• KIPS Transactions on Software and Data Engineering
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• v.6 no.3
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• pp.141-148
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• 2017

The current advancement of mobile devices enables users to collect a sequence of user positions by use of the positioning technology and thus the related research regarding positioning or location information are quite arising. An individual mobility model based on positioning data and time data are already established while group mobility model is not done yet. In this research, group mobility model, an extension of individual mobility model, and the process of establishment of group mobility model will be studied. Based on the previous research of group mobility model from two individual mobility model, a group mobility model with more than two individual model has been established and the transition pattern of the model is represented by Markov chain. In consideration of real application, the computing time to establish group mobility mode from huge positioning data has been drastically improved by use of GPGPU comparing to the use of traditional multicore systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.760-770
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• 2011

The existing mobility management schemes do not fully support the next generation network, which is composed of IP-based core network and various access networks. Currently, ETRI has been developing the AIMS (Access Independent Mobility Service) system which satisfies the ITU-T requirements of mobility management in the next generation network. The AIMS system is designed to provide a mobile host with a fast and reliable mobility service among heterogeneous access networks. Recently, many user devices have multiple communication interfaces, e.g., 3G and WLAN, and thus they can make two or more network connections at the same time. In this paper, we design a scheme of flow mobility, i.e., the movement of selected data flows from one access technology to another, to be applied in the AIMS system, and verify the proposed scheme through the NS-3 simulation study. From the simulation results, we can know that the proposed flow mobility scheme can utilize the network resource efficiently in the heterogeneous mobile networks.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.281-287
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• 2024

In general, design education related to transportation has been recognized as a department specialized in transportation design or as an area of detailed transportation majors within industrial design majors. However, as technological, social, and environmental factors change, the concept of mobility and the ecosystem related to the mobility industry are diversifying, and accordingly, the category of mobility-related design is expanding further. Based on this background, this study is not a mobility design major, but it aims to find implications by analyzing the trend and type of topic selection related to the mobility ecosystem among the last five years of graduation design topics conducted in the design engineering major. As a result of the study, of a total of 131 graduation design works conducted over the past five years, about 30 works were highly related to mobility, and their types were very diverse. In conclusion, it was confirmed that the change and expansion of the mobility ecosystem expanding from products to services and systems were also reflected in the selection of graduation works in that various topics approached from user-centered and user experience were proposed and made into works.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.3
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• pp.67-79
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• 2024

These instructions give you guidelines for preparing papers for JDCS. Recently, the use of digital devices like kiosks and smartphones has expanded, leading to the active provision of digital-based services in the transportation sector, such as choosing transportation modes and checking routes. This study analyzes the relationship between user discomfort when using digital transportation services and mobility. It also examines the moderating effect of technological proficiency on this relationship. The study found that 16.4% of participants experienced discomfort, with an average mobility score of 48.4 points and a technological proficiency score of 3.78 points. Discomfort with digital transportation services was positively correlated with mobility. Additionally, technological proficiency positively influenced mobility. This study analyzes and presents the impact of technology utilization ability on mobility. These findings can be used as basic data for making policy on the need to revitalize the use of digital-based transportation service and bridge the digital divide.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.135-144
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• 2003

Traffic performance in a microcellular system is much more affected by cell dwell time and channel holding time in each cell. Cell dwell time of a call is characterized by its mobility pattern, i.e., stochastic changes of moving speed and direction. Cell dwell time provides important information for other analyses on traffic performance such as channel holding time, handover rate, and the average number of handovers per call. In the next generation mobile communication system, the cell size is expected to be much smaller than that of current one to accommodate the increase of user demand and to achieve high bandwidth utilization. As the cell size gets small, traffic performance is much more affected by variable mobility of users, especially by that of pedestrians. In previous work, analytical models are based on simple probability models. They provide sufficient accuracy in a simple second-generation cellular system. However, the role of them is becoming invalid in a picocellular environment where there are rapid change of network traffic conditions and highly random mobility of pedestrians. Unlike in previous work, we propose an improved probability model evolved from so-called Random walk model in order to mathematically formulate variable mobility of pedestrians and analyze the traffic performance. With our model, we can figure out variable characteristics of pedestrian mobility with stochastic correlation. The above-mentioned traffic performance measures are analyzed using our model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5805-5825
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• 2019

Smartphones are important platforms because of their sophisticated computation, communication, and sensing capabilities, which enable a variety of applications in the Internet of Things (IoT) systems. Moreover, advancements in hardware have enabled sensors on smartphones such as environmental and chemical sensors that make sensor data collection readily accessible for a wide range of applications. However, dynamic, opportunistic, and heterogeneous mobility patterns of smartphone users that vary throughout the day, which greatly affects the efficacy of sensor data collection. Therefore, it is necessary to consider phone users mobility patterns to design data collection schedules that can reduce the loss of sensor data. In this paper, we propose a mobility-based weighted adaptive opportunistic scheduling framework that can adaptively adjust to the dynamic, opportunistic, and heterogeneous mobility patterns of smartphone users and provide prioritized scheduling based on various application scenarios, such as velocity, region of interest, and sensor type. The performance of the proposed framework is compared with other scheduling frameworks in various heterogeneous smartphone user mobility scenarios. Simulation results show that the proposed scheduling improves the transmission rate by 8 percent and can also improve the collection of higher-priority sensor data compared with other scheduling approaches.

• Journal of Institute of Convergence Technology
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• v.13 no.1
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• pp.19-22
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• 2023

The rise of electrification and the advancement of autonomous driving technologies are leading to new forms of mobility, such as serving and delivery robots. However, due to factors such as the small-scale production of various products and the high cost of autonomous driving sensors, product prices have risen, limiting accessibility to consumers. To improve this, we developed a multi-purpose mobility platform that is mass-producible, based on inexpensive, reliable sensors and a configurable human tracking system. As a result, the unit price is approximately 50% of the launch prices of other mobility products, and additional cost savings are possible through component optimization in the future. In addition, more added value will be created through the distribution of integrated mobility platforms that can be combined with various usable modules to meet a variety of user needs, such as cargo transportation, wheelchair power kits, and mobile monitors.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.97-103
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• 2016

In this paper, a smartphone-controlled personal mobility system (PMS) with semi-autonomous navigation is developed. The proposed PMS moves to waypoints and then reaches the destination where the waypoints and destination are selected by the user using Google maps in a smartphone. The hardware environment consists of a GPS (Global Positioning System) in the smartphone and a compass sensor. In addtion, while it is moving in autonomous mode, the user can intervene and change the direction and speed of the PMS in order to avoid obstacles that may be encountered accidentally in a dynamic environment. That is why it is called "semi-autonomous navigation". Experimental results showed that the proposed PMS is effectively able to migrate to the waypoints and destination in both autonomous and manual modes.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.47-50
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• 1998

In recent years, it is required that computing support mobile user with computer. The advantage of mobile computing is that users may access all their applications from any location, whether they are in another building or a different state. So, Internet combines with mobile computing technology to make new communication environment for supporting mobility. The research for solving the problem of mobility is actively in progress. This paper describes the implementation of tunneling method for flexible bypass between specific region. Tunneling method provide mobile service to mobile hosts. IP datagram's address tranform method is IP-within-IP encapsulation by which an IP datagram may be encapsulated within an IP datagram. The developed IP-within-IP protocol can provide not only enhanced performance because it is implemented in kernel mode, but also convenience of usage to the application developers because it gives user interface as a dynamic link library. Verification of IP packet tunneling was text file transfer program.

• The Magazine of the IEIE
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• v.24 no.2
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• pp.13-26
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• 1997

Throughout the world in major urban centers, the volume of vehicular traffic on roads continues to increase. ITS provides drivers with traffic information and new routing options on route In order to make them move quickly to their destinations. The higher mobility, the more productivity we gain. The ultimate goal of Intelligent Transport System is to improve mobility. ITS world is broad and quite varied, as demonstrated by ITS user services, their distinct needs, and complex Interactions and synergies. ITS ties the transportation and telecommunication worlds together. The complex world of telecommunications is evolving and expanding rapidly. Especially over the last two decades, the birth and unprecedented growth of wireless is really marvelous and further holds tremendous promise into the future. This wireless and emerging technologies will offer extensive opportunities to handle many ITS user services, and alter many of the traditional paradigms of transportation.