• Proceedings of the Korean Society for Information Management Conference
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• 2012.08a
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• pp.3-6
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• 2012

본 연구의 목적은 도서관 이용자들의 일상생활에서 공간들이 어떠한 관계성을 가지고 이용되는지를 분석하는 것이다. 관계성을 파악하기 위한 데이터로 미국 Puget Sound Region Transportation Department에서 수집한 Household Travel Survey 데이터를 이용하였다. 데이터 분석을 위한 도구로 소셜 네트워크 분석도구 중의 하나인 NodeXL을 사용하였다. 분석결과 선행연구에서와 유사하게 슈퍼마켓, 레스토랑, 쇼핑몰 등이 도서관 이용과 공간적으로 연관성이 있음이 나타났다. 또한 전체 이용자의 분석결과와 비교하여 도서관 이용자만이 가지고 사회적 공간이용의 특성을 발견되었고 도서관 정책개발에 이러한 특성이 반영될 필요가 있음을 제안하였다.

• Spatial Information Research
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• v.19 no.5
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• pp.63-74
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• 2011

Recently, there has been much interest in the spatial query which energy-efficiently acquires sensor readings from sensor nodes inside specified geographical area of interests. The centralized approach which performs the spatial query at a server after acquiring all sensor readings, though simple, it incurs high wireless transmission cost in accessing all sensor nodes. In order to remove the high wireless transmission cost, various in-network spatial indexing schemes have been proposed. They have focused on reducing the transmission cost by performing distributed spatial filtering on sensor nodes. However, these in-network spatial indexing schemes have a problem which cannot optimize both the spatial filtering and the wireless routing among sensor nodes, because these schemes have been developed by simply applying the existing spatial indexing schemes into the in-network environment. Therefore, we propose a new distributed spatial indexing scheme of the GR-tree. The GR-tree which form s a MBR-based tree structure, can reduce the wireless transmission cost by optimizing both the efficient spatial filtering and the wireless routing. Finally, we compare the existing spatial indexing scheme through extensive experiments and clarify our approach's distinguished features.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.363-365
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• 2012

최근 빠르게 확산되고 있는 소셜 네트워크 서비스(Social Network Service)는 사용자의 인맥을 관리하며 새로운 인맥을 형성하는 것을 목표로 한다. 또한 사용자들이 자신의 관심사에 관한 지식이나 정보를 공개함으로써 정보의 효율성을 높이고 다른 사용자들에게 정보를 전파한다. 하지만 현재의 소셜 네트워크 서비스는 새로운 인맥을 형성하는 것보다 실제 사회에서의 인맥을 가상의 공간에서도 유지하고 관리하여 실제로 만나지 않더라도 관계를 유지할 수 있도록 하는 용도로 사용되어 소셜 네트워크의 목표를 달성하지 못하고 있다. 하지만 특정한 공간의 동일한 관심사를 가진 사람들 간의 제한적 정보 공유는 소셜 네트워의 단점을 보안하고 궁극적 목표를 달성할 수 있다. 또한 특정 관심사를 기반으로 그룹을 생성함으로써 정보의 신뢰도를 높이며 새로운 인맥을 형성에도 효과적 일 것이다. 하지만 이러한 네트워크는 모바일 환경의 특징으로 인해 빠르게 변화할 수 있으며 위치를 기반으로 특정 공간의 다른 사용자들과 통신함으로 완전히 새로운 인맥을 형성하게 된다. 그러므로 안전하게 신뢰관계를 구축하기위해 사용자의 평판 관리가 필요하다. 본 논문에서는 소셜 네트워크에서 동일한 관심사를 가진 폐쇄적 정보공유에서의 악의적 노드의 고립을 위한 평판 메커니즘을 제안한다.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.51-65
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• 2007

In order to analyze moving object trajectories on road networks, its representation needs to be defined correctly. The most previous methods representing moving object trajectories on road networks defined moving object trajectories as a set of passed location and its time. It is required much time in processing analysis such as retrieval for moving object trajectories. In this paper, we focus on POI(Points of Interest) on road networks and propose methods simplifying moving object trajectories based on it. Our method simplifies moving object trajectories by reducing the number of POIs that moving object trajectories passed and maintains its form after moving object trajectories were simplified.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.9-14
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• 2005

교통정책과 계획수립에 가장 중요한 의사결정 과정은 통행수요 분석이고, 이에 활용되고 있는 필수적인 기초 데이터베이스는 분석용 네트워크와 기종점 통행량이 있다. 통행수요 추정과정의 합리성이 보장되도록 하기 위해서는 이러한 기본 입력 자료의 신뢰성은 중요하다. 하지만, 일반적으로 분석용 네트워크를 구축할 때 예산과 분석기간의 제약 때문에 실세계의 교통망 중 많은 부분을 단순화 시켜서 구축한다. 또한 기 구축된 네트워크에 대해서도 변경되는 교통망을 반영하기 위해 네트워크를 수정, 편집할 때에도 많은 재원과 시간이 소요된다. 본 연구에서는 이러한 문제점을 보완하고자 교통분석 목적의 패키지(EMME/2, TranPlan) 혹은 범용의 GIS 패키지(ArcGIS)에서 직접 이용할 수 있도록 기 구축된 네트워크를 기반으로 GIS 데이터로의 변환 혹은 네트워크를 추출하는 양방향 데이터 교환 시스템을 개발하였다. 이러한 GIS-T 통합 시스템은 네트워크의 편집과 분석에 효율적인 환경을 제공하여 보다 현실적인 교통망 모델링을 반영할 것으로 기대되며 다양한 교통문제에 대한 분석에 효과적인 도구로 활용될 수 있을 것이다.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.3
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• pp.492-507
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• 2008

Many classical network analysis methods approach networks in aspatial perspectives. Measuring network reliability and finding critical nodes in particular, the analyses consider only network connection topology ignoring spatial components in the network such as node attributes and edge distances. Using local network autocorrelation measure, this study handles the problem. By quantifying similarity or clustering of individual objects' attributes in space, local autocorrelation measures can indicate significance of individual nodes in a network. As an application, this study analyzed internet backbone networks in the United States using both classical disjoint product method and Getis-Ord local G statistics. In the process, two variables (population size and reliability) were applied as node attributes. The results showed that local network autocorrelation measures could provide local clusters of critical nodes enabling more empirical and realistic analysis particularly when research interests were local network ranges or impacts.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.93-107
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• 2007

In this paper, an adaptive range aggregation spatial index method is proposed for spatial range query in ubiquitous sensor networks. As the ubiquitous sensor networks are the new information-oriented paradigm, many energy efficient spatial range query methods in ubiquitous sensor networks environment are studied vigorously. In sensor networks, users can monitor environment scalar data such as temperature and humidity during user defined time and spatial ranges. In order to execute spatial range query efficiently, rectangle based index methods are proposed, such as SPIX. But they define the return path as the opposite of its query transmit path. However, the sensor nodes in queried ranges are closed to each other, they can't aggregate the sensed value in a queried range because their query transmission paths are different. As a result, the previous methods waste energy unnecessarily to aggregate sensing data out of the queried range. In this paper, an adaptive aggregation index method is proposed that can aggregate values in a user defined range adaptively by using its neighbor information. It is shown that sensor power is saved efficiently by using the proposed method over the performance evaluation.

• Spatial Information Research
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• v.23 no.1
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• pp.49-57
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• 2015

Due to high density of population and progress of high building construction technologies, the number of high buildings has been increasing. Several information services have been provided to figure out complex indoor structures of building such as indoor navigations and indoor map services. The most fundamental information for these services are indoor network information. Indoor network in building provides topological connectivity between spaces unlike geometric information of buildings. In order to make indoor network information, we have to edit network manually or derive network properties based on the geometric data of buildings. This process is not easy for complex buildings. In this paper, we suggest a method to generate indoor network automatically based on crowdsourcing. From the collected individual trajectories, we derive indoor network information with crowdsourcing. We validate our method with a sample set of trajectory data and the result shows that our method is practical if the indoor positioning technology is reasonably accurate.

• Journal of the Economic Geographical Society of Korea
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• v.6 no.1
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• pp.99-117
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• 2003

Major proposes of this study are to analyze Korean Shipbuilding's production network and cooperation between related firms and to understand their spatial features. The Geographical study about networks has focused on automobiles, electronics or communications industries. That's because those industries have distinctive spatial features thanks to the full growth of subcontract structures. The labor-centered, capital-centered shipbuilding industry, differently from other manufacturing industries, has production networks where outside trades are common. Today internet based communication is being reinforced and the flexibility of purchase circumstances is being positively proceeded. The central axes of the production network of Sumsung shipbuilding are internationally Europe and Asian area, nationally Busan and Gyeongnam province and Seoul Metropolitan areas, locally inside subcontracting firms. And In order to construct mutual trust with cooperation firms, Sumsung shipbuilding is trying to reinforce two-way cooperation relation through 'SungJoHoi' organized with outside subcontracting firms and 'inside cooperation firms conference'. In conclusion, Sumsung shipbuilding is trying to strengthen the competitiveness of shipbuilding industry, spatially by setting up the network through globalization-localization and functionally by constructing the partnership production network for mutual communication.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.119-124
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• 2010

The MAC layer in ad-hoc network which makes network of nodes without infrastructure for a time has became an issue to reduce delay, allocate fairly bandwidth, control TX/RX power and improve throughput. Specially, the problem to reduce power consumption in ad-hoc network is very important part as ad-hoc devices use the limited battery. For solution of the problem, many power control algorithms, such as distribute power control, PCM (Power Control MAC) and F-PCF (Fragmentation based PCM), are proposed to limit power consumption until now. Although the algorithms are designed to minimize power consumption, the latency communication zone is generated by power control of RX/TX nodes. However the algorithms don't suitably reuse the space. In this paper proposes the algorithm to improve data throughput through Spatial Reuse based on a power control method.