• Title/Summary/Keyword: 공간필터링

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A Design and Implementation of Virtual Grid for Reducing Frequency of Continuous Query on LBSNS (LBSNS에서 연속 질의 빈도 감소를 위한 가상그리드 기법의 설계 및 구현)

  • Lee, Eun-Sik;Cho, Dae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.4
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    • pp.752-758
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    • 2012
  • SNS(Social Networking Services) is oneline service that enable users to construct human network through their relation on web, such as following relation, friend relation, and etc. Recently, owing to the advent of digital devices (smart phone, tablet PC) which embedded GPS some applications which provide services with spatial relevance and social relevance have been released. Such an online service is called LBSNS. It is required to use spatial filtering so as to build the LBSNS system that enable users to subscribe information of interesting area. For spatial filtering, user and tweet attaches location information which divide into static property presenting fixed area and dynamic property presenting user's area changed along the moving user. In the case of using a location information including dynamic property, Continuous query occurred from the moving user causes the problem in server. In this paper, we propose spatial filtering algorithm using Virtual Grid for reducing frequency of query, and conclude that frequency of query on using Virtual Grid is 93% decreased than frequency of query on not using Virtual Grid.

New separation technique of regional-residual gravity anomaly using geostatistical spatial filtering (공간필터링을 이용한 중력이상의 광역-잔여 이상 효과 분리)

  • Rim, Hyoung-Rae;Park, Yeong-Sue;Lim, Mu-Teak;Koo, Sung-Bon;Lee, Young-Chal
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.155-160
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    • 2006
  • In this paper, we propose a spatial filtering scheme using factorial kriging, one of geostatistical filtering methodin order to separate regional and residual gravity anomaly. This scheme is based on the assumption that regional anomalies have longer distance relation and residual anomalies have effected on smaller range. We decomposed gravity anomalies intotwo variogram models with long and short effectiveranges by means of factorial kriging. And decomposed variogram models produced the regional and residual anomalies. This algorithm was examined using by a synthetic gravity data, and applied to a real microgravity data to figure out abandoned mineshaft.

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Spatial Filtering Characteristics on Rotation of Single Slit (단슬리트구조센서의 회전에 따른 필터링특성 연구)

  • Jun, Seung-Hwan;Moon, Serng-Bae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.250-251
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    • 2012
  • 여러 분야에서 공간적 물리량, 패턴 또는 분포 등의 공간정보를 공간적으로 처리하는 방법이 연구 개발되어 왔다. 공간필터링 또는 공간필터법이라고 불리기도 하는 이 기법은 현재 직선 회전 군속도, 표면거칠기, 토석류속도, 형상, 결함 등 여러 계측분야에서 활용되고 있다. 이들 분야에 활용되는 공간필터는 복수개의 슬리트로 구성되며, 최상의 계측목적을 달성하기 위해서는 최적하중함수를 설계하여 각각의 슬리트에 맞는 하중값을 적용하여야 한다. 본 연구에서는 계측계의 간략화를 구현하기 위한 기초연구로서 기본이 되는 단슬리트의 구조 및 회전에 따른 필터링특성을 분석하였다.

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A Spatial Filtering Neural Network Extracting Feature Information Of Handwritten Character (필기체 문자 인식에서 특징 추출을 위한 공간 필터링 신경회로망)

  • Hong, Keong-Ho;Jeong, Eun-Hwa
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.1
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    • pp.19-25
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    • 2001
  • A novel approach for the feature extraction of handwritten characters is proposed by using spatial filtering neural networks with 4 layers. The proposed system first removes rough pixels which are easy to occur in handwritten characters. The system then extracts and removes the boundary information which have no influence on characters recognition. Finally, The system extracts feature information and removes the noises from feature information. The spatial filters adapted in the system correspond to the receptive fields of ganglion cells in retina and simple cells in visual cortex. With PE2 Hangul database, we perform experiments extracting features of handwritten characters recognition. It will be shown that the network can extract feature informations from handwritten characters successfully.

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An Analysis of Urban Residential Crimes using Eigenvector Spatial Filtering (아이겐벡터 공간필터링을 이용한 도시주거범죄의 분석)

  • Kim, Young-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.2
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    • pp.179-194
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    • 2009
  • The spatial distribution of crime incidences in urban neighborhoods is a reflection of their socio-economic environment and spatial inter-relations. Spatial interactions between offenders and victims lead to spatial autocorrelation of the crime incidences. The spatial autocorrelation among the incidences biases the interpretation of the ecological model in OLS framework. This research investigates residential crimes using residential burglaries and robberies occurred in the city of Columbus, Ohio, for 2000. In particular, the spatial distribution of incidence rates of residential crimes are accounted in OLS framework using eigenvectors, which reflect spatial dependence in crime patterns. Result presents that handling spatial autocorrelation enhanced model estimation, and both economic deprivation and crime opportunity are turned out significant in estimating residential crime rates.

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Reconstruction Method of Spatially Filtered 3D images in Integral Imaging based on Parallel Lens Array (병렬렌즈배열 기반의 집적영상에서 공간필터링된 3차원 영상 복원)

  • Jang, Jae-Young;Cho, Myungjin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.3
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    • pp.659-666
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    • 2015
  • In this paper, we propose a novel reconstruction method of spatially filtered 3D images in integral imaging based on parallel lens array. The parallel lens array is composed of two lens arrays, which are positioned side by side through longitudinal direction. Conventional spatial filtering method by using convolution property between periodic functions has drawback that is the limitation of the position of target object. this caused the result that the target object should be located on the low depth resolution region. The available spatial filtering region of the spatial filtering method is depending on the focal length and the number of elemental lens in the integral imaging pickup system. In this regard, we propose the parallel lens array system to enhance the available spatial filtering region and depth resolution. The experiment result indicate that the proposed method outperforms the conventional method.

Extraction of Korean Information from Maps by Spatial Filtering Neural Network (공간 필터링 신경회로망에의한 지도에서의 한글 문자 정보의 추출)

  • Lee, U-Beom;Jeong, Ji-Uk;Hwang, Ha-Jeong;Kim, Uk-Hyeon
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.1
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    • pp.223-235
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    • 1998
  • 도면 중에 내재한 지리정보를 이해해서 공간 자료에 대한 사용자의 질의에 응답할 수 있는 지능형 시스템의 설계는 화상처리 연구의 중요한 응용분야이다. 특히, 지도도면에는 도로, 강, 지역경계, 문자, 심벌 등의 지리정보가 존재하며, 이 개체와 개체 사이의 관계를 포함하는 데이터베이스의 구축은 매우 어려운 일이다. 본 논문에서는 지도도면으로부터 문자정보의 추출과 인식을 위해서 시신경계의 특징추출 이론을 적용한 공간 필터링 신경회로망을 제안한다. 본 시스템을 국립지리원 발행의 1/5,000지도에 적용하여 그 유효성을 보인다.

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The GR-tree: An Energy-Efficient Distributed Spatial Indexing Scheme in Wireless Sensor Networks (GR-tree: 무선 센서 네트워크에서 에너지 효율적인 분산 공간색인기법)

  • Kim, Min-Soo;Jang, In-Sung
    • 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.

GPS Anti-Jamming Using Beamforming Technique (빔포밍 기법을 이용한 GPS 재밍 대응)

  • Choi, Chang-Mook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.2
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    • pp.451-456
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    • 2016
  • Because GPS signals are weak, system jamming is a real and present danger. This can happen when the receiver is subjected to intentional or unintentional interference by a transmitter. If the jamming signal is strong enough, the receiver can be operated to take corrective action automatically. Current methods to protect GPS receiver from jamming condition are based on spatial filtering. In this paper, the beamforming as referred to in signal processing technique used in arrays for directional signal reception was suggested and analyzed for anti-jamming. In order to change the directionality of the array when receiving a jamming signal, a beamformer can control the signal at each sensor. Therefore, cutoff angle ${\theta}$ was measured in the opposite direction of the jammer. GPS signals are only processed when the antenna element is within inside the cutoff angle. As a result, GPS positioning can be used in condition under cutoff angle $30^{\circ}$.