• The Journal of Korea Robotics Society
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• v.4 no.3
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• pp.169-176
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• 2009

Low-cost sensors have been widely used for mobile robot navigation in recent years. However, navigation performance based on low-cost sensors is not good enough to be practically used. Among many navigation techniques, building of an accurate map is a fundamental task for service robots, and mapping with low-cost IR sensors was investigated in this research. The robot's orientation uncertainty was considered for mapping by modifying the Bayesian update formula. Then, the data association scheme was investigated to improve the quality of a built map when the robot's pose uncertainty was large. Six low-cost IR sensors mounted on the robot could not give rich data enough to align the range data by the scan matching method, so a new sample-based method was proposed for data association. The real experiments indicated that the mapping method proposed in this research was able to generate a useful map for navigation.

• Spatial Information Research
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• v.13 no.1 s.32
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• pp.91-101
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• 2005

The Mobile Mapping System using the vehicle equipped the GPS, IMU, CCD Cameras is the effective system for the management of the road facilities, update of the digital map, and etc. If the geographic information which is acquired by the Mobile mapping System can be transmitted in realtime, users can process what they want using the latest data. In this research, the effective method was suggested for the transmission of the geographic information acquired by mobile mapping System such as position data, attitude data, and image data in the wireless internet environment in realtime.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1163-1175
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• 2021

In autonomous driving, road markings are an essential element for object tracking, path planning and they are able to provide important information for localization. This paper presents an approach to update and measure road surface markers with HD maps as well as matching using inverse perspective mapping. The IPM removes perspective effects from the vehicle's front camera image and remaps them to the 2D domain to create a bird-view region to fit with HD map regions. In addition, letters and arrows such as stop lines, crosswalks, dotted lines, and straight lines are recognized and compared to objects on the HD map to determine whether they are updated. The localization of a newly installed object can be obtained by referring to the measurement value of the surrounding object on the HD map. Therefore, we are able to obtain high accuracy update results with very low computational costs and low-cost cameras and GNSS/INS sensors alone.

• Journal of Internet of Things and Convergence
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• v.8 no.5
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• pp.33-39
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• 2022

A storage device used in the mobile computing field should have low power, light weight, durability, etc., and should be able to effectively store and manage large-capacity data generated by users. NAND flash memory is mainly used as a storage device in the field of mobile computing. Due to the structural characteristics of NAND flash memory, it is impossible to overwrite in place when a data update request is made, so it can be solved by accurately separating requests that frequently request data update and requests that do not, and storing and managing them in each block. The classification method for such a data update request is called a hot data identification method, and various studies have been conducted at present. This paper continuously records the occurrence of data update requests using a counting filter for more accurate hot data validation, and also verifies hot data by considering how often the requested update requests occur during a specific time.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.656-660
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• 2004

The Mobile Mapping System is an effective method to acquire the position and image data using vehicle equipped with the GPS (Global Positioning System), IMU (Inertial Measurement Unit), and CCD camera. It is used in various fields of road facility management, map update, and etc. In the general photogrammetry such as aerial photogrammetry, GCP (Ground Control Point)s are needed to compute the image exterior orientation elements (the position and attitude of camera). These points are measured by field survey at the time of data acquisition. But it costs much time and money. Moreover, it is not possible to make sufficient GCP as much as we want. However Mobile Mapping System is more efficient both in time and money because it can obtain the position and attitude of camera at the time of photographing. That is, Indirect Georeferencing must use GCP to compute the image exterior orientation elements, but on the other hand Direct Georeferencing can directly compute the image exterior orientation elements by GPS/INS. In this paper, we analyze about the positional accuracy comparison of ground point using the Direct Georeferencing and Indirect Georeferencing.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.11-17
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• 2005

This study is to improve the modification of survey data and efficiency of update using digital map based on PDA_based surveying mapping system. This object is achieved by developing wireless communication module of PDA which is adaptable to Totalstation, and contents for its usage. It is achieved by drawing up transformation module of dxf file to editing the text file and the drawing. And it is achieved by drawing up modification module to layer control. This system will be efficiently used to surveying parts of spatial location information for real time mapping ind point positioning in field work.

• Korean Journal of Geomatics
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• v.1 no.1
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• pp.51-59
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• 2001

The Government confirmed the action planning of digital mapping project for major thematic maps based on ‘Revised Plan for The Development of the National Geographic Information System’(NGIS). Mapping for major thematic maps was begun in 1998 when digital mapping project for topographic maps finished due to the delay of the action planning, and will selectively have produced the essential digital thematic maps according to the frequency of usage. The models of topographic-cadastral maps and administrative boundary maps around Suwon were produced in accordance with the presented draft. We presented specification for production of the most appropriate topographic-cadastral maps and administrative boundary maps through the analysis of the process of production, discussion and error check, and correction of the produced topographic-cadastral maps and administrative boundary maps. And we could make it easier to develop digital mapping project of topographic-cadastral maps and administrative boundary maps effectively by presenting the strategy for data input and maintenance, the cost model for carrying out the digital thematic map production, digital topographic maps, and the supplement of data model and data format. Topographic-cadastral maps has a wide range of usage but a lot of difficulties in the process of production and map update under use. So it seems that the study on users, university, private sector and municipal self-government must follow for promoting the use of topographic-cadastral maps.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.33-43
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• 2018

In this paper, we propose a method to automatically generate the description of an RDF graph structure. The description is expressed in Shape Expression Language (ShEx), which is developed by W3C and provides the syntax for describing the structure of RDF data. The RDF graphs to which this method can be applied are limited to those generated by the direct mapping, which is an algorithm for transforming relational data into RDF by W3C. A relational database consists of its schema including integrity constraints and its instance data. While the instance data can have been published in RDF by some standard methods such as the direct mapping, the translation of the schema has been missing so far. Unlike the users on relational databases, the ones on RDF datasets were forced to write repeated vague SPARQL queries over the datasets to acquire the exact results. This is because the schema for RDF data has not been provided to the users. The ShEx documents generated by our method can be referred as the schema on writing SPARQL queries. They also can validate data on RDF graph update operations with ShEx validators. In other words, they can work as the integrity constraints in relational databases.

• Steel and Composite Structures
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• v.44 no.4
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• pp.473-488
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• 2022

A high-speed railway (HSR) bridge may undergo long-term deformation due to the degradation of material stiffness, or foundation settlement during its service cycle. In this study, an analytical model is set up to evaluate the influence of this long-term vertical bridge deformation on the track geometry. By analyzing the structural characteristics of the HSR track-bridge system, the energy variational principle is applied to build the energy functionals for major components of the track-bridge system. By further taking into account the interlayer's force balancing requirements, the mapping relationship between the deformation of the track and the one of the bridge is established. In order to consider the different behaviors of the interlayers in compression and tension, an iterative method is introduced to update the mapping relationship. As for the validation of the proposed mapping model, a finite element model is created to compare the numerical results with the analytical results, which show a good agreement. Thereafter, the effects of the interlayer's different properties of tension and compression on the mapping deformations are further evaluated and discussed.

• 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.