• 대한수학회보
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• 제42권2호
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• pp.337-358
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• 2005

Let M be a real hypersurface with almost contact metric structure $(\phi,\;\xi,\;\eta,\;g)$ in a nonflat complex space form $M_n(c)$. In this paper, we prove that if the structure Jacobi operator $R_\xi$ commutes with both the structure tensor $\phi$ and the Ricc tensor S, then M is a Hopf hypersurface in $M_n(c)$ provided that the mean curvature of M is constant or $g(S\xi,\;\xi)$ is constant.

• 한국CDE학회논문집
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• 제14권4호
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• pp.217-224
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• 2009

Most divide-and-conquer implementations for Delaunay triangulation utilize quad-edge or winged-edge data structure since triangles are frequently deleted and created during the merge process. How-ever, the proposed divide-and-conquer algorithm utilizes the array based data structure that is much simpler than the quad-edge data structure and requires less memory allocation. The proposed algorithm has two important features. Firstly, the information of space partitioning is represented as a permutation vector sequence in a vertices array, thus no additional data is required for the space partitioning. The permutation vector represents adaptively divided regions in two dimensions. The two-dimensional partitioning of the space is more efficient than one-dimensional partitioning in the merge process. Secondly, there is no deletion of edge in merge process and thus no bookkeeping of complex intermediate state for topology change is necessary. The algorithm is described in a compact manner with the proposed data structures and operators so that it can be easily implemented with computational efficiency.

• 대한건축학회논문집:계획계
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• 제34권3호
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• pp.93-104
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• 2018

This study is about occurrence pattern of vacant spaces as a urban decline indicator to consider a decline of old hillside residential area from spatial structure perspective. For investigation based upon vacant space and the street structure, this study selects Ami Chojang-dong in Seo-gu, Busan, of which 79.7% of total area is over a gradient of $10^{\circ}$. Focused on relationship between occurrence pattern of vacant spaces and 'vertical alleys(link)' serving as main movement path of local residents in hillside residential area, the length, numbers, slopes, and use characteristic of vertical alleys were analyzed using Arc GIS 9.3 program to classify characteristic zone types of spacial structure in hillside residential area. After the occurrence pattern of vacant space are interpreted in relation with building density, vertical alleys' number length slope, the social and economic issues have been considered as well. After analyzing the occurrence pattern of vacant space, this study argues that the occurrence pattern of vacant space in old hillside residential area is rather affected by street structure system consisting of vertical alleys than the impacts of social economical issues.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.221-228
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• 2012

An active compensation method for the deformation of composite structures using additional controllable metal parts is proposed, and its feasibility is experimentally investigated in a simulated space environment. Composite specimens are tested in a vacuum chamber, which is able to maintain pressure on the order of 10-3 torr and interior temperature in the range of ${\pm}30^{\circ}C$. The displacement-measuring interferometer system, which consists of a heterodyne HeNe laser and an interferometer, is used to measure the displacement of the whole structure. Meanwhile, the strain of the composite part and temperature of both parts are measured by fiber Bragg grating sensors and thermistors, respectively. The displacement of the composite structure is maintained within a tolerance of ${\pm}1{\mu}m$ by controlling the elongation of the metal part, which is bonded to the end of the composite part. Also, the possibility of fiber Bragg grating sensors as control input sensors is successfully demonstrated using a proper corrective factor based on the specimen temperature gradient data.

• 한국통신학회논문지
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• 제19권9호
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• pp.1702-1709
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• 1994

한글인식 후처리에서 문맥정보의 저장구조는 인식율 및 인식속도를 결정짓는 중요한 요소이다. 단어사전의 형태로 문맥정보를 표현하기 위해서는 트라이(trie)를 주로 이용하지만, 기억공간 이용효율이 저조하다는 단점이 있다. 따라서 이 논문에서는 트라이의 장점을 유지하면서 공간효율을 향상시키는 기억구조를 제안한다. 한글은 조합문자이기 때문에 자모나 문자별로 기억시킬 수 있다. 그런데 자모단위로 기억시키면(P-모드) 검색시간은 빠르지만 공간효율이 나쁘고, 또한 문자단위로 기억시키면(C-모드) 공간효율은 좋지만 검색시간이 길어진다. 따라서 노드이용율과 분산율로 최적레벨을 선정한 다음, 입력단어의 시작자모부터 최적레벨까지는 자모 단위의 트라이로 기억시키고, 그 이상은 문자단위의 순차연결구조로 저장시켰다. (H-모드). 6가지 단어집합에 대하여 실험한 결과, H-모드에서의 검색시간은 P-모드만큼 빠르면서, 공간효율은 C-모드와 같게 되어 그 효용성을 확인할 수 있었다.

• 천문학회보
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• 제42권1호
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• pp.38.3-39
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• 2017

The N159 and N160 ionized regions in the Large Magellanic Cloud are an important extragalactic star-forming complex. The physical environments and the star formation stages are different in N159 and N160. We performed near-infrared polarimetry to those star forming regions with IRSF/SIRPOL 1.4-m telescope. Near-infrared polarization enabled us to trace the detailed structure of magnetic fields in star-forming regions. Through the polarimetric data of J, H, and Ks bands, we examined the magnetic field structures in the N159/N160 complex. In this presentation, we show complex distribution of the magnetic fields associated with dust and gas structures. We verify the local magnetic fields in each star-forming region, which appear to be related with local environments, such as interior and boundary of shell structure, star-forming HII regions, and boundaries between HII regions and dense dark clouds. We discuss the formation scenario of the N159/N160 complex suggested from the magnetic field structure.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2008년도 춘계 학술발표회 논문집
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• pp.119-124
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• 2008

대공간 구조물은 3차원적인 힘의 흐름과 면내력에 의해 외부하중에 대한 저항 능력을 극대화 시킨 형태 저항 구조로서, 일반적인 골조와는 달리 부재에 대한 유한 변형을 동반 하므로 정적, 동적 해석에 관계없이 비선형 해석이 요구 된다. 대공간 구조물의 정확한 구조 해석을 수행하기 위해서는 기하학적 비선형 및 재료적 비선형 뿐 아니라 복합적인 비선형 해석이 필요하다. 기하학적 비선형 문제가 구조재료의 특성 및 위치에 따른 비선형을 고려하지 못하고, 구조재료의 비선형 문제가 기하학적 형상에 따른 비선형을 고려하지 못한다는 상호간의 단점을 해결하기 위하여, 본 논문에서는 동일조건하에서 기하학적 비선형과 재료적 비선형을 함께 고려하며, 범용 유한요소 해석 프로그램인 ABAQUS를 이용하여 하중-변위 곡선을 추적하였다.

• 한국조경학회지
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• 제32권6호
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• pp.36-51
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• 2005

The purpose of this thesis is to analyse modem urbanization process and the morphological transformation of the urban tissues in Kunsan between the you 1899 and 2001, The method of this study is to investigate the transformation process of morphological elements such as plot structure, building layout, building facades, land use, exterior space structure and their use, with actual field surveys, the analysis of land registration maps in 1912, and various topological map. Morphological analysis on modern Kunsan is progressed by three steps-typo-morphological analysis of urban tissue in old-town area, interpretation of morphological process, and transformation process, of morphological structure in Japanese concession in view of plots system. As a result, it is found that there is cyclical relationship among the morphological transformation processes of morphological elements, plots, buildings, land-uses, and access space to buildings. From the view of town plan change, the period of restoration of war damage in 1950s and compressive growing period in 1960s have important meaning in the morphological process of old-town area. Particularly the first building plan and layout type together with plot form and structure is acted as the main factor to decide the subsequent plot transformation system, exterior space system and the particular streetscape in Kunsan.

• 한국항공우주학회지
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• 제34권6호
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• pp.108-116
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• 2006

• 대한건축학회논문집:계획계
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• 제35권10호
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• pp.63-70
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• 2019

The Busan branch of the former Toyo Takushoku Co. carried out the same business as a bank at the time of construction. This required an open space of long-span, which had no pillars, on the first floor where many customers frequently visited. In addition, an office space is required in the upper part, and a column is arranged so as to place a corridor in the center. It was designed with modern complex structures for space utilization and structural adaptation. As a result, scientific structural calculations of the modern era began and various structural technologies were introduced, the rationalization and value of various spatial characteristics and their structural design were analyzed from a technical historical perspective in the structure requiring long-span space. The Busan branch of the former Toyo Takushoku Co. is a complex structure with three structures. It is highly valuable as a building that tried to design its structure in a variety of spaces through calculation and introduction of new technology based on the principle of force in modern times.