• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.36.1-36.1
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• 2016

This is a presentation of the paper published as Kimm et al. 2016, ApJ, 823, 52. We investigate the formation of metal-poor globular clusters (GCs) at the center of two dark matter halos with $Mhalo{\sim}4{\times}107Msun$ at z>10 using cosmological radiation-hydrodynamics simulations. We find that very compact (${\leq}1$ pc) and massive (${\sim}6{\times}105Msun$) clusters form rapidly when pristine gas collapses isothermally with the aid of efficient $Ly{\alpha}$ emission during the transition from molecular-cooling halos to atomic-cooling halos. Because the local free-fall time of dense star-forming gas is very short (${\ll}1Myr$), a large fraction of the collapsed gas is turned into stars before stellar feedback processes blow out the gas and shut down star formation. Although the early stage of star formation is limited to a small region of the central star-forming disk, we find that the disk quickly fragments due to metal enrichment from supernovae. Sub-clusters formed in the fragmented clouds eventually merge with the main cluster at the center. The simulated clusters closely resemble the local GCs in mass and size but show a metallicity spread that is much wider than found in the local GCs. We discuss a role of pre-enrichment by Pop III and II stars as a potential solution to the latter issue. Although not without shortcomings, it is encouraging that a naive blind (not tuned) cosmological simulation presents a possible channel for the formation of at least some massive GCs.

• Journal of Korea Port Economic Association
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• v.17 no.2
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• pp.29-59
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• 2001

This paper aims to describe port competition in East Asia and the Korean government's port strategy. In doing so, the paper provides an overview of global changes in international trade, the shipping industry and the port business. It also delineates the status of port competition in the region. Particular examples are taken from the competition among the ports of Hong Kong, Singapore, and Malaysia, as well as those of Pusan and Kwangyang, Kaohsiung, Kobe, and Shanghai and Yantian. The port competition in East Asia is reviewed and classified in two groups: north-tier competition among traditional major players, such as Kobe and Pusan, and dark horses such as Shanghai, Kwangyang and perhaps Yokohama; and south-tier competition among the three traditionally big players Kaohsiung, Hong Kong and Singapore, and the relative newcomers of Yantian in China, and Tanjung Pelepas In Malaysia. Due to the enlarging of ships and expansion of port activities, the boundary between the two tier frontiers breakdown, or they may even merge, into one grand frontier, in the foreseeable future. Although it appears that Asian ports are not being very aggressive in preparing for the future of mega-carrier in their plans, it is true that China, Korea and Taiwan are moving full steam ahead in comprehensively developing their container ports on a large scale. It therefore seems to be the perfect time for rival ports to explore a port alliance strategy to fight against the trend toward alliances between of many shipping lines.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.429-431
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• 1998

본 논문에서는 의료 영상 중에서 성대 운동의 불규칙적인 움직임을 판단하여 자동으로 진단 파라미터를 구하는 비디오스트로보키모그래피(Videostrobokymography) 시스템에서 관심 영역을 추출하는 방법을 소개하고자 한다. CCD카메라에 의해 촬영된 영상은 비디오 테이프에 저장된 후 이미지 캡쳐 보드에서 그레이 이미지(gray-level)로 변환되어 저장된다. 입력된 영상은 움직이는 영상을 촬영한 것이므로 관심 영역의 위치가 각 프레임마다 다르다. 또한 실제로 입력된 성대영상들이 점진적인 농도 변화를 보이기 때문에 에지에 의해 영역을 추출하는 일반적인 영역 추출방법은 사용하기 어렵다. 본 논문에서는 두 번의 단계를 통하여 관심 영역을 추출하고 있다. 첫 번째는 입력된 영상에서 노이즈를 제거한 후 각 프레임에서 영상의 최소 에너지를 구한다. 두 번째로 농도 변화 값을 특징 값으로 이용하는 분할-합병 알고리즘(Split-merge Algorithm)을 적용하여 관심 영역을 추출하였다. 제안한 알고리즘을 19명의 성대 영상에 적용하여 분석한 결과 성대의 관심 영역을 추출할 수 있었다. 그리고, 영상의 에너지 값을 이용하는 스네이크 알고리즘(Snake Algorithm)에 적용하여 비교해본 결과 본 연구에서 제안하는 스네이크 알고리즘보다 좋은 성능을 보임을 확인할 수 있었다. 본 연구에서 제안하는 관심 영역 추출 방법은 동적인 변화를 보이는 영상에서 관심 영역을 추출할 수 있을 뿐 아니라 계산 량이 적어 200x280크기의 이미지를 초당 약 40프레임에 대한 관심 영역을 추출할 수 있는 장점이 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.511-513
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• 2000

PaP Smear 테스트는 자궁 경부암 진단에 가장 효율적인 방법으로 알려져 있다. 그러나 이 방법은 높은 위 음성률(false negative error, 15~50%)을 나타내고 있다. 이런 큰 오류율은 주로 다량의 세포 검사에 기인하여, 자동화 시스템의 개발이 절실히 요구되고 있다. 본 논문은 자궁 경부암의 특징인 군집을 이루는 암세포를 인식할 수 있는 시스템을 제안한다. 시스템은 두 부분으로 나누어진다. 첫 단계에서는 저 배율(100배)에서 간단한 영상처리와 최소 근접 트리(Minimum Spanning Tree)를 통해 군집을 이루는 세포를 찾는다. 두 번째 단계서는 고 배율(400배)로 확대하여 군집 세포들로부터 여러 가지 특징을 추출한 후 KNN(k-Neighbor) 방법을 통해 인식하는 단계이다. 50개의 영상 (640X 480, RGB True Color 25 개의 100배 영상 , 25개의 400배 영상)이 실험에 사용되었다. 한 영상을 처리하는데 약 3초 (2.984초) 소요되었으며, 이는 region growing(20초)나 split and merge(58초) 방법 보다 덜 소요되었다. 100배 영상에서 정상과 비정상의 두 그룹으로 나누었을 경우에는 96%의 높은 인식율을 나타내었으나 비정상을 다시 5개의 그룹으로 나누었을 때는 45%로 나타내었다. 이는 영역 추출(segmentation) 단계에서 오류와 트레이닝 데이터의 비정확성에 기인한다. 400배 영상에서는 각각 92%와 30%로 나타내었다. 이는 영역추출 단계에서 사용한 Watershed 방법의 오류로 기인한 것으로 본다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1130-1139
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• 1998

This paper presents an integrated solution for the content-based news video indexing and the retrieval. Currently, it is impossible to automatically index a general video, but we can index a specific structural video such as news videos. Our proposed model extracts automatically the key frames by using the structured knowledge of news and consists of the news item segmentation, caption recognition and search browser modules. We present above three modules in the following: the news event segmentation module recognizes an anchor-person shot based on face recognition, and then its news event are divided by the anchor-person's frame information. The caption recognition module detects the caption-frames with the caption characteristics, extracts their character region by the using split-merge method, and then recognizes characters with OCR software. Finally, the search browser module could make a various of searching mechanism possible.

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.216-224
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• 1997

We present IUE observations in far ultraviolet region for SS Lac in open cluster NGC 7209. The IUE short wavelength spectrum and long wavelength spectrum were merged to produce an energy distribution curve between $1200{AA}$ and $3200{AA}$. The curve has been unreddened to take out reddening effect. Then the surface temperature, gravity and abundance of SS Lac were determined based on the Kurucz model atmosphere. The photographic light curve produced before cessation of eclipse were analyzed for photometric solutions. We confirmed SS Lac is a member of open cluster NGC 7209 based on its possible distance. The main reason for the cessation of eclipse is the change of the system's orbital inclination rather than collisional merge of two stars.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.97-100
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• 2013

In this paper, we propose a detection method of the character rather than cursive, containing many components of the vertical and horizontal direction in complex background image. The characters have many dense corners but the background has few sparse corners. So we use harris corner detector and cluster the corners by using the position of the detected corners for detecting character regions. To merge or filter character regions, we analysis a histogram of gray image of character regions. In each improved region, we compare histograms of R, G, B channels to detect characters.

• Acta Via Serica
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• v.2 no.1
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• pp.109-120
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• 2017

The city of Basra, established on the shore of Basra Bay in the south of modern Iraq, played an important role in agriculture and trade for centuries, with its geography and its position where two great rivers of Mesopotamia flow. Before being established with its current name by the Muslim Arabs, the city was known as Teredon in the Chaldean period and VehiŞtebad ErdeŞir in the Sasanid period. It was reestablished with the name Basra in the early period of Islam by Arabs between Hijri 14-16 (635-637 CE). Afterward, the city became one of the most important centers of trade, science and thought; had a perfect cultural diversity; and hosted important schools of Arabic language and thought for centuries. Besides the commercial effects of its being a transfer point on the axis of Europe, Mesopotamia, Iran, and India, the schools of thought which emerged here were affected by this mobility. In this paper, we try to reveal the philosophical-religious approach which the Ikhwan al-Safa school of thought in Basra, one of the most important cities of the Silk Road, created in parallel with the characteristics of this city. Shiite Ismaili beliefs and thoughts in the region and its characteristics which feed different religions and traditions emerging from Egypt and with the scientific approach of Greek thought; with Indian-Iranian teachings that merge Greek thought and Neoplatonic philosophy, give us the summary of Silk Road civilizations.

• The Journal of Natural Sciences
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• v.6 no.1
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• pp.79-87
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• 1993

In the map of period-doubling bifurcation, stable fixed points bifurcate to $2^n$ fixed points, and in the chaotic region, the chaotic bands merge to 1/$2^n$ bands. In a typical map, the chaotic bands expand to a broad chaotic band during the merging process, so called crisis. In this paper, interior crises appearing during the merging process will be discussed by using our map and will be analyzed the characteristics of the phenomenon by obtaining the Lyapunov Exponents.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.211-230
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• 2022

In image segmentation, for the condition that objects (targets) and background in an image are intertwined or their common boundaries are vague as well as their textures are similar, and the targets in images are greatly variable, the deep learning might be difficult to use. Hence, a new method based on graph theory and guided feathering is proposed. First, it uses a guided feathering algorithm to initially separate the objects from background roughly, then, the image is separated into two different images: foreground image and background image, subsequently, the two images are segmented accurately by using the improved graph-based algorithm respectively, and finally, the two segmented images are merged together as the final segmentation result. For the graph-based new algorithm, it is improved based on MST in three main aspects: (1) the differences between the functions of intra-regional and inter-regional; (2) the function of edge weight; and (3) re-merge mechanism after segmentation in graph mapping. Compared to the traditional algorithms such as region merging, ordinary MST and thresholding, the studied algorithm has the better segmentation accuracy and effect, therefore it has the significant superiority.