• KIPS Transactions on Computer and Communication Systems
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• v.9 no.3
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• pp.67-76
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• 2020

With the fast development in wireless communications and vehicular technologies, vehicular ad hoc networks (VANETs) have enabled to deliver data between vehicles. Recently, VANETs introduce a Vehicular Cloud (VC) model for collaborating to share and use resources of vehicles to create value-added services. To construct a VC, a vehicle should search vehicles that intend to provide their own resource. The single-hop search cannot search enough provider vehicles due to a small coverage and non-line-of-sights of communications. On the other hand, the multi-hop search causes very high traffics for large coverage searching and frequent connection breakages. Recently, many Roadside Units (RSUs) have been deployed on roads to collect the information of vehicles in their own coverages and to connect them to Internet. Thus, we propose a RSU-aided vehicular resource search and cloud construction mechanism in VANETS. In the proposed mechanism, a RSU collects the information of location and mobility of vehicles and selects provider vehicles enabled to provide resources needed for constructing a VC of a requester vehicle based on the collected information. In the proposed mechanism, the criteria for determining provider vehicles to provide resources are the connection duration between each candidate vehicle and the requester vehicle, the resource size of each candidate vehicle, and its connection starting time to the requester vehicle. Simulation results verify that the proposed mechanism achieves better performance than the existing mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.287-293
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• 2017

The purpose of the study was to analyze the effects of work experience during higher education on employment. In particular, the study analyzed the difference in employment and permanent employment according to work experience or internship. In addition, the effects of the relatedness of college major and work experience as well as internship on college graduates' employment or permanent employment were investigated. The data came from the 2013 Graduates Occupational Mobility Survey (GOMS). The study covered the chi-square test and logistic regression analysis. The study found that there was a significant difference in the employment and permanent employment among the groups classified by work experience or internship. Internship had a positive effect on college graduates' permanent employment. Based on the study results, this study suggests that policies for internship during higher education need to be enhanced. The match between employment and the field of study in college needs to be increased. Interventions and policies for the establishment of competency-based employment should be improved.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.131-131
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• 2013

A single-layer graphene has been uniformly grown on a Cu surface at elevated temperatures by thermally processing a poly(methyl methacrylate) (PMMA) film in a rapid thermal annealing (RTA) system under vacuum. The detailed chemistry of the transition from solid-state carbon to graphene on the catalytic Cu surface was investigated by performing in-situ residual gas analysis while PMMA/Cu-foil samples being heated, in conjunction with interrupted growth studies to reconstruct ex-situ the heating process. The data clearly show that the formation of graphene occurs with hydrocarbon molecules vaporized from PMMA, such as methane and/or methyl radicals, as precursors rather than by the direct graphitization of solid-state carbon. We also found that the temperature for vaporizing hydrocarbon molecules from PMMA and the length of time the gaseous hydrocarbon atmosphere is maintained, which are dependent on both the heating temperature profile and the amount of a solid carbon feedstock are the dominant factors to determine the crystalline quality of the resulting graphene film. Under optimal growth conditions, the PMMA-derived graphene was found to have a carrier (hole) mobility as high as ~2,700 cm2V-1s-1 at room temperature, superior to common graphene converted from solid carbon.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.2
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• pp.193-201
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• 2010

Purpose : This study achieved to search the effect of the circuit exercise and conventional exercise on walking ability(walking speed, endurance, dynamic balance, speed, endurance and pedestrian crossing) in chronic stroke. Methods : Since is diagnosed by stroke, to 30 chronic stroke patients who more than 1 year past the 15 circuit exercise group, the 15 conventional exercise group random the circuit exercise group applied circuit exercise 3th 8 weeks each week after neurological treatment because assigning and the conventional exercise group executed round trip walk exercise in parallel bar 3th 8 weeks each week after neurological treatment. The data of 25 patients who complete experimental course were statistically analysed. Results : The results of this dissertation were as following : 1) There were significantly increased after experimental of 10 meter walk test, 6 minutes walk test and Timed "Up and Go" test in circuit exercise group (p<.001). 2) There were significantly increased after experimental of 2, 4 and 6 lane road crossing mobility in Walking circuit exercise group(p<.01). 3) There were significantly differences after experimental of 10 meter walk test, 6 minutes walk test and Timed "Up and Go" test change quantity between circuit exercise group and conventional exercise group(p<.05). 4) There were correlations were found between the TUG test and 2, 4 and 6 lane road (2 lane road; r=.463, p<.01., 4 lane road; r=515, p<.01., 6lane road; r=.710, p<.01), and there were correlations were found between the 10 meter walk test and 6 minutes walk test(r=.595, p<.01), TUG test(r=.662, p<.01) and 6 lane road(r=.527, p<.01). Conclusion : Even if improvement of walk function through training consists in room, transfer of actuality pedestrian crossing is no change outside the room. Because it is much variable of the weather, seasonal factor, temperature, pedestrian number, state of underneath etc. outside the room. Then, in room after direction promotion of walk function to be promotion of walk function in actuality life and need development of connectable training method consider.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.81-91
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• 2016

VANET is one of the most developed technologies many people have considered a technology for the next generation. It basically utilizes the wireless technology and it can be used for measuring the speed of the vehicle, the location and even traffic control. With sharing those information, VANET can offer Cooperative ITS which can make a solution for a variety of traffic issues. In this way, safety for drivers, efficiency and mobility can be increased with VANET but data between vehicles or between vehicle and infrastructure are included with private information. Therefore alternatives are necessary to secure privacy. If there is no alternative for privacy, it can not only cause some problems about identification information but also it allows attackers to get location tracking and makes a target. Besides, people's lives or property can be dangerous because of sending wrong information or forgery. In addition to this, it is possible to be information stealing by attacker's impersonation or private information exposure through eavesdropping in communication environment. Therefore, in this paper we propose Privacy Assurance Architecture for VANET to ensure privacy from these threats.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2105-2110
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• 2008

Embedding the compact wearable units to monitor the health status of a person has been analysed as a convenient solution for the home health care. This paper presents a method to detect fall from the other activities of daily living and also to classify those activities. This kind of ambulatory monitoring of the elderly and people with limited mobility can not only provide their general health status but also alarms whenever an emergency such as fall or gait has been occurred and a help is needed. A timely assistance in such a situation can reduce the loss of life. This work shows a detailed analysis of the data received from a chest worn sensor unit embedding a 3-axis accelerometer and depicts which features are important for the classification of human activities. How to arrange and reduce the features to a new feature set so that it can be classified using a simple classifier and also improving the classification resolution. Principal component analysis (PCA) has been used for modifying the feature set and afterwards for reducing the size of the same. Finally a Neural network classifier has been used to analyse the classification accuracies. The accuracy for detection of fall events was found to be 86%. The overall accuracy for the classification of Activities or daily living (ADL) and fall was around 94%.

• Korean Journal of Family Social Work
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• no.55
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• pp.265-297
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• 2017

This study aims to provide basic information about the policy and system improvements relevant to single elderly men, through an investigation concerning the use and needs of activity spaces near their housing environments. Eighteen single elderly men over 60-years-old living in Gunsan city of Jeonbuk province in Korea participated in in-depth interview, and the data were qualitatively analyzed. The results of the study are as follows: The social networks of the participants were focused on friends or colleagues, while mutual exchanges with their children were intermittently undertaken. Natural networks of the elderly were formed mainly in third places, such as parks, restaurants, or community facilities, and about a half of the elderly participants had no spatial needs, and the rest required spaces for meal services, the elderly living community, jobs, leisure/hobby activities, or facility improvements. The elements influencing use of activity spaces were access from the residence, health, social networks, and economic conditions. The results suggest the following: Exercise or leisure facilities supporting elderly mobility should be set up close to their residential environments. Senior facilities centered on systematic supports and shuttle buses circulating around the places that the elderly visit frequently should be considered. On the other hand, regular maintenance and education on residents' proper use of the facilities, and sufficient information and fee discounts for the general programs are needed so that the elderly could interact with the younger generation. From a public perspective, a rational system and policy based on understanding single elderly men's needs should be prepared for provision and management of the activity space.

• 재활복지
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• v.21 no.1
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• pp.71-95
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• 2017

The purpose of this research is to suggest implications for the elderly with disability by taking a look at the influence of disability of elderly on successful aging and a moderating effect of social support network. This study analyzed the $4^{th}$ panel data from KReIS and the subjects for this research are 3,906 of elderly aged over 65 years. For the statistical analysis, the IBM SPSS Statistics v23.0 program was utilized. Technical statistics was verified, multiple regression analysis was used in order to take a look at the effects of moderating variable. The results of this research are as the following: Firstly, the disability of elderly had an negative effect on successful age. Secondly, as a social support network, friend & neighborhood network and family network had an positive effect on successful age. Thirdly, friend & neighborhood network among social support network had a moderating effect on successful aging. In other words, the more disabled the elderly are, the lower the level of successive aging became, it turned out that the bigger the social support of friend & neighborhood network, the less the negative effect of disability on successive aging. On the basis of the result, it was proposed a case management for the elderly with disability, assurance of mobility right, and self-help meeting program for social support network.

• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.85-95
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• 2018

Objective : The purpose of this study was to investigate the awareness and availability on items of 2018 assistive devices distribution program for the disabled in the occupational therapists. Methods : A total of 132 occupational therapists participated in the survey from May 1 to May 31. Results : 96.2% of the occupational therapists responded that assistive device is helpful in lives of the disabled people. Especially, they responded that assistive device is the most helpful in 'movement and mobility'. Awareness on an angle spoon/fork with built-up handle and universal cuff was the highest, while a visual signaling indicator was the lowest. Availability on an air cushion was the highest, while a visual signaling indicator and a voice guidance system were the lowest. 67.4% responded that 'sometimes' they use the assistive device and 77.3% responded they will utilize the assistive device. To improve awareness and availability, 43.2% needed financial support, 32.6% needed to add insurance bill and 22.7% needed related education. Conclusion : In the future, this result will be available as a basic data for the education about assistive device for the occupational therapists.

• 한국노년학
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• v.38 no.3
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• pp.593-605
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• 2018

This study examines factors that influence older drivers to consider stopping driving in advance and whose advice plays an important role in the driving cessation decision. Data came from a nationally representative cross-sectional survey of community-dwelling older adults (N=2,076). About two thirds reported that they have considered stopping driving (62.8%) and they preferred to decide by themselves (66.0%). Logistic regression results showed that women and residents in urban areas were twice as likely to consider voluntary driving cessation compared to their counterparts. Each one year increase in age contributed to the probability that respondents would consider driving cessation by five percent. Those with greater difficulties in ADLs due to chronic illnesses were also more likely to consider driving cessation. No sociodemographic and health factors were related to whether older drivers preferred to decide by themselves or listen to others. These results imply that policies to promote self-motivation to stop driving among older drivers would be effective. Furthermore, they suggest it could be important to help older drivers plan their driving cessation in advance while still at a young-old age, and that more attention needs to be paid to men and those living in rural areas among older drivers.