• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.229-232
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• 2005

Many kinds of communication systems will be co-existed in the next generation communication environment. Location management will be one of the most important strategies in the future communication network. Whether the user gets the service in any kind of communication system, it is required to know the location of the user properly and manages this location information efficiently. In this paper, mobile IP and WCDMA systems are considered as next generation communication systems. We improve the performance of communication in heterogeneous networks adjusting the conventional region-based location management strategy in homogeneous network. This strategy can be adjusted dynamically to the communication system on the basis of packet-to-mobility ratio (PMR) in mobile IP system or call-to-mobility ratio (CMR) in WCDMA system, lots of different system parameters, and movement pattern of the user. This can be also based on the performance analysis with considering signaling cost and database access cost.

• Korea journal of population studies
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• v.20 no.1
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• pp.97-128
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• 1997

This paper was set out to study the structure of the career occupational mobility in the early and rapid phase of industrialization in Korea. By analyzing the individual life histories regarding occupational mobility and achievement, I propose a model of yearly career mobility of Korean men and Women during the period of 30 years between 1954 and 1983. With the occupational classification scheme of 5 groups - Upper Nonmanual, Lower Nonmanual, Self Employed, Manual, Farm - the mobility pattern in the person-year mobility table analyzed can be characterized primarily by the strong influence of immobility. The degree of immobility, however, is different by the occupational groups. The absolute amount of immobility can be summarized as being U-shaped. Overall, the pattern of mobility can be explained best by the concept of occupational distance. I then propose a model of relative career occupational mobility pattern that combines the conceptual and theoretical basis and the methodological rigor. The model is based on the notion of the reproduction of inequality, the labor market context, and the life history perspective. The model encompasses the 6 conceptual explanatory factors such as persistence effect, ceiling effect, traditional sector effect, nonmanual occupation effect, alternative mobility channel effect, and occupational distance effect, as well as the effects of both origin and destination occupations. The relative pattern of career mobiliity in Korea can be characterized by the following six findings. First, the persistence effect on the diagonal cells of the mobility table is dominant. Second, a clear evidence of the negative effect of occupational distance between nonmanual occupations and manual and farm occupations is found. Third, the out-mobility from farming took place regardless of the destination occupations. Fourth, the internal mobility within the nonmanual occupation block is high and bi-directional, and is exclusive against other occupations. Fifth, the 'self employed' occupation is serving a peculiar function in both inflow and outflow pattern. Last, the relative pattern of career occupation mobility is asymmetrical in terms of the upward and downward mobility.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.1
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• pp.1-9
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• 2013

Most calls of a called user are invoked by the group of calling users. This call pattern is defined as call locality. Similarly Internet sessions including IP telephony calls have this pattern. We define it session locality. In this paper, we propose a caching scheme to support session locality in hierarchical SIP networks. The proposed scheme can be applied easily by adding only one filed to cache to a data structure of the SIP mobility agent. And this scheme can reduce signaling cost, database access cost and session setup delay to locate a called user. Moreover, it distributes the load on the home registrar to the SIP mobility agents. Our performance evaluation shows the proposed caching scheme outperforms the hierarchical SIP scheme when session to mobility ratio is high.

• Korea journal of population studies
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• v.10 no.1
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• pp.28-38
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• 1987

This paper was set out to study the structure of the career occupational mobility in the early and rapid phase of industrialization in Korea. By analyzing the individual life histories regarding occupational mobility and achievement, I propose a model of yearly career mobility of Korean men and Women during the period of 30 years between 1954 and 1983. With the occupational classification scheme of 5 groups - Upper Nonmanual, Lower Nonmanual, Self Employed, Manual, Farm - the mobility pattern in the person-year mobility table analyzed can be characterized primarily by the strong influence of immobility. The degree of immobility, however, is different by the occupational groups. The absolute amount of immobility can be summarized as being U-shaped. Overall, the pattern of mobility can be explained best by the concept of occupational distance. I then propose a model of relative career occupational mobility pattern that combines the conceptual and theoretical basis and the methodological rigor. The model is based on the notion of the reproduction of inequality, the labor market context, and the life history perspective. The model encompasses the 6 conceptual explanatory factors such as persistence effect, ceiling effect, traditional sector effect, nonmanual occupation effect, alternative mobility channel effect, and occupational distance effect, as well as the effects of both origin and destination occupations. The relative pattern of career mobiliity in Korea can be characterized by the following six findings. First, the persistence effect on the diagonal cells of the mobility table is dominant. Second, a clear evidence of the negative effect of occupational distance between nonmanual occupations and manual and farm occupations is found. Third, the out-mobility from farming took place regardless of the destination occupations. Fourth, the internal mobility within the nonmanual occupation block is high and bi-directional, and is exclusive against other occupations. Fifth, the 'self employed' occupation is serving a peculiar function in both inflow and outflow pattern. Last, the relative pattern of career occupation mobility is asymmetrical in terms of the upward and downward mobility.

• Journal of the Korean Data and Information Science Society
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• v.26 no.5
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• pp.1061-1069
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• 2015

Recently, transportation big data generated in the transportation sector has been widely used in the transportation policies making and efficient system management. Bus passengers' mobility patterns are useful insight for transportation policy maker to optimize bus lines and time intervals in a city. We propose a new methodology to discover mobility patterns by using transportation card data. We first estimate the bus stations where the passengers get-off because the transportation card data don't have the get-off information in most cities. We then applies LDA (Latent Dirichlet Allocation), the most representative topic modeling technique, to discover mobility patterns of bus passengers in Cheong-Ju city. To understand discovered patterns, we construct a data warehouse and perform multi-dimensional analysis by bus-route, region, time-period, and the mobility patterns (get-on/get-off station). In the case of Cheong Ju, we discovered mobility pattern 1 from suburban area to Cheong-Ju terminal, mobility pattern 2 from residential area to commercial area, mobility pattern 3 from school areas to commercial area.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.245-253
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• 2020

This study has conducted to investigate the changes in the mobility of the three thoraco-abdominal lines(TAMs) during breathing and in the thoracic and lumbar spine mobility(TSM, LSM) during trunk forward flexion, after breathing pattern correction. The 30 subjects with lumbar instability(LI) have divided into the breathing pattern correction exercise(BPC) group of 15 subjects and the lumbar stabilization exercise(LSE) group of 15 subjects and performed each exercise for 40 minutes at one session, and a total of 18 sessions were applied for 6 weeks. As a result, The BPC group during breathing showed a significant increase in all TAMs(p<.001) and in the TSM(p<.001) than the LSE group. Besides, had a more decrease in the LSM than the LSE group(p<.001). The BPC showed high positive correlations with TAMs(rest: r=.868, forced: r=.870) and the TSM(r=.672) and had a negative correlation with the LSM(r=-.420). Based on this result of the study, the authors believe that the BPC in LI people could decrease the lumbar flexion mobility when they have motion of trunk forward flexion with promotions in the thoracic spine and rib joint mobility by improvements in relative mobility of thoraco-abdominal lines.

• IE interfaces
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• v.16 no.spc
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• pp.21-27
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• 2003

Objective of this paper is to develop the user mobility model(UMM) which is used for the performance analysis of location update and paging algorithm and at the same time, consider the user mobility pattern(UMP) in zone-based cellular networks. User mobility pattern shows correlation in space and time. UMM should consider these correlations of UMP. K-dimensional Markov chain is presented as a UMM considering them where the states of Markov chain are defined as the current location area(LA) and the consecutive LAs visited in the path. Also, a new two dimensional Markov chain composed of current LA and time interval is presented. Simulation results show that the appropriate size of K in the former UMM is two and the latter UMM reflects the characteristic of UMP well and so is a good model for the analytic method to solve the performance of location update and paging algorithm.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.451-460
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• 2006

Since low earth orbit (LEO) satellite constellations have important advantages over geosynchronous earth orbit (GEO) systems such as low propagation delay, low power requirements, and more efficient spectrum allocation due to frequency reuse between satellites and spotbeams, they are considered to be used to complement the existing terrestrial fixed and wireless networks in the evolving global mobile network. However, one of the major problems with LEO satellites is their higher speed relative to the terrestrial mobile terminals, which move at lower speeds but at more random directions. Therefore, handover management in LEO satellite networks becomes a very challenging task for supporting global mobile communication. Efficient and accurate methods are needed for LEO satellite handovers between the moving footprints. In this paper, we propose a new seamless handover management scheme for LEO satellites (SeaHO-LEO), which utilizes the handover management schemes aiming at decreasing latency, data loss, and handover blocking probability. We also present another interesting handover management model called satellite mobility pattern based handover management in LEO satellites (PatHO-LEO) which takes mobility pattern of both satellites and mobile terminals into account to minimize the handover messaging traffic. This is achieved by the newly introduced billboard manager which is used for location updates of mobile users and satellites. The billboard manager makes the proposed handover model much more flexible and easier than the current solutions, since it is a central server and supports the management of the whole system. To show the performance of the proposed algorithms, we run an extensive set of simulations both for the proposed algorithms and well known handover management methods as a baseline model. The simulation results show that the proposed algorithms are very promising for seamless handover in LEO satellites.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.2
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• pp.99-105
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• 2007

MANET(Mobile Ad-hoc network) have recently attracted a lot of attention in the research community as well as in industry. Although the previous research mainly focused on various of MANET in routing, we consider, in this paper, how to efficiently support applications such as variable geocasting basd on MANET. The goal of a geocasting protocol is deliver data packet to a group of nodes that are located within a specified geocasting region. Previous research that support geocast service in mobilie computing based on MANET have the non-optimization problem of data delivery path, overhead by frequent reconstruction of the geocast tree, and service disruption problem. In this paper, we propose the mobility pattern based geocast technique using variable service range according to the mobility of destination node and resource reservation to solve this problem. The experimental results show that our proposed mechanism has improved performance of Accessibility & Network Overhead than previous research.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.73-82
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• 2017

PURPOSE: Proprioceptive Neuromuscular Facilitation (PNF) has been shown to improve body function and activity/participation in people with functional dysfunctions. This study evaluates if active exercise using theraband in PNF pattern may induce similar benefits as exercise using manual PNF pattern performed by physiotherapists on promoting mobility, balance and fear of fall in community-dwelling elderly. METHODS: Twenty-three community-dwelling elderly with independent activities of daily living were recruited and randomly allocated into either PNF group - exercise in PNF pattern by trained physiotherapists or Theraband-PNF (T-PNF) group - exercise using theraband in PNF pattern, for an hour, twice weekly for 4 weeks. Functional outcomes such as Timed Up and Go test, Elderly Mobility Scale, Berg balance scale, functional reach and subjective measures including fear of fall (FOF) scale, bodily pain in visual analogue scale were measured pre and post-program. RESULTS: Twenty-one participants completed the program. PNF group demonstrated significant within-group improvements in all subjective measures and objective measures. Similar within-group improvements were demonstrated in all outcome measures except FOFS in T-PNF group. However, no between-group differences were found in any of the outcome measures. CONCLUSION: Comparable improvements in functional outcomes in community dwelling elderly were demonstrated in both groups. As manual PNF exercise traditionally need clinicians' contact and feedback on patient which limit the training to be carried out extensively in community setting. The current findings suggest that exercise using theraband in PNF pattern is feasible to be adopted as self-practice exercise for community-dwelling elderly to induce beneficial effects on functional outcomes.