• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.17-26
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• 2007

In this paper, we propose a basic virtual grid-based routing algorithm in order to devise an efficient routing method in ad hoc networks using the location information of nodes, energy level, etc. A packet is forwarded to the X-axis direction at first based on the location information of a destination node, and then it is forwarded to the Y-axis direction as its location becomes close to the destination from the viewpoint of the X-axis. Due to the selection of next hop nodes to deliver a packet from a certain node to a destination node, we can regard the whole network as a virtual grid network. The proposed routing algorithm determines routing paths using the local information such as the location information of a destination and its neighbor nodes. Thus, the routing path setup is achieved locally, by which we can expect reduction in network traffics and routing delays to a destination. To evaluate the performance of the proposed routing algorithm, we used the network simulator ns2 and compared its network throughput with that of an existing routing algorithm.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.55-62
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• 2011

To make service location protocol of IETF which is to be used in the wide area network to discover the location of desired service when computing resources are connected to the network, and to support simless connectivity between wired and wireless network in service viewpoint, to support the diversity trend of service agents in WIF, it needs to improve SLP, so as to add Liaison Agent and Forwarding Agent with FAAdvert message that is to communicate in between those entities. LA entity confirms the location of service located in wide area network, and FA transfers service information. The usage of existing messages such as SrvRqst, SrvRply, AttrRqst, AttrRply, DAAdvert, SrvReg, SrvAck, SrvDeReg is same as ever in wide area service network. The behaviors of improved protocol is modeled into petri-net and prove that it is free of deadlock and live-lock by execution of the model.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.121-128
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• 2010

Whenever and wherever, recognizing location of object such as human as well as things, ubiquitous Location-Based Service which provides useful service based on this are rising as an important service. In this paper, we implemented customized real time 1:1 e-CRM system that can communicate with user's mobile phone through using Location-Based Service of mobile phone. Among various scenarios that are applicable to designed system, development and test were conducted based on scenario that provides shopping information and discount information to customers through SMS as they approach to vicinity of large discount store and allow them to download discount coupons through Call Back. The suggested system will be applied to various service event and can be used as a customized real time marketing method according to user's personal activity area.

• Journal of KIISE:Databases
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• v.29 no.5
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• pp.335-346
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• 2002

LBS(Location Based Services) provide the location-based information to its mobile users. The primary functionality of these services is to provide useful information to its users at a minimum cost of resources. The functionality can be implemented through data mining techniques. However, conventional data mining researches have not been considered spatial and temporal aspects of data simultaneously. Therefore, these techniques are inappropriate to apply on the objects of LBS, which change spatial attributes over time. In this paper, we propose a new data mining technique for identifying the temporal patterns from the series of the locations of moving objects that have both temporal and spatial dimension. We use a spatial operation of contains to generalize the location of moving point and apply time constraints between the locations of a moving object to make a valid moving sequence. Finally, the spatio-temporal technique proposed in this paper is very practical approach in not only providing more useful knowledge to LBS, but also improving the quality of the services.

• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.351-362
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• 2006

This paper proposes an adaptive inter-agent communication protocol to considerably reduce the amount of agent location information maintained by each service node and the message delivery time while avoiding the dependency of the home node of a mobile agent. To satisfy this goal, the protocol enables each mobile agent to autonomously leave its location information only on some few of its visiting nodes. Also, it may significantly reduce the agent cache updating frequency of each service node by keeping the identifier of the location manager of each agent in the smart agent location cache of the node. Simulation results show that the proposed protocol reduces about $76%{\sim}80%$ of message delivery overhead and about $76%{\sim}79%$ of the amount of agent location information each service node should maintain compared with the traditional one.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.1-11
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• 2006

It is possible to track the moving vehicle as well as to develop the location based services actively according to the progress of wireless telecommunication and GPS, to the spread of network, and to the miniaturization of cellular phone. To provide these location based services, it is necessary for an index technique to store and search too much moving object data rapidly. However the existing indices require a lot of costs to insert the data because they store every position data into the index directly. To solve this problem in this paper, we propose a buffer node operation and design a GU-tree(Group Update tree). The proposed buffer node method reduces the input cost effectively since the operation stores the moving object location data in a group, the buffer node as the unit of a non-leaf node. hnd then we confirm the effect of the buffer node operation which reduces the insert cost and increase the search performance in a time slice query from the experiment to compare the operation with some existing indices. The proposed tufter node operation would be useful in the environment to update locations frequently such as a transportation vehicle management and a tour-guide system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.631-636
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• 2019

In recently, various kinds of services utilizing the location information of the user's smart phone have appeared. Based on this trend, we designed a new type of learning assistant system that utilizes geofencing technology, which is a field of location information technology. This system identifies the location of the classroom using the location information of learner's the smart phone and automatically provides the necessary learning contents to the learner's smart phone when the learner enters the classroom set as the virtual fence area while carrying the smart phone respectively. Our system provides learning contents in a form similar to the form of a message or a mobile coupon and learners are used to such mobile service environments very much. So the use of learning contents provided by our system is expected to help improve the learning effect of learners.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1005-1012
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• 2021

Recently, the use of various location-based services-based location information systems using maps on the web has been expanding, and there is a need for a monitoring system that can check power demand in real time as an alternative to energy saving. In this study, we developed a deep learning real-time virtual power demand prediction web system using open source-based mapping service to analyze and predict the characteristics of power demand data using deep learning. In particular, the proposed system uses the LSTM(Long Short-Term Memory) deep learning model to enable power demand and predictive analysis locally, and provides visualization of analyzed information. Future proposed systems will not only be utilized to identify and analyze the supply and demand and forecast status of energy by region, but also apply to other industrial energies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.235-236
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• 2021

As a result of analyzing the fire accident of the Jecheon complex that occurred at the end of 2017, there have been many casualties due to delays in checking the location information of isolated people. In order to prevent such an accident, various research has been conducted to estimate the location of requesters by means of detecting wireless communication information of mobile phones existing at disaster sites. The main concept is to detect an RF signal of a mobile phone at fire sites and, based on this, precisely estimate the location of the mobile phone on the LOS/NLOS. However, it is difficult to get visibility at fire sites due to smoke and the fire. Therefore, apart from estimating the location of requesters, a research is also needed to determine the direction of entry within fire sites. In this paper, we propose a method to determine a direction of entry to provide effective rescue activities using wireless communication information of mobile phones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2345-2351
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• 2013

LBS(Location Based System) usually uses GPS technology to measure the exact position of the moving object. However, the method of managing location which utilizes the WiFi technology of mobile phone has not been introduced so far. The method of managing moving objects in view of the location of guardian has also not been proposed. In this paper, a new location management system of moving objects which take guardian's location into consideration is proposed. Specifically, the three methods of searching for missing child proposed in this paper are as follows : 1) a method based on an app for smart phone, 2) a method based on control server, 3) a method based on control server and fixed APs. Because the proposed system reflects the location of the guardian, the guardian is able to identify the state of child immediately and the workload can be reduced.