• KIPS Transactions on Computer and Communication Systems
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• v.3 no.1
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• pp.7-14
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• 2014

The rapid increase of mobile devices such as smart phone and smart pad have raised the needs for seamless multimedia services during moving at anytime and anywhere. Current 4G mobile devices are equipped with both 4G (LTE) and WLAN (WiFi) interfaces, and mobile services operators provide wireless Internet services using 4G network with a wider coverage and WiFi zone. Generally users prefer to use the Internet services through WLAN rather than LTE in the coverage of WLAN. However, since WLAN has a long L2 handover latency, it is difficult to support seamless services during a handover. In this paper, we proposed an efficient handover scheme based on flow mobility for WLANs to support a seamless service during handovers by using the overlaid 4G network with a wider coverage. Also, we showed the outperformance of the proposed scheme on a testbed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.85-90
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• 2015

Work environments within the firm with a concept of mobile office is growing divided into two sections. It's Wi-Fi FMC(Fixed Mobile Convergence) field Which are implemented in a telephone service available from existing fixed-line service in the center of the smart phones and the EMS(Enterprise Mobility Service) field to make people will be able to handle PC the center of the information system within an enterprise using a smart phone instead of terminal facility connects to a system in the workplace and external. This paper developed FMC controller to allow execution IMS(IP Multi-Media Subsystem) services to complement the issues of the FMC corporation, telephony service associated. The controller includes FMC automatic enrollment services, voice quality enhancement of the mobile phone, anywhere within the firm on his mobile phone calls can provide mobility and is also implemented FMC LCR function that use status information from mobile soft-phone within the IP-PBX.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.107-114
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• 2011

Recently, interests for recruiting and the rates of using smart phones are growing fast. The paper proposes Recruid, which is a smart phone application based on android platform, that helps real-time communication matching between users. They can use every services of Recruid anywhere and anytime which reflects mobility characteristics of smart phones, and also use additional services on web pages. Recruid provides three main services. First, it provides mobile subscription and submission functionality on high mobility and convenience. Second, it provides group service that user can make their own groups. Last, it also provides reliability evaluation mechanism of activity data in Recruid thus, Recruid provides high credibility to users. The paper presents implementation of Recruid and shows the snapshots of the presented system.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.6
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• pp.509-521
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• 2020

This study aims to propose a mid- to long-term fostering plan for the hydrogen industry customized to Changwon City by reviewing the government's policy and the status of the domestic and foreign hydrogen industry. The adopted methodologies were policy analysis, literature review, field investigation, and committee operation that could consider institutions, knowledge (technology), and networking between activity subjects. The short-term projects and long-term projects for the fostering plan are established using these methodologies. The short-term projects were structured so that the ongoing hydrogen industry fostering plan leads to a successful result, and the hydrogen mobility field is expanded to not only land vehicles but also marine and air vehicles. The long-term projects consist of a high proportion of the hydrogen utilization field to take advantage of the industrial strength of Changwon City, and a support system for new and turning companies for localization of parts was added to provide industrial competitiveness.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.373-387
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• 2023

Scientific exploration of extraterrestrial planets has gripped human imagination since the advent of space travel. Human missions to Mars could produce insight into the essential questions of how, when and where life began on Earth. Such missions would only be feasible using local space resources materials, a concept called in situ-resource utilization (ISRU). The purpose of this paper is to provide a thorough review of the currently available Mars soil simulants and to determine those with geotechnical properties most appropriate for vehicle mobility studies. Sourcing and processing are considered since full-scale studies require bulk quantities of material on the order of tens of tons. This review identifies the simulants with the highest fidelity to Mars wind drift soils. In addition, recommendation guide for mars soil simulant development made.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.799-810
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• 2023

This paper analyzed changes in population mobility characteristics based on emergency disaster messages related to wildfires that occurred in 2022, using mobile data. The primary wildfires under analysis are the ones that occurred in Donghae City and Miryang City. Donghae City sent a total of six evacuation messages in response to the wildfire incidents, and all of the message contents specified particular evacuation locations. As a result, it was analyzed that there was a significant impact on changes in population mobility characteristics. On the other hand, in the case of Miryang City, a total of five evacuation messages were sent during the wildfire period, but not all messages specified a clear evacuation location,such as "A safe place". As a result, it was observed that there was minimal change in population mobility due to the lack of clear evacuation locations specified in the messages. These analysis results suggest the need for institutional improvements such as the standardization and specification of emergency alert message content when wildfires or similar disasters occur in different regions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.3
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• pp.47-58
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• 2021

Recently, personal mobility (PM)-related complaints and PM accidents have increased as the number of users soars due to growth in the domestic PM market and the emergence of a number of electric scooter-sharing services. As a result, the need for PM education and practice spaces is emerging as a way to reduce accidents caused by poor PM manipulation and operation. In this study, we analyze the relevant conflict factors in order to come up with a systematic operation and activation plan for PM, and as an alternative, we review and propose how to operate a PM playground and test zone. It is expected that basic data collection and analysis of rudimentary driver behavior through PM playground operations will improve users' operational safety, and various conflicts of interest between users and non-users will be resolved by installing facilities to secure their safety.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.330-336
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• 2023

Rapid urbanization is rapidly progressing around the world, and urban problems such as traffic congestion, environmental pollution, and noise pollution are emerging, due to this urban concentration phenomenon, logistics and transportation costs are increasing. Urban Air Mobility(UAM) is a three-dimensional futuristic urban transportation that is expected to become an important transportation axis of smart cities as a service(MaaS) linked to roads, railways, and personal transportation. However, as of July 2023, research on airspace systems, Bertieport design, navigation, and communication for UAM operation is actively being conducted, but little research has been conducted on the concept of pilot education and training and education and training programs. Therefore, this paper aims to present a suitable plan for the domestic pilot training system through SWOT analysis of vertical takeoff and landing(VTOL) pilot education and training programs in the United States and Europe.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.199-204
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• 2023

The COVID-19 pandemic, which began in early 2020, became an opportunity for unprecedented global reflection and change. And it served as an opportunity to promote a new paradigm in all areas of society, including politics, economy, culture, and industry. In the midst of this upheaval, the 2022 IAA exhibition, which was held in four years, was held as an exhibition that even proposed new concepts of smart logistics and mobility services. Among them, various concepts were also proposed in exhibitions related to last mile mobility, the focus of this study.As a result of this study, the main trend of last mile mobility shown in the IAA 2022 exhibition is that the property of physical products with functions as social interfaces is expanding into the PSS (Product-Service System) ecosystem in which products and services are systematically linked. As a result, the need for a methodological approach that can organically link the design planning of social services and the development of products corresponding to it was derived.

• The Journal of the Korea Contents Association
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• v.8 no.7
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• pp.17-25
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• 2008

The smart home environment focuses on recognizing the context and physical entities. And this is mainly focused on the personalized service supplied conversational interactions. In this paper, we proposed the recommendation using the context awareness based information filtering that dynamically applied by the context awareness as well as the meta data in the smart home. The proposed method defined the context information and recommended the profited service for the user’s taste using the context awareness based information filtering. Accordingly, the satisfaction of users and the quality of services will be improved the efficient recommendation by supporting the distributed processing as well as the mobility of services. Finally, to evaluate the performance of the proposed method, this study applies to MovieLens dataset in the OSGi framework, and it is compared with the performance of previous studies.