• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.857-866
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• 2009

Recently, IP mobility study of infra's common elements is undergoing processes to achieve FMC based on All-IP. Existing typical mobility technology based on IP is IETF's Mobile IP. However, it faced to limitations due to packet loss, delays when MN is moving on Mobile IP, also existing network infra - routers (FA)-needed to add/change the functions to support Mobile IP. In this paper, existing mobility problems based on IP and the suggested improvements for platforms which support mobility, quality, security are proposed. It discusses the performance on the current existing IP infrastructure derived from simulation analysis on mobility packet loss and delay. From the resulting data, improvements will also be outlined for optimal performance.

• Journal of the Korean housing association
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• v.25 no.4
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• pp.93-100
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• 2014

The purpose of this study, analyzing the primary factors for residential mobility and housing preference of Daegu citizens, is to provide a basic data for future housing policies. The results are as follows: First, 32.1% of Daegu citizens have intention of residential mobility. Especially the residents in central (50.0%), southern (59.0%) and western Daegu showed more intention than those in other districts. Second, we used the GLMM (Generalized Linear Mixed Models) to analyze the main factors for residential mobility. The results are as follows; 1) the residents who have lower housing satisfaction with the type of housing, parking, and educational environment, 2) those who are male and younger, 3) those who live in rented house have more intention of housing mobility. Third, based on the analysis on the preference change of the type of housing, the preference of the apartments is getting higher, while that of the detached houses is getting lower (past: 40.1%${\rightarrow}$present: 54.8%${\rightarrow}$future: 66.7%). 28.8% of the respondents (444) expressed intention to live in the public rental houses, in case they are provided in the areas they are moving to. Fourth, when we analyzed the size of the houses they actually lived in and that of the houses they prefer to live in case of moving, we found that in general they tend to move in smaller housing than in the past. The results of the analysis showed that in order to minimize the possible moving away from the current residential areas due to the dissatisfaction with the housing environment, in the first place the improvement in the quality of the houses, parking and education environment is needed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6B
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• pp.411-419
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• 2008

As the set of new mobile data networking service technologies, such as WiBro, mobile WiMAX and WCDMA-HSDPA, have been introduced in recent years, IP mobility management protocols which aim to provide seamless IP service over the mobile networking environment become one of the important building blocks for the successful mobile networks. IETF has introduced a basic mobility management protocol over IPv6 (MIPv6) and a set of enhanced protocols such as FMIPv6 and HMIPv6, followed by FHMIPv6, S-MIPv6 and HIMIPv6 which combine the benefits of the basic protocols. We have studied the impact of the various IP mobility management protocols over TCP sessions through extensive simulations with ns-2. Our simulation results show that TCP performance with the HIMIPv6 outperforms MIPv6, FMIPv6 and HMIPv6 over the various TCP protocols, due to its efficient combination of the hierarchical mobility management scheme of the HMIPv6, the predictive handover scheme of the FMIPv6 and the fast simulcasting scheme of the S-MIP.

• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.544-553
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• 2008

The general sensor network uses bundle method to collect fixed information from sensor node. However, this method is difficult to actively cope with major sensing objects in healthcare environment including status and position change of person and change of surrounding environment. In order to support the healthcare environment, certain information should be provided in accordance with the change of status of person and surrounding circumstance and also must cope with the change of network type by movement of person. This paper analyzes LEACH protocol which guarantees effectiveness of network as it constitutes clusters between Agilla model that is a representative multi agent middle ware and surrounding nodes. Based on the result of this analysis, it suggests LEACH_Mobile protocol which guarantees node mobility that is the weakest point of LEACH protocol. Moreover, it designs mobility agent middleware which supports dynamic function change of node and mobility agent module which supports dynamic function change of mobile node as components of LEACH_Mobile routing module. In addition, it is definitely increase performance which in mobile node of transfer data rate through LEACH_Mobile protocol of simulation result.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.2
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• pp.1-10
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• 2023

Background: The purpose of this study was to evaluate the pain, static balance, and dynamic balance abilities of women with chronic low back pain by performing thoracic and hip joint mobility exercises and lumbar stability exercises. Methods: The subjects of this study were 20 adult women with low back pain who lived in C city for more than 12 weeks. The experimental group performed the thoracic and hip mobility exercises with lumbar stability exercises and the control group performed the lumbar stability exercise with general exercise program. Both groups participated in the exercise program three times a week for six weeks, from December 20, 2022 to March 7, 2023. The balance ability were measured using BT4, and pain was measured using visual analog scale (VAS). The collected data were analyzed by independent sample t-test and paired t-test using SPSS version 23.0 program. Results: After 6 weeks of intervention, there was a significant change in VAS between the experimental group and the control group, and there was no difference between the two groups (p>.05). In the case of balance ability, there was a no significant increase in the experimental group (p>.05). Conclusion: Thoracic and hip joint mobility exercises and lumbar stability exercises for adult female patients with chronic low back pain may be partially effective in static balance and dynamic balance.

• The Korean Journal of Emergency Medical Services
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• v.27 no.2
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• pp.7-17
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• 2023

Purpose: This study aimed to identify the factors that contribute to head injuries among drivers of personal mobility devices and provide insights into safety perceptions. Methods: This retrospective study analyzed data of 221 trauma patients obtained from electronic medical records and the National Emergency Department Information System (NEDIS) over one year, from August 1, 2021, to July 31, 2022. The patients, all in their 20s and 30s, presented to a single emergency medical center following personal mobility device accidents (motorcycles, electric scooters, and bicycles). Results: Among motorcycle riders, 18.2% were not wearing helmets, while the percentage of e-scooter riders not wearing helmets was 87.5%. Wearing a helmet was associated with a 71.2% lower likelihood of head injuries (OR=0.288, CI=0.163 to 0.509, p=0.000). Of the personal mobility devices, motorcycles had a 0.431 times lower odds ratio for head injury compared to e-scooters (p=0.009), and there was no significant difference between e-scooters and bicycles (p=0.776). Conclusion: It is imperative to strengthen safety regulations by mandating helmet use for riders of personal mobility devices. A system to enhance driving enforcement for electric scooters, which are increasingly popular among young adults, should also be established.

• Journal of Communications and Networks
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• v.6 no.4
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• pp.387-396
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• 2004

One of the main problems associated with MANETs is that mobility and the associated route discovery and maintenance procedures of reactive routing protocols cause severe interruptions on real-time video streams. Some of these interruptions are too large to be concealed using any sort of video technology, resulting in communications breaks unpleasant for the final end user. We present a solution for enhanced video transmission that increases route stability by using an improved route discovery process based on the DSR routing protocol, along with traffic splitting algorithms and a preventive route discovery mechanism. We also present some video adaptative mechanisms that improve the overall performance of multipath routing in terms of video data replication and video packet splitting strategies. Combining our proposals, we achieve up to 97% less interruptions on communication with high mobility and over 1.2 dB of improvements in terms of video distortion.

• Korean Journal of Human Ecology
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• v.24 no.3
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• pp.341-358
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• 2015

This study aims to identify predictors of driving cessation among Korean elderly. Data from 2011 Elderly Survey conducted by Ministry of Health and Welfare and Korea Institute for Health and Social Affairs were used for the analysis. Based on Webber, Porter, Menec(2010)'s comprehensive theoretical framework for mobility, the model of this study tests five major determinants of driving cessation including financial, psychosocial, environmental, physical and cognitive factors. Results of logistic regression analysis showed that economic status, marital status, contacts with relatives and friends, residential location, taking medication, muscle strength, age, gender, and job were significant predictors of driving cessation of older drivers. Specifically, lower economic status, unmarried status, less contacts with relatives and friends, living in the city, taking medication, weaker muscle strength, older age, female, non-working status were significant risk factors for driving cessation. Practical implications in light of study findings were discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.181-187
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• 1998

The ionization energy and degree of ionization for p-type $Si_{1-x}Ge_x$ with boron doping are calculated taking into account the screening and broadening effects. The drift and Hall mobilities are then calculated using the relaxation time approximation and compared with the previously reported measurement data for relaxed and strained $Si_{1-x}Ge_x$ alloys to estimate the alloy scattering potential. From a fit, the alloy scattering potential is found to be 0.5 eV. The in-plane drift mobility for p-type strained $Si_{1-x}Ge_x$ grown on (001) Si substrate is approximately 1+$10x^2$ times higher than that for bulk Si in the high doping range.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.374-382
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• 2007

Robot mobility and intelligence become more important for robots to be used in various fields other than automation. The main purpose of providing mobility to a robot is to extend the robot's manipulability. In this paper, we introduce a small humanoid robot that can autonomously play golf as an example of incorporating robot intelligence, mobility, and manipulability. The robot has 12 degrees of freedom for legs and has various basic walking patterns. It can move to a desired position and change orientation by combining the basic waking patterns. The robot has a color CCD camera and can extract coordinates of the objects in the environments. The small humanoid robot has 8 degrees of freedom for arms and can play golf autonomously with two kinds of dexterous swing motions. Kinematic analysis of the robot arms, vision data processing for the recognition of the environments, algorithm for playing robotic golf have been performed or proposed. The experimental results show that the robot can play golf autonomously.