• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.70.1-70.1
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• 2013

New space program for "Next-Generation Small Satellite (NEXTSat)" launched last year after the success of the series of Science & Technology Satellite (STSAT). KASI proposed the near-infrared imaging spectrometer as a scientific payload onboard NEXTSat-1. It was selected as one of two scientific payloads. The approved scientific payload is the near-infrared imaging spectrometer for the study of star formation history (NISS). The efficient near-infrared observation can be performed in space by evading the atmospheric emission as well as other thermal noise. The observation of cosmic near-infrared background enables us to reveal the early Universe in an indirect way through the measurement of absolute brightness and spatial fluctuation. The detection of near-infrared spectral lines in nearby galaxies, cluster of galaxies and star forming regions give us less biased information on the star formation. In addition, the NISS will be expected to demonstrate our technologies related to the development of the Korea's leading near-infrared instrument for the future large infrared telescope, SPICA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.554-557
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• 2016

Recently, supercomputer has been increasingly adopted as a computing environment for scientific simulation as well as education, healthcare and national defence. Especially, supercomputing system with heterogeneous computing resources is gaining resurgence of interest as a next-generation problem solving environment, allowing theoretical and/or experimental research in various fields to be free of time and spatial limits. However, traditional supercomputing services have only been handled through a simple form of command-line based console, which leads to the critical limit of accessibility and usability of heterogeneous computing resources. To address this problem, in this paper, we provide the design and implementation of web-based HPC (High Performance Computing) job management framework for computational scientific simulation. The proposed framework has highly extensible design principles, providing the abstraction interfaces of job scheduler (as well as bundle scheduler plug-ins for LoadLeveler, Sun Grid Engine, OpenPBS scheduler) in order to easily incorporate the broad spectrum of heterogeneous computing resources such as cluster, computing cloud and grid. We also present the detailed specification of HTTP standard based RESTful endpoints, which manage simulation job's life-cycles such as job creation, submission, control and status monitoring, etc., enabling various 3rd-party applications to be newly created on top of the proposed framework.

• Journal of KIISE:Databases
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• v.29 no.5
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• pp.367-380
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• 2002

Due to recent increase in applications requiring huge amount of data such as spatial data analysis and image analysis, clustering on large databases has been actively studied. In a hierarchical clustering method, a tree representing hierarchical decomposition of the database is first created, and then, used for efficient clustering. Existing hierarchical clustering methods mainly adopted the bottom-up approach, which creates a tree from the bottom to the topmost level of the hierarchy. These bottom-up methods require at least one scan over the entire database in order to build the tree and need to search most nodes of the tree since the clustering algorithm starts from the leaf level. In this paper, we propose a novel top-down hierarchical clustering method that uses multidimensional indexes that are already maintained in most database applications. Generally, multidimensional indexes have the clustering property storing similar objects in the same (or adjacent) data pares. Using this property we can find adjacent objects without calculating distances among them. We first formally define the cluster based on the density of objects. For the definition, we propose the concept of the region contrast partition based on the density of the region. To speed up the clustering algorithm, we use the branch-and-bound algorithm. We propose the bounds and formally prove their correctness. Experimental results show that the proposed method is at least as effective in quality of clustering as BIRCH, a bottom-up hierarchical clustering method, while reducing the number of page accesses by up to 26～187 times depending on the size of the database. As a result, we believe that the proposed method significantly improves the clustering performance in large databases and is practically usable in various database applications.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11c
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• pp.1529-1532
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• 2003

최근 인터넷과 모바일 시스템이 급속히 발달함에 따라 이를 통하여 지리정보와 같은 공간데이터를 제공하는 서비스가 증가하였다. 이는 대용량 데이터에 대한 관리 및 빠른 처리와 급증하는 사용자에 대한 높은 동시처리량 및 높은 안정성을 요구하였고, 이를 해결하기 위하여 비공유 공간 데이터베이스 클러스터가 개발되었다. 비공유 공간 데이터베이스 클러스터는 고가용성을 위한 구조로서 문제가 발생할 경우 다른 백업노드가 대신하여 서비스를 지속시킨다. 그러나 기존의 비공유 공간 데이터베이스 클러스터는 클러스터 구성에 대한 회복을 위하여 로그를 계속 유지하므로 로그를 남기기 위해 보통의 질의처리 성능이 저하되었으며 로그 유지를 위한 비용이 증가하였다. 또한 노드단위의 로그를 갖기 때문에 클러스터 구성에 대한 회복이 직렬적으로 이루어져 고가용성을 위한 빠른 회복이 불가능 하였다. 따라서 본 논문에서는 비공유 공간 데이터베이스 클러스터에서 고가용성을 위한 병렬 회복 기법을 제안한다. 이를 위해 클러스터 구성에 대한 회복을 위한 클러스터 로그를 정의한다. 정의된 클러스터 로그는 마스터 테이블이 존재하는 노드에서 그룹내 다른 노드가 정지된 것을 감지할 때 남기기 시작한다. 정지된 노드는 자체회복을 마친 후 클러스터 구성에 대한 회복을 하는 단계에서 존재하는 복제본 테이블 각각에 대한 클러스터 로그를 병렬적으로 받아 회복을 한다. 따라서 정지된 노드가 발생할 경우에만 클러스터 로그를 남기므로 보통의 질의처리의 성능 저하가 없고 클러스터 로그 유지 비용이 적으며, 클러스터 구성에 대한 회복시 테이블단위의 병렬적인 회복으로 대용량 데이터인 공간데이터에 대해 빠르게 회복할 수 있어 가용성을 향상시킨다.들을 문법으로 작성하였으며, PGS를 통해 생성된 어휘 정보를 가지고 스캐너를 구성하였으며, 파싱테이블을 가지고 파서를 설계하였다. 파서의 출력으로 AST가 생성되면 번역기는 AST를 탐색하면서 의미적으로 동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는

• The KIPS Transactions:PartB
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• v.16B no.1
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• pp.7-16
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• 2009

Some clustering algorithms have a problem that an image is over-segmented since both the spatial information between the segmented regions is not considered and the number of the clusters is defined in advance. Therefore, they are difficult to be applied to the applicable fields. This paper proposes the new post-processing methods, a reclassification of the inhomogeneous clusters and a region merging using Baysian algorithm, that improve the segmentation results of the clustering algorithms. The inhomogeneous cluster is firstly selected based on variance and between-class distance and it is then reclassified into the other clusters in the reclassification step. This reclassification is repeated until the optimal number determined by the minimum average within-class distance. And the similar regions are merged using Baysian algorithm based on Kullbeck-Leibler distance between the adjacent regions. So we can effectively solve the over-segmentation problem and the result can be applied to the applicable fields. Finally, we design a classification system for the segmented regions to validate the proposed method. The segmented regions are classified by SVM(Support Vector Machine) using the principal colors and the texture information of the segmented regions. In experiment, the proposed method showed the validity for various real-images and was effectively applied to the designed classification system.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.107-114
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• 2002

In these days, rapid advances of the computer system and the high speed network have made the multimedia services popularized among various applications and services in the internet. Internet live broadcasting, a part of multimedia services, makes it possible to provide not only existing broadcasting services including audio and video but also interactive communications which also expand application scopes by freeing from both temporal and spatial limitation. In the Paper, an interned Personal-live broadcasting server system is developed by allowing individual users to actively create or join live-broadcasting services with such basic multimedia devices as a PC camera and a sound card. As the number of broadcasters and participants increases, concurrent multiple channels are established and groups are to be expanded. The system should also guarantee High Availability (HA) for continuous services even in the presence of partial failure of the cluster. Furthermore, a transmission mode switching is supported to consider network environments in the user system.

• Journal of the Korean association of regional geographers
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• v.22 no.4
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• pp.792-808
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• 2016

Due to the high importance of foreign trade in the national economy, Korea has a lot of ports designated as trade ports compared to the small land size. However, because of the poor utilization results, some small trade ports have been criticized for wasteful financing due to redundant investment in SOC. This is because the characteristics and comparative advantage of foreign trade in trade ports have not been analyzed in detail by region. Therefore, this study analyzes the patterns and types of change in the size of trade, number of cargo items handled, and the number of trade target countries in the past 20 years for 19 domestic small trade ports using the time-series cluster analysis technique. As a result of analysis, Korean small trade ports were classified into five growth pattern types according to the analysis index, and characteristics and implications for each type could be derived. Today, as the foreign trade environment changes drastically and the importance of balanced regional development is emphasized, it is very important to study the growth types and implications of small trade ports and the results of this study are expected to provide meaningful implications for regional port development and operation in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.18-30
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• 2017

The East Sea is almost entirely composed of sandy facies, and the facies type is the major factor influencing benthic polychaete communities. There have been few studies of the effects of environmental factors on benthic polychaetes in thermal discharge areas consisting of different sediment types. This study identified the spatial distribution patterns based on the species composition and distribution of benthic polychaete communities, and the environmental factors influencing benthic polychaetes near power plants were investigated. The polychaete communities in the Uljin, Hupo, and Gori coastal areas near the power plants in the East Sea were seasonally investigated from August 2006 to February 2013. As a result, 283 species were collected. The dominant species were Spiophanes bombyx, Magelona japonica, Lumbrineris longifolia, and Sternaspis scutata. Spiophanes bombyx was the dominant species at Uljin and Hupo, but M. japonica was the dominant species at Gori. Two dominant species from the coastal waters of the East Sea, Lumbrineris longifolia and M. japonica, were rare in the power plant water intake or drainage areas. Cluster analysis was performed to divide the study area into groups by the total organic carbon content, sediment grain size and facies patterns. This study suggests that the community structures of polychaetes are more affected by the total organic carbon, grain size of sediment and facies than by disturbance from thermal discharge, which only affected the polychaete community near power plant drainage areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.525-533
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• 1999

In the Korea Strait total of 96 copepod taxa (40 genera) were identified from the seasonal and vertically stratified samples. Species richness was the highest in fall and the abundance was the highest in spring. Spatial differences were not significant within each season, but was meaningful among seasons. The water column layers of high abundances were near bottom in spring, and surface in summer and fall. Species association of copepods was examined by the cluster analysis. There are the two different results on the timing of the intrusion of East Sea Cold Water to the Korea Strait in the deeper layer based on physical data [in winter (Lee et al., 1938) vs in summer (Cho and Kim (1998)]. This study based on the distributional characteristics of copepods supported Cho and Kim (1998)'s result. Although sea water temperatures was one of major controlling factors of the copepod distribution in this strait, biological interrelation among the species such as common or exclusive exploitation of the habitat was also responsible for the observed distributional patterns.

• Korean Journal of Remote Sensing
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• v.11 no.3
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• pp.1-21
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• 1995

The characteristics of the Asian summer monsoon have been investigated for the periods of 1993/1994, the contrasting years in a view of the summer monsoon precipitation. In order to investigate the monsoon features over the eastern Asian monsoon region, the cloudiness(using the extensive data derived by the geostationary meteorological satellite), the condition of underlying surface including sea-surface temperature, and the summer rainfall are analyzed and some comparisons with 1993 and 1994 are also made and the characteristic differences are discussed. An analysis of the 2-degree latitude-longitude gridded 5-day mean high cloud amount data shows the detailed movement and persistence of the convective activities. In order to describe the spatial and temporal structures of the intraseasonal oscillation for the movement and evolution of the monsoon cloud, the extended empirical orthogonal fnction analysis with the twenty-day window size is used for the each year. Also, in order to find out the periodicity of the equatorial convective cluster, Fourier harmonic analysis is applied to the each year. The most prevailing intraseasonal oscillations of high cloud amount are 61 day mode and 15day mode in the equatorial and the subtropical oceans. However it was found that the most prevailing modes over the equatorial western Pacific and Indian Ocean were different for each year, hence raising the possibillity that the contrasting monsoon presipitation may be more fundamentally related to the interaction of intraseasonal oscillations and seasonal variation of convective activities over the lower latitude ocean.