• Journal of Communications and Networks
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• 제14권1호
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• pp.91-103
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• 2012

Network mobility (NEMO) based on mobile IP version 6 has been proposed for networks that move as a whole. Route optimization is one of the most important topics in the field of NEMO. The current NEMO basic support protocol defines only the basic working mode for NEMO, and the route optimization problem is not mentioned. Some optimization schemes have been proposed in recent years, but they have limitations. A new NEMO route optimization scheme-involving a combination of the optimized route cache protocol (ORC) and reverse routing header (RRH) and the use of a quota mechanism for optimized sessions (OwR)-is proposed. This scheme focuses on balanced performance in different aspects. It combines the ORC and RRH schemes, and some improvements are made in the session selection mechanism to avoid blindness during route optimization. Simulation results for OwR show great similarity with those for ORC and RRH. Generally speaking, the OwR's performance is at least as good as that of the RRH, and besides, the OwR scheme is capable of setting up optimal routing for a certain number of sessions, so the performance can be improved and the cost of optimal routing in nested NEMO can be decreased.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.236-244
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• 2022

Network Mobility Basic Support (NEMO BS) protocol has been accredited and approved by Internet Engineering Task Force (IETF) working group for mobility of sub-networks. Trains, aircrafts and buses are three examples of typical applications for this protocol. The NEMO BS protocol was designed to offer Internet access for a group of passengers in a roaming vehicle in an adequate fashion. Furthermore, in NEMO BS protocol, specific gateways referred to Mobile Routers (MRs) are responsible for carrying out the mobility management operations. Unfortunately, the main limitations of this basic solution are pinball suboptimal routing, excessive signaling cost, scalability, packet delivery overhead and handoff latency. In order to tackle shortcomings of triangular routing and Quality of Service (QoS) deterioration, the proposed scheme (Diff-FH NEMO) has previously evolved for end-users in moving network. In this sense, the article focuses on an exhaustive analytic evaluation at Home Agent (HA) entity of the proposed solutions. An investigation has been conducted on the signaling costs to assess the performance of the proposed scheme (Diff-FH NEMO) in comparison with the standard NEMO BS protocol and MIPv6 based Route Optimization (MIRON) scheme. The obtained results demonstrate that, the proposed scheme (Diff-FH NEMO) significantly improves the signaling cost at the HA entity in terms of the subnet residence time, number of mobile nodes, the number of DMRs, the number of LFNs and the number of CNs.

• 항공우주정책ㆍ법학회지
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• 제31권1호
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• pp.63-97
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• 2016

최근 휠체어를 이용하여 비행기에 탑승하려던 승객이 항공사로부터 탑승거부를 당한 사례가 여럿 보도되었다. 우리나라 법에는 장애인을 포함한 고령자, 임산부 등 일상생활에서 이동에 불편을 느끼는 사람을 교통약자로 규정하여 이들의 이동권을 보장하고 있지만, 실제로 다양한 이유로 이들의 이동에 제약이 있는 실정이다. 그러나 국제사회에서는 항공교통이용자의 보호 및 안전을 위한 정책을 도입하고 실행 중에 있다. 이러한 움직임에 맞추어 우리나라도 항공교통이용자들의 피해를 미리 예방하고 보호할 수 있는 제도가 마련되어야 할 것이다. 본 논문은 승객에 대한 권리와 교통약자들의 권리에 관하여 해외의 규정들을 알아보고, 이에 비추어 부족한 우리나라의 제도를 검토하고 이에 따른 해결 방안을 제시하였다. 우선 교통약자라는 정의를 다시 파악함으로써 전체 국민의 25 %에 해당하는 이동에 불편을 느끼는 자를 위한 제도가 아닌 실지로 이동에 제한이 있는 자를 위한 현실적인 정책방안을 강구하였다. 이 과정에서 항공사와 교통약자와의 분쟁이 더욱 더 심각한 것은 항공사마다 제각기 다른 운송약관에 따라 운영의 범위가 다르므로 승객입장에서는 혼란을 야기할 수밖에 없음을 발견하곤 미국 등 국제사회의 법규범들에 비추어 항공교통이용자의 보호라는 목표를 위하여 항공 교통의 특수성과 우리 실정에 맞는 현실적인 규율을 통일적으로 제안을 해보았다. 또한, 현재 우리나라는 승객이 항공이용 중 피해가 발생하면 그 피해구제의 신청을 이용승객이 하도록 하고 있다. 이는 당연한 소비자의 권리로서 피해구제를 요청할 수 있는 것이다. 그러나 이러한 보상이 필요한 피해뿐만 아니라 항공교통이용자가 가지는 피해, 불만의 처리에 관한 모든 것을 집계하여야 하기 위하여 현장에서 발생하는 불만들의 정확한 집계를 위해 이를 그 서비스 제공자인 공항과 항공사에게 위임하도록 하는 방안을 제시 하였다. 이는 항공교통서비스 보고서가 가지는 목적. 서비스의 질을 향상시키고, 승객이 가질 수 있는 어려움을 보다 구체적으로 처리할 수 있는 정책을 만드는 데 큰 도움이 될 것이다. 우리나라의 교통약자 등에 관련된 시설 및 인식은 선진국에 비해 떨어지지 않으나 교통선진국가로서의 승객에 대한 권리향상의 움직임에 발맞추기 위해 보다 구체적이고 실질적인 정책이 필요한 시점이며, 이동권이 제약된 교통약자들의 처우를 개선하기 위하여 실효성 있는 제도를 제안했다.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.30-38
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• 2019

Recently, the spread of personal mobility has been rapidly increasing due to the development of environmentally friendly alternative transportation means. In addition, the level of battery technology is also rapidly developing, accelerating the popularization of personal mobility. Such personal mobility has convenience of location transfer, amusement, and high portability compared to other transportation devices. Most personal mobility, however, is made up of small wheels, which cannot overcome obstacles such as rugged roads or obstacles on the road. In this paper, to solve these problems, we tried to devise a device that can easily overcome obstacles by combining wheels with small moving means. The wheel size can be mounted on the front wheel of the small moving means in a protruding manner so that obstacles can be encountered before the front wheels and the safety and ride comfort of the running can be improved.

• Journal of Contemporary Eastern Asia
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• 제12권1호
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• pp.35-47
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• 2013

During the last a few decades, internationalisation of universities has emerged as an important issue not only in developed countries but in developing countries. South Korea as a fast catch-up country has experienced a remarkable change in its higher education system. This change is largely related to the South Korean government's higher education policy and to economic developmental stages. Against this backdrop, in order to assess the internationalisation of Korean higher education, we focus on international student mobility rather than other criteria such as infrastructure or programmes for international students and faculties. According to the recent statistics, the number of inbound foreign students involved in Korean higher education has increased significantly since 2005. Nevertheless, compared to other OECD and Asian countries, the number of outbound students in Korean higher education is high, whereas the number of inbound foreign students in higher education in Korea is very low. Against these observations, Korean government's recent policies and efforts of Korean universities to improve internationalization are discussed. Finally, some policy implications are put forward.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.13-17
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• 2008

This paper deals with the directional mobility of droplets on structured surfaces. Structured surfaces were micro-patterned with rectangular lines and spaces of varying pitch and height in the sub-millimeter range. The material used was polydimethylsiloxane, which is hydrophobic and wettable by oil. First, we studied the effect of the structural design on the sliding angle of pure water or oil through experiments. For pure water droplets, we found that a wider pitch enhanced the directionality. On the other hand, oil droplets spread along the groove because of their low surface tension and strong capillary force. The directionality of the sliding angle of oil droplets was larger than that of pure water, especially when the groove was narrower and deeper. Second, we poured a large amount of liquid on the structure and evaluated the removal rate on the tilted surface. We found that a parallel structure enhanced the liquid mobility for both pure water and oil.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.39-46
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• 2019

Human mobility estimation plays a key factor in a lot of promising applications including location-based recommendation systems, urban planning, and disease outbreak control. We study the human mobility estimation problem in the case where recent locations of a person-of-interest are unknown. Since matrix decomposition is used to perform latent semantic analysis of multi-dimensional data, we propose a human location estimation algorithm based on matrix factorization to reconstruct the human movement patterns through the use of information of persons with correlated movements. Specifically, the optimization problem which minimizes the difference between the reconstructed and actual movement data is first formulated. Then, the gradient descent algorithm is applied to adjust parameters which contribute to reconstructed mobility data. The experiment results show that the proposed framework can be used for the prediction of human location and achieves higher predictive accuracy than a baseline model.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.174-184
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• 2018

The efficiency and safety of social-overhead capital (SOC) public infrastructures have become an eminent social concern. In this regard, a continuous structural health monitoring has been widely implemented to oversee the robustness of such public infrastructures for the safety of the public. This paper deals with the analysis of a distributed mobility management (DMM) support for wireless sensor network (WSN) based information transmission system. The partial DMM support separates the data and control plane infrastructures, wherein, the control plane is managed by a particular mobility management network entity, while the data plane is distributed by the mobility anchors. The system will be able to optimize the information transmission for a wireless structural health monitoring of SOC public infrastructures specifically designed for bridges, and thus, guarantees the safety of public commuters.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.58-64
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• 2019

In recent years, small mobile devices called personal mobility or smart mobility have attracted attention. Personal mobility refers to electric-driven personal transportation that can travel at close range and medium distance, including small electric vehicles, electric bicycles, electric motorcycles and electric scooters. Most of the electric scooters used in Korea are mainly imported from China. This is due to the fact that the price competitiveness of major components of electric scooters is owned in China. At this point, the domestic research direction is preferable for the composition and design of the electric scooter body rather than cost reduction for the components. In this study, we propose a new model of portable folding structure that is easy to use for electric scooters, which are personal vehicles using electric energy. We also made a prototype for practical use.

• 경영과정보연구
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• 제36권2호
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• pp.239-260
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• 2017

본 연구는 혁신기술에 대한 사회적 수용의 관점에서 스마트 모빌리티(smart mobility)의 수용에 미치는 영향요인을 탐색하였다. 혁신기술의 사회적 수용과 확산에 관한 이론고찰을 통해 혁신-수용에 미치는 영향요인, 지각된 유용성의 인식과 수용의도에 미치는 일련의 과정에 대한 구조방정식 모형을 설정하고, 이를 실증적으로 분석하였다. 분석에 필요한 자료는 2016년 8월 1일에서 12일 사이에 설문을 통해 수집하였으며, 수집된 534개의 설문이 분석에 이용되었다. 실증분석결과, 적합성과 상대적 이점은 지각된 유용성을 매개로 스마트 모빌리티의 사회적 수용에 통계적으로 유의한 정(+)의 영향을 미쳤으나, 의사소통은 부(-)의 영향을 미치는 것으로 나타났다. 복잡성과 서비스품질은 통계적으로 유의한 영향을 미치지 못하는 것으로 나타났다. 본 연구의 결과에 기초하여 스마트 모빌리티의 사회적 수용과 관련된 시사점을 제공하였으며, 본 연구의 한계점과 이를 극복하기 위한 향후 연구방향도 제시하였다.