• Journal of Digital Convergence
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• v.17 no.7
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• pp.351-357
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• 2019

A number of case studies and type analyzes have been conducted on mobility platform services that are rapidly evolving around the world. However, since the actual user experience is important for the development of the mobility service, research on the user side is needed. In the mobility platform service, only the car-hailing was used, and the preference factors were analyzed through the questionnaire in seven aspects of the user experience. Studies have shown significant differences according to gender. While the safety of the woman, the comfort and the kindness of the vehicle have a great influence on the satisfaction, the male affirms that the familiarity is the factor affecting the satisfaction. This study focused on the customer experience as a real user and identified key factors of selecting mobility platform service, so it is expected that it will contribute to the development of mobility platform service in the future.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.92-99
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• 2013

The ratio of mobility handicapped was 12,110,000 in late 2009 about 24.4% of total population. The number of handicapped population is increasing continuously due to traffic accidents and industrial disasters. Therefore, the purpose of this research is to suggest a design for passengers on wheelchairs to get into and off to raise handicapped or elderly people's right of mobility. The scope of this research is mobility handicapped especially wheelchair passengers who use vans, small buses, and trains. The ramp design of vans is module form. The ramp is moved with screw jack and guides are installed on each side to increase stability. Moreover, a bridge was installed for smooth getting in and off of the van. The ramp design for small bus is lowed by 200m in order not to have obstacle such as speed bump when getting in or off. In order to reduce vulnerable environment and administration, air slide cylinder was chosen. Lastly, for the ramp design of train, the principle of link was used that the simpler structure made the weight lighter and installation in the train became easier. If we look at the conjugation condition of heterogeneous materials to produce a ramp, proper welding condition for cold steel plate and stainless plate is 3kW output and 3-5m/min of welding speed using laser beam seems proper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2180-2200
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• 2015

This paper considers mobility control to improve packet delivery in delay-tolerant networks (DTNs) under group mobility. Based on the group structure in group mobility, we propose two mobility control techniques; group formation enforcement and group purposeful movement. Both techniques can be used to increase the contact opportunities between groups by extending the group's reachability. In addition, they can be easily integrated into some existing DTN routing schemes under group mobility to effectively expedite the packet delivery. This paper is divided into 2 parts. First, we study how our proposed mobility control schemes reduce the packet delivery delay in DTNs by integrating them into one simple routing scheme called group-epidemic routing (G-ER). For each scheme, we analytically derive the cumulative density function of the packet delivery delay to show how it can effectively reduce the packet delivery delay. Then, based on our second proposed technique, the group purposeful movement, we design a new DTN routing scheme, called purposeful movement assisted routing (PMAR), to further reduce the packet delay. Extensive simulations in NS2 have been conducted to show the significant improvement of PMAR over G-ER under different practical network conditions.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.294-303
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• 2012

This study was designed to develop air force mechanic parka, evaluate it, and ultimately provide functionally superior parka to the air force. The development process was 1) conducting a survey, 2) identifying problems and shortcomings of currently-supplied parkas, and 3) improving the design, pattern and materials. The newly-developed parkas were evaluated in terms of their ease of fit, clothing mobility, and insulation. Ease of fit was evaluated by subjects' sensory tests, and clothing mobility was by fitness-for-motion tests and range-of-motion tests using a Goniometer. Evaluation on insulation was conducted by thermal manikins. Findings of this study were as follows: 1. In the subjective evaluation on clothing mobility, new parkas were considered to have sufficient ease of fit while previous ones scored much lower, confirming the improvement of the new version. 2. Both subjective tests and ROM measurements on fitness for motion verified the superiority of the new parkas. 3. Insulation tests found that although insulation capability of newly-developed parkas was at a similar level to those of the previous ones, their insulation capability per unit weight was superior, demonstrating that new parkas were better at blocking heat conduction. When making changes in parka patterns and designs to enhance the mobility, it was necessary to maintain the insulation function. The new parkas developed by this study was verified to be superior to the previous ones in their insulation and clothing mobility.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.245-250
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• 2008

Recently, mobile devices have supported wireless LAN as well as bluetooth, where the services such as heterogeneous network access and seamless mobility connection are important. Even though the mobility and physical network might be varied, an efficient communication mechanism for the network access and a robust mobility management of mobile devices are needed. In this paper, we design and implement a Bluetooth system with mobile LAN access capability. The proposed system has the following features; 1) IP connection is enabled by BENP in the link layer, 2) The networks devices of heterogeneous mobile devices are integrated into a single virtual network interface, 3) IP mobility between the bluetooth and wireless LAN is supported by mobile IP. The experimented results show that the packet loss and delay time during the handover duration is reduced by predicting the handover among different networks followed by the setup of any required parameters in advance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.658-667
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• 2009

NEMO (Network Mobility) introduces the concept of mobile router in order to supply users with group mobility over wireless and mobile networks. This paper investigates the advantages and disadvantages of NEMO in terms of the overhead of group mobility management. This paper proposes the additional requirements to enhance NEMO performance. Moreover, we analyze the main communication paths, CN-HA, HA-MR, and MR-MNN, in the real NEMO testbed.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.53-63
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• 2001

An efficient mobility management for mobile stations plays an important role in mobile communication network. This paper studies the mobility management scheme that combines a distance-based registration(DBR) and a selective paging (SP). We introduce an analytical model based on 2-dimensional random walk mobility model and evaluate the performance of the proposed mobility management scheme using the model to determine the optimal size of location area that results in the minimum signaling traffic on radio channels. Numerical results are provided to demonstrate the performance of the proposed mobility management scheme under various circumstances. These results can be used effectively in design and evaluation of registration methods considering the system circumstances.

• Journal of information and communication convergence engineering
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• v.19 no.3
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• pp.136-141
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• 2021

Research on wireless sensor networks has focused on the monitoring and characterization of large-scale physical environments and the tracking of various environmental or physical conditions, such as temperature, pressure, and wind speed. We propose a stochastic mobility model that can be applied to a MANET (Mobile Ad-hoc NETwork). environment, and apply this mobility model to a newly proposed clustering-based routing protocol. To verify its stability and durability, we compared the proposed stochastic mobility model with a random model in terms of energy efficiency. The FND (First Node Dead) was measured and compared to verify the performance of the newly designed protocol. In this paper, we describe the proposed mobility model, quantify the changes to the mobile environment, and detail the selection of cluster heads and clusters formed using a fuzzy inference system. After the clusters are configured, the collected data are sent to a base station. Studies on clustering-based routing protocols and stochastic mobility models for MANET applications have shown that these strategies improve the energy efficiency of a network.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.327-332
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• 2019

The purpose of this study is to derive the differentiation and improvement measures of Kakao T through a usability evaluation centered on the service. In-depth interviews were conducted by first identifying the status of the mobility O2O service and reconfiguring the usability principles of the Honeycomb model, focusing on the functions and interfaces. First, there are problems driven from the imbalance in supply and demand as a mobility service, but it is likely to be improved through the addition of future features, carpooling. Second, problems were elicited for not recognizing the need for incorporated functions of Kakao T in the presence of existing functional-specific applications. Improvements derived based on this study are expected to help increase the convenience of users of mobility O2O services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.5028-5057
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• 2015

In this paper, a new mathematical scheme of Macro Handover Management (MHM) in F-HMIPv6 networks based on Location Based Services (LBS) is proposed. Previous schemes based on F-HMIPv6 protocol usually suffer from three major drawbacks: First, They don't exploit the information about the user mobility behavior in order to reduce handover effects. Second, they only focus on the micro mobility level. Third, they don't consider the quality of service (QoS) of the traffic. The proposed MHM scheme avoids these drawbacks using the available information about Mobile Node (MN) such as user mobility patterns and MN's velocity to predict handover and improve network's QoS. It also takes the traffic type in consideration since it presents a major factor in locating QoS for the user. MHM is analyzed and compared with the F-HMIPv6. The results show that MHM improves the performance in terms of packet delivery cost, location update cost, and handover latency. The design of MHM comprises software package in the MN in addition to a hardware part in the network side. It has implications for communication, design, and pricing of mobile services.