• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1266-1272
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• 2004

Location-Based Services(LBS) give rise to location-dependent queries of which results depend on the positions of moving objects. Because positions of moving objects change continuously, indexes of moving object must perform update operations frequently for keeping the changed position information. Existing spatial index (Grid File, R-Tree, KDB-tree etc.) proposed as index structure to search static data effectively. There are not suitable for index technique of moving object database that position data is changed continuously. In this paper, I propose a dynamic hashing index that insertion/delete costs are low. The dynamic hashing structure is that apply dynamic hashing techniques to combine a hash and a tree to a spatial index. The results of my extensive experiments show the dynamic hashing index outperforms the $R^$ $R^*$-tree and the fixed grid.

• Journal of Korean Society of Rural Planning
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• v.29 no.3
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• pp.15-24
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• 2023

The sense of crisis regarding regional extinction due to low birth rates and an aging population is expanding. Generally, the local extinction index is used to analyze local extinction. However, it is challenging to diagnose the actual situation of village extinction risk in rural areas, even though the regional extinction index can be analyzed in units such as Si-Gun-Gu and Eup-Myeon-Dong. This difficulty arises because the regional extinction index solely relies on natural population growth indicators (elderly population and female population aged 20-39). Therefore, the purpose of this study is to develop a village extinction index that can identify the disappearance of rural villages. Additionally, the aim is to apply the developed indicators to the village (administrative ri) spatial unit. The existing regional extinction index used only mortality-related indicators as factors for natural population decline and fertility-related indicators as factors for natural population growth. However, the developed village extinction index included not only the factors of natural population change but also incorporated social population growth factors and factors related to the pace of village extinction. This is the key difference between the developed village extinction index and the existing regional extinction index. In this study, the indicators of "total population," "number of young women aged 20-44," "number of elderly population aged 70 or older," and "number of incoming population" were selected to develop a village extinction index. The village extinction index was developed by incorporating both natural population growth indicators and social population growth indicators. The developed village extinction index was applied to administrative villages. This research is expected to provide a more accurate understanding of the current state of rural villages facing extinction.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.203-209
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• 2012

Recently, k-nearest neighbors query methods based on wireless broadcasting environment are actively studied. The advantage of wireless broadcasting environment is the scalability that enables collective query processing for unspecified users connected to the server. However, in case existing k-NN query is applied in wireless broadcasting environment, there can be a disadvantage that backtracking may occur and consequently the query processing time is increasing. In this paper proposes a hierarchical bitmap-based spatial index in order to efficiently process the k-NN queries in wireless broadcasting environment. HBI reduces the bitmap size using such bitmap information and tree structure. As a result, reducing the broadcast cycle can reduce the client's tuning time and query processing time. In addition, since the locations of all the objects can be detected using bitmap information, it is possible to tune to necessary data selectively. For this paper, a test was conducted implementing HBI to k-NN query and the proposed technique was proved to be excellent by a performance evaluation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.191-194
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• 2001

The availability of the inexpensive, large main memories coupled with the demand for faster response time are bringing a new perspective to database technology. The Web GIS used by u unspecified number of general public in the internet needs high speed response time and frequent data retrieval for spatial analysis rather than data update. Therefore, it is appropriate to use main memory as a underlying storage structures for the Web GIS data. In this paper, we propose a data representation method based on relative coordinates and the size of the MBR. The method is able to compress the spatial data widely used in the Web GIS into smaller volume of memory. We also propose a memory resident spatial index with simple mechanism for processing point and region queries. The performance test shows that the index is suitable for managing the skewed data in terms of the size of the index and the number of the MBR intersection check operations.

• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.83-95
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• 2019

Recently, a variety of IoT data is collected by attaching geosensors to many vehicles that are on the road. IoT data basically has time and space information and is composed of various data such as temperature, humidity, fine dust, Co2, etc. Although a certain sensor data can be retrieved using time, latitude and longitude, which are keys to the IoT data, advanced search engines for IoT data to handle high-level user queries are still limited. There is also a problem with searching large amounts of IoT data without generating indexes, which wastes a great deal of time through sequential scans. In this paper, we propose a unified spatial index model that handles both grid and trajectory queries using a cell-based space-filling curve method. also it presents a visualization method that helps user grasp intuitively. The Trajectory query is to aggregate the traffic of the trajectory cells passed by taxi on the road searched by the user. The grid query is to find the cells on the road searched by the user and to aggregate the fine dust. Based on the generated spatial index, the user interface quickly summarizes the trajectory and grid queries for specific road and all roads, and proposes a Web-based prototype system that can be analyzed intuitively through road and heat map visualization.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.47-58
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• 2016

The purpose of this study was to select the sectoral vulnerable areas index in welfare field and analyze the socially vulnerable areas from comprehensive analysis. For this study, preceding research and theoretical background were reviewed. Through this, we selected for the analysis index and criteria, and data corresponding to the index are collected. Based on the index and criteria, the data analysis was performed in Seoul Metropolitan City selected as the spatial extent of this study. From the results of analysis, the sectoral lower rank 10% of social vulnerable areas was determined. In addition, Junggu, Yongsangu, and Seodaemungu from the comprehensive analysis of individual vulnerable areas were derived as a final vulnerable areas. In particular, Junggu was weak in all sectors; Yongsangu was in the medical sector; and Seodaemungu was poor in housing and education. Lower vulnerability index of all sectors (energy, housing, medical, transportation, and education) in 1st, 2nd, and 3rd residential areas by examining use zoning was showed. From the results of this study, we can expect time and labor saving of policy support in public sector.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.43-51
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• 2011

The recent development of the technology for wireless mobile computing and applied technology for location-based services has made it possible to support query processing faster than that in the past. However, some technological limitations on hardware and software still exist. The most critical aspects of query processing are accuracy and speed. For improving the accuracy, it is required that detailed information on the data involved in query processing be saved. In this case, the amount of information on the data increases, which decreases the speed. On the other hand, for increasing the speed, it is necessary to reduce the broadcast cycle, which enables rapid data acquisition as desired. In this case, because of insufficient index information, the listen time for the client increases, which may cause unnecessary energy consumption. Therefore, a trade-off occurs between the accuracy and speed. This paper proposes a hierarchical bitmap-based spatial index (HBI) as a solution for the aforementioned problems. HBI describes an object with 0 and 1 on the Hilbert curve map. It reduces the broadcast cycle by decreasing the index size on the basis of bit information and tree structure. Therefore, it is able to shorten the listen time and query processing time. In addition, HBI enables the detection of the locations of all the objects so that it is possible selectively listen to a broadcast. A performance evaluation of the proposed technique demonstrates that it is excellent.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.543-554
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• 2002

GIS (Geographic Information Systems) need faster access and better visualization. For faster access and better visualization in GIS, map generalization and levels of detail are needed. Existing spatial indexing methods do not support map generalization. Also, a few existing spatial indexing methods supporting map generalization do not support ail map generalization operations. We propose a new index structure, i.e. the LR-tree, supporting ail map generalization operations. This paper presents algorithms for the searching and updating the LR-tree and the results of performance evaluation. Our index structure works better than other spatial indexing methods for map generalization.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.626-637
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• 2019

Due to the rapid development of computer and digital technologies, those technologies were used in advertising. In order to meet the needs of marketing, a virtual space or character using 3D graphic augmented reality technology was developed and applied to advertisement. This study analyzed the characteristics of augmented reality in terms of interface design and spatial expression of augmented reality through case study. Firstly, we wanted to find the relationship between the types of the augmented reality advertisement and interface effects. Secondly, we wanted to find the spatial expression methods. The sample survey case studies based on 42 articles from 2012 to 2018 using Chinese and Korean site sharing augmented reality advertisement. The results of the case studies were divided into two parts. Firstly, the relationship between augmented reality types and interface effects were found basing on the augmented reality index. It means that the augmented reality index can be illustrated by using the augmented reality type. Simultaneously, the augmented reality type can be illustrated using the interface effect. The second part was that the types of display were used as a spatial representation. And the results showed that mobile display and public place display were the most frequently used.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.775-776
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• 2009

공간데이터를 관리하는 공간 index structure는 대부분 순차처리를 위한 구조를 가지고 있다. 많은 응용분야에서 방대한 양의 공간 데이터는 보조기억장치(예: disk)에 저장이 되어 사용이 되고 공간 index structure의 operation은 I/O에 대한 의존도가 크므로, I/O operation의 병렬처리는 공간 index structure의 질의반응시간을 현저하게 줄일 수 있다. 본 논문에서는 PPR-tree라는 병렬형 공간 index structure를 제안한다.