• ETRI Journal
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• v.33 no.4
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• pp.476-486
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• 2011

The quality of navigation service is determined by the accuracy of the available data. For existing navigation services, a full map update is provided in order to keep the map data of mobile devices current. As content and services of mobile devices have recently been diversifying, the size of map data managed in mobile devices has increased, reaching several gigabytes in size. It generally takes tens of minutes to write several gigabytes of data into mobile device storage. For traditional navigation systems, a complicated storage structure called a physical storage format (PSF) is used to assure maximum processing performance of map data in mobile devices within limited resources. Consequently, even though modified navigation map data actually affects only a portion of a map, the full map data is updated because partial updates are not possible. In this paper, a navigation system is studied to solve this difficult partial map update problem. The map air update navigation system, which is the result of this study, provides real-time partial map updating using wireless communications.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.101-106
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• 2009

Map update is essential for maintaining reliability of maps. Update could be performed using variety of data sources such as aerial photos, engineering plans, LiDAR data and in-site surveying data. Therefore, map update is essential for maintaining reliability of maps. Update could be performed using variety of data sources such ad aerial photos, engineering plans, LiDAR data and in-site surveying data. Map update requires cost, manpower and time. It is important to inform updated information to users in order to decide purchase the updated maps or not. This paper proposes the way to provide various updated information of maps. Therefore, map users efficiently utilize information from maps.

• Journal of Cadastre & Land InformatiX
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• v.44 no.1
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• pp.127-138
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• 2014

It can be effective to extract and apply the updated information from the newly updated map data for updating road data of topographic map. In this study, update target data and update reference data are overlaid and the update objects are explored using network matching technique. And the network objects are classified into five matching and update cases and the update processes for each case are applied to the test data. For this study, road centerline data of digital topographic map is used as an update target data and road data of Korean Address Information System is used as an update reference data. The buffer-based network matching method is applied to the two data and the matching and update cases are classified after calculating the overlaid ratio of length. The newly updated road centerline data of digital topographic map is generated from the application of update process for each case. As a result, the update information can be extracted from the different map dataset and applied to the road network data updating.

• Spatial Information Research
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• v.20 no.2
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• pp.137-153
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• 2012

Until now, many indexing methods that can reduce update cost have been proposed for managing massive moving objects. Because indexing methods for moving objects have to be updated periodically for managing moving objects that change their location data frequently. However these kinds indexing methods occur big load that exceed system capacity when the number of moving objects increase dramatically. In this paper, we propose the update frequency reducing method to combine MapReduce and existing indices. We use the update request grouping method for each moving object by using MapReduce. We decide to update by comparing the latest data and the oldest data in grouping data. We reduce update frequency by updating the latest data only. When update is delayed, for the data should not be lost and updated periodically, we store the data in a certain period of time in the hash table that keep previous update data. By the performance evaluation, we can prove that the proposed method reduces the update frequency by comparison with methods that are not applied the proposed method.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.19-26
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• 2007

The renewal update of the digital map constructed through NGIS has been conducted for the enhancement of usage, maintenance so that the latest data is guaranteed. The total update has been done every five years for five regions of the country using aerial photographs and satellite images. By launching the third phase of NGIS, the updating plan was changed from total to total or partial update including the real time update scheme. Furthermore, the update period was improved from five to two years and four years for a large and a small city, respectively. Therefore, it is necessary to develope a matching technique which combines various geographic information (such as drawing map, surveying drawing and map) with exact position on the digital map. In this study, we developed a matching algorithm based on central point and suggested a method which uses general surveying drawing for revision/update of the digital map. The general survey is conducted when a civilian development on lands are approved. Thus, the outcome from the survey, which is the general survey drawing, contains the latest various contents such as road, building, water pipe and manhole. A consistent and efficient method using the general survey drawing for near real time update of the digital map by applying the developed matching algorithm is presented.

• Journal of KIISE
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• v.44 no.6
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• pp.643-648
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• 2017

Among Wi-Fi based indoor positioning systems, fingerprinting localization is the most common technique with high precision. However, construction of the initial radio map and the update process require considerable labor and time effort. To address this problem, we propose an efficient method that constructs the initial radio map at each vertex based on a graph. In addition, we introduce a method to update the radio map automatically by mapping signal data acquired from users to the reference point created on each edge. Since the proposed method collects signal data manually only at the vertex of the graph to build the initial radio map and updates it automatically, our proposed method can dramatically reduce labor and time effort, which are the disadvantages of the conventional fingerprinting method. In our experimental study, we show validity of our radio map update method by comparing with the actual reference point data. We also show that our proposed method is able to construct the radio map with an accuracy of about 3.5m by automatically updating the radio map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.313-321
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• 2002

Supplying high-resolution satellite image, we take much interest in the update and the revision of digital map and thematic map based on the satellite image. This study presented the possibility of the update and the revision to the existing digital map on a scale of l/5,000 and 1/25,000 to take advantage of the IKONOS satellite image. We performed geometric correction to make use of the ground control points of the existing digital map in IKONOS mono-image and created ortho-image by extracting digital elevation model from three dimensional contour data and altitude on the existing digital map. We revised changed features in the method of screen digitizing by overlapping orthorectified satellite image and existing digital map and flawed features of the unchanged area on the satellite images for positional accuracy analysis. As a result, rectification error is calculated at $\pm$3.35m by RMSE. There is a good possibility of update of digital map under the scale of 1/10,000. It is possible to the update of the large scale digital map over the scale of l/5,000, as if we used the method of stereo image and ground control point surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.5
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• pp.365-373
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• 2013

Tile caching technology is a commonly used method that optimizes the delivery of map imagery across the internet in modern WebGIS systems. However the poor performance of the map tile cache update is one of the major causes that hamper the wider use of this technique for datasets with frequent updates. In this paper, we introduce a new algorithm, namely, Partial Area Cache Update (PACU) that significantly minimizes redundant update of map tiles where the update frequency of source map data is very large. The performance of our algorithm is verified with the cadastral map data of Pyeongtaek of Gyeonggi Province, where approximately 3,100 changes occur in a day among the 331,594 parcels. The experiment results show that the performance of the PACU algorithm is 6.6 times faster than the ESRI ArcGIS SERVER$^{(r)}$. This algorithm significantly contributes in solving the frequent update problem and enable Web Map Tile Services for data that requires frequent update.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.29-34
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• 2009

Map update is required to provide up-to-date information. In update process, the most adequate generalization is to be applied to all scales of maps simultaneously. Most of existing maps are composed of 2D data and represented in 2D space. However, maps for next generation are to be generated with 3D spatial information including ortho-images and DEMs. Therefore, 3D generalization is necessary for 3D digital map update. This paper proposes methods for 3D generalization and correction for logical errors possibly accompanied with generalization.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.135-143
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• 2009

The purpose of this research is to reduce editors' workload and automation to update(v) Digital Map(n) regarding changed topography. In Digital Map case, it usually uses the way of various survey to update(v). In this case, it costs a great deal and doesn't be efficient backup management. Accordingly, it can reduce editors' the period of the process and be efficiently managed the backup data due to well organized backup data management. We present update plan that used clipping and join for this result by analyzing Boundary of input data.