bio-imaging, solar cells, white light-emitting diodes and field-emission displays. Among these trivalent RE ions, dysprosium (Dy3+) was widely investigated due to its unique photoluminescence (PL) emissions. A series of Dy3+-activated CaWO4 phosphors were prepared by a facile high-temperature solid-state reaction method. The X-ray diffraction, PL spectra, cathodoluminescence (CL) spectra as well as PL decay curves were used to characterize the prepared samples. Under ultraviolet light excitation, the characteristic emissions of Dy3+ ions were observed in all the obtained phosphors. Furthermore, the PL emission intensity increased gradually with the increment of Dy3+ ion concentration, reaching its maximum value at an optimized Dy3+ ion concentration. Additionally, color-tunable emissions were obtained in Dy3+-activated CaWO4 system by adjusting the Dy3+ ion concentration and excitation wavelength. Ultimately, strong CL properties were observed in Dy3+-activted CaWO4 phosphors. These results suggested that the Dy3+-activted CaWO4 phosphors may have potential applications in the field of miniature color displays.

• 한국전기전자재료학회논문지
• /
• 제23권10호
• /
• pp.820-825
• /
• 2010

In this study, we intended to design the optimal Fermi filter to apply the k-space date that is knee image of the rheumatoid arthritis patient acquired from the MRI (magnetic resonance imaging) instrument. After deciding the suitable coefficient for the Fermi filter, the results were compared with modified Fermi filter and inverse Chebyshev filter, Chebyshev filter, Elliptic filter and Butterworth filter. Firstly, in comparison to the results, the radiologist confirmed that modified Fermi filter was best decision for boundary of the rheumatoid arthritis images. The number of the black voxels of the histogram showed the quantity of the results. At the proposed filter images, numbers of the blacks voxels were statistically decreased. That meant voxels only appeared the black color were changed to others voxels color. Because the number of the total voxels was fixed, the area appeared block color could be effected to the other areas. If the modified Fermi filter were used for rheumatoid arthritis patient, the result will be better than other filters.

• 한국멀티미디어학회논문지
• /
• 제18권12호
• /
• pp.1439-1444
• /
• 2015

Measuring spectral reflectance can be regarded as obtaining inherent color parameters, and spectral reflectance has been used in image processing. Model-based spectrum recovering, one of the method for obtaining spectral reflectance, uses ordinary camera with multiple illuminations. Conventional model-based methods allow to recover spectral reflectance efficiently by using only a few parameters, however it requires some parameters such as power spectrum of illuminations and spectrum sensitivity of camera. In this paper, we propose an enhanced model-based spectrum recovering method without pre-measured parameters: power spectrum of illuminations and spectrum sensitivity of camera. Instead of measuring each parameters, spectral reflectance can be efficiently recovered by estimating and using the spectrum characteristic matrix which contains spectrum parameters: basis function, power spectrum of illumination, and spectrum sensitivity of camera. The spectrum characteristic matrix can be easily estimated using captured images from scenes with color checker under multiple illuminations. Additionally, we suggest fast recovering method preserving positive constraint of spectrum by nonnegative basis function of spectral reflectance. Results of our method showed accurately reconstructed spectral reflectance and fast constrained estimation with unmeasured camera and illumination. As our method could be conducted conveniently, measuring spectral reflectance is expected to be widely used.