• 한국공간정보시스템학회 논문지
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• 제9권2호
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• pp.67-79
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• 2007

최근 LBS(location-based service) 및 텔레매틱스(telematics) 응용의 효율적인 지원을 위해, 유클리디언(Euclidean) 공간을 대신하여 실제 도로나 철도와 같은 공간 네트워크(network)를 고려한 연구가 활발하게 수행중이다. 그러나 기존 연구에서의 범위 질의 및 k-최근접 질의 처리 알고리즘은 범위나 k 값의 증가에 따라 검색에 필요한 노드 검색 및 거리 계산의 비용 증가로 인하여 선형적인 성능 감소를 보인다. 따라서, 본 논문에서는 공간 네트워크를 위한 기존 질의처리 알고리즘의 성능을 향상시키기 위해, 실체화 기법을 이용한 효율적인 범위 및 k-최근접 질의처리 알고리즘을 제안한다. 아울러, 기존 알고리즘과의 성능 비교를 통하여 제안하는 알고리즘이 우수함을 보인다.

• 한국병원경영학회지
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• 제23권2호
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• pp.28-41
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• 2018

Purpose: This study purposed to analyze the spatial accessibility of mental health institutions in Ganwon-Do using Geographic Information System and to suggest policy implications. Methodology: Network analysis was applied to assess the spatial accessibility of mental health institutions in Gangwon-Do. To perform the network analysis, network data set was built using administrative district map, road network, address of mental health institutions in Gangwon-Do. After building network data set, Two network analysis methods, 1) Service area analysis, 2) Origin Destination cost matrix were applied. Service area analysis calculated accessive areas that were within specified time. And using Origin Destination cost matrix, travel time and road travel distance were calculated between centroids of Eup, Myeon, Dong and the nearest mental health institutions. Result: After the service area analysis, it is estimated that 19.63% of the total areas in Gangwon-Do takes more than 60 minutes to get to clinic institutions. For hospital institutions, 23.08% of the total areas takes more than 60 minutes to get there. And 59.96% of Gangwon-do takes more than 30 minutes to get to general hospitals. The result of Origin-Destination cost matrix showed that most Eup Myeon Dong in Gangwon-Do was connected to the institutions in Wonju-si, Chuncheon-si, Gangneung-si. And it showed that there were large regional variation in time and distance to reach the institutions. Implication: Results showed that there were regional variations of spatial accessibility to the mental health institutions in Gangwon-Do. To solve this problem, Several policy interventions could be applied such as mental health resources allocation plan, telemedicine, providing more closely coordinated services between mental health institutions and community mental health centers to enhance the accessibility.

• Journal of Communications and Networks
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• 제12권2호
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• pp.103-113
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• 2010

In this paper, a tradeoff between the total energy consumption-per-bit and the end-to-end rate under spatial reuse in wireless multi-hop network is developed and analyzed. The end-to-end rate of the network is the number of information bits transmitted (end-to-end) per channel use by any node in the network that is forwarding the data. In order to increase the bandwidth efficiency, spatial reuse is considered whereby simultaneous relay transmissions are allowed provided there is a minimum separation between such transmitters. The total energy consumption-per-bit includes the energy transmitted and the energy consumed by the receiver to process (demodulate and decoder) the received signal. The total energy consumption-per-bit is normalized by the distance between a source-destination pair in order to be consistent with a direct (single-hop) communication network. Lower bounds on this energy-bandwidth tradeoff are analyzed using convex optimization methods. For a given location of relays, it is shown that the total energy consumption-per-bit is minimized by optimally selecting the end-to-end rate. It is also demonstrated that spatial reuse can improve the bandwidth efficiency for a given total energy consumption-per-bit. However, at the rate that minimizes the total energy consumption-per-bit, spatial reuse does not provide lower energy consumption-per-bit compared to the case without spatial reuse. This is because spatial reuse requires more receiver energy consumption at a given end-to-end rate. Such degraded energy efficiency can be compensated by varying the minimum separation of hops between simultaneous transmitters. In the case of equi-spaced relays, analytical results for the energy-bandwidth tradeoff are provided and it is shown that the minimum energy consumption-per-bit decreases linearly with the end-to-end distance.

• 한국측량학회지
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• 제32권2호
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• pp.95-107
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• 2014

일반적으로, 공간 도메인의 공간자료는 지형적인 현상을 도형적으로 표현하고 비공간 도메인의 속성자료는 공간 자료의 특징을 서술적으로 설명한다. GIS에서 속성자료를 이용한 분석은 조건을 이용한 검색이나 통계분석에 제한적으로 활용되고 있다. 최근 소셜 네트워크 분석의 그래프 모델링 및 네트워크 분석기법은 인문 사회적 현상을 분석하는데 사용되고 있으며, 본 연구에서는 이러한 네트워크 분석기법을 GIS의 비공간적인 속성자료 처리에 적용하여 분석기능을 다양하게 하였다. 또한, 공간 데이터베이스와 그래프 데이터베이스를 이용하여 GIS 공간분석과 비공간적 네트워크 분석의 통합분석 방법을 설계하였고, 이를 WebGIS를 구현하여 보다 효과적인 의사결정을 가능하도록 하였다. 구현된 WebGIS를 상수도 보급 대상 가구 선정 업무와 구제역 질병의 2차 전파 분석 업무에 적용하여 실험 및 평가하였다. 실험 결과, 구현된 시스템의 통합 분석을 통해 공간적인 요인 및 사회적 친밀도와 같은 비공간적인 요인을 고려한 방역을 제시하였으며, 이는 질병 전파의 효과적인 차단에 기여할 것으로 판단한다.

• 한국지리정보학회지
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• 제7권2호
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• pp.87-96
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• 2004

유역의 공간 DB를 DEM을 이용하여 구축할 경우에는 DEM으로부터 유역의 수문학적 지형특성 인자를 손쉽게 추출할 수 있으며, 이들이 자동으로 공간 DB의 속성으로 입력되어 관리될 수 있다. 본 연구에서는 유역정보를 관리하기 위한 기반정보인 프레임워크 공간 DB의 구축방안에 대하여 기술하였다. 이롤 위하여 프레임워크 공간 데이터의 범위를 결정하고, 이들의 상호 연관관계를 정의하였으며 실제 유역을 대상으로 프레임워크 공간 DB률 구축하였다. 한편 본 연구에서는 순수 국내기술로 수자원 공간자료 생성 및 수자원 시스템 개발 모듈인 HyGIS(Hydrological Geographic Information System)를 개발하였다. HyGIS를 이용하여 수문학적 지형특성인자 및 공간자료를 추출하였으며, 이들 자료를 실제 유역의 프레임워크 공간 DB를 구축하는 기본 데이터로 이용하였다. 본 연구에서는 이러한 과정을 통하여 하천 네트워크 기반의 유역관리시스템 개발을 위한 프레임워크 공간 DB의 구축방안을 제시하고자 한다.

• Computers and Concrete
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• 제26권5호
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• pp.411-420
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• 2020

Deep Convolution neural network (DCNN) has been widely used in the healthy maintenance of civil infrastructure. Using DCNN to improve crack detection performance has attracted many researchers' attention. In this paper, a light-weight spatial attention network module is proposed to strengthen the representation capability of ResNet and improve the crack detection performance. It utilizes attention mechanism to strengthen the interested objects in global receptive field of ResNet convolution layers. Global average spatial information over all channels are used to construct an attention scalar. The scalar is combined with adaptive weighted sigmoid function to activate the output of each channel's feature maps. Salient objects in feature maps are refined by the attention scalar. The proposed spatial attention module is stacked in ResNet50 to detect crack. Experiments results show that the proposed module can got significant performance improvement in crack detection.

• 한국측량학회지
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• 제30권6_2호
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• pp.653-663
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• 2012

Using soft classification, it is possible to obtain the land cover proportions from the remotely sensed image. These land cover proportions are then used as input data for a procedure called "super-resolution mapping" to produce the predicted hard land cover layers at higher resolution than the original remotely sensed image. Superresolution mapping can be implemented using a number of algorithms in which the Hopfield Neural Network (HNN) has showed some advantages. The HNN has improved the land cover classification through superresolution mapping greatly with the high resolution data. However, the super-resolution mapping is based on the spatial dependence assumption, therefore it is predicted that the accuracy of resulted land cover classes depends on the relative size of spatial features and the spatial resolution of the remotely sensed image. This research is to evaluate the capability of HNN to implement the super-resolution mapping for SPOT image to create higher resolution land cover classes with different zoom factor.

• 한국공간정보시스템학회 논문지
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• 제2권1호
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• pp.63-72
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• 2000

본 연구에서는 국가지리공간정보의 유통망의 구성 방안을 제시하였다. 국가지리공간정보의 유통망의 구성요소를 유통망 게이트웨이, 유통노드, 공간데이터 서버, 통신망, 관련 규약과 표준 그리고 사용자의 여섯가지로 나누고, 구성요소 각각의 역할과 상호관계에 대하여 기술하였다. 제시된 방안에 따라 국가지리공간정보 유통체계를 구축하여 활용함으로써 지리공간정보의 중복 구축을 방지하고, 지리공간정보의 가치를 높이며, 민간 사업자들이 지리공간정보 데이터베이스의 구축에 적극적으로 참여할 수 있도록 유도할 수 있으며 나아가 지리공간정보의 구축, 유통 및 활용 사업을 새로운 정보통신의 기반 산업으로 자리잡게 할 수 있을 것이다.

• 수산해양교육연구
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• 제23권3호
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• pp.477-485
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• 2011

For the identifying of spatial distribution pattern, Moran's Index(I) which has the range of values from -1 to +1 is common method for the spatial autocorrelation measurement. When I is close to 1, all neighboring features have close to the same value, indicating clustered pattern. Conversely, if the spatial pattern is dispersed, I is close to -1. And I closing to 0 means spatially random pattern. However, this index equation is influenced by how defining the neighboring features for target feature. To compare and understand the difference of neighborhood definition methods, fixed distance neighboring method and Gabriel Network method were used for I. In this study, these two methods were applied to two marine environments with water quality data. One is Gwangyang Bay which has complex geometric coastal structure located in South Sea of Korea. Another is Uljin area adjacent to open sea located in east coast of Korea. The distances between water quality observed locations were relatively regular in Gwangyang Bay, however, irregular in Uljin area. And for the fixed distance method popular Arc GIS tool was used, but, for the Gabriel Network, Visual Basic program was developed to produce Gabriel Network and calculate Moran's I and its Z-score automatically. According to this experimental results, different spatial pattern was showed differently for some data with using of neighboring definition methods. Therefore there is need to choose neighboring definition method carefully for spatial pattern analysis.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (C)
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• pp.83-87
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• 2006

Similarity search in moving object trajectories is an active area of research. In this paper, we introduce a new concept of measure that computes spatial distance (similarity) between two trajectories of moving objects on road networks. In addition, we propose an algorithm that generates a sequence of matching edge pairs for two trajectories that ate to be compared and computes spatial distance between them which is non Euclidian in nature. With an example, we explain how our algorithm works to show spatial similarity between trajectories of moving objects in spatial network.