• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.697-709
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• 2011

For improvement of wireless Internet service quality at vehicle's moving speed, it is advised to reduce the service disruption time by reducing the handover frequency on vehicle's moving path. Particularly, it is advantageous to avoid the handover to cell whose dwell time is short or can be ignored in terms of service continuity and average throughput. This paper proposes the handover scheme that is suitable for vehicle in order to improve the wireless Internet service quality. In the proposed scheme, the handover process continues to be learned before being modeled to Discrete-Time Markov Chain (DTMC). This modeling reduces the handover frequency by preventing the handover to cell that could provide service sufficiently to passenger even when vehicle passed through the cell but there was no need to perform handover. In order to verify the proposed scheme, we observed the average number of handovers, the average RSSI and the average throughput on various moving paths that vehicle moved in the given urban environment. The experiment results confirmed that the proposed scheme was able to provide the improved wireless Internet service to vehicle that moved to some degree of consistency.

• Journal of the Korean housing association
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• v.7 no.2
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• pp.69-77
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• 1996

Mobility in housing is a normative way to satisfy family needs for· better· living conditions. In the context of relative decisions. mobility can be understood as forced relocation or unforced relocation In making relocation. the household chooses a particular 'environmental quality profile. Therefore. the understanding of mobility and relocation in housing is needed for· the developing and planning of housing evnironment. The major findings are s follows ;1. The motives of mobility are composed of 4 factors('material porseperity’, 'convenience· safety'. environmental improvement' and 'forced relocation'). Especially, 'material prosperity' was defined the most fundamental factor· for. 2. The components of housing environment quality were composed of 3 factors related to the scale of home environment. They were 'neighborhood character factor', 'dwelling character· factor·'. And 'location character· factor'. The factor 'neighborhood character' was defined the basic factor· to choose for the housing environmental quality profile.3. It was examined that the motives of mobility and the components of home environmental quality were significantly different by the household characteristics (income. family life cycle. and tenure type).

• The Journal of Korean Institute of Information Technology
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• v.17 no.4
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• pp.87-97
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• 2019

SRS was proposed for immediate processing of the meaning of sensor data on mobile devices independent from specific sensor networks and sensor type. However, each time new sensor data is received, sensor data inspection operations are performed repeatedly, and it cause resulting in low performance. App profile-based SRS has been proposed to resolve the problem. The app profile-based SRS has improved the SRS problem through the profile, but has been tested in a virtual simulation environment. After that the test was experimented in a real-time environment, but has not been tested with a variety of dynamic factors. Therefore, this paper experiment considering such as user mobility and sensor density in real-time environment. And this paper also evaluate performance of the App profile-based through analysis of the results of the experiment. As a result, app profile-based SRS is high influence by density and sensor type, and the number of sensor node is not influence.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.215-221
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• 2003

It is expected that per-user customized services are widely used in next generation Personal Communication Network. To provide personalized services for each call, per-user service profiles are frequently referenced and signaling traffic is considerably large. Since the service calls are requested from the places where user stays, we can expect that the traffic is localized. In this paper, we propose a new service profile replication scheme, named Follow-Me Replication with local Anchor (FMRA). By replicating user's service profile in a user-specific location area, local anchor of each region, the signaling traffic for call and mobility can be distributed to local network. We compared the performance of the FMRA with two typical schemes: Intelligent Network-based !Central scheme and IMT-2000 based full replication scheme, as we refer it to Follow-Me Replication Unconditional (FMRU). Performance results indicate that FMRA lies between Central and FMRU schemes according to call to mobility ratio, and we identified the efficient ranges of CMR for FMRA depending on the various network parameters.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1125-1136
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• 2010

Lately there exist increasing demands for online abnormality monitoring over trajectory stream, which are obtained from moving object tracking devices. This problem is challenging due to the requirement of high speed data processing within limited space cost. In this paper, we present a FADA (Fuzzy Anomaly Detection Algorithm) which constructs normal profile by computing mobility feature information from the GPS (Global Positioning System) logs of mobile devices in MANETs (Mobile Ad-hoc Networks), computes a fuzzy dissimilarity between the current mobility feature information of the mobile device and the mobility feature information in the normal profile, and detects effectively the anomaly behaviors of mobile devices on the basis of the computed fuzzy dissimilarity. The performance of proposed FADA is evaluated through simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.503-516
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• 2010

In this paper, we propose the converged profile and authentication scheme for supporting converged media services of broadcasting & communications convergence in fixed mobile convergence networks. The proposed scheme supports the management of access, service, mobility and IPTV profiles on subscriber and a function of open API(Application Program Interface) for providing the subscriber profile for the third party service provider with the PUSH/PULL method. The open API is based on a web service and a REST(Representational State Transfer) and provides various services for the third party service provider with ease. In addition, the proposed scheme supports a function of SSO(Single Sign-on). After user succeeded in establishing an access connection, user can sustain the same authentication state with this function although connected access network is changed or IMS(IP Multimedia Subsystem) service network is attached. We evaluate and analyze the performance of the proposed scheme through the implementation of CUPS(Converged User Profile Server) system test-bed.

• Journal of information and communication convergence engineering
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• v.14 no.3
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• pp.137-146
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• 2016

In this paper, we introduce a quality of experience (QoE)-provisioning mobility management scheme. The emphasis is on a mobility-aware QoE solution enabling network components to recognize the mobility pattern of an end-user and to prepare a handover in advance. We further focus on an energy-adaptive QoE solution based on the energy profile providing the preferred pattern of energy consumption and an energy preference check engine determining whether the provision of the service that the end-user requested is suitable to QoE or not. Lastly, we concentrate on a network-based intelligent mobility management scheme adopting the calm service and the balance. Consequently, we conclude that the proposed schemes improve the handover latency, QoE metrics, and energy efficiency simultaneously.

• The Journal of Korean Association of Computer Education
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• v.8 no.6
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• pp.123-132
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• 2005

There are many research results for the location update cost minimization of location management in cellular networks. For minimizing the location update cost, we have to take in consideration of each users' mobility pattern. This paper suggests location area list generation and a 3-step paging method based on users' movement history with the users' profiles. Users' mobility has not only geographical regular patterns but also time-related regularity. So, the method extracts users' movement regularities in both geography and time from their movement history, and generate location area list considering the regularities. For the performance analysis of the suggested method, we have executed a simulation for suggested method with user's mobility model. The results of the simulation show that suggested algorithm has some merits in the location management cost.

• Journal of the Korean Data and Information Science Society
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• v.20 no.2
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• pp.387-399
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• 2009

Mobile wireless networks continue to be plagued by theft of identify and intrusion. Both problems can be addressed in two different ways, either by misuse detection or anomaly-based detection. In this paper, we propose a dissimilarity-based anomaly detection method which can effectively identify abnormal behavior such as mobility patterns of mobile wireless networks. In the proposed algorithm, a normal profile is constructed from normal mobility patterns of mobile nodes in mobile wireless networks. From the constructed normal profile, a dissimilarity is computed by a weighted dissimilarity measure. If the value of the weighted dissimilarity measure is greater than the dissimilarity threshold that is a system parameter, an alert message is occurred. The performance of the proposed method is evaluated through a simulation. From the result of the simulation, we know that the proposed method is superior to the performance of other anomaly detection methods using dissimilarity measures.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.615-624
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• 2005

In Mobile IP, several types of messages - binding update, binding request and binding acknowledgement - are used to support user mobility. It is necessary to exchange those messages frequently for seamless mobility but it incurs both the increase of network overhead and poor usage of mobile node battery power Thus, we need a mechanism that the server detects users location and also copes with the problems effectively, which is our main concern in this paper Each user records all moving logs locally and periodically makes out profile based on them in HMIPv6. By using profile, estimated resident time can be computed whenever he enters an area and the time is set up as the binding update message lifetime. Of course, the more correct lifetime nay be obtained IP arrival time as well as average resident time Is considered in profile. Through extensive experiments, we measure the bandwidth usage for binding update messages by comparing the proposed schemes with that in HMIPv6. From the results, Gain gets over $80\%$ when mobile node stays more than 13 minutes in a subnet. Namely, we come to know that our schemes improve network usage and energy usage in mobile node by decreasing the number of messages while they also manage users locations like that in HMIPv6.