• Journal of Korea Spatial Information System Society
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• v.7 no.3 s.15
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• pp.13-24
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• 2005

This paper proposes a model for the location information grading policy. Location information grading policy is that government would give a public notice of criterion for location information quality, and location information operators should elucidate the grade of provided location information. As the quality grade of services is provided in the 'terms of use' with the detailed quality specification and quality range, the user can understand the quality of location information, and can select more suitable service for their purposes. Additionally, the qualiy grading policy can enforce the location information operators and location service providers to support more stable and reliable service quality. In this paper, we propose the model of location information grades, the typical classification of quality, and the realitic policy applying model. Recent enacted 'Location Information Law' are expected to activate korean information market. In this situation, proposed location information grading policy take a role in protecting location privacy and improving the reliability of location information services.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.676-678
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• 2003

Recently, in according as rapid improvement of telecommunication markets and wireless internet technology, Location- Based Services (LBS) have been discussed as new 'Killer' application. The purpose of LBS is to determine location of user through mobile handset and to offer location information service to end-user. This paper has suggested an efficient transmission scheme of maps data as one of the important content services relating to data transmission of LBS in mobile environment. The basic system consists of three parts : (1) GIS (Geographic Information System) Server for storing, processing and handling map data, (2) Middleware Server for transmitting of map data by request of client, and (3) Client for requesting map data to Server and displaying them on handset. Also, in order to transmit map data, we are to expand WKB (Well Known Binary) in conformance to Simple Feature Specification of OGC (Open GIS Consortium), and increase efficiency of data transmission by developing trans mission data format to be able to transmit lightweight data and considering data compression technology.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.327-330
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• 2004

This research work is concerned with a location-based alert service in wireless communication network environment. The alert service automatically transfers alert message to subscriber in the disaster area. This research work deals with automatic alert services that automatically provide people in emergency area with the state of emergency. The alert service uses the mobile device to inform its urgency to the subscribers in its area. The location tracking service will give the list of people in emergency area. The all processes of this research work are followed as. First, when a disaster or a calamity comes in, an emergency management center receives the emergency to analyze its shape and size and to declare the place to 'the disaster area.' Secondly, then the center finds information of mobile device subscribers in the disaster area. Finally, the center automatically generates a shape of text or audio of alert message of the emergency to send the message to the subscribers in the disaster area. Our mobile automatic alert service proposed above is so efficient that the subscribers in disasters area may meet the emergency more efficiently and may save their own valuable lives and properties more safely.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.478-488
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• 2005

To conserve the usage of energy, indexing techniques have been developed in a wireless mobile environment. However, the use of interleaved index segments in a broadcast cycle increases the average access latency for the clients. In this paper, we present the broadcast-based location dependent data delivery scheme (BBS) for dynamic range queries. In the BBS, broadcasted data objects are sorted sequentially based on their locations, and the server broadcasts the location dependent data along with an index segment. Then, we present a data prefetching and caching scheme, designed to reduce the query response time. The performance of this scheme is investigated in relation to various environmental variables, such as the distributions of the data objects, the average speed of the clients, and the size of the service area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.888-893
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• 2012

Quality of Service (QoS) provisioning is an important issue in the design of next generation wireless network. In visible light communication (VLC) networks, link switching is a solution to maintain or improve the quality of communication. In this paper, we propose a novel link switching scheme using the location of mobile nodes (MNs). The current serving transmitter uses location history of the MN to find out which neighbor transmitter the MN is approaching. This neighbor transmitter is chosen to inform the MN as the next serving transmitter. The simulation results show that our proposed scheme gains better performance than non-predictive link switching scheme.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2812-2821
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• 1997

In this paper, we presents performance analysis of a location registration protocol using cluster concept to minimize the number of location registrations caused by reduction of cell size and explosive increasement of wireless communication subscribers. We analyze the relationship between the size of cluster and the location registration rate, and finally we apply this analysis to the hexagonal cell structure for justification.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1483-1495
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• 2007

Thanks to IEEE 802.11 technique, accessing Internet through a wireless LAN(Local Area Network) is possible in the most of the places including university campuses, shopping malls, offices, hospitals, stations, and so on. Most of the APs(access points) for wireless LAN are supporting 2.4 GHz band 802.11b and 802.11g protocols. This paper is introducing a C# library function which can be used to read RSSIs(Received Signal Strength Indicator) from APs. An LBS(Location Based Service) estimates the current location of the user and provides useful user's location-based services such as navigation, points of interest, and so on. Therefore, indoor, LBS is very desirable. However, an indoor LBS cannot be realized unless indoor position ing is possible. For indoor positioning, techniques of using infrared, ultrasound, signal strength of UDP packet have been proposed. One of the disadvantages of these techniques is that they require special equipments dedicated for positioning. On the other hand, wireless LAN-based indoor positioning does not require any special equipments and more economical. A wireless LAN-based positioning cannot be realized without reading RSSIs from APs. Therefore, our C# library function will be widely used in the field of indoor positioning. In addition to providing a C# library function of reading RSSI, this paper introduces implementation of indoor positioning modules making use of the library function. The methods used in the implementation are K-NN(K Nearest Neighbors), Bayesian and trilateration. K-NN and Bayesian are kind of fingerprinting method. A fingerprint method consists of off-line phase and realtime phase. The process time of realtime phase must be fast. This paper proposes a decision tree method in order to improve the process time of realtime phase. Experimental results of comparing performances of these methods are also discussed.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.159-167
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• 2013

Development of infusion pumps enabled injecting medical substances continuously and automatically to patients in hospitals. However, in cases when patients encountered emergent situations when moving to other areas, no clear measures were taken. The problem is that even the lightest error in injecting medical substances could be critical to the patient. That is why we proposes a remote infusion monitoring system using wireless network and RFID technology in this paper. When a problem occurs in the infusion pump, the medical personnel are informed of their patients' emergent situation and location information via wireless network so not only can they swiftly and accurately provide medical services but also can prevent safety accidents due to infusion pumps.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1862-1878
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• 2011

With the advances in wireless communication technology and the advent of smartphones, research on location-based services (LBSs) is being actively carried out. In particular, several spatial index methods have been proposed to provide efficient LBSs. However, finding an optimal indexing method that balances query performance and index size remains a challenge in the case of wireless environments that have limited channel bandwidths and device resources (computational power, memory, and battery power). Thus, mechanisms that make existing spatial indexing techniques more efficient and highly applicable in resource-limited environments should be studied. Bitmap-based Spatial Indexing (BSI) has been designed to support LBSs, especially in wireless broadcast environments. However, the access latency in BSI is extremely large because of the large size of the bitmap, and this may lead to increases in the search time. In this paper, we introduce a Selective Bitmap-based Spatial Indexing (SBSI) technique. Then, we propose an Adaptive Bitmap-based Spatial Indexing (ABSI) to improve the tuning time in the proposed SBSI scheme. The ABSI is applied to the distribution of geographical objects in a grid by using the Hilbert curve (HC). With the information in the ABSI, grid cells that have no objects placed, (i.e., 0-bit information in the spatial bitmap index) are not tuned during a search. This leads to an improvement in the tuning time on the client side. We have carried out a performance evaluation and demonstrated that our SBSI and ABSI techniques outperform the existing bitmap-based DSI (B DSI) technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1639-1649
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• 1998

For mobile multimedia services, wireless ATM(Asynchronous transfer Mode) network is studied actively. In wireless ATM network, the existing signaling protocols generate heavy traffics for HLR due to the centralized structure that all signaling loads mush be handled in HLR(Home Location Register). Also, centralized structure causes critical connection setup delays. Thus, it is important that wireless ATM reduces the connection setup delays occurred due to high traffic loads of signaling based on distributed processing. In this thesis, we propose a cache strategy for call delivery as well as the cache updates of registration based on ATM multicasting and compares the cost of cache scheme with that of conventional scheme. Our study shows that cache scheme has better performance than the conventional methods in the case that the portable mobility is low and traffic density is large.