• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.448-450
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• 2007

Peer-to-Peer system has emerged as a popular model aiming at further utilizing Internet information and resources, complementing the available client-server services. However, the mechanism of peers randomly choosing logical neighbors without any knowledge about underlying physical location aware topology can cause serious performance degradation. In this paper, we consider the network distance between peers so that it helps peers select neighbors located at the nearest when they exchange queries for sharing of resources. To reduce the unnecessary signaling traffic and delay of query exchange, we propose a location aware topology based Hybrid P2P system. This system calculates the network distance which combines the direct measurement such as RTT (Round Trip Time) with geographic space of peers using IP address

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.575-576
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• 2016

Recently utilizing GPS (Global Positioning System) technology has become the research in progress to improve the accuracy. However, if you encounter problems when you receive a satellite signal reception accuracy it is also significantly lowered. In this paper, we designed a system that combines the GPS technology and the GIS (Geographic Information System) technology, which provides information about the specified location to increase the accuracy. Compare the specified location and the user's location information to determine whether the user enters for the location. Accordingly, is utilized by the GIS technique considered to make improve the accuracy of the location information even when there is interference in the received satellite signal, the user receives a service specified location.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12B
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• pp.1199-1210
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• 2010

In recent years opportunistic computing has gained popularity in Ad-hoc network research area and it is highly required to research for actual services and related requirements. In this paper we summarized a virtual opportunistic service that is named "Children Care System" and proposed an Ad-hoc communication node (uMobile) that is connected with cellular phone and a sensor node (uClo) which is embedding into clothes. uMobile can support cellular phone communication and Ad-hoc communication and uClo can be embedded into clothes and recognize the user status using multiple sensors. In this paper we implemented the location awareness and user status awareness services using uMobile and uClo. We also tested them in indoor situation and showed the result. We expect that our research can play a significant role to inspire another various opportunistic computing services.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2011.05a
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• pp.83-84
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• 2011

• Journal of Korea Multimedia Society
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• v.13 no.6
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• pp.901-910
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• 2010

$IP^2$, as an extended concept of the next generation IMT network, is a concept of basically supporting mobility using two steps of IP address (i.e. IPha (IP Host address) and IPra (IP routing address)) in IP backbone network. Current $IP^2$system has a shortcoming of excess usage of network resources caused by sending paging messages to all cells in LA (Location Area) in paging procedure. Considering the evolving direction of network, which is taking mobility with various speed and integration of devices into consideration, this shortcoming must be overcome. In this paper, we proposed a method to reduce time and memory for paging by maintaining current information of MN (Mobile Node) not in Active state with proxy server. Performance evaluation based on NS-2 simulations has shown that the efficiency of network resources is improved in the proposed method.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.297-303
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• 2009

Automatic Identification System (AIS) is a VHF radio broadcasting system where transmits packets of data via VHF data link. It enables vessels and coastal-based station that equipped with AIS equipment to send and receive useful information. This information can be help in situational awareness and provide a means to assist in collision avoidance. In addition, AIS can be use as Aid-To-Navigation, by providing the location and additional information on buoys and lights. Besides, it can also contain details information in meteorological status of a particular ship location. This paper presents the standalone AIS system that able to receive and report own ship location, meteorological data collection and broadcast safety related information if necessary. With the unique ship's MMSI number, all the information of that particular ship can be monitor by using AIS program written in C++ programming language.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.9-14
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• 2008

Ubiquitous implementation of indoor location-based technology is recognized that one of the important elements of the technology. Specifically, the hospital management of patients, the silver-town management, the implementation of the smart home for the indoors rather than outdoors in a range of broadband users for location-aware technology is needed. This paper in wireless devices with an indoor location awareness shows about the system's technical design and implementation. Location-based technology for wireless LAN users aware of the strength of radio signals (Received Signal Strength Indication, RSSI) using trilateration. Topographic mapping system will be implemented wireless devices and servers, Access Point (AP), which is the system's development and testing throughout the physical environment to determine the potential for real-life applications.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.48-58
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• 2009

In recent years, construction worker safety in construction site is important. Especially, the frequent collapse accidents have happened in tunnels, utility tunnel and underground structure, so that the importance of worker safety is greatly emphasized. It is difficult to communicate with other workers in underground space, using the current cable or wireless communicator. When the accident is occurred, it can't rescue workers. This is the reason that it has a deficiency to find a location of survivor and communicate rescure crew and field workers. In this paper we extract the optimal technical factors of USFSS(Underground Structure Field Support System) based on integrated technique of wireless communication and location awareness. And USFSS developed in this study is suited for bad environment of underground structure construction and able to track 3D position of laborer and communicate mutually.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.266-269
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• 2008

Urban is more intelligent continuously with the help of the convergence with IT technology. And it requires an integrated control system, which can manage urban facilities or monitor large-scale events based on GIS data, to provide its citizen with various ubiquitous services such as u-Health, u-Traffic, context-awareness etc. In order to realize the intelligent city geo-sensors that have the functionalities of generic sensing as well as location awareness will be established everywhere in the near future. Our system we presented have a rule engine to handle a atomic event as well as complex events that contain control flow or branch among them. And it can allow for visualization and monitoring the results through KML (Keyhole Mark-up Language) in the Google Maps. This paper describes au-GIS event processing system that can deal effectively with u-GIS events coming from various geo-sensor data in ubiquitous computing environments.