• Title/Summary/Keyword: Spatial network analysis

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Analysis of Geographic Network Structure by Business Relationship between Companies of the Korean Automobile Industry (한국 자동차산업의 기업간 거래관계에 의한 지리적 네트워크 구조 분석)

  • KIM, Hye-Lim;MOON, Tae-Heon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.3
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    • pp.58-72
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    • 2021
  • In July 2021, UNCTAD classified Korea as a developed country. After the Korean War in the 1950s, economic development was promoted despite difficult conditions, resulting in epoch-making national growth. However, in order to respond to the rapidly changing global economy, it is necessary to continuously study the domestic industrial ecosystem and prepare strategies for continuous change and growth. This study analyzed the industrial ecosystem of the automobile industry where it is possible to obtain transaction data between companies by applying complexity spatial network analysis. For data, 295 corporate data(node data) and 607 transaction data (link data) were used. As a result of checking the spatial distribution by geocoding the address of the company, the automobile industry-related companies were concentrated in the Seoul metropolitan area and the Southeastern(Dongnam) region. The node importance was measured through degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality, and the network structure was confirmed by identifying density, distance, community detection, and assortativity and disassortivity. As a result, among the automakers, Hyundai Motor, Kia Motors, and GM Korea were included in the top 15 in 4 indicators of node centrality. In terms of company location, companies located in the Seoul metropolitan area were included in the top 15. In terms of company size, most of the large companies with more than 1,000 employees were included in the top 15 for degree centrality and betweenness centrality. Regarding closeness centrality and eigenvector centrality, most of the companies with 500 or less employees were included in the top 15, except for automakers. In the structure of the network, the density was 0.01390522 and the average distance was 3.422481. As a result of community detection using the fast greedy algorithm, 11 communities were finally derived.

Classification Analysis of Road Network-Based Land Use Considering Spatial Structure (공간구조를 고려한 도로망 기반 토지이용의 분류분석)

  • Kim, Hye-Young;Jun, Chul-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.24-34
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    • 2014
  • To understand urban space and make appropriate plans, the integrative analyses considering road and land use simultaneously are required. In addition, studies that involve both horizontal and vertical spaces must be taken into consideration. Therefore, the purpose of this study is to conduct a classification analysis of road network-based land use considering spatial structure. The methods of this study were as follows; first, a space syntax theory considering the structure of road network was introduced for roads. For land use, to consider both horizontal and vertical development densities of residential and commercial buildings were used. And the explanatory power of three variables-Euclidean distance, global integration and length-reflected global integration-were compared. Third, based on road as an appropriate variable, modified-IPA was conducted with land use and the results were categorized into four areas. The proposed method was applied to Gangnam-gu, a CBD area in Seoul, and results were analyzed and visualized using GIS.

Development for Wetland Network Model in Nakdong Basin using a Graph Theory (그래프이론을 이용한 낙동강 유역의 습지네트워크 구축모델 개발)

  • Rho, Paikho
    • Journal of Wetlands Research
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    • v.15 no.3
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    • pp.397-406
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    • 2013
  • Wetland conservation plan has been established to protect ecologically important wetlands based on vegetation integrity, spatial distribution of endangered species, but recently more demands are concentrated on the landscape ecological approaches such as topological relationship, neighboring area, spatial arrangements between wetlands at the broad scale. Landscape ecological analysis and graph theory are conducted to identify spatial characteristics related to core nodes and weak links of wetland networks in Nakdong basin. Regular planar model, which is selected for wetland networks, is applied in the Nakdong basin. The analysis indicates that 5 regional groups and 4 core wetlands are extracted with 15km threshold distance. The IIC and PC values based on the binary and probability models suggest that the wetland group C composed of main stream of Nakdong river and Geumho river is the most important area for wetland network. Wetland conservation plan, restoration projected of damaged and weak links between wetlands should be proposed through evaluating the node, links, and networks from wetlands at the local to the regional scale in Nakdong basin.

Methodology for Apartment Space Arrangement Based on Deep Reinforcement Learning

  • Cheng Yun Chi;Se Won Lee
    • Architectural research
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    • v.26 no.1
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    • pp.1-12
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    • 2024
  • This study introduces a deep reinforcement learning (DRL)-based methodology for optimizing apartment space arrangements, addressing the limitations of human capability in evaluating all potential spatial configurations. Leveraging computational power, the methodology facilitates the autonomous exploration and evaluation of innovative layout options, considering architectural principles, legal standards, and client re-quirements. Through comprehensive simulation tests across various apartment types, the research demonstrates the DRL approach's effec-tiveness in generating efficient spatial arrangements that align with current design trends and meet predefined performance objectives. The comparative analysis of AI-generated layouts with those designed by professionals validates the methodology's applicability and potential in enhancing architectural design practices by offering novel, optimized spatial configuration solutions.

Status Analysis and Activating Plan of Home Network for the Elderly (고령자를 위한 홈네트워크 현황 분석 및 활성화방안 수립 연구)

  • Kee, Ho-Young;Cheong, So-Yi
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.10
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    • pp.125-132
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    • 2011
  • The home network, contributing to improve the quality of life in dwelling, has expanded its installation and use in past years, but the elderly care system supporting self-reliance is not fully prepared. Although the aging society in Korea is progressing rapidly, inducting and spreading home network system is still required supporting of 'Aging in Place' for the elderly. This research is based the survey of spatial characteristics of housing of the elderly. Also, the research studied the technical level and policy of home network in domestic and abroad and analyze the professional view of experts in the home network field, as a result, suggested methods of building and activating the home network system.

Spatial Analysis of Cyberspace and Mapping Cyberspace (사이버스페이스의 공간적 분석과 지도화)

  • 이희연
    • Journal of the Korean Geographical Society
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    • v.37 no.3
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    • pp.203-221
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    • 2002
  • This study attempts to analyze the spatial characteristics of cyberspace and to map spatial variations of cyberspace. In order to analyze the spatial distribution of cyberspace, three measurement indices are selected such as commercial domain number, Internet backbone network, and Internet users, which are highly correlated to each other. The three sets of measurement showed that cyberspace in Korea is spreading in a highly uneven fashion, strongly favoring a few cities and unfavoring economically distressed cities. Seoul acts on overwhelmingly dominant role in cyberspace, by being concentrated a number of domains and having high-capacity bandwidth on Internet backbone network. Internet is selectively connecting several cities into highly interactive networks, while at the same time largely bypassing other cities. The development of Internet network through infrastructure investments at selected cities has resulted in an uneven accessibility and digital divide among cities. The regional disparity would be further reinforced by ICT development as the primary vehicle for unequal accessibility. The result of this study revealed that geography continues to matter, despite the recent rhetoric claiming of 'the death of distance'or 'the end of geography'.

A Performance Analysis of Video Smoke Detection based on Back-Propagation Neural Network (오류 역전파 신경망 기반의 연기 검출 성능 분석)

  • Im, Jae-Yoo;Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.4
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    • pp.26-31
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    • 2014
  • In this paper, we present performance analysis of video smoke detection based on BPN-Network that is using multi-smoke feature, and Neural Network. Conventional smoke detection method consist of simple or mixed functions using color, temporal, spatial characteristics. However, most of all, they don't consider the early fire conditions. In this paper, we analysis the smoke color and motion characteristics, and revised distinguish the candidate smoke region. Smoke diffusion, transparency and shape features are used for detection stage. Then it apply the BPN-Network (Back-Propagation Neural Network). The simulation results showed 91.31% accuracy and 2.62% of false detection rate.

A Neural Network and Kalman Filter Hybrid Approach for GPS/INS Integration

  • Wang, Jianguo Jack;Wang, Jinling;Sinclair, David;Watts, Leo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.277-282
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    • 2006
  • It is well known that Kalman filtering is an optimal real-time data fusion method for GPS/INS integration. However, it has some limitations in terms of stability, adaptability and observability. A Kalman filter can perform optimally only when its dynamic model is correctly defined and the noise statistics for the measurement and process are completely known. It is found that estimated Kalman filter states could be influenced by several factors, including vehicle dynamic variations, filter tuning results, and environment changes, etc., which are difficult to model. Neural networks can map input-output relationships without apriori knowledge about them; hence a proper designed neural network is capable of learning and extracting these complex relationships with enough training. This paper presents a GPS/INS integrated system that combines Kalman filtering and neural network algorithms to improve navigation solutions during GPS outages. An Extended Kalman filter estimates INS measurement errors, plus position, velocity and attitude errors etc. Kalman filter states, and gives precise navigation solutions while GPS signals are available. At the same time, a multi-layer neural network is trained to map the vehicle dynamics with corresponding Kalman filter states, at the same rate of measurement update. After the output of the neural network meets a similarity threshold, it can be used to correct INS measurements when no GPS measurements are available. Selecting suitable inputs and outputs of the neural network is critical for this hybrid method. Detailed analysis unveils that some Kalman filter states are highly correlated with vehicle dynamic variations. The filter states that heavily impact system navigation solutions are selected as the neural network outputs. The principle of this hybrid method and the neural network design are presented. Field test data are processed to evaluate the performance of the proposed method.

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Landslide Susceptibility Analysis and its Verification using Likelihood Ratio, Logistic Regression and Artificial Neural Network Methods: Case study of Yongin, Korea

  • Lee, S.;Ryu, J. H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.132-134
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    • 2003
  • The likelihood ratio, logistic regression and artificial neural networks methods are applied and verified for analysis of landslide susceptibility in Yongin, Korea using GIS. From a spatial database containing such data as landslide location, topography, soil, forest, geology and land use, the 14 landsliderelated factors were calculated or extracted. Using these factors, landslide susceptibility indexes were calculated by likelihood ratio, logistic regression and artificial neural network methods. Before the calculation, the study area was divided into two sides (west and east) of equal area, for verification of the methods. Thus, the west side was used to assess the landslide susceptibility, and the east side was used to verify the derived susceptibility. The results of the landslide susceptibility analysis were verified using success and prediction rates. The v erification results showed satisfactory agreement between the susceptibility map and the exis ting data on landslide locations.

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Refined identification of hybrid traffic in DNS tunnels based on regression analysis

  • Bai, Huiwen;Liu, Guangjie;Zhai, Jiangtao;Liu, Weiwei;Ji, Xiaopeng;Yang, Luhui;Dai, Yuewei
    • ETRI Journal
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    • v.43 no.1
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    • pp.40-52
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    • 2021
  • DNS (Domain Name System) tunnels almost obscure the true network activities of users, which makes it challenging for the gateway or censorship equipment to identify malicious or unpermitted network behaviors. An efficient way to address this problem is to conduct a temporal-spatial analysis on the tunnel traffic. Nevertheless, current studies on this topic limit the DNS tunnel to those with a single protocol, whereas more than one protocol may be used simultaneously. In this paper, we concentrate on the refined identification of two protocols mixed in a DNS tunnel. A feature set is first derived from DNS query and response flows, which is incorporated with deep neural networks to construct a regression model. We benchmark the proposed method with captured DNS tunnel traffic, the experimental results show that the proposed scheme can achieve identification accuracy of more than 90%. To the best of our knowledge, the proposed scheme is the first to estimate the ratios of two mixed protocols in DNS tunnels.