• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.169-175
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• 2007

Suffix arrays, fundamental full-text index data structures, can be efficiently used where patterns are queried many times. Although many useful full-text index data structures have been proposed, their O(nlogn)-bit space consumption motivates researchers to develop more space-efficient ones. However, their space efficient versions such as the compressed suffix array and the FM-index have been developed; those can not reduce the practical working space because their constructions are based on the existing suffix array. Recently, two direct construction algorithms of compressed suffix arrays from the text without constructing the suffix array have been proposed. In this paper, we compare practical performance of these algorithms of compressed suffix arrays with that of various algorithms of suffix arrays by measuring the construction times, the peak memory usages during construction and the sizes of their final outputs.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.192.1-192.1
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• 2012

영상레이더 (SAR: Synthetic Aperture Radar) 혹은 통신 안테나/탑재체를 장착한 위성은 원하는 주파수 대역의 운용을 위해 대형 안테나 구조물 장착이 필수적이다. 이러한 대형 구조물은 일체형으로 제작되어 위성체에 접속되었을 때, 요구 무게 및 점유하는 부피가 매우 큰 특징을 지닌다. 따라서, 대형 안테나 구조물의 중량으로 인해 발사비 증가가 불가피하며, 페어링 내부의 허용된 공간에 안테나 크기는 큰 제약적 요인이 된다. 그리고, 전개식이어도, 전개후 질량 관성이 큰 구조물이 된다. 위성체의 발사 비용과 직결되는 안테나의 경량화를 위한 많은 기술이 연구되고 있다. 특히, 접이식 팽창형 안테나는 반사체의 유연한 메쉬 구조 및 경량 지지구조물로 안테나의 무게를 줄이고 수납 효율을 향상시킨다. 또한, 전개 후 안테나의 목적한 기능을 충분히 보장함과 동시에 질량 관성이 작은 구조물에 의한 위성의 기동성을 극대화할 수 있다. 국내에서도 전천후 지상관측감시 및 통신 안테나의 필요성 증대에 따라 초경량 전개형 안테나 개발의 필요성이 크게 대두되고 있으나, 현재까지는 관련 기술개발 사례가 전무한 실정으로 국내 독자적 기술 확보가 시급한 실정이다.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.389-399
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• 1999

This study was conducted to develop an application software, SIDAS3D(Stand Inventory Data Analysis System for 3 Dimensional Representation), of which the purpose of development is to make it easier to analyze and display the 3D spatial structure of a forest stand, based on the data such as tree position, species, DBH, height, clear length of individual trees, and crown width. This program has a statistical analysis function for stand attributes per hectare and displays simple graphs of stand statistics such as the distribution of diameters, heights, and volumes. It also has two additional functions, of which one is to display the 3D image of stand structure and the other is to display the image of crown projection. In addition, this program provides an imaginary treatment simulation function, which can visually confirm the suitability of silvicultural treatments on computers. To test the precision and reliability of SIDAS3D, data obtained by the precision forest inventory method were used. Statistical analysis ability of SIDAS3D was compared with that of SAS. And its representational ability was compared with that of TreeDraw. According to the verification, SIDAS3D was superior to SAS and TreeDraw in both the data processing time and the interpretative ability of results. It was concluded that SIDAS3D could be used to help users efficiently make decisions for appropriate silvicultural treatments and rational management plans because it has analysis functions providing various valuable information.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.81-88
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• 2011

The studies of seismic response control are mainly conducted on rahmen structure until now. Spatial structures have the different dynamic characteristics from general rahmen structures. So, the results of these studies are very limited for vibration control and seismic design of spatial structures. TMD(Tuned Mass Damper) is one of the vibration control device that is mainly used to reduce the vibration level of high-rised building, bridge or stadium structure. In this study, an arch structure was used as an example structure because it has primary characteristics of spatial structures and the seismic behaviour of spatial structures may fundamentally differ from the conventional building structures. So, the vibration control performance is evaluated according to the change of TMD mass and TMD location. It is reasonable to install TMD at the quarter point that is dominant mode vector of 1st mode, And it is appropriate that TMD mass ratio is 2% in the seismic response control of arch structure.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.1-14
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• 2014

In this study, the change characteristics of urban spatial structure in Daegu were analyzed connecting with urban planning for efficient urban management. Urban development process from 1970 to 2010 in Daegu was analyzed utilizing Getis-Ord $G_i^*$ methodology, a spatial statistical method, and it was identified that Daegu was in the stage of disurbanization. However, as Daegu orients multi-nuclei city, it was difficult to explain the stage of urban development after disurbanization in 2000. Accordingly, to analyze detailed changes in spatial structure in multi-centric areas after 2000, population, land price and employment factor changes were analyzed using Bachi Measurement. According to analytical results, multi-centralization process has been continued in Daegu. Urban core area and Chilgok area showed spatial structure change into distribution process, Ansim area into concentration process, and Seongseo and Talseo area into concentration and distribution process. Therefore, urban planning considering the regional characteristics are needed for efficient urban management.

• Journal of the Korean association of regional geographers
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• v.10 no.2
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• pp.447-465
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• 2004

This paper is to analyze citizens' consciousness on urban changes, especially focusing on changes in urban environment, spatial structure, and urban planning, of large cities in S. Korea, that is, Seoul, Daejeon, Daegu, and Kwangju in the 1990s. Some significant points can be described as follows. First. The most important factor influencing on the change of urban spatial structure was the expansion of residential area inner and outside of cities promoted by the traditional construction industry, and not development of high-tech industries and their complex or location of multi-national firms which can be emphasized as major factors of new urbanization process of global cities. Secondly, citizens seem to have experienced improvement and deterioration of urban environment simultaneously, emphasizing regulatory environmental policy on the one hand, and recognize the necessity of sustainable urban development within given environmental capacity and restoration of destructed and polluted environment of cities. Thirdly, the building boom of new apartment complex was a major driving force of changing urban spatial structure, but it could neither alleviate a residential gap between the poor and the rich areas nor a relief of traffic congestion. Finally, the urban policy in general was felt somewhat improved by citizens, but not in sectoral details.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.2
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• pp.13-27
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• 2019

This study shows the changes in the space created by the planning and leisure activities of Hangang River Park, focusing on the Yeouido portion of the Hangang River Park, which has the most users and the greatest degree of planning. The relationship between planning, behavior, and space changes are explained based on Giddens's Structural Theory. As research material, Hangang River Park plans and satellite photos were interpreted and newspaper articles were used to identifying the space changes and their causes, and a model of the space changes was derived through the application of the theory. The flow of space change in the Yeouido portion of the Hangang River Park due to planning and leisure activities is as follows. In the 1970s, the first sports spaces are made due to need from residents near the riverside, but huge plans for the utilization of the entire space were not realized. In the 1980s, leisure spaces were planned and developed through a comprehensive plan. Various sports spaces were built, but the environment of the spaces became a slum. In the 1990s, various leisure activities were revitalized due to the revision of the legal system, regulations on the usage of space, and space maintenance, and from the late 1990s, ecological issues arose along the Hangang River. In the 2000s, there was an overall space improvement project directed by two comprehensive plans, and cultural and ecological issues appeared in the Hangang River Park plans. However, actual leisure spaces were developed along with the promotion of large-scale activities. Regarding the structuration theory, elements of interaction, modality, and structure are the aspects of space changes in the Yeouido portion Hangang River Park. As the flow of the space change, the proportions of the comprehensive plan and the individual plans were similar. The comprehensive plan was influenced by the change of public businesses and the proliferation of large-scale activities. Individual plans were influenced by the user's activities and opinions. However, both plans were influenced by the users and suppliers. The leisure space of the Hangang River Park can be viewed as a social space, in terms of the structuring as a theory due to the user repeatedly changing the use of the space. The purpos of this study is to investigate the changes in the Hangang River Park space through planning and leisure activities. Through this study, we can understand the characteristics of the Hangang River Park in planning the leisure activity space.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.5-5
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• 2017

최근의 하천복원사업은 인위적으로 축소 또는 소실된 하천공간을 지형학적으로 되돌리기 위한 방향과 강이 가진 자연의 역동성의 복원에 주안점을 두고 있다. 최근 국내에서도 하천공간 확보라는 측면에서 구하천 구역을 복원하려는 시도가 이뤄지고 있고 대표적으로 청미천, 함평천, 황구지천 등에서 기존의 제방을 후퇴시키고 과거의 하천공간을 하천으로 되돌려 주었다. 그러나 이러한 시도는 구하도 또는 폐천부지 복원사업의 일환으로 시행되었으며, 복원된 공간규모가 크지 않아 사업의 효과를 크게 장담할 수 없는 현실적인 한계가 있다. 따라서 홍수에 안전하며 자연과 인간이 공존하는 터전으로의 공간복원, 그에 따른 하천생태계의 보전과 복원, 레저와 레크레이션이 가능한 친수공간 조성 등 하천기능의 강화와 융합을 종합적으로 고려한 다차원 하천공간 복원계획과 설계의 절차가 필요하다. 이를 위해서는 먼저 유역기반의 문제점과 그 원인에 대한 인식이 선행되어야 하고 그 해법으로 하천공간 확대의 필요성이 도출되어야 한다. 이후, 하천공간 복원 및 활용과 관련된 기본방향이 설정되며 세부 복원목표가 설정되어야 한다. 복원목적과 목표가 세워진 후, 복원대상지를 선정하고 공간 활용방안이 제시되면, 목표달성 여부 판단을 위한 효과분석이 필요하다. 만약, 기대효과를 달성할 수 없을 것으로 예상된다면 복원목표 재설정 및 복원대상지의 재선정이 필요할 것이다. 이와같이 하천공간 복원사업을 시행함에 있어 간결하고 단계적으로 접근하기 위해 본 연구에서는 다차원 하천공간 복원프레임워크를 개발하여 제시하였다. 제안된 하천공간 복원프레임워크를 통해 하천공간복원으로 인해 영향을 미칠 수 있고 또한 영향을 받을 수 있는 물리, 생물, 사회, 경제 등의 다양한 분야의 구조를 통합한 하나의 방법을 제시함으로서 임시방편 수준의 파괴된 하천복원사업에 변화를 주고 프레임워크를 통해 하천공간복원에 대한 응집력 있는 접근법을 적용하도록 촉진하여 복원사업에 참여하는 사람들 간에 공통의 유대감을 형성하는데 도움이 되고자 한다.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.76-82
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• 2003

To guarantee the proper functions of a satellite in the extreme space environment, the several test models are developed generally. There are advantages that the design and the analysis of Flight Model(FM) can be validated through these test models, and the functional reliabilities can be increased by reflecting the modifications on the final design of FM. The integration and test of Structure & Thermal Model(STM) of KOMPSAT, being currently developed, have been completed. In this paper, the processes of design and analysis of the STM propulsion system, one of the KOMPSAT modules, are described.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.3
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• pp.25-36
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• 1996

Conventional radial-basis-function networks and fuzzy systems have serious problems in dealing with the non1inea:r approximations on high-dimensional spaces due to the explosive increase of the number of hidden nodes or fuzzy IF-THEN rules. In order to avoid such problems, this paper proposes a tree-structured intelligent system in which semi-local basis functions form its basic elements, and develops a training algorithm for the proposed system based on the modified genetic algorithm and LMS rule. Theoretical analysis is performed on the approximation capability of the proposed system, together with experimental studies which demonstrate the effectiveness of the developed methodology.