• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.255-257
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• 2004

The study for ubiquitous computing infra is proceeding actively, it make possible to use service and access network anywhere, anytime because of wire/wireless communication technology and progress of hardware. Domestically, study for the network mobility support technology which is the key technology for future ubiquitous computing realization have progressed, but that is insufficient. Especially, there is no study for independent mobility support study about railway wireless network. So, this study propose network mobility management technology for mobile network infra in railway and proper network model in train.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.117.5-117
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• 2002

. Mobility analysis for overconstrained mechanisms is not clearly explained. . Aims at mobility analysis of overconstrained mechanisms . Representative screws is employed as a tool . A method to identifying the representative screw is introduced . Mobility analysis for several overconstrained parallel mechanisms and mobile robots

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.100-115
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• 2020

The manufacturing-oriented mobility system is being reorganized around the future mobility system represented by electrification, sharing, and autonomy, driven by the social demand for sustainable development. Changes in future mobility systems are expected to accelerate thanks to advances in IT technology. To this end, this study conducted an expert survey (N=23) to predict the direction of changes in the future mobility system. Through the survey, 'mobility sharing' was selected as a key factor in the future mobility system among four future mobility. In addition, 'safety' was selected as the most important service factors in future mobility system among eight future mobility service factors. We hope that the results of this study will be used as basic information to design policies and service directions of preparation for the future mobility system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3568-3584
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• 2016

In mobile opportunistic networks (MONs), human-carried mobile devices such as PDAs and smartphones, with the capability of short range wireless communications, could form various intermittent contacts due to the mobility of humans, and then could use the contact opportunity to communicate with each other. The dynamic changes of the network topology are closely related to the human mobility patterns. In this paper, we propose a social motivation-aware mobility model for MONs, which explains the basic laws of human mobility from the psychological point of view. We analyze and model social motivations of human mobility mainly in terms of expectancy value theory and affiliation motivation. Furthermore, we introduce a new concept of geographic functional cells, which not only incorporates the influence of geographical constraints on human mobility but also simplifies the complicated configuration of simulation areas. Lastly, we validate our model by simulating three real scenarios and comparing it with reality traces and other synthetic traces. The simulation results show that our model has a better match in the performance evaluation when applying social-based forwarding protocols like BUBBULE.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.98-105
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• 2018

This study investigated whether housing accessibility plays a significant role in explaining the relation between mobility disability and residential satisfaction of seniors. Also, it identified people who are at greatest risk of mobility disability and living in homes without housing accessibility. We analyzed the 2011 American Housing Survey data with a sample of 20,089 households aged 55 and over living in single-family homes. Results show that although residential satisfaction decreased as mobility became more disabled, the key housing accessibility features were significant buffers against the negative impact of mobility disability on residential satisfaction. Seniors who were Black, low-income, housing-costs burden and renters in older housing in an urban area were more likely to have mobility limitations but fewer housing accessibility features. The moderating effect of housing accessibility on residential satisfaction was much greater for seniors with greater mobility disability. For vulnerable seniors living in an old single-family home, housing policymakers or local communities should consider home modification programs and services after evaluating housing accessibility.

• Journal of the Ergonomics Society of Korea
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• v.21 no.2
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• pp.35-46
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• 2002

This study was performed to determine the voluntary range of joint mobility for middle-aged Korean adults. One hundred and eighty-eight subjects(99 males and 89 females) at the age range of 40 to 60 participated for this study. Thirty body movements at various joints were conducted to measure the range of joint mobility. Subjects were grouped by Rohrer's into four based on 25th percentile. The data were analyzed to see the differences of range of joint mobility between sexes and Rohrer's index groups. The results of this study and previous studies were compared to see the differences of range of joint mobility due to the aging. Results of this study indicate that females are generally more flexible than males. Significant differences were found to exist in fourteen movement between sexes and in ten movements, females have larger range of joint mobility than males. There were no significant differences in range of joint mobility may have a tendency to decrease with ages. The results of this study provide important information in dynamic dimensions for middle-aged Korean and can be used to design the various and work places for the middle-aged.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.5
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• pp.181-190
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• 2013

PMIPv6(Proxy Mobile IPv6) is a network-based IP mobility management protocol, which can control the mobility without depending on the type of access system or the capability of mobile node. Combining it with SIP mobility, it can establish the route optimization effectively and ensure the terminal mobility and the session mobility. There are many literatures on PMIPv6-SIP in mobility management, but efficient performance analysis and mathematical modeling has not been standardized. For this, a new PMIPv6-SIP architecture is proposed to compare with Pure-SIP in terms of the handover delay and packet loss.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.1
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• pp.59-72
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• 2000

This study was performed to investigate the effects of tooth mobility and design of the direct retainer on the stress of supporting tissues in distal extension removable partial denture. Tooth mobility was simulated and four different types of direct retainer such as Alters clasp, I-bar clasp, wrought wire clasp, and Dalbo attachment were designed and stress on the support-ing tissues were measured and analyzed with straingauge method. The following conclusions were drawn from this study. 1. The stress revealed at the lingual side of alveolar bone of the abutment tooth in edentulous area was the largest. 2. The stress at the lingual side of alveolar bone of the abutment tooth in edentulous area was increased according to the increase of tooth mobility in I-bar clasp and Dalbo attachment. 3. The stress at the residual ridge crest was the great in Dalbo attachment on mobility 0, in I-bar clasp on mobility 1, and in wrought wire clasp on mobility 2. 4. There was little changes of stress according to the increase of tooth mobility at buccal and lingual side of the residual ridge crest and around the abutment teeth in dentulous area.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3018-3040
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• 2018

The mobility model is one of the most important factors that impacts the evaluation of any transportation vehicular networking protocols via simulations. However, to obtain a realistic mobility model in the dynamic urban environment is a very challenging task. Several studies extract mobility models from large-scale real data sets (mostly taxi GPS data) in recent years, but they do not consider the statuses of taxi, which is an important factor affected taxi's mobility. In this paper, we discover three simple observations related to the taxi statuses via mining of real taxi trajectories: (1) the behavior of taxi will be influenced by the statuses, (2) the macroscopic movement is related with different geographic features in corresponding status, and (3) the taxi load/drop events are varied with time period. Based on these three observations, a novel taxi mobility model (T-START) is proposed with respect to taxi statuses, geographic region and time period. The simulation results illustrate that proposed mobility model has a good approximation with reality in trajectory samples and distribution of nodes in four typical time periods.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.37-44
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• 2010

The mobility is one of the most important factor for mobile IPTV. However, mobility is highly vulnerable to eavesdropping and unauthorized access. Generally mobility of mobile services is based on handover techniques. But we showed that mobile IPTV must use other techniques to confirm mobility. In this paper, we analyzed security of wibro mobile IPTV from the viewpoint of mobility. We considered DCAS host must include new addresses of mobile devices. We analyzed total number of authentication for the proposed method. So we showed that proposed method was more efficient than wibro-mobile IPTV. We compared the security of our proposal to the security requirements of TTA.