• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.159-169
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• 2019

Today, the location based service(LBS) is globally developing with the advance of smart phones and IOT devices. The main purpose of this research is to provide users with the most efficient route information, analyzing big data of people with a variety of routes. This system will enable users to have a similar feeling of getting a direct guidance from a person who has often used the route. It is possible because the system server analyzes the route information of people in real time, after composing the distributed processing system on the basis of map information. In the future, the system will be able to amazingly develop with the association of various LBS services, providing users with more precise and safer route information.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.705-714
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• 2019

Precision positioning is necessary for various use of high-resolution UAV images. Basically, GCP is used for this purpose, but in case of emergency situations or difficulty in selecting GCPs, the data shall be obtained without GCPs. This study proposed a method of improving positional accuracy for x, y coordinate of UAV based 3 dimensional point cloud data generated without GCPs. Road vector file by the public data (Open Data Portal) was used as reference data for improving location accuracy. The geometric correction of the 2 dimensional ortho-mosaic image was first performed and the transform matrix produced in this process was adopted to apply to the 3 dimensional point cloud data. The straight distance difference of 34.54 m before the correction was reduced to 1.21 m after the correction. By confirming that it is possible to improve the location accuracy of UAV images acquired without GCPs, it is expected to expand the scope of use of 3 dimensional spatial objects generated from point cloud by enabling connection and compatibility with other spatial information data.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.347-356
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• 2015

Due to the rapid development of IoT(Internet of Things) technology, traditional taxis are connected through dispatchers and location systems. Typically, modern taxis have embedded with GPS(Global Positioning System), which aims for obtaining the route information. By analyzing the frequency of taxi trip events, we can find the frequent route for a given query time. However, a scalability problem would occur when we convert the raw location data of taxi trip events into the analyzed frequency information due to the volume of location data. For this problem, we propose a NoSQL based top-K query system for taxi trip events. First, we analyze raw taxi trip events and extract frequencies of all routes. Then, we store the frequency information into hash-based index structure of MongoDB which is a document-oriented NoSQL database. Efficient top-K query processing for frequent route is done with the top of the MongoDB. We validate the efficiency of our algorithms by using real taxi trip events of New York City.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.1-6
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• 2011

The Context-Awareness technology which can provide the appropriate information to the human after estimating a lot of information exceeds the time and space in the ubiquitous environment is being developed now. GIS (Geographic Information System) and LBS (Location Based Services) based context awareness is one of these kinds of technology. The context awareness based transfer guide service which can provide useful information, according to the different information which was got from different sensors which were set in different places, to the pedestrian who is using the transfer center will be introduced in this paper. About the result of the service prototype which was tested in test-bed, the context awareness information such as the inside location and density calculation's accuracy is 90%, and the response time of the service is in 10 seconds, and also, the reliability will be higher if more advanced based infra will be used, so it is consider that it can be used to provide service enough.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.19-30
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• 2009

Recent development in wireless communication technology and mobile equipment like PDA, cellular phone and GPS makes location-based services (LBSs) popular. However, because, in the LBSs, users continuously request a query to LBS servers by using their exact locations, privacy information could be in danger. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, this paper propose a grid-based cloaking area creation scheme supporting continuous LBSs. The proposed scheme creates a cloaking area rapidly by using grid-based cell expansion to efficiently support the continuous LBSs. In addition, to generate a cloaking area which makes the exposure probability of a mobile user to a minimum, we compute a privacy protection degree by granting weights to mobile users. Finally, we show from a performance analysis that our cloaking scheme outperforms the existing cloaking schemes, in terms of service time, privacy protection degree.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.489-498
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• 2012

Smartphone schedule management applications are widely used in mobile environment with the help of their effective user interface and high user accessibility. Unfortunately, since the applications do not consider frequent context changes like user status or location, they can not support schedule management which reflects the changes. In this paper, we propose an intelligent notification service which gathers context information of users such as location and status, and actively provides appropriate services according to the context information. Based on the notification service, we also present a smartphone application for smart schedule management. Using the GPS sensor of a smartphone, the service can be aware of the status of the user through location and schedule information of the user. Also, according to the changed contexts, it provides proactive notifications to user.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.4
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• pp.117-124
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• 2015

As recent developing computing environments, service is provided without time or place's limitation, and it is constituted dynamically. Above all, in terms of education supporting system, there is need to conceive user's information and provide optimal service as to right with applying context awareness under Ubiquitous computing environment. It should have groundwork based on user location and time. It is requires service providing based on user location under the condition of class to offer appropriate service with the context. In addition, context information providing technology is needed to offer right education support service in the class, where are different context information. Hence, in this research it is suggested education supporting system to provide context-based for instructor. The framework of this system has a foundation within previous work about Multi-agent based Distributed Framework. To examine implementation of context-based education supporting system in Ubiquitous computing environments suggested by this report, arranging system can fit information relates to instructor's location for service applying in the class.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.229-239
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• 2012

In 2011, more than 2000 million smartphone users are in our country. As a result, consumer demand have been developed for a variety of applications, especially in the information service-related applications that combine location-based services and augmented reality in addition to related information for the virtual reality of things are rapidly increased. This paper analysed location-based services and augmented reality technology as related research and designed and implemented the system that provides the same environment as if the user is shopping and purchasing the items in the real world and offers the information characterizing the real situation combines location-based service and augmented reality which provides with an excellent reality in the smart phone environment. The proposed system in this paper is excellent in mobility, scalability and reality as a result of analysis of functions and services compared to web-based systems and has advantages to apply for the suitable system in ubiqutous environment which can be used in anytime and anywhere.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.345-349
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• 2004

In order to index exactly moving objects(vehicle, mobile phone, PDA, etc.) in the mobile database, continuous updates of their locations are inevitable as well as time-consuming. The studies of pure spatial indices have focused on the efficient retrievals. However, the acquisition and management of the terminal Location of moving objects are more important than the efficiency of the query processing in the moving object databases. Therefore, it will be need to adopt parallel processing system for the moving object databases which should maintain the object's current location as precise as possible. This paper proposes a architecture of spatial indexing mobile objects using multiple processors. More precisely, we newly propose a method of splitting buckets using the properties of moving objects in order to minimize the number of database updates. We also propose a acquisition method for gathering the location information of moving objects and passing the information of the bucket extents in order to reduce the amount of passed messages between processors.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.138-143
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• 2021

As of this moment, we are tracing people who are closed contact with Covid-19 patients and trying to block the spread of Covid-19 through diagnostic tests. However, the incubation period of the confirmed case is two weeks, and it takes a lot of human resources, time, and money to trace the routes of the confirmed case. In particular, as the number of confirmed cases have been increasing, the cost for finding closed contacts and blocking them in advance exponentially have almost reached the limitation of the budget. In finding closed contacts, all citizens must record an electronic access list every time they visit an amenities such as a store or a restaurant. This is likely the invasion of the privacy of personal location information. In this study, we designed a system that keeps one's location in real time, it will download the movement information of the confirmed case which is collected by KDCA, and it will notify the user when there is an overlap. Moreover, then guide for diagnostic test in advance will be used. The proposed method can solve the difficulty of recording in an electronic access list when visiting a store, and it can block infringement of privacy without providing personal information from KDCA.