• Journal of KIISE:Databases
• /
• v.31 no.1
• /
• pp.13-22
• /
• 2004

With the proliferation of multimedia data, there is an increasing need to support the indexing and retrieval of high-dimensional image data. Although there have been many efforts, the performance of existing multidimensional indexing methods is not satisfactory in high dimensions. Thus the dimensionality reduction and the approximate solution methods were tried to deal with the so-called dimensionality curse. But these methods are inevitably accompanied by the loss of precision of query results. Therefore, recently, the vector approximation-based methods such as the VA- file and the LPC-file were developed to preserve the precision of query results. However, the performance of the vector approximation-based methods depend largely on the size of the approximation file and they lose the advantages of the multidimensional indexing methods that prune much search space. In this paper, we propose a new index structure called the GC-tree for efficient similarity search in image databases. The GC-tree is based on a special subspace partitioning strategy which is optimized for clustered high-dimensional images. It adaptively partitions the data space based on a density function and dynamically constructs an index structure. The resultant index structure adapts well to the strongly clustered distribution of high-dimensional images.

• Journal of the Economic Geographical Society of Korea
• /
• v.22 no.4
• /
• pp.381-404
• /
• 2019

The paper aims to identify how North Korean various economic agents respond to the economic crisis in North Korea, and how these multiple practices are entangled with its spatiality by through the questionnaire survey and in-depth interview targeted at North Korean refugees. The paper argues that it needs to examine the marketization in North Korea in terms of the domesticating recently debated in economic geography. In this perspective, the marketization in North Korea could be explained not as a grand project 'out there' with hegemonic power, but as various economic agents within their space are constantly (re)constructed through everyday life practices. Economic agents' responses to economic crisis, economic rupture, and economic marginalization could be identified in terms of articulation between economic and non-economic factors. More specifically, the paper emphasizes everyday life responses are over-determined by their economic and non-economic factors and its effectiveness is differentiated by their power relations.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.39-48
• /
• 2020

The purpose of this study was to understand changes in Seoul's downtown planning from the 1960s to 1990s. The approach was examined by classifying its formation process though urban conservation. The effects of modernization and urbanization on Seoul's downtown planning were as follows. In the 1960s, Seoul attempted to decentralize urban functions due to excessive population. In the 1970s, a policy to diversify urban functions according to Gangnam development was enacted. In the 1980s, the existing downtown declined, and the sub-downtown grew with changing urban functions. In the 1990s, the identity of the existing downtown was recognized through the Seoul Memorial Project. This study also analyzed downtown planning efforts concerned with urban conservation. First, the physical aspects of existing buildings and street facilities were maintained. Second, the spatial aspects for the maintenance of surrounding areas were proposed. Fourth, the social aspects for accessibility by Seoul citizens was improved. This analysis demonstrates the concept of urban conservation based on physical-spatial-social aspects.

• Journal of the Korean Geographical Society
• /
• v.45 no.2
• /
• pp.240-255
• /
• 2010

This empirical study researched the three major phenomena of differentiation of housing market under the large scale of new town construction in the metropolitan area, the spatial differentiation pattern of housing market due to the urban growth, and the relationship with the distribution of housing submarket and suburbanization. Yongin City, one of the most active growth cities among the metropolitan areas, is optimal place to investigate the spatial differentiation pattern of the housing submarket on the microscopic scale. Furthermore, Yongin City has not only the geographical benefit but also the strong influences from institutional, social, and environmental changes. This city is divided into four housing submarkets, where to Gangnam and Boondang, Gyeongbu and Youngdong expressway has significant effects. In addition, the housing tenure and size, household structure, educational background and income levels and so on also resulted in the differentiation of the housing submarket.

• Korean Journal of Remote Sensing
• /
• v.27 no.4
• /
• pp.421-433
• /
• 2011

The importance of acquisition of road information has recently been increased with a rapid growth of spatial-related services such as urban information system and location based service. This paper proposes an automatic road extraction method using object-based approach which was issued alternative of pixel-based method recently. Firstly, the spatial objects were created by MSRS(Modified Seeded Region Growing) method, and then the key road objects were extracted by using properties of objects such as their shape feature information and adjacency. The omitted road objects were also traced considering spatial correlation between extracted road and their neighboring objects. In the end, the final road region was extracted by connecting discontinuous road sections and improving road surfaces through their geometric properties. To assess the proposed method, quantitative analysis was carried out. From the experiments, the proposed method generally showed high road detection accuracy and had a great potential for the road extraction from high resolution satellite images.

• Journal of the Korean Geographical Society
• /
• v.46 no.3
• /
• pp.319-330
• /
• 2011

In this study, a soil moisture estimation model was proposed using the ground observation data of soil moisture, precipitation, surface temperature, MODIS NDVI and artificial neural networks. The model was calibrated and verified on the Yongdam dam watershed which has reliable ground soil moisture networks. The test statistics of calibration sites, Jucheon, Bugui, Sangjeon, showed that the correlation coefficients between observations and estimations are about 0.9353 and RMSE is about 1.4957%. Also that of the verification site, Cheoncheon2, showed that the correlation coefficient is about 0.8215 and RMSE is about 4.2077%. The soil moisture estimation model was applied to estimate the spatial distribution of soil moisture in the Yongdam dam watershed and results showed improved spatial soil moisture distribution since the model used satellite information of NDVI and artificial neural networks which can represent the nonlinear relationships between data well. The model should be useful to estimate wide range soil moisture information.

• Journal of the Korea Convergence Society
• /
• v.10 no.7
• /
• pp.155-162
• /
• 2019

The age and physical condition of users who use public libraries are becoming diverse in recent years. The need for universal design is recognized as important to create a public library with a convenient and pleasant environment in consideration of various users. The purpose of this research is to propose the universal design application method after analyzing level of application of common spaces in public libraries. First, the environment related to 'Perceptable Information' with low level of universal design should be improved first. Second, it is important to apply it from the initial planning phase to create a more advanced universal design environment. Third, careful consideration and awareness of all users of the library should precede to engance 'Flexibility in Use' related environment.

• The Journal of the Korea Contents Association
• /
• v.19 no.6
• /
• pp.236-248
• /
• 2019

Green belts can help to set boundary for city growth, provide ecological protection system and enhance the resilience of Beijing. During the implementation period of the current overall city planning of Beijing, the proportion of green space varies much among the sub-districts, villages and towns involved in the two green belts in the research. With this as starting point, by researching the correlations of 'city system factors' and 'planning policy factors' with the change in the scale of green space, the paper discussed the influential factors of implementing the planning of green space of Beijing, and conducted quantitative research, with such possible influential factors classified into 'city system factors' and 'planning policy factors'. Through multiple linear regression model, the paper tested the correlations of city system factors and planning policy factors (independent variable) with the increment in the construction land in green belts (dependent variable). Through influence to population aggregation and the expansion force of construction land, city system factors such as mountain land and water, house rent of unit area, accessibility of public transport and the newly-defined state-owned construction land generate correlation with the change in the scale of construction land in green belts.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.31 no.4
• /
• pp.95-119
• /
• 2020

The study examined the behavior of infant's caregivers using public libraries, measured the level of awareness of infant and toddler services in the library to determine the factors affecting their revisit or recommendation of use to others, and examined the impact of such recognition on the use behavior, revisit and willingness to recommend others. The study surveyed 146 caregivers of infants who use four public libraries in Gwangju Metropolitan City on demographic characteristics, library use behavior, level of awareness of library services, library revisit and recommendation to others. Analysis of this survey shows that the factors that influence the caregivers' revisit of the library or their desire to recommend to others through their caregivers' use of the library are the factors that influence the expansion of information data, the stability of space facilities, the accessibility of space facilities, and the ease of participation in programs among the various service factors provided by the library rather than the personal factors of infants and toddlers' caregivers.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.112-113
• /
• 2021

하천으로 유입되는 오염물질은 유수의 흐름에 따라 이송되며 혼합된다. 이러한 오염물질의 해석을 위해서는 확산 또는 분산계수 산정이 필요하다. 오염물질의 거동과 관련된 실험적 연구는 방사선 동위원소와 형광성 물질을 이용하여 수행되어 왔으나, 추적자 실험은 많은 비용 및 인력을 요하며, 고정식으로 설치한 계측장비로부터 수집한 시계열 농도자료만을 이용하여 분석하기 때문에 공간적 분포에 대한 자료 취득은 어렵다는 한계가 있다. 하천의 오염물질을 모니터링하기 위해서는 공간을 이동하는 입자의 관점에서 물리량을 표현하는 Lagrangian 방식보다 특정 위치에서 물리량 변화를 표현하는 Eulerian 방식이 적합하다. 그러나 드론을 활용한 하천원격탐사 연구의 대부분은 이동식 플랫폼으로 활용되어 특정 시간에 공간적 분광특성의 분포 파악이 한정적이며, 동일 지점에서 분광특성의 시간적 변화를 파악할 수 없다. 따라서 본 연구에서는 기존의 면단위를 측정하는 이동식 플랫폼의 한계를 극복하고 하천 모니터링에 적합한 Eulerian 방식을 적용하기 위하여 CCTV 형태의 고정식 초분광촬영 플랫폼을 도입하였다. 본 연구에서는 하천으로 유입되는 오염물질의 거동을 분석하기 위하여 자연하천에서 형광성물질인 Rhodamine WT를 이용하여 추적자 실험을 수행하였으며, 접촉식 센서를 활용한 농도측정과 동시에 드론과 초분광센서를 활용하여 CCTV 형태의 고정식 초분광영상을 획득하였다. 실험결과 도출된 전통적인 방식의 분산계수 산정과 시공간 초분광영상을 활용한 분산계수 산정을 비교하여 오염물질 거동 분석에 초분광영상 활용의 가능성을 검토하였다. 본 연구에서 제시한 드론기반 시공간 초분광영상 기법을 교량이나 기타 하천구조물에 초분광 센서를 설치하여 CCTV형식으로 활용할 경우, 공단이나 하·폐수 처리장 등의 점오염원이 밀집해 있는 지역에 직접 설치하여 화학사고의 감지 및 오염물질의 유출 확인 및 조류, 부유사 등의 다양한 수질항목의 농도 변화 감지가 가능하고, 수심변화 감지로 장기적으로 활용할 경우 특정 지점에서의 하상변동 조사가 가능하다. 또한, 오염물질의 유출 사고 발생 등의 사람이 직접 접근이 불가능한 지역에 드론을 활용하여 초분광센서를 이용한 오염물질 감지가 가능할 것으로 판단된다.