• Title/Summary/Keyword: Spatial Connectivity

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An Enhanced Density and Grid based Spatial Clustering Algorithm for Large Spatial Database (대용량 공간데이터베이스를 위한 확장된 밀도-격자 기반의 공간 클러스터링 알고리즘)

  • Gao, Song;Kim, Ho-Seok;Xia, Ying;Kim, Gyoung-Bae;Bae, Hae-Young
    • The KIPS Transactions:PartD
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    • v.13D no.5 s.108
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    • pp.633-640
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    • 2006
  • Spatial clustering, which groups similar objects based on their distance, connectivity, or their relative density in space, is an important component of spatial data mining. Density-based and grid-based clustering are two main clustering approaches. The former is famous for its capability of discovering clusters of various shapes and eliminating noises, while the latter is well known for its high speed. Clustering large data sets has always been a serious challenge for clustering algorithms, because huge data set would make the clustering process extremely costly. In this paper, we propose an enhanced Density-Grid based Clustering algorithm for Large spatial database by setting a default number of intervals and removing the outliers effectively with the help of a proper measurement to identify areas of high density in the input data space. We use a density threshold DT to recognize dense cells before neighbor dense cells are combined to form clusters. When proposed algorithm is performed on large dataset, a proper granularity of each dimension in data space and a density threshold for recognizing dense areas can improve the performance of this algorithm. We combine grid-based and density-based methods together to not only increase the efficiency but also find clusters with arbitrary shape. Synthetic datasets are used for experimental evaluation which shows that proposed method has high performance and accuracy in the experiments.

A Study on the Changes of Spatial Characteristics and Meaning of Namsan-Park from the Late 1900s through the Early 1980s - Focused on Hoehyeon district in Namsan Park - (1900년대 말부터 1980년대 초까지 남산공원의 공간적 특성과 의미 변화에 관한 연구 - 남산공원 회현지구를 중심으로 -)

  • Lee, Soo-Neon;Whang, Hee-Joon
    • Journal of architectural history
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    • v.20 no.6
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    • pp.7-20
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    • 2011
  • In this research, the changes of spaces on Namsan-Park and of the meaning of the park from the late 1900s through the early 1908s are analyzed, and the results are provided as follows. To begin with, inserting a concept of park to Namsan provided people with limitation in understanding definition of park, which indicated finite and constrained space, so that it distracted people from using spaces on Namsan. At that time, since the park was considered as one of key factors to establish Modern city, it was distinguished to the urban structure which had existed. After then, Joseon shrine, settled in Hanyang-Park, absorbed in functions of the park, so that the term of Hanyang-Park meant an area around the shrine or a boundary of the space. In addition, the particularity of Joseon shrine sometimes discouraged people from using the park spaces as well as spaces on the shrine, which led to decline the publicity of the park. However, Joseon shrine was correlated and planned with infrastructures of the city, Kyeongsung, not only physically but also visually in that Joseon shrine played role in one of components in Kyeongsung performed as an entertaining city such as a theme park. Lastly, Seoul is no longer subordinated and dependent city but has dramatically changed as a prominent city after regaining of independence in 1945. This indicates that the entertaining function of the old city was dismantled or reduced or transferred to public spaces, especially Namsan-Park. Consequently Namsan-Park has diverse and complex characteristics like traits of Kyeongsung, playing a pivotal role in providing cultural spaces, and its spatial organization is divided and planned based on various facilities and buildings on the park. This organization has a negative effect on the city and the park by decreasing in connectivity between them.

A Study on the Relationship between Light Environment and Visitors' Behavior in a Museum - Focus on the Interpretation of Tracking Score and Tracking Frequency with Intensity of Illumination - (박물관 빛 환경과 관람행태의 상관관계에 관한 연구 - 조도에 의한 관람확률과 관람빈도의 해석을 중심으로 -)

  • Lee, Mi-Youn;Jung, Sung-Wook
    • Korean Institute of Interior Design Journal
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    • v.19 no.4
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    • pp.82-89
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    • 2010
  • The studies published up to now, related to the correlation between spatial structure and visitors' behavior in a museum are rather relatively lacking when it comes to the in-depth consideration for the effect of the actual exhibition environment. So the main purpose of this study is to define the correlation between the light environment and the visitors' behavior. Towards this end, this study uses 'space syntax' to quantify the spatial structure with 'integration', 'connectivity' and 'control value'. Meanwhile, 'tracking score' and 'tracking frequency' were selected as the scope among the indices of behavior's analysis. The results of this study are as follows; First, integration and correlation of tracking score and tracking frequency are lowest when it comes to the extra large historical museums where the difference of intensity of illumination by each convex space. Meanwhile, the most considerable effect is exerted by control value. Compared to tracking score, tracking frequency is closely related to 'syntactic variables'. Second, visitors do not take the short cut the dark exhibition space even when very dark exhibition spaces continue after passing through relatively bright space. Analysis of visitors' behavior by control value in the exhibition space composed of this type of intensity of illumination environment is not valid. Third, visitors move to relatively brighter transitional space compared to the exhibition space with low intensity of illumination when passing through dark exhibition continually. Meanwhile, when visitors pass through the exhibition space there is some difference intensity of illumination they move to relatively dark exhibition center among the subsequent exhibition spaces. Accordingly, when the composition of exhibition space that continues onto the environment of low intensity of illumination is inevitable, differentiating intensity of illumination appropriately would be effective in inducing visit to the subsequent exhibition space.

Development of a GIS-based Decision Support System for the Locational Decision of Urban Parks (도시공원 입지선정을 위한 GIS기반의 의사결정 지원시스템의 개발)

  • 조규현;이인성
    • Spatial Information Research
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    • v.9 no.1
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    • pp.91-105
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    • 2001
  • This study aimed to develop an effective decision support system for the locational decision of urban parks through integrating decision analysis techniques with spatial analysis functions of GIS, and by doing so, to improve the efficiency and quality of the decision-making process. The system provides an efficient management process by integrating analysis, alternative generation and evaluation procedures into a coherent system environment. Evaluation criteria used in the system includes Equity, Efficiency, Service population, Land cost, Park ratio buildings, and Connectivity of greenery. The system also improves the efficiency and rationality of the decision-making process by incorporating various decision analysis techniques such as MAUT, AHP, and ELECTRE into a decision-making process. The analysis and decision support methods used in the system can be utilized for the locational decisions of other urban public facilities, and the system can also be expanded to a comprehensive park management system by incorporating general management functions for urban parks.

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Analysis of Groundwater Flow Characterization in Fractured Aquifer System (파쇄대 응회암 대수층의 지하수 유동 특성화 기법)

  • Kim Yong-Je;Kim Tae-Hee;Kim Kue-Young;Hwang Se-Ho;Chae Byung-Gon
    • Journal of Soil and Groundwater Environment
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    • v.10 no.4
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    • pp.33-44
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    • 2005
  • On the basis of a stepwise and careful integration of various field and laboratory methods the analysis of groundwater flow characterization was performed with five boreholes (BH-1, -2, -3, -4, -5) on a pilot site of Natural Forest Park in Guemsan-gun, Chungcheongbook-do, Korea. The regional lineaments of NW-SE are primarily developed on the area, which results in the development of many fractures of NW-SE direction around boreholes made in the test site for the study. A series of surface geological survey, core logging, geophysical logging, tomography, tracer tests, and heat-pulse flowmeter logging were carried out to determine fracture characteristics and fracture connectivity between the boreholes. In the result of fracture connectivity analysis BH-1 the injection well has a poor connectivity with BH-2 and BH-3, whereas a good with BH-4 and BH-5. In order to analyse the hydraulic connectivity between BH-1 and BH-5, in particular, a conspicuous groundwater outflux in the depth of 12 m and influx in the depth of 65 m and 70 m, but partly in/outflux occurred in other depths in BH-5 were observed as pumping from BH-1. On the other hand, when pumping from BH-5 the strong outflux in the depths of 17 m and 70 m was occurred. The spatial connectivity between the boreholes was examined in the depth of 15 m, 67 m, and 71 m in BH-1 as well as in the depth of 15 m, 17 m, 22 m, 72 m, and 83 m in BH-5.

Exploratory Study on Smart Usage of Smartphone Using the Second-order Measurement Model (스마트폰의 '스마트한 이용'에 대한 탐색적 연구 '스마트함', '스마트하다'의 이용행태에 대한 2차 측정모형을 중심으로)

  • Kim, Ki Yoon
    • Korean journal of communication and information
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    • v.74
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    • pp.72-108
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    • 2015
  • The more mobile technology evolves, the more users are trapped in mobile technology by being encouraging the replacement with state-of-the-art technology. However, the use of device is not entirely determined by technology's attributes itself. The meaning of smartness can be varied by 'how users accept and perceive immediate spatial perception from reality to mobile space' without recognizing the boundaries between them. This study focuses on the analysis of 'smart usage' for smartphone and this is verified the concept of 'smart usage' by the second-order measurement model. The result show that the concept organization of 'smart usage' had been differentiated and elicited by the six factors - 'multifunctional use readiness', 'administrative efficiency', 'embedded media', 'device connectivity', 'user-friendly optimization', and 'external connectivity(being connected). According to the conceptual factors, 'smart usage' can be explained in an individual's autonomous ability to control a mobile interface and to utilize a wide range of applications of smartphones.

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A Study of Land Suitability Analysis by Integrating GSIS with Artificial Neural Networks (GSIS와 인공신경망의 결합에 의한 토지적합성분석에 관한 연구)

  • 양옥진;정영동
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.2
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    • pp.179-189
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    • 2000
  • This study is tried to organic combination in implementing the suitability analysis of urban landuse between GSIS and ANN(Artificial Neural Network). ANN has merit that can decide rationally connectivity weights among neural network nodes through procedure of learning. It is estimated to be possible that replacing the weight among factors needed in spatial analysis of the connectivity weight on neural network. This study is composed of two kinds of neural networks to be executed. First neural network was used in the suitability analysis of landuse and second one was oriented to analyze of optimum landuse pattern. These neural networks were learned with back-propagation algorithm using the steepest gradient which is embodied by C++ program and used sigmoid function as a active function. Analysis results show landuse suitability map and optimum landuse pattern of study area consisted of residental, commercial. industrial and green zone in present zoning system. Each result map was written by the Grid format of Arc/Info. Also, suitability area presented in the suitability map and optimum landuse pattern show distribution pattern consistent with theroretical concept or urban landuse plan in aspect of location and space structure.

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Decreased White Matter Structural Connectivity in Psychotropic Drug-Naïve Adolescent Patients with First Onset Major Depressive Disorder (정신과적 투약력이 없는 초발 주요 우울장애 청소년 환아들에서의 백질 구조적 연결성 감소)

  • Suh, Eunsoo;Kim, Jihyun;Suh, Sangil;Park, Soyoung;Lee, Jeonho;Lee, Jongha;Kim, In-Seong;Lee, Moon-Soo
    • Korean Journal of Psychosomatic Medicine
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    • v.25 no.2
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    • pp.153-165
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    • 2017
  • Objectives : Recent neuroimaging studies focus on dysfunctions in connectivity between cognitive circuits and emotional circuits: anterior cingulate cortex that connects dorsolateral orbitofrontal cortex and prefrontal cortex to limbic system. Previous studies on pediatric depression using DTI have reported decreased neural connectivity in several brain regions, including the amygdala, anterior cingulate cortex, superior longitudinal fasciculus. We compared the neural connectivity of psychotropic drug naïve adolescent patients with a first onset of major depressive episode with healthy controls using DTI. Methods : Adolescent psychotropic drug naïve patients(n=26, 10 men, 16 women; age range, 13-18 years) who visited the Korea University Guro Hospital and were diagnosed with first onset major depressive disorder were registered. Healthy controls(n=27, 5 males, 22 females; age range, 12-17 years) were recruited. Psychiatric interviews, complete psychometrics including IQ and HAM-D, MRI including diffusion weighted image acquisition were conducted prior to antidepressant administration to the patients. Fractional anisotropy(FA), radial, mean, and axial diffusivity were estimated using DTI. FMRIB Software Library-Tract Based Spatial Statistics was used for statistical analysis. Results : We did not observe any significant difference in whole brain analysis. However, ROI analysis on right superior longitudinal fasciculus resulted in 3 clusters with significant decrease of FA in patients group. Conclusions : The patients with adolescent major depressive disorder showed statistically significant FA decrease in the DTI-based structure compared with healthy control. Therefore we suppose DTI can be used as a bio-marker in psychotropic drug-naïve adolescent patients with first onset major depressive disorder.

Spatial Structure Change of Triangle-Cities in Gwangyang Bay Region: From Central Place Structure to Network City (광양만권 트라이앵글 도시의 공간구조 변화: 중심지형에서 네트워크형으로)

  • Lee, Jeong-Rock
    • Journal of the Economic Geographical Society of Korea
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    • v.23 no.1
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    • pp.93-109
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    • 2020
  • The purpose of this study is to examine the effects of industrialization and urbanization of Gwangyang Bay Region on the change of urban system and spatial structure between triangle-cities located in Gwangyang Bay, Yeosu City, Suncheon City, and Gwangyang City, one of the famous industrial zones in Korea. Large-scale development projects carried out by the central government in the Gwangyang Bay Region such as construction of the Second Oil Refinery in the mid-1960s, completion of the POSCO Gwangyang Steelworks in the mid-1980s, construction of the Gwangyang Port Container Terminal in 1987 and designation of the Gwangyang Bay Area Free Economic Zone in 2003, and EXPO 2012 Yeosu Korea, affected to changes of the urban system and spatial structure between triangle-cities in Gwangyang Bay Region. The above four-development projects transformed the urban and spatial structures between the three cities in the Gwangyang Bay Region from a mononuclear urban system centered on Suncheon to a network city system. Historically, Suncheon has served as an exclusive center in the eastern region of Jeonnam, including the Gwangyang Bay Region. However, the hosting of the 2012 Yeosu Expo Korea is reorganizing the three cities into a network-type spatial structure with the strengthening of connectivity and integration in the region. And this trend is expected to intensify in the future.

A Study on the Accessability of the Bikeway Networks in the South of the Han River Using Space Syntax (Space Syntax를 이용한 한강이남 자전거도로망의 접근성 분석)

  • Oh, Chung-Won;Lim, Dong-Wook;Kim, Hyun-Jin;Park, Jun-Tae
    • International Journal of Highway Engineering
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    • v.14 no.3
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    • pp.97-110
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    • 2012
  • In case of the axial line bikeway, the residents in the riverside use it frequently but those in the city center hardly do as the axis is formed along the riverside of the Han river. This situation happens due to the inefficient connectivity between the bikeway that leads to the riverside and that in the city center, which means the administrative policies have been focused on the facilities rather than on raising connectivity of the bikeway networks in the south of the Han River. Also, this is the point of time when a reasonable improvement plan is needed to raise the accessibilities of the bikeways in Seoul, not just a utilization of those in the south of the Han River. This study intends to analyse the connectivity between Gangseo (west of the Han River) and Gangdong (East of the Han River) districts by comparing the current spatial structure in the southern areas of the Han River and that after the installation of the axial line, and that after installation of the ordinary bikeway respectively with use of the Space Syntax Model, and to predict resultant changes there of. The Space Syntax Model was used as the major method of analysis in this study to find out characteristics of the bikeways in the south of the Han River. Consequently, as the analysis shows that when the bikeways in the Gangseo and Gangdong-gu districts are connected, the accessibility of the bikeways in the south of the Han River will improve while the spatial structure intelligibility will be lowered, it can be said the prediction rate in the all areas is low compared with the current status. It is analyzed that the intelligibility of the current bikeways in the south of the Han River appeared highest when compared with those of plans for installation of the axial line and ordinary bikeway because they don't interconnect with other areas.