• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1135-1142
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• 2014

With the continued popularity of mobile devices such as smart-phones and tables, the development of the various kinds of digital contents making tools has not increased only the productivity of the digital contents, but also the demand of them rapidly. Geo-contents which means the digital contents related to location(geographic) information has enabled the user custom services. Especially, there are already some commercial location-based services that provide the user to POI (Points of Interest) with the geo-image contents such as photos tagged by the location. In the geo-video contents, there could be several related locations in the whole video, but only one representative location is used to tag a location to the video. In this paper, we have define the geo-video as a video content which has as many locations as the number of frames composing the video. We have also proposed the geo-video making tools and a viewer to create and utilize the geo-video contents. The geo-video contents proposed in this paper, are widely used in location based video contents searching services.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.161-169
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• 2022

With the development of mobile devices and global positioning systems, various location-based services can be utilized, which collects user's location information and provides services based on it. In this process, there is a risk of personal sensitive information being exposed to the outside, and thus Geo-indistinguishability (Geo-Ind), which protect location privacy of LBS users by perturbing their true location, is widely used. However, owing to the data perturbation mechanism of Geo-Ind, it is hard to accurately obtain the density distribution of LBS users from the collection of perturbed location data. Thus, in this paper, we aim to develop a novel method which enables to effectively compute the user density distribution from perturbed location dataset collected under Geo-Ind. In particular, the proposed method leverages Expectation-Maximization(EM) algorithm to precisely estimate the density disribution of LBS users from perturbed location dataset. Experimental results on real world datasets show that our proposed method achieves significantly better performance than a baseline approach.

• Journal of the Korea Society of Computer and Information
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• v.29 no.6
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• pp.69-76
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• 2024

Recent advances in sensor and mobile technologies have made it possible to collect user location data. This location information is used as a valuable asset in various industries, resulting in increased demand for location data collection and sharing. However, because location data contains sensitive user information, indiscriminate collection can lead to privacy issues. Recently, geo-indistinguishability (Geo-I), a method of differential privacy, has been widely used to protect the privacy of location data. While Geo-I is powerful in effectively protecting users' locations, it poses a problem because the utility of the collected location data decreases due to data perturbation. Therefore, this paper proposes a method using Geo-I technology to effectively collect user location data while maintaining its data utility. The proposed method utilizes the prior distribution of users to improve the overall data utility, while protecting accurate location information. Experimental results using real data show that the proposed method significantly improves the usefulness of the collected data compared to existing methods.

• Journal of the Semiconductor & Display Technology
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• v.7 no.3
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• pp.59-63
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• 2008

Geo-coding refers to the process of associating data with location information, and the system deals with geographic identifiers expressed as latitude and longitude or street addresses. Although many services have been launched, there still remains a problem for users to create geo-coded photo with manually labeling GPS(Global Positioning System) coordinate or synchronizing with separate devices. In this paper, we design and implement a geo-coding system which utilizes the time and location information embedded in digital photographs in order to automatically categorize a personal photo collection. An included GPS receiver labels a photograph with its corresponding GPS coordinates, and the position of the camera is automatically recorded into the photo image header at the moment of capture. The place and time where the photo was taken allows us to provide context metadata on the management and retrieval of information.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.438-447
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• 2011

geoContents have been closely related with personal life since the Google Earth and Street View by Google and the Road View by Daum were introduced. So, Location-based content, which is referred to geoContents, involving geometric spacial information and location-based image information is a sharp rise in demand. A mobile mapping system used in the area of map upgrade and road facility management has been having difficulties in satisfying the demand in the cost and time for obtaining these kinds of contents. This paper addresses geoData acquisition and processing system for producing panoramic images. The system consists of 3 devices: the first device is 3 GPS receivers for acquiring location information which is including position, attitude, orientation, and time. The second is 6 cameras for image information. And the last is to synchronize the both data. The geoData acquired by the proposed system and the method for authoring geoContents which are referred to a panoramic image with position, altitude, and orientation will be used as an effective way for establishing the various location-based content and providing them service area.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.47-53
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• 2012

In cellular geo-location systems, positioning performance is influenced by hearability of receivers. Hearability can be enhanced by using long integration at the receiver. When unknown residual frequency remains in baseband signals, however, the coherent integration loss increases as the residual frequency becomes larger. Consequently, length of coherent integration is determined by the residual frequency. By precise estimation and compensation of the residual frequency, integration length can be enlarged. This paper presents a residual frequency estimator for WiBro geo-location and analyzes its performance in multipath environment. By computer simulation, an optimal receiver structure to enhance the hearability of WiBro geo-location is proposed.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.141-148
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• 2002

The purpose of this study is to enhance geo-location accuracy of the image data acquired by the Electro-Optical Camera(EOC) onboard KOMPSAT-1. EOC image data were analyzed to verify geo-location error. It was found that the major contribution was the time mark inaccuracy and attitude knowledge error. This study shows that the geo-location accuracy can be enhanced by modifying the time and attitude data of the ancillary data.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.135-138
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• 2020

This paper suggests a method of automatic clustering to search of relevant digital photos using geo-coded information. The provided scheme labels photo images with their corresponding global positioning system coordinates and date/time at the moment of capture, and the labels are used as clustering metadata of the images when they are in the use of retrieval. Experimental results show that geo-location information can improve the accuracy of image retrieval, and the information embedded within the images are effective and precise on the image clustering.

• Spatial Information Research
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• v.18 no.1
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• pp.89-99
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• 2010

This study has been implemented a map-based festival information website with Google Map to overcome a limit that existing festival information web sites supplied location information only through text-based format. To get the newest festival information, this website uses GeoRSS function which transform rss feed offered by newspaper websites into location based information. Through this function, internet users can see festival information at a glance on the basis of a map. Through this study we confirmed the efficiency of offering location based festival information and possibility of GeoRSS function to provide the newest festival information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5B
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• pp.247-256
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• 2007

In this paper, we propose Geographical Back-off Routing (Geo-Back Routing) protocol for wireless sensor networks. Geo-Back uses the positions of nodes, a packet's destination and a optimal back-off time to make the packet forwarding decisions using only source and destination's location information without information about neighbor nodes' location or the number of one hop neighbor nodes. Under the frequent topology changes in WSNs, the proposed protocol can find optimal next hop location quickly without broadcast algorithm for update. In our analysis, Geo-Back's scalability and better performance is demonstrated on densely deployed wireless sensor networks.