• Title/Summary/Keyword: Spatial Index

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Using spatial misalignment Method to Measure and Evaluate unbalanced reginal tourism development in Southwest China

  • Lee, Rui;Kim, Hyung-Ho
    • International Journal of Advanced Culture Technology
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    • v.9 no.3
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    • pp.23-33
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    • 2021
  • "China's Western Development Policy" has brought multiple opportunities to the development of tourism in Southwest China including Sichuan, Guizhou, Yunnan, Chongqing and Tibet. The 4 provinces and 1 municipality overall show a certain degree of accumulation effect and coordinated development in tourism due to their location, traffic and traditional economic cooperation. This study takes the Southwest China as the research object and utilized the spatial dislocation model and the tourism spatial misalignment index to estimate the mismatch degree between tourism resources and tourism income among provinces and try to find out the internal reason background. The results show that each of the five provinces has its own advantages in index of economy, tourism resources, human resource, and transportation, leading to differences in the center of gravity of the entire region in all aspects. In view of the results of spatial dislocation analysis, suggestions for improvement and optimization are put forward to promote the high-quality development of tourism in Southwest region. development.

An Efficient Spatial Index Structure for Main Memory (메인 메모리를 위한 효율적인 공간 인덱스 구조)

  • Lee, Ki-Young;Lim, Myung-Jae;Kang, Jeong-Jin;Kim, Joung-Joon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.2
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    • pp.13-20
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    • 2009
  • Recently there is growing interest in LBS requiring real-time services and the spatial main memory DBMS for efficient Telematics services. In order to optimize existing disk-based spatial indexes of the spatial main memory DBMS in the main memory, spatial index structures have been proposed, which minimize failures in cache access by reducing the entry size. However, because the reduction of entry size requires compression based on the MBR of the parent node or the removal of redundant MBR, the cost of MBR reconstruction increases in index update and the efficiency of search is lowered in index search. Thus, to reduce the cost of MBR reconstruction, this paper proposed the RSMB (relative-sized MBR)compression technique, which applies the base point of compression differently in case of broad distribution and narrow distribution. In case of broad distribution, compression is made based on the left-bottom point of the extended MBR of the parent node, and in case of narrow distribution, the whole MBR is divided into cells of the same size and compression is made based on the left-bottom point of each cell. In addition, MBR was compressed using a relative coordinate and size to reduce the cost of search in index search. Lastly, we evaluated the performance of the proposed RSMBR compression technique using real data, and proved its superiority.

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Analysis of Relation Between Criminal Types and Spatial Characteristics in Urban Areas (도심지역의 범죄 종류와 공간적 특성 관계분석)

  • Cha, Gyeong Hyeon;Kim, Kyung Ho;Son, Ki Jun;Kim, Sang Ji;Lee, Dong Chang;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.6-11
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    • 2015
  • In this paper, we analyzed current states and spatial characteristics of crime occurring in A city of Colombia using big data of crime. The analysis draws on the crime statistics of Colombia National Police Agency from 2013 January to September. We also investigated spatial autocorrelation of crime using global and local Moran's Index. Spatial autocorrelation analysis shows significant spatial autocorrelation in the high frequency of crime. Global Moran's I analysis indicates that there are statistically significant value of crime area. Using local Moran's Index analysis, we also implement Local Indicators of Spatial Association(LISA) map and hot spot analysis helps us identify crime distribution.

An Efficient Adaptive Bitmap-based Selective Tuning Scheme for Spatial Queries in Broadcast Environments

  • Song, Doo-Hee;Park, Kwang-Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.10
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    • pp.1862-1878
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    • 2011
  • With the advances in wireless communication technology and the advent of smartphones, research on location-based services (LBSs) is being actively carried out. In particular, several spatial index methods have been proposed to provide efficient LBSs. However, finding an optimal indexing method that balances query performance and index size remains a challenge in the case of wireless environments that have limited channel bandwidths and device resources (computational power, memory, and battery power). Thus, mechanisms that make existing spatial indexing techniques more efficient and highly applicable in resource-limited environments should be studied. Bitmap-based Spatial Indexing (BSI) has been designed to support LBSs, especially in wireless broadcast environments. However, the access latency in BSI is extremely large because of the large size of the bitmap, and this may lead to increases in the search time. In this paper, we introduce a Selective Bitmap-based Spatial Indexing (SBSI) technique. Then, we propose an Adaptive Bitmap-based Spatial Indexing (ABSI) to improve the tuning time in the proposed SBSI scheme. The ABSI is applied to the distribution of geographical objects in a grid by using the Hilbert curve (HC). With the information in the ABSI, grid cells that have no objects placed, (i.e., 0-bit information in the spatial bitmap index) are not tuned during a search. This leads to an improvement in the tuning time on the client side. We have carried out a performance evaluation and demonstrated that our SBSI and ABSI techniques outperform the existing bitmap-based DSI (B DSI) technique.

A Study on Strategy Direction for Promoting the Geo-spatial Information Industry by Input-Output Analysis (산업연관분석을 통한 공간정보산업의 특징 및 정책방향성에 대한 연구)

  • Lim, Si Yeong;Ahn, Jong Wook;Yi, Mi Sook
    • Spatial Information Research
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    • v.20 no.6
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    • pp.69-76
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    • 2012
  • In this study, we derived the characteristics of the geo-spatial information industry by using input-output analysis. For this analysis, we classified the geo-spatial information industry and reorganized the input-output table. And we derived the production inducement coefficient, index of the power of dispersion and index of the sensitivity of dispersion in the geo-spatial information industry. We confirmed that geo-spatial information industry has a small production inducement coefficient and a great forward linkage effect. Based on these facts, we suggested the strategy direction as follows: 1) building the industrial eco-system, 2) managing both advance and applicability enhancement, 3) Establishing from a long-term point of view.

Design of Memory-Resident GIS Database Systems

  • Lee, J. H.;Nam, K.W.;Lee, S.H.;Park, J.H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.499-501
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    • 2003
  • As semiconductor memory becomes cheaper, the memory capacity of computer system is increasing. Therefore computer system has sufficient memory for a plentiful spatial data. With emerging spatial application required high performance, this paper presents a GIS database system in main memory. Memory residence can provide both functionality and performance for a database management system. This paper describes design of DBMS for storing, querying, managing and analyzing for spatial and non-spatial data in main-memory. This memory resident GIS DBMS supports SQL for spatial query, spatial data model, spatial index and interface for GIS tool or applications.

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Assessment of Photochemical Reflectance Index Measured at Different Spatial Scales Utilizing Leaf Reflectometer, Field Hyper-Spectrometer, and Multi-spectral Camera with UAV (드론 장착 다중분광 카메라, 소형 필드 초분광계, 휴대용 잎 반사계로부터 관측된 서로 다른 공간규모의 광화학반사지수 평가)

  • Ryu, Jae-Hyun;Oh, Dohyeok;Jang, Seon Woong;Jeong, Hoejeong;Moon, Kyung Hwan;Cho, Jaeil
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.1055-1066
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    • 2018
  • Vegetation indices on the basis of optical characteristics of vegetation can represent various conditions such as canopy biomass and physiological activity. Those have been mostly developed with the large-scaled applications of multi-band optical sensors on-board satellites. However, the sensitivity of vegetation indices for detecting vegetation features will be different depending on the spatial scales. Therefore, in this study, the investigation of photochemical reflectance index (PRI), known as one of useful vegetation indices for detecting photosynthetic ability and vegetation stress, under the three spatial scales was conducted using multi-spectral camera installed in unmanned aerial vehicle (UAV),field spectrometer, and leaf reflectometer. In the leaf scale, diurnal PRI had minimum values at different local-time according to the compass direction of leaf face. It meant that each leaf in some moment had the different degree of light use efficiency (LUE). In early growth stage of crop, $PRI_{leaf}$ was higher than $PRI_{stands}$ and $PRI_{canopy}$ because the leaf scale is completely not governed by the vegetation cover fraction.In the stands and canopy scales, PRI showed a large spatial variability unlike normalized difference vegetation index (NDVI). However, the bias for the relationship between $PRI_{stands}$ and $PRI_{canopy}$ is lower than that in $NDVI_{stands}$ and $NDVI_{canopy}$. Our results will help to understand and utilize PRIs observed at different spatial scales.

The change of land cover classification accuracies according to spatial resolution in case of Sunchon bay coastal wetland (위성영상 해상도에 따른 순천만 해안습지의 분류 정확도 변화)

  • Ku, Cha-Yong;Hwang, Chul-Sue
    • Journal of the Korean association of regional geographers
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    • v.7 no.1
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    • pp.35-50
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    • 2001
  • Since remotely sensed images of coastal wetlands are very sensitive to spatial resolution, it is very important to select an optimum resolution for particular geographic phenomena needed to be represented. Scale is one of the most important factors in spatial analysis techniques, which is defined as a spatial and temporal interval for a measurement or observation and is determined by the spatial extent of study area or the measurement unit. In order to acquire the optimum scale for a particular subject (i.e., coastal wetlands), measuring and representing the characteristics of attribute information extracted from the remotely sensed images are required. This study aims to explore and analyze the scale effects of attribute information extracted from remotely sensed coastal wetlands images. Specifically, it is focused on identifying the effects of scale in response to spatial resolution changes and suggesting a methodology for exploring the optimum spatial resolution. The LANDSAT TM image of Sunchon Bay was classified by a supervised classification method, Six land cover types were classified and the Kappa index for this classification was 84.6%. In order to explore the effects of scale in the classification procedure, a set of images that have different spatial resolutions were created by a aggregation method. Coarser images were created with the original image by averaging the DN values of neighboring pixels. Sixteen images whose resolution range from 30 m to 480 m were generated and classified to obtain land cover information using the same training set applied to the initial classification. The values of Kappa index show a distinctive pattern according to the spatial resolution change. Up to 120m, the values of Kappa index changed little, but Kappa index decreased dramatically at the 150m. However, at the resolution of 240 m and 270m, the classification accuracy was increased. From this observation, the optimum resolution for the study area would be either at 240m or 270m with respect to the classification accuracy and the best quality of attribute information can be obtained from these resolutions. Procedures and methodologies developed from this study would be applied to similar kinds and be used as a methodology of identifying and defining an optimum spatial resolution for a given problem.

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Spatial View Materialization Technique by using R-Tree Reconstruction (R-tree 재구성 방법을 이용한 공간 뷰 실체화 기법)

  • Jeong, Bo-Heung;Bae, Hae-Yeong
    • The KIPS Transactions:PartD
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    • v.8D no.4
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    • pp.377-386
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    • 2001
  • In spatial database system, spatial view is supported for efficient access method to spatial database and is managed by materialization and non-materialization technique. In non-materialization technique, repeated execution on the same query makes problems such as the bottle-neck effect of server-side and overloads on a network. In materialization technique, view maintenance technique is very difficult and maintenance cost is too high when the base table has been changed. In this paper, the SVMT (Spatial View Materialization Technique) is proposed by using R-tree re-construction. The SVMT is a technique which constructs a spatial index according to the distribution ratio of objects in spatial view. This ratio is computed by using a SVHR (Spatial View Height in R-tree) and SVOC (Spatial View Object Count). If the ratio is higher than the average, a spatial view is materialized and the R-tree index is re-used. In this case, the root node of this index is exchanged a node which has a MBR (Minimum Boundary Rectangle) value that can contains the whole region of spatial view at a minimum size. Otherwise, a spatial view is materialized and the R-tree is re-constructed. In this technique, the information of spatial view is managed by using a SVIT (Spatial View Information Table) and is stored on the record of this table. The proposed technique increases the speed of response time through fast query processing on a materialized view and eliminates additional costs occurred from repeatable query modification on the same query. With these advantages, it can greatly minimize the network overloads and the bottle-neck effect on the server.

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Selection of dominant meteorological indices related with heavy rainfall caused by BAIU activity

  • Koji, Nishiyama;Yoshitaka, I;Kenji, Jinno;Akira, Kawamura
    • Proceedings of the Korea Water Resources Association Conference
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    • 2003.05a
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    • pp.163-170
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    • 2003
  • In this study, paying much attention to notable features obtained from spatial distributions of strongly related indices (precipitable water, convergence of air, convective available potential energy) with precipitation, fatal problems in selecting strongly related indices with observed precipitation in a BAIU season were discussed. These results showed spatial distribution of a predicted index provided alternative and physically consistent interpretation for selecting dominant index for heavy rainfall even if the predicted index did not correlate with observed rainfall at a specific observational point as confirmed by the features of CONV (Convergence) or even if it correlated with observed rainfall as confirmed by those of PW (Precipitable Water). Therefore, dominant meteorological indices of heavy rainfall should be selected according to physically evidenced interpretation on features of spatial distributions of indices, and physically and statistically consistent relationship should be built up.

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