• Journal of Internet Computing and Services
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• v.13 no.1
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• pp.15-25
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• 2012

Mobile IPv6 (MIPv6) is a host-based protocol supporting global mobility while Proxy Mobile IPv6 (PMIPv6) is a network-based protocol supporting localized mobility. This paper makes its focus on how to reduce the longer delay and extra cost arising from the combination of authentication, authorization and accounting (AAA) and PMIPv6 further. Firstly, a novel authentication scheme (Proxy-AAA) is proposed, which supports fast handover mode and forwarding mode between different local mobility anchors (LMAs). Secondly, a cost analysis model is established based on Proxy-AAA. From the theoretical analysis, it could be noted that the cost is affected by average arrival rate and residence time.

• 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.

• TTA Journal
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• s.49
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• pp.114-123
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• 1997

본 고는 유럽 정보통신 표준화 선도기관인 ETSI(European Telecommunications Standards Institute)에서 발간한 GMM(Global Multimedia Mobility) 보고서로 향후 2000년대의 멀티미디어 이동통신 기술의 전망과 관련 표준화 추진방향을 그 내용으로 한다. 이에 필자는 상기 보고서 내용을 중심으로 범유럽의 이동통신기술 현황과 향후 표준화추진 정책방향을 2회에 걸쳐 정리하고, 우리의 대응책을 점검하고자 한다.

• TTA Journal
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• s.45
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• pp.161-170
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• 1996

TTA 대표로서 참가하였던 ETSI 제24차 기술총회(TA)와 제25차 총회(GA) 결과를 정리하였다. 이번 회의의 가장 큰 관심사는 EPII(European Project of Information Infrastructure) 작업결과였으며, GMM (Global Multimedia Mobility) 관련 작업보고서도 관심을 갖게 하는 분야다. 지면 관계상 항목별 상세 정보는 싣지 못하였으므로 관심있는 분은 참조문헌을 참조하기 바란다.

• TTA Journal
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• s.50
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• pp.95-105
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• 1997

본 고는 유럽 정보통신 표준화 선도기관인 ETSI(European Telecommunications Standards Institute)에서 발간한 GMM(Global Multimedia Mobility) 보고서로 향후 2000년대의 멀티미디어 이동통신 기술의 전망과 관련 표준화 추진방향을 그 내용으로 한다. 이에 필자는 상기 보고서의 내용을 중심으로 범유럽의 이동통신기술 현황과 향후 표준화추진 정책방향을 2회에 걸쳐 정리, 기술하고자 한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.73-80
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• 2012

In this article, we propose a P2P-based mobility management protocol for global seamless handover in heterogeneous wireless networks. Unlike previous mobility management protocols such as IETF MIPv4/6 and its variants, the proposed protocol can support global seamless handover without changing the existing network infrastructure. The idea of the proposed protocol is that the location management function for mobility management is separately supported from packet forwarding function, and bidirectional IP tunnels for packet transmission are dynamically constructed between two end-to-end mobile hosts. In addition, early handover techniques have been developed to avoid large handover delays and packet losses using the IEEE 802.21 Media Independent Handover functions. The architecture and signaling procedure of the proposed protocol have been designed in detail, and the mathematical analysis and simulation have been done for performance evaluation. The performance results show that the proposed protocol outperforms the existing MIPv6 and HMIPv6 in terms of handover latency and packet loss.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.377-388
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• 2021

With the growth of the global sharing economy market, various sharing services have recently appeared in South Korea. Seoul city unmanned public bicycle rental service, "Ttareuni" is one of the services representing the shared mobility industry in South Korea. Although many users use this service, the usability of the mobile application, which is the essential medium of utilizing the service, is not improving. In this regard, this study conducted usability testing and in-depth interviews for Ttareungi's main users in their 20s and 30s to improve the user experience of the mobile application of Ttareungi. As a result, the problems of Ttareungi mobile application were identified, and based on this, design considerations for shared mobility services having publicity like Ttareungi were proposed. This is expected to contribute to improving the user experience of shared mobility services.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.131-140
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• 2011

Proxy Mobile IPv6 (PMIPv6) is designed to provide a network-based localized mobility management protocol, but it does not handle the global mobility of hosts. In this paper, we propose a location management scheme based on Domain Name System (DNS) for PMIPv6. In this proposed scheme, DNS as a location manager provides PMIPv6 for global mobility. In addition, a paging extension scheme is introduced to PMIPv6 in order to support large numbers of mobile terminals and enhance network scalability. To evaluate the proposed location management scheme, we establish an analytical model, formulate the location update and the paging cost, and analyse the influence of the different factors on the total signalling cost. The performance results show how the total signal cost changes under various parameters.

• Journal of the Korean Geographical Society
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• v.48 no.6
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• pp.897-913
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• 2013

The main purpose of the paper is to examine the spatial characteristics of school choice through residential mobility by conducting a correlation analysis on the relationships between the middle schools' entrance rates to special high schools and the elementary schools' net transfer rates. Analyses are done at both the individual school level and the school catchment area level. Prior to the calculation, the two variables involved in the correlation analysis are transformed via a standardization equation, and the standardized scores are mapped and explored. Both the global and local correlation analyses are done for the standardized variables. Main findings are twofold. First, the global correlation analysis reports that there exists a statistically significant correlation between the two variables at both the analytical levels. Second, albeit the prominent positive correlation at the global level, the local analysis reveals the existence of a considerable level of spatial heterogeneity in terms of bivariate association. While several school catchment areas with very high local correlation coefficients (the HH association type) are popped up, other areas with various types of bivariate association including ones even opposite to the global trend are also observed.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.363-373
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• 2010

Purpose : The purpose of this study was to compare differences in thoracolumbar ranges of motions by comparing ratios among 4 type diagnosis for patient with chronic low back pain. Methods : The subjects were 58 chronic low back pain patients. A motion analysis program (Global Postural System) was used after photography for posture measurement. To analyze differences in mobility percentages and ratios of thoracolumbar ranges of motion, one-way ANOVA was used. Results : Regional difference spinal posture and movement were found to diagnosis patients with chronic low back pain. Comparison of thoracolumbar ranges of motion revealed significant differences in the thoracic region during forward-bending of the trunk (p<.05). In the upper thoracic region, the herniated intervertebral lumbar disc (HILD) group was significantly larger than the spinal stenosis/herniated intervertebral lumbar disc (SS/HILD) group (p<.05). In the lower thoracic region, chronic sprains (CS) were significantly greater than in the spinal stenosis (SS) group and in the (SS/HJLD) group (p<.05). Comparative analysis of thoracic/lumbar mobility ratio showed the CS group's ratio during forward bending was largest: 1.66, while the HILD group's ratio was smallest: 84 a significant difference between the two groups (p<.01). Diagnosis was not associated with difference in thoracolumbar backward-bending range of motion (p>.05). Conclusion : Theses results indicate the clinical efficacy of diagnosing for chronic low back pain by evaluating spinal mobility.